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Biomedical subjects

G Nicoletti

Publications and source records attributed to G Nicoletti.

At least 181 records · Page 10Linked to original sources
PubMed1989

Receptor-mediated stimulation of inositol phospholipid hydrolysis in human brain.

Stimulation of inositol phospholipid hydrolysis by transmitter receptor agonists was studied in slices from the occipital, temporal and cerebellar cortex that were surgically removed from three patients during ablation of brain tumors. Norepinephrine and the muscarinic acetylcholine agonist carbamylcholine increased the content of [3H]inositol monophosphate (InsP) in all the regions examined, whereas the glutamate receptor agonist quisqualate was effective only in the cerebellar slices. These results provide evidence that neurotransmitter receptors are coupled to inositol phospholipid hydrolysis in human brain tissue.

Adult↗
PubMed1989

In vivo and in vitro production of haemopoietic colony-stimulating activity by murine cell lines of different origin: a frequent finding.

The production of colony-stimulating factor (CSF) by murine transformed cells was investigated in 10 cell lines derived from spontaneous or chemically induced tumours and from cells transformed by SV40 or Moloney-MSV; histologic types included carcinomas, sarcomas and melanoma. Nine of 10 supernatants contained CSF activity as judged by in vitro proliferation and differentiation of normal murine monocytic and granulocytic progenitors in agar cultures. Tumours induced with CSF-producing cells caused alterations of haemopoiesis which can include leukocytosis, granulocytosis and splenomegaly. Haemopoietic alterations were also evident in the absence of a local tumour in mice bearing large experimental lung metastases. Production of CSF seems to be a frequent finding among murine cell lines, and its biological and immunological consequences on host-tumour relationships should be taken into account.

Animals↗
PubMed1989

Tumorigenic and metastatic ability of SV40-transformed BALB/c cell lines and MHC antigen expression.

Tumorigenic and metastatic potential were studied in relation to class I MHC expression in four different SV40-transformed BALB/c cell lines. All the lines studied, tumorigenic or not, expressed both H-2Kd and Dd, so MHC antigens did not seem to be involved in the control of SV40-transformed cells' growth in vivo. Lung metastases were observed in all tumour-bearing mice. Cells cultured after in vivo passage, obtained either from tumour tissue or from individual lung metastases, still expressed similar levels of H-2d antigens, thus suggesting that tumour growth and metastasis do not occur through the selection of variants with altered MHC expression.

Animals↗
PubMed1989

Human rhabdomyosarcoma cells in nude mice as a model for metastasis and differentiation.

We investigated the ability of alveolar (RMZ-RC2) and of embryonal (RD) human rhabdomyosarcoma cell lines to grow and metastasize in nude mice. Both cell lines produced local tumors, but failed to give rise to spontaneous metastases. When RD cells were injected intravenously into nude mice pretreated with cyclophosphamide (in order to depress primarily natural killer activity), several large lung colonies were obtained. Renal localization was also observed. In vitro cultures obtained from tumors or secondaries retained the ability to differentiate in the myogenic pathway shown by the parental cell lines. Intravenous injection into nude mice could therefore constitute an interesting experimental system to study metastatic ability and differentiation properties of human rhabdomyosarcoma cells.

Adrenal Gland Neoplasms↗
PubMed1989

In vitro bactericidal activity and post-antibiotic effect of dactimicin, a new aminoglycoside, alone and in combination with other antibiotics.

The bactericidal activity of dactimicin, a novel aminoglycoside, has been tested in vitro in combination with piperacillin, mezlocillin and ceftazidime against freshly isolated Gram-negative and Gram-positive aerobes and compared with that of amikacin. Using the checkerboard test, the combination of dactimicin and amikacin with the other drugs resulted in a synergistic interaction with the Enterobacteriaceae strains analysed in 36 out of 39 and 37 out of 39 cases, respectively. Antagonism was never encountered. With the Pseudomonas isolates, indifference prevailed with dactimicin, whereas synergism was observed with amikacin in combination with the other drugs. No case of antagonism was encountered. When the time-kill system was employed, synergism prevailed, indifference was a rare case, and antagonism was not observed. In experiments carried out with dactimicin-susceptible staphylococcal and enterococcal isolates, a synergistic outcome was obtained employing both methods. Dactimicin induced a post-antibiotic effect (PAE) which ranged from about 1 h with Enterobacter cloacae to 3 h with Escherichia coli after exposure of the bacteria for 1 h to 4 x MIC. The PAE was also evaluated employing several drug associations. An average of 0.6 h PAE was apparent when dactimicin was combined with piperacillin, mezlocillin and ceftazidime, and the bacteria were exposed for 1 h to drug concentrations corresponding to one-half their MICs.

Aminoglycosides↗