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Biomedical subjects

G Mosconi

Publications and source records attributed to G Mosconi.

At least 37 records · Page 2Linked to original sources

Involvement of tyrosine kinase and cAMP in growth hormone-induced vitellogenin synthesis in the anuran, Rana esculenta.

In the frog Rana esculenta, a multihormonal control of vitellogenin synthesis was previously demonstrated. Now in this study, the identity of intracellular second messengers that mediate the GH effects on hepatic VTG synthesis are described. The results clearly indicate that the effect of GH on frog hepatocytes, in vitro, works through a local production of IGF I; in fact, IGF I affects VTG synthesis and its action occurs faster with respect to that of GH. The effect of IGF I was abolished by the anti-estrogen tamoxifen, indicating the involvement of estrogen receptor in VTG induction by IGF I. Furthermore, in vitro treatment of frog hepatocytes with GH resulted in an increase of cAMP with maximum levels after 20 min of treatment. Besides the increase of cAMP, GH induced the appearance of a new phosphotyrosine protein at 20 min, suggesting the occurrence of tyrosine kinase activation. Addition of adenylate cyclase or protein tyrosine kinase inhibitors completely abolished the induction of VTG synthesis, indicating the involvement of cAMP and of a phosphotyrosine protein in VTG synthesis stimulated by both GH and IGF I.

Animals↗

Application of Prastat ELISA in the determination of anti-HLA specificity for immunized patients awaiting kidney transplant: five years' experience.

Three hundred sixty-five patients who underwent cadaver donor kidney transplantation between 1993 and 1998 were divided into four groups: 40 immunized patients with at least one peak panel-reactive antibody (PRA) value more than 50%, 11 hyperimmunized patients with more than three peak PRA values over 50%, 10 retransplanted patients and 304 control patients. Before transplantation, we ascertained the antibody specificities against individual HLA antigens (Prastat Sangstat ELISA method for HLA typing of first donor, husbands of multiparous women and potential donors against whom candidates gave positive cross-matches); thus, patients underwent transplantation excluding the presence of the HLA antigens previously detected and looking for high HLA (class I and II) compatibility. Actuarial graft survival after 12 months was satisfactory in all groups: 87% immunized, 81% hyperimmunized and 80% retransplanted vs 92% controls. Renal function at the end of the first year was similar and the number of rejection episodes in the first 3 months did not significantly differ.

Actuarial Analysis↗

Newt prolactin and its involvement in reproduction.

The amino acid sequence of newt (Cynops pyrrhogaster) prolactin deduced from the nucleotide sequence of its cDNA showed a relatively high homology with sequences of chicken and sea turtle prolactins as well as with those of anuran prolactins. Cynops prolactin receptor transcripts were detected in various tissues and organs, suggesting that prolactin plays multiple roles in urodeles. Urodele prolactin was purified from the pituitaries of C. pyrrhogaster. Antiserum against this prolactin was used for radioimmunoassay of plasma prolactin and immunoneutralization experiments. Endogenous prolactin was shown to induce migration to water, courtship behavior, and cessation of spermatocytogenesis in the Cynops newt. The hormone was found to be involved in the development of cloacal glands such as the lateral and abdominal glands, growth of the tail and Mauthner neurons, secretion of oviducal jelly, and enhanced synthesis of a female attracting pheromone (sodefrin), and responsiveness of the olfactory epithelium to sodefrin. In most of these cases, prolactin was found to act synergistically or antagonistically with sex steroids. We also discovered that hypersecretion of prolactin in the newts subjected to cold temperature was induced by hypothalamic stimulation rather than release from hypothalamic inhibition.

Amino Acid Sequence↗

Mathematical modeling of solute kinetics and body fluid changes during profiled hemodialysis.

A mathematical model of solute kinetics oriented to improve hemodialysis treatment is presented. It includes a two-compartment description of the main solutes (K+, Na+, Cl-, urea, HCO3-, H+, CO2), acid-base equilibrium through two buffer systems (bicarbonate and non-carbonic buffers) and a three-compartment model of body fluids (plasma, interstitial and intracellular). The main model parameters can be individually assigned a priori, on the basis of body weight and plasma concentration values measured before beginning the session. Model predictions are compared with clinical data obtained during 11 different hemodialysis sessions performed on six patients with profiled sodium concentration in the dialysate and profiled ultrafiltration rate. In all cases, the agreement between the time pattern of model solute concentrations in plasma and clinical data turns out fairly good as to urea, sodium, chloride and potassium kinetics. Finally, the time patterns of plasma bicarbonate concentration and pH can be reproduced fairly well with the model, provided CO2 concentration remains constant. Only in two sessions, blood volume was directly measured in the patient, and in both cases the agreement with model predictions was good. In conclusion, the model allows a priori computation of the amount of sodium removed during hemodialysis, and may enable the prediction of plasma volume changes and plasma osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Hence, it can be used to improve the dialysis session taking the characteristics of individual patients into account, in order to minimize intradialytic imbalances (such as hypotension or disequilibrium syndrome).

Acid-Base Equilibrium↗

Severe gastrointestinal bleeding in a uremic patient treated with estrogen-progesterone therapy.

Gastrointestinal bleeding is a frequent complication in hemodialysis patients; angiodysplasia is a potential cause, with a higher incidence in uremic patients. We describe a case of severe anemia (Hemoglobin up to 3.5 g/dl) secondary to diffuse angiodysplastic lesions in a hemodialysis patient with mixed connective tissue disease. The case is characterised both by the severity of the clinical picture (extension and entity of angiodysplastic lesions, frequency of bleeding episodes) and by the patient's religious faith which made her reject blood transfusions. We underline the efficacy of estrogen-progesterone therapy in view of the modest results obtained with other therapeutic strategies on bleeding.

Adult↗

Identification and spatial distribution of the mRNA encoding the gp49 component of the gilthead sea bream, Sparus aurata, egg envelope.

A cDNA encoding the precursor of one of the major components of gilthead sea bream, Sparus aurata, egg envelope has been cloned by reverse transcriptase polymerase chain reaction (RT-PCR) techniques. The clone was isolated starting from total RNA extracted from the liver of spawning female fish and estradiol-17 beta-treated male fish. Sequence analysis revealed that the cDNA encoded a protein of 405 aa corresponding to 49-kDa component (termed gp49), a glycoprotein belonging to the N-linked type. The gp49 protein is homologous to the Zl-3 of medaka Oryzias latipes, the mammalian ZPC and ZPC homologues of Xenopus laevis (xlZPC) and carp Cyprinus carpio (ccZPC). In addition, the open reading frame also encodes an additional aa sequence, the signal peptide, located in the N-terminal region of the protein. RT-PCR and in situ expression analyses evidenced an organ-restricted pattern: the mRNA was detected only in liver of spawning female and estradiol-17 beta-treated male fish but not in other tissues.

Amino Acid Sequence↗

Gilthead seabream (Sparus aurata) vitellogenin: purification, partial characterization, and validation of an enzyme-linked immunosorbent assay (ELISA).

VTG was purified from seabream Sparus aurata plasma by ion exchange chromatography on a DEAE-Sepharose column. The vitellogenin was characterized and its properties were determined. The molecular mass of the native form, obtained by Sephadex G-200 column, was around 450 kDa, whereas an apparent molecular mass of 180 kDa was detected by electrophoresis under denaturing and reducing conditions, suggesting a dimeric form for the native protein. The presence of carbohydrates was determined using concanavalin A, while the presence of phosphate groups was detected by Stains-all, a cationic stain. These data together with the sex specificity, the estrogen inducibility, and the cross-reactivity of the abVTG against the major yolk proteins identifies this protein as vitellogenin. The validated ELISA was used for a rapid and reliable measurement of plasma VTG changes related with those of estradiol-17beta in female broodstock.

Animals↗

Antimicrobial prophylaxis in orthopaedic surgery: the role of teicoplanin.

Orthopaedic joint replacement is generally considered 'clean' surgery characterized by a low incidence of infection. In recent years the use of a clean theatre environment, high local concentrations of antibiotic in the cement and systemic antibiotic prophylaxis have been recognized as important measures to reduce infection rates significantly, and this has been supported by clinical trials. Staphylococcus aureus and Staphylococcus epidermidis cause at least half of all orthopaedic surgical infections. Gram-negative bacilli are involved to a much lesser extent (10-30%). First- and second-generation cephalosporins are currently considered by most authors as standard prophylaxis in elective orthopaedic surgery. In the light of the increasing incidence of methicillin resistance in coagulase-positive and -negative staphylococci, it is becoming more important for antibiotics to act efficiently against such organisms if they are to be of value in prophylaxis in orthopaedic surgery. A combined, single-dose of vancomycin/gentamicin has been used successfully in an open, controlled study in patients undergoing total joint arthroplasty but, given the disadvantages associated with the use of vancomycin, teicoplanin may be an alternative choice in such procedures. This review analyses four comparative trials of the efficacy and safety of teicoplanin, two with cefamandole, one with cefuroxime and one with cephazolin, as prophylaxis in orthopaedic total joint replacement surgery.

Anti-Bacterial Agents↗

Gonadotropins and reproductive function in the anuran amphibian, Rana esculenta.

In this study, the measurement both of peripheral gonadotropins (FSH and LH) and of sex steroids in male and female wild anuran, Rana esculenta, was performed during the annual reproductive cycle; moreover, the role of gonadotropins in the vitellogenic process and in ovarian steroidogenesis was investigated through in vitro experiments. LH plasma changes in males showed high values during autumn-winter months and during the mating period, when high androgen levels were found. Conversely, for the first time in male vertebrates, a clear correspondence between plasma FSH and estradiol-17beta (E2) was shown. In females, FSH peak values were found at the beginning of the mating period in parallel with those of plasma vitellogenin (VTG) and E2; in contrast, high LH levels went together with ovarian weight (gonadosomatic index), which is considered a good marker for the plasma sequestration of VTG by growing oocytes. The in vivo results are corroborated by in vitro studies showing the direct effects of both FSH and LH in inducing hepatic VTG synthesis and release in the culture media. Lastly, although it is not yet known whether or not FSH and LH have separate functions in amphibians, it was clearly shown that they induce ovarian steroid production. These results are discussed in terms of the high seasonality previously demonstrated in this wild frog.

Androgens↗

Acetyl salmon endorphin-like and interrenal stress response in male gilthead sea bream, Sparus aurata.

The present study investigates the role of melanotrope proopiomelanocortin-derived peptide in the interrenal stress response to different stressors in male gilthead sea bream, Sparus aurata. Plasma cortisol and acetyl salmon endorphin (acetyl s-EP), as well as pituitary acetyl s-EP contents, were measured during two stress paradigms: (a) long-term (1-month) confinement and crowding, and (b) short-term (60-min) confinement, crowding, and manipulation. In addition, naltrexone, a highly specific opioid receptor antagonist, was employed in some experimental groups to evaluate the adaptability of the opioid response to interrenal stress. In the long-term (1-month) confinement and crowding, higher plasma cortisol levels and acetyl s-EP concentrations than in the control group were found. However, although plasma cortisol levels significantly increased in both types of stress paradigm, a significant rise in plasma acetyl s-EP was observed only in the case of confinement plus crowding. These data seem to suggest a direct correlation of acetyl s-EP plasma levels exclusively in cases of specific stress, and support previous observations about the different nature of the pituitary-interrenal stress response in salmonids and in mammals. The results obtained in the short-term (60-min) experiments demonstrate the double activation of both the opioid and corticotrope systems when manipulation plus crowding was applied.

Adaptation, Physiological↗

Susceptibility to hard metal lung disease is strongly associated with the presence of glutamate 69 in HLA-DP beta chain.

Clinical, epidemiological and experimental data indicate that inhaled metal dust containing cobalt may produce an interstitial lung disease termed "hard metal disease" (HMD). Some aspects of this pathology such as the lack of correlation with dose exposure, the low frequency of the disease and the presence of T cells in the inflammation site, all suggest the existence of a genetic susceptibility, possibly to an immunological response to cobalt or to self proteins modified by cobalt. Here we report that HMD is strongly associated with residue Glu-69 of the HLA-DP beta chain. All patients, except for one with a rare genotype, possessed this marker as compared to 17 out of 35 exposed unaffected individuals (p = 0.0014). These data allow us to genetically distinguish a subgroup of cobalt-exposed individuals at risk for HMD, independently from the more common allergic reaction.

Adult↗

A review of teicoplanin in the treatment of serious neonatal infections.

UNLABELLED: Gram-positive bacteria, notably coagulase negative staphylococci, have become an important cause of infection in neonates. Furthermore, many of these pathogens are now resistant to multiple antibacterial agents. Teicoplanin, a glycopeptide antibiotic, is active against a broad range of Gram-positive pathogens, including methicillin-resistant staphylococci. It has advantages over vancomycin in terms of tolerability, with a lower propensity to cause nephrotoxicity and anaphylactoid-like reactions, and in terms of ease of administration and monitoring requirements. The clinical utility of teicoplanin in neonates with Gram-positive infections has been investigated in several noncomparative studies. Clinical and bacteriological response rates in 173 neonates treated with teicoplanin 8-10 mg/kg intravenously or intramuscularly once daily after a loading-dose regimen of 10-20 mg/kg per day have ranged from 80%-100% and 83%-100%, respectively. Few adverse events related to teicoplanin have been reported in this patient population. CONCLUSION: Teicoplanin (8-10 mg/kg) administered intravenously or intramuscularly once daily after a loading-dose regimen of 15-20 mg/kg per day appears to be an effective and well tolerated treatment for Gram-positive infections in neonates.

Anti-Bacterial Agents↗

Acetyl salmon endorphin-like immunoreactivity in the ovary of two teleostean species: changes with environmental conditions.

The presence of salmon acetylated endorphin (acetyl sEP) in the ovary of seabream and sea bass was investigated through immunocytochemical and biochemical techniques in order to compare aquatic species with terrestrial ones. Endorphin-like immunoreactivity was found in the cytoplasm of oogonia and similar immunostaining was present in the granulosa layer of mature follicles. In both pituitary and ovarian extracts of the two teleostean species, acetyl sEP-like immunoreactivity was distributed over three main peaks, the second one corresponding to the elution time of the reference synthetic peptide. Serial dilutions of HPLC fraction II of the ovaries of both fishes ran parallel with the standard curve obtained with reference peptide. The ovarian content of acetyl sEP, obtained by calculating the integrated area of the fraction II peak, indicates large and highly significant (p < 0.01) differences in the amount of peptide found in ovarian tissues of wild seabream in comparison with that of farmed fish. Increased peptide values in wild animals with respect to farmed fish were also found in the sea bass. These data indicate that not only the pituitary, but also the ovary is sensitive to environmental cues, and strongly suggest the role of opioid peptides in adaptation.

Acetylation↗

A prospective, randomized trial of two antibiotic regimens in the treatment of peritonitis in CAPD patients: teicoplanin plus tobramycin versus cephalothin plus tobramycin.

A multicentre, comparative, randomized study was performed to compare the efficacy and tolerability of two antibiotic regimens in the treatment of peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients: teicoplanin plus tobramycin versus cephalothin plus tobramycin. After informed consent had been obtained, 68 patients were randomized prospectively to receive either teicoplanin plus tobramycin or cephalothin plus tobramycin. Patients were followed throughout the study and for up to 4 weeks after the end of treatment, when clinical and microbiological parameters were assessed again. The incidence of clinical failure was 4.6 times higher in the cephalothin plus tobramycin group than in the teicoplanin plus tobramycin group (7/28 versus 2/37; P < 0.05). There was no significant difference in bacterial eradication between the two groups. Local and systemic tolerability were good for both regimens. The study shows that teicoplanin plus tobramycin is more effective than cephalothin plus tobramycin and might become a 'first-line' treatment for peritonitis in CAPD patients.

Aged↗

Low-dosage ibopamine treatment in progressive renal failure: a long-term multicentre trial.

A multicentre trial (11 nephrology centres) was carried out to test the effects of ibopamine, an orally active dopamine-like drug, on the progression of chronic renal failure. For a 2-year period 189 chronic renal failure patients (serum creatinine level 1.5-4.0 mg/dl) were observed. They were homogeneous for basic nephropathy, degree of residual renal function, blood pressure, and proteinuria. The patients were randomly divided into two groups: 96 took ibopamine at a dosage of 100 mg/day (group A) and 93 served as controls (group B). All were on a low-protein diet (mean 0.8 g/kg body weight). By the end of the observation period, the rate of decrease of the renal function indexes in time proved significantly slower (1.8 times) in group A than in group B. The survival curves for renal function (pre-established end points were creatinine level increases equal to or > 20% and equal to or > 40% of the basal values) proved significantly better (p < 0.02 and p < 0.002 respectively) in group A than in group B. The mean plasma creatinine values rose by 17% in group A and by 36% in group B. The creatinine clearance decreased by 5% in treated patients and by 14% in the controls. Statistical analysis ruled out any possible centre effect. The trial suggests that low-dosage ibopamine administration may be used as a valid and safe pharmacological adjunct for retarding the progression of renal failure in patients with mild or moderate chronic renal impairment.

Adolescent↗