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Incidence of spontaneous tumors was examined in 77 male and 73 female SD-JCL rats reared throughout their lifespan of 5 to 36 months. Total tumor incidences were 60% and 95% for males and females, respectively. The sex difference was mostly attributable to a high incidence of mammary tumor in females. The pituitary tumor was found in 30% of males and 66% of females aged 5 to 36 months while islet cell tumor of the pancreas and thyroid tumor occurred later and the incidence of latter was particularly high in rats lived more than 2 years. Myeloid leukemia appeared to occur as early as 5 months of age.

Plipastatins, new inhibitors of phospholipase A2, were produced by a strain classified as Bacillus cereus BMG302-fF67. The plipastatins are a family of acylated decapeptides which differ from each other by amino acid composition and the nature of the fatty acid side chain. The fatty acids have been shown to be 3(R)-hydroxyhexadecanoic acid (n-C16h3) and 14(S)-methyl-3(R)-hydroxyhexadecanoic acid (a-C16h3) by mass, NMR and optical rotation. Amino acid sequence analysis by secondary ion mass spectrometry and additional physico-chemical evidence indicate that the structures of plipastatinic acids, the lactone-opened peptides are as follows: beta-Hydroxy fatty acid----L-Glu----D-Orn----L-Tyr----D-allo-Thr----L-Glu----D-Ala(Val)---- L-Pro----L-Gln----D-Tyr----L-Ile X OH.

Three cases of the popliteal vein entrapment syndrome have been encountered during the past 3 years. The third head of the gastrocnemius muscle appeared to be the cause of this rare condition with the vessels in their normal position. Partial resection of the excess muscle was sufficient to relieve symptoms.

A semi-synthetic bleomycin analogue and its DNA binding moiety, an alkylamino-2-methoxy-6-chloroacridine, have been found to inhibit human immunodeficiency virus-associated reverse transcriptase. The authors have synthesized various new alkylaminoacridine derivatives. Alkylaminoacridines with basic functional groups showed the enzyme inhibitory activity with less cytotoxicity.

Non-obese diabetic (NOD) mice spontaneously develop diabetic signs akin to those of Type I diabetes in man. Insulitis, i.e., lymphocytic infiltration around and into the pancreatic islets is one of the characteristics of such mice. It is also the etiologic pathological lesion in the development of diabetes mellitus in NOD mice. Thus, we chose insulitis as a marker for genetic analysis of the development of diabetes mellitus in NOD mice and clarified the mode of its inheritance. In breeding studies between NOD and C57BL/6J mice, insulitis was not observed in the F1 and (F1 X C57BL/6J) backcross generations, but was found with incidences of 3.9% in females and 1.4% in males in the F2 generation and 23.7% in females and 12.1% in males in the (F1 X NOD) backcross generation. These incidences in the F2 and (F1 X NOD) backcross females corresponded approximately to 1/16 and 1/4 of the incidences of 89.7% in the NOD females, respectively. A similar relationship was observed between the F2 and (F1 X NOD) backcross males and the NOD males. When the gene expressivity of both sexes for a double recessive homozygote was assumed to be the incidences of insulitis in 9-week-old NOD females and males, respectively, the expected numbers of both sexes with and without insulitis in the F2 and backcross generations agreed well with the observed ones. These observations suggest that two recessive genes on independent autosomal chromosomes are necessary for the development of insulitis in NOD mice.