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Biomedical subjects

J J Gilbert

Publications and source records attributed to J J Gilbert.

99 records · Page 6Linked to original sources
PubMed1968

Alpha tocopherol control of sexuality and polymorphism in the rotifer Asplanchna.

A dietary component that initiates both the tranisition from parthenogenetic to sexual reproduction and the production of lateral, posterodorsal, and posterior outgrowths of the body wall of females was isolated from the neutral lipids of dried grass and identified as (alpha)-tocopherol. The smallest concentrations eliciting both responses were below 100 nanograms per milliliter. Relative activities of (alpha)-, beta3-, and (gamma)-tocopherol and (alpha)-tocopheryl-quinone were roughly 100 : 100 : 20 : 0.4. The synthetic antioxidants tested were without activity.

Animals↗
PubMed1966

Rotifer ecology and embryological induction.

The rotifer Asplanchna releases into its environment a water-soluble, nondialyzable, pronase-sensitive factor which causes uncleaved eggs of another rotifer, Brachionus calyciflorus, to develop into individuals with a pair of long, movable spines which neither their mothers nor the unaffected controls have. These appendages protect the Brachionus from Asplanchna predation.

Adaptation, Biological↗
PubMedDate not supplied

NMR studies in the relapsing experimental allergic encephalomyelitis (EAE) model of multiple sclerosis in the strain 13 guinea pig.

Juvenile strain 13 guinea pigs sensitized with an emulsion of whole isologous central nervous system (CNS) tissue in complete Freund's adjuvant in the first two weeks of life develop a relapsing-remitting form of experimental allergic encephalomyelitis (EAE) which resembles multiple sclerosis (MS) both clinically and pathologically. In order to determine if this experimental model could be used to identify the tissue factors which contribute to the magnetic resonance imaging (MRI)-detected lesions in MS, we measured T1 and T2 relaxation times, tissue specific gravity and histology throughout the entire CNS in vitro in eighteen animals during the acute phase (first attack), and twenty-one animals during further periods of clinical worsening (relapses) and recovery (remissions). The neuropathological findings of spinal cord meningeal inflammation, perivascular and parenchymal infiltration (myelitis and encephalitis) and demyelination were more marked during periods of clinical worsening than when the animal had recovered clinically. Even though the histological changes of EAE were present in all experimental animals, NMR relaxation times and tissue specific gravity could not distinguish experimental (first attack, subsequent relapses and remissions) from control animals due to a wide range of values for each of these parameters. Although relapsing EAE in the strain 13 guinea pig has been an instructive model of MS, we have found that in vitro NMR relaxometry cannot be used to predict the presence or degree of pathological change in the nervous system of these experimental animals.

Animals↗
PubMedDate not supplied

Cerebral amyloid angiopathy: incidence and complications in the aging brain. I. Cerebral hemorrhage.

The clinical and pathologic findings in eleven patients with fatal cerebral hemorrhages related to cerebral amyloid angiopathy (CAA) are described. The hemorrhages were bihemispheric, though not necessarily of simultaneous onset in four patients, and favoured the fronto-parietal cortex and white matter in ten patients. Dissection into the subarachnoid space was common. Cerebrovascular lesions or cardiomegaly related to hypertension coexisted with those of CAA in three cases. Seven patients were not demented prior to the ictus. Ten of eleven brains contained abundant senile plaques and/or neurofibrillary tangles, whether or not the patient had been clinically demented. In the elderly, CAA is an important etiologic consideration for cerebral hemorrhage, especially if the hemorrhage occurs in a peripheral location in the brain and is superimposed on a history of dementia.

Aged↗
PubMedDate not supplied

Cerebral amyloid angiopathy: incidence and complications in the aging brain. II. The distribution of amyloid vascular changes.

Ten histologic sections were sampled from similar cortical regions in each of 84 autopsy brains removed from patients aged 60 to 97 years. The sections were stained by the Congo-red method and examined under polarized light for the presence of cortical (parenchymal) cerebral amyloid angiopathy (CAA). Some degree of CAA was found in 36% of all brains examined, with a higher proportion of patients affected in each successive decade of life. Angiopathy was seen most frequently and was of greater severity in the parietal and occipital gray matter. Overall, it was often a patchy and asymmetric lesion. There was sparing of subcortical white matter and the hippocampi. CAA was most severe in cases of Alzheimer's disease, but occurred in the absence of this condition.

Aged↗
PubMedDate not supplied

Hemichorea and hemiballismus: recent concepts.

An unusual case of severe hemichorea in an elderly hypertensive woman, precipitating acute pulmonary edema, is presented. There were small cystic infarctions in the contralateral neostriatum and thalamus, and intact subthalamic nuclei. The clinicopathologic correlation of hemichorea and hemiballismus is reviewed, and its relationship with the results of recent neuroanatomic research is discussed.

Aged↗