Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
J Comp Neurol ; 532(3): e25596, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38439568

RESUMEN

Late-onset peripheral neuropathy (LPN) is a heritable canine neuropathy commonly found in Labrador retrievers and is characterized by laryngeal paralysis and pelvic limb paresis. Our objective was to establish canine LPN as a model for human hereditary peripheral neuropathy by classifying it as either an axonopathy or myelinopathy and evaluating length-dependent degeneration. We conducted a motor nerve conduction study of the sciatic and ulnar nerves, electromyography (EMG) of appendicular and epaxial musculature, and histologic analysis of sciatic and recurrent laryngeal nerves in LPN-affected and control dogs. LPN-affected dogs exhibited significant decreases in compound muscle action potential (CMAP) amplitude, CMAP area, and pelvic limb latencies. However, no differences were found in motor nerve conduction velocity, residual latencies, or CMAP duration. Distal limb musculature showed greater EMG changes in LPN-affected dogs. Histologically, LPN-affected dogs exhibited a reduction in the number of large-diameter axons, especially in distal nerve regions. In conclusion, LPN in Labrador retrievers is a common, spontaneous, length-dependent peripheral axonopathy that is a novel animal model of age-related peripheral neuropathy that could be used for fundamental research and clinical trials.


Asunto(s)
Enfermedades del Sistema Nervioso Periférico , Humanos , Animales , Perros , Axones , Electromiografía , Extremidades , Miembro Posterior
2.
Am J Vet Res ; 85(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38382190

RESUMEN

OBJECTIVE: The aim of this study was to investigate whether plasma neurofilament light chain (pNfL) concentration was altered in Labrador Retrievers with idiopathic laryngeal paralysis (ILP) compared to a control population. A secondary aim was to investigate relationships between age, height, weight, and body mass index in the populations studied. ANIMALS: 123 dogs: 62 purebred Labrador Retrievers with ILP (ILP Cases) and 61 age-matched healthy medium- to large-breed dogs (Controls). METHODS: Dogs, recruited from August 1, 2016, to March 1, 2022, were categorized as case or control based on a combination of physical exam, neurologic exam, and history. Blood plasma was collected, and pNfL concentration was measured. pNfL concentrations were compared between ILP Cases and Controls. Covariables including age, height, and weight were collected. Relationships between pNfL and covariables were analyzed within and between groups. In dogs where 2 plasma samples were available from differing time points, pNfL concentrations were measured to evaluate alterations over time. RESULTS: No significant difference in pNfL concentration was found between ILP Cases and Control (P = .36). pNfL concentrations had moderate negative correlations with weight and height in the Control group; other variables did not correlate with pNfL concentrations in ILP Case or Control groups. pNfL concentrations do not correlate with ILP disease status or duration in Labrador Retrievers. CLINICAL RELEVANCE: There is no evidence that pNfL levels are altered due to ILP disease duration or progression when compared with healthy controls. When evaluating pNfL concentrations in the dog, weight and height should be considered.


Asunto(s)
Enfermedades de los Perros , Parálisis de los Pliegues Vocales , Perros , Animales , Parálisis de los Pliegues Vocales/veterinaria , Filamentos Intermedios , Enfermedades de los Perros/genética
3.
Front Genet ; 14: 1201628, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37645058

RESUMEN

Introduction: Spontaneous rupture of tendons and ligaments is common in several species including humans. In horses, degenerative suspensory ligament desmitis (DSLD) is an important acquired idiopathic disease of a major energy-storing tendon-like structure. DSLD risk is increased in several breeds, including the Peruvian Horse. Affected horses have often been used for breeding before the disease is apparent. Breed predisposition suggests a substantial genetic contribution, but heritability and genetic architecture of DSLD have not been determined. Methods: To identify genomic regions associated with DSLD, we recruited a reference population of 183 Peruvian Horses, phenotyped as DSLD cases or controls, and undertook a genome-wide association study (GWAS), a regional window variance analysis using local genomic partitioning, a signatures of selection (SOS) analysis, and polygenic risk score (PRS) prediction of DSLD risk. We also estimated trait heritability from pedigrees. Results: Heritability was estimated in a population of 1,927 Peruvian horses at 0.22 ± 0.08. After establishing a permutation-based threshold for genome-wide significance, 151 DSLD risk single nucleotide polymorphisms (SNPs) were identified by GWAS. Multiple regions of enriched local heritability were identified across the genome, with strong enrichment signals on chromosomes 1, 2, 6, 10, 13, 16, 18, 22, and the X chromosome. With SOS analysis, there were 66 genes with a selection signature in DSLD cases that was not present in the control group that included the TGFB3 gene. Pathways enriched in DSLD cases included proteoglycan metabolism, extracellular matrix homeostasis, and signal transduction pathways that included the hedgehog signaling pathway. The best PRS predictive performance was obtained when we fitted 1% of top SNPs using a Bayesian Ridge Regression model which achieved the highest mean of R2 on both the probit and logit liability scales, indicating a strong predictive performance. Discussion: We conclude that within-breed GWAS of DSLD in the Peruvian Horse has further confirmed that moderate heritability and a polygenic architecture underlies the trait and identified multiple DSLD SNP associations in novel tendinopathy candidate genes influencing disease risk. Pathways enriched with DSLD risk variants include ones that influence glycosaminoglycan metabolism, extracellular matrix homeostasis, signal transduction pathways.

4.
J Am Vet Med Assoc ; 261(11): 1-6, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37468124

RESUMEN

OBJECTIVE: To determine the presentation, diagnosis, progression, and family risk of fibrotic myopathy, a disease with marked breed predisposition in the German Shepherd Dog (GSD). ANIMALS: 41 dogs prospectively recruited to the University of Wisconsin-Madison Comparative Genetics and Orthopedic Laboratory between November 2019 to August 2022. METHODS: Medical records of dogs diagnosed with fibrotic myopathy were reviewed upon referral. The following data were recorded: sex, age, weight, regio interscapularis (withers) height, date of neutering, coat color and length, and age at fibrotic myopathy diagnosis. A pedigree was also obtained. RESULTS: In the study population, breeds included 37 GSDs, a Belgian Malinois, a Belgian Malinois cross, and 2 dogs with a GSD phenotype and no pedigree. Mean age at fibrotic myopathy diagnosis was 5.9 ± 2.0 years, and duration of lameness before diagnosis was 5.6 months and ranged from 0.75 to 18 months. Males were overrepresented at 61% of the study population. Inherited familial risk for fibrotic myopathy in the GSD was supported by pedigree analysis. CLINICAL RELEVANCE: This was the largest case series of fibrotic myopathy to date, providing a more comprehensive look at presentation and progression of the disease. The longer duration of lameness in bilaterally affected dogs likely represents disease progression rather than a more severe phenotype. Family history data support a genetic contribution to fibrotic myopathy, suggesting that further genetic investigation is warranted.


Asunto(s)
Contractura , Enfermedades de los Perros , Enfermedades Musculares , Humanos , Masculino , Perros , Animales , Estudios Prospectivos , Muslo , Cojera Animal , Enfermedades Musculares/genética , Enfermedades Musculares/veterinaria , Contractura/genética , Contractura/veterinaria , Enfermedades de los Perros/genética
5.
Disabil Rehabil ; 44(12): 2763-2773, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-33331793

RESUMEN

PURPOSE: Longitudinal fibular deficiency (LFD) is the most common congenital long bone deficiency. This study aimed to objectively assess the physical performance of children and adolescents with LFD compared with unaffected peers, and to examine trends over age for subgroups of the LFD population. METHODS: Differences between children with LFD and unaffected peers were examined with hand-held dynamometry for lower-limb muscle strength, Six-Minute Walk Test, Timed up and down stairs test, Star Excursion Balance Test, and Standing long jump. RESULTS: Thirty-nine children with LFD and 284 unaffected peers participated. Children with LFD performed at a lower level than their unaffected peers, on all measures of physical performance (mean 2.1 z-scores lower, all p < 0.01), except in long jump (p = 0.27). When comparing the performance of children with LFD to their unaffected peers across four age groups, there was a significant between-groups difference on all strength measures, and on the Six-Minute Walk distance, between children with and without LFD. These differences were smallest in young children (3-6 years) and largest in the older children (15-18 years) (all p < 0.01). Children with no lengthening surgery performed better on the Six-Minute Walk Test, covering a greater distance during the test, than those who had surgery (mean difference 83 metres, p < 0.01). There were no significant differences between children who had or had not undergone an amputation. CONCLUSIONS: Children with LFD performed at a significantly lower level than unaffected peers on all measures of physical performance other than jumping. The largest differences were in older children. This paper provides baseline functional data for future interventions in LFD. LEVEL OF EVIDENCE: Cross-sectional study.Implications for RehabilitationThis paper provides the first baseline functional data using validated objective measures on a consecutive cohort of children and adolescents with longitudinal fibular deficiency.Children with LFD performed significantly worse than their unaffected peers on all measures of physical performance other than jumping, with children falling further behind their peers as they age.Children who undergo an amputation typically have the most severe anatomical presentation and yet perform at an equivalent functional level.This paper identifies multiple modifiable impairments that represent potential opportunities for rehabilitation professionals to target with conservative treatment options to improve functional performance.


Asunto(s)
Ectromelia , Adolescente , Amputación Quirúrgica , Niño , Preescolar , Estudios Transversales , Ectromelia/cirugía , Peroné/anomalías , Peroné/cirugía , Humanos , Rendimiento Físico Funcional
6.
Neurosci Lett ; 744: 135593, 2021 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-33359734

RESUMEN

Plasma neurofilament light chain (pNfL) concentration is a biomarker for neuroaxonal injury and degeneration and can be used to monitor response to treatment. Spontaneous canine neurodegenerative diseases are a valuable comparative resource for understanding similar human conditions and as large animal treatment models. The features of pNfL concentration in healthy dogs is not well established. We present data reporting basic pNfL concentration trends in the Labrador Retriever breed. Fifty-five Labrador Retrievers were enrolled. pNfL concentration was measured and correlated to age, sex, neuter status, height, weight, body mass index, and coat color. We found increased pNfL with age (P < 0.0001), shorter stature (P = 0.009) and decreased body weight (P < 0.001). These are similar to findings reported in humans. pNfL concentration did not correlate with sex, BMI or coat color. This data further supports findings that pNfL increase with age in a canine population but highlights a need to consider weight and height when determining normal pNfL concentration in canine populations.


Asunto(s)
Envejecimiento/sangre , Envejecimiento/fisiología , Peso Corporal/fisiología , Proteínas de Neurofilamentos/sangre , Animales , Biomarcadores/sangre , Perros , Femenino , Humanos , Masculino , Plasma
7.
PeerJ ; 7: e7527, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31523503

RESUMEN

BACKGROUND: The degradation of nucleotides and their enzymes had been widely used to evaluate fish freshness. Immediately after fish death, adenosine triphosphate (ATP) degrades into inosine-5-monophosphate (IMP) via adenosine-5-diphosphate (ADP) and adenosine-5-monophosphate (AMP). IMP degradation continues to produce inosine (ino) and hypoxanthine (Hx) and further deteriorates the fish by producing xanthine and uric acid. The dephosphorylation of IMP to Ino is carried out by the enzyme 5'-nucleotidase (5'-NT), whereas the degradation of Ino to Hx is carried out by the enzyme nucleoside phosphorylase (NP). This study assesses the application of high pressure processing (HPP) in two species of fishes; haddock (Melanogrammus aeglefinus) and herring (Clupea harengus) as a means to extend the shelf-life by slowing down the rate of nucleotides degradation. METHODS: Haddock (Melanogrammus aeglefinus) and herring (Clupea harengus) fillets were subjected to HPP at 200, 250 and 300 MPa for 1 and 3 min before being stored for 14 days. In addition, 5'-NT and NP enzyme activities were determined on both fish species that were subjected to 100-600 MPa for 1 and 3 min. RESULTS: Adenosine triphosphate, ADP and AMP in both haddock and herring were lower at higher pressure levels. Inosine (Ino) increased (p < 0.05) after treatment at higher pressures in both species. Hx in herring decreased significantly (p < 0.05) at higher pressures but not in haddock. K values are the ratio of Ino and Hx to all nucleotides. K values in haddock were not significantly (p > 0.05) affected by the pressure treatment. H values are ratio of Hx to the sum of IMP, Ino and Hx. H values in haddock were significantly decreased (p < 0.05) with increasing pressure level. F values are ratio of IMP to the sum of IMP, Ino and Hx. F values showed no significant effects (p > 0.05) after pressure treatment. Furthermore, K values in control herring were significantly higher (p < 0.05) than those of the pressure-treated samples. H values in herring decreased significantly (p < 0.05) with increasing pressure level. F values in herring showed no significant effects (p > 0.05) after pressure treatment. Pressure treatment brought a significant decrease (p < 0.05) in protein content in both haddock and herring. 5'-NT activity was 20-35 fold higher compared to NP activity in haddock and 15-44 fold higher than NP activity in herring. 5'-NT and NP activities decreased significantly with increasing pressure level in both species. DISCUSSION: High pressure processing effectively slows down the conversion of Ino to Hx, delaying the undesirable flavour that develops in spoiling fish. The autolytic conversion of IMP to Ino by endogenous 5'-NT predominates in the earliest stages of storage is an autolytic process. However, both bacterial and endogenous NP enzymes are probably responsible for the gradual accumulation of Hx in fish. K values are recommended as a useful measurement of fish freshness.

8.
Can Med Educ J ; 10(3): e101-e106, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31388383

RESUMEN

BACKGROUND: There have been calls for the development of leadership attributes in healthcare practitioners through leadership development programs. However, understanding how leadership is conceptualized is needed to assure effective participant-centred leadership development programs. The purpose of this study was to elucidate how the construct of leadership is conceptualized by multiple stakeholder groups associated with medical school leadership programs. METHODS: We conducted a total of 77 semi-structured interviews with six major demographic groups: Trainees (n = 16), Mid-Level University Leaders (n = 10), Clinician Leaders (n = 17), Senior University Leaders (n = 10), Medical Scientists (n = 12), and Senior Leaders, external to the University (n = 12) to address the research question. RESULTS: Content analyses revealed that the leaders were expected to create a compelling vision and a foster a motivating culture within the organization. Integrity and a sense of passion about leading were viewed as being principal characteristics of a leader. The twin skills of technical competence and communication were endorsed as most important for a leader. Finally, leaders are expected to be accountable for outcomes. CONCLUSION: Medical school leadership training programs should strive to incorporate these characteristics, given their broad appeal to diverse interest groups.

9.
Arch Dis Child ; 103(7): 675-682, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29455160

RESUMEN

BACKGROUND: Congenital lymphoedema is a lifelong condition that has detrimental physical and psychosocial outcomes for young patients and burdensome treatment responsibilities that may hamper patients' motivation for self-management. There is limited research from the perspective of young people with primary lymphoedema. We aimed to describe the experiences and views of children and adolescents with lymphoedema to inform patient-centred practice. METHODS: Twenty patients (aged 8-21 years) with primary lymphoedema were purposively sampled from two paediatric clinics in Sydney, Australia, to participate in a semistructured interview. The transcripts were analysed thematically. RESULTS: We identified six themes: reinforcing abnormality (damaging self-esteem, self-consciousness, frustrating restrictions and isolation); negotiating uncertainties (fearing condition worsening, deprioritised and sidelined, questioning cause and permanence, widespread unawareness); vulnerability and caution (avoiding pain and discomfort, preventing severe and permanent consequences, depending on permission, limiting goals and aspirations); disruptive transition (resisting change, losing progress and support, avoiding treatment costs); developing resilience (focusing on the positives, embracing individuality, recalibrating normality, prioritising coping) and taking responsibility (individualising treatment, needing support, external pressure and motivation, sticking to a routine, seeking independence). CONCLUSION: Children and adolescents learn to adjust to the daily demands of lymphoedema management by individualising and accepting their treatment, but many continue to struggle with their self-esteem and lifestyle restrictions. Strategies are needed to empower young patients to advocate for themselves during their transition to adult care. Treatment plans that minimise social restrictions, address emotional consequences and incorporate patients' preferences could improve adherence, satisfaction and outcomes.


Asunto(s)
Actitud Frente a la Salud , Linfedema/psicología , Actividades Cotidianas , Adaptación Psicológica , Adolescente , Niño , Progresión de la Enfermedad , Miedo , Femenino , Humanos , Relaciones Interpersonales , Entrevistas como Asunto , Masculino , Autoimagen , Adulto Joven
10.
Leadersh Health Serv (Bradf Engl) ; 30(1): 16-28, 2017 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-28128041

RESUMEN

Purpose This study sought to identify the barriers and enablers to leadership enactment in academic health-care settings. Design/methodology/approach Semi-structured interviews ( n = 77) with programme stakeholders (medical school trainees, university leaders, clinical leaders, medical scientists and directors external to the medical school) were conducted, and the responses content-analysed. Findings Both contextual and individual factors were identified as playing a role in affecting academic health leadership enactment that has an impact on programme development, success and maintenance. Contextual factors included sufficient resources allocated to the programme, opportunities for learners to practise leadership skills, a competent team around the leader once that person is in place, clear expectations for the leader and a culture that fosters open communication. Contextual barriers included highly bureaucratic structures, fear-of-failure and non-trusting cultures and inappropriate performance systems. Programmes were advised to select participants based on self-awareness, strong communication skills and an innovative thinking style. Filling specific knowledge and skill gaps, particularly for those not trained in medical school, was viewed as essential. Ineffective decision-making styles and tendencies to get involved in day-to-day activities were barriers to the development of academic health leaders. Originality/value Programmes designed to develop academic health-care leaders will be most effective if they develop leadership at all levels; ensure that the organisation's culture, structure and processes reinforce positive leadership practices; and recognise the critical role of teams in supporting its leaders.


Asunto(s)
Centros Médicos Académicos , Liderazgo , Comunicación , Humanos , Entrevistas como Asunto , Cultura Organizacional , Competencia Profesional
11.
Public Health Rep ; 131 Suppl 2: 5-11, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27168655

RESUMEN

OBJECTIVE: In 2012, CDC's Division of Viral Hepatitis launched a public health initiative to increase hepatitis B virus (HBV) and hepatitis C virus (HCV) infection testing for those at risk and to improve linkage to medical care for those infected. We describe testing outcomes of previously unidentified people at risk for HBV and HCV infection and the lessons learned while linking patients to care. METHODS: CDC's Hepatitis Testing and Linkage to Care (HepTLC) initiative provided 34 financial awards to U.S. organizations that serve people at risk for viral hepatitis, 25 of which focused on HCV and nine of which focused on HBV. Grantees offered testing and test result notification to people at risk for HBV and/or HCV infection, as well as counseling, referral, and verification or notification of linkage to care for people with positive test results. We entered demographic data, self-reported risk factors, country of origin (for HBV), and testing outcomes into a confidential database. RESULTS: The 34 grantees tested 87,860 people at more than 260 sites in 17 states. Of the 23,144 people tested for HBV, 1,317 (6%) were positive. Of the 64,716 people tested for HCV, 57,570 (89%) received an HCV antibody (anti-HCV) test, of whom 7,580 (13%) tested anti-HCV positive. Of the 4,765 people who received an HCV RNA test, 3,449 (72%) tested positive. Of the 4,766 people who tested positive for either HBV or HCV infection, 2,116 (44%) were linked to care. CONCLUSION: Interventions targeting people at risk for HBV and HCV infection reached a substantial number of people for whom testing is recommended and identified a large proportion of those who had previously unrecognized infection. Patient navigation was critical for follow-up and linkage to care.


Asunto(s)
Accesibilidad a los Servicios de Salud , Hepacivirus/aislamiento & purificación , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B Crónica/diagnóstico , Hepatitis C Crónica/diagnóstico , Adulto , Centers for Disease Control and Prevention, U.S. , Diagnóstico Precoz , Femenino , Anticuerpos contra la Hepatitis B/sangre , Anticuerpos contra la Hepatitis C/sangre , Humanos , Masculino , Prevalencia , Evaluación de Programas y Proyectos de Salud , Estados Unidos
12.
Food Chem ; 190: 622-628, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26213019

RESUMEN

This study evaluated the effect of an industrial scale continuous flow microwave volumetric heating system in comparison to conventional commercial scale pasteurisation for the processing of tomato juice in terms of physicochemical properties, microbial characteristics and antioxidant capacity. The effect against oxidative stress in Caco-2 cells, after in vitro digestion was also investigated. Physicochemical and colour characteristics of juices were very similar between technologies and during storage. Both conventional and microwave pasteurisation inactivated microorganisms and kept them in low levels throughout storage. ABTS[Symbol: see text](+) values, but not ORAC, were higher for the microwave pasteurised juice at day 0 however no significant differences between juices were observed during storage. Juice processed with the microwave system showed an increased cytoprotective effect against H2O2 induced oxidation in Caco-2 cells. Organoleptic analysis revealed that the two tomato juices were very similar. The continuous microwave volumetric heating system appears to be a viable alternative to conventional pasteurisation.


Asunto(s)
Bebidas/análisis , Solanum lycopersicum/química , Antioxidantes/análisis , Calor , Microondas
13.
Dysphagia ; 29(6): 663-70, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25115856

RESUMEN

We sought to evaluate the swallowing function of 18 patients surviving nasopharyngeal cancer, who had been treated using an intensity-modulated radiotherapy (IMRT) protocol designed to minimise functional impairment. We compared the outcomes of a patient-reported oral function score with fiberoptic endoscopic examination of swallow (FEES), Australian Therapy Outcome Measures (AusTOMs) and a measure of trismus. While all patients returned to a fully oral diet, there was ongoing swallow dysfunction characterised by bolus residue and delay, but no aspiration. Dysphagia was of mild or moderate severity on all measures, generally because of the need for texture modification, impaired bolus transit or dysgeusia. There was xerostomia on self-reported measurement combined with reports of behaviours adaptive to xerostomia on AusTOMs; however, salivary functioning was less impaired on FEES. There was no trismus in this cohort. Our cohort lacked the morbidity experienced by cohorts reported in earlier studies, potentially due to the use of IMRT.


Asunto(s)
Deglución/efectos de la radiación , Neoplasias Nasofaríngeas/radioterapia , Radioterapia de Intensidad Modulada/efectos adversos , Adulto , Deglución/fisiología , Trastornos de Deglución/etiología , Trastornos de Deglución/fisiopatología , Femenino , Humanos , Laringe/fisiopatología , Laringe/efectos de la radiación , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/fisiopatología , Faringe/fisiopatología , Faringe/efectos de la radiación , Calidad de Vida , Radioterapia de Intensidad Modulada/métodos , Resultado del Tratamiento , Trismo/etiología , Trismo/fisiopatología
14.
Food Microbiol ; 30(1): 205-12, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22265302

RESUMEN

The microbial quality of untreated and pressure-treated carrot juice was compared during storage at 4, 8 and 12 °C. High pressure treatment at 500 MPa and 600 MPa (1 min/20 °C) reduced the total counts by approximately 4 log CFU ml⁻¹ and there was very little growth of the survivors during storage at 4 °C for up to 22 days. Total counts increased during storage of pressure-treated juice at 8 °C and 12 °C but took significantly longer to reach maximum levels compared to the untreated juice. The microflora in the untreated juice consisted predominantly of Gram-negative bacteria, identified as mostly Pantoea spp., Erwinia spp. and Pseudomonas spp. Initially the pressure-treated juice contained low numbers of spore-forming bacteria (Bacillus spp. and Paenibacillus spp.) and Gram-positive cocci; the spore-formers continued to dominate during storage. When irradiation-sterilised juice was inoculated with a cocktail of Listeria monocytogenes, numbers decreased during storage at 4 °C and 8 °C by 1.50 and 0.56 log CFU ml⁻¹ respectively. When the inoculated carrot juice was pressure treated (500 MPa/1 min/20 °C) no L. monocytogenes were found immediately after pressure treatment or during storage at 4, 8 and 12 °C (>6 log inactivation). In contrast, pressure treatment in TSBYE only resulted in 1.65 log inactivation and survivors grew rapidly. This suggests that the antilisterial effect of carrot juice is enhanced by HPP.


Asunto(s)
Bebidas/microbiología , Daucus carota/microbiología , Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Listeria monocytogenes/aislamiento & purificación , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Manipulación de Alimentos/métodos , Conservación de Alimentos/métodos , Presión Hidrostática , Listeria monocytogenes/crecimiento & desarrollo , Presión , Refrigeración
15.
Food Microbiol ; 28(8): 1426-31, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21925024

RESUMEN

The objective of this study was to assess the effect of High Pressure Homogenisation (HPH) compared with High Hydrostatic Pressure (HHP) on the microbiological quality of raw apple juice during storage at ideal (4 °C) and abuse (12 °C) temperatures. In the case of HPH, only low numbers of micro-organisms were detected after treatment at 300 MPa (typically between 2 and 3 log.ml⁻¹). These were identified as Streptomyces spp., and numbers did not increase during storage of the juice for 35 days, irrespective of storage temperature. In the case of HHP, the total aerobic counts were also reduced significantly (p < 0.05) after treatment for 1 min at 500 and 600 MPa and the numbers did not increase significantly during storage at 4 °C. However, during storage at 12 °C the counts did increase significantly (p < 0.05) and by day 14 counts at 500 MPa were not significantly different from the control juice. This confirms that good temperature control is important if the full benefits of HHP treatment are to be realised. Frateuria aurantia dominated the microbiota of the HHP apple juice stored at 12 °C along with low levels of Bacillus and Streptomyces spp. The HPH and HHP juices both turned brown during storage indicating that neither treatment was sufficient to inactivate polyphenol oxidase. The enzyme is known to be pressure resistant and this discolouration was controlled by a heat treatment (70 °C for 1 min) used in commercial practice and given prior to HP treatment.


Asunto(s)
Bebidas/microbiología , Malus/química , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bebidas/análisis , Manipulación de Alimentos , Presión Hidrostática , Malus/microbiología , Metagenoma
16.
Proc Natl Acad Sci U S A ; 107(17): 7835-40, 2010 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-20404182

RESUMEN

Microbial cells, and ultimately the Earth's biosphere, function within a narrow range of physicochemical conditions. For the majority of ecosystems, productivity is cold-limited, and it is microbes that represent the failure point. This study was carried out to determine if naturally occurring solutes can extend the temperature windows for activity of microorganisms. We found that substances known to disorder cellular macromolecules (chaotropes) did expand microbial growth windows, fungi preferentially accumulated chaotropic metabolites at low temperature, and chemical activities of solutes determined microbial survival at extremes of temperature as well as pressure. This information can enhance the precision of models used to predict if extraterrestrial and other hostile environments are able to support life; furthermore, chaotropes may be used to extend the growth windows for key microbes, such as saprotrophs, in cold ecosystems and man-made biomes.


Asunto(s)
Adaptación Biológica/fisiología , Ecosistema , Hongos/crecimiento & desarrollo , Modelos Biológicos , Temperatura , Crioprotectores/metabolismo , Crioprotectores/farmacología , Hongos/efectos de los fármacos , Glucosa/metabolismo , Glucosa/farmacología , Glicerol/metabolismo , Glicerol/farmacología , Presión , Sacarosa/metabolismo , Sacarosa/farmacología
17.
Food Microbiol ; 27(2): 266-73, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20141945

RESUMEN

Vacuum-packaged cooked poultry meat was treated at a range of pressures (400-600 MPa) and hold times (1, 2 and 10 min), followed by storage at 4 degrees , 8 degrees or 12 degrees C for up to 35 days. Weissella viridescens was found to be the dominant microorganism in the pressure-treated meat, constituting 100% of the microflora identified at 500 and 600 MPa. None of the pressure-treated samples had obvious signs of spoilage during the 35 day storage period, even when the Weissella count was >7 log(10) cfu/g. Studies on a typical W. viridescens isolate showed it to be relatively pressure-resistant in poultry meat, with <1 log reduction in numbers after a treatment of 2 min at 600 MPa. Agar diffusion assays showed that the isolate also caused the inhibition of a number of Gram-positive and Gram-negative pathogens, including strains of Clostridium botulinum, Listeria monocytogenes, Bacillus cereus and Escherichia coli. The selection of a pressure-resistant organism, such as this Weissella sp. could be advantageous in extending the shelf-life, and also microbiological safety, of the cooked meat, as it could give protection in addition to the pressure treatment itself.


Asunto(s)
Microbiología de Alimentos , Conservación de Alimentos/métodos , Carne/microbiología , Refrigeración/métodos , Animales , Bacterias/clasificación , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Pollos , Culinaria , Manipulación de Alimentos/métodos , Leuconostocaceae/crecimiento & desarrollo , Leuconostocaceae/aislamiento & purificación , Interacciones Microbianas , Presión
18.
Learn Disabil Res Pract ; 29(3): 133-144, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-22140297

RESUMEN

Contrasting adult literacy learners with and without specific learning disabilities This study of 311 adult education (AE) learners found 29% self-reported having a specific learning disability (SLD). Significant differences in demographic, academic, and life experience variables between the adult learners with and without SLD included: prior participation in special education, having both an SLD diagnosis and a high school diploma, low reading scores, middle age, and negative perceptions about limitations due to reading abilities. A post-hoc regression analysis found SLD status significantly contributes to variance in reading level when controlling for age and IQ. From these findings we conclude that SLD status should be considered an educationally relevant variable in adult education that warrants a diagnostic or clinical teaching approach.

19.
Adult Basic Educ Lit J ; 1(2): 83-92, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22348153

RESUMEN

This study identifies adult education program characteristics that predict improved learner outcomes through statistical analyses of data across four years in a single state. Data indicate that, collectively, several predictors contribute to our understanding of learner outcomes, including (a) learner entry level, (b) size of community, (c) staff qualifications, and (d) learner exposure to high quality services. A surprising finding was the lack of robust outcome predictors that maintain consistency from one year to another.

20.
Read Writ ; 42(2): 188-213, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23526865

RESUMEN

Readers' individual literacy practices involve a variety of materials such as books, newspapers, magazines, technical materials and work documents. This study explored the relationship between readership (reading as a form of communication, an advancement of culture, and the development of the individual) and readers' choice of materials for participants in adult education, whose skills varied from very low literacy to high school/General Education Development (GED) levels. In this study we reviewed adult education participants' pattern of reading materials and the frequency of usage among participants. A representative sample of 273 adult education participants was recruited from 12 Kansas adult education programs. Their literacy practices were evaluated in terms of age, education level, and reading skill levels. Our results pointed to differences based on age but not educational completion level. The implications are discussed in terms of matching curricular materials used in instruction to salient learner characteristics. Recommendations for literacy instructors are provided that could enhance the learners' persistence and success.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...