Biomedical subjects

M Farina

Publications and source records attributed to M Farina.

At least 37 records · Page 2Linked to original sources

PubMed2003

Steroid hormones augment nitric oxide synthase activity and expression in rat uterus.

Nitric oxide (NO) is synthesized in a variety of tissues, including rat uterus, from L-arginine by NO synthase (NOS), of which there are three isoforms, namely neuronal, endothelial and inducible NOS (nNOS, eNOS and iNOS, respectively). Nitric oxide is an important regulator of the biology and physiology of the organs of the reproductive system, including the uterus. Some studies have shown increased variation in NO production and NOS expression during the oestrous cycle. However, the factors that regulate NO production in the uterus remain unclear. Therefore, in the present study, we investigated the effect of sex steroids on NOS expression and activity in the ovariectomized rat uterus. Ovariectomized rats received progesterone (4 mg per rat) or 17beta-oestradiol (1 microg per rat). All rats were killed 18 h after treatment. Both progesterone and oestradiol were able to augment NOS activity. The effect of oestradiol was abolished by pre-incubation with 500 micro M aminoguanidine, an iNOS inhibitor, or by coadministration of oestradiol with 3 mg kg(-1) dexamethasone, but the effect of progesterone was not affected by these treatments. Uterine nNOS, eNOS and iNOS protein levels were assessed using Western blots. Ovariectomized rat uteri expressed iNOS and eNOS. Progesterone increased the expression of eNOS and iNOS, whereas oestradiol increased iNOS expression only. These results suggest that oestradiol and progesterone are involved in the regulation of NOS expression and activity during pregnancy and implantation in the rat.

Animals↗

PubMed2003

Interaction among beta-endorphin, nitric oxide and prostaglandins during ovulation in rats.

The aim of this study was to investigate the relationship between beta-endorphin and nitric oxide (NO) during the ovulatory process in rats. Immature rats were treated with equine chorionic gonadotrophin-hCG to induce ovulation. An intrabursal injection of beta-endorphin stimulated nitric oxide synthase (NOS) activity. This effect was completely reversed when naltrexone was co-injected with beta-endorphin. The stimulatory action of beta-endorphin on NOS activity was studied to determine whether it was exerted via prostaglandins. Treatment with prostaglandin E(2) (PGE(2)) completely reversed the beta-endorphin-induced stimulation of NOS activity. Moreover, intrabursal injection of meloxicam, an inhibitor of cyclooxygenase 2, increased NOS activity, but this effect was not altered by co-injection with beta-endorphin. The presence of both endothelial NOS (eNOS) and inducible NOS (iNOS) in the ovary at 10 h after hCG treatment was studied by western blot analysis. Local administration of beta-endorphin inhibited the expression of eNOS protein, whereas expression of iNOS protein was not detectable. Ovarian beta-endorphin content was diminished at 10 h after hCG injection. Treatment with prostaglandin synthesis inhibitors in vivo augmented the ovarian beta-endorphin content. In conclusion, these results indicate that beta-endorphin stimulates the activity of ovarian NOS indirectly by inhibiting prostaglandin production.

Animals↗

PubMed2003

Effects of in vivo administration of epidermal growth factor (EGF) on uterine contractility, prostaglandin production and timing of parturition in rats.

Prostaglandins synthesized by cyclooxygenases elicit uterine contractions during labour. Nitric oxide synthases (NOS) produce nitric oxide (NO), which maintains uterine quiescence during pregnancy. Epidermal growth factor (EGF) interacts with prostaglandins and NO in many biological systems. The aim of this work was to study the effect of the in vivo administration of EGF on uterine contractility, prostaglandin production and timing of parturition in rats. EGF was injected into the uterine lumen of pregnant rats on day 20, 21 or 22 of gestation. Intra-uterine administration of 500 ng EGF on day 21 of gestation delayed parturition for 18 h compared with control rats. Administration of EGF was able to: (i) reduce cyclooxygenase expression in the uterus (determined by western blot analysis) and production of prostaglandins by the uterus (evaluated by conversion of [(14)C]arachidonate to labelled prostaglandins); (ii) decrease prostaglandin concentrations in amniotic fluid (radioimmunoassay); (iii) increase NO production (evaluated by conversion of [(14)C]arginine into [(14)C]citrulline); (iv) increase serum progesterone concentrations to more than control concentrations (P<0.05; radioimmunoassay); and (v) reduce the amplitude of the uterine contractions. The overall effect was a delay in the onset of delivery. This in vivo effect raises the question of whether exogenous EGF plays a role in the initiation of parturition.

Amniotic Fluid↗

PubMed2002

Effects of aluminum sulfate on erythropoiesis in rats.

The aim of this study was to investigate the effects of chronically administered aluminum on erythropoiesis in rats. After treatment (i.p. injections of Al(2)(SO(4))(3), 50 micromol/kg body weight, five times a week) for 3 months, the treated (Al) group showed significantly decreased hemoglobin concentration (32%) and hematocrit (24%) compared with the control group. Serum iron decreased significantly in the Al group, whereas total iron binding capacity did not change. Treatment did not alter the activity of hepatic, renal or cerebral delta-ALA-D. Biochemical measurements related to 2-thiobarbituric acid-reactive substance (TBARS) levels from serum and hepatic, renal and cerebral homogenates also did not change after treatment. Hepatic concentrations of aluminum were higher in the Al group than in the control group. Renal and cerebral aluminum concentrations did not vary between groups. The present results indicate that exposure to aluminum sulfate promotes signs of anemia in rats as a consequence of alterations in iron status.

Adjuvants, Immunologic↗

PubMed2002

Umbilical cord blood collection in Cesarean section: a comparison before and after placental delivery.

Fetal stem cells transplants depend on nucleated cells from fetal blood. This study was a prospective randomized trials to compare the collection of fetal blood by gravity into a bag containing anticoagulant, before and after delivery of the placenta. The obstetric and the newborn characteristics in the two group were not significantly different. The mean volume of fetal blood collected while the placental was still in utero was 74.93+/-7.1 ml as against 35.78+/-3.6 ml for collection of fetal blood after delivery of the placenta.

Cesarean Section↗

PubMed2002

Comparison of dexa and ultrasonometry in the measurement of bone density.

The aim of our study was to evaluate the diagnostic agreement between quantitative sonography of the calcaneum (QUS) and dual energy X-ray absorptiometry (DEXA) of the spine and femur. 153 women enrolled in our study and were divided in three groups. Group A was composed of women aged between 45 and 55, Group B of women of 56-66 and Group C of women 67-77. Mean height cm 164+/-2.8; mean weight kg 68+/-3.2. The most concordant results were obtained in group B. This suggests that QUS screening for osteoporosis may be suitable for the "younger" perimenopausal patient.

Absorptiometry, Photon↗

PubMed2002

Cytoarchitectural features of Ucides cordatus (Crustacea Decapoda) hepatopancreas: structure and elemental composition of electron-dense granules.

Hepatopancreal tissue of the crab Ucides cordatus was investigated by light and electron microscopy. The observed epithelial cells were: E-cells (embryonic), located in the distal portion of the hepatopancreal tubules, R-cells (resorptive) F-cells (fibrillar) and B-cells (blister or secretory), found in its intermediate and proximal regions. Two types of electron-dense granules (EDGs) were found frequently in the cells of the proximal portion of the hepatopancreal tubule. Both types of EDGs presented alternating concentric electron-dense and electron-lucent layers. In order to better characterize these granules, energy dispersive X-ray analysis (EDXA) and glucose-6-phosphatase (G6Pase) cytochemistry were performed. One type of spherical granule was seen inside vacuoles surrounded by an association of myelin-like membranes as well as some small membrane-bound vesicles. This type of granule neither presented detectable Ca and P on EDXA spectra nor G6Pase cytochemical reaction products. The second type of granule had O, P and Ca characteristic peaks. G6Pase cytochemical products were observed inside these structures and showed that this mineralized type was surrounded by endoplasmic reticulum membranes. This result suggests that in U. cordatus the endoplasmic reticulum is associated with the genesis of mineralized EDGs. While amorphous mineral granules may be associated with a storage of Ca and P for the new carapace synthesis, EDGs covered by the non-mineralized spherical multi-layered membranes may be associated with late endosomes. No specific secretory pathway however was determined for the EDGs at the epithelial proximal portion.

Animals↗

PubMed2002

Ferritin in iron containing granules from the fat body of the honeybees Apis mellifera and Scaptotrigona postica.

It is already known that the behaviour of the honeybee Apis mellifera is influenced by the Earth's magnetic field. Recently it has been proposed that iron-rich granules found inside the fat body cells of this honeybee had small magnetite crystals that were responsible for this behaviour. In the present work, we studied the iron containing granules from queens of two species of honeybees (A. mellifera and Scaptotrigona postica) by electron microscopy methods in order to clarify this point. The granules were found inside rough endoplasmic reticulum cisternae. Energy dispersive X-ray analysis of granules from A. mellifera showed the presence of iron, phosphorus and calcium. The same analysis performed on the granules of S. postica also indicated the presence of these elements along with the additional element magnesium. The granules of A. mellifera were composed of apoferritin-like particles in the periphery while in the core, clusters of organised particles resembling holoferritin were seen. The larger and more mineralised granules of S. postica presented structures resembling ferritin cores in the periphery, and smaller electron dense particles inside the bulk. Electron spectroscopic images of the granules from A. mellifera showed that iron, oxygen and phosphorus were co-localised in the ferritin-like deposits. These results indicate that the iron-rich granules of these honeybees are formed by accumulation of ferritin and its degraded forms together with elements present inside the rough endoplasmic reticulum, such as phosphorus, calcium and magnesium. It is suggested that the high level of phosphate in the milieu would prevent the crystallisation of iron oxides in these structures, making very unlikely their participation in magnetoreception mechanisms. They are most probably involved in iron homeostasis.

Animals↗

PubMed2002

Two CD34+ stem cells from umbilical cord blood enrichment methods.

The authors describe the relation between clamping time and blood volume collected, and two enrichment systems of CD34+ stem cells from umbilical cord blood, to determine an excellent recovery with high proliferate ability and bone marrow reconstitution. After an obstetrician-based cord blood collection, the purification of stem cells was performed either with a combination of monoclonal antibodies (negative selections) using the Stem Sep method, or with a positive cells selection thanks to their surface CD34 antigens, using the Mini Macs system. An excellent recovery of hematopoietic progenitors, burst-forming unit erythroid, colony-forming unit granulocyte and macrophage, and colony-forming unit granulocyte, erythroid, monocyte, and macrophage, inversely related to the rising of clamping time, was performed with the Mini Macs system (54% of colonies, with a 90% purity), while with Stem Sep method, hematopoietic progenitor recovery was 35% (with an 80% purity). By applying early clamping of the umbilical cord blood a greater number of CD34+ cells was obtained and their clonogenic activity increased with enrichment. This is particularly useful, considering that the number of CD34+ stem cells contained in a unit of placental blood is enough for transplanting to a child, but not for an adult engraftment. Thus, using this method, a larger number of CD34+ stem cells can be obtained, which increases the possibility to reduce graft versus host disease also in adult patients, producing survival rates similar to the ones obtained with transplantation of bone marrow from unrelated donors.

Antibodies, Monoclonal↗

PubMed2002

VLA-2 and VLA-5 cell adhesion molecules expression in CD34+ cells from umbilical cord blood and from bone marrow.

BACKGROUND/AIMS: Umbilical cord blood contains a large number of early hematopoietic cells with high proliferating capacity, that has been used as an alternative to bone marrow transplantation. The aim of this study is to investigate the number of two cell adhesion molecules in cord blood and in bone marrow. METHODS: We investigated two integrins, named VLA-2 and VLA-5 (Very Late Appearing Antigen), expressed in the surface of CD34+ cells. The CD34+ cells, isolated with MACS CD34+ isolation kit, were labelled with the appropriate monoclonal antibodies. RESULTS: Cell adhesion molecules showed highly expressed in both cord blood and bone marrow CD34+ cells. CONCLUSION: There are no significant differences between the two sources of CD34+ populations.

Antigens, CD34↗

PubMed2002

Differences in umbilical cord blood units collected during cesarean section, before or after the delivery of the placenta.

Umbilical cord blood is largely employed as an alternative source of stem cells in the treatment of hemato-oncological diseases. Current results show that the success rate of purified umbilical cord blood engraftment is comparable to that obtained using bone marrow, and it is directly related to the number of pluripotent stem cells transplanted. The technique of fetal blood collection varies among different umbilical cord blood banks. Many authors collect umbilical cord blood during vaginal delivery, after placental detachment, while others collect it while the placenta is still within the uterus. In a previous randomized trial, we showed a greater collection of umbilical cord blood before placental detachment during vaginal delivery. The present study was performed to determine whether umbilical cord blood collection before placental detachment (group A) during cesarean section is superior to that after placental delivery (group B) puncturing the umbilical vein once and using a closed bag system. To accomplish this, 47 pregnant women subjected to cesarean section were enrolled in the study. Twenty-one of them were allocated to group A, while the remaining 26 formed group B. The volume of umbilical cord blood collected from the patients of group A was greater than that collected from patients of group B. The cord blood volume collected was 90.7 +/- 6.0 versus 60.9 +/- 13.7 ml; the cord blood nucleated cell number was 10.1 +/- 1.2 x 10(8) vs. 7.1 +/- 0.8 x 10(8); and the mean cord blood CD34+ cell number was 20.0 +/- 6.0 x 10(5) vs. 16.4 +/- 2.4 x 10(5), respectively.

Adult↗

PubMed2002

Influence of the kind of delivery on umbilical cord blood collection.

From December 1999 to February 2001, the Microbiological and Gynaecological Science Department of the University of Catania has been involved in the collection of umbilical cord blood samples. Eight hundred and sixty-three cord blood units were collected and sent to Sciacca's UCB bank. Among them, 429 were collected from newborns delivered vaginally, while the remaining were collected from Caesarean sections. The aim of this study was to evaluate the difference between umbilical cord blood samples collected during a vaginal delivery and those from a Caesarean section. In particular, the blood volume collected and cord blood CD34+ stem cell count were considered. The method of blood collection consisted of puncturing the umbilical cord vein with an 18-gauge needle and withdrawing the blood into a sterile bag immediately after clamping and newborn assistance. The blood was collected when the placenta was still in utero and the indication to the kind of delivery was, independently of the study, according to obstetrical good practice. The results of the analysis showed that the cord blood volume and the number of CD34+ cells collected were similar for the two groups. The higher median volume of blood collected from infants delivered by Caesarean section seems mainly due to the different clamping time, rather than to the kind of delivery.

Blood Specimen Collection↗

PubMed2002

Reaction of diphenyl diselenide with hydrogen peroxide and inhibition of delta-aminolevulinate dehydratase from rat liver and cucumber leaves.

The interaction of the product of H2O2 and (PhSe)2 with delta-aminolevulinate dehydratase (delta-ALA-D) from mammals and plants was investigated. (PhSe)2 inhibited rat hepatic delta-ALA-D with an IC50 of 10 microM but not the enzyme from cucumber leaves. The reaction of (PhSe)2 with H2O2 for 1 h increased the inhibitory potency of the original compound and the IC50 for animal delta-ALA-D inhibition was decreased from 10 to 2 microM. Delta-ALA-D from cucumber leaves was also inhibited by the products of reaction of (PhSe)2 with H2O2 with an IC50 of 4 microM. The major product of reaction of (PhSe)2 with H2O2 was identified as seleninic acid and produced an intermediate with a (lambda)max at 265 nm after reaction with t-BuSH. These results suggest that the interaction of (PhSe)2 with mammal delta-ALA-D requires the presence of cysteinyl residues in close proximity. Two cysteine residues in spatial proximity have been recently described for the mammalian enzyme. Analysis of the primary structure of plant delta-ALA-D did not reveal an analogous site. In contrast to (PhSe)2, seleninic acid, as a result of the higher electrophilic nature of its selenium atom, may react with additional cysteinyl residue(s) in mammalian delta-ALA-D and also with cysteinyl residues from cucumber leaves located at a site distinct from that found at the B and A sites in mammals. Although the interaction of organochalcogens with H2O2 may have some antioxidant properties, the formation of seleninic acid as a product of this reaction may increase the toxicity of organic chalcogens such as (PhSe)2.

Analysis of Variance↗

PubMed2002

Influence of sport and low animal saturated fats intake diet on lipid dismetabolisms in postmenopausal women.

BACKGROUND: An important aetiopathogenetic factor leading to menopausal age pathologies (such as hypertension, diabetes, cardiovascular diseases and so on) is certainly represented by the worsening of lipid dismetabolism. This condition is generally characterized by an increase in total mean cholesterol levels, LDL-cholesterol (low density lipoprotein-cholesterol), VLDL-cholesterol (very low density lipoprotein-cholesterol), triglycerides, with reduction of HDL-cholesterol (high density lipoprotein-cholesterol) mean levels. All these metabolic modifications are triggered or increased by the hypoestrogenemia typical of postmenopausal age. The aim of our study was to evaluate the influence on postmenopausal women's lipid metabolism of a low contribution of animal saturated fat diets, associated with physical training. METHODS: We enrolled in our study 36 mild hypercholesterolemic postmenopausal women (non smokers and not complaining of hypertension and diabetes) and we put them through aerobic training, consisting of 1 hour of a light continuous run, repeated 4 times per week. The final control of their metabolic status and of their lipid order was executed after 6 months, but during this period, all the women were observed bi-weekly or monthly, to assure a high uniform compliance in the group. None of the women enrolled took specific drugs for the lipid metabolism during the study. RESULTS: After 6 months from the beginning of the diet, with associated physical training, an important weight loss was observed. Increases of HDL-cholesterol mean levels (p<0.05) associated with a decrease of total cholesterol mean levels (p<0.05) were reported in all the subject examined. A statistically non-significant decrease in LDL and VLDL cholesterol mean levels was also noticed. CONCLUSIONS: A mild lipid dysmetabolism in postmenopause may be corrected advantageously by an opportune diet associated with moderate, but constant, physical training.

Cholesterol↗

PubMed2002

Evaluation of bone mass in young amenorrheic women with anorexia nervosa.

BACKGROUND: In the last 10 years an impressive increase in the frequency of food disorders (bulimia and anorexia) in teenagers has been recorded. Food disorders, present especially in girls, (part of more complex relational-familiar disorders) cause progressive repercussions on the general endocrine structure and in particular on the reproductive system of the subject. The most visible effect of this endocrine perturbation is the block of the ovarian function with secondary amenorrhoea and low levels of gonadotropins and estrogens due to the food disorder. In fact the qualitative and quantitative food deficit is responsible for the interruption of the normal hypothalamic and pituitary pulses regulating the correct monthly process of follicular growth. As in the physiological postmenopausal period, very low plasma levels of 17-b-estradiol (<30 pg/ml) can start the bone resorption with bone loss and/or osteoporosis related to the amount and the time of exposure to low levels of estrogens. OBJECTIVES: in our study we evaluate the influence of anorexia and amenorrhoea on bone mineral density. METHODS: We evaluate bone mineral density (BMD) with computerised bone mineralometry (MOC), a dual-energy-X-Ray (DEXA), in 18 women with anorexia nervosa and weight loss, 9-12 months amenorrhoea and with low plasma levels of 17-b-estradiol. The BMD was measured at the lumbar spine (L2-L4) and on total body in all subjects enrolled for this study. RESULTS: All the patients showed a decrease on the lumbar BMD with bone loss (49%) or osteoporosis (51%). On the other side the values of total body BMD were around the normal levels (86%) or showed bone loss (14%). CONCLUSIONS: Our data support the hypothesis that lower estrogenic levels associated with anorexia nervosa have an impact on BMD, especially at lumbar level, with early incidence for quantitative and qualitative lower food intake.

Adolescent↗

PubMed2002

Uterine bleeding pattern during low dosage Noretisterone acetate and 17-b-Estradiol treatment in postmenopausal patients.

BACKGROUND: Recent years have been characterized by progressive optimization of postmenopausal hormonal replacement therapy. More physiological therapeutic protocols have been, in fact, proposed to control the possible symptomatology and to prevent the associated risks, with estro-progestinic compounds characterized by lower effective dosages and suitable for the single patient need. However this therapy is not widely accepted by the women from our country for the fears and the inconvenience raised around such side effects as abnormal uterine bleeding and spotting. AIM: to obtain a good compliance and clinical benefits a continuous administration protocol of the hormonal replacement therapy, alternatively to the sequential one has been proposed. METHODS: Our research group has been observing a sample of 42 patients for 12 months, taking oral 17-b-estradiol 1 mg/noretisterone 0.5 mg in continuous administration. All of them were aged from 42 to 63 years and had been in symptomatic menopause for at least 3 months. The characteristics, the onset and the trend of vaginal bleeding were registered in appropriate monthly diaries. Endometrial thickness was evaluated by transvaginal sonography before starting the administration, not exceeding 4 mm in all the women considered. RESULTS: The incidence of bleeding (calculated as a percent of women who experienced a vaginal bleeding for al least a day during a menstrual cycle) was from 26% to 32% in the 1st trimester, reducing during the following months. At 6 months of therapy only 5% of women reported evident vaginal bleeding; at 12 months 90% of women complained with absence of bleeding or spotting. At 12 months no women showed an endometrial thickness over 6 mm. CONCLUSIONS: This observational study suggests that the majority of treated patients proved to be positively responsive to the treatment and that the 17-b-estradiol 1 mg/noretisterone 0.5 mg association reduces the incidence of bleeding and spotting with a sufficient endometrial protection from hyperplasia.

Adult↗

PubMed2001

Contribution of cryofixation and freeze-substitution to analytical microscopy: a study of Tritrichomonas foetus hydrogenosomes.

The hydrogenosome, an organelle that produces molecular hydrogen and ATP from the oxidation of pyruvate or malate under anaerobic conditions, presents some characteristics common to mitochondria. It is found in several trichomonad species, protists living in oxygen-poor environments, as well as certain free-living ciliates, rumen ciliates, and some fungi. We performed a comparative microanalytical study (energy dispersive X-ray analysis and electron spectroscopic imaging) of different fixation methods for electron microscopy analyzing hydrogenosomes of the bovine parasite Tritrichomonas foetus. The study included the elemental composition and the mapping of calcium, phosphorus, and oxygen. A preparation of T. foetus cells, based on cryoimmobilization by high-pressure freezing and freeze-substitution, was compared to a second preparation based on chemical fixation followed by dehydration and routine processing. The ultrastructural preservation achieved by the cryotechnique was far superior to the chemical fixation, since it allowed the successful cryoimmobilization of intracellular ion contents. The detection of several cations (Al, Mg, Co, Ca, Fe) by X-ray microanalysis inside the peripheral vesicle of the hydrogenosome was only possible in cryofixed cells. The presence of aluminum and cobalt ion in the hydrogenosomal vesicle was established for the first time. Electron-spectroscopic images of calcium showed that this element, in addition to the vesicle compartment, is present in the hydrogenosome's membrane in varying concentrations, which might reflect changes in the physiology of this organelle.

Animals↗

PubMed2001

Selenoxides inhibit delta-aminolevulinic acid dehydratase.

The effect of two selenides and their selenoxides on delta-aminolevulinic acid dehydratase (delta-ALA-D) from liver of adult rats was investigated. In vivo, selenides can be oxidized to selenoxides by flavin-containing monooxygenases (FMO) and selenoxides can regenerate selenides by thiol oxidation. Phenyl methyl selenide (PhSeCH3) and 1-hexynyl methyl selenide (C4H9Ctriple bondCSeCH3) were converted to selenoxides by reaction with H2O2. PhSeCH3 and C4H9Ctriple bondCSeCH3 had no effect on delta-ALA-D up to 400 microM. Conversely, their selenoxides inhibited delta-ALA-D, and the IC(50) for enzyme inhibition was about 100 and 70 microM, respectively. Partially purified delta-ALA-D (P(55)) from swine liver was also inhibited by these selenoxides. The inhibitory action of selenoxides was antagonized by dithiotreitol (DTT). Moreover, delta-ALA-D from a plant source was inhibited by the selenoxides, suggesting a possible involvement of SH groups in a distinct site of the homologous region implicated in Zn2+ binding in mammalian delta-ALA-D. After exposure to PhSeCH3 (500 micromol/kg/day) for 45 or 30 days, the activity of delta-ALA-D from liver of mice decreased to about 50% of the control group. The in vivo inhibitory action of this compound was not antagonized by DTT. PhSeCH3 and C4H9Ctriple bondCSeCH3 had no effect on the rate of DTT oxidation, but their selenoxides oxidized DTT. The results of the present study suggest that hepatic delta-ALA-D of rodents is a potential molecular target for selenides as a consequence of their metabolism to selenoxides by FMO.

Animals↗