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Biomedical subjects

C Rossi

Publications and source records attributed to C Rossi.

At least 271 records · Page 15Linked to original sources
PubMed1987

Reduction of neutral gene flow due to the partial sterility of heterozygotes for a linked chromosome mutation.

The effect of linkage between a chromosome mutation producing partially sterile heterozygotes and a neutral locus in reducing the gene flow at the neutral locus is studied using a two-population deterministic model. Chromosome mutations are more efficient in reducing gene flow with low migration rates than with high ones. The interaction between high values of partial heterozygote sterility and low recombination rates can produce, in the low migration pattern, a drastic reduction of gene flow. Nevertheless, since only chromosome mutations with low values of partial heterozygote sterility are likely to be involved in chromosomal speciation, a significant reduction of gene flow will probably occur only for a very limited part of the genome. Therefore, a single chromosome mutation is unlikely to play a primary role in speciation.

Biological Evolution↗
PubMed1987

Structural and dynamical characterization of piroxicam by 1H- and 13C-NMR relaxation studies.

Carbon spin-lattice relaxation rates of an anti-inflammatory drug, piroxicam, have been measured. These results have been used in determining the reorientational rates of the proton carbon vectors. An analysis of internal motions within the pyridinyl moiety of piroxicam was carried out. Selective proton-carbon nuclear Overhauser effect (NOE) measurements were made in order to determine the solution structure of piroxicam. The effect of indirect NOE arising from exchangeable protons has been analyzed and considered.

Carbon Isotopes↗
PubMed1987

The excised leader of human cytochrome c oxidase subunit I mRNA which contains the origin of mitochondrial DNA light-strand synthesis accumulates in mitochondria and is polyadenylated.

We identified a polyadenylated RNA species which contains the origin of human mitochondrial DNA light-strand synthesis and the surrounding complementary sequences of the four light-strand-encoded tRNAs. This RNA (RNA 9L) is probably derived from the leader portion of RNA 6 which is excised during the formation of the mature cytochrome c oxidase subunit mRNA (RNA 9). The high degree of secondary structure of this RNA is presumably responsible for its anomalous electrophoretic behavior in denaturing polyacrylamide gels.

Electron Transport Complex IV↗
PubMed1987

[Indications and results of transcatheter fibrinolysis in acute arterial occlusions].

The authors' experience is reported on intravascular fibrinolytic therapy with urokinase in acute arterial obstructions. Thirty-eight patients were treated, from 1983 to 1986, for acute thrombosis and/or thromboembolization, 22 of which developed on an atherosclerotic lesion, and 10 on a surgical stenotic by-pass graft. A complete vascular recanalization has been obtained, at the end of the procedure, in 69.4% of the cases, 77.7% had a definite final clinical improvement. The results correspond to the medium statistical level of the various casuistics analyzed for comparison. Surgery has been performed on 27.7% of the patients. Complications have been observed in 8% of the cases. IAF technique is of greatest value in the treatment of those lesions; better results have been obtained with intra-thrombus injection of the drug (as emphasized by many authors) in association with PTA and surgery. A close cooperation between interventional radiology, vascular surgery and angiology is therefore necessary in this field.

Acute Disease↗
PubMed1987

Studies on annelated 1,4-benzothiazines and 1,5-benzothiazepines. II. Synthesis of new series of 1- or 2-substituted 4H-s-triazolo[3,4-c]-1,4-benzothiazines and related compounds with potential CNS activity.

New series of 1- or 2-substituted 4H-s-triazolo[3,4-c]-1,4-benzothiazines have been prepared. The 1-substituted products were obtained starting from 3-hydrazino-2H-1,4-benzothiazine derivatives (III) by treatment with chloroacethyl chloride followed by cyclization of the resulting chloroacethylderivatives into the chloromethyltriazolobenzothiazines (IV a-e), which were then reacted with the appropriate amines to give the desired compounds (V a-n). Other 1-substituted compounds were prepared by ring closure of (III) with cyanogen bromide, affording 1-amino-4H-s-triazolo [3,4-c]-1,4-benzothiazines (XI a-e). The 2-substituted compounds (VIII) were prepared from 2,4-dihydro-1H-s-triazolo [3,4-c]-1,4-benzothiazin-1-ones (VII), synthesized from (I) by reaction with ethyl carbazate. The aminoalkyl side chain was introduced into (VII) in two steps: first by treatment with 1-bromo-3-chloropropane, then by refluxing the resulting product with the appropriate amine. Some 4H-tetrazolo[5,1-c]-1,4-benzothiazines (XII) were also synthesized from (III). Preliminary pharmacological data on the CNS activity of the synthesized tricyclic compounds are reported.

Animals↗
PubMed1987

Studies on annelated 1,4-benzothiazines and 1,5-benzothiazepines. III--Synthesis and CNS activity of some 1-substituted derivatives of the novel heterocyclic system 4,5-dihydro-s-triazolo [3,4-d]-1,5-benzothiazepine.

A series of new 4,5-dihydro-s-triazolo [3,4-d]-1,5-benzothiazepines has been prepared. All the described compounds are representative of a novel ring system. Some of these compounds were tested for their CNS activity and effects comparable with the ones of diazepam were observed.

Animals↗
PubMed1987

Doxorubicin distribution in human breast cancer.

Using a high-performance liquid chromatographic method coupled with fluorimetric detection, we evaluated plasma pharmacokinetics of doxorubicin (DX) and tissue distribution in seven patients suffering from locally advanced breast cancer. Tumor biopsies were performed 30 minutes and 24 hours after DX injection. In addition at 48 hours, during surgery, biopsies were obtained from primary breast cancer, nodes, and other accessible tissues, and DX concentrations were analyzed. A triexponential equation gave the best fit for plasma levels and the values (mean +/- SE) were: elimination half-life, 37.6 +/- 4.9 hours; volume of distribution, 605 +/- 61 L/m2; and clearance 200 +/- 27 ml/min/m2. There was greater interindividual variability in tumor DX concentrations than in plasma concentrations. DX reached much higher (range at 48 hrs, 1.54-14.17 micrograms/g) and longer-lasting concentrations in tumor than in plasma. At 48 hours tumor concentrations were 55.2-337.4 times the plasma concentrations. DX concentrations in normal breast were lower or similar to those in breast carcinoma. DX levels were very low in fat and skin, slightly higher in muscle, and very high in normal or metastasized lymph nodes.

Breast Neoplasms↗
PubMed1986

Synthesis and in vitro cytotoxic activity of semisynthetic derivatives in the santonin series.

The synthesis of two new santonin derivatives namely 3-oxo-6 beta-H-11 beta-phenylselenoeudesm-1,4-dien-6,13-olide and 3-oxo-6 beta H-eudesm-1,4,11-trien-6,13-olide is reported along with the results of a series of santonins tested for activity against the growth of KB cells in vitro, a human epidermoid nasopharynx carcinoma. Select compounds were found to be active at concentrations lower than 5 X 10(-5) M. In particular, the compound 2 alpha-bromo-3 beta-hydroxy-6 beta H-eudesm-11-en-6,13-olide exhibits an extremely low ID50 value at 0.33 X 10(-6) M. Some relationships between chemical structure and cytotoxic activity are suggested, i.e. the alpha-methylene-gamma-lactone moiety appears to be necessary for cytotoxic activity toward KB cells growth in vitro by santonin derivatives.

Antineoplastic Agents, Phytogenic↗
PubMed1986

Psychological profile of women with chronic pelvic pain.

Using the Middlesex Hospital Questionnaire (MHQ) and the Zung Self-Rating Depression Scale (SDS) psychological distress was measured in 30 women who underwent laparoscopy for chronic pelvic pain and in 30 matched controls. Both organic pelvic pain patients (OPPs) and idiopathic pelvic pain patients (IPPs) reported higher scores for somatisation than controls. IPPs scored higher than OPPs and controls on the Zung SDS, while no difference emerged in this scale between OPPs and controls. No correlations were found between age or duration of symptoms and somatisation and depression scores. On the basis of the above reported results the authors suggest that some forms of idiopathic chronic pelvic pain might represent an expression of a depressive disorder.

Adult↗
PubMed1986

Potassium para-aminobenzoate and liver function test findings.

Risk of hepatotoxicity has been raised with respect to potassium para-aminobenzoate (Potaba) therapy. In this regard relevant clinical and laboratory hepatic findings in the hospital records of 390 scleroderma patients were analyzed. There were 274 patients who had received potassium para-aminobenzoate at some time and 116 who never received it. No instance was found in which potassium para-aminobenzoate was the cause of an acute hepatic hypersensitivity reaction. There were random or intercurrent abnormalities in hepatic test findings over time, but these actually occurred more often in the group of patients never treated with potassium para-aminobenzoate. Further, there was no evidence that long-term potassium para-aminobenzoate therapy is hepatotoxic. These findings suggest that acute hepatic reaction to potassium para-aminobenzoate is at least uncommon if not rare.

4-Aminobenzoic Acid↗
PubMed1986

In vivo characterization of a doxorubicin resistant B16 melanoma cell line.

A doxorubicin-resistant line of B16 melanoma (B16VDXR) was obtained in vitro by continuous exposure to increasing concentrations of doxorubicin of an in vitro line (B16V) derived from the in vivo transplanted B16 melanoma. When injected s.c. into mice, B16VDXR exhibited histological features, metastatic behaviour, doubling time and tumourigenic potential similar to those of the parental B16V line. Tumours obtained by implantation of B16VDXR, however, had longer latency and permitted a longer survival time than B16V and had, as in vitro, a higher DNA content. After i.v. inoculation, B16VDXR cells had lower lung colonizing capability compared to B16V. B16V and B16VDXR had significantly lower metastatic potential compared to the B16 melanoma from which they derived. Doxorubicin treatment significantly delayed the growth of B16 and B16V transplanted s.c. and increased the life span of animals bearing B16V. B16VDXR was resistant to doxorubicin treatment when the in vitro resistance index was greater than 100. While the doxorubicin-resistance phenotype was stable in vitro for 50 passages, in vivo the resistance phenotype was lost in 5 passages and tumours grown from s.c. inocula of mixtures of similar percentages of sensitive and resistant cells behaved as sensitive tumours. Cis-diamminedichloroplatinum (II), although marginally active in animals bearing B16V, was highly effective in B16VDXR bearing animals, suggesting a collateral cis-diamminedichloroplatinum (II) sensitivity of the B16VDXR line. After a single i.v. administration, doxorubicin reached initially, in the B16VDXR line, levels similar to those found in the B16 and B16V lines, but its release was faster from the resistant line in comparison with the sensitive ones. Doxorubicin-resistance was not overcome by more frequent treatments with doxorubicin. This doxorubicin-resistant tumour line obtained in vitro and used as a first in vivo transplant, may be a suitable metastaizing model for in vivo study of the mechanisms of resistance and of collateral sensitivity and for screening new drugs.

Animals↗
PubMed1986

[Comparative study of hepatic metastasis with different modality ultrasound scanners].

57 patients affected by liver metastases were examined with different types of dynamic ultrasound scanners (linear-sector-convex) in order to assess the advantages and the limits of each scanner and to evaluate if a better diagnostic accuracy is possible by using 2 types of scanner in the same patient. The results were estimated at 3 different levels: quantitative analysis where we considered only the presence or not of liver metastases; complex quantitative analysis where we also evaluate number and site of the metastases; qualitative structural analysis where we compared the ultrasonographic appearance of the metastases. All the results were evaluated by a personal computer with a special program and a statistical analysis was elaborated.

False Negative Reactions↗