Antibodies directed against a meiosis-specific,chromatin-associated protein identify conserved meiotic epitopes

The molecular mechanisms by which meiotic events are regulated are at present unknown. To approach this problem, we have exploited the natural synchrony of Lilium meiocytes to compare the nuclear protein profiles of a variety of stages of meiosis. This approach has facilitated the identification of a number of nuclear proteins that appear and disappear in a stagespecific fashion. Here we report the presence of an abundant nuclear protein that first appears during premeiotic interphase, a period during which the irreversible commitment to meiosis occurs. Antibodies directed against this protein demonstrate its meiosis specificity as well as conservation of the epitope(s) in both mono-and dicotyledonous plant species. Chromatin fractionation studies indicate that this protein, which we have termed meiotin-1, is associated with strings of nucleosomes. Implications for meiotic chromatin packaging and chromosome structure are discussed.by J.H. Taylor     

Hepatotropin mRNA expression in human foetal liver development and in liver regeneration

A 569 bp probe against the β-chain of hepatotropin was used to examine expression of RNA for this growth factor in human adult and foetal liver, foetal kidney and pancreas, and rat liver after partial hepatectomy. Low level expression of a 6kb RNA occurred in human adult and normal rat liver. 70% hepatectomy increased expression, peaking at 10 h and returning to near normal levels 24 h after resection. The 6 kb band was strongly expressed in human foetal liver, as compared with adult, but not in foetal kidney or pancreas, suggesting a major role for hepatotropin in both foetal development and regeneration of the liver.     

Management of massive pulmonary embolism after jejuno-ileal bypass for morbid obesity

Four patients developed massive pulmonary embolism after jejuno-ileal bypass for morbid obesity. All patients were in Greenfield's Class IV and were in shock. Severe hypoxia was evidenced in their blood gases. The patients were managed with digitalis, diuretics, Solu-Medrol (methylprednisolone sodium succinate), oxygen, and heparin therapy. Each patient underwent partial vena cava interruption with Mobin Uddin's umbrella, and all four survived without residual complications.     

The amino acid sequence of chick skin collagen α1-CB7: The presence of a previously unrecognized triplet

Because alignment of the amino acid sequences of chick skin collagen α2-CB3 (1) with the relevant portion of chick skin collagen α1-CB7 (2) suggested that a Gly-X-Y triplet may have been missed in the latter, the peptide TM-2, produced by tryptic digestion of maleylated α1-CB7, was reinvestigated. Cleavage by trypsin at the unblocked lysine at position 18, and isolation of the resulting COOH-terminal peptide, showed this to be a 15-residue peptide containing a previously unrecognized Gly-Pro-Hyp triplet. Sequencing of the peptide showed this to occupy positions 4 through 6, or 56 through 58 of α1-CB7. The latter thus has 271 instead of 268 residues, and the α1[I] chain 1055 instead of 1052.