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Biomedical subjects

J Vincelette

Publications and source records attributed to J Vincelette.

52 records · Page 3Linked to original sources

Evaluation of the Sensititre system for identification of Enterobacteriaceae.

The Sensititre identification system (Seward Laboratory/GIBCO Laboratories) consists of a microplate containing a pattern of 24 biochemicals repeated four times together with an automatic inoculation device and a microcomputer-assisted data interpretation component. A total of 1,415 isolates of Enterobacteriaceae plus 6 isolates of other glucose-fermenting gram-negative bacilli were tested in three hospital laboratories in parallel with API 20E (Analytab Products). Discrepancies were resolved by conventional biochemical testing. Sensititre yielded correct identifications at the species level with 94.6% of the isolates and at the genus level with an additional 1.9%. API 20E yielded correct species identification with 91.1% and genus only identification with an additional 6.7% of the isolates. For the routine identification of clinical Enterobacteriaceae isolates, the Sensititre system compares favorably with API 20E and offers clinical laboratories the economy of a microtiter plate system as well as the benefit of a microcomputer capable of other microbiological and data management applications.

Bacteriological Techniques↗

Double-blind trial of perioperative intravenous metronidazole prophylaxis for abdominal hysterectomy.

A double-blind trial of perioperative intravenous metronidazole treatment to prevent infections at the operative site and unexplained fever after abdominal hysterectomy was conducted in 106 patients. Metronidazole prophylaxis reduced the rate of recovery of anaerobes from vaginal swabs for several days and prolonged the high rate of vaginal carriage of enterococci and aerobic gram-negative bacilli following hysterectomy. Although the fever index, calculated from the duration of a temperature above 37.3 degrees C, was significantly lower in the metronidazole-treated group than in the placebo-treated group, the frequency of postoperative infections, the proportion of patients requiring antibiotic treatment and the average duration of hospital stay were similar in the two groups. These results do not support the reported value of perioperative metronidazole prophylaxis in patients undergoing abdominal hysterectomy.

Adult↗

Microfilariae in the cerebrospinal fluid, and neurological complications, during treatment of onchocerciasis with diethylcarbamazine.

Microfilariae of Onchocerca volvulus were found in the cerebrospinal fluid (CSF) of 5/8 heavily infected onchocerciasis patients. During treatment with diethylcarbamazine citrate 10/11 patients showed increased numbers of 0. volvulus microfilariae in the CSF. Patients with concentrations of 8-31 mf/ml CSF developed severe vertigo, and some other neurological manifestations, during treatment. A hypothesis is put forward to account for this clinical piciture, and its importance in relation to the treatment of onchocerciasis is discussed.

Arachnoid↗

The populatin dynamics of Onchocerca volvulus microfilariae during treatment with suramin and diethylcarbamazine.

During treatment with suramin the numbers of O. volvulus microfilariae in the blood, urine, sputum, and anterior chambers of the eye fell before those in the skin. When diethylcarbamazine (DEC) was given after suramin, increased numbers of microfilariae appeared in the blood, urine, cerebrospinal fluid (CSF) and sputum, but the increase in the blood was less marked, and of shorter duration, than in similar patients receiving DEC without previous suramin. Microfilariae are thought to enter the urine, sputum and CSF directly from the blood by penetrating the capillary walls in the glomeruli, pulmonary alveoli, and choroid plexuses. Those in the aqueous humour do not appear to come directly from the bloodstream. The total numbers of microfilariae in the skin of some heavily infected onchocerciasis patients are estimated, as are the total numbers moving into the blood-stream under the influence of DEC and the proportion which escape into the urine, sputum and CSF. It is concluded that the majority of the microfilariae which appear in the blood during DEC therapy must be destroyed in the body, probably in the liver.

Anterior Chamber↗

Factors influencing the passage of Onchocerca volvulus microfilariae into the urine.

The effect of various substances on the output of Onchocerca volvulus microfilariae in the urine was investigated in volunteers infected with the Cameroon forest and Sudan-savanna strains of the parasite. Output of microfilariae in the urine tended to be higher during periods of normal activity than during sleep. During waking hours, the rate of output remained generally steady, but in some patients occasional showers of microfilariae appeared in the urine, possibly associated with the intake of food and drink. Drinking 1.2-2.5 litres water produced a shower of microfilariae in the urine of some subjects. This began within an hour of drinking and its onset preceeded that of the diuresis. Thiazide diuretics, acting on the convoluted tubules, produced no increase in microfilaruria. In savanna subjects intravenous injection of DT TAB vaccine caused pyrexia, and simultaneously large numbers of microfilariae appeared in the urine. There was no associated diuresis, and no increase in the concentration of microfilariae in the venous blood. In forest subjects DT TAB caused no increase in microfilaruria. In all subjects 25-50 mg diethylcarbamazine (DEC) caused large numbers of microfilariae to appear in the urine on day 0, within a few hours of the first dose; and there was an increased output of urine over the first 24 hours. Microfilaruria declined sharply on day 1 of treatment, but in subjects developing a high microfilaraemia, it rose again on day 2, and declined more slowly thereafter. Betamethazone, given in conjunction with DEC, appeared to slow the rate of destruction of microfilariae in the skin and lymph glands, and to prolong the duration of microfilaraemia and microfilaruria. The findings suggest that there is a reservoir of microfilariae in the glomerular capillaries, which fills slowly by accumulating microfilariae from the circulating blood. The microfilariae probably enter the urine by penetrating the glomerular capillary.

Adult↗

Illicit use of methadone among i.v. drug users in Montreal.

Few studies have been done on the prevalence of illicit methadone use. Five hundred fifty-nine IV drug users recruited in various ways in Montreal were interviewed concerning their drug use as part of a longitudinal study on HIV infection. Of this number, 133 had heroin as their drug of preference and 426 cocaine. Among the cocaine group, 202 also used heroin. The lifetime prevalence of any illicit methadone use was 59.4% in the heroin group, 26.7% in the cocaine/heroin group, and 3.6% in the cocaine-only group. The 6-month (preceding the interview) prevalence of any illicit use was 42.1%, 6.9%, and 1.3%, respectively, and the prevalence of at least weekly illicit use during that period was 6.3%, 2.0%, and 0%, respectively. The prevalence of illicit methadone use is significant in the population studied. Whether this level of use will be affected by more stringent control on methadone prescription and dispensation remains to be demonstrated.

Adult↗

Ineffectiveness of hepatitis B vaccination in cirrhotic patients waiting for liver transplantation.

Cirrhotic patients who undergo liver transplantation are at risk of acquiring de novo hepatitis B virus (HBV) infection at the time of transplantation. It is common practice to immunize these patients against HBV, but the efficacy of vaccination is uncertain. The response to vaccination with a recombinant HBV vaccine was examined in 49 patients with cirrhosis before liver transplantation. Patients received three doses (20 mg) of Engerix-B (SmithKline Beecham) at zero, one and two months before transplantation, and their response was measured on the day of liver transplantation (9.3+/-1.2 months after the initial dose of vaccine). Results were compared with those reported in healthy adults vaccinated according to the same schedule. Fourteen of 49 cirrhotic patients (28%) developed antibodies to hepatitis B surface antigen (anti-HBs) levels of more than 10 U/L after vaccination compared with 97% of healthy controls. Four patients (8%) had anti-HBs levels of more than 100 U/L compared with 83% in healthy individuals. Mean anti-HBs titre in the 14 responders was 62 U/L compared with 348 U/L in controls. No factor was identified that predicted response to vaccination. One of 49 patients acquired de novo HBV infection at the time of liver transplantation. Current HBV vaccination of cirrhotic patients waiting for liver transplantation is ineffective, and new strategies need to be developed to increase the response rate.

Female↗

Risk behaviours and HIV infection among men having sexual relations with men: baseline characteristics of participants in the Omega Cohort Study, Montreal, Quebec, Canada.

OBJECTIVE: To describe characteristics of men having sex with men (MSM) participating in the Omega Cohort, to describe HIV-positive participants at baseline interview, and to estimate HIV incidence. METHODS: The Omega Cohort is a study on the incidence and psychosocial determinants of HIV infection among MSM living in Montreal. MSM complete a questionnaire and are tested for HIV every six months. RESULTS: During the previous six months, 31% and 12% of 810 participants (mean age = 33 years) reported unprotected anal sex with regular and casual partners, respectively. Eight participants (0.98%) were HIV-infected at baseline. HIV incidence was 0.89 per 100 person-years (7/787 person-years) [95% confidence interval: 0.36-1.83]. CONCLUSION: A significant proportion of participants reported current risk behaviours. Despite this, HIV incidence is relatively low. It is important to target MSM who do not practice safe sex and to encourage those practicing safe sex to sustain these behaviours.

Adult↗

Needle sharing behaviour among injection drug users (IDUs) in treatment in Montreal and Toronto, 1988-1989.

Injection drug users (IDUs) entering treatment programs in Montreal and Toronto were recruited for a study of drug using behaviour and risk of HIV infection. Only those who had injected within 6 months of entering their treatment program were eligible for participation. 183 subjects were recruited in Montreal and 167 in Toronto between November, 1988 and October, 1989. Each participant completed a standardized interviewer-administered questionnaire which focussed on, among other things, drug history and needle sharing behaviour. Approximately three-quarters of respondents in both cities reported sharing needles and syringes within the 6-month period prior to their entry into treatment. Our analysis, which focussed on variables associated with needle sharing revealed that having a sexual partner who injected, trouble obtaining sterile needles and syringes and cocaine injection were significantly and independently associated with needle sharing in a logistic regression model which also controlled for city of recruitment.

AIDS Serodiagnosis↗

[Prognostic value of HIV serum antigens].

Human immunodeficiency virus (HIV) antigens can be detected during early infection but usually disappear afterwards. Their later reappearance in serum seems to herald a greater virus replication and a poor prognosis. The prognostic value of antigen detection at the first clinical visit was assessed among 37 symptomatic patients. Patients with detectable antigenemia at the first visit progressed more rapidly towards the acquired immunodeficiency syndrome (p less than 0.0001). Similarly, patients with detectable antigens at the time of a Pneumocystis carinii pneumonia had a shorter survival than patients without detectable antigens (p less than 0.0001). Four months after the hospital admission date, the survival rate was 31% among patients with detectable antigens and 100% among patients without detectable antigens (p less than 0.0001). In two of four patients tested, serial HIV antigens determinations suggested a spontaneous decrease of antigen titers during the terminal phase of the disease.

Acquired Immunodeficiency Syndrome↗