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Biomedical subjects

J Pascual

Publications and source records attributed to J Pascual.

At least 379 records · Page 21Linked to original sources
PubMed1984

A circulating IgG in Chagas' disease which binds to beta-adrenoceptors of myocardium and modulates their activity.

It has been shown that sera from chagasic patients with positive EVI serology could act in co-operation with complement or normal human lymphocytes as a partial beta-adrenoceptor agonist increasing the contractile tension and frequency of isolated rat atria, as occurs with IgG purified from chagasic serum. In this paper we demonstrated that IgG present in chagasic patients sera could bind to the beta-adrenoceptors of the heart and stimulate contractile activity of myocardium. The positive inotropic and chronotropic effect could be blocked by the specific beta 1-adrenoceptor antagonist but not by the beta 2-adrenoceptor antagonist. Chagasic IgG inhibited the binding of (-) 3H-DHA to beta-adrenoceptors of purified rat myocardial membranes behaving as non-competitive inhibitors. The reactivity of chagasic serum or IgG with beta 1-adrenoceptor was lost after absorptions with turkey red blood cells. In contrast, guinea-pig red blood cells were unable to remove the beta 1 reactivity of chagasic serum or chagasic IgG. This supports the specificity of beta 1-adrenoceptors of the chagasic IgG and the independence of beta 1-adrenoceptor reactivity in relation to the EVI system. Clinical specificity of the beta 1-adrenoceptor reactivity seems rather high in Chagas' disease since it was lacking in 14 individuals with other cardiopathies, such as ischaemic and rheumatic heart disease, even after heart surgery.

Animals↗
PubMed1984

Alloimmune IgG binds and modulates cardiac beta-adrenoceptor activity.

Purified IgG from murine alloimmune sera directed against class I products from the major histocompatibility complex of the mouse, could bind to the beta-adrenoceptors and stimulate contractile activity of myocardium. Immune IgG inhibited the binding of (-) 3H-DHA to beta-adrenoceptors of mouse myocardial membranes behaving as a competitive inhibitor. Moreover, immune IgG induced positive inotropic and chronotropic effects on isolated mouse atria. These effects could be blocked by beta-adrenoceptors antagonists. Data prove that immune IgG directed against specific alloantigens are able to recognize the beta-adrenoceptors and mimic the stimulation of the beta-adrenoceptor agonist.

Animals↗
PubMed1981

First record of angiostrongylus cantonensis in Cuba.

The occurrence of human eosinophilic meningoencephalitis in several localities of Havana, Cuba, prompted a search for the rat lungworm, Angiostrongylus cantonensis, in the same localities. Twenty rats (Rattus norvegicus) and about 370 terrestrial mollusks (70 slugs, Veronicella cubensis, and about 300 snails, mostly Bradybaena similaris) were collected in six communities of the Province of Havana, and in the gardens of the Pedro Kouri Institute for Tropical Medicine in Havana City. Adult lungworms were found in 12 of the rats and larvae were recovered from a large number of pooled lots of the mollusks. Observations on the morphology and life history of the parasites confirmed the presence of A. cantonensis in the American region.

Angiostrongylus↗
PubMed1979

[A study of 14 cases of Bourneville's tuberous sclerosis, including two pathological reports and seven cases investigated by computer tomography (author's transl)].

The authors studied 9 girls and 5 boys, with ages ranging from 9 months to 26 years, suffering from Bournevilles tuberous sclerosis, for an average period of 7 years. The various types of epileptic attacks and their progression were studied as well as the degree of mental retardation. Only two of the children had a normal IQ. The accepted value of computer tomography examinations in this disease is confirmed. Pathological examinations were conducted in two cases, one complete (autopsy) and one partially only (histological examination of a paraventricular tumor removed by operation).

Adolescent↗
PubMed1978

[Intracranial neurinoma of the spinal nerve (author's transl)].

A patient aged 56 years has developed a syndrome affecting the last cranial nerves--IX, X, XI and XII--on the left side progressively over the last two years, and, more recently, deafness. Apart from a simple radiological examination all other radiological tests were negative. The diagnosis was made during the surgical operation which revealed a neurinoma of nerve XI (spinal) in its intracranial path. The diagnosis was confirmed histologically. After reviewing the published literature, the authors conclude that this is an exceptional case, which justifies publication and enables differential diagnosis to be made between this tumor and the Jugular Glomus tumor.

Accessory Nerve↗
PubMedDate not supplied

Differential distribution of [3H]sumatriptan binding sites (5-HT1B, 5-HT1D and 5-HT1F receptors) in human brain: focus on brainstem and spinal cord.

We report on the autoradiographic distribution of 5-HT1B, 5-HT1D and 5-HT1F receptor subtypes in human brain, focusing on the brainstem and cervical spinal cord. We have used [3H]sumatriptan as a radioligand in the presence of suitable concentrations of 5-CT (5-carboxamidotryptamine) to define 5-HT1F receptors, and ketanserin, to discriminate between 5-HT1B and 5-HT1D receptors. In the brainstem the highest concentrations of [3H]sumatriptan binding sites were seen in substantia nigra. The spinal trigeminal nucleus, substantia gelatinosa of the spinal cord, nucleus of the tractus solitarius and periaqueductal grey, also showed significant levels of [3H]sumatriptan binding sites. In the brainstem and spinal cord the total population of 5-CT-insensitive receptors, corresponding to 5-HT1F receptors, ranged from 9.8% in the periaqueductal grey to 53.4% in the substantia gelatinosa. This population represented 67.0% of binding in layer V of the frontal cortex. The decrease in [3H]sumatriptan binding in the presence of 200 nM ketanserin, indicative of the presence of 5-HT1D receptors, was very limited throughout the human brain, only reaching 20% of total specific binding over the periaqueductal grey. The proportion of [3H]sumatriptan binding sites displaced by 5-CT and insensitive to ketanserin, corresponding to 5-HT1B receptors, was, in general, the most abundant, ranging from 43.8% in substantia gelatinosa to 69.9% in the periaqueductal grey. Significant levels of 5-HT1B and 5-HT1D receptors found in migraine control pain areas suggest their involvement in antinociceptive mechanisms.

Aged↗
PubMedDate not supplied

Evaluating elderly patients with syncope.

Age-related physiologic changes together with high prevalence of chronic illness and the use of multiple medications predispose older adults to syncope. The causes of many of these patients' syncope are unexplained and most remained symptomatic. A thoughtful diagnostic strategy is essential to pinpoint the cause in each patient. The initial assessment includes a comprehensive medical history, preferably with an eye witness account, and a thorough physical examination. The decision for further diagnostic tests often depends on whether there is evidence of underlying structural heart disease. In the absence of heart disease, tilt table testing and the related autonomic function testing are usually most productive. Various cardiac studies will be more appropriate for those with suspected structural heart disease. A cause of syncope can only be concluded if there is a sufficiently strong correlation between syncopal symptoms and the detected abnormalities on investigations. A strategic evaluation of syncope of the elderly subjects should allow a correct diagnosis and appropriate management.

Journal Article↗
PubMedDate not supplied

[Present and future of kidney transplantation].

Renal transplant is the treatment of choice for the patient with end stage renal disease. Spain is the country with the highest donation rate (33 ppm). However, at present this figure is stabilized. The development of non-beating heart programmes, living-donor nephrectomy (specially laparoscopic nephrectomy) programmes, and may be xenotransplantation in a non-immediate future could increase the transplantation activity. The knowledge of preservation mechanisms, specially with the use of perfusion machines allows to rescue for transplantation kidneys with a long warm-ischemia time. Furthermore, these machines are useful for analyzing viability markers. The new immunosuppressive drugs: Tacrolimus, Mycophenolate-Mophetil, Rapamycin and monoclonal antibodies against alpha chain of the interleukine-2 receptor (Basoliximab and Dazcizumab) have reduced the incidence of acute rejection in the immediate renal transplant period. However, its effect in the long-term follow-up period is still a matter of controversy. The incidence of tumour in the renal transplant recipient is increased, specially those of lymphoma, skin cancer and Kaposi sarcoma. Periodical exams for detecting the development of tumours are mandatory in this population. Finally, xenotransplantation is an attractive alternative, although immunological, infective and ethical barriers should previously be resolved.

Forecasting↗
PubMedDate not supplied

Non-seasonality of births in Tierra del Fuego (Chile).

Tierra del Fuego is situated at the southern tip of the American continent, which conditions its environmental and climatic characteristics. The colonizing population arrived, at the end of the 19th century, from other Chilean regions (particularly from Chiloé) and diverse European countries, especially Britain and Croatia, but also Germany, Spain and Italy. In the present study, the existence of a seasonal pattern in 5430 births registered in the Chilean population of Tierra del Fuego from 1890 to 1995 was analysed. The analysis showed no seasonal distribution of births in the periods 1890-1920 and from 1946 to the present day, a phenomenon rarely reported in the literature. The absence of seasonality in birth distribution could be related to the great diversity in the origins of the population's families, the constant renovation of this and the declining importance of the administrative capital of the province of Tierra del Fuego, Porvenir, in favour of Punta Arenas, capital of the Magellanic region. In the period of maximum development of the capital of the province, a seasonal pattern was detected with a peak in April and a trough in October, which corresponds with a maximum of conceptions in July and, in general, during the early southern winter and a decline in births from late spring to mid-summer, with a trough in January. This birth distribution is interpreted as a subordination of activity and social life to the annual sheep cycle. In addition to temporal trends, the influence on the observed patterns of environmental parameters, father's occupation, seasonality of marriage and the origin of the parents were analysed.

Birth Certificates↗