1α,25-dihydroxy-24-oxo-16-ene vitamin D3, a metabolite of a synthetic vitamin D3 analog, 1α,25-dihydroxy-16-ene vitamin D3, is equipotent to its parent in modulating growth and differentiation of human leukemic cells

1α,25(OH)₂-16-ene-D₃, a synthetic analog of the steroid hormone, 1α,25(OH)₂D₃, has great potential to become a drug in the treatment of leukemia and other proliferative disorders, because of its minimal in vivo calcemic activity associated with a potent inhibitory effect on cell growth. However, at present, the mechanisms through which 1α,25(OH)₂-16-ene-D₃ expresses its biological activities are still not completely understood. Our previous in vitro study in a perfused rat kidney indicated for the first time that 1α,25(OH)₂-16-ene-D₃ and 1α,25(OH)₂D₃ are metabolized differently. 1α,25(OH)₂-24-oxo-16-ene-D₃, an intermediary metabolite of 1α,25(OH)₂-16-ene-D₃ formed through the C-24 oxidation pathway, accumulated significantly in the perfusate when compared to 1α,25(OH)₂-24-oxo-D₃, the corresponding intermediary metabolite of 1α,25(OH)₂D₃. In a subsequent in vivo study, we also reported that 1α,25(OH)₂-24-oxo-16-ene-D₃ exerted immunosuppressive activity equal to its parent, without causing significant hypercalcemia. In order to establish further the critical role of 1α,25(OH)₂-24-oxo-16-ene-D₃, in generating some of the key biological activities ascribed to its parent, we performed the present in vitro study using a human myeloid leukemic cell line (RWLeu-4) as a model. Comparative target tissue metabolism studies indicated that 1α,25(OH)₂-16-ene-D₃ and 1α,25(OH)₂D₃ are metabolized differently in RWLeu-4 cells, and the differences were similar to the ones we previously observed in the rat kidney. The significant finding was the accumulation of 1α,25(OH)₂-24-oxo-16-ene-D₃ in RWLeu-4 cells because of its resistance to further metabolism. Biological activity studies indicated that both 1α,25(OH)₂-16-ene-D₃ and its 24-oxo metabolite produced growth inhibition and promoted differentiation of RWLeu-4 cells to the same extent, and these activities were several fold higher than those exerted by 1α,25(OH)₂D₃. In addition, the genomic action of each vitamin D compound was assessed in a rat osteosarcoma cell line (ROS 17/2.8) by measuring its ability to transactivate a gene construct containing the vitamin D response element of the osteocalcin gene linked to the growth hormone reporter gene. In these studies, both 1α,25(OH)₂-16-ene-D₃ and its 24-oxo metabolite exerted similar but potent transactivation activity which was several fold greater than that exerted by 1α,25(OH)₂D₃ itself. In summary, our results indicate that the production and slow clearance of the bioactive intermediary metabolite, 1α,25(OH)₂-24-oxo-16-ene-D₃, in RWLeu-4 cells contributes significantly to the final expression of the enhanced biological activities ascribed to its parent analog, 1α,25(OH)₂-16-ene-D₃.     

Citric acid fermentation by the mutant strain of theAspergillus niger resistant to manganese ions inhibition

Summary A new mutant strain,Aspergillus niger GS-III, showing resistance to manganese ions inhibition of citric acid fermentation on a sugarcane molasses containing medium was induced fromAspergillus niger KCU 520, a high citric acid-yielding strain. In submerged, surface or continuous cultures in the presence of manganese ions concentration upto 1.5 ppm the mutant strain yielded citric acid about 90 KgM^–3 . The citric acid yield was comparable to that obtained with the parental strain KCU 520 in the absence of manganese ions, but it was atleast 3-fold higher than that obtained by the latter in the presence of manganese ions. The mutant strain immobilized in calcium alginate beads was used in combination with surface-stabilized cultures for about 36-days in a continuous flow horizontal fermenter without any apparent loss in citric acid productivity. These results indicate that the manganese-resistant mutant is stable and may be used in the presence of sufficient manganese ions concentration (1.5 ppm) in the fermentation medium. This capability of the mutant strainA. niger GS-III has been correlated with greatly reduced levels (about one-thirds) of the NADP⁺ -isocitric dehydrogenase, one of the control points for citric acid accumulation.     

Effects of Guaianolide derivative I on fibre initiation and elongation in Gossypium arboreum L. in relation to adverse effects of cool temperature

Cotton ovules collected during late September with prevalent night cool temperature (15°C), cultured at 30°C/15°C i.e. cycling temperatures in Beasley and Ting medium had very few epidermal cells showing bulging. Supplementing cultures with guaianolide derivative I (E-13 methyldehydrocostus lactone) promoted fibre initiation. At—1 day preanthesis (DPA), IAA oxidase activity declined in guaianolide-treated cultures but increased during the elongation phase and was enhanced during the secondary wall thickening phase. However, o-diphenol oxidase activity was adversely affected during the fibre initiation phase. The activities of all the other enzymes studied viz. acid invertase, phenylalanine ammonia lyase, -glucosidase and IAA oxidase increased, except -galactosidase, during the later phase in comparison with the controls. The present study indicates that guaianolide derivative I triggers early initiation and promotes fibre elongation by regulatin o-diphenols and IAA-oxidation levels, which in turn check wall loosening. Considerable enhancement in the soluble acid invertase activity by this compound suggests its role in apoplastic sucrose hydrolysis, thereby preventing its accumulation.Abbreviations DPA days pre anthesis - DAC days after culturing - DAA days after anthesis     

Effect of Soil Temperature and pH on Resistance of Soybean to Heterodera glycines

Soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a major pest of soybean, Glycine max L. Merr. Soybean cultivars resistant to SCN are commonly grown in nematode-infested fields. The objective of this study was to examine the stability of SCN resistance in soybean genotypes at different soil temperatures and pH levels. Reactions of five SCN-resistant genotypes, Peking, Plant Introduction (PI) 88788, Custer, Bedford, and Forrest, to SCN races 3, 5, and 14 were studied at 20, 26, and 32 C, and at soil pH''s 5.5, 6.5, and 7.5. Soybean cultivar Essex was included as a susceptible check. Temperature, SCN race, soybean genotype, and their interactions significantly affected SCN reproduction. The effect of temperature on reproduction was quadratic with the three races producing significantly greater numbers of cysts at 26 C; however, reproduction on resistant genotypes remained at a low level. Higher numbers of females matured at the soil pH levels of 6.5 and 7.5 than at pH 5.5. Across the ranges of temperature and soil pH studied, resistance to SCN in the soybean genotypes remained stable.     

Detection of Genetic Variation in Alternaria brassicae by RAPD Fingerprints

Genetic variation in fourteen isolates of Alternaria brassicae collected from different geographical regions of the world was determined by RAPD (random amplified polymorphic DNA) analysis. Twenty random primers were tried to amplify genomic DNA of A. brassicae. Based on the PCR (polymerase chain reaction) amplification of genomic DNA of A. brassicae with four oligonucleotide random primers, fingerprints were generated for each isolate and the amplifed products were compared. Using this technique, intra- and intercontinental genetic variation among isolates of A. brassicae could be distinguished.     

Changes in profiles of serum sex steroids of male buffaloes from birth to maturity

Age-related changes in testosterone, progesterone and estradiol 17-beta were determined by radioimmunoassay (RIA) in the serum of 155 male buffalo calves of varying ages. The calves were classified into 17 age groups. The mean weight of calves increased from 33.6 +/- 9.6 kg at one week of age to 531 +/- 41.4 kg at 42 months. The testosterone levels were less than 100 pg/ml from birth until 15 months of age, followed by peak concentrations of 422 +/- 79 pg/ml at 24 to 30 months and 793 +/- 193 pg/ml at 42 to 48 months (corresponding to puberty and maturity, respectively). The progesterone levels were higher in newly born calves and mature bulls. Otherwise, the levels continued to be low throughout the period of growth and development. Estradiol 17-beta was significantly higher in postnatal calves up to two months of age. The testosterone revealed a positive correlation with weight and age while E2 17-beta showed a negative correlation with age. These results do not support a direct role of peripheral progesterone and estradiol 17-beta in the onset of puberty and sexual maturity of buffalo bulls.     

Commingling in the distributions of fat-related measures in Punjabi families

The distribution of anthropometric measurements related to fatness levels is examined to determine if skewness alone accounts for the nonnormality of such measures. A mixture of two normal distributions or a single skewed distribution fit the data significantly better than a single normal in all cases. For maximum hip width, knee diameter, and weight, two skewed distributions give a better fit than one skewed distribution, rejecting the null hypothesis of a single distribution even when skewness is considered. There is evidence for three skewed component distributions for biceps skinfold. Abdomen circumference, upper arm circumference, triceps skinfold, and calf skinfold are best approximated by a one component log-normal distribution. Children and parents show slightly different patterns in skewness and kurtosis when considered separately, but differences between them do not account for the commingling found in the combined distributions.     

Topography of retinal axons in the diencephalon of goldfish

Summary The projections of horseradish peroxidase-filled axons from each quadrant of the retina were studied to determine whether retinal projections of goldfish are topographically organized in diencephalic target nuclei. A distinct topography of the dorsal, nasal, ventral and temporal retina exists in the lateral geniculate nucleus and in the dorsolateral optic nucleus of the thalamus. The projections of retinal quadrants show minimal spatial overlap in each of these nuclei. The suprachiasmatic nucleus of the hypothalamus is extensively innervated by ventral retinal fibers, whereas the nucleus is sparsely innervated by fibers from the other three retinal quadrants. A rudimentary topography also exists in the pretectum where the dorsal pretectal area receives projections primarily from the ventral retina and the ventral pretectal area receives projections mostly from the dorsal retina. These data show that retinal projections to some diencephalic nuclei are topographically organized.This work was supported by Research Grant EY-01426 to S.C.S.     

High Levels of Resistance in Agropyron Species to Barley Yellow Dwarf and Wheat Streak Mosaic Viruses

Several Agropyron species were tested for new sources of resistance to barley yellow dwarf virus (Bydv ) and wheat streak mosaic virus (WSMV). With BYDV strain PAV, 11 of the 17 Agropyron species showed no virus transmission when plants were given access feed by viruliferous Rhopalosiphum padi. Similar trials with BYDV strain RMV (vectored by R. maidis) indicated that all plants, except susceptible control plants, remained virus free. Virus status was confirmed by enzyme-linked immunosorbent assays. When plants were mechanically inoculated with WSMV, 11 Agropyron species failed to express symptoms, while five other species showed a segregating response or had some accessions segregating and some resistant. Test results suggest that resistance to BYDV and WSMV in Agropyron species does not appear to be correlated with any specific genome of Agropyron species although most of the Agropyron species containing S genome were resistant to BYDV and WSMV.