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Biomedical subjects

W Drommer

Publications and source records attributed to W Drommer.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Iscom (Immuno Stimulating Complex)-vaccine of equine influenza virus--transmission electron microscopic investigation and literature review].

Vaccines on the base of immunostimulating complexes are very rare in human and veterinary practice. Until now, Iscom vaccines mainly have been developed for scientific experimental investigations. Synthesis and preparation of Iscom vaccines, mainly basing on the reviewed literature, as well as electron microscopical investigations of Iscom structures and the monitoring of vaccine fractions of Iscoms are described. The equine influenza Iscom vaccine, developed by the Mallinckrodt Veterinary GmbH, is one of the first commercial Iscom vaccine used in veterinary medicine. In comparison with other commercially used vaccines, depending on the high level of antigen presentation of Iscom structures, a ten times higher antibody response is to be expected by the use of Iscom vaccines.

Animals↗
PubMed1996

CD88 antibodies specifically bind to C5aR on dermal CD117+ and CD14+ cells and react with a desmosomal antigen in human skin.

The expression of the C5aR (CD88) on human epidermal and dermal cells was studied with five anti-C5aR mAb directed to the N-terminal domain of the receptor. All mAb bound to suspended dermal CD117+ mast cells and to dermal CD14+ cells. The binding to CD14+ and CD117+ cells could be blocked by rC5a and by peptide EX-1 representing amino acid residues 1-31 of the C5aR. In acetone-fixed frozen or in paraformaldehyde-fixed, paraffin-embedded tissue, we detected a binding of the Abs to dermal perivascular cells and, additionally, to keratinocytes and dermal epithelial cells that could be blocked by EX-1. Immunoelectromicroscopy revealed a binding of anti-C5aR mAb to desmosomal regions in human epidermis. However, the following results indicate that CD88 mAb cross-react with epithelium in a specific way: 1) the binding to suspended epidermal cells and to the epidermal cell line HaCat could be blocked by EX-1 but not by rC5a; 2) FITC-labeled C5a bound to CD117+ and to CD14+ cells but not to epidermal cells; 3) C5a led to transient calcium fluxes in CD14+ and CD117+ dermal but not in epidermal cells; 4) C5aR mRNA was detectable by reverse transcription PCR in granulocytes but not in keratinocytes or in HaCat. Our results show that CD88 mAb are good tools for the investigation of the C5aR on hemopoietic cells. Results with epithelial cells should be considered with caution, as the binding of CD88 mAb that were raised to a synthetic peptide sequence may be due to a cross-reactivity.

Antibodies, Monoclonal↗
PubMed1996

Ultrastructure of pre- and postcolostral enterocytes of the newborn calf.

Ten calves were used to elucidate the ultrastructure of enterocytes before and 24 h after colostral intake. Tissue samples were obtained from duodenum, jejunum (5 locations) and ileum. Protein A-gold technique was applied to immunoelectron-microscopically demonstrate colostral IgA. The prominent feature of the precolostral enterocytes are intracytoplasmic vacuoles. The frequency of vacuoles increases from cranial jejunum to ileum and from the villi bases to the tips. The appearance of absorptive vacuoles after colostral administration correlates with the incidence of precolostral empty vacuoles. Bovine IgA was detected in absorptive vacuoles and within the intestinal lumen of postcolostral calves. In addition to a diffuse IgA labelling of most vacuoles, a few corresponding enterocytic vacuoles labelled inhomogenously or negatively. This study demonstrates morphologically that the main site of colostral absorption is the middle-to-caudal region of the small intestine. Immunoelectron microscopy of IgA labelling provides indications of a selective IgA absorption in addition to pinocytosis.

Animals↗
PubMed1996

Immunohistochemical findings in eyes of cats serologically positive for feline immunodeficiency virus (FIV).

In this study the eyes of 15 cats in the terminal stage of FIV infection were examined. The findings were compared to those in cats, which were euthanized because of other infectious diseases for for non-infectious reasons. Thirteen FIV-infected cats showed an anterior uveitis by means of light microscopy. No accumulation of retinal lesions were found in FIV-infected cats compared to the other cats examined. Additionally, there were no indications of lesions caused by opportunistic infections. In the posterior segments of the eyes, immunohistochemical examinations proved the plasma proteins C3 and IgG to be predominantly intravascular. The eyes of 11 serologically FIV-positive cats were available for immunohistochemical examination. In all 11 cats at least one of the plasma proteins C3 or IgG could be detected in the extravascular tissue of the anterior uvea. The extravascular presence of plasma proteins within the tissue seemed to be caused by an increased permeability of the vessels due to inflammation. Furthermore, the similar extravascular distribution pattern of IgG and complement component C3 in four cases indicated that immune complexes may play a role in the anterior uveitis of FIV-infected cats.

Animals↗
PubMed1996

Retinal detachment in horses.

Ten horses with partial or total retinal detachment were investigated using light and electron microscopy (TEM, SEM). Several lesions were observed and compared with normal retinal morphology. Three weeks after the initial retinal detachment, hypertrophy of the pigment epithelium with transformation of the apical microvilli could be observed. The lesions were accompanied by progressive degeneration and atrophy of the sensory retina, starting at the photoreceptor outer segments. Hypertrophy of Müller cells was a concomitant finding. Retinal detachment represents a sequel either to inflammatory processes or trauma.

Animals↗
PubMed1996

[Tissue lipid peroxidation in nutritional encephalomalacia of broiler chickens].

The consequences of different dietary fats in combination with two vitamin E levels on peroxidative tissue damage of chicken brain and liver and its meaning for development of nutritional encephalomalacia (NE) were investigated. A feeding experiment was performed with 1-day-old chickens from hens on a vitamin-E-poor diet. The animals received a vitamin-E-deficient basic diet containing 10% fat, rich in either C18:3n3-, C18:2n6- or C18:1n9-fatty acids. The fat was given either fresh or oxidized (peroxidation number: 250) and 0 or 50 ppm alpha-tocopherylacetate was added. Typical symptoms of NE occurred mainly in those groups fed with n6-fatty acids beginning on day 7. In order to evaluate oxidative tissue damage, conjugated dienes, fluorescent pigments and TBA-reactive substances were determined in liver, cerebrum and cerebellum. Brain was examined histologically. In liver and cerebrum, the feeding of oxidized fats led to a 20% increase in conjugated dienes. Fluorescent pigments could be determined only in the brain tissues. However, feeding conditions had no effect, although autofluorescence was observed histologically in the affected animals. TBA-reactive substances were heightened in cerebrum (30%) and liver (130%) as a result of feeding linolenic acid. Vitamin E deficiency doubled TBA-reactive substances only in the liver. The parameters measured did not show intensified lipid peroxidation in the cerebellum of the animals fed the NE producing diet. Rather, the liver seems to be affected by the oxidative stress.

Animals↗
PubMed1995

Clinical, and light and electron microscopical findings in sows with cystitis.

The clinical findings, and urinary and morphological changes in the urinary bladder were investigated in 25 sows with a urinary tract infection. Eubacterium suis was isolated from 12 of the sows but not from the other 13. The clinical signs did not always correlate with the morphological changes. The only clinical sign indicating the beginning of cystitis appeared to be a significant bacteriuria. Other urinary changes occurred later when the inflammatory processes were more severe. In contrast with cystitis due to other bacteria, infection with E suis frequently resulted in a macrohaematuria and urinary pH values above 8.0. However, the light and electron microscopical findings in the bladder mucosa were similar in the sows with and without cystitis due to E suis. The transformation of goblet cells and the development of mucin cysts were probably due to the local bladder defence mechanisms. More severe lesions were observed with E suis infections, which resulted in changes in the ureterovesical junctions and in ascending renal infection and uraemia.

Animals↗
PubMed1995

[Light- and electron-microscopic studies of the structure of normal bladder epithelium in female swine].

A light- and electron-microscope investigation was performed to examine the normal structure of the porcine urinary bladder. Tissue biopsies were studied obtained from 10 healthy female pigs (four weanling pigs, six sows). The bladder wall showed a typical stratification consisting of a tunica (t.) mucosae, t. submucosae, t. muscularis and t. serosa. The mucosa consisted of an epithelium transitionale, a lamina propria, and a lamina muscularis mucosae. The urothelium was composed of a basal layer, one or more intermediate layer(s), and a superficial layer. The urothelial cells of all layers were connected by desmosomes, while tight junctions linked adjacent superficial cells. Surface cells were lined by a layer of mucus, which is believed to provide an important barrier against bacterial infection. The surface of the superficial cells was also characterized by numerous irregularly arranged microplicae. By contrast, intermediate cells, which are assumed to be immature cell forms, showed microvilli-like structures. When desquamation of superficial cells takes place, differentiation of underlying intermediate cells is accompanied by merging of microvilli to form microplicae. The morphology of the bladder surface structures may play an important role in the ability of bacteria to adhere to the urothelium.

Aging↗
PubMed1995

[Findings in the eyes of serologically FIV (feline immunodeficiency virus) positive cats].

The findings in the eyes of 19 serologically FIV-positive cats in the terminal stage of the disease were compared to those in 23 serologically FIV-negative cats. An inflammation of iris and ciliary body was more common in the FIV-group than in the other cats and could be seen in 16 out of 19 serologically FIV-positive cats. In most cases a diffuse infiltration of both lymphocytes and plasma cells could be observed. There were only few signs of acute inflammation in the posterior segment. Degenerative alterations of the retina were found in all groups. The most common degenerative finding was a cystoid atrophy of the retina. Due to these findings an association of FIV-infection and anterior uveitis seems to be very likely. It remained unclear whether the FIV was involved directly or whether indirect mechanisms like secondary infections or alterations in the immune system caused the inflammation.

Animals↗
PubMed1994

Immunoelectron microscopical demonstration of the absorption of colostral IgG by small intestinal enterocytes in newborn rats.

The protein A-gold technique was used in the cranial, transitional and caudal segments of the small intestine of 12 newborn rats to demonstrate the process of absorption of gold-labelled IgG through the enterocytes. The observation of the attachment of labelled IgG molecules to the wall of coated vesicles suggested a receptor-mediated transport of colostral IgG in the cranial segment of the small intestine. However, intracellular micropinocytotic transport predominated in the transitional and caudal segments of the small intestine. There was no evidence for paracellular transport. Lysosomal structures in the enterocytes did not appear to impede the absorptive activity during the absorption period, which lasted 20 days.

Animals↗
PubMed1994

An immunoelectron microscopic investigation of colostral IgG absorption across the intestine of newborn calves.

The protein A-gold was used to examine the transport of colostral IgG from the lumen of the gut to the circulation in four newborn calves and one 24-hour-old calf. The absorptive enterocytes of the duodenum, jejunum and ileum were investigated five to 60 minutes after administering colostrum, and 24 hours after birth. In the newborn calves, an intracellular micropinocytotic transport of IgG molecules was dominant throughout the entire small intestine. The amount transported increased from the duodenum to the ileum. In addition, evidence of a selective, receptor-mediated transport of IgG during the first few hours of life was provided by the presence of bovine clathrin at the microvillous membrane of the duodenal and jejunal enterocytes, indicating the existence of specialised vesicles for transport, the so-called 'coated' vesicles. No sign of paracellular transport was detected. Intestinal closure was interpreted as a multifactorial event comprising the replacement of the fetal intestinal epithelial cells by more mature populations, the initial cessation of transport at the basal and lateral cell membrane of the absorptive enterocytes, and an increase in intracellular proteolytic activity by lysosomes.

Animals↗
PubMed1994

Demonstration of Sindbis virus antigen in Lowicryl-embedded cultured cells by immunogold staining.

Eight monoclonal antibodies (MAbs) were tested for the use in immunogold staining of Sindbis virus (SIN) antigen in cultured Baby Hamster kidney (BHK) cells. The antibodies were directed against the capsid (C) protein (5) or against the glycoprotein E1 (3), respectively. Four out of five anti-C MAbs and two out of three anti-E1 Mabs reacted on frozen sections, whereas two of the anti-C antibodies and none of the anti-E1 antibodies reacted on Lowicryl K4M-embedded cells. The MAbs reacting, in particular the anti-C Mabs which react on Lowicryl K4M-sections, will allow further studies of the pathogenesis and replication of alphaviruses on the cellular level. The results also confirm the conformation-dependence of the glycoprotein epitopes.

Acrylic Resins↗
PubMed1994

[Scanning electron microscopic studies of the urinary bladder of sows with special reference to a Eubacterium suis infection].

Scanning electron microscopy was performed on bladder biopsies from 20 sows with cystitis. Results were compared with those of healthy control animals. Biopsy specimens were taken from nine sows infected only with commensal bacteria (E. coli, streptococci, staphylococci) and from 11 sows, where Eubacterium suis (E. suis) was involved in urinary tract infection and had caused a haemorrhagic cystitis. Increased losses of normal superficial cells covered with microplicae could be seen depending on the degree of cystitis. Desquamation of the surface layer exposed smaller cells patterned with short microvilli. These cells were presumed to be immature intermediate cells and goblet cells. Goblet cells were found only in infected organs. The varying surface structure of epithelial cells in relation to receptor quality is important for the bacterial adherence to bladder mucosa. All examined bladders infected with E. suis showed a total loss of superficial cells. Luminal cells covered with multiple short microvilli were accompanied by cells with long pleomorphic processes. Accumulating cell necrosis was indicated by a smooth surface structure. Funnel-shaped orifices between the epithelial cells were identified as excretory ducts of mucus-filled cysts, which are formed by the confluence of degenerating goblet cells. E. suis infection of the porcine bladder causes more severe alterations than infections due to other bacteria. However, debilitation of the urothelium due to previous infection is necessary to support infection of the bladder with E. suis.

Animals↗
PubMed1993

[Bilateral blindness after injury in a riding horse].

Bilateral blindness was diagnosed in a 5-year-old Hanoverian gelding presented for evaluation of a corneal opacity in one eye. About 12 months prior to the examination, the gelding had fallen head over, hitting his head and the cornea. Clinical and electroretinographic findings as well as pathohistologic and ultrastructural lesions of both eyes including the optic nerves are presented. Ophthalmoscopically visible pigment disruption of the non-tapetal fundus adjacent to the optic discs correlated morphologically with foci of degeneration and atrophy of the retina, whereas ophthalmoscopically visible accumulation of pigment was morphologically characterized by hypertrophy of the pigment epithelium, increased intracellular pigment accumulation and by migration of pigment cells into the inner lamina of the retina. Severe atrophy of the retinal neuronal layer was linked to traumatic optic nerve degeneration.

Animals↗
PubMed1992

[Scanning electron microscopic findings of the navicular bone and deep flexor tendon in podotrochlosis of horses].

In 25 adult horses the podotrochlea of 49 forelimbs was examined by means of light and electron microscopy in order to correlate clinical and morphological findings. According to the clinical diagnosis the animals were divided into three groups: lameness due to syndrome of podotrochlosis (group 1) or due to tendopathy (group 2) and horses without lameness (group 3). The most striking pathological findings of the navicular bone and the opposite surface of the deep flexor tendon were found in horses with podotrochlosis, consisting of loss of cartilage and tendon matrix with denudation of collagen fibrils, superficial degeneration and necrosis, focal occurrence of fissures and far-reaching defects, sometimes accompanied by adhesions between tendon and navicular bone surface. In radiologically only slightly altered tendons and navicular bones light and scanning electron microscopy often revealed moderate to severe pathological changes, which sometimes could also be seen in clinically healthy horses. The distribution of the lesions indicate that in course of podotrochlosis the initial alterations caused by repeated microtraumata start at the surface of the deep flexor tendon and subsequently spread to the opposite facies flexoria of the navicular bone. An involvement of the cartilage and the synovial layer of the hoof joint in cases with podotrochlosis could only be rarely observed and is to regard as a secondary manifestation.

Animals↗
PubMed1992

[Light and electron microscopic findings in the intestine of spontaneous and experimentally-produced African swine fever].

Light and electron microscopical studies were carried out after experimental induced and spontaneous infection with African swine fever virus. The experimental infection was performed in 18 pigs divided into two groups consisting of 9 animals. The pigs of group I were inoculated with virulent isolate E 70, those of group II with attenuated isolate E 75. Two infected pigs of group I and one control animal were killed on days 3, 5 or 7 p.i., two pigs of group II and one control animal were killed on days 9, 11 or 13 p.i. Additionally 19 spontaneous infected and seropositive animals and two seronegative pigs without clinical signs were examined. Infection with African swine fever virus resulted in slight morphological alterations of the intestine. The pathological findings showed a more intense involvement of the large intestine, especially the caecum and colon, than the small intestine, where the ileum was mostly affected. In all three groups edema and vacuolisation could be observed in endothelial cells. In spite of beginning degenerative signs, especially after spontaneous infection, the fenestrated structure of the endothelium was conserved in most of the cases. In animals infected with virulent isolate the vascular lumina contained aggregations of fibrin, which was severe pronounced in the pigs of the other groups. In the area of these alterations disturbance of permeability with extravasation could be found. In all groups single virions or virus aggregates could be identified in concave depressions of the erythrocyte membrane or free within the blood plasma, in some cases enveloped by a plasma-like material.(ABSTRACT TRUNCATED AT 250 WORDS)

African Swine Fever↗
PubMed1991

Morphological investigations on the pathology of Dictyocaulus viviparus infections in cattle.

Morphological investigations of lungs obtained from cattle that had been experimentally infected with Dictyocaulus viviparus were carried out using a new fixation technique that excludes post-mortem changes in the samples. Light and electron microscopical investigation showed a substantial loss of ciliated epithelial cells in the bronchi, severely affecting the mucociliary clearance. Bronchiolitis, peribronchiolitis and cell-rich mucus caused bronchial atelectasis and consolidation of the related alveoli. Interlobular septa completely separated diseased from normal tissue. Clara cells contained abundant intraplasmatic glycogen. Alveolary walls were thickened and showed cellular infiltration, loss of functional epithelial cells and hyperplasia of alveolar type II cells. Increased connective tissue indicated an irreversible chronic decline in lung performance. Lung eosinophilia and the cytotoxic abilities of eosinophils are discussed as a cause of the changes in lung tissue after infection with D. viviparus.

Animals↗