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Biomedical subjects

M Welsch

Publications and source records attributed to M Welsch.

At least 19 recordsLinked to original sources
PubMed2006

[Nuclear medicine techniques in the diagnosis of orthopaedic diseases].

Nuclear medicine techniques show metabolic processes, allowing the diagnoses of many bone and joint disorders. For most orthopaedic indications three-phase bone scintigraphy is used, showing inflammatory bone and joint diseases, traumatic and post-operative disorders as well as necrotic or malignant changes. In addition to bone scintigraphy, there are radiopharmaceuticals to depict inflammatory processes. Finally, positron emission tomography is a modern imaging technique used mainly for tumor diagnostics, but also for detection of inflammation.

Bone Diseases↗
PubMed2003

Hypereosinophilia-induced digital necrosis in a smoking patient.

Raynaud's phenomenon and digital necrosis of the fingers are rare complications of hypereosinophilia. We report a case of a smoking male who developed Raynaud's phenomenon and digital necrosis of the fingers associated with idiopathic hypereosinophilia with angiographically documented occlusion of small and medium arteries of the extremities. The eosinophils may play a thrombotic role in vascular pathology and eosinophil blood count should be checked when investigating patients with digital gangrene.

Adult↗
PubMed2001

Forearm vasoreactivity in type 1diabetic subjects.

This study compared forearm vasoreactivity in 15 Type I diabetic subjects with 15 healthy controls. The groups were matched for age, exercise capacity, and the absence of other cardiovascular risk factors. Vasoreactivity was measured using strain gauge plethysmography, at rest, after arterial occlusion (OCC), and following OCC coupled with handgrip exercise (ROCC). Forearm blood flows were significantly elevated between conditions 2.58 +/- 0.37ml/100mltissue at rest to 26.80 +/- 6.56 after OCC and 32.80 +/- 8.26ml/100mltissue following ROCC in Type I diabetic subjects. There were no differences in forearm blood flow between groups for any of the conditions. These data indicate the degree of forearm blood flow is directly related to the intensity of the vasodilatory stimulus. However, our study did not reveal evidence of impaired vasodilatory capacity in Type I diabetic subjects compared to controls in the absence of other risk factors.

Adult↗
PubMed2000

[The French pharmacovigilance system: structure and missions].

THE NETWORK: The French pharmacovigilance system is composed of a network of 31 regional pharmacovigilance centers located in convenient proximity to health care professionals. CAUSALITY ASSESSMENT: A causality assessment method is compulsory for all persons involved in pharmacovigilance in order to assess the causal relationship between an adverse effect and one or more drugs. PHARMACOEPIDEMIOLOGY: If necessary, an additional evaluation of the causal relationship is performed using pharmacoepidemiology methods. THE NATIONAL COMMISSION: A technical committee and a National Commission of Pharmacovigilance centralizes at the Agence Françiase de Sécurité Sanitaire (or AFSSAPS) and assesses all data in order to provide consensual advise to the relevant authorities on necessary measures, to prevent or reduce a drug-related adverse effect.

Adverse Drug Reaction Reporting Systems↗
PubMed2000

[Sodium intake and hypertension].

The guidelines for hypertension treatment recommend a reduction of dietary sodium intake. There is still a controversy, few studies showing an inverse correlation between cardiovascular morbidity and salt intake, about the benefit expected from a reduction of sodium intake on the blood pressure level. This controversy is explained by the great variability of the pressure response when individuals are exposed to different sodium intakes, diet and environmental factors playing an additional role of variability. Salt sensitivity is more frequent in hypertensive, obese and in elderly patients. There is no harm to reduce salt overtake moreover normalisation of the dietary sodium intake has clearly demonstrated its ability to reduce hypertension complications in patients at high cardiovascular risks.

Cardiovascular Diseases↗
PubMed1998

Ginseng supplementation does not enhance healthy young adults' peak aerobic exercise performance.

OBJECTIVE: To determine the short term effects (21 days) of 200 mg (7% standardized) Panax ginseng supplementation vs. placebo on peak aerobic exercise performance in healthy young adults, with unrestricted diets. METHODS: Twenty men and eight women (age = 23.2 +/- 3.2 years, height = 175.8 +/- 8.6 cm; weight = 75.2 +/- 15.3 kg) were randomly assigned to either a Panax ginseng or placebo group for a period of 3 weeks in a double blind design. Prior to and following treatment the subjects performed a symptom limited graded exercise test on a Schwinn Airdyne ergometer. The data were analyzed using an analysis of variance. RESULTS: No significant treatment effect was observed for the dependent variables of VO2, exercise time, workload, plasma lactate and hematocrit at peak levels, or for heart rate and rate of perceived exertion at 150 watts, 200 watts and peak. CONCLUSIONS: The results of this study do not support an ergogenic effect on peak aerobic exercise performance following a 3-week supplementation period of 200 mg 7% Panax ginseng in healthy young adults with moderate exercise capacities and unrestricted diets.

Adult↗
PubMed1996

Primary hepatic pheochromocytoma.

Pheochromocytomas are uncommon tumors that represent a potentially curable cause of hypertension. They are usually located in the adrenal glands, but 10% arise from extra-adrenal sites, located along the paravertebral sympathetic chains. We report a case of primary hepatic pheochromocytoma responsible for a severe hypertension in a 24-year-old man. Echotomography showed a lightly heterogeneous mass located in the segment 8 of the liver. Iodine 131-metaiodobenzylguanidine scintigraphy showed a large hepatic concentration of the tracer and no other localization. This tumor appeared highly vascularized on enhanced CT scan and on aortic angiography. Magnetic resonance imaging revealed a hepatic tumor with a high signal intensity on T2-weighted images and with a signal isointense to the liver on T1-weighted images. The hepatic venous sampling contained the highest catecholamine level, whereas the adrenal venous sampling was normal. After surgical resection of the hepatic tumor, the tension level and catecholamines plasmatic level normalized. No recurrent symptoms appeared during a 3-year follow-up.

3-Iodobenzylguanidine↗
PubMed1996

Interruption of prolonged ramipril treatment in hypertensive patients: effects on the renin-angiotensin system.

The increase in renin secretion and the induction of the converting enzyme (ACE) observed during treatment by ACE inhibitors (CEIs) could result in increased angiotensin II (ang II) synthesis when the treatment is stopped. The object of this study was to compare changes in the components of the renin-angiotensin system with changes in arterial pressure in hypertensives, following the cessation of long-term ramipril treatment. Twenty hypertensives, treated for at least three months with ramipril, in monotherapy for the last three weeks, were randomly allocated to two parallel groups and received for fifteen days, on a double-bind basis, either a placebo (withdrawal group W, n = 12) or ramipril at the previous doses (treated group T, n = 8). Blood pressure was measured using four different techniques. The active renin (AR), angiotensinogen, angiotensin I (ang I), angiotensin II (ang II) and aldosterone plasma concentrations were measured, as was plasma angiotensin I converting enzyme (ACE) activity in vitro (colorimetric and fluorimetric method) and in vivo (the ang II/ang I ratio). The biological effects of cessation of long-term ramipril treatment in hypertensives were a decline in AR and angiotensin I concentrations, an increase in ACE activity and no significant changes in angiotensinogen, angiotensin II and aldosterone levels. Fifteen days after withdrawal, the different parameters of the renin-angiotensin system appear to have returned to basal value. A slow rise in blood pressure was also observed but no rebound increase was noted during the 15 days neither in angiotensin II levels nor in blood pressure. Following the cessation of prolonged ramipril treatment, in vivo converting enzyme inhibition disappears slowly, probably on account of the slow tight binding inhibitor properties of ramiprilat, the active metabolite of this CEI. The gradual decline in AF, plasma levels, together with the prolonged ACE inhibition as measured in vivo by the ang II/ang I ratio, explains the absence of a rise in ang II synthesis.

Aldosterone↗
PubMed1994

Over-additive protective effect of dizocilpine and NBQX against neuronal damage.

Several reports have indicated that the two glutamate receptor antagonists, dizocilpine (that binds to the phencyclidine recognition site of the NMDA (N-methyl-D-aspartate) receptor) and NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline, that binds to the AMPA (alpha-amino-3-hydroxy-5-methyl-isoxazole) receptor), protect neurons against damage caused by hypoxia, ischemia or excitotoxicity. We, therefore, used a combination of these drugs to achieve enhanced neuroprotection. Primary cultures of rat hippocampal neurons were challenged by glutamate intoxication. Both dizocilpine and NBQX produced dose-dependent increases in the percentage of viable neurons. Combined treatment with both glutamate receptor antagonists had an over-additive neuroprotective effect. Simultaneous administration of dizocilpine and NBQX also had a pronounced neuroprotective effect in vivo in mice subjected to focal cerebral ischemia and rats with global forebrain ischemia. This suggest that such a combination may have therapeutic relevance.

Animals↗
PubMed1993

Effects of serotonergic drugs in experimental brain ischemia: evidence for a protective role of serotonin in cerebral ischemia.

We have examined the significance of the serotonergic system in the pathophysiology of ischemic brain damage. Permanent occlusion of the middle cerebral artery (MCA) was performed in male NMRI mice. After 48 h, the animals received a transcardiac injection of carbon black. The area of ischemia was restricted to the neocortex and its size was determined planimetrically by means of an image analyzing system. In control experiments, the NMDA antagonist dizocilpine (MK-801), the AMPA/kainate antagonist NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(F)-quinoxaline) and the L-type calcium channel blocker nimodipine all produced a significant reduction in ischemic injury of the mouse neocortex. Interestingly, all of the 5-HT1A agonists tested (ipsapirone, CM 57493 [4-(3-trifluoromethylphenyl)-1-(2-cyanoethyl)-1,2,3,6-tetrahydropyridine ] and urapidil) were equally efficacious in reducing ischemic injury. On the other hand, the 5-HT2 antagonist naftidrofuryl failed to protect the brain tissue significantly against ischemic brain damage. Roxindole, a 5-HT1A agonist and 5-HT uptake inhibitor, was the most potent serotonergic compound tested. In order to examine the effects of 5-HT1A receptor activation in a different context, 10 min of forebrain ischemia was induced in male Wistar rats by a bilateral occlusion of the common carotid arteries combined with systemic hypotension. Administration of the 5-HT1A agonist CM 57493 reduced the neuronal damage within the ventral hippocampus and the entorhinal cortex as assessed histologically 7 days after ischemia. Finally, we found that 5-HT1A agonists are capable of reducing neuronal damage of cultured neocortical and hippocampal neurons subjected to a chemical hypoxia or glutamate in a dose dependent manner. These data suggest that 5-HT, released during ischemia, may have protective effects in the pathophysiology of ischemic brain damage through a direct action on neurons mediated via the inhibitory 5-HT1A receptor subtype. The results obtained from different in vivo and in vitro models indicate that 5-HT1A agonists are promising agents for the treatment of ischemic brain disorders.

Animals↗
PubMed1993

[Captopril test for detecting renal artery stenosis: changes in plasma renin concentration].

The aim of this study was to demonstrate the diagnostic value of changes in active renin concentration during the captopril test (measurements of plasmatic active renin concentrations, before 12.5 or 37.5 mg of captopril p.o., and 30 and 90 minutes after) in order to screen a significant renal artery stenosis. After a renal angiography, 88 hypertensive patients suspected of renovascular hypertension were classified according to the percentage of stenosis in the main renal artery: class I (< 30% - n = 50), II (30 to < 75% - n = 21), III (75 to < 90% - n = 8) and IV (90 to 100% - n = 11). The results of the captopril test were compared to those of renal angiography. The active renin before the test (basal AR), the greater increase in active renin after captopril (max AR), the difference between max AR and basal AR (DIF) and the active renin relative change after the test (RC) were compared in the 4 classes (ANOVA). There were no differences in diastolic blood pressure (> or = 90 mmHg) natriuresis (100 mmol/24 h in mean) between these different classes. The basal AR, the max AR, the DIF and the RC significantly differed between the 4 classes. They were greater in class III and IV than in class I. The positive criteria for the captopril test were max AR, DIF and RC. The positivity thresholds were max AR > or = 70 ng/l, DIF > or = 50 ng/l and RC > or = 165% (upper limit in the class I 95% confidence interval for each criterion).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Ambulatory or single measurement of blood pressure: comparison in a controlled trial in patients with hypertension].

Single measurement during a visit and the calculation of blood pressure pattern from an ambulatory record are different criteria for evaluation of the efficacy of antihypertensive treatment. Results obtained by these two methods were compared in a controlled trial. Acebutolol or enalapril were given double-blind to 17 patients with uncomplicated moderate essential hypertension. After a two week run-in period (with dummy treatment), patients were allocated at random into two parallel groups. They took acebutolol (400 mg) or enalapril (20 mg) as a single daily dose for 3 months. Ambulatory measurement of blood pressure for 24 hours (Spacelabs 5200 SPM) was carried out the day prior to final inclusion, and at the end of the first then the third month of active treatment. A single measurement of blood pressure took place at the same times. Safety/acceptability of treatment based upon clinical and laboratory parameters was good. At inclusion, single measurements showed that all patients had a diastolic blood pressure (DBP) over 95 mmHg. However, ambulatory BP was significantly lower in the enalapril group. With treatment, the fall in DBP by single measurement was significant only at the first month with enalapril and at the third month with acebutolol while the effects of both drugs were significant on ambulatory systolic blood pressure (SBP) and DBP by the first month. Ambulatory BP revealed a superior antihypertensive action of acebutolol on SBP at the third month but this was not shown by single BP measurements. These results confirm the specificity of trial protocols of antihypertensive drugs based upon ambulatory BP measurements.

Acebutolol↗
PubMed1992

A mouse model of focal cerebral ischemia for screening neuroprotective drug effects.

The aim of the present study was to investigate if the infarct area on the brain surface after middle cerebral artery (MCA) occlusion in the mouse is representative for the infarct volume and if this determination of brain injury can be used for screening neuroprotective drug effects. Cerebral infarction was induced by coagulating electrically the stem of the left MCA. After 48 hr, the brains were perfused with carbon black and the unstained infarct area was determined by means of an image analyzing system. The infarct volume was determined by calculating the infarct area on coronal slices and the distance between succeeding slices. The correlation between the area and the volume of infarction was significant (r = 0.81; p less than 0.001). N-methyl-D-aspartate (NMDA) antagonists, calcium antagonists, 5-hydroxytryptamine-1A (5-HT-1A) agonists, radical scavengers, and various drugs were investigated in the mouse model of MCA occlusion. Drugs were usually applicated before ischemia. The drugs that were found to be neuroprotective in the mouse model revealed similar effects in rat models of focal or global cerebral ischemia. These findings show that the presented mouse model with its simple technique of measuring the infarct size is suitable for screening purposes.

Animals↗
PubMed1992

In vitro stability of the inhibition of serum converting enzyme by fosinopril.

With captopril, it has been shown that an erroneous measurement of serum angiotensin converting enzyme (ACE) can be induced by the dissociation of the inhibitor-ACE complex during long-term storage. We have studied the possible dissociation of the fosinopril-ACE complex during the storage of serum samples from healthy male volunteers given a single dose of fosinopril. Serum samples were collected from 5 volunteers, 5 min before, then 4 and 24 h after a unique oral dose of 10 mg fosinopril. ACE activity was measured by a colorimetric and a fluorimetric assay during the hour following the sampling (day 0) and after 21 or 61 days of storage at -20 or -196 degrees C. The degree of ACE inhibition measured in vitro in fresh serum samples differed according to the technique used. Fosinopril has a long-lasting effect with 80% inhibition 24 hours after drug administration. Storage at -20 and -196 degrees C induced a significant decrease in the degree of inhibition measured with the colorimetric method. With the fluorimetric method, a decrease in ACE inhibition was only observed after storage at -20 degrees C but not at -196 degrees C.

Administration, Oral↗