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1.
Case Reports Plast Surg Hand Surg ; 10(1): 2256541, 2023.
Article in English | MEDLINE | ID: mdl-37744664

ABSTRACT

Hemangioendothelioma is a malignant vascular tumor, according to ISSVA classification of vascular tumors. This patient presented an epithelioid hemangioendothelioma; this type of tumor can exhibit significant local destruction, sometimes requiring limb amputation. With deferred Mohs micrographic surgery and reconstructive surgery with multiple conventional and microsurgical techniques, partial or total amputation of the hand was avoided.

2.
Am J Obstet Gynecol MFM ; 4(6): 100733, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36038068

ABSTRACT

BACKGROUND: Substance use including opioids, methamphetamines, benzodiazepines, and barbiturates during pregnancy is harmful for the pregnant person and the fetus. Routine screening using validated questionnaires is recommended, but often biologic sampling is done instead. There is often bias in urine drug screening on labor and delivery units. OBJECTIVE: This study aimed to compare characteristics of people who did and did not receive urine drug screening during labor and delivery and to examine the relationship of maternal results to neonatal results. STUDY DESIGN: This was a retrospective chart review examining all people in 2017 who delivered in the labor and delivery unit at our institution. We collected urine drug screening result information, maternal demographic data, follow-up after positive maternal tests, and neonatal test results. Individual characteristics and obstetrical outcomes were analyzed. RESULTS: Of 6265 deliveries, 297 urine drug screening tests were ordered. People who were tested identified most commonly as Native Hawaiian or Pacific Islander (P<.0001). The most common indications for ordering tests were a history of substance use and insufficient prenatal care (P<.0001). People who tested positive were more likely to self-identify as White (P=.03) and have history of substance use (P<.0001). Among the positive test results, 24 (24%) were caused by a provider-ordered medication. Self-identification as Native Hawaiian or Pacific Islander was not predictive of a positive result. Of the tested people, 36% (108/297) had a positive result on preliminary testing, and 33% (98/295) on confirmatory testing. CONCLUSION: Native Hawaiians and Pacific Islanders were more likely to undergo testing, whereas White people were more likely to have a positive result. Maternal results were not reliable for predicting neonatal drug test results and vice versa. With rising rates of substance use disorders in the pregnant and reproductive-age population, standardized unbiased race-neutral guidelines for urine drug screening should be implemented using laboratory test results that include preliminary and reflex confirmatory results.

3.
Iatreia ; 35(2): 98-107, abr.-jun. 2022. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1421624

ABSTRACT

Resumen Introducción: la diabetes mellitus (DM) es una epidemia mundial. La retinopatía diabética proliferativa (RDP), el edema macular diabético (EMD) y las complicaciones de la diabetes mellitus son las principales causas de discapacidad visual y ceguera en los adultos en la edad productiva. Aproximadamente, 1 de cada 3 personas con DM tiene retinopatía diabética (RD) y 1 de cada 10 tiene RDP o EMD. En el presente estudio se hace énfasis en esta última, siendo el primero con estas características en Colombia. Métodos: estudio transversal descriptivo donde se incluyeron 1.203 pacientes con diagnóstico de DM atendidos en la jornada "No más ciegos por Diabetes" del Hospital San Vicente Fundación de Medellín, en el 2017 y 2018. Se evaluó la presencia de RD y EMD clínico y sus características epidemiológicas en un análisis bivariado. Resultados: del total de pacientes con DM tamizados (1.203), el 5,4 % (65) tenían EMD; dentro de estos, el 7,7 % tenía DM tipo 1 y el 89,2% DM tipo 2. El 10,8 % tenía RDP, 73,8% tenía RD no proliferativo (RDNP). En un 93,8 % se hizo diagnósticos de novo de RD. La mediana del tiempo de la diabetes fue de 14 años, con un rango intercuartílico (RIQ) entre 7 y 19,5. La mediana de la hemoglobina glicosilada (HbA1C) fue de 8,3 % (RIQ: 7,1-11). De 65 pacientes con EMD, 28 (56 ojos de los 130 con EMD) fueron estudiados con tomografía de coherencia óptica (OCT) y al 85,7 % se le confirmó EMD. La mediana del grosor macular central fue de 249 micras (RIQ: 231-341) en los pacientes con EMD por OCT (n = 48 ojos). Conclusión: las complicaciones de la diabetes son más prevalentes en los pacientes con RD. La media del tiempo de aparición de EMD fue similar al tiempo de inicio de las complicaciones microvasculares de la diabetes reportada en la literatura, pero debe ser considerada en el contexto del control metabólico de los pacientes.


Summary Introduction: Diabetes Mellitus (DM) is a worldwide epidemic disease, with significant microvascular compromise. Proliferative diabetic retinopathy (PDR) as well as diabetic macular edema (DME) are currently two of the leading causes of visual impairment and blindness in adults of productive age. Approximately one in three people with DM have diabetic retinopathy (DR), and 1 in 10 have PDR or DME. This study emphasizes in the last one, being the first one with these characteristics in Colombia. Methods: This descriptive cross-sectional study includes 1203 patients diagnosed with DM evaluated in the "No more blindness due to diabetes" diabetic retinopathy-screening program of the San Vicente Foundation Hospital in Medellín between 2017 and 2018. The presence of DR and clinical macular edema with the epidemiologic variables were evaluated in a bivariate analysis. Results: From the total number of patients with DM screened (1203), 5,4% (65) had DME, 7,7% had DM type 1 and 89,2% had DM type 2, 10,8% had PDR and 73.8% had nonproliferative diabetic retinopathy NPDR. Most of the patients (93,8%) were diagnosed de novo with DR. The median illness time was 14 years with interquartile range (IQR) between 7 and 19,5. The median glycosylated hemoglobin (HbA1C) was 8.3% (IQR:7,1-11). Optical coherence tomography (OCT) study was done in 28 out of 65 patients with DME (56 out of 130 eyes with DME), in which 85.7% of patients were confirmed to have DME and the mean central macular thickness was 249 microns (IQR:231-341) (n=48 eyes). Conclusion: DM complications were more frequent in patients suffering from DR. The median onset time of DME symptoms was found to be similar to the time of microvascular complications appear; however, it should be considered along with the patient's metabolic control.

4.
Foods ; 11(20)2022 Oct 14.
Article in English | MEDLINE | ID: mdl-37430950

ABSTRACT

Raw milk adulteration with cheese whey is a major problem that affects the dairy industry. The objective of this work was to evaluate the adulteration of raw milk with the cheese whey obtained from the coagulation process, with chymosin enzyme using casein glycomacropeptide (cGMP) as an HPLC marker. Milk proteins were precipitated with 24% TCA; with the supernatant obtained, a calibration curve was established by mixing raw milk and whey in different percentages, which were passed through a KW-802.5 Shodex molecular exclusion column. A reference signal, with a retention time of 10.8 min, was obtained for each of the different percentages of cheese whey; the higher the concentration, the higher the peak. Data analysis was adjusted to a linear regression model, with an R2 of 0.9984 and equation to predict dependent variable (cheese whey percentage in milk) values. The chromatography sample was collected and analyzed by three tests: a cGMP standard HPLC analysis, MALDI-TOF spectrometry, and immunochromatography assay. The results of these three tests confirmed the presence of the cGMP monomer in adulterated samples with whey, which was obtained from chymosin enzymatic coagulation. As a contribution to food safety, the molecular exclusion chromatography technique presented is reliable, easy to implement in a laboratory, and inexpensive, compared with other methodologies, such as electrophoresis, immunochromatography, and HPLC-MS, thus allowing for the routine quality control of milk, an important product in human nutrition.

5.
Am J Obstet Gynecol MFM ; 1(4): 100055, 2019 11.
Article in English | MEDLINE | ID: mdl-33345845

ABSTRACT

BACKGROUND: The postpartum period can be a particularly vulnerable time for exposure to opioid medications, and there are currently no consensus guidelines for physicians to follow regarding opioid prescribing during this period. OBJECTIVE: The purpose of this study was to evaluate inter- and intrahospital variability in opioid prescribing patterns in postpartum women and better understand the role of clinical variables in prescribing. STUDY DESIGN: Data were extracted from electronic medical records on 4248 patients who delivered at 6 hospitals across the United States from January 2016 through March 2016. The primary outcome of the study was postpartum opioid prescription at the time of hospital discharge. Age, parity, route of delivery, and hospital were analyzed individually and with multivariate analyses to minimize confounding factors. Statistical methods included χ2 to analyze frequency of opioid prescription by hospital, parity, tobacco use, delivery method, and laceration type. An analysis of variance was used to analyze morphine equivalent dose by hospital. RESULTS: The percentage of women prescribed postpartum opioids varied significantly by hospital, ranging from 27.6% to 70.9% (P <0.001). Oxycodone-acetaminophen was the most commonly prescribed medication (50.3%) with each hospital having its preferred opioid type. Median number of tablets prescribed ranged from 20 to 40 (P < .0001). Primiparous women were more likely to receive opioids than multiparous women when broken down by a parity of 1, 2, 3, 4, and ≥5 (52.8%, 48.0%, 47.6%, 40.1%, and 45.8%, respectively, P = .0005). Among women who had vaginal deliveries, opioid prescription rates were higher in women who experienced either a second-degree laceration (35.5%, P = .0002) or a third-/fourth-degree laceration (59.3%, P < .001). CONCLUSION: Postpartum opioid prescription rates vary widely among hospitals, but providers within the same hospital tend to follow similar prescribing trends. The variation in prescribing found in our study illustrates the need for clear consensus guidelines for postpartum pain management.


Subject(s)
Analgesics, Opioid , Practice Patterns, Physicians' , Analgesics, Opioid/therapeutic use , Delivery, Obstetric , Female , Humans , Pain Management , Postpartum Period , Pregnancy , United States/epidemiology
6.
Univ. sci ; 22(1): 45-70, Jan.-Apr. 2017. tab, graf
Article in English | LILACS, COLNAL | ID: biblio-904705

ABSTRACT

Abstract Using Response Surface Methodology (RSM) we evaluated the culture conditions (nitrogen source, carbon source, pH and agitation rate) that increase the biomass of Acidocellafaalis strain USBA-GBX-505 and therefore enhance the production of its lipolytic enzyme, 505 LIP. RSM results revealed that yeast extract and agitation were key culture factors that increased the growth-associated lipolytic activity by 4.5-fold (from 0.13 U.mg-1 to 0.6 U.mg-1). The 505 LIP lipase was partially purified using size-exclusion chromatography and ion-exchange chromatography. Its molecular weight was >77 kDa. The enzyme shows its optimum catalytic activity at 55 °C and pH 7.5. EDTA, PMSF, 1-butanol and DMSO inhibited enzymatic activity, whereas Tween 20, acetone, glycerol and methanol increased it. Metallic ions are not required for the activity of 505 LIP, and even have an inhibitory effect on the enzyme. This study shows the potential use of A. facilis strain USBA- GBX-505 for the production of a newly identified lipolytic enzyme, 505 LIP, which is stable at moderate temperatures and in the presence of organic solvents. These are important characteristics for the synthesis of many useful products.


Resumen Por medio de la Metodología de Respuesta de Superficie (RSM) evaluamos las condiciones de cultivo (fuente de N, fuente de C, pH y tasa de agitación) que incrementan la biomasa de Acidocella facilis cepa USBA-GBX-505 y, como consecuencia, la producción de su enzima lipolítica, llamada 505 LIP. Los resultados de la RSM revelaron que el extracto de levadura y la agitación fueron factores de cultivo claves, que incrementaron de 4 a 5 veces la actividad lipolítica asociada al crecimiento (de 0.13 U.mg-1 a 0.6 U.mg-1). La lipasa 505 LIP se purificó parcialmente usando cromatografía de exclusión por tamaño y cromatografía de intercambio iónico. Su peso molecular fue > 77 kDa. La enzima muestra su actividad catalítica óptima a 55 °C y pH 7.5. El EDTA, el PMSF, el 1-butanol y el DMSO inhibieron la actividad enzimática, mientras que el Tween 20, la acetona, el glicerol y el metanol la incrementaron. La enzima 505 LIP no requiere iones metálicos para su actividad, e incluso se inhibe en presencia de ellos. Este estudio muestra el uso potencial de A. facilis cepa USBA-GBX-505 para la producción de una nueva enzima lipolítica, 505 LIP, que es estable a temperaturas moderadas y en la presencia de solventes orgánicos. Estas son características importantes en la síntesis de muchos productos útiles.


Resumo Utilizando a Metodologia de Superfície de Resposta (MSR) avaliamos as condições de cultivo (fontes de nitrogénio e carbono, pH e taxa de agitação) que aumentam a biomassa de Acidocella facilis cepa USBA-GBX-505, e, portanto, elevam a produção de sua enzima lipolítica 505 LIP. Os resultados da MSR revelaram que o extrato de levedura e a agitação foram fatores de cultivo chave que permitiram aumentar 4 a 5 vezes a atividade lipolítica associada ao crescimento (de 0,13 U.mg-1 a 0,6 U.mg-1). A lipase 505 LIP foi parcialmente purificada utilizando cromatografia por exclusão de tamanho e cromatografia de intercambio iónico. Seu peso molecular foi > 77 kDa. A enzima mostra sua atividade catalítica ótima a 55 °C e pH 7,5. EDTA, PMSF, 1-butanol e DMSO inibiram a atividade enzimática, enquanto que Tween 20, acetona, glicerol e metanol aumentaram esta atividade. Íons metálicos não são necessários para a atividade da 505 LIP, apresentando inclusive efeito inibitório da enzima. Este estudo demonstra o potencial uso de A. facilis cepa USBA-GBX-505 para a produção de uma nova enzima lipolítica, 505 LIP, a qual é estável a moderadas temperaturas e na presença de solventes orgánicos. Estas características são importantes para a síntese de diversos produtos úteis.


Subject(s)
Chromatography, Ion Exchange/methods
7.
Pathol Res Pract ; 212(12): 1133-1137, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27712975

ABSTRACT

AIM: Polo-like kinase 1 (Plk1) plays a key role in mitotic cell division and DNA damage repair. It has been observed that either up-regulated or down-regulated Plk1 could induce mitotic defects that results in aneuploidy and tumorigenesis, probably depending on the context. Few previous reports have associated Plk1 expression with prognosis and response to radiotherapy in rectal carcinomas. The aim of this study is to investigate the prognostic impact of Plk1 expression and its role in predicting response to neoadjuvant cheomoradiotherapy in rectal cancer. METHODS AND RESULTS: Immunohistochemical analysis of Plk1 expression was performed in the pre-treatment tumour specimens from 75 rectal cancer patients. We analysed the assocation between Plk1 expression and clinicopathological parameters, pathologic response and outcome. Opposed to previous reports on this issue, low expression of Plk1 was significantly associated with a high grade of differentiation (P=0.0007) and higher rate of distant metastasis (P=0.014). More importantly, decreased levels of Plk1 were associated with absence of response after neoadjuvant therapy (P=0.049). Moreover, low Plk1 expression emerged as an unfavourable prognostic factor for disease-free survival in the non-responder group of patients (P=0.037). CONCLUSIONS: Decreased Plk1 expression was associated with poor pathologic response and worse disease-free survival in rectal cancer patients receiving neoadjuvant chemoradiotherapy, suggesting Plk1 as a clinically relevant marker to predict chemoradiotherapy response and outcome.


Subject(s)
Cell Cycle Proteins/metabolism , Drug Resistance, Neoplasm/physiology , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Rectal Neoplasms/metabolism , Aged , Chemoradiotherapy, Adjuvant , Disease-Free Survival , Female , Humans , Immunohistochemistry , Male , Middle Aged , Neoadjuvant Therapy , Prognosis , Rectal Neoplasms/drug therapy , Rectal Neoplasms/mortality , Rectal Neoplasms/radiotherapy , Survival Rate , Polo-Like Kinase 1
8.
J Cell Mol Med ; 20(9): 1729-36, 2016 09.
Article in English | MEDLINE | ID: mdl-27171907

ABSTRACT

Rectal cancer represents about 30% of colorectal cancers, being around 50% locally advanced at presentation. Chemoradiation (CRT) followed by total mesorectal excision is the standard of care for these locally advanced stages. However, it is not free of adverse effects and toxicity and the complete pathologic response rate is between 10% and 30%. This makes it extremely important to define factors that can predict response to this therapy. Focal adhesion kinase (FAK) expression has been correlated with worse prognosis in several tumours and its possible involvement in cancer radio- and chemosensitivity has been suggested; however, its role in rectal cancer has not been analysed yet. To analyse the association of FAK expression with tumour response to CRT in locally advanced rectal cancer. This study includes 73 patients with locally advanced rectal cancer receiving standard neoadjuvant CRT followed by total mesorectal excision. Focal adhesion kinase protein levels were immunohistochemically analysed in the pre-treatment biopsies of these patients and correlated with tumour response to CRT and patients survival. Low FAK expression was significantly correlated with local and distant recurrence (P = 0.013). Low FAK expression was found to be a predictive marker of tumour response to neoadjuvant therapy (P = 0.007) and patients whose tumours did not express FAK showed a strong association with lower disease-free survival (P = 0.01). Focal adhesion kinase expression predicts neoadjuvant CRT response in rectal cancer patients and it is a clinically relevant risk factor for local and distant recurrence.


Subject(s)
Chemoradiotherapy , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Neoadjuvant Therapy , Neoplasm Recurrence, Local/pathology , Rectal Neoplasms/enzymology , Rectal Neoplasms/therapy , Adult , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Rectal Neoplasms/pathology , Risk Factors , Tissue Array Analysis , Treatment Outcome
10.
BMC Cancer ; 14: 965, 2014 Dec 16.
Article in English | MEDLINE | ID: mdl-25515240

ABSTRACT

BACKGROUND: DEK is a transcription factor involved in stabilization of heterochromatin and cruciform structures. It plays an important role in development and progression of different types of cancer. This study aims to analyze the role of DEK in metastatic colorectal cancer. METHODS: Baseline DEK expression was firstly quantified in 9 colorectal cell lines and normal mucosa by WB. SiRNA-mediated DEK inhibition was carried out for transient DEK silencing in DLD1 and SW620 to dissect its role in colorectal cancer aggressiveness. Irinotecan response assays were performed with SN38 over 24 hours and apoptosis was quantified by flow cytometry. Ex-vivo assay was carried out with 3 fresh tumour tissues taken from surgical resection and treated with SN38 for 24 hours. DEK expression was determined by immunohistochemistry in 67 formalin-fixed paraffin-embedded tumour samples from metastatic colorectal cancer patients treated with irinotecan-based therapy as first-line treatment. RESULTS: The DEK oncogene is overexpressed in all colorectal cancer cell lines. Knock-down of DEK on DLD1 and SW620 cell lines decreased cell migration and increased irinotecan-induced apoptosis. In addition, low DEK expression level predicted irinotecan-based chemotherapy response in metastatic colorectal cancer patients with KRAS wild-type. CONCLUSIONS: These data suggest DEK overexpression as a crucial event for the emergence of an aggressive phenotype in colorectal cancer and its potential role as biomarker for irinotecan response in those patients with KRAS wild-type status.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Biomarkers, Tumor/physiology , Camptothecin/analogs & derivatives , Chromosomal Proteins, Non-Histone/physiology , Colorectal Neoplasms/drug therapy , Oncogene Proteins/physiology , Adult , Aged , Apoptosis , Biomarkers, Tumor/analysis , Camptothecin/therapeutic use , Cell Line, Tumor , Cell Movement , Cell Survival , Chromosomal Proteins, Non-Histone/analysis , Colorectal Neoplasms/chemistry , Colorectal Neoplasms/pathology , Down-Regulation , Female , Gene Expression , Gene Knockdown Techniques , Humans , Irinotecan , Male , Middle Aged , Oncogene Proteins/analysis , Phenotype , Poly-ADP-Ribose Binding Proteins , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , ras Proteins/genetics
11.
Gynecol Oncol ; 126(1): 25-9, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22507531

ABSTRACT

OBJECTIVE: To retrospectively compare results from lymphatic mapping of pelvic sentinel lymph nodes (SLN) using fluorescence near-infrared (NIR) imaging of indocyanine green (ICG) and colorimetric imaging of isosulfan blue (ISB) dyes in women with endometrial cancer (EC) undergoing robotic-assisted lymphadenectomy (RAL). A secondary aim was to investigate the ability of SLN biopsies to increase the detection of metastatic disease. METHODS: Thirty-five patients underwent RAL with hysterectomy. One mL ISB was injected submucosally in four quadrants of the cervix, followed by 0.5 mL ICG [1.25mg/mL] immediately prior to placement of a uterine manipulator. Retroperitoneal spaces were dissected for colorimetric detection of lymphatic pathways. The da Vinci(®) camera was switched to fluorescence imaging and results recorded. SLN were removed for permanent analysis with ultra-sectioning, H&E, and IHC staining. Hysterectomy with RAL was completed. RESULTS: Twenty-seven (77%) and 34 (97%) of patients had bilateral pelvic or aortic SLN detected by colorimetric and fluorescence, respectively (p=0.03). Considering each hemi-pelvis separately, 15/70 (21.4%) had "weak" uptake of ISB in SLN confirmed positive with fluorescence imaging. Using both methods, bilateral detection was 100%. Ten (28.6%) patients had lymph node (LN) metastasis, and 9 of these had SLN metastasis (90% sensitivity, one false negative SLN biopsy). Seven of nine (78%) SLN metastases were ISB positive and 100% were ICG positive. Twenty-five had normal LN, all with negative SLN biopsies (100% specificity). Four (40%) with LN metastasis were detected only by IHC and ultra-sectioning of SLN. CONCLUSIONS: Fluorescence imaging with ICG detected bilateral SLN and SLN metastasis more often than ISB, and the combination resulted in 100% bilateral detection of SLN. Ultra-sectioning/IHC of SLN increased the detection of lymph node metastasis.


Subject(s)
Endometrial Neoplasms/pathology , Lymph Nodes/pathology , Sentinel Lymph Node Biopsy/methods , Adult , Aged , Aged, 80 and over , Colorimetry/methods , Endometrial Neoplasms/surgery , Female , Humans , Laparoscopy/methods , Lymph Nodes/surgery , Microscopy, Fluorescence/methods , Middle Aged , Neoplasm Staging , Retrospective Studies , Robotics/methods
12.
Rev. colomb. quím. (Bogotá) ; 41(1): 133-157, Jan.-Apr. 2012. ilus, tab
Article in English | LILACS | ID: lil-663809

ABSTRACT

A new strategy is presented for the design and synthesis of peptides that exhibit ice-binding and antifreeze activity. A pennant-type dendrimer polypeptide scaffoíd combining an a-helical backbone with four short (β-strand branches was synthesized in solid phase using Fmoc chemistry in a divergent approach. The 51-residue dendrimer was characterized by reverse phase high performance liquid chromatography, mass spectrometry and circular dichroism. Each (β-strand branch contained three overlapping TXT amino acid repeats, an ice-binding motif found in the ice-binding face of the spruce budworm (Choristoneura fumiferana) and beetle (Tenebrio molitor) antifreeze proteins. Ice crystals in the presence of the polypeptide monomer displayed fiat, hexagonal plate morphology, similar to that produced by weakly active antifreeze proteins. An oxidized dimeric form of the dendrimer polypeptide also produced fiat hexagonal ice crystals and was capable of inhibiting ice crystal growth upon temperature reduction, a phenomenon termed thermal hysteresis, a defining property of antifreeze proteins. Linkage of the pennant-type dendrimer to a tri-functional cascade-type polypeptide produced a trimeric macromolecule that gave flat hexagonal ice crystals with higher thermal hysteresis activity than the dimer or monomer and an ice crystal burst pattern similar to that produced by samples containing insect antifreeze proteins. This macromolecule was also capable of inhibiting ice recrystallization.


Una nueva estrategia se presenta para el diseño y síntesis de péptidos que se unen al hielo y evidencian actividad anticongelante. Un polipéptido dendrímero del tipo banderín, que combina en su estructura un núcleo a-hélice con cuatro ramificaciones cortas de hojas β, se sintetizó en fase sólida utilizando la química Fmoc con una estrategia divergente. El dendrímero de 51 residuos se caracterizó por cromatografía líquida de alta resolución, espectrometría de masas y dicroís-mo circular. Cada ramifcación de hoja β contiene tres repeticiones de los motivos de aminoácidos TxT sobrelapados, un motivo de unión al hielo presente en la cara de unión de las proteínas anticongelantes del gusano de brotes de abeto (Choristoneura fumiferana) y en el escarabajo (Tenebrio molitor). Los cristales de hielo en presencia del polipéptido monomérico presentan una morfología hexagonal plana, similar a la producida por las proteínas anticongelantes con una débil actividad. Un dímero oxidado del polipéptido también produce cristales de hielo hexagonales planos que fueron capaces de inhibir el crecimiento de los cristales de hielo a medida que se disminuía la temperatura, un fenómeno conocido como histéresis térmica, esto es, una propiedad que define las proteínas anticongelantes. La vinculación del dendrímero tipo banderín a un polipéptido tipo cascada trifuncional produjo una macro-molécula trimérica que generó cristales de hielo hexagonales planos con una mayor actividad de histéresis térmica que los dímeros y los monómeros y un patrón de estallido del cristal de hielo muy similar al producido por las muestras que contienen proteínas anticongelantes de insectos. Estas moléculas además fueron capaces de inhibir la recristianización del hielo.


Uma nova estratégia é apresentada para o desenho e síntese de peptídeos que se unem ao gelo e apresentam atividade anticongelante. Um polipeptídeo dendrímero do tipo pennant que combina em sua estrutura um núcleo a-hélice com quatro ramifcacoes curtas de folhas β foi sintetizado em fase sólida utilizando a química Fmoc com uma estratégia divergente. O dendrímero de 51 resíduos foi caracterizado por cromatografa líquida de alta resolução, espectrometria de massas e dicroísmo circular. Cada ramifcacao de folha (β contém três repeticoes dos motivos de aminoácidos TxT sobrepostos, um motivo de união ao gelo presente na cara de união das proteínas anticongelantes do verme de Choristoneura fumiferana e no escaravelho (Tenebrio molitor). Os cristais de gelo, em presença do polipeptídeo monomérico, apresentam urna morfologia hexagonal plana, similar à produzida pelas proteínas anticongelantes com uma atividade fraca. Um dímero oxidado do polipeptídeo também produz cristais de gelo hexagonais planos e fo-ram capazes de inibir o crescimento dos cristais de gelo à medida que a temperatura diminuia, um fenômeno conhecido como histerese térmica una propriedade que def ne as proteínas anticongelantes. A vinculação do dendrímero tipo pen-nant a um polipeptídeo tipo cascata tri-funcional produziu uma macromolécula trimérica que gerou cristais de gelo hexa-gonais planos com uma maior atividade de histerese térmica que os dímeros e os monómeros e um padrão de estouro do cristal de gelo muito similar ao produzi-do pelas amostras que contêm proteínas anticongelantes de insetos. Estas moléculas, aliás, foram capazes de inibir a recristalização do gelo.

13.
Arch. venez. pueric. pediatr ; 73(1): 10-13, ene.-mar. 2010. ilus, tab, graf
Article in Spanish | LILACS | ID: lil-589186

ABSTRACT

El tratamiento de las diversas deformidades del pie varia según las patologías y es precisamente en el niño por su gran plasticidad biológica, en quien se pueden aplicar los diferentes resursos que se poseen para el tratamiento ortopédico conservador. En el presente trabajo se plantea una alternativa para el tratamiento del retropié valgo, con la férula termo formada tipo UCBL (University of California Biomechanics Laboratory. Demostrar la utilidad de la férula tipo UCBL en el tratamiento conservador del retropié valgo para postegar y/o evitar tratamientos quirúrgicos por deformidades severas. La muestra utilizada fue de 15 pacientes (6 niñas, 9 niños, con edades entre 2 años 6 meses y 10 años) con disfunción del brazo de palanca por pérdida de la rigidez ósea, debido a la subluxación de la articulación sub-astragalina (retropié valgo flexible), en quienes se utilizó la férula termoformada tipo UCBL con seguimiento promedio de 12 a 36 meses. Se evaluó clínicamente la flexibilidad del pié y la maniobra de Silverskiold y radiologicamente en bípeda estación estática, el ángulo Costa-Bertani, Astrágalo calcáneo y astrágalo-1er metatarsiano. 10 pacientes presentaron mejoría clínica y radiológica, 5 de los casos no evidenciaron cambios, sin embargo, mantuvieron su flexibilidad. La férula resultó útil, inclusive en los casos donde no se demostró corrección radiológica, ya que evitó estructuración de la deformidad.


The adequate treatment for foot deformities varies depending on the pathology, and because of the high plasticity found in children, it is in this age group where the available conservative treatment resources can be applied. An alternative for the valgus hindfoot treatment is presented in this paper, using the UCBL (University of California Biomechanies Laboratory) thermoshaped orthesis. To prove utility of the thermoformed UCBL type orthesis in the treatment of flexible pes valgus in orden to avoid fuseverity deformities. The study included 15 patients (6 female, 9 male, ages between 2 years 6 months and 10 years) with lever-arm dysfunction due to loss of bony rigidity with sub-astragaline joint subluxation (flexible valgus hindfoot), in whom UCBL thermoshaped orthesis was indicated with an average follow up between 12 to 36 monts. Foot flexibility was clinical evaluated; also Silverskiold maneuver and static bipedestation x-rays angles were measured. Ten patients showed clinical and radiological improvement, 5 patients showed no change, although flexibility was maintained. The UCBL orthesis was useful, even in cases were no radiological change was observed, because it avoided structuration of bony deformity.


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Foot Deformities/etiology , Tarsal Bones/physiopathology , Flatfoot/pathology , Flatfoot/therapy , Radiology/methods , Talus , Ferula , Orthotic Devices
14.
Biochem Biophys Res Commun ; 332(3): 771-81, 2005 Jul 08.
Article in English | MEDLINE | ID: mdl-15907793

ABSTRACT

The process of Mycobacterium tuberculosis infection of the macrophage implies a very little-known initial recognition and adherence step, important for mycobacterial survival; many proteins even remain like hypothetical. The Rv1510c gene, encoding a putatively conserved membrane protein, was investigated by analysing the M. tuberculosis genome sequence data reported by Cole et al. and a previous report that used PCR assays to show that the Rv1510 gene was only present in M. tuberculosis. This article confirmed all the above and identified the transcribed gene in M. tuberculosis, Mycobacterium africanum, and in M. tuberculosis clinical isolates. Antibodies raised against peptides from this protein recognised a 44 kDa band, corresponding to Rv1510c theoretical mass (44,294 Da). Assays involving synthetic peptides covering the whole protein binding to U937 and A549 cell lines led to recognising five high activity binding peptides in the Rv1510 protein: 11094, 11095, 11105, 11108, and 11111. Their affinity constants and Hill coefficients were determined by using U937 cells. Cross-linking assays performed with some of these HABPs showed that they specifically bound to a U937 cell line 51 kDa protein, but not to Hep G2 or red blood cell proteins, showing this interaction's specificity.


Subject(s)
Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Mycobacterium tuberculosis/metabolism , Amino Acid Sequence , Antibodies, Bacterial , Bacterial Proteins/genetics , Bacterial Proteins/immunology , Base Sequence , Binding Sites/genetics , Cell Line , Circular Dichroism , Cross-Linking Reagents , DNA, Bacterial/genetics , Genes, Bacterial , Humans , Kinetics , Membrane Proteins/genetics , Membrane Proteins/immunology , Molecular Sequence Data , Molecular Weight , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/immunology , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , U937 Cells
15.
Biochimie ; 87(5): 425-36, 2005 May.
Article in English | MEDLINE | ID: mdl-15820749

ABSTRACT

Several EBA-175 paralogues (EBA-140, EBA-165, EBA-175, EBA-181, and EBL-1) have been described among the Plasmodium falciparum malaria parasite proteins, which are important in the red blood cell (RBC) invasion process. EBA-181/JESEBL is a 181 kDa protein expressed in the late schizont stage and located in the micronemes; it belongs to the Plasmodium Duffy binding-like family and is able to interact with the erythrocyte surface. Here, we describe the synthesis of 78, 20-mer synthetic peptides derived from the reported EBA-181/JESEBL sequence and their ability to bind RBCs in receptor-ligand assays. Five peptides (numbered 30030, 30031, 30045, 30051, and 30060) displayed high specific binding to erythrocytes; their equilibrium binding parameters were then determined. These peptides interacted with 53 and 33 kDa receptor proteins on the erythrocyte surface, this binding being altered when RBCs were pretreated with enzymes. They were able to inhibit P. falciparum merozoite invasion of RBCs when tested in in vitro assays. According to these results, these five EBA-181/JESEBL high specific erythrocyte binding peptides, as well as the entire protein, were seen to be involved in the molecular machinery used by the parasite for invading RBCs. They are thus suggested as potential candidates in designing a multi-sub-unit vaccine able to combat the P. falciparum malaria parasite.


Subject(s)
Antigens, Protozoan/metabolism , Erythrocytes/metabolism , Peptide Fragments/metabolism , Plasmodium falciparum/pathogenicity , Animals , Antigens, Protozoan/genetics , Binding, Competitive , In Vitro Techniques , Plasmodium falciparum/chemistry , Protein Binding , Protein Structure, Tertiary
16.
Biochem Biophys Res Commun ; 321(4): 835-44, 2004 Sep 03.
Article in English | MEDLINE | ID: mdl-15358103

ABSTRACT

Erythrocyte binding antigen-160 (EBA-160) protein is a Plasmodium falciparum antigen homologue from the erythrocyte binding protein family (EBP). It has been shown that the EBP family plays a role in parasite binding to the erythrocyte surface. The EBA-160 sequence has been chemically synthesised in seventy 20-mer sequential peptides covering the entire 3D7 protein strain, each of which was tested in erythrocyte binding assays to identify possible EBA-160 functional regions. Five EBA-160 high activity binding peptides (HABPs) specifically binding to erythrocytes with high affinity were identified. Dissociation constants lay between 200 and 460 nM and Hill coefficients between 1.5 and 2.3. Erythrocyte membrane protein binding peptide cross-linking assays using SDS-PAGE showed that these peptides bound specifically to 12, 28, and 44 kDa erythrocyte membrane proteins. The nature of these receptor sites was studied in peptide binding assays using enzyme-treated erythrocytes. HABPs were able to block merozoite in vitro invasion of erythrocytes. HABPs' potential as anti-malarial vaccine candidates is also discussed.


Subject(s)
Antigens, Protozoan/genetics , Antigens, Protozoan/metabolism , Erythrocytes/parasitology , Plasmodium falciparum/genetics , Plasmodium falciparum/immunology , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Amino Acid Sequence , Animals , Binding Sites/genetics , Binding, Competitive , Circular Dichroism , Humans , In Vitro Techniques , Kinetics , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/immunology , Peptide Fragments/metabolism , Plasmodium falciparum/pathogenicity , Virulence
17.
Int J Cancer ; 107(3): 416-24, 2003 Nov 10.
Article in English | MEDLINE | ID: mdl-14506742

ABSTRACT

Human papillomaviruses (HPVs) are the cause of epithelial lesions, HPV type 16 and type 18 being associated with the development of anogenital cancer. The L1 Major Capsid Protein (L1) represents about 90% of total HPV protein and is involved in virus-host cell interaction, but little is known about this binding process. L1 sequences from HPV types 16 and 18 were synthesized in 56 20-mer peptides, covering the entire protein, HPLC-purified, (125)I-radiolabeled and tested in VERO and HeLa cell-binding assays to identify those peptides with high specific binding activity. Peptides 18283 (residues 54-77) and 18294 (274-308) from HPV16 L1, as well as 18312 (59-78) and 18322 (259-278) from HPV18 L1, presented high specific target cell binding activity. Peptide 18283 and 18294 affinity constants were 300 and 600 nM, respectively. Enzyme cell treatment before binding assay indicated that VERO and HeLa cell peptide receptor is a surface-exposed protein. There was a 60% reduction in peptide 18283 binding to heparin lyase-treated cells. Cross-linking assays showed that these proteins molecular weights were around 69 and 54 kDa. Peptides 18283 and 18294 specifically inhibited HPV-16 VLP binding to HeLa cells. According to the L1- and VLP-reported structure, both peptides are close on the VLP-surface, belonging to the outer surface broad pockets suggested as being potential receptor sites. Furthermore, it has been reported that a conserved motif from peptide 18294 is the target for neutralizing antibodies. These results suggest that such binding sequences are used by the virus as cell-binding regions.


Subject(s)
Capsid Proteins , Capsid/physiology , Oncogene Proteins, Viral/physiology , Papillomaviridae/physiology , Peptide Fragments/physiology , Virion/physiology , Amino Acid Sequence , Animals , Chlorocebus aethiops , HeLa Cells , Heparin/pharmacology , Humans , Molecular Sequence Data , Vero Cells
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