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Biomedical subjects

P Gasser

Publications and source records attributed to P Gasser.

At least 19 recordsLinked to original sources

Capillary blood cell velocity in finger nailfold: effect of enalapril and mibefradil in patients with mild to moderate hypertension.

Outpatients with essential hypertension were randomized to receive antihypertensive treatment with either mibefradil or enalapril. Ambulatory blood pressure measurement (ABPM) and video capillary microscopy of the finger nailfold were performed at baseline and after 12 weeks of treatment. In the enalapril group (n = 21) baseline ABP was 156 +/- 12/100 +/- 9 mm Hg and decreased to 140 +/- 17/89 +/- 10 mm Hg after 12 weeks. In the mibefradil group (n = 22) mean 24-h ABP decreased from 159 +/- 14/102 +/- 7 to 140 +/- 10/89 +/- 7 mm Hg. Capillary blood cell velocity (CBV) without treatment was 0.90 +/- 0.58 mm/s (mean +/- SD) and 0.83 +/- 0.46 mm/s at rest and 0.30 +/- 0.22 and 0.21 +/- 0.20 mm/s immediately after local finger cooling in the mibefradil and the enalapril group, respectively. In the Enalapril group CBV at week 12 was 0.99 +/- 0. 60 mm/s (n.s.) at rest and 0.40 +/- 0.28 mm/s immediately after local cooling (P = 0.005 compared to 0.21 +/- 0.20 mm/s without treatment). Twelve weeks after initiation of treatment CBV was 0.76 +/- 0.48 mm/s (n.s.) at rest and 0.31 +/- 0.28 mm/s (n.s.) immediately after local cooling in the mibefradil group. Finger nailfold CBV immediately after local finger cooling was increased by enalapril compared to baseline. The T-channel-inhibiting calcium antagonist mibefradil did not change CBV in finger nailfold capillaries.

Adult↗

Retrobulbar and peripheral capillary blood flow in hypercholesterolemic subjects.

PURPOSE: To assess retrobulbar blood flow velocities and finger nailfold capillary blood flow velocities (two readily accessible vascular beds) in subjects with primary hypercholesterolemia before and during lipid-lowering therapy. METHODS: Retrobulbar blood flow velocities and finger nailfold capillary blood flow velocities were assessed in 15 hypercholesterolemic subjects and in 15 age-matched and sex-matched healthy control subjects. In addition, the change in blood flow velocities after a 3-month period of lipid-lowering therapy was evaluated. RESULTS: No alterations in retrobulbar blood flow velocities after lipid-lowering therapy could be observed in hypercholesterolemic patients. Nailfold capillary blood flow velocity was slower in hypercholesterolemic subjects than control subjects immediately after local cooling (P = .0052), but this vascular dysregulation did not improve after lipid-lowering therapy (P = .58). CONCLUSIONS: Blood flow alterations, potentially caused by perturbed vascular endothelial function, may occur in nailfold capillaries of hypercholesterolemic subjects. Such alterations were not seen in retrobulbar vessels, and blood flow measures did not change during lipid-lowering therapy.

Blood Flow Velocity↗

Body mass index in glaucoma.

PURPOSE: To compare body mass index (BMI) of patients with open-angle glaucoma or normal-tension glaucoma with BMI in control subjects. METHODS: BMI was calculated for 288 control subjects, 42 patients with open-angle glaucoma with treated intraocular pressure (IOP) higher than 21 mmHg, 87 patients with open-angle glaucoma with progression of glaucomatous damage despite IOP less than 21 mmHg, and 57 patients with normal-tension glaucoma. RESULTS: There was no statistical difference in BMI between patients with glaucoma and control subjects. If anything, there was a tendency for patients with glaucoma to have a lower BMI than control subjects. CONCLUSION: These data show that obesity seems not to be a risk factor for glaucoma.

Aged↗

Effects of losartan titrated to losartan/hydrochlorothiazide and amlodipine on blood pressure and peripheral capillary microcirculation in patients with mild-to-moderate hypertension.

OBJECTIVE: To measure the effects of losartan and amlodipine on peripheral capillary microcirculation in hypertension. SETTING: Medical out-patient clinic, Basel, in a university teaching hospital. METHODS: After a 4-week placebo run-in period 20 patients aged 50 +/- 8 (range 36-65) years with mild-to-moderate hypertension were randomly allocated to receive active treatment with losartan 50 mg titrated to losartan 50 mg/hydrochlorothiazide (HCT) 12.5 mg, or amlodipine 5 mg titrated to 10 mg for a 12 week period. Titration was performed if diastolic blood pressure (BP) was > or=90 mm Hg after 6 weeks of treatment. BP measurements as well as video capillary microscopy of the finger nailfold at the end of the placebo period and after 12 weeks of active treatment were compared. Capillary blood cell velocity was measured at rest and immediately, 1 min and 2 min after local finger cooling. RESULTS: After 3 months of treatment with amlodipine (n = 10) and losartan titrated to losartan-HCT (n = 10) sitting BP decreased significantly from 160 +/- 7/103 +/- 4 mm Hg and 147 +/- 7/98 +/- 6 mm Hg to 131 +/- 10/86 +/- 7 mm Hg and 134 +/- 17/89 +/- 9 mm Hg, respectively (P < 0.01). After local finger cooling the area under the curve (AUC) of capillary blood cell velocities was 1.13 +/- 0.58 mm (median +/- s.d.) at baseline and increased to 1.94 +/- 1.15 (P < 0.05) in losartan/losartan-HCT treated patients. In amlodipine treated patients the increase in AUC of capillary blood cell velocity did not reach the level of statistical significance (1.59 +/- 1.36 to 2.14 +/- 1.05 mm). CONCLUSION: This small trial shows that the area under the curve of capillary blood cell velocity increases in hypertensive patients treated with both losartan/losartan-HCT and amlodipine compared with baseline values.

Adult↗

Effect of moxonidine and cilazapril on microcirculation as assessed by finger nailfold capillaroscopy in mild-to-moderate hypertension.

Disorders in peripheral microcirculation are observed in arterial hypertension and may be improved by antihypertensive treatment. In this pilot study the authors measured capillary blood cell velocity in the finger nailfold in 14 patients (mean age 50 +/- 14 years, range 30-71 years; 9 men, 5 women) with mild-to-moderate essential hypertension. After a 3-week placebo period, patients received double-blind randomized treatment with either 0.2- to 0.4-mg moxonidine (n=7) or 2.5- to 5.0-mg cilazapril (n=7). Finger nailfold video capillaroscopy was performed at baseline and after 8 weeks of treatment. Blood pressure was measured by conventional office technique. Capillary blood cell velocity, 1 minute after local finger cooling, increased in the Moxonidine group (0.65 +/- 0.53 mm/sec to 1.13 +/- 0.77 mm/sec; p<0.05) after 8 weeks treatment compared to the baseline. The increase in the Cilazapril group from 0.79 +/- 0.45 mm/sec to 0.93 +/- 1.03 mm/sec did not reach a level of statistical significance. Blood pressure decreased from 151 +/- 8/101 +/- 5 to 147 +/- 6/98 +/- 7 mmHg in the Moxonidine group and from 164 +/- 12/102 +/- 6 to 140 +/- 9/93 +/- 9 mmHg in the cilazapril group. Moxonidine increased nailfold capillary blood cell velocity 1 minute after local finger cooling in patients with mild-to-moderate hypertension. This improvement of the peripheral microcirculation may be associated with reversal of vascular dysfunction in hypertension.

Adult↗

Inverse correlation between endothelin-1-induced peripheral microvascular vasoconstriction and blood pressure in glaucoma patients.

BACKGROUND: The potent vasoconstrictor peptide endothelin-1 has been shown to participate in the control of peripheral vascular tone and in the regulation of ocular perfusion. In glaucoma patients vasospasms and arterial hypotension have been identified as risk factors for the progression of glaucomatous damage, and the regulation of endothelin-1 release is disturbed in some of these patients. The aim of this study was to assess the relationship between resting blood pressure and cutaneous vascular responsiveness to endothelin-1 and phenylephrine in patients with glaucoma and in matched controls. METHODS: In 9 patients with primary open-angle glaucoma (POAG), 7 patients with normal tension glaucoma (NTG), and 16 age- and sex-matched controls, endothelin-1 and phenylephrine responses were assessed in the human forearm microcirculation using laser Doppler flowmetry during intra-arterial drug administration. Blood pressure was measured intra-arterially. RESULTS: In contrast to alpha 1-adrenergic effects, endothelin-1 responses were inversely correlated to both systolic (r2 = 0.27, P = 0.05) and diastolic (r2 = 0.54, P = 0.001) blood pressure in glaucoma patients, whereas there was no such correlation in controls. Patients with lower blood pressure values were more sensitive to the vasoconstrictor effects of endothelin-1. Cutaneous responsiveness to endothelin-1 and phenylephrine was similar in glaucoma patients and in controls. CONCLUSION: These results reveal that glaucoma patients appear to have peripheral microvascular abnormalities which are exhibited as altered responsiveness to endothelin-1. Thus, this study supports the hypothesis that endothelin-1-related microvascular dysfunction may be involved in the pathogenesis of glaucomatous damage.

Adult↗

Cold-induced acral vasospasm in migraine as assessed by nailfold video-microscopy: prevalence and response to migraine prophylaxis.

In order to learn the prevalence of cold-induced vasospasm in migraine patients, blood cell velocity measurements of finger nailfold capillaries were performed in 58 consecutive patients suffering from migraine with and without aura. In 5 (8.6%) patients capillaroscopy could not be performed because of reduced nailfold transparency; 21 of the remaining 53 patients (39.6%) showed blood flow stop due to vasospasm under cold provocation. There was no significant difference (P = 0.69) in the occurrence of vasospastic reaction between migraine with (12 of 32 patients = 37.5%) and without (9 of 21 patients = 42.9%) aura. The clinical and capillaroscopic course under migraine prophylaxis was observed in 18 vasospastic patients. After sixteen weeks 14 patients showed good clinical improvement of their migraine. The vasospastic reaction persisted in only 1 patient. This patient and 3 others with abolished vasospasm were still suffering from migraine. These findings suggest that observing blood cell velocity noninvasively in nailfold capillaries under cold provocation could be useful for objectively monitoring the response to prophylactic treatment in migraine patients or for testing new potentially antimigraine drugs.

Adult↗

Reaction of capillary blood cell velocity in nailfold capillaries to L-carnitine in patients with vasospastic disease.

By using nailfold videomicroscopy in conjunction with local cold exposure, the haemodynamic responses in capillary blood cell velocity were evaluated in 12 patients with vasospastic disease after receiving L-carnitine 3 g per day orally for 20 days. The results obtained showed that the cold-induced blood flow stop duration was significantly (P < 0.05) decreased and capillary blood cell velocity significantly (P < 0.05) increased after local cooling. Systolic blood pressure was significantly (P < 0.05) decreased after treatment with L-carnitine. Diastolic blood pressure, heart rate and skin temperature did not differ significantly before and after treatment. There were no significant differences in the meteorologic data such as atmospheric temperature, atmospheric pressure or atmospheric hygrometry between the two investigations. It is concluded that L-carnitine might be a useful agent in the treatment of digital vasospastic disease. In addition, in vivo videomicroscopy is one of the few non-invasive and clinically useful direct methods for evaluating the effect of a drug on the microcirculation.

Administration, Oral↗

[What is the role of the sympathetic nervous system in digital vasospasms?].

The sympathetic activity is modulated by the cerebral cortex, hypothalamus, medullary vasomotor centers, and spinal cord. Finger blood flow is mainly under the control of the sympathetic nervous system. In digital vasospasm, an increased activity of the sympathetic nervous system is opposed to a local abnormality in the digital arteries. This controversy is discussed with respect to general and local control mechanisms in the peripheral blood circulation.

Cerebral Cortex↗

Silent myocardial ischemia in glaucoma and cataract patients.

BACKGROUND: Glaucoma and cataract are multifactorial diseases. They have been described to be associated with cardiovascular risk factors. METHODS: Twenty-four-hour ECG monitoring was done in 22 normal-tension glaucoma patients, 27 open-angle glaucoma patients, 25 cataract patients, and 20 normal controls. The frequency of silent myocardial ischemia (SMI) as well as that of ventricular extrasystoles (VES) was evaluated. RESULTS: At least one episode of significant asymptomatic ST-T segment depression occurred in 45% of the normal-tension glaucomas, in 25.9% of open-angle glaucomas, in 12% of cataract patients, and in 5% of normal controls. The frequency of VES was not significantly different among the groups. CONCLUSIONS: Glaucoma, especially normal-tension glaucoma, is significantly associated with the occurrence of episodic asymptomatic myocardial ischemias. Cataract patients, however, had only a slightly, statistically not significantly increased frequency of both SMI and VES compared with normals.

Aged↗

The influence of magnesium on visual field and peripheral vasospasm in glaucoma.

Previous studies indicated calcium channel blockers to be of some help for normal-tension glaucoma patients. The present study evaluates the effect of magnesium, a 'physiological calcium blocker', in 10 glaucoma patients (6 with primary open-angle glaucoma, 4 with normal-tension glaucoma). All patients had a digital cold-induced vasospasm. Magnesium (121.5 mg) was administered twice a day for a month. After 4 weeks of treatment, the visual fields tended to improve. All three video-nailfold-capillaroscopic parameters [blood cell velocity (in mm/s) before and after cooling, cold-induced blood flow cessation (in seconds) as well as the number of capillaries per microscopic field which showed such a blood flow cessation] as well as digital temperature improved significantly. Systemic blood pressure and pulse rate remained stable. In conclusion, magnesium improves the peripheral circulation and seems to have a beneficial effect on the visual field in glaucoma patients with vasospasm.

Blood Flow Velocity↗

[The use of capillary videomicroscopy in the therapeutic assessment of acral vasospastic phenomena: microcirculatory effect of ketanserin and nifedipine].

In-vivo videomicroscopy is one of the few noninvasive and clinically useful direct methods for evaluating the effect of a drug on microcirculation of normal and ischemic areas. By using nailfold videomicroscopy in conjunction with local exposure to cold air, the hemodynamic effects of ketanserine and nifedipine are reviewed in patients with primary Raynaud's disease.

Capillaries↗

[Vasospasm--a generalized vascular event?].

Many factors have been implicated in the pathophysiology of vasospastic disease. The coincidence of vasospastic syndromes suggests that a systemic factor (blood-borne or neurologic) or a generalized functional abnormality of vascular smooth muscle causes vasospasms in different vascular beds. The evidence of vasospastic disease is discussed with respect to our knowledge of general and local control mechanisms in peripheral blood flow.

Blood Flow Velocity↗