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W Hermanns

Publications and source records attributed to W Hermanns.

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

[Acute myeloid leukemia (promyelocytic leukemia) with detection of virus particles in a boar. Histologic, histochemical and ultrastructural findings].

Acute myeloid leukemia is a rare finding in swine. A case of acute promyelocytic leukemia is described by light microscopy, enzyme- and immunohistochemistry as well as electron microscopy. Tumour cells can be demonstrated in bone marrow, lymph nodes, liver, spleen, kidneys, small intestine and myocardium. The tumorous neutrophil precursor cells are positive for naphthol-AS-D-chloroacetate esterase and lysozyme. They show ultrastructurally numerous granules as typical for promyelocytes. Virus particles of the oncorna-c-type can be demonstrated within the tumour cells.

Animals↗
PubMed1995

[Demonstration of cells of the mononuclear phagocyte system of the cat using enzyme and immunohistochemistry methods].

The suitability of enzyme- and immunohistochemical methods for the demonstration of mononuclear phagocytes in cats is treated. The activity of nonspecific esterases with the substrates alpha-naphthyl-acetate, alpha-naphthyl-butyrate and naphthol-AS-acetate, and of acid phosphatases with the substrate naphthol-AS-BI-phosphate is demonstrated in paraffin and plastic sections of the liver, lungs, spleen and lymph node. Even with modified methods, only slight reactions were obtained in cat tissues compared to sections of rat organs. Four antibodies against human macrophage antigens were tested in paraffin sections. Only the antibody against alpha-1-antichymotrypsin showed no cross-reactions in the cat. Neutrophilic granulocytes reacted strongly, macrophages only very slight with the anti-lysozyme-antisera and the monoclonal antibody MAC 387. Apart from some macrophages, interdigitating reticulum cells, B- and T-lymphocytes in the cat were stained by the anti HLA-DR antibody TAL-1B5.

Animals↗
PubMed1995

[Toxoplasmosis causing death in a mole (Talpa europaea)].

Pathologic lesions caused by Toxoplasma gondii in a juvenile male common mole are described. Main degenerative lesions are localized in liver, heart and lung combined with excessive proliferation of the typical microparasitic cysts. Besides of this a moderate coccidiosis in the mucosa of bile ducts was diagnosed.

Animals↗
PubMed1994

Sensitive detection of human growth hormone mRNA in routinely formalin-fixed, paraffin-embedded transgenic mouse tissues by non-isotopic in situ hybridization.

A sensitive technique of non-isotopic in situ hybridization (NISH) is presented, which permits the detection of human growth hormone (hGH) mRNA in routinely formalin-fixed, paraffin-embedded transgenic mouse tissues and human post mortem pituitaries; the latter were used as positive tissue controls in this study. In addition, a double staining procedure combining NISH and immunohistochemistry for the visualization of both hGH and hGH mRNA in the same paraffin section is described. Digoxigenin-labelled antisense hGH RNA was used for NISH of hGH mRNA. The NISH protocol was based upon an established radioactive method. Alkaline phosphatase and horseradish peroxidase-based immunoenzymatic procedures for the detection of digoxigenin-labelled RNA probes using different chromogens [4-nitro blue tetrazolium chloride (NBT), Fast Blue BB, New Fuchsin, and 3,3'-diaminobenzidine tetrahydrochloride (DAB) with or without intensification of the DAB staining] were compared. The proteolytic tissue pretreatment and the detection procedure were found to be the most critical steps for successful visualization of hGH mRNA. After optimization of the permeabilization conditions, hGH mRNA could be visualized in each case studied when alkaline phosphatase/NBT-based detection was employed. The NISH technique presented here, performed either separately or in combination with immunohistochemistry, permits retrospective analyses, of hGH (trans)gene expression in archival, paraffin-embedded specimens.

Animals↗
PubMed1994

Detection of canine parvovirus DNA in paraffin-embedded tissues by polymerase chain reaction.

Canine Parvovirus (CPV) is seemingly a 'new' virus which suddenly appeared during the mid-1970's in an epizootic of disease in dogs. The virus is very similar to the feline panleukopenia virus (FPV), and recent studies have underlined the possible emergence of CPV as a variant of a virus from some other carnivore--possibly from FPV (Parrish, 1990). Several conserved amino-acid changes between CPV and FPV isolates have been defined by cloning and sequencing the capsid-protein gene. An alternative to cloning and sequencing the entire capsid-protein gene would be to use PCR amplification of short regions of the gene containing the appropriate variable amino-acid codons. In addition, use of PCR would also facilitate the study of virus samples which cannot be recovered as infectious agents, e.g. after having undergone formalaldehyde fixation and paraffin-embedding procedures. This study reports on the amplification of CPV DNA from 15-year-old tissue sections which have been prepared by formaldehyde or paraformaldehyde-lysine-periodate-glutaraldehyde fixation, using PCR with various primer pairs within the capsid-protein gene of CPV.

Animals↗
PubMed1994

Specificity of the immunohistochemical demonstration of mycobacterial antigens.

The specificity of immunohistological reactions of commercial polyclonal antibodies to antigens of various mycobacteria (Mycobacterium bovis, Mycobacterium duvalii and Mycobacterium paratuberculosis) was tested in connection with a number of pathogens and with the help of the indirect immunoperoxidase technique. Positive reactions occurred with various mycobacterial antigens and some Gram-positive bacteria and fungi. These investigations indicate that when the above antibodies are used in histopathological diagnostics, false-positive results can be expected.

Animals↗
PubMed1994

Light microscopic, ultrastructural, and immunohistochemical examinations of two calcifying epithelial odontogenic tumors (CEOT) in a dog and a cat.

Two calcifying epithelial odontogenic tumors from a 10-year-old cross-breed dog and a 9-year-old cat were characterized histologically and electron microscopically. Important characteristics were plexiform to squamous epithelial structure, amyloid in the tumor tissue with partial calcification (Liesegang's rings), and a low rate of mitosis. The amyloid found in the tumors was subjected to immunohistochemical examination, using a series of antibodies (anti-AA, -AL, -AF, -ASc1, -AB, -cytokeratin, -vimentin, -desmin, -laminin). The exclusive reaction to anti-cytokeratin and anti-laminin suggests that the amyloid is of epithelial origin.

Amyloid↗
PubMed1994

Familial nephropathy in Bernese mountain dogs.

Between January 1988 and March 1992 nephropathies were frequently diagnosed in Bernese Mountain Dogs. During this period, 20 animals (16 females, four males), ages 2-5 years (average age at time of diagnosis = 3.3 years) presented with clinically renal insufficiency. Morphologic diagnosis of the renal lesions was identical in all cases, i.e., membranoproliferative glomerulonephritis (MPGN) with concomitant interstitial nephritis. Deposits of immunoglobulin-M (IgM) and of the third complement component were regularly demonstrated immunohistochemically in the glomeruli; deposits of immunoglobulin-A (IgA) and immunoglobulin-G (IgG) were found only in isolated cases. Reduplication of glomerular basement membranes, mesangial interposition, and subendothelial deposits of the immunocomplex type were also detected by electron microscopy. A pedigree analysis indicated that the MPGN in these 20 Bernese Mountain Dogs of approximately the same age was of hereditary genesis. Thus, MPGN should be allocated to the group of familial nephropathies. Serologically, high IgG titers against Borrelia burgdorferi were found in 17 dogs. These findings are discussed in relation to familial nephropathies in humans.

Animals↗
PubMed1994

[Transgenic animals in experimental medicine].

In this article the possibilities and limitations of transgenic animals in experimental medicine are discussed, guided by the following three questions: Which techniques have to be applied to produce transgenic animals? What can gene transfer and transgenic animals be used for? What ethical consideration have to be made in working with transgenic animals?

Animals↗
PubMed1993

Demonstration of feline and canine platelet glycoproteins by immuno- and lectin histochemistry.

Canine and feline platelet cytocentrifuge preparations (CCPs), cryostat and paraffin-embedded bone marrow sections were used in this study. We evaluated whether platelets, megakaryocytes and megakaryocyte precursor cells could be labelled by monoclonal antibodies (Y2/51, CLB-thromb/1, HPL1) against human platelet membrane glycoprotein GP IIIa and the GP IIb/IIIa complex or by the following 10 biotinylated lectins: concanavalin A (Con A), Lens culinaris agglutinin (LCA), Pisum sativum agglutinin (PsA), wheat germ agglutinin (WGA), peanut agglutinin (PNA), Phaseolus vulgaris lectin (PHA-L), Ricinus communis agglutinin 120 (RCA120), Ulex europaeus agglutinin-I(UEA-1), soybean agglutinin (SBA) and Dolichos biflorus agglutinin (DBA). Monoclonal antibodies Y2/51 and HPL1 cross reacted with platelets and megakaryocytic cells from both species, whereas CLB-thromb/1 was unreactive with canine preparations. Only Y2/51 labelled megakaryocytic cells in paraffin-embedded samples. LCA, PSA, WGA and PHA-L labelled feline and canine platelets and different numbers of morphologically identifiable megakaryocytes and numerous other, mostly myeloid, cells. Immunoblots of dog and cat platelet lysates using Y2/51 visualized a single protein of 95 kDa (unreduced), a mol.wt value within the range of those reported for GP IIIa. Some of the platelet (but not necessarily megakaryocyte) glycoproteins reacting with LCA, PSA and WGA could be identified in lectin blots following one- or two (nonreduced/reduced)-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Thus in dogs and cats, the immunohistochemical detection of GP IIIa (and eventually GP IIb/IIIa) rather than lectin binding patterns could be important for the diagnosis of megakaryoblastic leukaemias.

Animals↗
PubMed1993

Effects of long-term elevated serum levels of growth hormone on life expectancy of mice: lessons from transgenic animal models.

In this study, we characterize transgenic mice carrying fusion genes, in which the genes coding for human (h) or bovine (b) growth hormone (GH) have been put under the transcriptional control of the mouse metallothionein I (MT) or the rat phosphoenolpyruvate carboxykinase (PCK) promoter as models for investigating the long-term effects of elevated GH on life expectancy. Circulating GH concentrations ranged from 3000 to 900,000 ng/ml, from 320 to 2960 ng/ml and from 34 to 1050 ng/ml in transgenic mice belonging to the MThGH, the PCKbGH and the MTbGH groups, respectively, and were high on a short-, medium-, and long-term basis. As a consequence of excess GH in their serum, GH transgenic mice exhibited drastically reduced life span which was primarily due to severe kidney lesions (glomerular hypertrophy, sclerosis and hyalinosis associated with tubulo-interstitial changes) consistently found in these animals. Alterations of the liver observed in transgenic mice included both hepatocellular megaly and various degrees of regressive, regenerative and fibrotic changes. In older MTbGH and PCKbGH transgenic mice, hepatocellular neoplasms including both adenoma and carcinoma were frequently found in addition to non-neoplastic changes. Our study points out the suitability of GH transgenic mice to evaluate the effects of various levels of GH in long-term studies without having to take antibody production against the heterologous hormone into account. Findings in GH transgenic animals suggest that the long-term benefits and risks of GH therapy should be carefully evaluated.

Aging↗
PubMed1993

Synthesis and distribution of atrial natriuretic peptide (ANP) in hearts from normal dogs and those with cardiac abnormalities.

The cardiac distribution of immunoreactive atrial natriuretic peptide (IR-ANP) and ANP-specific mRNA was studied in 35 normal dogs and 44 dogs with primary and secondary heart abnormalities. According to clinical and pathological findings the dogs were assigned to seven groups: Group 1, normal young dogs (< 12 months); Group 2, normal adult dogs (> 12 months); Group 3, low to moderate hypertrophy; Group 4, severe hypertrophy; Group 5, dilated cardiomyopathy; Group 6, renal failure with secondary left ventricular hypertrophy; and Group 7, other heart abnormalities. In comparison with hearts of normal dogs, the amount of IR-ANP and ANP-specific mRNA was reduced in the atria and increased in the ventricles of dogs with hypertrophy and cardiomyopathy. The immunoreactivity in normal canine atria was far lower than in control rats and hamsters. The pattern of ventricular immunoreactivity was faint and patchy. Only in a few ventricular localizations of three dogs of Group 5 and one dog of Group 6 was there a granular pattern suggesting the presence of secretory granules. A state of intense secretory stimulation in cardiomyopathy was indicated by electron microscopy. Due to its low concentration and localized pattern, however, IR-ANP does not seem to be a reliable marker for the presence of hypertrophic or cardiomyopathic changes in dogs.

Animals↗
PubMed1993

Immunoglobulin-producing tumours in dogs and cats.

Tumours with a plasmacytoid pattern taken from 32 dogs and four cats were examined for the presence of immunoglobulins, which would allow them to be designated as B-cell lymphomas. Within a total of 19 immunoglobulin-positive tumours, three types could be distinguished: extramedullary plasmacytoma (15), multiple myeloma (two) and immunocytoma (two). These tumours occurred in 18 of the dogs, and in one cat (extramedullary plasmacytoma). The characteristics of the immunoglobulin-producing tumours were investigated by light and electron-microscopy as well as by immunohistochemical methods. Seventeen of the 19 tumours expressed lambda-type light chains and one tumour kappa-type light chains. Heavy chains were also synthesized by five tumours.

Animals↗
PubMed1993

Papovavirus-induced trichogenous tumours in Syrian hamsters (Mesocricetus auratus).

Tumorous, virus-induced skin lesions in two golden hamsters (Mesocricetus auratus) were characterized macroscopically and by means of light- and electron-microscopy. Evidence of a virus was demonstrated in the ultra-thin sections and by the negative staining method. The morphological findings confirm the assumption that infections with papoviruses--probably of the polyomavirus genus--were involved.

Animals↗
PubMed1993

Acute megakaryoblastic leukemia in one cat and two dogs.

The clinical, hematologic, and histologic features of acute megakaryoblastic leukemia are described for an 8-year-old female Domestic Shorthair cat, a 3-year-old female mixed-breed dog, and a 3-year-old male German Shepherd Dog. The neoplastic cells were characterized as belonging to the megakaryocytic lineage. The following techniques were used: electron microscopy; detection of antibodies against human von Willebrand factor (vWF) and human platelet glycoprotein GP IIIa using a modified avidin biotin peroxidase complex technique on formalin-fixed paraffin sections; and enzyme histochemical methods on plastic sections for alkaline phosphatase, acid phosphatase, myeloperoxidase, alpha-naphthyl acetate esterase, alpha-naphthyl butyrate esterase, naphthol AS acetate esterase, and naphthol AS-D chloroacetate esterase. In addition, benign megakaryocytic cells, platelets, and neoplastic cells were labeled with lectins that have partially been shown to bind to platelet glycoproteins of other species. In healthy cats and dogs, the megakaryocytes and platelets reacted with lectins PSA, LCA, PHA-L, and WGA. Megakaryocytes and platelets from healthy cats were also labeled by lectin PNA. The lectins PHA-L and WGA reacted with neoplastic cells from the cat and both dogs. Lectin PNA bound to neoplastic cells from the cat, and lectins PSA, LCA, and SBA bound to neoplastic cells from both dogs. For the retrospective examination of paraffin-embedded material, the detection of vWF and GP IIIa appears to be the most reliable method for the identification of megakaryocytic cells.

Animals↗
PubMed1993

[Chronic gastritis caused by Ollulanus tricuspis (Leuckart, 1865) in a tiger].

A chronic gastritis caused by an infestation with O. tricuspis is described. The differential-diagnostic importance of this parasitosis in chronic maldigestive diseases is emphasized. Conventional coproscopic diagnostic procedures fail as the life cycle of the parasite is confined to the gastrum of the host.

Animals↗
PubMed1992

[Old age--a disease?].

The process of aging is discussed in relation to the environment of an individual and the evolution. Aging occurs hierarchically at a molecular, cellular, and systemic level. These physiologic processes of aging are accompanied by diseases, age-dependent and age-related diseases can be differentiated.

Aging↗