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1.
Ann Oncol ; 34(10): 899-906, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37597579

RESUMEN

BACKGROUND: We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy. PATIENTS AND METHODS: We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence. RESULTS: Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12. CONCLUSIONS: Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.


Asunto(s)
Neoplasias de la Mama , ADN Tumoral Circulante , Neoplasias de la Mama Triple Negativas , Humanos , Femenino , ADN Tumoral Circulante/genética , Terapia Neoadyuvante/efectos adversos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Neoplasia Residual/genética , Neoplasia Residual/patología , Estudios Prospectivos , Neoplasias de la Mama/etiología , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/genética
2.
J Bone Oncol ; 29: 100375, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34131559

RESUMEN

Optimum management of patients with cancer during the COVID-19 pandemic has proved extremely challenging. Patients, clinicians and hospital authorities have had to balance the risks to patients of attending hospital, many of whom are especially vulnerable, with the risks of delaying or modifying cancer treatment. Those whose care has been significantly impacted include patients suffering from the effects of cancer on bone, where delivering the usual standard of care for bone support has often not been possible and clinicians have been forced to seek alternative options for adequate management. At a virtual meeting of the Cancer and Bone Society in July 2020, an expert group shared experiences and solutions to this challenge, following which a questionnaire was sent internationally to the symposium's participants, to explore the issues faced and solutions offered. 70 respondents, from 9 countries (majority USA, 39%, followed by UK, 19%) included 50 clinicians, spread across a diverse range of specialties (but with a high proportion, 64%, of medical oncologists) and 20 who classified themselves as non-clinical (solely lab-based). Spread of clinician specialty across tumour types was breast (65%), prostate (27%), followed by renal, myeloma and melanoma. Analysis showed that management of metastatic bone disease in all solid tumour types and myeloma, adjuvant bisphosphonate breast cancer therapy and cancer treatment induced bone loss, was substantially impacted. Respondents reported delays to routine CT scans (58%), standard bone scans (48%) and MRI scans (46%), though emergency scans were less affected. Delays in palliative radiotherapy for bone pain were reported by 31% of respondents with treatments often involving only a single dose without fractionation. Delays to, or cancellation of, prophylactic surgery for bone pain were reported by 35% of respondents. Access to treatments with intravenous bisphosphonates and subcutaneous denosumab was a major problem, mitigated by provision of drug administration at home or in a local clinic, reduced frequency of administration or switching to oral bisphosphonates taken at home. The questionnaire also revealed damaging delays or complete stopping of both clinical and laboratory research. In addition to an analysis of the questionnaire, this paper presents a rationale and recommendations for adaptation of the normal guidelines for protection of bone health during the pandemic.

3.
Nat Commun ; 9(1): 1691, 2018 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-29703982

RESUMEN

Liquid biopsies including circulating tumor cells (CTCs) and cell-free DNA (cfDNA) have enabled minimally invasive characterization of many cancers, but are rarely analyzed together. Understanding the detectability and genomic concordance of CTCs and cfDNA may inform their use in guiding cancer precision medicine. Here, we report the detectability of cfDNA and CTCs in blood samples from 107 and 56 patients with multiple myeloma (MM), respectively. Using ultra-low pass whole-genome sequencing, we find both tumor fractions correlate with disease progression. Applying whole-exome sequencing (WES) to cfDNA, CTCs, and matched tumor biopsies, we find concordance in clonal somatic mutations (~99%) and copy number alterations (~81%) between liquid and tumor biopsies. Importantly, analyzing CTCs and cfDNA together enables cross-validation of mutations, uncovers mutations exclusive to either CTCs or cfDNA, and allows blood-based tumor profiling in a greater fraction of patients. Our study demonstrates the utility of analyzing both CTCs and cfDNA in MM.


Asunto(s)
Biomarcadores de Tumor/genética , ADN Tumoral Circulante/genética , Secuenciación del Exoma/métodos , Mieloma Múltiple/genética , Células Neoplásicas Circulantes , Adulto , Anciano , Anciano de 80 o más Años , Médula Ósea/patología , Variaciones en el Número de Copia de ADN/genética , Progresión de la Enfermedad , Femenino , Humanos , Biopsia Líquida/métodos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/patología , Mutación/genética , Medicina de Precisión/métodos
4.
Food Microbiol ; 36(2): 248-53, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24010604

RESUMEN

The effect of marination on the survival and growth of the pathogens Salmonella enterica and Listeria monocytogenes on beef pieces was investigated. Five marinades were used: soy sauce base marinade without (SB) or with lactic acid (SBLA), red wine base marinade without (WB) or with 0.5% v/v oregano essential oil (WBO), and sterile saline used as control (C). Inoculated fresh beef pieces were marinated for 18 h at 5 °C, removed from the marinade and subjected to storage trials at 5 °C and 15 °C. Heat inactivation studies were also performed on the isolates after exposure to the marinades to determine if marination affects heat resistance of the pathogens. The marinades with antimicrobials caused a significant decrease in viable count of the pathogens during marinations at 5 °C for 18 h of up to 2.1 and 3.4 log cfu cm(-2) for Salmonella and L. monocytogenes, respectively. Marinades without antimicrobials were less bactericidal resulting to reductions ranging from 0.3 to 0.4 and 1.3 to 2.0 log cfu cm(-2) for Salmonella and L. monocytogenes, respectively. Growth of L. monocytogenes was observed in the controls at both tested temperatures, while growth of Salmonella was observed in the controls stored at 15 °C. No growth of the pathogens was observed in any of the marinated samples at both temperature tested. No significant changes of heat resistance of the tested pathogens after exposure to the marinades were observed demonstrating the enhanced safety of the marinated beef product.


Asunto(s)
Conservación de Alimentos/métodos , Conservantes de Alimentos/farmacología , Listeria monocytogenes/crecimiento & desarrollo , Carne/microbiología , Salmonella enterica/crecimiento & desarrollo , Animales , Bovinos , Conservación de Alimentos/instrumentación , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/aislamiento & purificación , Salmonella enterica/efectos de los fármacos , Salmonella enterica/aislamiento & purificación
5.
J Appl Microbiol ; 115(4): 987-94, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23848299

RESUMEN

AIMS: To investigate the potential use of oregano essential oil as an antimicrobial agent in liquid soap for hand washing and for food contact surface cleaning. METHODS AND RESULTS: Oregano essential oil (O.E.O.) was emulsified in liquid detergent solution. This was challenge tested against a commercial antimicrobial soap in hand washing trials using natural flora. Soap with O.E.O. was as effective as the commercial antimicrobial soap at reducing aerobic plate count on the hands and more effective than plain soap with no additives. Cloths wetted with soap with O.E.O. were used to clean three different surfaces contaminated with four bacterial pathogens. For three of the four pathogens, the addition of 0·5% v/v O.E.O. to the soap solution enhanced cleaning performance and also reduced bacterial survival on the cloth after cleaning. CONCLUSIONS: Oregano essential oil (0·5%) is effective as an antimicrobial additive to detergent solutions for hand washing and surface cleaning. SIGNIFICANCE AND IMPACT OF STUDY: This preliminary study has shown that oregano essential oil is a potential alternative to antimicrobials used in various detergents, such as chloroxylenol and triclosan, which can have adverse environmental and health effects. Further development could lead to a commercial product.


Asunto(s)
Desinfectantes/farmacología , Desinfección de las Manos , Aceites Volátiles/farmacología , Origanum , Aceites de Plantas/farmacología , Detergentes , Microbiología de Alimentos , Mano/microbiología , Humanos
6.
Food Microbiol ; 28(1): 158-63, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21056788

RESUMEN

Fresh beef slices were marinated by immersion in marinades based on soy sauce without (SB) or with lactic acid (SBLA) or red wine base without (WB) or with 0.5% v/v oregano essential oil (WBO). For control samples (immersed in saline), a mean increase of 0.9log CFU/cm(2) in total viable counts (TVCs) occurred during the 24h treatment. During marination with WB and SB, mean TVC decreased by 0.7 and 0.3log CFU/cm(2), respectively. The mean decrease in TVC for samples marinated in WBO or SBLA was 1.2log CFU/cm(2). Subsequent storage of beef resulted in a rapid increase of TVC in control samples, to ≥9.5log CFU/cm(2) after 8 days at 5°C or 3 days at 15°C. Significant (P<0.05) microbial growth occurred in marinated samples stored at 5°C. During storage at 15°C TVC increased in only WB samples but the final numbers of 5.9log CFU/cm(2) were significantly lower (P<0.05) than the numbers in the control. Results similar to those for TVC were observed for Pseudomonas spp. All marinades also gave meat with significant lower TBARS values than the controls. There were no significant differences (P>0.05) in the toughness of the marinated samples compared to the control, except for SBLA samples which had significantly higher (P<0.05) shear force values. Marination with soy sauce or red wine marinades can evidently control microbial spoilage and oxidation of meat.


Asunto(s)
Microbiología de Alimentos , Carne/microbiología , Aceites Volátiles/metabolismo , Alimentos de Soja , Vino , Recuento de Colonia Microbiana , Conservación de Alimentos/métodos , Inocuidad de los Alimentos , Concentración de Iones de Hidrógeno , Ácido Láctico/metabolismo , Origanum/química , Pseudomonas/crecimiento & desarrollo
7.
Food Microbiol ; 26(4): 357-76, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19376457

RESUMEN

This review examines the prevalence of three important pathogens, verocytotoxigenic Escherichia coli (VTEC), Salmonella enterica and Listeria monocytogenes, in cattle and beef from the farm to the final, ready-to-eat product. Factors affecting prevalence of pathogens in the beef chain, such as the season and cattle rearing method, are examined. Data from many key surveys are summarized in table form. The observed prevalence of pathogens in cattle and beef varies considerably from survey to survey. An indication of relative prevalence of pathogens at different stages can be obtained by calculating average prevalences observed over multiple surveys, weighted by sample number. Based on the data presented in the tables in this review, for E. coli O157 at selected processing stages the mean prevalences (and range of means from individual surveys) are faeces 6.2% (0.0-57%), hides 44% (7.3-76%), chilled carcasses 0.3% (0.0-0.5%), and raw beef products 1.2% (0.0-17%). For Salmonella the mean prevalence data are faeces 2.9% (0.0-5.5%), hides 60% (15-71%), chilled carcasses 1.3% (0.2-6.0%), and raw beef products 3.8% (0.0-7.5%). For L. monocytogenes the mean prevalence data are faeces 19% (4.8-29%), hides 12% (10-13%), and raw beef products 10% (1.6-24%). Seasonal variation was evident in many surveys, faecal prevalences of E. coli O157 and Salmonella generally being higher in the warmer months. The influence of animal type, animal age, feed and housing on pathogen carriage has also been examined. The significance of non-O157 serotypes of VTEC and their detection and classification are discussed.


Asunto(s)
Bovinos/microbiología , Industria de Procesamiento de Alimentos/normas , Listeria monocytogenes/aislamiento & purificación , Salmonella enterica/aislamiento & purificación , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Recuento de Colonia Microbiana , Heces/microbiología , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Carne/microbiología , Prevalencia , Estaciones del Año , Piel/microbiología
8.
Vet Ther ; 10(4): E1-8, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20425730

RESUMEN

This study evaluated the induction of bovine viral diarrhea virus (BVDV) cell-mediated and humoral immune responses after vaccination with an adjuvanted inactivated product. In vaccinated animals, there was an overall treatment effect (P less than .05), for an increased percentage of BVDV-specific CD8 T cells expressing interferon-γ (IFN-γ). The percentages of IFN-γ producing γδ-T cells in the vaccinated group were increased on days 7 (P =.10), 14 (P =.09), and 31 (P = .12). CD4 T cells expressing IFN-γ were increased on day 42 (P = .05). Stimulated peripheral blood mononuclear cells of the vaccinated group had increased IFN-γ production on days 14 and 35 (P less than .05). Testing for BVDV types 1 and 2 titers began at day 14, with peak titers on days 42 and 35, respectively. In summary, the intracellular accumulation and release of IFN-γ, a T helper cell 1 cytokine, indicates that an adjuvanted inactivated BVDV vaccine is capable of invoking a cell-mediated response while delivering a targeted humoral response.


Asunto(s)
Diarrea Mucosa Bovina Viral/prevención & control , Virus de la Diarrea Viral Bovina/inmunología , Vacunas Virales/inmunología , Adyuvantes Inmunológicos , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Bovinos , Inmunidad Celular , Masculino
9.
J Food Prot ; 71(11): 2272-7, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19044272

RESUMEN

The aim of the study was to investigate the ability of pectic oligosaccharides (POS) to inhibit adhesion of three strains of verotoxigenic Escherichia coli, three strains of enteropathogenic E. coli, and one nonclinical strain of Desulfovibrio desulfuricans to human intestinal epithelial cell cultures. Lactobacillus acidophilus and Lactobacillus gasseri were included for comparison. Attachment was determined in the human HT29 cell line by viable count of adherent bacteria. POS in buffer at pH 7.2 were antiadhesive at a dose of 2.5 mg ml(-1), reducing adhesion of enteropathogenic E. coil and verotoxigenic E. coli strains to less than 30% of control values. Concentrations resulting in 50% inhibition ranged from 0.15 to 0.46 mg ml(-1). L. acidophilus was not significantly affected, but adhesion of L. gasseri was reduced to 29% of the control value. POS reduced the adhesion of D. desulfuricans to 0.33% of the control value. POS also had a protective effect against E. coli verocytotoxins VT1 and VT2 at concentrations of 0.01 and 1 microg ml(-1), respectively.


Asunto(s)
Adhesión Bacteriana/efectos de los fármacos , Escherichia coli/fisiología , Mucosa Intestinal/microbiología , Oligosacáridos/farmacología , Adhesión Bacteriana/fisiología , Recuento de Colonia Microbiana , Desulfovibrio desulfuricans/patogenicidad , Desulfovibrio desulfuricans/fisiología , Relación Dosis-Respuesta a Droga , Escherichia coli Enterotoxigénica/patogenicidad , Escherichia coli Enterotoxigénica/fisiología , Escherichia coli/patogenicidad , Células HT29 , Humanos , Lactobacillus/patogenicidad , Lactobacillus/fisiología , Lactobacillus acidophilus/patogenicidad , Lactobacillus acidophilus/fisiología , Escherichia coli Shiga-Toxigénica/patogenicidad , Escherichia coli Shiga-Toxigénica/fisiología
10.
J Food Prot ; 71(1): 19-26, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18236658

RESUMEN

This survey was launched after an unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in food service premises in England and Wales. Between November 2005 and December 2006, 9,528 eggs (1,588 pooled samples of 6 eggs) were collected from 1,567 food service premises in the United Kingdom, most of which (89%) were produced in the United Kingdom. Salmonella was isolated from 6 (0.38%) pools of eggs. Of these, 5 (0.31%) were Salmonella Enteritidis, which were further characterized to phage types (PTs): PT 4 (0.19%), PT 8 (0.06%), and PT 12 (0.06%). Salmonella Mbandaka was also isolated (0.06%). Salmonella was detected from five and one of pooled eggs samples that were produced in the United Kingdom and Germany, respectively; these were from different producers. The study showed evidence of poor egg storage and handling practices in food service premises, in that 55% did not store eggs under refrigerated conditions; 20.7% of eggs had expired "best before" dates or were in use after 3 weeks of lay, indicating poor stock rotation; and 37.1% pooled eggs not intended for immediate service. Eggs are a commonly consumed food that may occasionally be contaminated with Salmonella at different rates, according to their country of origin. The food service sector needs to be aware of this continuing hazard, receive appropriate food safety and hygiene training on storage and usage of raw shell eggs, adopt appropriate control measures, and follow advice provided by national food agencies in order to reduce the risk of infection.


Asunto(s)
Huevos/microbiología , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Servicios de Alimentación/normas , Intoxicación Alimentaria por Salmonella/epidemiología , Salmonella enteritidis/aislamiento & purificación , Animales , Seguridad de Productos para el Consumidor , Brotes de Enfermedades , Cáscara de Huevo/microbiología , Manipulación de Alimentos/normas , Microbiología de Alimentos , Humanos , Medición de Riesgo , Salmonella enteritidis/crecimiento & desarrollo , Reino Unido/epidemiología
11.
Food Microbiol ; 25(2): 304-12, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18206773

RESUMEN

Two studies of retail fresh, ripened and semi-hard cheeses made from raw, thermized or pasteurized milk were undertaken in the UK during 2004 and 2005 to determine the microbiological quality of these products. Using microbiological criteria in European Commission Recommendations 2004/24/EC and 2005/175/EC, 2% of both raw, thermized (37/1819 samples) and pasteurized (51/2618 samples) milk cheeses were of unsatisfactory quality. Raw or thermized milk cheeses were of unsatisfactory quality due to levels of Staphylococcus aureus at 10(4)cfu g(-1), Escherichia coli at 10(5)cfu g(-1), and/or Listeria monocytogenes at 10(2)cfu g(-1), whereas pasteurized milk cheeses were of unsatisfactory quality due to S. aureus at 10(3)cfu g(-1) and/or E. coli at 10(3)cfu g(-1). Salmonella was not detected in any samples. Cheeses were of unsatisfactory quality more frequently when sampled from premises rated as having little or no confidence in management and control systems, and stored/displayed at above 8 degrees C. Raw or thermized milk cheeses were also more likely to be of unsatisfactory quality when they were unripened types, and pasteurized milk cheeses when they were: semi-hard types; from specialist cheese shops or delicatessens; cut to order. These results emphasize the need for applying and maintaining good hygiene practices throughout the food chain to prevent contamination and/or bacterial growth. Labelling of cheeses with clear information on whether the cheese was prepared from raw milk also requires improvement.


Asunto(s)
Queso/microbiología , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Higiene , Leche , Animales , Bovinos , Queso/normas , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Escherichia coli/crecimiento & desarrollo , Escherichia coli/aislamiento & purificación , Contaminación de Alimentos/prevención & control , Microbiología de Alimentos , Calor , Humanos , Listeria monocytogenes/crecimiento & desarrollo , Listeria monocytogenes/aislamiento & purificación , Leche/microbiología , Leche/normas , Control de Calidad , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/aislamiento & purificación , Reino Unido
12.
J Dairy Sci ; 88(10): 3455-9, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16162518

RESUMEN

Caseinoglycomacropeptide (CGMP) derived from kappa-casein was investigated for its ability to inhibit the adhesion of 3 strains of verotoxigenic Escherichia coli (VTEC) and 3 strains of enteropathogenic Escherichia coli (EPEC) to human HT29 tissue cell cultures. Effects on adhesion of Desulfovibrio desulfuricans, Lactobacillus pentosus, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus gasseri were also investigated. Generally, CGMP exerted effective anti-adhesive properties at a dose of 2.5 mg/mL, albeit with a high degree of strain specificity. The CGMP reduced adhesion of VTEC strains to <50% of the control and reduced adhesion of EPEC strains to between 80 and 10% of the control. The CGMP also reduced the adhesion of L. pentosus and L. casei to 44 and 42%, respectively. A slight but significant reduction of L. acidophilus, to 81%, was observed, but no significant effects were detected with either Dsv. desulfuricans or L. gasseri. Further investigation of the dose response relationships with the E. coli strains gave IC50 values ranging between 0.12 and 1.06 mg/mL.


Asunto(s)
Adhesión Bacteriana/efectos de los fármacos , Caseínas/farmacología , Células/microbiología , Escherichia coli/fisiología , Fragmentos de Péptidos/farmacología , Adenocarcinoma , Línea Celular Tumoral , Neoplasias del Colon , Desulfovibrio desulfuricans/efectos de los fármacos , Desulfovibrio desulfuricans/fisiología , Escherichia coli/efectos de los fármacos , Humanos , Lactobacillus/efectos de los fármacos , Lactobacillus/fisiología
14.
Ment Retard ; 39(2): 114-29, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11340961

RESUMEN

A multivariate analysis was done to determine the relative importance of facility, resident, and community characteristics to expenditures. Facility factors associated with higher expenditures included ownership, facility size, facility services, and location. Individuals with a greater number of activity of daily living limitations, developmental disabilities, and more severe levels of mental retardation had higher expenses. Findings could improve our understanding of the costs of long-term residential care, assisting us to economically and effectively bring this population into the community. Data used are from the 1987 National Medical Expenditure Survey Institutional Population Component.


Asunto(s)
Gastos en Salud , Discapacidad Intelectual/economía , Asistencia Médica/economía , Personas con Discapacidades Mentales/psicología , Instituciones Residenciales/economía , Adulto , Anciano , Evaluación de la Discapacidad , Femenino , Encuestas de Atención de la Salud , Humanos , Discapacidad Intelectual/psicología , Discapacidad Intelectual/rehabilitación , Masculino , Persona de Mediana Edad , Análisis Multivariante , Personas con Discapacidades Mentales/rehabilitación , Encuestas y Cuestionarios , Estados Unidos
15.
Int J Food Microbiol ; 71(2-3): 235-44, 2001 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-11789941

RESUMEN

The mode of antimicrobial action of chitosan (polymeric beta-1,4-N-acetylglucosamine) on gram-negative bacteria was studied with special emphasis on its ability to bind to and weaken the barrier function of the outer membrane (OM). Chitosan (250 ppm) at pH 5.3 induced significant uptake of the hydrophobic probe 1-N-phenylnaphthylamine (NPN) in Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium. The effect was reduced (E. coli, salmonellae) or abolished (P. aeruginosa) by MgCl2. No NPN uptake was observed during exposure of the salmonellae to chitosan at pH 7.2. Chitosan also sensitized P. aeruginosa and the salmonellae to the lytic effect of sodium dodecyl sulfate (SDS); such sensitization was not blocked by MgCl2 and was reversible by washing chitosan-treated cells prior to SDS exposure. Chemical and electrophoretic analyses of cell-free supernatants of chitosan-treated cell suspensions showed that interaction of chitosan with E. coli and the salmonellae involved no release of lipopolysaccharide (LPS) or other membrane lipids. However, chitosan rendered E. coli more sensitive to the inhibitory action of dyes and bile acids used in selective media. Highly cationic mutants of S. typhimurium were more resistant to chitosan than the parent strains. Electron microscopy showed that chitosan caused extensive cell surface alterations and covered the OM with vesicular structures. Chitosan thus appeared to bind to the outer membrane, explaining the loss of the barrier function. This property makes chitosan a potentially useful indirect antimicrobial for food protection.


Asunto(s)
Permeabilidad de la Membrana Celular/fisiología , Quitina/farmacología , Conservantes de Alimentos/farmacología , Bacterias Gramnegativas/fisiología , Proteínas de la Membrana Bacteriana Externa , Membrana Celular/ultraestructura , Permeabilidad de la Membrana Celular/efectos de los fármacos , Quitina/análogos & derivados , Quitosano , Concentración de Iones de Hidrógeno , Lipopolisacáridos , Microscopía Electrónica
17.
Appl Environ Microbiol ; 66(1): 80-6, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10618206

RESUMEN

The objective of this study was to determine whether chitosan (poly-beta-1,4-glucosamine) and hydrolysates of chitosan can be used as novel preservatives in foods. Chitosan was hydrolyzed by using oxidative-reductive degradation, crude papaya latex, and lysozyme. Mild hydrolysis of chitosan resulted in improved microbial inactivation in saline and greater inhibition of growth of several spoilage yeasts in laboratory media, but highly degraded products of chitosan exhibited no antimicrobial activity. In pasteurized apple-elderflower juice stored at 7 degrees C, addition of 0.3 g of chitosan per liter eliminated yeasts entirely for the duration of the experiment (13 days), while the total counts and the lactic acid bacterial counts increased at a slower rate than they increased in the control. Addition of 0.3 or 1.0 g of chitosan per kg had no effect on the microbial flora of hummus, a chickpea dip; in the presence of 5.0 g of chitosan per kg, bacterial growth but not yeast growth was substantially reduced compared with growth in control dip stored at 7 degrees C for 6 days. Improved antimicrobial potency of chitosan hydrolysates like that observed in the saline and laboratory medium experiments was not observed in juice and dip experiments. We concluded that native chitosan has potential for use as a preservative in certain types of food but that the increase in antimicrobial activity that occurs following partial hydrolysis is too small to justify the extra processing involved.


Asunto(s)
Antiinfecciosos/farmacología , Quitina/análogos & derivados , Microbiología de Alimentos , Conservantes de Alimentos/farmacología , Antibacterianos , Antiinfecciosos/metabolismo , Bacterias/efectos de los fármacos , Bebidas , Quitina/metabolismo , Quitina/farmacología , Quitosano , Medios de Cultivo , Manipulación de Alimentos , Conservantes de Alimentos/metabolismo , Oxidación-Reducción , Rosales/microbiología , Cloruro de Sodio , Levaduras/efectos de los fármacos
18.
Am J Prev Med ; 15(1): 60-4, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9651640

RESUMEN

INTRODUCTION: Physicians have a unique role to play in the prevention of elder suicide, yet they may not be sufficiently attentive to the prominence of firearms in the rising trend in suicide by elder persons. This study sought to examine the extent to which physicians inquired about firearms with their depressed and suicidal elderly patients and further identified factors associated with physicians' likelihood of asking about firearms. METHODS: A probability sample of 300 primary care physicians in Illinois was drawn from the American Medical Association Physician Masterfile. Physicians were chosen from the specialties most likely to be involved with elderly persons: internal medicine and family practice. A mailed questionnaire yielded a 63% response rate. RESULTS: Although they were treating depressed and suicidal older patients, a sizable proportion of the respondents (42%) reported that they did not ask such patients or their family members whether they had access to a firearm. Several factors distinguished physicians who assessed for firearms from those who did not. The most salient predictors were: continuing medical education training in suicide risk assessment, expertise in geriatric mental health, confidence in diagnosing depression, having a patient mention suicide in the past year, and indicating patient reluctance as a barrier to mental health treatment. DISCUSSION: Physicians working with depressed and suicidal elderly persons need to be informed about the prevalence of elder suicide and about the likelihood of elderly persons using firearms as a method of suicide. Effective suicide prevention will require physician training that directly addresses geriatric mental health and firearm suicide, in particular, at the student, residency, and continuing education levels.


Asunto(s)
Armas de Fuego/estadística & datos numéricos , Servicios de Salud para Ancianos/estadística & datos numéricos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Atención Primaria de Salud/estadística & datos numéricos , Prevención del Suicidio , Anciano , Actitud del Personal de Salud , Distribución de Chi-Cuadrado , Competencia Clínica/estadística & datos numéricos , Intervalos de Confianza , Depresión/diagnóstico , Depresión/terapia , Educación Médica , Educación Médica Continua/estadística & datos numéricos , Femenino , Evaluación Geriátrica/estadística & datos numéricos , Psiquiatría Geriátrica/educación , Encuestas de Atención de la Salud , Humanos , Illinois , Modelos Logísticos , Masculino , Medicina/estadística & datos numéricos , Persona de Mediana Edad , Oportunidad Relativa , Aceptación de la Atención de Salud , Medición de Riesgo , Muestreo , Especialización
19.
Stat Bull Metrop Insur Co ; 79(2): 2-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9592922

RESUMEN

This paper briefly describes changes in the nursing home market over a nine-year period, 1987 to 1996. Estimates are based on the "Institutional Population Component" of the 1987 National Medical Expenditure Survey (NMES) and the "Nursing Home Component" of the 1996 Medical Expenditure Panel Survey (MEPS). Both surveys were sponsored by the Agency for Health Care Policy and Research. On January 1, 1996, approximately 1.56 million residents were receiving care in 16,840 nursing homes with 1.76 million beds. This compares to 1.36 million residents in 14,050 nursing homes with 1.48 million beds in 1987, increases of 15, 20 and 19 percent, respectively. The average size of a nursing home remained constant. The occupancy rate decreased from 92 percent in 1987 to 89 percent in 1996, in spite of the growth of the elderly population, both in relative and absolute terms. There was also a significant drop in the supply of nursing home beds relative to the elderly population; this decrease was observed in all four regions of the country, with the greatest drop being in the West. In 1987 only 28 percent of nursing homes were certified by both Medicare and Medicaid (dually certified), while this proportion increased to 73 percent in 1996. Conversely, while only 17 percent of nursing homes were certified by only Medicaid in 1996, a full 50 percent were certified as such in 1987. By far the most common type of nursing home in both 1987 and 1996 was the nursing home with only nursing home beds. Such nursing homes represented 87 percent of the market in 1987 but just 77 percent in 1996. The remaining were either hospital-based or nursing homes with personal care and/or independent living beds in addition to nursing home beds or were part of a continuing care retirement community.


Asunto(s)
Hogares para Ancianos/estadística & datos numéricos , Casas de Salud/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Ocupación de Camas/estadística & datos numéricos , Certificación/estadística & datos numéricos , Recolección de Datos , Humanos , Tiempo de Internación/estadística & datos numéricos , Medicaid/estadística & datos numéricos , Casas de Salud/economía , Casas de Salud/legislación & jurisprudencia , Casas de Salud/normas , Propiedad/estadística & datos numéricos , Estados Unidos
20.
Transplantation ; 56(1): 113-20, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8333033

RESUMEN

Clinical acute graft-versus-host disease (aGVHD) was correlated with alterations in PBL phenotype and skin immunohistology in 52 patients transplanted with HLA-identical bone marrow. Concurrent with the emergence of aGVHD, there was a profound decrease in absolute number of CD3- T cells and an increase in CD3-CD16+, CD56+ (a subset of which coexpress CD8+ "dim") NK cells in the PBL. CD4+ T and CD20+ B lymphocytes failed to recover within 90 days in the patients with grades II-IV aGVHD. Ex vivo partial T cell depletion, in itself, did not significantly impair T cell recovery as compared to that in non-T-depleted recipients unless aGVHD occurred. Although leukocytic cellular infiltration in the skin was generally sparse, CD16+ NK lymphocytes were significantly increased in grades II-IV aGVHD. By contrast, there was no significant increase in CD3+, CD4+, or CD8+ lymphocytes in these lesions as compared to skin biopsies obtained from BMT patients without aGVHD or from normal skin. Taken together, these findings suggest that NK cells may be important in the pathogenesis of human aGVHD.


Asunto(s)
Trasplante de Médula Ósea/inmunología , Enfermedad Injerto contra Huésped/inmunología , Células Asesinas Naturales/inmunología , Enfermedad Aguda , Adolescente , Adulto , Antígenos CD/análisis , Subgrupos de Linfocitos B/inmunología , Complejo CD3/análisis , Niño , Citometría de Flujo , Enfermedad Injerto contra Huésped/prevención & control , Prueba de Histocompatibilidad , Humanos , Inmunofenotipificación , Metotrexato/uso terapéutico , Persona de Mediana Edad , Receptores de IgG/análisis , Piel/inmunología , Piel/patología , Subgrupos de Linfocitos T/inmunología
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