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PubMed2003

Down-regulating alpha-galactosidase enhances freezing tolerance in transgenic petunia.

Alpha-galactosidase (alpha-Gal; EC 3.2.1.22) is involved in many aspects of plant metabolism, including hydrolysis of the alpha-1,6 linkage of raffinose oligosaccharides during deacclimation. To examine the relationship between endogenous sugars and freezing stress, the expression of alpha-Gal was modified in transgenic petunia (Petunia x hybrida cv Mitchell). The tomato (Lycopersicon esculentum) Lea-Gal gene under the control of the Figwort Mosaic Virus promoter was introduced into petunia in the sense and antisense orientations using Agrobacterium tumefaciens-mediated transformation. RNA gel blots confirmed that alpha-Gal transcripts were reduced in antisense lines compared with wild type, whereas sense plants had increased accumulation of alpha-Gal mRNAs. alpha-Gal activity followed a similar trend, with reduced activity in antisense lines and increased activity in all sense lines evaluated. Raffinose content of nonacclimated antisense plants increased 12- to 22-fold compared with wild type, and 22- to 53-fold after cold acclimation. Based upon electrolyte leakage tests, freezing tolerance of the antisense lines increased from -4 degrees C for cold-acclimated wild-type plants to -8 degrees C for the most tolerant antisense line. Down-regulating alpha-Gal in petunia results in an increase in freezing tolerance at the whole-plant level in nonacclimated and cold-acclimated plants, whereas overexpression of the alpha-Gal gene caused a decrease in endogenous raffinose and impaired freezing tolerance. These results suggest that engineering raffinose metabolism by transformation with alpha-Gal provides an additional method for improving the freezing tolerance of plants.

Acclimatization↗
PubMed1999

[Extract of the Echinacea purpurea herb: an allopathic phytoimmunostimulant].

In Northamerican folk medicine Echinacea purpurea L. Moench (purple coneflower) was used as a medicinal plant. Nowadays various formulations containing stabilized or dried pressed juice from Echinacea purpurea as an active ingredient are often administered to treat common colds. These preparations are very well tolerated and safe. Allergic reactions, mainly reversible skin reactions, may occur especially in persons showing hypersensibility after contact with plants from the Compositae family. Pharmacological data let assume purple coneflower pressed juice preparations stimulate the innate immune system and increase the resistance to common colds. In this context the stimulation of the oxidative burst as well as the modulation on monokine secretion by the pressed juice of purple coneflower are reviewed. Also relevant clinical studies are presented concerning the treatment of infections respectively of common cold.

Adjuvants, Immunologic↗
PubMed2001

Perceptions of pain in women with headache: a laboratory investigation of the influence of pain-related anxiety and fear.

The present study compared the responses of women with headache (chronic tension-type, n = 27; migraine, n = 27) and controls (n = 27) to an acute pain laboratory task, the cold pressor test. Participants' pain perception (i.e., threshold and tolerance) and their fear/anxiety associated with pain were assessed during days 1, 2, or 3 of menses. Analyses pertaining to participants' responses to the cold pressor test (ie, pain threshold and tolerance) failed to show statistically significant group differences, even when covarying pain-related anxiety/fear. Analyses did, however, reveal significant group differences between migraineurs and controls in cognitive anxiety. Correlational analyses also revealed that cognitive anxiety, somatic anxiety, fear, and escape/avoidance were all significantly correlated with pain tolerance in the group with chronic tension-type headache, but not in the other two groups. Subsequent multiple regressions, however, showed that the relationship between anxiety and pain tolerance was primarily a function of somatic anxiety. These results suggest that headache frequency plays a role in mediating the relationship between fear of pain and pain tolerance and that the models by Lethem and colleagues and McCracken may be relevant for understanding tension headache sufferers' responses to head pain.

Adult↗
PubMed1989

Epidural morphine delays gastric emptying and small intestinal transit in volunteers.

The influence of a painful stimulus and lumbar epidural morphine on gastric emptying, the orocecal transit time and small intestinal transit were studied in nine healthy volunteers. Acetaminophen absorption was used as a measure of the rate of gastric emptying. Orocecal transit time was determined by measuring the end-expiratory hydrogen concentration. Small intestinal transit was calculated from measurements of the orocecal transit time and gastric emptying. Cold pain stress with intermittent immersion of the feet in ice-cold water was used as a painful stimulus. Each volunteer was investigated on 3 different days: once after receiving 4 mg of epidural morphine and during cold pain; once during cold pain; and once under control conditions without pain and epidural morphine. Immersion of the feet in ice-cold water was always very painful, but was more tolerable during epidural morphine analgesia. The increase in blood pressure which accompanied the cold pain was the same whether this pain was induced without or during epidural morphine analgesia. Gastric emptying, orocecal transit time and small intestinal transit were delayed during epidural morphine analgesia compared with the findings under the control and plain cold pain conditions. Cold pain stress alone did not influence gastric emptying, orocecal transit time or intestinal transit. To conclude, epidural morphine in itself delayed gastric emptying, orocecal transit and transit through the small intestine in healthy volunteers.

Adult↗
PubMed1990

The role of cold ischemia in a provincial organ-sharing program in the cyclosporine era.

Prolonged cold ischemia has been associated with impaired early cadaver renal allograft function. The role of CsA in potentiating these effects is not well understood, but CsA has been implicated in promoting delayed graft function and potentiating renal ischemic injury. In order to establish whether CsA is safely tolerated by kidneys subjected to protracted cold ischemia, we examined patient and graft outcome in a series of 1081 patients receiving cadaver-kidney transplants over an 8-year period (1981-1988). All patients received a standard immunosuppressive regimen that included CsA. Overall actuarial 1-year patient and graft survival rates were 96% and 80%, respectively. Renal preservation was achieved either by pulsatile perfusion (n = 261, 24%) or simple cold storage (n = 820, 76%). Results were analyzed according to total cold ischemic time as follows: 0-23 hr (n = 512; range, 0-23.9 hr); 24-35 hr (n = 380; range, 24.0-35.9 hr); 36-47 hr (n = 161; range, 36.0-47.7 hr); greater than or equal to 48 hr (n = 28; range, 48.0-70.6 hr). These groups did not differ significantly in recipient age, sex, incidence of diabetes, number of pretransplant blood transfusions, level of presensitization, or HLA match. There were no differences in overall actuarial 1-year patient or graft survival rates, incidence of rejection, or renal function at 1 year. There was a higher incidence of impaired early graft function for kidneys preserved greater than or equal to 48 hr, but eventual graft outcome, including serum creatinine at 1 year, was unchanged. Delayed introduction of CsA resulted in improved 1-year graft survival (84.4% vs. 74.7%, P less than 0.05) compared to CsA treatment begun at the time of transplantation ("initial CsA"). This improvement was present regardless of total cold ischemia time. The incidence of permanent graft nonfunction, which has been previously reported to increase with CsA therapy, was influenced by the timing of CsA therapy (initial: 12%; delayed: 3%, P less than 0.05) but was not affected by duration of cold ischemia. Thus, safe preservation of cadaver kidneys for up to 70 h can be achieved by standard techniques even when CsA is incorporated into the immunosuppressive regimen. The most important determinants of graft survival in these patients are the timing of CsA therapy and the presence of early graft function, not the duration of renal preservation.

Blood Group Incompatibility↗
PubMed1993

The relationship between children's coping styles and psychological interventions for cold pressor pain.

This study examined the hypothesis that matching pain management interventions to children's preferred coping methods would increase pain tolerance and decrease self-reported pain during the cold pressor pain paradigm. Children aged 8-10 years were classified as 'attenders' (focusing on the stimulus) or 'distractors' (focusing away from the stimulus) based upon their spontaneous coping responses during a baseline exposure to the cold pressor. Children were then randomly assigned to 1 of 3 intervention conditions (sensory focusing, imagery, or no intervention) and completed the cold pressor procedure again 2 weeks later. A significant interaction was found between coping style and intervention. Children who were classified as distractors demonstrated greater tolerance when taught to use imagery techniques (a 'matched' intervention). Although pain ratings tended to be lower for distractors using imagery, the significant interaction resulted from an increase in ratings for the distractors using sensory focusing (i.e., a 'mismatched' intervention). Results suggest that, for distractors, interventions that are consistent with natural coping methods are most effective in enhancing abilities to cope with pain, while a mismatched intervention reduces coping abilities. The findings also suggest further study regarding how to provide effective pain intervention with attenders, since neither intervention enhanced coping in this group.

Adaptation, Psychological↗
PubMed2004

Decreased pain tolerance and mood in recreational users of MDMA.

RATIONALE: 3,4-Methylenedioxymethamphetamine (MDMA) is known to affect brain serotonin (5-HT) neurons in experimental animals. However, its effects on humans are more difficult to infer. Serotonin is implicated in the body's ability to modulate the effects of pain and to regulate mood. OBJECTIVE: The aim of this research is to test nociceptive responses and mood in MDMA users as an index of central 5-HT function. METHOD: Measurements of pain tolerance were obtained using the cold-pressor test for 15 polydrug users who regularly use MDMA, 3-4 days after the most recent usage, and ten matched polydrug users who do not use MDMA. A rating on mood was obtained for each participant using the Nowlis Mood Adjective checklist. RESULTS: Measurements of pain tolerance and mood were significantly lower in the MDMA group. A positive correlation between mood and pain tolerance was found in the MDMA group, whereas no correlation was found between these variables in the non-MDMA group CONCLUSION: This study found an association between pain tolerance and MDMA usage and confirmed the association between MDMA and depressed mood. The current results suggest that MDMA, at least in the short term, may cause serotonin-mediated alterations in pain sensitivity.

Adult↗
PubMed2001

Survival of clinical and poultry-derived isolates of Campylobacter jejuni at a low temperature (4 degrees C).

Campylobacter jejuni is a leading cause of bacterial gastroenteritis in humans, and contamination of poultry has been implicated in illness. The bacteria are fastidious in terms of their temperature requirements, being unable to grow below ca. 31 degrees C, but have been found to be physiologically active at lower temperatures and to tolerate exposure to low temperatures in a strain-dependent manner. In this study, 19 field isolates of C. jejuni (10 of clinical and 9 of poultry origin) were studied for their ability to tolerate prolonged exposure to low temperature (4 degrees C). Although substantial variability was found among different strains, clinical isolates tended to be significantly more likely to remain viable following cold exposure than poultry-derived strains. In contrast, the relative degree of tolerance of the bacteria to freezing at -20 degrees C and freeze-thawing was strain specific but independent of strain source (poultry versus clinical) and degree of cold (4 degrees C) tolerance.

Animals↗
PubMed1999

The Arabidopsis CBF gene family is composed of three genes encoding AP2 domain-containing proteins whose expression Is regulated by low temperature but not by abscisic acid or dehydration.

We have identified two genes from Arabidopsis that show high similarity with CBF1, a gene encoding an AP2 domain-containing transcriptional activator that binds to the low-temperature-responsive element CCGAC and induces the expression of some cold-regulated genes, increasing plant freezing tolerance. These two genes, which we have named CBF2 and CBF3, also encode proteins containing AP2 DNA-binding motifs. Furthermore, like CBF1, CBF2 and CBF3 proteins also include putative nuclear-localization signals and potential acidic activation domains. The CBF2 and CBF3 genes are linked to CBF1, constituting a cluster on the bottom arm of chromosome IV. The high level of similarity among the three CBF genes, their tandem organization, and the fact that they have the same transcriptional orientation all suggest a common origin. CBF1, CBF2, and CBF3 show identical expression patterns, being induced very rapidly by low-temperature treatment. However, in contrast to most of the cold-induced plant genes characterized, they are not responsive to abscisic acid or dehydration. Taken together, all of these data suggest that CBF2 and CBF3 may function as transcriptional activators, controlling the level of low-temperature gene expression and promoting freezing tolerance through an abscisic acid-independent pathway.

Abscisic Acid↗
PubMed1994

Evaluation of cold-adapted, reassortant influenza B virus vaccines in elderly and chronically ill adults.

The safety and immunogenicity of two recent cold-adapted reassortant influenza B viruses were evaluated in persons at high risk for influenza-related morbidity and mortality. Ambulatory adults > 65 years old or with chronic high-risk conditions were randomly assigned to receive parenteral trivalent inactivated influenza vaccine containing either influenza B/Ann Arbor/86 or B/Yamagata/88 hemagglutinin antigens, cold-adapted reassortant influenza B/Ann Arbor/1/86 or B/Yamagata/16/88 viruses (10(7.2) TCID50), or placebo in double-blind fashion. Cold-adapted vaccine viruses were well tolerated, with similar rates of respiratory symptoms in all groups. There were no changes in spirometry or oxygen saturation following vaccination. Immune responses to both types of vaccine were modest, with serum antibody responses occurring significantly more frequently and with higher magnitude in those receiving inactivated than in those receiving cold-adapted vaccine. Cold-adapted, reassortant influenza B vaccines are safe in the elderly and those with chronic illness but are not optimally immunogenic in this group.

Aged↗
PubMed1995

Cold Acclimation of Arabidopsis thaliana (Effect on Plasma Membrane Lipid Composition and Freeze-Induced Lesions).

Maximum freezing tolerance of Arabidopsis thaliana L. Heyn (Columbia) was attained after 1 week of cold acclimation at 2[deg]C. During this time, there were significant changes in both the lipid composition of the plasma membrane and the freeze-induced lesions that were associated with injury. The proportion of phospholipids increased from 46.8 to 57.1 mol% of the total lipids with little change in the proportions of the phospholipid classes. Although the proportion of di-unsaturated species of phosphatidylcholine and phosphatidylethanolamine increased, mono-unsaturated species were still the preponderant species. The proportion of cerebrosides decreased from 7.3 to 4.3 mol% with only small changes in the proportions of the various molecular species. The proportion of free sterols decreased from 37.7 to 31.2 mol%, but there were only small changes in the proportions of sterylglucosides and acylated sterylglucosides. Freezing tolerance of protoplasts isolated from either nonacclimated or cold-acclimated leaves was similar to that of leaves from which the protoplasts were isolated (-3.5[deg]C for nonacclimated leaves; -10[deg]C for cold-acclimated leaves). In protoplasts isolated from nonacclimated leaves, the incidence of expansion-induced lysis was [less than or equal to]10% at any subzero temperature. Instead, freezing injury was associated with formation of the hexagonal II phase in the plasma membrane and subtending lamellae. In protoplasts isolated from cold-acclimated leaves, neither expansion-induced lysis nor freeze-induced formation of the hexagonal II phase occurred. Instead, injury was associated with the "fracture-jump lesion," which is manifested as localized deviations of the plasma membrane fracture plane to subtending lamellae. The relationship between the freeze-induced lesions and alterations in the lipid composition of the plasma membrane during cold acclimation is discussed.

Journal Article↗
PubMed2005

[Efficacy of Derinox assessed with one PNIF (Peak Nasal Inspiratory Flow) in patients suffering from common cold].

OBJECTIVES: The aim of this study was to compare the efficacy and tolerance of Dérinox (D) to Rhinofluimucil (R) and placebo (P) in the treatment of common cold, using an objective measure of nasal obstruction, the Peak Nasal Inspiratory Flow (PNIF--Clement Clarke International, Harlow, Angleterre). PATIENTS AND METHODS: This randomized, double-blind, double-dummy, parallel group study enrolled 354 patients (34 P, 165 D et 155 R) included by 85 general practitioners. The treatment duration was 5 days at usual recommended dosage regimens. PNIF measures were done before drug administration (T0) as well as 15 min and 3 h after each intake. Moreover, nasal obstruction, rhinorrhea and global discomfort were subjectively assessed. RESULTS: The efficacy of D was superior to that of P and R when comparing PNIF from T0 to T3 h after the first intake. At T15 min, rhinorrhea was significantly improved with both active treatments and global discomfort was significantly improved with D only. Treatment tolerance was satisfactory and comparable between the 3 groups. CONCLUSION: Efficacy of Dérinox(R) was superior to that of P and R for the improvement of the nasal obstruction (PNIF) between T0 and T3h (main criteria) after the first intake in patients suffering from common cold.

Acetylcysteine↗
PubMed1998

Soil hydric characteristics and environmental ice nuclei influence supercooling capacity of hatchling painted turtles Chrysemys picta.

Hatchling painted turtles (Chrysemys picta) hibernate in their shallow natal nests where temperatures occasionally fall below -10 C during cold winters. Because the thermal limit of freeze tolerance in this species is approximately -4 C, hatchlings rely on supercooling to survive exposure to extreme cold. We investigated the influence of environmental ice nuclei on susceptibility to inoculative freezing in hatchling C. picta indigenous to the Sandhills of west-central Nebraska. In the absence of external ice nuclei, hatchlings cooled to -14.6 1.9 C (mean s.e.m.; N=5) before spontaneously freezing. Supercooling capacity varied markedly among turtles cooled in physical contact with sandy soil collected from nesting locales or samples of the native soil to which water-binding agents (clay or peat) had been added, despite the fact that all substrata contained the same amount of moisture (7.5 % moisture, w/w). The temperature of crystallization (Tc) of turtles exposed to frozen native soil was -1.6 0.4 C (N=5), whereas turtles exposed to frozen soil/clay and soil/peat mixtures supercooled extensively (mean Tc values approximately -13 C). Hatchlings cooled in contact with drier (less than or equal to 4 % moisture) native soil also supercooled extensively. Thus, inoculative freezing is promoted by exposure to sandy soils containing abundant moisture and little clay or organic matter. Soil collected at turtle nesting locales in mid and late winter contained variable amounts of moisture (4-15 % w/w) and organic matter (1-3 % w/w). In addition to ice, the soil at turtle nesting locales may harbor inorganic and organic ice nuclei that may also seed the freezing of hatchlings. Bulk samples of native soil, which were autoclaved to destroy any organic nuclei, nucleated aqueous solutions at approximately -7 C (Tc range -6.1 to -8.2 C). Non-autoclaved samples contained water-extractable, presumably organic, ice nuclei (Tc range -4.4 to -5.3 C). Ice nuclei of both classes varied in potency among turtle nesting locales. Interaction with ice nuclei in the winter microenvironment determines whether hatchling C. picta remain supercooled or freeze and may ultimately account for differential mortality in nests at a given locale and for variation in winter survival rates among populations.

Animals↗
PubMed1992

Treatment of the picornavirus common cold by inhibitors of viral uncoating and attachment.

The human rhinoviruses are the leading cause of the ubiquitous, mild, and self-limiting infections generally referred to as the common cold. Considerable research effort has been expended in the search for well tolerated antiviral agents capable of preventing and treating the common cold. Although no antirhinovirus drug is yet commercially available, considerable progress has been made in the discovery and development of novel, viral specific inhibitors of rhinovirus replication. This report reviews the history and current status of the research that has focused on inhibitors of the early steps in the virus life cycle: attachment to the cellular receptor and uncoating of the viral RNA. Molecules directed at these targets currently possess the greatest potential for generating a safe and efficacious treatment for the rhinovirus common cold.

Antiviral Agents↗
PubMed2002

Physiological basis of temperature-dependent biogeography: trade-offs in muscle design and performance in polar ectotherms.

Polar, especially Antarctic, oceans host ectothermic fish and invertebrates characterized by low-to-moderate levels of motor activity; maximum performance is reduced compared with that in warmer habitats. The present review attempts to identify the trade-offs involved in adaptation to cold in the light of progress in the physiology of thermal tolerance. Recent evidence suggests that oxygen limitations and a decrease in aerobic scope are the first indications of tolerance limits at both low and high temperature extremes. The cold-induced reduction in aerobic capacity is compensated for at the cellular level by elevated mitochondrial densities, accompanied by molecular and membrane adjustments for the maintenance of muscle function. Particularly in the muscle of pelagic Antarctic fish, among notothenioids, the mitochondrial volume densities are among the highest known for vertebrates and are associated with cold compensation of aerobic metabolic pathways, a reduction in anaerobic scope, rapid recovery from exhaustive exercise and enhanced lipid stores as well as a preference for lipid catabolism characterized by high energy efficiency at high levels of ambient oxygen supply. Significant anaerobic capacity is still found at the very low end of the activity spectrum, e.g. among benthic eelpout (Zoarcideae). In contrast to the cold-adapted eurytherms of the Arctic, polar (especially Antarctic) stenotherms minimize standard metabolic rate and, as a precondition, the aerobic capacity per milligram of mitochondrial protein, thereby minimizing oxygen demand. Cost reductions are supported by the downregulation of the cost and flexibility of acid-base regulation. At maintained factorial scopes, the reduction in standard metabolic rate will cause net aerobic scope to be lower than in temperate species. Loss of contractile myofilaments and, thereby, force results from space constraints due to excessive mitochondrial proliferation. On a continuum between low and moderately high levels of muscular activity, polar fish have developed characteristics of aerobic metabolism equivalent to those of high-performance swimmers in warmer waters. However, they only reach low performance levels despite taking aerobic design to an extreme.

Acclimatization↗
PubMed2006

Sex, gender, and age: contributions to laboratory pain responding in children and adolescents.

UNLABELLED: A cross-sectional design across late childhood and adolescence examined the influence of sex, gender socialization, and age on responses to controlled laboratory pain tasks. Healthy children and adolescents (n = 240, 50% female, age 8 to 18 years) completed the Child Sex Role Inventory, a self-report measure of identification with stereotypically masculine and feminine personality traits, as an index of gender socialization and participated in pressure, cold pressor, and heat pain tasks. Pain tolerance, pain intensity, and bothersomeness of each pain task were assessed. Masculinity correlated with lower heat pain ratings in boys but not girls. Logistic regression indicated cold pain intensity ratings were predicted by sex, gender score, and the age-by-gender score interaction. Heat pain intensity was predicted by age, gender score, age-by-gender score interaction, and sex-by-gender score. PERSPECTIVE: The current findings support closer examination of the influence of gender socialization on young people's pain responses and highlight the importance of a multifactorial, developmental approach to studying the impact of gender socialization on the emergence of sex differences in pain responses after puberty.

Adolescent↗
PubMed2003

Use of serial analysis of gene expression technology to reveal changes in gene expression in Arabidopsis pollen undergoing cold stress.

We have characterized the global gene expression patterns of Arabidopsis pollen using Serial Analysis of Gene Expression (SAGE). A total of 21,237 SAGE tags were sequenced and 4,211 unique tags were identified. Interestingly, the number of unique tags in pollen was low compared with the SAGE library of the leaf constructed on a similar scale. The transcript profiles of pollen reflect accurately the characteristics of pollen as a reproductive organ. Functional classification of the expressed genes reveals that those involved in cellular biogenesis such as polygalacturonase, pectate lyase, and pectin methylesterase make up more than 40% of the total transcripts. However, genes involved in energy and protein synthesis, which are prevalent in leaves, were expressed at a relatively low level. The expression level of the great majority of transcripts was unaffected by cold treatment at 0 degrees C for 72 h, whereas pollen tube growth and seed production were substantially reduced. Interestingly, many genes thought to be responsible for cold acclimation such as COR, lipid transfer protein, and beta-amylase, that are highly induced in Arabidopsis leaves, were only expressed at their normal level or weakly induced in the pollen. The expression patterns of the cold-responsive transcripts identified by SAGE were confirmed by microarray analysis. Our results strongly suggest that poor accumulation of proteins that play a role in stress tolerance may be why Arabidopsis pollen is cold sensitive.

Arabidopsis↗