Formation of an animal virus within a bacterium

Conclusions Incubation of competent cells ofB. subtilis with a DNA-like subviral entity from vaccinia virus leads to the formation of complete vaccinia virus in the bacteria. The significance of this finding in regard to the concept of a universal genetic code is discussed.With 2 Figures in the TextA preliminary report of these results was presented at the XI. International Congress of Genetics in The Hague, September, 1963.Habilitandenstipendiat 1962/63 of Deutsche Forschungsgemeinschaft.     

Effects of Additives on the Survival of Lactic Streptococci in Frozen Storage

Three single-strain cultures, Streptococcus lactis C₂, S. cremoris R₁, and S. diacetilactis DRC₂, were frozen and stored in skim milk, in skim milk containing apple juice, and in skim milk containing one of the following additives: glycerol (10%, v/v), dimethyl sulfoxide (10%, v/v), l-malic acid (0.5 and 2.0%, w/v), acetamide (0.5 and 2.0%, w/v), or succinimide (0.5 and 2.0%, w/v). Cultures were frozen and stored at -23.3 C, frozen and stored at -196 C in liquid nitrogen, or frozen at -196 C and stored at -23.3 C. Cultures frozen and stored at -196 C in liquid nitrogen gave the greatest recovery of viable cells. The number of cells surviving after storage at -23.3 C was greater when the cells had been frozen in liquid N₂ than when they had been frozen at -23.3 C. All strains stored at -23.3 C showed a decrease in numbers of surviving cells; additives, particularly l-malic acid and apple juice, were advantageous in preserving the viability of the S. lactis C₂ and S. cremoris R₁ strains, but had little or no effect on the survival of S. diacetilactis DRC₂. l-Malic acid and apple juice stimulated acid production for all cultures in activity tests following incubation after thawing, whereas glycerol and dimethyl sulfoxide retarded its development.     

The androgen-dependent rat prostate protein,probasin, is a heparin-binding protein that co-purifies with heparin-binding growth factor-1

Summary Rat prostate extracts contain an abundant 20–22 kilodalton heparin-binding protein with near identical chromatographic properties, but only 0.2–1% of the mitogenic activity, of bovine brain heparin-binding growth factor-1 (acidic fibroblast growth factor). Amino terminal amino acid sequence (met-met-thr-asp-lys-asn-leu-lys-lys-lys-ile-glu-gly-asn-trp-arg-thr-val-tyr-leu-ala-ala-ser-?-val-glu-lys-ile-asn-glu-gly-ser-pro) and immunochemical analysis revealed that the protein is identical to the androgen-dependent protein “probasin”. This work was supported in part by NCI grant CA37589 (W. L. M., J. W. C.) and the Medical Research Council of Canada (R. J. M.).     

Regulation of fibrinogen assembly. Transfection of Hep G2 cells with B beta cDNA specifically enhances synthesis of the three component chains of fibrinogen

Previous studies indicated that synthesis of B beta chain may be a rate-limiting factor in the production of human fibrinogen since Hep G2 cells contain surplus pools of A alpha and gamma but not of B beta chains, and fibrinogen assembly commences by the addition of preformed A alpha and gamma chains to nascent B beta chains attached to polysomes. To test whether B beta chain synthesis is rate limiting Hep G2 cells were transfected with B beta cDNA, and its effect on fibrinogen synthesis and secretion was measured. Two sets of stable B beta cDNA-transfected Hep G2 cells were prepared, and both cell lines synthesized 3-fold more B beta chains than control cells. The B beta-transfected cells also synthesized and secreted increased amounts of fibrinogen. Transfection with B beta cDNA not only increased the synthesis of B beta chain but also increased the rate of synthesis of the other two component chains of fibrinogen and maintained surplus intracellular pools of A alpha and gamma chains. Transfection with B beta cDNA did not affect the synthesis of albumin, transferrin, or anti-chymotrypsin and had a small inhibitory effect on the synthesis of C-reactive protein. Taken together these studies demonstrate that increased B beta chain synthesis specifically causes increased production of the other two component chains of fibrinogen and that unequal and surplus amounts of A alpha and gamma chains are maintained intracellularly.     

Regionally selective alterations in enzymatic activities and metabolic fluxes during thiamin deficiency

To further elucidate the molecular basis of the selective damage to various brain regions by thiamin deficiency, changes in enzymatic activities were compared to carbohydrate flux through various pathways from vulnerable (mammillary bodies and inferior colliculi) and nonvulnerable (cochlear nuclei) regions after 11 or 14 days of pyrithiamin-induced thiamin deficiency. After 11 days,large decreases (–43 to –59%) in transketolase (TK) occurred in all 3 regions; 2-ketoglutarate dehydrogenase (KGDHC) declined (–45%), but only in mammillary bodies; pyruvate dehydrogenase (PDHC) was unaffected. By day 14, TK remained reduced by 58%–66%; KGDHC was now reduced in all regions (–48 to –55%); PDHC was also reduced (–32%), but only in the mammillary bodies. Thus, the enzyme changes did not parallel the pathological vulnerability of these regions to thiamin deficiency.¹⁴CO₂ production from¹⁴C-glucose labeled in various positions was utilized to assess metabolic flux. After 14 days, CO₂ production in the vulnerable regions declined severely (–46 to 70%) and approximately twice as much as those in the cochlear nucleus. Also by day 14, the ratio of enzymatic activity to metabolic flux increased as much as 56% in the vulnerable regions, but decreased 18 to 30% in the cochlear nuclei. These differences reflect a greater decrease in flux than enzyme activities in the two vulnerable regions. Thus, selective cellular responses to thiamin deficiency can be demonstrated ex vivo, and these changes can be directly related to alterations in metabolic flux. Since they cannot be related to enzymatic alterations in the three regions, factors other than decreases in the activity of these TPP-dependent enzymes must underlie selective vulnerability in this model of thiamin deficiency.Abbreviations KGDHC 2-ketoglutarate dehydrogenase complex EC 1.2.4.2., EC 2.3.1.61, EC 1.6.4.3. - PDHC pyruvate dehydrogenase complex EC 1.2.4.2., EC 2.3.1.12, EC 1.6.4.3 - TK transketolase (EC 2.2.1.1) - TPP thiamin pyrophosphate     

Plant-soil interactions in primary succession at Hawaii Volcanoes National Park

Summary Plant nutrient status and physiological processes were examined in relation to soil nutrient characteristics under individuals of five species colonizing a young cinder deposit in Hawaii Volcanoes National Park. Two exotic species, Buddeleja asiatica and Myrica faya, had high photosynthetic rates and high nitrogen concentrations and relatively easily decomposed leaves; soils under them had high concentrations of nitrogen, cations, and organic matter and high rates of net nitrogen mineralization. At the other extreme, the natives Metrosideros polymorpha and Vaccinium reticulatum had low plant concentrations and photosynthetic rates, and low concentrations and turnover rates of N in the soil. Thus, a strong correlation exists between soil processes and plant processes, suggesting a positive feedback cycle.     

Evidence for Distinct 5-Hydroxytryptamine2 Binding Site Subtypes in Cortical Membrane Preparations

5-Hydroxytryptamine (5-HT) displays a sixfold higher affinity for 5-HT2 binding sites labeled by [3H]ketanserin in rat (IC50 = 200 +/- 40 nM) and human (IC50 = 190 +/- 50 nM) cortex than for 5-HT2 sites in bovine cortex (IC50 = 1,200 +/- 130 nM). The Hill slopes of the 5-HT competition curves are 0.67 +/- 0.04 in rat, 0.69 +/- 0.08 in human, and 0.96 +/- 0.02 in bovine cortex. Scatchard analysis of (+/-)-[3H]4-bromo-2,5-dimethoxyamphetamine ([3H]DOB) binding in the rat indicates a population of binding sites with a KD of 0.38 +/- 0.04 nM and a Bmax of 1.5 +/- 0.05 pmol/g tissue. In contrast, specific [3H]DOB binding cannot be detected in bovine cortical membranes. These data indicate that species variations exist in 5-HT2 binding site subtypes and that [3H]ketanserin appears to label a homogeneous population of 5-HT2 binding site subtypes in bovine cortex.     

Effect of temperature on the spectral properties of coenzyme F420 and related compounds.

The uv-visible spectra of 7,8-didemethyl-8-hydroxy-5-deazaflavin-5'-phosphoryllactyl glutamate (coenzyme F420), a naturally occurring 5-deazaflavin derivative, in three different buffers changed with a rise in temperature; the effect on the extinction coefficient at 420 nm (epsilon 420) was as follows: In phosphate-buffered solutions at pH less than 7.5, the epsilon 420 increased (at pH 5.0 for a temperature shift from 15 to 60 degrees C, delta epsilon 420 was +87%), but between pH 7.5 and 8, epsilon 420 changed very little. At pH greater than 8.0 in phosphate- or borate-buffered solutions, epsilon 420 decreased slightly. In morpholineethanesulfonic acid (Mes)-buffered F420 solutions at pH 5 and 5.5, epsilon 420 changed very little, whereas at pH 6-8, the epsilon 420 decreased. Absorbance of F420 at 401 nm in phosphate buffer at pH 5 to 9 was not significantly affected by temperature. Changes in epsilon 420 due to temperature change corresponded to changes in the pKa of 8-OH of the deazaflavin molecule; studies with adenylated F420 showed that the 8-OH of F420 was responsible for these changes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Establishment of anaerobic,reducing conditions in lake sediment after deposition of acidic,aerobic sediment by a major storm

Hurricane Danny resulted in the rapid deposition of 10cm of oxidized, acidic sediment in the Contrary Creek arm of Lake Anna, Virginia. Several biological and geochemical parameters were monitored with time to ascertain how long it took the newly-deposited lake sediments to attain the anaerobic, circumneutral, actively sulfate-reducing state normally observed in this portion of the lake. The sediment platinum-electrode potential dropped from 350 mV to 100 mV within the first week after the storm. The pH of the pore water increased from 4.5 to 5.8 within three weeks, and titratable alkalinity was detected within two weeks and three weeks at 3 cm and 1 cm depths, respectively. Accumulation of reduced products of sulfate reduction (acid volatile sulfide) began by three to four weeks after the storm event. Both methanogens and sulfate reducers were present in high and approximately equal numbers in the freshly deposited material. The rapid neutralization of the acidity in the fresh sediment prior to the onset of sulfate reduction suggests that reactions other than sulfate reduction caused the initial increase in pH and alkalinity in this system.