Homogenates of human polymorphonuclear leucocytes (granulocytes) contain a Ca2+-dependent phospholipase A with optimal activity pH7.0. This enzyme is membrane-bound and is enriched in crude cytoplasmic-granule fraction. Ratezonal centrifugation of the cytoplasmic-granule fraction demonstrates that the phospholipase A is associated not only with specific- and azurophilic-granule populations but also with an 'empty' vesicular fraction containing 85% of the total alkaline phosphatase activity of whole homogenate. Thus this phospholipase is associated with granule as well as with other cellular membranes of human granulocytes.

A new sugarcane (Saccharum officinarum L.) fructanase which hydrolyzes both high molecular weight polysaccharides IFructose4:Galactitol5l,, (SP) and moderate-sized carbohydrates IFructose2:Galactitol33l,, (MMWC) has been purified from sugarcane juice. The Km, value has been estimated to be 33.7 micrograms per milliliter and 20 micrograms per milliliter for SP and MMWC, respectively. The optimal pH and temperature values are 6.0 and 300C, respectively. Purified protein has a pi value of 6.35 and a molecular weight of 13.2 kilodaltons. Fructanase activity appears to be Mn2 -dependent.

Threshold dosages of the photoisomers of cyclodiene insecticides, namely photochlordane, photodieldrin, and photoheptachlor, for the induction of hepatic microsomal cytochrome P450 (P450) and liver hypertrophy in male rats were at least one-quarter of those reported for corresponding parent cyclodienes. Maximum increase in total P450 concentration (30%) and demethylases activities (100%) was always respectively one-third or one-tenth of that reported for parent cyclodienes. The P450 isozymic form induced by photoheptachlor resembled that induced by pentobarbital (P4502B1) in its substrate specificity, spectral characteristics, and electrophoretic mobility. The induction of P450 was initially followed by hepatic hypertrophy. However, higher dosages of photoisomers caused wasting and lowered both the liver weight and the activity of aniline hydroxylase while those of mirex and endrin, which also caused wasting and lowered aniline hydroxylase activity, continued causing further hepatic hypertrophy.

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