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Biomedical subjects

P Martin

Publications and source records attributed to P Martin.

At least 649 records · Page 36Linked to original sources
PubMed1991

[Prevalence of antibodies to the hepatitis C virus in pregnant foreign residents in France].

Blood transfusion and intravenous drug use are the two main modes of transmission of the hepatitis C virus (HCV). Sexual intercourse seems to play a less significant part in transmission of the HCV and data are still lacking on vertical mother-to-offspring transmission. HCV seroprevalence was determined in 1,084 pregnant foreign residents of France living in a single city (Limoges). Antibodies to the HCV were detected in sera using both the first and second generation Abbott ELISA kits. Sera yielding reproducible positive results with either kit were retested with a blocking test (HCV EIA Neutralization, Abbott) and a second generation RIBA (Ortho) for confirmation. For screening, use of tests detecting both nonstructural and structural antibodies improved results noticeably (5 of 16 sera). Use of confirmation tests was found to be indispensable. Overall seroprevalence was 1.47%. However, results varied across geographic regions or origin, ranging from 0% for Europe, 1.9% for North Africa and 1.78% for South-East Asia, to 4.76% for black Africa. These findings demonstrated the potential for mother-to-offspring transmission among women from high prevalence areas. A prospective study in African an Asian women is being considered to evaluate ineffectiveness and transmission using serial serologic tests and viral genome detection by polymerase chain reaction studies (PCR).

Adult↗
PubMed1991

Multidimensional work sampling to study the activities of decentralized clinical pharmacists.

Self-reported multidimensional work sampling (MDWS) was used to study the activities of decentralized clinical pharmacists at six hospitals in Portland, Oregon, and Seattle-Tacoma, Washington, in March through June 1989. A community hospital, a university hospital, and a hospital associated with a health maintenance association were selected in each city, and pharmacists at each site who provided clinical services were recruited. Each pharmacist wore a random reminder device and recorded the activity during which the device sounded by writing on a card numbers assigned to describe work activity, contact, location, and function. Of 6609 classifiable observations, 34.5% (2280) were of clinical activities and 35.8% distributive activities. Pharmacists spent 28.6% of their clinical time reviewing and assessing patients' charts, 17.1% on clinical rounds, 15.9% on activities related to therapeutic drug monitoring, 10.2% providing drug information, 11.6% attending or giving formal education, 6.1% doing research, and 2.6% attending meetings. The average pharmacist spent less than 10 minutes each day with patients but spent a substantial portion of time providing clinical services to other health professionals. Self-reported, multidimensional work sampling appears to be a valuable method for describing and monitoring decentralized pharmacists' work activities at multiple sites and work settings.

Hospitals, Community↗
PubMed1991

Recurrence of hepatitis C virus infection after orthotopic liver transplantation.

Identification of the hepatitis C virus--the main cause of posttransfusion and sporadic non-A, non-B hepatitis--and the development of a diagnostic serological test have allowed us to study possible recurrence of this type of hepatitis after liver transplantation. Six of 34 consecutive transplant recipients were found to have had antibodies to hepatitis C before transplantation. All six patients had possible exposure to hepatitis C through blood transfusion or intravenous drug use. Five of the six patients were positive for antibodies to hepatitis C after 1 yr of follow-up. Two of these patients had clinical and histological evidence of acute viral hepatitis in their allografts. In one patient this led to hepatic injury and dysfunction of two successive grafts. In contrast, none of the twenty-eight patients who were seronegative for hepatitis C virus antibodies before transplantation has converted to seropositivity after transplantation despite perioperative blood transfusions. These results suggest that hepatitis C diagnosed serologically recurs in a minority of transplant recipients and that de novo seroconversion must be uncommon.

Adult↗
PubMed1991

[Changes in resistance of Pseudomonas aeruginosa to beta-lactams in a general intensive care unit over a three-year period. Role of piperacillin].

Nosocomial infections by Pseudomonas aeruginosa seen in a general intensive care unit from January 1987 through December 1989 were studied. Use of piperacillin, ticarcillin, cefsulodine, ceftazidime, and imipenem over the same period were recorded. Rate of infection by P. aeruginosa among the 1,844 patients admitted during the study period was 3.2%; 32% of all nosocomial infections during this period were due to P. aeruginosa. The proportion of P. aeruginosa strains exhibiting in vitro susceptibility to ticarcillin rose from 45.5% in 1987 to 59% in 1988 and 86% in 1989. Concomitantly, the proportion of P. aeruginosa strains simultaneously resistant to ticarcillin, piperacillin, cefsulodine and ceftazidime fell from 32% to 18.5% then 0%. A statistically significant correlation was found between the decrease in piperacillin use and the fall in penicillinase-producing ticarcillin-resistant strains of P. aeruginosa. Because piperacillin has undesirable effects on the intestinal flora and promotes the emergence of resistant strains of P. aeruginosa, the authors now use narrow spectrum antimicrobial agents as first line treatment of nocosomial infections.

Cefsulodin↗
PubMed1991

Elevated intracranial pressure and computed tomography of the brain in fulminant hepatocellular failure.

Cerebral herniation is a leading cause of death in patients with fulminant hepatocellular failure. Classical signs of elevated intracranial pressure are often absent in these patients. A reliable noninvasive method by which the presence of cerebral edema could be determined is much needed. To assess the efficacy of computed tomography of the brain in this setting, we compared the radiographic findings to the intracranial pressure measured by an epidural monitor in patients with fulminant hepatic failure. Unfortunately, a considerable difference existed between the presence of cerebral edema diagnosed by computed tomography of the brain and elevation of the intracranial pressure. Our observations suggest that in patients with fulminant hepatic failure and advanced hepatic encephalopathy, computed tomography of the brain is of little value in detecting cerebral edema. Pressure monitoring is most important to establish the presence and guide the therapy of intracranial hypertension.

Brain↗
PubMed1991

[Contact hypersensitivity to Kathon CG. Apropos of 35 cases among 977 tested subjects].

Kathon CG (Rohm and Haas) is a mixture of two isothiazolinones: chloromethylisothiazolinone and methylisothiazolinone. It is widely used in aqueous solution as antimicrobial agent in cosmetics (CG means cosmetic grade) instead of parabens. Routine testing is effected with Kathon CG in aqueous solution at 100 ppm (Trolab) in finn chamber tests on scanpor (ICDRG directives). Between September 1987 and September 1989, 977 patients (538 women, 439 men) referred for suspected contact allergy were tested. Thirty-five patients (77 p. 100 of whom were young women) with a history of allergy to cosmetics were found to be positive. Face, hands or both were involved in 15, 7 and 9 cases respectively, and a lupus-like reaction was observed in one patient. Our results (frequency: 3.6 p. 100) were compared with previously published results ranging from 0.67 p. 100 to 16.1 p. 100 (tables IV and V). Such wide variations can be explained by different selections of patients, different uses of cosmetics and lack of standardization in testing. Patch tests were strongly positive (quoted + +) in all cases. None of the irritant effects previously reported (3, 8, 28) was detected. In a control study carried out two months later, diluted patch tests (100, 50, 25, 15 and 7.5 ppm) were performed in 15 patients and were positive in 11 of them: 5 at 25 ppm, 1 at 15 ppm and 5 only at 100 ppm. Contrary to previous suggestions (7, 28, 36), there was no correlation between allergenic potential and minimal concentration, so that the "no response concentration" concept could not be confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesives↗
PubMed1990

Tricyclic antidepressants, thyroid function, and their relationship with the behavioral responses in rats.

We first studied the effects of tricyclic antidepressants (TCAs) on thyroid function in rats in the learned helplessness paradigm. TCAs (clomipramine 32 mg/kg, desipramine 16, 24 mg/kg, or imipramine 8, 16, 32 mg/kg per day) were injected IP for 5 consecutive days. Blood samples were collected 1 hr after the last administration of the antidepressant for radioimmunoassay determination of triiodothyronine (T3) and thyrotropin. Whereas inducing helplessness did not result in any change in T3 and thyroid-stimulating hormone (TSH) levels, TCA therapy dose dependently decreased the T3 levels without changing TSH levels in helpless animals and in naive control rats. To further the investigation, the effects of TCAs on thyroid function were examined using two models of experimentation, one involving diabetes induction, the other using food deprivation; both are known to induce a resistance to TCAs that is reversible under T3 treatment. In both models, a decreased T3 level existed prior to the TCA administration. Although they had no effect on behavior, TCAs further decreased the T3 levels in diabetic and food-restricted rats. This study confirms that TCAs decrease thyroid function and suggests that the antidepressant effect of TCAs is not related to their T3 decreasing effects.

Animals↗
PubMed1990

Effects of selective dopamine D1 and D2 receptor agonists on the rate of GABA synthesis in mouse brain.

The effects of dopamine D1 and D2 receptor agonists and antagonists on the rate of GABA synthesis in four regions of mouse brain (corpus striatum, cerebellum, cortex and hippocampus) were examined after irreversible inhibition of 4-aminobutyrate: 2-oxoglutarate aminotransferase (EC 2.6.1.19; GABA-T) by gabaculine. The dopamine D2 receptor agonists PPHT, LY 171555 and RU 24213 exerted a dose-related inhibitory effect on GABA synthesis in these four regions. The decreases in the rate of GABA formation were prevented by the dopamine D2 receptor antagonist S(-)-sulpiride. The dopamine D1 receptor agonists SKF 77434 and SKF 38393 augmented gabaculine-induced GABA accumulation in the corpus striatum only, and this effect was blocked by the dopamine D1 receptor antagonist SCH 23390. However, SKF 81297 and SKF 82958, two other dopamine D1 receptor agonists, did not affect or only marginally altered the rate of GABA synthesis. Stimulation of D2 receptors thus induces a decrease in the rate of GABA formation in the four brain areas examined, whereas stimulation of D1 receptors either increases GABA synthesis in the corpus striatum or does not alter it. This effect appears to be independent of the degree of receptor occupancy.

Animals↗
PubMed1990

Involvement of angiotensin-converting enzyme inhibition in reversal of helpless behavior evoked by perindopril in rats.

Several clinical investigations have suggested that captopril, an angiotensin-converting enzyme inhibitor (ACEI) currently used as an anti-hypertensive agent, exhibits antidepressant properties in humans. In the present study we evaluated the action of perindopril, another ACEI, and two of its metabolites, the di-acide form perindoprilat, which possesses ACE inhibitory properties, and BDM-4, an inactive metabolite, in the learned helplessness paradigm. In order to confirm a possible action of these drugs via dipeptidyl carboxypeptidase inhibition, we also investigated two inactive analogues of perindopril and perindoprilat. Perindopril (0.06-8 mg/kg per day) and perindoprilat (0.25-8 mg/kg per day) induced a reversal of escape deficits. BMD-4 and two analogues failed to reverse helpless behavior. These results support the hypothesis that ACE inhibition is a key factor in the behavioral antidepressant-like activity of perindopril and perindoprilat.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

What role for prednisone in prevention of acute graft-versus-host disease in patients undergoing marrow transplants?

One hundred forty-seven consecutive patients with leukemia, myelodysplastic syndrome, or aplastic anemia were treated by marrow grafts from genotypically HLA-identical siblings (n = 122) or HLA-haploidentical family members (n = 25). Haploidentical recipients differed from their donors for no more than one HLA locus on the nonshared haplotype. All were given postgrafting immunosuppression with a combination of methotrexate and cyclosporine. In a randomized study we explored whether prednisone administered from day 0 through 35 along with methotrexate/cyclosporine could improve prevention of acute graft-versus-host disease (GVHD). The GVHD incidence in patients not given prednisone was comparable with that previously reported with methotrexate/cyclosporine. Unexpectedly, significant increases in acute and also chronic GVHD were seen in HLA-identical recipients administered prednisone, but not in the small number of patients administered HLA-nonidentical grafts. However, the resultant increase in transplant-related mortality in patients administered prednisone was offset by an increase in leukemic relapse in patients not administered prednisone, presumably related to the absence of a graft-versus-leukemia effect. Therefore, overall disease-free survival of the two groups of patients was comparable, with slightly more than 50% of the patients being alive at more than 2 years after transplantation. We speculated that prednisone adversely affected GVHD prophylaxis, interfering with methotrexate's cell cycle-dependent suppression of donor lymphocyte proliferation in response to host antigens. In a pilot study we explored whether beginning prednisone on day 15, after completion of methotrexate administration, would avoid this adverse effect. The GVHD incidence in patients administered methotrexate/cyclosporine along with "late" prednisone was comparable with that in patients not administered prednisone. We conclude that methotrexate/cyclosporine is effective in decreasing the incidence of grade II through IV GVHD, and that the addition of prednisone to this regimen is not beneficial in recipients of HLA-identical marrow grafts.

Acute Disease↗
PubMed1990

Antidepressant-like action of 8-OH-DPAT, a 5-HT1A agonist, in the learned helplessness paradigm: evidence for a postsynaptic mechanism.

In animal models of depression, the 5-HT1A agonists, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), buspirone, gepirone and ipsapirone administered i.p. have been shown to mimic the behavioural effects of antidepressants. For instance, in the present study, using the learned helplessness paradigm, 8-OH-DPAT dose-dependently reversed helpless behaviour. To assess the possible role of pre- or postsynaptic 5-HT1A receptors in this effect, the ability of 8-OH-DPAT to reduce helpless behaviour was investigated following (1) i.p. administration (0.125 or 0.25 mg/kg/day) in rats whose ascending 5-HT neurons were partially destroyed by previous 5,7-dihydroxytryptamine (5,7-DHT) injection (5 micrograms free base in 0.6 microliter) into the raphe nuclei or (2) after local microinjection (0.1 or 1.0 microgram in 0.5 microliter) into the raphe nuclei or into the septum. The reversal of helpless behaviour by 8-OH-DPAT (i.p.) was still observed in 5,7-DHT-treated rats with telencephalic 5-HT uptake reduced by 50-75% depending on the region. 8-OH-DPAT microinjected into the raphe nuclei did not reverse helpless behaviour; in contrast, 8-OH-DPAT microinjected into the septum reversed helpless behaviour. These results suggest that the ability of 8-OH-DPAT to reverse helpless behaviour probably involved the stimulation of postsynaptic rather than presynaptic 5-HT1A receptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Captopril as an antidepressant? Effects on the learned helplessness paradigm in rats.

Several clinical investigations have suggested that captopril, an angiotensin-converting enzyme inhibitor (ACEI), currently used as an antihypertensive agent, exhibited anti-depressant properties in humans. The present experiment was evaluated for potential antidepressive activity of captopril on the learned helplessness paradigm in rats. Captopril (8, 16, 32 mg/kg/day, IP) induced a reversal of escape deficits but did not affect significantly the motor activity, suggesting that this effect was not due to motor stimulation. This antidepressant-like activity was comparable to that of imipramine (16, 32 mg/kg/day, IP). Naloxone (0.5; 1 mg/kg, IP) blocked the effect of captopril (16 mg/kg, IP) in this test. These results suggest that an opioid mediation could be responsible at least in part for its behavioral effect.

Animals↗
PubMed1990

Use of an anti-pan T-lymphocyte ricin a chain immunotoxin in steroid-resistant acute graft-versus-host disease.

Acute steroid-resistant graft-versus-host disease (AGVHD) after allogeneic bone marrow transplantation is frequently fatal. A new treatment for this T-lymphocyte-mediated condition uses an immunotoxin, H65-RTA, comprised of a monoclonal antibody that recognizes the CD5 lymphocyte differentiation antigen coupled to ricin A chain, a cytotoxic enzyme that inhibits protein synthesis. The safety and efficacy of this lymphocyte-targeted immunotoxin was evaluated in patients with severe AGVHD in a phase I-II dose escalation study with group expansion at the two middle doses. Thirty-four patients received up to 14 daily intravenous infusions of the immunotoxin. The principal side effects were constitutional symptoms such as fatigue and myalgias, and hypoalbuminemia with weight gain was seen at all doses. Thirty-two patients were evaluated for improvement or resolution of disease. Durable complete or partial responses were not dose-related and were seen in 16 patients. Skin GVHD had the highest incidence of response (73%), although improvement or resolution in gastrointestinal tract (45%) and liver (28%) GVHD was also noted. Survival in responding patients was significantly prolonged at all times as compared with those with no response (P = .03). Treatment was associated with a rapid decrease in peripheral blood T lymphocytes, which persisted for greater than 1 month after therapy. Anti-immunotoxin antibodies were seen in 6 of the 23 patients tested; these were of low titer and did not block immunotoxin binding to T cells. Results of this study indicate that anti-T-lymphocyte immunotoxins may form a new class of immunosuppressive agents useful in T-lymphocyte-mediated diseases.

Adrenal Cortex Hormones↗
PubMed1990

Detection of experimental thrombi in rabbits with an 131I-labelled fibrin-specific monoclonal antibody.

The detection of thrombi in rabbits has been investigated with 131I-labelled DD-3B6/22, a monoclonal antibody (Mab) reactive at high affinity (Kd = 2.68 x 10(-10) M) with human D Dimer (DD). DD-3B6/22 bound well to both "fresh" and "aged" human clots in an in vitro assay but showed poor binding to rabbit clots. However, reactivity was restored to rabbit blood if it was seeded, before clotting, with human DD covalently coupled to Sepharose beads. Thus, a rabbit model was developed in which blood was allowed to clot around DD-Sepharose beads introduced into the jugular vein. Gamma camera imaging showed that intact 131I-labelled DD-3B6/22 localised to these clots within 24 h. Uptake at this time was 0.202 +/- 0.012% injected dose per gram (%ID/g) compared with 0.086 +/- 0.018%ID/g after injection of control antibody. 131I-labelled F(ab')2 fragments of DD-3B6/22 allowed earlier scintigraphic detection of the clot which was evident 4 h after injection. Uptake in the clot at 24 h was 0.154 +/- 0.038 %ID/g compared with 0.109 +/- 0.027 %ID/g for a control F(ab')2. As antigen levels in the clot are estimated to be less than 300 micrograms DD, thus representing a very small human clot, the DD-3B6/22 Mab would appear to have a good potential for the sensitive detection of thrombi in a clinical setting.

Animals↗