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Biomedical subjects

G W Hacker

Publications and source records attributed to G W Hacker.

52 records · Page 3Linked to original sources
PubMed1991

Regulatory peptides and general neuroendocrine markers in human nasal mucosa, soft palate and larynx.

Various peptide immunoreactivities in the respiratory system have been reported, indicating complex physiological mechanisms. There is only little information on the upper respiratory system of man. The present study was carried out to demonstrate regulatory peptides in the nasal mucosa, larynx (vocal cords and ventricular folds) and soft palate of man using highly efficient immunocytochemical methods. In addition, some peptide immunoreactivities were measured by use of radioimmunoassay (RIA). Using indirect immunofluorescence and immunogold-silver staining (IGSS) with silver acetate autometallography, a series of peptides could be detected, including vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), galanin, calcitonin gene-related peptide (CGRP), substance P, neuropeptide tyrosine (NPY), C-flanking peptide of NPY (CPON) and somatostatin. In addition, antibodies to protein gene-product (PGP) 9.5, neuron-specific enolase (NSE), S-100, PHE-5 and neurofilament proteins gave positive reactions in tissue sections. Using RIA, CGRP, substance P, and neurokinin A were measured. Our results demonstrate a complex network of regulatory peptide-containing nerve fibers and the possible existence of endocrine cells regulating various functions of the upper respiratory system, which need to be further investigated.

Biomarkers↗
PubMed1990

Gastrin- and somatostatin-immunoreactive cells of the antral mucosa in patients with duodenal or gastric ulcers. An immunocytochemical study.

Gastrin- and somatostatin-immunoreactive cells in biopsies taken from the prepyloric portion of the antrum from 15 patients with duodenal ulcer, 16 patients with gastric ulcer, and a control group of 19 patients without histopathological alterations of the antral mucosa were studied using peroxidase anti-peroxidase and immunogold-silver staining methods in combination with morphometry. Numerical densities and sizes (immunoreactive areas) of the cells demonstrated were measured and compared between all three groups. Gastrin- and somatostatin-immunoreactive cells were located most frequently in the lower midzone of the gastric crypts. None of the parameters measured showed a correlation with age or sex. The group with duodenal ulcer tended to exhibit gastrin- and somatostatin-cell-hyperplasia whereas the size of both cell types remained unchanged. In comparison with the control group, the numerical density of gastrin-immunoreactive cells was significantly increased in gastric ulcer patients, whereas the numerical density of somatostatin-immunoreactive cells was decreased in this group. Immunoreactive areas of both cell types were significantly increased in patients with gastric ulcer.

Adult↗
PubMed1990

[Application of silver acetate autometallography in histopathology: a new detection method for use in immunogold silver staining, lectin histochemistry and in situ hybridization].

Modern histochemical techniques allow the specific detection of tissue constituents in situ. Routinely formalin fixed, paraffin embedded tissues may present problems to the pathologist since destruction of substances can lead to false negative results. Immunogold-silver staining (IGSS) can be a way to overcome some of these problems. A highly efficient method allows silver enhancement to be carried out without the necessity of a dark box (silver acetate autometallography). To test the new modification, antisera to a variety of antigens were used on paraffin and semithin resin sections. The system was also tested for its applicability in multiple immunostaining techniques and for the in situ hybridisation of viral DNA and for demonstration of carbohydrates by lectin histochemistry. It showed a very high detection efficiency with low background staining.

Acetates↗
PubMed1988

Multiple peptide production and presence of general neuroendocrine markers detected in 12 cases of human phaeochromocytoma and in mammalian adrenal glands.

In this study, antibodies to a range of markers of neuroendocrine differentiation were evaluated for their use in the histopathological assessment and characterisation of phaeochromocytomas. Routinely processed wax blocks from eleven adrenal phaeochromocytomas (10 benign and 1 malignant) and one benign phaeochromocytoma of the urinary bladder were investigated. In addition to these tumours, normal human, cat and piglet adrenal glands were examined. In the phaeochromocytomas, immunostaining was obtained with 21 of the 25 antisera used. Of the general neuroendocrine markers, neuron-specific enolase was found in all tumours, and chromogranin and protein gene-product 9.5 in most of the cases. A range of regulatory peptide immunoreactivities could be demonstrated, such as enkephalin, neuropeptide tyrosine (NPY), 7B2, galanin and vasoactive intestinal polypeptide (VIP). In addition, two peptides were found which have not been reported previously in these tumours, peptide histidine methionine (PHM) and the cryptic fragment of the precursor encoding VIP. Co-localisation studies revealed that peptides derived from the same precursor or peptide family were found in the same tumour cells (e.g. VIP and PHM, NPY and its C-flanking peptide CPON). In the normal adrenal medulla, all the peptides previously reported to be present could be demonstrated immunocytochemically. Galanin was present in a subpopulation of cells also immunoreactive for enkephalin. Neuropeptide tyrosine and CPON were demonstrated in another subpopulation. Occasionally, cells were found to contain all four antigen immunoreactivities. Using antisera to enzymes involved in catecholamine synthesis, galanin was found to be present in noradrenaline-containing cells. The study demonstrates the presence of various antigens in chromaffin tissue of the adrenal gland. A range of substances can also be identified immunocytochemically in phaeochromocytoma tissue, using routinely-processed material.

Adrenal Gland Neoplasms↗
PubMed1986

Localization and molecular forms of galanin in human adrenals: elevated levels in pheochromocytomas.

Galanin immunoreactivity was measured by RIA, using antibodies directed against both the non-C- and C-terminal positions of porcine galanin, in tissue extracts of normal adrenals and pheochromocytomas and also in the plasma of normal subjects and patients with pheochromocytomas. No C-terminal galanin-like immunoreactivity was detected in plasma or tissue, suggesting differences in the amino acid sequence of human compared with porcine galanin. A non-C-terminally directed antibody was, therefore, used to characterize human galanin immunoreactivity by gel permeation chromatography and reverse phase high pressure liquid chromatography and to localize it by immunocytochemistry. The galanin content of whole adrenal gland was 2.6 +/- 0.9 (+/- SEM) pmol/g (n = 5). In contrast, however, pheochromocytomas had much greater concentrations (21 +/- 2.3 pmol/g; n = 16). Gel chromatography and reverse phase high pressure liquid chromatography revealed 2 molecular forms of galanin immunoreactivity with identical elution positions in both normal adrenals and tumors. The concentration of galanin in plasma from both normal subjects and pheochromocytoma patients was below the detection limit of the assay (less than 10 pmol/liter). Using immunocytochemistry, galanin was localized to scattered cells or clusters of tumor cells in 5 of 11 pheochromocytomas and only a few chromaffin cells and cortical nerve fibers in normal adrenals.

Adrenal Gland Neoplasms↗
PubMed1985

Cytochemical relationships in the paracervical ganglion (Frankenhäuser) of rat studied by immunocytochemistry.

Vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) immunoreactivities have been demonstrated in the paracervical ganglion of the rat using immunocytochemistry. Dopamine beta-hydroxylase (D beta H) and neurofilament protein triplet immunoreactivities have also been demonstrated in this region. The VIP, NPY, D beta H and neurofilament immunoreactivities were located in ganglion cells and nerve fibres, while CGRP immunoreactivity was localized only in nerve fibres. Many cells immunoreactive with D beta H antiserum were also immunoreactive with NPY antiserum. A small number of cells immunoreactive with VIP antiserum were also immunoreactive with NPY antiserum. CGRP-immunoreactive nerve fibres were distributed in certain regions of the ganglion only.

Animals↗
PubMed1985

Antibodies to neurofilament protein and other brain proteins reveal the innervation of peripheral organs.

Monoclonal and polyclonal antibodies to neurofilament proteins, neuron-specific enolase, glial fibrillary acidic protein and S-100 have been used to demonstrate nerves, ganglion cells and the supportive glial system of the innervation of various organs. The female genitalia, the urinary tract, the respiratory system, the pancreas, the heart and the skin of several mammalian species, including rat, mouse, guinea pig, cat, pig, monkey and man were fixed in para-benzoquinone and portions of each organ were snap frozen. Serial or free-floating thick cryostat sections were stained using indirect immunofluorescence and peroxidase anti-peroxidase immunocytochemistry. In addition, the newly described and highly sensitive immunogold-silver staining technique was used on Bouin's-fixed and wax-embedded tissues. Antibodies to neurofilament proteins seemed to react with neuronal structures in all the species studied. Alternately stained serial sections showed a similar distribution of neurofilament proteins and neuron-specific enolase-containing nerves. Neuron-specific enolase staining had a diffuse appearance and was found to be highly variable, indicating that the neuron-specific enolase content might be related to the physiological state of the nerves and ganglion cells, whereas antibodies to neurofilament protein gave a consistently intense and very clear picture of the ganglion cells and nerve fibres. Antibodies to S-100 stained supportive elements of the peripheral nervous system in all tissues examined, whereas antibodies to glial fibrillary acidic protein were more selective.

Animals↗
PubMed1985

Investigation of immunogold-silver staining by electron microscopy.

Deposition of metallic silver on colloidal gold immunoreagents has been shown to be a very sensitive immunostaining technique capable of detecting low levels of immunoreactivity in tissue sections. Using electron microscopy we have shown that immunolabelling is highest with small sizes of gold which can penetrate sections better and achieve higher densities of particles in the section than larger particles. Chemical permeabilisation of the embedding medium aids the penetration of colloidal gold. The silver enhancement step in immunogold-silver staining was shown to be progressive, allowing optimisation of staining and the selection of the final size of silver deposits required. Some poorly understood features of the technique are rationalised and the additional knowledge gained will aid the wider application of this method.

Animals↗
PubMed1985

The immunogold-silver staining method. A powerful tool in histopathology.

Immunostaining of routinely fixed, wax embedded tissues may present problems to the pathologist since destruction of antigens can lead to false negative results. In an attempt to overcome this problem, we have compared the results of the standard peroxidase anti-peroxidase (PAP) method with those obtained using the newly developed and very sensitive immunogold-silver staining (IGSS) method. Sections from routine histopathological material as well as from normal tissue specimens were used in the comparison. Antisera to a variety of antigens commonly employed in pathology were used, including regulatory peptides and a range of other markers. In all cases the IGSS method was found to give superior or at least equal results to those obtained with the PAP technique. In some cases staining was obtained with IGSS method when the PAP technique gave no result. The intense black reaction product allowed much easier and more rapid screening of immunostained preparations as well as permitting sections to be counterstained with routine histological stains such as haematoxylin and eosin. It is therefore suggested that immunogold-silver staining is a valuable technique for the pathologist, particularly when examining overfixed or badly processed tissues.

Animals↗
PubMed1984

The potential of the immunogold-silver staining method for paraffin sections.

The immunogold-silver staining technique is shown to be of great value in the detection of regulatory peptide-containing nerves and endocrine cells in routinely fixed, paraffin-wax-embedded tissues. The method appears to be better for this system than peroxidase anti-peroxidase (PAP) which can yield poor or variable results. Antibodies to regulatory peptides, including calcitonin gene-related peptide (CGRP), substance P, neuropeptide tyrosine (NPY), glucagon, pancratic polypeptide, and somatostatin 14 and 28, as well as to neurofilaments, neuron-specific enolase (NSE) and S-100, were used on sections of a variety of tissues from rat and pig including respiratory tract, skin, gut, pancreas, vagina, uterus, fallopian tube and kidney. In all cases, stronger immunostaining of nerves was obtained with the immunogold-silver technique than with PAP. The inherent density of the staining was also found to improve the visibility of endocrine cells in the section, and to permit the use of routine histological stains for counterstaining. As immunogold-silver staining is sensitive, rapid, cheap and avoids hazardous reagents, we feel it has great potential for the immunostaining of nerves and endocrine cells that contain regulatory peptides in routinely fixed and embedded tissues and may prove useful in pathology.

Animals↗
PubMedDate not supplied

Co-localization of neuropeptide tyrosine (NPY) and its C-terminal flanking peptide (C-PON).

Neuropeptide tyrosine (NPY) is one of the most abundant and widespread peptides in the mammalian nervous system. Recent isolation and sequencing of the DNA encoding NPY has predicted the existence of a 97 amino acid precursor peptide. Proteolytic processing of this precursor could yield three separate peptide products, an N-terminal signal peptide, neuropeptide tyrosine and a 30 amino acid C-terminal flanking peptide (C-PON). Here, we present evidence that the predicted C-flanking peptide of NPY is widely distributed in both the central and peripheral nervous systems of several mammalian species including man, and has an identical distribution to NPY. It was also demonstrated, using correlative light microscopic immunostaining on serial sections and double electron microscopic immunocytochemistry, that C-PON and NPY immunoreactivities are co-localized in neuronal cell bodies of the brain cortex, sympathetic ganglion cells, norepinephrine-containing granules of the adrenal medulla and in human pheochromocytoma tumor cells.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Distribution of galanin immunoreactivity in the genitourinary tract of man and rat.

Galanin has been shown to be present in substantial quantities in the human and rat genitourinary tract by radioimmunoassay and immunocytochemistry. The highest concentrations measured by radioimmunoassay were found in the human vas deferens, corpus cavernosum and spongiosum and in the vagina and cervix. In man gel chromatographic analysis showed two molecular forms. The earlier eluting peak was different from porcine galanin standard. There was only one molecular form in the rat which emerged in an earlier position than the porcine standard. Galanin immunoreactive nerve fibres demonstrated in the genitourinary tract were found both in man and rat. They were found within smooth muscle and in close relationship to blood vessels. The presence and distribution of galanin in the genitourinary system suggest the possibility that this neuropeptide could play a role in the regulation of smooth muscle tone, blood flow and motility.

Animals↗
PubMedDate not supplied

Detection of single HPV copies in SiHa cells by in situ polymerase chain reaction (in situ PCR) combined with immunoperoxidase and immunogold-silver staining (IGSS) techniques.

Detection of HPV by means of in situ hybridization techniques may often present problems if the number of HPV copies is too small, especially when using nonradioactive detection systems. A new way of amplifying extremely small amounts of virus DNA copies is the polymerase chain reaction (PCR), which is mostly used in vitro. In this study, we present a method for in situ PCR combined with immunogold-silver staining (IGSS) and immunoperoxidase (IMP) methods which allows the detection of single copies of HPV-DNA in SiHa cells. This method may have wide applications in routine diagnostic histopathology.

Base Sequence↗
PubMedDate not supplied

Neuropeptides in the human penis: an immunohistochemical study.

In the present study, the distribution of neuropeptides in the human penis is demonstrated by immunohistochemistry (IHC). IHC screening detected a complex network of nerve fibers containing vasoactive intestinal polypeptide (VIP), peptide histidine-methionine (PHM), prepro-VIP (111-122), neuropeptide Y (NPY), C-flanking peptide of NPY (C-PON), calcitonin gene-related peptide, substance P, and galanin immunoreactivities. Special attention was also given to the recently isolated, VIP-related lizard peptide helospectin, which could also be detected in neuronal elements in the penis. Colocalization studies showed the coexistence of VIP, PHM, and partly helospectin, and of NPY with C-PON within nerve fibers in the cavernous and spongious body, the glans penis, and the urethra.

Adult↗
PubMedDate not supplied

Primary neuroendocrine differentiated mucinous adenocarcinoma of the vulva: case report and review of the literature.

Only a few cases on mucinous adenocarcinomas of the vulva have been reported. In this study, we present a case of a 75-year-old woman with a tumor in the left major labium. Because biopsy had shown formations of squamous cell carcinoma, radical vulvectomy with bilateral inguinal and femoral lymph node dissection were performed. At that time, histology was interpreted as small-cell, anaplastic carcinoma, with focal epidermoid differentiation. Postoperative radiation therapy was performed. Sixteen months after surgery, the patient presented with bilateral breast carcinomas. Histology showed a scirrhous carcinoma of the left and a medullary carcinoma of the right breast, but no lymph node metastases. Histochemical and immunohistochemical re-examination of the vulvar carcinoma now revealed a mucinous adenocarcinoma with neuroendocrine differentiation. The tumor expressed neuroendocrine markers such as chromogranin A and protein gene-product (PGP) 9.5, as well as peptides of the vasoactive intestinal polypeptide (VIP) family, and serotonin. Histochemical silver stains demonstrated Grimelius argyrophilia and Masson argentaffinity. Because of positive estrogen and progesterone receptor status of both breast cancers, postoperative Tamoxifen therapy was performed. The patient is still alive four years after vulvectomy.

Adenocarcinoma, Mucinous↗