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Biomedical subjects

C Balbi

Publications and source records attributed to C Balbi.

At least 55 records · Page 3Linked to original sources
PubMed1983

Studies on DNA damage: discordant responses of rate of DNA disentanglement (viscosimetrically evaluated) and alkaline elution rate, obtained for several compounds. Possible explanations of the discrepancies.

Alkaline elution is a well-known method for detecting DNA damage. Recently we have developed a viscosimetric method that is even more sensitive than alkaline elution. Here we report that the two methods, although apparently both revealing alkaline DNA fragmentation, can give dramatically different results for a significant series of compounds. We suspect that alkaline elution might reveal not only DNA fragmentation but also the extent of disentanglement of chromatin structure, whereas this DNA disentanglement rate, when evaluated viscosimetrically , is more strictly correlated with the initiation of DNA unwinding.

Animals↗
PubMed1982

Decreased viscosity of rat-liver DNA treated by 3'-methyl-4-dimethylaminoazobenzene, detected with a new viscometric approach.

DNA damage induced in vivo by 3'-methyl-4-dimethylaminoazobenzene (3'CH3DAB) was investigated with 2 differently sensitive techniques: the alkaline elution assay and the viscometric measurement of DNA damage. 3'CH3DAB appeared to be falsely negative with the alkaline elution assay, whereas with the viscometric approach, which is about 30-50 times more sensitive, it appeared positive, and the DNA damage was dose-dependent.

Animals↗
PubMed1982

Comparison between sensitivity of a viscometric method and sensitivity of the alkaline elution assay for the determination of DNA damage induced by dimethylsulfate in vitro.

DNA damage induced by dimethylsulfate (DMS) was measured with a new oscillating crucible viscometer, having a U-shaped circular channel. Rat liver nuclei were treated in vitro. Viscosity was measured by lysing nuclei in an aklaline lysing solution (pH 12.5; 25 degrees C). Nuclei were lysed immediately in the viscometer and released DNA started to uncoil. In control samples the viscosity increased very slowly with time, reaching a maximum only after about 8 h. A progressively more rapid increase in viscosity was seen with increasing concentrations of DMS. The time of DNA disentanglement was sensitive to about 30 times less breaks than the alkaline elution assay.

Animals↗
PubMed1982

DNA damage in liver, kidney, bone marrow, and spleen of rats and mice treated with commercial and purified aniline as determined by alkaline elution assay and sister chromatid exchange induction.

Aniline of unknown purity has been reported to induce spleen hemangiosarcoma in rats. Aniline has been found to be negative in terms of mutagenicity in both bacteria and yeasts. We have found that both commercial (already rather pure) and repurified aniline are clearly positive to a similar extent in inducing DNA damage in vivo in liver and kidney of rats. Both the commercial and repurified product are also clearly positive in induction of sister chromatid exchanges in vivo in male Swiss mice bone marrow cells. Liver, kidney, and bone marrow DNA damage was absent in male Swiss mice.

Aniline Compounds↗
PubMed1981

[Specific effects of Cr ions on DNA: a comparison between the interaction of CrIII with purified DNA and with DNA from cultured cells].

Affinity between CrIII and purified calf thymus DNA were studied by equilibrium dialysis at different pHs. Chromium was dosed by atomic spectrometry. This affinity was compared with Chromium-DNA affinity after treatment of living mammalian cells with CrVI and its intracellular reduction. Preliminary results seem to suggest that affinity is similar in both cases and not especially high (K approximately 10(5) 1/mole).

Animals↗
PubMed1981

[Affinity between CrIII and purified DNA, studied by competition with an intercalating agent: ethidium bromide].

The affinity between CrIII and purified calf- thymus DNA was studied at neutral pH by competition with ethidium bromide. Competition results indicated an affinity between CrIII and DNA of the order of 10(5) 1/mole. These results are in good agreement with previous results CrIII - DNA affinity was studied by the independent method of equilibrium dialysis and chromium dosage by atomic spectrometry.

Animals↗
PubMed1981

[DNA damage after treatment in-vivo with several aromatic amines: 2,4-diaminotoluene, 4-aminobenzene (aniline) and paradimethylaminoazobenzene (butter yellow)].

Three aromatic amines, 2,4 diaminotoluene, aminobenzene and paradimethylaminoazobenzene were examined for their capability of damaging rat liver DNA. Compounds were tested by the "in vivo"/DNA alcaline elution assay. 2,4 diaminotoluene was very positive, aminobenzene weakly positive, paradimethylaminoazobenzene probably negative. All the compounds were tested at doses already clearly toxic.

Aniline Compounds↗
PubMedDate not supplied

Predictive ability of the autoradiographic repair assay in rat liver cells compared with the Ames test.

Data from the literature for 25 compounds belonging to different chemical classes were collected and their potency in the autoradiographic repair assay in rat liver cells was compared with their carcinogenic potency. A very modest correlation was found between the two parameters (r = 0.36). For 21 of the compounds it was also possible to compare mutagenic potency in the Ames test with carcinogenic potency. Even in this case the correlation was low (r = 0.40). The results are compared with those of previous studies of different short-term tests used to predict carcinogenic potency.

Animals↗
PubMedDate not supplied

[Macrophage-colony stimulating factor and ovarian cancer].

BACKGROUND: In this study the use of macrophage-colony stimulating factor (M-CSF) as tumor marker for ovarian cancer is evaluated. METHODS: Serum samples were obtained from 74 patients, 43 of these were affected by ovarian carcinoma and 31 by benign ovarian tumors. The M-CSF levels were assayed with an ELISA method and compared with those of 148 healthy women. CA 125 levels were also evaluated. RESULTS: In healthy women the M-CSF levels were 770.4 +/- 145.9 U/ml, the upper limit of normal level was considered 1056 U/ml. Serum M-CSF levels were significantly high in patients with ovarian cancer (1425.3 +/- 1007.1 U/ml; p < 0.001) and in 29 of the 43 patients exceeded the limit of 1056 U/ml. No differences were observed among the histologic types. There were no significant differences between patients with benign ovarian pathology and healthy women. No definite relationship was found with CA 125, but evaluating at the same time M-CSF and CA 125 positive results were found in 95.3% of cases. CONCLUSIONS: Therefore M-CSF can be considered a marker for ovarian cancer, and the assay of its serum levels can be particularly useful in association with those of CA 125.

Adenocarcinoma↗
PubMedDate not supplied

[Obstetric conduct in IUGR].

Purpose of the study is to identify the correct attitude that the obstetrician must engage in the management of pregnancy and birth in case of IUGR. Different methods of diagnosis and therapy of IUGR and the formalities of assistance to the birth have been examined and compared. Accurate clinical examinations of the mother, the study of fetal kariotype and ultrasonography, are essential for the diagnosis of IUGR. The genetic study could be performed by collecting chorionic villi, amniocentesis, cordocentesis or placenta biopsy. Ultrasonography identifies the cases of IUGR, and distinguishes early IUGR from late IUGR. Color Doppler identifies the pathology of the flow in the umbilical artery, in the abdominal aorta and in the middle cerebral artery. After the 26th week, the follow-up of the fetus with IUGR is done with cardiotocography with or without acoustic stimulation or oxytocin. The amelioration of maternal conditions is obtained by avoiding the cigarette smoking, preferring to rest in bed and a balanced feeding; the hyperoxygenation doesn't find unanimous consent. The treatment off IUGR can consist of abdominal decompression, intra-abdominal infusion of amniotic liquid, or use of aspirin. The birth is carried out in the hospital, when the fetus has reached a sufficient maturity. The management of IUGR requires an accurate follow-up and an adequate antepartum therapy. The goal is a birth with less risk.

Counseling↗