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Biomedical subjects

J Pearson

Publications and source records attributed to J Pearson.

At least 217 records · Page 12Linked to original sources
PubMed1981

Progressive sensory loss in familial dysautonomia.

Clinical variability in sensory impairment was demonstrated among 75 patients with familial dysautonomia. Older patients had a greater tendency toward increased dysfunction in pain sensation, joint position and Romberg's sign, and vibratory sense. Significant worsening with increased age was supported by retesting of 53 patients after a five-year interval. Sensory and motor axon loss were indicated by electrodiagnostic testing of peripheral nerves and abnormal cortical somatosensory evoked potentials. Familial dysautonomia is a hereditary disease with variable penetrance which involves both failure of intrauterine development of neurons and their postnatal maintenance.

Adolescent↗
PubMed1980

Dorsal root ganglion neurons are destroyed by exposure in utero to maternal antibody to nerve growth factor.

Rats and guinea pigs, when immunized with mouse nerve growth factor, produce antibodies that cross-react with their own nerve growth factor. The antibodies reach developing offspring of these animals both prenatally (rats and guinea pigs) and postnatally (rats). Depriving the fetus of nerve growth factor in this way results in the destruction of up to 85 percent of dorsal root ganglion neurons as well as destruction of sympathetic neurons. Sensory neurons of placodal origin in the nodose ganglion were not affected. These data demonstrate that dorsal root ganglion neurons go through a phase of nerve growth factor dependence in vivo.

Animals↗
PubMed1980

Hazard visibility and occupational health problem solving the case of the uranium industry.

Recent evidence from European research challenges the adequacy of current U.S. exposure guidelines for underground mine radiation. This study traces the history of government regulatory agency and industry response to the hazard of excessive mine radiation in the uranium industry in Colorado some 30 years ago. Problem-solving activity by government agencies and companies is shown to coincide with how visible the health hazard to uranium miners becomes. Hazard visibility and key problem-solving variables are defined and measured. The article also discusses a number of social factors that affect societal response to evidence of an occupational health hazard. Those factor include (1) the elusiveness of the disease and its symptoms, (2) the social class of the victim, (3) the level of medical and scientific interest in its cause and cure, and (4) the economic costs of the disease.

Costs and Cost Analysis↗
PubMed1980

Renal disease in familial dysautonomia.

A study of renal disease in familial dysautonomia identified excess glomerulosclerosis in 10 or 13 autopsied and biopsied patients. Sympathetic nerve terminals could not be found on renal vessels in biopsied tissue; they were invariably demonstrable in controls. Altered renovascular responsivity to systemic hypotension in familial dysautonomia may lead to ischemia and subsequent sclerosis of glomeruli. Review of 79 living outpatients showed that clinically overt renal disease was rare in familial dysautonomia. Nevertheless, frequent observations of elevations of serum creatinine concentrations (32% of patients) and blood urea concentrations (76% of patients) indicated a high prevalence of abnormality. An association was found between hypotension and renal dysfunction.

Adolescent↗
PubMed1980

Appearance of tyrosine hydroxylase immunoreactivity in the human embryo.

Tyrosine hydroxylase was detected immunohistochemically in 3 human fetuses aged 5 1/2-6, 9-10 and 13-14 weeks. In the youngest fetus only the developing sympathetic chains were stained. By 9-10 weeks sympathetic terminals, adrenal medulla, carotid bodies, locus ceruleus, substantia nigra and basal ganglia showed positive reactions. In the oldest fetus a dense sympathetic innervation was present in the ductus venosus. Catecholaminergic neuronal systems, including their terminal axons, are well developed by 2 1/2 months of human gestation. PAP immunohistochemistry has the advantage of being applicable to archival formalin-fixed, paraffin-embedded tissue.

Brain↗
PubMed1980

Gastric mucus: isolation and polymeric structure of the undegraded glycoprotein: its breakdown by pepsin.

Human gastric mucus has been obtained from mucosal scrapings of gastric resection specimens. The glycoprotein was isolated from the mucus gel--undegraded and free of noncovalently bound protein--by equilibrium centrifugation in a CsCl density gradient. Ultracentrifugation studies showed this glycoprotein was a single component of molecular weight of 2 X 10(6). Analysis by gel filtration showed the undegraded glycoprotein was a polymer that was split into glycoprotein subunits, of about 5 X 10(5) mol wt, by pepsin and other proteolytic enzymes. Reduction with mercaptoethanol, but not with 2 M NaCl, also split the glycoprotein into subunits, which indicated that these subunits are joined together by disulphide bridges to form the undegraded glycoprotein. This structure is very similar to that described for the previously characterized pig gastric mucus glycoprotein, and it shows that results obtained using pig gastric mucus as a model are directly applicable to human gastric mucus. It also follows that pepsin in humans, by destroying this polymeric structure of the constituent glycoproteins, solubilizes the surface mucus gel, and liberates the degraded glycoprotein subunits into the gastric lumen. The relevance of this to changes in the thickness of the surface mucus gel in vivo and possible effects on mucosal protection in pathologic conditions is discussed.

Animals↗
PubMed1979

Tyrosine hydroxylase immunoreactivity in familial dysautonomia.

Tyrosine hydroxylase antigen was localized immunohistochemically in sympathetic neurons from human autopsy tissue. The reaction persists in paraffin-embedded tissue, and the method is applicable to archival specimens. Increased amounts in this antigen per cell may partially compensate for decreased numbers of sympathetic neurons in familial dysautonomia.

Adolescent↗
PubMed1979

Nucleolar organizing regions of human chromosomes.

Silver-stained cells from 49 parents with a history of several abortions were compared with cells from 35 parents with normal liveborn children. The modal and mean number of silver-stained NORs (Ag-NORs) observed on D- or G-group chromosomes was similar in both groups and between males and females. Ag-NORs were randomly distributed on all five acrocentric pairs. The distribution and size of Ag-NORs within an individual was not random and was fairly consistent from cell to cell. The mean number of associations per cell was similar in both males and females of the abortion group and was less than the number of associations in controls. The probability of D- or G-group chromosomes being associated was near the expected probability of 0.6 for D-association and 0.4 for G-association. The frequency of association of any chromosome combination did not differ statistically from the expected values, though the number of associations, 15/22, was higher than expected.

Abortion, Spontaneous↗
PubMed1978

Quantitative studies of dorsal root ganglia and neuropathologic observations on spinal cords in familial dysautonomia.

Intrauterine development and postnatal maintenance of dorsal root ganglion neurons are abnormal in familial dysautonomia, an autosomal recessive disorder associated with autonomic, motor and sensory deficits. Normally, dorsal root ganglion weight increases with age. This does not occur in the cervical plexus ganglia of dysautonomic patients. Neurons in dorsal root ganglia are found to be markedly diminished in the youngest patients and slow degeneration causes further depletion with age. Quantitative studies on C8 dorsal root ganglia show the normal neuron content to be between 42,500 and 53,600. In 3 patients with familial dysautonomia the range was 4,090-8,590 with the smallest number being in the oldest patient. Lateral root entry zones and Lissauer's tracts are severely depleted of axons. In older patients loss of dorsal column myelinated axons becomes evident and is first seen in lumbar fasciculus gracilis, cervical fasciculus cuneatus and interfascicular fasciculus. Temperature sensation is markedly impaired from infancy in familial dysautonomia. Loss of pain sensation is prominent and worsens with age. Vibration sense diminishes in adolescence and coordination of limb movements becomes poor in older patients. Neuron depletion in dorsal root ganglia and the progressive pattern of cord changes correlate well with these clinical observations.

Adolescent↗
PubMed1978

Quantitative studies of sympathetic ganglia and spinal cord intermedio-lateral gray columns in familial dysautonomia.

In adult patients with familial dysautonomia the mean volume of superior cervical sympathetic ganglia is reduced to 34% of the normal of 222 mm3. Packing density of neurons is reduced to 37% of normal. The mean total number of ganglionic neurons is 120,000 as compared to 1,060,000 in controls. The mean totals of preganglionic neurons in the first three thoracic cord segments are 13,600 in patients and 25,150 in controls. Deficits in sympathetic neurons account for many of the clinical, pharmacological and biochemical manifestations of familial dysautonomia.

Adolescent↗
PubMed1978

Quantitative studies of ciliary and sphenopalatine ganglia in familial dysautonomia.

In 3 patients with familial dysautonomia (FD) sphenopalatine ganglia were less than one fifth normal in volume and their total neuronal content was reduced to a mean of 1,510 (control mean 56,500). Parasympathetic denervation accounts for absence of overflow tears in FD. Ciliary ganglia were not reduced in volume and in 4 patients the mean neuron total was only slightly diminished to 2,900 (control 3,670, P less than or equal to 0.05). This does not appear sufficient to account for pupillary supersensitivity to methacholine in FD on the basis of denervation. Temporal differences in the embryogenesis of sphenopalatine and ciliary ganglia may underlie the observed differences in neuronal populations and suggest that the developmental anomaly in FD does not occur early in gestation.

Adolescent↗
PubMed1978

Fatal cerebral injury in the elderly.

A medical examiner's series of 71 elderly patients with fatal internal cerebral injuries demonstrated age differences with respect to the type of cerebral lesion and the causal incident. The elderly showed relatively fewer severe cerebral contusions than did a young group, but a higher incidence of subdural and intraparenchymal hematomas. Falls, the most common cause of injury in the elderly, were often precipitated by physical illness or ingestion of alcohol. Consumption of alcohol was also a prominent factor in the fatal assault cases.

Accidents↗
PubMed1978

Rearrangements involving four chromosomes in a child with congenital abnormalities.

This report describes a complex structural rearrangement between chromosomes X and 1 and a 7;13 translocation (together involving six break points) in a child with multiple congenital defects. Both parents showed a normal chromosome complement, suggesting that the changes may have originated either in a gametic nucleus or at a very early stage of zygotic development.

Abnormalities, Multiple↗