Chemistry of glucal halohydrins(II): An unusual protecting group effect in the competitive formation of formyl furanosides and methyl glycosides

A remarkable protecting group influence was observed in the base-induced reaction of protected halohydrins derived from -glycals. Tri-O-methyl and tri-O-benzyl halohydrins react with cesium carbonate in methanol at room temperature to give methyl glycosides as the major product and unsaturated formyl furanosides as the minor product. Whereas, the tri-O-tert-butyldimethylsilyl (t-BuMe₂Si)-protected halohydrins reacted with cesium carbonate in methanol at room temperature to give a mixture of epimeric formyl furanosides, and at reflux to give an unsaturated formyl furanoside, as the only products. The tri-O-methyl and tri-O-benzyl halohydrins react slowly at elevated temperature to give predominantly furans. In comparison, the tri-O-t-BuMe₂Si halohydrins reacted completely after five minutes to give a mixture of epimeric formyl furanosides. The tri-O-t-BuMe₂Si iodohydrins were oxidized to the corresponding iodolactones, which also underwent a based-induced ring contraction in methanol to give the furanose 1-methylcarboxylate esters.     

Effects of four different doses of organic manures in the production of Ceriodaphnia cornuta

Mass culture of Ceriodaphnia cornuta was done by using a mixture of organic manures: cattle manure:poultry droppings:mustard oil cake (1:1:1) at four different doses: 0.263 kg/m3 (first dose), 0.526 kg/m3 (second dose), 1.052 kg/m3 (third dose) and 2.104 kg/m3 (fourth dose). The peak of C. cornuta was found on 10th day of inoculum in first two doses and on 14th and 18th day in third and fourth doses, respectively. Among these four doses, significantly (P<0.01) higher numbers of organisms (1930/l) were found in the fourth dose followed by third (1470/l), second (1017/l) and first (733/l) doses, respectively. The number of organisms decreased faster in two lower doses than higher doses. pH ranged from 7.20 to 8.09, 7.46 to 8.01, 7.55 to 7.89 and 7.61 to 8.03 in first, second, third and fourth doses, respectively. Dissolved oxygen showed inverse relationship with the dose of manures applied and direct relationship with number of organisms. This study showed that 3.28-4.63 mg/l dissolved oxygen was optimum to obtain the bloom of C. cornuta under the present manure schedule. Maximum number of organism was found when unionized ammonia and phosphate levels ranged between 0.65-0.85 mg/l and 0.42-0.98 mg/l, respectively. The fourth dose of organic manure is optimum for the culture of C. cornuta in outdoor condition and the bloom of the live food can be obtained within 18 days of inoculum.     

Effects of oral contraceptive pills on drug metabolizing enzymes and acid soluble sulfhydryl level in mouse liver.

The present paper reports the modulatory influence of two widely used combined oral contraceptive pills "OVRAL" and "NORACYCLINE" on hepatic phase I and II drug metabolizing enzymes and acid soluble sulfhydryl group of the mouse. Three different doses of the pills were used in this study i.e. D1 (1/2000th of a pill), D2 (1/200th of a pill) and D3 (1/20th of a pill). The sulfhydryl group increased significantly with the D1 and D2 dose of Ovral and the D2 dose of Noracycline. Dose D2 of both pills decreased cyt.P450 and cyt.b5 contents. D3 of Noracycline, however increased both the cytochrome levels. Dose D3 of Ovral and all three doses of Noracycline reduced the glutathione S-transferase activity.     

RNA polymerase of influenza virus. III. Isolation of RNA polymerase-RNA complexes from influenza virus PR8

Ribonucleoprotein (RNP) cores with RNA-synthesizing activity were prepared in two fractions, M protein-free and M protein-associated, from detergent-treated influenza virus PR8 by centrifugation through a discontinuous triple gradient of cesium sulfate, glycerol, and NP-40. The M-free RNP was fractionated by phosphocellulose column chromatography into two major RNP forms, A and B, which differed in the content of P proteins, while the M-associated RNP gave only the low P-content Form-B RNP. Starting from the high P-content Form-A RNP, an RNA-P proteins complex virtually free from NP protein was isolated by cesium sulfate equilibrium centrifugation. The complex, containing only three P proteins (P1, P2, and P3), was still active in catalyzing RNA synthesis in vitro without addition of exogenous template, indicating that NP protein is not required for the catalysis of RNA synthesis. RNA synthesis by the isolated RNA-P proteins complex was dependent on either ApG or capped RNA primers, and required four ribonucleoside triphosphates as substrates. The RNA product in this reaction was hybridizable to viral RNA. A complex of one each of the three P proteins was separated from RNA by glycerol gradient centrifugation after ribonuclease treatment or cesium chloride equilibrium centrifugation.     

The effects of K+ growth conditions on the accumulation of cesium by the bacterium Thermus sp. TibetanG6

The accumulation of cesium by the bacterium Thermus sp. TibetanG6 was examined under different K⁺ growth conditions. The effects of external pH and Na⁺ on the accumulation of cesium were also studied, and the mechanism involved was discussed. K⁺ regimes played an important role in the accumulation of cesium by the strain TibetanG6. The quantity of cesium accumulated (24 h) was much higher in K⁺-deficient regime than that in K⁺-sufficient regime. The pH and Na⁺ had different effects on the accumulation of cesium in the two K⁺ regimes. IR spectra analyses indicated that the biosorption is a process of homeostasis with cesium initially accumulated on the cell wall.     

The effects of K+ growth conditions on the accumulation of cesium by the bacterium Thermus sp. TibetanG6

The accumulation of cesium by the bacterium Thermus sp. TibetanG6 was examined under different K⁺ growth conditions. The effects of external pH and Na⁺ on the accumulation of cesium were also studied, and the mechanism involved was discussed. K⁺ regimes played an important role in the accumulation of cesium by the strain TibetanG6. The quantity of cesium accumulated (24 h) was much higher in K⁺-deficient regime than that in K⁺-sufficient regime. The pH and Na⁺ had different effects on the accumulation of cesium in the two K⁺ regimes. IR spectra analyses indicated that the biosorption is a process of homeostasis with cesium initially accumulated on the cell wall.     

Cesium Accumulation and Growth Characteristics of Rhodococcus erythropolis CS98 and Rhodococcus sp. Strain CS402

Growth and cesium accumulation characteristics of two cesium-accumulating bacteria isolated from soils were investigated. Rhodococcus erythropolis CS98 and Rhodococcus sp. strain CS402 accumulated high levels of cesium (approximately 690 and 380 μmol/g [dry weight] of cells or 92 and 52 mg/g [dry weight] of cells, respectively) after 24 h of incubation in the presence of 0.5 mM cesium. The optimum pH for cesium uptake by both Rhodococcus strains was 8.5. Rubidium and cesium assumed part of the role of potassium in the growth of both Rhodococcus strains. Potassium and rubidium inhibited cesium accumulation by these Rhodococcus strains. It is likely that both Rhodococcus strains accumulated cesium through a potassium transport system.     

Cation exchange binding of rubidium and cesium by rat liver cell microsomes

The rubidium and cesium binding characteristics of rat liver cell microsomes were studied by an equilibration, centrifugation and washing procedure. Concentration dependence experiments, in which microsomes were equilibrated in media containing 0 to 400 mM rubidium or cesium chloride at pH 6.9, yielded saturation type adsorption isotherms similar to those previously reported for sodium and potassium. Mass law analysis of the data yielded apparent dissociation constants of 21 × 10^?3 eq/liter and 19 × 10^?3 eq/liter for rubidium and cesium binding, respectively. The results indicate that cesium is bound slightly more strongly than rubidium, and that both these cations may be bound more strongly than sodium or potassium. The maximum binding capacity at pH 6.9 was approximately 1.3 meq rubidium or cesium/g nitrogen. Sodium, potassium, magnesium and calcium generally associated with the isolated microsomes decreased concomitantly with increasing bound rubidium or cesium, demonstrating the ion exchange nature of the binding. Results of pH-dependence experiments showed that following equilibration of the microsomes in media containing approximately 96 mM rubidium or cesium at various pH values, bound rubidium or cesium was essentially zero at pH less than five, increased sharply between pH 5 and 7, and tended to level off at higher pH. The present results further characterize the cation binding properties of the microsomal material.     

Induction of micronuclei in mouse polychromatic erythrocytes by the administration of non-radioactive CsCl by the oral and intraperitoneal route

In the present study, we describe the effects of the concentration and route of administration of non-radioactive cesium chloride (CsCl) in inducing micronuclei in mouse bone marrow polychromatic erythrocytes (PCEs). When the dose of 500mg/kg body weight was administered perorally (p.o.), no significant incidence of micronuclei was detected. However, when the same dose was administered intraperitoneally (i.p.), a significant induction of micronuclei in PCEs was observed compared to control. At the dose of 1000mg/kg, both routes were efficient, with no significant difference in micronucleus frequencies. We conclude that both the p.o. and i.p. routes are efficient in inducing micronuclei, with the i.p. route being more efficient when lower CsCl doses are used.     

Effects of ACTH on the uterine weight response to HCG in mice.

The effects of ACTH and dexamethasone on the uterine weight of immature mice treated with HCG or oestradiol-17 beta were studied. The animals were treated daily for 3 days and wet and dry uterine weights were measured on the 4th day. Low doses of ACTH (1-25 mug/day) raised the sensitivity of the uterine weight response to threshold doses of HCG (0-05 to 0-1 i.u.). By increasing the doses of ACTH or HCG, the stimulation gradually turned into inhibition. By itself, ACTH was ineffective and it had no influence on the increase in uterine weight induced by oestradiol-17 beta. Dexamethasone failed to stimulate the effect of HCG.     

Structure-activity relationships of several cardiotonic steroids with respect to inhibition of ion transport in frog muscle

Cesium uptake by sodium-loaded frog sartorius muscles was inhibited 100% by 10^-6 M ouabain and 10^-6 M cymarin. The doses for 50% inhibition of cesium uptake by five cardiotonic aglycones were 1.5 x 10^-6 M for strophanthidin, 2 x 10^-7 M for telocinobufagin, 1.6 x 10^-6 for digitoxigenin, 2.4 x 10^-6 M for periplogenin, and 6.3 x 10^-6 M for uzarigenin. Because of the limited solubility of sarmentogenin the maximum concentration studied was 2 x 10^-6 M which inhibited cesium uptake about 36%. Inhibition of cesium uptake by cymarin was not reversed during a 3.5 hr incubation in fresh solution while the muscles treated with ouabain and strophanthidin recovered partly during this time. Cymarin was a more potent inhibitor of sodium efflux than strophanthidin and periplogenin was less potent. Increased cesium ion concentration in the external solution decreased the strophanthidin inhibition of cesium uptake but 25 mM cesium did not overcome the inhibition by 10^-8-10^-6 M strophanthidin. Increased potassium ion concentration in the external solution decreased but did not completely overcome inhibition of sodium efflux by strophanthidin. It is concluded that potassium or cesium ions do not compete with these drugs for a particular site on the ion transport complex. The same structural features of the drugs are necessary for inhibition of ion transport in frog muscle as are required for inhibition of ion transport in other tissues, inhibition of sodium-potassium-stimulated ATPases, and toxicity to animals.     

Effect of 17 beta-estradiol on different parts of central nervous system of female Singi fish (Heteropneustes fossilis Bloch) in relation to reproductive stages

Effects of different doses of 17 beta-estradiol (1, 2 and 4 micrograms/g, 3 consecutive days injections) on the protein, RNA and DNA contents of cerebrum (CB), cerebellum (CE), midbrain (MB), medulla oblongata (MO) and spinal cord (SC) of female non-vitellogenic (NV) and vitellogenic (V) Singi fish (Heteropneustes fossilis Bloch) were investigated. The amounts of these macromolecules in all these substructures of the central nervous system were enhanced on the 4th and/or 7th day in NV fish by estradiol depending on the dose. The higher dose(s) caused more marked effect. The dose of 1 microgram/g was ineffective in case of protein and mostly in case of DNA. There was no enhancement of protein content with any dose of estradiol on the 4th day in CE, MB, MO and SC, but in CB 4 micrograms of estradiol/g increased the protein content on this day. However, the increase was marked on the 7th day in all substructures. The enhancement of RNA content was elicited earlier (4th day) even with lower dose of 1 microgram/g in NV fish in most of the substructures, except MO. With exception of this substructure again, the DNA content of any part did not increase with the hormone on the 4th day with 1 microgram of estrogen/g. The changes in protein and nucleic acid contents of the different substructures of central nervous system in V fish with 17 beta-estradiol were mostly opposite to those in NV fish. Depending on the dose and time, protein and RNA contents of these parts decreased with estradiol in V fish. No change in DNA content, however, was found, except MO where this cellular constituent was surprisingly enhanced on the 4th and 7th day with all doses of estradiol used. The spinal cord of V fish did not show any change in RNA and DNA contents with the hormone. Thus a reproductive stage-specificity of estrogen action in fish brain is documented.     

Induction of lethal mutations in female mice by 9 generations of gamma-irradiation during foetal development.

Female CBA mice were chronically gamma-irradiated in utero during either of two periods, the 10th to 14th days or the 14th to 18th days of gestation. The doses administered were 34 rad/generation in the earlier group and 160 rad/generation in the latter with dose rates of 0.3 rad/h and 1.7 rad/h, respectively. The doses were given through 9 generations. The effect of the irradiation was expressed as an increased frequency in the rate of recessive lethal equivalents by just above 4%. This corresponds to a mutation rate of 1.5 X 10(-4) mutation/rad/genome in the animals irradiated during the 10th to 14th gestational days and 0.3 X 10(-4) mutation/rad/genome in the 14th to 18th day group. As in earlier investigations, neither dominant mutations nor dominance effects of induced recessive lethal equivalents were found.     

Action of the phenothiazine derivative methophenazine on prenatal development in rats.

Single doses of 100-400 mg/kg or multiple doses of 10 or 50 mg/kg of the phenothiazine derivative methophenzaine were given per osto Wistar rats at various times on the 7th-14th days fo gestation and the fetuses examined near term. Results indicated that methophenazine was mainly embryolethal when administered on the 8th-11th days, and was teratogenic at later times, producing types of malformations that depended on the day of treatment, the most susceptible period being the 13th and 14th days of gestation. Teratogenicity occurred only when the dosages were highly toxic to the pregnant rats. Ribovlavin given ip on the 14th day significantly reduced the embryolethal but not the teratogenic action of methophenazine.     

Teratogenic effects of chlorambucil on in vivo and in vitro organogenesis in mice.

Pregnant ICR/DUB mice were each given a single oral injection of chlorambucil (14.2 or 20 mg/kg) on the 10th, 11th, 12th, or 13th day of gestation (plug day = 1st day). Fetuses examined on the 18th day were decreased in weight and had tail, cranial, and limb defects. They type and frequency of malformations differed according to the dosage and day of treatment. Limb defects resulted from treatment on the 11th or 12th days of gestation and tail defects from treatment on all days. Control limb buds from 12th day embryos cultured for 6 days in serum-supplemented BGJ medium containing 0.5-2 mug/ml chlorambucil were retarded in development and had cartilage abnormalities. The extent of the deformities was dose related. Limb buds were also taken from embryos 24 h after in vivo exposure to teratogenic doses of chlorambucil and cultured in control medium. After 6 days in culture these limbs also had growth impairment and cartilage abnormalities. The defects in limbs exposed in vitro were similar to those in limbs exposed in vivo.     

Glycogenesis and lipogenesis from 14C-glucose in vivo in rats irradiated with fractionated doses of gamma rays

Irradiation with fractionated doses is a specific form of stress and the data concerning these problems are topical for recent radiobiology, radiology and oncology. Interest in this present paper is focused on tissue glycogenesis and lipogenesis from U-14C-glucose in vivo in rats irradiated with fractionated doses of 2.39 Gy once a week. Analyses were done after 1-6 fractions, up to total accumulated doses of 2.39, 4.78, 7.17, 9.76, 11.95 and 14.34 Gy, which means LD50/30 for this experimental model. Fractionated irradiation of rats led to glycogen deposition and increased incorporation of 14C-glucose into the liver, heart and skeletal muscles, but not into brain glycogen. The ascertained changes were not dose-dependent. 14C-glucose was incorporated into the liver and adipose tissue lipids to a small extent, and synthesis of liver cholesterol increased only after the 5th and 6th fractions. A decreased concentration of hepatic lipids, especially of cholesterol, was observed from the 3rd to the 6th fractions.     

Perinatal mortality in Germany following the Chernobyl accident

Perinatal mortality in Germany was investigated with respect to a possible relationship to the nuclear accident in Chernobyl on April 26, 1986. Using annual data of perinatal mortality, a trend analysis based on an appropriately chosen statistical model was performed which showed a significant increase in 1987. In addition, we calculated the cesium concentration in women's bodies using data of the cesium concentration in milk. We found two peaks of cesium concentration that were associated with the observed two peaks of monthly perinatal mortality data with a delay of 7 months. Received: 14 October 1994 / Accepted in revised form: 14 October 1996     

Verapamil inhibits proliferation but not steroidogenesis of regenerating rat adrenal cortex

The effect of verapamil, a calcium channel antagonist, on proliferation and steroidogenesis was investigated in regenerating rat adrenal cortex. Verapamil was given subcutaneously in two doses (1 and 5 mg/kg) to male Wistar rats subjected to adrenal enucleation combined with contralateral adrenalectomy. It was found that verapamil inhibited the mitotic activity of adrenocortical cells on the 4th and 8th day after surgery in a dose-dependent manner. However, no changes in corticosterone secretion were observed.