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Biomedical subjects

L Stella

Publications and source records attributed to L Stella.

At least 55 records · Page 3Linked to original sources
PubMed1992

Effects of flunoxaprofen, a non-steroidal anti-inflammatory agent, on the cardiovascular system.

The effects of flunoxaprofen (FL) were investigated using anesthetized normotensive and spontaneously hypertensive (SHR) young and old rats. The animals were divided into two groups. One group received a non-steroidal anti-inflammatory agent at doses significantly inhibiting prostaglandin (PG)-cyclooxygenase; the other received no non-steroidal anti-inflammatory drugs. Oral pretreatment of anesthetized rats with flunoxaprofen (6.6, 11.5, and 19.9 mg/kg/day in the feed for 560 days) significantly increased the following responses: occlusion of the common carotid arteries, and reactivity to L-noradrenaline (NA) (i.v.), and angiotensin II (Ang) (i.v.). Pressor responses also increased in normotensive and in SHR rats treated with FL (20 mg/kg/day for seven days). The effects were more intense in the SHR rats. Moreover, oral pretreatment of normotensive rats with FL (20 mg/kg/day for seven days) partially yet significantly reduced the antihypertensive activity of etozolin (ET), a diuretic and antihypertensive drug. Our data confirm the important role of prostaglandins in the regulation of the cardiovascular system, and an increase in arachidonic acid metabolite biosynthesis with vasodilatory effects being part of the mechanism of action of some antihypertensive drugs.

Administration, Oral↗
PubMed1992

Central arrhythmogenic effects of N-methyl-D-aspartate (NMDA) in anesthetized rats: influence of the denervation of the carotid-sinus baroreceptors on the susceptibility to arrhythmias.

The intracerebroventricular (i.c.v.) administration of NMDA into urethane anesthetized rats could induce centrogenic cardiac arrhythmias. There were some important differences between sodium glutamate- and NMDA-induced arrhythmias which rendered it difficult to accept the assumption that glutamate-induced arrhythmias were due to the stimulation of only NMDA receptors. Denervation of the carotid-sinus baroreceptor zones enhanced the central arrhythmogenic activity of both sodium glutamate and NMDA.

Anesthesia↗
PubMed1991

Differential detection of plasma hydroperoxides in sepsis.

OBJECTIVE: To determine whether plasma lipid hydroperoxides may be a useful marker for sepsis. DESIGN: Exploratory, open-label study. SETTING: Critical care unit at a university medical center. PATIENTS: Twelve patients with sepsis syndrome requiring hemodynamic monitoring with pulmonary artery catheters. Seven patients were diagnosed with pulmonary infections and five patients had intra-abdominal infections. INTERVENTIONS: Fatty acid hydroperoxide was measured in the fresh arterial plasma (radial artery) and mixed venous plasma (pulmonary artery) from each patient. Hydroperoxide was determined using a sensitive assay based on activating the cyclooxygenase reaction of prostaglandin H synthase. MEASUREMENTS AND MAIN RESULTS: The mean difference between the amount of fatty acid hydroperoxide measured in the plasma draining involved regions (arterial plasma for pulmonary sepsis, mixed venous plasma for intra-abdominal sepsis) compared with the paired, uninvolved regions was 0.45 +/- 0.14 microM (mean +/- SEM; p less than .005). CONCLUSIONS: Increased lipid hydroperoxides in blood-draining septic foci are markers of oxyradical release associated with severe infection, although they are not specific for infectious conditions, being released also from nonseptic regions of surgical trauma. Assays for hydroperoxides may be useful when relatively free of other tissue trauma.

Adult↗
PubMed1991

Cardiovascular and respiratory effects of dermorphin in rats.

The cardiovascular and respiratory effects of dermorphin (D) have been evaluated in freely moving or anesthetized normotensive and spontaneously hypertensive male rats. Intravenously or intracerebroventricularly administration of D produced arterial hypotension with sinus bradycardia and respiratory depression. Naloxone antagonized the effects of D. Atrial natriuretic antipeptide IgG reduced the cardiovascular responses without any significant modification of respiratory response. ICI 174864, naloxonazine and binaltorphimine did not reduce the cardiovascular and respiratory effects. In hypertensive rats D produced more intense and longer cardiovascular effects than those seen in normotensive animals. D effects involve the activation of mu and k opioid receptors for cardiovascular responses and mu 2 opioid receptors for respiratory depression without any significant effect on delta receptors. The release of atrial natriuretic peptide also appears to be involved in the cardiovascular effects of D.

Analgesics, Opioid↗
PubMed1990

Ascorbyl free radical as a reliable indicator of free-radical-mediated myocardial ischemic and post-ischemic injury. A real-time continuous-flow ESR study.

The real-time kinetics of the release of ascorbyl free radicals in the coronary perfusate from isolated rat hearts submitted to an ischemia/reperfusion sequence has been achieved by continuous-flow ESR using high-speed acquisition techniques. Enhanced ESR detection of ascorbyl free radicals was obtained by addition of dimethyl sulfoxide (Me2SO), a strong cation chelator and oxidizing agent. A continuous-flow device allowed a direct monitoring of the ascorbyl free radical and/or ascorbate leakage in coronary perfusate by observation of the ascorbyl radical doublet (aH = 0.188 mT and g = 2.0054). 1. The results showed that ascorbyl free radical release occurred mainly during sequences of low-flow ischemia (90 min) coupled or not with 30 min of zero-flow ischemia followed by reperfusion (60 min). The kinetic profiles of ascorbyl-free-radical detection confirm in quantitative terms the expected correlation between the duration of the ischemic insult and the magnitude of ascorbate extracellular release upon reperfusion. There is indication that ascorbyl free radical depletion could be secondary to oxygen-derived-free-radical-induced cellular damage. 2. The amount of residual ascorbic acid was quantitated on myocardial tissue at the end of reperfusion using Me2SO as extracting solvent. Intense oxidation of ascorbate and chemical stabilization of the resulting free radical species provided by Me2SO allowed ESR measurement of a marked tissue ascorbate depletion related to the duration of ischemia. 3. Perfusion of superoxide dismutase during low-flow ischemia and the first 10 min of reperfusion greatly inhibited both extracellular release and endogenous ascorbate depletion. These results suggest that the ascorbate redox system constitutes a major protective mechanism against free-radical-induced myocardial injury. 4. The proposed direct ESR detection of ascorbyl free radicals in the coronary perfusates or in tissue extracts does not require extensive chemical preparation and conditioning of effluent or tissue samples. It provides an interesting straightforward alternative to the evaluation of detrimental free radical processes affecting the myocardium during ischemia and reperfusion.

Animals↗
PubMed1990

3,5-Diphenyl-1H-pyrazole derivatives. IV--N,N-disubstituted 3-(3,5-diphenyl-1H-pyrazol-1-yl)propanamides and 3-(3,5-diphenyl-1H-pyrazol-1-yl)propanamines with sedative, platelet antiaggregating and local anesthetic activities.

The synthesis of N,N-disubstituted 3-(3,5-diphenyl-1H-pyrazol-1-yl)propanamides 2 a-d and 3-(3,5-diphenyl-1H-pyrazol-1-yl)propanamines 3 a-d starting from 3-(3,5-diphenyl-1H-pyrazol-1-yl)propanoic acid is described. Some of the above compounds showed considerable sedative and local anesthetic activities in mice, as well as a remarkable platelet antiaggregating activity in vitro. Moreover, the above compounds usually exhibited moderate analgesic and antiinflammatory activities in mice and rats, respectively.

Amides↗
PubMed1990

3,5-Diphenyl-1H-pyrazole derivatives. VI--Esters and 2-dialkylaminoethyl ethers of 1(2-hydroxy-2-phenylethyl)-3,5-diphenyl-1H-pyrazole and N,N-disubstituted 1-(2-amino-2-phenylethyl)-3,5-diphenyl-1H-pyrazoles with depressant and platelet antiaggregating activities.

The syntheses of 1-(2-hydroxy-2-phenylethyl)-3,5-diphenyl-1H-pyrazole 1 by reaction of 2-hydrazino-1-phenylethanol with dibenzoylmethane, of esters 2 and 2-dialkylaminoethyl ethers 3 starting from 1 as sodium salt and acyl chlorides or 2-chloroethyldialkylamines, respectively, as well as of N,N-disubstituted 1-(2-amino-2-phenylethyl)-3,5-diphenyl-1H-pyrazoles 5 by reaction of secondary amines with the tosylate of 1, are described. Some of the above compounds showed a considerable sedative effect in mice and a remarkable platelet antiaggregating activity in vitro, as well as moderate local anesthetic, analgesic and antiinflammatory activities in mice and rats.

Anesthetics, Local↗
PubMed1990

3,5-Diphenyl-1H-pyrazole derivatives. VII--Esters, 2-dialkylaminoethyl ethers and N-substituted carbamates of 1-(2-hydroxy-3-phenoxypropyl)-3,5-diphenyl-1H-pyrazole with depressant and platelet antiaggregating activities.

The syntheses of 1-(2-hydroxy-3-phenoxypropyl)-3,5-diphenyl-1H-pyrazole 2 by reaction of 1-hydrazino-3-phenoxy-2-propranolol with dibenzoylmethane, of esters 3 and 2-dialkylaminoethyl ethers 4 starting from 2 as sodium salt and acyl chlorides or 2-chloroethyldialkylamines, respectively, as well as of N-aryl carbamates 5 by reaction of 2 with aryl isocyanates, are described. Some of the above compounds showed a considerable sedative effect in mice and a remarkable platelet antiaggregating activity in vitro, as well as moderate local anesthetic, analgesic and antiinflammatory activities in mice and rats.

Anesthetics, Local↗
PubMed1990

Cerebral gliosarcomas: correlation of computed tomographic findings, surgical aspect, pathological features, and prognosis.

The cases of 5 patients with cerebral gliosarcomas examined by computed tomography are reported and the correlations among the computed tomographic (CT) findings, the surgical and histological aspects, and the prognosis are discussed. In some patients, these tumors appear on CT scan as intracerebral lesions, with large necrotic areas and peripheral contrast enhancement; this CT aspect, similar to that of glioblastomas, corresponds to a diffusely infiltrating growth of the tumor and the prevalence of a gliomatous component. In other patients, the tumor appears on the CT scan as a hyperdense mass with well-defined margins and homogenous contrast enhancement; this CT finding, which may mimic that of a meningioma, corresponds to a rather well-demarcated surgical aspect and the prevalence of sarcomatous component. In our series, we have also noticed a more prolonged survival in a patient with a CT aspect that suggested a meningioma and prevalence of the sarcomatous component.

Adult↗
PubMed1990

2H-[1]benzothiepino [5,4-b]pyran derivatives with local anesthetic and antiarrhythmic activities.

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-[1]benzothiepino [5,4-b]pyran-2-ones by reaction of phenylchloroketene with a series of N,N-disubstituted (E)-4-aminomethylene-3,4-dihydro-1-benzothiepin-5(2H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. The 4-methylphenylamino derivative showed a local anesthetic activity in mice superior to that of lidocaine and the 4-morpholino derivative showed an antiarrhythmic activity in rats comparable to that of quinidine.

Anesthetics, Local↗
PubMed1989

Giant sacral perineurial cyst. A case report.

A rare case of giant sacral perineurial cyst, causing sciatic pain, explored by myelography and computerized tomography, is reported. The cyst, associated with large erosion of the sacrum, was poorly visualized on the myelography, because of its large size, whereas it was better defined on CT scan. Sacral perineurial cysts are usually small and asymptomatic and rarely cause radicular symptoms. The radiological diagnosis and the treatment of these nerve root cysts are briefly discussed.

Adult↗
PubMed1989

Tumors of the neuron series presenting as cysts with mural nodules.

Two cases of tumors of the neuron series presenting as cysts with mural tumor nodules are described. This radiographic and surgical aspect may be observed in astrocytomas, meningiomas or ependymomas, whereas it is more rare for neuroblastomas and ganglioneuromas. There are not CT features which allow to differentiate cystic tumors of the neuron series from the other cystic tumors. The finding of cyst with enhancing mural tumor nodule and unenhanced wall is more favorable from a surgical point of view; the complete removal of the nodule with preservation of the reactive cyst wall results in the cure of patients with ganglioneuroma and ganglioglioma and in good long-term survival in those with cerebral neuroblastomas.

Adolescent↗
PubMed1989

Prenatal and postnatal vanadium exposure in rats: effect on vasomotor reactivity development of pups.

The study has been carried out on albino rats pre and/or postnatally exposed to vanadate (1 and 10 mg/dl). In pups pre- and postnatal or postnatal vanadate exposure significantly decreased on the 30th and 60th day of age the pressor response to 1-noradrenaline, and increased the pressor response to sinus-carotid baroreceptor stimulation and the hypotensive responses to 1-isoprenaline and acetylcholine. The effects were observed at vanadate doses that did not interfere with gestation, maternal and pup body weight, maternal systolic arterial blood pressure during pregnancy, and pup systolic arterial blood pressure. These doses have not determined any macroscopic teratogenic effects.

Animals↗