Alcohol and its variable effect on human thermoregulatory response to exercise in a warm environment

The aim of this study was to observe the effect of alcohol ingestion on body temperature and local sweat rate during endogenous and exogenous heat stress. After ingesting either alcohol (1.2 g alcohol/kg of body weight) or a placebo drink, 8 subjects exercised for 60 minutes at 45% VO2max in a warm environment (35 degrees C, 45% RH). Varying patterns of response were observed in these subjects, with no consistent effect on the thermoregulatory response seen. The absence of any significant change in skin and body temperature and in sweat rate suggests that the capacity of the body to struggle against exogenous and endogenous heat is not fundamentally altered by alcohol ingestion. The difference in individual response observed in our experiment is in accord with the previous lack of clearcut effect of alcohol reported in the literature.     

Murine splenic proliferative response to human recombinant erythropoietin along hypoxia

Hypoxia is the best physiological stress to disturb the erythropoietic steady state. The present study has been undertaken in the aim to analize the splenic erythropoietic proliferative response with different doses of recombinant human erythropoietin under hypoxic conditions along 18 days using the DNA synthesis assay. Normoxic splenic progenitors failed to show significative erythroid replication at 0 days. A clearly rh Epo response was noticed from 2 to 8 days of hypoxia. Splenic proliferation returned to basal pattern from 10 days to the end of the experience. The highest proliferative activity, 25 fold increase over control (p < 0.001), was found at 6 days from 62.5 to 250 mU/ml rh Epo. These results support suggestions that hypoxia induces a transiently erythroid splenic proliferative response changing its quantitative parameters in the Epo dose-response relationship during the physiological adaptation.     

Electroconvulsive therapy increases circadian amplitude and lowers core body temperature in depressed subjects

BACKGROUND: Reduced amplitude of the circadian temperature rhythm and elevated nocturnal body temperature normalize after successful pharmacotherapy of major depression. METHODS: Core body temperature was continually monitored in three groups: a) 6 depressed patients before an electroconvulsive therapy (ECT) course and b) after an ECT course; and c) 6 healthy, sex-matched controls of similar age. RESULTS: The 24-hour profile of temperature was significantly different in patients pre-ECT than in patients post-ECT or in controls. Post-ECT subjects and controls manifested 24-hour profiles similar to one another. Circadian temperature rhythm amplitude increased after ECT. The mean asleep and mean 24-hour temperatures were significantly higher in patients pre-ECT than post-ECT and controls. CONCLUSIONS: We find that ECT restores a disrupted circadian temperature rhythm in depressed patients.     

Leukocyte functional antigen 1 lowers T cell activation thresholds and signaling through cytohesin-1 and Jun-activating binding protein 1

Leukocyte functional antigen 1 (LFA-1), with intercellular adhesion molecule ligands, mediates T cell adhesion, but the signaling pathways and functional effects imparted by LFA-1 are unclear. Here, intracellular phosphoprotein staining with 13-dimensional flow cytometry showed that LFA-1 activation induced phosphorylation of the beta(2) integrin chain and release of Jun-activating binding protein 1 (JAB-1), and mediated signaling of kinase Erk1/2 through cytohesin-1. Dominant negatives of both JAB-1 and cytohesin-1 inhibited interleukin 2 production and impaired T helper type 1 differentiation. LFA-1 stimulation lowered the threshold of T cell activation. Thus, LFA-1 signaling contributes to T cell activation and effects T cell differentiation.     

A mathematical model of the human temperature regulatory system--transient cold exposure response

The pathology, particularly the ocular pathology, is described in a 42-year-old mildly retarded man with a history of vomiting in infancy. He had an elfin-like face. He died having a pancreatic carcinoma. At autopsy, a supravalvular aortic stenosis and a hypoplastic aorta found clinically were confirmed. Stainings for calcium were positive in the aortic wall, the kidneys, the adrenals and the spleen. In the eyes, calcium was found in the corneal epithelium and endothelium, in corneal keratocytes and stroma, in conjunctival epithelium and in the sclera. Electron microscopy of the eyes revealed that calcium was deposited as hydroxyapatite intracellularly in aggregations of needle-like crystals and extracellularly as spherules morphologically different from the intracellular deposits. Although the serum values of calcium in this patient were normal during his adult life, the histopathological examination indicates an earlier period of raised serum calcium. We find it probable that he had idiopathic hypercalcaemia in infancy, thereby connecting this infantile condition with the elfin face and supravalvular aortic stenosis. In similar cases, the use of the above-mentioned technique is recommended for revealing abnormal calcium storage post-mortem and in vivo (by conjunctival biopsy) in order to substantiate the diagnosis of hypercalcaemia.     

冷作硬化非调质钢的连续冷却相变规律

钢的连续冷却相变曲线(CCT)是组织调控的基本依据,为了优化紧固件用冷作硬化非调钢热轧态的组织和力学性能,采用DIL805A相变仪测定了试验钢在0.1～50℃/s不同冷却速率下的热膨胀曲线,结合金相硬度法确定相变类型,并绘制了试验钢的CCT曲线.结果 表明,试验钢马氏体转变点(Ms)为280℃,在不同冷速范围内均有铁素...     

An additive effect of cold exposure and hypoxia on pulmonary artery pressure in sheep

When shorn sheep were exposed to cold (3 degrees C) pulmonary artery pressure (PPA) increased by 24 per cent. When they were caused to breathe an air mixture containing only 11 per cent oxygen there was a similar rise in PPA (27 per cent). During simultaneous exposure to 3 degrees C and low oxygen tension, the rise in PPA was greater than the sum of the two separate treatments (61 per cent). These results indicate the possible significance of cold exposure in the occurrence of high mountain sickness.     

Thermogenic and vocalization responses to cold in the chicken hatchling during normoxia and hypoxia.

We investigated the vocalization and the thermogenic responses to cold during hypoxia in chicken hatchlings during the first postnatal day. Calls were quantified in number and sound characteristics (amplitude and frequency); the change in oxygen (O2) consumption, measured by an open-flow methodology, represented thermogenesis. The cold challenge consisted of a decrease in ambient temperature (Ta) from ~39 to 28 °C, in steps of 2 °C, or an acute exposure to ~28 °C, either in normoxia or hypoxia (10% O2). Hypoxia lowered thermogenesis and the critical Ta, suggesting a decrease in the set point for thermoregulation. The vocalization response to cold was rapid; did not progress with the duration or intensity of the cold stimulus; was similar in very young (     

控冷工艺对冷镦钢力学性能和显微组织的影响

对冷镦钢(SWRCH22A)进行两种不同控冷工艺试验,将获得的冷却曲线与该钢的CCT曲线结合分析得到该钢2种不同控冷工艺条件下关键控冷工艺参数.分析认为调节钢的实际冷却曲线位置可调节钢的强度,调节钢在铁素体相变区内的冷却速率来调节钢的屈强比.据此对控冷工艺进行优化,使产品力学性能和组织符合技术要求和用户的要求.     

Nitric oxide dose response during moderate and severe hypoxia in swine

The vectorial nature of redox Bohr effects (redox-linked pK shifts) in cytochrome c oxidase from bovine heart incorporated in liposomes has been analyzed. The Bohr effects linked to oxido-reduction of heme a and CuB display membrane vectorial asymmetry. This provides evidence for involvement of redox Bohr effects in the proton pump of the oxidase.     

焊后冷却对冷轧马氏体钢的硬度和组织的影响

研究了980 MPa级冷轧马氏体钢辊压成形焊后冷却对焊点、热影响区和焊点临近区域硬度的影响。发现焊后冷却条件对马氏体钢的组织和硬度有较大的影响,焊后空冷焊点周围区域软化严重;焊点附近自然散热条件也对焊后硬度和组织有较大影响,传导散热好的区域和传导散热差的区域相比,焊后空冷的硬度较高;焊后水冷可以有效提高焊后硬度,减小软化区的尺寸;焊后水冷可以改善零部件因局部硬度过低引起的保险杠弯圆时的局部缩颈和开裂。     

The effects of substrate and fluid provision on thermoregulatory, cardiorespiratory and metabolic responses to prolonged exercise in a cold environment in man

We propose a method for selecting quality-of-life instruments for use in phase III trials using the convergent validity of patient responses collected in phase I and II clinical trials. Two generic and two disease-specific instruments were administered to patients with breast cancer undergoing peripheral blood progenitor cell mobilization and transplantation. They included the visual analog scale from the EuroQoL EQ5D instrument, the SF-36, the European Organization for Research and Treatment of Cancer (EORTC)-QLQ-C30, and the Functional Assessment of Cancer Therapy instrument. No single instrument was found to have superior convergent validity in all domains, but the EORTC-QLQ-C30 seemed to perform better than the SF-36.     

Differential signaling and hierarchical response thresholds induced by an immunodominant peptide of myelin basic protein and an altered peptide ligand in human T cells

Changes in peptide antigen concentration or structure can have a profound effect on T cell responsiveness by inducing selected T cell effector functions. In this study, we have compared the biological responses of an MBP83-99-specific human Th0 T cell clone (TCC) stimulated with increasing concentrations of native peptide or an altered peptide ligand (APL). Our results show that the hierarchy of response thresholds for proliferation and cytokine secretion is similar for native peptide and APL. However, because a much higher concentration of the APL is required to evoke the same degree of response, the cytokine profile is shifted towards a Th2-like response relative to the same concentration of native peptide. In addition, we observed qualitative differences in TCR signal transduction triggered by native peptide and a weak agonist APL even at concentrations that elicit similar biological responses. Thus, the relationship between TCR signaling and biological responses may be more complex than previously recognized.     

Functional activity of peripheral blood neutrophils of rats during combined effects of hypoxia, hypercapnia and cooling

Functional activity of neutrophilic leukocytes was studied in blood of rats immediately following single and repeated gradual increase in carbon dioxide and decrease in oxygen concentrations with the ambient temperature at 2 to 3 degrees C. Phagocytic activity was shown to alter as the number of phagocytic neutrophilic granulocytes, absorptivity or the phagocytic index, and the coefficient of phagocytosis completeness were elevated and levels of oxygen-dependent and oxygen-independent metabolism were reduced.     

Major differences in response to graded hypoxia between hypoglossal and neocortical neurons

Allogeneic T cells are capable of discriminating between leukemia cells and non-malignant hematopoetic cells. This has been concluded from clinical BMT data and demonstrated by in vitro experiments. We analyzed the frequency and specificity of leukemia-reactive T cells from syngeneic and allogeneic blood donors by limiting dilution assays for interleukin-2-producing (TH1) and cytotoxic (CTLp) T cells. Target cells were leukemia blasts obtained from a patient with common ALL. Control targets were generated by EBV transformation. Effector cells were generated from the peripheral blood of the patient in remission, from his syngeneic brother and from eight healthy, HLA-mismatched volunteers. The effector cells were stimulated with leukemia cells and interleukin-2. Neither the patient nor his brother were able to generate anti-leukemic CTLp or TH1. The HLA-mismatched allogeneic donors displayed anti-leukemic CTLp frequencies with a range from 0 to 68 million. TH1 cells with anti-leukemic specificity were not detectable. We conclude that there are great inter-individual differences in the GVL potential of fully allogeneic peripheral T lymphocytes. It is possible to identify T cell lines with reactivity against leukemia blasts and non-reactivity against normal hematological cells from the same individual. These cell lines are potential effector cells for immunotherapy of human leukemia.     

A mathematical expression to describe the ventilatory response to hypoxia and hypercapnia

Analytical techniques using multiple-exposure roentgenograms were employed to investigate surgical repositioning of either the femoral or the tibial attachment of the medial collateral ligament. The motion of the femoral attachment of the ligament with respect to the tibial attachment was used to compute the changes in length of the borders of the ligament for normal knees and for knees with repositioned attachments. The results support the conclusion that when advancement of the medial collateral ligament is utilized in the treatment of medial instability, optimization is accomplished by distal and anterior advancement with the knee in 30 degrees of flexion. Femoral displacement (proximal realignment) or tibial displacement at knee-flexion angles greater than 45 degrees is not recommended.     

冷却速度对 900 MPa 级冷轧马氏体钢组织性能的影响

以高氢冷却工艺连退生产线为基础,以 900 MPa 级冷轧马氏体超高强钢为研究对象,研究了连续冷却相变区转变规律和连退快速冷却工艺对钢的力学性能和显微组织的影响。结果表明,连续冷却相变区由先共析铁素体转变区、贝氏体转变区和马氏体转变区组成,随着冷却速度的增加,先共析铁素体含量逐渐下降,贝氏体和马氏体含量逐渐上升,当冷却速度大于 40 ℃/s 时,不再有先共析铁素体生成;当冷却速度大于 80 ℃/s 时,则完全进入马氏体转变区。随着连退快冷工艺中冷却速度的增加,钢的屈服强度、抗拉强度和屈强比逐渐增加,断后伸长率逐渐下降。当冷却速度为 50 ℃/s 时,钢的屈服强度、抗拉强度和断后伸长率就已经达到了 900 MPa 级冷轧马氏体超高强钢的力学性能要求。     

Bronchial obstruction and exhaled nitric oxide response during exercise in cold air

This study examines whether exhausting exercise in cold air induces bronchial obstruction and changes in exhaled [NO] and in exhaled NO output (V'NO). Thus, eight well-trained males performed two incremental exercise tests until exhaustion, followed by 5 min of recovery in temperate (22 degrees C) and cold (-10 degrees C) environments, at random. At -10 degrees C, they were dressed in warm clothes. Ventilation (V'E), oxygen consumption (V'O2), carbon dioxide production, cardiac frequency (fC), and [NO] and V'NO were measured continuously. Before and after each test, the subjects' maximal expiratory flow-volume curves and peak expiratory flow, forced expiratory volume in one second (FEV1) and forced expiratory flow at 25 (FEF25), 50 (FEF50) and 75% (FEF75) of forced vital capacity were determined. At -10 degrees C, significant decreases in FEV1 and FEF75 were observed after exercise. At rest and at the same submaximal intensity, V'O2, V'E and fC did not differ significantly. At rest and up to approximately 50% peak V'O2, [NO] and V'NO values were lower at -10 degrees C than at 22 degrees C. Thereafter, and during recovery, the V'NO response became similar at both -10 and 22 degrees C. This study confirms that considerable hyperpnoea in cold air causes a detectable airway obstruction. This airway cooling also induces an initial decrease in the exhaled NO response. Since endogenous NO-production is involved in bronchial dilation, it cannot be excluded that this lack of production may favour the appearance of airway obstruction.     

Expression and immune response to hepatitis C virus core DNA-based vaccine constructs

Primary antiphospholipid syndrome (pAPS) can be experimentally induced in mice by immunization with anti-cardiolipin (aCL) antibodies (Abs). Recently, we have pointed to the pathogenic role of antiphosphatidylserine (aPS) Abs by inducing an experimental model of pAPS in naive mice following passive transfer of human aPS to the tail vein of ICR mice. The aim of the present study was to induce experimental pAPS in mice following active immunization with aPS. Mice were immunized with IgG and IgM aPS, purified from two patients with pAPS. The sera of the mice were examined for the presence of different antiphospholipid Abs, and the beta 2 GPI dependency of aPS, using an enzyme-linked immunosorbent assay (ELISA). Inhibition ELISA studies, with silica beads coated with phospholipids, were used to detect cross-reactivity of aPS or aCL to other phospholipids. The mice were also tested for the presence of thrombocytopenia, prolonged activated partial thromboplastin time (APTT), and the percentage of fetal resorptions. The purified IgG aPS but not IgM aPS had a strong lupus anticoagulant activity. Both IgG and IgM aPS were beta 2 GPI dependent and did not bind PS in the absence of the glycoprotein. The mice immunized with IgG aPS, but not IgM aPS, developed high titers of mouse aPS. The mice generated polyspecific Abs, cross-reacting with aCL and aPS, as well as individual aPS or aCL Abs. Only the mice immunized with IgG aPS developed clinical parameters of pAPS: prolonged APTT, thrombocytopenia, and an increased fetal resorption rate. In conclusion, active immunization with IgG, but not IgM, aPS induces experimental pAPS in naive mice, thus pointing to the participation of aPS in the idiotypic network.     

Blood flow to the brown adipose tissue of conscious young rabbits during hypoxia in cold and warm conditions

Histidine-proline-rich glycoprotein (HPRG) is a protein that is synthesized by parenchimal liver cells. The protein has been implicated in a number of plasma-specific processes, including blood coagulation and fibrinolysis. We have recently reported the association of an HPRG-like protein with rabbit skeletal muscle AMP deaminase (AMPD). The results of the immunological analysis reported here demonstrate that an antibody against human plasma HPRG reacts with an AMPD preparation from human skeletal muscle. To probe the localization of the putative HPRG-like protein in human skeletal muscle, serial sections from frozen biopsy specimens were processed for immunohistochemical and histoenzymatic stains. A selective binding of the anti-HPRG antibody to Type IIB muscle fibers was detected, suggesting a preferential association of the novel protein to the AMPD isoenzyme contained in the fast-twitch glycolytic fibers.