Inducing sporulation in Alternaria solani I. Effect of water treatment

The sporulation was induced when fully grown cultures were given dip or spray treatment with distilled water (cold or hot) and thereafter, kept partially covered at different temperatures. Cultures dipped in cold water (4° C) for 4 minutes or sprayed with cold water (4° C) or hot water (58° C) and thereafter incubated at room temperature (13–26° C) in diffused sunlight, produced maximum number of spores within 60 hours. Incubating water treated cultures in diffused sunlight or complete darkness and age and scraping of the cultures had a considerable effect upon intensity of sporulation. The cultures yield a number of subsequent crops of spores when scraped and given dip treatment with cold or hot water, after obtaining each crop of spores.     

Machine perfusion at 20°C reduces preservation damage to livers from non-heart beating donors

We previously reported that machine perfusion (MP) performed at 20 °C enhanced the preservation of steatotic rat livers. Here, we tested whether rat livers retrieved 30 min after cardiac arrest (NHBDs) were better protected by MP at 20 °C than with cold storage. We compared the recovery of livers from NHBDs with organs obtained from heart beating donors (HBDs) preserved by cold storage. MP technique: livers were perfused for 6 h with UW-G modified at 20 °C. Cold storage: livers were perfused in situ and preserved with UW solution at 4 °C for 6 h. Both MP and cold storage preserved livers were reperfused with Krebs-Heinselet buffer (2 h at 37 °C). AST and LDH release and mitochondrial glutamate dehydrogenase (GDH) levels were evaluated. Parameters assessed included: bile production and biliary enzymes; tissue ATP; reduced and oxidized glutathione (GSH/GSSG); protein–SH group concentration. Livers preserved by MP at 20 °C showed significantly lower hepatic damage at the end of reperfusion compared with cold storage. GDH release was significantly reduced and bile production, ATP levels, GSH/GSSG and protein–SH groups were higher in livers preserved by MP at 20 °C than with cold storage. The best preserved morphology and high glycogen content was obtained with livers submitted to MP at 20 °C. Liver recovery using MP at 20 °C was comparable to recovery with HBDs. MP at 20 °C improves cell survival and gives a better-quality of preservation for livers obtained from NHBDs and may provide a new method for the successful utilization of marginal livers.     

Effects of hyperthermia and hypothermia on spontaneous contractions of the adult rabbit testicular capsule

Spontaneous contractions of the isolated testicular capsule of the adult rabbit have been found to be markedly sensitive to heat and cold stress. Testicular capsular contractions may provide a propulsive pumping action for transporting nonmotile sperm out of the testis and into the epididymis where they can then attain motility. An optimal temperature for the amplitude of spontaneous contractions of the rabbit testicular capsule occurred at 32 – 34°C. An increase in thein vitro organ bath temperature from 37 to 40°C caused a marked decrease in the amplitude of spontaneous contractions. A complete and irreversible cessation of spontaneous contractions occurred at 48°C for at least 30 min after cooling to 37°C. A decrease in temperature from 37 to 26°C resulted in a marked decrease in frequency and amplitude progressing to a complete but reversible cessation of spontaneous contractions at 16°C. Marked changes in the frequency and amplitude of spontaneous contractions of the isolated testicular capsule began to be observed when the tissue was exposed to organ bath temperatures of 3°C above and below the normal intra-testicular temperature. These data suggest that exposure of men to fever or excessively hot baths as well as swimming in excessively cold water or extreme cold weather exposure may have inhibitory effects on testicular capsular spontaneous contractions which may interfere with sperm transport.     

Hormonal growth-promotant effects on grain-fed cattle maintained under different environments

Six steers (3/4 Charolais×1/4 Brahman) (mean body weight 314±27 kg) and six spayed heifers (3/5 Shorthorn×2/5 Red Angus) (mean body weight 478±30 kg) were used to determine the effects of climatic conditions and hormone growth promotants (HGP) on respiration rate (RR; breaths/min), pulse rate (beats/min), rectal temperature (RT; °C), and heat production (HP; kJ). Cattle were exposed to the following climatic conditions prior to implantation with a HGP and then again 12 days after implantation: 2 days of thermoneutral conditions (TNL) [21.9±0.9°C ambient temperature (T_A) and 61.7±22.1% relative humidity (RH)] then 2 days of hot conditions [HOT; 29.2±4°C (T_A) and 78.3±13.2% (RH)], then TNL for 3 days and then 2 days of cold conditions [COLD; 17.6±0.9°C (T_A) and 63.4±1.8% (RH); cattle were wet during this treatment]. The HGP implants used were: estrogenic implant (E), trenbolone acetate implant (TBA), or both (ET). Both prior to and following administration of HGP, RRs were lower (P<0.05) on cold days and greater (P<0.05) on hot days compared to TNL. On hot days, RTs, were 0.62°C higher after compared to before implanting. Across all conditions, RTs were >0.5°C greater (P<0.05) for E cattle than for TBA or ET cattle. On cold days, RTs of steers were >0.8°C higher than for the heifers, while under TNL and HOT, RTs of steers were 0.2–0.35°C higher than those of heifers. Prior to implantation, HP per hour and per unit of metabolic body weight was higher (P<0.05) for cattle exposed to hot conditions, when compared to HP on cold days. After implantation, HP was greater (P<0.05) on hot days than on cold days. Under TNL, ET cattle had the lowest HP and greatest feed intake. On hot days, E cattle had the lowest HP, and the highest RT; therefore, if the potential exists for cattle death from heat episodes, the use of either TBA or ET may be preferred. Under cold conditions HP was similar among implant groups.     

Selective synthesis of 1,6-anhydro-β-d-mannopyranose and -mannofuranose using microwave-assisted heating

The dehydration of d-mannose and the demethanolization of methyl-α-d-mannopyranoside (MαMP) or methyl-α-d-mannofuranoside (MαMF) were examined using microwave-assisted heating for a 3-min irradiation at temperature from 120 to 280 °C in ordinary or dry sulfolane without any catalyst. The microwave-assisted heating of MαMP and MαMF smoothly proceeded to selectively afford the anhydromannoses, 1,6-anhydro-β-d-mannopyranose (AMP) and 1,6-anhydro-β-d-mannofuranose (AMF), respectively, in high yields. For MαMP in ordinary sulfolane at 240 °C, AMP was selectively obtained in the AMF:AMP ratio of 4:96, whereas AMF was the major product at the AMF:AMP ratio of 97:3 from MαMF in dry sulfolane at 220 °C.     

Abscisic acid and mefluidide in the regulation of cold hardiness development in Solanum tuberosum L. potato

Plants of Solanum tuberosum L. potato do not cold acclimate when exposed to low temperature such as 5°C, day/night. When ABA (45 M) was added to the culture medium, stem-cultured plantlets of S. tuberosum, cv. Red Pontiac, either grown at 20°C/15°C, day/night, or at 5°C, increased in cold hardiness from –2°C (killing temperature) to –4.5°C. The increase in cold hardiness could be inhibited in both temperature regimes if cycloheximide (70 M) was added to the culture medium at the inception of ABA treatment. Cycloheximide did not inhibit cold hardiness development, however, when it was added to the culture medium 3 days after ABA treatment.When pot-grown plants were foliar sprayed with mefluidide (50 M), ABA content increased from 10 nmol to 30 nmol g^–1 dry weight and plants increased in cold hardiness from –2°C to about –3.5°C. The increases in free ABA and cold hardiness occurred only in plants grown at 20°C/15°C; neither ABA nor cold hardiness increased in plants grown at 5°C.The results suggest that an increase in ABA and a subsequent de novo synthesis of proteins are required for the development of cold hardiness in S. tuberosum regardless of temperature regime, and that the inability to synthesize ABA at low temperature, rather than protein synthesis, appears to be the reason why S. tuberosum does not cold acclimate.     

Studies on cold pressor response of subjects who suffered from frostbite at high altitude

Seven lowlander soldiers who had 1st to 3rd degree of frostbite and 8 lowlander soldiers who recovered from high altitude pulmonary oedema were tested for cold pressor response at 260 m, 26°C, 6.8°C and 4,085 m, 26°C, 6.8°C. 8 lowlander soldiers (Control subjects) of comparable age group were tested for their cold pressor response at 260 m, 26°C and 3,300 m, 26°C. Another group of control subjects from the laboratory were also tested at 2,121 m, 26°C. There was a highly significant decrease in cold pressor response of the frostbite subjects at 260 m, 26°C and a very significant increase at 260 m, 6.8°C as compared to non-frostbite subjects. The subjects who recovered from high altitude pulmonary oedema did not show significant differences as compared with the control subjects. The results suggest certain basic physiological differences in regulation of supply of blood to the extremities under condition of general and local cold exposure.     

Effects of hot ground water on a small swamp-stream in Nova Scotia,Canada

We examined the effects of hot spring water (35–45 °C) on the ecology of a small, intermittant swamp-stream in Nova Scotia, Canada. Temperatures diminished quickly with distance downstream from the hot spring because of abundant inflow of cold ground water (<10 °C), but elevated temperature effects were detectable 130 m downstream. The brook below the hot spring supported a dense mat of the cyanobacterium Oscillatoria (10 m) followed by the green alga Vaucheria taylorii (40 m). Herbaceous vegetation below the algal zones was also altered by the hot water inflow, even where the temperature increase was slight. The structure of the sparse community of benthic invertebrates was sharply different at sites of different stream temperature: only oligochaete worms, ostracods, chironomids, and a single species of snail thrived at the warmest sites; cold downstream sites supported a typical headwater stream community. Mass loss from decomposing leaves of speckled alder was fast at all sites and strongly correlated with water temperature. The changes in community composition and decomposition rate in response to added heat persisted even where the temperature increase was small, indicating a tight coupling of ecosystem structure and function with the physical environment.     

The Influence of Temperature on Metabolic and Cellular Protection of the Heart during Long-Term Ischemia: A Study Using P-31 Magnetic Resonance Spectroscopy and Biochemical Analyses

We have compared the influence of two different cold temperatures (below 10°C) for cardiac ischemia by measuring a large variety of hemodynamic and metabolic parameters during ischemia and reflow. Isolated isovolumic rat hearts were arrested with a preservation solution which was developed in our laboratory and then submitted to 5 h of cold storage (4°C, group I; and 7.5°C, group II) in the same solution. After an additional period of 50 min of ischemia at 15°C with intermittent cardioplegic infusion, hearts were reperfused for 60 min at 37°C. Function was assessed during the control period and reflow. High-energy phosphates and intracellular pH were followed by³¹P magnetic resonance spectroscopy. Analyses of metabolites and enzymes were performed by biochemical assays and HPLC in coronary effluents and in freeze-clamped hearts to assess cellular integrity. The energetic pool was better preserved at 4°C during ischemia (ATP at the end of 4°C ischemia, 59 ± 7% in group I vs 31 ± 5% in group II,P< 0.01) and reflow (P< 0.05) but membrane protection was higher when increasing the temperature to 7.5°C (reduction of creatine kinase leakage, 89 ± 16 IU/min in group I vs 51 ± 5 IU/min in group II,P< 0.05). As a result, functional recovery, represented by the rate pressure product, was higher in hearts preserved at 7.5°C (52 ± 6% recovery in group I vs 77 ± 7% in group II at the end of reflow,P< 0.05). Altogether, cold storage at 7.5°C provides a better protection than storage at 4°C.     

Supramaximal heat production induced by aminophylline in temperature-acclimated rats

Previous studies have shown that aminophylline, a phosphodiesterase inhibitor (thereby increasing intracellular cyclic AMP concentration) elicits supramaximal heat production and improves cold tolerance in rats acclimated to 22°C. To test whether aminophylline-stimulated supramaximal thermogenesis is independent of both the thermogenic capacity (i.e. aerobic fitness) and the mode of thermogenesis (shivering vs. non-shivering), rats (adult male Sprague-Dawley, approximately 400 g) of two different ages (4–11 month and 9–17 month, n=12 for each) were acclimated to 5, 15, and 25°C in succession and their thermogenic responses to aminophylline subsequently assessed. Aminophylline elicited supramaximal thermogenesis and improved cold tolerance regardless of age or acclimating temperatures. Further, the absolute net increase in heat production stimulated by aminophylline was also similar for all acclimating temperatures. After acclimating to 15°C, a single injection of aminophylline in the older rats elicited thermogenesis greater than that of the controls acclimated to 5°C; in the younger rats, aminophylline duplicated 46% of the increase in thermogenesis observed after acclimating to 5°C. These results indicated that the aminophylline-stimulated extra heat production is independent of both the thermogenic capacity and the mode of thermogenesis. It is possible that an enhanced substrate mobilization consequent to increased intracellular cyclic AMP concentration by aminophylline underlies the common mechanism via which supramaximal thermogenesis is elicited in temperature-acclimated rats.     

Prebiotic Oligomerization on or Inside Lipid Vesicles in Hydrothermal Environments

Oligomerization of amino acids proceeded on or inside lipid vesicles as a model of prebiotic cells in a simulated hydrothermal environment. When the suspension of lipid vesiclestaking up monomeric glycine underwent a sudden temperature dropby traversing from a hot (180 °C) to a cold (0 °C) region repeatedly while circulating through a closedreaction circuit, oligopeptides up to heptaglycine were formed even in the absence of condensing agents.     

Regulation of glycogen phosphorylase in fat body ofCecropia silkmoth pupae

Summary Glycogen phosphorylase of pupal fat body of the silkmoth,Hyalophora cecropia, and its activation by different stimuli have been studied. Spectrophotometric assay in the direction of glycogenolysis, used in most of the experiments, indicated higher amounts of phosphorylasea than assay by release of P_i from glucose-1-phosphate; both assays, however, estimated changes in proportion of phosphorylasea equally. TheK _ms for P_i were estimated as 5 mM for phosphorylasea in the absence of AMP and 18 mM for phosphorylaseb with 2 mM AMP.When diapausing pupae were held at 4°C, fat body phosphorylase was quickly activated by conversion to thea form up to about 50% of the total, and then declined again after 30 days, when glycerol had accumulated in the hemolymph. Cold activation in vivo was quickly reversed at 25°C. Removal of the brain did not prevent cold activation. After storage at 15°C, sensitivity to cold activation was diminished. Locusts and crickets also showed activation of phosphorylase after chilling.Exposure of fat body to air, transfer to Ringer solution, or physical agitation, caused activation of phosphorylase which is classed as shock activation. After about 1 h incubation in Ringer at 25°C, this effect reversed spontaneously. Activation also occurred in fat body in vitro after transfer to 0°C (cold activation), and was reversed at 25°C. The previously reported inhibition of activation by glycerol, however, could not be consistently reproduced.In fat body homogenates, phosphorylaseb was converted to phosphorylasea by incubation with ATP and Mg²⁺, which indicates activity of phosphorylase kinase. In preparations treated with Sephadex G-25 and then incubated, the reverse conversion took place, which was inhibited by fluoride, and indicates activity of phosphorylase phosphatase.Cyclic AMP added to fat body in vitro, or theophylline either in vivo or in vitro, stimulated the activation of phosphorylase. In fat body in vitro, shock activation was paralleled by elevation of tissue cyclic AMP, whereas cold activation was not. Cyclic GMP did not stimulate activation, and showed no significant changes in tissue levels.It is concluded that the conversion of silkmoth pupal fat body phosphorylaseb to phosphorylasea can be stimulated by a shock-initiated mechanism involving cyclic AMP and a distinct cold-initiated mechanism independent of cyclic AMP.Abbreviations DTT dithiothreitol - cyclic AMP 3,5-cyclic adenosine monophosphate - cyclic GMP 3,5-cyclic guanosine monophosphate - P _i inorganic phosphate This investigation was begun in the Department of Biology, Yale University, New Haven, Connecticut, USA     

The effect of cyclic adenosine 3′,5′-monophosphate on the uptake of estradiol by the neonatal mouse uterus

Summary Uterine tissue from neonatal mice was incubated in vitro at 0° C for 1 h in a medium containing 1×10^-8 M ³H-estradiol with or without 1×10^-4M dibutyryl cyclic AMP. In some incubations the temperature was raised to 37° C for 15 min after incubation in the cold, in others the temperature was kept at 0° C during this 15 min period. The tissue was frozen in liquid propane cooled in liquid nitrogen, sectioned at 2 or 4 microns, and autoradiograms prepared according to the dry-mount procedure. cAMP increases the cellular uptake of ³H-estradiol in uterine tissue. After rising the temperature to 37° C, grains appeared over the nuclei. cAMP at low temperature increased the cellular uptake of ³H-estradiol, but the grains were not associated with the nuclei. In the autoradiograms the grain number above the epithelium was markedly less than above the stroma.This work has been supported by grants from the Norwegian Research Council for Science and the Humanities, and from the Norwegian Cancer Society (Landsforeningen mot Kreft)     

The synthesis of cold shock proteins and cold acclimation proteins in the psychrophilic bacteriumAquaspirillum arcticum

The synthesis of cold shock proteins (csps) in response to cold shock, and of cold acclimation proteins (caps) in response to continuous growth at low temperature, in the psychrophileAquaspirillum arcticum was investigated. With two-dimensional gel electrophoresis and computing scanning laser densitometry, cold shock treatments (10° to 0°C, 5° to 0°C, and 10° to 5°C) induced a total of 14 csps, 6 of which were induced by all three cold shocks. The production of caps in response to continuous growth at 0°C was also found. Five of the 8 caps produced were also csps which suggests that these proteins may share a common involvement in cold adaptation.     

Induction of cold shock proteins in Bacillus subtilis

The cold shock response in the Gram-positive soil bacterium Bacillus subtilis is described. Cells were exposed to sudden decreases in temperature from their optimal growth temperature of 37°C. The B. subtilis cells were cold shocked at 25°C, 20°C, 15°C, and 10°C. A total of 53 polypeptides were induced at the various cold shock temperatures and were revealed by two-dimensional gel electrophoresis. General stress proteins were identified by a comparative analysis with the heat shock response of B. subtilis. Some unique, prominent cold shock proteins such as the 115 kDa, 97 kDa, and 21 kDa polypeptides were microsequenced. Sequence comparison demonstrated that the 115-kDa protein had homology to the TCA cycle enzyme, aconitase.     

Heat and cold shock responses in different strains of Thiobacillus ferrooxidans

Different strains of Thiobacillus ferrooxidans were examined for their ability to produce a heat shock and a cold shock response. Strain A1, heat shocked from 20° to 35°C, acquired thermotolerance, as it showed a 1000-fold reduction in cell mortality when exposed to the supermaximum temperature of 42°C, as compared to a non-heat-shocked control. A heat shock from 25° to 35°C yielded similar results, although a higher degree of thermotolerance was achieved for the shorter exposure times. Cultures heat shocked for 5 h showed a five-log reduction in viable counts after 41 h at 42°C, whereas non-heat-shocked cultures showed a similar reduction in viability in 28 h. Conferred thermotolerance was immediate and sustained for the duration of the exposure to 42°C. Heat-shocked cultures were not significantly protected against loss of viability due to freezing (-15°C for 24 h). Strain S2, cold shocked from 25° to 10°C, and strain D6, cold shocked from 25° to 5°C, were not protected against freezing at-15°C. An analysis of proteins extracted from heat-shocked cells of strain A1 showed the presence of at least one newly induced protein and eight hyper-induced proteins. The molecular weights of the heat shock proteins were in the range of 15–80.3 kDa.     

Stimulation of androgenesis in white cabbage (Brassica oleracea var. capitata) anthers by low temperature and anther dissection

Anther culture was performed on two local cultivars, Ljubljansko and Varadinsko, and the F₁ cv. Krautman (Bejo-Zaden). The effects on androgenesis of hot and cold temperature treatments and different dissections of anthers were evaluated. In contrast to cv. Krautman, cvs. Ljubljansko and Varadinsko produced more embryos after cold pretreatment of flower buds (4°C, 48 h) than after standard treatment (35°C, 24h). Simultaneous cutting of the anther tip and removal of the filament gave the best results in comparison to other tested dissections. Microscopical observations of sectioned anthers revealed enhanced embryo development near the cut ends of the anthers. Ploidy analysis revealed the presence of haploids among embryos resulting from cold treatment (4°C, 48 h), treatment at elevated temperature (35°C, 24 h), and among embryos resulting from dissections of anther tips.     

Thermal adaptability of large white pigs in the tropical environment

Twenty-four Large White weaners-twelve males and twelve females, were randomly divided into three groups of eight (four males and four females per two separate pens) and were assigned to three groups of two pens each for the males and the females weaners.One group of two pens was without wallow facility (control), one other group was provided with wallows (wet) and the third group was in air-conditioned room (cold). Twice a day, the respiratory rate and the rectal temperatures were measured early in the mornings at 8.00–9.00 hrs (A.M.) and late in the early evenings at 16.00–18.00 hrs.The mean respiratory frequency (A.M) ranged from 7 to 9; 6–12 and 8–13 breaths per minute for the cold, wet and control respectively while the mean respiratory frequency (P.M.) ranged from 6 to 9, 10 to 17 and 13 to 19 breaths per minute for the cold, wet and control respectively.The mean rectal temperatures (A.M.) ranged very slightly from 38.54° to 39.12°C; 38.50° to 39.05°C and 38.61°C to 39°C for the cold, wet as control respectively while the mean rectal temperatures (P.M.) ranged from 39.00° to 39.22°C; 38.97° to 39.29°C and 39.28° to 39.55°C for the cold, wet and control respectively.The animals were maintained for another seven to ten weeks and were slaughtered. The slaughter characteristics did not indicate an appreciable thermal stress except for the reproductive organs which showed weight increase indicating reduced efficiency of the thermally stressed animals as is the case in the tropical environment.     

Effects of Cold Acclimation and Salicylic Acid on Changes in ACC and MACC Contents in Maize during Chilling

The effect of 0.5 mM salicylic acid (SA) pretreatment and of growing at hardening temperatures on chilling-induced changes in 1-aminocyclopropane-1-carboxylic acid (ACC) and malonyl 1-aminocyclopropane-1-carboxylic acid (MACC) was investigated in young maize (Zea mays L.) plants grown in hydroponic solution at 22/20 °C. Chilling at 5 °C caused an increase in ACC content;however, this increase was less pronounced in plants cold acclimated at 13/11 °C 4 d before the chilling treatment, and in those which were pretreated with SA for 1 d before the cold stress. Changes in MACC at low temperature showed no correlation with chilling tolerance in maize.     

Genome-wide expression analysis of yeast response during exposure to 4°C

Adaptation to temperature fluctuation is essential for the survival of all living organisms. Although extensive research has been done on heat and cold shock responses, there have been no reports on global responses to cold shock below 10°C or near-freezing. We examined the genome-wide expression in Saccharomyces cerevisiae, following exposure to 4°C. Hierarchical cluster analysis showed that the gene expression profile following 4°C exposure from 6 to 48 h was different from that at continuous 4°C culture. Under 4°C exposure, the genes involved in trehalose and glycogen synthesis were induced, suggesting that biosynthesis and accumulation of those reserve carbohydrates might be necessary for cold tolerance and energy preservation. The observed increased expression of phospholipids, mannoproteins, and cold shock proteins (e.g., TIP1) is consistent with membrane maintenance and increased permeability of the cell wall at 4°C. The induction of heat shock proteins and glutathione at 4°C may be required for revitalization of enzyme activity, and for detoxification of active oxygen species, respectively. The genes with these functions may provide the ability of cold tolerance and adaptation to yeast cells.