Human endogenous retroviral expression by leukocytes.

Budding endogenous retroviral particles were identified on the plasma membrane of a high percentage of neurotrophils in four widely varied pathological specimens.

Establishment and characterization of a feline large granular lymphoma cell line expressing interleukin 2 receptor alpha-chain.

A feline large granular lymphocyte (LGL) cell line was established from a cat with an alimentary-form lymphoma. This cell line, designated as FGL, had many large azurophilic granules in the cytoplasm, which were typical to LGL cells. Proviral genome of feline leukemia virus was detected in the chromosomal DNA of FGL cells, and reverse transcriptase activity was also demonstrated in the culture supernatant. Furthermore, we found expression of interleukin 2 (IL-2) receptor alpha-chain on the cell surface of FGL and its natural killer activity against human erythroblastic leukemia cell line, K562.

Expression of growth factor peptides and their receptors in neuroendocrine tumors of the digestive system.

Neuroendocrine tumors of the digestive system are slow growing neoplasms which often present with pronounced fibrosis around tumor cells and in the peritoneal cavity. In this report 30 midgut carcinoids and endocrine pancreatic tumors were examined for the expression of peptide growth factors and their receptors, both by immunohistochemistry and in situ hybridization. Our data indicate that multiple peptide growth factors, PDGF, TGF-beta, and bFGF are expressed by these tumors. PDGF was expressed on tumor cells and stroma in 70% of tissues examined. PDGF alpha-receptor was seen on clusters of tumor cells and occasionally on adjacent stroma, whereas PDGF beta-receptor was seen only in the stroma. Our data suggest that PDGF may be involved in the autocrine stimulation of tumor cells and stimulation of stromal cell growth through paracrine and possibly autocrine mechanism. In addition, tumor tissues express all three isoforms of TGF-beta in more than half of the tissues examined. Tumor cells produce small latent complexes causing an escape from potent inhibitory effect of TGF-beta and stimulation of stromal cell growth and matrix deposition through paracrine mechanism. bFGF, a potent stimulant of endothelial cell growth, was expressed by all tumor tissues examined. Our data suggest that multiple peptide growth factors may have an important role in tumor progression and desmoplastic reaction accompanying these tumors.

[Ultraimmunocytochemical diagnosis of squamous cell cancer of the digestive tract]. / Ul'traimmunotsitokhimicheskaia diagnostika ploskokletochnogo raka pishchevaritel'nogo trakta.

Procedure using fluorescent and peroxidase labeling and monoclonal antibodies to basal-cell antigen of multilayer epithelium showed the antigen to occur in squamous cell cancer irrespective of site and degree of cell differentiation; this, however, was not the case with tumors of other origins. Ultraimmunocytochemical method was used to identify localization of the antigen at cellular and subcellular levels, namely, in tonofilaments and desmosomes. Said situation is considered to suggest squamous cell carcinoma.

[Recklinghausen's disease with digestive localizations associated with gastric acid hypersecretion suggesting Zollinger-Ellison syndrome]. / Maladie de Recklinghausen à localisations digestives associée à une hypersécrétion gastrique acide evoquant un syndrome de Zollinger-Ellison.

We report the case of a 49 year old male patient who had Recklinghausen's disease associated with hyperchlorhydria. The principal features of Recklinghausen's disease were cutaneous localizations and countless digestive tumors, found mainly on the small bowel. The ultrastructural aspect of these tumors was neurinoma or schwannoma. Basal acid gastric hypersecretion and a positive secretin test were highly suggestive of a Zollinger-Ellison syndrome. Gastrinoma was not found at laparotomy even though a gastrin gradient had been demonstrated by pancreatic venous sampling. In a patient with Recklinghausen's disease, neuroendocrine tumors (APUDomas) should be looked for systematically.