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Biomedical subjects

A Ricci

Publications and source records attributed to A Ricci.

At least 181 records · Page 10Linked to original sources
PubMed1993

Cholinergic neurotransmission in the hippocampus of aged rats: influence of L-alpha-glycerylphosphorylcholine treatment.

The influence of aging and of L-alpha-glycerylphosphorylcholine (GFC) treatment on the acetylcholine synthesizing and degradating enzymes choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) and on cholinergic muscarinic M-1 and M-2 receptors were assessed in the hippocampus using immunocytochemical, histochemical and radioligand binding techniques, respectively. The investigation was performed on male Wistar rats of 2 months (young), 12 months (adult), and 27 months (old). Oral GFC was given at the dose of 100 mg/Kg/day from the 21st to the 27th month of age. ChAT revealed the highest immunostaining in the hippocampus of adult rats followed by young and old animals. The highest expression of AChE reactivity was noticeable in the hippocampus of adult rats followed by old and young animals. Treatment with GFC restored in part ChAT immunoreactivity and AChE reactivity in the hippocampus of aged rats. Muscarinic M-1 and M-2 receptors were labeled with [3H]-pirenzepine and [3H]-AF-DX-116 respectively. The density of M-1 muscarinic receptors decreased with age, whereas M-2 muscarinic receptors did not change. GFC treatment countered in part the loss of M-1 receptors in old rats and was without effect on M-2 receptors.

Acetylcholine↗
PubMed1993

Pharmacological characterization and autoradiographic localization of dopamine D1 receptors in the human umbilical artery.

Combined in vitro radioreceptor binding and autoradiographic techniques with [3H]SCH 23390 as a ligand were used to analyze the pharmacological profile and anatomical localization of dopamine D1 receptor sites in sections of human umbilical artery. The ligand was bound to sections of the artery in a manner consistent with the labelling of D1 receptors. These receptors, which show a fetal-to-maternal gradient with the highest concentration near the placenta, are located within the smooth muscle layer of the umbilical artery. The above findings suggest that endogenous dopamine may be involved in the control of the tone of the umbilical artery through the interaction with D1 receptors.

Adult↗
PubMed1993

Radioligand binding and autoradiographic analysis of dopamine receptors in the human heart.

The effects of dopamine on the 3',5-'cyclic adenosine monophosphate (cAMP) generating system were analyzed in membrane particles from the human right and left cardiac ventricle. In addition, the pharmacological profile and the anatomical localization of dopamine receptors were assessed on frozen sections of human cardiac atrial or ventricular tissue. Dopamine increased cAMP levels, in a concentration-dependent manner, in membranes of the right and the left ventricle. These effects were abolished by the beta-adrenoceptor antagonist (-)-propranolol, but not by the D1 receptor antagonist SCH 23390 or by the non selective D1/D2 receptor antagonist haloperidol. No specific binding of the D1 receptor antagonist [3H]-SCH 23390 was noticeable within the atrial or ventricular portions of the heart examined using either radioligand binding or autoradiographic techniques. The D2 receptor antagonist [3H]-spiroperidol, in the presence of concentrations of ketanserin sufficient to block possible binding to 5-HT2 sites, was specifically bound to sections of human heart with a dissociation constant value of about 2.6 nmol/l. The highest density of [3H]-spiroperidol binding occurred in the right ventricle followed, in descending order, by the right atrium, the upper part of the left ventricle, the lower part of the left ventricle, the left atrium and the interventricular septum. The binding profile of [3H]-spiroperidol to sections of human heart was consistent with the labeling of dopamine D2 sites. Light microscope autoradiography revealed silver grains throughout the atrial and ventricular walls and these were frequently accumulated in clusters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Dopexamine hydrochloride in the human kidney: localization, receptor binding and effect on 3'-5'-cyclic adenosine monophosphate generation.

Dopexamine hydrochloride is a synthetic dopamine analogue recently developed to improve myocardial and renal performance in patients suffering from low cardiac output states. The present study was designed to assess the pharmacological profile and the anatomical localization of [3H]-dopexamine binding sites within the human nephron. The effects of dopexamine on the 3'-5'-cyclic adenosine monophosphate (cAMP)-generating system in membrane particles of the human kidney were also investigated. It was found that [3H]-dopexamine was specifically bound by sections of the human kidney. The binding was partly inhibited by the DA-1 receptor antagonist SCH 23390, by the beta 2-adrenoceptor antagonist ICI 118,551 and by the DA-2 receptor antagonist domperidone. The 3 antagonists in combination reduced [3H]-dopexamine binding to nonspecific values. Light microscope autoradiography revealed the accumulation of silver grains, corresponding to [3H]-dopexamine binding sites, within the different portions of the human nephron. The incubation of sections of the human kidney with [3H]-dopexamine plus SCH 23390 caused a remarkable reduction in the density of silver grains within the proximal tubule and the macula densa and a moderate decrease in the density of silver grains within the ascending and descending limbs of the loop of Henle as well as within the distal tubule. The incubation of sections of human kidney with [3H]-dopexamine plus ICI 118,551 caused a pronounced reduction in the density of silver grains within the glomerulus, the limbs of the loop of Henle, the distal tubule and the medullary collecting tubules and a moderate decrease in the density of silver grains within the macula densa and the proximal collecting tubule.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1993

[Autohemotransfusion in cardiac reoperations].

OBJECTIVE: To evaluate the efficacy of intraoperative autotransfusion with hemodilution (AHT) to reduce postoperative transfusion of blood or blood products (BT) after cardiac surgery reoperation. DESIGN: Retrospective study, follow-up control. SETTING: Italian Institution of Cardiac Surgery (IICC). PATIENTS: 169 patients (51 males, 118 females; mean age 49.5 years) undergoing a reoperation from May 1982 to December 1991. INTERVENTIONS: 143 patients single valve replacement, 16 patients double valve replacement and 10 patients radical correction for tetralogy of Fallot. AHT (mean 620.2 +/- 226.9 ml) was performed in all patients. The shed blood was reinfused at the end of the surgery. PT, PTT, TT, TT Coagulase, FDP, pre- and postoperative platelet count, bleeding and needs for BT were recorded. RESULTS: Preoperatively: PT 71.3 +/- 8.1, PTT (sec.) 36.9 +/- 3.5, TT (sec.) 16.2 +/- 2.3, TTC (sec.) 16.9 +/- 1.7, FDP (ng% ml) 3.8 +/- 2.7, Platelet count (No./mu 11 170 +/- 58. Postoperatively: PT 36.5 +/- 6.5, PTT(sec.) 49.5 +/- 8.7, TT(sec.) 19.1 +/- 1.8, TTC(sec.) 18.9 +/- 2.1, FDP (ng% ml) 13.5 +/- 8.9, Platelet count (No./mu 11) 85 +/- 34. We had one reentry because of bleeding. The mean units of blood or blood products need after surgery were 2.2 +/- 1.02. Bleeding from the drainage was 105.2 +/- 103.8. Two patients died in the postoperative period because of low output syndrome. In a period of one year of F.U. we had only one patient with hepatitis B. CONCLUSIONS: These data suggest that AHT is a safe method, reduces needs for banked blood or blood products, risks of infectious disease transmission and of immunologic reactions and presents hemorheologic benefits because of the diminished blood viscosity.

Blood Transfusion, Autologous↗
PubMed1993

2,4-Dimethyl-6 H-pyrido[3,2-b]carbazole, an isomer of the antitumor alkaloid ellipticine via the Combes-Beyer reaction.

The synthesis of 2,4-dimethyl-6 H-pyrido[3,2-b]carbazole (2a) and of its 9-methoxy (2b) and 9-hydroxy (2c) derivatives via the Combes-Beyer reaction is described. Pyridocarbazole 2a has been obtained by two different routes. In the course of the synthesis of 2b either a partial or a total demethoxylation has been observed depending on the route employed.

Antineoplastic Agents↗
PubMed1993

Long-term follow-up of cardiac myxomas (7-31 years).

Between 1961 and 1985, 14 patients (9 males, 5 females; mean age 42.3 +/- 7.26 years) underwent surgery for excision of cardiac myxoma. Origin of the neoplasm was left atrium in all patients. In the last 7 cases diagnosis was obtained by echocardiographic examination. The clinical manifestations were dyspnea in 8 cases, palpitation in 5 and neurological symptoms in 3. One patient with concomitant mitral and aortic incompetence died on the 13th postoperative day because of low-output syndrome. All 13 operative survivors are alive and well without echocardiographic evidence of neoplastic recurrence at a follow-up ranging from 7 to 31 years. These results indicate a low incidence of recurrence with a complete tumor excision even without its extension to the normal atrial endocardium.

Adult↗
PubMed1993

Atypical seminoma--histologic features, immunohistochemical characterization, and correlation with survival.

Classical seminoma and embryonal carcinoma are two points in the spectrum of histologic differentiation in testicular germ cell tumors. The validity of an intermediate category, ie, atypical seminoma (AS) is questionable. Histopathologic and clinical data on 42 patients treated for primary testicular germ cell tumor from 1975 to 1985 were reviewed. Twenty-seven cases were identified as classical seminoma and nine were embryonal carcinoma. The remaining six cases were somewhat problematic to classify, combining the growth pattern of seminoma with cytologic features of embryonal carcinoma. Immunocytochemically, four of these tumors suggested some progression towards the embryonal carcinoma phenotype on the basis of cytokeratin expression. Survival for classical seminoma, AS, and embryonal carcinoma were 90%, 80%, and 63% respectively (mean follow-up, 8.6 years). Although the survival differences were not statistically significant, when considered with morphologic and selected immunocytochemical data, they tend to support the concept of an AS as an intermediate lesion between classical seminoma and embryonal carcinoma.

Adolescent↗
PubMed1993

Autoradiographic localization of dopamine D1 receptors in the human kidney.

The pharmacological profile and the anatomical localization of the selective D1-receptor antagonist [3H][R]-(+)-8-chloro-2,3,4,5-tetrahydro-5-phenyl-1H-3-benzazepin-7 -al- hemimaleate ([3H]SCH 23390) were studied in frozen sections of human kidney by using combined in vitro radioreceptor binding and autoradiographic techniques. [3H]SCH 23390 was bound by sections of human kidney in a manner consistent with the labeling of D1 sites, with a Kd value of 3.87 nM and with a Bmax value of 143 fmol/mg protein. Light microscope autoradiography revealed the highest density of [3H]SCH 23390 binding sites within the macula densa and the proximal tubules followed in descending order by the ascending limb of the loop of Henle, the distal tubules and the descending limb of the loop of Henle. No specific binding was noticeable within the glomeruli or within the epithelium of collecting tubules. [3H]SCH 23390 binding sites were also observed within the medial layer of intrarenal artery branches. These findings show that dopamine D1 receptor sites in the human kidney have a localization similar to that described in laboratory mammals with a higher density of tubular than of vascular receptors. The above data account for the vascular, diuretic and natriuretic effects elicited by D1 receptor stimulation in man.

Adult↗
PubMed1992

[The prevention of venous thromboembolism in Italy].

A questionnaire concerning the prophylaxis of venous thromboembolism was filled in by 326 surgical departments in Italy. In 58% the prophylaxis was routinely used and in 29% more than one method was used. The most used method of prevention was subcutaneous heparin followed by elastic compression. In 51% of the centers the prophylaxis was used only in high risk patients and in 22% it was not used at all. The most relevant risk factors in the development of thrombosis were considered age, tumors and obesity. Finally in a questionnaire sent to 350 vascular laboratories it was found that--according to the operators--76% of all documented thromboses were possibly consequent to surgical procedures (in 86% no prophylaxis had been used).

Bandages↗
PubMed1992

Pericardial agenesis and focal aplasia cutis in tetrasomy 12p (Pallister-Killian syndrome).

We report a stillborn female infant with multiple internal and external anatomic abnormalities and mosaicism for isochromosome 12p. These abnormalities included webbed neck, low-set ears, lower jaw tooth bud, left simian crease, shield chest, focal aplasia cutis, diaphragmatic hernia, hypoplastic lungs, agenesis of pericardium, and Meckel's diverticulum. Karyotypic analysis on cord blood lymphocytes showed 10% mosaicism of 46,XX/47,XX, + i(12p), and analysis of skin fibroblasts showed 50% mosaicism for the same karyotype. The parental karyotypes were normal. There are many reported cases describing the anomalies seen in isochromosome 12p. None of these cases, however, have displayed pericardial agenesis or aplasia cutis. The clinical and cytogenetic features of Pallister-Killian syndrome are reviewed.

Abnormalities, Multiple↗
PubMed1992

Localization of 5-hydroxytryptamine-like immunoreactive cells and nerve fibers in the rat female reproductive system.

The presence of 5-hydroxytryptamine (5-HT)-like immunoreactivity (IR) was studied in the rat female reproductive system using polyclonal antibodies directed against 5-HT. Moreover, 5-HT levels in the ovary, oviduct, uterus, and cervix were measured by high-pressure liquid chromatography with electrochemical detection. The highest 5-HT concentrations were found in the oviduct, followed in descending order by the cervix, the ovary, and the uterus. Most 5-HT-like IR was observed in the cytoplasm of mast cells. These cells were found in the connective tissue around the fimbria, in the oviduct, in the uterus, and in the ovary. Mast cells are clustered in the proximity of the parenchymal blood vessels. Moreover, a few 5-HT-like nerve fibers were found distributed mainly perivascularily in the uterine cervix and in the uterine horns as well as in the oviduct. IR nerve fibers were rarely seen within the ovary. The present data provide direct evidence that 5-HT in the female reproductive system not only is associated with mast cells but is located in nerve fibre-like structures as well. The functional significance of this probable 5-HT-ergic innervation of the female reproductive tract discovered in the present study should be clarified in future investigations.

Animals↗
PubMed1992

Direct demonstration of dopamine D1-like receptor sites in the ciliary body of the rabbit eye by light microscope autoradiography.

The pharmacological characteristics and the anatomical localization of [3H]-SCH 23390 in sections of the ciliary body of the rabbit eye were analyzed using a radioreceptor assay and autoradiographic techniques. [3H]-SCH 23390 was bound to sections of rabbit ciliary body in a manner consistent with the labelling of D1-like receptor sites. The dissociation constant (Kd) was 0.62 nmol/l, while the maximum binding capacity (Bmax) was 117 +/- 9 fmol/mg tissue. Light microscope autoradiography revealed [3H]-SCH 23390 binding sites within the epithelium of the ciliary processes, which is the ocular structure involved in the secretion of aqueous humor. No specific accumulation of silver grains was noticeable within the iridocorneal angle, which is the structure involved in the outflow of aqueous humor. These findings suggest that the rise in intraocular pressure caused by D1 receptor agonists is probably mediated by an increase of aqueous humor formation rather than by an inhibition of the outflow of aqueous humor.

Animals↗
PubMed1992

Oral choline alfoscerate counteracts age-dependent loss of mossy fibres in the rat hippocampus.

Mossy fibres represent a major intrahippocampal associative pathway. They consist of axons of granule cells of the dentate gyrus and show an age-dependent loss as do the granule cells of the dentate gyrus. The present study was designed to assess whether long-term treatment of rats with choline alfoscerate in their drinking water would be effective in countering the loss of mossy fibres and of granule cells occurring with aging. Choline alfoscerate is a precursor in the biosynthesis of brain phospholipids and increases the bioavailability of choline in nervous tissue. Male Sprague-Dawley rats of 18 months of age were divided into two groups. One group received a daily dose of 100 mg/kg choline alfoscerate for 6 months; the other group was used as an untreated control. Twelve-month-old untreated animals were used as a reference group. The area occupied by mossy fibres, as well as their density, was significantly reduced in 24-month-old control rats in comparison with 12-month-old rats. The same is true for the density granule cells of the dentate gyrus which was decreased by about 20% in the oldest animals. In choline alfoscerate-treated rats both the area occupied by mossy fibres and their density were significantly higher than in age-matched controls. Moreover, the number of granule neurons of the hippocampus was higher by about 7% in choline alfoscerate-treated than in control 24-month-old rats. The above data suggest that choline alfoscerate treatment counteracts some anatomical changes of the rat hippocampus occurring in old age.

Administration, Oral↗
PubMed1992

Propionyl-L-carnitine: a new compound in the metabolic approach to the treatment of effort angina.

The effects of propionyl-L-carnitine on exercise tolerance of 12 patients with stable exertional angina were assessed in a double-blind, placebo-controlled, cross-over protocol using serial exercise tests. Compared to placebo, propionyl-L-carnitine significantly increased total work from 514 +/- 199 to 600 +/- 209 W (P less than 0.05) (17%) and prolonged exercise time and time to ischemic threshold from 515 +/- 115 to 565 +/- 109 sec (P less than 0.05) (10%) and from 375 +/- 102 to 427 +/- 93 sec (P less than 0.01) (14%), respectively. ST segment depression at the highest common work level was significantly reduced from 0.19 +/- 0.08 to 0.15 +/- 0.08 mV (P less than 0.05) (21%). No significant changes in heart rate, systolic blood pressure, and rate-pressure product at rest, at the highest common work level, on appearance of the ischemic threshold, or at peak exercise were observed after propionyl-L-carnitine treatment. No side effects were observed under propionyl-L-carnitine treatment. This study shows that propionyl-L-carnitine can significantly improve exercise tolerance in patients with stable angina. Our data seem to confirm that propionyl-L-carnitine most likely exerts its protective action via the metabolic pathway.

Adult↗
PubMed1992

Adenoid cystic carcinoma of Cowper's gland.

We report an additional case of primary adenoid cystic carcinoma of Cowper's gland in an otherwise healthy asymptomatic 66-year-old man. Based on a review of similar lesions presenting in the head and neck, our treatment plan entailed pelvic exenteration followed by radiation therapy. Whether adenoid cystic carcinoma of Cowper's gland behaves as aggressively as it does in the head and neck remains unclear. However, in view of the extensive local invasion in our patient and a previously successful outcome, a combined surgical and radiation approach appears to be the most appropriate therapy.

Aged↗