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Biomedical subjects

J Pearson

Publications and source records attributed to J Pearson.

At least 199 records · Page 11Linked to original sources
PubMed1983

Iniencephaly: a neuropathologic study.

Five cases of iniencephaly are reviewed. Numerous central nervous system malformations were found at all levels, including microencephaly, polymicrogyria, heterotopic glial tissue in the leptomeninges, atresia of the ventricular system, marked disorganization of the brain stem, vermian agenesis, large cerebellar cyst, and disorganization of the spinal cord tissue. The cerebellum was normal in one case. Numerous skeletal anomalies were found as well as marked retroflexion of the craniocervical junction. We concluded that cerebral anomalies, although severe, are not specific for iniencephaly. Cerebellar anomalies, on the other hand, were considered to share some morphologic features between Dandy-Walker and Arnold-Chiari, i.e., Chiari type II and Chiari type III, malformations.

Abnormalities, Multiple↗
PubMed1982

Effect of exposure to anti-NGF on sensory neurons of adult rats and guinea pigs.

Nerve growth factor (NGF) deprivation was produced in adult rats and guinea pigs by immunization against mouse NGF. Exposure of adult animals to anti-NGF had no effect on sensory ganglion neuronal number or size-frequency histograms. However, the substance P content of sensory ganglia, spinal cord and hind paw skin decreased to as great an extent as was seen in animals exposed to anti-NGF in utero. We conclude that NGF has two separate effects on sensory neurons: adult sensory neurons require NGF for normal function whereas developing neurons require NGF for both survival and transmitter expression.

Animals↗
PubMed1982

Effects of autoimmune NGF deprivation in the adult rabbit and offspring.

An experimental autoimmune approach to the production of nerve growth factor deprivation, which we have previously described in the rat and guinea pig, has been applied to the rabbit. This species was chosen for study because of several potential advantages. The rabbit produces large litters and has a relatively short gestation period. More importantly, rabbits generate high titers of antibody against mouse NGF and large amounts of maternal antibody are passively transferred to the developing rabbit fetus compared to most other species, particularly the rat. The sympathetic nervous system of adult rabbit immunized against mouse NGF underwent degeneration with up to an 85% decrease in neuronal numbers in the superior cervical ganglion after 10 months of immunization, thus providing further evidence that NGF is required for the survival of mature sympathetic neurons. Despite the fact that newborn rabbits born to anti-NGF producing mothers had much higher titers of anti-NGF than did rats, the effects on the developing sympathetic and sensory nervous systems were not found to be any greater than in rats. Reductions in norepinephrine levels in the heart and spleen of adult rabbits born to anti-NGF producing mothers were greater than in small intestine. Prenatal exposure to maternal anti-NGF caused reductions (up to 70%) in the number of neurons in the dorsal root ganglia. Substance-P immunoreactivity was reduced in the substantia gelatinosa of the spinal cord of rabbit exposed to maternal anti-NGF. These changes, however, were not greater than seen in the rat. We conclude that although the rabbits offers some advantage in the study of the effects of NGF deprivation in the adult animal, it appears less well suited than the rat or guinea pig to the study of the effects of NGF deprivation on development.

Animals↗
PubMed1982

Relatively high levels of dopamine in nucleus accumbens of levodopa treated patients with Parkinson's disease.

The dopamine levels were found to be low in the putamen and relatively high in the nucleus accumbens in two Parkinson disease patients treated with levodopa up to the time of their deaths. Tyrosine hydroxylase immunocytochemistry revealed a severe degeneration of the nigro-striatal dopamine neuronal system in both postmortem brains. The relatively high dopamine levels in the nucleus accumbens may be responsible for the occurrence of dyskinesias.

Aged↗
PubMed1982

Liquid formula diet for human metabolic studies.

A liquid formula diet for use in studies with human subjects has been developed. All of the components can be obtained readily from commercial sources. For preparation of the diet, only equipment that customarily is found in institutional kitchens is needed. Acceptability over periods of several months is manifested by a large number of patients who consumed the liquid formula diet as their sole source of food.

Adult↗
PubMed1982

Changes in the structure of the mucous gel on the mucosal surface of the stomach in association with peptic ulcer disease.

The glycoprotein of human gastric mucus has been isolated and purified from mucous gel scraped from the surface of resected mucosa. All samples of mucus when analyzed by gel filtration were found to contain native, gel-forming, polymeric glycoprotein, together with varying amounts of the lower-molecular-weight glycoprotein. The galactosamine and glucosamine content of the lower-molecular-weight glycoprotein was the same as that for the native polymeric glycoprotein. The absence of serum glycoproteins and proteoglycans in the glycoprotein preparations was demonstrated. Gastric mucus from normal mucosa obtained by resection of the antrum during pancreatoduodenectomy, from duodenal ulcer patients, and from gastric ulcer patients contained 33.4% +/- 5.1%, 50.2 +/- 3.3%, and 65.1 +/- 2.8%, respectively, of the lower-molecular-weight glycoprotein. These results show the total mucous gel of the gastric ulcer group [and to a lesser extent, of the duodenal ulcer group] contains more lower-molecular-weight mucous glycoprotein, which from previous studies in vitro would suggest a weaker mucous gel structure.

Adult↗
PubMed1981

Hormone receptors in renal cell carcinoma. Their utility as predictors of response to endocrine therapy.

We have performed 23 estrogen and 24 progesterone receptor assays on tumor specimens from 26 patients with renal cancer, ten of whom subsequently received hormonal therapy for metastatic disease. Only one of these specimens contained measurable estrogen receptor levels, three contained low, but measurable progesterone receptor levels, and the remaining specimens contained no measurable estrogen or progesterone receptors. None of ten patients with metastases showed evidence of an objective response to hormonal therapy. Our data suggest that few, if any, renal cancers have high titers of estrogen or progesterone receptors, and that those patients whose tumors have low receptor titers are unlikely to respond to hormonal therapy.

Adenocarcinoma↗
PubMed1981

Neuronal survival and peripheral tissue size during human embryogenesis: study of a partial twinning.

The relationship between somatic tissue size and development of the nervous system was studied in a partially divided human uniovular twin. In the neck region where tissues were symmetrical in each twin the spinal cords, sensory ganglia and sympathetic ganglia were also normally formed. The bodies remained fused below the necks, but the spinal cords and related neuronal structures had developed separately. Mirror image asymmetry of tissue size existed in relationship to each spinal cord. The asymmetry was reflected in size and neuron content of motor and sensory structures. Stellate ganglia on the sides of the missing arms were also hypoplastic. This abnormal human development reproduces animal experiments in which limb ablation reduces embryogenetic survival of related neurons. It is indicates that human neurons are affected by alterations in tissue bulk during ontogenesis.

Embryo, Mammalian↗
PubMed1981

Neurotransmitter analysis of dermal neurofibromas: implications for the pathogenesis and treatment of neurofibromatosis.

We examined 15 dermal neurofibromas from five adults with disseminated neurofibromatosis. All tumors contained axons that reacted for catecholamines and tyrosine hydroxylase on histochemical stains. Assay of tissue homogenates identified norepinephrine as the catecholamine. Assays for dopamine and choline acetyltransferase were negative. Some axonal components of dermal neurofibromas may originate in sympathetic adrenergic neurons. Most dermal neurofibromas do not contain neuronal cell bodies, and some of the axons may maintain functional connections with proximal sympathetic neuronal cell bodies. Sympathetic denervation may therefore affect the growth of these dermal neurofibromas.

Adult↗