Biomedical subjects

P Gasser

Publications and source records attributed to P Gasser.

At least 37 records · Page 2Linked to original sources

PubMed1994

Cold-induced vasospasm in patients with fibromyalgia and chronic low back pain in comparison to healthy subjects.

Using capillary videomicroscopy of the nail fold, the frequency of cold-induced vasospasm and capillary hemodynamic parameters were studied after application of cold in 50 patients with primary fibromyalgia, 50 patients with chronic low back pain, and 50 healthy controls. Cold-induced vasospasm was detected in 38% of the patients with fibromyalgia. In this group it was significantly more frequent than in the patients with chronic low back pain (20%, p < 0.05) and healthy subjects (8%, p < 0.001). In the fibromyalgia group, the magnitude of vasospasm as measured by the capillary blood flow deceleration after cold application correlated negatively with the pain intensity as measured by pain score (r = -0.3839, p < 0.01). No differences in clinical appearance were found between patients with and without cold-induced vasospasm in both the fibromyalgia and low back pain group.

Adult↗

PubMed1994

Nail fold capillaroscopy and echocardiography in mild-to-moderate hypertension treated with cilazapril plus hydrochlorothiazide: first results.

Essential hypertension is characterized by parallel and potentially reversible vascular and cardiac adaptations. In our study, capillaroscopy, echocardiography, and 24-h ambulatory blood pressure profiles were performed in 17 patients (aged 33-63 years; mean, 52 years) with mild-to-moderate hypertension. We measured morphological and hemodynamic parameters of capillary microcirculation as well as morphological echocardiographic parameters at baseline and after 6 weeks' treatment with 5 mg of cilazapril plus 12.5 mg of hydrochlorothiazide. Digital capillary blood flow measurements were assessed by nail fold video capillaroscopy. After 6 weeks of treatment with cilazapril plus hydrochlorothiazide, mean diastolic 24-h ambulatory blood pressure decreased from 98 +/- 6 to 85 +/- 7 mm Hg. Capillary blood cell velocity was 0.6 +/- 0.4 mm/s at baseline and increased to 0.6 +/- 0.4 mm/s. There were no significant changes in morphological capillaroscopic and echocardiographic parameters. In conclusion, we observed a trend toward higher capillary blood cell velocity as early as after 6 weeks of treatment with cilazapril plus hydrochlorothiazide in mild-to-moderate hypertension.

Administration, Oral↗

PubMed1994

Efficacy and tolerability of 5 mg of cilazapril plus 12.5 mg of hydrochlorothiazide in mild-to-moderate hypertension: results of 24-hour ambulatory blood pressure monitoring.

The efficacy and tolerability of a fixed combination of 5 mg of cilazapril and 12.5 mg of hydrochlorothiazide against hypertension was evaluated in 36 patients (26 men and 10 women) between 33-68 years old. Twenty-two had newly diagnosed hypertension and 14 had previously treated hypertension. Twenty-four-hour noninvasive ambulatory blood pressure monitoring (ABPM) was performed after a 2-week washout period. Measurements were taken at 20-min intervals during the day (from 8 a.m. to 10 p.m.) and at 30-min intervals during the night (from 10 p.m. to 8 a.m.). Patients with a mean diastolic daytime pressure of > or = 90 < 115 mg Hg were then given 5 mg of cilazapril plus 12.5 mg of hydrochlorothiazide once daily between 6 a.m. and 8 a.m. for 6 weeks. After this period, a second 24-h ABPM was performed. Office blood pressure measurements were taken at weeks -2, 0, 2, and 6. Routine laboratory blood samples were taken at weeks 0 and 6. Single blood pressure readings did not change significantly during the washout period (between weeks -2 and 0). The ABPM 24-h mean systolic pressure changed between weeks 0-6 from 143 +/- 13 to 126 +/- 11 mm Hg (p < 0.0001), and the mean diastolic pressure from 100 +/- 9 to 90 +/- 9 mm Hg (p < 0.0001). Twenty-eight patients (80) responded to treatment (response criteria: mean diastolic daytime pressure at week 6 < 90 mm Hg and/or a difference between weeks 0-6 > or = 5 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

[Diagnosis of vascular occlusion of the posterior eye segment].

Retinal arterial occlusion, retinal vein occlusion and anterior ischemic optic neuropathy are commonly found diseases of the eye. In general the diagnosis is verified by ophthalmoscopic examination. Further diagnosis is necessary for evaluation of possible treatment and prophylaxis of following cerebral or ocular occlusive events. In occlusive diseases vascular dilatation, improvement of rheologic parameters and in some cases treatment of inflammation are the first therapeutic aim. Furthermore, the pathophysiologic origin of the vascular occlusion should be clarified for more specific prophylactic treatment. Diagnostic tools and possible therapeutic consequences are discussed.

Diagnosis, Differential↗

PubMed1992

[Acral vasospasm in Crohn's disease].

55 patients with Crohn's disease and 55 sex- and age-matched healthy controls were studied by nailfold capillary microscopy for evidence of microcirculatory abnormalities. Digital capillary blood flow measurements in combination with a local cooling test were assessed by videocapillaroscopy using the flying-sport technique. We found a blood flow stop with cold exposure in 44 of the 55 patients with Crohn's disease (mean duration 39 seconds) but in 5 of the 55 control subjects only (mean duration 19 seconds). There was no significant difference in skin temperature between the two groups. Intravital microscopy of nailfold capillaries revealed a marked reduction in capillary density (p less than 0.001) compared to normal subjects. The association of vasoconstrictive reaction in finger microcirculation of patients with Crohn's disease suggests a vasospastic tendency in this disorder.

Adult↗

PubMed1992

[The controversy of primary Raynaud syndrome].

Idiopathic Raynaud's disease is characterized by abnormally prolonged episodic peripheral vasospasm in response to cold or emotional stimuli. Its pathogenetic mechanism remains still unknown, although two theories attempt to explain it. Raynaud hypothesized an overactivity of the sympathetic nervous system, whereas Lewis postulated a 'local defect' at the level of precapillary resistance vessels. The controversy in both theories is discussed with respect to our knowledge of general and local control mechanisms in the peripheral vasculature.

Humans↗

PubMed1992

Nailfold microcirculation in normotensive and essential hypertensive subjects, as assessed by video-microscopy.

OBJECTIVE: To compare morphological and hemodynamic parameters of skin microcirculation in the fingertip in patients with essential hypertension and normotensive control subjects. DESIGN: Consecutive sample of patients. METHODS: Digital capillary blood flow measurements under normal and cooled conditions were assessed by nailfold video capillaroscopy using the technique of flying spot. RESULTS: There was a significant reduction in capillary density in hypertensive patients, compared with normotensive subjects. There was a correlation between capillary density and mean diastolic blood pressure. After local cooling the frequency of the blood flow stop was significantly higher in hypertensive patients. CONCLUSION: The finding of abnormal vasoconstriction in finger microcirculation in essential hypertension suggests a vasospastic tendency in the disease.

Blood Flow Velocity↗

PubMed1992

Effects of carbon dioxide, Nd:YAG and carbon dioxide-Nd:YAG combination lasers at high energy densities on synthetic hydroxyaptite.

The aim of this study was to determine the crystalline structure and chemical alterations of synthetic hydroxyapatite after irradiation with either CO2, Nd:YAG or CO2-Nd:YAG combination lasers at high energy densities of 500-3,230 J.cm2. Further, dissolution kinetics of the lased material were analysed and compared with those of unlased apatite. Electron microscopy showed that the lased material consisted of two kinds of crystals. From the micrographs their diameters varied from 600 to 1,200 A and from 3,000 to 6,000 A, respectively. The larger crystals showed 6.9-Angström periodic lattice fringes in the transmission electron microscope. alpha-Tricalcium phosphate (TCP) was identified by X-ray diffraction. Selective-area electron diffraction identified the large crystals to consist of tricalcium phosphate while the smaller crystals were probably hydroxyapatite. Assays of dissolution kinetics showed that at these high energy densities lased material dissolved more rapidly than unlased synthetic hydroxyapatite due to the higher solubility of TCP.

Aluminum Silicates↗

PubMed1992

Evaluation of reflex cold provocation by laser Doppler flowmetry in clinically healthy subjects with a history of cold hands.

The aim of the present study was to investigate capillary blood flow and the reaction to cold provocation by means of laser Doppler flowmetry (LDF) and measurement of skin temperature at the fingertip of 39 healthy subjects who had a history of cold hands and feet but were free of any clinically significant vasospastic symptoms. A group of 39 sex- and age-matched healthy subjects without such complaints served as the control. The anamnestic complaints about cold hands and feet could be substantiated by the presence of a lower baseline skin perfusion and temperature. However, the maintenance of the normal range of reagibility to a reflex contractile stimulus with an unaltered potential to recover distinctly separates these subjects from patients with Raynaud's disease.

Adult↗

PubMed1992

Nailfold videomicroscopy and local cold test in type I diabetics.

Twenty-five type I diabetics (9 men, 16 women) with a mean disease duration of 19.9 years and 25 sex- and age-matched healthy control subjects were studied. Digital capillary blood flow measurements in combination with a local cooling test were assessed by nailfold videocapillaroscopy using the technique of flying spot and compared with nailfold capillary microscopy in four subgroups divided according to (A) disease duration, (B) retinopathy, (C) fasting blood glucose level, and (D) HbA1c values. Differences in morphologic capillary diameters and capillary density were found between the diabetics and the healthy control subjects. These were attributable to the patients with retinopathy. The hemodynamic findings at rest and after local cooling were unable to differentiate either between type I diabetics and healthy controls or within the different subgroups.

Adult↗

PubMed1991

Blood-cell velocity in the nailfold capillaries of patients with normal-tension and high-tension glaucoma.

We compared the capillary blood-cell velocity in the fingertips of 30 patients with high-tension glaucoma, 30 patients with normal-tension glaucoma, and 30 control subjects by nailfold capillaroscopy. There were no measurable differences in the morphologic findings. The blood-flow velocity, however, was reduced significantly in the patients with normal-tension glaucoma compared with the control subjects (P less than .05). This difference was especially pronounced after cold provocation (P less than .0005). After cooling, 25 of 30 patients with normal-tension glaucoma had a blood standstill of 12 seconds or more, whereas only three of 30 control subjects and four of 30 patients with high-tension glaucoma had a measurable blood standstill.

Adult↗

PubMed1991

The role of nailbed vasospasm in Crohn's disease.

Local cooling of the nailfold capillaries produces a typical blood flow stop reaction in patients with Raynaud's phenomenon. We applied the same test to 35 patients with Crohn's disease and compared the results with the findings in a control group of 35 healthy subjects matched for age and sex by nailfold videomicroscopy. We found a flow stop with cold exposure in 27 of the 35 patients with Crohn's disease (mean duration 38 s) in contrast to 2 of the 35 control subjects only (mean duration 12 s). There was no significant difference in skin temperature between the two groups. Intravital microscopy of nailfold capillaries revealed an evident reduction of the capillary density (p = 0.001) and crest diameter of the capillary loop (p = 0.02) compared to normal subjects. The strong association of a vasoconstrictive reaction in finger microcirculation in patients with Crohn's disease suggests a vasospastic tendency in this disorder that might manifest in the mesenteric capillaries also. This new finding of microcirculatory disturbance may play a role in the pathophysiology of Crohn's disease and be related to a general vasospastic syndrome.

Adolescent↗

PubMed1991

Dynamic fracture of hybrid endodontic hand instruments compared with traditional files.

The purpose of this study was to analyze in vitro the dynamic fracture of some endodontic hand instruments. The K file and H file were tested as reference traditional files; the K-Flex, Flexofile, Unifile, and Helifile were tested as newly developed hybrid instruments. The files were mounted in a lathe and rotated with cyclical axial motion in the lumen of a curved tempered steel groove until failure occurred. The results showed that the life span of instruments, the distance between the instrument tip and the rupture point, and the resistance to fracture were dependent on the size and design of the instruments. Moreover, scanning electron microscopic photographs revealed two types of breakage patterns. The K file, H file, Unifile, and Helifile showed a distinct fracture starting point with crack striations and ductile fractures. The K-Flex and Flexofile showed only plastic deformations and axial fissures.

Equipment Failure↗

PubMed1991

[Ocular vasospasm. 2: Diagnosis of vasospastic syndrome using nailfold capillary videomicroscopy].

Nailfold capillary videomicroscopy provides a very useful method to verify vasospastic disorders in ophthalmic patients. Capillary videomicroscopy at the nailfold in connection with a local cold exposure test are presented as a method with clinical applicability in vasospastic disease. This method allows not only differential diagnosis of Raynaud's phenomenon and evaluation of follow up but also to achieve pharmacological tests with different drugs which possess a specific action at the microvascular bed.

Arousal↗

PubMed1991

[Ocular vasospasm. 3: Contribution of choroid angiography].

In patients with ocular vasospasm a disturbance of papillary blood flow is discussed. The peripapillary choroidal circulation is of great interest because it supplies the papillary circulation. The Indocyanine green video-fluorescence angiography provides evaluation of choroidal blood-flow. In some cases of ocular vasospasm disturbance of choroidal blood flow could be found. Examples of these cases are demonstrated.

Aged↗

PubMed1991

Finger microcirculation in classical migraine. A video-microscopic study of nailfold capillaries.

We assessed microcirculation in nailfold capillaries of 22 patients with classical migraine and 22 normal subjects matched for age and sex using video-microscopy. Blood flow measurements were performed under standardized room temperature, after a 3-min warm water bath and after local cooling. Under standardized conditions, skin temperature at the fingertip was significantly lower in patients with migraine. Morphological differences, however, could not be found between patients and controls. After cooling of the nailfold area, blood flow stop due to vasospasm occurred in 18 of the 22 migraine patients in contrast to 1 of the 22 control subjects only. Capillary blood cell velocity was significantly decreased in the migraine group under all test conditions. Drug treatment did not account for the different prevalences of vasospasm in migraine patients and normal controls. Our findings demonstrate that patients with migraine often have subclinical microcirculatory disorders of the upper limbs.

Adolescent↗

PubMed1991

Clinical syndromes with vasoconstrictor response.

Vasospasm implies reversible vasoconstriction that may diminish blood flow to the perfused tissues followed by an ischaemia of varying severity. The exact pathophysiology of the condition remains unknown to this day. Vasospasms are not only present in Raynaud's disease, migraine, Prinzmetal's variant angina, visual field defects and partially in low-tension glaucoma, but may also be involved in the pathogenesis of Crohn's disease. Vasospastic diseases may result from more than one mechanism. It is difficult to determine which of the underlying abnormalities is the most important in vasospastic syndromes of different vascular beds.

Coronary Vasospasm↗

PubMed1991

[Laser Doppler flow measurement of the finger during cold provocation: results in 140 patients with healthy blood vessels].

Flow patterns of the cutaneous circulation of the third left finger was studied before and after standardized cold challenge in 140 healthy subjects by means of Laser-Doppler flowmetry. Flow behaviour showed no statistical differences regarding to age, sex and day time. Nevertheless, the results may serve only to a limited extent as a reference in the evaluation of individual test results for everyday angiological diagnosis since the interindividual variability of the flux values is considerable. However, the present data obtained from a relatively large normal population are suitable as a reference basis for scientific investigations using groups of healthy subjects or patients.

Adult↗