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Biomedical subjects

A Valentin

Publications and source records attributed to A Valentin.

125 records · Page 7Linked to original sources
PubMed1989

In vitro relationship of CD4 cells from type I diabetic patients and xenogeneic beta-cell membranes.

In a rosette assay, 63 patients with recent-onset type I (insulin-dependent) diabetes mellitus had a higher (P less than .001) number of lymphocytes adhering to rat insulinoma RINm5F cells (diabetic rosettes) than 153 healthy control (background rosettes) or 20 nondiabetic subjects with other organ-specific autoimmune diseases. Furthermore, lymphocytes from diabetic patients displayed a highly correlated (r = .97, P less than .001) binding on two different xenogeneic beta-cell lines (RIN and hamster insulinoma HIT cells). This phenomenon was not found on a panel of seven non-beta-cell lines (e.g., exocrine pancreatic cells, endocrine cells). By increasing lymphocyte-to-RIN ratios (0.25:1 to 30:1), the supernumerary RIN-adherent lymphocytes from diabetic patients, expressed as the percentage of lymphocytes involved conjugates, were only detectable at lower ratios (0.25:1 to 4:1), and their binding efficiency was two times higher than that of control lymphocytes. This efficiency fell at higher ratios (greater than 4:1) to the level of background rosettes that remained constant through the ratio scale. This specific RIN-rosette formation was abrogated when lymphocytes from diabetic patients were preabsorbed on beta-cells (either HIT or RIN) but not on non-beta-cells, whereas preabsorption of control lymphocytes did not modify the number of background rosettes. In addition, diabetic rosettes, but not background rosettes, were inhibited by competition with RIN membrane extracts but not by non-beta-cell extracts. Moreover, diabetic rosettes were inhibited during blocking experiments with anti-CD3 monoclonal antibody (MoAb) but not with unrelated MoAbs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Effects of naftidrofuryl in patients with intermittent claudication.

In a randomized, double-blind, placebo-controlled study in patients with peripheral arterial occlusive disease stage IIb of Fontaine's classification, the efficacy of naftidrofuryl, a vasoactive substance, was investigated. Forty patients--31 men and 9 women with an average age of 62.98 +/- 10.65 years--were admitted to the study. All had a history of claudication for at least six months. The duration of the trial was eighteen weeks. After a washout period of two weeks the patients received either two times 400 mg naftidrofuryl or two identical placebo tablets daily for eight weeks. Subsequently a crossover from verum to placebo and vice versa was carried out and the alternative medication was administered for another eight weeks. Clinical results were evaluated by measuring painfree and maximal walking distance by treadmill test at a speed of 3.2 km/h and an inclination of 12 degrees. Systolic ankle pressure and brachial pressure were measured by Doppler ultrasound, and ankle/arm pressure ratio was calculated. Treadmill test, Doppler ultrasound examination, and laboratory data analysis were performed at the beginning of every study period, every four weeks during and at the end of the study. Results. The patients in both groups showed an initial homogeneity of age, risk factors, concomitant diseases, walking distance, and Doppler indices. After eight weeks naftidrofuryl resulted in a statistically significant increase in painfree (p less than 0.02) and maximal walking distance (p less than 0.05). The placebo-treated group showed only a slight, statistically nonsignificant increase in both painfree and maximal walking distance.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Cerebral ischemia in children and young adults.

Cerebral ischemia is very rare in children and young adults. There can be a multitude of causes; in many cases etiology remains undetermined. We report here on 7 cases, 11 to 25 years of age. Pathogenetic factors (lupus erythematodes, endocarditis, fibromuscular dysplasia) and risk factors (cigarette smoking, oral contraceptives) were found in 5 patients whereas in 2 cases the etiology was not determinable. Three patients were treated with low weight dextrans, two patients received prostaglandin E1, and in 2 cases regional thrombolysis was performed. Three female patients died, two with occlusions of the rostral part of the basilar artery and one with an occlusion of the carotid artery and lupus erythematodes as the primary disease. Long-term observations of the surviving patients showed good recovery from neurological deficits. Prognosis quoad sanationem seems better in this age group than in elderly patients.

Adolescent↗
PubMed1987

Different effects of beta-1-adrenergic blocking agents with ISA or without ISA on peripheral blood flow.

Until recently beta-adrenergic blocking agents were considered contraindicated in peripheral arterial occlusive disease (PAOD). However, in recent years several studies have failed to show negative effects on peripheral blood flow. It was the aim of this study to compare the effects of celiprolol, a beta-1-adrenergic blocking agent with intrinsic sympathomimetic activity (ISA), and of metoprolol, a beta-1-adrenergic blocking agent without ISA, on peripheral blood flow of patients with and without PAOD. In an acute trial 24 patients (group I: 12 patients with PAOD stage I and II; group II: 12 patients without PAOD received a single dose of 200 mg celiprolol or 200 mg metoprolol in a double-blind crossover design. Celiprolol induced no significant changes in calf and skin blood flow at rest or during reactive hyperemia. Basal vascular resistance (BVR) and minimal vascular resistance (MVR) were not affected. Metoprolol, however, significantly reduced muscle blood flow and increased BVR in both groups. Subsequently the patients were treated in a randomized double-blind design with a daily dose of 200 mg celiprolol or metoprolol for three weeks. In long-term treatment skin and muscle blood flow at rest and during reactive hyperemia, BVR, and MVR were not affected by celiprolol. Metoprolol significantly lowered calf blood flow at rest in patients with PAOD; other parameters remained unchanged. In patients without PAOD, metoprolol caused a significant decrease of calf blood flow at rest and an increase of BVR. Calf blood flow during reactive hyperemia, as well as skin blood flow at rest and during reactive hyperemia, showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Psychophysiological and behavioral differences as a function of age and Parkinson's disease.

Differences related to age and to specific neurological (Parkinsonian) damage were studied by contrasting, respectively, old (mean age 64 years) and young (27 years) subjects (N = 15), and old-normal (N = 15) and old-Parkinsonian (N = 15) subjects. Both behavioral as well as psychophysiological dependent variables were employed. The behavioral measure was performance on a discrimination learning task, while the psychophysiological measures were based on habituation to a repeated tone stimulus and on a Pavlovian differential conditioning preparation. The behavioral task showed predominantly age-related differences, with the young learning faster. Another age-related difference was interpreted as showing a more insight-like learning process in the young. Response-bias (beta) values did not differ between groups. Age-related differences also emerged more clearly than specific-neurological-damage differences in the psychophysiological data. The older subjects manifested markedly less autonomic conditioning, which was probably due to a lowering of reactivity, as well as the emergence of habituation to the (loud-noise) unconditional stimulus. A correlational analysis of discrimination conditioning also yielded age-related differences. Most notably, reactivity played a greater role in conditioning in the old than in the young subjects. The results illustrated how psychophysiological measures can provide information that complements those provided by behavioral measures.

Adult↗
PubMedDate not supplied

Antimalarial activity in vitro of Cochlospermum tinctorium tubercle extracts.

Resistance of Plasmodium falciparum to current antimalarial compounds has drastically increased during the last few years and is now a major public health problem. We have studied plants traditionally used in Africa against malaria. Extracts of the tubercles of Cochlospermum tinctorium A. Rich, commonly used in Burkina Faso, were tested in vitro on 2 strains of P. falciparum, one (FcB1-Colombia) chloroquine resistant and the other (F32-Tanzania) chloroquine sensitive. Extracts were obtained by infusion and decoction. The 50% inhibitory concentrations (IC50) were determined by measuring [3H]hypoxanthine incorporation and also by microscopical examination which permitted the determination of parasite stages. We obtained similar results with fresh extracts, frozen extracts, and lyophilized extracts of C. tinctorum. IC50 values were of the order of 1-2 micrograms/mL, about one-tenth of those reported for extracts of neem leaves (Azadirachta indica) and about half the values reported for Artemisia annua extracts.

Animals↗
PubMedDate not supplied

Avoiding pitfalls in tibial bone plug fixation in anterior cruciate ligament reconstruction.

Performing arthroscopic anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone autograft normally includes placing sutures in the femoral bone plug to be able to pull the graft through the joint, and in the tibial bone plug to be able to apply tension to the graft as you insert the distal interference screw. We have used one No. 5 Ethibond suture (Ethicon, Somerville, NJ) for the femoral bone plug, and normally place two similar sutures into the tibial bone plug. This is to reduce the risk of loosing tension if one of the sutures is cut while inserting the tibial fixation screw. This article suggests a solution to the problems that will arise in cases of accidentally cutting both of the sutures in the tibial bone plug.

Anterior Cruciate Ligament↗
PubMedDate not supplied

Control of Candida albicans vaginitis in mice by short-duration butoconazole treatment in situ.

A short-duration treatment for candidal vaginitis applying butoconazole in situ was tested in an experimental mouse model. One week after artificial induction of an oestrus state (by oestradiol benzoate injection), mice were inoculated intravaginally with 1.5 x 10(7) blastospores of Candida albicans (strain ATCC 44858). Treatment consisted of butoconazole solutions (1%, 2.5% and 5%) administered intravaginally. The development of the infection was monitored daily for 12 days and then three times a week by local samples plated on BiGGY agar. In parallel, twice a week, the vaginas of three mice in each group (control and treated groups) were isolated in order to estimate organ invasion by C. albicans. This was assessed by anatomopathological studies on a fixed and stained part of the organ and by serial dilutions of a homogenate of the remaining part plated on Sabouraud glucose chloramphenicol agar. After a 48-h incubation period the number of colony forming units per gram of tissue was counted. For each treatment, a remission of 10-15 days was observed, but was followed by a recurrence for the lower dose of butoconazole; only the higher butoconazole concentrations tested (2.5% and 5%) gave an apparent full cure for most of the mice tested. The use of the mouse model of candidal vaginitis confirms that short-duration treatment is possible when elevated doses of butoconazole are used.

Animals↗
PubMedDate not supplied

[Method of formalization and transfer of emergency psychiatric expertise].

The different steps of the project and mainly the knowledge acquisition process in the field of emergency medicine meant for French Navy warships are described. We focus on Psychiatry and more especially on the subset of pathologies that may lead to suicide. A knowledge base dealing with these questions is connected to a hypothetico-deductive automaton that is able to simulate physician's reasoning. From initial symptoms gathered by the user, the system dynamically focuses the interferences in order to suggest an adequate policy, even under relative uncertainty, taking into account the logistic and operational conditions on board. The final goal is to integrate other emergency medicine fields into the expert system shell.

Clinical Protocols↗
PubMedDate not supplied

Impact of thrombolytic therapy for myocardial infarction in the Bayamón Public Health Care Sector--1993-1995 experience.

UNLABELLED: The study was designed to evaluate the compliance of general management guidelines, determine the effectiveness of Thrombolytic therapy (TTX), determine the complications, statistics and the "Door to Needle" time (DTN) in the management of Myocardial Infarction (MI) in the Bayamón public health care sector. METHODS: Retrospective record review and SPSS statistical calculations were performed. RESULTS: 66 cases (49m, 17f) discharged with MI from January 1993 to June 1995 were included. 27 received TTX. 80% were between 30-69 y/o, while 20% from 70-87 y/o. Past hx and habits; smoker 62%, ETOH 45%. Labs in adm; hypoMG 15%, hypoK 11%. The Q MI = 63%, Non Q = 38%. The sinoatrial and ventricular arrhythmias were seldom seen (7.5% SVT, AIVR 3%). Intra and atrioventricular block (3%). The most frequent cardiac complication was CHF 10% and the non cardiac; BKP 16.5%. The mortality was (6.1%). The mean stay was 9.34 days. Therapy used; IV NTG 97%, ASA 84%, beta B 39%, TTX 42.2%, ACE inhibitors 32%. Absence of TTX was usually due to absence of EKG criteria (63%). TTX complications; hypotension 10.5%. The mean DTN was 1hr 58m,. 91% were discharged home, 23.3% cath, deaths 6%. The ER MD assessment of MI was correct in only 29%. CONCLUSIONS: The complications of patients with MI in the TTX era are below the ones before TTX. Mortality and morbidity have improved with the use of TTX. The medical therapy guidelines of MI are generally followed in HURRA. Improvement in the DTN is needed. The prolonged DTN and the inconsistency of the admission assessment by the ER personnel establishes the need to develop a training program which would regulate this abnormality.

Adult↗
PubMedDate not supplied

Survey of Babesia divergens antibody kinetics in cattle in western France.

Data collected from a longitudinal survey carried out over a 2-year period, in four dairy herds in western France, were used to assess Babesia divergens antibody kinetics. Farms were visited once a month. The total number of animals monitored was 236 including calves, heifers and cows of the Holstein and Normande breeds. An ELISA was used to follow the humoral response levels against Babesia divergens. When the study began, in the autumn of 1991 (200 animals), half of the animals were already seropositive (57.5%). In all four herds, the percentage of positive animals decreased during winter, and increased during spring. Antibody levels remained stable in 49 animals, high for some, very low or negative for others. Most seropositive animals showed at least one antibody peak at some time during the 2-year period, but some presented two to five. Among the calves, 61.3% showed seroconversion during the first pasture season. Similarly, 60% of the newly purchased cows showed increases in antibody levels during the 3 months after their introduction into a new herd, regardless of the initial antibody level. Only three dairy cows had expressed a clinical babesiosis, these cows were already seropositive. Clinical incidence is low in the four farms, nevertheless serological prevalence and incidence are high.

Aging↗