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Biomedical subjects

M Lundqvist

Publications and source records attributed to M Lundqvist.

At least 19 recordsLinked to original sources
PubMed1998

Shared tumor antigens in colorectal carcinoma and neuroendocrine tumors.

ND4 monoclonal antibody recognizes a tumor marker found on poorly differentiated colorectal cancer. We demonstrate its expression in 25% of gastrointestinal neuroendocrine tumors, which also express CEA in 37% of cases. As in colorectal cancer the ND4 marker is predominantly membrane bound in a colonic neuroendocrine tumor cell line, LCC-18 (p < 0.05). The ND4 marker is absent in a poorly differentiated colorectal cancer cell line that does not express CEA or other tumor antigens. Shed antigen in the serum of patients with neuroendocrine tumors is detected in only five of seven patients with the carcinoid syndrome and two of four of those without evidence of the syndrome. However, the reactivity was less in the patients with localized disease, and this test is unlikely to be of diagnostic utility in this group of patients. The sharing of this antigen in colorectal cancer and neuroendocrine tumors is not universal, but does support the common-cell progenitor theory for the origin of these tumors.

Animals↗
PubMed1996

Ig light chain gene in the Siberian sturgeon (Acipenser baeri).

Elasmobranch and teleost fish have their Ig light (L) chain loci organized in multiple clusters (VL-JL-CL). The VL segments of teleosts are in opposite transcriptional orientation to the CL genes, suggesting that in teleosts and elasmobranchs there may have been separate evolutionary events leading to this organization. To address this problem, the IgL locus from the Siberian sturgeon (Acipenser baeri) (representative of a branch between elasmobranchs and teleosts) was investigated. Sequence analysis of cDNA clones shows that sturgeon VL genes are most similar to those of teleosts, but that sturgeon CL genes are more similar to those of the sharks. Southern blot analyses of sturgeon erythrocyte DNA with VL- and CL-specific probes showed that there are more than 20 VL segments in both the tetraploid Siberian sturgeon and the diploid sterlet (Acipenser ruthenus), but only a few CL segments in the genome of the Siberian sturgeon and up to four CL segments in that of the sterlet. Screening of an unamplified genomic library gave more than 300 VL-positive and four CL-positive clones. None of these contained inserts positive for both probes. PCR analysis of a genomic CL clone using IC and CL-specific primers suggested that upstream of the CL segment there are at least seven JL segments. it is concluded that sturgeons have a kappa-like organization of their IgL locus and that the clustered organization of IgL loci in bony fish and sharks arose from two distinct evolutionary events.

Amino Acid Sequence↗
PubMed1996

EGF-receptors in human normal and pathological thyroid tissue.

Expression of the epidermal growth factor receptor (EGFR) was studied in cryosections from human thyroid tissues. Normal tissue (4 cases), nodular goitre (12), toxic goitre (9), adenoma (9), follicular carcinoma (1), papillary carcinoma (7) and poorly differentiated carcinoma (1) were used for immunohistochemistry. Northern blot analysis was performed in two nodular goitres, three adenomas, two papillary carcinomas, one follicular carcinoma and the adjacent normal tissue in five cases as well as in two cell lines from anaplastic carcinomas. Epidermal growth factor receptor immunoreactivity was detected in all tissues examined. The amount of EGFR mRNA did not differ between normal and abnormal tissues. However, the EGFR staining was weaker in normal thyroid tissue compared to the adjacent neoplastic areas suggesting an upregulation at the posttranslational level in the latter. A strong staining was also seen in hyperfunctioning thyroid glands. The EGFR location was mainly basal or basolateral in all thyroid tissues with normal histology and in toxic diffuse goitre. Pericellular and sometimes cytoplasmatic staining was seen in neoplastic tissues. In nodular goitre the staining was both basal, lateral and apical and varied in intensity. Our data suggest that a non-polarized location of EGFR probably indicates a loss of the normal epithelial cell polarity and could be interpreted as an early sign of dedifferentiation. Furthermore, a role for the EGFR is proposed, not only in the development of thyroid neoplasias but also in goitre formation.

Adenocarcinoma, Follicular↗
PubMed1995

Omeprazole inhibits growth of cancer cell line of colonic origin.

The direct effects of omeprazole on colonic cells has not been evaluated. Controversy exists regarding the potential adverse effects of omeprazole on cell proliferation. In order to mimic the in vivo situation in the patient treated with omeprazole, proliferation cell culture experiments were performed, monitoring directly the effects of gastrin and omeprazole both alone and in combination. Three colonic cancer cell lines were used, two with neuroendocrine features (NCI-H716, LCC-18) and one (DLD-1) not known to have these features. In these in vitro proliferation experiments, only the NCI-H716 colorectal cancer cell line responded to omeprazole by decreased proliferation (P < 0.05). The effect was concentration dependent shown for all doses of omeprazole used. Gastrin had a statistically significant effect on increasing proliferation in the NCS-H716 cell line alone but only at the highest concentration (10(-6) M). Omeprazole has a cytostatic effect on one of three colorectal cancer cell lines but the mechanism for this effect of omeprazole and its potential role in treatment awaits elucidation.

Cell Division↗
PubMed1991

Characterisation of a cell line (LCC-18) from a cultured human neuroendocrine-differentiated colonic carcinoma.

A cell line (LCC-18) from a neuroendocrine colonic tumour was established. The tumour cells retained their endocrine characteristics through more than 100 passages and showed positive immunocytochemistry for synaptophysin, vasoactive intestinal polypeptide (VIP) and glucagon. The culture medium also contained VIP and glucagon, which indicates that mechanisms for release of some of the active peptides were preserved. Transplantation of LCC-18 tumour cells into nude rats resulted in tumour formation with similar endocrine characteristics. The c-myc gene was amplified which might have been a prerequisite for establishment of the cell line. The chromosomes in LCC-18 were studied by G-banding and C-banding. The cell line had a distinctive mode in the hypotriploid region, at S = 61. The double minute (Dms) positive stemline karyotype showed numerical and structural aberrations more similar to findings in ordinary colonic adenocarcinomas than to observations in previously studied, pure intestinal neuroendocrine tumours. The Dms may be correlated with amplification of c-myc. LCC-18 may become valuable for studies of neuroendocrine differentiation, regulation of growth and production and release of hormones and for studies of drug effect.

Adult↗
PubMed1990

Silver stains for identification of neuroendocrine cells. A study of the chemical background.

The chemical background of silver stains used for visualization and characterization of peripheral neuroendocrine cells in the gastrointestinal tract and pancreas, and of their corresponding tumours, was studied in tissue sections and by a dot-blot technique. Sequential staining of pancreatic islets with an immunohistochemical procedure and silver staining of the same tissue section revealed that chromogranin A immunostained cells also displayed an argyrophil reaction with the Grimelius method, but no argentaffin reaction with the Masson technique. Accordingly, purified chromogranin A (15 micrograms or less) treated in formalin and applied to nitrocellulose did not show any argentaffin reaction but displayed a dose-related argyrophil reaction. Equal quantities of other polypeptide components did not give rise to any silver reaction. Further dot-blot studies showed that the tryptophan and tyrosine metabolites, dopamine, norepinephrine, 5-hydroxytryptamine and 5-hydroxinodole caused strongly argentaffin and argyrophil reactions while epinephrine, 5-hydroxyindole-3-acetic acid and 5-hydroxytryptophan gave only the former reaction. Among other chemical components studied, only guanine displayed weak silver staining. The results indicate that the reaction products between aldehydes and the granular content of biogenic amines synthesized from tryptophan and tyrosine display an argentaffin reaction and that the granular chromogranin A caused an argyrophil but no argentaffin reaction.

Animals↗
PubMed1989

Histogenesis of a duodenal carcinoid.

A duodenal carcinoid with a diameter of 9 mm was cut serially into 5 microns thin sections from one end to the other. Every fourth section was stained with the argyrophil method of Grimelius, while representative sections in between were used for immunohistochemical analyses. The tumor displayed an argyrophil reaction and was chromogranin A immunoreactive and S-100 protein negative. Furthermore, the majority cell population was gastrin-immunoreactive, while minor cell populations stained for somatostatin and serotonin. The serial sectioning revealed that the tumor arose from differentiated endocrine cells located in the mucosal crypts. In the duodenal mucosa in the vicinity of the tumor the epithelial crypts exhibited an increased number of endocrine cells, preferentially displaying gastrin immunoreactivity. The results indicate that in this particular case the carcinoid tumor arose from hyperplastic and differentiated endocrine cells in the epithelial crypts of the duodenal mucosa.

Biogenic Amines↗
PubMed1989

In vitro culture of neuroendocrine tumors of the pancreas and gut.

Long-time culturing of neuroendocrine tumors from gut and pancreas obtained by surgery was performed with the addition of different growth factors, such as nerve growth factor (NGF), fibroblast growth factor (FGF) and platelet derived growth factor (PDGF) to Hite's medium. Furthermore, the cells were also cultured on epithelial cell matrix (ECM) coated flasks with or without 5% fetal calf serum (FCS) supplemented to the medium. In ECM coated flasks the cells displayed a flattened, non-overlapping pattern and sometimes glandular formation. On the addition of 5% FCS to the culture medium single cells often appeared in cord-like pattern. Culturing in uncoated flasks led to free floating cell colonies or cell clusters attached to fibroblasts present. When different growth factors were added to tumor cells in uncoated culture flasks, no morphological difference could be noticed between the experiments. The tumor cells aggregated to big cell colonies, free-floating in the medium. However, the addition of growth factors to the culture medium showed varying degrees of positive silver staining in cultured tumor cells, while cells cultured in Hite's medium only, with or without FCS supplemented, were negative. The result might indicate that the cells cultured with growth factors retained their endocrine differentiation even after long-term culture. This observation correlated to positive immunostaining to chromogranin A and synaptophysin. Different growth factors might stimulate different fractions of tumor cells to retain the endocrine characteristics.

Carcinoid Tumor↗
PubMed1989

Gastrointestinal carcinoid tumours. Histogenetic, histochemical, immunohistochemical, clinical and therapeutic aspects.

The increased knowledge of the pathobiology of gastrointestinal carcinoid (neuroendocrine) tumours and the improved therapeutic possibilities have brought a demand for more precise diagnosis. Although the carcinoid tumours can often be tentatively recognized in routinely processed microscopic slides, their more accurate identification requires additional diagnostic procedures. General neuroendocrine markers such as the argyrophil reaction of Grimelius and immunohistochemistry with application of antibodies against chromogranin A and of neuron-specific enolase are discriminatory staining methods which are used to reveal the neuroendocrine origin of almost all highly differentiated carcinoid tumours of the gastrointestinal tract. Mid-gut carcinoids, which predominate among these tumours almost unexceptionally contain serotonin. This biogenic amine can be demonstrated by the argentaffin reaction of Masson, serotonin immunoreactively or by formalin-induced fluorescence. The characteristic staining pattern of mid-gut carcinoids is almost invariably preserved in the metastatic deposits and consequently the staining methods for identifying serotonin can also be used on metastases to reveal a primary mid-gut carcinoid. The enterochromaffin-like (ECL) cell carcinoids of the body and fundic area of the stomach often seen in association with pernicious anaemia are argyrophil with the Sevier-Munger silver stain. Other neuroendocrine tumours, viz. antral, duodenal and rectal carcinoids should be studied by a battery of relevant peptide hormone antisera for adequate diagnosis. During the last decade new peptide hormones have been found in circulation in patients with carcinoid tumours, but serotonin and urinary 5-HIAA are still the most important markers for carcinoids of the mid-gut origin. Other clinically useful tumour markers are chromogranin A + B, pancreatic polypeptide, human chorionic gonadotropin alpha and beta subunits. For localizing procedures, angiography is the most reliable investigative method for primary tumours in the gut, whereas CT-scan and ultrasound investigations are good for detection of liver metastases. During the last five years, the therapy for malignant carcinoid tumours has been considerably improved. Chemotherapy has only revealed objective response rates in about 10-30% of the patients giving median survivals from start of therapy of about 10 months. Recently treatment with alpha interferons and the new somatostatin analogue octreotide have given objective responses in 50-75% of patients with malignant mid-gut carcinoid tumours. These patients have now a median survival from start of therapy of 70 months when treated with alpha interferons. In the future new therapies will come into use such as monoclonal antibodies and perhaps also agents blocking different growth factors.

Gastrointestinal Neoplasms↗
PubMed1988

Glucagon and glucagon-like immunoreactive cells in mid- and hindgut carcinoids.

The occurrence of glucagon/glucagon-like immunoreactivity in 31 small intestinal, 34 rectal and 18 appendiceal carcinoids were investigated immunocytochemically using, sequence specific antisera. Glucagon/GLI immunoreactive cells were found in five small-intestinal and five rectal carcinoids, but none were observed in any of the appendiceal carcinoids examined. Glucagon/GLI immunoreactive cells constituted a minor cell population, except in one rectal carcinoid, where most of the tumour cells were of this type. Glucagon/GLI immunoreactive cells were detected with only some sequence-specific antisera, and not with antisera directed against the rest of the glucagon/glicentin molecule. This might indicate that these cells contain a molecule which shares some antigenic binding sites with glucagon/glicentin rather than genuine glucagon/glicentin. It is concluded that this finding contributes to explain why hindgut carcinoids rarely give rise to symptoms related to neuro-endocrine product(s).

Appendiceal Neoplasms↗
PubMed1988

Neuroendocrine tumours of the upper gastrointestinal tract and pancreas.

Neuroendocrine tumours of upper gastrointestinal tract fall into two main categories. First carcinoid tumours of the stomach and duodenum and secondly endocrine pancreatic tumours. The endocrine tumours of the gastric mucosa include two main types, so called ECL-oma of the corpus and fundic region and gastrin producing carcinoids or hyperplasia of the antrum and duodenum. The endocrine tumours of pancreas include entopically secreting insulinomas, glucagonomas, somatostatinomas, PP-omas, and ectopically secreting tumours, such as gastrinomas and tumours producing ACTH, GHRH, and calcitonin. The diagnosis of a neuroendocrine tumour of the upper gastrointestinal tract is based on the recognition of certain clinical syndromes and the determination of certain humoral products. A broad battery of radioimmunological assays for determination of different peptides is mandatory for the diagnosis and follow up of these patients. The diagnosis is also based on histological and immunocytochemical investigation of tissue specimens obtained at operation or by biopsy. Ultrasound investigation is the best non-invasive technique to detect metastases from neuroendocrine gut and pancreatic tumours, but angiography might unveil metastases down to a size of less than 5 mm. Surgery is still the primary treatment procedure but other treatments are needed because many patients have metastases already at the time of diagnosis. Chemotherapy with streptozocin combined with 5-fluorouracil or adriamycin and human leucocyte interferon has demonstrated objective response rate of about 70%. The new somatostatin analogue SMS 201-995 is an important adjunct in controlling clinical symptoms in patients with neuroendocrine gut and pancreatic tumours. A combination of different treatment procedures is needed for long-term management of these patients.

Carcinoid Tumor↗
PubMed1987

A study of the histopathogenesis of carcinoid tumors of the small intestine and appendix.

A specimen from the small intestine with multiple (three) classic carcinoid tumors and one appendiceal carcinoid tumor displaying argentaffinity, argyrophilia (Grimelius stain), and serotonin and neuron specific enolase immunoreactivity was examined by light microscopy with regard to the tumor cell histopathogenesis. The smallest tumor (diameter 0.5 cm) from the small intestine was cut into 512 and the appendiceal tumor into 511 serial sections, which were stained with the argyrophil technique. In the small intestine an increased number of endocrine cells and small proliferating aggregates of endocrine cells were observed among nonendocrine enterocytes in the crypts of Lieberkühn. They seemed to grow initially inside the crypts and to later infiltrate through the basement membrane into the lamina propria of the mucosa. This finding suggests that classic carcinoid tumors of the small intestine develop from mucosal endocrine (enterochromaffin) cells. Since proliferating argentaffin cells were also seen in the mucosal crypts in one of the other two carcinoid tumors (2 cm in diameter) in the same intestine specimen, it is suggested that when multiple carcinoid tumors occur in the small intestine they arise from multiple sites. There was no apparent connection between the mucosal crypts and the carcinoid tumor of the appendix. Thus in this particular case, the appendiceal carcinoid tumor did not appear to derive from the mucosal endocrine cells but from the subepithelial endocrine cells that are present in the lamina propria and submucosa of the appendix wall. Supporting this view is the fact that S-100 protein immunoreactive cells are found both in close relation to subepithelial endocrine cells and as an integral component of appendiceal carcinoid tumors.

Appendiceal Neoplasms↗