Calidad microbiológica de embutidos crudos: estudio del caso en Latinoamérica / Microbiology of raw sausages: a case of study in Latin America

Introducción. Los embutidos crudos se componen de carne fragmentada y otros ingredientes no cárnicos (sal, especias, fosfatos, nitritos) pero cuya formulación varía según el país; son productos altamente perecederos y podrían representar un riesgo para el consumidor. Objetivo. Los embutidos frescos son de alto consumo en varios países de Latinoamérica, por ello, el objetivo de esta revisión bibliográfica es compilar la información disponible sobre la calidad microbiológica de este tipo de productos en la región. Materiales y métodos. Se realizó una búsqueda de literatura (desde el 2006 a la fecha) en las principales bases de datos. Resultados. Se determinó que la calidad microbiológica de los embutidos crudos latinoamericanos no es adecuada según la reglamentación. Las bacterias más estudiadas son los microorganismos totales aerobios mesófilos (MTAM), y las bacterias ácido-lácticas (BAL); estos dos grupos son los referentes para determinar la vida útil. Los patógenos más analizados son Salmonella spp. y Listeria monocytogenes y llama la atención que Staphyloccoccus aureus no se utiliza como indicador de malas prácticas de higiene o de inocuidad. Conclusiones. En general se confirma que los embutidos frescos podrían ser un riesgo para la salud pública ya que presentan recuentos microbiológicos altos, en ocasiones no regulados. Algunos agentes antimicrobianos como los compuestos etanólicos de propóleos (EEP), compuestos fenólicos y bacteriófagos han sido estudiados. Sin embargo, no está claro si a nivel artesanal este tipo de ingredientes son utilizados del todo. Finalmente, destaca la necesidad de armonizar las metodologías de estudio y la normativa vigente en los distintos países(AU)

Introduction. Raw sausages are products composed of comminuted meat and other non- meat ingredients (salt, spices, phosphates, nitrites) but the formulation varies in each country. Given this nature, raw sausages are highly perishable and may represent an important risk for consumers. Aim. As raw sausages are highly consumed in many Latin-American countries, the objective of this literature review was to compile the available information about studies of the microbial quality of these products in the region. Materials and methods. For that purpose, a literature search was performed on main data bases to compile studies from 2006 to nowadays. Results. In general, it was found that microbiological quality of Latin-American raw sausages is not adequate according to current regulation. Total aerobic mesophilic microorganisms (TAMM) and Lactic Acid Bacteria (LAB) were the most studied indicators; these two groups are the main reference to establish shelf life. Salmonella spp. and Listeria monocytogenes were the most studied pathogens, and it is noticeable that Staphyloccoccus aureus is not used as an indicator for safety or manipulation. Conclusions. It is perceived that raw sausages in the region could represent a public health risk as they frequently present high microbiological counts, not regulated in many cases. For conservation, antimicrobial agents as propolic ethanoplic extracts (PEE), phenolyc compounds, and bacteriophages have been studied. However, it is not clear if these ingredients are used at the artisanal level, even though it can be assumed that they are not given the high microbial numbers that are reported. Finally, it stands out the need of harmonization of methodologies and current regulation in the countries(AU)

Image features for quality analysis of thick blood smears employed in malaria diagnosis.

BACKGROUND: The World Health Organization (WHO) provides protocols for the diagnosis of malaria. One of them is related to the staining process of blood samples to guarantee the correct parasite visualization. Ensuring the quality of the staining procedure on thick blood smears (TBS) is a difficult task, especially in rural centres, where there are factors that can affect the smear quality (e.g. types of reagents employed, place of sample preparation, among others). This work presents an analysis of an image-based approach to evaluate the coloration quality of the staining process of TBS used for malaria diagnosis. METHODS: According to the WHO, there are different coloration quality descriptors of smears. Among those, the background colour is one of the best indicators of how well the staining process was conducted. An image database with 420 images (corresponding to 42 TBS samples) was created for analysing and testing image-based algorithms to detect the quality of the coloration of TBS. Background segmentation techniques were explored (based on RGB and HSV colour spaces) to separate the background and foreground (leukocytes, platelets, parasites) information. Then, different features (PCA, correlation, Histograms, variance) were explored as image criteria of coloration quality on the extracted background information; and evaluated according to their capability to classify images as with Good or Bad coloration quality from TBS. RESULTS: For background segmentation, a thresholding-based approach in the SV components of the HSV colour space was selected. It provided robustness separating the background information independently of its coloration quality. On the other hand, as image criteria of coloration quality, among the 19 feature vectors explored, the best one corresponds to the 15-bins histogram of the Hue component with classification rates of > 97%. CONCLUSIONS: An analysis of an image-based approach to describe the coloration quality of TBS was presented. It was demonstrated that if a robust background segmentation is conducted, the histogram of the H component from the HSV colour space is the best feature vector to discriminate the coloration quality of the smears. These results are the baseline for automating the estimation of the coloration quality, which has not been studied before, but that can be crucial for automating TBS's analysis for assisting malaria diagnosis process.

Microbiological Safety and Presence of Major Mycotoxins in Animal Feed for Laboratory Animals in a Developing Country: The Case of Costa Rica.

Safety and quality of compound feed for experimental animals in Costa Rica is unknown. Some contaminants, such as Salmonella spp. and mycotoxins, could elicit confounding effects in laboratory animals used for biomedical research. In this study, different batches of extruded animal feed, intended for laboratory rodents in Costa Rica, were analyzed to determine mycotoxin and microbiological contamination (i.e., Salmonella spp., Escherichia coli, total coliform bacteria, and total yeast and molds enumeration). Two methods for Salmonella decontamination (UV light and thermal treatment) were assessed. Only n = 2 of the samples were negative (representing 12.50%) for the 26 mycotoxins tested. Enniatins and fumonisins were among the most frequent toxins found (with n = 4+ hits), but the level of contamination and the type of mycotoxins depended on the supplier. None of the indicator microorganisms, nor Salmonella, were found in any of the tested batches, and no mold contamination, nor Salmonella growth, occurs during storage (i.e., 2-6 months under laboratory conditions). However, mycotoxins, such as enniatins and fumonisins tend to decrease after the fourth month of storage, and Salmonella exhibited a lifespan of 64 days at 17 °C even in the presence of UV light. The D-values for Salmonella were between 65.58 ± 2.95 (65 °C) and 6.21 ± 0.11 (80 °C) min, and the thermal destruction time (z-value) was calculated at 15.62 °C. Results from this study suggest that laboratory rodents may be at risk of contamination from animal feed that could significantly affect the outcomes of biomedical experiments. Thus, improved quality controls and handling protocols for the product are suggested.

Machine learning for surgical time prediction.

BACKGROUND AND OBJECTIVE: Operating Rooms (ORs) are among the most expensive services in hospitals. A challenge to optimize the OR efficiency is to improve the surgery scheduling task, which requires the estimation of surgical time duration. Surgeons or programming units (based on people's experience) typically do the duration estimation using an experience-based strategy, which may include some bias, such as overestimating the surgery time, increasing ORs' operational cost. METHODS: This paper analyzes a machine learning-based solution for surgical time predictions. We apply and compare four machine-learning algorithms (Linear Regression, Support Vector Machines, Regression Trees, and Bagged Trees) to predict the surgical time duration at a tertiary referral university hospital in Bogotá, Colombia. Historical data from 2004 until 2019 was used to train the algorithms. Comparison among algorithms was given in terms of the Root Mean Square Error (RMSE) of the predicted surgery duration and the algorithms' computing time. The algorithm with the best performance was compared to the currently used experience-based method. RESULTS: All the ML algorithms predict the surgery duration with an error between 26 and 37 min. The best overall performance was obtained using Bagged Trees (26 min RMSE, 3.16 min training time, 0.49 min testing time) when using a subset of the DB with the nine specialties containing 80% of the surgeries. Bagged Trees also outperformed the experience-based method with a lower RMSE; however, it also shifted from a predominant overestimation to underestimating surgeries' duration. CONCLUSIONS: Different ML algorithms for predicting the surgical time duration, showing and comparing their performance. Bagged Trees showed the best performance in terms of RMSE and computing time. Depending on the initial data, Bagged Trees outperformed the experience-based method, but future work is necessary to suit it, like any other ML algorithm, to the hospitals' needs.

Do the 2013 United States Preventive Services Task Force guidelines for lung cancer screening fail high-risk African American smokers? An institutional retrospective observational cohort study.

BACKGROUND: Lung cancer cause nearly 1.76 million deaths worldwide in 2018. In 2011, the National-Lung-Cancer-Screening-Trial showed 20% relative risk reduction with LDCT and subsequently led to the current USPSTF screening guidelines. However, the predominant focus on elderly, Caucasian questions its generalizability to communities with young, African Americans such as our institution. Hence, the objective of our study is to investigate the need to modify the current screening guidelines at our institution by assessing the applicability of newer individual risk-based prediction models for LDCT screening. METHODS: This is a retrospective observational cohort study of newly diagnosed lung cancer patients at LSU Health Sciences Center Shreveport from 2011 to 2015. One-third of the patients did not meet the current USPSTF screening guidelines. We categorized them into high-risk (groups1 and 2), moderate-risk, and low-risk according to 2018 NCCN Lung Cancer Screening Guidelines Version 1.2020. The high-risk groups were differentiated using the Tammemagi lung cancer risk calculator. RESULTS: Among those who did not meet the screening guidelines, nearly 50% were African American, 95% with known smoking history, and 80% diagnosed at advanced stage at the time of diagnosis. After employing the Tammemagi Risk based calculator, 12.5% were categorized into high-risk group 2, who are also eligible for annual LDCT. CONCLUSION: The current USPSTF guidelines have failed in our population consisting of young African American smokers, questioning the health disparity in medicine. By employing individual risk-based prediction models, we could potentially identify tailored high-risk populations leading to appropriate use of LDCT screening.

Optimization of the In Vitro Bactericidal Effect of a Mixture of Chlorine and Sodium Gallate against Campylobacter spp. and Arcobacter butzleri.

ABSTRACT: Campylobacter spp. and Arcobacter butzleri are foodborne pathogens associated with the consumption of contaminated raw chicken meat. At the industry level, the combination of new and common antimicrobials could be used as a strategy to control the presence of pathogens in chicken carcasses. The objective of this study was to determine the bacteriostatic and bactericidal effects of a mixture of chlorine (Cl) and sodium gallate (SG) on a mixture of two Campylobacter species (Campylobacter jejuni and Campylobacter coli) and A. butzleri. Using a central composite experimental design, it was established that the optimum inhibitory SG-Cl concentration for Campylobacter spp. was 44 to 45 ppm. After 15 h of incubation, Campylobacter species growth was reduced by 37.5% and the effect of Cl was potentiated by SG at concentrations above 45 ppm. In the case of A. butzleri, optimum levels of 28 and 41 ppm were observed for SG and Cl, respectively; no synergism was reported, as this bacterium was more sensitive to lower Cl concentrations than Campylobacter. After a 20-min pretreatment with peracetic acid (50 ppm), the optimum condition to achieve a >1.0-Log CFU/mL reduction of Campylobacter spp. was exposure to 177 ppm of Cl and 44 ppm of SG for 56 min. As A. butzleri showed lower resistance to the bacteriostatic effect of the Cl-SG combination, it was assumed that optimum bactericidal conditions for Campylobacter spp. were effective to control the former; this was confirmed with subsequent validation of the model. The SG-Cl combination has bactericidal properties against Campylobacter and A. butzleri, and it may be a useful strategy to improve sanitary practices applied in the poultry industry.

Passive UV imaging polarimeter.

The static polarimeter concept has a design and application flexibility potentially covering spectral ranges from <220nm to ∼2500nm. The original breadboard model of the passive UV polarimeter with sensitivity to 260 nm included elliptical analysis for general application such as biomedical, industrial, and commercial technology. It was adapted to be responsive to atmospheric and oceanic science and exoatmospheric planetary missions to provide linear polarization-resolved imagery in four spectral passbands between ∼415nm and ∼340nm in 5∘×10∘ fields of view. Simultaneous polarimetry is collected without electro-optical or mechanically moving or birefringent modulation of retardance. The compact, lightweight, rugged architecture uses instead stable thin-film components with low systematic instrumental polarization to provide high polarimetric accuracy. An internal polarization calibrator/stability monitor subsystem provides in-flight corrections for differential errors that might be induced by external environmental stresses.

Cancer-Related Pneumopericardium: A Case Report and Literature Review.

Pneumopericardium is a relatively rare entity mostly described in the literature as a result of causes such as penetrating/blunt trauma and iatrogenic causes during cardiothoracic procedures. We are presenting a case of pneumopericardium as a complication of progressed gastroesophageal junction tumor along with a literature review of all cancer-related pneumopericardium cases reported in the last decade. We present the case of a 65-year-old male with a past medical history significant for locally advanced gastroesophageal junction adenocarcinoma who presented to the hospital with complaints of shortness of breath and fever. A chest X-ray showed an intact esophageal stent along with radiolucency around the cardiac silhouette which suggested pneumopericardium. Computed tomography scan of the chest confirmed the presence of pneumopericardium in posterior pericardium with foci of gas above the esophageal stent likely to be communicating with the pericardium. An echocardiogram was obtained which showed no signs of tamponade. Given the advanced nature of the disease we applied a conservative management given that the pneumopericardium was deemed to be small with no tamponade. Goals of care were discussed with the patient and his family and the patient opted for comfort care measures. This case report prompted us to perform an extensive literature review of cancer-related pneumopericardium from 2008 to 2019. We found 11 cases where it was reported secondary to malignancies of different kinds. Our aim is to compile a review for clinicians to view varied presentations and better direct therapy dependent on the individual case and clinical presentation in patients with cancer-related pneumopericardium. Moreover, although pneumopericardium is rare, it should be considered in differential diagnosis in patients presenting with shortness of breath or chest pain especially with cancers involving the cardiothoracic region.

Polymeric scaffolds for three-dimensional culture of nerve cells: a model of peripheral nerve regeneration.

Understanding peripheral nerve repair requires the evaluation of 3D structures that serve as platforms for 3D cell culture. Multiple platforms for 3D cell culture have been developed, mimicking peripheral nerve growth and function, in order to study tissue repair or diseases. To recreate an appropriate 3D environment for peripheral nerve cells, key factors are to be considered including: selection of cells, polymeric biomaterials to be used, and fabrication techniques to shape and form the 3D scaffolds for cellular culture. This review focuses on polymeric 3D platforms used for the development of 3D peripheral nerve cell cultures.

Clinical and histological evaluation of socket grafting using different types of bone substitute in adult patients.

PURPOSE: This clinical and histological study evaluated the healing of extraction sockets after implantation of a biphasic calcium sulfate (CS) alone or in combination with a gamma-radiated human mineralized allograft. MATERIALS AND METHODS: Ten healthy adult patients participated in the study. A minimum of 2 teeth, per patient, extracted for different reasons were evaluated. Each socket was randomly filled to the crest with either (a) a biphasic CS or (b) large particulate gamma-radiated human mineralized allograft in combination with a biphasic CS. RESULTS: No complications during reentry of the socket site during bone core retrieval, such as inflammation/immunogenic response, were observed. Histological findings showed a mean new bone (NB) of 33% for sockets filled with biphasic CS and 31% for sockets filled with biphasic CS in combination with allograft material. There was no statistically significant difference in the percentage of NB and the presence of soft tissue between graft materials. CONCLUSION: Biphasic CS used alone or in combination with an allograft resulted in the same amount of NB formation in alveolar ridge preservation procedures.

Development and testing of coatings for orbital space radiation environments.

Specific coating processes and materials were investigated in the quest to develop multilayer coatings with greater tolerance to space radiation exposure. Ultraviolet reflection (UVR) and wide-band antireflection (AR) multilayer coatings were deposited on solar cell covers and test substrates and subsequently exposed to simulated space environments and also flown on the Materials International Space Station Experiment-7 (MISSE-7) to determine their space environment stability. Functional solar cells integrated with these coatings underwent simulated UV and MISSE-7 low earth orbit flight exposure. The effects of UV, proton, and atomic oxygen exposure on coatings and on assembled solar cells as related to the implemented deposition processes and material compositions were small. The UVR/AR coatings protected flexible polymer substrate materials that are intended for future flexible multijunction cell arrays to be deployed from rolls. Progress was made toward developing stable and protective coatings for extended space-mission applications. Test results are presented.

Effect of meat ingredients (sodium nitrite and erythorbate) and processing (vacuum storage and packaging atmosphere) on germination and outgrowth of Clostridium perfringens spores in ham during abusive cooling.

The effect of nitrite and erythorbate on Clostridium perfringens spore germination and outgrowth in ham during abusive cooling (15 h) was evaluated. Ham was formulated with ground pork, NaNO2 (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 547 ppm). Ten grams of meat (stored at 5 °C for 3 or 24 h after preparation) were transferred to a vacuum bag and inoculated with a three-strain C. perfringens spore cocktail to obtain an inoculum of ca. 2.5 log spores/g. The bags were vacuum-sealed, and the meat was heat treated (75 °C, 20 min) and cooled within 15 h from 54.4 to 7.2 °C. Residual nitrite was determined before and after heat treatment using ion chromatography with colorimetric detection. Cooling of ham (control) stored for 3 and 24 h, resulted in C. perfringens population increases of 1.46 and 4.20 log CFU/g, respectively. For samples that contained low NaNO2 concentrations and were stored for 3 h, C. perfringens populations of 5.22 and 2.83 log CFU/g were observed with or without sodium erythorbate, respectively. Residual nitrite was stable (p > 0.05) for both storage times. Meat processing ingredients (sodium nitrite and sodium erythorbate) and their concentrations, and storage time subsequent to preparation of meat (oxygen content) affect C. perfringens spore germination and outgrowth during abusive cooling of ham.

Inhibition of Clostridium perfringens spore germination and outgrowth by lemon juice and vinegar product in reduced NaCl roast beef.

UNLABELLED: Inhibition of Clostridium perfringens spore germination and outgrowth in reduced sodium roast beef by a blend of buffered lemon juice concentrate and vinegar (MoStatin LV1) during abusive exponential cooling was evaluated. Roast beef containing salt (NaCl; 1%, 1.5%, or 2%, w/w), blend of sodium pyro- and poly-phosphates (0.3%), and MoStatin LV1 (0%, 2%, or 2.5%) was inoculated with a 3-strain C. perfringens spore cocktail to achieve final spore population of 2.5 to 3.0 log CFU/g. The inoculated products were heat treated and cooled exponentially from 54.4 to 4.4 °C within 6.5, 9, 12, 15, 18, or 21 h. Cooling of roast beef (2.0% NaCl) within 6.5 and 9 h resulted in <1.0 log CFU/g increase in C. perfringens spore germination and outgrowth, whereas reducing the salt concentration to 1.5% and 1.0% resulted in >1.0 log CFU/g increase for cooling times longer than 9 h (1.1 and 2.2 log CFU/g, respectively). Incorporation of MoStatin LV1 into the roast beef formulation minimized the C. perfringens spore germination and outgrowth to <1.0 log CFU/g, regardless of the salt concentration and the cooling time. PRACTICAL APPLICATION: Cooked, ready-to-eat meat products should be cooled rapidly to reduce the risk of Clostridium perfringens spore germination and outgrowth. Meat processors are reducing the sodium chloride content of the processed meats as a consequence of the dietary recommendations. Sodium chloride reduces the risk of C. perfringens spore germination and outgrowth in meat products. Antimicrobials that contribute minimally to the sodium content of the product should be incorporated into processed meats to assure food safety. Buffered lemon juice and vinegar can be incorporated into meat product formulations to reduce the risk of C. perfringens spore germination and outgrowth during abusive cooling.

Investigating the prevalence of queuine in Escherichia coli RNA via incorporation of the tritium-labeled precursor, preQ(1).

There are over 100 modified bases that occur in RNA with the majority found in transfer RNA. It has been widely believed that the queuine modification is limited to four transfer RNA species in vivo. However, given the vast amount of the human genome (60-70%) that is transcribed into non-coding RNA (Mattick [10]), probing the presence of modified bases in these RNAs is of fundamental importance. The mechanism of incorporation of queuine, via transglycosylation, makes this uniquely poised to probe base modification in RNA. Results of incubations of Escherichia coli cell cultures with [(3)H] preQ(1) (a queuine precursor in eubacteria) clearly demonstrate preQ(1) incorporation into a number of RNA species of various sizes larger than transfer RNA. Specifically, significant levels of preQ(1) incorporation into ribosomal RNA are observed. The modification of other large RNAs was also observed. These results confirm that non-coding RNAs contain modified bases and lead to the supposition that these modifications are necessary to control non-coding RNA structure and function as has been shown for transfer RNA.

UV optical properties of thin film oxide layers deposited by different processes.

UV optical properties of thin film layers of compound and mixed oxide materials deposited by different processes are presented. Japan Electron Optics Laboratory plasma ion assisted deposition (JEOL PIAD), electron beam with and without IAD, and pulsed DC magnetron sputtering were used. Comparisons are made with published deposition process data. Refractive indices and absorption values to as short as 145 nm were measured by spectroscopic ellipsometry (SE). Electronic interband defect states are detected that are deposition-process dependent. SE might be effective in identifying UV optical film quality, especially in defining processes and material composition beneficial for high-energy excimer laser applications and environments requiring stable optical properties.

Inhibition of Clostridium perfringens spore germination and outgrowth by buffered vinegar and lemon juice concentrate during chilling of ground turkey roast containing minimal ingredients.

Inhibition of Clostridium perfringens spore germination and outgrowth in ground turkey roast containing minimal ingredients (salt and sugar), by buffered vinegar (MOstatin V) and a blend (buffered) of lemon juice concentrate and vinegar (MOstatin LV) was evaluated. Ground turkey roast was formulated to contain sea salt (1.5%), turbinado sugar (0.5%), and various concentrations of MOstatin V (0.75, 1.25, or 2.5%) or MOstatin LV (1.5, 2.5, or 3.5%), along with a control (without MOstatins). The product was inoculated with a three-strain spore cocktail of C. perfringens to obtain initial spore levels of ca. 2.0 to 0.5 log CFU/g. Inoculated products were vacuum packaged, heat shocked for 20 min at 75 degrees C, and cooled exponentially from 54.4 to 4.0 degrees C in 6.5, 9, 12, 15, 18, or 21 h. In control samples without MOstatin V or MOstatin LV, C. perfringens populations reached 2.98, 4.50, 5.78, 7.05, 7.88, and 8.19 log CFU/g (corresponding increases of 0.51, 2.29, 3.51, 4.79, 5.55, and 5.93 log CFU/g) in 6.5, 9, 12, 15, 18, and 21 h of chilling, respectively. MOstatin V (2.5%) and MOstatin LV (3.5%) were effective in inhibiting C. perfringens spore germination and outgrowth in ground turkey roast to <1.0 log CFU/g during abusive chilling of the product within 21 h. Buffered vinegar and a blend (buffered) of lemon juice concentrate and vinegar were effective in controlling germination and outgrowth of C. perfringens spores in turkey roast containing minimal ingredients.

[Prophylactic thyroidectomy in children at risk for medullary thyroid carcinoma]. / Tiroidectomía profiláctica en pacientes pediátricos con riesgo de carcinoma medular tiroideo.

The medullary thyroid carcinoma (MTC) is a rare neoplasia occurring during childhood. At present time the molecular examination of the proto-oncogen RET, related to syndromes of multiple endocrine neoplasia (MEN II) and familial medullary thyroid carcinoma (FMTC) to allows identify patients with risk of suffering of medullary thyroid carcinoma in early ages, before the disease becomes clinically pronunced. Children with familial antecedents of MEN II or FMTC were biochemically (pentagastrin-stimulated) and genetically studied with the purpose of determining the risk of developing a MTC and in order to assess the possibilities of making a prophylactic thyroidectomy.

Método sistemático de ayuda académica para el diagnóstico de desórdenes craneomandibulares / Sistematic method for the diagnosis of cranial disorders

La aplicación de los computadores en la odontología ha sido poco explorada en el campo de la capacitación y la educación odontológica. La nueva era de la capacitación y de la educación asistida por la informática se basa en el desarrllo de programas realizados por multimedia como medio auxiliar.El proyecto que realizamos pretende aplicar un método lógico,científico y concreto de manera objetiva,mediante la utilización de un programa computarizado de Sofware,como ayuda al estudiante de pregrado,en la capacitación y entendimiento de los desórdenes craneomandibulares,en su definición,etiología,diagnóstico clínico,signos y síntomas,medios diagnósticos y plan de tratamiento.