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M Nicotra

Publications and source records attributed to M Nicotra.

At least 37 records · Page 2Linked to original sources
PubMed1996

Phosphotyrosine-protein-phosphatases and human reproduction: an association between low molecular weight acid phosphatase (ACP1) and spontaneous abortion.

ACP1 (low molecular weight acid phosphatase) genetic polymorphism has been studied in 173 women with a history of two or more consecutive spontaneous abortions and in 1508 control subjects, including 482 normal pregnant women. The proportion of carriers of ACP1*C allele (*A/ *C, *B/*C) in women with a history of repeated spontaneous abortion is lower than in normal pregnant women and other control groups. Women with repeated spontaneous abortion show a specific decrease of ACP1 S isoform concentration as compared to normal pregnant women. The other component of ACP1 activity, the F isoform, does not show a significant difference between the two groups. The data suggest that women with ACP1 genotypes showing a high concentration of S isoform are relatively 'protected' against spontaneous abortion. Preliminary analysis of a sample of 352 normal puerperae along with their newborn babies supports this hypothesis.

Abortion, Habitual↗
PubMed1995

A conformationally homogeneous combinatorial peptide library.

In search for a rational way to convert the information encoded in peptide structures into peptidomimetics, major progress could be made by coupling the power of selection methods, now enormously increased in number as a result of the development of combinatorial peptide libraries, with the rational design of structure-inducing templates for the selectable sequences. The availability of libraries of peptides with predetermined structure would enable selection-driven peptidomimetic design, whereby a conformational model for the peptide pharmacophore would be directly derived from the screening, allowing the design of a suitable non-peptidic scaffold to replace the peptide backbone. We describe here the first example of a conformationally homogeneous combinatorial peptide library, which yields ligands with the expected structure upon selection. The library was built by randomising five positions in the alpha-helical portion of a 26 amino acid Cys2His2 consensus "zinc-finger" motif. Since in zinc-fingers metal coordination and folding are coupled, in our library metal-dependent binding represents a built-in control against the selection of structurally undefined sequences. The alpha-helical library was produced as both fusion with the pVIII protein of filamentous phage and soluble peptides by chemical synthesis, the latter enabling the expansion of the selectable repertoire by the inclusion of non-coded amino acids. The two libraries were independently screened with the same receptor (a monoclonal IgA reactive against the lipopolysaccharide of the human pathogen Shigella flexneri), yielding a very similar consensus. In particular, the peptides defined by both methods showed very strong, zinc-dependent binding to the IgA. The geometrical arrangement of the side-chains of the selected peptide pharmacophore was shown by circular dichroism, Co(II)-complex absorption and high-resolution NMR to be structurally invariant with respect to the parent zinc-finger.

Amino Acid Sequence↗
PubMed1995

Interaction between ABO blood groups and ADA genetic polymorphism during intrauterine life. A comparative analysis of couples with habitual abortion and normal puerperae delivering a live-born infant.

A total of 203 couples with unexplained habitual abortions and 364 consecutive normal puerperae along with their live-born babies were studied. The analysis of wife-husband joint ABO blood group distribution in couples with habitual abortion showed an excess of A incompatible mating type and a defect of B incompatible type as compared with expected proportions assuming random mating. The joint wife-husband ABO blood group distribution was further analysed in relation to the adenosine deaminase (ADA) genotype. A defect of O-A and A-O couples when the wife carries the ADA*1/*1 genotype and the husband carries the ADA*2 allele, and a defect of O-O and A-A when the wife carries the ADA*2 allele were observed. In the sample of normal puerperae, analysis of the joint mother-newborn ABO distribution in relation to the ADA genotype showed a pattern similar to that observed in couples with habitual abortion, i.e. there is a defect of O-A and A-O when the mother carries the ADA*1/*1 genotype and the newborn carries the ADA*2 allele and a defect of O-O and A-A types when the mother carries the ADA*2 allele. Altogether the data suggest an early loss of O-A and A-O zygotes when they carry the ADA*2 allele and an early loss of O-O and A-A zygotes when the mother carries the ADA*2 allele resulting in a deficit of these zygotic classes among both spontaneously aborted fetuses and live-born infants. The pattern of association observed in the mother-fetus type O-A (incompatible according to conventional terminology) appears similar to that observed for the reciprocal A-O type (compatible according to conventional terminology). Therefore strictly conventional immunological mechanisms cannot explain the whole pattern of associations. Cell to cell intereactions involving ABO antigens may have an important role at implantation: ADA, through the control of local adenosine concentration, could modulate these interactions influencing the probability of successful implantation.

ABO Blood-Group System↗
PubMed1994

Blood levels of lipids, lipoperoxides, vitamin E and glutathione peroxidase in women with habitual abortion.

Plasma levels of triglycerides, cholesterol, cholesterol esters, phospholipids, lipoperoxides, vitamin E and erythrocyte glutathione peroxidase activity showed no significant differences between 40 women with habitual abortion and controls. However, the levels of free fatty acids (FFA), which are extremely cytotoxic compounds, were significantly higher in women with habitual abortion (HA) than in controls (16.8 +/- 6.7 vs. 8.6 +/- 3.7 mg/100 ml, p < 0.01, respectively). The high amounts of FFA in HA women during pregnancy were probably due to a continuous and/or excessive stress-dependent discharge into the blood of catecholamines from autonomic nerve endings. These catecholamines can induce a strong uterine vasoconstriction and placental ischemia-hypoxia which, in association with additional insults caused by reoxygenation, might lead to eventual miscarriage.

Abortion, Habitual↗
PubMed1993

Chromosome heteromorphisms and early recurrent abortions.

In order to identify the role played by heterochromatic polymorphisms in miscarriage, an analysis was carried out on 257 couples, 137 of them with two or more abortions and 120 serving as a control. All couples were taken from two Italian populations: 77 cases and 70 controls came from an exogamic population whilst 60 cases and 50 controls came from an almost endogamic one. Out of the 137 cases, six couples in the exogamic and five in the endogamic groups were excluded because at least one partner had balanced chromosomal aberrations. Four controls from the exogamic group were also excluded for the same reason. The remaining 126 cases were analysed to detect the presence of chromosomal heteromorphism in one or both partners. The results suggested that chromosomal heteromorphism does not induce miscarriage. In fact, only one heteromorphism, inv(9)(p11q12), seems to be marginally related to recurrent abortion and only in the exogamic population. In addition no differences were found in the distribution of chromosomal heteromorphism in the couples analysed in relation to the number of abortions, i.e. two or more than two.

Abortion, Habitual↗
PubMed1992

Treatment of malignant mesothelioma with epirubicin and ifosfamide: a phase II cooperative study.

From May 1988 to March 1990, 17 consecutive patients with histologically proven malignant mesothelioma were treated with epirubicin 75 mg/sqm i.v. on day 1 and ifosfamide 1.8 gr/sqm/day i.v. from day 1-5. Treatment was repeated every 3 weeks until progression. Fifty-three chemotherapy cycles were administered to the 17 patients treated (median, 3 cycles/patient). No complete responses, 1 partial response, 8 stable diseases and 8 progressions were noted. Toxocity was acceptable and no treatment-related deaths occurred. Actuarial median survival was 6 months. In this study, a combination of full doses of epirubicin and ifosfamide did not prove to be active in malignant mesothelioma.

Adult↗
PubMed1991

Epirubicin in the treatment of malignant mesothelioma: a phase II cooperative study. The North-Eastern Italian Oncology Group (GOCCNE)--Mesothelioma Committee.

From September 1986 to April 1988, all consecutive patients with histologically proven (pathologic review mandatory) malignant mesothelioma, measurable disease, age less than 75 years, Karnofsky performance status equal to or greater than 40, and no previous chemotherapy were treated with epirubicin at the dosage of 75 mg/m2 i.v. every 3 weeks. Of the 23 patients who entered the study, 2 were retrospectively found not to have malignant mesothelioma. In the 21 eligible patients (all evaluable), no complete remission, 1 partial remission, 11 stable diseases and 9 progressions were noted. Toxicity was very mild. Median survival was 7.5 months. At the dosage used, epirubicin proved to be of little value in the management of these patients. Whether higher doses are more effective, as has been noted in other tumors, remains to be ascertained.

Aged↗
PubMed1991

HLA-DR and DQ antigens and anticardiolipin antibodies in women with recurrent spontaneous abortions.

IgG anticardiolipin antibodies (ACL) have been shown to occur in a high proportion of women with repeated unexplained miscarriages. Forty-nine women with unexplained recurrent spontaneous abortions (RSA), previously assayed for the presence of ACL by an enzyme-linked immunoabsorbent assay, were typed for HLA-DR and DQ antigens by the classical microlymphocytotoxicity test. Twenty-five women were positive for ACL and 24 were negative. HLA-DR7 was found in 24.5% of 49 habitually aborting women vs. 28% of healthy controls; but the DR7 frequency was 40% in ACL positive patients vs. 8.3% in ACL negative patients (P = 0.011). These results show that in the Italian population an association between HLA-DR7 antigen and ACL is present in women with unexplained RSA, suggesting that HLA-DR genes might control the susceptibility to specific autoantibody production.

Abortion, Habitual↗
PubMed1983

Intrauterine death: an approach to the analysis of genetic heterogeneity.

A study of survival time of zygotes in utero and the relationship with parental phenotype of a series of genetic polymorphisms was carried out in 41 couples with habitual abortion. Variability of intrauterine survival time was found to be much higher between families than within families suggesting that several genetic entities contribute to the condition clinically defined as habitual abortion. Significant differences of survival time were found in relation to the length of the paternal Y chromosome and to the maternal phenotypes of PGM1 and Ss. These observations are in line with previous data suggesting intrauterine selection in these polymorphisms. Further studies of the timing of intrauterine death in relation to 'normal' genetic polymorphisms may help to clarify the aetiology of spontaneous fetal loss.

Abortion, Habitual↗
PubMed1982

Genetic polymorphisms and human reproduction: a study of phosphoglucomutase in spontaneous abortion.

Theoretical arguments suggest that variation of metabolic parameters due to genetically determined enzyme polymorphisms may exert important effects on implantation and zygote development. The polymorphic enzyme phosphoglucomutase controlled by locus 1 (PGM1) is a phosphotransferase which plays a key role in carbohydrate metabolism and it is present in high concentrations in placental tissue. The enzyme has been studied in 47 couples with habitual abortion, in 36 women with single episodes of spontaneous abortion, in 48 women with induced abortion, and in control samples of normal individuals from the same population. Among couples with habitual abortion a significant increase of mean survival time of fetuses was observed in PGM1-heterozygote mothers as compared to homozygotes. An increased proportion of couples which may produce the hypothetical PGM1-null phenotype was also observed in habitual abortion, which suggests that homozygosity for PGM10 allele may contribute to fetal loss. Investigations on polymorphic enzymes involved in placental and fetal metabolism may contribute significantly to the problem of genetic etiology of spontaneous abortion.

Abortion, Habitual↗
PubMed1981

Adenosine deaminase polymorphism. Associations at clinical level suggest a role in cell functions and immune reactions.

It is well known that subjects homozygous for a rare silent allele of ADA may experience a severe combined immunodeficiency. By analogy we have investigated the possible relationship of normal ADA polymorphism with some situations, such as reproductive defects and fetomaternal interactions, in which immunological mechanisms may play an important role. A total of 572 consecutive newborns, 93 consecutive low birthweight infants, 46 couples with unexplained habitual abortion, and 24 couples with unexplained sterility were studied. The proportion of ADA 2-1 phenotype was reduced in couples with reproductive defects. In the sample of consecutive newborns the proportion of ABO incompatible babies was higher among ADA 2-1 than among ADA 1 types. ADA 2-1 phenotype was also associated with a reduction in the variability of gestational length. These associations were much more marked among male than among female babies. The proportion of ADA 2-1 was significantly lower in low birthweight infants than in the consecutively studied infants and normal adults. The present data suggest that biochemical variability resulting from the normal ADA polymorphism may be, at least in part, responsible for the variability of some immunological functions and related physiological variables and pathological conditions. They also provide evidence in favour of a selective advantage of ADA heterozygotes.

ABO Blood-Group System↗
PubMed1980

Blood groups and histocompatibility antigens in habitual abortion.

Forty-six couples with at least two consecutive abortions were examined. The morphological and the functional clinical check-ups were constantly negative. In all the couples a karyotype analysis was carried out including an investigation of C and/or G bands. The phenotypes of ABO, Rh, MNSs and HLA-systems were also determined. No significant difference was observed in the distribution of ABO phenotypes between males and females, or between subjects with abortions and controls. Regarding the Rh system, the most important findings are the absence of phenotypes with the E allele in double dose, the reduction of the frequency of the CCDee phenotype and the increase in the frequency of the ccDEe phenotype. Concerning MNSs system, an increase in the frequency of the phenotypes with the S allele in double dose is observed. Females with habitual abortions show a higher incidence of Bw35 as compared both to males and to the controls. No significant differences were observed for other antigens. The persistence of a genetic disequilibrium both in the Rh and the MNSs systems suggests that the selection might act against certain antigenic combinations, independently from the state of materno-foetal compatibility. Though preliminary, our data seem to give some support to this hypothesis. They also suggest that Bw35 antigen may be important in human reproduction.

Abortion, Habitual↗
PubMedDate not supplied

Phosphoglucomutase genetic polymorphism of newborns.

An association of the phosphoglucomutase locus 1 (PGM1) genetic polymorphism with repeated spontaneous abortion (RSA), with intrauterine development in both normal and diabetic pregnancies, and with fertility has been reported in previous studies. In view of the evolutionary interest and of a possible clinical relevance of PGM1 selection during intrauterine life, this study considers healthy puerperae, consecutive newborns, and couples with RSA as well as two alleles (PGM1*1 and PGM1*2). The joint maternal-neonatal PGM1 distribution in a sample from an Italian rural population is significantly different from that expected assuming Hardy-Weinberg conditions for equilibrium. Deviation is dependent on maternal age and parity. The joint mother-newborn PGM1 genotype distribution is significantly associated with a positive history of previous spontaneous miscarriage, suggesting that the presence of the PGM1*2 allele in the father predisposes to spontaneous abortion. This hypothesis is also supported by the observation that in couples with RSA, the delivery of a live born infant within 5 years from the first episode of miscarriage is negatively associated with the presence of a PGM1*2 allele in the husband. Altogether these observations suggest the hypothesis of PGM1 maternal selection at the reproductive level involving a differential role of PGM1*1 and PGM1*2 alleles of paternal origin.

Abortion, Habitual↗