Search PubMed⌕ Search

Biomedical subjects

M Persico

Publications and source records attributed to M Persico.

11 recordsLinked to original sources
PubMed1992

Dependence of hypotensive effect of neuropeptide-Y 18-36 fragment on intact vagus nerves.

Effects of neuropeptide Y (NPY 2.35-4.7 nmol) and the fragment NPY 18-36 (3.6-36 nmol) were studied in anaesthetized rats before and after vagotomy for actions on blood pressure (a postjunctional action) and on the change in pulse interval evoked by stimulation of the cut, peripheral vagus nerve (a prejunctional action). In intact rats NPY increased blood pressure. Low doses of NPY 18-36 (2.3-4.7 nmol) also increased blood pressure slightly but higher doses only transiently increased blood pressure and this was followed by a prolonged decrease in blood pressure. In vagotomised rats NPY increased blood pressure and attenuated cardiac vagal action. In higher doses the presynaptic effect of NPY 18-36 was more marked than its pressor action. NPY 18-36 (3.6-36 nmol) also increased blood pressure and attenuated cardiac vagal action. Thus, we conclude that the hypotensive action of NPY 18-36 depends on the intact vagus nerves: in the vagotomised rat NPY 18-36 has similar biological activity to NPY, but with reduced potency. To examine further the mechanism of hypotensive action of NPY 18-36 arterial rings from the central artery of the rabbit ear were also tested for direct actions of the peptides. This preparation is also suitable for testing any potentiation of contraction evoked by injection of noradrenaline. Neither NPY nor NPY 18-36 caused direct constrictor action in concentrations up to 10 microM. NPY 18-36 had no relaxing effect on constricted arterial rings.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Responsiveness to phenobarbital in an adult with Crigler-Najjar disease associated with neurological involvement and skin hyperextensibility.

We present the case of a 23-yr-old man who had had since birth marked and sustained unconjugated non-hemolytic hyperbilirubinemia and who had had several attacks of grand mal seizures. Analysis of serum bilirubin by diazoreactive methods showed serum levels of unconjugated bilirubin as high as 445 mumol/L that were not affected by phenobarbital administration. However, analysis of serum bile pigments by high-pressure liquid chromatography demonstrated marked decrease of unconjugated bilirubin after phenobarbital treatment (from 432.4 mumol/L to 291.0 mumol/L) associated with slight increase of bilirubin monoconjugates and disconjugates (from 0.25 mumol/L to 0.42 mumol/L). Furthermore, in the past few years the patient had exhibited striking skin hyperextensibility and diaphragm eventration. This case confirms that alkaline methanolysis-high-pressure liquid chromatography is the most reliable method for assessment of serum fraction bilirubin levels; that clinical parameters such as neurological signs do not unequivocally discriminate between type I and II Crigler-Najjar disease and that response to phenobarbital treatment remains the main diagnostic tool.

Adult↗
PubMed1990

Abnormal hepatic uptake of low doses of sulfobromophthalein in Gilbert's syndrome: the role of reduced affinity of the plasma membrane carrier of organic anions.

The plasma disappearance rate of sulfobromophthalein (VBSP; mumol/kg/min) was measured in 15 Gilbert's syndrome patients and 12 control subjects after intravenous injection of two different doses (0.59 and 5.90 mumol/kg) of the dye. Plasma disappearance rate was significantly reduced in Gilbert's syndrome patients after administration of 0.59 mumol sulfobromophthalein/kg (0.119 +/- 0.016 vs. 0.146 +/- 0.018 mumol/kg/min; mean +/- S.D.; p less than 0.001), whereas no difference was found with the higher dose (0.754 +/- 0.040 vs. 0.767 +/- 0.072 mumol/kg/min). Significant reduction was also found after administration to four Gilbert's syndrome patients and four control subjects of 0.29 and 2.95 mumol sulfobromophthalein (0.060 +/- 0.005 mumol/kg/min vs. 0.077 +/- 0.07 mumol/kg/min and 0.480 +/- 0.012 mumol/kg/min vs. 0.591 +/- 0.015 mumol/kg/min, respectively; p less than 0.01). Competition studies with combined administration of sulfobromophthalein (0.59 mumol/kg) and different doses of rifamycin SV (0.59, 1.47 and 2.95 mumol/kg) showed a significant (p less than 0.001) reduction in plasma disappearance rate in Gilbert's syndrome patients but not in controls. The rifamycin SV dose at which a 50% inhibition in plasma disappearance rate was observed was 0.8 mumol/kg. The apparent affinity (Km) of the hepatic transport was higher in Gilbert's syndrome patients than in control subjects (3.61 +/- 0.37 mumol sulfobromophthalein/kg vs. 2.76 +/- 0.29 mumol sulfobromophthalein/kg, mean +/- S.D.; p less than 0.01), whereas no difference was found in Vmax (0.95 +/- 0.11 mumol sulfobromophthalein/kg vs. 0.93 +/- 0.10 mumol sulfobromophthalein/kg/min, mean +/- S.D.; N.S.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Age-associated decline of hepatic handling of cholephilic anions in humans is reverted by S-adenosylmethionine (SAMe).

Decreased fluidity of hepatocyte plasma membrane may contribute to the age-associated changes of liver function. This study aimed at investigating whether the hepatic clearance of organic anions declines with age and whether S-adenosylmethionine (SAMe), a substance proven to be effective in reversing the age-related decrease of membrane fluidity, might influence this process. Nicotinic acid (NA) half-life and serum bilirubin pharmacokinetics after NA load (5.9 mumol/kg body weight i.v.) were studied in 10 healthy young males (YM) aged 14-28 years and in 10 healthy elderly males (EM) aged 65-81 years, before and after SAMe administration (800 mg/day intravenously for 10 days). At baseline, EM showed serum total bilirubin (STB) levels significantly higher than YM. Similarly, the bilirubinaemic mean curves, STB peak and STB time curve concentration after NA load, expressed as area under the curve (AUC), were significantly higher in EM than in YM (p less than 0.01). NA half-life was also significantly prolonged in the aged group (p less than 0.001). SAMe treatment was followed by a significant decrease of basal STB, STB peak and AUC of STB after NA load in EM (p less than 0.01 vs pre-treatment values) while NA half-life was significantly shortened in both groups (p less than 0.001). As NA and bilirubin share a common carrier protein for hepatic uptake, bilitranslocase, the changes observed in EM may be attributed to the reduced lateral mobility of hepatocyte plasma membrane proteins occurring with age. SAMe, by improving membrane fluidity, may increase the diffusion coefficient of bilitranslocase restoring the hepatic handling of organic anions.

Adolescent↗
PubMed1990

Dissociation between vascular and metabolic effects of nicotinic acid in Gilbert's syndrome.

The relationship between the vasodilating and the hyperbilirubinaemic effect of low and high doses (50 and 300 mg i.v.) of nicotinic acid was studied in baseline conditions and after indomethacin pretreatment in healthy controls and patients with Gilbert's syndrome (a condition characterized by fluctuating, nonhaemolytic unconjugated hyperbilirubinaemia). The hyperbilirubinaemic effect of nicotinic acid was confirmed to be more pronounced in Gilbert's syndrome patients than in controls. The magnitude of hyperbilirubinaemia in the two groups was not dependent on the dose of nicotinic acid or indomethacin pretreatment. A dose-dependent vasodilation which was inhibited by indomethacin could be demonstrated in both controls and Gilbert's syndrome subjects. Vasodilating properties of nicotinic acid were therefore found to be dissociated from the effect on bilirubin.

Adolescent↗
PubMed1975

Regulation of protein synthesis at the translational level in neuroblastoma cells.

Protein synthesis in reuroblastoma cells has been studied in a cell-free system. The activity of lysates from cells grown insuspension and monolayer has been compared. A higher level of activity has been found in monolayer cells. The activity of some components of the lysate that are involved in protein synthesis has been analyzed. The data suggest that the controlling step of protein synthesis in this system might be in the initiation process. The correlation between activation of protein synthesis and neurite outgrowth in monolayer cultures is discussed.

Animals↗
PubMedDate not supplied

Otitis media with effusion: a steroid and antibiotic therapeutic trial before surgery.

Eustachian tube dysfunction has been considered the main factor in the etiology of otitis media with effusion (OME). A short-term systemic steroid therapy, with combined chemotherapeutics, yielded 53.1% cure in 160 children in which OME had been diagnosed, whereas only 12.5% of similar 116 children were cured by chemotherapeutic treatment alone. It is postulated that steroids, acting by a mechanism much similar to the one in the newborn lung, increase the level of a tubal surface active agent, thus enhancing Eustachian tube refunctioning. This combined treatment, we believe, deserves its place as a routine conservative trial before surgery.

Adolescent↗