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Biomedical subjects

W Kühnel

Publications and source records attributed to W Kühnel.

At least 19 recordsLinked to original sources
PubMed1992

Development and distribution of adipose tissue in the human pelvis.

The development of the pelvic adipose tissue was studied using 300-600 microns thick sections through the pelves of 9-37-week-old fetuses and newborn children. During fetal life three different anlagens of adipose tissue appear within the pelvic cavity. Development and topography of these anlagens are described, and correlations with the development of the connective tissue compartments within the pelvis were demonstrated.

Adipose Tissue↗
PubMed1992

The antitumor potency of progesterone antagonists is due to their differentiation potential.

A new therapy for the progesterone receptor positive mammary carcinoma may be the treatment with progesterone antagonists. This new class of antihormones causes a strong inhibition of tumor growth comparable to the potency of ovariectomy in a panel of experimental mammary carcinomas. The mechanisms of the strong tumor-inhibiting action of progesterone antagonists on experimental mammary carcinomas mainly depends on a progesterone receptor mediated process leading to induction of terminal differentiation and a blockade of the cell cycle. To further characterize the antitumor mechanism of progesterone antagonists we analyzed the effects of Onapristone and ZK 112.993 on DMBA- and MNU-mammary tumors of the rat and MXT-tumors of the mouse after different therapy intervals. These hormone-dependent mammary tumors normally display intraductal growth in papillary, cribiform or solid formation, whereas after treatment periods of 2-6 weeks with progesterone antagonists they displayed dysplastic ductal and acinous formations, usually filled with secretory material. Whereas tumor size, mitotic index, and the grade of tumor malignancy decreased distinctly, the volume fraction of glandular structures in the tumors as well as the appearance of apoptosis increased 3-fold compared to the controls. In addition, the mammary glands of progesterone antagonist treated animals showed the morphological features of differentiation with the appearance of secretory activity. Interestingly, the staining pattern of some of the lectins used, especially UEA 1 binding pattern, fits to the concept of differentiation since recent studies revealed a higher degree of fucosylation only in benign lesions of human breast cancers. Therefore, these data underline the concept of a differentiation potential of progesterone antagonists on progesterone receptor positive mammary carcinomas.

Animals↗
PubMed1992

Immunohistochemistry for intermediate filaments in the enteric nervous system of the porcine small intestine.

Antibodies against the cytoskeletal neurofilament protein 200 and gliafilament acidic protein were used for an immunohistochemical staining of nerve and glia cells in porcine small intestine. In sections as well as in whole mount preparations, the morphological and topographical features of the enteric nerve plexus could be demonstrated. The enteric glia cells are characterized by an abundance of immunoreactive GFAP, which allows a subsequent staining of the plexus. NFP 200 is immunohistochemically recognized only in a part of the neurons. This immunoreactive neuronal population can be identified morphologically as Typ II-neurons, which are defined as adendritic and pseudouniaxonal to multiaxonal. The immunostaining of intermediate filaments is an easy and reproducible means for studying the enteric nervous system and invaluable for the histopathological diagnosis of its morphological abnormalities.

Animals↗
PubMed1992

Endothelial cell helix in small arterioles of human ureters. A study by scanning electron microscopy (SEM).

Microvessel corrosion casts of human ureters were prepared. Portions of casts were longitudinally cut by use of a pulsed Eximer laser beam in order to get insight into microvessel branches studied in SEM. Larger arterioles (greater than 30 microns in diameter) showed oval imprints of endothelial cell nuclei along the vessel axis. Imprints were found in furrows parallel to resin ridges. Smaller arterioles (less than microns in diameter) displayed imprints of nuclei aligned in a helix around the vessel axis. With regard to capillaries, one nucleus imprint was spaced far apart from the other. Venules demonstrated a reticular network of thick, attenuated resin ridges and of small meshes which consisted of round or oval nucleus imprints. It is concluded that smaller arterioles form an endothelial cells helix.

Arterioles↗
PubMed1992

SEM studies on unmanageable hair.

The manageability of the hair is dependent on the surface composition of the hair shaft. Exogenously caused damage leads to unmanageability by massive superficial defects in the hair cuticle. The symptoms of trichorrhexis nodosa and trichoptilosis are present, and superficial horny scales are bent up and curve under in tunnel-like fashions. Appropriate hair care can improve these defects. Endogenous damage to the hair leading to unmanageability is characterized by spiral furrows along the shaft. It can not usually be improved by the use of care products. The examples presented in the paper demonstrate that exogenous and endogenous causes of unmanageability are characterized by different alterations in the hair shaft.

Hair↗
PubMed1992

[The olfactory region of the bat Scotophilus heathi. Light and electron microscopic studies].

The present investigation reports light and electron microscopical aspects of the main olfactory epithelium (MOE) of the insectivorous bat Scotophilus heathi. Serial frontal sections of the nose and associated structures reveal: 1) that the MOE is located on most of the ethmoturbinals and on the proximal upper portion of the nasal septum; and 2) that the vomeronasal organ is absent in this species. The ultrastructure of the MOE of Scotophilus heathi is similar to that observed in other vertebrates. Moreover, we did not observe significant morphological differences between the MOE of male and female animals. Nevertheless, the supra-nuclear region of the supporting cells of males and females shows a different amount and distribution of "lysosome-like" cell organelles at the two times of the year investigated.

Animals↗
PubMed1992

[The effect of cyclooxygenase inhibitors on the course of hereditary retinal dystrophy in RCS rats].

Daily administration of acetyl salicylic acid (ASA) and ibuprofen leads to an appreciable retardation in the process of retinal degeneration in the RCS rat which is dependent on the dosage given. The photoreceptor cell nuclei and inner segments are relatively well preserved in all regions of the retina. While the outer nuclear layer of 32 day old RCS rats is usually composed of only 3-4 rows, we found 8-9 nuclear rows exhibiting minimal pyknotic change in animals which had been treated with higher doses of ASA. These differences in layer thickness could be confirmed using morphometric analysis. The outer segments show evidence of degenerative change although they are in a clearly better condition than those found in untreated animals and in those animals treated at lower dose. Phagolysosomal structures which are not otherwise apparent in this strain of rat are detected only in the RPE cells of animals treated with higher dose. The animals treated with ibuprofen show essentially the same morphological changes although a corresponding effect in regard to the thickness of the outer nuclear layer was only achieved after a high dose. The determined dose for the optimal preservation (thickness) of the outer nuclear layer lies around 160 mg/kg body weight for acetyl salicylic acid and at 400 mg/kg body weight for ibuprofen.

Animals↗
PubMed1991

Postnatal changes in the ultrastructure of the rat olfactory epithelium: the supranuclear region of the supporting cells.

The present electron-microscopical study reports ultrastructural changes occurring in the supranuclear region of the supporting cells of the rat olfactory epithelium during the first 16 days of postnatal life. These changes are concerned with the enclosure of receptor cell dendrites and an increase in the amount of smooth endoplasmic reticulum, which has a specific distribution in the supporting cell. An increase in microvillous projections at the free cell surface is also observed. Moreover, this report demonstrates that the cytoarchitecture of the apical portion of the olfactory epithelium at the 16th day of postnatal life is similar, with respect to the relationship between supporting cells and receptor cell dendrites, to that of adult animals.

Animals↗
PubMed1991

[Lectin histochemistry on the olfactory region and the vomeronasal organ or rats and golden hamsters].

The present investigation describes the lectin-binding properties of the regio olfactoria (RO) and the vomeronasal organ (VNO) of the rat and golden hamster. Special attention is paid to the lectin-binding properties of the chemosensory epithelia as well as to the reactions of their specific glands. The following lectins were used: wheat germ agglutinin (WGA), horseshoe crab agglutinin (LPA), gorse agglutinin (UEA I), peanut agglutinin (PNA), soybean agglutinin (SBA), and horse gram agglutinin (DBA). Lectin-binding procedure was performed on paraffin sections of the RO and VNO using the peroxidase-antiperodixase method. Comparisons of the lectin-binding properties of the surface of the main olfactory epithelium (MOE) with that of the neuroepithelium (NE) of the VNO as estimated by the intensity of staining demonstrate that in both species differences exist between the lectin-binding properties, of the MOE and VNO-NE. Moreover, some reactions of the MOE and VNO-NE differ from species to species.

Animals↗
PubMed1989

[CT of the upper ankle joint. Anatomy--pathology].

Diagnosis of ligament ruptures via the possibilities of conventional radiology is often insufficient. To verify CT efficiency, postmortem specimens were scanned in axial, coronal and sagittal planes and compared with anatomical findings of sections in identical planes. After the preliminary examinations we conducted a study on 32 patients. The examinations of the anterior talofibular ligament showed a correlation between CT and operative findings in 30 of 32 cases.

Adolescent↗
PubMed1989

Mechanistic study on formaldehyde-induced hepatotoxicity.

In isolated, hemoglobin-free perfused livers of fasted rats, formaldehyde at an initial concentration of 10 mmol/l produced toxicity as evidenced by a release of enzymes (GPT, SDH) and of glutathione (mainly GSSG) into the perfusate, an accumulation of calcium in the liver, and a depletion of hepatic glutathione. Formaldehyde also led to an enhanced release of malondialdehyde into the perfusate, indicating peroxidative processes and decreased hepatic oxygen consumption by about 50-70%. The electron microscopic investigation of formaldehyde-exposed livers showed a destruction of the mitochondria (ruptured membranes, loss of the cristae) and some damage of the rough endoplasmic reticulum. Feeding the rats prior to surgery attenuated the hepatotoxic effects of 10 mmol/l formaldehyde. At an initial concentration of 3 mmol/l, formaldehyde did not release enzymes from livers of fed or fasted rats but only from those whose glutathione content had been depleted by treatment with phorone (250 mg/kg ip 2 h earlier). Formaldehyde liberated glucose and lactate from the livers of fed but not from those of fasted rats, indicating anaerobic energy supply in the fed state. The hepatotoxic action of formaldehyde is not due to its metabolism to formate or to the 10% methanol added as a stabilizing agent to the commercially available 37% solution named formalin. In conclusion, by destruction of mitochondria, formaldehyde inhibits aerobic energy supply and thereby presumably produces hepatocellular damage.

Alanine Transaminase↗
PubMed1989

[beta-Thromboglobulin concentration, thrombocyte count and thrombocyte volume from four selected sample collections].

beta-Thromboglobulin, blood platelet count and blood platelet volume are presented by a reference group (N = 30) and are compared with a group of patients having mild thrombocytopenia, migraine and renal disease before, during as well as after dialysis. Patients with migraine have statistically significant differences regarding these three parameters in comparison to the reference group. Renal patients demonstrate a marked increase of the beta-thromboglobulin values during dialysis and a rapid decrease two hours afterwards.

Adult↗
PubMed1989

[Short-term versus long-term chemoprevention of recurrence with Epodyl following transurethral resection of superficial urinary bladder cancer].

This investigation compares the short and long-term administration of intravesical Epodyl (etoglucid), following transurethral bladder tumor resection. This chemoprophylactic agent was used specifically in the treatment of bladder tumors that displayed different associated tumor risk factors: solitary versus multiple tumors, grade(s) I-III, primary versus recurrent tumors, and the presence of associated dysplasia. Within this study, 114 patients with carcinoma of the bladder underwent primary transurethral resection (TUR), followed in 10 days by short-term intravesical therapy (STIT) or long-term intravesical therapy (LTIT). Short-term intravesical therapy was administered to 56 patients. The therapy consisted of a 1% solution of Epodyl, which was given once per week for 6 weeks. Long-term intravesical therapy was given to 58 patients. This consisted of the short-term intravesical therapy protocol, followed by an additional dose once a month during an observation period of 2 years. The follow-up in both groups was for a minimum of 2 years. When the total number of recurrences in patients receiving (STIT) or (LTIT) was compared, no marked differences were noted (39% vs 38%). However, there was a difference when the individual tumor risk features were compared, e.g. for solitary tumors, the recurrence rate was 67% within the (STIT) group and 43% within the (LTIT). These results demonstrate that the decision of whether superficial bladder carcinomas are to be treated with short- or long-term Epodyl should be based on tumor-associated risk factors. Furthermore, if multiple tumor risk factors are present, maximal therapy is require; in the absence of risk factors TUR alone may be sufficient.

Administration, Intravesical↗