Significado biológico y utilidad clínica del lactato en la sepsis / Biological significance and clinical utility of lactate in sepsis

La sepsis es un problema global de salud y la progresión hacia el shock séptico se asocia con un incremento marcado de la morbimortalidad. En este escenario, el aumento del lactato plasmático demostró ser un indicador de gravedad y un predictor de mortalidad, y suele interpretarse casi exclusivamente como marcador de baja perfusión tisular. Sin embargo, últimamente se produjo un cambio de paradigma en la exégesis del metabolismo y propiedades biológicas del lactato. En efecto, la adaptación metabólica al estrés, aun con adecuado aporte de oxígeno, puede justificar la elevación del lactato circulante. Asimismo, otras consecuencias fisiopatológicas de la sepsis, como la disfunción mitocondrial, se asocian con el desarrollo de hiperlactatemia sin que necesariamente se acompañen de baja perfusión tisular. Interpretar el origen y la función del lactato puede resultar de suma utilidad clínica en la sepsis, especialmente cuando sus niveles circulantes fundamentan las medidas de reanimación.

Sepsis is a global health problem; progression to septic shock is associated with a marked increase in morbidity and mortality. In this setting, increased plasma lactate levels demonstrated to be an indicator of severity and a predictor of mortality, and are usually interpreted almost exclusively as a marker of low tissue perfusion. However, a recent paradigm shift has occurred in the exegesis of lactate metabolism and its biological properties. Indeed, metabolic adaptation to stress, even with an adequate oxygen supply, may account for high circulating lactate levels. Likewise, other pathophysiological consequences of sepsis, such as mitochondrial dysfunction, are associated with the development of hyperlactatemia, which is not necessarily accompanied by low tissue perfusion. Interpreting the origin and function of lactate may be of great clinical utility in sepsis, especially when circulating lactate levels are the basis for resuscitative measures.

Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw / Análise do comportamento mecânico da fixação do enxerto suíno em um bloco de poliuretano usando um parafuso de interferência PLA impresso em 3D

Abstract Objective The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Resumo Objetivo O interesse em utilizar a impressão 3D na área da saúde tem crescido ao longo dos anos, dadas as suas vantagens e o seu potencial na rápida fabricação de dispositivos e implantes personalizados com geometrias complexas. Assim, o objetivo do presente estudo foi comparar o comportamento de fixação mecânica de um parafuso de interferência impresso em 3D, produzido pela modelagem fundida de deposição do filamento de ácido polilático (PLA), com o de um parafuso de interferência de titânio. Métodos Oito tendões suínos flexores profundos, de aproximadamente 8 mm de largura e 9 cm de comprimento, foram utilizados como enxerto e fixados em um bloco de poliuretano de 40 PCF em cada uma de suas extremidades. Um grupo foi fixado apenas com parafusos de interferência de titânio (grupo 1) e o outro apenas com parafusos PLA impressos em 3D (BR 20 2021 018283-6 U2) (grupo 2). Os testes foram realizados utilizando uma máquina de teste universal eletromecânica EMIC DL 10.000 no modo de tração axial. Resultados O grupo 1 (titânio) obteve força máxima de 200 ± 7 N com deformação média do enxerto de 8 ± 2 mm, e a força máxima do grupo 2 (PLA) foi de 300 ± 30 N e deformação média do enxerto de 7 ± 3 mm. Ambos os parafusos de titânio e PLA forneceram boa fixação de enxerto no bloco de poliuretano, sem deslizamento ou deformação aparente. Em todas as amostras o teste culminou na ruptura do enxerto, com cerca de 20 mm de deformação em relação ao comprimento inicial. Conclusão O parafuso PLA impresso em 3D proporcionou boa fixação, semelhante à de sua contraparte de titânio, produzindo resultados satisfatórios e promissores.

Clinical implementation of comprehending dentin on a microscopic level

SUMMARY: The aim of the present in vitro study is to visualize dentin to get an in-depth knowledge of the nature of dentin that could provide useful information regarding conditioning dentinal substrate when treating dentinal lesions. Forty-nine extracted human third molars were obtained and prepared to produce artificial dentinal lesions through demineralizing with acetic acid for 7 and 14 days, or lactic acid for 7 days. The teeth were divided into groups and treated with either NaOCl, pepsin, trypsin, or phosphoric acid. To obtain information on the morphology of the treated dentinal surfaces, all samples were visualized under high resolution field emission scanning electron microscope. With high magnification reaching x50000 dentin was clearly visualized together with its constitutes. The effect of various demineralization approaches and various treatment protocols were demonstrated clearly. The relationship between the conditioning procedure steps and the subsequent bond strength was discussed. To our best knowledge, there is no previous clear highly magnified scanning electron microscope images for dentin, and dentinal components and constitutes with and without various treatments. The current in vitro study suggests the complexity nature of dentin as a substrate that should be treated carefully especially with technique sensitive procedures such as adhesive restorations.

El objetivo del presente estudio in vitro fue visualizar la dentina para obtener un conocimiento completo de la naturaleza de ella lo que podría proporcionar información útil sobre el acondicionamiento del sustrato dentinario en el tratamiento de lesiones dentinarias. Se obtuvieron 49 terceros molares humanos extraídos y se prepararon para producir lesiones dentinales artificiales mediante desmineralización con ácido acético por 7 y 14 días, o ácido láctico por 7 días. Los dientes se dividieron en grupos y se trataron con NaOCl, pepsina, tripsina o ácido fosfórico. Para obtener información sobre la morfología de las superficies dentinarias tratadas, todas las muestras se visualizaron bajo un microscopio electrónico de barrido de emisión de campo de alta resolución. Con un gran aumento que alcanzó x50000, la dentina se visualizó claramente junto con sus componentes. Se demostró el efecto de varios enfoques de desmineralización y varios protocolos de tratamiento. Se discutió la relación entre los pasos del procedimiento de acondicionamiento y la subsiguiente fuerza de unión. Hasta donde sabemos, no hay imágenes claras previas de microscopio electrónico de barrido altamente ampliadas para la dentina y los componentes y constituyentes de la dentina con y sin diferentes tratamientos. El estudio in vitro actual sugiere la naturaleza compleja de la dentina como sustrato que debe tratarse con cuidado, especialmente en los procedimientos sensibles a la técnica, tal como las restauraciones adhesivas.

Lactate-induced up-regulation of PLEKHA4 promotes proliferation and apoptosis of human glioma cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of lactic acid-induced upregulation of PLEKHA4 expression on biological behaviors of glioma cells and the possible molecular mechanism.@*METHODS@#GEO database and GEPIA2 website were used to analyze the relationship between PLEKHA4 expression level and the pathological grade of glioma. A specific PLEKHA4 siRNA was transfected in glioma U251 and T98G cells, and the changes in cell proliferation ability were assessed by real-time cell analysis technology and Edu experiment. The colony-forming ability of the cells was evaluated using plate cloning assay, and cell cycle changes and cell apoptosis were analyzed with flow cytometry. The mRNA expression of PLEKHA4 was detected by PCR in glioma samples and controls and in glioma cells treated with lactic acid and glucose. Xenograft mice in vivo was used to detect tumor formation in nude mice; Western blotting was used to detect the expressions of cyclinD1, CDK2, Bcl2, β-catenin and phosphorylation of the key proteins in the MAPK signaling pathway.@*RESULTS@#The results of GEO database and online website analysis showed that PLEKHA4 was highly expressed in glioma tissues and was associated with poor prognosis; PLEKHA4 knockdown obviously inhibited the proliferation and attenuated the clone-forming ability of the glioma cells (P < 0.05). Flow cytometry showed that PLEKHA4 knockdown caused cell cycle arrest in G1 phase and promoted apoptosis of the cells (P < 0.01). PLEKHA4 gene mRNA expression was increased in glioma samples and glioma cells after lactate and glucose treatment (P < 0.01). PLEKHA4 knockdown, tumor formation ability of nude mice decreased; PLEKHA4 knockdown obviously lowered the expression of cyclinD1, CDK2, Bcl2 and other functional proteins, inhibited the phosphorylation of ERK and p38 and reduced the expression of β-catenin protein (P < 0.01).@*CONCLUSION@#PLEKHA4 knockdown inhibited the proliferation of glioma cells and promoted apoptosis by inhibiting the activation of the MAPK signaling pathway and expression of β-catenin. Lactic acid produced by glycolysis upregulates the expression of PLEKHA4 in glioma cells.

Analysis of clinical characteristics and risk factors of early heat stroke-related acute liver injury / 中华危重病急救医学

OBJECTIVE@#To analyze the clinical characteristics and risk factors of early acute liver injury in patients with heat stroke (HS), and to provide basis for early identification of HS-related liver injury and its pathogenesis in clinical practice.@*METHODS@#The clinical data of patients with HS admitted to the department of critical care medicine of Haian People's Hospital from June 2015 to August 2022 were retrospectively analyzed. The patients with HS were divided into early liver injury group and early non-liver injury group according to the occurrence of acute liver injury within 24 hours of admission. The differences of basic data, clinical data, laboratory indexes and clinical outcomes of the two groups were analyzed. Logistic regression was used to analyze the risk factors for early HS-related acute liver injury, and receiver operator characteristic (ROC) curves were drawn to evaluate their value in predicting the occurrence of early HS-related acute liver injury.@*RESULTS@#A total of 76 patients with HS were enrolled, and 46 patients with acute liver injury, accounting for 60.53%. In the early liver injury group, 14 patients (30.43%) had elevated aminotransferase alone, 9 patients (19.57%) had elevated total bilirubin (TBil) alone, and 23 patients (50.00%) had elevated both aminotransferase and TBil. Among the patients with elevated aminotransferases, 24 patients (64.87%) had mild elevation, 5 patients (13.51%) had moderate elevation, 8 patients (21.62%) had severe elevation. Compared with the early non-liver injury group, acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), arterial blood lactate (Lac), interleukin-6 (IL-6), procalcitonin (PCT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), TBil, γ-gamma glutamyl transferase (γ-GGT), lactate dehydrogenase (LDH), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB), cardiac troponin I (cTnI), myoglobin (MYO), N-terminal B-type pro-brain natriuretic peptide (NT-proBNP), prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer in the early liver injury group were significantly increased, while platelet count (PLT) were significantly decreased within 24 hours after admission, the 28-day mortality was significantly increased [28.26% (13/46) vs. 6.67% (2/30)], and the differences were statistically significant (all P < 0.05). Univariate Logistic regression analysis showed that APACHE II score, SOFA score, PLT, Lac, IL-6, PCT, γ-GGT, LDH, CK, CK-MB, cTnI, MYO, PT, APTT, D-dimer were risk factors of early HS-related acute liver injury (all P < 0.05). Multivariate Logistic regression analysis showed that PLT, IL-6, and LDH were independent risk factors of early HS-related acute liver injury [odds ratio (OR) and 95% confidence interval (95%CI) were 0.986 (0.974-0.998), 1.027 (1.012-1.041), and 1.002 (1.000-1.004), all P < 0.05]. The ROC curve analysis showed that the area under the ROC curve (AUC) of PLT, IL-6 and LDH for predicting the occurrence of early HS-related acute liver injury was 0.672 (95%CI was 0.548-0.797), 0.897 (95%CI was 0.824-0.971) and 0.833 (95%CI was 0.739-0.927), respectively. IL-6 had the highest predictive value for early HS-related liver injury. When the optimal diagnostic threshold of IL-6 was 48.25 ng/L, the sensitivity was 95.7%, the specificity was 73.3%, and the predictive value of PLT was the lowest.@*CONCLUSIONS@#The early HS-related liver injury is mainly manifested as the simultaneous elevation of aminotransferase and TBil, and most of cases are mild liver injury. PLT, IL-6 and LDH are independent risk factors of early HS-related acute liver injury.

Correlation between four limbs perfusion index and lactic acid in patients with severe neurological diseases / 中华危重病急救医学

OBJECTIVE@#To observe the correlation between the four limbs perfusion index (PI) and blood lactic acid in patients with neurosis, and evaluate the predictive value of PI on microcirculation perfusion metabolic disorder in patients with neurosis.@*METHODS@#A prospective observational study was conducted. Adult patients admitted to the department of neurological intensive care unit (NICU) of the First Affiliated Hospital of Xinjiang Medical University from July 1 to August 20 in 2020 were enrolled. Under the condition of indoor temperature controlled at 25 centigrade, all patients were placed in the supine position, and the blood pressure, heart rate, PI of both fingers and thumb toes and arterial blood lactic acid were measured within 24 hours and 24-48 hours after NICU. The difference of four limbs PI at different time periods and its correlation with lactic acid were compared. Receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of four limbs PI on patients with microcirculatory perfusion metabolic disorder.@*RESULTS@#A total of 44 patients with neurosis were enrolled, including 28 males and 16 females; average age (61.2±16.5) years old. There were no significant differences in PI of the left index finger and the right index finger [2.57 (1.44, 4.79) vs. 2.70 (1.25, 5.33)], PI of the left toe and the right toe [2.09 (0.85, 4.76) vs. 1.88 (0.74, 4.32)] within 24 hours after entering the NICU, and the PI of the left index finger and the right index finger [3.17 (1.49, 5.07) vs. 3.14 (1.33, 5.36)], PI of the left toe and the right toe [2.07 (0.75, 5.20) vs. 2.07 (0.68, 4.67)] at 24-48 hours after NICU admission (all P > 0.05). However, compared to the PI of the upper and lower limbs on the same side, except for the 24-48 hours after ICU of the PI difference between the left index finger and the left toe (P > 0.05), the PI of the toe was lower than that of the index finger at the other time periods (all P < 0.05). The correlation analysis showed that the PI value of four limbs of patients in both time periods were significantly negatively correlated with arterial blood lactic acid (the r values of the left index finger, the right index finger, the left toe and the right toe were -0.549, -0.482, -0.392 and -0.343 respectively within 24 hours after entering the NICU; the r values of the left index finger, the right index finger, the left toe and the right toe were -0.331, -0.292, -0.402 and -0.442 respectively after entering the NICU 24-48 hours, all P < 0.05). Taking lactic acid ≥ 2 mmol/L as the diagnostic standard for metabolic disorder of microcirculation perfusion (total 27 times, accounting for 30.7%). The efficacy of four limbs PI in predicting microcirculation perfusion metabolic disorder were compared. ROC curve analysis showed that the area under the curve (AUC) and 95% confidence interval (95%CI) of left index finger, right index finger, left toe and right toe predicting microcirculation perfusion metabolic disorder were 0.729 (0.609-0.850), 0.767 (0.662-0.871), 0.722 (0.609-0.835), 0.718 (0.593-0.842), respectively. There was no significant difference in AUC compare with each other (all P > 0.05). The cut-off value of PI of right index finger for predicting microcirculation perfusion metabolic disorder was 2.46, the sensitivity was 70.4%, the specificity was 75.4%, the positive likelihood ratio was 2.86, and the negative likelihood ratio was 0.30.@*CONCLUSIONS@#There are no significant differences in PI of bilateral index fingers, bilateral toes in patients with neurosis. However, unilateral upper and lower limbs showed lower PI in the toe than in the index finger. There is a significantly negatively correlation between PI and arterial blood lactic acid in all four limbs. PI can predict the metabolic disorder of microcirculation perfusion, and its cut-off value is 2.46.

Prognostic value of serum sodium variability within 72 hours and lactic acid combined with severity score in patients with sepsis / 中华危重病急救医学

OBJECTIVE@#To explore the predictive value of serum sodium variability within 72 hours, lactic acid (Lac), sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation II (APACHE II) in predicting the 28-day prognosis of sepsis patients.@*METHODS@#The clinical data of patients with sepsis admitted to the department of intensive care unit (ICU) of the Affiliated Qingdao Municipal Hospital of Qingdao University from December 2020 to December 2021 were retrospectively analyzed, including age, gender, previous medical history, temperature, heart rate, respiratory rate, systolic pressure, diastolic pressure, white blood cell count (WBC), hemoglobin (Hb), platelet count (PLT), C-reactive protein (CRP), pH value, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), Lac, prothrombin time (PT), activated partial thromboplastin time (APTT), serum creatinine (SCr), total bilirubin (TBil), albumin (Alb), SOFA, APACHE II score, and 28-day prognosis. Multivariate Logistic regression was used to analyze the risk factors of death in sepsis patients. Receiver operator characteristic curve (ROC curve) was used to analyze the predictive value of serum sodium variability within 72 hours, Lac, SOFA, APACHE II alone and in combination on the prognosis of patients with sepsis.@*RESULTS@#A total of 135 patients with sepsis were included, 73 survived and 62 died at 28 days, with 28-day mortality of 45.93%. (1) Compared with the survival group, SOFA, APACHE II, Lac and serum sodium variability within 72 hours in the death group were significantly higher [SOFA: 10.00 (8.00, 12.00) vs. 6.00 (5.00, 8.00), APACHE II: 18.00 (16.00, 21.25) vs. 13.00 (11.00, 15.00), Lac (mmol/L): 3.55 (2.90, 4.60) vs. 2.00 (1.30, 2.80), serum sodium variability within 72 hours: 3.4% (2.6%, 4.2%) vs. 1.4% (1.1%, 2.5%)], the differences were statistically significant (all P < 0.01). (2) Multivariate Logistic regression showed that SOFA, APACHE II, Lac, serum sodium variability within 72 hours were independent risk factors of prognosis in patients with sepsis [SOFA: odds ratio (OR) = 1.479, 95% confidence interval (95%CI) was 1.114-1.963, P = 0.007; APACHE II: OR = 1.163, 95%CI was 1.009-1.340, P = 0.037; Lac: OR = 1.387, 95%CI was 1.014-1.896, P = 0.040; serum sodium variability within 72 hours: OR = 1.634, 95%CI was 1.102-2.423, P = 0.015]. (3) ROC curve analysis showed that SOFA, APACHE II, Lac and serum sodium variability within 72 hours had certain predictive value for the prognosis of sepsis patients [SOFA: the area under the ROC curve (AUC) = 0.858, 95%CI was 0.795-0.920, P = 0.000; APACHE II: AUC = 0.845, 95%CI was 0.776-0.913, P = 0.000; Lac: AUC = 0.840, 95%CI was 0.770-0.909, P = 0.000; serum sodium variability within 72 hours: AUC = 0.842, 95%CI was 0.774-0.910, P = 0.000]. The combined predictive value of the four indicators (AUC = 0.917, 95%CI was 0.870-0.965, P = 0.000) was higher than that of any single indicator, and has higher specificity (79.5%) and sensitivity (93.5%), indicating that the combined index has higher predictive value for the prognosis of sepsis patients than any single index.@*CONCLUSIONS@#SOFA, APACHE II, Lac, serum sodium variability within 72 hours are independent risk factors for 28-day death in patients with sepsis. The combination of SOFA score, APACHE II score, Lac and serum sodium variability within 72 hours has higher predictive value for prognosis than single index.

Yinlai Decoction Protects Microstructure of Colon and Regulates Serum Level of D-Lactic Acid in Pneumonia Mice Fed with High-Calorie and High-Protein Diet / 中国结合医学杂志

OBJECTIVE@#To investigate the effect of Yinlai Decoction (YD) on the microstructure of colon, and activity of D-lactic acid (DLA) and diamine oxidase (DAO) in serum of pneumonia mice model fed with high-calorie and high-protein diet (HCD).@*METHODS@#Sixty male Kunming mice were randomly divided into 6 groups by the random number table method: normal control, pneumonia, HCD, HCD with pneumonia (HCD-P), YD (229.2 mg/mL), and dexamethasone (15.63 mg/mL) groups, with 10 in each group. HCD mice were fed with 52% milk solution by gavage. Pneumonia mice was modeled with lipopolysaccharide inhalation and was fed by gavage with either the corresponding therapeutic drugs or saline water, twice daily, for 3 days. After hematoxylin-eosin staining, the changes in the colon structure were observed under light microscopy and transmission electron microscope, respectively. Enzyme-linked immunosorbent assay was used to detect the protein levels of DLA and DAO in the serum of mice.@*RESULTS@#The colonic mucosal structure and ultrastructure of mice in the normal control group were clear and intact. The colonic mucosal goblet cells in the pneumonia group tended to increase, and the size of the microvilli varied. In the HCD-P group, the mucosal goblet cells showed a marked increase in size with increased secretory activity. Loose mucosal epithelial connections were also observed, as shown by widened intercellular gaps with short sparse microvilli. These pathological changes of intestinal mucosa were significantly reduced in mouse models with YD treatment, while there was no significant improvement after dexamethasone treatment. The serum DLA level was significantly higher in the pneumonia, HCD, and HCD-P groups as compared with the normal control group (P<0.05). Serum DLA was significantly lower in the YD group than HCD-P group (P<0.05). Moreover, serum DLA level significantly increased in the dexamethasone group as compared with the YD group (P<0.01). There was no statistical significance in the serum level of DAO among groups (P>0.05).@*CONCLUSIONS@#YD can protect function of intestinal mucosa by improving the tissue morphology of intestinal mucosa and maintaining integrity of cell connections and microvilli structure, thereby reducing permeability of intestinal mucosa to regulate the serum levels of DLA in mice.

The "weekend effect" does not impact on outcome of trauma laparotomy - Experience from a level 1 trauma centre in New Zealand / 中华创伤杂志(英文版)

PURPOSE@#Trauma centres have been proven to provide better outcomes in developed countries for overall trauma, but there is limited literature on the systematic factors that describe any discrepancies in outcomes for trauma laparotomies in these centres. This study was conducted to examine and interrogate the effect of systematic factors on patients undergoing a trauma laparotomy in a developed country, intending to identify potential discrepancies in the outcome.@*METHODS@#This was a retrospective study of all laparotomies performed for trauma at a level 1 trauma centre in New Zealand. All adult patients who had undergone an index laparotomy for trauma between February 2012 and November 2020 were identified and laparotomies for both blunt and penetrating trauma were included. Repeat laparotomies and trauma laparotomies in children were excluded. The primary clinical outcomes reviewed included morbidity, length of hospital stay, and mortality. All statistical analysis was performed using R v.4.0.3.@*RESULTS@#During the 9-year study period, 204 trauma laparotomies were performed at Waikato hospital. The majority (83.3%) were performed during office hours (170/204), and the remaining 16.7% were performed after hours (34/204). And 61.3% were performed on a weekday (125/204), whilst 38.7% were performed on the weekend/public holiday (79/204). Most of the parameters in office hours and after hours groups had no statistically significant difference, except lactate (p = 0.026). Most of the variables in weekday and weekend groups had no statistically significant difference, except pH, lactate, length of stay, and gastrointestinal complications (p = 0.012, p < 0.001, p = 0.003, p = 0.020, respectively).@*CONCLUSION@#The current trauma system at Waikato hospital is capable of delivering care for trauma laparotomy patients with the same outcome regardless of working hours or after hours, weekday or weekend. This confirms the importance of a robust trauma system capable of responding to the sudden demands placed on it.

Immobilization of Lactobacillus bulgaricus with gellan gum and its application in continuous fermentation of D-lactic acid from corn straw / 生物工程学报

Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.

Electrocardiographic changes and changes in cardiac lactate and troponin I levels associated with search and rescue physical activity in military dogs / Alterações eletrocardiográficas e nos níveis de lactato e troponina I cardíaca associadas à atividade física de busca e salvamento em cães militares

Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60'EXER), and in the recovery phase [RCT] at 30'RCT and 60'RCT, and cTnI at 60'RCT, 120'RCT, and 4hRCT. P wave duration was significantly higher at 60'EXER, 15'RCT, and 30'RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30'RCT, and the ST segment presented a significant difference at 60'EXER, 15'RCT, and 60'RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.(AU)

Cães de busca e resgate intercalam a intensidade da atividade desenvolvida que desencadeia alterações metabólicas significativas, bem como na fisiologia cardíaca. Assim, foram avaliadas as alterações que a simulação de busca produz nos níveis de glicose, lactato, troponina I cardíaca (cTnI), bem como na frequência cardíaca e atividade eletrocardiográfica durante a fase de atividade e recuperação, a fim de predizer a adaptação fisiológica ao exercício. Cinco cães adultos saudáveis do Serviço de Resgate e Salvamento do Corpo de Bombeiros Militares foram submetidos à simulação de operação de busca de 60 minutos na mata e cobriram uma área florestal de aproximadamente 50.000 m2. Os cães estavam soltos, acompanhados pelo condutor e estavam livres para realizar qualquer tipo de atividade física. Foram avaliados os níveis séricos de glicose, lactato e troponina I cardíaca, atividade eletrocardiográfica e frequência cardíaca em repouso, na fase de exercício e no tempo de recuperação. Não foram detectadas alterações nos níveis de glicose, frequência cardíaca e ritmo cardíaco. Em comparação com os valores basais houve aumento de lactato ao final da fase de exercício [EXER] (60'EXER) e na fase de recuperação [RCT] aos 30'RCT e 60'RCT; e cTnI aos 60'RCT, 120'RCT e 4hRCT. Duração da onda P foi significativamente maior em 60'EXER, 15'RCT e 30'RCT, sem alterações na amplitude da onda. Duração do intervalo QRS teve aumento significativo em 30'RCT e o segmento ST apresentou diferença significativa em 60'EXER, 15'RCT e 60'RCT quando comparado ao basal. As alterações moderadas nos níveis de lactato e cTnI, bem como a pouca alteração na atividade eletrocardiográfica e manutenção da frequência cardíaca sugerem boa adaptação dos cães de busca e resgate ao tipo, intensidade e duração da operação de busca simulada realizada.(AU)

Effectiveness of 100% tea tree oil (Melaleuca alternifolia) versus salicylic acid + lactic acid solution in the treatment of common warts: A randomized controlled trial

Background@#Common warts are a common malady among patients. Not only does it affect the person physically but also mentally and socially. Several treatment modalities are available; however, the major concerns are the treatment cost and adverse effect profile. Salicylic + lactic acid (SLA) solution is one of the standard treatment modalities owing to its strong keratolytic properties; however, its cost and adverse effects limit its use among patients. A cost-effective and safe alternative treatment is ideal to bring about a more favorable clinical outcome and better patient satisfaction. 100% tea tree oil (TTO) solution was used in this study due to its natural antiviral and anti-inflammatory properties.@*Objective@#The study aimed to compare the safety and effectiveness of 100% TTO versus SLA solution in the treatment of common warts.@*Methods@#A total of 17 patients with a total of 74 warts were included in the study. Each wart was assigned to either of the two treatment groups. the SLA group and the 100% TTO group. A treatment period of 6 weeks was used to assess the effectiveness of both treatment groups.@*Results@#The study showed no significant difference between the SLA solution and 100% TTO in the treatment of common warts. The 100% tea tree group reported lesser adverse effects. Both treatment groups reported favorable treatment satisfaction.@*Conclusion@#100% TTO is a potentially safe and cost-effective alternative in the treatment of common warts.

Analysis of the biocompatibility of a biocelulose and a poly L- lactic acid membrane

The use of selective barriers as resorbable membranes has become a routine clinical procedure for guided bone regeneration. Therefore, the production of membranes with a low inflammatory potential during their resorption process has become the goal of a considerable number of researches. Aim: The purpose of the present study was to evaluate the biocompatibility of poly (L- lactic acid) (PLLA) and biocelulose membranes (BC) inserted in the subcutaneous tissue on the dorsum of rats. Methods: Fifteen animals underwent surgical procedures for the insertion of 4 types of membranes: COL (Collagen membrane) ­ Control Group; BC (Biocellulose membrane); BCAg (Biocellulose membrane impregnated with Silver); PLLA (Poly (L-lactic acid) membrane). All membrane types were inserted into each animal. Animals were euthanized after 3, 7, and 15 days of the surgical procedure. Descriptive histological analyses were carried out to investigate host tissue reaction to membrane presence by assessing the anti-inflammatory process composition associated with the membrane resorption and the presence of foreign-body reaction or encapsulation. Results: The BC membranes showed a higher degree of inflammation and poor pattern of integration with the surrounding tissues than the PLLA and COL membranes. Conclusion: The PLLA and COL membranes present better biocompatibility than the BC membranes

Hiperwarburgismo: la "hipoglucemia feliz" de los pacientes oncológicos: Revisión narrativa / Hyperwarburgism: the "Happy hypoglycemia" of cancer patients: Case report and review of literature

Introducción: La glucosa es el combustible energético cerebral, esta relación es establecida de manera integral en la inmensa mayoría de revisiones, debido al ávido consumo -y casi exclusivo - glucósico por parte del tejido neuronal. En esta esfera, la hipoglucemia se traduce por defecto en un conjunto de síntomas neurológicos, resultado del estado neuroglucopénico. Cuando la caída de estos niveles glicémicos es pronunciada desencadena alteraciones del estado sensorial, pudiendo llegar al coma con daños irreversibles de sostenerse en el tiempo. Propósito de la revisión: El objetivo de la revisión es presentar un caso de hipoglucemia severa sin sintomatología neuroglucopénica. Recientes hallazgos: Al ausencia de sintomatología neurológica se da debido al consumo del lactato ­ tradicionalmente producto anaerobiótico ­ como una vía metabólica energética alternativa al consumo de glucosa. La hipoglucemia puede ser compensada a nivel neurológico con sistemas lanzadores de lactato en el tejido neuronal, este puede sustituir a la glucosa como sustrato energético del cerebro. Conclusiones: La hipoglicemia sin síntomas adrenérgicos o neuroglucopénicos es un tema vinculado a pacientes oncológicos, y propone al lactato como combustible del tejido nervioso adicional a la glucosa. Por otra parte, la asociación lactato = hipoperfusión, es otra entidad que debe ser revisada y reanalizada por todo lo que implica el lactato dentro de la vía fisiopatológica metabólica corporal.

Introduction: Glucose is the cerebral energy fuel; this relationship is fully established in most re-views due to neuronal tissue's avid and almost exclusive glucose consumption. In this sphere, hypoglycemia is translated by default into a set of neurological symptoms resulting from the neuroglycopenic state. When the drop in these glycemic levels is pronounced, it triggers alterations in the sensory state, being able to reach a coma with irreversible damage if sustained over time. Purpose of the review: The objective is to present a case of severe hypoglycemia without neu-roglycopenic symptoms. Recent findings: The absence of neurological symptoms is due to the consumption of lactate ­ traditionally an anaerobic product ­ as an alternative energy metabolic pathway to glucosa consumption. Hypoglycemia can be compensated at the neurological level with lactate launching systems in neuronal tissue, replacing glucose as the brain's energy substrate. Conclusions: Hypoglycemia without adrenergic or neuroglycopenic symptoms is an issue linked to cancer patients, and lactate is proposed as fuel for nervous tissue in addition to glucose. On the other hand, the lactate-hypoperfusion association is another entity that must be reviewed and reanalyzed for everything that lactate implies within the body's metabolic pathophysiological pathway.

Comparação do efeito de beta alanina, bicarbonato de sódio e limão como agentes tamponantes entre ciclistas em exercício de alta intensidade / Comparison of the effect of beta alanine, sodium bicarbonate and lemon as tamponant agents among high-intensity exercise cyclists

Alguns suplementos exercem atividade tamponante e têm sido reconhecidos por sua contribuição anaeróbica em exercícios de alta intensidade, retardando a fadiga muscular periférica e potencializando assim a performance esportiva. O objetivo deste estudo foi comparar o benefício ergogênico no tamponamento e dano muscular, dos suplementos beta alanina, bicarbonato de sódio e suco de limão por meio da dosagem de lactato sanguíneo e creatinofosfoquinase (CPK) e na performance de ciclistas submetidos a exercício anaeróbico de alta intensidade. Estudo transversal crossover, realizado em quatro etapas, com ciclistas do sexo masculino. A suplementação foi constituída de 6 g de beta alanina, 0,2 g/kg de bicarbonato de sódio e 30 mL de suco de limão. Lactato sanguíneo e enzima CPK foram dosados pelo método teste ultravioleta enzimático e cinético, respectivamente, em cada uma das etapas. A performance correspondeu à rotação máxima por minuto (RPM) da Air Bike. Participaram do estudo sete ciclistas, com média de idade de 31,14 ± 3,71 anos. O lactato e a CPK apresentaram significância entre os momentos em todas as etapas avaliadas, porém as suplementações comparadas entre si não apresentaram diferença estatística. Não houve melhora da performance (p>0,05) com as utilizações de bicarbonato de sódio, beta alanina e suco de limão em ciclistas. Para os parâmetros avaliados, nenhum dos suplementos apresentou superioridade nas variáveis de tamponamento, dano muscular e performance no treinamento.

Some supplements exert buffering activity and have been recognized for their anaerobic contribution to high-intensity exercise, delaying peripheral muscle fatigue and thus enhancing sports performance. The aim of this study was to compare the ergogenic benefit in muscle buffering and damage of beta alanine, sodium bicarbonate and lemon juice supplements through the measurement of blood lactate and creatine phosphokinase (CPK) and on the performance of cyclists submitted to high intensity anaerobic exercise. Cross-sectional study, carried out in 4 stages, with male cyclists. Supplementation was 6 g beta alanine, 0.2 g/kg of sodium bicarbonate and 30 mL of lemon juice. Blood lactate and creatine phosphokinase enzyme were measured by the enzymatic and kinetic ultraviolet test method, respectively, in each of the steps. Performance corresponded to the maximum rotation per minute (RPM) of the Air Bike. Seven cyclists participated in the study, with a mean age of 31.14 ± 3.71 years. Lactate and CPK presented significance between the moments in all the evaluated stages, however the supplements compared to each other showed no statistical difference. There was no performance improvement (p>0.05) with the use of sodium bicarbonate, beta alanine and lemon juice in cyclists. For the parameters evaluated, none of the supplements showed superiority in the variables of buffering, muscle damage and training performance.

Fórmula artesanal a base de lactosuero: complemento alimenticio para niños preescolares / Artisanal whey-based formula: food supplement for preschool children

Resumen Se pretendió desarrollar una fórmula artesanal, a base de lactosuero, como complemento alimenticio para niños preescolares. Se realizó una investigación descriptiva ejecutada en tres fases: 1. Ensayos preliminares para la determinación del esquema tecnológico; 2. Evaluación fisicoquímica para la caracterización del producto y determinación de macronutrientes y 3. Evaluación sensorial donde se midió el nivel de agrado del producto final. Los datos obtenidos de los análisis se tabularon en cuatro repeticiones y se analizaron a través de estadísticas descriptivas de tendencia central y en frecuencias expresadas en tablas y gráficos mediante el programa estadístico SPSS versión 20.0. Se obtuvo que en el análisis proximal del requesón deshidratado, éste aportó por cada 100 gramos de producto: 480,28 kcal, 46,5% de proteínas, 22,36% de grasas y 23,26% de hidratos de carbono. La formulación final de la bebida constó de 2,9 g de requesón deshidratado, 3,6 g de arroz previamente cocido y 1,8 g de azúcar diluidos por cada onza preparada. Se determinó que es una fórmula hipocalórica-hiperproteica e isoosmolar, con una viscosidad de 275cP, un pH de 5,1 y con 0,291% de ácido láctico. La fórmula artesanal a base de lactosuero fue de agrado para 41 niños que participaron en el análisis sensorial. Se recomienda su uso en niños que se encuentren en condición de vulnerabilidad nutricional.

Abstract The main objective of this research was to develop an artisan formula based on whey as food supplement directed to preschool children. It was a descriptive study carried out in three phases: 1. Preliminary tests, for the determination of the technological scheme; 2. Physical-chemical evaluation, for the characterisation of the product and determination of nutrients and, 3. Sensory evaluation: the level of satisfaction of the final product measured. The data obtained from the analysis were tabulated in four repetitions and analysed through descriptive statistics of central tendency and in frequencies expressed in tables and graphs using the statistical program SPSS version 20.0. As a result, for each 100 grams of dehydrated cottage cheese this malnuprovides: 480.28 kcal, 46.5% protein; 22.36% fat and 23.26% carbohydrates. The final formulation of the drink consisted of 2.9 g of dehydrated cottage cheese, 3.6 g of previously cooked rice and 1.8 g of diluted sugar for each prepared ounce. It was determined as a hypocaloric-hyperproteic and isomolar formula, with a viscosity of 275cP, a pH of 5.1 and with 0.291% lactic acid. The artisan formula based on whey was liked by 41 children who participated in the sensory analysis. As a conclusion, it can be recommended as food supplement in children with nutritional vulnerability conditions.

Resumo O objetivo principal desta pesquisa foi desenvolver uma fórmula artesanal à base de soro de leite como suplemento alimentar direcionado a crianças pré-escolares. Foi realizado um estudo descritivo em três fases: 1. Ensaios preliminares, para determinação do esquema tecnológico; 2. Avaliação físico-química, para caracterização do produto e determinação de macronutrientes e 3. Avaliação sensorial: mediu-se o grau de satisfação do produto final. Os dados obtidos das análises foram tabulados em quatro repetições e analisados por meio de estatísticas descritivas de tendência central e em frequências expressas em tabelas e gráficos utilizando o programa estatístico SPSS versão 20.0. Como resultado da análise proximal, para cada 100 gramas de requeijão desidratado fornece: 480,28 kcal, 46,5% de proteína; 22,36% de gordura e 23,26% de carboidratos. A formulação final da bebida consistiu em 2,9 g de requeijão desidratado, 3,6 g de arroz previamente cozido e 1,8 g de açúcar diluído para cada onça preparada. O resultado concluiu que é uma fórmula hipocalórica-hiperproteica e isoosmolar, com viscosidade de 275cP, pH de 5,1 e com 0,291% de ácido lático. A fórmula artesanal à base de soro de leite foi apreciada por 41 crianças que participaram da análise sensorial. É recomendado seu uso em crianças que se encontrem em condições de vulnerabilidade nutricional.

Medición de los niveles de lactato sérico y frecuencia cardiaca en caninos (Canis lupus familiaris) braquicefálicos, mesocefálicos y dolicocefálicos sometidos a prueba de esfuerzo en trotadora motorizada / Measurement of serum lactate levels and heart rate in canines (Canis lupus familiaris) Brachycephalic, Mesocephalic and Dolichocephalic submitted to a stress test on a motorized treadmill

RESUMEN Se analizaron los niveles de lactato sérico y de frecuencia cardiaca (FC) en 15 perros clinicamente sanos que fueron sometidos a pruebas de esfuerzo en trotadora motorizada, buscando verificar un grado de fatiga muscular frente a una prueba de esfuerzo intenso. Se consideraron pacientes con morfologia craneana de tipo braquicefálico, mesocefálico y dolicocefálico. Las mediciones séricas de lactato fueron conseguidas por medio de un medidor portátil, mientras que las frecuencias cardiacas se obtuvieron a través de un oximetro portátil a los tiempos 0, 10, 20 y 30 minutos, en los diferentes momentos de esfuerzo fisico en la trotadora motorizada, la cual fue adaptada en su inclinación en 15% y a un máximo de velocidad de 10 km/h. Las medias de los niveles séricos entre perros mesocefálicos y dolicocefálicos fueron significativas, a diferencia de los perros braquicefálicos los cuales resultaron no significativos. Las medias de las frecuencias cardiacas no tuvieron diferencia significativa bajo un 95% de confianza.

ABSTRACT Serum lactate and heart rate (HR) levels were analyzed in 15 clinically healthy dogs that were subjected to stress tests on a motorized treadmill, seeking to verify a degree of muscle fatigue compared to an intense exercise test. Patients with brachycephalic, mesocephalic and dolichocephalic type cranial morphology were considered. Serum lactate measurements were procured by means of a portable meter, while heart rates were obtained through a portable oximeter at the times 0, 10, 20, and 30 minutes at different moments of physical effort on the motorized treadmill, which was adapted in its inclination by 15% and at a maximum speed of 10 km/h. Mean serum levels between mesocephalic and dolichocephalic dogs were significant, unlike brachycephalic dogs, which were not significant. The mean heart rates did not have a significant difference under 95% confidence.

The effect of lactic acid fermentation of Bactronophorus thoracites on antimicrobial activity against rice pathogens

Aims@#Leaf blight disease caused by Pantoea spp. reduces rice yields in numerous nations. However, the exact strategy to combat Pantoea spp. has yet to be determined. Bactronophorus thoracites is a promising source of natural antimicrobial agents due to their potential as a substrate to generate peptides with high antimicrobial activity. This study determined the effects of lactic acid fermentation using Lactobacillus casei ATCC334 as a starter culture on antimicrobial activity against rice pathogens, proximate composition, and amino acid profiles from B. thoracites crude extract.@*Methodology and results@#Bactronophorus thoracites was washed and deshelled to collect the flesh and homogenised at 4 °C before freeze-drying. The freeze-dried samples were fermented with L. casei for 4 to 8 days at 37 °C. The antimicrobial activity, MIC and MBC were determined using a spectrometer. The fermented protein was subjected to proximate and amino acid analyses. The antimicrobial activity of fermented B. thoracites protein (FBTP) was significantly (p<0.05) decreased with the increased fermentation days (from 4 to 8 days). The antimicrobial activity was also increased when the glucose concentration increased from 2% to 3%. However, raising the glucose concentration to 4% decreased the antimicrobial activity. The antimicrobial activity was significantly (p<0.05) increased when the substratewater (S/W) ratio increased from 0.84% to 0.96%. The FBTP (4 days, 3% glucose concentration and 0.96% S/W ratio) showed high antimicrobial activity against Pantoea ananatis and P. stewartii. The MIC and MBC values for FBTP were 500 μg/mL and 250 μg/mL against P. ananatis and P. stewartii. The zones of inhibition value for FBTP were 16.0 ± 0.5 mm (1000 μg/mL) and 9.33 ± 0.57 mm (500 μg/mL) for P. ananatis, and 11.7 ± 0.61 mm (1000 μg/mL), 9.33 ± 0.58 mm (500 μg/mL) and 7.17 ± 0.77 mm (250 μg/mL) for P. stewartii. The proximate composition and amino acid profiles of the freeze-dried protein hydrolysate powder were characterised. FBTP produced a higher value of protein (61.56%) and ash (32.38%) and a lower value of total fat (0.273%) and carbohydrates (6.27%) than the B. thoracites crude extract. Total amino acid content was 39.480 g/100 g in B. thoracites crude extract and 155.442 g/100 g in FBTP. The essential amino acid glutamine was the most abundant in B. thoracites crude extract and methionine in FBTP.@*Conclusion, significance and impact of study@#This study showed that lactic acid fermentation could produce FBTP using L. casei with improved functional characteristics and as a source of a natural antimicrobial agent against rice pathogens.

Blood lactate as a biomarker of depression: a comparative study between runners and sedentary people

Abstract Aim: The main objective of this work is to investigate whether recreational running, considered an aerobic exercise, would stimulate blood lactate production, reducing the risk of symptoms of depression. Methods: To accomplish this, we compared the depressive symptoms with the Beck Depression Inventory-II, the intensity of physical activity with the International Physical Activity Questionnaire, and blood samples of the D-lactate assay in two groups of participants who practiced and did not practice street running. Results: The results showed a negative correlation between blood lactate levels and the severity of symptoms of depression. In addition, running volunteers had significant blood lactate levels and low depression scores compared to non-running volunteers. Conclusion: This evidence suggests that street running may reduce symptoms of depression by stimulating blood lactate levels.

Metabolomic Profile in Patients with Malignant Disturbances of the Prostate: An Experimental Approach / Perfil metabolómico en pacientes con alteraciones malignas de la próstata: Un enfoque experimental

Purpose To identify metabolites in humans that can be associated with the presence of malignant disturbances of the prostate. Methods In the present study, we selected male patients aged between 46 and 82 years who were considered at risk of prostate cancer due to elevated levels of prostate-specific antigen (PSA) or abnormal results on the digital rectal examination. All selected patients came from two university hospitals (Hospital Universitario del Valle and Clínica Rafael Uribe Uribe) and were divided into 2 groups: cancer (12 patients) and non-cancer (20 patients). Cancer was confirmed by histology, and none of the patients underwent any previous treatment. Standard protocols were applied to all the collected blood samples. The resulting plasma samples were kept at -80°C, and a profile of each one was acquired by nuclear magnetic resonance (NMR) using established experiments. Multivariate analyses were applied to this dataset, first to establish the quality of the data and identify outliers, and then, to model the data. Results We included 12 patients with cancer and 20 without it. Two patients were excluded due to contamination with ethanol. The remaining ones were used to build an Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) model (including 15 non-cancer and 10 cancer patients), with acceptable discrimination (Q2 = 0.33). This model highlighted the role of lactate and lipids, with a positive association of these two metabolites and prostate cancer. Conclusions The primary discriminative metabolites between patients with and without prostate cancer were lactate and lipids. These might be the most reliable biomarkers to trace the development of cancer in the prostate.

Objetivo Identificar metabolitos en humanos que pueden estar asociados con la presencia de alteraciones malignas de la próstata. Métodos Se incluyeron muestras de pacientes masculinos entre 46 y 82 años y que se consideraron en riesgo de cáncer de próstata debido a la elevación del antígeno prostático específico (PSA) o el examen rectal anormal. Todos los pacientes seleccionados procedían de dos hospitales universitarios (Hospital Universitario del Valle y Clínica Rafael Uribe Uribe) y se dividieron en dos grupos: Oncológicos (12) vs no oncológicos (20). El cáncer fue confirmado por histología, y ninguno de ellos recibió tratamiento previo. Se aplicaron protocolos estándar a todas las muestras de sangre recolectadas. Las muestras de plasma resultantes se mantuvieron a −80°C y se adquirió un perfil de cada muestra mediante RMN. Se aplicaron análisis multivariantes a este conjunto de datos, primero para establecer la calidad de los datos e identificar valores atípicos, y para modelar los datos. Resultados Se incluyeron 12 pacientes con cáncer y 20 pacientes sin cáncer. Dos pacientes fueron excluidos por contaminación con etanol. Los restantes se utilizaron para construir un modelo OPLS-DA (15 pacientes no oncológicos y diez oncológicos), con una discriminación aceptable (Q2 = 0,33). Este modelo destacó el papel del lactato y los lípidos, encontrando una asociación positiva entre estos dos metabolitos y el cáncer de próstata. Conclusiones Los principales metabolitos discriminativos entre pacientes con cáncer de próstata versus no cáncer fueron el lactato y los lípidos. Estos podrían ser los biomarcadores más confiables para rastrear el desarrollo del cáncer en la próstata.