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Biomedical subjects

A Bollinger

Publications and source records attributed to A Bollinger.

At least 91 records · Page 5Linked to original sources
PubMed1991

Evidence for microvascular thrombosis obtained by intravital fluorescence videomicroscopy.

A pattern of enlarged capillaries densely packed with red cells and not filled by the intravital dye Na-fluorescein for 10-20 min is described. Probably it corresponds to microvascular thrombosis. Alternative explanations like prolonged stasis appear unlikely. Up to now the pattern has been detected in severe chronic venous incompetence, collagen vascular disease and essential thrombocytosis.

Blood Flow Velocity↗
PubMed1991

Measurement of different human microvascular dimensions by combination of videomicroscopy with Na-fluorescein (NaF) and indocyanine green (ICG) in normals and patients with systemic sclerosis.

Using a double tracer technique with the two dyes indocyanine green (ICG) and Na-fluorescein (NaF) it becomes possible to measure diameters of the capillary, red blood cell column plasma layer and pericapillary halo. 12 healthy controls and 12 patients with systemic sclerosis were studied. The first three mentioned diameters were significantly enlarged in the patient group on the arteriolar, venular and apical side of the nailfold capillaries (p less than 0.03-0.001). Halo diameter was only significantly increased at the apex and not at the two capillary limbs. This finding confirms the visual impression of "dwarf hat formation" or "apical capping" after NaF injection as an important sign for microangiopathy due to collagen vascular disease. It corresponds to preferential halo enlargement at the loop apex. Since ICG couples almost completely to plasma proteins it permits delineation of the inner capillary contours and visualization of capillary aneurysms even when they are completely filled by plasma.

Adult↗
PubMed1991

Microangiopathy in mild chronic venous incompetence (CVI): morphological alterations and increased transcapillary diffusion detected by fluorescence videomicroscopy.

We investigated morphology of skin capillaries and pericapillary halos and transcapillary diffusion of Na-fluorescein in 15 patients with mild chronic venous incompetence (CVI) and in 15 healthy controls. Transcutaneous fluorescence videomicroscopy was performed at the medial ankle region. To assess transcapillary diffusion the fluorescent light intensity was monitored within a densitometer window encompassing 3.2mm2 of skin surface. Only a few capillaries exhibited the features of microangiopathy described in patients with severe CVI. A minority of microvessels of the patients with mild CVI showed moderate dilations or increased tortuosity. Inhomogenous perfusion, extremely tortuous microvessels resembling glomeruli, obliterations of vessels or avascular fields frequent in severe forms of the disease were not detected and the density of skin capillaries was identical to controls. Although skin capillary alterations were mild or moderate, mean diameter and range of pericapillary halos were significantly (p less than 0.05) enhanced in the group with mild CVI, indicating increased transcapillary diffusion. This finding contrasts to the results in healthy volunteers and to the values previously measured in patients with severe CVI, in whom normal fluorescent light intensities were determined in skin areas of identical location and size. We conclude that in mild CVI enhanced transcapillary diffusion predominates, while morphological alterations of capillaries typical for severe CVI are just beginning to emerge.

Capillaries↗
PubMed1991

[Diagnostic importance of the jugular veins].

Inspection, auscultation and doppler-sonographic examination of the jugular veins may give a clue for diagnosis of cardiac diseases. Angiological diseases include isolated thrombosis of the jugular vein and congenital ectasia. The neck veins are enlarged with thrombosis of the major upper extremity veins, if the orifice of the subclavian vein is also occluded and the normal outflow of the jugular vein is impeded. Thrombosis of the superior vena cava, compression of the mediastinal trunks by tumors, fibrosis or pericardial alterations causes dilatation of neck veins on both sides, best seen in the jugular veins.

Cardiovascular Diseases↗
PubMed1990

[Reversible microangiopathies following massive weight loss].

A 17-year-old patient presented with loss of weight, acrocyanosis and trophic lesions of the tips of the toes. There were no clinical or immunological signs of connective tissue disease. Capillary microscopy revealed a severe organic microangiopathy and arteriolar spasm. A change in the patient's occupational conflict situation was followed by complete recovery and capillary findings normalized. The possible connection between anorexia-like affection and capillariopathy remains unclear.

Adolescent↗
PubMed1990

Calcitonin gene-related peptide (CGRP) causes redistribution of blood flow in humans.

In normal human subjects (n = 6), blood flow in the common carotid artery, assessed with an ultrasonic duplex-scanning unit, was increased up to 152% of basal levels by 60-min infusions of human calcitonin gene-related peptide I (alpha CGRP) 80 pmol.kg-1.h-1, but it was not affected by 20 pmol.kg-1.h-1 CGRP or 88 pmol.kg-1.h-1 human calcitonin. In the superior mesenteric artery, on the other hand, blood flow was reduced by 80 pmol.kg-1.h-1 CGRP to 58% of the basal level, but not by 20 pmol.kg-1.h-1 CGRP or with 88 pmol.kg-1.h-1 calcitonin. Blood flow in the abdominal aorta remained largely unchanged under the same conditions. Skin blood flow, assessed by a laser Doppler unit, was increased up to 682% of the basal level by 80 pmol.kg-1.h-1 CGRP, but not by 20 pmol.kg-1.h-1 CGRP or calcitonin. Thus CGRP increased regional blood flow to the brain and the skin at the expense of the gastrointestinal tract.

Adult↗
PubMed1990

The frequency histogram--a new method for the evaluation of laser Doppler flux motion.

A digital filter system (DFS) was implemented to describe the frequency components of laser Doppler signals. The DFS calculates a frequency histogram on the basis of the prevalence of a certain frequency band during the sample period. This approach seems to be more suitable for the detection of low-power small-amplitude flux motion components recorded by laser Doppler as compared to the commonly used fast Fourier algorithm. Fourier analysis provides an amplitude-relevant frequency spectrum which may overlook relevant frequency components with small amplitude due to low power or short duration. DFS allows better detection of such signals as demonstrated by the initial clinical results of this study evaluating flux motion on the feet of 4 healthy controls and 10 patients with peripheral arterial occlusive disease. Three frequency components are easily distinguished corresponding to low (3.6 +/- 1.5 cycles/minute) and high (18.6 +/- 4.5 cycles/min) frequency flux motion and the pulsatile waves due to cardiac action.

Aged↗
PubMed1990

Flow motion waves with high and low frequency in severe ischaemia before and after percutaneous transluminal angioplasty.

UNLABELLED: STUDY OF OBJECTIVE: The aim was to evaluate skin flux and prevalence of low and high frequency flow motion waves in patients with severe ischaemia due to peripheral arterial occlusive disease before and after percutaneous transluminal angioplasty (PTA) with and without local thrombolysis. DESIGN: Flow motion was recorded by the laser Doppler technique at the dorsum of the foot before, one day, and one month after PTA. The results were separately analysed in patients with successful and unsuccessful treatment. SUBJECTS: 18 patients with rest pain or incipient gangrene were included. Mean pretreatment systolic ankle pressure was 55.8(SD 25.5) mm Hg, and mean transcutaneous PO2 at 43 degrees C was 5.2(9.4) mm Hg. Arteriography revealed relevant stenoses or occlusions of the femoropopliteal and calf arteries. MEASUREMENTS AND RESULTS: Before treatment two patterns of flow motion with characteristic frequency ranges were observed at the foot dorsum and at a probe temperature of 32 degrees C: low frequency (LF) waves with a mean frequency of 2.2(0.5) cycles.min-1 and a mean amplitude of 0.73(0.42) arbitrary units (AU) and high frequency (HF) waves with a mean frequency of 22.6(4.2) cycles.min-1 and a mean amplitude of 0.39(0.33) AU. PTA was successful in 11 of the 18 patients. After successful treatment, prevalence of HF waves decreased from 10/11 to 4/11 cases (p less than 0.001), but remained nearly unchanged after failed procedure. Prevalence of LF waves before and after PTA did not differ significantly. CONCLUSIONS: Our data support the hypothesis that HF waves represent a reaction of skin microcirculation to severe ischaemia. With reference to animal studies it is proposed that HF waves originate from terminal arterioles. They may function as a compensatory mechanism of flow regulation involved in pathophysiology of ischaemia.

Adult↗
PubMed1990

Diameters of lymphatic capillaries in patients with different forms of primary lymphedema.

Fluorescence microlymphography was performed near the medial ankle in 12 healthy controls, 12 patients with congenital and 12 with sporadic lymphedema of the lower extremities. Diameters of lymphatic capillaries were determined on the videoscreen by playback of the tape recordings using a morphometric technique. In the patients with congenital disease (Nonne-Milroy) aplasia of microlymphatics was diagnosed in 8 instances, ectasia in 4. Patients with sporadic lymphedema and manifestation after puberty exhibited initial lymphatics of normal caliber. In controls mean capillary diameter was 56.3 +/- 9.0 microns, in congenital disease with ectasia 99.3 +/- 9.0 microns (difference significant at the p less than 0.005 level) and in the sporadic form 49.7 +/- 7.7 microns. Congenital lymphedema may be subdivided into a form with aplastic and ectatic microvessels which possibly show different responses to therapy.

Adolescent↗
PubMed1989

M-mode echovenography: a new technique for the evaluation of venous wall and valve motion.

The M-mode technique which is widely used in echocardiography allows continuous recording of spontaneous venous wall movements. Compliance of the vein can be quantified. The diameter of the normal vein changes with respiration, while only minor changes are induced by cardiac function. Distensibility and compressibility of the common femoral vein (CFV) were documented. During Valsalva manoeuvre the mean diameter of the CFV increased from 1.05(SD 0.18) cm to 1.52(0.25) cm (p less than 0.01) in the recumbent position and from 1.50(0.20) cm to 1.63(0.17) cm (NS) in the upright position. A patent vein can be completely compressed by the scan head, a thrombosed vein is incompressible. The valve of the normal subclavian vein describes a characteristic M-shaped tracing. The waveform is modulated by cardiac and respiratory function. The study of venous wall movement and venous valve motion provides new insights into venous physiology.

Adult↗