Growth hormone and prolactin responses during partial and whole body warm‐water immersions

Aim: To elucidate the role of core and skin thermoreceptors in the release of growth hormone (GH) and prolactin (PRL), a sequence of two experiments using whole‐body (head‐out) and partial (one forearm) hot water immersions was performed. Methods: Experiment 1: Nine healthy men were exposed to head‐out and partial water immersions (25 min, 38–39 °C). Results: Head‐out immersion increased the core temperature (38.0 ± 0.1 vs. 36.7 ± 0.1 °C, P < 0.001) and plasma concentration of the hormones (GH, 16.1 ± 4.5 vs. 1.2 ± 0.4 ng mL^?1, P < 0.01; PRL, 9.1 ± 1.0 vs. 6.4 ± 0.4 ng mL^?1, P < 0.05). During the partial immersion the core temperature was slightly elevated (36.8 ± 0.1 vs. 36.6 ± 0.1, P < 0.001), the concentration of GH increased (4.8 ± 1.7 vs. 0.6 ± 0.3, P < 0.05), while plasma PRL decreased (7.6 ± 0.8, 6.0 ± 0.6, 5.2 ± 0.6, P < 0.01). Experiment 2: Seven volunteers immersed one forearm once in 39 °C and once in 38 °C water. The measurements were performed in 5‐min intervals. The GH concentration increased gradually from the beginning of the immersions (min 10; 39 °C: 1.9 ± 1.0 vs. 0.6 ± 0.3 ng mL^?1, P < 0.01; 38 °C: 0.19 ± 0.03 vs. 0.14 ± 0.03, P < 0.05) and peaked after their completion (39 °C: +10 min, 3.7 ± 2.0, P < 0.001; 38 °C: +15 min, 0.86 ± 0.61, P < 0.01). The core temperature was unchanged until min 15 of the 39 °C bath. Thereafter, it increased about 0.15 °C above the baseline (P < 0.01). Immersion in 38 °C water did not induce core temperature changes. Conclusions: Peripheral thermoreceptors are involved in GH release when the body is exposed to elevated environmental temperature while a substantial elevation of core temperature is a precondition of PRL release.     

Prediction of the thermoregulatory response for clothed immersion in cold water

Summary A multi-compartmental thermoregulatory model was applied to data of ten resting clothed males immersed for 3 h in water at 10 and 15°C. Clothing consisted of a dry suit and either a light or heavy undergarment, representing a total insulation of 0.15 (0.95) or 0.20 m²°CW⁻¹ (1.28 clo), respectively. Data were grouped according to low (<14%) and high (14 to 24%) body fat individuals. Mean decreases in rectal temperature ranged from 0.79 to 1.38°C, mean decreases in the mean weighted skin temperature ranged from 6.3 to 10.2°C, and mean increases in the metabolic rate ranged from 33.9 to 80.8 W. The model consists of eight segments, each representing a specific region of the body. Each segment is comprised of compartments representing the core, muscle, fat, skin, and clothing. Each compartment is assigned thermophysical values of heat conduction and heat capacitance, and with the exception of clothing, physiological values of blood flow and metabolic heat production. During cold exposure, responses are directed towards increased heat production in the form of shivering and heat conservation in the form of vasoconstriction and convective heat exchange at the vascular level. Agreement between the model predictions and the experimental observations was obtained by adjusting the parameters governing these responses. These adjusted parameters were 1) the onset of limb shivering with an exponential half-time of 30 min, 2) the fractional value of 0.5 for the convective heat exchange between the core compartments of the limbs and the blood flowing through these compartments, 3) the fractional contribution of trunk shivering to overall shivering, which ranged from 0.77 to 0.95, and 4) the onset of vasoconstriction with exponential half-times that ranged from 3 to 25 min. Steady state was predicted to occur within 4 h and a heat balance analysis indicated that the limbs were responsible for most of the body's heat loss while acquiring most of their own heat from the trunk through convective heat exchange with the central blood.     

兔膝关节开放性海水浸泡损伤模型的构建

目的：探索并构建理想的兔膝关节开放性海水浸泡损伤的动物模型。方法取新西兰白兔60只,建立兔膝关节开放性损伤模型,按照不同的海水浸泡时间分为对照组、0.5 h组、1 h组、3 h组和6 h组,每组各12只。对照组不予处理,各实验组制备膝关节开放性伤口,分别给予相应的海水浸泡时间。术后观察实验动物伤口及存活情况,于术后7 d抽取各组白兔膝关节液,采用酶联免疫吸附法检测关节液中炎性因子白细胞介素1-β(IL-1β)和肿瘤坏死因子-α(TNF-α)的含量。结果3 h组和6 h组的7 d存活率分别为91.7%、75.0%,其余各组均为100.0%;1 h组、3 h组和6 h组的14 d存活率分别为91.7%、83.3%和58.3%,其余各组均为100.0%。术后7 d,3 h组和6 h组中关节液IL-1β水平分别为(37.50±6.1) pg/mL和(38.40±5.1) pg/mL,明显高于其他各组,差异均有统计学意义(P>0.05),而3 h组和6 h组中关节液IL-1β水平比较差异无统计学意义(P>0.05);术后7 d,1 h组和3 h组关节液中的TNF-α水平分别为(297.48±35.7) pg/mL和(312.84±34.0) pg/mL,高于0.5 h组和对照组,低于6 h组,差异均有统计学意义(P<0.05),而1 h组和3 h组关节液中的TNF-α水平比较差异无统计学意义(P>0.05)。结论海水浸泡3 h构建兔膝关节海水浸泡损伤的动物模型具有动物存活率高、炎性反应活跃等特点,是一种理想的关节开放性海水浸泡损伤的动物模型。     

四种正畸粘接剂的粘接性能研究

考察了两种非调和型，两种调和型正畸粘接剂在不同浸水时间，放置时间，酸蚀时间条件下的粘接抗张强度，结果表明：（１）４种粘接剂在３７℃１００％ｒｈ环境中５ｍｉｎ后的粘接强度均大于２．５ＭＰａ，在３７℃水中浸泡１ｄ后的粘接强度均大于６ＭＰａ，两种非调和型粘接的粘接强度在１ｄ内随时间延长而增加；（２）在３７℃，１００％ｒｈ环境中，４种粘妆剂的液剂先涂于牙面１～１０ｍｉｎ后再粘接，所得粘接强度无明显变化；（     

Protective effect of palm vitamin E and α-tocopherol against gastric lesions induced by water immersion restraint stress in Sprague-Dawley rats

Objective:

Stress can lead to various changes in the gastrointestinal tract of rats. The present study was designed to compare the effect of palm vitamin E (PVE) and α-tocopherol (α-TF) supplementations on the gastric parameters important in maintaining gastric mucosal integrity in rats exposed to water immersion restraint stress (WRS). These parameters include gastric acidity, plasma gastrin level, gastric prostaglandin E₂ (PGE₂), and gastric lesions.

Materials and Methods:

Sixty male Sprague-Dawley rats (200-250 g) were divided into three equal groups: a control group, which received a normal rat diet (RC), and two treatment groups, receiving oral supplementation of either PVE or α-TF at 60 mg/kg body weight for 28 days. Each group was further divided into two groups: the nonstress and stress groups. The stress groups were subjected to 3.5 h of WRS once at the end of the treatment period. Blood samples were then taken to measure the gastrin level, after which the rats were killed. Gastric juice was collected for measurement of gastric acidity and gastric tissue was taken for measurement of gastric mucosal lesions and PGE₂.

Results:

Exposure to stress resulted in the production of gastric lesions. PVE and α-TF lowered the lesion indices as compared to the stress control group. Stress reduced gastric acidity but pretreatment with PVE and α-TF prevented this reduction. The gastrin levels in the stress group were lower as compared to that in the nonstress control. However, following treatment with PVE and α-TF, gastrin levels increased and approached the normal level. There was also a significant reduction in the gastric PGE₂ content with stress exposure, but this reduction was blocked with treatment with both PVE and α-TF.

Conclusion:

In conclusion, WRS leads to a reduction in the gastric acidity, gastrin level, and gastric PGE₂ level and there is increased formation of gastric lesions. Supplementation with either PVE or α-TF reduces the formation of gastric lesions, possibly by blocking the changes in the gastric acidity, gastrin, and gastric PGE₂ induced by stress. No significant difference between PVE and α-TF was observed.     

生理性海水鼻喷剂治疗儿童鼻窦炎疗效观察

目的:探讨生理性海水鼻喷剂治疗小儿鼻窦炎的临床疗效。方法:将临床确诊的鼻窦炎患儿120例随机分为观察组和对照组各60例,对照组使用抗生素、黏液促排剂以及鼻渊通窍颗粒治疗,观察组在对照组治疗基础上配合使用生理性海水鼻喷剂治疗,两组均连续治疗6周,期间停用其他一切可影响鼻通气的药物。结果:治疗后观察组总有效率为93.33%,高于对照组的78.33%(P<0.05);VAS 总分、Lund-Kennedy 总分均低于对照组(P均<0.05)。结论:生理性海水鼻喷剂配合常规药物治疗可有效提高儿童鼻窦炎的疗效,减少不良反应的发生。     

Isolation of Vibrio alginolyticus from seawater aquaria

The seawater bacterium Vibrio alginolyticus was detected in 5 of 20 water samples from seawater aquaria (from 3 of 5 units) and also from the surface of diseased stony corals. A total of 45 isolates were differentiated biochemically, of which 13 isolates (29%) proved to be V. alginolyticus. All those strains produced the virulence factors caseinase and lipase, 11 strains amylase and gelatinase. 7 strains showed lecithinase activity and 2 strains produced hemolysins. All examined strains showed a marked toxicity to vero cells proven by the MTT-bioassay, but no toxicity to plant cells with the saline alga Asteromonas gracilis as model. The isolates were mostly resistant to β-lactam antibiotics, macrolides and lincomycin. However, they proved to be susceptible to aminoglycoside- and polypeptide-antibiotics as well as to tetracyclines, chloramphenicol, florfenicol, enrofloxacin and sulfamethoxazol-trimethoprim. The possible participation of this bacterium in the bleaching and dying of stony corals is mentioned as well as its role as human pathogen.     

高频喷射通气对兔海水淹溺肺水肿时肺CYTO与血PaO_2和SO_2的影响

目的　探讨高频喷射通气（ＨＦＪＶ）对海水淹溺肺水肿（ＰＥ－ＳＷＤ）兔肺毛细血管内皮细胞的细胞色素氧化酶（ＣＹＴＯ）、动脉血氧分压（ＰａＯ２ ）和血氧饱和度（ＳＯ２ ）的影响及其机制。方法　复制兔ＰＥ－ＳＷＤ模型,用细胞化学和图像定量分析法测定兔肺ＣＹＴＯ 活性,血气分析仪测定ＰａＯ２ 和ＳＯ２。结果　通气组ＣＹＴＯ 活性、ＰａＯ２ 和ＳＯ２ 比未通气组有明显升高（Ｐ＜ ０．０１ 或Ｐ＜ ０．０５）,但未恢复到海水淹溺前水平。结论　ＨＦＪＶ 改善肺泡通气功能,提高ＰａＯ２ 和ＳＯ２ ,改善低氧血症,恢复ＣＹＴＯ活性,减轻细胞水肿,减轻或延缓肺不张,改善肺换气功能。同时,ＣＹＴＯ活性的恢复,又有利于肺换气功能和通气功能的改善。     

微重力条件下人体体液调节模型的分析与改进思考

航天和模拟微重力时研究表明：微重力与现有模拟微重力模型时人体生理学变化的主要差异表现在低压区循环和体液、电解质代谢。微重力生理研究的人体模型在进一步了解微重力对人体的生理影响和机理中不可缺少,有必要将现有人体模拟微重力模型加以改进。利用人体不同角度和不同压力制度的立位倾斜（ＨＵＴ）加下体正压、头低位卧床（ＨＤＴ）加上体负压,测量心血管参数、体液调节因子、肾排泄的有关指标,与航天中的相应指标对照,筛     

海水浸泡火器伤失活肌组织的外科判定标准

目的　探讨外科标准“4C”(颜色、致密度、收缩性、出血 )在判定海水浸泡肢体火器伤失活肌组织的可靠性。方法　以滑膛枪发射质量为 0 .2 5 g、速度为 6 0 0～ 80 0 m/ s钢球击中兔后肢 ,将致伤兔浸泡于人工海水中 30～ 6 0 min后出水。伤后 6～ 8h以“4C”标准分级判定肌组织活力 ,并运用图象分析技术 ,观察损伤组织显微病理改变与“4C”标准之间的关系。结果　 χ2 检验显示“4C”标准中与失活组织的密切程度依次为 :收缩性、出血、致密度 ,而颜色与肌组织活力无关。病理观察显示肌组织变性、坏死 ,尤以肌间隙肿胀明显。结论　判定海水浸泡火器伤失活组织主要依据肌组织的收缩性、出血与致密度的变化。