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Biomedical subjects

J C Bear

Publications and source records attributed to J C Bear.

36 records · Page 2Linked to original sources
PubMed1983

Identification of subsets of patients with Graves' disease by cluster analysis.

We have applied cluster analysis methods to forty-nine laboratory and clinical characteristics (including 26 HLA-A, B antigens) observed in 196 Graves' disease patients. Three subgroups could be identified: group I (seventy-nine patients) had small goitres, low indices of autoimmunity and a tendency to remission with medical treatment; group IIa (twenty-nine patients) had clinical and laboratory features of 'Hashitoxicosis'; Group IIb (eighty-four patients) had a high incidence of ophthalmopathy, familial aggregation, marked evidence of autoaggression and a tendency to relapsing hyperthyroidism. The prevalence of HLA-B8 was 8.9% in group I, 20.7% in group IIa and 86.9% in group IIb. This study demonstrates that Graves' disease can be subdivided using cluster analysis into clinically relevant subgroups which are further distinguished by their correlation with HLA-B8. Possible immunological bases for these observed patterns are discussed.

Adolescent↗
PubMed1983

Additional data on spontaneous abortion and facial cleft malformations.

Examination of fetal wastage data for a large collection of CL +/- P and CP sibships reported previously (Bear 1978) does not indicate the frequency of recognized abortion to be higher in the sibships of CL + P vs CL index cases, female vs male CL +/- P index cases, bilateral vs unilateral CL +/- P index cases, female bilateral CL +/- P index cases vs male unilateral CL +/- P index cases, or male vs female CP index cases. These observations fail to confirm those reported by Dronamraju (Dronamraju et al. 1982, Dronamraju & Bixler 1983a, b), and provide no evidence of a positive relation between degree of liability to facial cleft malformation and fetal mortality.

Abnormalities, Multiple↗
PubMed1983

Cylindrical refractive error: a population study in western Newfoundland.

The distribution of cylindrical refractive error (right eye only) is presented for 957 persons, comprising approximately 80% of the population (aged 5 years and over) of three western Newfoundland communities. In 72% of males and 60% of females no cylindrical error was found; 12% of males and 19% of females had errors greater than 0.5 D. Cylindrical errors of 2 D or greater were found in 2.5% of females of but only 0.5% of males, affecting females of all ages but males aged less than 15 years only. Persons aged 45 years and up had fewer cylindrical errors, more against-the-rule and less with-the-rule astigmatism than persons below that age. Cylindrical error and spherical error, and in particular against-the-rule error and myopia, commonly occurred together. Among persons aged 5 to 14 years an association of with-the-rule error with nearwork is suggested.

Adolescent↗
PubMed1982

Immunoglobulin levels, immunodeficiency and HLA in type 1 (insulin-dependent) diabetes mellitus.

In 129 patients with Type 1 (insulin-dependent) diabetes mellitus, 100 healthy control subjects and 91 non-diabetic first degree relatives of Type 1 patients, we investigated variation in serum IgA, IgG and IgM concentrations with sex and HLA-B phenotype. Two patients with onset before the age of 15 years were completely IgA-deficient. One additional patient was completely IgG-deficient. Excluding these three cases, diabetic patients had serum IgA and IgM concentrations comparable to control subjects. IgG levels of patients were, however, significantly lower than those of control subjects (11.66 versus 12.69 g/l, p = 0.003). Non-diabetic first degree relatives of patients had IgG levels intermediate between those of diabetic patients and control subjects. There was some indication that IgA concentrations were lower in the 53 patients with HLA-B8 (1.91 versus 2.21 g/l, p = 0.038). No association was found between IgM or IgG levels and HLA phenotypes.

Adult↗
PubMed1982

Association of hypergammaglobulinemia G with HLA-DR3 in Graves' disease.

Serum levels of immunoglobulins (Ig) IgA, IgG and IgM were measured in 96 HLA-typed patients with Graves' disease and an equal number of sex and age matched controls. Patients showed significantly increased serum immunoglobulin levels compared to controls. HLA DR3-positive patients had larger elevations of IgG concentration than their HLA-DR3-negative counterparts. Variation in serum immunoglobulin levels was not associated with sex, treatment or ophthalmopathy. It is suggested that the hypergammaglobulinemia of Graves' disease is related to defective suppressor cells triggered by Ig or Ig-linked genes. HLA-related gene(s) must, in addition, be involved to account for hypergammaglobulinemia G in the HLA DR3-positive subset of patients.

Adult↗
PubMed1981

Nearwork and familial resemblances in ocular refraction: a population study in Newfoundland.

There is considerable epidemiological evidence that the nearwork associated with formal education can cause myopia. The potential for nearwork and education, as aspects of common familial environment, to inflate resemblances among nuclear family members in ocular refraction, was therefore investigated in a sample of 957 persons aged 5 years and over, comprising approximately 80% of the population above that age in three communities on the west coast of Newfoundland. Refraction was evaluated using standard optometric methods, nearwork measured in hours/day as reported by each subject, education measured as last completed school grade in years. The effects of nearwork and education on refraction resemblances were evaluated by adjusting refraction for age and sex, then comparing correlations or regressions among relatives before and after further linear regression adjustment of refraction for nearwork and education. Reductions in sib-sib correlations and offspring-parent regressions were achieved in this way, suggesting that these environmental factors inflate familial resemblances in refraction. Patterns of resemblances among relatives after adjustment suggest that the effects of nearwork and education on refraction resemblances were not completely removed by the linear regression adjustment used.

Adolescent↗
PubMed1980

The distribution of refraction in three isolated communities in Western Newfoundland.

Data were collected on refraction in three isolated communities in western Newfoundland. Altogether 971 persons, about 80% of the population, were refracted. Subjects were not visually selected. Females showed a greater range of refractions than males at most ages, generally had more negative refractions than males, in particular at younger ages, and showed negative age group means earlier than males. Persons under 30 had more negative mean refractions, and more formal education than persons over 30. The age distribution of refraction in this population is compared with that reported by several others, and arguments presented that exposure to formal education is associated with increased myopia.

Adolescent↗
PubMed1980

Refraction, nearwork and education. A population study in Newfoundland.

There is little information directly relating ocular refraction and nearwork habits in representative human populations. Ocular refraction (diopters), nearwork (hours per day), and education (years) were therefore measured for 957 persons comprising 80% of the population aged 5 years and above of 3 communities in western Newfoundland. Refraction was moderately, consistently and significantly correlated with nearwork from ages 5 to 60, and remained so after adjustments for the association of refraction and nearwork levels with age, sex and education. Multiple regression coefficients relating refraction to nearwork decreased from -0.43 D/h at ages 5-14 years to -0.22 D/h at ages 60 years and up. The magnitude of this association, and its consistency and persistence over a wide age range, suggest that large amounts of nearwork in childhood may contribute to the prevalence of clinical myopia.

Adolescent↗
PubMed1978

The association of sex ratio anomalies with pyloric stenosis.

Published family data were examined for evidence of aberrant sex ratios in relatives of pyloric stenosis index cases. An excess of males over females was found among unaffected members of sibships in which there occurred more than one case of pyloric stenosis. The male excess among affected members of these sibships did not differ from that among index cases without affected sibs. An unusual frequency of spontaneous abortions in these subships, which might account for the observed excess of males, was not observed. No evidence was found of sex ratio anomalies in other classes of relative of pyloric stenosis index cases, whether or not the index cases had affected sibs.

Abortion, Spontaneous↗
PubMed1978

Spontaneous abortion, sex ratio and facial cleft malformations.

In family and reproductive data combined from five treatment centers, relating to 861 index cases with cleft lip (with or without cleft palate, CL+/-P), maternally recognized spontaneous abortions were found to be significantly less frequent in sibships including two or more cases of CL+/-P than in sibships including only one case. In data relating to 379 index cases with cleft palate (CP), maternally recognized spontaneous abortions were reduced to a degree short of formal significant in sibships including two or more cases of CP by comparison with sibships including only one case of CP. The sex ratio among the sibs of parents of CL+/-P index cases was elevated when the index case was the only affected child and reduced when the index case had one or more affected sibs. Considered in combination with the results of other investigations, these findings indicate the existence of inherited factors reducing abortion frequency in the sibships of CL+/-P index cases. These factors appear to be unrelated to those for liability to CL+/-P.

Abortion, Spontaneous↗
PubMed1976

A genetic study of facial clefting in Northern England.

A family is reported of 500 facial cleft index cases, attendees for plastic surgery review at hospitals in northern England. Cases displaying malformation syndromes (29 cases, 5.8% of series) were excluded from analysis, after which CL +/- P and CP pedigree data were examined for evidence of polygenic inheritance. The frequencies of affected among parents, aunts and uncles, and first cousins of 324 CL +/- P index cases are respectively 21, 6 and 4 times the population incidence. The sex ratio among index cases increases with severity of defect. Both of these findings are in good agreement with the polygenic mode of inheritance favored for this condition. The frequencies of affected among parents, aunts and uncles, and first cousins of 147 CP index cases are respectively 30, 5, and 9 times the population incidence. Since syndrome-associated clefts have been excluded from analysis, this elevated incidence in first cousins favors the suggestion that multiple genetic forms of CP may exist.

Adult↗