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Biomedical subjects

O Stark

Publications and source records attributed to O Stark.

At least 55 records · Page 3Linked to original sources
PubMed1982

The major histocompatibility complex and insulin-dependent diabetes in BB rats.

The partially inbred strain of BB-Wistar rats showed a varying incidence of the insulin-dependent diabetes-like syndrome. The serological typing of a large sample of BB rats verified the homozygosity for the RTlu haplotype, whereas its parental non-inbred Wistar stock segregated for RTlu and RTla haplotypes. The histogenetical typing of BB rats by skin grafting showed a significantly prolonged rejection of grafts from RTla donors unusual in other RTlu recipients. The presumption of some recombinational or mutational events in the RTl haplotype of BB rats was not verified by the simple F1 skin grafting test from LEW.1U/RTlu standard/donors to F1/LEW X BB/recipients. Skin grafts survived permanently. When trying to get a clear-cut answer whether the RTlu haplotype is associated with the spontaneous occurrence of diabetes in F2/LEW X BB/ X /LEW X BB/hybrids, only 7.4% of RTlu homozygotes were found among 359 weaned animals. Moreover, the partial strain of BB rats became extinct with the F1 generation mainly due to an infection by the mycoplasma. A new sample of outbred BB rats with a low incidence of spontaneous diabetes was found as homogeneous for the RTlu haplotype, too. Preliminary results of typing these rats for the secondary antibody response to pig insulin indicate the low responsiveness contrary to the results given earlier for the RTlu typing strains as high responders. All these results support the idea that the RTlu haplotype of the BB rats might be a variant carrying some mutational change(s) at the RTl.B region.

Animals↗
PubMed1981

Longitudinal study of obesity in the National Survey of Health and Development.

In a nationally representative cohort of 5362 children born in one week in March 1946 weights and heights were recorded at 6, 7, 11, 14, 20, and 26 years. Overweight was defined as a weight that exceeded the standard weight for height, age, and sex by more than 20% (relative weight greater than 120%). The prevalence of overweight was 1.7% and 2.9% in boys and girls respectively at 6 years; 2.0% and 3.8% at 7 years; 6.4% and 9.6% at 11 years; 6.5% and 9.6% at 14 years; 5.4% and 6.5% at 20 years; and 12.3% and 11.2% at 26 years. The risk of being overweight in adulthood was related to the degree of overweight in childhood and was about four in 10 for overweight 7-year-olds. Analysis of the data in the reverse direction showed that 7% and 13% respectively of 26-year-old overweight men and women had been overweight at the age of 7. These results suggest that there is no optimal age during childhood for the prediction of overweight in adult life and that excessive weight gain may begin at any time. Overweight children are more likely to remain overweight than their contemporaries of normal weight are to become overweight.

Adolescent↗
PubMed1981

On the optimal choice of capital intensity in LDCs with migration.

"Sen's classic work on the choice of capital intensity of investment is generalized in the light of new theoretical developments and empirical findings concerning rural-to-urban migration in LDCs. This is done by explicitly incorporating a migration function into the basic choice model. Revised conditions for maximization of surplus are derived and compared with Sen's original condition. Some justification for the particular migration function used in the presence of risk-aversion is suggested."

Demography↗
PubMed1980

Genetic definition of a further gene region and identification of at least three different histocompatibility genes in the rat major histocompatibility system.

Two new recombinant haplotypes of the rat major histocompatibility system, RT1, have been detected in [LEW.1A (RT1a) x LEW.1W (RT1U)] x LEW.1N(RT1n) segregating hybrids. Recombinant r3 carries the RT1.A region (determining classical transplantation antigens) and the RT1.B region (determining strong mixed lymphocyte reactivity and genetic control of antipolypeptide immune responsiveness) of the RT1a parent, bur rejects RT1a skin grafts. Recombinant r4 carries the A and B regions of the RT1u parent, but rejects RT1u skin grafts. The two histocompatibility genes detected are allelic to each other. The relevant locus, designated as H-C, maps to the B-region side of the RT1 system and appears to mark a third RT1 gene region, RT1.C. Availability of haplotypes r3 and r4 allowed the definition of a histocompatibility locus in the B region, H-B. The products of H-C, H-B and of the previously described H-A gene vary in antigenic strength.

Animals↗
PubMed1979

Comparison of the haplotypes of the major histocompatibility complex in the rat. IV. The six original Ag-B haplotypes.

The six original haplotypes described in the Ag-B system were compared with their counterparts in the H-1 system. Antisera to the Ag-B haplotypes raised in inbred rats and antisera to H-1 haplotypes raised in congenic lines were tested against various panels of cell from inbred and congenic lines by the dextran and Ficoll haemagglutination methods. The private and strong public specificities detected in both systems were the same, but there were some minor differences in the intermediate and weak reactivities detected. The cross-reactivity of the antisera raised in inbred rats was broader than that of antisera raised in congenic lines. The identity of the antigenic products detected in the two systems by the dextran and Ficoll tests was further confirmed by a variety of absorption analyses and by F1 tests. This study completes the systematic serological comparison of the haplotypes of the major histocompatibility complex of the rat described originally in the Ag-B and H-1 systems.

Animals↗
PubMed1978

At least two loci of the major histocompatibility complex can determine mixed lymphocyte stimulation in the rat.

Analysis of a recombinant haplotype of the major histocompatibility complex showed that two genetically separable loci (or groups of loci), LD--1 and LD--2, determine mixed lymphocyte stimulation in the rat. LD--1 maps into the H--1B region which contains the Ir genes and is associated with strong, mixed lymphocyte stimulation. LD--2 maps into the H--1A region and determines weak stimulation. LD--1 and LD--2 determinants can be detected by primed lymphocyte typing.

Animals↗