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Biomedical subjects

D Castelli

Publications and source records attributed to D Castelli.

At least 37 records · Page 2Linked to original sources
PubMed1986

Ovarian function during aflatoxin B1-induced hepatocarcinogenesis in the rat.

Study of the endocrine status, which is often disturbed during hepatocarcinogenesis, is particularly valuable because gonadal function and hormone production regulate hepatic metabolism of the carcinogen. Sex steroids can even promote carcinogenesis. After aflatoxin B1 induction of liver carcinogenesis in adult female Sprague Dawley rats, livers were examined by histology, fluorescence microscopy of the carcinogen and its metabolites, and alphafetoprotein (AFP) assays. Ovarian activity was assessed, and both progesterone and estradiol levels were determined. Administration of a diet containing 10.32% total protein plus 2 ppm aflatoxin B1 was observed to prevent development of liver tumors during the 300 day study period. This finding is especially interesting for the study of populations suffering from malnutrition and exposed to dietary carcinogens. Under study conditions, aflatoxin B1 did not cause elevation of AFP levels, as occurs with other hepatotoxic substances. This absence of a rise in AFP despite liver alterations explains the surprising lack of ovarian modifications. In other experiments, AFP has been shown to cause genital function blockade which leads to reduced levels of hormonal promoters, for example during N2 fluorenylacetamide carcinogenesis. The endocrine reaction implicated in the development of tumors during carcinogenesis thus appears closely related to the nature of the carcinogen, AFP production, and the composition of the diet.

2-Acetylaminofluorene↗
PubMed1985

Quality control in antiepileptic drug monitoring in Italy.

Measurement of drug concentrations in physiological fluids is increasingly becoming part of the routine management of drug therapy, thus calling for particular care to ensure reliability and avoid misguided management. As part of a long-term national project to set up a network of hospitals where clinical chemists, pharmacists, and physicians could interact and evaluate their activities in connection with therapeutic drug monitoring, the results of a quality control scheme for antiepileptic drugs, which included 50 national hospital laboratories, are described here.

Anticonvulsants↗
PubMed1984

[Alpha-fetoprotein and blockade of the sexual cycle].

During chemical hepatocarcinogenesis by N-2 fluorenylacetamide in adult female Rats, vaginal cycle alterations were observed after 30 days of carcinogenic diet, and a blocking at the metestrus stage appeared from the 70th day. This may be explained by the very low serum progesterone level prevailing after the 50th day. An important drop in ovary weight was also noticed; together with the blocking of follicular maturation and ovulation leading to a marked follicular atresia. Simultaneously, alpha-fetoprotein (AFP) seems to interact in the lowering of progesterone level, and AFP was found ten times higher in the serum of treated animals than in controls. AFP was localized in degenerative oocyte cytoplasm by immunofluorescence in the treated animals, but not in the controls. In conclusion, a blocking role of AFP on genital cycles and a relationship between AFP and follicular atresia are suggested.

2-Acetylaminofluorene↗
PubMed1982

Immunolocalization of alpha-fetoprotein in the ovary and hypophysis of immature female rats.

Alpha-fetoprotein (AFP), an oestrogen-binding protein, has been localized in the ovary and hypophysis of prepuberal rats. In the ovary, AFP was localized in secondary follicles, its distribution being limited to the liquor folliculi and the zona pellucida. In the hypophysis, AFP was only found in blood vessels. The intra-ovarian localization of the protein is consistent with our previous hypothesis that AFP might act as a regulator of ovarian activity by decreasing the local free oestradiol level.

Animals↗
PubMed1982

Role of alpha-fetoprotein (AFP) in the regulation of ovarian activity during hepatocarcinogenesis and post-natal development.

N-fluorenylacetamide produces an augmentation of serum AFP which is accompanied by a drastic decrease of ovarian activity. A passive augmentation of the AFP level of adult rats, produced by injection of this protein provokes the same phenomenon: i.e. a decrease of follicular maturation, a decrease number of corpora lutea and finally a drop in the plasma progesterone level. The study of ovarian post-natal development shows that ovarian maturity occurs on the 35th day of life when AFP level reaches its adult serum concentration. These facts support the hypothesis that AFP plays a role in the regulation of ovaries during the sexual maturation of the female rat.

Animals↗
PubMed1982

Sex steroid hormones levels and testicular activity during hepatocarcinogenesis by N-2-fluorenylacetamide.

During hepatocarcinogenesis by N-2-fluorenylacetamide, the hormonal status of male Sprague-Dawley rats is modified. The testes present a reduced activity which is evidenced by a decreased spermatogenetic activity accompanied by a drastic decrease of the plasma testosterone level. In contrast, plasma progesterone and estradiol-17 beta levels were not modified despite the 80 fold augmentation of alpha-fetoprotein, an estrogen binding protein synthesized during liver carcinogenesis.

2-Acetylaminofluorene↗
PubMed1982

Thyroid activity during hepatocarcinogenesis by N-2-fluorenylacetamide in the male rat.

During chemical hepatocarcinogenesis by N-2-fluorenylacetamide, the hormonal status of male Sprague Dawley rats is modified. The histological study of the thyroid gland demonstrates a decreased activity evidenced by an augmentation of the follicle size and a reduced size of follicular epithelium. The level of T3 and T4 reflects in part this decreased activity. Comparison with female rats treated in the same conditions shows an opposite effect of N-2-fluorenylacetamide. Indeed in the female, the thyroid gland presented an hyperactive state accompanied by a drastic decrease of serum T3 and T4. This difference in thyroid activity might take an important part in the mechanism responsible for the sex difference in liver cancer induction by N-2-fluorenylacetamide.

2-Acetylaminofluorene↗
PubMed1977

Plasma levels of di-no-propylacetate and clonazepam in epileptic patients.

Plasma levels of DPA and CNP and associated antiepileptic drugs were measured in groups of respectively 106 and 30 epileptic patients aged from 3 to 49 years. A poor correlation between daily oral dose and plasma levels of both drug was observed when the whole group of patients was considered. A better correlation was seen in a group of adult patients who received DPA and PB. Children below 10 years of age disposed both drugs faster than adults and the difference was significant (p less than 0.01) in groups receiving PB as associated drug. Patients medicated with PB and DPA or CNP showed lower plasma levels of both drugs; on the other hand DPA appeared to cause a decrease of PB clearance which was more marked in children. The clinical significance of the fluctuations of daily plasma levels of both drugs are discussed in relationship to the schedule of administration and plasma sampling. Observations on the therapeutic ranges and adverse effect of the drugs are reported.

Adolescent↗