Biomedical subjects

E Wilander

Publications and source records attributed to E Wilander.

At least 73 records · Page 4Linked to original sources

PubMed1995

Vulvar papillomatosis, aceto-white lesions, and normal-looking vulvar mucosa evaluated by microscopy and human papillomavirus analysis.

BACKGROUND AND OBJECTIVES: To assess the presence of human papillomavirus (HPV) DNA in vulvar papillomatosis, since some women with this complaint have symptoms associated with HPV infection, such as itching, burning, and dyspareunia. GOAL: To reassure the patients that they do not have a transmissible viral disease, by excluding a HPV origin of their condition. STUDY DESIGN: Vulvar biopsy specimens from 22 females with vulvar papillomatosis, from 10 females with prominent aceto-white vulvar lesions, and from 14 healthy controls were analyzed histologically for signs of HPV infection and by in situ hybridization and polymerase chain reaction for the presence of HPV DNA. RESULTS: Specimens from women with vulvar papillomatosis showed some histological signs associated with HPV infection, but no koilocytotic atypia or dysplasia and thus resembled normal-looking vulvar mucosa. Aceto-white lesions frequently displayed histological features suggestive of HPV infection, including dysplasia. HPV DNA was detected in 6 of 10 patients with aceto-white lesions, but only in 1 of 22 patients with papillomatosis and in no healthy controls. CONCLUSIONS: According to our results, HPV DNA, which is generally found in cervical lesions and subclinical infections, is not present in vulvar papillomatosis even though symptoms associated with HPV infection are frequent complaints.

Adult↗

PubMed1995

HPV infection in male partners of women with squamous intraepithelial neoplasia and/or high-risk HPV.

In order to estimate the prevalence of HPV infection in male partners of women with squamous intraepithelial lesions and/or high risk HPV, we examined 25 men. In situ hybridisation or polymerase chain reaction was used to detect HPV DNA in biopsied tissue or cell samples from the genital epithelium. Twenty (80%) of the male consorts had clinical features suggestive of HPV infection. Of these, 18 (90%) had detectable HPV DNA, 11 (65%) of the high risk type. In 9 cases HPV DNA was detected by in situ hybridisation and in 9 by polymerase chain reaction. Concordance between female and male HPV type was found in 8 cases (32%), but regarding high-risk HPV carriage as such, 10 (40%) couples corresponded. A search for HPV infection in male partners of women known to be infected with high-risk HPV seems worthwhile.

Adolescent↗

PubMed1995

Expression and prognostic significance of TGF-beta isotypes, latent TGF-beta 1 binding protein, TGF-beta type I and type II receptors, and endoglin in normal ovary and ovarian neoplasms.

BACKGROUND: The etiology and biology of ovarian carcinogenesis is largely unknown. Recent results have indicated prognostic significance of growth factors in this malignancy. TGF-beta is a widely distributed growth factor with multifactorial effects in in vitro systems. Studies on the in vivo expression pattern of TGF-beta and its receptors might help us to understand its biologic significance in this malignancy. EXPERIMENTAL DESIGN: Tissue samples of normal ovary and benign as well as malignant ovarian neoplasms were examined for expression of transforming growth factor (TGF)-beta 1, -beta 2, and -beta 3, the latent TGF-beta-binding protein (LTBP), TGF-beta type I (T beta R-II) receptors and endoglin by immunohistochemistry and in situ hybridization. Furthermore, the results of the immunohistochemical analysis were compared with patient survival. RESULTS: Expression of all ligands was significantly increased in tumor cells compared with the normal epithelial cells. In contrast, LTBP immunoreactivity was detected significantly more often in normal epithelium than in tumor cells. T beta R-I and T beta R-II as well as endoglin were found in tumor tissues and normal ovary without any difference among the groups. In the blood vessels of malignant tumors, significantly increased TGF-beta 1 reactivity and decreased TGF-beta 2 reactivity were found when they were compared with those of normal ovaries and benign tumors. Patients with malignant tumors expressing TGF-beta 1, T beta R-I, or endoglin in blood vessels demonstrated longer survival than those having negatively stained tumors. In contrast, positive endoglin staining in tumor cells correlated with decreased survival even in advanced disease or in patients having residual tumor bulk after surgery. CONCLUSIONS: The differential expression of TGF-beta ligand and the significant correlations between expression of ligands or receptors and patient survival indicate involvement of the TGF-beta system in ovarian tumor development.

Antigens, CD↗

PubMed1994

Prognostic value of N-myc immunoreactivity in medullary thyroid carcinoma.

BACKGROUND: The analysis of N-myc expression in some neuroendocrine tumors has been reported to provide prognostic information. To the authors' knowledge, no attempts have been made thus far to correlate N-myc expression with the clinical outcome of medullary thyroid carcinoma (MTC). METHODS: N-myc gene product immunoreactivity was evaluated in 34 patients with MTC with long term follow-up, using the OA-11-803 polyclonal antiserum. The results were related to patient age and sex, sporadic or familial disease, tumor size, stage, growth rate (as determined by proliferating cell nuclear antigen [PCNA] immunostaining), and to clinical outcome. RESULTS: Patients harboring tumors with greater than 10% neoplastic cells immunoreactive to the N-myc antiserum (58% of the cases investigated) had significantly greater tumor size (P = 0.031) than patients with fewer or no N-myc immunoreactive cells. Deregulated expression of N-myc protein in tumor cells was not due to gene amplification, as demonstrated by multiplex polymerase chain reaction (PCR). In univariate analysis, patients with more than 10% immunoreactive neoplastic cells showed a significantly shorter disease free survival than did the remaining patients (P = 0.002). Among the other clinicopathologic parameters evaluated, male sex (P = 0.039) and sporadic disease (P = 0.035) also were associated with shorter disease free survival. In multivariate analysis, N-myc immunoreactivity (P = 0.039) and male sex (p = 0.050) retained a significant correlation with poor prognosis. CONCLUSIONS: Our results suggest that immunoreactivity to the N-myc antiserum, but not tumor growth fraction as evaluated by PCNA immunostaining, is a novel and useful adjunct to predict clinical behavior of MTC.

Adolescent↗

PubMed1994

p53 expression in epithelial ovarian neoplasms: relationship to clinical and pathological parameters, Ki-67 expression and flow cytometry.

Epithelial ovarian tumors of varying malignancy as well as normal ovaries were examined for their expression of p53 with the monoclonal antibody PAb1801. Immunohistochemical detection of p53 protein is possible when the gene has been mutated, but not when the normal gene product alone is present. Our results indicate that this tumor suppressor gene may be involved in tumorigenesis, as its expression was detected in both borderline and malignant tumors while normal ovaries and benign ovarian tumors were unstained with the p53 antibody. The presence of p53 was also related to dissemination of disease, residual tumor bulk, and poor differentiation as well as the presence of the proliferation variable Ki-67, another negative prognostic variable. No significant relation could be detected to S-phase fraction or DNA ploidy. Furthermore, the presence of p53 in malignant epithelial ovarian tumors was related to significantly decreased patient survival, with only 36% alive compared to 70% in the p53-negative group (P = 0.002). In the subgroup of patients with residual tumor burden after surgery, those with p53-positive tumors had a significantly (P = 0.05) decreased survival compared to those with p53-negative neoplasms, which further supports an independent role in ovarian cancer malignancy.

Biomarkers, Tumor↗

PubMed1994

Development of polyclonal antibodies and evaluation of a sensitive radioimmunoassay for detection and measurement of synaptophysin.

Polyclonal antibodies directed towards synaptophysin were raised against a synthesised peptide corresponding to amino acids 246 to 260 of the human synaptophysin sequence. The antibodies, when applied for immunocytochemical staining, showed a staining pattern identical to that of the commercially available monoclonal antibody SY-38. A radioimmunoassay for measurements of synaptophysin was developed using these antibodies and the peptide as standard and tracer. The radioimmunoassay was used for optimising the conditions for purification of synaptophysin from rat brain. No synaptophysin was detected in blood plasma in humans, not even during an embolisation treatment of tumour metastases in the liver, which induced tumour cell necrosis, in a patient with carcinoid tumours. By radioimmunoassay, synaptophysin was detected in cell homogenate from the PC-12 (160 ng/mg) and LCC-18 (40 ng/mg) cell lines and in the cell culture media. In the LCC-18 cell line the synaptophysin immunoreactivity was found in the plasma membrane, and the presence of synaptophysin was confirmed both by radioimmunoassay measurements and by the Northern blot technique. These data indicate that measurements of synaptophysin using this radioimmunoassay are reliable and that the assay can serve as a useful tool in further explorations of the biological effects of synaptophysin.

Animals↗

PubMed1994

Impact of familial amyloid associated polyneuropathy on duodenal endocrine cells.

Duodenal endocrine cells in 11 patients with familial amyloid associated polyneuropathy (FAP) were compared with those in 12 healthy volunteers by means of immunohistochemistry and morphometry. The total endocrine cell content, determined by the argyrophilic reaction and chromogranin A immunoreactivity, was significantly reduced in FAP patients compared with controls. There was a significant reduction in the serotonin, cholecystokinin/gastrin, and secretin immunoreactive cell content. A decreased cell content was also noted for somatostatin and gastric inhibitory polypeptide immunoreactive cells but this was not statistically significant. Amyloid deposits were noted in seven of the 11 biopsy specimens from FAP patients, but otherwise the duodenum was histologically normal in both groups. The reduction in endocrine cell content was not correlated with the degree of amyloid deposit in the duodenum. These findings indicate that patients with FAP have reduced intestinal endocrine cells. This does not seem to be related to amyloid deposits in the mucosa or to villous or crypt abnormalities. The observed changes in endocrine cells may contribute to the development of intestinal motility dysfunction and maldigestion in these patients.

Adult↗

PubMed1994

Exposure of the duodenum to high concentrations of hydrochloric acid. Effects on mucosal permeability, alkaline secretion, and blood flow.

Proximal duodenum was perfused with HCl for 5 min and the effects on blood-to-lumen clearance of 51Cr-EDTA (ED-Cl), morphology, luminal alkalinization, and blood flow determined in anesthetized rats. The rate of alkalinization was determined by back titration and blood flow assessed by laser Doppler flowmetry or by ultrasonic transit time flowmetry. Perfusion of duodenum with 30, 50 or 100 mM HCl for 5 min increased ED-Cl in a concentration-dependent manner and induced a small increase in alkalinization but had no effect on blood flow. At 55 min after cessation of perfusion with 100 mM HCl ED-Cl was 2.2-fold higher than control whereas the ED-Cl values in animals perfused with 30 or 50 mM HCl were not different from pre-acid control values. 100 mM HCl also induced an increase in 14C-mannitol and 14C-polyethylene glycol 4000 clearance, suggesting that HCl does indeed increase mucosal permeability. The 100 mM HCl-induced rise in mucosal permeability most probably reflects disturbance of mucosal integrity because three of five animals exhibited villous tip damage. The increases in ED-Cl in response to 100 mM HCl were the same in control rats as in rats with the renal pedicles ligated, indicating that the acid susceptibility is not affected by acute functional nephrectomy.

Alkalies↗

PubMed1994

Interferon treatment of neuroendocrine tumour xenografts as monitored by MRI.

The neuroendocrine-differentiated colonic carcinoma cell line (LCC-18) was transplanted to 29 nude mice (Balb/c). The purpose of the present study was to establish an animal model that would allow monitoring with magnetic resonance imaging (MRI) of changes induced by interferon (IFN) therapy and to evaluate whether the therapeutic response, as expressed by changes in MR signal characteristics and tumour proliferation activity, could be modulated by different IFN dosages. IFN did not seem to have any obvious antiproliferative effect on the LCC-18 tumour cell line transplanted to nude mice and no convincing treatment-related changes in rho values or T1 and T2 relaxation values were observed. The animal model was probably unsuitable for demonstration of IFN effects.

Animals↗

PubMed1993

Expression and prognostic significance of platelet-derived growth factor and its receptors in epithelial ovarian neoplasms.

The expression of platelet-derived growth factor (PDGF), PDGF-alpha receptor (PDGFR alpha) and PDGF-beta receptor (PDGFR beta) was studied in normal ovaries and ovarian neoplasms by immunohistochemical analysis. PDGF was detected in tumor cells in 33 of 45 malignant tumor samples but in none of 20 benign tumors (P < 0.001) or 11 normal ovaries (P < 0.001). In borderline tumors, 4 of 7 tissues stained positive in tumor cells. PDGFR alpha was detected in tumor cells in 16 of 45 malignant tumors, while no epithelial staining was found in 16 benign tumors (P = 0.002) or in 10 normal ovaries (P = 0.023). In 1 of 7 borderline neoplasms, tumor cells expressed PDGFR alpha. Neither normal epithelium nor tumor cells stained positive with antibodies against PDGFR beta. Patients with ovarian cancer and PDGFR alpha-positive tumor cells demonstrated an overall shorter survival compared to those who had negatively stained tumors (P < 0.005). A similar correlation was found in patients having stage III ovarian cancer (P < 0.01), which further supports an independent role for PDGFR alpha as a prognostic factor. Thus, the concomitant expression of PDGF and PDGFR alpha in tumor cells is related to progression of malignant ovarian tumors, indicating a functional role of PDGF via autocrine growth stimulation.

Antibodies, Monoclonal↗

PubMed1993

Cosecretion of islet amyloid polypeptide (IAPP) and insulin from isolated rat pancreatic islets following stimulation or inhibition of beta-cell function.

The aim of this work was to simultaneously study the secretion of islet amyloid polypeptide (IAPP) and insulin from isolated rat pancreatic islets in vitro. For examination of stimulated beta-cells, nutrient secretagogues (16.7 mM glucose, 10 mM leucine + 2 mM glutamine), phosphodiesterase inhibition (5 mM theophylline), a sulphonylurea (0.5 microgram/ml glipizide), a non-nutrient amino acid (10 mM arginine), cholinergic stimulation (0.1 mM carbamylcholine) and insulinotropic peptides (0.1 microM vasoactive intestinal polypeptide and 0.1 microM glucagon), were used. For beta-cell suppression glucose phosphorylation inhibition (10 mM mannoheptulose), depletion of extracellular calcium, activation of the ATP-regulated K(+)-channel (0.5 mM diazoxide), adrenoreceptor stimulation (3 microM adrenaline), paracrine modulation (0.1 microM somatostatin), short-term treatment with a selective beta-cytotoxin (1.1 and 2.2 mM streptozotocin) and long-term treatment with a cytokine (25 U/ml interleukin-1 beta), were studied. The compounds with known effects on insulin secretion exerted their expected actions and this was paralleled by similar relative changes, with a possible exception for glucagon, in the IAPP secretion. The ratio of IAPP/insulin released did not change significantly under any of the tested experimental conditions, except for a slight increase following carbamylcholine stimulation. On a molar basis approx. 1% of IAPP was released when compared with insulin. These results are consistent with the hypothesis that the regulation of IAPP secretion from beta-cells of isolated rat pancreatic islets is essentially regulated by the same mechanisms as insulin secretion.

Amino Acids↗

PubMed1993

Inhibition of insulin secretion, but normal peripheral insulin sensitivity, in a patient with a malignant endocrine pancreatic tumour producing high amounts of an islet amyloid polypeptide-like molecule.

Islet amyloid polypeptide or amylin is a polypeptide secreted mainly from the pancreatic beta cells together with insulin upon stimulation. High levels of islet amyloid polypeptide have also been shown to increase the peripheral insulin resistance and consequently a role for islet amyloid polypeptide in the glucose homeostasis has been suggested. We have studied the glucose homeostasis in a patient with a malignant endocrine pancreatic tumour producing large amounts of an islet amyloid polypeptide-like molecule (about 400 times the upper reference level for islet amyloid polypeptide). This patient developed insulin-requiring diabetes mellitus shortly after the tumour diagnosis. Both intravenous and oral glucose tolerance tests revealed inhibited early responses in insulin and C-peptide release, but the insulin and C-peptide response to glucagon stimulation was less affected. Aneuglycaemic insulin clamp showed normal insulin-mediated glucose disposal. In vitro experiments, where isolated rat pancreatic islets were cultured with serum from the patient, showed a moderately decreased islet glucose oxidation rate and glucose-stimulated insulin release compared to islets cultured with serum from healthy subjects. However, culture of rat islets with normal human serum supplemented with synthetic rat islet amyloid polypeptide did not affect the glucose-stimulated insulin release. In conclusion, the observed effects show that the diabetic state in this patient was associated with an impaired glucose-stimulated insulin release but not with an increased peripheral insulin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Amyloid↗

PubMed1993

Use of Probemix and OmniProbe biotinylated cDNA probes for detecting HPV infection in biopsy specimens from the genital tract.

AIMS: To compare two commercially available pan probes for the identification of human papillomavirus (HPV) DNA expression in histological sections and to type the HPV positive cases. METHODS: 97 formalin fixed, paraffin wax embedded biopsy specimens from the genital tract were tested for HPV positivity with in situ hybridisation using biotinylated cDNA pan probes--Probemix (Enzo) and OmniProbe (Digene). The HPV positive cases were further tested with HPV types 6/11, 16/18, and 31/33/35/51, and the HPV type was related to the histological diagnosis. Formalin fixed, HeLa cells (10-50 HPV 18 copies per cell) and SiHa cells (1-2 HPV 16 copies per cell) were used as reference cell lines. RESULTS: 32% of the specimens gave positive nucleic signals with both Probemix and OmniProbe. Of these, 84% could be further characterised with regard to HPV types 6/11, 16/18, and 31/33/35/51; 4% of all cases were positive with either Probemix or OmniProbe. The concordance of these probes was high, 96% altogether. HeLa cells stained positive but SiHa cells did not. CONCLUSION: There is no difference between Probemix and OmniProbe for the general detection of HPV. The mean detection limit of these probes is about 20 copies a cell.

Adolescent↗

PubMed1993

Vasoactive intestinal polypeptide reduces hydrochloric acid-induced duodenal mucosal permeability.

The duodenum in anesthetized rats was perfused with HCl, and mucosal integrity was assessed by measuring the clearance of 51Cr-labeled EDTA from blood to lumen and/or by morphological examination (lesion score). Duodenal blood flow was determined by laser Doppler flowmetry and luminal alkalinization as well as H+ disappearance by backtitration. Intravenous infusion of vasoactive intestinal polypeptide (VIP; 13.5 micrograms.kg-1.h-1) increased luminal alkalinization threefold and decreased clearance of 51Cr-EDTA by 50%. VIP also decreased arterial blood pressure and induced a small and irregular decrease in duodenal blood flow. Perfusion with 10 mM HCl increased clearance of 51Cr-EDTA 2.1-fold, but the lesion score was not different from that in saline-perfused animals. Perfusion with 20 mM HCl increased clearance of 51Cr-EDTA four-fold and induced a greater lesion score than did 10 mM. Perfusion with either 10 or 20 mM HCl did not affect the duodenal blood flow. VIP reduced the rise in clearance of 51Cr-EDTA in response to 10 mM but not that to 20 mM HCl. Intravenous injection of prazosin (50 micrograms/kg) decreased luminal alkalinization, clearance of 51Cr-EDTA, blood pressure, and duodenal blood flow. In prazosin-pretreated rats, perfusion with 10 mM HCl increased clearance of 51Cr-EDTA 2.6-fold, and the lesion score was greater in this group than in animals infused with VIP. A positive linear correlation was obtained between HCO3- secretion and the mean rate of H+ disappearance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Fragments of chromogranin A are present in the urine of patients with carcinoid tumours: development of a specific radioimmunoassay for chromogranin A and its fragments.

Chromogranin A is a well-known protein constituent in granules of neuroendocrine cells. It is also known that plasma levels of chromogranin A increase considerably in patients with neuroendocrine tumours and thus chromogranin A is used as a marker for these tumours. In the present study, we have shown that fragments of chromogranin A are excreted into the urine in some patients with carcinoid tumours. The chromogranin A molecule appeared in the urine N-terminally cleaved at amino acid positions 116 and 210, which are previously reported cleavage sites of the molecule. The fragments identified were mainly of about 35 kDa in size. The unprocessed chromogranin A molecule was not excreted in the urine. Five out of 40 patients excreting the fragments had slight tubular dysfunction in the kidneys. We also showed that these renally excreted split products of chromogranin A were immunogenic and could be used for production of antibodies against chromogranin A. These antibodies were used both for immunocytochemistry and for the development of a specific and sensitive radioimmunoassay for chromogranin A and its fragments. Measurements of plasma chromogranin A by radioimmunoassay appeared to be a better marker for tumour growth than were measurements of chromogranin A in the urine.

Adult↗

PubMed1993

Cytokeratin expression in small intestinal and appendiceal carcinoids. A basis for classification.

For a study of histogenesis of intestinal carcinoids a collection of 5 classical small intestinal carcinoids, 6 appendiceal carcinoids and 9 pheochromocytomas, were evaluated. The tumors were identified by routine morphology, silver staining and chromogranin immunocytochemistry and were then examined with regard to the expression of intermediate filaments of cytokeratin type. Eight different antisera identifying individual or combinations of cytokeratins were employed. All classical small intestinal carcinoids displayed cytokeratin immunoreactivity and an almost identical cytokeratin reaction was observed in the normal enterocytes of the small intestinal mucosa. Of the individual cytokeratin types, number 18 was most heavily expressed. The appendiceal carcinoids, like the pheochromocytomas, almost totally lacked a cytokeratin staining despite a positive reaction in the mucosa of the appendix. This, in agreement with some previous studies, indicates that the small intestinal carcinoids are histogenetically related to the epithelial cells of the intestinal mucosa, while the appendiceal carcinoids have a different histogenesis and are more like pheochromocytomas. The appendiceal carcinoid may represent a distinct type of intestinal paraganglioma. This offers one explanation for the different biological behavior of appendiceal carcinoids in comparison with the other intestinal carcinoids.

Adrenal Gland Neoplasms↗

PubMed1993

Whole-body autoradiography of 123I-labelled islet amyloid polypeptide (IAPP). Accumulation in the lung parenchyma and in the villi of the intestinal mucosa in rats.

Islet amyloid polypeptide (IAPP) in a 37 amino-acid pancreatic islet polypeptide, displaying about 50% amino-acid homology with neuropeptide calcitonin gene-related peptide (CGRP). IAPP is co-stored with insulin in the beta-cell secretory granules and co-released with insulin upon stimulation. Human IAPP has the ability to precipitate in the shape of amyloid in patients with type II (non-insulin dependent) diabetes but otherwise its functional or pathophysiological role is enigmatic. In the present study 125I-labelled rat IAPP was injected i.v. into female Sprague-Dawley rats and the distribution of the peptide was examined by whole-body autoradiography at intervals from 2 to 30 min after administration. Already after 2 min high radioactivity occurred in the lung parenchyma and in the villi of the small intestinal mucosa. The high radioactivity in these tissues persisted at 10 min but at 30 min the radioactive labelling had decreased to a level only slightly higher than that observed in the blood. A high uptake of radioactivity was also seen in the cortex of the kidney. In other tissues, including the liver, the skeletal muscle, and the exocrine and endocrine pancreas, the radioactivity was low and did not exceed that of the blood. The uptake of 125I-IAPP in the lungs and in the small intestine was inhibited by simultaneous injections of either an excess of unlabelled rat IAPP or unlabelled rat CGRP. This indicates that the labelled structures observed in the lung and the small intestine after injection of 125I-IAPP alone was due to binding to receptors for IAPP or CGRP in these tissues. The accumulation of radioactivity in the kidneys was not affected by pretreatment with high doses of unlabelled IAPP or CGRP. This unspecific uptake of radioactivity may be due to reabsorption of labelled IAPP in the proximal tubuli. Our results indicate the presence of receptors binding IAPP in the lung parenchyma and in the villi of the small intestinal mucosa. This, in turn, may imply prominent biological activities of IAPP at these sites.

Amyloid↗

PubMed1993

Identification, characterization and classification of endocrine tumours.

Tumours deriving from the endocrine cell system can be organized into two main categories namely: endocrine and neuroendocrine tumours. The endocrine group contains all tumours developing from the follicular cells of the thyroid gland (papillary, follicular and undifferentiated carcinomas) and from the suprarenal cortex (adenomas and adenocarcinomas). Such tumours are as a rule identified and evaluated by routine histological staining and special histochemical techniques are usually not applied. The neuroendocrine tumour group is characterized by its content of intracytoplasmic hormonal secretory granules, which can be visualized at the light microscopical level with techniques such as the Grimelius argyrophil reaction or by chromogranin immunocytochemistry. The neuroendocrine tumours can be further subgrouped into those of neuroectodermal or endodermal (epithelial) origin. The neuroectodermal tumours originate from the suprarenal medulla (phaeochromocytomas and neuroblastomas) and from the paraganglia. The endodermal tumours arise in the pituitary gland, the parathyroid gland, the C-cells of the thyroid gland (medullary thyroid carcinoma), the pancreatic islets (insulomas) or in the diffuse endocrine cell system of luminal organs, chiefly the gastrointestinal tract (carcinoids). The carcinoids include some of presumably neuroectodermal type. These contain a cytoskeleton with intermediate filament of neuronal type (neurofilament), whereas the endodermal tumours usually express cytokeratin filament. Individual tumours within each organ can be distinguished by their specific production of various peptide hormones and biogenic amines. Furthermore, amyloid deposits in the stroma may be of use in tumour diagnosis. Modern tissue sampling techniques are presented here, as also are certain aspects of studies on biological behaviour of neuroendocrine tumours by examination of nuclear DNA and proliferating antigen.

Amyloid↗