First heterotransplantation of a human carcinoid tumor into nude mice.

The first successful heterotransplantation of a human carcinoid tumor into nude mice is reported. CSH, a voluminous hepatic metastasis of a primary bronchial carcinoid tumor (CSB) was resected and transplanted into three irradiated nude (Swiss-nu/nu) mice both by subcutaneous (SC) and intramuscular (IM) routes; the success rate was five of six. Heterotransplanted tumors took 4 to 5 months to appear in the mice and 1 month to attain a width of 0.

Genetic difference in sensitivity to beta-carboline: evidence for the involvement of brain benzodiazepine receptors.

The convulsive effects of methyl beta-carboline-3-carboxylate (beta-CCM), a benzodiazepine receptor ligand, are different in two inbred strains of mice: BALB/cBy mice are more sensitive to beta-CCM than C57BL/6J mice. In the present article, we report the effects of [3H]flunitrazepam binding in these two strains, which suggest a possible explanation of the differences in their sensitivity to beta-CCM by the involvement of brain benzodiazepine receptors.

Prosomatostatin is processed in the Golgi apparatus of rat neural cells.

Proteolytic processing of somatostatin precursor produces several peptides including somatostatin-14 (S-14), somatostatin-28 (S-28), and somatostatin-28 (1-12) (S-28(1-12)). The subcellular sites at which these cleavages occur were identified by quantitative evaluation of these products in enriched fractions of the biosynthetic secretory apparatus of rat cortical or hypothalamic cells. Each of the major cellular compartments was obtained by discontinuous gradient centrifugation and was characterized both by specific enzyme markers and electron microscopy.

Alteration of Platelet Shape Change Response to Vasopressin in Patients with Diabetes mellitus.

An unaltered platelet aggregatory response to vasopressin (VP) with a lower number of platelet VP-receptors have been described in patients with Diabetes mellitus. A possible explanation could be that the lost receptors are related to a cellular event different from aggregation. We have explored VP-induced platelet shape change in diabetic and healthy subjects.

Microtubule affinity chromatography: a new technique for isolating microtubule-binding proteins from rat pancreas.

We have developed an affinity chromatography method for the isolation of microtubule-associated proteins (MAPs) from soluble cytoplasmic extracts of rat pancreas. Among the ten proteins which copurify with pancreas tubulin on a colchicine derivatives-affinity chromatography, three polypeptides of respectively 58, 55 and 48 kDa strongly bind to the microtubule affinity column. To begin to characterize these proteins, we have generated polyclonal antibodies against tau polypeptides from brains of immature chicken or rat.

[Plasma releasing factors in common migraine].

Many platelet abnormalities have been described in migraine, but they are now regarded as secondary phenomena rather than primary causative factors. In this study, we attempted to assess the presence of bioamine-releasing factors in the plasma of patients with common, non-dietary migraine. Blood samples were collected from 17 such patients, either during attacks (n = 9) or during attack-free periods (n = 8).

Serotonin uptake, storage, and synthesis in an immortalized committed cell line derived from mouse teratocarcinoma.

We report the isolation and characterization of a serotoninergic cell line, 1C11, derived from a mouse teratocarcinoma. The clone 1C11 was immortalized through the expression of the simian virus 40 oncogenes. 1C11 presents two states: an immature epithelial-like state (1C11 precursor) and a more differentiated state (1C11).

[Proteins, genes and early diagnosis of Alzheimer's disease].

Proteic (neuritic plaques, amyloid substances...

[A strategy for immortalizing lines committed to endoderm, neuroectoderm or mesoderm from mouse teratocarcinoma].

With the aim of immortalizing embryonic cells fixed at early embryonic stages, various plasmids carrying the SV40 early region were introduced into the mouse embryonal carcinomas (EC) F9 and 1003. Only the construction PK4, in which the SV40 oncogenes are placed under the control of the adenovirus E1A promoter, led to the immortalization of the cells at the onset of differentiation. Clones corresponding to committed precursors of each embryonic lineage (neuroectoderm, mesoderm and endoderm) were then selected with high efficiency according to the following strategy: selection of immature cells which: have lost EC cell markers, keep a stable phenotype, are immortalized by the expression of the SV40 oncogenes and are still able to differentiate along a restricted lineage in vitro or in vivo.

Homologous regulation of human platelet vasopressin receptors does not occur in vivo.

Large variations in the functional responsiveness of human platelets to arginine vasopressin (AVP), related to maximal platelet AVP-binding capacity, have been observed among individuals. The effects of dehydration and overhydration on maximal platelet AVP-binding capacity, plasma AVP, platelet-associated AVP, and AVP-induced platelet aggregation were examined in healthy human volunteers to determine whether homologous regulation of platelet AVP receptors occurs in vivo within the physiological range of circulating AVP fluctuations. Although significant variations of plasma AVP were observed under both conditions, no correlation could be found in the same individual with any change in 1) the maximal AVP-binding capacity, 2) platelet aggregatory responses to AVP, or 3) the platelet AVP fraction.

Plasma histamine levels and kinetics in chronic hemodialysis patients.

Pruritus is frequently observed in hemodialyzed patients; its etiology seems to be multifactorial. Increased plasma histamine levels have been reported in chronic renal failure. As histamine is a potent inducer of pruritus.

Glyceraldehyde-3-phosphate dehydrogenase is a microtubule binding protein in a human colon tumor cell line.

A protein which binds to tubulin polymer was isolated from a human colonic tumor cell line. This protein has a molecular mass of 35 kDa, as determined by polyacrylamide slab gel electrophoresis. The protein was purified by affinity chromatography on taxol-stabilized microtubules, and it did not cross-react with anti-MAP2 or anti-tau antibodies.

Serotonin and human immunodeficiency viruses.

This preliminary study shows, for the first time to our knowledge, decreased whole blood serotonin levels in AIDS patients as compared to healthy controls and cancer patients. The lowest serotonin levels were found in AIDS patients with neuropsychiatric symptoms. Finally the present data suggest an inverse relationship between serotonin level and AIDS severity.

Congenital dyschromia with erythrocyte, platelet, and tryptophan metabolism abnormalities.

The case of a female child with a unique generalized congenital dyschromia is reported. She had hypopimented skin, with hypomelanosis and hypomelanocytosis, and many pigmented macules, which consisted of epidermal and dermal hypermelanosis without hypermelanocytosis. Biochemical investigations revealed normal catecholamine metabolism but abnormal tryptophan metabolism, including a decrease in blood serotonin and melatonin.

Purification and characterization of a trypsin-like protein from rat pancreas.

The purification of the latent form of a rat pancreas trypsin-like protein was performed by ion-exchange and hydrophobic chromatographies. After partial activation, the affinity on immobilized soybean trypsin inhibitor allowed the isolation of an active and an inactive form. They had 30,000 and 32,000 molecular weight, respectively, as checked by polyacrylamide slab gel electrophoresis.

Damaging effects of Clostridium perfringens delta toxin on blood platelets and their relevance to ganglioside GM2.

The lytic effect of Clostridium perfringens delta toxin was investigated on goat, human, rabbit, and guinea pig platelets. In contrast to erythrocytes from the latter three species, which are insensitive to the toxin, the platelets were equally lysed by the same amount of toxin. These results suggest the presence of GM2 or GM2-like ganglioside(s) as a specific recognition site of the toxin on platelet plasmic membrane as previously established for sensitive erythrocytes.

Platelets as a model for neurones?

The multiple biochemical and pharmacological similarities existing between blood platelets and 5-hydroxytryptamine (5-HT)-containing neurones of the CNS point to the platelets as a reliable model for the biochemical characterization of 5-HT releasers and uptake blockers which interfere with the storage and the active carrier mechanism of 5-HT in the neurones, respectively. In addition, the affinity displayed by dopamine and by dopaminergic neurotoxin MPP+ for the platelet 5-HT transport and storage indicates also some similarities between platelets and the dopaminergic system of the CNS. Since human platelets contain almost exclusively monoamine oxidase type B (MAO-B), they can be used as a source for the purification and characterization of this human enzyme.