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Biomedical subjects

A Romagnoli

Publications and source records attributed to A Romagnoli.

At least 37 records · Page 2Linked to original sources
PubMed1991

Assessment of the biological activity of synthetic salmon calcitonin by intranasal administration in healthy volunteers.

The authors conducted an open crossover trial of the biological activity of single-dose salmon calcitonin (sCT) 100 I.U. by nasal spray versus single-dose sCT 50 I.U. by intramuscular route in six healthy volunteers. The biological activity of the hormone was assessed on the changes in the blood levels of calcium, cAMP and osteocalcin recorded in the 4 h following administration. The increase in plasma cAMP shows that the hormone acts effectively by the nasal route. Further, the lack of statistically significant differences between the two modes of administration in any of the parameters considered demonstrates the bioequivalence of 50 I.U. of sCT i.m. and 100 I.U. of sCT intranasally.

Administration, Intranasal↗
PubMed1990

[Biliary diseases in acquired immunodeficiency syndrome. Apropos of 2 cases].

Biliary complications have recently been reported in patients with AIDS. This may take the form of acalculous cholecystitis or more commonly cholangitis, which may or may not be associated with stenosis of the papilla. These conditions must be sought in patients presenting with right hypochondrial pain and elevated alkaline phosphatase. Infection with Cryptosporidium or cytomegalovirus is often associated.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Clinical evaluation of diacerein in the treatment of osteoarthrosis].

Diacereine was given to 40 patients whose age ranged from 45 to 87 years; they were suffering from radiologically controlled osteoarthrosis. The oral dosage was 50 mg twice a day and it was given for 4 weeks. The results were classified good in 78% of the patients. Improvement become usually manifest after 2 weeks from starting treatment. Diarrhoea was the only collateral effect in 15% of the cases. In conclusion, Diacereine gives positive effects on osteoarthrosis treatment.

Aged↗
PubMed1987

Mechanism of polyamine inhibition of a leaf protease.

The inhibition of a highly purified alfalfa (Medicago sativa) leaf protease by naturally occurring polyamines is reported. The tetraamine spermine shows the highest inhibitory effect, with the maximum inhibition at 0.1 mM. Kinetic data indicate an apparent hyperbolic competitive inhibition. CD measurements show that in the presence of 0.1 mM spermine the enzyme undergoes a conformational change with the loss of 16% alpha-helix secondary structure content. Both the inhibition and the conformational change are prevented by high ionic strength. These data suggest a novel control mechanism of proteolytic activity in the leaf.

Circular Dichroism↗
PubMed1986

Effect of surgery and cardiopulmonary bypass on indocyanine green pharmacokinetics.

The pharmacokinetics of indocyanine green (ICG), a marker for hepatic blood flow (HBF), were studied at selected times during the initial 24-hour postoperative period in patients undergoing cardiac surgery with (n = 33) and without (n = 13) cardiopulmonary bypass. Cardiopulmonary bypass (CPB) caused a depression in ICG clearance and, by implication, HBF, reaching 48% of the pre-anesthetic and 60% of the pre-bypass values 2 hours post-CPB, returning to control values between 8 and 12 hours post-CPB. Similar decreases, although to a lesser extent, were seen in the non-CPB patients. Simulations with model compounds showed that these changes could produce clinically significant alterations in drug concentration-time profiles.

Journal Article↗
PubMed1986

Low ceiling respiratory depression by ciramadol.

Ciramadol, an agonist-antagonist analgesic of lesser milligram potency than morphine, given intravenously at 30 mg/70 kg produced respiratory depression equivalent to that observed with morphine 10 mg/70 kg. Respiratory depression was measured in terms of drug induced displacement of the carbon dioxide response curve of healthy volunteers. In contrast to the progressive respiratory depression by each 10 mg/70 kg increment of morphine, further doses of ciramadol up to 90 mg/70 kg failed to increase respiratory depression. The ceiling of respiratory depression by ciramadol was half the ceiling previously demonstrated for nalbuphine and dezocine. Ceiling respiratory depression may be a general characteristic of agonist-antagonist type analgesics in contrast to pure agonist analgesics.

Benzylamines↗
PubMed1985

Significance of diffuse granularity and nodularity of the esophageal mucosa at double-contrast radiography.

Out of 5000 consecutive double-contrast examinations of the esophagus, 50 cases presented a diffuse finely granular or nodular appearance of the mucosa. Endoscopy was subsequently performed in 38 cases and biopsy in the majority of these. In 23 of the 38 verified cases the diagnosis was reflux esophagitis. In the other 15 cases the diagnoses were: candidal esophagitis (4), leukoplakia (2), glycogenic acanthosis (1), and diffuse leiomyomatosis (1). A normal mucosa was demonstrated in 7 cases. Our study indicates that a radiologically granular or nodular appearance of the esophageal mucosa often indicates reflux esophagitis and less commonly identifies diffuse lesions of variable origin.

Biopsy↗
PubMed1985

Purification and characterization of two leaf polypeptide inhibitors of leaf protease from alfalfa (Medicago sativa).

Two polypeptides with antiproteolytic activities have been isolated from alfalfa leaves. Polypeptide I resembles the previously described plant protease inhibitors in both structural and functional features; it has a molecular weight of 15,000, a random coil secondary structure, and inhibits exogenous protease as well as alfalfa leaf protease. Polypeptide II is a novel type of plant inhibitor with a molecular weight of 6300 and a highly organized structure with a high (40-50%) alpha-helix content. It only inhibits endogenous protease with a molar stoichiometry polypeptide/enzyme protein of 1.

Amino Acids↗
PubMed1984

Papaverine disposition in cardiac surgery patients and the effect of cardiopulmonary bypass.

Cardiac surgery involving cardiopulmonary bypass (CPB) causes substantial physiologic changes which may potentially alter the pharmacokinetic properties of drugs used during and after the procedure. Studies with fentanyl have implied a relationship between prolonged elimination half-lives following CPB and decreased liver perfusion during and after the procedure. To further test this hypothesis, the effects of CPB on the pharmacokinetics of papaverine, a coronary vasodilator currently being added to the cardioplegic solution to prevent vasospasm, were studied. The drug was given to two groups of patients, one (n = 6) undergoing surgery with and one (n = 5) without CPB, the latter serving as controls. Plasma papaverine concentrations declined biexponentially in the control patients with a mean elimination half-life of 1.30 +/- 0.25 h, total plasma clearance of 13.8 +/- 3.75 ml/min/kg, volume of distribution of 1.52 +/- 0.45 l/kg and volume of distribution, steady-state, of 0.992 +/- 0.530 l/kg. For the CPB group, only half-life was estimated, and averaged 2.77 +/- 0.28 h, significantly greater (p less than 0.01) than that in the controls. These results further confirm the increased half-lives seen with other hepatically cleared drugs following CPB and have implications in the clinical management of patients given drugs eliminated in this manner.

Adult↗
PubMed1984

Ceiling respiratory depression by dezocine.

Dezocine in equianalgesic intravenous doses depressed respiratory response to CO2 breathing of six healthy subjects to approximately the same degree as morphine but with a more rapid onset and higher peak depression. The depression was dose related up to 30 mg/70 kg but was not increased by an additional 10 mg/70 kg dose. Its duration of effect was approximately the same as that of morphine. Respiratory depression by dezocine was promptly and almost completely antagonized by 0.4 mg naloxone, but antagonism lasted less than 1 hr. Healthy subjects found dezocine less pleasant than morphine and after large doses reported sensations suggestive of psychotomimetic effects. A ceiling effect for respiratory depression has now been demonstrated for three agonist-antagonist analgesics: nalorphine, nalbuphine, and dezocine. It is not yet clear to what extent this is a general characteristic of agonist-antagonist analgesics.

Adult↗
PubMed1981

Effect of cardiopulmonary bypass on fentanyl distribution and elimination.

Fentanyl kinetics was studied in two groups of six patients, one group undergoing surgery with and one without cardiopulmonary bypass; the latter served as the controls. Plasma fentanyl concentrations declined biexponentially in the control patients with an average half-life (t1/2 beta) of 3.3 +/- 1.1 hr, total plasma clearance of 11.2 +/- 3.4 ml/min/kg, and volume of distribution (Vd beta) of 3.2 +/- 1.5 l/kg. The plasma concentration/time curves were severely disrupted during cardiopulmonary bypass but appeared to regain a log-linear decay once bypass was complete. This elimination phase had a t1/2 of 5.2 +/- 2.7 hr, longer than that in the control patients. Since fentanyl is eliminated primarily by hepatic metabolism, decreased liver plasma flow observed during and after bypass, as evidenced by a 30% decrease in indocyanine green clearance, may contribute to the extended t1/2. The prolonged t1/2 had clinical importance because of potentially prolonged effects and their relation to other drugs and the clinical management of the patient.

Arteriosclerosis↗
PubMed1981

Pharmacokinetics of high-dose meperidine in surgical patients.

Intravenous meperidine is used during surgical procedures at doses up to 5 mg/kg. At the commonly used analgesic intravenous doses of 50 to 100 mg (0.7 to 1.4 mg/kg), the drug exhibits two-compartment open model pharmacokinetics with elimination primarily by hepatic metabolism (> 90% of a dose). Drugs eliminated to a large extent by metabolism may, however, be subject to dose-dependent kinetics. We therefore studied the pharmacokinetics of surgery involving the lower part of the abdominal aorta and the femoral and popliteal arteries. Serial blood samples were collected over 10 hours and plasma meperidine concentrations were determined by a gas chromatographic assay. Semilogarithmic plots of plasma meperidine concentration vs time were biphasic; however, the curves' irregularities during the time the arterial vessels were clamped suggest that the data should be analyzed in a model-independent manner. These irregularities suggest that the disposition of meperidine is altered during the clamping period and that these alterations are quickly reversed following removal of the clamp. Our findings agree with those reported in the literature following a total dose of 50 mg (half-life average 4.4 hours, total plasma clearance 10.4 ml/min/kg, and apparent volume of distribution 3.74 L/kg). The present results thus indicate that although meperidine is eliminated to a large extent by metabolism, the processes involved are apparently not saturated at doses 7 times greater than normal.

Aged↗
PubMed1980

Ceiling effect for respiratory depression by nalbuphine.

The respiratory depressant capacities of intravenous nalbuphine, a potent analgesic of the narcotic antagonist type, and of morphine were compared in 23 healthy subjects using displacement of CO2 response by a steady-state method as the index of respiratory depression. At equianalgesic doses of 10 mg/70 kg, respiratory depression by nalbuphine was equal to that by morphine. When increments of 10 mg/70 kg were given hourly the dose-effect curve for respiratory depression by nalbuphine was flatter than that of morphine, and maximum respiratory depression occurred after 30 mg/70 kg. In a separate study of 10 subjects nalbuphine was administered in 10 mg/70 kg increments to a total dose of 60 mg/70 kg; doses in excess of 30 mg/70 kg failed to increase respiratory depression beyond that induced by morphine 20 mg/70 kg. A ceiling effect for respiratory depression previously known to exist only for nalorphine was thereby demonstrated to apply to nalbuphine. The respiratory depression of nalbuphine was readily antagonized by naloxone 0.4 mg, nalorphine 10 mg, and levallorphan 1.0 mg. Subjective effects of nalbuphine were milder than those of morphine, and dysphoria suggestive of the psychotomimetic effects of narcotic antagonists was reported only 4 times in 24 subject exposures. The ceiling effect for respiratory depression by nalbuphine provides a unique safety factor among potent analgesics.

Adult↗
PubMed1980

Variation of acidic prealbumins in the donkey (Equus asinus).

Starch gel electrophoresis of 55 donkey serum samples revealed three prealbumin (Pr) phenotypes temporarily designated Pr M, Pr MT and Pr T. The distribution was in agreement with a genetic theory of two codominant alleles of frequencies, PrM = 0.87 and PrT - 0.13. Variation was also observed for proteins migrating with the same rate as the Xh zones in the horse.

Alleles↗