Biomedical subjects
Publications and source records attributed to A Sessa.
Fourteen Italian patients affected with X-linked Alport syndrome were analyzed by Southern blotting, using cDNA probes of the COL4A5 gene. One proband was shown to carry a large deletion (greater than 38 kb) that included the 5' part of the gene.
Chronic ethanol feeding as 12% or 36% of total calories caused a dose-dependent diminution of diamine oxidase activity in rat liver. Hepatic cadaverine and histamine levels were unmodified by ethanol, whereas putrescine increased, partially in relation to the decrease in diamine oxidase activity. Such results may be of interest in view of an aggravation of ethanol-induced hepatic damage when exogenous diamines and polyamines reach the liver in potentially toxic amounts.
Cells from the cysts of patients with autosomal dominant polycystic kidney disease (PKD) were grown in vitro under standard conditions without the aid of collagen-pretreated surfaces, and both the synthesis and composition of the extracellular matrix were investigated. At confluence, PKD cells presented the typical features of epithelial cells, but showed a different collagen composition from fibroblasts. Compared with normal tubular epithelia (NTE), PKD monolayers produced an excess of extracellular matrix, which accounted for 30% of the total incorporation of [3H] proline, although this value was considerably lower (by a factor of 10) in the case of NTE. Immunohistochemical and electrophoretic techniques revealed a complex collagen composition in the extracellular matrix which included [alpha (III)]3 and collagen IV. However, part of the collagen components remained unidentified in spite of the fact that they exhibited a typical M(r) of alpha 1(I) and alpha 2(I) in the presence of urea. Immunoprecipitation with monospecific antibodies and Northern blotting with specific probes failed to recognize alpha 1(I) and alpha 2(I), but demonstrated their presence in fibroblasts. Purification and cyanogen bromide digestion demonstrated a strong interhomology in fingerprint peptide composition among the uncharacterized collagens synthesized by PKD cells, thus suggesting a common identity. These observations document a markedly augmented production of extracellular matrix by PKD cultured cells in vitro, and show the presence of collagens which do not share homologies with the major collagen molecules. A better characterization of extracellular matrix composition is central to any comprehension of the cytogenetic mechanisms in vivo.
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The administration of 17 beta-estradiol to ovariectomized rats stimulated in uterus the activity of spermidine N1-acetyltransferase, the rate-limiting enzyme in the polyamine interconversion pathway. Such a stimulation was largely prevented by cycloheximide and actinomycin D, which indicates that it was due to an enzyme induction. During the estrous cycle, uterine enzyme activity was highest at proestrus and lowest at estrus, when estrogen plasma levels are known to be high and low, respectively. The induction of the enzyme was associated with the appearance or an increase in N1-acetylspermidine in uterus. The results suggest that estrogens regulate spermidine N1-acetyltransferase activity in uterus.
Hepatic preneoplastic nodules and hepatomas obtained in a multistep protocol of rat hepatocarcinogenesis (diethylnitrosamine, 2-acetylaminofluorene, and partial hepatectomy) showed high values of spermidine N1-acetyltransferase activity, the rate-limiting enzyme in polyamine interconversion. Such an increase was associated with the appearance of N1-acetylspermidine, an enhancement in putrescine, and a decline in spermine. Such changes suggest an activation of the interconversion pathway of high into lower polyamines in hepatic preneoplastic nodules and hepatomas.
Antiepileptic drug (AED) consumption, expressed according to a standardized measurement of the average daily doses of each active principle (the defined daily dose, DDD), was assessed as a source of morbidity data to calculate the prevalence of AED takers. In a population of 51,220 from three areas in Italy (Arcisate, Treviglio, S. Giovanni Rotondo) all the patients treated with AEDs, traced by the local general practitioners, were examined by a neurologist. The diagnosis of epilepsy was confirmed in 199 of 223 AED takers, giving an overall prevalence rate of 3.94 per 1,000 (Arcisate 3.96; Treviglio 4.04; S. Giovanni Rotondo 3.89). There was a significant overlap between the observed and expected number of AED takers (the latter obtained from regional sales and expressed in DDD). Prevalence rates calculated from drug sales were 5.58 in Arcisate and 6.11 in Treviglio. The ratio of patients with epilepsy to AED takers in the two areas was 0.7 and corresponded to the mean proportion of AEDs prescribed for epilepsy in the years 1983-1988 by a sample of Italian physicians. Although the prevalence rate calculated from AED sales tends to approximate that of treated epilepsy, AEDs can be reasonably used as 'tracers' of disease for the easy access to drug sales in Italy, the appropriateness of the DDD as a standard measure of the daily doses of AED, the steady pattern of consumption, the comparability of data covering different areas and periods, and the stable proportion of drugs delivered for epilepsy.
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ADPKD is the most widespread genetic nephropathy. Only twenty-five per cent of patients are symptomatic. In order to prevent the disease it is important early screening by ultrasonography that shows a typical picture only in adults. Familiar history is determinant for diagnosis in intrauterine age, in newborns and in infants. Ultrasonographic diagnosis is certain only after twenty-five weeks of pregnancy.
Treatment of rats with a complete hepatocarcinogenic regimen (diethylnitrosamine, 2-acetylaminofluorene and partial hepatectomy) produced a prolonged stimulation of diamine oxidase activity in liver, which showed early and persistent preneoplastic nodules. Diethylnitrosamine or partial hepatectomy tested separately caused a transient increase in enzyme activity. Early nodules, which were positive for gamma-glutamyltransferase activity, and hepatomas showed diamine oxidase activity of approximately 5- and 13-fold that of control liver, respectively. These results indicate an activation of terminal catabolism of polyamines in preneoplastic nodules and in hepatomas.
The activity of diamine oxidase, the principal enzyme for diamine catabolism, was evaluated in brain and liver from male rats fed nutritionally complete diets, of which 36% of total calories was given as ethanol or as isocaloric carbohydrates for 4 months. Ethanol caused an increase in diamine oxidase activity in the brain and a decrease in the liver, tissues with a low and high rate of ethanol oxidation, respectively.
Diamine oxidase activity was studied in female rat tissues during the estrous cycle and after 17 beta-estradiol administration. During the estrous cycle, uterine and hepatic enzyme activities were highest at proestrus and lowest at estrus, when estrogen plasma levels are known to be respectively high and low. The administration of 17 beta-estradiol to ovariectomized rats caused a rapid and prolonged increase in enzyme activity in uterus and only a transient increase in the liver. Such increases were prevented by cycloheximide and by actinomycin D administration. No changes were observed in renal enzyme activity during estrus or after hormone treatment. Our data suggest that estrogens regulate diamine oxidase activity in rat uterus by a mechanism of enzyme induction.
Genetic factors could play an important role in the pathogenesis of idiopathic membranous nephropathy, and a few cases of familial membranous nephropathy have been described: an increased incidence of some HLA antigens as DR3 and others has been reported. We present two brothers with idiopathic membranous nephropathy and sensorineural deafness. HLA typing was performed in the two patients and in the members of the family, and it showed the absence of linkage of an HLA antigen with the renal disease in the family.