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Biomedical subjects

M J Aguilar

Publications and source records attributed to M J Aguilar.

At least 19 recordsLinked to original sources
PubMed1986

Pharmacological investigation into the effects of histamine and histamine analogues on guinea-pig and rat colon in vitro.

The effects of histamine and specific histamine agonists has been examined on isolated longitudinal colon strips of guinea-pig and rat. Histamine and 2-pyridyl-ethylamine but not 4 methylhistamine produced a concentration-related contractile response in the guinea-pig colon. The H1-antagonist clemizole antagonized competitively the effect of histamine but the H2-antagonist ranitidine did not modify the dose-response curve to histamine in the guinea-pig colon. Atropine, hexamethonium, prazosin and propranolol failed to modify the contractile response to histamine. Tone induced with KCl in guinea-pig isolated colon was not modified by histamine agonists even in tissues pretreated with clemizole or ranitidine. Histamine and histamine analogues were without effect on the isolated longitudinal strip of the rat colon. It is concluded that histamine produced dose-dependent contractions of the guinea-pig colon due to direct activation of H1-histamine receptors. There is no evidence in favour of the existence of H2-histamine receptors in this preparation. The lack of effect of histamine agonists in rat colon strip argues against the existence of histamine receptors in this preparation.

Animals↗
PubMed1984

Passive transfer experiments in amyotrophic lateral sclerosis.

To test the hypothesis that a serum factor might play a role in the pathogenesis of amyotrophic lateral sclerosis, whole plasma obtained by plasmapheresis from patients with the disease was injected daily intraperitoneally into mice for periods of up to three months. Similar experiments were carried out with an isolated immunoglobulin fraction. Control experiments were carried out simultaneously. The animals were tested electrophysiologically, and histologic examinations of the brain, spinal cord, and peripheral nerves were performed. No ill effects were noted in the animals, and no neurophysiologic or microscopic abnormalities were detected.

Adult↗
PubMed1984

Lipofuscin in amyotrophic lateral sclerosis.

Lipofuscin has been reported to accumulate in abnormal amounts in motor neurons of patients with amyotrophic lateral sclerosis (ALS). Microdensitometry was used to quantitate such lipid masses in spinal motor neurons in normal subjects compared with spinal motor neurons in ALS cases. No overall difference in lipofuscin level was found between the normal and the ALS material. Some neurons of intermediate size did show increased amounts of lipofuscin, which is attributed to shrinkage during degeneration by larger cells having proportionately more lipofuscin originally.

Aged↗
PubMed1981

Cerebral amyloid angiopathy.

Cerebral amyloid angiopathy is nonspecific disease entity that has been associated with a number of neuropathologic conditions, the most prominent being dementia and cerebral hemorrhage. It occurs more commonly than is generally appreciated, with implications that may be overlooked. Amyloid deposits are found in the vessels of the leptomeninges and cerebral cortex. There is often a close topographic relation to senile plaques, the histologic abnormality characteristic of Alzheimer's disease and senile dementia. Because of this relation and the well documented presence of amyloid in senile plaques, a similar natural history has been postulated for each. Histochemical studies indicate, however, that there are distinct differences between the amyloid deposits in cerebral vessels and senile plaques. An association between cerebral amyloid angiopathy and other forms of amyloidosis has similarly failed to be established, and a successful form of therapy has yet to be devised.

Aged↗
PubMed1979

Mediastinal meningioma.

A case of meningioma appearing to arise from the stellate ganglion and associated with a unilateral Horner syndrome of long standing is presented. Clinical absence of central nervous system involvement and a normal computerized tomographic scan of the brain favor the neoplasm as being a primary extracranial meningioma. Light and electron microscopy showed characteristic structural features. A brief review of the literature is made, and theories concerning the origin of extracranial primary meningioma are presented.

Humans↗
PubMed1976

Corticosteroids and prevention of pulmonary damage following cardiopulmonary bypass in puppies.

A technique of inducing hypothermia using surface cooling and rewarming with a pump oxygenator has been applied clinically in infants with satisfactory results. Respiratory problems postoperatively, however, are reported to be among the complications contributing most to mortality and morbidity. Prednisolone sodium succinate (Solumedrol) has helped to obviate pulmonary damage in hemorrhagic and endotoxic shock and therefore may be effective in preventing pulmonary damage following hypothermia. This hypothesis was investigated in 12 mongrel puppies, 6 that had hypothermic cardiopulmonary bypass and circulatory arrest but were not given Solumedrol, and 6 that were treated preoperatively with Solumedrol. In lung biopsies taken immediately after bypass the pathological changes in both the group treated with steroids and the control group were similar. At six hours, however, lung biopsies from the control group showed further signs of progressive damage, while in the steroid-treated group there was a striking improvement with some lung biopsies showing a normal appearance. Thus, Solumedrol did not prevent initial lung damage, but the progressive and probably permanent changes were reduced.

Air Sacs↗
PubMed1975

Tubular particles in a case of recurrent lymphocytic meningitis followed by amyotrophic lateral sclerosis.

A patient suffered recurrent episodes of aseptic lymphocytic meningitis for many years and then developed amyotrophic lateral sclerosis (ALS). Immune-complexes were deposited in the renal glomerular basement membrane and mesangia. The necropsy study revealed both lymphocytic meningitis and ALS. Study of the motor neurons with the electron microscope revealed proliferation of endoplasmic reticulum, small cytoplasmolytic areas and focal neurofibrillar accumulations in axons. Interwoven, serpentine 10-15 nm. tubules first appeared with ER proliferation and, presumably at a later stage, were sometimes present in large masses. These tubules might be virus material but virus cultures, including tissue culture, and animal inoculations have thus far been negative.

Amyotrophic Lateral Sclerosis↗
PubMed1975

Protection from lung damage by blood filtration during deep hypothermia in puppies.

Ten puppies underwent deep hypothermia with surface cooling and bypass cooling. They were subjected to circulatory arrest for 30 minutes and then were rewarmed by means of bypass. There were 5 control puppies and 5 for which a Swank filter was placed in the arterial perfusion line. All puppies had some degree of lung damage, but it was more severe in those in which perfused blood was not filtered. The damage involved the lung vessels, interstitial tissue, and alveoli. Platelet-fibrin aggregates and margination and sequestration of leukocytes appeared to be important pathological findings. Apparently, the Swank blood filter protects the lung by removing leukocytes and damaged platelets from the circulation.

Animals↗
PubMed1970

Pathological changes in brain and other target organs of infant and weanling mice after infection with non-neuroadapted Western equine encephalitis virus.

Infant and weanling mice infected experimentally with non-neuroadapted Western equine encephalitis virus exhibited a differing spectrum of target-organ pathology as well as a different clinical response. The infant mice sickened and died within 48 hr. Pathological changes in this group were largely limited to such mesodermally derived tissues as muscle, cartilage, and bone marrow elements. The central nervous system was uninvolved, as were heart, lung, liver, and other body organs. The young adult mice, on the other hand, showed no clinical evidence of disease throughout the 376-hr postinfection period. Nevertheless, after 216 hr they developed acute diffuse meningoenceophalitis of the viral type, with concomitant changes in heart, lung, liver, kidney, and brown fat. The most striking and consistent finding in the infant group was acute necrotizing degeneration of the bone marrow. The most dramatic change in the young adult group was acute necrotizing meningoencephalitis.

Journal Article↗