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F Arena

Publications and source records attributed to F Arena.

At least 55 records · Page 3Linked to original sources
PubMed1991

Evidence for distinct endothelin receptors in the pulmonary vascular bed in vivo.

The present study was undertaken to investigate the effects of endothelin (ET) isopeptides on the pulmonary vascular bed of the intact, spontaneously breathing cat under conditions of constant pulmonary blood flow and left atrial pressure. When pulmonary vasomotor tone was actively increased by intralobar infusion of U46619, intralobar bolus injections of ET-1 (1 micrograms), ET-2 (1 micrograms), and ET-3 (3 micrograms) produced marked reductions in pulmonary and systemic vascular resistances. The pulmonary vasodilator response to each ET isopeptide was not altered by atropine (1 mg/kg i.v.), indomethacin (2.5 mg/kg i.v.), or ICI 118551 (1 mg/kg i.v.), but was significantly inhibited by an intra-arterial (i.a.) infusion of glybenclamide at 5 mg/kg. This dose of glybenclamide significantly inhibited the decrease in lobar arterial and systemic arterial pressures in response to intralobar injection of pinacidil (30 and 100 micrograms), whereas the pulmonary vasodilator responses to acetylcholine (0.03 and 0.1 micrograms) and prostaglandin I2 (0.1 and 0.3 micrograms) were not altered. The systemic vasodilator response to each ET isopeptide was not changed by glybenclamide or by the other blocking agents studied. The present data demonstrate for the first time that ET-1, ET-2, and ET-3 dilate the pulmonary vascular bed in vivo. The present data suggest that the pulmonary vasodilator response to ET isopeptides depends, in part, on activation of potassium channels and is mediated differently from the systemic vasodilator response to these substances. Contrary to earlier work, the present data indicate the pulmonary vascular response to ET isopeptides depends on the pre-existing level of pulmonary vasomotor tone. Furthermore, the present data suggest that in the lung ET-1, ET-2, and ET-3 may serve as endogenous agonists for potassium channels, a newly described vasodilator mechanism in the pulmonary vascular bed of intact adult animals.

Animals↗
PubMed1991

Research on heterocyclic compounds. XXVIII. Imidazo[1,2-c]pyrimidines.

A group of 24 imidazo[1,2-c]pyrimidines was taken into consideration in order to study their relationships between chemical structure and antiinflammatory activity. Some of these compounds were synthesized by us in the past, the others have been synthesized and characterized to complete the series. Antiinflammatory, analgesic, antipyretic and gastric ulcerogenic activities of such compounds were compared with those of indomethacin and discussed in terms of the effects exerted by the presence on the heterocyclic system of various substituents and an acidic or nonacidic moiety.

Acetates↗
PubMed1990

Research on heterocyclic compounds. XXVII. Synthesis and antiinflammatory activity of 2-phenylimidazo[1,2-b]pyridazine-3-carboxylic acids.

A group of ethyl esters of 2-phenylimidazo[1,2-b]pyridazine-3-carboxylic acids 3 were obtained by reaction in anhydrous ethanol of some substituted 3-aminopyridazines 1 with ethyl 2-benzoyl-2-bromoacetate 2. The acids 4 obtained via alkaline hydrolysis were tested in vivo for their antiinflammatory, analgesic and ulcerogenic actions and in vitro for their ability to inhibit the prostaglandin biosynthesis. Almost all of the new compounds showed high analgesic activity, whereas the activities exhibited in the other tests were sharply lower. These results are discussed in terms of mechanism of action.

Animals↗
PubMed1990

Research on heterocyclic compounds. XXVI. Antiinflammatory and related activities of some 2-phenylimidazo[1,2-b]pyridazines.

Five acidic phenyl derivatives of the imidazo[1,2-b]pyridazine system were subjected to some tests in vivo in order to evaluate their biological activity. Antiinflammatory activity was studied by means of the carrageenin rat paw edema, whereas writhing induced in mice by acetic acid was used to assess analgesic activity. The irritative and ulcerogenic action on the rat gastric mucosa was examined after oral administration of larger doses. The inhibitory activity on platelet malondialdehyde production was studied in vitro. The experimental results are discussed from the point of view of structure-activity relationships and mode of action.

Analgesics↗
PubMed1989

Immunocytochemical detection of lactoferrin in human gastric carcinomas and adenomas.

In gastric carcinomas, including 20 cases of intestinal type and 10 cases of diffuse type, in adenomas with mild to severe dysplasia (20 cases), and in hyperplastic polyps (10 cases), the presence of lactoferrin was investigated by immunohistochemistry. Incomplete or complete intestinal metaplasia or both and normal gastric mucosa were also tested. Preoperative hematocrit and serum iron levels (18 patients) were recorded. An evident reactivity for lactoferrin was encountered in intestinal type carcinomas, adenomas, and incomplete intestinal metaplasia, whereas diffuse-type carcinomas, hyperplastic polyps, and complete intestinal metaplasia were always unstained; mucous neck cells of the antrum and body were also positive for lactoferrin. The results are discussed in relation to the increased requirement of iron by neoplastic cells, although in gastric carcinomas serum iron levels appear to be unrelated to the immunohistochemical presence of lactoferrin.

Adenoma↗
PubMed1988

Peanut and Lotus tetragonolobus binding sites in human kidney from congenital nephrotic syndrome of Finnish type.

The authors have studied kidney tissues from two cases of Congenital Nephrotic Syndrome of Finnish Type (CNS:FT), two cases of infantile polycystic disease and five normal newborns using Peanut (PNA) and Lotus Tetragonolobus (LTA) peroxidase-labeled lectins. In CNS:FT a positive reaction for LTA has been documented at the luminal surface of the microcysts, while no staining was observed with PNA. In infantile polycystic disease the cysts were stained by PNA, whereas LTA binds selectively proximal undilated tubules. In normal kidney distal tubules as well as collecting ducts and proximal tubules were stained by PNA and LTA respectively. The results suggest that in CNS:FT microcystic transformation of the kidney can originate from proximal tubules according to microdissection studies elsewhere reported.

Binding Sites↗
PubMed1988

Research on heterocyclic compounds. XXIV. Antiinflammatory activity of some imidazo[1,2-c]pyrimidine derivatives.

A group of four acidic imidazo[1,2-c]pyrimidine derivatives were subjected to a series of tests in vivo in order to assess their pharmacological activity. Antiinflammatory activity was studied by means of the carrageenin-induced paw edema and pleurisy in rats. Hot plate test and writhing induced by acetic acid in mice were employed to evaluate analgesic activity, whereas the yeast-induced hyperthermia in rats was used to study antipyretic activity. The irritative and ulcerogenic action on the rat gastric mucosa was examined at higher doses. The inhibitory activity on the platelet malondialdehyde production was studied in order to obtain information about the mechanism of action of test compounds.

Acetates↗
PubMed1987

Peanut lectin binding to the alveolar lining layer in hyaline membrane disease.

The authors have studied the histochemical pattern of Peanut lectin (PNA) binding sites in lungs of seven newborns with hyaline membrane disease (HMD) and ten controls. The alveolar lining layer was positive in HMD and no changes in the PNA pattern was noted after neuraminidase digestion. Hyaline membranes were generally unstained but occasional reactivity was encountered in some parts. No reaction with PNA was observed in control lungs, but positivity was seen after neuraminidase pretreatment. Our histochemical data document the presence of accessible galactosyl residues with absence of terminal sialic acid in the alveolar lining layer of newborns with HMD. The authors suggest that PNA reactivity in HMD reflects an histochemical feature described in fetal lungs at the pseudoglandular and canalicular stages.

Fluorescein-5-isothiocyanate↗
PubMed1987

Factors associated with decreased platelet MAO activity in chronic schizophrenics.

Platelet MAO activity was determined in a sample of chronic schizophrenics, including drug-free and neuroleptic-treated patients, and in a normal control group. Patients with MAO values below and above the median were compared with respect to several clinical, historical, neuroradiological and neuropsychological variables. The enzyme activity was significantly decreased in the whole patient group and in the subgroup of neuroleptic-treated patients, but not in the subgroup of drug-free patients. The only significant difference between low MAO and high MAO patients concerned drug status (higher percentage of patients on neuroleptics in the former subgroup). On stepwise discriminant function analysis, drug status (on neuroleptics vs. off neuroleptics) correctly classified 63.4% of patients.

Adult↗
PubMed1987

Research on heterocyclic compounds. XXII. Imidazo[1,2-a]pyrimidines.

We have taken into consideration a group of 21 imidazo [1,2-a]pyrimidine derivatives, some of which were already known, whereas the others were synthesized and characterized by us to complete the series. Antiinflammatory, analgesic, antipyretic and ulcerogenic activities of such compounds were evaluated in comparison with indomethacin, in order to get useful information about structure-activity relationships.

Animals↗
PubMed1986

Research on heterocyclic compounds. XIX--2-Methylimidazo[1,2-a]pyridine-3-acetic acids.

A group of methyl substituted imidazo[1,2-a]pyridine-3-acetic acids was synthesized by reaction of some methyl derivatives of 2-aminopyridine with ethyl 3-bromolevulinate and subsequent hydrolysis. These new acidic compounds were tested for their antiinflammatory, analgesic, antipyretic and ulcerogenic activities in order to compare the results with those previously obtained with similar compounds.

Animals↗
PubMed1986

Distribution of glial fibrillary acidic protein in normal and gliotic human retina.

The distribution of glial fibrillary acidic protein (GFAP) in normal human retina and in retinae with gliosis due to different diseases was studied by immunohistochemical methods. In normal retina, an evident GFAP-positivity is encountered only in the nerve fiber and ganglion cell layers; Müller cells do not stain. In retinal gliosis, together with an enhanced positivity of the perivascular and accessory glia, a strong staining for GFAP is observed in Müller cells, which extends from the inner to the outer limiting layers. A correlation between the intensity of immunohistochemical glial staining, its anatomical localization and the degree of retinal changes is suggested.

Adolescent↗
PubMed1985

Research on heterocyclic compounds. XVIII. Imidazo[2,1-b]-1,3,4-thiadiazole derivatives.

The synthesis of a series of 6-carbethoxy-, 6-carbethoxy-methyl-, and 5-carbethoxy-6-methylimidazo[2,1-b]-1,3,4-thiadiazoles was accomplished by reacting some 2-amino-1,3,4-thiadiazoles with ethyl bromopyruvate, 4-chloroacetoacetate, and 2-chloroacetoacetate, respectively; such carbethoxy derivatives afforded the corresponding carboxylic acids by hydrolysis. The antiinflammatory, analgesic, antipyretic and ulcerogenic activities were studied on three of the new acidic compounds.

Animals↗
PubMed1985

Factors associated with response to lithium prophylaxis in DSM III major depression and bipolar disorder.

The relationship of some clinical, personality and biological variables to the outcome of lithium prophylaxis was investigated in two patient samples fulfilling, respectively, the DSM III definitions of "major depression, recurrent" and "bipolar disorder". In major depressives, the presence of psychomotor retardation and melancholia during the index episode was associated with a favorable response to treatment, whereas the presence of mood-incongruent psychotic features during the same episode, a high score on the "anxiety" and "phobic" subscales of the Middlesex Hospital Questionnaire and a high score on the "neuroticism" subscale of the Eysenck Personality Questionnaire were related to a poor response. These findings are discussed in the light of the heterogeneity of DSM III major depression and of the reported common occurrence of an "anxiety-phobic" personality profile in unipolar depressives. In bipolar patients, a family history of bipolar affective illness and a high lithium ratio were associated with a good response to treatment, and the presence of the HLA-A3 antigen with an unfavorable response. These findings seem to support a role of pharmacogenetic factors in conditioning response to lithium prophylaxis.

Adult↗
PubMed1985

24-hour plasma levels of prolactin, cortisol, growth hormone and catecholamines in schizophrenic patients.

The 24-hour pattern of prolactin, cortisol and growth hormone (GH) secretion, and the diurnal variations of plasma catecholamine levels, were tested in a sample of DSM III schizophrenics and in a control population of patients hospitalized in the same ward and diagnosed as suffering from neurotic disorders. All subjects were acclimated to the ward and kept free from any drug for at least 2 weeks. No difference between schizophrenics and controls was observed with respect to the 24-hour profile of plasma prolactin and cortisol levels. The nocturnal peak of GH secretion was absent in 10 out of the 23 schizophrenics. These patients did not differ from the other schizophrenics with respect to the mean scores on any item of the Comprehensive Psychopathological Rating Scale. The mean plasma noradrenaline levels were significantly higher in schizophrenics than in controls during the wake period, but not during the sleep hours. A consistent decrease of the amine levels during the sleep period was observed in both groups. Since the nocturnal surge of plasma GH concentration has been associated with slow-wave sleep, which has been reported to be reduced in schizophrenic patients, the possibility is considered that this abnormality of sleep pattern can explain the alteration of GH release in schizophrenics. On the other hand, findings concerning plasma noradrenaline are interpreted as an indication that the state of increased autonomic arousal of schizophrenic patients is closely linked to daytime social interaction.

Adolescent↗
PubMed1984

Plasma cortisol, catecholamine and cyclic AMP levels, response to dexamethasone suppression test and platelet MAO activity in manic-depressive patients. A longitudinal study.

Plasma cortisol, catecholamine and cyclic AMP levels, response to dexamethasone suppression test and platelet MAO activity have been determined in 15 patients suffering from bipolar affective psychosis, each examined during a depressive, a manic and an euthymic phase, and in 15 sex- and age-matched normal controls. Mean basal and post-dexamethasone cortisol levels have been found to be enhanced in patients during depression, but not during mania or free intervals. Non-suppression of cortisol secretion after dexamethasone has been observed in 46.7% of patients while in a state of depression, but in none of them during mania or euthymia. Mean plasma noradrenaline and adrenaline levels, which are thought to be the most reliable biochemical indices of emotional arousal, have been found to be increased in patients during mania, but not during depression. No significant difference has been observed between patients during any phase of their illness and controls with regard to mean plasma cyclic AMP levels and platelet MAO activity. These results confirm the state-dependent overactivity of HPA axis in endogenous depression, and suggest that it should not be regarded as a correlate of emotional hyperarousal. Moreover, they do not support the postulated role of plasma cyclic AMP as a state variable and of platelet MAO activity as a trait variable for manic-depressive illness.

Adult↗