Search PubMed⌕ Search

Biomedical subjects

T P Beresford

Publications and source records attributed to T P Beresford.

At least 19 recordsLinked to original sources
PubMed2007

Lipolysis in cheddar cheese made from raw, thermized, and pasteurized milks.

The evolution of free fatty acids (FFA) was monitored over 168 d of ripening in Cheddar cheeses manufactured from good quality raw milk (RM), thermized milk (TM; 65 degrees C x 15 s), and pasteurized milk (PM; 72 degrees C x 15 s). Heat treatment of the milk reduced the level and diversity of raw milk microflora and extensively or wholly inactivated lipoprotein lipase (LPL) activity. Indigenous milk enzymes or proteases from RM microflora influenced secondary proteolysis in TM and RM cheeses. Differences in FFA in the RM, TM, and PM influenced the levels of FFA in the subsequent cheeses at 1 d, despite significant losses of FFA to the whey during manufacture. Starter esterases appear to be the main contributors of lipolysis in all cheeses, with LPL contributing during production and ripening in RM and, to a lesser extent, in TM cheeses. Indigenous milk microflora and nonstarter lactic acid bacteria appear to have a minor contribution to lipolysis particularly in PM cheeses. Lipolytic activity of starter esterases, LPL, and indigenous raw milk microflora appeared to be limited by substrate accessibility or environmental conditions over ripening.

Animals↗
PubMed2006

Production of ingredient-type cheddar cheese with accelerated flavor development by addition of enzyme-modified cheese powder.

Fast-ripened Cheddar cheeses for ingredient purposes were produced by addition of a dried enzyme-modified cheese (EMC; 0.25 and 1 g/100 g of milled curd) at the salting stage during a standard Cheddar cheese-making procedure. Populations of starter and nonstarter lactic acid bacteria (NSLAB), levels of proteolysis and lipolysis, volatile analysis, and flavor development (by quantitative descriptive sensory analysis) were monitored over a 6-mo ripening period. Levels of free AA and free fatty acids were elevated in the experimental cheeses on d 1 because of inclusion of the EMC. Counts of NSLAB were also elevated in the experimental cheeses compared with the control cheese from the start of ripening. Levels of free AA were slightly elevated in the experimental cheeses at 1, 2, and 4 mo, but significantly greater accumulations were detected by 6 mo of ripening, with His, Leu, and glutamate reflecting the greatest increases. Levels of long-chain free fatty acids increased up to 2 mo, indicating an initial stimulation of lipolysis, but had decreased by 6 mo, indicating greater catabolism, probably caused by NSLAB and increased starter lysis. Principal component analysis of the volatile compounds showed few differences in the aroma profiles among the cheeses up to 4 mo of ripening, but a large separation of the cheeses supplemented with EMC relative to the control was observed by 6 mo. Sensory analysis of the cheeses with added EMC showed an acceleration of 2 mo in flavor development compared with the control cheese with the addition of 1 g/100 g of EMC developing a flavor profile at 4 mo similar to the control cheese at 6 mo of ripening. However, atypical Cheddar flavors developed on prolonged storage. This study shows the potential of adding EMC during Cheddar production to produce a fast-ripened ingredient-type Cheddar cheese.

Amino Acids↗
PubMed2005

Genetic diversity in the lactose operons of Lactobacillus helveticus strains and its relationship to the role of these strains as commercial starter cultures.

Two novel insertion sequence elements, ISLhe1 and ISLhe15, were located upstream of the genes encoding the beta-galactosidase enzyme in Lactobacillus helveticus commercial starter strains. Strains with the IS982 family element, ISLhe1, demonstrated reduced beta-galactosidase activity compared to the L. helveticus type strain, whereas strains with the ISLhe15 element expressed beta-galactosidase in the absence of lactose.

Base Sequence↗
PubMed2001

Neuropsychiatric complications of liver and other solid organ transplantation.

1. Mental status changes are often the earliest indication of an untoward complication after transplantation. These may be obvious, such as hallucinations or paranoid delusions, or they may be subtle, appearing as changes in personality or motivation. 2. The three most common categories of neuropsychiatric posttransplant complications include the following: (1) concurrent pathological processes, such as mass lesion; (2) effects of vasoconstriction secondary to immunosuppressive medications; and (3) central nervous system pharmacodynamic effects of the immunosuppressive medications. 3. This differential diagnosis should guide the history as well as the mental status and neurological examinations. Suspected acute processes deserve computed tomography scanning. Magnetic resonance imaging, more sensitive to subtle structural change, should be generally reserved for cases suggesting such chronic change or those in which treatment appears ineffective. 4. Treatment follows the differential diagnosis. Concurrent diagnoses dictate specific treatment, such as in drainage of a subdural hematoma or administration of antibiotics for cerebral abscess. Symptoms referable to vasoconstriction suggest switching the primary immunosuppressive agent. Symptoms suggesting delirium indicate lowering the dosage of immunosuppressive medication, as in the case of generalized seizure, or use of very low-dose antipsychotic medication, as in cases of confusion, amotivational states, or personality changes.

Animals↗
PubMed2001

Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov., isolated from the surface of a smear-ripened cheese.

Ten isolates each of two different bacterial species isolated from the surface of a smear-ripened cheese were found to exhibit many characteristics of the genus Corynebacterium. The isolates were Gram-positive, catalase-positive, non-spore-forming rods that did not undergo a rod/coccus transformation when grown on complex media. Chemotaxonomic investigation revealed that the strains belonged unambiguously to the genus Corynebacterium. Their cell walls contained arabinose, galactose and short-chain mycolic acids (C22 to C36) and their peptidoglycan contained meso-diaminopimelic acid. The G+C content of the DNA was 51-60 mol%. MK-9 (H2) was the principal menaquinone. The 16S rDNA sequences of four isolates of each bacterium were determined and aligned with those of other members of the coryneform group. Phylogenetic analysis showed that the strains represented two new sublines within the genus Corynebacterium; Corynebacterium variabile and Corynebacterium ammoniagenes were their nearest known phylogenetic neighbours. Corynebacterium variabile and Corynebacterium ammoniagenes showed the highest levels of sequence homology with the isolates; however, DNA-DNA hydridization studies indicated that the Corynebacterium strains isolated from the cheese smear did not belong to either Corynebacterium variabile or Corynebacterium ammoniagenes (26 and 46% chromosomal similarity, respectively). On the basis of the phylogenetic and phenotypic distinctiveness of the unknown isolates, it is proposed that the bacteria be classified as two new Corynebacterium species, for which the names Corynebacterium mooreparkense sp. nov. and Corynebacterium casei sp. nov. are proposed. Type strains have been deposited in culture collections as Corynebacterium mooreparkense LMG S-19265T (= NCIMB 30131T) and Corynebacterium casei LMG S-19264T (= NCIMB 30130T).

Biomass↗
PubMed2001

Microbacterium gubbeenense sp. nov., from the surface of a smear-ripened cheese.

Phenotypic and phylogenetic studies were performed on 11 strains of a Microbacterium-like organism isolated from the surface of a smear-ripened cheese. The isolates were Gram-positive, catalase-positive, facultatively anaerobic, oxidase-negative, non-spore-forming, non-motile, small, slender rods and grew in 12% (w/v) NaCl. Chemotaxonomic investigation revealed that all the isolates belonged unambiguously to the genus Microbacterium. They contained type B1 peptidoglycans with L-lysine as the diamino acid and glycolyl acyl types; rhamnose and galactose were the cell wall sugars. The G+C content ranged from 69 to 72 mol%. The major menaquinones were MK-11 and MK-12 and the major fatty acids were anteiso C15:0 and C17:0 and iso C16:0. Phylogenetic analysis of the 16S rRNA sequences of four isolates showed that they represented a new subline in the genus Microbacterium, with Microbacterium barkeri as their nearest phylogenetic neighbour. M. barkeri showed the highest sequence similarity to the isolates; however, DNA-DNA hybridization showed that the isolates had only 38% chromosomal similarity to M. barkeri. Based on the phylogenetic and phenotypic distinctiveness of the isolates, it is proposed that they be classified as a new Microbacterium species, for which the name Microbacterium gubbeenense sp. nov. is suggested. The type strain has been deposited as LMG S-19263T (= NCIMB 30129T). The GenBank accession number for the 16S rDNA sequence of the type strain is AF263563.

Actinomycetales↗
PubMed2001

The CRABEL score--a method for auditing medical records.

Medical record keeping has become increasingly important particularly for research, audit and medico-legal purposes. The authors present a protocol, the CRABEL score, that is quick and easy to use for the assessment of the quality of medical record keeping with the purpose of standardizing the audit of medical records and improving their quality.

Clinical Protocols↗
PubMed2000

A rapid PCR based method to distinguish between Lactococcus and Enterococcus.

Phenotypic characterisation of Lactococcus and Enterococcus species remains unreliable as strains of both genera have been isolated which do not conform to the traditional criteria for separation of these genera. A bank of 131 isolates was phenotypically characterised by three methods: (a) traditional broth tests, (b) API Rapid ID 32 Strep and (c) BBL Crystal ID kits. Differences in genus designation between commercial kits were evident for 12 strains (9%), while 7 strains (5%) remained unidentified by either kit. Published 16S rRNA sequences were aligned and used to design genus-specific primers which, when used in separate PCR reactions, were capable of distinguishing all type strains of Lactococcus and Enterococcus. These primers did not react with known species of Streptococcus, Pediococcus, Lactobacillus, Leuconostoc or Tetragenococcus. Isolates which could not be identified by phenotype were assigned to either genus on the basis of the gene primers.

DNA Primers↗
PubMed2000

Use of hydrostatic pressure for inactivation of microbial contaminants in cheese.

The objective of this study was to determine the effect of high pressure (HP) on the inactivation of microbial contaminants in Cheddar cheese (Escherichia coli K-12, Staphylococcus aureus ATCC 6538, and Penicillium roqueforti IMI 297987). Initially, cheese slurries inoculated with E. coli, S. aureus, and P. roqueforti were used as a convenient means to define the effects of a range of pressures and temperatures on the viability of these microorganisms. Cheese slurries were subjected to pressures of 50 to 800 MPa for 20 min at temperatures of 10, 20, and 30 degrees C. At 400 MPa, the viability of P. roqueforti in cheese slurry decreased by >2-log-unit cycles at 10 degrees C and by 6-log-unit cycles at temperatures of 20 and 30 degrees C. S. aureus and E. coli were not detected after HP treatments in cheese slurry of >600 MPa at 20 degrees C and >400 MPa at 30 degrees C, respectively. In addition to cell death, the presence of sublethally injured cells in HP-treated slurries was demonstrated by differential plating using nonselective agar incorporating salt or glucose. Kinetic experiments of HP inactivation demonstrated that increasing the pressure from 300 to 400 MPa resulted in a higher degree of inactivation than increasing the pressurization time from 0 to 60 min, indicating a greater antimicrobial impact of pressure. Selected conditions were subsequently tested on Cheddar cheese by adding the isolates to cheese milk and pressure treating the resultant cheeses at 100 to 500 MPa for 20 min at 20 degrees C. The relative sensitivities of the isolates to HP in Cheddar cheese were similar to those observed in the cheese slurry, i.e., P. roqueforti was more sensitive than E. coli, which was more sensitive than S. aureus. The organisms were more sensitive to pressure in cheese than slurry, especially with E. coli. On comparison of the sensitivities of the microorganisms in a pH 5.3 phosphate buffer, cheese slurry, and Cheddar cheese, greatest sensitivity to HP was shown in the pH 5.3 phosphate buffer by S. aureus and P. roqueforti while greatest sensitivity to HP by E. coli was exhibited in Cheddar cheese. Therefore, the medium in which the microorganisms are treated is an important determinant of the level of inactivation observed.

Cheese↗
PubMed2000

Methylphenidate treatment of neuropsychiatric symptoms of central and extrapontine myelinolysis.

OBJECTIVE: Previous reports describe the presentation and course of the neurobehavioral manifestations of central and extrapontine myelinolysis; as of yet, however, there are no specific recommendations for treatment of these problems. We offer the first report of successful treatment. METHOD: We describe a 55-year-old man with chronic alcoholism who developed central and extrapontine myelinolysis following an episode of heavy drinking and rapid correction of hyponatremia. The patient acutely developed motor, cognitive, emotional and behavioral problems best accounted for by central pontine and bilateral striatal myelinolysis. These neuropsychiatric symptoms were treated with methylphenidate over the course of 1 month in an off-on-off-on fashion. The Neuropsychiatric Inventory and other tests were used to assess treatment response. RESULTS: Marked improvements in the patient's neuropsychiatric status were noted only during treatment with methylphenidate. CONCLUSIONS: Methylphenidate effectively reversed the neuropsychiatric symptoms associated with the patient's demyelinating lesions. We discuss possible underlying mechanisms of both symptom formation and treatment effect.

Alcoholism↗
PubMed1999

The influences of age and gender on blood ethanol concentrations in healthy humans.

OBJECTIVE: Previous cross-section studies suggested that blood ethanol concentrations (BAC) increase with age. To establish this, and to account for putative gender differences, we studied four cohorts of nonalcoholic subjects. METHOD: Fifty-seven subjects were studied: 14 men and 14 women in the young (21-40 years) and 14 men and 15 women in the old (> or = 60 years) groups. All subjects received ethanol (0.3 g/kg) on three occasions: orally (PO) after an overnight fast; PO after a standard meal; and by intravenous (IV) infusion after a standard meal. RESULTS: In all four cohorts, PO ethanol in the fasted state produced the greatest average areas under the curve (AUC) for ethanol, followed by IV ethanol and PO ethanol, both in the fed state. Pooled by age, blood ethanol AUCs were significantly greater in old subjects given PO ethanol when fasted (p = .001) and IV ethanol when fed (p < .004) but not after PO ethanol in the fed state. Pooled by gender, blood ethanol AUCs did not separate men and women in any of the experiments. Corrected for relative volumes of distribution (Vdist) among the four cohorts, only elderly women evidenced AUC values that could not be explained by Vdist alone and only in the fasted state. Both elderly men and women in the fasted state showed higher average peak ethanol levels than gender-matched younger cohorts; this effect was most pronounced in elderly women (47% vs 12%). CONCLUSIONS: The data confirm the influence of age, but fail to confirm that of gender, on blood ethanol response after a moderate dose of ethanol. They also show that feeding state can negate differences due to Vdist alone. In the fasted state, Vdist alone explains AUC and peak increases in elderly men but not in elderly women. Neither gastric metabolism nor motility account for age/BAC differences since these were independent of route. These data suggest caution for elderly drinkers or for those prescribing alcoholic beverages to elderly persons as well as for studies of ethanol ingestion that do not account for age and for feeding state.

Administration, Oral↗
PubMed1998

Screening for alcoholism among medical inpatients: how important is corroboration of patient self-report?

Little is known about the utility of collateral reports in substantiating self-report for individuals assessed in nonalcoholism treatment contexts. This study examined the concordance of 581 pairs of medical patient and collateral responses to a commonly used alcohol screening instrument, the CAGE Questions, as well as to reports of the patient's drinking consequences and alcohol consumption. Results demonstrated that patient/collateral concordance was marginal, but acceptable, on CAGE cut-off scores and, that similar to reports from alcoholism treatment settings, patients generally reported more drinking consequences than collaterals. Patient and collateral reports of the patient's alcohol consumption did not differ significantly. This pattern of patient and collateral reporting of alcohol consequences and consumption was found for both men and women, as well as for patients with a DSM-III-R diagnosis of alcohol dependence. The findings support the validity of patient self-report on alcoholism screening measures in medical settings. Furthermore, results demonstrated that the addition of collateral reports to information directly obtained from patients only modestly improved the identification of alcohol dependence. The overall findings indicate that alcohol screening can be done effectively and efficiently in medical settings.

Adolescent↗
PubMed1997

Alcohol use after liver transplantation in alcoholics: a clinical cohort follow-up study.

The purposes of this study were to determine among a cohort of long-term alcoholic survivors after liver transplantation (1) the incidence of alcohol use, (2) its effect on allograft integrity and extrahepatic health, and (3) the validity of the pretransplant alcohol prognosis screening process. Retrospective clinical cohort study of all alcoholic patients undergoing orthotopic liver transplantation at a single center from February 1987 until January 1991 with follow-up through December 1994, giving a median duration of follow-up of 63 months (range, 6-89 months). Multidisciplinary liver transplantation program at a tertiary-care academic medical center. Fifty alcoholic, long-term liver transplant recipients. The frequency of alcohol relapse, defined as any alcohol use in the period after transplantation, was determined by two questionnaire studies and by clinical follow-up. Allograft integrity was assessed by coded review of serial percutaneous allograft biopsies. Potential systemic effects of alcohol relapse were assessed by chart review. The alcohol prognosis screening process was evaluated by retrospectively comparing pretransplant estimates of putative indicators of alcoholism prognosis in posttransplant alcohol users and abstainers. Thirty-three recipients (66%) consistently denied any alcohol use throughout the duration of posttransplant follow-up, whereas 17 (34%) were identified as having consumed alcohol at least once since the transplant. There were no significant differences at the time of evaluation between abstainers and alcohol users in age, sex distribution, severity of liver dysfunction, median duration of abstinence, or University of Michigan alcoholism prognosis score. The median interval from transplantation to alcohol relapse was 17 months, with a range of 3 to 45 months. Recurrent alcohol use was associated with significant medical complications sufficient to require admission to the hospital in 6 patients. One patient died of graft dysfunction, noncompliance with immunosuppressant medications, and presumed graft rejection while drinking. Mild or progressive hepatitis, which was the most common abnormality in posttransplant liver biopsy findings, was equally distributed between both alcohol users and abstainers and sometimes occurred in the absence of antibody to hepatitis C virus antibodies. There was a similar frequency of biopsy-proven acute cellular rejection in alcohol users and abstainers. Typical histological features of alcoholic liver injury were present in posttransplant biopsies from 1 alcohol user only. Alcohol use by alcoholics is uncommon in the first 5 years after liver transplantation, and alcohol-associated liver injury is unusual. Mild nonspecific hepatitis is common in both alcohol users and nonusers alike. Among a small subset of alcoholic transplant recipients, drinking behavior after liver transplantation is associated with considerable morbidity, requiring hospital admissions and occasionally leading to graft loss and death.

Alcohol Drinking↗