PubMed Health⌕ Search

Biomedical subjects

P Ferretti

Publications and source records attributed to P Ferretti.

52 records · Page 3Linked to original sources
PubMed1985

The localization and rate of disappearance of a synaptic vesicle antigen following denervation.

A proteoglycan-specific antiserum has been used to monitor the effects of denervation in the electric organ of Torpedo marmorata. The antiserum was produced by injecting a highly purified synaptic vesicle fraction prepared from the electric organs of Torpedo marmorata. Following absorption the serum appears to be specific towards synaptic vesicles. The ultrastructural localization of the antigen determined by immuno-electron microscopy confirmed the specificity of the antiserum and showed that it did not cross-react with the proteoglycans of the basal lamina. The rate of disappearance of the vesicle proteoglycans following denervation was evaluated by means of the antiserum and was compared to the rate of disappearance of other vesicular and nerve terminal-associated markers. The results suggest that degeneration affects the vesicular constituents at varying rates resulting in a progressive disappearance of the entire functional capacity of the synaptic vesicles.

Acetylcholine↗
PubMed1985

[Effect of blood levels of carboxyhemoglobin (COHb) on erythrocyte filtration time in young smokers].

The effects of chronic exposure to carbon monoxide on some rheologic parameters (erythrocyte filtration time in particular) and on FEV1, and on FEF25-50 were studied in young smokers. A positive correlation among number of cigarettes day, COHb blood levels and erythrocyte filtration time was found. Packed red cell volume, fibrinogen concentration and platelet count were unaffected; no evidence of small-airway obstruction was observed. The alteration of erythrocyte deformability may be an early sign of hemorheological impairment which can progressively worse if high COHb blood levels are chronically maintained, with damaging effects on vessel function.

Adult↗
PubMed1985

[Noninvasive study of the bone using single- and dual-photon densitometry: effects of age and menopause on bone density of normal and osteoporotic female population].

The assessment of bone status is so far usually performed by means of the relatively simple methods of radiographs and radiogrammetry, which are not always able to give a correct information about bone mineral content (B.M.C.) especially in cases of cortical osteoporosis. Among the other non-invasive methods, single- and dual-photon absorptiometry are of particular interest for their relatively low cost, precision, accuracy and repetitibility, giving the patient a very slight dose of radioactivity. Dual-photon device, in particular, offers the possibility to investigate B.M.C. in the bones surrounded with large amount of tissue, even in obese people. To assess bone status of feminine population, we have analyzed 238 patients, divided into 3 groups (normal pre- and post-menopausal women, and osteoporotic) measuring their radius and lumbar spine B.M.C. with single- and dual-photon absorptiometry. As a result, B.M.C. of both measuring sites appears closely correlated with age, and with the duration of menopause. In our group, cortical bone density showed a postmenopausal rate of loss higher than the trabecular. Vertebral measurements, too, were more closely correlated with age when corrected for body surface area. Osteoporotic group showed a B.M.C. significantly lower than the age-matched group of normal women both in spine and in radius: in conclusion, all these findings stress the importance of a widespread population surveillance in order to individuate and treat the patients at risk of spontaneous fractures.

Adolescent↗
PubMed1984

Depletion and recovery of neuronal monoamine storage in rats of different ages treated with reserpine.

The effect of reserpine on dopamine, noradrenaline, adrenaline and serotonin concentrations in different brain regions, and the recovery of normal levels of these monoamines after such treatment were studied in rats aged 5, 15 and 27 months. In a preliminary experiment we found that distribution of the drug was not altered in the aged rats. Then we observed that a single dose of reserpine (5 mg/kg IP) had a similar depleting effect on all the brain monoamines, in all the brain regions considered in all three age groups. The curves expressing recovery of monoamine storage in all the nerve terminals, several days after treatment, were superimposable. These results suggest that in the rat, age does not influence the effect of reserpine on the storage mechanism of brain monoamines. Moreover, as restoration of this mechanism depends on the synthesis of new vesicles, the similarity in the rates of recovery in adult, old and very old rats indicated indirectly that synthesis of these neuronal organelles is not affected by aging.

Aging↗
PubMed1984

Effect of denervation on a cholinergic-specific ganglioside antigen (Chol-1) present in Torpedo electromotor presynaptic plasma membranes.

The presence of Chol-1, an antigen identified in the plasma membrane of cholinergic electromotor nerve terminals of Torpedo marmorata, was investigated in Torpedo electric organ after 3, 6, and 9 weeks' denervation. Denervation was monitored by the cessation of stimulus-evoked discharge potentials, by the reduction in nerve terminals seen morphologically, and by the decrease in ACh and ChAT contents. The content of ganglioside-bound sialic acid did not show any appreciable change with time. Some modification of ganglioside pattern on TLC was observed after 9 weeks' denervation. The presence of Chol-1 after denervation was assayed by its activity in inhibiting the selective complement-induced lysis of the cholinergic subpopulation of guinea pig cortical synaptosome which is mediated by the anti-Chol-1 antiserum. Denervation did not affect Chol-1 immunoreactivity although it did alter the distribution of the immunoreactivity among gangliosides. The possible significance of the results is discussed.

Acetylcholine↗
PubMed1984

Biochemical effects of minaprine on striatal dopaminergic neurons in rats.

The biochemical effects of minaprine, a new psychotropic drug, were investigated on striatal dopaminergic neurons in the rat. Minaprine did not displace [3H]spiperone in-vitro binding from striatal membranes but had clear effects on dopamine (DA) metabolites. Homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) were significantly decreased in a dose-dependent manner after intraperitoneal administration of minaprine 30 min before killing. In rats injected with minaprine 15 mg kg-1 i.p. at different intervals, the decrease in striatal HVA and DOPAC was time-dependent and a concomitant rise in 3-methoxytyramine (3-MT) concentrations was observed. The maximum of these effects was reached 30 min after minaprine. When administered 5 min after a monoamineoxidase (MAO) inhibitor (pargyline, 100 mg kg-1 i.p.) and 30 min before killing, minaprine did not affect pargyline-induced changes in HVA, DOPAC and 3-MT levels. This together with other data suggests that minaprine affects DA metabolism by acting, at least partially, at presynaptic level through in-vivo inhibition of MAO activity.

Animals↗
PubMed1984

Non-acid gastroesophageal reflux. Detection and evaluation by means of combined esophageal and gastric pH-monitoring.

One hundred and fifteen partially-gastrectomized patients were submitted to combined gastric and esophageal pH-monitoring with the aim of studying non-acid gastroesophageal reflux (GER). Since the detection of non-acid GER seems to be linked to the possibility of detecting entero-gastric reflux, only those patients (61) in whom entero-gastric reflux could be evaluated were considered. 37.7% of the patients showed non-acid GER according to the personal definition of such a reflux (any sudden esophageal pH change of 0.5 or more with earlier or simultaneous entero-gastric reflux). On the contrary, with De Meester and coworkers' criteria, only 21.3% of the patients were considered alkaline refluxers. Slight symptoms and slight endoscopical/histological changes were present in 20-30% of both non-refluxers and refluxers (whichever method of GER evaluation was considered). Therefore, correlations between GER and symptoms, endoscopical changes and manometric findings seemed poor using either method of GER evaluation. However, since the theoretical basis of combined gastric and esophageal pH-monitoring seems correct and the application of new techniques and the development of the parameters of "normality" can hopefully increase our understanding, the routine use of gastric and esophageal pH-monitoring should not be abandoned.

Adult↗
PubMed1983

Effects of dopaminergic agents on monoamine levels and motor behaviour in planaria.

1. Dopamine, serotonin and, in lesser amounts, norepinephrine were detected in Dugesia gonocephala using electrochemical detection coupled with liquid chromatography (LCED). 2. Treatment with L-dopa induced hyperkinesias, and a rise in dopamine, serotonin and norepinephrine content, whereas reserpine reduced motor activity and the concentrations of all three monoamines. 3. Haloperidol reduced motor activity and dopamine and norepinephrine levels. 4. Apomorphine induced hyperkinesias without altering monoamine levels.

Animals↗
PubMed1983

Morphine tissue levels and reduction of gastrointestinal transit in rats. Correlation supports primary action site in the gut.

Overnight-fasted male rats given a single dose of tritium-labeled morphine either intraperitoneally or intravenously were fed a charcoal test meal by stomach tube. The drug remaining in tissues was assayed by liquid scintillation counting of thin-layer chromatograms from homogenates, and gastrointestinal transit was tested by measuring the portion of the small intestine traversed by charcoal in 5 min. Morphine, 0.15 mg/kg, given intraperitoneally either 10 min or 30 min before testing substantially reduced gastrointestinal transit (to 23% and 55% of drug-free controls, respectively), and produced maximum drug levels 5 min after administration in small intestine longitudinal muscle with attached myenteric plexus (500 +/- 42 ng/g, mean +/- SE, n = 4). Intact small intestine, plasma, and brain, respectively, contained decreasing drug concentrations that, in the latter, never exceeded 2%-3% of that in longitudinal muscle. Rats receiving 0.15 mg/kg morphine intravenously presented only minor and short-lived inhibition of gastrointestinal transit that was significantly below (approximately 35%) that of drug-free controls at 10 min, but not 30 min, after drug administration. Morphine levels in the brain and plasma of these rats were up to five times higher, and in the intact small intestine longitudinal muscle were up to 20 times lower than in intraperitoneally treated rats. Morphine concentration in the tissues assayed was plotted against the effect on gastrointestinal transit at the same interval for individual rats regardless of dose, administration route, and observation time: data analysis, in small intestine longitudinal muscle, but not in the brain or plasma, indicated a highly significant correlation and fitting of computer-generated curves described by a currently accepted equation according to the receptor occupation theory of drug response. In view of these findings, and of the complete prevention by the "peripherally selective" narcotic antagonist N-methyl naloxone of gastrointestinal transit inhibition after an intravenous analgesic dose of morphine (1 mg/kg), the investigated animal model is consistent with the primary role of a gut-located action site in opiate-induced constipation.

Animals↗
PubMed1983

[Evaluation of age-related changes of erythrocyte filtration].

In two groups of subjects (young and elderly), the red blood cell (RBC) deformability was examined determining the filtration time by means of two different methods (filtration of whole blood and filtration of RBC suspension with hematocrit adjusted at 20%, respectively). In addition, the DFE (Debit de filtration erythrocytaire), an indirect index of capillary blood flow, was mathematically derived. Since the filtration times appear to be positively correlated with age, it is conceivable that in the elderly, erythrocytes are less deformable than in the young, and that this change may impair both capillary blood flow and tissue oxygen delivery; this alteration is further emphasized when the relationship between whole blood filtration time and hematocrit is taken into account.

Adult↗
PubMed1977

[Enzymatic assessment of the area of necrosis. I. Diagnosis and quantitative evaluation of acute myocardial infarct by means of MB creatine kinase isoenzyme. Comparison with deduced from creatine kinase activity].

On the purpose of specifying more and more the peculiarity of the isoenzymes MBCK in regard to enzyme CK, in the diagnosis as well as in the quantitative evaluation of myocardial infarction, we examined 34 patients hospitalized in U.C.I.C. The curves of the MBCK and CK were obtained through samples taken every 2-3 hours still the 12th hour, after the enzymatic concentration have exceeded the normal level and successively every 4 hours till the enzymatic activity regains its limits. The values of I.S.MBCK and I.S.CK were compared and we obtained two correlations based on the enteric work (r = 0.79) or on selected cases (r = 0.96). We conclude, for the major practicality and usefulness of measurement of MBCK in the evaluation of size, because this measurement can be obtained on the total enumeration of cases of myocardial infarction, not takine into consideration all those factors which could produce an increase of CK; moreover the MBCK is able to show the extension of myocardial infarction that would not be detectable with CK.

Aged↗
PubMedDate not supplied

Evaluation of whole blood filterability with increasing age in healthy men and women.

Whole blood filterability, expressed as volume of red blood cells filtered per minute (VRBC), was evaluated in 53 healthy men and 56 healthy women; in each sex, subjects were divided into 4 groups according to their age: adult age (20-50 yr.), advanced adult age (51-60 yr); presenile age (61-70 yr.) and senile age (greater than 70 yr.). In addition, plasma fibrinogen, PCV, white cell and platelet total counts were measured and correlated with VRBC. Whole blood filterability and plasma fibrinogen levels were also correlated with age. VRBC and PCV decreased, whereas fibrinogen levels increased with increasing age. VRBC values showed a significant negative correlation with age and plasma fibrinogen values; a significant positive correlation was found between fibrinogen levels and age. No other examined parameter changed with increasing age nor correlated with VRBC values. These findings indicate that with aging there are modifications of some rheological parameters, such as an increase in plasma fibrinogen levels and a decrease in whole blood filterability.

Adult↗
PubMedDate not supplied

[The prevention of the aorto-mesenteric compression syndrome in interventions for ileoanal anastomoses].

Restorative proctocolectomy with ileal-anal anastomosis can induce a duodenal stenosis due to the compression between superior mesenteric artery (SMA) and aorta when the ileum is pulled-down to the anus stretching the SMA. This situation may require prolonged nasogastric intubation or even surgery. In our experience this occurred in 10% of pts. Aiming to avoid this complication we have performed an intestinal derotation just before ileal-anal anastomosis abolishing any possibility of duodenal compression. Comparing this latter group of patients to those who didn't receive intestinal derotation, we observed a significant reduction of nasogastric tube drainage and of the nasogastric intubation time. We think that intestinal derotation could be effective in preventing SMA syndrome after restorative proctocolectomy and ileal-anal anastomosis.

Adolescent↗