Biomedical subjects
Publications and source records attributed to L Conti.
A female patient with Down syndrome due to unbalanced Robertsonian translocation (14;21) is reported. A different Robertsonian translocation involving a chromosome no. 14 was observed in her father, who was a carrier of a balanced Robertsonian t(13;14), while the maternal karyotype was normal. Hypotheses about the origin of the translocation in the daughter are discussed.
We measured platelet 3H-imipramine binding parameters in 16 subjects affected by different types of mental deficiency, all characterized by hyperactive and/or aggressive behaviour, and in 16 healthy controls. The patients had a lower maximum binding capacity than the controls, with no difference in Kd, irrespectively of the type of mental disorder. These findings suggest a link between 5-HT disturbances, reflected by reduced imipramine binding sites, and behavioural dyscontrol, expressed as hyperactivity and aggression.
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The vinyl chloride metabolite chloroacetaldehyde (CAA) was tested for the induction of mitotic chromosome malsegregation in Aspergillus nidulans. Exposure of germinating conidia to CAA (16-64 microM) produced high rates of abnormal colonies with segregation of the whole first chromosome in the diploid strain P1, and abnormal, putative hyperploids in the haploid strain 35, indicating that CAA primarily induces abnormal chromosome segregation. Comparative assays with the known spindle poison chloral hydrate (CH), active in the dose range 6-10 mM, highlighted the unusual effectiveness of CAA in aneuploidy induction (the lowest effective concentration was 16 microM). Experiments on brain tubulin polymerization revealed an inhibitory effect by CAA only at concentrations 100-fold higher than those active in the induction of chromosome misdistribution in A. nidulans, possibly suggesting the involvement of alternative targets in its mechanism of action.
A psychotic received neuroleptics and lithium salts for a few days, developing a classic clinical presentation of a neuroleptic malignant syndrome. Treatment in our ICU was started with dantrolene sodium and bromocriptine p.o., associated with artificial cooling of the body and cardiac, respiratory and metabolic measures. In this way we were able to normalize the clinical conditions of the patients. The clinical description of this case allows a general review of the literature on this "rare" syndrome, starting from the anaesthesiologist point of view.
Sixty-five commercial samples of natural flavouring substances were screened for mutagenicity in the Salmonella typhimurium strains TA98 and TA100. The results obtained demonstrated a significant mutagenic activity in onion and garlic extracts, both in assays with and without exogenous metabolic activation. The response pattern obtained in tester strains with different genetic backgrounds suggests the involvement of mutagenic flavone(s) in the genotoxic effects observed.
The activity of ethyl alcohol and acetaldehyde on mitotic chromosome segregation and conidial germination in Aspergillus nidulans was studied. Ethanol effectively induced malsegregation in a narrow range of concentrations (4.5-5.5%, v/v) and was inactive at doses which arrested conidial germination (above 6%). The same bell-shaped dose-response curve was shown by the spindle poison chloral hydrate, which was active in the range 6-10 mM. Acetaldehyde displayed a diphasic dose-response curve. Genetic analysis of induced segregants suggests that the disturbance of chromosome segregation is the primary genetic effect at low doses (0.025-0.037%), while at higher doses (above 0.1%), when growth was arrested, chromosome damage was primarily induced. The same pattern of segregants was produced by hydroquinone, a substance which indirectly affects chromosome segregation in A. nidulans. These differences in the genotoxic profiles of ethanol and acetaldehyde suggest that the effect exerted by ethanol on A. nidulans mitosis is not dependent on its conversion into acetaldehyde. In the absence of an effect of ethanol on in vitro polymerization of tubulin (actively inhibited by acetaldehyde at doses above 0.075%), a direct effect of ethanol on cell membranes is hypothesized. Comparison of the inhibition of growth and the effectiveness in aneuploidy induction displayed by ethanol, methanol, n-propanol and n-butanol demonstrates, in fact, a fair correlation with logP, a descriptor of lipophilicity related to the partitioning of compounds in biological membranes.
1. Glycosaminoglycan polysulfate is a mixture of sulfo-muco-polysaccharides with hypolipidemic activity. A number of clinical studies have indicated that it is effective in improving psychopathology in patients with cardiac and/or cerebral disease associated with arteriosclerosis. 2. A multicenter clinical trial was performed to compare the effects of two different dosages of glycosaminoglycan polysulfate upon depressive symptomatology in patients with multi-infarct dementia and primary degenerative dementia. 3. A total of 39 patients were treated in an 18-week clinical trial which followed a single-blind parallel design. 4. Results indicated that patients with both diagnoses improved significantly in depressive symptomatology over the course of treatment, with particular improvement noted in cognitive disturbance. Drug dosage was not a significant determinant of treatment response for either diagnostic group.
A family with inv8(p23q22), in which one girl with a derivative chromosome 8 showed the characteristic phenotype, is reported. Our case differs from the 32 known families with inv8(p23q22), being the first of apparently non-Hispanic descent. The anomaly may, however, have its origins in the Spanish domination of Sicily.
The 3H-imipramine binding parameters (Bmax and Kd) were studied in platelets from female suicide attempters and from healthy volunteers. The Bmax was significantly lower among suicide attempters, with no modification of the Kd. These results provide support of the hypothesis that decreased serotonin function may play a role in suicidal behavior.
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Three chloromethanes (dichloromethane, chloroform and carbon tetrachloride) and 8 chlorinated ethanes (1,1- and 1,2-dichloroethane, 1,1,1- and 1,1,2-trichloroethane, 1,1,1,2- and 1,1,2,2-tetrachloroethane, pentachloroethane and hexachloroethane) were assayed in tests for the induction of mitotic segregation in Aspergillus nidulans diploid strain P1. Eight of the 11 compounds assayed (dichloromethane, chloroform, carbon tetrachloride, 1,1- and 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1,2- and 1,1,2,2-tetrachloroethane) significantly increased the frequency of morphologically abnormal colonies which produced euploid whole-chromosome segregants (haploids and non-disjunctional diploids). Only in one case (1,1,1,2-tetrachloroethane) was a borderline increase in crossing-over frequency observed, thus suggesting the involvement of non-DNA targets in aneuploidy induction by these chlorinated hydrocarbons. Conclusive evidence for the induction of aneuploidy as the primary genetic event was provided by experiments in haploid strain 35 with 1,2-dichloroethane and 1,1,1,2-tetrachloroethane. Mutagenic, lethal and growth-arresting activities were quantitatively estimated and compared to a series of descriptors of physical and chemical properties of the molecules by means of multivariate statistical analysis. Lipophilicity, known to be related to c-mitotic activity, did not show any significant relationship with aneuploidizing activity, whereas a possible correlation among physico-chemical descriptors and toxic properties of test chemicals was highlighted.
The contribution of nitro compounds to airborne particulate mutagenicity was studied with Salmonella typhimurium strains TA98, TA98NR, TA98/1,8DNP6. The results obtained indicate that nitropyrenes play a minor role in air particulate mutagenicity. Seasonal variations indicate a relatively greater contribution of nitro compounds to the mutagenicity of spring and summer samples. Fractionation of extracts into acidic, neutral and basic components shows that neutral compounds account for about two-thirds of the total mutagenic activity. Attempts to extract mutagens adsorbed onto particulate matter with aqueous media were almost completely negative. No significant mutagenicity was detected in urine and faecal extracts and in plasma samples of Sprague-Dawley rats treated with air particulate extracts at 80 mg/kg either per os or by i.p. injection. Negative results were obtained in the micronucleus test with Swiss mice treated at 200 and 400 mg/kg (twice by i.p. injection). A significant decrease in liver aminopyrine-N-demethylase was observed in Swiss mice injected with air particulate extracts or its basic and neutral fractions. In vitro experiments suggest a direct interaction of test materials with microsomal cytochrome P-450.
Leucinostatins A, B, C, D, E, G, H, and K were thoroughly investigated for their genotoxic activity using the modul Aspergillus nidulans as the test organism. The results of assays for gene mutation (8-azaguanine resistance and methionine suppressors), gene conversion, mitotic crossing-over and mitotic aneuploidy induction suggest that these peptide antibiotics lack significant mutagenicity and that non-genotoxic mechanism(s) underlie their cytotoxic properties.
Antiglobulin Test (AT), and Dixon Tests (DT) have been studied in 100 patients with CLL. Thirty-five patients were Rai stage 0 and I, 19 patients stage 2, 13 patients stage 3 and 33 patients stage 4. Twelve patients showed a Red Blood Cells Autoantibodies (RBCAb) positivity; a positivity (direct, indirect, or both) of DT was present in 74% of patients. The presence of autoantibodies against erythrocytes and platelets did not influence survival curves, but anemia and thrombocytopenia are risk factors for survival, independently of the presence of an autoimmune disorder. Nine patients RBCAb positive and DT positive showed the worst survival curve, five out of these were anemic and one thrombocytopenic and anemic.
A case of trisomy 9p syndrome is reported. The karyotype showed a tandem duplication of the short arm and of the inverted heterochromatic block of chromosome 9. Unequal sister chromatid exchange seems to be the only possible cause of this finding.
10 "false negative" chemical carcinogens, i.e. ineffective in bacterial mutagenicity assays, were thoroughly investigated for their genotoxic activity in the mould Aspergillus nidulans. Forward mutations (methionine suppressors), mitotic crossing-over and chromosome malsegregation were the end-points scored. Positive results were obtained in tests for the induction of mitotic segregation with benzene, ethylenethiourea and urethane, which increased the frequency of abnormal presumptive aneuploid colonies with euploid sectors showing whole chromosome segregation (i.e. non-disjunctional diploids and haploids). The same compounds were ineffective in increasing the frequency of mitotic crossing-over or forward mutations. The other chemical carcinogens investigated, namely acetamide, amitrole, dieldrin, heptachlor epoxide, nitrilotriacetic acid, p,p'-DDT and thiourea were ineffective both as inducers of forward mutations and mitotic segregation.