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Biomedical subjects

G Hauck

Publications and source records attributed to G Hauck.

At least 19 recordsLinked to original sources

[Contribution of prelymphatic structures to lymph drainage].

Vitalmicroscopic findings confirm the existence of a "low resistance pathway" for the transinterstitial fluid movement from the pillaries to the initial lymphatics. One part of this prelymphatic system is represented by submicroscopical spaces along the connective tissue fibres between ground substance (high resistance pathway) and fibre surface. The other part is represented by a network of prelymphatic tissue channels which are open connected with the initial lymphatic system.

Humans

Light and electron microscopy of the structural organization of the tissue-lymphatic fluid drainage system in the mesentery: an experimental study.

Supplementing vital microscopy and histophysiology, we examined using combined light and electron microscopy the tissue fluid-lymphatic drainage system of the mesentery isolated from guinea pigs, rabbits, and tree shrews. In silver impregnated tissue, different types of lymphatics and blood vessels were able to be distinguished along with argyrophilic and argyrophobic structures in the connective tissue. Some initial lymphatic pathways were interrupted by non-endothelialized tissue zones thus forming separate but discrete vascular "islands". After carbon labeling of the lymphatic collectors, carbon particles were seen to escape from the initial lymphatic lumen at various sites. Electron microscopy revealed wide apertures in the lymphatic endothelial cells of these microvessels. These morphological findings support the concept of an "open" prelymphatic-lymphatic system in the mesentery. The special histometrical features exhibited by a flat membranous organ like the mesentery are discussed in terms of physiologic function of mesenteric tissue fluid transport.

Animals

[Diagnosis of "fatal ethanol poisoning in the absorption phase"].

In cases of disputed fatal alcohol intoxication during the absorption (pre-peak) period it is strongly recommended to examine the blood ethanol level not only in blood taken from a peripheral vessel but also simultaneously in blood from at least one central. In the case reported, without such a duplex determination of the blood ethanol concentration it would have been impossible to establish the actual cause of death.

Aged

Changes in lymphocyte subpopulations after prolonged exercise.

In order to assess the changes in the cellular immune system, 27 healthy male subjects were selected who participate in leisure-time sports and in whom measurements of the lymphocyte subsets in venous blood were carried out before and after a standardized endurance exercise test (EI, 60 minutes in length, intensity: 63% of maximum performance). The percentages of the following parameters were measured: total T-lymphocytes, B-lymphocytes and O-lymphocytes as well as T4-lymphocytes (helper T-lymphocytes, CD4+) and T8-lymphocytes (cytotoxic/suppressor T-lymphocytes, CD8+). In a subgroup consisting of 8 subjects, the parameters indicated above were measured again 24 hours following E. In order to check the reproducibility of the findings, the endurance exercise test was repeated 21/2 weeks later (EII).

Adult

[Improvement in the diagnosis of scrotal diseases using color-coded duplex sonography].

Two hundred and twenty-two patients with abnormalities of their scrotal contents were examined with colour-coded duplex sonography. The aim of this prospective study was to evaluate this new procedure for the investigation of the scrotal organs. Differentiation between testicular torsion and inflammation by colour-coded duplex sonography achieved 95% accuracy. The diagnosis of varicoceles was simplified and expedited (accuracy = 99%). In other abnormalities of the scrotum, particularly testicular tumours, a knowledge of the blood flow did not provide any important additional diagnostic information compared with conventional sonography.

Acute Disease

[Physiology of the lymph vessel system].

Using an incomplete darkfield transillumination technique a prelymphatic network of tissue channels, connected with the initial lymphatics could be observed vitalmicroscopically in the mesentery of homeotherm animals. Furthermore, channels are found also paravascularly along the venules marked by a maximum of protein permeation in the capillary bed. Here exists a short way for the protein uptake by the prelymphatic system and initial lymphatics. This is important for the osmotically released movement of fluid into the lymphatic vessels. Supported by the connecting tissue fibres the prelymphatic system represents a preformed low resistance pathway for fluid movement convected to the initial lymphatics through the interstitial spaces.

Animals

The effect of the gradient of vascular permeability on fluid and plasma protein exchange in the mesenteric microcirculation.

The present work is a theoretical analysis of the intramural and transmural flows of fluid and plasma proteins. The transvascular fluxes are treated on the basis of a phenomenological approach resulting from the irreversible thermodynamics. The concept leads to a generalization of the well known Starling equation for the fluid exchange and to an additional equation which accounts for the exchange of plasma proteins. The key element in the theory is the incorporation of axial variations of the vascular permeability in the model. Numerical results are obtained for the cat mesentery taking into account the particular angioarchitecture of that tissue. The strength of the present model lies in the precise localization of the transvascular fluxes which results from the differential treatment of the fluid dynamic and mass transfer problem. The results confirm vital microscopic findings of various authors that fluid filtration and the plasma exchange occur predominantly on the arteriolar and venular side of the microcirculatory bed. In contrast, the exchange in the capillaries is relatively small regardless of the actual value of the gradient of permeability. In the organ specific situation studied, the transvascular fluxes are directed outward everywhere to the tissue. The general effect of the vascular gradient of permeability is to enhance the local transvascular fluxes on the venous side.

Blood Proteins

Cathodoluminescence technique combined with blue light fluorescence microscopy for the investigation of the transport of molecules through the extravascular space of mammalians.

The mechanisms of transport of molecules across the extravascular spaces represent an open problem. Vital microscopic results with marked proteins using the blue light luminescence technique indicate a movement of fluid along the connective tissue fibres. Furthermore, the findings suggest that the elastic fibres play an important role in this movement. It may also be possible to elucidate the extravascular pathway for molecules by means of the cathodoluminescence technique in the scanning electron microscope. The investigations were performed using the mesentery of mammalians anaesthetized by Nembutal. The biological material for cathodoluminescence applications was selected from animals without injection of luminescent dye as well as with animals following intravenous injection of marked proteins. Two techniques, critical point drying and freeze drying, were used in the preparation. Stained and unstained tissues were investigated in the scanning electron microscope with a special cathodoluminescence detector system. Simultaneously observations of the tissue surfaces were performed by means of the secondary electron or backscattered electron mode. The results obtained agree with the findings observed by the blue light fluorescence microscopy and confirm the concept of an extravascular fluid pathway along the elastic fibres in the tissue.

Animals

[Control of the intensive treatment of thallium intoxications (author's transl)].

A report is given on the control of the thallium level at poisoning during therapy with forced diuresis and extracorporeal hemodialysis. The success of these methods was controlled ty the determination of the thallium level in vomit, blood, urine and dialysate by flameless atomic absorption spectrophotometry. Since the results are obtained within a few minutes, thallium measurements may be helpful for the decision on the therapy to be applied.

Adolescent