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Biomedical subjects

C Bianchi

Publications and source records attributed to C Bianchi.

At least 235 records · Page 13Linked to original sources
PubMed1990

Alternative promoter and 5' exon generate a novel Gs alpha mRNA.

Several species of mRNA have been shown to encode the alpha subunit of the stimulatory GTP-binding regulatory protein, Gs alpha. The various Gs alpha mRNAs are generated through alternative splicing of a single precursor RNA and through the use of alternative acceptor splice sites. We now report the existence of a Gs alpha mRNA that uses a previously unidentified promoter and leading exon (termed exon 1'). In both the canine and human Gs alpha genes, exon 1' is located 2.5 kilobases 5' of exon 1. Exon 1' does not contribute an in-frame ATG, and thus its mRNA encodes a truncated form of Gs alpha. Initiation of translation is predicted to begin at an AUG in exon 2, as demonstrated both by in vitro translation and COS cell expression studies.

Animals↗
PubMed1990

Different effects of 8-OH-DPAT, a 5-HT1A receptor agonist, on cortical acetylcholine release, electrocortigram and body temperature in guinea pigs and rats.

8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) dose dependently increased cortical acetylcholine (ACh) release and the body temperature of freely moving guinea pigs. Moreover, it evoked an electroencephalographic (EEG) arousal reaction in phenobarbital-pretreated animals. 8-OH-DPAT was about 10 times less effective in increasing cortical ACh release in the rat than in the guinea pig, and did not modify the phenobarbital-synchronized EEG but dose dependently decreased body temperature. The possibility that 5-HT1A receptors play different roles, depending on the animal species, is discussed.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Influence of chronic chlorimipramine treatment on the serotonergic modulation of acetylcholine release from guinea pig caudate nucleus slices.

The influence of chronic chlorimipramine (10 mg/kg daily s.c. for 14 days) treatment (CCT) on 5-HT modulation of basal 3H-choline overflow from guinea pig caudate nucleus slices was studied. The increase in basal tritium overflow induced by 5-HT (3-100 mumol/l) or by DOI (30-100 mumol/l) in normal slices was significantly lower in CCT slices. When tetrodotoxin 0.5 mumol/l was added, the facilitatory effect by 5-HT was cancelled, its late inhibitory effect became more evident and to the same extent in normal and CCT slices. This inhibition was cancelled by ICS 205-930 30 mumol/l. These results indicate that the 5-HT2-mediated facilitatory response of intrastriatal cholinergic neurones to 5-HT is reduced by CCT, while the inhibitory response is unaffected.

Acetylcholine↗
PubMed1990

Cigarette smoking and bladder cancer.

The relation between cigarette smoking and risk of bladder cancer was analysed in a case-control study in Northern Italy of 337 cases of histologically confirmed invasive bladder cancer and 392 controls admitted to the same network of hospitals with acute, non-neoplastic, non-urological conditions. Compared with never-smokers, the multivariate relative risk (RR) was 1.9 (95% confidence interval, CI 1.2-3.1) for ex-smokers and 3.3 (95% CI 2.2-5.0) for current smokers. The risk was directly and significantly related to duration of smoking (RR 3.5 for 30 years or more) and dose (RR 3.9 for 20 cigarettes per day or more), and consistent among strata of sex and age (though the RRs were systematically higher at older ages). Smokers of black tobacco only had a RR of 3.7, compared with 2.6 for smokers of blond cigarettes or mixed types. The interaction between tobacco and several occupations associated with bladder cancer risk fitted an additive rather than a multiplicative model: compared with non-exposed never-smokers, RR was 2.5 for exposed non-smokers, 2.8 for non-exposed smokers and 3.7 for occupationally exposed smokers.

Adult↗
PubMed1990

Medical treatment of mild endometriosis in infertile women: analysis of a failure.

The easy access to the pelvis of infertile women by laparoscopy favours early diagnosis of endometriosis in an increasing number of subjects with minimal and mild disease. These initial forms have been associated with and considered as the cause of infertility despite the absence of relevant scientific evidence. Various hormone therapies, some with severe side-effects and high costs, have been used by numerous authors. However, no study comparing medically treated with untreated women has ever shown any drug to be more effective than expectant management. The possible explanations of treatment failures are reviewed.

Buserelin↗
PubMed1990

Growth acceleration and final height after treatment for delayed diagnosis of celiac disease.

The only presenting clinical feature of diagnosing celiac disease (CD) late may be short stature. At the start of treatment with a gluten-free diet (GFD), celiac children show an accelerated growth rate. The real duration of catch-up growth and influence of diet on the final stature has not yet been defined. In order to evaluate the effect of a GFD on growth parameters, 24 children diagnosed late with CD were studied at our center. During the period of diagnosis, weight, height standard deviation score (HSDS), weight and height velocities (WV and HV), bone age (BA), and pubertal stage were recorded. Predicted height (PH) according to the Tanner method, parental height, and target height (TH) were also evaluated at diagnosis. All patients initially presented because of short stature or retarded growth (100% of patients with height less than 5th percentile). Patients showed an increased HV and WV during the first 3 years on a GFD, with maximum growth velocity occurring during the first year, but the catch-up growth was incomplete over 3 years (mean HSDS +/- SD, -1.77 +/- 0.6). Puberty began in all patients at a normal age. The 12 patients who completed pubertal development reached their target height, whatever the duration of the GFD. The final height (between the 1st and 25th percentile) seemed influenced mainly by familial characteristics; height was below the 3rd percentile in 31% of parents examined.

Adolescent↗
PubMed1990

5-HT1A agonists increase and 5-HT3 agonists decrease acetylcholine efflux from the cerebral cortex of freely-moving guinea-pigs.

1. The influence of 5-hydroxytryptamine1A (5-HT1A), 5-HT2 and 5-HT3 agonists and antagonists on acetylcholine (ACh) release from the cerebral cortex was studied in freely moving guinea-pigs. 2. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 0.01-1 mg kg-1, s.c.) caused the 5-HT syndrome and dose-dependently increased ACh release. Ru 24969 (1-10 mg kg-1, s.c.) shared the same effects, but it was less potent. (-)-Propranolol (5 mg kg-1) and metitepine (2 mg kg-1) prevented these behavioural and neurochemical responses. 3. (+/-)-1(4-Iodo-2,5-dimethoxyphenyl)2-aminopropane (DOI) up to 2 mg kg-1 did not modify ACh release and ketanserin (0.5 mg kg-1) was ineffective on 5-HT-induced changes of ACh outflow. 4. 2-Methyl-5-HT (500 micrograms, i.c.v.) and 5-HT (500 micrograms, i.c.v.) plus metitepine (2 mg kg-1, s.c.) inhibited the gross behaviour and ACh release. ICS 205-930 (0.5 mg kg-1) prevented these responses. 5. 2-Methyl-5-HT, up to 10 mumols 1(-1), and 8-OH-DPAT, up to 0.1 mumols 1(-1), (like 5-HT) did not change [3H]-choline efflux from cerebral cortex slices. 6. These results suggest that exogenous 5-HT and related selective agonists modulate guinea-pig cortical cholinergic structures through 5-HT1A and 5-HT3 receptors. The stimulation of 5-HT1A autoreceptors may lead to disinhibition of the cholinergic cells, tonically inhibited by the tryptaminergic control. Conversely, the stimulation of 5-HT3 receptors inhibits ACh release, possibly through an interneurone. No direct 5-HT modulation of the cholinergic nerve endings was found.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Localization and characterization of binding sites for circulating and cerebroventricular atrial natriuretic factor in rat choroid plexus.

In vitro autoradiographic studies showed that high-affinity atrial natriuretic factor (ANF) binding sites are present on rat choroid plexus (Kd = 83.8 pM, Bmax = 22.9 fmol/mg protein). Guanylate cyclase-coupled receptors (ANF-R1) represent 30% and non-guanylate cyclase-coupled ANF receptors (ANF-R2) represent 70% of the total ANF receptors present in this tissue. To provide detailed cellular localization of the binding sites, the technique of electron-microscopic autoradiography was applied using 125I-ANF (Ser 99-Tyr 126) as an in vivo ligand. In order to identify possible binding sites at the basolateral and the apical aspects of the choroid plexus, the ligand was injected into the carotid artery or into the lateral cerebral ventricles, respectively. Light-microscopic autoradiography demonstrated that ANF binds specifically to choroid plexus regardless of its route of administration. Electron-microscopic autoradiography showed that silver grains were localized primarily on epithelial cells of the choroid plexus (96-99%) and marginally on endothelial and pial cells. In choroidal epithelial cells, ultrastructural analysis of silver grain distribution revealed that, at 2 min after intracarotid or intracerebroventricular 125I-ANF injection, lysosomes were the most distinctly labeled organelle (highest relative specific radioactivity). HPLC Chromatographic analysis disclosed that 96-99% of choroid plexus-bound ANF was already degraded 2 min after injection and that at least 63-66% of the degradation took place at the plasma membrane. These results indicate that ANF binding sites are present on both aspects of choroidal epithelium, and suggest that ANF is very quickly degraded in choroid plexus by membrane-associated as well as lysosome-associated processes.

Animals↗
PubMed1990

Early changes in the rat pancreatic B cell size induced by glucose.

The perimeter, cell area and volume density (Vvi) of B cells and exocytotic images present in these cells were measured in rat pancreas perfused with 3.3 or 16.6 mM glucose. Four minutes after the beginning of 16.6-mM glucose perfusion and coincident with the appearance at the apex of the first phase of insulin secretion, all these parameters underwent a significant increase. The changes observed in the perimeter, the cell area and the Vvi of B cells suggest an increase in their surface area. An imbalance in the rate of endocytosis:exocytosis processes with a relative predominance of the latter would increase the length of the plasma membrane and could be responsible, at least partly, for the changes in the B cell size.

Animals↗
PubMed1990

Asbestos content of lung tissue, lymph nodes, and pleural plaques from former shipyard workers.

Autopsy samples from eight former shipyard workers were collected from lung parenchyma, tracheal lymph nodes, and pleural plaques. The tissue from each respective area was prepared by a modified bleach digestion technique, and the residue was collected on a 0.2-micron pore polycarbonate or 0.22-micron mixed cellulose ester filter. Quantitation of ferruginous bodies and uncoated fibers was done by light and transmission electron microscopy, respectively. Differences in the asbestos burden were noted for each site. Ferruginous bodies were observed in both parenchyma and nodes but not in plaques. Three subjects were found to have more ferruginous bodies per gram dry weight in their lymph nodes than in their lung parenchyma. Likewise, all subjects were found to have more uncoated fibers per gram in the nodes than in the parenchyma. Amphibole and chrysotile fibers were noted in the lung and extrapulmonary sites, with chrysotile being the predominant asbestiform in plaques. The majority of the uncoated fibers in both the nodes and the plaques were less than or equal to 5 microns in length. However, some fibers with dimensions conforming to the "Stanton hypothesis" reached both areas. These residual patterns most likely reflect the impact of clearance on lung burden as opposed to the eventual accumulation and stasis in the extrapulmonary areas.

Aged↗
PubMed1990

Effects on renal hemodynamics and tubular function of the contrast medium iohexol in renal patients.

Renal function was assessed in 20 (11 female and 9 male, age 21-76 years, mean 53) renal patients with a creatinine clearance 25-145 ml/min, mean 95, to evaluate the effects of iohexol, a non-ionic low-osmolar contrast medium. Intravenous urography was performed in 16 patients and computed body tomography in 4, using a dose of iohexol ranged between 0.6-3.3 (mean 1.17) g/kg b.w. Different parameters of renal function were determined in the week preceding and 1, 3 and 5 days after the administration of iohexol. The principal renal effect of iohexol was an increase of urinary alanine aminopeptidase, gamma-glutamyltransferase, lactate dehydrogenase, alkaline phosphatase and N-acetyl-beta-D-glucosaminidase. The maximum increase of enzymuria was observed on day 1 after the administration of iohexol. In most cases enzymes returned to base-line values within 3 days. No relevant variation of renal hemodynamics (glomerular filtration rate and effective renal plasma flow) was observed after iohexol. In conclusion, iohexol can increase of urinary enzymes, but the effect is rapidly reversible and is not accompanied by a clinically significant impairment of renal hemodynamics.

Acetylglucosaminidase↗
PubMed1990

Protection by pyroglutamic acid and some of its newly synthesized derivatives against glutamate-induced seizures in mice.

The protection by pyroglutamic acid (CAS 98-79-3) and derivatives Ia-i (injected i.p.) against glutamate- and NMDA (N-methyl-D-aspartate) (i.c.v.) induced seizures in mice has been studied in comparison with known antiepileptics and antagonists of excitatory aminoacids. The potency of pyroglutamic acid and some derivatives (Id,f,g,h) against glutamate-induced convulsions was similar to that shown by glutamic acid diethylester and by valproic acid. Interestingly, pyroglutamic acid did not affect NMDA-induced convulsions which were well antagonized by both 2-amino-5-phosphono valeric acid and by diazepam. Thus, pyroglutamic acid may represent the starting for synthesis of excitatory aminoacid antagonists acting at non NMDA receptors.

Animals↗
PubMed1989

Sites of inhibition of mitochondrial electron transport by rhein.

The effect of rhein on the oxygen consumption, oxidative phosphorylation, ATPase activity and redox state of electron carriers of rat liver mitochondria has been studied. Rhein inhibits ADP- and uncoupler-stimulated respiration on various NAD-linked substrates and succinate, but stimulates state 4 respiration of mitochondria respiring on succinate. Experiments on specific segments of the respiratory chain showed that rhein does not inhibit electron flow through cytochrome oxidase. Electron flow through site 2, the ubiquinone-cytochrome b-cytochrome c1 complex, was also unaffected by rhein, which failed to inhibit the oxidation of duroquinol. Rhein affects oxidative phosphorylation by inhibiting both electron transfer and ADP-driven H+ uptake. The inhibition of succinate oxidation by rhein was found to take place at a point between succinate and ubiquinone, perhaps at the level of succinic dehydrogenase. Spectroscopic evidence demonstrated that rhein induces a NAD(P)H oxidation in mitochondria respiring either on endogenous substrates or on glutamate + malate, and an inhibition of the cytochrome b reduction by succinate. These observations, together with other evidence, suggest that rhein inhibits electron transport in rat liver mitochondria at the dehydrogenase-coenzyme level, particularly when the electron carriers are in a relatively oxidized state and/or when the inner membrane-matrix compartment is in the condensed state.

Adenosine Triphosphatases↗