BACKGROUND & AIMS: OBJECTIVE:Conventional hemodialysis (HD) predominates over peritoneal dialysis (PD) around the world. Prospective and comparative studies comparing the costs of these modalities are scarce. In the present prospective assessment, we describe the resources used and total patient costs for both HD and PD. ♢ METHODOLOGY:We assessed 249 patients on HD and 228 on PD. All patients were 18 years of age or older and on stable dialysis. The information was collected at three points over 1 year, using standard questionnaires. The sources for costs were the Brazilian public and private health care systems. Societal perspective was considered. ♢ STATISTICAL ANALYSIS:Core trends and dispersions were measured. Regression models assessed the impact of modality on the average total cost per patient per year. ♢ RESULTS:Of the 249 HD patients and 228 PD dialysis patients, 189 (74%) and 160 (70%) respectively completed follow-up. The mean age for women was 55.8 years; for men, it was 59.8 years (p = 0.001). The average total cost per patient-year was US$28 570 for HD and US$27 158 for PD. By category, the costs consisted of direct medical-hospital costs (82.3% for HD, 86.5% for PD), direct nonmedical costs (5.3% for HD, 3.7% for PD), and indirect costs (12.4% for HD, 9.8% for PD). Overall costs were less for PD patients than for their HD counterparts (p = 0.025). ♢ CONCLUSIONS:Maintenance dialysis represented the most important source of costs for both modalities; loss of productivity incurred significant costs. Future studies should contemplate the social consequences arising from each modality.

背景与目标：

BACKGROUND & AIMS: INTRODUCTION:Vismodegib was assessed as being of low risk for QT interval prolongation based on prior nonclinical and clinical experience. A dedicated study was conducted to further assess the potential for vismodegib to prolong the QTc interval. METHODS AND RESULTS:Given the nonlinear pharmacokinetics of vismodegib, a thorough QTc study as is typically designed was not possible, and an innovative design was employed. This dedicated QTc study was powered to exclude a 20-millisecond change from the baseline QTc interval. The subjects were administered daily oral 150 mg of vismodegib for 7 days, or a single dose of 400 mg of moxifloxacin, with corresponding matching placebos. The upper limits of the 90% confidence intervals for the difference in ΔQTcF between vismodegib and placebo at steady state were <20 milliseconds at all timepoints with a maximum of 10 milliseconds at 12 hours postdose. Exposure-response analysis yielded an estimated slope equal to 0.11 ms/μM, which was not statistically significant. After a single dose of moxifloxacin was administered, the lower limits of the 90% confidence interval of the difference in ΔQTcF between moxifloxacin and placebo were >5 milliseconds from 1-12 hours postdose, thereby establishing assay sensitivity. CONCLUSIONS:There was no effect of vismodegib on the QTc interval when dosed daily at 150 mg to steady state.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Fatty infiltration (FI) compromises outcomes of rotator cuff repairs. Most clinicians consider FI of the infraspinatus, whether it is torn or intact, because it is most rapidly affected. The purpose of this study was to report long-term outcomes of isolated supraspinatus repairs and to determine their associations with FI of the infraspinatus and supraspinatus. METHODS:The records of 182 patients who underwent repair of isolated supraspinatus tears and had preoperative magnetic resonance imaging were retrieved. Of these, 147 patients were evaluated at 10 years' follow-up using the Constant score and magnetic resonance imaging scans. RESULTS:Preoperative FI was greater in the supraspinatus (52% stage ≥1) than in the infraspinatus (29% stage ≥1). The 10-year Constant scores were influenced by FI of the supraspinatus (P = .006) but not of the infraspinatus (P = .422). Multivariable regression confirmed that Constant scores were significantly lower for female patients, repetitive work, and stage 1 and stage 2 FI of the supraspinatus in addition to open surgery. Retear rates (Sugaya types IV-V) were also influenced by FI of the supraspinatus (P = .001) but not of the infraspinatus (P = .979). Shoulders with supraspinatus FI at stages 0, 1, and 2 had retear rates of 10%, 22%, and 31%, respectively. Multivariable regression affirmed that the odds of retears are significantly increased by both stage 1 and stage 2 FI of the supraspinatus. CONCLUSIONS:The Constant scores and retear rates were significantly associated with FI of the torn supraspinatus (stage ≥1) but not of the intact infraspinatus. The authors recommend that rapid surgical intervention be considered, before accumulation of fat, especially for young, active patients.

背景与目标：

BACKGROUND & AIMS: OBJECTIVES:This paper seeks to further explore the question of how best to monitor and govern innovative clinical procedures in their earliest phase of development. We examine the potential value of proposed governance frameworks, such as the IDEAL model, and examine the functioning of a novel procedures review committee. METHODS:The paper draws upon 20 qualitative, semi-structured interviews. Nine interviews were conducted with members of a committee that was established as a means of governing innovative procedures within a large National Health Service Foundation Trust hospital in the UK. Eleven interviews were conducted with health providers involved with the development of a variety of novel clinical procedures. RESULTS:Prominent themes from the data include the potential willingness of clinicians to engage with regulatory frameworks for innovative procedures, existing ways in which clinicians and others attempt to ensure patient's safety and manage uncertainty in the context of novel procedures, views on the potential benefits and drawbacks of engaging with a review committee for novel procedures, and the pragmatic considerations and potential unintended consequences that are entailed in the implementation of regulatory requirements for the monitoring of innovative procedures. CONCLUSIONS:The views of committee members and clinical innovators help us to understand the practical issues of implementing governance structures for novel clinical procedures. The data illustrate those factors that must be taken into account if governance is to support innovation rather than act as an inhibiting factor in the development of new clinical procedures.

背景与目标：

BACKGROUND & AIMS: PURPOSE:The aim of this study was to assess the measurement properties of the 5-level classification system of the EQ-5D (5L), in comparison with the 3-level EQ-5D (3L). METHODS:Participants (n = 3,919) from six countries, including eight patient groups with chronic conditions (cardiovascular disease, respiratory disease, depression, diabetes, liver disease, personality disorders, arthritis, and stroke) and a student cohort, completed the 3L and 5L and, for most participants, also dimension-specific rating scales. The 3L and 5L were compared in terms of feasibility (missing values), redistribution properties, ceiling, discriminatory power, convergent validity, and known-groups validity. RESULTS:Missing values were on average 0.8% for 5L and 1.3% for 3L. In total, 2.9% of responses were inconsistent between 5L and 3L. Redistribution from 3L to 5L using EQ dimension-specific rating scales as reference was validated for all 35 3L-5L-level combinations. For 5L, 683 unique health states were observed versus 124 for 3L. The ceiling was reduced from 20.2% (3L) to 16.0% (5L). Absolute discriminatory power (Shannon index) improved considerably with 5L (mean 1.87 for 5L versus 1.24 for 3L), and relative discriminatory power (Shannon Evenness index) improved slightly (mean 0.81 for 5L versus 0.78 for 3L). Convergent validity with WHO-5 was demonstrated and improved slightly with 5L. Known-groups validity was confirmed for both 5L and 3L. CONCLUSIONS:The EQ-5D-5L appears to be a valid extension of the 3-level system which improves upon the measurement properties, reducing the ceiling while improving discriminatory power and establishing convergent and known-groups validity.

背景与目标：

BACKGROUND & AIMS: :To study the force-velocity characteristics of human knee-hip extension movement, a dynamometer, in which force was controlled by a servo system, was developed. Seated subjects pressed either bilaterally or unilaterally a force plate, a horizontal position of which was servo-controlled so as to equalize the measured force and a force command generated by a computer at a time resolution of 2 ms (force clamp). The force command was based on the relation between maximum isometric force and foot position within the range between 70% and 90% of "leg length" (LL: longitudinal distance between the sole of the foot and the hip joint), so that the same force relative to the maximum isometric force was consistently applied regardless of the foot position. By regulating the force according to this function, the force-velocity relation was determined. The force-velocity relation obtained was described by a linear function (n=17, r=-0.986 for 80% LL, r=-0.968 for 85% LL) within a range of force between 0.1 and 0.8F(0) (maximum isometric force). The maximum force extrapolated from the linear regression (F(max)) coincided with F(0) (n=17, F(0)/F(max)=1.00+/-0.09 for 80% LL and 1.00+/-0.20 for 85% LL). Also, the velocity at zero force (V(max)) was obtained from the extrapolation. When compared to the bilateral movements, unilateral movements gave rise to a smaller F(max) but the same V(max), suggesting that V(max) is independent of force and therefore represents the proper unloaded velocity. It is suggested that some neural mechanisms may be involved in the force-velocity relation of the knee-hip extension movement, and make it exhibit a linear appearance rather than a hyperbola.

背景与目标： : 为了研究人体膝关节-髋关节伸展运动的力-速度特性，开发了一种测力计，该测力计由伺服系统控制。就座的对象在两侧或一侧按压一个测力板，其水平位置受到伺服控制，以使测得的力和计算机以2 ms的时间分辨率 (力夹) 产生的力命令相等。力命令基于最大等距力和足部位置之间的关系，范围在 “腿长” 的70% 和90% 之间 (LL: 脚底和髋关节之间的纵向距离)，因此，无论脚的位置如何，都始终施加相对于最大等距力的相同力。通过根据此函数调节力，确定了力-速度关系。在0.1和0.8F(0) (最大等距力) 之间的力范围内，通过线性函数 (n = 17，对于80% LL，r =-0.986，对于85% LL，r =-0.968) 描述获得的力-速度关系。从线性回归外推的最大力 (F(max)) 与F(0) 一致 (对于80% LL，n = 17，F(0)/F(max)= 1.00 +/-0.09，对于85% LL，1.00 +/-0.20)。此外，通过外推获得了零力 (V(max)) 的速度。与双边运动相比，单边运动产生的F(max) 较小，但V(max) 相同，这表明V(max) 与力无关，因此代表适当的空载速度。建议某些神经机制可能参与膝髋伸展运动的力-速度关系，并使其表现出线性外观而不是双曲线。

BACKGROUND & AIMS: :Microtubules are organized into diverse cellular structures in multicellular organisms. How is such diversity generated? Although highly conserved overall, variable regions within alpha- and beta-tubulins show divergence from other alpha- and beta-tubulins in the same species, but show conservation among different species. Such conservation raises the question of whether diversity in tubulin structure mediates diversity in microtubule organization. Recent studies probing the function of beta-tubulin isotypes in axonemes of insects suggest that tubulin structure, through interactions with extrinsic proteins, can direct the architecture and supramolecular organization of microtubules.

背景与目标： : 微管在多细胞生物中被组织成不同的细胞结构。这种多样性是如何产生的？尽管总体上高度保守，但在同一物种中，α-和 β-微管蛋白中的可变区域显示出与其他 α-和 β-微管蛋白的差异，但在不同物种之间显示出保守性。这种保护提出了一个问题，即微管蛋白结构的多样性是否介导了微管组织的多样性。最近对昆虫轴突中 β-微管蛋白同种型功能的研究表明，微管蛋白结构通过与外部蛋白质的相互作用可以指导微管的结构和超分子组织。

BACKGROUND & AIMS: OBJECTIVES:Iopentol (Nycomed Imaging AS, Oslo, Norway) and iopromide (Schering AG, Berlin, Germany) are low-osmolar, non-ionic, iodinated contrast media (CM) used in abdominal CT examinations. The intravenous safety profile and radiological efficacy of iopentol and iopromide were studied in 518 patients. Specifically, frequency of adverse events (AEs), subjective change in quality of diagnostic information, and quantitative enhancement characteristics were compared. MATERIALS AND METHODS:A prospective, double-blind, randomized, multicentre, parallel-group study was conducted at 8 hospitals. Patients received 100 ml of either iopentol 300 mg I/ml or iopromide 300 mg I/ml. RESULTS:The incidence of patients with AEs was statistically significantly lower in the iopentol group compared to the iopromide group (2.3% vs. 8.9%, p < 0.001). Discomfort was frequent in both groups (44.8% vs. 49.4%, p = 0.33), sensation of heat and warmth being most common. Overall, diagnostic information was similar in both groups. Both CM gave high percentages of examinations rated as optimal (87.1% vs. 90.5%, p = 0.34) and in which diagnostic confidence was increased (87.5% vs. 91.1%, p = 0.22). No significant differences between the two CM were found concerning quantitative enhancement characteristics. CONCLUSIONS:In this study iopentol was significantly safer than iopromide for contrast enhanced CT examination of the abdomen. Radiological efficacy was similar with both CM.

背景与目标：

BACKGROUND & AIMS: A monoclonal antibody raised to a Teladorsagia circumcincta 31-33 kDa doublet antigen was used to immunoscreen a T. circumcincta cDNA expression library. Sheep antibodies eluted from the proteins expressed by two clones immunopositive with the monoclonal antibody specifically recognised the doublet antigen on Western blots of third stage larval extract, confirming that these clones coded for the antigen. Database searches revealed high levels of similarity with beta-galactoside-binding lectin-like proteins (Ga1BPs or galectins) from Caenorhabditis elegans and Onchocerca volvulus. By analogy with these sequences, both T. circumcincta cDNA clones contain the full-length protein coding region. The native doublet proteins could be preferentially extracted from homogenates of third stage larvae with lactose and could be affinity purified on an asialofetuin column, confirming the identity of these bands as galectins. Reverse transcriptase-polymerase chain reaction amplification using a primer based on the C. elegans Spliced Leader SL1 sequence showed that the corresponding T. circumcincta mRNAs are also trans-spliced at their 5' ends. While there are considerable nucleotide differences between the two clones, the majority are located in the non-coding regions. Within the coding region there are 87 nucleotide differences but only three of these result in amino acid substitutions.

背景与目标： 使用针对teradorsagia cireccinta 31-33 kDa双峰抗原产生的单克隆抗体免疫筛选了T.Cireccincta cDNA表达文库。从两个克隆表达的蛋白中洗脱的绵羊抗体与单克隆抗体免疫阳性，特异性地识别了第三阶段幼虫提取物Western印迹上的doublet抗原，证实了这些克隆编码了该抗原。数据库搜索显示，秀丽隐杆线虫和盘旋虫的 β-半乳糖苷结合凝集素样蛋白 (Ga1BPs或半乳糖苷) 具有高度的相似性。与这些序列类似，两个T. circumcincta cDNA克隆均包含全长蛋白质编码区。可以优先从具有乳糖的第三阶段幼虫的匀浆中提取天然双峰蛋白，并可以在去唾液酸纤维蛋白柱上进行亲和纯化，从而确认这些条带与半乳糖蛋白的身份。使用基于秀丽隐杆线虫剪接的前导SL1序列的引物进行的逆转录酶-聚合酶链反应扩增表明，相应的T.Circucincta mrna也在其5' 末端被反式剪接。尽管两个克隆之间存在相当大的核苷酸差异，但大多数位于非编码区。在编码区内有87个核苷酸差异，但其中只有三个会导致氨基酸取代。

BACKGROUND & AIMS: :The asexual blood stage of Plasmodium falciparum is comprised of morphologically distinct ring, trophozoite and schizont stages. Each of these developmental stages possesses a distinct pattern of gene expression. Regulation of P. falciparum gene expression is thought to occur, at least in part, at the promoter level. Previously, we have found that although the hrp3 mRNA is only seen in ring-stage parasites, deletion of a specific sequence in the 5' end of the promoter region decreased ring-stage expression of hrp3 and enabled detection of its transcripts in trophozoite-stage parasites. In order to investigate this stage specific regulation of gene expression, we employed a series of nested deletions of the 1.7-kb hrp3 promoter. Firefly luciferase gene was used as a reporter to evaluate the role of promoter sequences in gene regulation. Using this approach, we identified a ring-stage specific regulatory region on the hrp3 promoter located between -1.7 kb and -1.1 kb from the ATG initiation codon. Small 100-150 bp truncations on this enhancer-like region failed to uncover discrete regulatory sequences, suggesting the multipartite nature of this element. The data presented in this study demonstrate that stage specific promoter activity of the hrp3 gene in P. falciparum blood stage parasites is supported, at least in-part, by a small promoter region that can function in the absence of a larger chromosomal context.

背景与目标： : 恶性疟原虫的无性血液阶段由形态上不同的环，滋养体和裂殖体阶段组成。这些发育阶段中的每个阶段都具有独特的基因表达模式。恶性疟原虫基因表达的调节被认为至少部分发生在启动子水平。以前，我们已经发现，尽管hrp3 mRNA仅在环状寄生虫中可见，但启动子区域5' 末端的特定序列的缺失会降低hrp3的环状表达，并能够在滋养体中检测其转录本阶段寄生虫。为了研究这一阶段基因表达的特异性调控，我们采用了1.7-kb hrp3启动子的一系列嵌套缺失。萤火虫荧光素酶基因被用作报告基因，以评估启动子序列在基因调控中的作用。使用这种方法，我们从ATG起始密码子确定了位于-1.7 kb和-1.1 kb之间的hrp3启动子上的环阶段特异性调节区域。在该增强子样区域上的小100 150 bp截断未能发现离散的调节序列，表明该元件的多部分性质。这项研究中提供的数据表明，恶性疟原虫血液阶段寄生虫中hrp3基因的阶段特异性启动子活性至少部分受到小启动子区域的支持，该启动子区域可以在没有较大染色体背景的情况下起作用。

BACKGROUND & AIMS: PURPOSE:Long-term evaluation of an empirically based program for the treatment of morbidly obese, low-income, minority adolescents. METHODS:In the first year, 150 participants received cognitive-behavior therapy, nutritional education, medical monitoring, and structured exercise training. Weights and heights were collected at follow-up. Successful and Less Successful groups were delineated based on change in body mass index z-scores. Medical record review provided weight and height data one year before treatment for a subset of participants (comparison group). Analyses of variance examined differences between groups. Discriminant function analyses examined predictors of success in the domains of socioeconomic status, individual factors and psychological functioning, family factors, and prior weight loss behaviors. Correlates of success were explored. RESULTS:Eighty-three adolescents participated in the follow-up, on average 23 months (SD = 3.8) after initial assessment. Nineteen (23%) participants achieved clinically meaningful weight change (-.70 z-scores or better). Discriminant function analyses, correlations, and direct comparisons showed that the Successful group, compared with the Less Successful group, on average, attended 50% more sessions over 84% more weeks, were heavier initially, had somewhat better critical weight control skills (e.g., self-monitoring) before and during the program, and were somewhat more psychologically and intellectually challenged before treatment. CONCLUSION:Although some of these very high risk adolescents made clinically significant progress, more intensive treatments, like long-term residential treatments and bariatric surgery, may produce even more favorable outcomes.

背景与目标：

BACKGROUND & AIMS: In the present study, we examine rod photoreceptor development in dissociated-cell cultures of neonatal mouse retina. We show that, although very few rhodopsin+ rods develop in the presence of 10% foetal calf serum (FCS), large numbers develop in the absence of serum, but only if the cell density in the cultures is high. The rods all develop from nondividing rhodopsin- cells, and new rods continue to develop from rhodopsin- cells for at least 6-8 days, indicating that there can be a long delay between when a precursor cell withdraws from the cell cycle and when it becomes a rhodopsin+ rod. We show that FCS arrests rod development in these cultures at a postmitotic, rhodopsin-, pre-rod stage. We present evidence that FCS acts indirectly by stimulating the proliferation of Müller cells, which arrest rod differentiation by releasing leukaemia inhibitory factor (LIF). These findings identify an inhibitory cell-cell interaction, which may help to explain the long delay that can occur both in vitro and in vivo between cell-cycle withdrawal and rhodopsin expression during rod development.

背景与目标： 在本研究中，我们检查了新生小鼠视网膜解离细胞培养物中杆状感光细胞的发育。我们表明，尽管在存在10% 胎牛血清 (FCS) 的情况下很少有视紫红质棒形成，但在不存在血清的情况下却有大量的视紫红质棒形成，但前提是培养物中的细胞密度很高。所有的视紫红质细胞均由未分裂的视紫红质细胞发育，新的视紫红质细胞继续发育至少6-8天，这表明在前体细胞退出细胞周期与前体细胞之间可能会有很长的延迟。成为视紫红质杆。我们显示FCS在有丝分裂后，视紫红质，杆前阶段阻止了这些培养物中的杆发育。我们提供的证据表明，FCS通过刺激m ü ller细胞的增殖间接起作用，m ü ller细胞通过释放白血病抑制因子 (LIF) 来阻止杆分化。这些发现确定了抑制性细胞-细胞相互作用，这可能有助于解释在杆发育过程中细胞周期退出和视紫红质表达之间在体外和体内可能发生的长时间延迟。

BACKGROUND & AIMS: :Aboriginal Australians, including Aboriginal Health Workers (AHWs), smoke at rates double the non-Aboriginal population. This study utilized concept mapping methodology to identify and prioritize culturally relevant strategies to promote smoking cessation in AHWs. Stakeholder participants included AHWs, other health service employees and tobacco control personnel. Smoking cessation strategies (n = 74) were brainstormed using 34 interviews, 3 focus groups and a stakeholder workshop. Stakeholders sorted strategies into meaningful groups and rated them on perceived importance and feasibility. A concept map was developed using multi-dimensional scaling and hierarchical cluster analyses. Ten unique clusters of smoking cessation strategies were depicted that targeted individuals, family and peers, community, workplace and public policy. Smoking cessation resources and services were represented in addition to broader strategies addressing social and environmental stressors that perpetuate smoking and make quitting difficult. The perceived importance and feasibility of clusters were rated differently by participants working in health services that were government-coordinated compared with community-controlled. For health service workers within vulnerable populations, these findings clearly implicate a need for contextualized strategies that mitigate social and environmental stressors in addition to conventional strategies for tobacco control. The concept map is being applied in knowledge translation to guide development of smoking cessation programs for AHWs.

背景与目标： : 澳大利亚原住民，包括土著卫生工作者 (ahw)，吸烟率是非土著人口的两倍。这项研究利用概念映射方法来确定和确定与文化相关的策略以促进ahw戒烟。利益相关者参与者包括AHWs，其他卫生服务员工和烟草控制人员。通过34次访谈，3个焦点小组和利益相关者研讨会，对戒烟策略 (n = 74) 进行了头脑风暴。利益相关者将策略分为有意义的组，并根据感知的重要性和可行性对其进行评分。使用多维缩放和分层聚类分析开发了概念图。描述了十种独特的戒烟策略，这些策略针对个人，家庭和同龄人，社区，工作场所和公共政策。除更广泛的策略外，还提供了戒烟资源和服务，以解决使吸烟永久化并使戒烟困难的社会和环境压力源。与社区控制相比，在政府协调的卫生服务中工作的参与者对集群的重要性和可行性的评价有所不同。对于弱势人群中的卫生服务工作者，这些发现显然暗示了除了传统的烟草控制策略之外，还需要有针对性的策略来减轻社会和环境压力。概念图已应用于知识翻译中，以指导ahw戒烟计划的开发。

BACKGROUND & AIMS: BACKGROUND/AIMS:Cardiovascular disease (CVD) is increased in chronic kidney disease (CKD), and contributed to by the CKD-mineral bone disorder (CKD-MBD). CKD-MBD begins in early CKD and its vascular manifestations begin with vascular stiffness proceeding to increased carotid artery intima-media thickness (cIMT) and vascular calcification (VC). Phosphorus is associated with this progression and is considered a CVD risk factor in CKD. We hypothesized that modifying phosphorus balance with lanthanum carbonate (LaCO3) in early CKD would not produce hypophosphatemia and may affect vascular manifestations of CKD-MBD. METHODS:We randomized 38 subjects with normophosphatemic stage 3 CKD to a fixed dose of LaCO3 or matching placebo without adjusting dietary phosphorus in a 12-month randomized, double-blind, pilot and feasibility study. The primary outcome was the change in serum phosphorus. Secondary outcomes were changes in measures of phosphate homeostasis and vascular stiffness assessed by carotid-femoral pulse wave velocity (PWV), cIMT and VC over 12 months. RESULTS:There were no statistically significant differences between LaCO3 and placebo with respect to the change in serum phosphorus, urinary phosphorus, tubular reabsorption of phosphorus, PWV, cIMT, or VC. Biomarkers of the early CKD-MBD such as plasma fibroblast growth factor-23, Dickkopf-related protein 1 (DKK1), and sclerostin were increased 2- to 3-fold at baseline, but were not affected by LaCO3. CONCLUSION:Twelve months of LaCO3 had no effect on serum phosphorus and did not alter phosphate homeostasis, PWV, cIMT, VC, or biomarkers of CKD-MBD.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Mortality of hemorrhagic shock primarily depends on whether or not the patients can endure the loss of circulating volume until radical treatment is applied. We investigated whether hydrogen (H2) gas inhalation would influence the tolerance to hemorrhagic shock and improve survival. METHODS:Hemorrhagic shock was achieved by withdrawing blood until the mean arterial blood pressure reached 30-35 mm Hg. After 60 minutes of shock, the rats were resuscitated with a volume of normal saline equal to four times the volume of shed blood. The rats were assigned to either the H2 gas (1.3% H2, 26% O2, 72.7% N2)-treated group or the control gas (26% O2, 74% N2)-treated group. Inhalation of the specified gas mixture began at the initiation of blood withdrawal and continued for 2 hours after fluid resuscitation. RESULTS:The survival rate at 6 hours after fluid resuscitation was 80% in H2 gas-treated rats and 30% in control gas-treated rats (p < 0.05). The volume of blood that was removed through a catheter to induce shock was significantly larger in the H2 gas-treated rats than in the control rats. Despite losing more blood, the increase in serum potassium levels was suppressed in the H2 gas-treated rats after 60 minutes of shock. Fluid resuscitation completely restored blood pressure in the H2 gas-treated rats, whereas it failed to fully restore the blood pressure in the control gas-treated rats. At 2 hours after fluid resuscitation, blood pressure remained in the normal range and metabolic acidosis was well compensated in the H2 gas-treated rats, whereas we observed decreased blood pressure and uncompensated metabolic acidosis and hyperkalemia in the surviving control gas-treated rats. CONCLUSIONS:H2 gas inhalation delays the progression to irreversible shock. Clinically, H2 gas inhalation is expected to stabilize the subject until curative treatment can be performed, thereby increasing the probability of survival after hemorrhagic shock.

背景与目标：