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Biomedical subjects

A J Smit

Publications and source records attributed to A J Smit.

133 records · Page 8Linked to original sources
PubMed1982

Antinuclear and antinative DNA antibodies during captopril treatment.

Antinuclear antibodies (ANA) developed in 13 out of 78 patients treated with captopril for a mean period of 11 months. In another 11 patients, who were ANA-positive before captopril therapy, no increase in ANA titer was observed during treatment. Neither the development nor the presence of ANA before captopril treatment were associated with (drug-induced) lupus erythematosus or increased incidence of clinical side-effects, although development of ANA was accompanied by a serum-sickness-like syndrome in one patient. The ANA were mainly of the IgM class, did not fix complement and were transiently present. In three patients, antinative DNA antibodies, exclusively of IgM class and not complement-fixing, were transiently present without clinical signs of systemic lupus erythematosus, although recurrence of these antibodies was associated with slight proteinuria in one of them.

Adult↗
PubMed1979

Competition for L-glutamate between specialised and versatile Clostridium species.

Clostridium cochlearium could be reproducibly enriched in an L-aspartate- and L-glutamate-limited, anaerobic chemostat inoculated with anaerobic sludge. L-glutamate, L-glutamine and L-histidine were the only fermentable substrates. Less specialised clostridia of the C. tetanomorphum type could only be isolated from batch enrichments with L-glutamate and L-aspartate as energy sources. Competition experiments with C. cochlearium and C. tetanomorphum in a L-glutamate-limited chemostat resulted in the selective elimination of the latter species. Addition of glucose to the medium resulted in coexistence of both species. The molar growth yields for L-glutamate at different dilution rates at 30 degrees C were determined for both species. The maximum specific growth rates on L-glutamate were 0.55 h-1 for C. cochlearium and 0.35 h-1 for C. tetanomorphum.

Anaerobiosis↗
PubMedDate not supplied

Isolated systolic hypertension from a vascular point of view.

Due to the results of antihypertensive intervention studies, isolated systolic hypertension (ISH) has gained new interest lately. Yet, apart from increased aortic stiffness, the specific pathophysiological features of ISH have remained largely undetermined. Therefore, we investigated the elastic properties of the vascular bed of an upper arm segment in uncomplicated ISH patients and matched normotensive controls using an electrical bioimpedance technique. Compared with the controls, the compliance of the arterial bed as a whole at normotensive blood pressure level was on the average 108.0% higher (p < 0.005) in the hypertensive patients. The blood volume of the arterial bed as a whole at operating blood pressure level and that of the larger arteries were significantly higher (40.5%, p < 0.05, and 40.5%, p < 0.01, respectively). The same held true for the venous blood volume (64.4%, p < 0.05), and for the width of the arterial compliance-pressure relation (34.6%, p < 0.01). We concluded that ISH is a separate pathophysiological entity in which all parts of a peripheral vascular bed are changed and the decreased buffering function of the aorta and large arteries is partly compensated for by an increase in small artery compliance.

Aged↗
PubMedDate not supplied

Improved reproducibility of the 'large-window' method of assessing transcapillary and interstitial fluorescein diffusion in the skin in healthy subjects and in subjects with insulin-dependent diabetes mellitus.

The transcapillary and interstitial diffusion of intravenously administered sodium fluorescein is used as a marker for capillary permeability. Fluorescein diffusion has been expressed by different parameters with reported coefficients of variation of 14-20%. Aim of the present study is to select a parameter which combines excellent reproducibility with the potential for discriminating insulin-dependent diabetic patients from healthy subjects. We performed three experiments to assess day-to-day reproducibility: 5 healthy subjects were measured twice, 1 healthy subject was measured 6 times and 1 subject with insulin-dependent diabetes mellitus was measured 5 times. We averaged the relative fluorescence light intensity (IREL(t)] from dye arrival until a certain time point [IAV(t)], instead of using the relative intensity at one time point. IAV (7 min) showed markedly improved reproducibility, expressed as geometric mean of the coefficients of variation of the three separate experiments: 10%. In addition, a group of 12 insulin-dependent diabetic subjects was compared with 12 healthy control subjects. Median IAV (7 min) was 69.5% (95% CI: 65.3-78.1%) in the diabetic subjects and 54.9% (95% CI: 52.1-60.0%) in the control subjects (p < 0.001). Since IAV (7 min) combines excellent reproducibility with a good discriminating power, we advise its use in further studies.

Adult↗
PubMedDate not supplied

Use of dopamine in the ICU. Hope, hype, belief and facts.

Dopamine is frequently administered in the ICU to critically-ill patients. The widespread use of dopamine does not only involve states of distributive and cardiogenic (imminent) shock, but also prophylaxis for deterioration and/or improvement of kidney- and bowel perfusion. Although many studies have shown an increase of renal- and (in some studies) improvement of splanchnic circulation, well controlled studies have failed to demonstrate a better outcome with respect to renal function and/or survival of prophylactic dopamine administration. Furthermore, evidence exists that norepinephrine is more efficacious in fluid resuscitated septic shock patients to restore blood pressure than dopamine, without jeopardizing the renal function. It is concluded that the widespread use of dopamine in the ICU should be reassessed.

Dopamine↗
PubMedDate not supplied

[New dopamine agonists in cardiovascular therapy].

Dopamine, a naturally occurring catecholamine, has been extensively used in intensive care for many years. Dopamine stimulates different types of adrenergic receptors: alpha-1 and -2, beta-1 and -2, and dopamine-1 and -2. The renal effects of dopamine are the result of dopamine-1 receptor (DA1) stimulation: renal vasodilation and natriuresis. DA2-receptor stimulation lowers plasma aldosterone and norepinephrine levels. Recently, several new dopamine agonists have been developed. Fenoldopam, a selective DA1-agonist, induces renal and systemic vasodilation with an increase in renal blood flow. This is accompanied by an increase in natriuresis and diuresis. Dopexamine, a DA1- and beta-2 agonist, is administered intravenously. It is used, like dopamine, in the treatment of congestive heart failure. However, the use of dopamine (and dopexamine) is limited by its unique intravenous availability. Ibopamine is an selective dopamine agonist for oral use. Several clinical studies have demonstrated the efficacy of ibopamine in the treatment of patients with congestive heart failure and its mild renal effects.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗