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Eighteen of the NH2-terminal 27 amino acids of a murine H-2K molecule have been assigned. The approach used was to label murine splenocytes with a single radioactive amino acid, isolate the H-2K molecule by specific immunoprecipitation, electrophorese the dissolved precipitate on sodium dodecyl sulfate polyacrylamide gels, and subject the isolated H-2K peak to amino-acid analysis and automated sequencing.

The recent introduction of a reliable, T-lymphocyte proliferation assay, which utilizes thioglycollate-induced, nylon wool column-passed, peritoneal exudate lymphocytes from immune mice (PETLES), allowed us to investigate the genetic control of murine immune responses at the T-lymphocyte level. Examination of the blast cells generated in this population 5 days after stimulation with antigen, revealed that 85% of the cells bore the Thy 1 antigen on their surface, whereas only 5% bore immunoglobulin. Thus, the assay can be considered to measure almost exclusively T-lymphocyte function. This assay was used to examine the T-lymphocyte proliferative responses to seven different antigens: poly(Glu60Ala30Tyr10), poly(Glu58Lys38Tyr4), poly-(Tyr,Glu)-poly-D,L-Ala--poly-Lys, poly-(Phe,Glu)-poly-D,L-Ala--poly-Lys, staphylococcal nuclease, lactate dehydrogenase H4, and the BALB/c IgA myeloma protein, TEPC-15. PETLES from a large number of different inbred mouse strains, including H-2 congenic resistant lines and H-2 recombinants, were studied. The strains could be classified as high responders, low responders, or nonresponders to a particular antigen as judged by the magnitude of the T-lymphocyte proliferative response. In every case but one this classification corresponded to the responder status given the strain based on its ability to mount an in vivo antibody response to the same antigen. For two of the antigens, poly-(Tyr,Glu)-poly-D,L-Ala--poly-Lys and TEPC-15, the immune response genes controlling the T-lymphocyte proliferative response were mapped to the K region or I-A subregion of the major histocompatibility complex, as had previously been shown for the control of the antibody responses to these antigens. This tight linkage of the two phenotypic responses very strongly suggests that the same immune response gene controls the expression of both the proliferative and antibody responses. Since there is essentially no contribution from B lymphocytes in the T-lymphocyte proliferation assay, it seems reasonable to conclude that none of the seven immune response genes studied are expressed solely in B lymphocytes.

Five cases of hemochromatosis arthropathy are presented and the distinctive radiological features of the disease are described. Although the condition is typically degenerative, showing subchondral cyst formation, sclerosis, and thinning of cartilage, its distribution is characteristic. Selective degenerative changes of the second and third metacarpophalangeal joints are striking, particularly in the hands, while abnormalities in the intercarpal joints are variable and the interphalangeal joints are spared. Chondrocalcinosis involving both fibrous and hyaline cartilage is frequently seen as well, particularly in the large joints. The calcification is due to deposition of calcium pyrophosphate crystals, perhaps resulting from iron inhibition of pyrophosphatase.

Deep-vein thrombosis (D.V.T.) was detected by the fibrinogen-uptake test in six out of a total of thirty-one young women undergoing emergency abdominal surgery who gave a history of recent oral contraceptive intake. In contrast, no D.V.T. developed in nineteen similar patients who were not on oral contraceptives (P less than 0-01). Plasma-antithrombin-III activity was significantly lower preoperatively in patients taking oral contraceptives; postoperative D.V.T. subsequently developed in three out of five patients with preoperative antithrombin-III activity below 50%. In seventy-eight dental patients undergoing molar extraction, antithrombin-III activity was measured before, during, and after operation. Activity fell in all patients during operation, but the fall was significantly greater in women taking oral contraceptives (P less than 0-01). The intra-operative fall in antithrombin-III activity was prevented by a small preoperative dose of subcutaneous heparin.