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Biomedical subjects

A Bollinger

Publications and source records attributed to A Bollinger.

At least 145 records · Page 8Linked to original sources
PubMed1986

Microangiopathy of progressive systemic sclerosis. Evaluation by dynamic fluorescence videomicroscopy.

Morphologic changes of the nail-fold capillaries have been studied extensively in progressive systemic sclerosis (PSS). With videomicroscopy after intravenous injection of fluorescein sodium as a tracer, a more accurate morphologic description became possible, including data on the pericapillary interstitial space and the measurement of transcapillary diffusion of dye (videodensitometry). The results in 13 patients with PSS and Raynaud's phenomenon were compared with those obtained in 12 healthy volunteers. The diameters of the patients' nail-fold capillaries were significantly increased. The normal barriers for diffusion of the dye are located at the capillary wall and at the outer border of the skin papilla (halo). Both were less effective in PSS, with significantly enhanced fluorescent light intensities in the juxtacapillary region and outside of the halo. "Streetlike" or "lakelike" areas are stained in the remote parts, demonstrating abnormal architecture of the interstitial space. The technique could facilitate early detection of PSS.

Absorptiometry, Photon↗
PubMed1985

[Postprandial hyperemia of the superior mesenteric artery].

With the use of ultrasonic duplex scanning it is now possible to assess the blood flow dynamics in the human mesenteric artery noninvasively. The changes associated with a standardized food load were measured and the results compared with the blood flow of the common carotid artery. 20 healthy subjects (age 30.1 +/- 5 years) were studied fasting and 6 times at 15 minutes interval after the test meal (1000 kCal). While the flow parameters of the carotid artery were virtually unaffected by food intake, a steep increase in mesenteric blood flow was observed. Maximal hyperemia (2.7-fold increase, range 1.4-5.7) was reached 45 minutes after food intake.

Adult↗
PubMed1985

[New aspects of lymphedema].

Present knowledge on primary and secondary lymphedema of the extremities is reviewed. Conventional lymphography with contrast media requires surgical cannulation of pedal lymphatics and is indicated only in a few specific situations. Clinical findings, results of the patent blue test and possibly fluorescence microlymphography with fluorescent dextrans, indirect lymphography with iotasul, or isotope studies, suffice for correct diagnosis. In hereditary lymphedema present at birth (Milroy's disease) the lymphatic capillaries and precollectors are aplastic, whereas in sporadic lymphedema with postpubertal onset the large collectors are hypoplastic or aplastic. Conventional lymphography still yields the best results in differentiating between primary lymphedema with aplasia of the aorto-iliac collectors and a secondary form due to neoplastic disease. Combined physical therapy with tight bandages and stockings, massage and use of pneumatic devices for intermittent compression considerably reduces the edema and renders surgery unnecessary in most patients. Diuretics have a beneficial effect during early management, and benzopyrones for longterm treatment.

Adolescent↗
PubMed1985

[Capillary damage following freezing of the extremities, evaluated by fluorescence videomicroscopy].

Four patients with subacute cold injury of the fingers have been examined by dynamic fluorescence videomicroscopy after intravenous bolus injection of Na-fluorescein. Avascular skin areas with no perfused capillaries were detected, a finding best explained by destruction of the microvessels induced by cold injury. Microvascular spasms play an additional role. Transcapillary diffusion of the fluorescent tracer seems to be enhanced in some preserved capillary groups. Cold injury induces microangiopathy characterized by spasms of precapillary vessels, destruction of capillaries in large skin areas, and increased permeability of microvessels still perfused.

Adult↗
PubMed1985

Function of the precapillary vessels in peripheral vascular disease.

This article reviews the present knowledge of vasomotion in skin capillaries of patients with peripheral vascular disease, in particular Raynaud's disease and acrocyanosis. The data are based on measurements of red blood-cell velocity and of fluorescent-dye distribution in capillary areas obtained by videomicroscopy in combination with videodensitometric evaluation. Normally, adjacent skin capillaries exhibit similar flow patterns and are filled at the same time after i.v. Na-fluorescein injection, whereas in acrocyanosis, pathological vasomotion occurs frequently (different flow patterns in adjacent capillaries, delayed filling of single capillaries or capillary groups). Inhomogeneous perfusion is also common in microangiopathy caused by scleroderma. Hypersensitivity to a standardized cold stimulus is the main feature of primary Raynaud's disease.

Blood Pressure↗
PubMed1985

Transcapillary diffusion of Na-fluorescein measured by a 'large window technique' in skin areas of the forefoot.

A method is introduced for the study of transcapillary diffusion of 20% Na-fluorescein (0.3 ml/l of blood given intravenously) in skin areas by a fluorescence video-microscopy system which has been used earlier for measurements at the single capillary level or on axes crossing capillary groups. Two groups of 17 and 14 healthy volunteers respectively were included in a test-retest experiment (first measurement at day one, second measurement at day three). The appearance of the dye was visualized and the intensity of fluorescent light measured by a quadratic video densitometer window at the forefoot in an area of 2 mm2 containing 78 capillaries on the average. In both groups with and without control of the skin temperature, there were no statistically significant differences of the mean values measured at the first and second day of study. However, the mean intraindividual differences and the coefficients of variance were significantly (p less than 0.005) higher in the subjects without temperature control. It is concluded that the method is suited to detect transcapillary diffusion of Nafluorescein in skin areas by an almost atraumatic procedure with acceptable reproducibility. Potentially, it may be used to follow the natural history of microvascular diseases and to test the effect of various treatment modalities.

Adult↗
PubMed1984

The oscillating 'vena cava syndrome' during quiet standing--an unexpected observation in late pregnancy.

While studying the lung function of pregnant women at term in four different postures, we were surprised to note marked cyclic accelerations in the heart rate in two-thirds of the women when in a standing position. The mean cycle length was 105 s (range: 1-4 min) and the amplitude had a mean of 27 beats/min (range: 9-51). Blood flow velocity measurements with ultrasound Doppler over the femoral vein showed that there was an intermittent reduction of flow during quiet standing. When the venous return ceased, maternal heart rate increased, cardiac output decreased and blood pressure fell. After the venous blood flow was restored, maternal heart rate, cardiac output and blood pressure returned to normal until the cycle started again. Concomitant with these maternal heart rate changes, different patterns of fetal heart rate were observed. About 70% of the fetuses showed reduction in the long-term variability, increase in fetal heart rate or periodic accelerations. Although no woman fainted during quiet standing, the maternal circulatory changes were consistent with those seen in the classical vena cava syndrome.

Blood Flow Velocity↗
PubMed1984

Transcutaneous oxygen tension and capillary morphologic characteristics and density in patients with chronic venous incompetence.

The transparent oxygen electrode, recently developed by Huch and his co-workers, permits monitoring of transcutaneous oxygen tension (tcPO2) at defined sites on the capillaroscopic image obtained by videomicroscopy. This combined system has been applied to study the nutritional skin capillaries of patients with chronic venous incompetence (CVI). The results of 44 studies in 17 patients with CVI demonstrated a direct correlation between tcPO2 and density and morphologic characteristics of the superficial capillaries. The mean tcPO2 was 47.7 +/- 14.4 mm Hg at the site of incompetent perforating veins of the ankle without major trophic changes. There was no statistically significant difference between the mean values obtained in patients and control subjects (56.8 +/- 9.9 mm Hg). Videomicroscopic examination revealed dilated and tortuous capillaries surrounded by halo formations. In areas of hyperpigmentation, induration, and hyperkeratosis, significantly decreased mean tcPO2 (22.5 +/- 7.0 mm Hg; p less than .001) corresponded to reduced capillary density (less than 10 capillaries/mm2). In avascular skin areas (scar tissue, white atrophy) tcPO2 was measured at 0 mm Hg. No capillaries, or a greatly reduced number, were visible at such sites, resulting in a distance between capillary and cathode tip of the oxygen sensor of greater than 100 micron. The combined system of tcPO2 measurement and simultaneous videomicroscopy gives new pathophysiologic information on the development of skin ulcers and may be useful for the objective comparison of different therapeutic modalities at the microcirculatory level.

Adult↗
PubMed1984

Permeability of superficial lymphatic capillaries in human skin to FITC-labelled dextrans 40 000 and 150 000.

The paper describes a technique for measuring the permeability of superficial lymphatic capillaries of human skin. The microvessels were visualized under the fluorescence microscope after a subepidermal injection of 0.005 ml of a 25% solution of FITC-dextran 40 000 and 150 000. Pericapillary fluorescent light intensities (FLI) reflecting transcapillary passage of the dyes were determined at different sites and times by videodensitometers on single frames of the television recording. In 13 healthy volunteers (20 capillaries) permeability was assessed by injection of both dye molecules in the medial ankle region. As a rule the microlymphatics were permeable for dextran 40 000 and impermeable for dextran 150 000. For instance, 20 min after filling of the capillary selected for study, mean FLI 0.2 mm outside of the capillary centre (site C) was 94.2 +/- 44.7 arbitrary units for the smaller and 63.2 +/- 48.4 for the larger molecule (p less than 0.001). After 30 min the transcapillary passage of the tracer has to be differentiated from the interstitial diffusion of dye from the original deposit. Potentially, the method may be used to study the pathophysiology and pharmacology of lymphatic capillary permeability in human skin.

Adult↗
PubMed1983

[Transcapillary diffusion of Na-fluorescein in skin areas of the dorsum of the foot in juvenile diabetics].

Fluorescence videomicroscopy after intravenous injection of Na-fluorescein serves to quantitate dye diffusion out of single capillaries or capillary groups in an almost atraumatic manner [2, 4, 6, 8, 9]. In 14 young patients with a mean disease duration of 10 years and in 16 healthy controls, fluorescent light intensity was measured continuously during one hour at the dorsum of the foot by a videodensitometer covering an average of 68 capillaries. 1 second and 5 minutes after first appearance of the dye in the foot skin, the amount of the tracer detected in the area of measurement was significantly increased in the diabetics (p less than 0.05-0.001). At 1 minute, for example, mean fluorescent light intensity reached 47.2 +/- 18.1% of the maximal individual intensity and in the normals only 29.3 +/- 10.8% (p less than 0.01). In the patients the capillaroscopic image was characterized by early blurring, whereas the pericapillary halo of the controls contained more dye than the more remote interstitial space and remained well delineated for a much longer time. The new technique offers the possibility of studying transcapillary diffusion as an expression of microangiopathy in different groups of diabetic patients, and of following the effect of therapeutic regimens.

Adult↗