REVIEW: The Zero-Stress State of the Gastrointestinal Tract:

The stresses and strains that remain in an organ when the external load is removed (the no-load state) are called residual stresses and strains. They can be relieved by cutting up the organ to obtain the zero-stress configuration. This phenomenon was demonstrated more than 15 years ago in cardiovascular research but until recently it was not realized by the gastrointestinal research community. The function of the gastrointestinal tract is to propel food by peristaltic motion, which is a result of the interaction of the tissue forces in the wall and the hydrodynamic forces in the food bolus. To understand the tissue forces, it is necessary to know the stress–strain relationships of the tissues that must be measured in reference to the zero-stress state. It has become clear that the zero-stress configuration of the gastrointestinal tract is very different from that of the no-load condition and that the zero-stress state is sensitive to structural and mechanical remodeling. The purpose of this review is to describe the basic theory and experiments of residual stress and to explore its physiological and pathophysiological implications in the gastrointestinal system.     

不同能量及营养结构饮食对雌性大鼠性发育的影响

Objective To investigate the effects of diets with different calorie and nutritional values on pubertal onset in female rats. Method Female Wistar rat models receiving calorie-deprived (group R) (Experiment 1) ,fat-rich(group F) ,glucose-rich(group G) and protein-rich(group P) (Experiment 2) test diets were established,and rats receiving diets with normal caloric value were considered as control group (group C). The body weight (BW) ,food-intake and vaginal patency (VP) were observed. The rats were killed at the day of vaginal patency. The BW, uterus weight (UW), uterus index (UI), calorie intake per day (CI), perirenal fat weight (PFW) and perirenal fat index (PFI) were measured. The serum levels of leptin, ghrelin, IGF- Ⅰ were tested by means of ELISA.Results Experiment 1:The VP was retarded in group R compared with group C (P<0. 01). There was a significant difference in BW, UW,UI ,CI,leptin and ghrelin at the VP day between group R and group C (all P<0.01) ,and no significant difference in IGF- Ⅰ levels between these two groups. Experiment 2 :The VP was retarded in group F,group G and group P in comparison with group C (P<0.01). The BW, PFW and PFI in group G and group F were markedly higher than those in group P and group C. The leptin level in group F was the highest, and the lowest in group P. The ghrelin level in group G was the highest,and that in group P was the lowest. However,there were no significant differences in IGF- Ⅰ and UI among these, four groups. Conclusion The normal pubertal onset of female rats requires sufficient caloric stores and balanced nutrient. Diets malnutrition and fat-rich, glucoserich and protein-rich test diets all delay pubertal onset in female rats.     

Systolic Stretch Characterizes the Electromechanical Substrate Responsive to Cardiac Resynchronization Therapy

ObjectivesIn this study, the authors tested the hypotheses that the systolic stretch index (SSI) developed by computer modeling and applied using echocardiographic strain imaging may characterize the electromechanical substrate predictive of outcome following cardiac resynchronization therapy (CRT). They included patients with QRS width 120 to 149 ms or non-left bundle branch block (LBBB), where clinical uncertainty for CRT exists. They further tested the hypothesis that global longitudinal strain (GLS) has additional prognostic value.BackgroundResponse to CRT is variable. Guidelines favor patient selection by electrocardiographic LBBB with QRS width ≥150 ms.MethodsThe authors studied 442 patients enrolled in the Adaptive CRT 94-site randomized trial with New York Heart Association functional class III–IV heart failure, ejection fraction ≤35%, and QRS ≥120 ms. A novel computer program semiautomatically calculated the SSI from strain curves as the sum of posterolateral prestretch percent before aortic valve opening and the septal rebound stretch percent during ejection. The primary endpoint was hospitalization for heart failure (HF) or death, and the secondary endpoint was death over 2 years after CRT.ResultsIn all patients, high longitudinal SSI (≥ group median of 3.1%) was significantly associated with freedom from the primary endpoint of HF hospitalization or death (hazard ratio [HR] for low SSI: 2.17; 95% confidence interval [CI]: 1.45 to 3.24, p < 0.001) and secondary endpoint of death (HR for low SSI: 4.06; 95% CI: 1.95 to 8.45, p < 0.001). Among the 203 patients with QRS 120 to 149 ms or non-LBBB, those with high longitudinal SSI (≥ group median of 2.6%) had significantly fewer HF hospitalizations or deaths (HR for low SSI: 2.08; 95% CI: 1.27 to 3.41, p = 0.004) and longer survival (HR for low SSI: 5.08; 95% CI: 1.94 to 13.31, p < 0.001), similar to patients with LBBB ≥150 ms. SSI by circumferential strain had similar associations with clinical outcomes, and GLS was additive to SSI in predicting clinical events (p = 0.001).ConclusionsSystolic stretch by strain imaging characterized the myocardial substrate associated with favorable CRT response, including in the important patient subgroup with QRS width 120 to 149 ms or non-LBBB. GLS had additive prognostic value.     

Characterization of Open-Cell Sponges via Magnetic Resonance and X-ray Tomography

The applications of polymeric sponges are varied, ranging from cleaning and filtration to medical applications. The specific properties of polymeric foams, such as pore size and connectivity, are dependent on their constituent materials and production methods. Nuclear magnetic resonance imaging (MRI) and X-ray micro-computed tomography (µCT) offer complementary information about the structure and properties of porous media. In this study, we employed MRI, in combination with µCT, to characterize the structure of polymeric open-cell foam, and to determine how it changes upon compression, µCT was used to identify the morphology of the pores within sponge plugs, extracted from polyurethane open-cell sponges. MRI T₂ relaxation maps and bulk T₂ relaxation times measurements were performed for 7° dH water contained within the same polyurethane foams used for µCT. Magnetic resonance and µCT measurements were conducted on both uncompressed and 60% compressed sponge plugs. Compression was achieved using a graduated sample holder with plunger. A relationship between the average T₂ relaxation time and maximum opening was observed, where smaller maximum openings were found to have a shorter T₂ relaxation times. It was also found that upon compression, the average maximum opening of pores decreased. Average pore size ranges of 375–632 ± 1 µm, for uncompressed plugs, and 301–473 ± 1 µm, for compressed plugs, were observed. By determining maximum opening values and T₂ relaxation times, it was observed that the pore structure varies between sponges within the same production batch, as well as even with a single sponge.     

A systematic review of risk of HIV transmission through biting or spitting: implications for policy

Objectives

The perceived threat of HIV transmission through spitting and biting is evidenced by the increasing use of “spit hoods” by Police Forces in the UK. In addition, a draft parliamentary bill has called for increased penalties for assaults on emergency workers, citing the risk of communicable disease transmission as one justification. We aimed to review literature relating to the risk of HIV transmission through biting or spitting.

Methods

A systematic literature search was conducted using Medline, Embase and Northern Lights databases and conference websites using search terms relating to HIV, AIDS, bite, spit and saliva. Inclusion and exclusion criteria were applied to identified citations. We classified plausibility of HIV transmission as low, medium, high or confirmed based on pre‐specified criteria.

Results

A total of 742 abstracts were reviewed, yielding 32 articles for full‐text review and 13 case reports/series after inclusion and exclusion criteria had been applied. There were no reported cases of HIV transmission related to spitting and nine cases identified following a bite, in which the majority occurred between family (six of nine), in fights involving serious wounds (three of nine), or to untrained first‐aiders placing fingers in the mouth of someone having a seizure (two of nine). Only four cases were classified as highly plausible or confirmed transmission. None related to emergency workers and none were in the UK.

Conclusions

There is no risk of transmitting HIV through spitting, and the risk through biting is negligible. Post‐exposure prophylaxis is not indicated after a bite in all but exceptional circumstances. Policies to protect emergency workers should be developed with this evidence in mind.     

Penile dog bite in an adolescent

Dog bites to the external genitalia are rare. In this case, a 16-year-old boy suffered a dog bite wound to the penis. The wound was cleansed with copious amounts of sterile normal saline by means of high-pressure syringe irrigation. The child had an uneventful recovery.     

心内直视术后应激性溃疡发生机制

应激性溃疡是心内直视手术后的严重并发症之一，一旦发生。将大大增加病人ICU的滞留时间和医疗费用，同时也增加了围手术期病死率。现就心内直视手术后应激性溃疡的发生机制综述如下。     

系统训练模式对鼻咽癌放疗后张口困难的影响

目的探讨系统张口训练模式对改善鼻咽癌放疗后张口困难的效果。方法将93例鼻咽癌患者随机分为2组,实验组46例在常规放疗后护理的同时采用系统张口训练模式,对照组47例则仅给予常规放疗后护理,比较2组于放疗后6个月及放疗后1年发生张口困难的例数与困难程度。结果实验组放疗后6个月及放疗后1年发生张口困难的例数显著少于对照组(P<0.05),且实验组发生Ⅲ级张口困难的人数显著少于对照组(P<0.05)。结论系统张口训练模式能降低鼻咽癌放疗后张口困难的发生率并减轻张口困难的严重程度。     

Lizard Bites of the Head and Neck

Background

As the ownership of lizards becomes more prevalent in the United States, injuries from these exotic pets will increase. Emergency and primary care physicians must be familiar with the proper management of lizard bites to the head and neck.

Objectives

The aim of this case report is to discuss the potential complications and proper management of lizard bites to the head and neck.

Case Report

A 47-year-old man presented to the emergency department 3 h after his 5-foot iguana bit his face. The wounds were irrigated and primarily closed. Tetanus prophylaxis was administered. He was given oral amoxicillin/clavulanate potassium for 7 days. Sutures were removed 1 week after the repair.

Conclusions

Topical antiseptic care, verification of tetanus status, primary wound closure, and careful monitoring of non-venomous lizard bites is recommended for lizard bites to the head and neck. Wounds at risk for infection should be treated with a quinolone or other antibiotics covering Salmonella as well as human skin flora. Venomous lizard (e.g., Gila monster and Mexican Beaded Lizard) bites require prompt attention due to potentially significant morbidities including anaphylaxis, disseminated intravascular coagulation, and acute myocardial infarction.     

犬咬伤伤口一期缝合与延迟缝合的对比分析

目的：探讨对犬咬伤伤口行一期缝合的可行性,比较该法与延迟缝合在伤口感染率以及伤口愈合美观性等方面的差异。方法：采用前瞻性随机队列研究,将需伤口缝合的犬咬伤患者随机分为2组：一期缝合组130例,延迟缝合组50例。评价伤口换药及拆线时伤口感染率及伤口愈合美观性评分。结果：在130例行一期缝合的犬咬伤患者中,共有8例（6.1%）发生伤口感染,无全身性感染出现;对照组50例,共2例（4.0%）发生伤口感染,无全身性感染出现。一期缝合组共计73例（56.1%）患者伤口愈合美观性评分为最佳;对照组共计17例（34.0%）患者伤口愈合美观性评分为最佳。结论：对犬咬伤伤口行一期缝合,尽管其感染率较对照组稍高,但考虑到患者对伤口美观的要求,仍在可接受的合理范围内。