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Biomedical subjects

M Ciaccio

Publications and source records attributed to M Ciaccio.

35 records · Page 2Linked to original sources
PubMed1989

DNA sequence and pattern of expression of the sea urchin (Paracentrotus lividus) alpha-tubulin genes.

To study the molecular aspects of the regulation of transcription of a multigene family, we have isolated and sequenced cDNA and genomic clones coding for the alpha-tubulin of the sea urchin Paracentrotus lividus. Two cDNA clones, P alpha 10 and P alpha 4, contain respectively the coding information for 391 C-terminal and for 338 N-terminal amino acids of the 452 residues that constitute the complete protein. They show silent nucleotide substitutions only, suggesting that P alpha 10 and P alpha 4 represent the cloned copies of two allelic gene transcripts, which encode for two alpha-tubulin isoforms with identical amino acid sequence in the region of the overlap. The comparison of the predicted amino acid sequence of the composite P alpha 4-10 and of the mouse M alpha-6 (Villasante et al., Mol Cell Biol 1986; 6:2409-2419) reveals a conservation of 97% between the two polypeptides. By RNA blotting hybridization six major alpha-tubulin transcripts were identified. Two, of 3.5 kb and 2.0 kb, are expressed in the unfertilized eggs and during early cleavage. The other two maternal mRNAs, of 2.4 kb and 1.8 kb, are expressed in both early and late cleavage embryos, but in the intestine the 1.8 kb RNA, which specifically reacted with the 3' specific probe of the P alpha 10 cDNA, is the only transcript detected. Finally, the 1.5 kb and 1.9 kb mRNAs represent the transcription of stage- and tissue-specific genes, respectively. In fact, the former becomes detectable at blastula stage and accumulates during late development, whereas the latter is found in the testis only. The sequence data of the 3' terminus of the alpha-3 genomic clone suggests that it encodes for a divergent alpha-tubulin, and it most probably corresponds to the testis-specific gene.

Amino Acid Sequence↗
PubMed1989

Myasthenia gravis and lupus erythematosus.

Two patients are described in whom myasthenia gravis was associated with systemic lupus erythematosus. The review of the literature shows that such association is not frequent and that it affects mostly women (6 women:1 man), and that myasthenia gravis usually precedes lupus erythematosus. Thymectomy was a precipitating factor in 25% of the cases. Most of those patients present with general symptoms rather than with dermatologic signs.

Adult↗
PubMed1989

Skin necrosis due to intravenous heparin.

A patient on intravenous heparin is described who developed an acute hemorrhagic necrosis of her legs. Thrombi without vasculitis were seen in the dermal blood vessels. This appears to be the 4th reported case of skin necrosis after intravenous heparin at sites unrelated to injections. Skin necrosis after intravenous heparin should warn the dermatologist of a possible fatal outcome from myocardial or cerebral infarction.

Aged↗
PubMed1989

Decrease of serum sex hormone-binding globulin as a marker of androgen sensitivity. Correlation with clinical response.

An evaluation of the usefulness of determining the decrease in serum sex hormone-binding globulin after exogenous testosterone was studied in 55 prepubertal patients with ambiguous external genitalia or micropenis. The biochemical response (androgen sensitivity test) was compared with the clinical response as judged by signs of androgen stimulation of external genitalia. Patients were divided in two groups according to age. Group I, 11 patients younger than 3 months and Group II, 44 patients older than 3 months. Only in 54% of Group I was there a correlation between the androgen sensitivity test and the clinical response to androgens in either a positive (4 patients) or negative sense (2 patients). On the other hand, the androgen sensitivity test and the clinical response to androgens correlated in 91% of the patients of Group II in either a positive (35 patients) or negative sense (5 patients). Two of the 4 patients with lacking correlation had a negative androgen sensitivity test and micropenis secondary to pituitary deficiency. It is concluded that in prepubertal patients older than 3 months with abnormalities of sex differentiation, the androgen sensitivity test and the clinical response to androgens are useful for evaluating androgen sensitivity. The clinical response to androgens is useful in early life when a positive response is found.

Chorionic Gonadotropin↗
PubMed1988

Epidermal antigens in pemphigus vegetans. Report of a case.

A patient is described who had typical pemphigus vegetans, according to clinical, histopathological and immunofluorescence criteria. To determine the specific molecules bound by antibodies in the serum of this patient, an immunoprecipitation analysis was performed with extracts of [14C]-amino acid labelled cultured normal human keratinocytes. The patient's serum precipitated the 130 kd and 85 kd polypeptides of the pemphigus vulgaris antigen, but also precipitated other polypeptides, the significance of which is not clear.

Antibody Specificity↗
PubMed1987

Soluble and nuclear oestrogen receptor status of advanced endometrial cancer in relation to subsequent clinical prognosis.

Both soluble and nuclear oestrogen receptors have been measured in at least two separate sections from 72 endometrial cancers and 12 normal endometria. Concentration of oestrogen receptor is shown to be, in our hands, more meaningful when expressed per unit DNA than per unit protein, whether for soluble or nuclear receptor. Endometrial cancer cells from the central part of the tumour are shown to be receptor negative more frequently than those from peripheral tumour. Thus, in large cancers, biopsies from different areas are required before a tumour can be correctly designated as receptor positive, heterogeneous or receptor negative. The intratumoral variation of receptor status may relate to poor prognosis, since patients with homogeneous receptor-positive disease survive significantly longer than those with tumours showing either heterogeneous distribution of receptor or homogeneous absence of receptor. Intratumoral variation in receptor status is found to be more common in the group of patients who are within 7 years of their menopause, than in older patients.

Adult↗
PubMed1985

Modulation of oestrogen excretion profiles by adjuvant chemotherapy in pre- and postmenopausal breast cancer.

Modulation of steroid status by conventional chemotherapy was studied in 31 breast cancer patients receiving CMF and in 31 age-matched breast cancer patients without any therapy, taken as controls. This was achieved through the study of oestrogen excretion profiles using previously identified parameters and referring not only to classical but also to the "other", namely catechol and unusual, oestrogen metabolites. After CMF treatment the premenopausal patients exhibit a modified excretion pattern, mainly concerning a marked and significant reduction of classical oestrogens, as shown by pattern indices. Because there is evidence that oestriol metabolism is not markedly affected by CMF treatment, such a significant decrease in classical oestrogens must be attributed to the secretory function, presumably ovarian ab origine. To the contrary, after treatment, pattern indices show significantly higher median values in postmenopausal patients. Mean oestriol ratio values also display a significant increase, thus supporting the hypothesis that conventional cytotoxic drugs may act by enhancing oestrogen metabolic rates. In fact, the postmenopausal treated subgroup proved to have significantly higher excretion levels of most of the oestrogens considered to date. Surprisingly, E1 + E1-S fractions were strongly reduced in this subgroup and this leads to the suggestion of an increased steroid metabolic rate by CMF treatment. However, comparing 9 breast cancer patients, when having had both short-term and non-short-term CMF treatment, the effects on steroid excretion patterns appear to arise at an early stage.

Adrenal Cortex↗
PubMed1982

Chromatin structure of histone genes in sea urchin sperms and embryos.

The nucleosomal organization of active and repressed alpha subtype histone genes has been investigated by micrococcal nuclease digestion of P. lividus sperm, 32-64 cell embryo and mesenchyme blastula nuclei, followed by hybridization with 32P-labeled specific DNA probes. In sperms, fully repressed histone genes are regularly folded in nucleosomes, and exhibit a greater resistance to micrococcal nuclease cleavage than bulk chromatin. In contrast, both coding and spacer alpha subtype histone DNA sequences acquire an altered conformation in nuclei from early cleavage stage embryos, i.e., when these genes are maximally expressed. Switching off of the alpha subtype histone genes, in mesenchyme blastulae, restores the typical nucleosomal organization on this chromatin region. As probed by hybridization to D.melanogaster actin cDNA, actin genes retain a regular nucleosomal structure in all the investigated stages.

Animals↗
PubMed1982

Transcription of sea-urchin mesenchyme blastula histone genes after heat shock.

Mesenchyme blastula sea-urchin embryos were heat-shocked at 31 degrees C and pulse-labelled with [3H]uridine. The nuclear RNA was fractionated on glyoxal/agarose gels and each RNA fraction hybridized with cloned early blastula histone DNA. The results showed that after heat shock there is an accumulation of histone RNA molecules larger than the messenger and a decrease, with respect to the control, of 9-S histone RNA. Chasing of the heat shock RNA by incubation of the embryos with unlabelled uridine and cytidine restores the radioactivity, as well as the hybridization profiles, of control embryos. Furthermore saturation curves obtained by hybridizing histone DNA with labelled 9-S RNA, showed an absence of the histone messenger in the cytoplasm of heat-shocked embryos, whereas it is present in both control and chased embryos. These results are consistent with the hypothesis that the accumulated histone RNA in heat-shocked embryos is the precursor of mature messengers.

Animals↗
PubMedDate not supplied

Correlation between the effects of retinoic acid and dexamethasone on liver tyrosine aminotransferase.

A single dose of 50 microg of trans-retinoic acid administered to rats significantly raised the level of hepatic tyrosine after a few hours. This effect was compared with that of dexamethasone and a possible correlation between these effectors was also investigated. An equal increase in enzyme activity level caused by retinoic acid was observed in adrenalectomized rats, leading to the suggestion that the effect of retinoic acid on liver tyrosine aminotransferase is independent of glucocorticoids. However, the study of the binding activity of the liver nuclear glucocorticoid receptors vs dexamethasone showed that this activity is favoured by retinoic acid, whereas no variation was evidenced for retinoic acid receptors caused by dexamethasone. In the adrenalectomized rat, the synergistic effect produced by the association of retinoic acid and dexamethasone at the lowest doses used led us to conclude that retinoic acid is an efficient effector of liver tyrosine aminotransferase. It probably affects tyrosine aminotransferase activity in a dependent and an independent way, regulated respectively by the glucorticoid status and by the provision of retinoic acid.

Adrenalectomy↗