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PubMed1988

Modeling of therapeutic dialysis of cerebrospinal fluid by epidural cooling in spinal cord injuries.

Paraplegias of traumatic origin may be classified as primary or secondary. Secondary traumatic paraplegia (STP) is believed to result from an autodestructive process. Different authors have published results supporting or contradicting the therapeutic effects of durotomy alone or associated with exposed spinal cord and perfusion with a saline solution at normal or cold temperatures. It appears that although decompression and open dialysis might be beneficial, the surgical trauma over the injured region is detrimental. A method of local epidural spinal cord cooling has been developed and successfully used to treat STP. With this method, no surgical injury or damage is imposed on the dura, cerebrospinal fluid (CSF), or spinal cord. Furthermore, several of the beneficial effects attributed to hypothermia in the traumatized area are evident, including reduction of metabolic demands, edema, swelling, vasospasm, and blood pressure. Aware of the benefits that dialysis may have in STP, as well as of the encouraging results obtainable with local epidural spinal cord cooling, we hypothesized that this method of hypothermia may in some way trigger CSF dialysis. Based on this hypothesis, a model was developed approximating the behavior of the CSF in the situation where a cold source is applied to the dura. Using dimensionless analysis techniques, we predict that CSF under the cooled region of the dura undergoes convective motion, even in adverse situations where the spinal cord has swollen. Under steady-state conditions, the moving fluid forms several Bénard cells directly under the cold source. The size of these Bénard cells was estimated. The range of probe temperatures at which convective flow is generated was considered, as well as the relative benefits of hypothermia versus flow. Results of more rigorous analysis are discussed.

Cerebrospinal Fluid↗
PubMed2005

Long oligonucleotide microarrays in wheat: evaluation of hybridization signal amplification and an oligonucleotide-design computer script.

A computer script was written in the Perl language to design equal-length long oligonucleotides from DNA sequences. The script allows the user to specify G + C content, melting temperature, self-complementarity, the maximum number of contiguous duplicate bases, whether to start with the first start codon and whether to report reverse complements. Microarrays were fabricated with 95 oligonucleotides (60 mers) representing 41 genes. The microarray was interrogated with cDNA from roots and shoots of two near-isogenic lines and a commercial cultivar of Triticum aestivum L. (hexaploid wheat) challenged with cold temperature, hot temperature, or the biological control bacterium Pseudomonas fluorescens. Self-complementarity of the oligonucleotides was negatively correlated with signal intensity in 23 of 54 arrays (39%; P <0.01). Tyramide signal amplification was essential for signal generation and detection. Genes involved in signal transduction pathways responded similarly following exposure to cold, heat and P. fluorescens, suggesting intersection of the pathways involved in response to these disparate stress factors. Microarray results were corroborated by quantitative real-time PCR in 75% of samples assayed. We conclude that long oligonucleotide microarrays for interrogation with cDNA from hexaploid wheat should be constructed from oligonucleotides having minimal self complementarity that also meet user-specified requirements of length, G + C content and melting temperature; multiple oligonucleotides should be used to represent each gene; and Tyramide signal amplification is useful in wheat oligonucleotide microarray studies.

Base Sequence↗
PubMedDate not supplied

Benzodiazepine-resistant "brown fat" pattern in positron emission tomography: two case reports of resolution with temperature control.

PURPOSE: Supraclavicular uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) on positron emission tomography (PET) scan is attributed to lymph node, muscle, or brown fat activity. Differentiation between physiological or pathological etiologies is necessary. Benzodiazepine premedication to reduce physiological uptake has been attempted with variable success. A relationship between brown-fat FDG uptake and cold temperature has also been established. To our knowledge, no case reports or studies have been published to demonstrate whether controlling the temperature can alter the physiological uptake in these regions. PROCEDURES: Two teenage female patients with these patterns on PET scans performed with oral benzodiazepine administration underwent repeat imaging with temperature-controlled environment settings. RESULTS: Resolution of supraclavicular FDG uptake with temperature control in two patients in whom benzodiazepine had no prior effect. CONCLUSION: Although the exact mechanism remains unknown, we propose that the control of temperature reduces the metabolism of glucose by brown fat. Further studies are warranted to confirm the above observations, and, if confirmed, to determine the most efficient and effective use of temperature control to minimize supraclavicular and axillary FDG uptake.

Adipose Tissue, Brown↗
PubMed2005

Temperature differentially affects adenosine triphosphatase activity in Hsc70 orthologs from Antarctic and New Zealand notothenioid fishes.

To test the temperature sensitivity of molecular chaperones in poikilothermic animals, we purified the molecular chaperone Hsc70 from 2 closely related notothenioid fishes--the Antarctic species Trematomus bernacchii and the temperate New Zealand species Notothenia angustata--and characterized the effect of temperature on Hsc70 adenosine triphosphatase (ATPase) activity. Hsc70 ATPase activity was measured using [alpha-32P]-adenosine triphosphate (ATP)-based in vitro assays followed by separation of adenylates by thin-layer chromatography. For both species, a significant increase in Hsc70 ATPase activity was observed across a range of temperatures that was ecologically relevant for each respective species. Hsc70 from T bernacchii hydrolyzed 2-fold more ATP than did N angustata Hsc70 at 0 degrees C, suggesting that the Antarctic molecular chaperone may be adapted to function more efficiently at extreme cold temperatures. In addition, Q10 measurements indicate differential temperature sensitivity of the ATPase activity of Hsc70 from these differentially adapted fish that correlates with the temperature niche inhabited by each species. Hsc70 from T bernacchii was relatively temperature insensitive, as indicated by Q10 values calculated near 1.0 across each temperature range measured. In the case of Hsc70 purified from N angustata, Q10 values indicated thermal sensitivity across the temperature range of 0 degrees C to 10 degrees C, with a Q10 of 2.714. However, Hsc70 from both T bernacchii and N angustata exhibited unusually high thermal stabilities with ATPase activity at temperatures that far exceeded temperatures encountered by these fish in nature. Overall, as evidenced by in vitro ATP hydrolysis, Hsc70 from T bernacchii and N angustata displayed biochemical characteristics that were supportive of molecular chaperone function at ecologically relevant temperatures.

Adenosine Triphosphatases↗
PubMed1978

The effects of lumicolchicine, colchicine and vinblastine on pigment migration in fish chromatophores.

The effects of lumicolchicine, colchicine, vinblastine and cold temperature on the pigment migration in melanophores and xanthophores of Fundulus heteroclitus and Oryzias latipes were examined by light and electron microscopy. Xanthophores of both species which contain numerous microfilaments and a poorly developed microtubule system were extremely sensitive to the alkaloids. Lumicolchicine and colchicine induced irreversible dispersion while vinblastine caused permanent aggregation of the pigments. Treatment in lumicolchicine or colchicine at 5 mM for 60 minutes did not disrupt microtubules of melanophores to an appreciable degree, however, melanosome aggregation was partially inhibited by these drug in Oryzias. When melanophores were kept in the cold in the presence of colchicine at 1 mM, almost all microtubules were disrupted and their repolymerization at room temperature was nearly completely inhibited by colchicine. These melanophores lacking in microtubules responded to epinephrine with slow aggregation. Vinblastine at 0.1 mM induced partial aggregation of melanosomes and disruption of microtubules but most melanophores were still able to respond with pigment migration. Vinblastine at 1 mM made all melanophores punctate and immobile. Large vinblastine-induced crystals were frequently seen in the dendritic processes. The results of the present investigation suggest that cytoplasmic microtubules in fish melanophores facilitate melanosome migration only in directional orientation and appear not be responsible for the motive force.

Animals↗
PubMed1998

Meteorological conditions and self-report of low back pain.

STUDY DESIGN: Six months of daily low back pain ratings for 94 individuals were tested for the influence of prevailing weather conditions during the spring, summer, and fall seasons. Intergroup differences were tested for study participants who reported weather sensitivity and for those who did not. OBJECTIVES: To investigate the relation between pain ratings and prevailing weather conditions in a population with chronic or recurrent low back pain. SUMMARY OF BACKGROUND DATA: Weather conditions have been reported to influence pain perception in some disease states, including low back pain. Investigations of this relation in chronic or recurrent low back pain have involved varied methodologies, and conflicting results have been reported. METHODS: The effects of eight weather variables reported to influence musculoskeletal pain were tested on daily pain ratings. A post hoc weather sensitivity questionnaire was used to disperse 73 individuals into groups based on perceived weather sensitivity, and group differences were tested. RESULTS: Significant effects on pain scores were found, most notably for temperature and vapor pressure. The magnitude of the effects were small compared with autocorrelation of an individual's own pain scores. Significant differences were found between the group of individuals who were insensitive to weather conditions and that of individuals with perceived sensitivity to cold temperatures. No significant intergroup differences were found for damp, rainy conditions or changes in barometric pressure. CONCLUSIONS: Weather conditions may influence subjective reporting of low back pain significantly. Although the effects are small in magnitude, they should be considered in clinical treatment of the patient with chronic, nonspecific low back pain. Pain scores may demonstrate greater interaction with certain weather conditions in individuals perceiving sensitivity to those conditions.

Adult↗
PubMed2001

Temperature has a major influence on cardiac natriuretic peptide in salmon.

1. Natriuretic peptides have a major role in fluid and electrolyte homeostasis in vertebrates. Ambient temperature has a major influence on physiological processes in ectothermic animals. Here we have studied the mechanisms of regulation of a natriuretic peptide, sCP (salmon cardiac peptide), in salmon (Salmo salar) acclimatised and acclimated to varying temperatures. 2. The circulating and cardiac levels of sCP were found to be markedly upregulated in warm-acclimatised and warm-acclimated salmon. The release of sCP from isolated in vitro perfused salmon ventricle was, however, not increased by acclimation to higher temperatures, either in basal conditions or when stimulated by mechanical load. 3. Concomitant measurements of circulating sCP and the biologically inert N-terminal fragment of pro-sCP showed that the upregulation of circulating sCP at warm ambient temperature results from decreased elimination rather than increased secretion of sCP. This is the first direct evidence that changes in the elimination of a natriuretic peptide are used for important physiological regulation. 4. We found a paradoxical increase in cardiac sCP mRNA levels at cold temperatures which coincided with hypertrophy of the heart. sCP gene expression may therefore serve as a marker of cardiac hypertrophy in salmon, in analogy to that of atrial and brain natriuretic peptide (ANP and BNP, respectively) in mammals. 5. These results show that temperature has a major influence on the regulation of natriuretic peptide production and clearance in salmon. Salmon CP offers a novel model for the study of the endocrine function of the heart.

Acclimatization↗
PubMed1990

An intragenic revertant of a poliovirus 2C mutant has an uncoating defect.

A revertant was isolated from a temperature-sensitive poliovirus 2C mutant, 2C-31, which is defective in viral RNA synthesis. This revertant, called 2C-31R1, grew well at 39 degrees C and was not defective in RNA synthesis. However, in contrast to its parental mutant, 2C-31R1 was cold sensitive and could hardly grow at all at 32 degrees C. Analysis of a single-cycle growth revealed that 2C-31R1 was defective in virion uncoating at 32 degrees C, and a substantial amount (more than 30%) of input viruses could be recovered as infectious particles from an infected cell lysate up to 6 h postinfection. The uncoating defect and the inability to grow at cold temperatures could be overcome by a brief incubation at the permissive temperature (39 degrees C) before the infection was continued at 32 degrees C. cDNA cloning and mix-and-match recombination experiments indicated that the defect in uncoating was the result of two secondary point mutations, seven nucleotides apart, in the 2C-coding sequence downstream of the inserted linker which is the original mutation in the parental 2C-31 genome. Another revertant, 2C-31R3, isolated from the same 2C-31 stock, was not defective in uncoating and appeared to be a secondary revertant that contained an intragenic suppressor for the uncoating defect. The uncoating defect of 2C-31R1 could be complemented by type 2 poliovirus. These results suggested that protein 2C, in addition to its role in viral RNA synthesis, has a function in determining virion structure.

Base Sequence↗
PubMed2005

Development of a novel microbial sensor with baker's yeast cells for monitoring temperature control during cold food chain.

A novel microbial sensor containing a commercial baker's yeast with a high freeze tolerance was developed for visibly detecting inappropriate temperature control of food. When the yeast cells fermented glucose, the resulting gas production triggered the microbial sensor. The biosensor was a simple, small bag containing a solution of yeast cells, yeast extract, glucose, and glycerol sealed up with multilayer transparent film with barriers against oxygen and humidity. Fine adjustment of gas productivity in the biosensor at low temperatures was achieved by changing either or both concentrations of glucose and yeast cells. Moreover, the amount of time that food was exposed to inappropriate temperatures could be deduced by the amount of gas produced in the biosensor. The biosensor was stable without any functional loss for up to 1 week in frozen storage. The biosensor could offer a useful tool for securing food safety by maintaining low-temperature control in every stage from farm to fork, including during transportation, in the store, and at home.

Biosensing Techniques↗
PubMed1998

Effect of temperature on a voltage-sensitive electrical synapse in crayfish.

The effects of temperature on transmission through the voltage-sensitive giant motor synapse (GMS) were investigated in crayfish both experimentally and in computer simulation. The GMS is part of the fast reflex escape pathway of the crayfish and mediates activation from the lateral giant (LG) command neurone to the motor giant (MoG) flexor motoneurone. The investigation was motivated by an apparent mismatch between the temperature sensitivity of the activation time constant of the GMS, with a Q10 reported to be close to 11, and that of the active membrane properties of LG and MoG, which are thought to have Q10 values close to 3. Our initial hypothesis was that at cold temperatures the very slow activation of the GMS conductance would reduce the effectiveness of transmission compared with higher temperatures. However, the reverse was found to be the case. Effective transmission through the GMS was reliable at low temperatures, but failed at an upper temperature limit that varied between 12 degrees C and 25 degrees C in isolated nerve cord preparations. The upper limit was extended above 30 degrees C in semi-intact preparations where the GMS was less disturbed by dissection. The results of experiments and simulations both indicate that transmission becomes more reliable at low temperatures because the longer-duration presynaptic spikes are able to drive more current through the GMS into the MoG, which is more excitable at low temperatures. Conversely, effective transmission is difficult at high temperatures because the transfer of charge through the GMS is reduced and because the input resistance of MoG is lowered as its current threshold is increased. The effect of the high Q10 of the GMS activation is to help preserve effective transmission through the synapse at high temperatures and so extend the temperature range for effective operation of the escape circuit.

Action Potentials↗
PubMed1994

[Chronic cold agglutinin disease accompanied with an increase of CD20+/CD5+ cells; a case report].

A 61-year-old male complained of acrocyanosis and dark urine when exposing to cold temperatures. This had continued for several years. His physical examinations showed neither lymphadenopathy nor hepatosplenomegaly. Laboratory findings were as follows; RBC 305 x 10(4)/microliters, Hb 10.3 g/dl, reticulocytes 4.32%, platelets 27.3 x 10(4)/microliters, WBC 7,400/microliters with 50% lymphocytes, and a high cold agglutinin titer (2,048-fold) with anti-I specificity. Bone marrow smear preparations showed erythroid hyperplasia and increase of lymphocytes (52%). Immunophenotypic analysis showed an increase of CD20+/B-lymphocytes in peripheral blood (32.6%) and in bone marrow, and 94% of these cells co-expressed CD5. Most B-lymphocytes expressed surface IgM-lambda, suggesting a monoclonal proliferation of B-lymphocytes. At this point we diagnosed cold agglutinin disease (CAD) because there was no evidence of lymphoma, and the absolute number of peripheral blood lymphocytes was lower than the criteria of chronic lymphocytic leukemia (CLL) proposed by the International Workshop (1989). However, there still remains the possibility of the transitional form between "idiopathic" CAD and B-CLL or lymphoma.

Anemia, Hemolytic, Autoimmune↗
PubMed1992

[A successful case of thoracic aortic aneurysm with mixed cryoglobulinemia].

Cold-reactive proteins, such as cold agglutinins, cryoglobulins, and cryofibrinogens, are reversibly precipitates, or gel, upon exposure to cold temperatures. Cryoglobulins are usually not of importance, but under special conditions, such as surgical hypothermia, hyperviscosity and damage in microcirculation may occur in patients with high plasma concentration of cryoglobulins. Several groups have reported their efforts to reduce further the risks of surgical hypothermia in patients with cold agglutinins, but rarely in patients with cryoglobulins. A 57-year-old woman with thoracic aneurysm, requiring replacement of the ascending aorta and the aortic arch, had mixed cryoglobulinemia (cryocrit 29%) associated with rheumatoid arthritis. Steroids therapy and preoperative plasmapheresis were performed, and cryocrit levels were decreased until 0% before operation. Systemic hypothermia (25 degrees C), hemodilution techniques during cardiopulmonary bypass, and cold crystalloid cardioplegia were successfully employed, and no clinical evidence of microcirculation damage was posed after operation.

Aorta, Thoracic↗
PubMed1984

Kinetic characterization of the lactate dehydrogenase (LDH-B4) allozymes of Fundulus heteroclitus.

In order to evaluate whether functional differences exist between allelic variants (allozymes) of the B-type lactate dehydrogenase (L-lactate:NAD+ oxidoreductase, EC 1.1.1.27) in the fish Fundulus heteroclitus, the kinetic properties were examined. Differences in product inhibition between allelic isozymes were observed. LDH-Bb4 was found to be inhibited by lower concentrations of both lactate and pyruvate than either LDH-Ba/Bb or LDH-Ba4. While the pH and temperature dependence for maximal catalysis (Vmax) in both the forward and reverse directions were indistinguishable among the allozymes, reaction velocities at low substrate concentrations (Vmax/Km) were significantly different. These differences could be explained by LDH-Bb4 having a greater substrate affinity than LDH-Ba4 at cold temperatures while the reverse was true at elevated temperatures. At a given pH, LDH-Bb4 showed a greater reaction rate at lower temperatures (e.g. 10 degrees C) than LDH-Ba4. The phenomenon was reversed at higher temperatures (e.g. greater than 35 degrees C). When reaction rates were compared at constant relative alkalinity, that is, a constant [OH-]/[H+] ratio, similar findings were obtained. The response for the heterozygous allozyme, LDH-Ba/Bb, was not the arithmetic average of the two homotetrameric allozymes. The biological significance of these allozymic differences is discussed.

Alleles↗
PubMed2002

Control of Penicillium expansum and Botrytis cinerea on apples and pears with the combination of Candida sake and Pantoea agglomerans.

The effectiveness of Candida sake (CPA-1) in combination with Pantoea agglomerans (CPA-2) for controlling Penicillium expansum and Botrytis cinerea on pears and apples was determined. The concentrations tested were 2 x 10(6) and 2 x 10(7) CFU/ml for C. sake and 2 x 10(7) and 8 x 10(7) CFU/ml for P. agglomerans. At room temperature, the two antagonists were combined in proportions of 0 to 100% in 25% increments. At the proportion of 50:50, no rot development was observed in pears, and the greatest control of blue mold in apples was observed at this proportion for all the tested concentrations. Under cold temperature on pears, the highest effectiveness of the mixture was observed when C. sake at 2 x 10(7) CFU/ml was combined with P. agglomerans at 2 x 10(7) or at 8 x 10(7) CFU/ml at the proportion 50:50. Under these conditions, no rot development of blue mold was reported, and gray mold lesion size was reduced by more than 95%. On apples, the mixture of C. sake at 2 x 10(7) CFU/ml and P. agglomerans at 8 x 10(7) CFU/ml at the proportion 50:50 reduced blue and gray mold incidence by 90%. Populations of the two antagonists had the same growth pattern at 20 degrees C when they were applied individually or in combination, but the population level was always higher when they grew alone. In contrast, at 1 degrees C, the population of both antagonists in combination formed a stable community with the same levels as individual application during the first 30 days; after that, C. sake dominated, and P. agglomerans decreased on apples and pears. At both temperatures, the maximum population level of C. sake was observed in apples, and themaximum population level of P. agglomerans was observed in pears.

Botrytis↗
PubMed2003

Behavioral thermoregulation in Hemigrapsus nudus, the amphibious purple shore crab.

The thermoregulatory behavior of Hemigrapsus nudus, the amphibious purple shore crab, was examined in both aquatic and aerial environments. Crabs warmed and cooled more rapidly in water than in air. Acclimation in water of 16 degrees C (summer temperatures) raised the critical thermal maximum temperature (CTMax); acclimation in water of 10 degrees C (winter temperatures) lowered the critical thermal minimum temperature (CTMin). The changes occurred in both water and air. However, these survival regimes did not reflect the thermal preferences of the animals. In water, the thermal preference of crabs acclimated to 16 degrees C was 14.6 degrees C, and they avoided water warmer than 25.5 degrees C. These values were significantly lower than those of the crabs acclimated to 10 degrees C; these animals demonstrated temperature preferences for water that was 17 degrees C, and they avoided water that was warmer than 26.9 degrees C. This temperature preference was also exhibited in air, where 10 degrees C acclimated crabs exited from under rocks at a temperature that was 3.2 degrees C higher than that at which the 16 degrees C acclimated animals responded. This behavioral pattern was possibly due to a decreased thermal tolerance of 16 degrees C acclimated crabs, related with the molting process. H. nudus was better able to survive prolonged exposure to cold temperatures than to warm temperatures, and there was a trend towards lower exit temperatures with the lower acclimation (10 degrees C) temperature. Using a complex series of behaviors, the crabs were able to precisely control body temperature independent of the medium, by shuttling between air and water. The time spent in either air or water was influenced more strongly by the temperature than by the medium. In the field, this species may experience ranges in temperatures of up to 20 degrees C; however, it is able to utilize thermal microhabitats underneath rocks to maintain its body temperature within fairly narrow limits.

Animals↗