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Biomedical subjects

S Ueberschär

Publications and source records attributed to S Ueberschär.

At least 19 recordsLinked to original sources
PubMed2002

Blood plasma concentrations of oestradiol-17beta, testosterone and testosterone/oestradiol ratio in dogs with neoplastic and degenerative testicular diseases.

Oestradiol-17beta and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL]x100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4-48.3 pg/mL; median, minimum-maximum; P=0.0256, Mann-Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4-17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6-31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03-0.77 ng/mL) when compared to the control group (1.95, 0.05-3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58-35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06-2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17beta concentration.

Animals↗
PubMed2000

Epidermolytic ichthyosis in a dog: clinical, histopathological, immunohistochemical and ultrastructural findings.

Epidermolytic hyperkeratosis (EH) in man is a complex of congenital, ichthyosiform skin diseases characterized clinically by blistering and hyperkeratosis. These clinical signs are the result of a collapse of the cytoskeleton, seen ultrastructurally as tonofilament clumping and cytolysis within terminally differentiating epidermal cells. In man, specific mutations in keratin 1, 2e, 9 or 10 underlie the various types of EH. This report describes the clinical, histopathological, immunohistochemical and ultrastructural findings in a 6-month-old dog with severe multifocal hyperkeratosis. The morphological changes were comparable with those of EH in man, indicating that this disease, presumably with a similar underlying pathogenetic mechanism, also occurs in the dog.

Animals↗
PubMed1999

[Pathologic-anatomic investigations in laying hens in various housing systems].

Gross pathologic and histologic changes were investigated in a total of 1000 end-of-lay hens. Thirty animals were drawn from free range stocks, 270 from deep litter stocks, and 700 from caging systems. The following changes were evaluated with regards to housing systems: Pododermatitis, deformation of the keel bone and amputated beaks occurred primarily in free range hens. Deep litter hens also suffered from pododermatitis, keel bone deformation and amputated beaks in addition to pecking wounds. In caged hens severe fatty liver syndromes, injuries of the claws and inflammation of the feather follicles were mainly found. Furthermore, injuries and fractures due to handling and transport were almost exclusively found in caged hens. It has to be concluded that all of the investigated housing systems can predisposed hens to certain lesions. The documented changes--e.g. chronic inflammation, skelettal deformities and injuries--are painful and may lead to permanent alterations. Therefore, these changes should be condemned as conflicting with animal protection regulations.

Animals↗
PubMed1996

[Results of pathological-anatomical studies of limbs and spinal column].

The pathomorphological study was carried out on a total of 360 broiler chicken which had been random-sampled on days 22 and 35 of the mast period, respectively, from those flocks that were to be compared. Furthermore, 161 animals with evidence of movement disturbance that were slaughtered in the last two mast weeks, were also evaluated. With regard to incidence, severity of movement disturbance and the spectrum of pathomorphological changes of the skeleton there were no differences between the different groups. When histological and morphometrical methods were applied, no differences in the skeleton structure were noted between flocks with conventional housing and flocks with reduced population density. Equally, no differences were ascertained with regard to dry substance and ash content of the bones including the minerals calcium and phosphorus. Furthermore, there were no group differences in serum calcium, phosphorus and alkaline phosphatase. In numerous chicken from all groups a plantar pododermatitis with differing incidence and strongly varying intensity was observed. The lesions were characterized by a papillomatous proliferation of the basal epithelial layers. There was widespread inflammation with loss of the epithelial layer and deep necroses of the sole. A latent infection with papilloma viruses is discussed. About 90% of the random-sampled chicken of all groups showed bending of the vertebral column by 20 degrees at the height of the 6th thoracic vertebra. In numerous chicken the 6th thoracic vertebra was dislocated and slightly rotated which caused encroachment of the vertebral canal. Whether this alteration may be responsible for the frequently observed movement disturbance of broilers in the last third of the mast period can not be decided on the basis of the pathomorphological study. In any case it must be assumed that both the pododermatitis and the bending and encroachment of the vertebral column cause pain. Thus, both lesions should be evaluated from the viewpoint of animal protection.

Animals↗
PubMed1993

In vitro induction of type II pneumocyte-related differentiation in a clonal fetal bronchiolo-alveolar epithelial cell line (M3E3/C3).

The aim of the present study is to investigate the differentiation of a cloned fetal Syrian hamster lung epithelial cell line, M3E3/C3, to assume morphological and biochemical features of Type II pneumocytes (phospholipid synthesis). The use of a soft agar overlay and a differentiation medium, based on RPMI 1640 combined with hormone supplements, increased the cellular content of phosphatidylcholine (PC) from 48.6% in the conventional culture without any of these factors (referred to as 'control') to 64.7% (p < 0.02). The other cell membrane-associated components, phosphatidylethanolamine (p < 0.05), sphingomyelin (p < 0.001), phosphatidylserine (n. s.), phosphatidic acid (p < 0.02) and phosphatidylinositol (p < 0.02) decreased. The content of phosphatidylglycerol showed no essential change (from 11.2% to 8.4%) and the content of disaturated phospholipids decreased from 32.0 to 23.4 micrograms/10(6) cells (p < 0.002). The phospholipid pattern of these differentiated cells is in rough accordance with that of primary isolated Type II pneumocytes. They incorporated 3H-choline over a period of four hours at a higher rate in the Type II pneumocyte-specific phospholipids, PC and dipalmitoyl-phosphatidylcholine (DPPC), than the undifferentiated control. The radiolabelling of PC and DPPC in the differentiated cells, after 3 hours of incubation with 3H-choline, was about 3.2-fold and 2.2-fold, respectively, higher than that in the control cells (p < 0.001). Intracytoplasmatic phospholipid granules were evident in the differentiated cells by light and fluorescence microscopy (modified Papanicolaou stain, Phosphin 3 R fluorescence). Furthermore, the differentiated cells had a high activity of alkaline phosphatase, whereas the control cells showed only little activity of this enzyme. Ultrastructurally, many concentric multilayered osmiophilic bodies, well developed Golgi apparatuses and many cytoplasmic protrusions comparable to microvilli, were detectable in the cuboidal shaped differentiated cells. The control cells remained wide and flattened on the plastic surface and produced a fibrillar extracellular matrix. In the simultaneously studied fetal lung fibroblasts none of these specific features were noted. These results indicate a specific differentiation capacity of the clonal fetal cell line, M3E3/C3, by closely resembling Type II pneumocytes.

Animals↗
PubMed1993

Morphology and histogenesis of squamous cell metaplasia of the rat lung after chronic exposure to a pyrolized pitch condensate and/or carbon black, or to combinations of pyrolized pitch condensate, carbon black and irritant gases.

Female Wistar rats were exposed to different concentrations of a pyrolized pitch condensate and/or carbon black particles and/or a combination of irritant gases for 18 hours/day, 5 days/week for 10 months, followed by a clean air period of up to 20 months. Bronchiolo-alveolar hyperplasia and squamous metaplasia were important components of the resulting lesions. Squamous metaplasia and associated hyperplasia was investigated by routine histology, scanning and transmission electron microscopy, and by immunohistochemical detection of various cytokeratins (CKs). Intensely CK positive squamous metaplasia lacking a distinct stratum spinosum was distinguishable from squamous metaplasia with a distinct stratum spinosum that reacted weakly CK positive or CK negative. The CK positive type was histologically characterized by narrow intercellular spaces, the weakly CK positive or CK negative type had markedly enlarged intercellular spaces. Differentiated hyperplastic epithelium and the normal lung parenchyma reacted CK negative. In poorly differentiated hyperplasia of the alveolar type associated with squamous metaplasia scattered cells with characteristics of squamous differentiation were detected. Ultrastructurally these cells showed increased amounts of filament bundles and immunohistochemically a positive reaction with the CK antibody. These cells were regarded as precursor stages of squamous metaplasia of the lung periphery in rats.

Animals↗
PubMed1989

Isolation of bovine type II pneumocytes in high yield and purity.

A method has been developed for the isolation of bovine type II pneumocytes by enzymatic tissue dissociation and subsequent density gradient centrifugation. After mechanical defibrination, the crude cell suspension contains 71.9 +/- 26.6 X 10(7) cells (viability greater than 95%) with a type II cell purity of 39.4 +/- 10.9%. Due to their low buoyant density, bovine type II pneumocytes can be purified in a single step to 95.7 +/- 1.7% by discontinuous density gradient centrifugation on a 1.040 g/ml Percoll gradient. Isolated cells are identified by light and fluorescence microscopy that show their characteristic intracytoplasmatic surfactant granules. The fine structure of the surfactant lamellar bodies is examined in ultra thin sectioned and freeze-fractured type II pneumocytes. Isolation of bovine type II pneumocytes for the in vitro study of the surfactant system offers an alternative to the use of laboratory animals and provides an ideal system for the isolation of any desired cell number from one animal by simply increasing the size of the lung segment to be trypsinized.

Animals↗
PubMed1989

Biochemical and metabolic properties of bovine type II pneumocytes in primary culture.

Bovine type II pneumocytes were isolated from lungs of adult cattle by enzymatic tissue dissociation and subsequent purification by density gradient centrifugation on a 1.040 g/ml Percoll gradient. By quantitative and qualitative high-performance liquid chromatographic (HPLC) analysis of freshly isolated, highly purified bovine type II pneumocytes, six phospholipid components (phosphatidylcholine, phosphatidylglycerol, phosphatidyl-ethanolamine, phosphatidylinositol, phosphatidylserine, and sphingomyelin) were detected regularly and their composition was compared to that of whole lung homogenates. Total phospholipid content of 10(6) bovine type II cells was 34.7 micrograms (quantitative HPLC). Suspended and adherent bovine type II cells incorporated [14C]choline into their phospholipids. The rate of synthesis of suspended cells (289 pmol/h x 10(6) cells) was constant for at least 4 h, while adherent type II cells incorporated [14C]choline with a constant rate of 160 pmol/h x 10(6) cells for at least 20 h. These data further establish the use of cultured bovine type II pneumocytes as a high-purity model for the in vitro investigation of the surfactant system.

Animals↗
PubMed1988

[Light and electron microscopic studies on the dose and time dependency of the hepatotoxicity of benzopyrones].

Both male and female Wistar rats were treated with daily oral doses of a combination of the active components coumarin and troxerutin (Venalot-Depot) corresponding to 1, 8, 64 and 128 mg coumarin/kg b.w., respectively. Goal of the study was to study coumarin at the target organ liver for a longer period, after it had turned out from a fertility and teratogenicity study that liver alterations were observed in the P-generation following the elevated doses' treatment up to 10 weeks (male) and 3 weeks (female). Light and electron microscopic examinations of the livers revealed the following findings: The lesions are dose- and time-dependent. First signs of coumarin-induced hepatocellular alterations are fine granular protein-like precipitations in the region of the sER (smooth endoplasmatic reticulum) which conflux to large areas. The glycogen content decreases significantly at the same time. This is followed by an osmotically controlled water redistribution in the cytoplasm and an increased water inflow from the extracellular space (vacuolar degeneration) as well as an overload of the cytoplasm with lipids, taken in by nutrition. Doses of 64 and 128 mg/kg b.w. of the test substance produced extensive hepatic alterations, associated with hypertrophy of the liver, with a focal onset in the globular periphery, subsequently extending to peripheral and intermediate lobular areas. Since light or electron microscopic alterations were not observed following doses of 1 and 8 mg/kg b.w., the dose of 8 mg coumarin/kg b.w. can be determined as no effect dose for the rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effects of ATP and cyclic AMP on the (Na+ + K+ + 2Cl-)-cotransport system in turkey erythrocytes.

As turkey erythrocytes were progressively depleted of ATP by preincubation with dinitrophenol, the (Na+ + K+ + 2Cl-)-cotransport system (assayed by the bumetanide-sensitive fraction of 86Rb+ influx) became less responsive to activation. The dependence upon intracellular ATP concentration was significantly steeper for transport activated by hypertonic shock (halfmaximal activity at 0.7 mM ATP) than for that activated by either epinephrine or cyclic AMP (halfmaximal activity at 1.7 mM ATP). Upon removal of epinephrine or cyclic AMP from cells that had been preincubated with those substances, bumetanide-sensitive transport activity declined sharply, even though the intracellular cyclic AMP concentration was still over 10-fold that required to maximally activate the transport system. These data are in agreement with the notion that the (Na+ + K+ + 2Cl-)-cotransport system in turkey erythrocytes is activated by cyclic AMP, presumably through the 'classical' pathway involving a protein kinase. They do however indicate that some other, as yet undefined aspect of cyclic AMP metabolism is important for the maintenance of transport activity.

Adenosine Triphosphate↗
PubMed1984

[Reproduction toxicologic studies on rats following oral administration of benzopyrone preparations].

The influence of the benzopyrone preparation Venalot (active substances: coumarin and troxerutin; in the following briefly called CT) on the fertility and teratogenicity as well as on the perinatal and postnatal development of a total of 3 generations was evaluated in a combined study. The 1-, 8-, 64-, and 128fold of the daily therapeutical doses for humans was suspended in tap water and administered orally by gavage to 95 male and 190 female SPF rats (Wistar) (test groups 2 to 5). 23 male and 46 female rats (test group 1) served as controls and were given tap water alone. The male animals were subjected to a pretreatment of 10, the female animals to one of 3 weeks. The treatment was continued during the phase of mating. The animals scheduled for cesarian section received the test substance until the day of the laparatomy (gestation day 20), those selected for littering throughout lactation (day 24 post partum). With the aid of a stepwise histological technique, the teratological examination could also disclose non lethal malformations of the organs. The treatment resulted in a decreased food consumption in the animals of group 5 and in a reduced gain of body weight as well as pathologic-anatomically and histologically demonstrable, definitely dose related hepatic lesions. The test substance had no effect on either the treated P generation nor the untreated F1 generation. As teratogenic effects could also not be demonstrated and the peri- and postnatal development of the filial generations 1 and 2 was undisturbed, the present study does not indicate a reproduction toxicological risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗
PubMed1983

Bumetanide-sensitive potassium transport and volume regulation in turkey erythrocytes.

The bumetanide-sensitive (K+ + Na+ + 2Cl-)-cotransport system in turkey erythrocytes is activated by either of two treatments: addition of epinephrine or an increase in osmolarity. At elevated (20 mM) K+ concentration, cotransport activity induced by epinephrine slowly (within 90 min) declines to background level again. This time-dependent inactivation has been linked to bumetanide-sensitive cell swelling. We have compared both the initial rate of cotransport activity and its time dependence after induction by either epinephrine, increased osmolarity or a combination of the two treatments. As a measure of cotransport activity we took the bumetanide-sensitive fraction of 86Rb+ influx. Immediately after activation, several kinetic characteristics of this flux (Vmax; Km towards K+; Ki towards bumetanide; pH profile) were identical in cells activated by either treatment. By contrast, cotransport activated by hypertonicity was significantly more resistant towards subsequent inactivation. We show this to be due to the increase in intracellular ion concentrations brought about by hypertonic cell shrinkage. This tended to reverse the driving force for cotransport, and thereby prevented the bumetanide-sensitive swelling associated with inactivation. Our data support the notion that cell volume plays a key role both in the activation and in the time-dependent inactivation of bumetanide-sensitive transport.

Animals↗