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Biomedical subjects

M Marra

Publications and source records attributed to M Marra.

At least 91 records · Page 5Linked to original sources
PubMed1997

Müllerian-inhibiting substance in follicular fluid and serum: a comparison of patients with tubal factor infertility, polycystic ovary syndrome, and endometriosis.

OBJECTIVE: To determine Müllerian inhibiting substance (MIS) levels in follicular fluid (FF) and sera of IVF patients. DESIGN: Prospective study. SETTING: Fertility center. PATIENT(S): Sixty-six patients: 20 with tubal factor infertility, 17 with polycystic ovary syndrome (PCOS), and 29 with endometriosis. INTERVENTION(S): All patients underwent ovarian stimulation with hMG and/or FSH, as well as oocyte retrieval for IVF. MAIN OUTCOME MEASURE(S): Follicular fluid and serum MIS levels and oocyte fertilization rates. RESULT(S): Levels of MIS in FF and sera of PCOS patients were significantly higher than those in tubal factor patients: 7.01 +/- 1.52 versus 1.65 +/- 0.23 ng/mL (mean +/- SE) and 2.97 +/- 0.52 versus 0.92 +/- 0.19 ng/mL, respectively. In endometriosis patients, follicular fluid and serum MIS levels were not significantly different from those in tubal factor patients. In PCOS patients, the percentage of immature oocytes retrieved (17.9% +/- 5.0%) was significantly higher compared with tubal factor (1.5% +/- 1.0%) and endometriosis (9.2% +/- 2.3%) patients. The percentage of oocytes fertilize was significantly lower in PCOS patients (30.2% +/- 5.3%) compared with tubal factor (62.2% +/- 5.5%) and endometriosis (37.5% +/- 5.7%) patients. CONCLUSION(S): Women with PCOS had higher serum and follicular fluid MIS levels, a higher percentage of immature oocytes, and lower fertilization rates than women with endometriosis or pelvic adhesions.

Adult↗
PubMed1997

Dietary restriction affects antioxidant levels in rat liver mitochondria during ageing.

Six experimental groups of young (7-month-old) and aged (24-32-month-old) rats, underwent different dietary manipulations (i.e. dietary restriction and/or a vitamin E-depleted diet), and their liver mitochondria were assayed for several antioxidants and peroxidation markers. Glutathione levels were affected both by age and dietary treatment. Coenzyme Q9 and C0Q10 showed the highest levels in the oldest rats where ageing, as well as other oxidative stresses, could induce ubiquinone biosynthesis.

Aging↗
PubMed1997

The prediction of total body water from bioelectrical impedance in patients with anorexia nervosa.

Total body water (TBW) was measured by deuterium oxide (D2O) dilution and predicted from bioelectrical impedance (Z) in nineteen anorexic and twenty-seven control women. The equation of Kushner et al. (1992) based on the impedance index (ZI = height2/Z) gave biases of 0.9 (SD 2.5) and 0.8 (SD 2.5) litres in controls and patients respectively (NS, ANOVA). The ZI-based equation of Deurenberg et al. (1993) gave biases of 1.5 (SD 2.4) litres (NS) and 3.0 (SD 2.1) litres (P < 0.001) in controls and patients respectively. Despite the fact that weight was the most powerful predictor of TBW on the study sample (n 46, r2 0.90, P < 0.0001, SE of the estimate 1.6 litres, CV 5.7%), the formulas of Segal et al. (1991) and Kushner et al. (1992) based on the association of weight and ZI gave an inaccurate prediction of TBW in both control and anorexic subjects, with a bias ranging from -3.2 (SD 2.4) to 2.9 (SD 2.1) litres (P < or = 0.001). Population-specific formulas based on ZI (n 46) gave a more accurate prediction of TBW by bioelectrical impedance analysis on the study subjects, with biases of -0.1 (SD 1.8) and 0.5 (SD 1.7) litres in controls and patients respectively (NS). However, the individual bias was sometimes high. It is concluded that bioelectrical impedance analysis can be used to predict TBW in anorexic women at a population level, but the predictions are less good than those based on body weight alone.

Adult↗
PubMed1997

[Evaluation of body composition in anorexia nervosa].

Bioimpedance analysis (BI) of body composition has been carried out in 116 women: 22 patients with anorexia nervosa (AN) and IMC between 16 and 18.5 kg/m2 (MPE-I: weight 45.3+/-3.1 kg; BMI 17.0+/-0.7 kg/m2); 39 AN patients with BMI< 16 kg/m2 (MPE-II: weight 37.2+/-3.8 kg; BMI 14.5+/-1.0 kg/ m2; 55 healthy women (control= CTR: weight 60.5+/-9.0 kg; BMI 22.8+/-3.1 kg/m2). BI was determined for the whole body and for body segments (arms, legs and trunk): phase angle (AF) of 50 kHz and impedance (Z) of 100, 50 and 5 kHz. Body water was estimated from Z to 50 kHz according to Kushner et al. (AJCN 1993). AF and Z100/Z5 (multifrequency BI) were considered as related to the ratio between extracellular water and intracellular water. Total body water was significantly different between the three groups: 26.5+/-2.9 L in the MPE-II group, 23.6+/-2.9 L in the MPE-I group; 30.3+/-3.7 L in the CTR women. In comparison with the CTR group whole-body AF and leg-AF was lower (p<0.01) in the MPE-II patients while both the MPE groups differed from the CTR group with respect to arm-AF. Multifrequency BI showed differences (p<0.01) between all the groups for the whole-body and segmental measures. Significant correlations for AF and Z100/Z5 vs BMI and % BF were apparent only in the MPE-II group. In conclusion, in the AN the marked modifications of BI parameters indicated a relative increase of extracellular water and were related to BMI and % BF in the very undernourished patients.

English Abstract↗
PubMed1996

Food restriction increases the protection of erythrocytes against the hemolysis induced by peroxyl radicals.

We have investigated the susceptibility to peroxidation of erythrocytes from young, adult and old ad libitum (AL) fed, as well as from adult and old food restricted rats, measuring the rate of hemolysis under controlled peroxidative condition. Food restriction has been applied on an every-other-day (EOD) schedule starting from the age of 3.5 months. The oxidation of red blood cells by molecular oxygen was performed in an aqueous suspension using the azo-compound 2-2'-azo-bis-(2-amidinopropane)hydrochloride (AAPH) as the free radical initiator. Several parameters were calculated from the time-dependent curve of AAPH induced hemolysis. The time required to achieve 50% hemolysis decreased with aging and this decrease was prevented by food restriction. The lag time, which reflects the capacity of the cell to buffer free radicals, was longer in young than in old AL fed animals also this impairment was almost completely prevented in EOD fed animals. The same beneficial effect of food restriction was observed considering the maximal amount of hemolysis attained with the dose of AAPH applied and the time necessary to reach this level. The general picture emerging from the present study is that erythrocyte membranes from EOD fed rats are better protected, than those from AL fed ones, against damages caused by peroxidation. This effect may be due to a difference in the chemical composition of the erythrocyte membranes as it was found in other organs.

Aging↗
PubMed1996

Melatonin protects LDL from oxidation but does not prevent the apolipoprotein derivatization.

Protective effect of melatonin against Cu++ induced peroxidative modification of low density lipoprotein (LDL) was studied in vitro. Melatonin was used for this purpose because of its known scavenging capacity against hydroxyl and peroxyl radicals. It was demonstrated by the diene formation kinetic analysis that melatonin protected polyunsaturated fatty acids of LDL lipids against peroxidation. Lag time duration was prolonged, peak time was delayed, whereas rate of diene formation was decreased in melatonin treated LDL; however, parameters related to apolipoprotein (apo-B) showed that the protein was derivatized. Fluorescence, relative electrophoretic mobility, lysine residues analysis data, as well as the uptake by macrophages all showed properties similar to those of oxidised LDL. Present data suggest that by-products of melatonin oxidation might react with lysine residues of apo-B, transforming LDL in its atherogenic form.

Animals↗
PubMed1996

The H+-ATPase purified from maize root plasma membranes retains fusicoccin in vivo activation.

The activity of 'P-type' ATPases is modulated through the C-terminal autoinhibitory domain. The molecular bases of the regulation are unknown. Their understanding demands functional and structural studies on the activated purified enzyme. In this paper the plasma membrane H+-ATPase from maize roots activated in vivo by fusicoccin was solubilised and fractionated by anion-exchange HPLC. Results showed that the H+-ATPase separated from fusicoccin receptors retained fusicoccin activation and that it was more evident after enzyme insertion into liposomes. These data suggest that fusicoccin stimulation does not depend on a direct action of the fusicoccin receptor on the H+-ATPase, but rather, fusicoccin brings about a permanent modification of the H+-ATPase which very likely represents a general regulatory mechanism for 'P-type' ATPases.

Cell Membrane↗
PubMed1996

Glycosylated hemoglobin and fructosamines: does their determination really reflect the glycemic control in diabetic patients?

The present experiment was designed to determine whether scavenging capacity of serum, in addition to glucose level, influences hemoglobin and serum protein glycosylation in non-insulin dependent diabetic patients. For this purpose forty-seven patients homogeneous for age, disease duration, therapy and glyco-metabolic control were selected. Fasting and post-prandial glycemia and insulinemia as well as glycosuria were weekly analysed during the sixty days preceding glycosylated hemoglobin (HbA1c), fructosamines and serum scavenging capacity determination. This last parameter has been evaluated by a method based on the property of beta-phycoerythrin (beta-PE) to loss its fluorescence when damaged by oxygen radicals, that were produced by Cu++ and H2O2. The oxygen radical absorbance capacity (ORACOH) of serum was assayed as the ability of serum to delay the loss of beta-PE fluorescence. As expected, a statistically significant positive correlation was found comparing both fructosamines and HbA1c levels with mean fasting glycemia measured over twenty and sixty days, respectively. The key result of this study is represented by the finding that both HbAlc and fructosamines levels show a statistically significant negative correlation with ORACOH values. This correlation can explain a large percent of the data dispersion occurring when ORACOH is not taken into account. In order to better describe the role of ORACOH, patients were separated into two sub-groups with an ORACOH lower (L-ORACOH) and greater (H-ORACOH) than 100 U/ml. Examining the correlation between mean fasting glycemia and the two glycosylated proteins considered in these two sub-groups, curves with different slopes were obtained, supporting that the rate of glycosylation of both proteins was higher in L-ORACOH patients as compared to those with H-ORACOH. Present data suggest that for a proper interpretation of the HbA1c and fructosamines data in diabetic patients, the scavenging capacity level of serum should be taken into account.

Aged↗
PubMed1996

End sequence determination from large insert clones using energy transfer fluorescent primers.

Genome mapping strategies depend heavily on confirmatory data of several types to establish overlaps between contiguous stretches of cloned DNA derived from genomic regions. One type of ancillary data that can contribute to establishing these overlaps is DNA sequence data derived from the ends of large (> 30 kb) inserts in genomic clones. This type of data can be difficult to obtain routinely, because large clones are often unstable and microgram quantities of highly purified DNA are required in each sequencing reaction to obtain sufficient signal for accurate base calling and maximum read length. Recently, we have been experimenting with methods to consistently obtain up to 800 bases of high-quality sequence data from the ends of large insert clones using ThermoSequenase DNA polymerase and Energy Transfer fluorescent primers. Our experimental approach and results, described in this paper, indicate that routinely obtaining high-quality sequence data from the ends of large insert genomic clones is feasible. Such data can contribute to the assessment of common regions between large insert clones, to the establishment of conservation of synteny between closely related species, and to the detection of additional contiguous clones.

Chromosome Mapping↗
PubMed1996

Generation and analysis of 280,000 human expressed sequence tags.

We report the generation of 319,311 single-pass sequencing reactions (known as expressed sequence tags, or ESTs) obtained from the 5' and 3' ends of 194,031 human cDNA clones. Our goal has been to obtain tag sequences from many different genes and to deposit these in the publicly accessible Data Base for Expressed Sequence Tags. Highly efficient automatic screening of the data allows deposition of the annotated sequences without delay. Sequences have been generated from 26 oligo(dT) primed directionally cloned libraries, of which 18 were normalized. The libraries were constructed using mRNA isolated from 17 different tissues representing three developmental states. Comparisons of a subset of our data with nonredundant human mRNA and protein data bases show that the ESTs represent many known sequences and contain many that are novel. Analysis of protein families using Hidden Markov Models confirms this observation and supports the contention that although normalization reduces significantly the relative abundance of redundant cDNA clones, it does not result in the complete removal of members of gene families.

Adult↗
PubMed1995

Pseudomonas syringae pv. syringae phytotoxins reversibly inhibit the plasma membrane H(+)-ATPase and disrupt unilamellar liposomes.

The Pseudomonas syringae pv. syringae phytotoxins syringomycin-E and syringopeptins 22-A and 25-A reversibly and noncompetitively inhibit purified H(+)-ATPase solubilized from plasma membrane of maize roots. Moreover, they increase the passive permeability to protons in phosphatidylcholine/phosphatidylethanolamine liposomes. Both effects are more pronounced with syringopeptins than with syringomycin-E. Activity on phospholipid bilayers is detectable at phytotoxin concentrations not affecting H(+)-ATPase activity.

Bacterial Toxins↗
PubMed1995

The fungal H(+)-ATPase from Neurospora crassa reconstituted with fusicoccin receptors senses fusicoccin signal.

Fusicoccin affects several physiological processes regulated by the plasma membrane H(+)-ATPase in higher plants while other organisms having P-type H(+)-ATPases (e.g., fungi) are fusicoccin-insensitive. We have previously shown that fusicoccin binding to its receptor is necessary for H(+)-ATPase stimulation and have achieved the functional reconstitution into liposomes of fusicoccin receptors and the H(+)-ATPase from maize. In this paper we show that fusicoccin sensitivity can be conferred on the H(+)-ATPase from Neurospora crassa, a fungus insensitive to fusicoccin. In fact, H+ pumping by purified H(+)-ATPase from Neurospora crassa reconstituted into liposomes containing crude or partially purified fusicoccin receptors from maize was markedly enhanced by fusicoccin. The stimulation of H+ pumping by fusicoccin is dependent upon pH, fusicoccin, and protein concentration, as was reported for the system reconstituted with both proteins from maize.

Glycosides↗
PubMed1995

Dose-effect models for ozone exposure: tool for quantitative risk estimation.

Short-term ozone exposure causes lung function decrements, increased airway reactivity, airway inflammation, increased respiratory symptoms and hospital admissions. Exposure to long-term elevated ozone levels seems to be associated with reduced lung function (aging), increase of respiratory symptoms, exacerbation of asthma, and airway cell and tissue changes. Health risk caused by exposure to ozone has been evaluated mainly in a qualitative way by comparing ozone air quality data with health-based guidelines or standards. A preliminary approach to quantifying health risk from short-term exposure to oxidant air pollution has been taken by expert judgement, describing known or expected effects at specific levels of ozone. For quantitative assessment of the health impact of distinct ozone exposure conditions (acute, repeated daily, chronic) specific exposure-dose-response models are being developed which can be linked to human exposure data. Exposure-(dose-)response models using data from epidemiological, human-clinical and animal toxicity studies are presented.

Air Pollution↗
PubMed1995

[Lateral calcaneal flap in the reconstruction of the calcaneal and malleolar region].

The authors discuss the efficacy of the lateral calcaneal artery flap in repairing the calcaneal and malleolar regions. The lateral calcaneal artery flap is a safe flap, with constant vascularization represented by the lateral calcaneal artery and the external saphenous vein; the flap has a sensory nerve (the sural nerve) and is a sensory flap. Its use in the calcaneal and malleolar region is very safe, because the vascular pedicle is constant and surgical transfer easy.

Ankle↗
PubMed1995

The impairment of mitochondrial membrane potential and mass in proliferating lymphocytes from vitamin E deficient animals is recovered by glutathione.

The time-dependent changes of mitochondrial membrane potential and mass have been investigated on splenocytes from control and vit. E deficient rats, stimulated to proliferate with Concanavalin A, in the presence and absence of reduced glutathione (GSH, 5 mM). Rhodamine-123 (Rh-123) and nonyl acridine orange (NAO) were used as specific probes to monitor the membrane potential and mass of mitochondria, respectively, by means of flow cytometry. Rh-123 uptake was high in an increasing number of cells from normally fed animals during the three-day culture period. On the contrary, splenocytes from vitamin E deficient rats showed a biphasic pattern. The number of cells showing a high uptake of Rh-123 increased after 24 hrs. from mitogenic stimulation, then it decreased at the other two time points considered. In parallel, a continuous increase of the number of cells with depolarized organelles (up to 60% by 72 hrs.) has been observed in vit. E deficiency. This impairment was fully prevented by GSH supplementation to the culture medium. In the presence of the thiol, about 80-85% of cells showed activated mitochondria, whereas the number of splenocytes with depolarized organelles did not exceed 17%, irrespective of the diet applied to the animals. The same pattern was observed considering the changes of mitochondrial mass, measured using NAO as a probe. Present results support that GSH may substitute vitamin E in protecting mitochondria from peroxidative damage.

Acridine Orange↗
PubMed1994

Melatonin: a peroxyl radical scavenger more effective than vitamin E.

We have compared the peroxyl radical scavenger ability to melatonin with that of vitamin E, vitamin C and reduced glutathione (GSH). In the assay system, beta-phycoerythrin (beta-PE) was used as fluorescent indicator protein, 2-2'-azo-bis(2-amidinopropane)dihydrochloride as a peroxyl radical generator and the water soluble vitamin E analogue. Trolox, as reference standard. Results are expressed as oxygen radical absorbing capacity (ORAC(perox)) units, where 1 ORAC unit equals the net protection produced by 1 microM Trolox. A linear correlation of ORAC values with concentration (0.5-4 microM) of all the substances tested has been observed. However, on molar basis, the relative ORAC(perox) of Trolox, vitamin C, GSH and melatonin was 1:1.12:0:68:2.04, respectively. Thus, melatonin, which is a lipid-soluble compound, was twice more active than vitamin E, believed to be the most effective lipophilic antioxidant.

Amidines↗
PubMed1994

Attenuation of acute lung injury by ozone inhalation--the effect of low level pre-exposure.

The attenuating influence of a pre-exposure of rats to a low concentration of ozone (O3) for 7 days on a subsequent O3 challenge was investigated. Effects of O3 were quantified by measuring indicators of lung permeability and inflammation in bronchoalveolar lavage fluid. The results suggest that pre-exposure to relatively low levels of O3 produces a diminished permeability response in lower airways of rats upon a following challenge with a higher level of O3. Extrapolated to human exposure situations, these data suggest that health effect evaluation of repeated exposure periods of enhanced O3 levels is rather complex and needs further investigation.

Administration, Inhalation↗