The dynamics of the induction and regression of puffs 87A, 87C and 93D in the polytene chromosomes of Drosophila melanogaster under the action of anoxia and high temperature]

A study was made of the heat shock puff activity in salivary glands of Drosophila melanogaster larvae after 5 and 20 min treatments with anoxia (dipping into physiological solution), heat shock (37 degrees C), and simultaneously with both the agents. The simultaneous treatment with heat shock and anoxia, as well as treatment with anoxia only blocked the induction of heat shock puffs. They appeared 10-15 min after the treatment during recovery under aerobic conditions. There was a super-additive effect of the simultaneous treatment on the heat shock puffing duration. A specific regulation of the 93D locus was observed. The 93D puff was induced by a 5 min simultaneous treatment with anoxia and heat shock and, as a rule, was not induced by the analogous 20 min treatment. The role of anoxia in blocking heat shock puff induction under simultaneous effects of heat shock and anoxia is discussed.     

Synthesis of soluble heat shock proteins in seminal root tissues of some cultivated and wild wheat genotypes

Effect of heat stress on the synthesis of soluble heat shock proteins (HSPs) and the regrowth in seminal roots of three cultivated and three wild wheat genotypes was examined. In regrowth experiments, 2-d-old etiolated seedlings were exposed to 23 (control), 32, 35, 37 and 38 degrees C for 24 h, and 35 and 37 degrees C (24 h) followed by 50 degrees C (1 h). The lengths of the seminal roots generally decreased significantly at the end of 48 and 72 h recovery growth periods at 35, 37 and 38 degrees C temperature treatments compared with control. Genotypic variability was significant level at all temperature treatments for the seminal root length. Also, genotypic differences for the number of seminal roots were determined among the wheat cultivars and between the wild wheat species and the wheat cultivars at all temperature treatments; but genotypic differences among wild wheat species were only detected at 37-->50 degrees C treatment. Acquired thermotolerance for the seminal root length is over 50% at 37-->50 degrees C treatment. The genotypic variability of soluble heat shock proteins in seminal root tissues were analyzed by two-dimensional electrophoresis (2-DE). Total number of low molecular weight (LMW) HSPs was more than intermediate-(IMW) and high- (HMW) HSPs at high temperature treatments. The most of LMW HSPs which were generally of acidic character ranged between 14.2-30.7 kDa. The genotypes had both common (43 HSP spots between at least two genotypes and 23 HSP spots between 37 and 37-->50 degrees C) and genotype-specific (72 HSP spots) LMW HSPs.     

The effect of chlorpromazine on the temperature and osmotic sensitivity of erythrocytes]

The effect of chlorpromazine on the development of cold shock in erythrocytes exposed to sodium chloride was shown to depend on the tonicity of the medium in which the cells were cooled from 37 degrees C down to 0 degrees C as well as on the amphipate concentration. After cooling of erythrocytes in a NaCl (0.75-1.5 M)-containing medium with chlorpromazine (7 x 10(-5) M, 2.1 x 10(-4) M and 3.5 x 10(-4) M) the hypertonic cold shock was inhibited, the protective effect of the amphipate being less pronounced at its increasing concentrations. After cooling of cells under conditions of moderate hypertonicity (0.3-0.6 M NaCl) no modifying effect of chlorpromazine on the sensitivity of erythrocytes to the temperature decrease from 37 degrees C down to 0 degrees C was manifested. However, under iso- and hypertonic conditions chlorpromazine used at 2.1 x 10(-4) M and 3.5 x 10(-4) M stimulated the cold shock development in erythrocytes. A sharp increase in the medium tonicity (up to 1.8-3.0 M and higher) the cells underwent isothermal hemolysis which was more expressed at 0 degrees C than at 37 degrees C. These data suggest that chlorpromazine significantly activates the hemolytic process at low temperatures.     

Modifying effect of concanavalin A and diamide on erythrocyte sensitivity to cold shock]

The temperature (0 degrees C and 37 degrees C) and the medium tonicity (0.15-1.20 M NaCl) were shown to affect erythrocyte agglutination by concanavalin A. Treatment of cells with lectin caused no significant decrease in the erythrocyte hemolysis upon cooling. Diamide, unlike concanavalin A used at concentrations above 2.0 M decreases the cell sensitivity to the cold shock. The changes in the erythrocyte susceptibility to cooling within the temperature range of 37-0 degrees C correlate with changes in the electrophoretic spectrum of membrane proteins. The progressive decrease in the spectrin bands intensity with a simultaneous formation of high molecular weight protein aggregates not included in the gel composition was observed after diamide treatment. The diamide effect depends on the medium tonicity, at which the treatment was performed, being especially well pronounced in hypertonic media with 0.8-1.2 M NaCl concentrations, the maximal spectrin aggregation being observed under these conditions. It is suggested that the main factor of the mechanism underlying the erythrocyte hypertonic cold shock is the increase in the association of peripheral cytoskeleton proteins with plasma membrane in osmotically dehydrated cells which limits the ability of lipids to adapt during cooling and results in the stabilization of defects in the membrane structure at low temperatures. Diamide eliminates these unfavourable changes eventually resulting in the dissociation of peripheral proteins from the cytoplasmic surface of the membrane on the protein aggregation.     

Effect of hyperthermia on the frequency of sister-chromatid exchanges in patients with cancer of cervix uteri

The frequencies of sister-chromatid exchanges (SCE) were studied in patients with cancer of the cervix uteri and normal controls at 37 degrees C and 40 degrees C. At 37 degrees C the mean frequency of SCE was found to be 8.26 +/- 1.91 in untreated patients with cervical cancer and 7.91 +/- 1.68 in cancer patients treated with radiotherapy; these values were significantly higher than the control value of 5.34 +/- 1.28 exchanges. Increase of the growth temperature to 40 degrees C elevated the SCE frequency to 11.95 +/- 2.12 in patients without radiotherapy treatment, 13.37 +/- 2.17 in patients with radiotherapy treatment and 7.82 +/- 1.84 in normal controls. These data indicate that there is a differential induction of SCEs by hyperthermia in the lymphocytes of control women and patients with cancer of the cervix uteri.     

Influence of treatment temperature on the genotoxic effects of cisplatin in CHO cells: cytotoxicity, mutagenicity and induction of lesions in DNA

In cells exposed in vitro to the cytotoxic and mutagenic antitumor drug cisplatin (cis-Pt(NH3)2Cl2), various adducts with nuclear DNA are formed. A comparative study was made of the influence of temperature variation during treatment of cultured Chinese hamster ovary (CHO) cells with cisplatin on cytotoxicity, mutation induction and Pt-DNA adduct formation. Before and after treatment (1 h at 32, 37 or 40 degrees C) cells were kept at 37 degrees C. Cytotoxicity increased with temperature; D0 values were 29.6 +/- 1.6, 21.1 +/- 1.2 and 11.4 +/- 0.6 microM at 32, 37 and 40 degrees C, respectively. Pt-DNA binding to DNA at 40 degrees C was 2.0 (+/- 0.3) times as high as at 32 degrees C. This factor remained practically constant over a 24-h post-treatment incubation of the cells, during which about 60% of DNA-bound Pt were removed. As the increase in cytotoxicity between 32 and 40 degrees C was roughly in proportion to that in Pt binding, no substantial changes in the spectrum of adducts appeared to occur. The induction of DNA interstrand cross-links, studied at 32 and 40 degrees C, varied linearly with dose. Influence of temperature on cross-link formation was comparable to that on total Pt binding. Amounts of cross-links highly increased during 24 h after treatment. Plots of cross-links against survival after treatments at 32 and 40 degrees C almost coincided. Induction of 6-thioguanine-resistant (HGPRT) mutants at various cisplatin concentrations did not show a clear temperature dependency. Consequently, equitoxic treatments were significantly more mutagenic at 32 degrees C than at 40 degrees C, the opposite of what has been reported for E. coli.     

PHYSIOLOGICAL AND BIOCHEMICAL MECHANISMS OF TEMPERATURE SHOCKS ON OVERWINTERING MATURE LARVAE OF PINE NEEDLE GALL MIDGE THECODIPLOSIS JAPONENSIS (DIPTERA: CE-CIDOMYIIDAE)*

Abstract The supercooling points of cold (-10C and -5C) and heat (37 C, 40 C and 45 C) shocked overwintering larvae were nearly the same as that of un-shocked ones (ca. -20C). Temperature shocks enhanced the ability to endure subzero temperature (- 15C, 3 h), and the cold shock treatment had more significant effect on maintaining larval survival than that of heat shock. It is the third insect that heat shock and cold shock enhanced its survival rate under low temperature simultaneously. A special stress protein (MW = 83 kD) was expressed under cold shock at -10 C and heat shock at 40 C or 45 C. It is also a few instances that a stress protein was expressed in the same insect under both heat shock and cold shock simultaneously. Meanwhile, the antioxidant system under different treatments was studied. Rapid cold hardening process had no oxidative stress because of the increase content of reduced glutathione and activity of glutathione reductase, but other treatments had.     

Varying patterns of protein synthesis in bread wheat during heat shock

High temperatures during seedling growth are considered as one of the factors that can modify surviving properties in wheat (Triticum aestivum L.) plant. This work attempts to evaluate the heat shock responses of seedling of winter wheat (Bezostaya-1) using growth parameters (seedling length, embryonal root length and embryonal root number), membrane stability index (MSI) and two dimensional (2D) gel electrophoresis analysis of heat shock proteins (HSPs) during heat shock. Seedlings grown until first leaf opening at controlled conditions (23 degrees C, 200 micromol m(-2) s(-1), 16h day/8h night, 50-60% humidity) were exposed to 37 degrees C or 45 degrees C high temperatures for 2, 4 and 8 hours. While 37 degrees C did not cause any significant change, 45 degrees C heat treatments caused significant decrease in terms of seedling and root length, and leaf MSI for all exposure times. However, all the plants from 45 degrees C heat treatments continued to grow during recovery period. 2D protein analysis indicated that 37 degrees C, 8 hours exposure caused stronger and more diverse heat shock response than the other treatments, followed by 37 degrees C, 4 hours, 45 degrees C, 8 hours, 45 degrees C, 4 hours, 45 degrees C, 2 hours treatments. 5 protein spots, ranging from 6-7.8 pl (isoelectric point) and 27-31.7 kDA molecular weight, were expressed at 37 degrees C, 2 hours and continued at 37 and 45 degrees C for all exposure times. This suggests that these early proteins and other newly synthesized proteins may have protective effects at 37 and 45 degrees C and provide plants for healthy growth during the recovery period.     

Elevated serine catabolism is associated with the heat shock response in Escherichia coli.

The biochemical events associated with the heat shock response are not well understood in any organism, nor have the signals that initiate the induction of heat shock protein synthesis been identified. In this work, we demonstrate that the rate of serine catabolism of Escherichia coli cells grown in glucose minimal medium supplemented with serine is elevated three- to sevenfold when the growth temperature is shifted from 37 to 44 degrees C. Elevations in growth temperature and mutations or treatments that lead to elevated basal rates of serine catabolism at 37 degrees C result in the excretion into the culture medium of acetate derived from exogenous serine. Increases in the basal level of serine catabolism at 37 degrees C do not per se induce a heat shock response but are associated with abnormalities in the pattern of induction of heat shock polypeptides following a temperature shift. We postulate that the events responsible for or resulting from the elevation in serine catabolism associated with a shift-up in temperature modulate the induction of 3 of the 17 heat shock polypeptides identified in E. coli. These observations suggest that heat shock diverts serine away from the production of glycine and C1 units, which are required for initiation of protein synthesis and for nucleotide biosynthesis, and towards acetyl coenzyme A and acetate.     

Effect of moderate electric field on the metabolic activity and growth kinetics of Lactobacillus acidophilus

Moderate electric fields (MEF), applied across microbial growth media may potentially affect the permeability of cell membranes. We investigated the effects of MEF on bacteriocin (lacidin A) production during fermentation and on microbial growth kinetics of Lactobacillus acidophilus OSU 133. We comparatively investigated the following treatments: conventional, MEF (1 V/cm, 60 Hz, for 40 h), combinations of MEF (1 V/cm, 60 Hz, for the first 5 h) and conventional fermentation (for 35 h), and discrete MEF (1 V/cm, 2 min on and off, for 40 h). In all treatments, except as noted below, temperature was set at 30 degrees C. The two exceptions were control (conventional) and discrete MEF treatment, which were conducted both at 30 and 37 degrees C. MEF treatments at the early stage of fermentation at 30 degrees C showed the maximum bacteriocin activity. Minimum bacteriocin production was observed under conventional fermentation at 37 degrees C. A mathematical model based on Monod growth kinetics was used to predict bacteriocin production and showed results consistent with conventional treatment data. MEF did not have a significant effect on the lag time, maximum specific growth rate, biomass production and pH change under the different experimental conditions at each specific temperature. Based on the observations, bacteriocin activity under the presence of MEF at the early stage of fermentation increased without significant change in the final biomass.     

Proteomic study of cold shock protein in Bacillus stearothermophilus P1: Comparison of temperature downshifts

The thermophilic bacterium Bacillus stearothermophilus P1 is unique in its ability to thrive in extreme environments such as high temperatures or high pH conditions. The study of cold shock response is very interesting and interpreted as a shock response to express the genes involved in synthesis of specific proteins. This study investigated the study of cold shock protein of B. stearothermophilus P1 when the cell culture temperature shifted from 65 degrees C to 37 degrees C and 25 degrees C. Cell growth at 37 degrees C weakly increased in the previous 3 h and then slowly decreased. In contrast, cell growth at 25 degrees C was slowly decreased. The protein contents after temperature downshifts were analyzed by proteomic techniques using protein chip and two-dimensional (2-D) electrophoresis that are highly effective and useful for protein separation and identification. The different proteins after a temperature decrease from 65 degrees C to 37 degrees C and 25 degrees C were expressed on 2-D gel patterns and the cold shock protein was detected in the acidic area with the isoelectric point and molecular mass approximately 4.5 and 7.3 kDa, respectively. The NH(2)-terminal sequence of a major cold shock protein from B. stearothermophilus P1 was MQRGKVKWFNNEKGFGFIEVEGGSD, similar to other cold shock proteins from Bacillus sp. up to 96% identity, but different from the other bacteria with homology less than 80% identity.     

Response of superoxide dismutase isoenzymes in tomato plants (Lycopersicon esculentum) during thermo-acclimation of the photosynthetic apparatus

Seedlings of Lycopersicon esculentum Mill. var. Amalia were grown in a growth chamber under a photoperiod of 16 h light at 25 degrees C and 8 h dark at 20 degrees C. Five different treatments were applied to 30-day-old plants: Control treatment (plants maintained in the normal growth conditions throughout the experimental time), heat acclimation (plants exposed to 35 degrees C for 4 h in dark for 3 days), dark treatment (plants exposed to 25 degrees C for 4 h in dark for 3 days), heat acclimation plus heat shock (plants that previously received the heat acclimation treatment were exposed to 45 degrees C air temperature for 3 h in the light) and dark treatment plus heat shock (plants that previously received the dark treatment were exposed to 45 degrees C air temperature for 3 h in the light). Only the heat acclimation treatment increased the thermotolerance of the photosynthesis apparatus when the heat shock (45 degrees C) was imposed. In these plants, the CO(2) assimilation rate was not affected by heat shock and there was a slight and non-significant reduction in maximum carboxylation velocity of Rubisco (V(cmax)) and maximum electron transport rate contributing to Rubisco regeneration (J(max)). However, the plants exposed to dark treatment plus heat shock showed a significant reduction in the CO(2) assimilation rate and also in the values of V(cmax) and J(max). Chlorophyll fluorescence measurements showed increased thermotolerance in heat-acclimated plants. The values of maximum chlorophyll fluorescence (F(m)) were not modified by heat shock in these plants, while in the dark-treated plants that received the heat shock, the F(m) values were reduced, which provoked a significant reduction in the efficiency of photosystem II. A slight rise in the total superoxide dismutase (SOD) activity was found in the plants that had been subjected to both heat acclimation and heat shock, and this SOD activity was significantly higher than that found in the plants subjected to dark treatment plus heat shock. The activity of Fe-SOD isoenzymes was most enhanced in heat-acclimated plants but was unaltered in the plants that received the dark treatment. Total CuZn-SOD activity was reduced in all treatments. Darkness had an inhibitory effect on the Mn-SOD isoenzyme activity, which was compensated by the effect of a rise in air temperature to 35 degrees C. These results show that the heat tolerance of tomatoplants may be increased by the previous imposition of a moderately high temperature and could be related with the thermal stability in the photochemical reactions and a readjustment of V(cmax) and J(max). Some isoenzymes, such as the Fe-SODs, may also play a role in the development of heat-shock tolerance through heat acclimation. In fact, the pattern found for these isoenzymes in heat-acclimated Amalia plants was similar to that previously described in other heat-tolerant tomato genotypes.     

Heat and cold shock protein synthesis in arctic and temperate strains of rhizobia.

We compared heat shock proteins (HSPs) and cold shock proteins (CSPs) produced by different species of Rhizobium having different growth temperature ranges. Several HSPs and CSPs were induced when cells of three arctic (psychrotrophic) and three temperate (mesophilic) strains of rhizobia were shifted from their optimal growth temperatures (arctic, 25 degrees C; temperate, 30 degrees C) to shock temperatures outside their growth temperature ranges. At heat shock temperatures, three major HSPs of high molecular weight (106,900, 83,100, and 59,500) were present in all strains for all shock treatments (29, 32, 36.4, 38.4, 40.7, 41.4, and 46.4 degrees C), with the exception of temperate strains exposed to 46.4 degrees C, in which no protein synthesis was detected. Cell survival of arctic and temperate strains decreased markedly with the increase of shock temperature and was only 1% at 46.4 degrees C. Under cold shock conditions, five proteins (52.0, 38.0, 23.4, 22.7, and 11.1 kDa) were always present for all treatments (-2, -5, and -10 degrees C) in arctic strains. Among temperate strains, five CSPs (56.1, 37.1, 34.4, 17.3, and 11.1 kDa) were present at temperatures down to 0 degrees C. The 34.4- and the 11.1-kDa components were present in all temperate strains at -5 degrees C and in one strain at -10 degrees C. Survival of all strains decreased with cold shock temperatures but was always higher than 50%. These results show that rhizobia can synthesize proteins at temperatures not permissive for growth. In all shock treatments, no correspondence between the number of HSPs or CSPs produced and rhizobial survival was found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of temperature on chemically induced sister-chromatid exchange in human lymphocytes

Lymphocytes from healthy adults were studied for sister-chromatid exchanges (SCEs) when pulse-treated in G0 with mitomycin C (MMC), ethyl methanesulfonate (EMS), or 4-nitroquinoline N-oxide (4NQO) at various temperatures ranging from 0 degrees C to 41 degrees C and then cultured in medium containing 5-bromodeoxyuridine at 37 degrees C. The results showed that the frequencies of SCEs induced by MMC or EMS varied according to the treatment temperature. In MMC- or EMS-exposed cultures, the SCE frequency increased continuously with increasing treatment temperature; treatment at 37 degrees C resulted in a 3-4 times greater induction of SCEs than did that at room temperature (25 degrees C). On the other hand, SCE frequencies in cells exposed to 4NQO remained within normal deviation, showing no temperature-dependent changes. Baseline SCE frequencies remained almost constant within the temperature range tested. These data indicate that treatment temperature is a very critical factor in determining the sensitivity of cells to the chemical induction of SCEs.     

Heat and cold shock protein synthesis in arctic and temperate strains of rhizobia.

We compared heat shock proteins (HSPs) and cold shock proteins (CSPs) produced by different species of Rhizobium having different growth temperature ranges. Several HSPs and CSPs were induced when cells of three arctic (psychrotrophic) and three temperate (mesophilic) strains of rhizobia were shifted from their optimal growth temperatures (arctic, 25 degrees C; temperate, 30 degrees C) to shock temperatures outside their growth temperature ranges. At heat shock temperatures, three major HSPs of high molecular weight (106,900, 83,100, and 59,500) were present in all strains for all shock treatments (29, 32, 36.4, 38.4, 40.7, 41.4, and 46.4 degrees C), with the exception of temperate strains exposed to 46.4 degrees C, in which no protein synthesis was detected. Cell survival of arctic and temperate strains decreased markedly with the increase of shock temperature and was only 1% at 46.4 degrees C. Under cold shock conditions, five proteins (52.0, 38.0, 23.4, 22.7, and 11.1 kDa) were always present for all treatments (-2, -5, and -10 degrees C) in arctic strains. Among temperate strains, five CSPs (56.1, 37.1, 34.4, 17.3, and 11.1 kDa) were present at temperatures down to 0 degrees C. The 34.4- and the 11.1-kDa components were present in all temperate strains at -5 degrees C and in one strain at -10 degrees C. Survival of all strains decreased with cold shock temperatures but was always higher than 50%. These results show that rhizobia can synthesize proteins at temperatures not permissive for growth. In all shock treatments, no correspondence between the number of HSPs or CSPs produced and rhizobial survival was found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of the expression of the two major proteins of the 70 kilodalton mammalian heat shock family

This study compares the expression after heat shock of the two major variants of the mammalian 70 kilodalton heat shock family in three separate systems. The ability of wild type and temperature sensitive mutant (ts85) FM3A cells to elicit a heat shock response following a 45 degrees C, 12 min exposure was examined. The ts85 cells were found to be both significantly more thermosensitive than parent FM3A cells and to induce a 66kDa heat shock protein (hsp66) not visibly synthesized in the parent line by this exposure. However, a constitutive (synthesized at 37 degrees C) 68kDa heat shock protein (hsp68) is comparably induced in both cell lines after heat. A relationship between the severity of the heat exposure as seen by the cell and hsp66 expression is suggested and tested in Chinese hamster ovary cells. In CHO cells a brief 45 degrees C heat shock induces the constitutive hsp68 (but not hsp66), while longer and more severe exposures are required for the expression of hsp66. The induction of these two proteins is also examined in situ in mouse skeletal muscle. In this case both hsp66 and hsp68 are induced following comparatively mild heat treatments, and the 'threshold' for hsp66 induction observed in cultured cells either does not occur or is greatly reduced. However, once again, hsp68 is naturally synthesized at 37 degrees C while hsp66 appears to be de novo synthesized after heat shock.     

Effect of moderate electric field frequency on growth kinetics and metabolic activity of Lactobacillus acidophilus

Moderate electric fields (MEF) have been previously shown to alter the metabolic activity of microbial cells; thus, the effect of frequency and electric field would be of considerable interest. We investigated herein the effects of MEF frequency on microbial growth kinetics and bacteriocin (Lacidin A) production of Lactobacillus acidophilus OSU 133 during fermentation. The following fermentation treatments were compared: conventional (for 40 h), MEF (1 V cm(-1), for 40 h), combination of MEF (1 V cm(-1), for the first 5 h) and conventional (for 35 h) at various frequency levels (45, 60, and 90 Hz) all at 30 degrees C, and control (conventional) fermentation at 37 degrees C. MEF treatments with purely sinusoidal waveforms at all frequencies at 30 degrees C produced a shorter lag phase than conventional fermentation. However, no lag phase reduction was found for a 60 Hz waveform that contained high-frequency harmonics. There was, however, a significant increase in the bacteriocin production under early MEF treatment at 60 Hz with high-frequency harmonics. On the basis of these observations, the fermentation process is accelerated by applying pure sinusoidal MEF at the early stage of growth while a significant increase in the bacteriocin production occurs when sinusoidal field at 60 Hz with harmonics is applied at the early stage of the growth.