Familial clustering of scleroderma spectrum disease.

This is the second case report of familial scleroderma (systemic sclerosis) in South Carolina. The family includes two cases of scleroderma meeting American Rheumatism Association criteria, one of systemic sclerosis sine scleroderma, and two other cases of undifferentiated connective tissue disease with features of scleroderma spectrum disorders; there are also two cases of Raynaud's phenomenon (one associated with rheumatoid arthritis), for a total of seven affected relatives. Evidence of scleroderma spectrum disorders was sought in six siblings of the two co-index cases and in 23 of the 35 offspring. Laboratory studies included antinuclear antibody determinations and typing for the following genetic markers: HLA (A, B, C, DR), complotypes, Gm and Km allotypes, and alpha-1 antitrypsin phenotypes. No common genetic markers restricted to affected members of this family were found, and no environmental exposures were detected that could explain this familial clustering of cases. This report should, however, add to the slowly accumulating information on the genetic characteristics of families at unusually high risk for scleroderma spectrum disorders. Positive antinuclear antibody tests at a titer of 1/40 or higher were present in 57 percent of the first-degree relatives of the affected cases.

Base composition studies on transfer RNA from normal and regenerating rat liver.

The base composition of bulk tRNA isolated from regenerating rat liver, 12, 18, 24 and 30 h after partial hepatectomy, was determined by a 3H derivative method. Only a few minor statistically significant changes (2--11%), as compared to sham-operated liver, were found at 18, 24 and 30 h after hepatectomy. These included a reduction in the amounts of adenosine and 3-(3-amino-3-carboxypropyl)-uridine, and an increase in the amounts of 1-methyl-adenosine, 1-methylguanosine, 3-methylcytidine and pseudouridine. Similarly, when the base composition of tRNA fractions from control and 24-h regenerating rat liver, partially purified by one-dimensional polyacrylamide gel electrophoresis, was determined, no gross differences were observed. These results suggest that the process of liver regeneration is not accompanied by a gross alteration of the modification pattern of tRNA.