Transplant renal artery stenosis: Study of incidence using doppler ultrasound, risk factors and analysis is effect in graft outcomes.

INTRODUCTION AND OBJECTIVES: Transplant renal artery stenosis (TRAS) is a vascular complication after kidney transplantation which estimated incidence is 13%. It could cause refractory arterial hypertension, kidney dysfunction and premature death in transplant recipients. METHODS: We carried out a retrospective study including every patient who underwent renal transplantation between 2014 and 2020. They were evaluated with a systematic post-transplant renal Doppler ultrasound. To identify independent risk factors for transplant renal artery stenosis we performed a multivariate analysis. RESULTS: Seven hundred twenty-four kidney transplants were included, 12% ​​were living donors and 88% were deceased donors. The mean age was 54.8 in recipients and 53 in donors. Transplant renal artery stenosis was diagnosed in 70 (10%) recipients, the majority in the first 6 months after surgery. 51% of patients with transplant renal artery stenosis were managed conservatively. The multivariate analysis showed diabetes mellitus, graft rejection, arterial resuture and donor body mass index as independent risk factors for transplant renal artery stenosis. Survival of the grafts with transplant renal artery stenosis was 98% at 6 months and 95% at two years. CONCLUSIONS: The systematic performance of Doppler ultrasound in the immediate post-transplant period diagnosed 10% of transplant renal artery stenosis in our cohort. Despite the above risk factors, an adequate monitoring and treatment could avoid the increased risk of graft loss in patients with transplant renal artery stenosis.

Quality of health care perceived by users in Catalan prisons.

OBJECTIVES: To describe inmates' perceptions of healthcare quality in Catalonian prisons. MATERIAL AND METHOD: Transversal study of 6,856 inmates in Catalan prisons in September 2017. Randomized simple screening was used to randomly distribute 1,048 polls in which different aspects of perceived quality of healthcare were evaluated. The results were also categorized according to age, sex, time spent in prison, background and academic levels. We also analysed the differences between results in healthcare quality according to socio-demographic variables. RESULTS: 84.87% of patients show satisfaction with the quality of healthcare received. Women are more satisfied with consultations than men (OR: 2.04; p = 0.009). Patients with a higher educational level are less satisfied than those with a lower educational level, with significant differences in 11 of the 14 items. Those over 65 years of age were more satisfied than the rest in 11 of the 14 items evaluated. Foreign patients were more satisfied than Spanish inmates in time flexibility (OR: 0.69; p = 0.018) and in waiting times for visits (OR: 0,63; p = 0.006), whereas they are less satisfied with the healthcare professionals' image (OR: 1.97; p = 0.03). DISCUSSION: Noteble features of our study include the fact that although global satisfaction is high, some dimensions, like reliability, could improve. The results were submitted to the General Directorate to enable more in-depth study of the variables where there is less satisfaction and to design further improvements.

Strong visible photoluminescence emission of ZnO nanosheets and nanoflowers by a facile hydrothermal route.

Zinc oxide nanostructures such as nanosheets (NS) and nanoflowers (NF) were obtained by a facile hydrothermal synthesis using zinc chloride (ZnCl2) as precursor with low molar concentrations and a short synthesis time (2 h) at 200 °C. By means of X-ray diffraction and Raman spectroscopy measurements, the wurtzite-type ZnO structure was confirmed with high crystalline quality. SEM micrographs showed the influence of ZnCl2 concentration on ZnO morphology; ZnO NF were obtained at low concentrations (0.02 and 0.05 M), while ZnO NS were seen for higher concentrations (0.2-0.6 M) and their thicknesses can be estimated from 15 to 60 nm. In addition, TEM images showed a large number of pores with sizes below 15 nm in both ZnO nanostructures. Raman and photoluminescence displayed the surface defects density for ZnO nanostructures. Raman spectra showed the E1(LO) mode localized at ∼581 cm-1, associated with oxygen vacancies and zinc interstitials, being more intense for ZnO NF, while photoluminescence results showed a strong yellow-orange emission (centered from 587 to 618 nm) relative to UV emission, being more intense for ZnO NF. These properties reveal further potential for high performance luminescent devices based on ZnO NF and NS.

Infecciones urinarias adquiridas en la comunidad que requieren hospitalización: factores de riesgo, características microbiológicas y resistencia a antibióticos / Community-associated urinary infections requiring hospitalization: Risk factors, microbiological characteristics and patterns of antibiotic resistance

Objetivo: Las infecciones del tracto urinario (ITU) suelen manejarse ambulatoriamente. Sin embargo, un pequeño porcentaje requiere ingreso hospitalario. Nuestro objetivo fue analizar los factores de riesgo y características microbiológicas de las infecciones urinarias adquiridas en la comunidad (ITU-AC) que requieren hospitalización. Material y métodos: Realizamos un estudio prospectivo desde noviembre de 2011 a diciembre de 2013 evaluando la incidencia, factores de riesgo, patrones microbiológicos y tasas de resistencia en los pacientes con ITU-AC que requieren ingreso. Resultados: Cuatrocientos cincuenta y siete pacientes ingresaron en nuestro servicio con diagnóstico de ITU-AC. La edad media fue 56,2 ± 19,85 años, el 52,1% eran mujeres, el 19,7% portaban catéter urinario y el 11,4% habían presentado ITU en los meses previos. Los microorganismos más frecuentemente aislados fueron Escherichia coli (60,6%), Klebsiella (9,2%), Enterococcus (8,4%) y Pseudomonas (7,2%). Enterobacteriaceae diferentes a E. coli fueron más frecuentes en pacientes de mayor edad. Enterococcus fueron más frecuentemente aislados en pacientes que habían tenido ITU previa y en aquellos portadores de catéter urinario. E. coli mostró unas resistencias del 23,5% para amoxicilina/ácido clavulánico, 16,6% para cefalosporinas de tercera generación, 31,3% para quinolonas y16,7% para aminoglucósidos. Del total de E. coli 11,4% fueron productores de betalactamasas de espectro extendido (BLEE). Los Enterococcus y Pseudomonas mostraron resistencias a quinolonas del 50,0% y 61,5% respectivamente. Conclusiones: ITU-AC que requieren hospitalización se presentan más frecuentemente en varones de mayor edad, portadores de catéter urinario, litiasis urinaria y con episodios previos de ITU. Estos factores también se asocian con infecciones producidas por gérmenes diferentes a E. coli y altas tasas de resistencia

Objective: Although patients with urinary tract infections (UTIs) are usually managed as outpatients, a percentage of them requires hospitalization. To review risk factors and microbiological characteristics of community-associated UTIs (CAUTIs) requiring hospitalization has been our objective. Material and methods: A prospective observational study was carried out from November 2011 to December 2013. Incidence, microbiological characteristics and antibiotic resistance patterns in patients with CAUTIs that required hospitalization were analyzed. Risk factors (including diabetes mellitus, urolithiasis, urinary catheterization) and resistance rates of each pathogen were also analyzed. Results: Four hundred and fifty seven patients were hospitalized in our department with CAUTI. The mean age was 56.2 ± 19.85 years. Of them, 52.1% patients were women, 19.7% had urinary indwelling catheter and 11.4% have had a previous UTI. The most frequently isolated pathogens were Escherichia coli (60.6%), followed by Klebsiella (9.2%), Enterococcus (8.4%) and Pseudomonas (7.2%). Enterobacteriaceae other than E.coli were more prevalent in male and older patients. On the other side the most frequently isolated pathogen in patients with a previous UTI and a urinary catheter was Entercoccus. The resistance rates E. coli against ampicillin/amoxicillin + βlactamase inhibitor was 23.5%, against third-generation cephalosporins 16.6%, against fluoroquinolones 31.3% and 16.7% against aminoglycosides. 11.4% E. coli strains were producers of extended-spectrum Beta-lactamases (ESBL). Finally, the resistance rates of Enterococcus and Pseudomonas against quinolones were of 50.0% and 61.5%, respectively. Conclusions: CAUTIs that require hospitalization are most frequent in older age, male gender, and presence of urinary catheter, with urolithiasis and with previous episodes of UTI. These factors are also related to isolation of pathogens other than E. coli and higher resistance rates

Cell disruption for microalgae biorefineries.

Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies.

Community-associated urinary infections requiring hospitalization: risk factors, microbiological characteristics and patterns of antibiotic resistance.

OBJECTIVE: Although patients with urinary tract infections (UTIs) are usually managed as outpatients, a percentage of them requires hospitalization. To review risk factors and microbiological characteristics of community-associated UTIs (CAUTIs) requiring hospitalization has been our objective. MATERIAL AND METHODS: A prospective observational study was carried out from November 2011 to December 2013. Incidence, microbiological characteristics and antibiotic resistance patterns in patients with CAUTIs that required hospitalization were analyzed. Risk factors (including diabetes mellitus, urolithiasis, urinary catheterization) and resistance rates of each pathogen were also analyzed. RESULTS: Four hundred and fifty seven patients were hospitalized in our department with CAUTI. The mean age was 56.2±19.85 years. Of them, 52.1% patients were women, 19.7% had urinary indwelling catheter and 11.4% have had a previous UTI. The most frequently isolated pathogens were Escherichia coli (60.6%), followed by Klebsiella (9.2%), Enterococcus (8.4%) and Pseudomonas (7.2%). Enterobacteriaceae other than E.coli were more prevalent in male and older patients. On the other side the most frequently isolated pathogen in patients with a previous UTI and a urinary catheter was Entercoccus. The resistance rates E. coli against ampicillin/amoxicillin + ß lactamase inhibitor was 23.5%, against third-generation cephalosporins 16.6%, against fluoroquinolones 31.3% and 16.7% against aminoglycosides. 11.4% E. coli strains were producers of extended-spectrum Beta-lactamases (ESBL). Finally, the resistance rates of Enterococcus and Pseudomonas against quinolones were of 50.0% and 61.5%, respectively. CONCLUSIONS: CAUTIs that require hospitalization are most frequent in older age, male gender, and presence of urinary catheter, with urolithiasis and with previous episodes of UTI. These factors are also related to isolation of pathogens other than E. coli and higher resistance rates.

Estudio de seguridad de la biopsia renal percutánea con aguja de calibre 16 G / Renal biopsy with 16 G needle: A safety study

Introducción y objetivo: Recientemente se vuelve a discutir sobre la implantación de la biopsia renal percutánea como procedimiento rutinario en el diagnóstico de masas renales. Sin embargo, aunque infrecuentes, esta técnica no está exenta de complicaciones y morbilidad. Nuestro objetivo es realizar un estudio descriptivo de las complicaciones y resultados de las biopsias renales ortotópicas con aguja de 16 G. Material y métodos: Llevamos a cabo una revisión retrospectiva de 180 biopsias renales ortotópicas ecodirigidas realizadas en nuestro servicio entre enero de 2008 y mayo de 2010. La técnica se realiza utilizando una aguja de diámetro 16 G acoplada a una pistola automática. Se recogen múltiples variables clínicas, así como las complicaciones tempranas derivadas del procedimiento y la actitud adoptada respecto a ellas. Se estudió la tasa de complicaciones, así como la relación entre factores de riesgo y aparición de complicaciones. Resultados: La edad media fue de 55,8 años, obteniéndose una media de 2,49 cilindros por intervención. La tasa global de complicaciones fue del 5,6%. Únicamente en 3 (1,67%) pacientes de los 180 fue necesaria una actitud intervencionista derivada de complicación del procedimiento. No hubo necesidad de intervenciones quirúrgicas ni se produjeron fallecimientos derivados del procedimiento. No se demostró relación entre HTA (p = 0,09), anticoagulación previa (p = 0,099) o antiagregación previa (p = 0,603) y complicaciones. El 2,8% de las biopsias presentaron material insuficiente para el diagnóstico. Conclusiones: La biopsia renal percutánea ecodirigida con aguja de 16 G es una técnica segura y con una rentabilidad diagnóstica elevada

Introduction and objective: The development of percutaneous renal biopsy as a routinary diagnostic procedure for renal masses is topic of discussion for the last few years. However, this technique has been associated with some complications, although infrequent, and morbidity. Our objective is to carry out a descriptive study about complications and outcomes of orthotopic kidney biopsies with 16 G needle. Material and methods: A retrospective review of 180 orthotopic ultrasound-guided renal biopsies performed in our service among January 2008 to May 2010 was carried out. The procedure was developed using an automated biopsy gun (16G needle). Multiple clinical variables, early post-procedure complications and its management were collected. Complication rates as well as the relationship between risk factors and occurrence of complications were studied. Results: Mean age was 55.8 years. The average number of biopsy cylinders per intervention was 2.49. The overall complication rate was 5.6%. An interventionist attitude derived from complication of the procedure was necessary in only 3 patients (1.67%). No surgical interventions were required and no death as consequence of procedure was registered. No relationship between hypertension (P = .09) previous anticoagulation (P = .099) or previous antiaggregation (P = .603) and complications were demonstrated. In 2.8% of biopsies the material obtained was insufficient for diagnosing. Conclusions: Percutaneous ultrasound-guided renal biopsy with 16G needle is a safe technique with high diagnostic performance

Calidad de vida en pacientes con cistectomía y conducto ileal por cáncer de vejiga / Quality of Life in Patients with Ileal Conduit Cystectomy Due to Bladder Cancer

Objetivo: Determinar las variables que influyen en la calidad de vida de pacientes tratados mediante cistectomía radical y conducto ileal. Material y método: Analizamos la calidad de vida utilizando el cuestionario EQ-5D-3L, que valora movilidad, cuidado personal, actividades cotidianas, dolor/malestar, ansiedad/depresión y una escala de autoevaluación del estado de salud. Comparamos los resultados con variables demográficas (sexo, edad, situación laboral, estudios, ingresos, pareja) y clínicas (clasificación ASA, estadio tumoral, tiempo desde la realización de la cistectomía, quimioterapia adyuvante, recidiva y complicaciones del estoma). El análisis estadístico incluyó estudio descriptivo, análisis univariante y multivariante. Resultados: Cincuenta y nueve pacientes incluidos, con una media de edad de 69 años (47-84). El tiempo medio desde la cistectomía es de 43 meses (12-83), con un porcentaje de complicaciones asociadas al estoma del 61%.Las complicaciones del estoma se relacionaron con limitaciones en el cuidado personal, dolor/malestar, ansiedad, depresión y calidad de vida en general. El sexo femenino se asocia con limitaciones en las actividades cotidianas y la quimioterapia adyuvante lo hace con la ansiedad/depresión y con la calidad de vida en general. El resto de variables no alcanzaron significación estadística en el análisis multivariante. Conclusiones: Las limitaciones en la calidad de vida en pacientes con cistectomía y conducto ileal se asocian con las complicaciones asociadas al estoma. Otras variables relacionadas son el sexo femenino y la administración de quimioterapia adyuvante

Objective: To determine the variables that affect quality of life of patients treated by radical cystectomy with ileal conduit. Material and method: We analyzed quality of life using the EQ-5D-3L questionnaire. This questionnaire evaluates mobility, personal care, daily activities, pain/discomfort, anxiety/depression and a self-rating scale of the health condition. We compared the result with demographic variables (gender, age, work situation, studies, income, partner) and clinical variables (ASA classification, tumor stage, time since cystectomy was performed, adjuvant chemotherapy, recurrent and complications of the stoma). The statistical analysis included a descriptive study, univariate and multivariate analysis. Results: A total of 59 patients were included in the study, with a mean age of 69 years (47-84). Mean time from cystectomy was 43 months (12-83), with 61% complications associated to the stoma. Stoma complications were related with limitations in personal care, pain/discomfort, anxiety, depression and quality of life in general. Female gender was associated with limitations in daily activities and adjuvant chemotherapy with anxiety/depression and quality of life in general. The rest of the variables were not statistically significant in the multivariate analysis. Conclusions: The limitations in quality of life in patients with cystectomy and ileal conduit are associated with the stoma-associated complications. Other related variables are female gender and administration of adjuvant chemotherapy

Renal biopsy with 16G needle: a safety study.

INTRODUCTION AND OBJECTIVE: The development of percutaneous renal biopsy as a routinary diagnostic procedure for renal masses is topic of discussion for the last few years. However, this technique has been associated with some complications, although infrequent, and morbidity. Our objective is to carry out a descriptive study about complications and outcomes of orthotopic kidney biopsies with 16 G needle. MATERIAL AND METHODS: A retrospective review of 180 orthotopic ultrasound-guided renal biopsies performed in our service among January 2008 to May 2010 was carried out. The procedure was developed using an automated biopsy gun (16G needle). Multiple clinical variables, early post-procedure complications and its management were collected. Complication rates as well as the relationship between risk factors and occurrence of complications were studied. RESULTS: Mean age was 55.8 years. The average number of biopsy cylinders per intervention was 2.49. The overall complication rate was 5.6%. An interventionist attitude derived from complication of the procedure was necessary in only 3 patients (1.67%). No surgical interventions were required and no death as consequence of procedure was registered. No relationship between hypertension (P=.09) previous anticoagulation (P=.099) or previous antiaggregation (P=.603) and complications were demonstrated. In 2.8% of biopsies the material obtained was insufficient for diagnosing. CONCLUSIONS: Percutaneous ultrasound-guided renal biopsy with 16G needle is a safe technique with high diagnostic performance.

Quality of life in patients with ileal conduit cystectomy due to bladder cancer.

OBJECTIVE: To determine the variables that affect quality of life of patients treated by radical cystectomy with ileal conduit. MATERIAL AND METHOD: We analyzed quality of life using the EQ-5D-3L questionnaire. This questionnaire evaluates mobility, personal care, daily activities, pain/discomfort, anxiety/depression and a self-rating scale of the health condition. We compared the result with demographic variables (gender, age, work situation, studies, income, partner) and clinical variables (ASA classification, tumor stage, time since cystectomy was performed, adjuvant chemotherapy, recurrent and complications of the stoma). The statistical analysis included a descriptive study, univariate and multivariate analysis. RESULTS: A total of 59 patients were included in the study, with a mean age of 69 years (47-84). Mean time from cystectomy was 43 months (12-83), with 61% complications associated to the stoma. Stoma complications were related with limitations in personal care, pain/discomfort, anxiety, depression and quality of life in general. Female gender was associated with limitations in daily activities and adjuvant chemotherapy with anxiety/depression and quality of life in general. The rest of the variables were not statistically significant in the multivariate analysis. CONCLUSIONS: The limitations in quality of life in patients with cystectomy and ileal conduit are associated with the stoma-associated complications. Other related variables are female gender and administration of adjuvant chemotherapy.

Evaluation of BACTEC™ MGIT™ 960 and the nitrate reductase assay in the National Laboratory Network of Colombia.

SETTING: The Mycobacteria Group of the National Reference Laboratory, National Laboratory Network, National Institute of Health and the Public Health Laboratories of Antioquia, Atlántico and Valle del Cauca, Colombia. OBJECTIVE: To compare BACTEC™ MGIT™ (Mycobacteria Growth Indicator Tube) 960 and the nitrate reductase assay (NRA) with the proportion method on Löwenstein-Jensen medium and to determine resistance to first-line anti-tuberculosis drugs. METHODS: Evaluation of diagnostic assays using time-adjusted convenience sampling. We analysed 183 isolates of Mycobacterium tuberculosis to compare MGIT 960 and NRA with the proportion method. RESULTS: MGIT 960 had a sensitivity and specificity of 90% for isoniazid (INH), and respectively 100% and 99.4% for rifampicin (RMP). NRA had a sensitivity and a specificity of respectively 86% and 94.7% for INH and 100% and 99% for RMP. CONCLUSION: Given its high sensitivity and specificity, and easy accessibility and interpretation of results, the NRA should be implemented in the National Laboratory Network for the detection of resistance to INH and RMP.

Membrane permeabilization and cellular death of Escherichia coli, Listeria monocytogenes and Saccharomyces cerevisiae as induced by high pressure carbon dioxide treatment.

In this study, the relationship between (irreversible) membrane permeabilization and loss of viability in Escherichia coli, Listeria monocytogenes and Saccharomyces cerevisiae cells subjected to high pressure carbon dioxide (HPCD) treatment at different process conditions including temperature (35-45 degrees C), pressure (10.5-21.0 MPa) and treatment time (0-60 min) was examined. Loss of membrane integrity was measured as increased uptake of the fluorescent dye propidium iodide (PI) with spectrofluorometry, while cell inactivation was determined by viable cell count. Uptake of PI by all three strains indicated that membrane damage is involved in the mechanism of HPCD inactivation of vegetative cells. The extent of membrane permeabilization and cellular death increased with the severity of the HPCD treatment. The resistance of the three tested organisms to HPCD treatment changed as a function of treatment time, leading to significant tailing in the survival curves, and was dependent on pressure and temperature. The results in this study also indicated a HPCD-induced damage on nucleic acids during cell inactivation. Transmission electron microscopy showed that HPCD treatment had a profound effect on the intracellular organization of the micro-organisms and influenced the permeability of the bacterial cells by introducing pores in the cell wall.

The development of Escherichia coli and Listeria monocytogenes variants resistant to high-pressure carbon dioxide inactivation.

AIMS: The objective of this study was to investigate whether bacterial cells could develop resistance (as a part of their adaptation strategy) to high-pressure CO(2) (HPCD) inactivation. METHODS AND RESULTS: Alternating cycles of exposure to pressurized CO(2) (10.5 MPa, 35 degrees C, 400 min(-1), 70% working volume ratio during 10 min) and re-growth of the surviving subpopulation were used to investigate possible increases in the resistance of Escherichia coli and Listeria monocytogenes to HPCD. The results show an increased resistance of both pathogens tested after seven cycles of inactivation. Increase in the resistance after 15 cycles resulted in a difference of 2.4 log CFU ml(-1) in log N(0)/N(i) when parental (N(0)) and treated cultures (N(i)) of E. coli and L. monocytogenes were compared. CONCLUSIONS: Current findings indicate the ability of micro-organisms to adapt to HPCD preservation technology. SIGNIFICANCE AND IMPACT OF THE STUDY: The occurrence of HPCD-resistant micro-organisms could pose a new hazard to the safety and stability of HPCD-processed foods.

Influence of type of microorganism, food ingredients and food properties on high-pressure carbon dioxide inactivation of microorganisms.

High pressure carbon dioxide (HPCD) treatment is currently considered as an attractive non-thermal process for preserving food. Industrial application of this technique requires, among others, systematic (quantitative) data on the inactivation of food relevant pathogenic and spoilage microorganisms, and in-depth information on the effect that the composition and the properties of a food matrix have on the inactivation efficacy. The first objective of this study, therefore, is to evaluate and compare the HPCD susceptibility of several food pathogens and spoilage microorganisms under the same treatment conditions. In the second part, the influence of different food components (NaCl, oil, starch, whey protein and emulsifier) and food properties (pH, fluid viscosity and water activity) on the inactivation efficacy of HPCD was determined. For the first aim, a range of Gram-negative and Gram-positive bacteria, yeasts and spores were treated with pressurized CO(2) at 10.5 MPa and 35 degrees C during 20 min. Bacterial susceptibility towards HPCD treatments followed the sequence Gram-negative approximately Gram-positive>yeasts>spores and appeared to be related to the acid resistance of the organisms. To study the effect of different food compounds on HPCD inactivation, the reduction degree of Pseudomonas fluorescens was determined in media with and without these components at 10.5 MPa and 35 degrees C after 5 or 20 min, depending on the tested component. NaCl and the emulsifiers Tween 80 and sucrose stearate enhanced bacterial reduction, while oil reduced the bactericidal efficacy of HPCD. Starch and whey proteins did not influence inactivation. Finally, the influence of pH, fluid viscosity and water activity was investigated by determining the reduction of P. fluorescens at 10.5 MPa and 35 degrees C in suspensions from which the pH, viscosity and water activity were adjusted with respectively NaOH or HCl, gelatin or polyethylene glycol, and sucrose, NaCl or glycerol. Treatment time depended on the studied food property with 5 min for the pH experiments, while other experiments lasted 20 min. The results indicated that P. fluorescens cells became more sensitive to HPCD treatments at low pH and viscosity. Not water activity but the kind of soluble solute used to lower water activity influenced inactivation. High NaCl-concentrations lead to total inactivation, while sucrose and glycerol strongly protected the cells against inactivation.

High pressure carbon dioxide inactivation of microorganisms in foods: the past, the present and the future.

Thermal pasteurization is a well known and old technique for reducing the microbial count of foods. Traditional thermal processing, however, can destroy heat-sensitive nutrients and food product qualities such as flavor, color and texture. For more than 2 decades now, the use of high-pressure carbon dioxide (HPCD) has been proposed as an alternative cold pasteurization technique for foods. This method presents some fundamental advantages related to the mild conditions employed, particularly because it allows processing at much lower temperature than the ones used in thermal pasteurization. In spite of intensified research efforts the last couple of years, the HPCD preservation technique has not yet been implemented on a large scale by the food industry until now. This review presents a survey of published knowledge concerning the HPCD technique for microbial inactivation, and addresses issues of the technology such as the mechanism of carbon dioxide bactericidal action, the potential for inactivating vegetative cells and bacterial spores, and the regulatory hurdles which need to be overcome. In addition, the review also reflects on the opportunities and especially the current drawbacks of the HPCD technique for the food industry.

Individual and combined effects of ph and lactic acid concentration on Listeria innocua inactivation: development of a predictive model and assessment of experimental variability.

In food technology, organic acids (e.g., lactic acid, acetic acid, and citric acid) are popular preservatives. The purpose of this study was to separate the individual effects of the influencing factors pH and undissociated lactic acid on Listeria innocua inactivation. Therefore, the inactivation process was investigated under controlled, initial conditions of pH (pH0) and undissociated lactic acid ([LaH]0). The resulting inactivation curves consisted of a (sometimes negligible) shoulder period followed by a descent phase. In a few cases, a tailing phase was observed. Depending on the conditions, the descent phase contained one or two log-linear parts or had a convex or concave shape. In addition, the inactivation process was characterized by a certain variability, dependent on the severity of the conditions. Furthermore, in the neighborhood of the growth/no growth interface sometimes contradictory observations occurred. Overall, the individual effects of the influencing factors pH and undissociated lactic acid could clearly be distinguished and were also apparent based on fluorescence microscopy. Appropriate model types were developed and enabled prediction of which conditions of pH0 and [LaH]0 are necessary to obtain a predetermined inactivation (number of decimal reductions) within a predetermined time range.

Changes in thiamin intake and blood levels in young, overweight/obese women following hypocaloric diets based on the increased relative consumption of cereals or vegetables.

OBJECTIVE: To analyse the changes in thiamin intake and blood levels of young, overweight/obese women following slightly hypocaloric diets based on the increased relative consumption of foods whose intakes were most removed from the ideal: cereals and vegetables. DESIGN: The women were randomly assigned to one of two slightly hypocaloric diets: diet V, in which the consumption of vegetables was increased, or diet C, in which the consumption of cereals (especially breakfast cereals) was increased. SUBJECTS: The study subjects were 67 young women with a body mass index of 24-35 kg/m2. INTERVENTIONS: Dietetic, anthropometrics and biochemical data were collected at the start of the study and again at 2 and 6 weeks. RESULTS: The reduction in energy intake was similar in both groups. However, diet C subjects lost significantly more weight. Blood thiamin concentration was higher in group C women than in group V women at 2 and 6 weeks. Compared to initial values, group C subjects showed a higher blood thiamin level at 2 weeks. The highest blood thiamin levels seen in group C women may have been due to their greater thiamin intake, their higher thiamin dietetic density, and a higher thiamin/carbohydrates ratio at both week 2 and 6 of the intervention period. CONCLUSIONS: Increasing the relative consumption of breakfast cereals within the context of a slightly hypocaloric diet can help in weight control and improve thiamine intake and blood levels.

[Response to a weight control program based on approximating the diet to its theoretical ideal]. / Respuesta ante un programa de control de peso basado en la aproximación de la dieta al ideal teórico.

UNLABELLED: Obesity is a risk factor for a number of degenerative diseases common in industrial societies and the number of overweight/obese people continues to grow. The control of body weight is therefore a priority public health objective. OBJECTIVE: To analyze the response to a weight loss program based on approximating the diet to the theoretical ideal (by increasing the consumption of recommended foods under-represented in the diet: cereals and vegetables). SUBJECTS: The study involved 67 women aged between 20 and 35 years with a body mass index (BMI) of between 24 and 35 kg/m2. These women were randomly assigned to two groups with the aim of improving weight control and of approximating the diet to the theoretical ideal. INTERVENTIONS: Both groups were advised to follow a slightly hypocaloric diet, but with one group increasing the intake of greens and vegetables (H) and the other increasing the intake of cereals (especially breakfast cereals) (C). Dietary data were obtained via the keeping of a daily food record over three days, including a Sunday. Anthropometric data were obtained at the start of the study and again 2 and 6 weeks later. RESULTS: Both treatments approximated the energy profile of the diets to the theoretical ideal. The amount of energy gained from lipids fell and that gained from carbohydrates increased (both at 2 and 6 weeks), significantly more so for group C. Fifty seven women completed the study and showed a mean reduction in body weight of 2.4 +/-1.4 kg. The weight lost by group C was significantly greater than that lost by group H (2.8 +/- 1.4 kg compared to 2.0 +/- 1.3 kg; p < 0.05). The women who followed diet C showed a greater number of skin folds of significantly reduced size, both at 2 and 6 weeks. More group C women completed the study (93.5% compared to 77.8% of group H women). CONCLUSION: In overweight or slightly obese women, approximating the diet to the theoretical ideal (by increasing the intake of vegetables of cereals) can help to control body weight and improve the quality of the diet (both in terms of the number and size of food rations, and the overall energy profile). The present results show that increasing the consumption of breakfast cereals may be of particular use owing to their high fiber, vitamin and iron contents.