Studies on antiviral glycosides. II. Mode of action for virucidal effects on Sendai virus

Treatment of Sendai virus with $\text{p-(sec-}\text{butyl)-phenyl-6-chloro-6-deoxy-β-}\text{d}\text{-glucopyranoside}$, followed by freezing and thawing resulted in a loss of hemolytic and cell fusion activities as well as infectivity without affecting hemagglutinating and neuraminidase activities. The anti-hemolytic activity of this compound was reversed by the addition of phosphatidyl choline to the virus samples. $\text{p-}\text{Azidophenyl-6-chloro-6-deoxy-β-}\text{d}\text{-[}{}^3\text{H]glucopyranoside}$ was successfully used for photoaffinity labeling of a specific virion site, and we confirmed the affected site of the glucoside to be the lipid components in the viral envelopes.     

Relationship between secondary constrictions and nucleolus organizing regions inAllium sativum chromosomes

Summary Allium sativum L. (2 n=16) had three types of clones with regard to the number of chromosomes carrying well-defined secondary constrictions: the first type had two secondary constricted chromosomes (type I), the second had three (type II) and the third had four (type III). Silver staining was applied to these three types of cells to determine the number of nucleolus organizing regions (NORs) per cell and to study the relationship between the morphological appearance of the secondary constrictions and the ability of the chromosomes to form nucleoli. Ag-positive regions appeared on two chromosomes in type I, on three in type II and on four in type III. The comparison of Giemsa and Feulgen stained chromosomes with the silver stained ones clearly indicated that the positive reaction with silver occurred exclusively on the secondary constricted regions that responded negatively to both Giemsa and Feulgen staining, indicating that the size of the achromatic secondary constrictions directly reflects the volume of the Ag-positive materials. However, all three types of clones had a maximum of four nucleoli at interphase. Of the four nucleoli, either two or one was extremely small (less than 1 m in diameter) in types I and II respectively. The size variations of the other nucleoli seemed to be positively correlated with those of the Ag-positive regions. This and the observation that the maximum number of nucleoli per cell did not coincide with the number of Ag-positive regions on the metaphase chromosome complement suggest strongly that the NORs responsible for the minute nucleoli cannot be detected on the metaphase chromosomes. The present observations indicate that not all NORs are indicated by the morphological appearance of secondary constrictions.     

Location of Lyb-2 on mouse chromosome 4

TheLyb-2 locus responsible for the B-lymphocyte alloantigen system Lyb-2 is located on chromosome 4 at a distance of 20.6±4.9 map units fromPgm-2. A three-point cross indicated the orderLyb-2: Mup-1b Pgm-2.     

Chromatographic separation, of extracellular acid phosphatase of tobacco cells cultured under Pi-supplied and omitted conditions

An extracellular acid phosphatase preparation of tobacco XD-6cells cultured in suspension was resolved into three fractionsby sequential chromatography. Two of these were neutral pyrophosphatasewith diesterase activity, having optimum pH at 6.8. The otheris a nonspecific acid phosphatase having optimum pH at 5.8.The latter was concluded to be involved in the increase in extracellularactivity upon Pi-depletion. (Received August 31, 1976; )     

Studies on the function of proplastids in the metabolism of in vitro-cultured tobacco cells III. Source of reducing power for amino acid synthesis from nitrite

Evidence to show the presence of glucose-6-phosphate dehydrogenase,6-phospho-gluconate dehydrogenase, and NADP-dependent malicenzyme in proplastids of in vitro-cultured tobacco cells wasobtained. Amino acid synthesis from nitrite and 2-oxoglutaratein the proplastids was stimulated by addition of 20 mM glucose-6-phosphate.6-Phosphogluconate, malate, and isocitrate did not affect thesynthesis. Nitrite reduction and glutamate synthesis in theproplastids are assumed to be supplied with NADPH₂ as the sourceof reducing power through the reactions catalyzed by glucose-6-phosphatedehyrdogenase and 6-phosphoglyconate dehydrogenase. (Received March 22, 1977; )     

Isolation of citrate-positive variants of Escherichia coli from domestic pigeons, pigs, cattle, and horses.

Twenty-seven isolates of citrate-positive variants of Escherichia coli were obtained from domestic pigeons, pigs, cattle, and horses. With the exception of citrate utilization, all isolates closely resembled typical E. coli in their biochemical reactions. These isolates were multiply resistant to antibiotics in in vitro susceptibility tests. Transfer experiments of multiple-drug resistance to the E. coli K-12 strain showed that all citrate-positive isolates from domestic pigeons, pigs, and cattle, resistant to three or more drugs, carried R plasmids showing temperature-sensitive transfer.     

Analysis of dansyl amino acids by reverse-phase high-performance liquid chromatography

All 24 dansyl amino acids were separated by reverse-phase high-performance liquid chromatography on Develosil C8-5, using a linear gradient made from Tris-HCl buffer (pH 7.75) and methanol. A linear relationship between the amount of sample and peak area was found over the range of 6 to 300 ng (0.02–1 nmol) of dansyl derivatives. An application of this method to the NH₂-terminal analysis of lysozyme is described.     

Increased metabolism of retinoic acid after chronic ethanol consumption in rat liver microsomes

In rat liver microsomes, all-trans-[11,12-³H]retinoic acid was found to be metabolized to polar products in the presence of NADPH. One of the metabolites was coeluted with 4-hydroxyretinoic acid on reverse-phase high-pressure liquid chromatography (HPLC). This reaction required oxygen and was inhibited by carbon monoxide as well as aminopyrine, aniline, and ethanol, suggesting the involvement of cytochrome P-450. Isolated rat hepatocytes also metabolized all-trans[³H]retinoic acid to polar compounds, with an elution pattern on HPLC similar to that in microsomal preparations. Microsomal activity was compared in rats pair-fed with diets containing either ethanol or isocaloric carbohydrate for 4–6 weeks. Ethanol-fed rats showed enhanced microsomal retinoic acid metabolism (50%, P < 0.01) accompanied by increased microsomal cytochrome P-450 content (34%, P < 0.005). On the other hand, microsomal β-glucuronidation of retinoic acid in the presence of uridine diphosphoglucuronic acid (UDPGA) was not affected by chronic ethanol feeding. The increased hepatic microsomal cytochrome P-450-dependent metabolism of retinoic acid after chronic ethanol consumption may contribute to the accelerated catabolism of retinoic acid in vivo.