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The complete amino-acid sequence of BS-RNAse, a dimeric ribonuclease isolated from bovine seminal plasma, was determined. The reduced and S-carboxymethylated subunit chain of the enzyme was cleaved by trypsin and chymotrypsin. The resulting peptides, purified by cation-exchange chromatography were sequenced by dansyl-Edman, subtractive Edman degradation and carboxypeptidase A and B digestion. Chymotryptic peptides were used for the alignment. Automated Edman degradation of the native protein, through the N-terminal 41 amino-acid residues, completed the sequence information. The subunit chain of BS-RNAse, composed of 124 amino-acid residues, with a molecular mass of 13,610 Da, is highly homologous (81%) to pancreatic ribonuclease A. A good degree of homology (31%) was also found with human angiogenin. No N-linked carbohydrate-attachment sites, such as Asn-X-Ser/Thr, were found in the protein.

With the recent open door policy of the People's Republic of China, the west has begun to see first hand the advances made in microsurgery in China. During a one month externship at Zhongshan Medical College, the author observed microsurgical procedures, learned basic microsurgery techniques and performed a clinical trial. The Chinese have rapidly applied microsurgery to many clinical problems and have met with encouraging success.

The effects of analogs of diadenosine 5',5'''-p1,p4-tetraphosphate (Ap4A) were examined on the ADP-ribosylation reaction of histone H1 catalysed by purified bovine thymus poly(ADP-ribose)transferase. Among the compounds tested, epsilon Ap4A and ApCH2pppA were shown to be the most efficient inhibitors of the enzyme. From kinetic studies of their action, it appears that epsilon Ap4A and ApCH2pppA might be 'mixed type' inhibitors.

Isolated, intact bull testis nuclei were incubated with [14C] NAD. A large amount of radioactivity was associated to loosely bound chromosomal proteins extracted with 0.35M NaCl and fractionated with trichloroacetic acid. The labelled nuclear proteins included essentially a number of components belonging to the low mobility group. Mg2(+)-catalyzed alkali digestion of radioactive proteins and further analysis demonstrated that the final products were 5'-AMP and phospho-ribosyl-AMP, which arise from the hydrolysis of poly(ADP-ribose).

Studies were conducted to investigate the effect of ovine luteinizing hormone (LH) treatment on steroid and LH secretion and ovulation in intact, saline-primed hens and in pregnant mare serum gonadotropin (PMSG)-primed hens. Intact, saline-primed hens, injected 12 hr prior to the first (C1) ovulation of the sequence, responded with fully potentiated preovulatory surges of progesterone (P4) (peak value was 371% above preinjection values), estradiol-17 beta (E2) (117% above baseline), LH (220% above baseline), and premature ovulation. By comparison, those hens injected at the same time prior to the second (C2) ovulation responded with a lesser increase in plasma P4 (peak value was 305% above baseline) and E2 (72% above baseline), and there was no significant increase in plasma LH. Within this group, 4 of 5 hens failed to ovulate prematurely. All groups of PMSG-primed hens had significantly higher preinjection concentrations of P4 and E2, and lower basal concentrations of LH, compared to saline-primed hens. Subsequent to treatment of PMSG-primed hens with 25 or 100 micrograms ovine LH, there was a significant increase in plasma P4 to approximately 200% above preinjection concentrations. By contrast, there was a nonsignificant increase in plasma LH (50% above baseline values) and no significant increase in plasma E2. The ovulatory response following PMSG-priming was greatest in hens injected with 100 micrograms ovine LH (5 of 5 hens ovulated), while 3 of 5 hens injected with 25 micrograms ovine LH and 6 of 6 saline-challenged hens failed to ovulate.(ABSTRACT TRUNCATED AT 250 WORDS)