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Biomedical subjects

M Gay

Publications and source records attributed to M Gay.

At least 19 recordsLinked to original sources
PubMed2003

Impact of preheating on the behavior of Listeria monocytogenes in a broth that mimics Camembert cheese composition.

The effect of preheating on the survival of L. monocytogenes in Richard's broth, which mimics the composition of Camembert cheese composition, was examined. Experiments were carried out to reproduce contamination of cheese with environmental heat-stressed cells of L. monocytogenes surviving hot-cleaning procedures. Cells in mid-log phase were heated for 30 min at 56 degrees C before being inoculated into Richard's broth. The pHs and temperatures of Richard's broth were chosen to recreate the conditions of curd dripping (pH 5, 25 degrees C), of the beginning of cheese ripening (pH 5, 12 degrees C), and of the beginning (pH 5, 4 degrees C) and the end (pH 7, 4 degrees C) of cheese storage. Immediately after heat treatment, the viability loss was especially high for strain 306715, which exhibited only 0.6% +/- 0.2% survival, compared with 22% +/- 8.7% for strain EGD. The percentages of the surviving heated cells that were injured were 93% +/- 8% for strain 306715 and 98% +/- 3% for strain EGD. The destruction of the surviving L. monocytogenes cells was accelerated when they encountered the pH and temperature conditions of Camembert cheese during manufacturing, ripening, and cold storage (pH 5 at 25, 12, and 4 degrees C, respectively). The multiplication of the surviving heated cells was retarded under favorable growth conditions similar to those of storage by the distributor and the consumer (pH 7 at 4 and 12 degrees C, respectively).

Cheese↗
PubMed2002

Multicenter study of street foods in 13 towns on four continents by the food and environmental hygiene study group of the international network of pasteur and associated institutes.

An international multicenter study of ready-to-eat foods, sandwiches, and ice creams or sorbets sold in the streets and their vendors was carried out to assess the microbiological quality of these foods and to identify characteristics of the vendors possibly associated with pathogens. Thirteen towns in Africa, America, Asia, and Oceania were involved in the study. A single protocol was used in all 13 centers: representative sampling was by random selection of vendors and a sample of foods bought from each of these vendors at a time and date selected at random. Microbiological analyses were carried out using standardized Association Française de Normalisation methods, and the use of a standardized questionnaire to collect data concerning the characteristics of the vendors. Fifteen surveys were carried out, with 3,003 food samples from 1,268 vendors. The proportion of unsatisfactory food samples was between 12.7 and 82.9% for ice creams and sorbets and between 11.3 and 92% for sandwiches. For ice creams and sorbets, the sale of a large number of units (>80 per day) increased the risk of unsatisfactory food by a factor of 2.8 (95% confidence interval [CI]: 1.5 to 5.1), lack of training in food hygiene by 6.6 (95% CI: 1.1 to 50). and by a factor of 2.8 (95% CI: 1.4 to 5.4) for mobile vendors. These risk factors were not identified for sandwiches, this difference may be due to the presence of a cooking step in their preparation. These results show that the poor microbiological quality of these street foods constitutes a potential hazard to public health, that the extent of this hazard varies between the cities studied, and that vendors' health education in food safety is a crucial factor in the prevention of foodborne infections.

Colony Count, Microbial↗
PubMed2001

Evidence that infectious stages of Tetracapsula bryosalmonae for rainbow trout Oncorhynchus mykiss are present throughout the year.

Proliferative kidney disease (PKD) is a hyperplastic condition of the lymphoid tissue of salmonids infected with the spores of Tetracapsula bryosalmonae, a myxozoan parasite formerly designated PKX, which has recently been described as a parasite of several species of bryozoans. The occurrence of PKD is generally associated with seasonal increase in water temperature, with research indicating that transmission of the disease does not occur below 12 to 13 degrees C. This suggested that the infectious stages are absent from about November to March/April. Here we document the transmission of PKD at water temperatures and seasons previously considered to be non permissive for PKD infection. The exposure of naive rainbow trout Oncorhynchus mykiss (Walbaum) to PKD-infected water ranging from 8 to 13 degrees C during the Autumn, Winter and early Spring, resulted in the infection of kidney interstitium once the trout were transferred to 16 degrees C. In addition, cohabitation studies were conducted with the bryozoan host Fredericella sultana collected from a river at times of low seasonal temperatures because this bryozoan species overwinters as living colonies. Cohabitation of trout with colonies of F sultana in parasite-free city water at 16 degrees C, also led to renal lymphoid tissue infection with the parasite and even to nephromegaly. Our results provide evidence that the infectious stages of T bryosalmonae for rainbow trout were present in the water throughout the entire year and that the impact of temperature on the development of PKD is primarily a result of the kinetics of Tetracapsula multiplication in bryozoan and fish hosts.

Animals↗
PubMed2001

Breakthrough cancer pain: a randomized trial comparing oral transmucosal fentanyl citrate (OTFC) and morphine sulfate immediate release (MSIR).

Oral transmucosal fentanyl citrate (OTFC); Actiq) is a drug delivery formulation used for management of breakthrough cancer pain. Previous studies with open-label comparisons indicated OTFC was more effective than patients' usual opioid for breakthrough pain. The objective of this study was to compare OTFC and morphine sulfate immediate release (MSIR) for management of breakthrough pain in patients receiving a fixed scheduled opioid regimen. This double-blind, double-dummy, randomized, multiple crossover study was conducted at 19 US university- and community-based hospitals and clinics and comprised 134 adult ambulatory cancer patients. Patients were receiving a fixed scheduled opioid regimen equivalent to 60-1000 mg/day oral morphine or 50-300 microg/h transdermal fentanyl, were using a 'successful' MSIR dose (15-60 mg) as defined by entry criteria, and were experiencing 1-4 episodes of breakthrough pain per day. In open-label fashion, OTFC was titrated such that a single unit (200-1600 microg) provided adequate pain relief with acceptable side effects. Successfully titrated patients entered the double-blind phase of the study and received ten prenumbered sets of randomized capsules and oral transmucosal units. Five sets were the successful OTFC dose paired with placebo capsules, and five sets were placebo OTFC paired with capsules containing the successful MSIR dose. Patients took one set of study medication for each episode of target breakthrough pain. Pain intensity (PI), pain relief (PR) and global performance of medication (GP) scores were recorded. Pain intensity differences (PID) were calculated and 15-min PID was the primary efficacy variable. Adverse events were recorded. Sixty-nine percent of patients (93/134) found a successful dose of OTFC. OTFC yielded outcomes (PI, PID, and PR) at all time points that were significantly better than MSIR. GP also favored OTFC and more patients opted to continue with OTFC than MSIR following the study. Somnolence, nausea, constipation, and dizziness were the most common drug-associated side effects. In conclusion, OTFC was more effective than MSIR in treating breakthrough cancer pain.

Administration, Oral↗
PubMed2001

Action sequence for layperson cardiopulmonary resuscitation.

Although some minor modifications were forged, the general consensus was to maintain most of the current guidelines for phone first/phone fast, no-assisted-ventilation CPR, the A-B-C (vs C-A-B) sequence of CPR, and the recovery position. The decisions to leave these guidelines as they are were based on a lack of evidence to justify the proposed changes, coupled with a reluctance to make revisions that would require major changes in worldwide educational practices without such evidence.Nonetheless, some major changes were made. The time-honored procedure ol pulse check by lay rescuers was eliminated altogether and replaced with an assessment for other signs of circulation. Likewise, it was recommended that even the professional rescuer now check for these other signs of circulation. Although professional rescuers may simultaneously check for a pulse, they should do so only for a short period of time (within 10 seconds). There was also enthusiasm for deleting the ventilation aspect of EMS dispatcher-assisted CPR instructions that are provided to rescuers at the scene who are inexperienced in CPR. lt was made clear, though, that the data are applicable only to adult patients who are receiving CPR and that the data are appropriate most for EMS systems with rapid response times.

Adult↗
PubMed1999

Comparative susceptibility of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta to Myxobolus cerebralis, the cause of salmonid whirling disease.

The susceptibility of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta to Myxobolus cerebralis, the cause of salmonid whirling disease, was assessed following dosed exposures to the infectious stages (triactinomyxons). Parallel groups of age-matched brown trout and rainbow trout were exposed to 10, 100, 1000 or 10,000 triactinomyxons per fish for 2 h and then placed in aquaria receiving single pass 15 degrees C well water. Severity of infection was evaluated by presence of clinical signs (whirling and/or black tail), prevalence of infection, severity of microscopic lesions, and spore counts 5 mo after exposure. Clinical signs of whirling disease, including a darkened caudal region (black tail) and radical tail chasing swimming (whirling), occurred first among rainbow trout at the highest dose at 6 to 7 wk post exposure. Black tail and whirling occurred among rainbow trout receiving 1000 and 100 triactinomyxons per fish at 8 to 9 wk post exposure. Only 1 of 20 fish had a black tail among rainbow trout receiving 10 triactinomyxons per fish, although 30% of the fish were infected at 5 mo post exposure. Black tails were observed in brown trout at 1000 and 10,000 triactinomyxons per fish beginning at 11 and 7 wk post exposure, respectively. There was no evidence of the tail chasing swimming (whirling) in any group of brown trout. The prevalence of infection, spore numbers, and severity of microscopic lesions due to M. cerebralis among brown trout were less at each exposure dose when compared to rainbow trout. Infections were found among rainbow trout at all doses of exposure but only among brown trout exposed to doses of 100 triactinomyxons per fish or greater. Risk of infection analyses showed that rainbow trout were more apt to be infected at each exposure dose than brown trout. Spore counts reached 1.7 x 10(6) per head among rainbow trout at the highest dose of exposure compared to 1.7 x 10(4) at the same exposure dose among brown trout. Spore numbers increased with dose of exposure in rainbow trout but not in brown trout. As microscopic lesion scores increased from mild to moderate, spore numbers increased in rainbow trout but not brown trout. The mechanisms by which brown trout resist infections with M. cerebralis were not determined. Cellular immune functions, including those of eosinophilic granular leukocytes that were more prominent in brown trout than rainbow trout, may be involved.

Animals↗
PubMed1999

Construction of spectral sensitivity function using polychromatic UV sources.

A procedure is presented for constructing the spectral sensitivity functions of biological dosimeters, using five polychromatic UV sources possessing different emission spectra. Phage T7 and uracil biological dosimeters have been used for measuring the dose rates of the lamps. Their spectral sensitivity functions consisting of two exponential terms have been constructed. The parameters of the spectral sensitivity functions have been determined by comparing the directly measured and calculated dose-rate values. The parameters of the sensitivity function are accepted as correct values when the deviation of the measured and calculated values is a minimum. Based on the deviations between the constructed and the experimentally determined spectral sensitivities with monochromatic sources, the differences between the measured and calculated results are interpreted. The importance of the correct spectral sensitivity data is demonstrated through the effectiveness spectra of a TL 01 lamp for phage T7 killing, uracil dimerization and erythema induction.

Bacteriophage T7↗
PubMed1998

Dose proportionality and pharmacokinetics of oral transmucosal fentanyl citrate.

BACKGROUND: The pharmacokinetics of a single dose (15 microg/kg) of oral transmucosal fentanyl citrate (OTFC) have been characterized. A range of doses may eventually be used in clinical practice. The goal of this study was to determine if the pharmacokinetics of OTFC are dose proportional for doses ranging from 200 to 1,600 microg. METHODS: Twelve healthy male volunteers were studied on four different occasions, receiving 200, 400, 800, and 1,600 microg OTFC in a double-blind, randomized protocol. Venous blood samples were collected at selected times during and after dosing for a 24-h period and assayed for fentanyl using a radioimmunoassay. Maximum concentration, time to maximum concentration, area under the curve, and elimination half-life were determined for each dose administered. In addition, respiratory rate, need for verbal prompting to breathe, and supplemental oxygen requirements were noted. RESULTS: Mean fentanyl concentration time curves were similarly shaped with increasing doses. Both peak concentrations and area under the curve increased linearly with an increase in dose, whereas time to reach peak serum concentrations did not vary significantly between doses. Except for the 200-microg dose, the apparent elimination half-life remained relatively constant (358-386 min). The incidence of low respiratory rate, supplemental oxygen requirement, and number of breathing prompts significantly increased with increasing doses. CONCLUSIONS: Oral transmucosal fentanyl citrate exhibits dose-proportional pharmacokinetics over the dose range of 200-1,600 microg.

Administration, Oral↗
PubMed1997

Significance of temperature and preincubation temperature on survival of Listeria monocytogenes at pH 4.8.

Listeria monocytogenes is a food-borne pathogenic bacterium that can be found in soft cheese. At the beginning of cheese ripening, the pH is about 4.85-4.90. The aim of this work was to study the influence of temperature, preincubation temperature (temperature at which the inoculum was cultivated) and initial bacterial concentration on the survival of L. monocytogenes (strain Scott A) at pH 4.8. It was demonstrated in an earlier study that these factors did influence growth kinetics. Survival studies of L. monocytogenes were done in a laboratory broth simulating cheese composition. Four test temperatures (2, 6, 10 and 14 degrees C) and two preincubation temperatures were studied (30 degrees C or the test temperature). Listeria monocytogenes (strain Scott A) was unable to grow at pH 4.8 under all conditions tested. The time for 10% survival was about 11 and 2 d, at 2 degrees C with preincubation at 2 degrees C and 30 degrees C, respectively; 9 d at 6 degrees C with preincubation at 6 degrees C; 4 d at 6 degrees C with preincubation at 30 degrees C; and 1 d at 14 degrees C with preincubation at 14 degrees C or at 30 degrees C. The results show that survival of L. monocytogenes (strain Scott A) at pH 4.8 is not dependent on initial bacterial concentration but on both the test and preincubation temperatures.

Cheese↗
PubMed1997

Heparin versus citrate regional anticoagulation during autotransfusion in a porcine intra-abdominal hemorrhage model.

Our objective was to determine the effects of anticoagulants and blood loss on hemodynamic, hematologic, and coagulation parameters following autotransfusion in an animal model of intraabdominal hemorrhage. We performed a prospective, randomized observational animal study at an animal research laboratory at a university medical center. Eight Landrace, domestic pigs, weighing 17-23 kg, each underwent jugular venous and iliac arterial catheterization and laparotomy with retroperitoneal dissection for aortic exposure to simulate an operative environment. Following baseline laboratory and hemodynamic determinations, intra-abdominal hemorrhage was accomplished via aortotomy in three sequential 10 mL/kg blood volumes. After allowing pooling in the exposed retroperitoneum to ensure tissue contact, the shed blood was suctioned, processed, and washed in an autotransfusion device utilizing either heparin (n = 4) or acid-citrate-dextrose (n = 4) as a system anticoagulant. Prior to autologous transfusion, each pig received a 20 mL/kg intravenous bolus of 0.9 per cent saline to treat shock. The processed blood was then infused, and laboratory and hemodynamic measurements were repeated following each cycle of hemorrhage and autotransfusion. Sequential fixed volume hemorrhage resulted in significant reductions in mean arterial pressure. Despite crystalloid infusion and transfusion of processed shed blood, postresuscitation mean arterial pressure did not return to baseline values, with no difference noted between anticoagulant groups. Infusion of increasing volumes of autologous blood resulted in significant reductions in hematocrit, platelet count, fibrinogen, antithrombin III, ionized calcium, and total protein. The decrease in concentration of each variable was independent of the choice of anticoagulant with the exception of antithrombin III, with higher levels noted in animals receiving blood anticoagulated with acid-citrate-dextrose. Prothrombin time and partial thromboplastin time were unaffected by volume of autologous transfusion or choice of anticoagulant. We conclude that changes in hemodynamic, hematologic, and coagulation parameters associated with hemorrhage and autotransfusion appear related more to the volume of blood loss and the cumulative pheresis of plasma than to the choice of anticoagulant.

Animals↗
PubMed1996

Significance of pre-incubation temperature and inoculum concentration on subsequent growth of Listeria monocytogenes at 14 degrees C.

The influence of the bacterial concentration of an inoculum (10(1) or 10(3) cfu ml-1) of two strains of Listeria monocytogenes (Scott A: serotype 4b and V7: serotype 1) and one strain of L. innocua (Lin 11), and the time and temperature at which the inoculum was stored (cold storage: 4 degrees C for 4 weeks, or without cold storage: -20 degrees C before immediate transfer), and the temperature at which cells were pre-incubated (30 degrees C and 14 degrees C) on subsequent growth in Richard's broth at 14 degrees C was investigated. Richard's broth at a pH 5.9 was used to simulate potential growth in soft cheese (camembert type) and an incubation temperature of 14 degrees C was used to simulate storage-temperature ripening of cheese. Enumeration of the number of viable cells was by plate count method, except where viable cell numbers were less that 10(3) cfu ml-1, when the MPN (Most Probable Number) technique was used. With cold storage and an inoculum of 10(3) cfu ml-1 (high bacterial concentration) the pre-incubation temperatures (30 degrees C and 14 degrees C) did not significantly influence the subsequent growth curve: there was no significant lag (less that 21 h) and cell numbers peaked in about 8.5 d. However, with cold storage and an inoculum of 10(1) cfu ml-1 (low bacterial concentration) and a pre-incubation temperature of 30 degrees C a significant shift in the growth curve was observed over that pre-incubated at f14 degrees C, with the appearance of a lag of about 7.7 d. At a pre-incubation temperature of 14 degrees C with the low inoculum concentration, there was a measurable lag of about 1 d. Without cold storage and a pre-incubation temperature of 30 degrees C, there was a lag time of 2.3 d. Storage conditions, pre-incubation temperature and inoculum concentration therefore appear to influence the subsequent growth curve. Importantly, however, the growth curves for cultures from inocula, pre-incubated at either 30 degrees C or 14 degrees C, appeared to involve two distinct values of the exponential growth rate (k): the initial portion of the growth curve described by a low value of k and the subsequent portion by a consistently and significantly greater value. The appearance of two distinct growth phases was reproduced in further data determined for all the studied strains of the microorganism. Further study to explain these unexpected and reproducible findings is being conducted.

Colony Count, Microbial↗
PubMed1992

Persistent impairment of clomipramine demethylation in recently detoxified alcoholic patients.

The purpose of the present study was to investigate whether the metabolism of clomipramine is altered by chronic alcohol drinking. Eleven recently detoxified alcoholic patients were included (experimental group EG) and compared to a reference group of patients with no history of alcoholism (reference group RG, n = 102). Blood concentrations of clomipramine and its metabolites were measured as part of the routine drug monitoring program. Clearances were estimated from trough concentrations, according to a model developed previously. Results indicate strong inhibition of demethylation clearance in group EG, when compared to group RG (median values 9.9 and 24.2 L/h), with significant increase of the clomipramine to desmethylclomipramine ratio (median values 1.00 and 0.36). No difference was found for hydroxylation. In addition, high correlation is observed between hydroxylation and demethylation clearances in group EG (Spearman rs = 0.82), but not in reference group RG (rs = 0.29). Follow-up data indicate that impairment of demethylation capacity can persist for several weeks or months after withdrawal from alcohol. The interest of calculating clomipramine to desmethylclomipramine ratios during routine drug monitoring is emphasized, values of 1 or larger often being associated with liver disease and/or alcohol-related problems.

Adult↗
PubMed1991

Results of a survey of forensic psychiatrists on the validity of the sadistic personality disorder diagnosis.

OBJECTIVE: The purpose of this study was to determine how often forensic psychiatrists evaluated individuals with sadistic personality disorder; their views about the usefulness of the diagnosis; the frequency of certain childhood factors; and the sensitivity and specificity of the individual diagnostic criteria. METHOD: A questionnaire to be answered anonymously was sent to all of the 1,390 members of the American Academy of Psychiatry and the Law. Two hundred seventy-nine usable questionnaires were returned for data analysis. RESULTS: Approximately 50% of the respondents had, at some time, evaluated in a forensic setting a subject who exhibited behavior that met the criteria for the disorder. Four percent of the cases seen in the preceding year by those respondents who had ever seen a case would have met the criteria for the disorder. Most of the forensic psychiatrists who had experience with the disorder believed that the diagnosis is useful for a variety of clinical and forensic purposes, but most also believed that the category has significant potential for being misused in legal settings. Almost all cases described by the respondents involved male patients, and there was frequently a history of childhood abuse and parental loss. The diagnostic criteria in these cases had high sensitivity and specificity. CONCLUSIONS: In forensic settings the diagnosis of sadistic personality disorder is probably not rare. The results of this study suggest that the diagnosis has both descriptive and construct validity and that further study of the disorder with the DSM-III-R diagnostic criteria is needed.

Antisocial Personality Disorder↗
PubMed1988

Breast cancer melanosis in a postmastectomy scar.

Pigmented skin lesions developed in the postmastectomy scar of a 42-year-old woman, 3 years after mastectomy, clinically mimicking malignant melanoma. A histologic study of the skin showed neoplastic mucin secreting glands and melanocyte colonization. Literature pertaining to melanin pigmentation of epithelial tumors not primary in the skin is reviewed.

Adult↗
PubMed1988

Monitoring problem drug use in Bristol.

A prospective multi-agency survey of problem drug use associated with illicit drugs and solvents in the city of Bristol in 1984-1985 found 759 problem drug users, giving a period prevalence rate of 0.4-0.8% of those aged 10-44 years. The group was a young one, with 92% under the age of 35. Over half had problems associated with opiates, mainly illicit heroin; 17% had problems associated with solvents, 9% with cannabis, 13% with stimulants, mainly illicit amphetamine, and 3% with hallucinogens. There was little indication of problematic use of barbiturates or cocaine. The problems associated with drugs and solvents were wide-ranging and not specific for individual drugs. Future community surveys would find it cost-effective to concentrate on the five best sources identified here, and to supplement these with indications of drug-taking among teenagers. The difficulties of using the definition of problem drug use for research and the value of case-register surveys for community drug monitoring are discussed.

Adolescent↗