Composition of partially purified NADPH oxidase from pig neutrophils.

The superoxide (O2.-)-forming enzyme NADPH oxidase from pig neutrophils was solubilized and partially purified by gel-filtration chromatography. The purification procedure allowed the separation of NADPH oxidase activity from NADH-dependent cytochrome c reductase and 2,6-dichlorophenol-indophenol reductase activities. O2.-forming activity was co-purified with cytochrome b-245 and was associated with phospholipids. However, active fractions endowed with cytochrome b were devoid of ubiquinone and contained only little FAD. The cytochrome b/FAD ratio was 1.13:1 in the crude solubilized extract and increased to 18.95:1 in the partially purified preparations. Most of FAD was associated with fractions containing NADH-dependent oxidoreductases. These results are consistent with the postulated role of cytochrome b in O2.-formation by neutrophil NADPH oxidase, but raise doubts about the participation of flavoproteins in this enzyme activity.     

Effect of some smooth muscle relaxant drugs on calcium-related phenomena

Some smooth muscle relaxant drugs devoid of anticholinergic action have been tested for their interaction with calmodulin, calmodulin-stimulated cyclic nucleotide phosphodiesterase activity, and uterine membrane binding sites for nitrendipine and adenosine. The myolytic activity of octylonium bromide and pinaverium bromide may be due to their interaction with calmodulin-dependent systems. Trimebutine maleate does not bind either to calmodulin or to nitrendipine and adenosine receptors. Tiropramide has no effect on calmodulin-dependent systems and on Ca2+ channels but it shows a competition for the A2-type adenosine receptors.     

Natural resistance against hematopoietic cells in lethally-irradiated mice infected with Friend leukemia virus

Summary The influence of in vivo infection with the polycythemic substrain of Friend leukemia virus on noninducible (natural) resistance against allogeneic normal or malignant grafts was studied in lethally irradiated mice. Parallel studies were performed on the NK system in the same experimental conditions. The results indicate that FLV-P infection of mice with full (DBA/2) vs partial (BALB/c and CD2F1) susceptibility did not suppress their in vivo natural resistance against bone marrow or El-4 leukemia cells. On the other hand, a decline in NK activity paralleled the progression of leukemic disease in the more susceptible DBA/2 hosts. Abbreviations used: FLV-P, N-tropic polycythemic substrain of Friend Leukemia Virus Complex; NR, natural resistance; NR in vivo, natural resistance against normal or malignant hemopoietic grafts occurring in vivo in lethally irradiated mice; NK, natural killer; (¹²⁵I)IUdR, ¹²⁵I-labeled 5-iodio-2-deoxyuridine; IV, intravenous     

Proline excretion in Escherichia coli: A comparison of an argD + strain and a proline-excreting argD − derivative

In an attempt to deduce the physiological basis of proline excretion in argD ^– strains of Escherichia coli K12, several properties of an argD ⁺ (nonexcreting) and an argD ^– (excreting) derivative were compared. No difference was found in the transport or in the utilization of either proline or its immediate precursor, ¹-pyrroline-5-carboxylate (PCA). Furthermore, no differences were found in the physical or kinetic properties of partially purified preparations of the enzyme mediating the final step in proline biosynthesis, PCA reductase. The specific activity of PCA reductase was, however, consistently higher in crude extracts prepared from the argD ^– mutant.This work was supported by grants from the National Institutes of Allergy and Infectious Diseases (Public Health Service No. AI-10862) and The University of Connecticut Research Foundation (to C. M. B.). J. J. R. was supported by an NDEA Predoctoral Fellowship.     

Leu-enkephalin-stimulated growth hormone and prolactin release in the rat: comparison with the effect of morphine

The effect of Leu⁵-enkephalin on growth hormone (GH) and prolactin (PRL) release was studied $\text{in vivo}$ in the infant rat and compared to that of morphine. In 10 day-old pups, intracerebroventricular injection of Leu⁵-enkephalin (50, 75 and 100 μg) resulted in a dose-related increase in plasma GH; morphine was active as GH releaser at the dose of 5 and 10 μg, but not at 2.5 μg. Pretreatment with naloxone (2 mg/kg ip) suppressed the GH-releasing effect of either Leu⁵-enkephalin (100 μg) or morphine (10 μg). Leu⁵-enkephalin (75 and 100 μg) induced a rise in plasma PRL which was neither dose-related nor antagonized by naloxone; morphine (5 and 10 μg) was active as PRL releaser and its effect was antagonized by naloxone. These results indicate that: 1) Leu⁵-enkephalin stimulates both GH and PRL release; 2) the release of GH by Leu⁵-enkephalin but likely not that of PRL involves specific opiate receptors; 3) morphine releases GH and PRL through specific opiate receptors.     

Production of amylase(s) by Schwanniomyces castellii and Endomycopsis fibuligera

Schwanniomyces castellii and Endomycopsis fibuligera Produced extracellular amylase(s) when grown on various carbon sources and at different pH values. Both yeast species showed significant amylase synthesis in the presence of either maltose or soluble starch. On the other substrates tested (glucose, cellobiose, sucrose, trehalose, melezitose, raffinose, ethanol, glycerol) differences were found regarding growth and amylase production. Free glucose in the culture medium apparently inhibited enzyme synthesis. The pH range allowing maximal growth and amylase production was 4.5–6.0 for E. fibuligera and 5.5–7.0 for S. castellii.     

Partial trisomy 21 with 45 chromosomes due to translocation of two chromosomes 21 onto a chromosome 14 : 45,XX-14,-21,+t(14q21q21q) (author's transl)

A patient with the phenotype of trisomy 21 and increased activity of superoxide dismutase A is reported with partial trisomy for the distal portion of 21q. The exceptional feature in this case is a 45-chromosome karyotype due to the translocation of two chromosomes 21 onto the distal end of 14q.     

Interstitial deletion (2)(p13p15)

Summary A dysmorphic 5-year-old girl with severe growth and mental deficiency was studied. She presented a de novo interstitial 2p deletion. Karyotype: 46,XX,del(2)(p13p15).