Epirubicin in the Treatment of Malignant Mesothelioma: A Phase II Cooperative Study

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 epiru-blcin 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.

The relationship between p53 codon 72 genetic polymorphism and sperm parameters. A study of men with varicocele

Purpose

Regulation of the apoptotic process has an important role in spermatogenesis. p53 has a prominent function in apoptosis and recent data suggest a relationship between varicocele and p53 codon 72 polymorphism and male infertility. This prompted us to study the relationship between this polymorphism and spermatic parameters.

Methods

We studied 134 subjects with varicocele admitted consecutively to the outpatients Department of Infertility at the University of Rome La Sapienza. We investigated in these subjects the effect of a strong apoptosis inducer, the p53 codon 72 *Arg/*Arg genotype, on spermatic parameters.The p53 codon 72 genotype was determined by DNA analysis.

Results

The proportion of spermatozoa with abnormal (curvilinear) motility is higher in men with the *Arg/*Arg genotype than in men carrying the *Pro allele (p = 0.003). No statistical significant relationship has been observed with spermatozoa concentration and atypical spermatozoa.

Conclusions

We conclude: the p53 codon 72*Arg/*Arg genotype, with its strong apoptotic effects, negatively influences spermatozoa motility and male fertility.

A Quantitative Structural Investigation of the 0.1 wt % Nb-SrTiO3(001)/H2O Interface

Surface X-ray diffraction has been employed to elucidate the structure of the interface between a well-characterized (001) surface of 0.1 wt % Nb-SrTiO₃ and liquid H₂O. Results are reported for the clean surface, the surface in contact with a drop of liquid water, and the surface after the water droplet has been removed with a flow of nitrogen. The investigation revealed that the clean surface, prepared via annealing in 1 × 10^-2 mbar O₂ partial pressure, is unreconstructed and rough on a short length scale. The surface is covered with large terraces, the topmost layer of which is either TiO₂ or SrO with an area ratio of about 7/3. For the surface in contact with water, our results reveal that associative H₂O adsorption is favored for the TiO₂-terminated terrace whereas adsorption is dissociative for the SrO-terminated terrace, which validates recent first-principles calculations. After removal of the water droplet, the surface largely resembles the water-covered surface but now with a disordered overlayer of water present on the surface.

Fertility transition: forecast for demography

By the end of the 20th century most industrialized nations had undergone the so-called fertility transition, characterized by a reduction in fertility to below replacement level and a delay in age at initiation of child-bearing. An emerging concern is the severe economic and social consequences of this demographic decline. We present an overview of fertility changes in Italy in the second half of the 20th century and a mathematical model that may provide projections for the future of the demographic situation. Starting in 1950 the increment of the number of children born in Italy is initially positive; however, beginning in 1965 the trend suddenly becomes negative, and this negative trend further increased in 1975. A slight improvement is observed in 1980, followed by a stable situation beginning in 1987. Relevant socioeconomic and cultural events in Italy coincide with these variations in the fertility trend. Malnutrition, which had been endemic for centuries in some areas of central and southern Italy, disappeared rather abruptly in early 1960. The improvement in the economic situation was also associated with a decrease in illiteracy and with many sociocultural changes, with the emergence of new demands that decreased propensity for childbearing. The additional deceleration observed in 1975 corresponds to the diffusion of contraceptive procedures. The progression of sociocultural changes has led to a progressive liberation of women from the biological burden of childbearing. Two phenomena seem relevant in this context: women's emerging interest in entering the workforce and the possibility to disconnect sex from childbearing. The social function of feminism has overwhelmed the primary function of survival and diffusion of the species, giving rise to relevant and worrying demographic effects. However, the modern woman has an unconscious memory of her primary biological role, depending on both her genetic structure and cultural heritage, that should bring about a change in the present strong tendency to demographic decline. The basic notion of memory functions is widely recognized in sciences, for example, in the evolutionary theory of Darwin. Here, we introduce into the equations governing population growth a memory mechanism and a perturbation, and we estimate the reactions of the system to perturbations caused by environmental changes and subsequent delayed effects, such as those that appear in the birth rate beginning in 1965 and 1975. The mathematical modeling of the effects of perturbations of the fertility rate in the Italian population, with the introduction of a mathematical memory formalism, suggests that the effect is strongly reduced, with a relaxation time of about 10 years when the fertility rate approaches a stable value.

Repeated spontaneous abortion. Cooperative effects of ADA and ACP1 genetic polymorphisms

PROBLEM

In consideration of the effect of adenosine deaminase (ADA) and ACP1 (a low-molecular-weight protein tyrosine phosphatase) on T-cell receptor activity, we have analysed the joint distribution of these polymorphisms in a sample of women with primary repeated spontaneous abortion (RSA) to search for possible interactive effects on susceptibility to RSA.

METHOD OF STUDY

ACP1 and ADA phenotypes were determined in 170 women with primary RSA in 79 healthy consecutive puerperae and in 160 female newborns from the Caucasian population of Rome and in 357 healthy consecutive puerperae from the Caucasian population of Penne. Chi-square test of independence and three way contingency table analysis by a log-linear model were performed.

RESULTS

Women with low-ADA activity and high-ACP1 activity show the lowest susceptibility to RSA. Women with high-ADA activity and low-ACP1 activity, on the contrary, show the highest susceptibility to RSA and also the highest incidence of auto antibodies and of A blood group incompatibility.

CONCLUSION

The data are in agreement with those expected on the basis of the effects of ACP1 and ADA genetic variability on T-cell receptor activity and suggest a cooperative effect of the two polymorphic systems in the susceptibility/resistance to repeated spontaneous abortion.

Feto-maternal ACP1 activity ratio and intrauterine survival

OBJECTIVE

Genetic differences in the activity of phosphotyrosine phosphatases between mother and embryo could result in a differential activation of signals induced by growth factors in the two sides of placenta. Previous observations suggest that this may have important effects on intrauterine development and survival. The aim of the present study is to confirm previous observations and show new data.

STUDY DESIGN

We have studied 573 mother/newborn pairs, 169 wife/husband couples with repeated spontaneous abortion and 34 fertile wife/husband couples

RESULTS

In mother/newborn pairs, the analysis of joint mother/infant ACP1 distribution has shown a deficit of pairs with the mother having low ACP1 S isoform concentration and the infant having high S isoform concentration, and an excess of pairs with the mother having high S isoform concentration and the infant having low S isoform concentration. In RSA couples there is an excess of couples in which the wife has low S isoform concentration and the husband has high S isoform concentration and a deficit of couples in which the wife has high S isoform concentration and the husband has low S isoform concentration. In fertile couples the pattern is reversed.

CONCLUSION

The data suggest that when the mother to fetus S isoform concentration ratio is in favour of the mother, the probability of survival of the fetus is greater than in the opposite situation.

Is delayed childbearing changing gene frequencies in Western populations?

Experimental data and clinical observations suggest that delaying childbearing influences the biology of the mother-fetus relationship, with a negative effect on fetal development and predisposition to severe diseases such as type 1 diabetes. We reason that advanced maternal age may influence intrauterine selection, favoring genotypes that are more adapted to the intrauterine environment of less young women. In the present study we have investigated the relationship of maternal age to HP genotype and PGM1-Rh area (chromosome 1) that have been previously found to be associated with fertility and developmental parameters. HP phenotype was determined in 679 consecutive puerperae from the population of central Italy. PGM1 phenotype and Rh C phenotype were determined in 222 puerperae and 200 newborns. The HP 1,1 phenotype decreases and the HP 2,2 phenotype increases with maternal age. The proportion of phenotypes carrying both the Rh C and PGM1*1 alleles is much higher in puerperae older than 36 years than in puerperae of age 22 years. The frequency of the PGM1*1-Rh C haplotype increases and the frequency of the PGM1*2-Rh C haplotype decreases with maternal age. The changes in these genetic systems with advancing maternal age are similar in mothers and newborns. The delay of childbearing age, associated in Western countries with the fertility transition in addition to detrimental effects on intrauterine development and increased susceptibility to severe disorders, could bring about changes in the genetic composition of a population.

Intrauterine development and MNSs blood groups in repeated spontaneous abortion

OBJECTIVES

To determine whether the maternal MNSs genotype has an effect on the birth weight and gestation duration of the live offspring of women with repeated primary spontaneous abortion (RSA).

METHODS

The study sample consisted of 239 healthy white women who had been delivered of a live infant, and 137 women with a history of primary RSA-54 of whom had recently been delivered of a live infant and 83 who had had a spontaneous abortion. Maternal MNSs phenotypes were determined by standard serological methods, and the results were analyzed for relationships between these phenotypes and the mothers' reproductive status and the infants' birth weight and gestational age. Analysis of variance, the chi(2)-test of independence, and the Mantel-Haenszel test for linear association were performed for data analysis.

RESULTS

Infants born to mothers with the Ss genotype showed significantly lower birth weight and gestational duration compared with the infants of mothers with other genotypes. Additionally, the MNSs haplotype was found to be associated with birth weight.

CONCLUSIONS

Previous studies have shown that the MNSs system influences the gestational age of aborted fetuses in cases of RSA. The present study supports the hypothesis that this genetic factor influences intrauterine growth and development in women experiencing RSA.

Smoking, haptoglobin and fertility in humans

A prospective study on two samples of consecutive puerperae (total n° 667) from two populations has been carried out in order to investigate the possible effect of smoking habit on relationship between fertility and haptoglobin phenotype.

In both populations the negative association previously reported between age of pueperae and Haptoglobin *1/*1 phenotype is present only in women with smoking habit pointing to an interaction between Hp and smoke on human fertility. This suggests that the effects of smoke on fertility are dependent on the Hp phenotype.

Smoking and the genetics of signal transduction: an association study on retinopathy in type 1 diabetes

BACKGROUND

Recent studies suggest a complex association between smoking and retinopathy that probably depends on the interaction between many variables. We have reported an association between ACP1 phenotype and retinopathy in type 1 diabetes. Additionally, the deleterious effects of smoking on intrauterine growth are dependent on ACP1, a low-molecular-weight tyrosine phosphatase that modifies signal transduction. We examine here the interaction between smoking and ACP1 as a mediator of susceptibility to diabetic retinopathy in a sample of puerperae with type 1 diabetes.

SUBJECTS AND METHODS

Seventy-eight women who had just delivered live infants were studied. ACP1 phenotype was determined by starch gel electrophoresis. Three-way contingency tables were analyzed.

RESULTS

There is a significant epistatic interaction between smoking and ACP1 phenotype concerning their effects on retinopathy. In subjects with low ACP1 activity, frequency of retinopathy was slightly higher in smokers than in nonsmokers. However, in subjects with medium-high ACP1 activity, frequency of retinopathy was significantly lower in smokers than in nonsmokers. A logistic regression analysis using retinopathy as the dependent variable revealed that smoking, ACP1, and ACP1 by smoking interaction, as well as the interaction between smoking and age of the women, are the most robust predictors of retinopathy.

CONCLUSIONS

The effect of smoking on retinopathy in women with type 1 diabetes depends on many variables, which supports the hypothesis of complex interactions between smoking and other variables in the pathogenesis of this disease. Variability of genetic factors involved in signal transduction may affect endothelium proliferation through the regulation of growth factors and through regulation of glycemic levels. Because cigarette smoke influences signal transduction, its impact on diabetic retinopathy may be mediated by ACP1.

Smoking, haptoglobin and fertility in humans

A prospective study on two samples of consecutive puerperae (total n° 667) from two populations has been carried out in order to investigate the possible effect of smoking habit on relationship between fertility and haptoglobin phenotype.

In both populations the negative association previously reported between age of pueperae and Haptoglobin *1/*1 phenotype is present only in women with smoking habit pointing to an interaction between Hp and smoke on human fertility. This suggests that the effects of smoke on fertility are dependent on the Hp phenotype.

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.

Proton release on binding of glutathione to alpha, Mu and Delta class glutathione transferases

Potentiometric, spectroscopic and stopped-flow experiments have been performed to dissect the binding mechanism of GSH to selected glutathione S-transferases (GSTs), A1-1, M2-2 and Lucilia cuprina GST, belonging to Alpha, Mu and Delta classes respectively. Both Alpha and Mu isoenzymes quantitatively release the thiol proton of the substrate when the binary complex is formed. Proton extrusion, quenching of intrinsic fluorescence and thiolate formation, diagnostic of different steps along the binding pathway, have been monitored by stopped-flow analysis. Kinetic data are consistent with a multi-step binding mechanism: the substrate is initially bound to form an un-ionized pre-complex [k(1)>/=(2-5)x10(6) M(-1).s(-1)], which is slowly converted into the final Michaelis complex (k(2)=1100-1200 s(-1)). Ionization of GSH, fluorescence quenching and proton extrusion are fast events that occur either synchronously or rapidly after the final complex formation. The Delta isoenzyme shows an interesting difference: proton extrusion is almost stoichiometric with thiolate formed at the active site only up to pH 7.0. Above this pH, at least one protein residue acts as internal base to neutralize the thiol proton. These results suggest that the Alpha and Mu enzymes retain not only a similar catalytic outcome and overall three-dimensional structure but also share a similar kinetic mechanism for GSH binding. The Delta GST, which is closely related to the mammalian Theta class enzymes and is distantly related to Alpha and Mu GSTs in the evolutionary pathway, might display a different activation mechanism for GSH.

Molecular dynamics simulations of human glutathione transferase P1-1: analysis of the induced-fit mechanism by GSH binding

We report here a 1-ns molecular dynamics simulation on the ligand-free monomer of human glutathione transferase P1-1 in bulk water. The average conformation obtained from the last 500 ps of simulation is taken as a model for the apo-structure of this protein and compared to the available crystallographic data. Remarkable changes in the tertiary structure take place during the simulation and are ascribed to the removal of the ligand. They support an induced fit mechanism occurring upon glutathione binding, whose major features can be described in detail. A portion of helix 2 (residues 42-50), which participates in the formation of the active site, undergoes the most prominent conformational changes. Other protein segments, such as the C-terminal loop and helix 4, also show relevant structural rearrangements. All these transitions cause a significant shielding from the solvent of the hydrophobic binding site of the co-substrate, whose exposed surface goes from 4.6 nm(2) in the holo-structure to about 3.1 nm(2) in the apo-conformation. The results of this simulation are consistent with numerous experimental observations previously obtained on GST P1-1 and provide new insights for their explanation at the molecular level. Proteins 1999;37:1-9.

Molecular dynamics simulations of human glutathione transferase P1-1: conformational fluctuations of the apo-structure

We have investigated by molecular dynamics simulations the conformational fluctuations of the monomer of human apo-glutathione transferase P1-1. After attainment of steady-state dynamics, the structural fluctuations involve mainly the protein segments that participate also in the holo-apo transition discussed in the accompanying article (Stella et al., 1999:37:1-9.). The most mobile region is the C-terminal segment of helix 2. In contrast, helices 1, 6, 7, and 8 constitute a relatively rigid protein core. An "essential dynamics" analysis of the simulation shows that the largest fluctuations involve specific regions of glutathione transferases. In such regions, atomic motions are correlated. Motions of helix 2 are accounted for by the second most prominent principal component, which reveals a fluctuation between two distinct conformations. The residues that constitute the H-site undergo a breathing motion, possibly relevant during the binding of hydrophobic cosubstrates. Based on our simulation, several experimental findings can be rationalized, including the viscosity-dependent reactivity of Cys 47 and Cys 101 as well as the selective proteolysis of the peptide bond between Lys 44 and Ala 45. We have also modeled the structural changes that lead to the formation of an intrachain disulfide bridge between cysteines 47 and 101 and to the inactivation of the enzyme. The resulting structure maintains essentially the native fold except for helix 2, which closes the G-site. Proteins 1999;37:10-19.

Temperature adaptation of glutathione S-transferase P1-1. A case for homotropic regulation of substrate binding

Human glutathione S-transferase P1-1 (GST P1-1) is a homodimeric enzyme expressed in several organs as well as in the upper layers of epidermis, playing a role against carcinogenic and toxic compounds. A sophisticated mechanism of temperature adaptation has been developed by this enzyme. In fact, above 35 degrees C, glutathione (GSH) binding to GST P1-1 displays positive cooperativity, whereas negative cooperativity occurs below 25 degrees C. This binding mechanism minimizes changes of GSH affinity for GST P1-1 because of temperature fluctuation. This is a likely advantage for epithelial skin cells, which are naturally exposed to temperature variation and, incidentally, to carcinogenic compounds, always needing efficient detoxifying systems. As a whole, GST P1-1 represents the first enzyme which displays a temperature-dependent homotropic regulation of substrate (e.g. GSH) binding.

Flexibility of helix 2 in the human glutathione transferase P1-1. time-resolved fluorescence spectroscopy

Time-resolved fluorescence spectroscopy and site-directed mutagenesis have been used to probe the flexibility of alpha-helix 2 (residues 35-46) in the apo structure of the human glutathione transferase P1-1 (EC 2.5.1.18) as well as in the binary complex with the natural substrate glutathione. Trp-38, which resides on helix 2, has been exploited as an intrinsic fluorescent probe of the dynamics of this region. A Trp-28 mutant enzyme was studied in which the second tryptophan of glutathione transferase P1-1 is replaced by histidine. Time-resolved fluorescence data indicate that, in the absence of glutathione, the apoenzyme exists in at least two different families of conformational states. The first one (38% of the total population) corresponds to a number of slightly different conformations of helix 2, in which Trp-38 resides in a polar environment showing an average emission wavelength of 350 nm. The second one (62% of the total population) displays an emission centered at 320 nm, thus suggesting a quite apolar environment near Trp-38. The interconversion between these two conformations is much slower than 1 ns. In the presence of saturating glutathione concentrations, the equilibrium is shifted toward the apolar component, which is now 83% of the total population. The polar conformers, on the other hand, do not change their average decay lifetime, but the distribution becomes wider, indicating a slightly increased rigidity. These data suggest a central role of conformational transitions in the binding mechanism, and are consistent with NMR data (Nicotra, M., Paci, M., Sette, M., Oakley, A. J., Parker, M. W., Lo Bello, M., Caccuri, A. M., Federici, G., and Ricci, G. (1998) Biochemistry 37, 3020-3027) and pre-steady state kinetic experiments (Caccuri, A. M., Lo Bello, M., Nuccetelli, M., Nicotra, M., Rossi, P., Antonini, G., Federici, G., and Ricci, G. (1998) Biochemistry 37, 3028-3034) indicating the existence of a pre-complex in which GSH is not firmly bound to the active site.

HLA and complement factors alleles sharing in Italian couples with recurrent spontaneous abortions

Recurrent Spontaneous Abortion (RSA) is postulated to be due to several factors including immunogenetic mechanisms. Many studies have been conducted on the effect of the MHC region in the reproductive phenomena suggesting an immunological or genetic involvement in RSA. We studied couples with 3 or more abortions among a larger group of couples in which female partners were anti-cardiolipin antibodies negative, resulting in a population of 43 couples typed for HLA-A, B, C, DR, DQ. In 16 of these 43 couples, complement factors C4A, C4B, and Bf were typed. The data shows a statistically significant increase of C4B*Q0 in RSA patients (N = 32) compared with the control population (N = 44) (pc = .00147) and also a statistically significant increase of C4B*Q0 sharing in aborting couples (43.75%) against the expected sharing rate in the control population (1.86%) (p < .001). Frequency increase of C4B*Q0 allele in aborting population leads to the hypothesis that an imbalance of complement factors expression and activity can have detrimental effects on implantation and embryo survival. Additionally, the significant sharing rate of C4B*Q0 in couples with RSA could indicate the existence of a gene in linked to this allele predisposing to RSA and acting in a recessive manner if present in double copies in the fetus.

Adenosine deaminase and human reproduction: a comparative study of fertile women and women with recurrent spontaneous abortion

PROBLEM

We have investigated the possible role of adenosine deaminase (ADA) genetic polymorphism in human fertility through a comparative study of couples with recurrent spontaneous abortion (RSA) and healthy puerperae.

METHOD OF STUDY

Adenosine deaminase phenotype has been determined in 209 women with repeated episodes of unexplained spontaneous abortion (RSA) and their husbands, as well as in 115 healthy pregnant women from the population of Rome. An independent sample of 286 puerperae along with their newborn infants in the population of Penne was also studied.

RESULTS

The proportion of carriers of ADA*2 allele, which is associated with the lowest enzymatic activity, is lower among women with RSA than among healthy pregnant women from the same population of Rome. Preliminary observations suggest a protective effect of ADA*2 against the development of autoantibodies in RSA. Such an effect seems to be mediated by an interaction with AB0 blood groups. In the population of Penne the proportion of women carrying ADA*2 allele is higher among those who have had two or more previously born children than among women with only one or no children.

CONCLUSIONS

The data suggest that women carrying the ADA*2 allele are better protected against the spontaneous loss of embryos and have a higher fertility rate.

Solution structure of glutathione bound to human glutathione transferase P1-1: comparison of NMR measurements with the crystal structure

The conformation of the bound glutathione (GSH) in the active site of the human glutathione transferase P1-1 (EC 2.5.1.18) has been studied by transferred NOE measurements and compared with those obtained by X-ray diffraction data. Two-dimensional TRNOESY and TRROESY experiments have been performed under fast-exchange conditions. The family of GSH conformers, compatible with TRNOE distance constraints, shows a backbone structure very similar to the crystal model. Interesting differences have been found in the side chain regions. After restrained energy minimization of a representative NMR conformer in the active site, the sulfur atom is not found in hydrogen-bonding distance of the hydroxyl group of Tyr 7. This situation is similar to the one observed in an "atypical" crystal complex grown at low pH and low temperature. The NMR conformers display also a poorly defined structure of the glutamyl moiety, and the presence of an unexpected intermolecular NOE could indicate a different interaction of this substrate portion with the G-site. The NMR data seem to provide a snapshot of GSH in a precomplex where the GSH glutamyl end is bound in a different fashion. The existence of this precomplex is supported by pre-steady-state kinetic experiments [Caccuri, A. M., Lo Bello, M., Nuccetelli, M., Nicotra, M., Rossi, P., Antonini, G., Federici, G., and Ricci, G. (1998) Biochemistry 37, 3028-3034] and preliminary time-resolved fluorescence data.

Proton release upon glutathione binding to glutathione transferase P1-1: kinetic analysis of a multistep glutathione binding process

The fate of the thiol proton coming from the ionization of the sulfhydryl group of GSH in the active site of glutathione transferase P1-1 has been studied. pH changes caused by the binding of GSH to the enzyme in the absence of any inorganic buffer indicate that the thiol proton leaves the active site when the binary complex is formed. The amount of protons released is stoichiometric to the amount of GSH thiolate formed in the G-site. The apparent pKa value for the bound GSH, calculated with this potentiometric approach, is 6.18 +/- 0.09; very similar values are found by spectrophotometric (6.20 +/- 0.12) and by kinetic (6.00 +/- 0.08) experiments. Binding of S-hexylglutathione does not cause any proton release. Stopped-flow data obtained by means of an acid-base indicator show that the proton extrusion process (apparent t1/2 = 1.1 +/- 0.1 ms at 15 degrees C) is not rate limiting in turnover (apparent t1/2 = 34 +/- 4 ms at 15 degrees C). By comparing the kinetic behavior of three distinct events occurring during the binding of GSH to the enzyme, i. e., proton release, ionization of bound GSH and quenching of intrinsic fluorescence, it appears that the binding process follows a multistep mechanism possibly involving the conformational transition of a weak precomplex into the final Michaelis complex. This step is modulated by helix 2 motions and may be rate limiting at physiological GSH concentrations. These findings, coming from kinetic studies, are consistent with NMR data [Nicotra, M., Paci, M., Sette, M., Oakley, A. J., Parker, M. W., Lo Bello, M., Caccuri, A. M., Federici, G., and Ricci, G. (1998) Biochemistry 37, 3020-3027] and time-resolved fluorescence experiments [Stella, L., Caccuri, A. M., Rosato, N., Nicotra, M., Lo Bello, M., De Matteis, F., Mazzetti, A. P., Federici, G., and Ricci, G., manuscript in preparation].

The genetics of signal transduction and the feto-maternal relationship. A study of cytosolic low molecular weight phosphotyrosine phosphatase

Intracellular kinases mediate positive signalling from surface receptors by phosphorylating critical target proteins whereas phosphatases inhibit this process. Differential phosphatase activity at the feto-maternal interface could determine the appropriate relative growth and development on each side of the placenta. The highly polymorphic cytosolic low molecular weight phosphotyrosine-phosphatase (ACP1-cLMWPTPase) has been studied in 170 women who had at least two consecutive spontaneous abortions along with their husbands and in 352 normal puerperae along with their newborn babies. Symmetry analysis of joint wife/husband and mother/infant distribution suggests that when ACP1 activity is lower in the mother than in either her aborted fetus or her child, the probability of abortion is higher and the survival to term is lower as compared to pairs in which the ACP1 activity is higher in the mother than in her fetus. Further analysis has shown that the effect is due to S isoform: i.e. a high mother/fetus S isoform ratio favours intrauterine survival. Analysis of gestational duration and birth weight suggests that a high ACP1 maternal activity coupled with a low or moderate fetal activity favour fetal growth and developmental maturation. The present data indicate that maternal-fetal genetic differences in signal transduction could contribute significantly to variability of intrauterine developmental parameters and to pathological manifestation of pregnancy.

Catalytic mechanism and role of hydroxyl residues in the active site of theta class glutathione S-transferases. Investigation of Ser-9 and Tyr-113 in a glutathione S-transferase from the Australian sheep blowfly, Lucilia cuprina

Spectroscopic and kinetic studies have been performed on the Australian sheep blowfly Lucilia cuprina glutathione S-transferase (Lucilia GST; EC 2.5.1.18) to clarify its catalytic mechanism. Steady state kinetics of Lucilia GST are non-Michaelian, but the quite hyperbolic isothermic binding of GSH suggests that a steady state random sequential Bi Bi mechanism is consistent with the anomalous kinetics observed. The rate-limiting step of the reaction is a viscosity-dependent physical event, and stopped-flow experiments indicate that product release is rate-limiting. Spectroscopic and kinetic data demonstrate that Lucilia GST is able to lower the pKa of the bound GSH from 9.0 to about 6.5. Based on crystallographic suggestions, the role of two hydroxyl residues, Ser-9 and Tyr-113, has been investigated. Removal of the hydroxyl group of Ser-9 by site-directed mutagenesis raises the pKa of bound GSH to about 7.6, and a very low turnover number (about 0.5% of that of wild type) is observed. This inactivation may be explained by a strong contribution of the Ser-9 hydroxyl group to the productive binding of GSH and by an involvement in the stabilization of the ionized GSH. This serine residue is highly conserved in the Theta class GSTs, so the present findings may be applicable to all of the family members. Tyr-113 appears not to be essential for the GSH activation. Stopped-flow data indicate that removal of the hydroxyl group of Tyr-113 does not change the rate-limiting step of reaction but causes an increase of the rate constants of both the formation and release of the GSH conjugate. Tyr-113 resides on alpha-helix 4, and its hydroxyl group hydrogen bonds directly to the hydroxyl of Tyr-105. This would reduce the flexibility of a protein region that contributes to the electrophilic substrate binding site; segmental motion of alpha-helix 4 possibly modulates different aspects of the catalytic mechanism of the Lucilia GST.

Structural flexibility modulates the activity of human glutathione transferase P1-1. Role of helix 2 flexibility in the catalytic mechanism

Presteady-state and steady-state kinetic studies performed on human glutathione transferase P1-1 (EC 2.5.1.18) with 1-chloro-2, 4-dinitrobenzene as co-substrate indicate that the rate-determining step is a physical event that occurs after binding of the two substrates and before the final sigma-complex formation. It may be a structural transition involving the ternary complex. This event can be related to diffusion-controlled motions of protein portions as kcat degrees /kcat linearly increases by raising the relative viscosity of the solution. Similar viscosity dependence has been observed for Km GSH, while Km CDNB is independent. No change of the enzyme structure by viscosogen has been found by circular dichroism analysis. Thus, kcat and Km GSH seem to be related to the frequency and extent of enzyme structural motions modulated by viscosity. Interestingly, the reactivity of Cys-47 which can act as a probe for the flexibility of helix 2 is also modulated by viscosity. Its viscosity dependence parallels that observed for kcat and Km GSH, thereby suggesting a possible correlation between kcat, Km GSH, and diffusion-controlled motion of helix 2. The viscosity effect on the kinetic parameters of C47S and C47S/C101S mutants confirms the involvement of helix 2 motions in the modulation of Km GSH, whereas a similar role on kcat cannot be ascertained unequivocally. The flexibility of helix 2 modulates also the homotropic behavior of GSH in these mutants. Furthermore, fluorescence experiments support a structural motion of about 4 A occurring between helix 2 and helix 4 when GSH binds to the G-site.

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.

Transvaginal sonography of the yolk sac in normal and abnormal pregnancy

A cross-sectional study comprising 117 consecutive first trimester singleton pregnancies was performed using transvaginal sonography (TVS) to evaluate size abnormalities of the secondary yolk sac (YS) vis-à-vis pregnancy outcome. In normal pregnancy outcome (NPO) the YS diameter showed an increase from the 5th to the 11th week, menstrual age, followed by a decrease and its disappearance after 12 weeks. A YS of abnormal size was statistically significant (p < 0.001) in spontaneous abortion (SA) versus NPO, with a sensitivity of 68.7%, a specificity of 99%, a positive predictive value of 91.6% and a negative predictive value of 95.2%. These preliminary results indicate that a measurement of the YS very early in gestation may be a useful marker of pregnancy outcome.

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.

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.

[Psychosomatic sterility. Search for a hypothesis for personaity structure using Moretti's graphology method]

Over the past three years the authors have performed a random clinical study on couples who came to the aim of identifying the possible presence, in those cases in which it was not possible to pinpoint an organic or functional etiological factor, of a relationship between personality structure and so-called "sterility sine cause" which according to the recent studies by Pancheri and Zichella on reproductive emotionality, is thought to caused by a factor of psychosomatic origin, The substantiality of the concept of reproductive emotionality, otherwise referred to as sexual instinct, was put forward in 1962 by Padre Gerolamo Moretti, a leading figure of Italian graphology. Research to date, carried out using traditional methods of clinical psychology, interview and tests, in an attempt to determine a particular personality profile, has not produced completely satisfactory results. From the literature it does not appear that graphological analysis has been applied in research of this nature. Graphology, if used by competent and appropriately trained persons, is certainly a powerful and refined diagnostic method which enables an idiographic, holistic and integrated personality profile (intelligence and temperament) tp be obtained for the subject in question. Moretti's temperament classification was used to define the personality structure of patients: assault, resistance, assignment and expectation. Research using graphological techniques has revealed that it is possible to define a personality structure within which suspected "sine cause" patients may be classified. In comparison to the control group, there was a prevalent attitude expressing a tendency to reserve, introversion, diffidence, anxiety, excessive and sometimes unmotivated concern regarding persons and things, attachment to one's own ideas, inflexibility of one's own position, scarce capacity to make oneself available, excessive attention to formal aspects. A number of practical considerations also emerged from the research: the good level of acceptance and compliance with the diagnostic instrument used and the fact that the patient in question does not necessarily have to be present. Due to the ease of obtaining an example of the patient's handwriting, graphological analysis could be outinely requested as the first approach in suspected cases of sterility due to psychosomatic causes.

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.

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.

Purified FSH as a treatment for a cervical hostility

Abnormal cervical mucus (CM) quality and quantity is considered one of the causes of infertility which occurs in only 2 to 8 per cent of infertile couples. The periovulatory mucus with its specific properties is necessary to determine a correct Post Coital Test (PCT). Twenty patients, with infertility for over 18 months and with a baseline negative PCT (repeated at least three times) for abnormal CM, were treated with pFSH. Our results show that the pFSH improves the quality and quantity of CM in all for our patients including an improvement of penetration and motility spermatozoa in 55 per cent of our cases. Therefore we suggest the routine pFSH use in case of cervical hostility and recurrent negative PCT.

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.

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.

Subclinical hypothyroidism and hyperprolactinemia

The authors have studied 25 women aged 22 to 26 years with a diagnosis of prolactinemia moderately increased in primary sterility. Among 25 women under observation, 7 (28%) showed a hormone picture of subclinic hypothyroidism. In fact the evaluation of TSH after stimulation with TRH showed a curve typical of the subclinic hypothyroidism. In 8 women (32%) the authors have found an increase of the thyroid gland, and in 3 patients (12%) galactorrhea. The increase of volume of the thyroid gland was constant in all the women with subclinic hypothyroidism. Considering the results obtained by this study, the authors point out a correlation between subclinic hypothyroidism-hyperprolactinemia and sterility. The data obtained are in accordance with that has been reported in literature.

Hysterosalpingographic abnormalities in infertile women: radiological and clinical interpretation

A review of 1035 hysterosalpingographies (HSG) has shown a frequency of acquired and congenital morphological alteration in 272 patients with spontaneous abortion and in 763 infertile couples. The frequency of congenital anomalies was 25.5% in spontaneous abortions and 5.3% in infertility. Acquired morphological anomalies were 11.7% in spontaneous abortion and 34.6% in infertility. Tubal problems represent 25% of lesions in infertility. Furthermore couples have been studied by correlating the male factor i.e. the sperm quality to various types of morphological anomalies observed in order to better evaluate the actual damage evidence by HSG.

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.

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.