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Biomedical subjects

H Lenz

Publications and source records attributed to H Lenz.

At least 91 records · Page 5Linked to original sources
PubMed1975

[Functional studies on the differential diagnosis of so-called cardiospasm and esophageal achalasia. Simultaneous electromanometric and serial radiographic studies].

The characteristic esophageal pressure tracings and radiological appearances of diffuse spasm and achalasia are reported. In two patients of the series spastic activity involves the gastroesophageal junction. The findings indicate that differentiation of so-called cardiospasm and achalasia can only be obtained by simultaneous electromanometric pressure measurement and serial film technique. The resulting surgical methods are briefly reviewed.

Adult↗
PubMed1975

[The minimal freezing temperature for a necrosis of the epidermis and the influence of cryoprotective agents (author's transl)].

The sensitiveness to cold of the epidermis (cold threshold) is determined on the auricular skin of 24 rabbits, using freezing temperatures of -10, -15, -20, -25, -30, and -40 degrees C and a freezing time of 30 sec. The experiments are performed with and without application of cryoprotective agents (DMSO, glycerol and aethanol in a 10% solution) before cryosurgery. Only at -20 degrees C a necrosis of the epidermis is seen whereas after application of cryoprotective agents before freezing a necrosis of the epidermis first appears at -30 degrees C. Following these experiments clinically it might be possible to protect the epidermis in the periphery of the freezing area up to a certain degree with the use of cryoprotective agents, so that a topographically more concentrated epidermis-necrosis and therefore a limitation of the cryoeffect to the epidermis to a certain degree could be possible.

Animals↗
PubMed1975

[The surface of nasal polyps in the scanning electron microscope].

23 specimens with endonasal polyposis are examined scanning-electron-microscopically. There is a domination of kinocilia-free epithelium. The latter is bulging out in a dome-shaped manner, extensively loosened, showing transitional forms from cylindrical epithelium to more cube-like and finally squamous epithelium. The cylindrical epithelium is partly closely joined, showing ballon-like bulgings, cytoplasmatic protuberances, filled beaker cells with reduced or missing microvilly and partially granulating surface as well as emptying beaker cells with a thin microvilly edge. The covered surface shows partially normal lawn- and/or bundle-like, long and most parallel kinociliae, and short thin kinociliae in small bundles. All of them have a coordinated direction and a morphologically evident function-phase. In addition there is a network of kinociliae without function-phase and coordinated direction, which may or may not be covered by mucous, as well as damage and reproliferation of kinociliae. By reason of the morphological findings one can come to the conclusion that there is an extensive decrease in function of the mucociliar system in case of polyposis and as a consequence of this bacterial and viral infections might be favoured.

Cilia↗
PubMed1975

[The cryoeffect on the growing bone (morphological findings on the kneejoints of rabbits as an example) (author's transl)].

The cryoeffect on growing long bones is studied. The kneejoints including the bordering surrounding epiphyseal disks of the femur, tibia and fibula of 35 young (4-6 weeks old) and 6 adult rabbits were frozen by dipping the knee joints totally or partially into liquid nitrogen (-196 degrees C). The freezing time varies 3-5 min. After different times of survival maximally up to 397 days the animals are sacrified. The length of the cryosurgical treated and untreated extremities are measured and the kneejoints, especially the epiphyseal disks, are studied lightmicroscopically. Totally or partially frozen joints show after a complete necrosis in the phase of regeneration and reparation an uncoordinated overgrowth of cartilage-and bone cells and a proliferation of connective tissue with deformation of the epiphysis. The above mentioned facts and the disturbance of growth in length in young animals is mainly caused by the irregular function of the epiphysical disks after being treated cryosurgically. Also the epiphysical disks being only partially treated cryosurgically show growth disturbances and deformities. Deducing from the animal experiments clinical cryosurgery, has to be applied with extreme caution in the surrounding area of growing bone in children so that the centers of growing bone are not be frozen. Treating bones of adult rabbits cryosurgically there are only time limited reversible morphological findings so that clinically cryosurgery can be used in the surroundings areas of adult bones, especially joints, without any remarkable morphological long term findings.

Age Factors↗
PubMed1975

[The effect of the argon laser on the vessels, the macro- and microcirculation of the mucosa of the hamster cheek-pouch. An intravitalmicroscopic study (author's transl)].

The mucosa of the cheek-pouch of five golden Syrian Hamsters was irradiated with the beam of an argonionlaser (diameter 0.5 mm and 200 mW). The effect on the micro- and macro-vessels and the bloodstream, especially of the microcirculation, is studied intravitalmicroscopically. In the microcirculation and also in the small and large venous and arterial vessels a restriction of bloodstream, praestasis, pendulumstream, stream reversal and some white microthrombi, -- emboli and agglutination of erythrocytes are visible. The bloodless welding of the vessels takes place even before the evaporation and coagulation necrosis of the surrounding epithelium of the mucosa as a result of the relatively selective effect of the Argon Laser on the reddish vessel-system by a continuous narrowing of the vessels-walls to the complete loss of their lumen rather than by a thrombosis. Firstly the capillaries, the venoles and the arterioles are obliterated, then those of middle size and at last the large venae and arteries in which case large vessels function for a moment as smaller ones. A continuously growing imbibition with increasing duration of the laser irradiation can be observed. Three clinically important phenomenon, depending on the laserdose can be observed: 1. a partial, 2. a subtotal and total obliteration of the network of the vessels, and 3. a total destruction of the blood-vessels and also of the tissue. Therefore clinically a subtotal or total network obliteration of the blood-vessels of strongly vascularised tissues, haemangiomas, teleangiectasias in case of morbus Rendu-Weber-Osler and livid enlarged nasal conchae might be obtained. Further a total tissue-destruction with a break in the continuity of the tissue for example with strongly vascularised carcinoma or its metastases might be effected.

Animals↗
PubMed1975

[Critical evaluation and rational use of nuclear medical techniques in the diagnosis of thyroid function (author's transl)].

The diagnosis of thyroid function has been decisively improved by the in-vitro tests and the radioimmunologic assays of total tri-iodothyronine- and TSH levels before and after stimulation with TRH. The high specificity and value of in-vitro tests lies in the quantitative measurement of peripheral hormoneconcentrations. The radio-iodine test, however, is only a qualitative technique giving information on movements of intrathyreoid radio iodine. The in-vitro tests are not falsified by iodine contamination. Extrathyreoidal protein-changes can be excluded with the ETR test. The radio-iodine test will now have to be done only in rare special cases. As a rule thyroid metabolism can be assessed safely by combining clinical examination with an in-vitro testblock adapted to the individual diagnostic problem with additional technetium scintigraphy.

Humans↗