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Biomedical subjects

W Kühnel

Publications and source records attributed to W Kühnel.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Morphology in intracytoplasmic sperm injection].

OBJECTIVE: Was to determine if severe morphological defects of spermatozoa in Oligo-Astheno-Teratozoospermia (OAT) have any impact on the fertilization process in intracytoplasmic sperm injection (ICSI) and, if there are any specific morphological characteristics of unfertilized oocytes after the ICSI procedure. METHODS: Ejaculates of males with severe subfertility and unfertilized oocytes after the ICSI procedure were investigated by transmissionelectronmicroscopy. RESULTS: ICSI provided a fertilization rate of 66% in cases of severe defective spermatozoa. The ultrastructure revealed severe head and neck alterations in particular. The ultrastructure of the unfertilized oocyte displayed mostly no signs of activation and lack of decondensation of sperm chromatin. CONCLUSIONS: Our findings support the hypothesis that not severe sperm defects but the lack of intracytoplasmic sperm-oocyte interaction displays the most critical role in the fertilization process in intracytoplasmic sperm injection.

Female↗
PubMed1994

Storage lesion of human platelets as revealed by ultrathin sections and freeze-fracture replicas.

We report the ultrastructural changes occurring in human platelets during eight days of storage. Extension of pseudopodia is frequently observed, but a concentration of organelles in the centre of the platelets is found only in a minor fraction (approximately 5%). Striking changes can be observed in both the granules and the open canalicular system. In fresh platelets, the latter often has the form of stacked membranes that have no lumen, but these membranes separate and spread with increasing storage time. However, the openings of this system on the outer surface of the platelet remain unchanged. Some of these features differ from the morphological description of platelets activated by thrombin or ADP, and suggest that the storage lesion is the result of a prolonged weak activation that leads to an incomplete release reaction within the first five days.

Blood Platelets↗
PubMed1994

Localization of lysosomal enzymes in the retina and retinal pigment epithelium of RCS rats.

Using ultrahistochemical and immunohistochemical techniques, localization of acid phosphatase and cathepsin D was demonstrated in the retina and pigment epithelium of 1 to 42 day old RCS rats and its nonaffected congenic rat strain. Both enzymes are present in the pigment epithelium of the normal and dystrophic rat eye. As early as the age of 1 week, it was found that the lysosomes in the dystrophic rat retina are less stable in releasing acid phosphatase than those of control animals. Infiltration of cathepsin D into the subretinal space could first be detected with certainty in 2-week-old animals. The fragility of the lysosomal membrane and, therefore, the release of both enzymes became more pronounced as the animals aged. The findings of this study indicate that the instability of the lysosomal membrane in the RCS rat pigment epithelium may initiate degeneration of photoreceptors and pigment epithelium. The demonstration of cathepsin D activity has proved very helpful in revealing the physiological or pathophysiological condition of retinal pigment epithelium.

Acid Phosphatase↗
PubMed1994

Distribution of NADPH-diaphorase-positive neurons in the enteric nervous system of the human colon.

Recent investigations have demonstrated the colonization of NOS-immunoreactivity and NADPH-diaphorase staining in central and peripheral neurons. The current study investigates the presence and distribution of NADPH-diaphorase-stained nerve cells and fibres in whole-mount preparations of the enteric nervous system of the human colon. Numerous NADPH-diaphorase-stained nerve cell bodies were found in the plexus myentericus and in the plexus submucosus externus. In contrast, we found but very few NADPH-diaphorase-stained nerve cells in the plexus submucosus internus. The majority of the NADPH-diaphorase-stained nerve cells had morphological characteristics similar to those of the Dogiel type I neuron, i.e. possessing broad flat dendrites and one major axonal projection. NADPH-diaphorase-stained nerve fibres can be observed in all three ganglionic networks and in the aganglionic plexus of the circular muscle layer.

Colon↗
PubMed1994

The vomeronasal organ of the New World monkey Saguinus fuscicollis (Callitrichidae). A light and transmission electron microscopic study.

The vomeronasal organ (VNO) of the New World monkey Saguinus fuscicollis (Callitrichidae) is located at the base of the most distal portion of the nasal septum opening into the nasal portion of the ductus nasopalatinus which also communicates with the oral cavity. The lumen of the VNO is limited medially and laterally by a neuroepithelium which is devoid of intraepithelially located blood vessels and composed of receptor, supporting and basal cells. Ultrastructural analysis of the VNO of Saguinus fuscicollis reveals morphological features which lead one to postulate the functional capacity of this organ in these primates. A possible mechanism through which scent marks may be incorporated into the VNO is discussed.

Animals↗
PubMed1994

Immunohistochemistry of markers of the enteric nervous system in whole-mount preparations of the human colon.

In this study we tested the immunohistochemical reactions of various markers for the enteric nervous system in whole-mount preparations of the human colon. For that purpose we used polyclonal antibodies against the neuronal markers--protein gene product 9.5 (PGP), neuron-specific enolase (NSE), neurofilament protein 200 (NFP), microtubule-associated proteins (MAPs); and the glial markers--S-100 protein and glial fibrillary acidic protein (GFAP) for the immunoperoxidase reaction. Whole-mount preparations are more suitable for histopathological evaluation and interpretation than sections, because the enteric nervous system consists of three-dimensional plexuses lying within the layers of the intestinal wall. Sections show only a part of the plexuses, neurons and glial cells. On the other hand, whole-mount preparations reveal the morphology of the plexuses as a whole. Among the neuronal and glial markers used, S-100 protein, the neurofilament protein, and the protein gene product 9.5 (PGP) produced the best results. Furthermore, this developing method provides new possibilities for the histopathological analysis of defects in the enteric nervous system, such as neuronal intestinal dysplasia (NID).

Biomarkers↗
PubMed1994

Histopathological features of neuronal intestinal dysplasia of the plexus submucosus in whole mounts revealed by immunohistochemistry for PGP 9.5.

Neuronal intestinal dysplasia (NID) is wellknown, but its definition is a topic of debate. The histopathological diagnosis of NID is based on traditional enzyme-histochemical methods such as the acetylcholinesterase and dehydrogenase reaction on native cryosections. In this study, we have investigated the enteric nervous system in whole mount preparations of resected intestinal segments affected by NID of the plexus submucosus (type B). The plexuses of the tunica mucosa and tunica submucosa were visualized by immunohistochemical methods using a polyclonal antibody to protein gene produce 9.5 (PGP 9.5). PGP 9.5 is a novel general cytoplasmatic marker specific for the nervous system. The morphology of the plexuses is revealed in full, making possible changes easily discernible. Known pathological findings of the NID can be identified and judged more precisely with this method. Numerous enlarged nerve trunks run within the tunica submucosa and tunica mucosa. Hyperplastic ganglia with an unusually high nerve cell number in the tunica submucosa can be demonstrated as well as heterotopic nerve cells in the tunica mucosa.

Adolescent↗
PubMed1993

Topography of the enteric nervous system in Peyer's patches of the porcine small intestine.

The mechanisms of intercommunication between the immune and nervous systems are not fully understood. In the case of the intestine, the enteric nervous system is involved in the regulation of immune responses. It was therefore decided to employ immuno-histochemical techniques to investigate the structural organization of the enteric nervous system in Peyer's patches of the porcine small intestine. Using antibodies against various nervous system-specific markers (protein gene product 9.5, neuron-specific enolase, neurofilament 200, S-100 protein and the glial fibrillary acidic protein), an intimate and specific structural association could be demonstrated between enteric nerves and the compartments of Peyer's patches: follicles, interfollicular regions and domes. Peyer's patches have a close topographical relationship to the two submucosal plexuses. Enteric nerves are located around the follicle in the interfollicular area--the so-called "traffic area"--and in the dome area, which plays an important role in the uptake and presentation of antigens.

Animals↗
PubMed1993

Distribution of nitric oxide synthase-immunoreactive neurons in the submucosal plexus of the porcine small intestine.

This study analyses the occurrence of NOS-immunoreactive neurons in the enteric nervous system of the porcine small intestine, and particularly their distribution pattern in the ganglia of the two submucosal plexuses, the external submucosal plexus and the internal submucosal plexus. Numerous NOS-immunoreactive nerve cell bodies were found in the external submucosal plexus, as well as in the myenteric plexus. In 1 cm2 of the surface of the submucosal whole-mount preparation, we counted 186 NOS-immunoreactive nerve cell bodies in the external submucosal plexus, which is about 27% of the total number of nerve cells in that plexus. As against this, we found only very few NOS-immunoreactive nerve cells in the internal submucosal plexus. In the external submucosal plexus, these cells are often located together, forming aggregates within the ganglia. NOS-immunoreactive nerve cells are of different sizes and shapes. Some of them have a multidendritic uniaxonal appearance. NOS-immunoreactive nerve fibres can be observed in all three ganglionic networks, surrounding NOS-immunoreactive as well as nonimmunoreactive nerve cell bodies and forming varicosities in close proximity to the nerve cell bodies.

Amino Acid Oxidoreductases↗
PubMed1993

Immunohistochemical demonstration of nerves and nerve cells in human and porcine ureters.

There are divergent opinions about the origin of ureteral motility. It is either a myogenic or a neutral phenomenon. Furthermore, the existence of nerve cells in the ureter is also a controversial question. In the present study we applied immunohistochemical methods to human and porcine ureters in an attempt to clarify the mattern. As neuronal markers we used anti-PGP 9.5 and anti-NSE, and as a glial marker anti-S-100. In the whole mount preparations of pig ureter we observed two neuronal plexuses on both sides of the tunica muscularis. The inner plexus consisted of both nerve bundles and nerve cells, whereas the outer one did not contain any nerve cells. In the human ureter we found a ganglion with nerve cells beneath the tunica muscularis and the tunica adventitia.

Animals↗
PubMed1993

Immunohistochemical visualization of the enteric nervous system using antibodies against protein gene product (PGP) 9.5.

Both the investigation of the enteric nervous system and the diagnosis of its pathological changes require reliable staining methods. In order to assess the potential of protein gene product (PGP) 9.5 as a marker for the enteric nervous system, we examined its immunoreaction in whole-mount preparations of the guinea pig and porcine small intestine, using a rabbit polyclonal antiserum. The immunohistochemical technique reveals the fundamental architectural features of the ganglionic and aganglionic plexuses. Furthermore, it enables a reproducible and differentiated visualization of the enteric nerve cells to be made, so that the various nerve cell types can be morphologically identified.

Animals↗
PubMed1993

Morphology of the rat uterus after long-term treatment with progesterone antagonists.

The effects of long-term treatment with the progesterone antagonists ZK 98.299 and ZK 112.993 on the uterus of intact mature rats were investigated with light and electron microscopy. After 3-4 weeks treatment with both progesterone antagonists, the uterine luminal epithelium showed ongoing mitotic activity, increased apoptosis and invasion by granulocytes. Many uteri showed metaplastic areas with stratified squamous epithelium. Basically, the same changes occurred, but to a lesser extent, in the glandular epithelium. At the ultrastructural level, the epithelial cells displayed the morphological features of a certain degree of differentiation. The dissociation of collagen fibres, infiltration by granulocytes and dilatation of small vessels were observed in the subepithelial connective tissue. The myometrium increased in thickness and electron microscopic examination revealed hypertrophic myocytes with a well developed granular endoplasmic reticulum. Most of the morphological reactions may be regarded as due to the direct inhibitory action of progesterone antagonists at the level of the different uterine tissues and the resulting unopposed action of estrogen. The metaplastic changes and the suppression of the anti-proliferative action of progesterone on uterine epithelial cells should be taken into account when treating women in their reproductive years with these drugs for long periods of time, as may be necessary for the endocrine treatment of mammary cancer and endometriosis.

Animals↗
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↗