Early Diagnosis of Colonic Anastomotic Leak With Peritoneal Endoscopy

Background and Objectives:

At present, we do not have a reliable method for the early diagnosis of colorectal anastomotic leakage (AL). We tested peritoneal flexible endoscopy through a port placed in the abdominal wall in the early postoperative course, as a new diagnostic method for detection of this complication and evaluated the suggested method for safety, feasibility, and accuracy.

Methods:

Ten swine were randomized into 2 groups: group A, colorectal anastomosis without leakage; and group B, colorectal anastomosis with leakage. A button gastrostomy feeding tube was inserted percutaneously into the peritoneal cavity. Colorectal anastomosis (with or without defect) was created 48 hours after the first operation. The swine were examined by peritoneal flexible endoscopy 8 and 24 hours after the colonic operation, by a consultant surgeon who was blinded to both the presence and the allocated location of the of the anastomotic defect.

Results:

None of the animals showed signs of illness 48 hours after the intraperitoneal gastrostomy tube placement. More than half of the anastomosis circumference was identified in 60 and 10% of the animals at endoscopy 8 and 24 hours, respectively, after the anastomosis was created. Excessive adhesion formation was observed in all animals, irrespective of AL. The sensitivity and specificity of endoscopy in detecting peritonitis 24 hours after AL were both 60%.

Conclusions:

Peritoneal endoscopy is a safe and simple procedure. Visualization of the peritoneal cavity in the early postoperative course was limited due to adhesion formation. Further studies are needed to clarify the accuracy of the procedure and to address additional methodological concerns.     

Fecal DNA testing compared with conventional colorectal cancer screening methods: a decision analysis

BACKGROUND & AIMS: Fecal DNA testing is an emerging tool to detect colorectal cancer (CRC). Our aims were to estimate the clinical and economic consequences of fecal DNA testing vs. conventional CRC screening. METHODS: Using a Markov model, we estimated CRC incidence, CRC mortality, and discounted cost/life-year gained for screening by fecal DNA testing (F-DNA), fecal occult blood testing (FOBT) and/or sigmoidoscopy, or colonoscopy (COLO) in persons at average CRC risk from age 50 to 80 years. RESULTS: Compared with no screening, F-DNA at a screening interval of 5 years decreased CRC incidence by 35% and CRC mortality by 54% and gained 4560 life-years per 100,000 persons at USD $47,700/life-year gained in the base case. However, F-DNA gained fewer life-years and was more costly than conventional screening. The average number of colonoscopies per person was 3.8 with COLO and 0.8 with F-DNA. In most 1-way sensitivity analyses and Monte Carlo simulation iterations, F-DNA remained reasonably cost-effective compared with no screening, but COLO and FOBT dominated F-DNA. Assuming fecal DNA testing sensitivities of 65% for CRC and 40% for large polyp, and 95% specificity, a screening interval of 2 years and a test cost of USD $195 would be required to make F-DNA comparable with COLO. CONCLUSIONS: Fecal DNA testing every 5 years appears effective and cost-effective compared with no screening, but inferior to other strategies such as FOBT and COLO. Fecal DNA testing could decrease the national CRC burden if it could improve adherence with screening, particularly where the capacity to perform screening colonoscopy is limited.     

Impact of flexible insulin therapy on blood glucose variability,oxidative stress and inflammation in type 1 diabetic patients: The VARIAFIT study

AimsHbA_1c only partially predicts vascular risk in patients with type 1 diabetes (T1D), and a role for blood glucose variability (BGV) is a matter of debate. For this reason, this study investigated the impact of an educational programme of flexible insulin therapy (FIT) on BGV and oxidative stress.MethodsTests were conducted on 30 adult T1D patients in a prospective, single-centre trial at baseline (M0), and at 3 and 6 months (M3 and M6, respectively) of the FIT programme to determine BGV, as reflected by mean amplitude of glycaemic excursions (MAGE), low blood glucose index (LBGI), lability index (LI), average daily risk range (ADRR), glycaemic lability (scored by two diabetologists), urinary leukotriene E₄ (LTE4), 11-dehydro-thromboxane B₂ (TXB2) and 8-iso-prostaglandin F2α (PGF2).ResultsHbA_1c (7.7 ± 0.9%), ADRR, MAGE, LBGI and LI did not change from M0 to M3 and M6, although ADRR and LBGI significantly improved at M3 and M6 in patients with the highest baseline indices (≥ 40 and ≥ 5, respectively). TXB2 declined at M6 (832 ± 625 vs. 633 ± 972 pg/mg; P = 0.048), whereas LTE4 and PGF2 remained stable. ADRR showed the strongest correlation with glycaemic lability scores at all visits (r ≥ 0.84, P < 0.0001).ConclusionA FIT educational programme improved BGV only in patients with the highest baseline variability, and led to no changes in HbA_1c, while ADRR closely correlated with glycaemic lability score. Our data do not support a relationship between BGV and oxidative stress in T1D patients, although the impact of variability on TXB2 deserves further investigation (ClinicalTrials.gov NCT00973492).     

Fabrication of a Flexible Photodetector Based on a Liquid Eutectic Gallium Indium

A fluidic gallium-based liquid metal (LM) is an interesting material for producing flexible and stretchable electronics. A simple and reliable method developed to facilitate the fabrication of a photodetector based on an LM is presented. A large and thin conductive eutectic gallium indium (EGaIn) film can be fabricated with compressed EGaIn microdroplets. A solution of LM microdroplets can be synthesized by ultrasonication after mixing with EGaIn and ethanol and then dried on a PDMS substrate. In this study, a conductive LM film was obtained after pressing with another substrate. The film was sufficiently conductive and stretchable, and its electrical conductivity was 2.2 × 10⁶ S/m. The thin film was patterned by a fiber laser marker, and the minimum line width of the pattern was approximately 20 μm. Using a sticky PDMS film, a Ga₂O₃ photo-responsive layer was exfoliated from the fabricated LM film. With the patterned LM electrode and the transparent photo-responsive film, a flexible photodetector was fabricated, which yielded photo-response-current ratios of 30.3%, 14.7%, and 16.1% under 254 nm ultraviolet, 365 nm ultraviolet, and visible light, respectively.     

Adaptive optoelectronic camouflage systems with designs inspired by cephalopod skins

Octopus, squid, cuttlefish, and other cephalopods exhibit exceptional capabilities for visually adapting to or differentiating from the coloration and texture of their surroundings, for the purpose of concealment, communication, predation, and reproduction. Long-standing interest in and emerging understanding of the underlying ultrastructure, physiological control, and photonic interactions has recently led to efforts in the construction of artificial systems that have key attributes found in the skins of these organisms. Despite several promising options in active materials for mimicking biological color tuning, existing routes to integrated systems do not include critical capabilities in distributed sensing and actuation. Research described here represents progress in this direction, demonstrated through the construction, experimental study, and computational modeling of materials, device elements, and integration schemes for cephalopod-inspired flexible sheets that can autonomously sense and adapt to the coloration of their surroundings. These systems combine high-performance, multiplexed arrays of actuators and photodetectors in laminated, multilayer configurations on flexible substrates, with overlaid arrangements of pixelated, color-changing elements. The concepts provide realistic routes to thin sheets that can be conformally wrapped onto solid objects to modulate their visual appearance, with potential relevance to consumer, industrial, and military applications.Recently established understanding of many of the key organ and cellular level mechanisms of cephalopod metachrosis (1–5) creates opportunities for the development of engineered systems that adopt similar principles. Here, critical capabilities in distributed sensing and actuation (6–9) must be coupled with elements that provide tunable coloration, such as the thermochromic systems reported here or alternatives such as cholesteric liquid crystals (10–13), electrokinetic and electrofluidic structures (14, 15), or colloidal crystals (16–19). Although interactive displays that incorporate distributed sensors for advanced touch interfaces (20–22) might have some relevance, such capabilities have not been explored in flexible systems or in designs that enable adaptive camouflage. The results reported here show that advances in heterogeneous integration and high-performance flexible/stretchable electronics provide a solution to these critical subsystems when exploited in thin multilayer, multifunctional assemblies. The findings encompass a complete set of materials, components, and integration schemes that enable adaptive optoelectronic camouflage sheets with designs that capture key features and functional capabilities of the skins of cephalopods. These systems combine semiconductor actuators, switching components, and light sensors with inorganic reflectors and organic color-changing materials in a way that allows autonomous matching to background coloration, through the well-known, separate working principles of each component. The multilayer configuration and the lamination processes used for assembly, along with the photopatternable thermochromic materials, are key to realization of these systems. Demonstration devices capable of producing black-and-white patterns that spontaneously match those of the surroundings, without user input or external measurement, involve multilayer architectures and ultrathin sheets of monocrystalline silicon in arrays of components for controlled, local Joule heating, photodetection, and two levels of matrix addressing, combined with metallic diffuse reflectors and simple thermochromic materials, all on soft, flexible substrates. Systematic experimental, computational, and analytical studies of the optical, electrical, thermal, and mechanical properties reveal the fundamental aspects of operation, and also provide quantitative design guidelines that are applicable to future embodiments.The skin of a cephalopod enables rapid, patterned physiological color change, or metachrosis, in a thin three-layered system (2, 23–25). The topmost layer is pigmentary coloration: chromatophore organs that retract or expand rapidly by direct control of muscles that are in turn controlled by nerves originating in the brain. This physiological on/off speed change ranges from ca. 250 to 750 ms. The middle and bottom layers are composed of structural coloration components. The middle layer comprises iridophore cells that can reflect all colors depending on angle of view; some are passive cells and others are physiologically controlled by a slower system: They can be turned on/off in 2–20 s (depending on species, or different cell types on different parts of the body). The bottom layer comprises leucophores (i.e., “white cells”) that are entirely passive (i.e., no physiological control; they are always “on”). This layer diffuses white in all directions (25) and can act as a bright backdrop against which expanded pigmentary chromatophores are viewed; this provides one way in which contrast of the pattern can be controlled (i.e., darkly pigmented chromatophores next to bright white reflective elements).The central control of skin patterning resides in the eyes, which, together with the central and peripheral nervous system, sense the visual background and route control signals throughout the skin to produce a coordinated pattern for communication or camouflage. In addition, the skin contains molecules known as opsins, which are known to be photosensitive in the retina and are thought to be photosensitive in the skin as well. They are hypothesized to play a role in distributed light sensing and control in the periphery (26), thus potentially adding a noncentralized component for skin patterning that enables sensing and actuation independent of the brain.One of the most important features of cephalopod skin—one that provides maximum optical diversity of appearances—is the coordinated action of (i) chromatophores, (ii) iridophores, (iii) leucophores, (iv) muscles, (v) central ocular organs, and (vi) distributed opsins (2, 23–25). The work described here demonstrates pixelated devices that include analogs to each of these key elements, except for the second and fifth, which can be easily incorporated with known photonic materials and conventional digital imagers.     

7-乙基-10-羟基喜树碱脂质体在大鼠体内的代谢和排泄

目的考察7-乙基-10-羟基喜树碱(SN-38)脂质体经静脉注射后,在大鼠尿液、粪便中的代谢产物以及以SN-38原形药物排泄的量。方法大鼠尾静脉单次给予2.77 mg/kg SN-38脂质体,分别于0～6、6～12、12～24、24～48 h分段收集尿液、粪便,采用UPLC/Q-TOFMS法对SN-38脂质体在大鼠尿液、粪便中的代谢产物进行鉴定,并且建立HPLC法,用于大鼠尿液及粪便样品中SN-38原形药物的排泄量的测定。结果 SN-38脂质体的在大鼠体内的代谢产物经鉴定为SN-38G。48 h内脂质体组共有1.57%的原形药物经过尿液排出,共有12.94%的SN-38原形药物经过粪便排出。结论 SN-38脂质体只有少部分以原形药物经尿液和粪便排出体外。     

Learning predator promotes coexistence of prey species in host-parasitoid systems

Ecological theory suggests that frequency-dependent predation, in which more common prey types are disproportionately favored, promotes the coexistence of competing prey species. However, many of the earlier empirical studies that investigated the effect of frequency-dependent predation were short-term and ignored predator-prey dynamics and system persistence. Therefore, we used long-term observation of population dynamics to test how frequency-dependent predation influences the dynamics and coexistence of competing prey species using insect laboratory populations. We established two-host-one-parasitoid populations with two bruchid beetles, Callosobruchus chinensis and C. maculatus, as the hosts and the pteromalid wasp Anisopteromalus calandrae as their common parasitoid. When the parasitoid was absent, C. chinensis was competitively excluded in ～20 wk. Introducing the parasitoid greatly enhanced the coexistence time to a maximum of 118 wk. In the replicates of long-lasting coexistence, the two host species C. maculatus and C. chinensis exhibited periodic antiphase oscillations. Behavioral experiments showed frequency-dependent predation of A. calandrae that was caused by learning. Females of A. calandrae learned host-related olfactory cues during oviposition and increased their preference for the common host species. Numerical simulations showed that parasitoid learning was the essential mechanism that promoted persistence in this host-parasitoid system. Our study is an empirical demonstration that frequency-dependent predation has an important role in greatly enhancing the coexistence of prey populations, suggesting that predator learning affects predator-prey population dynamics and shapes biological communities in nature.     

Ventral Hernia Repair: a Practical Point of View

Purpose: To evaluate the effect of PVP-I liposome hydrogel on intraperitoneal postoperative adhesions. Material and Methods: Thirty Wistar-Albino male rats were randomly divided into three groups. After midline laparotomy, a 1 cm² area of the caecum was abraded with a sterile gauze until subserosal haemorrhage had developed. A 1 χ 1 cm patch of peritoneum located opposite of caecal abrasion was completely dissected. In group 1 (control group, C) adhesion induction was performed and nothing was applied to the wounds. In group 2 and 3, PVP-I solution (3%) (group 2, PI) and PVP-I liposome hydrogel (group 3, PIL) were applied to the caecal abrasion areas and peritoneal defects. Adhesions were classified according to a classification system based on the evaluation of the appearance, extent and strength of the adhesions on postoperative 21^st day.

Results: There was no significant difference of the adhesion scores between the groups (U1 = 45, p > 0.05; U2 = 48, p > 0.05; U3 = 47.5, p > 0.05).

Conclusions: We found that PVP liposome hydrogel did not influence postoperative intraabdominal adhesions and should be further explored for its potential use in various intraabdominal procedures.     

输尿管软镜联合硬镜治疗女性肾盂结石30例报告

目的：评价输尿管软镜联合硬镜治疗女性肾盂结石患者的安全性、有效性及优越性。方法：2012年6月～2013年4月采用输球管软镜联合硬镜治疗女性肾高结行（结石直径〉2cm而≤3cm）患者30例。结果：27例一期碎石成功．一次性碎石率为90％;3例二期碎石成功。无输尿管穿孔、脓肾等严重并发症发生。手术时间54～76min．平均58min。术后住院时间2～5d,平均3．8d。留营双J管2～3脚后拔除。结论：输尿管软镜联合硬镜治疗女性肾孟结石（结石直径≥2cm而≤3cm）是安全、高效的,同时具有创伤小、并发症少的优点,值得在临床上进一步推广使用。