The feasibility and reliability of using circular electrode for sphincter of Oddi electromyography in anaesthetised rabbits

Sphincter of Oddi manometry (SOM) is the gold standard for assessing sphincter of Oddi dysfunction (SOD), but is considered a diagnostic sensitivity of 30-80% and associated with significant complications of pancreatitis. Electromyography (EMG) of sphincter of Oddi (SO) using a circular electrode (CE) may be useful in improving diagnostic accuracy and reducing complications. To evaluate the feasibility and reliability of the CE, we record myoelectric activity of SO in rabbits using the CE to compare with the traditional needle electrode (NE). The CE was prepared using a double-channel biogel catheter with two silver rings at the head of the catheter. The CE was then inserted into the lumen of the SO through the duodenal papilla, and myoelectric activity was recorded in the SO in 30 rabbits. An EMG recorded using an NE was performed at the same time, when the SO was in basal state, after injection of cholecystokinin and N-butylscopolamine bromide. Electromyographs recorded by the two methods were then evaluated. Satisfactory SO EMGs were acquired using the CE without any injury. Simultaneous recording revealed a very similar traces and one-to-one correspondence of SO spike bursts (SOSB). Linear regression analysis showed a significant direct correlation between the two methods for SOSB duration and amplitude. The results suggested that CE was comparable with NE in terms of recording efficacy. The CE also has advantages of easy fixation, accurate localisation, broad applicability and ease of achieving satisfactory outcomes without trauma, compared with the NE.

Serum bilirubin levels on ICU admission are associated with ARDS development and mortality in sepsis

BACKGROUND

Hyperbilirubinaemia is a common complication of sepsis. Elevated bilirubin may induce inflammation and apoptosis. It was hypothesised that increased serum bilirubin on Intensive Care Unit (ICU) admission contributes to sepsis-related acute respiratory distress syndrome (ARDS).

METHODS

Serum bilirubin on ICU admission was measured in 1006 patients with sepsis. Serial serum bilirubin was analysed prospectively in patients with sepsis who had ARDS for a period of 28 days. The effects of clinical factors and variants of the UGT1A1 gene on serum bilirubin levels were determined. Outcomes were ARDS risk and mortality.

RESULTS

During 60-day follow-up, 326 patients with sepsis developed ARDS, of whom 144 died from ARDS. The hyperbilirubinaemia (>or=2.0 mg/dl) rate in patients with ARDS (22.4%) was higher than in those without ARDS (14.1%, p = 0.002). For each 1.0 mg/dl increase in admission bilirubin, ARDS risk and 28- and 60-day ARDS mortalities were increased by 7% (OR = 1.07; p = 0.003), 20% (OR = 1.20; p = 0.002) and 18% (OR = 1.18; p = 0.004), respectively. Compared with subjects with bilirubin levels <2.0 mg/dl, patients with hyperbilirubinaemia had higher risks of ARDS (OR = 2.12; p = 0.0007) and 28-day (OR = 2.24; p = 0.020) and 60-day ARDS mortalities (OR = 2.09; p = 0.020). In sepsis-related ARDS, serial bilirubin levels in non-survivors were consistently higher than in survivors (p<0.0001). Clinical variables explained 29.5% of the interindividual variation in bilirubin levels, whereas genetic variants of UGT1A1 contributed 7.5%.

CONCLUSION

In sepsis, a higher serum bilirubin level on ICU admission is associated with subsequent ARDS development and mortality.

Preservation and transplantation of porcine testis tissue

Grafting of immature mammalian testis tissue to mouse hosts can preserve the male germline. To make this approach applicable to a clinical or field situation, it is imperative that the testis tissue and/or spermatozoa harvested from grafted tissue are preserved successfully. The aim of the present study was to evaluate protocols for the preservation of testis tissue in a porcine model. Testis tissue was stored at 4 degrees C for short-term preservation or cryopreserved by slow-freezing, automated slow-freezing or vitrification for long-term storage. Preserved tissue was transplanted ectopically to mouse hosts and recovered xenografts were analysed histologically. In addition, spermatozoa were harvested from xenografts and cryopreserved. Total cell viability and germ cell viability remained high after tissue preservation. Complete spermatogenesis occurred in xenografts preserved by cooling up to 48 h, whereas spermatogenesis progressed to round spermatids in the xenografts that were frozen-thawed before grafting. Approximately 50% of spermatozoa harvested from xenografts remained viable after freezing and thawing. The in vivo developmental potential of cryopreserved tissue was reduced despite high post-thaw viability. Therefore, it is important to evaluate germ cell differentiation in vivo in addition to cell viability in vitro when optimising freezing protocols for testis tissue.

Prediction of nutritional status and intestinal tumor involvement in patients with primary or recurrent ovarian cancer: Results of a prospective study

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Background: Global malnutrition is widespread among patients with ovarian cancer. The objective of this study was to investigate the influence of the nutritional status on the clinical outcome of patients with primary or recurrent ovarian and peritoneal cancer. Methods: In a two-year-period (January 2007 - December 2008) 152 consecutive patients were analysed. 79 (52%) of them had primary and 73 (48%) recurrent disease. At the time of admission for surgical therapy, the body composition was analysed with Bioelectrical Impedance Analysis (BIA) using phase angle alpha and ratio of extra-cellular mass and body cell mass (ECM/BCM). Serum protein parameters were registered. The risk of malnutrition was estimated by Nutritional Risk Score (NRS). During operation a standardised and validated tumor documentation tool (IMO) was performed. Nutritional parameters were correlated with IMO-parameters. Results: The median age of patients was 56 years (range 48–66) with median BMI 24.4 kg/m2 (range 21.8–27.3). In 23% primary and 14% recurrent cases a high nutritional risk was classified (NRS≥3). These patients had significantly lower serum albumin, pre-albumin and transferrin levels compared to patients with NRS<3 (p < 0.05). FIGO stage and NRS correlated negatively with phase angle alpha and positively with ECM/BCM in patients with primary diagnosis (p < 0.05). Patients with primary or recurrent disease who required surgical resection of small or large intestine, phase angle alpha and serum albumin level were significantly lower than in patients with no intestinal involvement (p < 0.05). Conclusions: Independent of tumor stage, the preoperative evaluation of BIA, especially phase angle α, is a valid method to predict surgical outcome in patients with ovarian and peritoneal cancer.

No significant financial relationships to disclose.

Impact of malnutrition on surgical outcome of patients with ovarian cancer: Results of a prospective study

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Background: The purpose of this study was to examine an influence of poor nutritional status on surgical outcome in patients with ovarian cancer. Methods: Data from 152 consecutive patients with histologically confirmed ovarian cancer were prospectively analyzed. Overall 79 suffered from primary and 73 from recurrent disease. All patients received a systematic nutritional assessment prior to cytoreductive surgery and postoperative all complications were analyzed in detail. The Nutritional Risk Score (NRS-2002) was used to identify patients at high nutritional risk (NRS≥3). Intraoperatively, a standardized documentation script (IMO) was applied including tumor localization, surgical interventions, and postoperative residual tumor mass. Results: 29 patients (19%) were classified as malnourished, including 19 (24%) with primary and 10 (14%) with recurrent disease. These patients showed a significantly poorer performance status preoperatively compared to patients with NRS<3 (p < 0.05), which was assessed according to the American Society of Anesthesiologists (ASA). Also an intra-operatively documented tumor spread was significantly more extended in group with NRS≥3 than among patients with NRS<3 (p < 0.05). In malnourished patients complete resection rate was significantly decreased (31% vs. 69%, p < 0.001) and they required more often a colo- or ileostoma (17% vs. 6%, p = 0.041). Malnourished patients suffered more often from post-operative complications (62% vs. 37%, p < 0.05), especially infectious like pneumonia or sepsis. All postoperative mortality events (3 cases) occurred in the malnourished group. Conclusions: Malnourished ovarian cancer patients have significantly more often post-operative complications. They suffer from more extended tumor spread and were less frequently postoperatively tumor-free. Based on our results further prospective trials of preoperative nutritional therapy to improve surgical outcome are warranted.

No significant financial relationships to disclose.

Heparin use and venous thromboembolism (VTE) among cancer patients receiving chemotherapy with a prior history of VTE

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Background: Heparin is an effective treatment option for the prevention of venous thromboembolism (VTE) in cancer patients on chemotherapy. To date, information on the use of both low molecular weight heparin (LMWH) and non-LMWH in cancer patients receiving chemotherapy that have had a prior VTE is lacking. We evaluated heparin treatment patterns as well as the incidence of VTE in a cohort of cancer patients receiving chemotherapy, who have had a VTE prior to their cancer diagnosis. Methods: We conducted a retrospective cohort study using a large claims database representing the U.S. commercially-insured population. The cohort included all patients 18–64 years old from 2000 to 2007 who were diagnosed with cancer, were on chemotherapy, and who had a VTE occurring up to 12 months before cancer (n=331). We defined a diagnosis of cancer as two ICD-9 claims 30 days apart or more. A combination of ICD-9, HCPCS, and CPT codes were used to capture chemotherapy treatment after cancer. A VTE was identified by a single ICD-9 claim of 415.1, 451.2, 451.81, 451.9, 453.1, 453.2, 453.8, or 453.9. VTE claims occurring within 6 months of the index claim were considered part of the same VTE event. A patient was considered to have a VTE after cancer if they had a VTE claim that occurred both after the cancer diagnosis and at least 6 months beyond the most recent pre-cancer index VTE date. Results: Fifty-one percent of cancer patients with a history of VTE were prescribed an anticoagulant (n = 171). Fewer patients took LMWH compared to non-LMWH (6.7% versus 27.8%) while a portion took both (17.2%). A VTE after cancer was experienced by 49.1% of those on any kind of anticoagulant, 45.4% of those taking LMWH, 43.5% of those taking non-LMWH, and 59.6% of those who had taken both types. Fewer VTEs were reported among those taking no anticoagulants (29.4%). Conclusions: Approximately half of all cancer patients receiving chemotherapy were receiving heparin, with a smaller proportion using only LMWH. Even with prophylaxis, VTE recurs in half of cancer patients with a VTE history who receive chemotherapy. Recurrent VTE is a serious risk despite heparin or LMWH prophylaxis.

[Table: see text]

Rat model of reperfused partial liver infarction: characterization with multiparametric magnetic resonance imaging, microangiography, and histomorphology

BACKGROUND

Rat model of reperfused partial liver infarction (RPLI) has been increasingly used in studying new diagnostics and therapeutics.

PURPOSE

To characterize the RPLI model using magnetic resonance imaging (MRI), microangiography, and histopathology.

MATERIAL AND METHODS

RPLI was induced in eight rats by occluding hepatic inflow to the right liver lobe for 3 hours. MRI was performed at a 1.5 T clinical scanner 6 hours after reperfusion to obtain T2-weighted (T2WI), T1-weighted (T1WI), contrast-enhanced (CE) T1WI, diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) maps, T1-weighted dynamic contrast-enhanced (T1-DC) perfusion-weighted imaging (PWI), and T2*-weighted dynamic susceptibility contrast-enhanced (T2*-DSC) PWI images. Rats were sacrificed for microangiography and histomorphology. In vivo morphological and functional MRI parameters, including maximum initial slope (MIS), K value, relative blood flow (rBF), relative blood volume (rBV), time to peak (TTP), and mean transit time (MTT), were matched with postmortem findings.

RESULTS

The infarcted lobe was conspicuous from normal liver with lower and higher signal intensity on T1WI (P=0.018) and T2WI (P=0.001), respectively. Contrast between infarcted and normal liver reversed on CE-T1WI after gadolinium injection. The infarction averaged 37.5% of total liver volume. DWI and ADC maps were able to detect subtle perfusion-related differences (P<0.05). With T1-DC-PWI, increased extravasation and vascular permeability were reflected by significantly greater MIS (P=0.034) and K value (P=0.014) in infarction. T2*-DSC-PWI showed lower rBF and rBV with shorter TTP and MTT in infarcted liver (P<0.05). In vivo MRI findings corresponded well with postmortem outcomes.

CONCLUSION

RPLI in rats could be characterized by multiparametric MRI and postmortem assessments, with insight into the no-reflow phenomenon, which implies its further application for preclinical assessments of new pharmaceutics.

Unusual doping dependence of the electronic structure and coexistence of spin-density-wave and superconductor phases in single crystalline Sr1-xKxFe2As2

The nature of the spin-density wave (SDW) and its relation with superconductivity are crucial issues in the newly discovered iron-pnictide superconductors. Particularly, it is unclear whether the superconducting phase and SDW are truly exclusive from each other. We here report splittings of the band structures in Sr1-xKxFe2As2 (x=0, 0.1, 0.18), and their unusual doping dependence. Our data on single crystalline samples prove that the SDW and superconductivity could coexist in iron pnictides.

Electron transport in single molecules: from benzene to graphene

Electron movement within and between molecules--that is, electron transfer--is important in many chemical, electrochemical, and biological processes. Recent advances, particularly in scanning electrochemical microscopy (SECM), scanning-tunneling microscopy (STM), and atomic force microscopy (AFM), permit the study of electron movement within single molecules. In this Account, we describe electron transport at the single-molecule level. We begin by examining the distinction between electron transport (from semiconductor physics) and electron transfer (a more general term referring to electron movement between donor and acceptor). The relation between these phenomena allows us to apply our understanding of single-molecule electron transport between electrodes to a broad range of other electron transfer processes. Electron transport is most efficient when the electron transmission probability via a molecule reaches 100%; the corresponding conductance is then 2e(2)/h (e is the charge of the electron and h is the Planck constant). This ideal conduction has been observed in a single metal atom and a string of metal atoms connected between two electrodes. However, the conductance of a molecule connected to two electrodes is often orders of magnitude less than the ideal and strongly depends on both the intrinsic properties of the molecule and its local environment. Molecular length, means of coupling to the electrodes, the presence of conjugated double bonds, and the inclusion of possible redox centers (for example, ferrocene) within the molecular wire have a pronounced effect on the conductance. This complex behavior is responsible for diverse chemical and biological phenomena and is potentially useful for device applications. Polycyclic aromatic hydrocarbons (PAHs) afford unique insight into electron transport in single molecules. The simplest one, benzene, has a conductance much less than 2e(2)/h due to its large LUMO-HOMO gap. At the other end of the spectrum, graphene sheets and carbon nanotubes--consisting of infinite numbers of aromatic rings--have small or even zero energy gaps between the conduction and valence bands. Between these two limits are intermediate molecules with rich properties, such as perylene derivatives made of seven aromatic rings; the properties of these types of molecules have yet to be fully explored. Studying PAHs is important not only in answering fundamental questions about electron transport but also in the ongoing quest for molecular-scale electronic devices. This line of research also helps bridge the gap between electron transfer phenomena in small redox molecules and electron transport properties in nanostructures.

Electronic structure and unusual exchange splitting in the spin-density-wave state of the BaFe2As2 parent compound of iron-based superconductors

The magnetic properties in the parent compounds are often intimately related to the microscopic mechanism of superconductivity. Here we report the first direct measurements on the electronic structure of a parent compound of the newly discovered iron-based superconductor, BaFe2As2, which provides a foundation for further studies. We show that the energy of the spin density wave in BaFe2As2 is mainly lowered through exotic exchange splitting of the band structure.

Potential for pulmonary protection by nebulized milrinone during warm ischemia

OBJECTIVE

A method to compensate for the donor shortage may be the utilization of donation after cardiac death. The control of lung injury against warm ischemia is crucial in manipulating donors after cardiac death. Nebulization is a simple and feasible drug delivery route after cardiac death. Herein we have examined the potential effect of nebulized milrinone, a phosphodiesterase III inhibitor, on pulmonary warm ischemia.

MATERIALS AND METHODS

Deeply anesthetized rats were euthanized by exsanguination. Lungs were exposed to warm ischemia with ventilation up to 2 hours. Milrinone was nebulized for 10 minutes at the beginning of warm ischemia (n = 5). In the control group (n = 5), normal saline was nebulized for the same time. At given intervals, the lungs were partially resected to measure adenine nucleotide and cyclic adenosine monophosphate levels.

RESULTS

In both groups, lung tissue cyclic adenosine monophosphate levels decreased significantly at 2 hours after warm ischemia; however, there was no significant difference between the groups. Lung tissue adenosine triphosphate levels significantly decreased at 2 hours after ischemia in the control group, while they did not drop up to 2 hours in the milrinone group. Further, lung tissue adenosine triphosphate levels at 2 hours after ischemia were higher in the milrinone group than the control group.

CONCLUSIONS

Our results confirmed that milrinone nebulization during warm ischemia maintained lung tissue adenosine triphosphate levels. Therefore, milrinone nebulization may have potential for lung protection against warm ischemia.

Association analysis of TIM-1 -232G > A and 5383_5397 insertion/deletion polymorphisms with childhood asthma and total serum immunoglobulin E levels in middle China

BACKGROUND

One of the members of the T cell immunoglobulin (Ig) domain and mucin domain (TIM) gene family, TIM-1, located in the chromosome 5q31-33 region, has been associated with the development of T helper (T(H)) 2-biased immune responses and may be selectively expressed in T(H)2 cells. Previous studies have also shown an association between polymorphisms in the TIM-1 gene and asthma or asthma-related phenotypes.

OBJECTIVE

The aim of the present study was to analyze the association between the TIM-1 polymorphisms -232G > A and 5383_5397 insertion/deletion (ins/del) and susceptibility to asthma in a group of patients from middle China.

METHODS

Polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and PCR-polyacrylamide gel electrophoresis were used to detect -232G > A and 5383_5397 ins/del genotypes in 302 asthmatic children and 206 controls. Serum total IgE was measured by chemiluminescence and specific IgE to common aeroallergens by immunoblot analysis.

RESULTS

We found no association between the -232G > A polymorphism and asthma or total serum IgE levels or statistically significant differences between asthma and control subjects in terms of genotype and allele frequency for the 5383_5397 ins/del polymorphism.We did, however, detect a difference in total serum IgE levels for 5383_5397 ins/ins genotypes in individuals with atopic asthma (P < .05) in that they had higher IgE levels than those with del/del and del/ins genotypes.

CONCLUSION

Our results suggest that the 5383_5397 ins/ins genotype in the TIM-1 gene is associated with elevated serum total IgE levels, particularly in individuals with atopic asthma. Further studies are needed to confirm such an association.

Sex-specific association of epidermal growth factor gene polymorphisms with acute respiratory distress syndrome

Epidermal growth factor (EGF) is involved in alveolar epithelial repair, lung fluid clearance and inflammation, and is regulated by sex hormones. An unmatched, nested case-control study was conducted to evaluate the associations of EGF variants with acute respiratory distress syndrome (ARDS) and the role of sex on the associations between EGF variants and ARDS. Patients with ARDS risk factors upon intensive care unit admission were enrolled. Cases were 416 Caucasians who developed ARDS and controls were 1,052 Caucasians who did not develop ARDS. Cases were followed for clinical outcomes and 60-day mortality. One functional single nucleotide polymorphism (SNP), rs4444903, and six haplotype-tagging SNPs spanning the entire EGF gene were genotyped. No individual SNP or haplotype was associated with ARDS risk or outcomes in all subjects. Sex-stratified analyses showed opposite effects of EGF variants on ARDS in males versus in females. SNPs rs4444903, rs2298991, rs7692976 and rs4698803, and haplotypes GGCGTC and ATCAAG were associated with ARDS risk in males. No associations were observed in females. Interaction analysis showed that rs4444903, rs2298991, rs7692976 and rs6533485 significantly interacted with sex for ARDS risk. The present study suggests that associations of epidermal growth factor gene variants with acute respiratory distress syndrome risk are modified by sex. The current findings should be replicated in other populations.