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A Barrio

Publications and source records attributed to A Barrio.

18 recordsLinked to original sources
PubMed1983

Ca2+-dependence of 3H-catecholamines release evoked by black widow spider venom gland extract in rat hypothalamus, occipital cortex and caudate nucleus.

The release of 3H-catecholamines evoked by Black Widow spider venom gland extract (BW-GE) has been studied in the isolated rat hypothalamus (HT), occipital cortex (OC), preloaded with 3H-noradrenaline, and isolated caudate nucleus (CN) preloaded with 3H-dopamine. The BWGE at a concentration of 0.04 gland/ml increased significantly 3H-output in isolated slices of rat HT, OC and CN. This effect was markedly depressed when control calcium concentration in the medium (1.68 mM) was reduced (0-0.56 mM) or enhanced (3 mM), as well as in the presence of an organic Ca2+ antagonist, verapamil (10 microM), or ionophore A 23187 (40 microM), a substance that increases the influx of calcium into the cell. Morphine (up to 0.4 mM) evoked no effect upon 3H-noradrenaline release induced by BWGE. Morphine (10 microM), but not ionophore A 23187 or high Ca2+ (3 mM), reduced 3H-noradrenaline release induced by 20 mM K+. Low Ca2+ and verapamil produced similar effects than those observed for BWGE. Our results demonstrate differences between BWGE and potassium stimuli, and indicate that BWGE releases 3H-catecholamines by a calcium dependent process.

Animals↗
PubMed1980

Metabolism of 3H-noradrenaline released from isolated rat hypothalamus by extracts of black widow spider glands.

In the isolated rat hypothalamus preincubated with 3H-noradrenaline, an extract from the venom glands of Latrodectus mactans elicited on overflow of tritium which consisted of 70--71% 3H-noradrenaline and 18% 3H-3,4-dihydroxyphenylglycol. Exposure to cocaine or pargyline diminished the formation of 3H-3,4-dihydroxyphenylglycol, suggesting that the glycol is formed presynaptically after neuronal reuptake of the transmitter released by the venom. Our data suggest that the venom depolarizes the noradrenergic neurones of rat hypothalamus, and that the depolarization leads to calcium-dependent release of 3H-noradrenaline.

Animals↗
PubMedDate not supplied

[Pseudotumor cerebri associated with maxillary sinusitis: clinico-pathological study].

INTRODUCTION: The pseudotumor cerebri is characterized by increased intracranial pressure in the absence of a space occupying lesions or obstruction to the circulation of cerebrospinal fluid (CSF). Increased pressure but normal composition of the CSF is the diagnostic criterion. Ear infections and other infections such as sinusitis have been cited as possible, but rare, causes. CLINICAL CASE: A 12 year old girl presented with diplopia 10 days after starting treatment for sinusitis. On examination there was paresia of the VI cranial nerve to the left eye and marked bilateral papilledema. She had normal visual acuity with visual field measurements showing increased blind spot field in both eyes. Resonance studies only showed maxillary sinusitis. CSF pressure was 35 cm H2O, with 40 lymphomonocytes and normal biochemical findings. After 15 cm of CSF had been removed treatment was started with acetazolamide, dexamethasone and cefotaxime. A week later the diplopia had disappeared and the CSF pressure was 25, with no cells present. Two months later the visual fields and fundus oculi were normal. After follow-up for one year there was no recurrence. CONCLUSIONS: We describe a case of pseudotumor cerebri associated with maxillary sinusitis. We do not know whether this is a chance association or whether there was a pathophysiological basis. The possibility should be considered so as to treat the cause or predisposing factor. The initial CSF pleocytosis would support the possibility of a relationship of the pseudotumor with an infectious condition (meningeal irritation or para-infectious pleocytosis meningeal irritation or para-infections pleocytosis in the context of an ENT infection), which might have precipitated the problem by interfering with the reabsorption of CSF.

Acetazolamide↗
PubMedDate not supplied

[Prospective therapeutic trial of masking treatment in patients with tinnitus].

We report the results of a therapeutic trial of patients with tinnitus of different characteristics that was unresponsive to other medical or surgical treatments. Treatment was based on a combination of biofeedback training designed to reduce stress and either pure masking therapy or masking therapy consisting of a hearing aid and masker. The results showed an improvement in subjective perceptions and in the audiometric parameter of pitch in a significant percentage of patients.

Hearing Aids↗