Relationship between thermophysiological responses and psychological thermal perception during exercise wearing aerobic wear

This paper studies the relationships among human physiological and psychological thermal and moisture responses in tight-fit aerobic wear. Results showed that both physiological and psychological responses were significantly influenced by time, garment, body location and some of their interactions. Objectively measured skin humidity and moisture sensation at individual locations were highly correlated and significant at p levels of 0.01. Overall clothing comfort may be best described with thermal sensation at outer thigh, humidity at inner thigh. The correlation coefficient of predicted with experimental clothing comfort score was 0.76, and a t-test showed that there was no significant difference between the two data sets.     

Thermal sensation and thermophysiological responses to metabolic step-changes

This study investigated the effect on thermal perception and thermophysiological variables of controlled metabolic excursions of various intensities and durations. Twenty-four subjects were alternately seated on a chair or exercised by walking on a treadmill at a temperature predicted to be neutral at sedentary activity. In a second experimental series, subjects alternated between rest and exercise as well as between exercise at different intensities at two temperature levels. Measurements comprised skin and oesophageal temperatures, heart rate and subjective responses. Thermal sensation started to rise or decline immediately (within 1 min) after a change of activity, which means that even moderate activity changes of short duration affect thermal perceptions of humans. After approximately 15–20 min under constant activity, subjective thermal responses approximated the steady-state response. The sensitivity of thermal sensation to changes in core temperature was higher for activity down-steps than for up-steps. A model was proposed that estimates transient thermal sensation after metabolic step-changes. Based on predictions by the model, weighting factors were suggested to estimate a representative average metabolic rate with varying activity levels, e.g. for the prediction of thermal sensation by steady-state comfort models. The activity during the most recent 5 min should be weighted 65%, during the prior 10–5 min 25% and during the prior 20–10 min 10%.     

Effects of room temperature on physiological and subjective responses during whole-body bathing,half-body bathing and showering

The effects of bathroom thermal conditions on physiological and subjective responses were evaluated before, during, and after whole-body bath (W-bath), half-body bath (H-bath) and showering. The air temperature of the dressing room and bathroom was controlled at 10 degrees C, 17.5 degrees C, and 25 degrees C. Eight healthy males bathed for 10 min under nine conditions on separate days. The water temperature of the bathtub and shower was controlled at 40 degrees C and 41 degrees C, respectively. Rectal temperature (Tre), mean skin temperature (Tsk), blood pressure (BP), heart rate (HR), body weight loss and blood characteristics (hematocrit: Hct, hemoglobin: Hb) were evaluated. Also, thermal sensation (TS), thermal comfort (TC) and thermal acceptability (TA) were recorded. BP decreased rapidly during W-bath and H-bath compared to showering. HR during W-bath was significantly higher than for H-bath and showering (p < 0.01). The double products due to W-bath during bathing were also greater than for H-bath and showering (p < 0.05). There were no distinct differences in Hct and Hb among the nine conditions. However, significant differences in body weight loss were observed among the bathing methods: W-bath > H-bath > showering (p < 0.001). W-bath showed the largest increase in Tre and Tsk, followed by H-bath, and showering. Significant differences in Tre after bathing among the room temperatures were found only at H-bath. The changes in Tre after bathing for H-bath at 25 degrees C were similar to those for W-bath at 17.5 degrees C and 10 degrees C. TS and TC after bathing significantly differed for the three bathing methods at 17.5 degrees C and 10 degrees C (TS: p < 0.01 TC: p < 0.001). Especially, for showering, the largest number of subjects felt "cold" and "uncomfortable". Even though all of the subjects could accept the 10 degrees C condition after W-bath, such conditions were intolerable to half of them after showering. These results suggested that the physiological strains during H-bath and showering were smaller than during W-bath. However, colder room temperatures made it more difficult to retain body warmth after H-bath and created thermal discomfort after showering. It is particularly important for H-bath and showering to maintain an acceptable temperature in the dressing room and bathroom, in order to bathe comfortably and ensure warmth.     

Disproportionate thermophysiological strain between intensively- and extensively-managed goats during summer

Goat keeping is feasible for smallholder farmers in many world regions especially those best suited for extensive management. However, summertime grazing in arid zones entails major challenges to animal thermoregulation and well-being. An experiment was conducted to evaluate the thermoregulatory performance and selected hemogramic parameters in intensively (INT) or extensively (EXT) managed goat kids (N = 14). We applied a previously established technique to evaluate body thermal state of freely ranging animals, in which contemporaneous temperatures of the core (T_c) and periphery (T_p) are chronically recorded. Animals were initially kept for 12 days under INT management. Subsequently, seven animals were transferred to a grazing pasture and gradually transitioned over a four-day acclimatization period, then kept for the last 22 days under EXT conditions. Water drinking was limited to twice daily in both groups. Excessive solar radiation-induced heat load – with daytime black globe temperatures (T_bg) often exceeding 40 °C – under EXT was primarily responsible (r² = 0.49; P < 0.05) for 0.57 and 1.72 °C rises in T_c and T_p, respectively, over INT kids. Unlike the typically biphasic pattern noticed for daily temperatures of both body sites in INT goats, that of EXT counterparts became rather polyphasic, whereby water drinking had drastic and prolonged thermolytic effect, inducing 0.40–0.41 and 0.79–1.45 °C declines in T_c and T_p, on midday and afternoon watering bouts, respectively. Despite indication for added daytime heat load, EXT goats displayed lower early morning T_c than INT. All animals exhibited hypohydration, as reflected by rises in hematocrit, serum osmolality, albumin, potassium, and sodium, being more pronounced in EXT conditions. Results emphasize the excessive thermophysiological strain facing grazing animals in arid zones during the summer.     

The effects of two different types of clothing on seasonal cold acclimation of thermophysiological responses

The work described in this paper investigated the effects of two types of clothing, leaving the legs covered or uncovered, on seasonal cold acclimation in women. Experiments were carried out to observe the different thermal physiological responses between two groups of subjects, who dressed themselves in kneelength skirts or trousers during the daytime for 3 months from September to November. It was found that rectal temperatures and heart rates in the subjects wearing skirts were shifted to lower levels when the season gradually became colder. The results suggest that the clothing type worn in daily life may play a potential role in seasonal cold acclimation of thermal physiological responses in man.     

Validation of the Fiala multi-node thermophysiological model for UTCI application

The important requirement that COST Action 730 demanded of the physiological model to be used for the Universal Thermal Climate Index (UTCI) was its capability of accurate simulation of human thermophysiological responses across a wide range of relevant environmental conditions, such as conditions corresponding to the selection of all habitable climates and their seasonal changes, and transient conditions representing the temporal variation of outdoor conditions. In the first part of this study, available heat budget/two-node models and multi-node thermophysiological models were evaluated by direct comparison over a wide spectrum of climatic conditions. The UTCI-Fiala model predicted most reliably the average human thermal response, as shown by least deviations from physiologically plausible responses when compared to other models. In the second part of the study, this model was subjected to extensive validation using the results of human subject experiments for a range of relevant (steady-state and transient) environmental conditions. The UTCI-Fiala multi-node model proved its ability to predict adequately the human physiological response for a variety of moderate and extreme conditions represented in the COST 730 database. The mean skin and core temperatures were predicted with average root-mean-square deviations of 1.35 ± 1.00°C and 0.32 ± 0.20°C, respectively.     

Regulated glycosylation patterns of IgG during alloimmune responses against human platelet antigens

Various biological activities of immunoglobulin G (IgG) including antibody-dependent cellular cytotoxicity (ADCC) are modulated by the structural features of the N-glycans in the Fc part. In this study, we describe a population of IgG1 alloantibodies which are formed during pregnancy against human platelet antigens (HPA) of the fetus, causing fetoneonatal alloimmune thrombocytopenia. By analyzing the Fc-glycosylation of the pathogenic, affinity-purified IgG1 alloantibodies at the glycopeptide level using mass spectrometry, we found markedly decreased levels of core-fucosylation as well as increased levels of galactosylation and sialylation as compared to glycosylation patterns of total serum IgG1 of the same patients. Because IgG1 Fc-core-fucosylation is known to influence ADCC activity, modulation of core-fucosylation may have a profound effect on disease severity and prognosis. Studies in large patient cohorts will have to be performed to establish such correlations. Moreover, experiments in animal models as well as in vitro immunological tests will be needed to unravel the mechanisms regulating IgG Fc glycosylation.     

Oxidative responses of human and murine macrophages during phagocytosis of Leishmania chagasi.

Leishmania chagasi, the cause of South American visceral leishmaniasis, must survive antimicrobial responses of host macrophages to establish infection. Macrophage oxidative responses have been shown to diminish in the presence of intracellular leishmania. However, using electron spin resonance we demonstrated that murine and human macrophages produce O2-during phagocytosis of opsonized promastigotes. Addition of the O2- scavenger 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl to cultures resulted in increased infection, suggesting that O2- enhances macrophage leishmanicidal activity. The importance of NO. produced by inducible NO synthase (iNOS) in controlling murine leishmaniasis is established, but its role in human macrophages has been debated. We detected NO. in supernatants from murine, but not human, macrophages infected with L. chagasi. Nonetheless, the iNOS inhibitor N(G)-monomethyl-L-arginine inhibited IFN-gamma-mediated intracellular killing by both murine and human macrophages. According to RNase protection assay and immunohistochemistry, iNOS mRNA and protein were expressed at higher levels in bone marrow of patients with visceral leishmaniasis than in controls. The iNOS protein also increased upon infection of human macrophages with L. chagasi promastigotes in vitro in the presence of IFN-gamma. These data suggest that O2- and NO. each contribute to intracellular killing of L. chagasi in human and murine macrophages.     

Fatigue responses of human triceps surae muscles during repetitive maximal isometric contractions.

Nine healthy men (22-45 yr) completed 100 repetitive maximal isometric contractions of the ankle plantar flexor muscles in two knee positions of full extension (K0) and flexion at 90 degrees (K90), positions that varied the contribution of the gastrocnemii. Electromyographic activity was recorded from the medial and lateral gastrocnemii and soleus muscles by using surface electrodes. Plantar flexion torque in K0 was greater and decreased more rapidly than in K90. The electromyographic amplitude decreased over time, and there were no significant differences between muscles and knee joint positions. The level of voluntary effort, assessed by a supramaximal electrical stimulation during every 10th contraction, decreased from 96 to 70% (P < 0.05) with no difference between K0 and K90. It was suggested that a decrease in plantar flexion torque was attributable to both central and peripheral fatigue and that greater fatigability in K0 than in K90 would result from a greater contribution and hence more pronounced fatigue of the gastrocnemius muscle. Further support for this possibility was provided from changes in twitch torque.     

The partial characterisation of maternal anti-trophoblast antibody responses generated during normal human pregnancy

The anti-trophoblast antibody response generated during a normal human pregnancy and detected by a recently developed enzyme-linked immunosorbent assay, was partially characterised in terms of maternal influences, nature of the antibodies and nature of the antigenic determinants present on the syncytiotrophoblast plasma membrane. The level and incidence of the response was significantly affected by maternal parity, while the maternal ABO, but not Rhesus, blood group antigens exerted a minor influence. The antibody response was predominantly mediated by IgG molecules of the IgG1,2 and 4 subclasses. The IgG molecules existed in the maternal sera either in the form of 'free' molecules or were involved in immune complexes. The antibodies interacted with determinants that were present on all the placental membranes tested and hence are possibly organ specific. The antigenic specificities were absent from erythrocytes and peripheral blood lymphocytes.     

Molecular analysis of shower curtain biofilm microbes

Households provide environments that encourage the formation of microbial communities, often as biofilms. Such biofilms constitute potential reservoirs for pathogens, particularly for immune-compromised individuals. One household environment that potentially accumulates microbial biofilms is that provided by vinyl shower curtains. Over time, vinyl shower curtains accumulate films, commonly referred to as "soap scum," which microscopy reveals are constituted of lush microbial biofilms. To determine the kinds of microbes that constitute shower curtain biofilms and thereby to identify potential opportunistic pathogens, we conducted an analysis of rRNA genes obtained by PCR from four vinyl shower curtains from different households. Each of the shower curtain communities was highly complex. No sequence was identical to one in the databases, and no identical sequences were encountered in the different communities. However, the sequences generally represented similar phylogenetic kinds of organisms. Particularly abundant sequences represented members of the alpha-group of proteobacteria, mainly Sphingomonas spp. and Methylobacterium spp. Both of these genera are known to include opportunistic pathogens, and several of the sequences obtained from the environmental DNA samples were closely related to known pathogens. Such organisms have also been linked to biofilm formation associated with water reservoirs and conduits. In addition, the study detected many other kinds of organisms at lower abundances. These results show that shower curtains are a potential source of opportunistic pathogens associated with biofilms. Frequent cleaning or disposal of shower curtains is indicated, particularly in households with immune-compromised individuals.     

时空监测海水浴场粪大肠菌群和人类腺病毒方法的探讨（英文稿）

[目的]人类腺病毒(40/41)与人类急性胃肠炎显著相关,被用作娱乐水体中人类病毒污染的指示生物.粪大肠菌群(FC)作为传统的细菌指示生物,用来估计水环境中病原微生物的潜在风险.了解水传播的病原微生物的时空分布对公众健康和疾病的预防具有十分重要的意义.[方法]于2008年5月到10月,在中国10个典型海水浴场共采集30个表层海水样品,分别用定量PCR和细胞培养的方法分析人类腺病毒和FC.[结果]腺病毒的含量为1.7×106-1.1×108基因拷贝/L,其阳性检出率为30％,而普通PCR的阳性检出率为26.7％.其中7个海水浴场的FC超出了景观娱乐水质标准(2 000 CFU/L).时间分布趋势表明,人类腺病毒从8月份到10月份的污染较其他月份严重(P＜0.05).在该实验条件下,不论是在同一浴场的不同站位还是在不同浴场,腺病毒的空间分布差异都不明显(P＞0.05).同样,FC在不同浴场的时空分布也无明显差异(P＞0.05),但是其分布与离岸距离的远近显著相关(P＜0.05).此外,在我们所研究的浴场,细菌和病毒这两种指示生物之间并没有相关性.[结论]为避免在游泳季节胃肠道疾病的大规模爆发,必须加强卫生设施建设和肠道细菌、病毒两种指示生物的监测.     

Thermophysiological responses of human volunteers during controlled whole-body radio frequency exposure at 450 MHz

Thermoregulatory responses of heat production and heat loss were measured in seven adult volunteers (four women and three men, aged 21–57 yr) during 45-min dorsal exposures of the whole body to 450 MHz continuous wave radio frequency (RF) fields. Two power densities (PD) (local peak PD = 18 and 24 mW/cm²; local peak specific absorption rate = 0.320 [W/kg]/[mW/cm²]) were tested in each of three ambient temperatures (T_a = 24, 28, and 31 °C) plus T_a controls (no RF). No changes in metabolic heat production occurred under any exposure conditions. Vigorous increases in sweating rate on back and chest, directly related to both T_a and PD, cooled the skin and ensured efficient regulation of the deep body (esophageal) temperature to within 0.1 °C of the normal level. Category judgments of thermal sensation, comfort, sweating, and thermal preference usually matched the measured changes in physiological responses. Some subtle effects related to gender were noted that confirm classic physiological data. Our results indicate that dorsal exposures of humans to a supra-resonant frequency of 450 MHz at local peak specific absorption rates up to 7.68 W/kg are mildly thermogenic and are counteracted efficiently by normal thermophysiologic heat loss mechanisms, principally sweating. Bioelectromagnetics 19:232–245, 1998. Published 1998 Wiley-Liss, Inc.     

Nonvisual responses to light exposure in the human brain during the circadian night

The brain processes light information to visually represent the environment but also to detect changes in ambient light level. The latter information induces non-image-forming responses and exerts powerful effects on physiology such as synchronization of the circadian clock and suppression of melatonin. In rodents, irradiance information is transduced from a discrete subset of photosensitive retinal ganglion cells via the retinohypothalamic tract to various hypothalamic and brainstem regulatory structures including the hypothalamic suprachiasmatic nuclei, the master circadian pacemaker. In humans, light also acutely modulates alertness, but the cerebral correlates of this effect are unknown. We assessed regional cerebral blood flow in 13 subjects attending to auditory and visual stimuli in near darkness following light exposures (>8000 lux) of different durations (0.5, 17, 16.5, and 0 min) during the biological night. The bright broadband polychromatic light suppressed melatonin and enhanced alertness. Functional imaging revealed that a large-scale occipito-parietal attention network, including the right intraparietal sulcus, was more active in proportion to the duration of light exposures preceding the scans. Activity in the hypothalamus decreased in proportion to previous illumination. These findings have important implications for understanding the effects of light on human behavior.