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Biomedical subjects

C Bianchi

Publications and source records attributed to C Bianchi.

At least 307 records · Page 17Linked to original sources
PubMed1985

Effect of morphine on acetylcholine content of electrically stimulated brain slices.

Acetylcholine (ACh) levels were measured in guinea-pig thalamic and caudatal slices kept at rest or electrically stimulated for different times (2-30 min.). The decrease of ACh content caused by electrical pulses at 1 Hz and 2 Hz in caudate nucleus and thalamus slices, respectively, was directly related to the time of stimulation. The depletion was potentiated by HC-3 10 microM. In this condition the relationship between ACh content and time of stimulation was shifted to the left. In the presence of HC-3, Morphine (Mo) 30 microM did not affect the ACh levels of thalamic and caudatal slices kept at rest. The opioid, on the contrary, reduced the depletion of ACh caused by 10 min stimulation. Naloxone (Nx) 10 microM antagonized the opioid effect in caudate nucleus, while it increased the stimulus-induced ACh depletion in the thalamus treated with Morphine 30 microM. In conclusion, the electrically-stimulated brain tissue perfused with HC-3 may be a suitable tool to study drug effects on ACh depletion. This may offer an indirect, mirror-like evaluation of ACh apparent turnover and release. The results obtained with Mo and Nx support this statement.

Acetylcholine↗
PubMed1985

Single-dose netilmicin therapy of complicated and uncomplicated lower urinary tract infections in children.

Thirty children (age 3 months to 10 years) with complicated and uncomplicated lower urinary tract infections were treated with a single intramuscular injection of netilmicin 4.5 mg/kg. The diagnosis of lower urinary tract infection was based on the absence of fever and the presence of normal values for erythrocyte sedimentation rate, C-reactive protein concentration and urinary excretion of N-acetyl-beta-D-glucosaminidase. Follow-up urine cultures in all children demonstrated a cure rate of 97% and reinfection and relapse rates each of 7% respectively. The subgroup (12 children) with radiological abnormalities of urinary tract showed a cure rate of 92%, and reinfection and relapse rates of 9% respectively. The rates of cure, reinfection and relapse in the complicated and uncomplicated urinary tract infections were not statistically different (p greater than 0.05). A pharmacokinetic study (performed in 5 children) demonstrated that netilmicin urinary concentrations were over the MIC's of the infecting organisms up to 96 hours after the single-dose injection. Netilmicin was well tolerated and no side effects appeared during treatment. Single-dose netilmicin therapy is an effective and safe regimen for complicated and uncomplicated urinary tract infections in children. The response to single-dose netilmicin therapy seems to be related to its prolonged urinary elimination.

Bacterial Infections↗
PubMed1985

Atrial natriuretic factor inhibits Ca(2+)-dependent K+ fluxes in cultured vascular smooth muscle cells.

The interaction of the synthetic fragment Arg101-Tyr126 of atrial natriuretic factor (ANF) with Ca(2+)-dependent K+ efflux was studied in the following six different cell models: cultured vascular smooth muscle cells from rat aorta; isolated rat glomeruli; human platelets; cultured endothelial cells from bovine aorta; peritoneal mouse macrophages; human red cells. In human red cells and mouse macrophages, the dose-response curves of K+ efflux as a function of Ca2+ ionophore, A23187, concentration were not modified by addition of ANF. In endothelial cells and platelets, ANF slightly inhibited Ca(2+)-dependent K+ efflux. In renal glomeruli, ANF inhibits about one-third of this flux and in vascular smooth muscle cells ANF induced a five- to tenfold increase in the EC50 of A23187 effect. In experiments performed at constant concentrations of A23187, the IC50 of ANF was approximately 10(-9) mol/l. Similar results were obtained in mouse macrophages with cyclic GMP (cGMP). Our results suggest that ANF is able to counterbalance an increase in cytosolic free Ca2+ content in vascular smooth muscle and some glomerular cells. This effect may result from the ability of this hormone to stimulate cGMP synthesis.

Animals↗
PubMed1985

Pseudo-precocious puberty associated with mediastinal teratoma and polycystic ovary.

A 10-month-old girl with sexual precocity of recent onset was found to have elevated levels of estrogens, progesterone and androgen precursors, associated with a polycystic left ovary. After ovariectomy, estrogen and androgen levels were normal, and the clinical symptoms began to regress. A few months later, a huge mediastinal mass was unexpectedly discovered. Removal of the mass, identified later as a benign teratoma, was followed by the total normalization of the clinical and hormonal findings. The patient's pseudo-precocious puberty might have been due to an ovarian overproduction of estroprogestins and androgens, associated with a paraneoplastic production of progesterone, or in theory, it might have been due to a gonadotropin-like stimulation of the ovary by the teratoma.

Chorionic Gonadotropin↗
PubMed1984

Different approaches to study acetylcholine release: endogenous ACh versus tritium efflux.

Superfused slices of guinea-pig cerebral cortex (CC), caudate nucleus (CN) and thalamus (Th) were used to compare i) the resting and electrically-evoked release of endogenous acetylcholine (ACh) in the presence of physostigmine (Phys) and ii) the resting and electrically-evoked tritium efflux (after preloading with 3H choline) in the absence or in the presence of Phys and hemicholinium (HC-3). In addition, the effect of GABA, morphine and their antagonists on both effluxes was investigated. By matching the ACh and tritium outflow on a molar basis, an average ratio of 100: 2-4 was found. When expressed as a percentage of tissue content, the ACh release at 2 Hz (2 min) was 4.1 in CN, 0.92 in CC and 0.44 in Th. Lower percent values in the same rank order, were found for tritium outflow with Phys. Thus, CN has the highest secretory activity. Tritium evoked outflow in the presence of Phys was nearly halved in comparison with the normal values (without Phys). Therefore, the autoreceptor-mediated negative feed-back seems to be similar in the three areas. Tritium evoked outflow in the presence of HC-3 was more than doubled in Th (less so in CC and CN) in comparison with the normal values. A second stimulation at 2 Hz (2 min) gave rise to the same outflow in Th while an evident fall in radiolabel efflux was found in CN. Therefore the blockade of high affinity choline uptake plays a different role in Th and CN.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1984

99mTc-aprotinin: a new tracer for kidney morphology and function.

Aprotinin (Ap), a low-molecular-weight polypeptide (6500 dalton), is a protease inhibitor which is electively and stably accumulated in the kidney. In 112 adult patients, with either uni- or bilateral renal disease with different degrees of renal impairment (from normal GFR to advanced renal failure), renal scans were performed by means of Ap labelled with 99mTc. Highly satisfactory renal scans were obtained in all patients. In 20 patients with renal failure (serum creatinine 1.8-8.5 mg/dl, mean 4.7) a comparison was made of the renal scans obtained with 99mTc-Ap and with 99mTc-DMSA. 99mTc-Ap was slightly better than 99mTc-DMSA, especially in patients with far advanced renal failure. Some aspects of the pharmacokinetics of 99mTc-Ap were studied in 72 cases. In 22 of these patients plasma clearance of 99mTc-Ap was determined by the single injection method using a two-compartment model. In patients with GFR greater than 90 ml/min plasma clearance of 99mTc-Ap was 67.6 +/- 8.4 SD ml/min. A good correlation was observed between plasma clearance of 99mTc-Ap and GFR (r = 0.74). After IV injection 99mTc-Ap was stably fixed by the kidney. Renal radioactivity remained stable between the second and eighth hour after the injection. Urinary excretion of radioactivity measured in 35 patients in the first and in the second 2-h interval after IV injection of 99mTc-Ap was negligible in all patients (2.7 +/- 1.5 SD percent of the dose in the first 2 h; 2.8 +/- 1.4 SD between the second and fourth hour). 99mTc-Ap is an excellent agent for renal imaging. It also seems promising for renal function studies.

Adolescent↗
PubMed1984

Effect of gamma-aminobutyric acid on cyclic nucleotides content of guinea-pig cerebral cortex slices.

The effect of GABA and related drugs on 3'5' cAMP and 3'5' cGMP was investigated in slices of guinea-pig cerebral cortex, kept at rest or electrically stimulated. GABA 1 X 10(-4) - 1 X 10(-3) M raised the cAMP basal levels, bud reduced its increase due to electrical stimulation. These effects were antagonized by picrotoxin 1.6 X 10(-5) M. On the contrary, endogenous GABA did not influence cAMP and cGMP content. In fact, neither ethanolamine-O-sulphate 2 X 10(-3) M nor picrotoxin 1.6 X 10(-5) M affected the normal nucleotide values at all. Higher picrotoxin concentrations (3.2 - 8 X 10(-5) M), however, increased both cyclic nucleotides. Phentolamine counteracted the actions of both GABA 1 X 10(-4) M and picrotoxin 8 X 10(-5) M: therefore, the observed increase in cyclic nucleotides were due to norepinephrine release. Tetrodotoxin antagonized GABA but not picrotoxin metabolic effects. Thus it is suggested that the exogenous amino acid released norepinephrine through a sodium-dependent process, while picrotoxin released the monoamine directly from its storage sites. Clearly, attention must be paid when putative transmitters or their antagonists are added at high concentrations to isolated tissue to study the effect of endogenous compounds.

Adenosine↗
PubMed1984

Pyroglutamic acid administration modifies the electrocorticogram and increases the release of acetylcholine and GABA from the guinea-pig cerebral cortex.

Pyroglutamic acid (1-PCA), a cyclic derivative of glutamic acid, was administered i.p. (7.7 mmol/kg) or intracerebroventricularly (25 - 50 mumol) to freely moving guinea-pigs, provided with semi-permanently implanted epidural cups. The effect of this compound on cortical Acetylcholine (ACh) and GABA outflow, as well as on gross behaviour and electrocorticogram (E.Co.G.) was investigated. 1-PCA increased the release of ACh and GABA from the cortical surface, did not change their cortical content, decreased the spontaneous motor activity and synchronized the E.Co.G.. These results suggest that 1-PCA increases GABA release, possibly by changing amino acid transport through the biological barrier or by acting as antagonist on the receptors for glutamic acid. In turn, the activation of the GABA system increases, as previously demonstrated, the cortical ACh release and causes mild sedation and E.Co.G. synchronization.

Acetylcholine↗
PubMed1984

Cord blood prolactin and thyroid hormone levels after antenatal administration of betamethasone or ambroxol for prevention of respiratory distress syndrome (RDS).

Several studies showed that ambroxol is efficacious in enhancing fetal lung maturation, provided large doses are given. We investigated cord blood levels of PRL and thyroid hormones in 31 infants born after antenatal administration of betamethasone, in 31 infants born to mothers treated with ambroxol for prevention of RDS and in 27 infants whose mothers had not received any drug enhancing fetal lung maturity. The only significant difference (p less than 0.05) between the groups was noted in T3 mean levels that were higher in the ambroxol group than in the betamethasone group between the 33th to 36th week of gestation. Hormone levels did not appear significantly different in infants who developed RDS rather than in infants who did not.

Ambroxol↗
PubMed1983

[Daniels' prescalenic biopsy in the diagnosis of pulmonary sarcoidosis].

Prescalene biopsy according to Daniels has proved an excellent method for the histological detection of pulmonary sarcoidosis. Cooperation over a period of 15 years between the ear, nose and throat division of the Bassini Hospital, Milan, and the Lombardy Provincial Anti-TB Consortia (especially that of Milan) led to the performance of 533 biopsies in about 1700 cases with morphological and radiological pictures indicative of pulmonary sarcoidosis. Overall positivity was 81%. The disease has five radiological stages: I, I + II, II, II + III, and III. Patients with hilo-mediastinal polyadenopathy predominated numerically. Histological positivity greater in group A (stages I & I + II), i.e. 86%, 74% in group B (stage II), and 60% in group C (stages II + III, and III). The dependence of positivity on stage was further confirmed when series from different consortia were compared. Stress is laid on the high productivity of the method, its low risk, and its ready application to patients usually in apparently good health, following their detection by mass screening or general pneumological examinations.

Adolescent↗
PubMed1983

Diazepam antagonizes GABA- and muscimol-induced changes of acetylcholine release in slices of guinea-pig cerebral cortex.

The acetylcholine (ACh) release was studied in superfused, electrically-stimulated slices of guinea-pig cerebral cortex. Muscimol and 4,5,6,7-tetrahydroisoxazolo (5-4-c)-pyridin-3-ol (THIP), as well as exogenous GABA, reduced the electrically-evoked ACh release and enhanced its spontaneous outflow. Picrotoxin antagonized these effects. In addition, picrotoxin and ethanolamine-O-sulphate (EOS) caused opposite changes in transmitter outflow, suggesting the existence of an exogenous GABAergic control on the cholinergic nerve endings. Neither flurazepam 6.6 X 10(-6)--3.3 X10(-5) mol/l nor diazepam 3.3 X 10(-6)--3.3 X 10(-5) mol/l by themselves affected ACh release. Diazepam prevented GABA-, muscimol- and EOS-induced changes in spontaneous and 1 Hz-evoked outflow. Ro 15-1788 3.3 X 10(*-6) mol/l abolished diazepam antagonism vs exogenous GABA. The ineffectiveness of flurazepam and diazepam on normal release (i.e. the lack of potentiation vs the endogenous GABAergic control) supports the view that "synaptic" GABA receptors acting upon the cholinergic nerve endings are not coupled with Benzodiazepine receptors. The unexpected diazepam antagonism vs exogenous GABA and GABA-like compounds can be explained with an unusual Diazepam negative cooperation with "extrasynaptic" GABA receptors, possibly present on the cholinergic terminals. Thus, the rule of benzodiazepine-GABA synergism does not seem always tenable, at least at certain pre-synaptic sites.

Acetylcholine↗