Biophysical mechanisms underlying tefluthrin-induced modulation of gating changes and resurgent current generation in the human Nav1.4 channel

Human skeletal muscle contraction is triggered by activation of Nav1.4 channels. Nav1.4 channels can generate resurgent currents by channel reopening at hyperpolarized potentials through a gating transition dependent on the intracellular Navβ4 peptide in the physiological conditions. Tefluthrin (TEF) is a pyrethroid insecticide that can disrupt electrical signaling in nerves and skeletal muscle, resulting in seizures, muscle spasms, fasciculations, and mental confusion. TEF can also induce tail currents through other voltage-gated sodium channels in the absence of Navβ4 peptide, suggesting that muscle spasms may be caused by resurgent currents. Further, intracellular Navβ4 peptide and extracellular TEF may show competitive or synergistic effects; however, their binding sites are still unknown. To address these issues, electrophysiological recordings were performed on CHO-K1 cells expressing Nav1.4 channels with intracellular Navβ4 peptide, extracellular TEF, or both. TEF and Navβ4 peptide induced a hyperpolarizing shift of activation and inactivation curves in the Nav1.4 channel. TEF also substantially prolonged the inactivation time constants, while simultaneous application of Navβ4 peptide partially reversed this effect. Resurgent currents were enhanced by TEF and Navβ4 peptide at negative potentials, but TEF more potently enhances resurgent currents and dampens decay of resurgent currents. With longer depolarization, peak resurgent currents decay was fastest with the TEF alone. Molecular docking suggested that TEF and Navβ4 peptide binding site(s) are not in the narrowest part of the channel pore, but rather in the bundle-crossing regions and in the domain linkers, respectively. TEF can induce resurgent currents independently and synergistically with Navβ4 peptide, which may explain the muscle spasms observed in TEF intoxication.

Study of Atomic Layer Deposition Nano-Oxide Films on Corrosion Protection of Al-SiC Composites

In recent years, aluminum matrix composites (AMCs) have attracted attention due to their promising properties. However, the presence of ceramic particles in the aluminum matrix renders AMCs a high corrosion rate and makes it challenging to use traditional corrosion protection methods. In this study, atomic layer deposition (ALD) techniques were used to deposit HfO2, ZrO2, TiO2, and Al2O3 thin films on AMC reinforced with 20 vol.% SiC particles. Our results indicate that the presence of micro-cracks between the Al matrix and SiC particles leads to severe micro-crack-induced corrosion in Al-SiC composites. The ALD-deposited films effectively enhance the corrosion resistance of these composites by mitigating this micro-crack-induced corrosion. Among these four atomic-layer deposited films, the HfO2 film exhibits the most effective reduction in the corrosion current density of Al-SiC composites in a 1.5 wt% NaCl solution from 1.27 × 10-6 A/cm2 to 5.89 × 10-11 A/cm2. The electrochemical impedance spectroscopy (EIS) investigation shows that HfO2 deposited on Al-SiC composites has the largest Rp value of 2.0 × 1016. The HfO2 film on Al-SiC composites also exhibits effective inhibition of pitting corrosion, remaining at grade 10 even after 96 h of a salt spray test.

[The diagnostic performance of galactomannan detection in invasive pulmonary aspergillosis with severe and critically ill influenza]

Objective: To analyze the diagnostic performance of serum and bronchoalveolar lavage fluid (BALF) galactomannan (GM) test in invasive pulmonary aspergillosis(IPA) with severe and critically ill influenza. Methods: A retrospective study was performed for 157 patients with severe and critically ill influenza admitted to the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from December 2017 to April 2019.Clinical characteristics and serum and BALF GM values were collected. The patients were divided into an IPA group (n=18) and a non-IPA group (n=139). The definition of IPA modified from AspICU algorithm taken as the gold standard (The corresponding clinical manifestations, imaging manifestations and microbiological diagnostic criteria should be met simultaneously), the performance of serum and BALF GM test and their combination to IPA with influenza were analyzed respectively and receiver operating characteristic curve (ROC) was drawn. Results: A total of 157 cases were enrolled, 95 were critically ill, and the mortality of IPA with influenza was 55.6%(10/18). The APACHE Ⅱ score, PSI score, urea nitrogen, influenza severity (Percentage of critically ill influenza) and invasive ventilator in IPA group were (16±6), (110±31), 10.7 (8.4, 17.8) mmol/L, 88.9% and 66.7%, respectively, which were significantly higher than those in non-IPA group [(10±5), (83±30), 5.2 (3.6, 7.6) mmol/L, 56.8% and 24.5%, P<0.05]. All patients received serum GM test and 32 patients performed BALF GM test at the same time. When the cut-off valve of serum GM test was 0.5 μg/L, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 66.7% (12/18), 95.0% (132/139), 63.2% (12/19) and 95.7% (132/138) respectively. When the cut-off value of BALF GM test was 1.0 μg/L, the sensitivity, specificity, PPV and NPV were 80%(8/10),86.4%(19/22),72.7%(8/11)and 90.5%(19/21)respectively. The BALF GM cut-off value of 0.88 μg/L showed the highest diagnostic efficacy for IPA, for which the sensitivity and specificity were 90%(9/10) and 86.4%(19/22). The areas under the ROC curve of serum GM, BALF GM, and the combination of them were 0.81, 0.85, and 0.94 respectively. The difference was statistically significant (P<0.05) and the combined diagnosis efficiency was higher. Conclusions: Critically ill influenza patients should be alert for IPA. The sensitivity of serum GM test in the diagnosis of IPA with influenza was low, while the NPV was high. The optimum BALF GM cut-off value was 0.88 μg/L. The combination with BALF and serum GM test can improve the diagnostic performance.

Lung Cancer Cell-Derived Secretome Mediates Paraneoplastic Inflammation and Fibrosis in Kidney in Mice

Simple Summary

Paraneoplastic nephrotic syndrome is a complication arising in lung cancer patients. In the present study, we established an LLC1 cell orthotopic xenograft C57BL/6 mice model to translation paraneoplastic nephrotic syndrome (PNS). The pathological aspects of PNS were characterized in TGF-β signaling-engaged renal fibrosis, and renal inflammation with IL-6 expression in kidney. To reveal how the lung cancer cells remotely drive pathogenic progression, secretome derived from LLC1 cells and A549 cells were proteomically profiled. Additionally, the secretome profiling was subjected to diseases and biofunctions assessment by Ingenuity Pathway analysis (IPA). As matter of secretome profiling and IPA prediction, the Fibronectin, C1r, and C1s are potential of nephrotoxicity linked to paraneoplastic effects on glomerular pathogenesis in these lung cancer mice.

Abstract

Kidney failure is a possible but rare complication in lung cancer patients that may be caused by massive tumor lysis or a paraneoplastic effect. Clinical case reports have documented pathological characteristics of paraneoplastic syndrome in glomeruli, but are short of molecular details. When Lewis lung carcinoma 1 (LLC1) cells were implanted in mice lungs to establish lung cancer, renal failure was frequently observed two weeks post orthotopic xenograft. The high urinary albumin-to-creatinine ratio (ACR) was diagnosed as paraneoplastic nephrotic syndrome in those lung cancer mice. Profiling the secretome of the lung cancer cells revealed that the secretory proteins were potentially nephrotoxic. The nephrotoxicity of lung cancer-derived secretory proteins was tested by examining the pathogenic effects of 1 × 10⁶, 2 × 10⁶, and 5 × 10⁶ LLC1 cell xenografts on the pathogenic progression in kidneys. Severe albuminuria was present in the mice that received 5 × 10⁶ LLC1 cells implantation, whereas 10⁶ cell and 2 × 10⁶ cell-implanted mice have slightly increased albuminuria. Pathological examinations revealed that the glomeruli had capillary loop collapse, tumor antigen deposition in glomeruli, and renal intratubular casts. Since IL-6 and MCP-1 are pathologic markers of glomerulopathy, their distributions were examined in the kidneys of the lung cancer mice. Moderate to severe inflammation in the kidneys was correlated with increases in the number of cells implanted in the mice, which was reflected by renal IL-6 and MCP-1 levels, and urine ACR. TGF-β signaling-engaged renal fibrosis was validated in the lung cancer mice. These results indicated that lung cancer cells could provoke inflammation and activate renal fibrosis.

[Diagnostic performance of pathology, culture and ROSE of lung biopsy for suspected pulmonary infectious diseases]

Objective: To explore the diagnostic performance of CT guided percutaneous lung biopsy (PTLB) with pathology, culture and rapid on-site evaluation (ROSE) in patients with pulmonary infectious diseases. Methods: From January 2016 to June 2018, a retrospective study was implemented in the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University. Patients who received PTLB, suspected with lung infection were included. The basic information, clinical symptoms, imaging findings, diagnostic methods, complications, and changes in treatment of cases were collected. The diagnostic sensitivity of histopathology, microbial culture, and ROSE were evaluated at the same time. Results: A total of 529 cases were enrolled, including 354 males and 175 females, (59±14) years old in average. Tuberculosis was identified in 197 cases, non-tuberculosis mycobacteria (NTM) pulmonary disease in 8, cryptococcosis in 95, pulmonary aspergillosis in 27, filamentous fungal pneumonia in 3, talaromyces marneffei pulmonary infection in 3 and pulmonary candidiasis in 1, bacterial pneumonia in 39, and pathogen were unknown in 156 cases. A total of 417 cases were submitted for histopathology and microbial culture at the same time, the diagnostic value of pathology and microbial culture were 35.0% (146/417) and 45.6% (190/417), respectively. Combined pathology with microbial culture, the diagnostic value increased to 62.8% (262/417). The diagnostic accuracy of ROSE was 51.8% (71/137). The most common complication of PTLB was pneumothorax 26.1% (138/529). 56.1% (297/529) of the patients received targeted treatment after the diagnosis was confirmed, and 43.9% (232/529) maintained the original treatment. Conclusion: The pathology, microbial culture, and ROSE of PTLB have relative high diagnostic value for pulmonary infectious diseases.

Rapid Biochemical Mixture Screening by Three-Dimensional Patterned Multifunctional Substrate with Ultra-Thin Layer Chromatography (UTLC) and Surface Enhanced Raman Scattering (SERS)

We present a three-dimensional patterned (3DP) multifunctional substrate with the functions of ultra-thin layer chromatography (UTLC) and surface enhanced Raman scattering (SERS), which simultaneously enables mixture separation, target localization and label-free detection. This multifunctional substrate is comprised of a 3DP silicon nanowires array (3DP-SiNWA), decorated with silver nano-dendrites (AgNDs) atop. The 3DP-SiNWA is fabricated by a facile photolithographic process and low-cost metal assisted chemical etching (MaCE) process. Then, the AgNDs are decorated onto 3DP-SiNWA by a wet chemical reduction process, obtaining 3DP-AgNDs@SiNWA multifunctional substrates. With various patterns designed on the substrates, the signal intensity could be maximized by the excellent confinement and concentrated effects of patterns. By using this 3DP-AgNDs@SiNWA substrate to scrutinize the mixture of two visible dyes, the individual target could be recognized and further boosted the Raman signal of target 15.42 times comparing to the un-patterned AgNDs@SiNWA substrate. Therefore, such a three-dimensional patterned multifunctional substrate empowers rapid mixture screening, and can be readily employed in practical applications for biochemical assays, food safety and other fields.

Effect of metformin on kidney function in patients with type 2 diabetes mellitus and moderate chronic kidney disease

Background

Impaired renal function can lead to the accumulation of metformin, and elevated concentrations of metformin have been associated with lactic acidosis. The aim of this study was to evaluate the effect of continuous metformin treatment in patients with type 2 diabetes mellitus (DM) and moderate chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR) 30–0 ml/min/1.73 m²) on renal function.

Methods

A total of the 616 patients were enrolled from the research database of Kaohsiung Medical University Hospital from January 1 to 2009 and December 31, 2013. The patients were divided into two groups: those who continued metformin treatment (continuation group; n = 484), and those who discontinued metformin treatment for at least 100 days (interruption group; n = 132).

Results

The slope of eGFR in the metformin interruption group was statistically lower than that in the metformin continuation group (0.75 ± 0.76 vs. –1.32 ± 0.24 mL/min/1.73 m²/year, p = 0.0007). After adjusting for baseline covariates in the multivariate linear regression analysis, the continuation of metformin (unstandardized coefficient β, –2.072; 95% confidence interval, –3.268– –0.876) was a risk factor for the patients with DM and moderate CKD.

Conclusions

Metformin may have an adverse effect on renal function in patients with type 2 DM and moderate CKD.

[The diagnostic performance of galactomannan detection for invasive pulmonary aspergillosis in non-neutropenic hosts]

Objective: To evaluate the diagnostic performance of galactomannan(GM)detection in serum and BALF for invasive pulmonary aspergillosis (IPA) in non-neutropenic hosts. Methods: A pospective study was performed for 1 356 non-neutropenic hosts admitted to the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from September 2014 to October 2015. Serum GM test was performed for all, and BALF GM test for a proportion of the patients. The patients were divided into an IPA group and a non-IPA group. SPSS 20.0 was adopted for statistical analysis. Results: A total of 1 361 cases were enrolled, aging 18-96 years, with an average age of (64±15) years. There were 879 male and 477 female patients. Thirty-nine cases were diagnosed as IPA, accounting for 2.9%. For serum GM test, the sensitivity, specificity, PPV and NPV were 43.6%(17/39), 94.1%(1 239/1 317), 17.9%(17/95)and 98.3%(1 239/1 261)respectively. Ninety-six cases received serum and BALF GM tests at the same time. If the cut-off value of BALF GM test was 0.8, the sensitivity, specificity, PPV and NPV were 86.7%(13/15), 60.5%(49/81), 28.9%(13/45), 96.1%(49/51)respectively, but if the value was 1.0, the sensitivity, specificity, PPV and NPV were 86.7%(13/15), 74.1%(60/81), 38.2%(13/34), 96.8%(60/62)respectively. The ROC curve area of BALF GM, serum GM and the combined serum and BALF GM was 0.87, 0.75 and 0.90, respectively. Conclusions: The sensitivity of serum GM test in non-neutropenic hosts was low, but it had a high negative predictive value.The best BALF GM cut-off value was 1.0. The combined serum and BALF GM tests improved the diagnostic performance.

Adverse health outcomes and health concerns among survivors of various childhood cancers: Perspectives from mothers

Advanced therapies have improved outcomes and also resulted in a growing risk of long-term adverse health events. This study intends to estimate incidences of adverse health events and examine differences in adverse health events among childhood cancer survivors, and to understand the concerns of mothers after their child has completed cancer treatment. An explanatory sequential mixed-method was used. A total of 201 paediatric cancer survivors' mothers with mean age 43.6 years were recruited. Of the survivors, 12.4% experienced five or more adverse health events. The incidence of adverse health events of altered body image, fatigue and neurocognitive problems were 31.54%, 14.77% and 12.53% respectively. Among survivors, significant differences in adverse health events of pain, endocrine problems and altered body image issues were identified. Survivors receiving radiotherapy, bone marrow transplants or completing treatment after 6-10 years experienced significantly more adverse health events. Maintaining health was the greatest concern for mothers, and the qualitative reports of their concerns could be categorised: living in uncertainty, and keeping forward-looking. Childhood brain tumour survivors were identified as experiencing more adverse health events than other survivors. The need for healthcare teams to consider mothers' health concerns was highlighted.

Association of Serum Uric Acid Concentration with Diabetic Retinopathy and Albuminuria in Taiwanese Patients with Type 2 Diabetes Mellitus

Patients with type 2 diabetes mellitus (DM) may experience chronic microvascular complications such as diabetic retinopathy (DR) and diabetic nephropathy (DN) during their lifetime. In clinical studies, serum uric acid concentration has been found to be associated with DR and DN. The goal of this study was to evaluate the relationship between the increases in serum uric acid level and the severity of DR and albuminuria in Taiwanese patients with type 2 DM. We recorded serum uric acid concentration, the severity of DR, and the severity of albuminuria by calculating urinary albumin-to-creatinine ratio (UACR) in 385 patients with type 2 DM. In multivariate logistic regression analysis, a high uric acid concentration was a risk factor for albuminuria (odds ratio (OR), 1.227; 95% confidence interval (CI) = 1.015–1.482; p = 0.034) and DR (OR, 1.264; 95% CI = 1.084–1.473; p = 0.003). We also demonstrated that there was a higher concentration of serum uric acid in the patients with more severe albuminuria and DR. In conclusion, an increased serum uric acid level was significantly correlated with the severity of albuminuria and DR in Taiwanese patients with type 2 DM.

MTTP-297H polymorphism reduced serum cholesterol but increased risk of non-alcoholic fatty liver disease-a cross-sectional study

Background

Microsomal triglyceride transfer protein (MTP) works to lipidate and assemble the apoB-containing lipoproteins in liver. It closely links up the hepatic secretion of lipid to regulate serum lipid and atherosclerosis. Cases of MTTP gene mutation is characterized by abetalipoproteinemia and remarkable hepatic steatosis or cirrhosis. Several MTTP polymorphisms have been reported relating to metabolic syndrome, hyperlipidemia and steatohepatitis. We supposed the regulation of serum lipids and risk of non-alcoholic fatty liver disease (NAFLD) formation may be modified by individual susceptibility related to the MTTP polymorphisms.

Methods and results

A cross-sectional population of 1193 subjects, 1087 males and 106 females mean aged 45.9 ± 8.9 years, were enrolled without recognized secondary hyperlipidemia. Fasting serum lipid, insulin, and non-esterified fatty acid were assessed and transformed to insulin resistance index, HOMA-IR and Adipo-IR. After ruling out alcohol abuser, non-alcoholic fatty liver disease (NAFLD) was diagnosed by abdominal ultrasound. Five common MTTP polymorphisms (promoter -493G/T, E98D, I128T, N166S, and Q297H) were conducted by TaqMan assay. Multivariate regression analysis was used to estimate their impact on serum lipid and NAFLD risk. Assessment revealed a differential impact on LDL-C and non-HDL-C, which were sequentially determined by the Q297H polymorphism, insulin resistance, body mass index and age. Carriers of homozygous minor allele (297H) had significantly lower LDL-C and non-HDL-C but higher risk for NAFLD. Molecular modeling of the 297H variant demonstrated higher free energy, potentially referring to an unstable structure and functional sequence.

Conclusion

These results evidenced the MTTP polymorphisms could modulate the lipid homeostasis to determine the serum lipids and risk of NAFLD. The MTTP 297H polymorphism interacted with age, insulin resistance and BMI to decrease serum apoB containing lipoproteins (LDL-C and non-HDL-C) but increase the risk of NAFLD formation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0242-6) contains supplementary material, which is available to authorized users.

Automated detection of fovea in fundus images based on vessel-free zone and adaptive Gaussian template

This study developed a computerised method for fovea centre detection in fundus images. In the method, the centre of the optic disc was localised first by the template matching method, the disc-fovea axis (a line connecting the optic disc centre and the fovea) was then determined by searching the vessel-free region, and finally the fovea centre was detected by matching the fovea template around the centre of the axis. Adaptive Gaussian templates were used to localise the centres of the optic disc and fovea for the images with different resolutions. The proposed method was evaluated using three publicly available databases (DIARETDB0, DIARETDB1 and MESSIDOR), which consisted of a total of 1419 fundus images with different resolutions. The proposed method obtained the fovea detection accuracies of 93.1%, 92.1% and 97.8% for the DIARETDB0, DIARETDB1 and MESSIDOR databases, respectively. The overall accuracy of the proposed method was 97.0% in this study.

Neuroprotective effect of agmatine in rats with transient cerebral ischemia using MR imaging and histopathologic evaluation

PURPOSE

This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation.

MATERIALS AND METHODS

Following surgical induction of MCAO for 90min, agmatine was injected 5min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3h-72h in a 1.5T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections.

RESULTS

Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3h and peaked at 24h-48h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72h) point except for significantly smaller ADC lesions in the MCAO model (P<0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P<0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P<0.05).

CONCLUSION

Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after transient cerebral ischemia.

Oncogenic mutations regulate tumor microenvironment through induction of growth factors and angiogenic mediators

Activating mutations in the tyrosine kinase domain of HER2 (ErbB2) have been identified in human cancers. Compared to wild-type HER2, mutant HER2 shows constitutively activate kinase activity and increased oncogenicity. Cells transformed by mutant HER2 are resistant to EGFR tyrosine kinase inhibitors and exhibit an attenuated response to the HER2 antibody trastuzumab. We investigated herein pathways through which mutant HER2 alters the extracellular environment, potentially leading to drug resistance and the effect of simultaneously targeting HER2 and the tumor cell microenvironment with a therapeutic intent. Expression of mutant HER2 in mammary epithelial cells activated autocrine transforming growth factor (TGF) β1 signaling through a mechanism involving Rac1 and JNK-AP1-dependent transcription. Cells transformed by an activating mutant of H-Ras (G12V) also expressed higher TGF-β1 level through Rac1 activation. In addition, mutant HER2 induced the EGFR ligands TGF-α and amphiregulin at the mRNA and protein levels. Vascular endothelial growth factor (VEGF), a target of the TGF-β-Smad transcriptional regulation, was also induced as a result of expression of mutant HER2. Inhibition of TGF-β signaling with the Alk5 small molecule inhibitor LY2109761 reduced growth and invasiveness of cells expressing mutant HER2. Combined inhibition of intracellular and paracrine effects of mutant HER2 by trastuzumab and the EGFR antibody cetuximab was more efficient than single-agent therapies. These data suggest that mutations in oncogenes such as HER2 and Ras not only alter intracellular signaling and also influence on other components of the tumor microenvironment by inducing several pro-invasive growth factors. In turn, these serve as extracellular targets of novel therapeutic strategies directed at both cancer-driving oncogenes and the modified tumor microenvironment.

High-sensitivity C-reactive protein and silent myocardial ischemia in Chinese with type 2 diabetes mellitus

Coronary artery disease (CAD) is a major cause of morbidity and mortality in patients with type 2 diabetes mellitus. When diabetes exists in patients with established CAD, absolute risk for future events is very high. Diabetic patients often have severe, yet asymptomatic, CAD. Although high-sensitivity C-reactive protein (hsCRP) is a strong independent risk factor for cardiovascular events, there is an unclear association between it and silent myocardial ischemia in diabetic patients. In this study, we assess the relationship between hsCRP and silent myocardial ischemia in Chinese with type 2 diabetes mellitus. We designed a cross-sectional study with 225 asymptomatic diabetic patients having no known CAD. Ischemia was assessed by myocardial perfusion imaging. A total of 109 patients (48.4%) was found to have silent myocardial ischemia. Logistic regression analysis revealed age (odds ratio = 4.01, P = .002) (95% confidence interval, 1.98-7.44) and hsCRP (odds ratio = 2.58, P = .005) (95% confidence interval, 1.33-5.01) to be associated with greater risk of silent myocardial ischemia. Using the American Diabetes Association screening guidelines to evaluate risk, we found silent myocardial ischemia to be equally distributed between diabetic patients with 2 or more cardiac risk factors and those with less than 2 risk factors. Twenty-seven (24.8%) patients with silent myocardial ischemia were missed when the American Diabetes Association guidelines were used alone. High-sensitivity C-reactive protein was associated with silent myocardial ischemia in our study. High-sensitivity C-reactive protein might help detect silent myocardial ischemia in diabetic Chinese who may need aggressive treatment to reduce future CAD morbidity and mortality in Taiwan.

The association of endothelial nitric oxide synthase G894T polymorphism with C-reactive protein level and metabolic syndrome in a Chinese study group

Some studies have reported a possible relationship between endothelial nitric oxide synthase (eNOS) and metabolic syndrome (MS), which is associated with an increased risk for cardiovascular disease. A recent meta-analysis study found the eNOS G894T polymorphism to be associated with ischemic heart disease. Here, we examine the association of eNOS G894T polymorphism with MS in a Chinese population (n = 397). The eNOS T+ (TT and GT) genotypes (56.92% vs 38.86%; odds ratio, 2.08; 95% confidence interval, 1.21-3.56; P = .007) and T allele (33.08% vs 23.34%; odds ratio, 1.62; 95% confidence interval, 1.08-2.44; P = .019) were significantly more frequent in subjects who had MS. Furthermore, subjects with eNOS T+ genotypes had significantly higher plasma C-reactive protein levels as compared with GG subjects (P = .004). This study shows that, in a Chinese population, eNOS G894T polymorphism is associated with an elevated C-reactive protein level and MS.

Antiangiogenic and radiotherapy for cancer treatment

Tumor growth and progression depends on tumor angiogenesis, the growth of tumor blood vessels, therefore, targeting tumor angiogenesis is a very promising approach for controlling tumor growth and/or causing regression. Tumor blood vessels have been recognized as a critical component of radiation response to the point of being independent of tumor oxygenation during radiation. An anti-angiogenic approach has been considered less likely to develop drug resistance. But recent findings suggest that anti-angiogenesis causes hypoxia that selects tumor cells (due to genetic instability) that are less dependent on blood supply and leads to drug resistance. The approach of combination of anti-angiogenesis with ionizing radiation by targeting both endothelial and tumor cells should minimize this possibility. The combination may produce a synergistic anti-tumor effect.

EP2, a receptor for PGE2, regulates tumor angiogenesis through direct effects on endothelial cell motility and survival

Prostaglandin E2 (PGE2), a major cyclooxygenase (COX) metabolite, plays important roles in tumor biology. We studied the role of EP2, a receptor for PGE2, in tumor angiogenesis using EP2 knockout mice. We found that deletion of the EP2 receptor impaired tumor angiogenesis and this finding was confirmed by an in vivo corneal angiogenesis model and an ex vivo aortic ring assay. To further characterize the cellular mechanisms of the EP2 receptor in angiogenesis, we isolated primary pulmonary endothelial cells (ECs) from wild-type (wt) and EP2-/- mice and observed that EP2-/- ECs exhibited defects in vascular branch formation when compared to wt ECs. In addition, EP2-/- ECs showed impaired cell motility on collagen-coated surface and they responded poorly to PGE2-induced cell migration compared to control cells. However, no difference in cell proliferation was observed between the EP2-/- and wt Ecs. In addition, EP2-/- ECs were more susceptible to apoptosis than wt cells under growth factor depletion conditions. Collectively, our data demonstrate that EP2 signaling in endothelium directly regulates tumor angiogenesis by contributing to cell survival and endothelial cell motility. Moreover, our finding suggests that EP2 is a major receptor in PGE2-mediated cell motility in ECs.

Human cervix contains functional luteinizing hormone/human chorionic gonadotropin receptors

The upper genital tract of women contains functional LH/human chorionic gonadotropin (hCG) receptors. Whether the cervix, an anatomical continuum of the uterus and fallopian tubes, also contains these receptors has never been investigated. Multiple receptor detection techniques revealed their presence with higher levels in endocervix than in ectocervix. The receptor positive cells include stratified squamous luminal epithelium of the ectocervix, columnar epithelium, glands, blood vessels, and smooth muscle in the endocervix. Treatment of cervical tissue minces with hCG resulted in a significant increase in cAMP levels and a decrease in cyclooxygenase-2 protein levels in endocervix, but not in ectocervix. In summary, human cervix contains functional LH/hCG receptors, which suggests that LH during the menstrual cycle and hCG during pregnancy may regulate cervical functions.

Prevention of PONV with dexamethasone in female patients undergoing desflurane anesthesia for thyroidectomy

BACKGROUND

Desflurane is associated with a higher incidence of 24-h postoperative nausea and vomiting (PONV) as compared with sevoflurane or isoflurane. Dexamethasone 5 mg i.v. is suggested to be the minimum effective dose for prophylaxis of PONV in women undergoing thyroidectomy with isoflurane anesthesia. The objective of this study was to investigate whether a 5 mg dose of dexamethasone could be enough for, or a larger dose at 8 mg, could be more capable of preventing PONV in women undergoing desflurane anesthesia for thyroidectomy.

METHODS

One hundred and thirty five patients were assigned to receive one of three treatment regimens prior to induction i.e., dexamethasone 8 mg i.v. (Group D8), dexamethesone 5 mg i.v. (Group D5) or saline (Group S).

RESULTS

It was demonstrated that the prophylactic administration of either dexamethasone 8 mg or 5 mg significantly reduced the overall incidence of PONV in patients undergoing thyroidectomy with desflurane anesthesia (P < 0.001, Group D8 vs. Group S; Group D5 vs. Group S). However, patients who received dexamethasone 8 mg showed a higher incidence of complete responses (no vomiting or need of rescue antiemetic medication for a 24-h postoperative period) in comparison with those receiving dexamethasone 5 mg (86% vs. 67%; P < 0.01).

CONCLUSIONS

The results of this study showed that in PONV prophylaxis, in female patients undergoing desflurane anesthesia for thyroidectomy, the effect of dexamethasone 8 mg was superior to that of dexamethasone 5 mg.

Low dose fentanyl and propofol improve the speed and quality of tidal-breathing induction techniques in sevoflurane anesthesia for adults

BACKGROUND

The objective of this study was to investigate whether low dose fentanyl, with or without low dose propofol, as pretreatment agent/s is capable of speeding up and improving the quality of laryngeal mask airway (LMA) insertion in tidal-breathing induction technique with high-concentration sevoflurane.

METHODS

One hundred and twenty patients were assigned to one of the three groups: Group S, induction with 8% sevoflurane only; Group F + S, 1.0 microgram/kg fentanyl prior to induction; and Group F + P + S, 1.0 microgram/kg fentanyl and 0.5 mg/kg propofol prior to induction.

RESULTS

It was demonstrated that the time from administration of drug (drugs) to loss of eyelash reflex (P < 0.05, Group F + P + S vs. F + S; P < 0.01, Group F + P + S vs. S), to jaw relaxation (P < 0.05, Group F + P + S vs. S) and time taken for LMA insertion (P < 0.01, Group F + P + S vs. S) were all shorter in Group F + P + S, with fewer complications (coughing and involuntary movement) during induction, however, the first time success rate with LMA insertion did not significantly differ among the comparing groups. According to a postoperative inquiry (by questionnaire), there were significantly more patients in the Group F + P + S (57.5%) who considered the induction as pleasant (P < 0.05), of whom 75% expressed that they would be willing to undergo an induction of the same form again in the future (P < 0.05). This more positive rating may be related to the mild sedative effects of the agents given and shorter induction time, which significantly helped reduce the rate of recall of the unpleasant gas.

CONCLUSIONS

The results of this study of LMA insertion, for ASA I or II adult patients undergoing the tidal-breathing technique with 8% sevoflurane, suggest that pretreatment with 1 microgram/kg fentanyl plus 0.5 mg/kg propofol is superior in comparison with either pretreatment with 1 microgram/kg fentanyl or absence of pretreatment.

Inhibition of vascular endothelial growth factor receptor signaling leads to reversal of tumor resistance to radiotherapy

Certain refractory neoplasms, such as glioblastoma multiforme (GBM) and melanoma, demonstrate a resistant tumor phenotype in vivo. We observed that these refractory tumor models (GBM and melanoma) contain blood vessels that are relatively resistant to radiotherapy. To determine whether the vascular endothelial growth factor receptor-2 (Flk-1/KDR) may be a therapeutic target to improve the effects of radiotherapy, we used the soluble extracellular component of Flk-1 (ExFlk), which blocks vascular endothelial growth factor binding to Flk-1 receptor expressed on the tumor endothelium. Both sFlk-1 and the Flk-1-specifc inhibitor SU5416 eliminated the resistance phenotype in GBM and melanoma microvasculature as determined by both the vascular window and Doppler blood flow methods. Human microendothelial cells and human umbilical vein endothelial cells showed minimal radiation-induced apoptosis. The Flk-1 antagonists sFlk-1 and SU5416 reverted these cell models to apoptosis-prone phenotype. Flk-1 antagonists also reverted GBM and melanoma tumor models to radiation-sensitive phenotype after treatment with 3 Gy. These findings demonstrate that the tumor microenvironment including the survival of tumor-associated endothelial cells contributes to tumor blood vessel resistance to therapy.

Interference microscopy for three-dimensional imaging with wavelength-to-depth encoding

A novel interference microscope for three-dimensional (3D) imaging based on a wavelength-to-depth encoding technique is presented. Wavelength-to-depth encoding is realized by use of a diffractive lens and wavelength tuning. A high depth resolution of 0.71 mum is obtained with 0.90-N.A. objective lenses. Experimental measurements of a four-level grating are presented, and the results are found to be comparable with those obtained with a Dektak profilometer and a similar interference microscope that uses mechanical depth scanning. The system is promising for fast, noncontact, high-resolution 3D imaging.

Nontranslational three-dimensional profilometry by chromatic confocal microscopy with dynamically configurable micromirror scanning

A confocal microscope profilometer, which incorporates chromatic depth scanning with a diffractive optical element and a digital micromirror device for configurable transverse scanning, provides three-dimensional (3D) quantitative measurements without mechanical translation of either the sample or the microscope. We used a microscope with various objective lenses (e.g., 40x, 60x, and 100x) to achieve different system characteristics. With a 100x objective, the microscope acquires stable measurements over a 320 microm x 240 microm surface area with a depth resolution of 0.39 microm at a 3-Hz scan rate. The total longitudinal field of view is 26.4 microm for a wavelength tuning range of 48.3 nm. The FWHM value of the longitudinal point-spread function is measured to be 0.99 microm. We present 3D measurements of a four-phase-level diffractive element and an integrated-circuit chip. The resolution and the accuracy are shown to be equivalent to those found with use of conventional mechanical scanning.

Initial experience with a modification of the follicle aspiration, sperm injection, and assisted rupture technique

OBJECTIVE

To establish cycle fecundity with a modification of the follicle aspiration, sperm injection, and assisted rupture (FASIAR) technique.

DESIGN

Prospective, observational study.

SETTING

University and health maintenance organization-based infertility centers.

PATIENT(S)

Infertile couples were enrolled from our professional practices. All patients were </=41 years of age and had documentation of at least one patent tube.

INTERVENTION(S)

After administration of clomiphene citrate, patients were given an intramuscular injection of hCG when the lead ovarian follicle was >16-18 mm in diameter by transvaginal ultrasonography. A modified FASIAR procedure was performed 22 to 28 hours after hCG injection.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate.

RESULT(S)

No clinical pregnancies were observed with the modified FASIAR technique.

CONCLUSION(S)

The FASIAR technique is still an attractive and economical technique. Our modification of the FASIAR technique, however, resulted in a suboptimal cycle fecundity.

Group A streptococcal necrotizing fasciitis after varicella: report of two cases

The most common complication in children with varicella is cutaneous superimposed infection with pyogenic bacteria. The association between varicella and group A beta-hemolytic streptococci (GABHS) necrotizing fasciitis has been recorded for over 50 years. Two cases with the specific problems are presented here together with a review of the literature. This infection is caused by GABHS superinfection of the skin lesions due to chickenpox. It can be unrecognized or late-diagnosed, with fatal consequences. Because of prompt recognition and aggressive surgical and medical treatment, the two patients survived without loss of the affected limb.

Single-shot depth-section imaging through chromatic slit-scan confocal microscopy

A chromatic confocal microscope constructed with a white-light source in combination with a diffractive lens provides wavelength-to-depth coding for profile measurements of a three-dimensional sample. We acquired depth-section images nonmechanically and in parallel by incorporating a slit-scan confocal technique into the system. A system using a 100x objective obtained a depth resolution of 0.023 mum comparable with surface profilometers that operate using conventional confocal microscopy. Experimental measurements of a four-phase-level diffractive element and of a machined, metal bearing are presented.

The maternal and fetal effects of the addition of sufentanil to 0.5% spinal bupivacaine for cesarean delivery

BACKGROUND

Opioid added to local anesthetic for spinal anesthesia was first introduced into clinical practice in 1979 with intrathecal morphine as a forerunner. As morphine is water soluble and has prolonged action, late respiratory depression following spinal anesthesia is not infrequent and is the most serious complication that causes our concern. Sufentanil which is more hydrophobic than morphine also with shorter duration of action and quicker onset when injected into the subarchnoid space could be more effective and a safer drug as an adjuvant to local anesthetic in spinal anesthesia.

METHODS

Forty-one parturients who had given consent to spinal anesthesia for Cesarean delivery, were anesthetized with 12.5 mg of 0.5% bupivacaine alone or in combination with 10 micrograms sufentanil in a randomized double blind manner. They were assigned either to C group (Control group) in which nothing is added to the local anesthetic and S group (Study group) in which sufentanil was added to the local anesthetic.

RESULTS

Perioperatively, hypotension occurred more in S group (17 against 11) but chest discomfort was less (3 against 7). Within 3 h after anesthesia 3 out of 19 parturients in S group requested analgesics but almost all parturients in C group did so.

CONCLUSIONS

The addition of intrathecal sufentanil to 0.5% bupivacaine for spinal anesthesia improved perioperative discomfort and significantly reduced the demand of post-operative analgesia but on the other hands, it tended to increase perioperative hypotension and cause mild pruritus.

Comparing the effectiveness of different educational programs for patients with total knee arthroplasty

PURPOSE

To compare the effects of preadmission and postadmission educational programs for patients with total knee arthroplasty.

DESIGN

Quasiexperimental study.

SAMPLE

60 total knee arthroplasty patients.

METHODS

Subjects in the experimental group received preadmission preoperative teaching with an instruction booklet during a preoperative outpatient clinic visit. Upon admission to the hospital, they were presented with an educational video tape. The control group received only postadmission preoperative teaching with the same instruction booklet and no video. PREADMISSION AND POSTADMISSION: Preoperative anxiety level, knowledge about postoperative care, exercise performance and postoperative recovery were used as outcome measures.

FINDINGS

The research results found: 1. there was no significant difference between the two groups in reduction of preoperative anxiety score: 2. the experimental group had a significantly higher knowledge level than the control group; 3. the experimental group performed exercise more regularly and correctly than those in the control group; 4. the experimental group had greater flexion of the operative knee joint than the control group.

CONCLUSION

Preadmission teaching with a videotape program and a health manual for patients with total knee arthroplasty is recommended.

IMPLICATIONS FOR NURSING RESEARCH

More indicators such as postoperative pain and patient satisfaction can be used to investigate the effectiveness of intervention. In addition, increasing the sample size is recommended for future studies.

Ultrasound compared with clinical examination in infantile hypertrophic pyloric stenosis

OBJECTIVES

To assess the accuracy of clinical examination as compared with ultrasound imaging in the diagnosis of infantile hypertrophic pyloric stenosis. Duration of hospital stay, time between admission and surgery, and financial implications were also considered.

DESIGN

A prospective study of patients referred to the surgical team with a possible diagnosis of pyloric stenosis from May 1993 to January 1995.

SETTING

Neonatal and paediatric surgical wards and imaging department of a paediatric teaching hospital.

SUBJECTS

116 patients referred to the surgical team with a possible diagnosis of pyloric stenosis.

RESULTS

75 patients in this study had pyloric stenosis (64.6%). Clinical examination had a sensitivity of 72%, specificity of 97%, with a positive and negative predictive value of 98% and 61% respectively. There were 16 diagnostic errors (one false positive and 15 false negative). Ultrasound imaging had a sensitivity of 97%, specificity of 100%, with a positive and negative predictive value of 100% and 98% respectively. There was one diagnostic error (one false negative). Eight patients required repeat scans for confirmation of the diagnosis. On review of the initial scans in these patients, seven were noted to have inaccurate measurements due to poor technique. The average time between repeated scans was 28.2 hours. Ultrasound imaging cost 13.90 pounds per scan and initiated a change in management only in the clinically false negative group at a cost of 52 pounds per patient. The average duration of hospital stay was 3.1 days and the mean time between admission and surgery was 19.2 hours. The total cost for treatment of a patient with pyloric stenosis was 1602 pounds.

CONCLUSION

Ultrasound imaging should be reserved for those cases where clinical examination is negative and should be carried out by sonographers who see enough cases to maintain their expertise.

Detection of submaximal effort in isometric and isokinetic knee extension tests

The use of torque variability and slope measures to detect submaximal efforts has been studied in isometric tests, but not fully investigated in isokinetic tests. The purpose of this study was to investigate differences between maximal and submaximal efforts in isometric and isokinetic knee extension using torque variability and slope measures obtained from 32 volunteers (age = 25.2 +/- 4.7 years). The coefficient of variation of average torque, coefficient of variation of peak torque, and slope to peak torque were obtained from maximal and submaximal torque curves during isometric and two isokinetic tests (60 degrees/sec and 180 degrees/sec). Significant differences between effort levels (maximal and submaximal) were shown for all variables in isometric and isokinetic tests. An optimized cut-off value to determine submaximal efforts without false positives was determined for each variable. The coefficient of variation of average torque detected 75% of submaximal efforts at 180 degrees/sec and slope to peak torque detected 63% of submaximal efforts at 60 degrees/sec. For both speeds, combining the coefficient of variation of average torque with slope improved the submaximal detection rate to 84%. No variable provided a satisfactory detection rate for the isometric test. Therefore, submaximal isokinetic knee extensions are detectable with torque variability and slope measures, but submaximal isometric exercise is not detectable.

Preparation and evaluation of sodium diclofenac controlled-release tablets. II. Dibasic calcium phosphate as a retardant in mixtures for direct compression

The dissolution behaviour of a direct compression compact prepared with sodium diclofenac and dibasic calcium phosphate (DCP) in different weight ratios with or without Biosoluble polymer (acrylic-based resin) was investigated in distilled water and in a medium with changing pH. The results indicate that the amount of sodium diclofenac released from the compact was dependent on the amount of drug and DCP used in the compact, and was also controlled by the amount of Biosoluble polymer added. A chemical reaction forming diclofenac acid might occur on the surface of the sodium diclofenac compact during exposure to the acidic medium, which was confirmed by diffuse-reflectance spectroscopy. The tablet with a 1:2 weight ratio of sodium diclofenac to DCP exhibited a sustained-release behaviour, similar to commercial sustained-release products (Voltaren SR-100 and Grofenac Retard), but a lower release rate was found as compared to the commercial products. The dissolution behaviour of the study tablet and the commercial products was found to be dependent on the dissolution medium and the rotating speeds. Glass beads were added to the dissolution assembly to simulate the influence of food, and the enhanced friction between tablet and glass beads might result in a higher dissolution rate of the tablet and the commercial products.

[Postoperative hypoglycemia after pheochromocytoma resection]

A case of severe hypoglycemia (30 mg/dL) after resection of unilateral pheochromocytoma is reported. Consciousness regained after 20 gm dextrose water was given intravenously. Rebound insulin storm is highly suspected as the main mechanism for the development of post-operative hypoglycemia. Administration of alpha and beta adrenergic blockers may also contribute to the severity of the hypoglycemia. Closely monitoring blood sugar level during the perioperative period is the only way to prevent the occurrence of such a catastrophe.

Agenesis of posterior urethra in a male child and its operative reconstruction

An 8-year-old boy passing urine through both fecal and urinary outlets since birth is reported. Investigations showed absence of the posterior urethra. A surgical procedure for reconstruction of the posterior urethra is described. The embryological explanation is also discussed.

Identification of the guanine binding domain peptide of the GTP-binding site of glucagon

Glucagon, a peptide hormone synthesized and secreted by alpha islet cells, regulates glucose homeostasis by several mechanisms. Using [gamma 32P]8N3GTP, a proven photoaffinity probe for GTP, a specific nucleotide binding site on human glucagon was detected that showed preference for GTP. Half-maximal saturation of photoinsertion into the polypeptide hormone was at 8-12 microM with either [alpha 32P]8N3GTP or [gamma 32P]8N3GTP. GTP protected photolabeling with an apparent kd of 15 microM, whereas ATP was less effective as a protector, exhibiting an apparent kd of about 30 microM. Maximal protection by GTP and ATP was over 90%. UTP, CTP, GDP, ADP, GMP, AMP, guanosine, adenosine, guanine, and adenine were much less effective protectors, indicating that binding is specific for purine nucleoside triphosphates, particularly GTP. Mg2+ at 150 microM enhanced photoinsertion (twofold), whereas at 2-10 mM, it inhibited photoinsertion. Both Ca2+ and Zn2+ at 0.2 mM decreased photoinsertion about 45%. Purification of chymotryptic and tryptic digests of photolabeled glucagon by reverse-phase high performance liquid chromatography (HPLC) revealed that the N-terminal peptide, HSQGTF, was the only peptide region covalently photomodified by [32P]8N3GTP. GTP, if present during photolysis, greatly reduced both photoinsertion into glucagon and the amount of radiolabeled peptide recovered on HPLC. The specificity of binding to the N-terminal region is suggestive of a physiological role for a glucagon-GTP complex in the mechanism of action of this hormone.

Evaluation of the Behring Nephelometer for detection of low level urinary albumin

Mildly increased urinary albumin excretion rates and concentrations, below the quantity normally detected by conventional urinary protein and albumin methods, have prognostic significance for the development of nephropathy in patients with diabetes mellitus. The authors evaluated the automated Behring Nephelometer using Behring reagents for the detection of low level urinary albumin. Within run coefficients of variation (CVs, N = 20) are 1.7%, 1.3%, and 2.4% at mean urinary albumin levels of 16, 70, and 217 mg/L, respectively. Between run CVs (N = 20) are 4.5%, 2.6%, and 4.4% at mean albumin levels of 19, 71, and 239 mg/L, respectively. The method is sensitive to 3 mg/L. Hemoglobin, immunoglobulins, bilirubin, urea, and radiographic contrast media beyond a few hours of injection show no significant interference at levels normally expected from clinical specimens. Analysis is unaffected by pH within the physiologic range. Most urine specimens are stable for at least eight days when refrigerated at 4 degrees C. Specimen centrifugation before analysis is essential to avoid a negative bias that occurs when analyzing uncentrifuged refrigerated samples. Preanalytical freezing produces results higher than those observed in fresh or refrigerated samples. The authors conclude that automated nephelometry using the Behring Nephelometer is a convenient, simple, and accurate technique for the determination of low level urinary albumin.