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D Marchetti

Publications and source records attributed to D Marchetti.

46 records · Page 3Linked to original sources
PubMed1987

Receptors for nerve growth factor on rat spleen mononuclear cells.

Considerable evidence is mounting to support the concept of a modulatory role for the brain and neuroendocrine system on the immune response. This neuroimmunomodulation occurs in part through the interaction of specific neurosubstances with receptors on lymphocytes and monocytes. Nerve growth factor (NGF) is a neuronotrophic factor necessary for the development and maintenance of sympathetic and embryonic sensory neurons. This trophic effect is initiated through binding of NGF at specific cell surface receptor sites on NGF-responsive cells. Several recent studies suggest that NGF may interact with cells of the immune system and may play a role in the regulation of some immunologic reactions. In this study we report on the presence of specific receptors for NGF on the surface of mononuclear cells from rat spleens. The NGF-binding sites are of the low-affinity type with Kd's in the 10(-9) M range. These receptors migrate on SDS-PAGE as two molecular species of approximately 190 and 125 kilodaltons. Our findings of receptors for NGF on lymphocytes and accessory cells support other evidence that NGF may influence immunoreactivity in vivo.

Animals↗
PubMed1987

Nerve growth factor receptors in human neuroblastoma cells.

Receptors for the nerve growth factor protein (NGFR) present in the human neuroblastoma cell line LAN-1 were characterized. LAN-1 cells display high-affinity (type I, with KD value of 5.9 X 10(-11) M) and low-affinity (type II, with KD value of 9.2 X 10(-9) M) binding to NGF. NGFR were fractionated by preparative isoelectric focusing in a granulated gel (PEGG). High-affinity binding was found in the 5.9-6.2 pH region of the PEGG, and low-affinity binding in the 4.6-4.8 and 8.8-9.3 pH ranges. After further analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) we observed both 92.5- and 200-kDa molecular species associated with NGF binding activity. The 200-kDa protein was found in fractions displaying high-affinity NGF binding and the 92.5-kDa protein in fractions displaying low-affinity NGF binding. Equilibrium binding analysis of NGF in PEGG fractions confirmed the presence of two specific saturable binding sites with KD values similar to those observed for whole dissociated cells. When NGFR II activity from the acidic region of the PEGG chromatogram was incubated with NGFR II from the basic region of the PEGG chromatogram, there was no change in NGF binding or in the number of apparent NGF receptors. However, incubation of these same fractions with a fraction having only NGFR I showed an apparent increase in high-affinity NGF binding and a decrease in low-affinity NGF binding. Immunoprecipitation of this "mixed" fraction and analysis on SDS-PAGE under reduced and nonreduced conditions showed 200-kDa and 92.5-kDa proteins under nonreduced conditions and a 92.5-kDa protein under reduced conditions. Our findings are consistent with the hypothesis that there are two distinct NGF receptors in NGF-responsive cells. The interconvertibility of low- and high-affinity receptors and the possible existence of a modulator type protein or of "silent" type receptors are also in agreement with our findings.

Humans↗
PubMed1983

Liposome-mediated insertion of intact DNA into isolated nuclei. Potential for a new in vitro transcription system.

DNA molecules sequestered within negatively charged liposomes became nuclei-associated following interaction between isolated mouse plasmacytoma nuclei and liposomes. Few if any liposomes appeared to adhere to washed nuclei following their interaction with liposomes, suggesting that DNA was internalized. Liposome-delivered, radioactive pBR322 DNA re-extracted from nuclei appeared intact, whereas DNA from nuclei incubated with naked DNA was degraded. Up to 2 X 10(10) D of DNA were inserted into each nucleus. DNA delivered into nuclei via liposome was transcribed as shown by the fact that about 1% of the RNA synthesized in nuclei injected with pBR322 or E. coli DNA hybridized with moderate excess of homologous DNA. pBR322-specific RNA synthesized in isolated nuclei consisted of large MW transcripts. Experiments in which SV40 DNA and pBR322 DNA were delivered simultaneously in equimolar amounts into nuclei indicated that SV40 DNA was transcribed as efficiently as pBR322 DNA.

Animals↗
PubMed1981

Determination of alkaline phosphatase in casein: collaborative study.

A collaborative study was made to determine alkaline phosphatase in casein samples by the rapid colorimetric test. Six to eight collaborators tested 10 unknown casein samples containing various amounts of residual phosphatase with and without the addition of magnesium acetate. Results indicated that magnesium acetate significantly increased phosphatase activity. The collaborators correctly analyzed 95% of the samples with the added magnesium acetate. The method has been adopted official first action.

Alkaline Phosphatase↗
PubMedDate not supplied

Weekly paclitaxel in patients with recurrent or persistent advanced ovarian cancer.

The purpose of the study is to assess the role of palliative chemotherapy with weekly paclitaxel in patients with persistent or recurrent advanced ovarian cancer. Twenty-eight patients with predominantly paclitaxel- and platinum-resistant ovarian cancer disease were treated with weekly paclitaxel at 80 mg/m2 for 6-8 weeks. In 25 patients (89.2%), this combination represented at least a third line of therapy and for 14 patients (50%) it was more than the fifth line. A clinical response rate of 50% (14 partial responses) was obtained in the 28 patients with evaluable disease. Five patients (17.9%) had stable disease and nine patients (32.1%) had progression of disease. In patients with stable disease or a response, the median progression-free interval was 6 months and overall median survival is 8+ months. All the responses in paclitaxel-resistant tumors were seen in patients with a paclitaxel-free interval of more than 12 months. This regimen is well tolerated with acceptable toxicity. These data suggest that weekly paclitaxel has considerable antitumor activity in heavily pretreated patients with platinum- and paclitaxel-resistant advanced ovarian cancer.

Adult↗
PubMedDate not supplied

Efficacy of adjuvant CYVADIC chemotherapy in early-stage uterine sarcomas: results of long-term follow-up.

Data on adjuvant chemotherapy in early-stage uterine sarcomas are conflicting and most often based on small patient groups with relatively short duration of follow-up. Approximately 60% of patients present with stage I disease with an overall 5-year survival of 30-50% when treated with surgery alone. This study examines the efficacy and results of long-term follow-up of a multiagent chemotherapy regimen of cyclophosphamide, vincristine, doxorubicin, and dacarbazine (CYVADIC) as adjuvant treatment for patients with stage I uterine sarcoma. Between 1982 and 1999, 24 evaluable patients with completely staged uterine sarcomas received adjuvant multiagent chemotherapy with vincristine sulfate (1mg /m(2)) on days 1 and 4, doxorubicin (40 mg /m(2)) and cyclophosphamide (400 mg /m(2)) on day 2, and dacarbazine (200 mg /m(2)) on days 1 through 4 for a total of nine monthly cycles or until recurrence of disease was documented. Survival distributions were calculated by the Kaplan-Meier method, and statistical significance was determined with the log-rank test. Factors significant on univariate analysis were analyzed in a multivariate fashion using Cox proportional hazards model. The histologic distribution of patients was 46% leiomyosarcoma, 33% mixed mullerian tumors, 13% stromal sarcomas, 4% adenosarcomas, and 4% hemangiosarcoma. The patients received 206 of a planned 216 cycles of chemotherapy. The median follow-up of the patient population was 93 months (range 11-213 months). Eight patients (33%) developed recurrent disease. The median time to recurrence was 19 months (range 7-184 months). The estimated survival for the entire group was 88, 75, and 69% at 2, 5, and 15 years, respectively. Factors that did not affect survival included age, histology, and tumor grade. Four patients required dose reductions secondary to grade 2-3 toxicities (hematologic). Grade 1 neurotoxicity was observed in six patients (25%) and grade 2 neurotoxicity in one patient (4%). Adjuvant CYVADIC chemotherapy appears to be safe and well tolerated in patients with stage I uterine sarcomas. Our data provide information on the longest duration of follow-up ever reported and suggests that CYVADIC may have a potential role in the adjuvant treatment of early-stage uterine sarcoma.

Adult↗
PubMedDate not supplied

Involvement of neurotrophins and growth factors in brain metastasis formation.

The formation of brain metastases is an important clinical end point in patients with cancer. The brain provides a unique microenvironment enclosed by the skull, lacking lymphatic drainage and maintaining a highly regulated vascular transport barrier. In the brain microcirculation, brain-metastatic tumor cells must attach to endothelial cells, respond to brain-derived invasion factors, and invade the blood-brain barrier. Neurotrophins are important brain invasion-stimulating factors in this process, and in responsive tumor cells neurotrophins can promote invasion by enhancing the production of basement-membrane-degradative enzymes (gelatinase and heparanase) capable of locally destroying the blood-brain barrier. We examined human melanoma variant lines that express low-affinity p75 neurotrophin receptor in relation to their brain-metastatic potentials. Expression of p75 in these variants occurs in the absence of expression of trkA, the gene encoding the high-affinity nerve growth factor (NGF) tyrosine kinase receptor. Brain-metastatic tumor cells can also produce factors and inhibitors that influence their growth, invasion and survival in the brain. We found that brain-metastatic melanoma cells synthesize transcripts for tumor growth factor-beta, basic fibroblast growth factor, tumor growth factor-alpha, and interleukin-1 beta. Synthesis of these factors may influence the production of neurotrophins by adjacent brain tissues. In support of this, we found increased amounts of NGF in tumor-adjacent tissues at the invasion front of human melanoma tumors in the brain. These and other factors may determine whether metastatic cells can successfully invade, colonize, and grow in the central nervous system.

Base Sequence↗