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Biomedical subjects

P U Heitz

Publications and source records attributed to P U Heitz.

18 recordsLinked to original sources
PubMed1992

Distribution and localization of Epstein-Barr virus subtypes A and B in AIDS-related lymphomas and lymphatic tissue of HIV-positive patients.

Tissue samples of 21 HIV-positive patients have been studied for the presence and distribution of Epstein-Barr virus (EBV) subtypes A and B. This was done by PCR, EBER in situ hybridization, and immunohistochemical detection of EBV latent membrane protein (LMP) in AIDS-associated malignant lymphomas (16 cases) and lymphatic organs of patients without lymphoma (5 cases). Eleven cases were considered to be EBV-positive, with type A in four, and type B virus in four other cases. In patients with malignant lymphoma, EBV was localized in tumour tissue exclusively. One patient without lymphoma presented with multiple EBV genome type B-positive cells in all the lymphoid tissue samples examined. In HIV-positive patients, both subtypes of EBV, A and B, may play a role in the pathogenesis of lymphoproliferative lesions.

Adult↗
PubMed1992

Distribution patterns of proinsulin and insulin in human insulinomas: an immunohistochemical analysis in 76 tumors.

The distribution of proinsulin and insulin immunoreactivity was studied in 76 human insulinomas and in normal pancreas. One trabecular and two solid insulinomas showed the staining pattern of normal beta cells. A "near normal" staining pattern (perinuclear proinsulin and diffuse or polarized insulin staining) existed in 10 of 27 trabecular and 11 of 44 solid insulinomas. An "intermediate" staining pattern (intense perinuclear as well as weaker diffuse proinsulin staining with diffuse or polarized insulin staining) was observed in 10 of 27 trabecular and 20 of 44 solid insulinomas. Different "abnormal" staining patterns were found in 6 of 27 trabecular and 6 of 44 solid insulinomas. Of the 5 glandular insulinomas, 4 exhibited a "near normal" and one an "abnormal" staining pattern. No correlation was found between any particular staining pattern and the multihormonality or malignancy of the insulinomas. The diffuse labeling for proinsulin in about 50% of the insulinomas is suggestive of abnormal prohormone processing.

Antibodies, Monoclonal↗
PubMed1992

[Demonstration of Epstein-Barr virus DNA and determination of immunoglobulin and T-cell receptor gene rearrangerments in diagnostic lymph node biopsies from patients with Hodgkin's disease].

Lymph node biopsies of 52 patients with Hodgkin's disease were analyzed by Southern blot hybridization for the presence of monoclonal rearrangements of immunoglobulin and T cell receptor genes. The same tissues were tested for Epstein-Barr virus DNA by the polymerase chain reaction using four different sets of primers. Monoclonal rearrangements were identified in only four tumors, whereas Epstein-Barr virus was present in 79% of biopsies. A correlation between the degree of infiltration by Reed-Sterberg cells, clonality and the presence of Epstein-Barr virus could not be found. These results are in agreement with similar studies reported in the literature. The nature of the malignant cell in Hodgkin's disease and the role of Epstein-Barr virus in the etiology of this tumor remains to be established.

Base Sequence↗
PubMed1992

Hypercalcaemia and pancreatic ultrastructure in cats.

OBJECTIVE: To study the effects of local and systemic infusions of calcium on the ultrastructure of the pancreas in cats. DESIGN: Controlled study. INTERVENTIONS: Three groups of four cats each had local infusions (into the splenic artery) of calcium gluconate 0.6 mmol/kg.hour or potassium chloride 1.1 mmol/kg.hour, or sodium chloride 0.9%, for three hours. Two groups of eight cats each had systemic infusions (into the jugular vein) of either calcium gluconate 0.6 mmol/kg.hour or sodium chloride 0.9%, for twelve hours. In the group that was given calcium, the infusion rate was reduced after three hours to 0.3 mmol/kg.hour to maintain the hypercalcaemic state for a further nine hours. RESULTS: Local infusion of calcium caused destruction of acinar cells with hydropic degeneration of nuclei, discharge of cell organelles into the interstitial spaces, and extravasation of red blood cells but no apparent damage to the capillaries. There were no ultrastructural changes of any importance in the groups that received potassium or sodium chloride. Systemic infusion of calcium resulted in a 1.8 fold increase in the ionised calcium concentration in the serum, progressive signs of overstimulation of the Golgi apparatus with hypertrophy, fusion of condensing vacuoles, and disruption of the acinar cell polarization. This was followed by clumping of nuclear chromatin and destruction of acinar cells. CONCLUSION: Acute pancreatitis in cats can result from stimulation and destruction of acinar cells by hypercalcaemia.

Acute Disease↗
PubMed1992

Studies on the Thomsen-Friedenreich antigen in human colon with the lectin Amaranthin. Normal and neoplastic epithelium express only cryptic T antigen.

The lectin Amaranthin has been shown to be highly specific for the galactose beta 1,3 N-acetylgalactosamine-alpha and sialic acid alpha 2,3 galactose beta 1,3 N-acetylgalactosamine-alpha sequence which represents the Thomsen-Friedenreich (T) antigen and its cryptic form, respectively. Previously, we demonstrated the usefulness of gold-labeled Amaranthin for the histochemical detection of the T antigen and its cryptic form. Application of the galactose oxidase (GO)-Schiff sequence abolished lectin binding to the T antigen but not its cryptic form, and therefore permitted their differentiation. In the present study we have analyzed by light and electron microscopy the distribution and subcellular localization of Amaranthin binding sites in normal, dysplastic and neoplastic colonic epithelium. Furthermore, a monoclonal antibody raised against synthetic galactose bera 1,3 N-acetylgalactosamine-alpha-bovine serum albumin was applied as a reagent for the T antigen. In normal colonic mucosa, two different Amaranthin staining patterns existed: (a) reactivity restricted to the lower portion of the crypts which was principally observed in the left colon, and (b) reactivity along the entire length of the crypts and in the surface epithelium with goblet cell staining in the upper portion of the crypts which was principally observed in the right colon. This Amaranthin staining was resistant to GO-Schiff treatment. No immunostaining with the monoclonal anti-T antigen was observed. Investigation of transitional mucosa, adenocarcinomas of different degrees of differentiation and mucinous carcinomas as well as adenomas with different degrees of dysplasia all revealed positive Amaranthin staining. The lectin staining was resistant to GO-Schiff treatment, and immunolabeling with the monoclonal antibody against the T antigen was absent. These results indicate that only the cryptic form of the T antigen is expressed in normal, dysplastic and neoplastic human colonic epithelium.

Antigens, Neoplasm↗
PubMed1992

Improved accuracy in diagnostic immunohistochemistry, lectin histochemistry and in situ hybridization using a gold-labeled horseradish peroxidase antibody and silver intensification.

BACKGROUND: Improvements in the use of the avidin-biotin peroxidase complex technique and direct as well as indirect labeled avidin-biotin methods for application in diagnostic immunohistochemistry, lectin histochemistry and in situ hybridization are reported. The new technology combines the advantages of immunoenzyme and immunogold silver staining techniques and can be performed on routinely fixed and paraffin-embedded tissues. EXPERIMENTAL DESIGN: The basic modification of the labeling procedures was introduced at the final revealing step. The histochemical visualization of catalytic activity of horseradish peroxidase by the diaminobenzidine reaction was replaced by the detection of horseradish peroxidase immunoreactivity using anti-horseradish peroxidase-gold complexes and their intensification with silver acetate which is relatively light insensitive. RESULTS: The use of gold-labeled anti-horseradish peroxidase antibodies eliminates the need for quenching of endogenous peroxidase activity. Furthermore, the immunogold silver staining provides improved lateral resolution, higher contrast, and lower background staining as compared with the diaminobenzidine reaction. The new technology has been applied for the localization of different polypeptides in endocrine cells, cytoskeletal elements, cell surface receptors, basal lamina type IV collagen, endothelial cell marker, lectin binding sites, and DNA of various viruses. CONCLUSIONS: We concluded that the anti-horseradish peroxidase-gold complex is of general use in a variety of techniques applying horseradish peroxidase as a marker and should be a valuable alternative to existing enzyme substrate techniques.

Gold↗
PubMed1979

[Ectopic hormone formation and tumor markers in bronchial neoplasms].

Carcinoma of the bronchus can produce several polypeptide hormones and therefore has the capacity to cause most syndromes of endocrine hyperfunction. All pituitary hormones can be synthesized ectopically; furthermore, the production of hormones from the hypothalamus (CRF), the placenta (HCG, HPL) and the C-cells of the thyroid (calcitonin), as well as parathormone and prostaglandins has been described. The paraneoplastic syndrome may often be more dangerous for the patient than the tumor growth itself, and can lead to early death. On the other hand, it may allow the early detection of an unsuspected tumor. The ectopic hormones and other nonendocrine proteins and peptides can be used as tumor markers, and can demonstrate the effect of treatment and early recurrence or metastases. An ideal tumor marker should have the following characteristics: 1. production exclusively by neoplastic tissue, 2. direct correlation with tumor size, 3. substances common to all tumor types ("large spectrum tumor marker") although specific tumor markers for special tumors should be available, 4. the assays must be easy and automation should be possible. At present no tumor marker satisfies all these conditions. The measurement of several tumor markers and the use of discriminant analysis may extend their diagnostic value and open the way for biochemical detection of cancer in the future.

Adrenocorticotropic Hormone↗
PubMed1979

The neuroendocrine system of the gastrointestinal tract.

The use of increasingly refined techniques in endocrinologic research resulted in a challenge to the classical concept of hormones. The regulatory activity of the highly complicated neuroendocrine system is mediated not only by hormones but by neurotransmitters, paracrine substances, and possibly by substances secreted into the gastrointestinal lumen as well. The system is divided into the central and peripheral nervous system and the endocrine system. The latter consists of the endocrine glands and the disseminated endocrine system. Research into the activities of the system will result in important advances in the fields of physiology, pathophysiology and pathology.

Digestion↗
PubMed1979

Multihormonal pituitary adenomas.

66 pituitary tumors detected at autopsy were investigated for the presence of corticotropin, beta-lipotrophin, growth hormone, prolactin, thyrotropin and gonadotropins by immunocytochemistry. 56 tumors contained hormone-producing cells; 45 were found to contain 2 or more hormones. This finding confirms and extends previous morphologic and clinical observations. The majority of pituitary tumors are mixed and they probably arise from impaired regulation at the hypothalamic and/or pituitary level.

Acromegaly↗
PubMed1979

Pathology of the endocrine pancreas.

An immunocytochemical analysis of 94 pancreatic endocrine tumors revealed that 73 tumors were multicellular. Significant amounts of somatostatin and human pancreatic polypeptide were found by radioimmunoassay in extracts of 19 and 17 tumors resp., in addition to the hormone causing the clinical syndrome. Numerous tumors contained ductular structures. In the surrounding pancreatic parenchyma a proliferation of small ducts and budding-off from the ductular epithelium of endocrine cells was often observed. These features are hallmarks of nesidioblastosis of the endocrine pancreas which is a hyperplasia. In multiple endocrine neoplasia I hyperplasia of the endocrine pancreas is combined with larger nodules, currently labeled tumors. On the basis of these findings it is conceivable that pancreatic endocrine tumors are not primarily neoplastic and autonomous but that they are rather of hyperplastic origin.

Adenoma, Islet Cell↗
PubMed1979

The effects of endogenous hypergastrinemia and hypogastrinemia on the exocrine and endocrine rat pancreas.

The effects of endogenous hypergastrinemia and hypogastrinemia on the exocrine and endocrine pancreas were studied in the rat. Hypergastrinemia was induced by antral exclusion, and hypogastrinemia by antral resection. The studies were made 14 weeks after surgery. The total weight of the pancreas was increased both in hypergastrinemic and hypogastrinemic animals, due to hypertrophy of the exocrine cells. In contrast, the volume and total weight of the pancreatic islets were decreased. There was no numerical difference in the A-, D-, PP-cells between the hyper- and hypogastrinemic animals, respectively, and the controls. The number of insulin-producing (B-) cells was certainly reduced after the induction of hypogastrinemia. There was, however, signs of increased B-cell activity, which might contribute to an underestimation of the number of B-cells with the technique used. These findings do not support the hypothesis that antral gastrin has trophic influence on either exocrine or endocrine pancreas.

Animals↗
PubMed1979

Effects of prolonged administration of metiamide on serum gastrin, gastrin content of the antrum and gastric corpus, and G-cell population in the rat.

The effect of prolonged metiamide administration on serum gastrin, gastrin content of the antrum and gastric corpus, and G-cell population was studied in the rat. A single subcutaneous injection of metiamide (200 mg/kg) at the onset of 16 days of continous treatment with three daily injections was followed by a fivefold increase in serum gastrin level at 4 hr in fasted and at 4 and 6 hr in fed rats. After 16 days of metiamide, the fed rats showed a peak in serum gastrin level of the same magnitude as on day 1, but only at 4 hr. Two hours later, the levels decreased rapidly to basal values. In the fasted animals, the response to metiamide was reduced to a threefold increase at 2 hr. There was no difference in gastrin content of the antrum and gastric corpus nor in volume density of the G-cells after the prolonged treatment compared with the controls. It is concluded that in spite of rises in serum gastrin, prolonged metiamide medication has no effect on the gastrin content of the antrum and gastric corpus nor on the G-cell population in the rat. Furthermore, after prolonged treatment, metiamide-induced gastrin release is diminished.

Animals↗
PubMed1978

Immunohistochemical localisation of urogastrone to human duodenal and submandibular glands.

Urogastrone has been localised by immunostaining to granules of the cells of human duodenal (Brunner's) glands and their ducts and of acinar cells in the human submandibular gland. The immunoreactive peptide is present in large quantities in duodenal glands and their secretory ducts. Urogastrone or human epidermal growth factor promotes cellular proliferation in vivo as well as in vitro and inhibits gastric acid secretion and may, therefore, be one of the duodenal factors inhibiting gastric activity. Thus it may have an important regulatory and protective function for the intestinal mucosa and may possibly become a useful therapeutic agent.

Brunner Glands↗
PubMed1978

Immunoelectron cytochemical localization of motilin in human duodenal enterochromaffin cells.

Two types of enterochromaffin cells can be demonstrated in the human duodenal mucosa by means of the Masson-Fontana reaction for argentaffinity applied to ultrathin sections. The 22-amino acid peptide motilin has now been localized exclusively to the duodenal type of enterochromaffin cell by immunoelectron microscopy. This cell occurs predominantly in the duodenum and upper jejunum. It is concluded that at least two types of enterochromaffin cells exist in the human gut mucosa and that they produce at least one biogenic amine as well as two peptides. Therefore they could provide a useful model for studies of the interrelationship of storage and release of amines and peptides.

Chromaffin System↗
PubMed1977

Nesidioblastosis: the pathologic basis of persistent hyperinsulinemic hypoglycemia in infants. Morphologic and quantitative analysis of seven cases based on specific immunostaining and electron microscopy.

Seven surgical specimens of pancreas, obtained at laparotomy from infants suffering from persistent hyperinsulinemic hypoglycemia, were analyzed by qualitative and quantitative immunocytochemistry and by electron microscopy. In five cases a multifocal ductuloinsular proliferation, in one a focal adenomatosis, and in one a solitary encapsulated nodule (adenoma) were observed. Combinations of the different patterns of proliferation were seen in six cases. Budding off from the ductular epithelium and interposition of endocrine cells between ductular epithelial cells were prominent features common to all cases. An almost fivefold increase of the mean total area occupied by endocrine tissue was found over that of age-matched controls. Four cell types were seen to participate regularly in the proliferation, and their ratios were remarkably constant in all cases, mean figures being 62:21:9:8% for B:A:D:D1 cells, respectively. The ratio of B cells per total endocrine area in nesidioblastosis was very close to that per islet of the controls (62:59%). Since common features were found in all or in the majority of cases, it is suggested that the various patterns of proliferation are merely morphologic variations of the same basic defect. Nesidioblastosis may result from inappropriately controlled development of the endocrine pancreas that is not arrested but carries on beyond birth and during infancy. The application of specific immunocytochemistry as a necessity for full appreciation of the extent of endocrine proliferation is stressed.

Adenoma, Islet Cell↗