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H Miranda

Publications and source records attributed to H Miranda.

29 records · Page 2Linked to original sources
PubMed1976

Vas deferens desensitization by noradrenaline and other drugs.

Desensitization of the isolated rat vas deferens was demonstrated by using noradrenaline, 5-hydroxytryptamine, carbachol, acetylcholine or barium chloride as a test concentration after a large concentration (concentration producing a contraction that was 80% of the maximum) of the same agonist. The large concentration of noradrenaline caused desensitization in response to 5-hydroxytryptamine and acetylcholine but not to carbachol and barium chloride. Desensitization is not altered by reserpine--in pretreatment of rats with reserpine or reserpine in Tyrode solution--imipramine and 6-hydroxydopamine. Surgical denervation or modification of the sodium and calcium concentration of the Tyrode solution did not either alter desensitization. Results show that in the rat isolated vas deferens desensitization is not mediated by an action of noradrenaline on the adrenergic neuron.

Acetylcholine↗
PubMedDate not supplied

Depression scores following migraine treatment in patients attending a specialized center for headache and neurology.

OBJECTIVE: To determine the changes in clinical characteristics and depression levels among patients following treatment for migraine. BACKGROUND: Epidemiologic studies have provided consistent evidence regarding an association between migraine and depression. In Puerto Rico, however, migraine has not yet been systematically investigated. METHODS: A chart review of 144 Puerto Rican patients who presented with migraine, diagnosed according to the International Headache Society criteria, and depression over a 2-year period was performed. The level of depression, before and after migraine treatment, was evaluated using the Zung Self-rating Depression Scale. RESULTS: The mean age of patients was 37.0 +/- 14.4 years; 77.1% were women. More than half (52.8%) reported severe headache and 56.9% reported a monthly frequency of five attacks or more. Nearly 9% were using antidepressant therapy and 8% were under psychiatric treatment. The mean Zung index score at baseline was 50.6 +/- 10.9. Following treatment with triptans, the intensity and frequency of migraine and the Zung index score decreased significantly (P<.00001). A trend for a greater reduction in Zung index scores among patients receiving triptan medications for more than a year was demonstrated (P =.07). CONCLUSIONS: These results indicate that migraine treatment with triptans appears to be effective in decreasing the headache frequency and intensity, and depression levels, independent of antidepressant medication use or psychiatric treatment.

Adult↗
PubMedDate not supplied

[Central pontine myelinolysis and pregnancy: a case report and review of literature].

INTRODUCTION: The 'rapid' correction of hyponatremia, itself a dangerous condition, is dangerous to the patient involved. There is an association between the 'rapid' correction of plasma sodium and the osmotic demyelination syndrome, characterized by the loss of myelin in the pontine neurons, and in extra-pontine sites such as the internal capsule, basal ganglia, cerebellum and cerebrum. Although cases of hyponatremia during pregnancy have been described, it has rarely been possible to demonstrate the condition, by imaging techniques or autopsy, showing demyelination lesions of the cerebrum. We report the case of a pregnant patient who developed this complication and had an interesting response to levodopa. CLINICAL CASE: A 27 year old woman had a history of progressive generalized muscle weakness for the previous six days. She had recently been discharged after receiving treatment for hyperemesis gravidarum. Imaging studies showed pontine and extrapontine myelinolysis. She was treated with levodopa which improved her extrapyramidal symptoms. CONCLUSIONS: Hyponatremia is the most commonly observed electrolyte disorder in the hospital population. The classical symptoms of myelinolysis are spastic quadriparesia and pseudobulbar paralysis, which reflect damage to corticospinal and corticobular paths. Serious symptomatic hyponatremia is a medical emergency which should be managed by specially trained personnel, since the treatment is as dangerous as the condition itself. More investigations are necessary to identify the precise risk factors and the mechanism by which an increase in sodium causes damage to myelin.

Adult↗
PubMedDate not supplied

[Corrected cerebrospinal fluid manometry by measurement of the density and its relation with its biochemical composition].

INTRODUCTION AND AIMS: We question the suitability of the usual methods for taking the pressure of cerebrospinal fluid (CSF). We suspect that the composition of CSF and, in consequence, its density have an important effect on its manometric value. MATERIAL AND METHODS: We obtained 322 CSF samples, with known cytological and biochemical composition, density and manometric values. We corrected the manometric measurements and, for each case, we calculated the exact pressure exerted by the column of CSF from its density, which was already known. The working variable was set as the manometric error (ME) that resulted from: Abs (calculated pressure of the column of CSF from its density manometry) (absolute value of the difference). RESULTS: It was found that protein concentration levels in CSF had an important effect on the ME of the CSF, especially in values above 150 mg/cm3, and this result is extrapolated from our ad hoc mathematical model: corrected manometry (mmH2O) = manometry (mmH2O) + [cerebrospinal fluid protein (mg/cm3) / 50] 2. CONCLUSION: This model proved to be a suitable predictor of ME in our sample, with a= 0.005.

Cerebrospinal Fluid↗