Design of Digital-Twin Human-Machine Interface Sensor with Intelligent Finger Gesture Recognition

In this study, the design of a Digital-twin human-machine interface sensor (DT-HMIS) is proposed. This is a digital-twin sensor (DT-Sensor) that can meet the demands of human-machine automation collaboration in Industry 5.0. The DT-HMIS allows users/patients to add, modify, delete, query, and restore their previously memorized DT finger gesture mapping model and programmable logic controller (PLC) logic program, enabling the operation or access of the programmable controller input-output (I/O) interface and achieving the extended limb collaboration capability of users/patients. The system has two main functions: the first is gesture-encoded virtual manipulation, which indirectly accesses the PLC through the DT mapping model to complete control of electronic peripherals for extension-limbs ability by executing logic control program instructions. The second is gesture-based virtual manipulation to help non-verbal individuals create special verbal sentences through gesture commands to improve their expression ability. The design method uses primitive image processing and eight-way dual-bit signal processing algorithms to capture the movement of human finger gestures and convert them into digital signals. The system service maps control instructions by observing the digital signals of the DT-HMIS and drives motion control through mechatronics integration or speech synthesis feedback to express the operation requirements of inconvenient work or complex handheld physical tools. Based on the human-machine interface sensor of DT computer vision, it can reflect the user's command status without the need for additional wearable devices and promote interaction with the virtual world. When used for patients, the system ensures that the user's virtual control is mapped to physical device control, providing the convenience of independent operation while reducing caregiver fatigue. This study shows that the recognition accuracy can reach 99%, demonstrating practicality and application prospects. In future applications, users/patients can interact virtually with other peripheral devices through the DT-HMIS to meet their own interaction needs and promote industry progress.

An Accessible, Open-Source Dexterity Test: Evaluating the Grasping and Dexterous Manipulation Capabilities of Humans and Robots

Evaluating the dexterity of human and robotic hands through appropriate benchmarks, scores, and metrics is of paramount importance for determining how skillful humans are and for designing and developing new bioinspired or even biomimetic end-effectors (e.g., robotic grippers and hands). Dexterity tests have been used in industrial and medical settings to assess how dexterous the hands of workers and surgeons are as well as in robotic rehabilitation settings to determine the improvement or deterioration of the hand function after a stroke or a surgery. In robotics, having a comprehensive dexterity test can allow us to evaluate and compare grippers and hands irrespectively of their design characteristics. However, there is a lack of well defined metrics, benchmarks, and tests that quantify robot dexterity. Previous work has focused on a number of widely accepted functional tests that are used for the evaluation of manual dexterity and human hand function improvement post injury. Each of these tests focuses on a different set of specific tasks and objects. Deriving from these tests, this work proposes a new modular, affordable, accessible, open-source dexterity test for both humans and robots. This test evaluates the grasping and manipulation capabilities by combining the features and best practices of the aforementioned tests, as well as new task categories specifically designed to evaluate dexterous manipulation capabilities. The dexterity test and the accompanying benchmarks allow us to determine the overall hand function recovery and dexterity of robotic end-effectors with ease. More precisely, a dexterity score that ranges from 0 (simplistic, non-dexterous system) to 1 (human-like system) is calculated using the weighted sum of the accuracy and task execution speed subscores. It should also be noted that the dexterity of a robotic system can be evaluated assessing the efficiency of either the robotic hardware, or the robotic perception system, or both. The test and the benchmarks proposed in the study have been validated using extensive human and robot trials. The human trials have been used to determine the baseline scores for the evaluation system. The results show that the time required to complete the tasks reduces significantly with trials indicating a clear learning curve in mastering the dexterous manipulation capabilities associated with the imposed tasks. Finally, the time required to complete the tasks with restricted tactile feedback is significantly higher indicating its importance.

Aerosol deposition and airflow dynamics in healthy and asthmatic human airways during inhalation

Inhalation of aerosols such as pharmaceutical aerosols or virus aerosol uptake is of great concern to the human population. To elucidate the underlying aerosol dynamics, the deposition fractions (DFs) of aerosols in healthy and asthmatic human airways of generations 13-15 are predicted. The Navier-stokes equations governing the gaseous phase and the discrete phase model for particles' motion are solved using numerical methods. The main forces responsible for deposition are inertial impaction forces and complex secondary flow velocities. The curvatures and sinusoidal folds in the asthmatic geometry lead to the formation of complex secondary flows and hence higher DFs. The intensities of complex secondary flows are strongest at the generations affected by asthma. The DF in the healthy airways is 0%, and it ranges from 1.69% to 52.93% in the asthmatic ones. From this study, the effects of the pharmaceutical aerosol particle diameters in the treatment of asthma patients can be established, which is conducive to inhibiting the inflammation of asthma airways. Furthermore, with the recent development of COVID-19 which causes pneumonia, the predicted physics and effective simulation methods of bioaerosols delivery to asthma patients are vital to prevent the exacerbation of the chronic ailment and the epidemic.

Analysis of microparticle deposition in the human lung by taguchi method and response surface methodology

The deposition phenomenon of microparticle and SAR-CoV-2 laced bioaerosol in human airways is studied by Taguchi methods and response surface methodology (RSM). The data used herein is obtained from simulations of airflow dynamics and deposition fractions of drug particle aerosols in the downstream airways of asthma patients using computational fluid dynamics (CFD) and discrete particle motion (DPM). Three main parameters, including airflow rate, drug dose, and particle size, affecting aerosol deposition in the lungs of asthma patients are examined. The highest deposition fraction (DF) is obtained at the flow rate of 45 L min^-1, the drug dose of 200 μg·puff^-1, and the particle diameter of 5 μm. The optimized combination of levels for the three parameters for maximum drug deposition is performed via the Taguchi method. The importance of the influencing factors rank as particle size > drug dose > flow rate. RSM reveals that the combination of 30 L min^-1, 5 μm, 200 μg·puff^- has the highest deposition fraction. In part, this research also studied the deposition of bioaerosols contaminated with the SAR-CoV-2 virus, and their lowest DF is 1.15%. The low DF of bioaerosols reduces the probability of the SAR-CoV-2 virus transmission.

A Smart Home Energy Management System Using Two-Stage Non-Intrusive Appliance Load Monitoring over Fog-Cloud Analytics Based on Tridium's Niagara Framework for Residential Demand-Side Management

Electricity is a vital resource for various human activities, supporting customers’ lifestyles in today’s modern technologically driven society. Effective demand-side management (DSM) can alleviate ever-increasing electricity demands that arise from customers in downstream sectors of a smart grid. Compared with the traditional means of energy management systems, non-intrusive appliance load monitoring (NIALM) monitors relevant electrical appliances in a non-intrusive manner. Fog (edge) computing addresses the need to capture, process and analyze data generated and gathered by Internet of Things (IoT) end devices, and is an advanced IoT paradigm for applications in which resources, such as computing capability, of a central data center acted as cloud computing are placed at the edge of the network. The literature leaves NIALM developed over fog-cloud computing and conducted as part of a home energy management system (HEMS). In this study, a Smart HEMS prototype based on Tridium’s Niagara Framework^® has been established over fog (edge)-cloud computing, where NIALM as an IoT application in energy management has also been investigated in the framework. The SHEMS prototype established over fog-cloud computing in this study utilizes an artificial neural network-based NIALM approach to non-intrusively monitor relevant electrical appliances without an intrusive deployment of plug-load power meters (smart plugs), where a two-stage NIALM approach is completed. The core entity of the SHEMS prototype is based on a compact, cognitive, embedded IoT controller that connects IoT end devices, such as sensors and meters, and serves as a gateway in a smart house/smart building for residential DSM. As demonstrated and reported in this study, the established SHEMS prototype using the investigated two-stage NIALM approach is feasible and usable.

Successful bailout stenting strategy against rare spontaneous retrograde dissection of partially absorbed magnesium-based resorbable scaffold: A case report

BACKGROUND

In the development of coronary stent technology, bioresorbable scaffolds are promising milestones in improving the clinical treatment of coronary artery disease. The “leave nothing behind” motto is the premise of the fourth revolution in percutaneous coronary intervention (PCI). Studies proving the safety and efficacy of the magnesium-based resorbable scaffolds (MgBRSs) include the BIOSOLVE-I and BIOSOLVE-II trials and the latest BIOSOLVE-IV registry. However, spontaneous retrograde dissection of a partially absorbed MgBRS may still occur, albeit rarely.

CASE SUMMARY

We describe an unusual case of coronary artery disease in a patient who had undergone a successful PCI 8 mo earlier, where an MgBRS was implanted into the left anterior descending artery (LAD) and left circumflex artery with drug-coated balloons for a ramus intermedius branch stenosis to achieve the “leave nothing behind” therapeutic intention and was currently presenting with a gradual worsening of chest tightness. The distal edge vascular response, during subsequent attempts with balloon angioplasty was performed smoothly. However, spontaneous retrograde dissection of a partially absorbed MgBRS in the LAD ensued. Successful bailout stenting was performed with revascularization of the entry and exit sites created by spontaneous dissection and complete sealing of the intramural hematoma. The patient recovered well and was discharged after 2 d of intervention. When followed up in August 2020 (7 mo later), the patient showed uneventful recovery.

CONCLUSION

Spontaneous retrograde dissection of a partially absorbed MgBRS was successfully treated using bailout sirolimus-eluting coronary stent strategy.

Employing Pneumatic, Telescopic Actuators for the Development of Soft and Hybrid Robotic Grippers

Traditionally, the robotic end-effectors that are employed in unstructured and dynamic environments are rigid and their operation requires sophisticated sensing elements and complicated control algorithms in order to handle and manipulate delicate and fragile objects. Over the last decade, considerable research effort has been put into the development of adaptive, under-actuated, soft robots that facilitate robust interactions with dynamic environments. In this paper, we present soft, retractable, pneumatically actuated, telescopic actuators that facilitate the efficient execution of stable grasps involving a plethora of everyday life objects. The efficiency of the proposed actuators is validated by employing them in two different soft and hybrid robotic grippers. The hybrid gripper uses three rigid fingers to accomplish the execution of all the tasks required by a traditional robotic gripper, while three inflatable, telescopic fingers provide soft interaction with objects. This synergistic combination of soft and rigid structures allows the gripper to cage/trap and firmly hold heavy and irregular objects. The second, simplistic and highly affordable robotic gripper employs just the telescopic actuators, exhibiting an adaptive behavior during the execution of stable grasps of fragile and delicate objects. The experiments demonstrate that both grippers can successfully and stably grasp a wide range of objects, being able to exert significantly high contact forces.

Comparative Study of a Biomechanical Model-based and Black-box Approach for Subject-Specific Movement Prediction. Annu Int Conf IEEE Eng Med Biol Soc 2020;2020:4775-4778. [PMID: 33019058 DOI: 10.1109/embc44109.2020.9176600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The performance and safety of human robot interaction (HRI) can be improved by using subject-specific movement prediction. Typical models include biomechanical (parametric) or black-box (non-parametric) models. The current work aims to investigate the benefits and drawbacks of these approaches by comparing elbow-joint torque predictions based on electromyography signals of the elbow flexors and extensors. To this end, a parameterized biomechanical model is compared to a non-parametric (Gaussian-process) approach. Both models showed adequate results in predicting the elbow-joint torques. While the non-parametric model requires minimal modeling effort, the parameterized biomechanical model can lead to deeper insight of the underlying subject specific musculoskeletal system.

On Alternative Uses of Structural Compliance for the Development of Adaptive Robot Grippers and Hands

Adaptive robot hands are typically created by introducing structural compliance either in their joints (e.g., implementation of flexures joints) or in their finger-pads. In this paper, we present a series of alternative uses of structural compliance for the development of simple, adaptive, compliant and/or under-actuated robot grippers and hands that can efficiently and robustly execute a variety of grasping and dexterous, in-hand manipulation tasks. The proposed designs utilize only one actuator per finger to control multiple degrees of freedom and they retain the superior grasping capabilities of the adaptive grasping mechanisms even under significant object pose or other environmental uncertainties. More specifically, in this work, we introduce, discuss, and evaluate: (a) a design of pre-shaped, compliant robot fingers that adapts/conforms to the object geometry, (b) a hyper-adaptive finger-pad design that maximizes the area of the contact patches between the hand and the object, maximizing also grasp stability, and (c) a design that executes compliance adjustable manipulation tasks that can be predetermined by tuning the in-series compliance of the tendon routing system and by appropriately selecting the imposed tendon loads. The grippers are experimentally tested and their efficiency is validated using three different types of tests: (i) grasping tests that involve different everyday objects, (ii) grasp quality tests that estimate the contact area between the grippers and the objects grasped, and (iii) dexterous, in-hand manipulation experiments to evaluate the manipulation capabilities of the Compliance Adjustable Manipulation (CAM) hand. The devices employ mechanical adaptability to facilitate and simplify the efficient execution of robust grasping and dexterous, in-hand manipulation tasks.

Crack Detection on a Retaining Wall with an Innovative, Ensemble Learning Method in a Dynamic Imaging System

In this study, an innovative, ensemble learning method in a dynamic imaging system of an unmanned vehicle is presented. The feasibility of the system was tested in the crack detection of a retaining wall in a climbing area or a mountain road. The unmanned vehicle can provide a lightweight and remote cruise routine with a Geographic Information System sensor, a Gyro sensor, and a charge-coupled device camera. The crack was the target to be tested, and the retaining wall was patrolled through the drone flight path setting, and then the horizontal image was instantly returned by using the wireless transmission of the system. That is based on the cascade classifier, and the feature comparison classifier was designed further, and then the machine vision correlation algorithm was used to analyze the target type information. First, the system collects the target image and background to establish the samples database, and then uses the Local Binary Patterns feature extraction algorithm to extract the feature values for classification. When the first stage classification is completed, the classification results are target features, and edge feature comparisons. The innovative ensemble learning classifier was used to analyze the image and determine the location of the crack for risk assessment.

Successful Management of New-Onset Diabetes Mellitus and Obesity With the Use of Laparoscopic Sleeve Gastrectomy After Kidney Transplantation-A Case Report

In kidney transplantation, obesity is associated with poorer graft survival and patient survival. Bariatric surgery may provide benefit for these patients, not only by inducing weight loss, but also via reduction of diabetes. We report a case of morbid obesity, poorly controlled new-onset diabetes mellitus, and gout after kidney transplantation that was treated with laparoscopic sleeve gastrectomy 3 years after kidney transplantation. After 1 year of follow-up, 76% excessive body weight loss was attained. No complications were noted. The operation also provided total remission of diabetes and gout as well as good graft survival. Based on our experience, laparoscopic sleeve gastrectomy may be a feasible treatment for obese patients after renal transplantation to help resolve obesity and control new-onset diabetes. However, the timing of operation and the long-term potential for graft and patient survivals with this operation require further study.

A quantitative structure-activity relationship approach for assessing toxicity of mixture of organic compounds

Four types of reactivity indices were employed to construct quantitative structure-activity relationships for the assessment of toxicity of organic chemical mixtures. Results of analysis indicated that the maximum positive charge of the hydrogen atom and the inverse of the apolar surface area are the most important descriptors for the toxicity of mixture of benzene and its derivatives to Vibrio fischeri. The toxicity of mixture of aromatic compounds to green alga Scenedesmus obliquus is mainly affected by the electron flow and electrostatic interactions. The electron-acceptance chemical potential and the maximum positive charge of the hydrogen atom are found to be the most important descriptors for the joint toxicity of aromatic compounds.

Deletion of the gene encoding the reductase component of 3-ketosteroid 9α-hydroxylase in Rhodococcus equi USA-18 disrupts sterol catabolism, leading to the accumulation of 3-oxo-23,24-bisnorchola-1,4-dien-22-oic acid and 1,4-androstadiene-3,17-dione

The gene encoding the putative reductase component (KshB) of 3-ketosteroid 9α-hydroxylase was cloned from Rhodococcus equi USA-18, a cholesterol oxidase-producing strain formerly named Arthrobacter simplex USA-18, by PCR according to consensus amino acid motifs of several bacterial KshB subunits. Deletion of the gene in R. equi USA-18 by a PCR-targeted gene disruption method resulted in a mutant strain that could accumulate up to 0.58 mg/ml 1,4-androstadiene-3,17-dione (ADD) in the culture medium when 0.2% cholesterol was used as the carbon source, indicating the involvement of the deleted enzyme in 9α-hydroxylation of steroids. In addition, this mutant also accumulated 3-oxo-23,24-bisnorchola-1,4-dien-22-oic acid (Δ^1,4-BNC). Because both ADD and Δ^1,4-BNC are important intermediates for the synthesis of steroid drugs, this mutant derived from R. equi USA-18 may deserve further investigation for its application potential.

Gender and Age Differences in Short- and Long-Term Outcomes Following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

BACKGROUND

Studies have reported that women with ST elevation myocardial infarction (STEMI) have worse short- and long-term outcomes than men. It has not yet been confirmed whether these differences reflect differences in age between men and women.

METHODS

We retrospectively enrolled 1035 consecutive STEMI patients treated with primary percutaneous coronary intervention (PCI). Baseline clinical characteristics, coronary anatomy, and outcome were compared between young (< 65 years old) and older patients (≥ 65 years old) of both sexes.

RESULTS

Younger women presented with a lower incidence of typical angina (83% vs. 93%, p = 0.03), single-vessel disease (21% vs. 35%, p = 0.03), and total occlusion of infarct-related artery (65% vs. 83%, p = 0.001) than younger men, with no gender difference noted in the older group. Younger women in the study had a higher incidence of reinfarction, heart failure requiring admission, or mortality (23% vs. 6%, p < 0.001) during follow-up, compared with younger men, with no gender difference in the older group. Using the Kaplan-Meier analysis, younger women had lower rates of event-free survival (p < 0.001 by log-rank test) than younger men, with no gender difference in the older group. In multivariate analysis, age could predict long-term outcome in men (Hazard ratio 4.43, 95% confidence interval: 2.89-6.78, p < 0.001) but not in women.

CONCLUSIONS

In STEMI patients receiving primary PCI, sex-related long-term outcome differences were age-dependent, with younger women likely to have a worse long-term outcome when compared with younger men.

KEY WORDS

Coronary heart disease; Gender; Myocardial infarction.

Lens of controllable optical field with thin film metallic glasses for UV-LEDs

In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

Promising antimicrobial capability of thin film metallic glasses

Thin film metallic glasses (TFMGs) are demonstrated to exhibit excellent surface flatness, high corrosion resistance and satisfactory hydrophobic properties. Moreover, the antimicrobial and biocompatibility abilities of TFMGs are examined and the results are compared with the behavior of pure Ag and 316L stainless steel. Three TFMGs, Al48Ag37Ti15, Zr54Ti35Si11, and Zr59Ti22Ag19, are prepared by sputtering to assess the antimicrobial performance against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, which are the most common nosocomial infection pathogens. Experimental results show that the antimicrobial effect of the Al- or Ag-containing AlAgTi and ZrTiAg TFMGs is similar to that of the pure Ag coating. The ZrTiSi TFMG with no Ag or Al shows poor antimicrobial capability. The physical properties of highly smooth surface and hydrophobic nature alone are not sufficient to result in promising antimicrobial ability. The chemical metal ion release still plays a major role, which should be born in mind in designing biomedical devices.

Three-dimensional analysis of the surface registration accuracy of electromagnetic navigation systems in live endoscopic sinus surgery

BACKGROUND

Studies on the performance of surface registration with electromagnetic tracking systems are lacking in both live surgery and the laboratory setting. This study presents the efficiency in time of the system preparation as well as the navigational accuracy of surface registration using electromagnetic tracking systems.

METHODOLOGY

Forty patients with bilateral chronic paranasal pansinusitis underwent endoscopic sinus surgery after undergoing sinus computed tomography scans. The surgeries were performed under electromagnetic navigation guidance after the surface registration had been carried out on all of the patients. The intraoperative measurements indicate the time taken for equipment set-up, surface registration and surgical procedure, as well as the degree of navigation error along 3 axes.

RESULTS

The time taken for equipment set-up, surface registration and the surgical procedure was 179 +- 23 seconds, 39 +- 4.8 seconds and 114 +- 36 minutes, respectively. A comparison of the navigation error along the 3 axes showed that the deviation in the medial-lateral direction was significantly less than that in the anterior-posterior and cranial-caudal directions.

CONCLUSION

The procedures of equipment set-up and surface registration in electromagnetic navigation tracking are efficient, convenient and easy to manipulate. The system accuracy is within the acceptable ranges, especially on the medial-lateral axis.

Properties of lymphocyte chemotactic factor (lymphotactin) in thymus

Aqueous extracts of calf thymus from immunologically stimulated animals contain trypsin- and neuraminidase-labile macromolecules with molecular weights of less than 30,000 daltons which will specifically attract chemotactically lymphocytes. This activity we ascribe to "lymphotactin."

Ab initio random structure search for 13-atom clusters of fcc elements

The 13-atom metal clusters of fcc elements (Al, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au) were studied by density functional theory calculations. The global minima were searched for by the ab initio random structure searching method. In addition to some new lowest-energy structures for Pd13 and Au13, we found that the effective coordination numbers of the lowest-energy clusters would increase with the ratio of the dimer-to-bulk bond length. This correlation, together with the electronic structures of the lowest-energy clusters, divides the 13-atom clusters of these fcc elements into two groups (except for Au13, which prefers a two-dimensional structure due to the relativistic effect). Compact-like clusters that are composed exclusively of triangular motifs are preferred for elements without d-electrons (Al) or with (nearly) filled d-band electrons (Ni, Pd, Cu, Ag). Non-compact clusters composed mainly of square motifs connected by some triangular motifs (Rh, Ir, Pt) are favored for elements with unfilled d-band electrons.

Diagnostic Performance of 64- versus 256-Slice Computed Tomography Coronary Angiography Compared with Conventional Coronary Angiography in Patients with Suspected Coronary Artery Disease

PUPOSE

The newer 256-slice computed tomography coronary angiography (CTCA) has the capability of improving diagnostic performance in the detection of obstructive coronary artery disease (CAD) compared to 64-slice CTCA. The aim of this study was to compare the diagnostic performance of 64- versus 256-slice CTCA in two similar populations.

METHODS

Our study included 120 consecutive patients who were referred for CTCA and subsequently underwent conventional coronary angiography (CCA). Sixty patients were studied by 64-slice CTCA, with the other 60 by 256-slice CTCA. We compared the technical characteristics and diagnostic performance of 64- and 256-slice CTCA for the detection of ≥ 50% stenosis of the coronary arteries on CCA.

RESULTS

The 256-slice CTCA had a shorter scanning time (4.4 ± 0.6 sec vs. 5.0 ± 0.7 sec, p < 0.001) compared to 64-slice CTCA. The diagnostic accuracy rates of 256-slice CTCA based on patient analysis (97% vs. 83%, p < 0.05), vessel analysis (95% vs. 85%, p < 0.05), and segment analysis (94% vs. 88%, p < 0.05) were significantly superior to those of 64-slice CTCA. The diagnostic accuracy rates of 64- and 256-slice CTCA were affected by the presence of stent (65% vs. 75%, respectively, p > 0.05) and severe calcifications (75% vs. 82%, respectively, p > 0.05).

CONCLUSIONS

In two similar populations, 256-slice CTCA displayed superior diagnostic performance than 64-slice CTCA. However, the performance of 256-slide CTCA is affected in those segments that are severely calcified and/or stented.

KEY WORDS

Computed tomography coronary angiography (CTCA); Conventional coronary angiography; Diagnostic performance; 64-slice helical CTCA; 256-slice helical CTCA.

Correlates of anti-EBV EBNA1 IgA positivity among unaffected relatives from nasopharyngeal carcinoma multiplex families

Background:

To determine whether non-viral nasopharyngeal carcinoma (NPC) risk factors might be associated with (and mediated through) Epstein–Barr virus (EBV) serological responses linked to NPC risk, we evaluated predictors of risk of anti-EBNA1 IgA seropositivity and other markers among unaffected relatives from a large NPC family study in Taiwan.

Methods:

Multivariate logistic regression conditioned on family was used to examine the associations between sociodemographic, dietary, lifestyle, and occupational variables and risk of anti-EBV EBNA1 IgA positivity, anti-VCA IgA, and anti-DNase positivity.

Results:

Among 2393 unaffected relatives from 319 multiplex families, 1180 (49.3%) were anti-EBV EBNA1 IgA seropositive. None of the associations with anti-EBNA1 IgA were statistically significant, except for being 31–50 years of age (vs <30, adjusted ORs 0.51–0.57). For one or more EBV serological markers, there were suggestive associations for older age, GuangDong firm salted fish, betel use, current alcohol use, and male gender.

Conclusion:

Overall, we found little evidence to suggest that non-viral NPC risk factors significantly alter EBV serological patterns, suggesting that non-viral NPC risk factors act through pathways independent of EBV serological responses.

A global analysis of molecular markers and phenotypic traits in local chicken breeds in Taiwan

Molecular and phenotypic data have been combined to characterize the genetic diversity of six local chicken breeds maintained with a long-term conservation programme. Hua-Tung, Hsin-Yi, Ju-Chi and Quemoy originated from Taiwan, Shek-Ki is from South China, and Nagoya is from Japan. Molecular tools included 24 microsatellite markers, melanocortin 1 receptor (alpha melanocyte stimulating hormone receptor) (MC1R), the LEI0258 marker located within the major histocompatibility complex (MHC), and mitochondrial DNA. Performance was recorded on the same individuals for body weight, panting rate in summer and antibody response (antigens: Newcastle disease virus and sheep red blood cells). A multivariate method previously proposed for taxonomy was used to combine the different data sets. Melanocortin 1 receptor (alpha melanocyte stimulating hormone receptor) and the MCW330 marker contributed the most to the first axis of the multiple coinertia analysis of molecular markers. Melanocortin 1 receptor (alpha melanocyte stimulating hormone receptor) showed evidence of selection, probably related to its effect on feather colour. The MHC exhibited a large diversity, with 16 alleles of the LEI0258 marker. Immune response traits contributed the most to the principal component analysis of phenotypic data. Eight mitochondrial DNA haplotypes related to clades A, B, C and E were distributed across breeds and revealed an important contribution of Indian and European breeds to Ju-Chi, Quemoy and Hsin-Yi. Phenotypic data contributed less than molecular data to the combined analysis, and two markers, LEI0258 and LEI0228, contributed the most. The combined analysis could clearly discriminate all breeds, except Ju-Chi, which was similar to Quemoy for many criteria, except immune response.

Acute ST-elevation myocardial infarction in young patients: 15 years of experience in a single center

BACKGROUND

There have been few studies done regarding young patients with ST-elevation myocardial infarction (STEMI). The purpose of this study was to investigate the clinical characteristics and coronary angiographic features in young patients with STEMI.

METHODS

We collected data on 849 consecutive patients with STEMI from 1992 to 2006. Baseline clinical characteristics, coronary anatomy, and outcome were compared in young (< or =45 yrs) and older patients (>45 yrs).

RESULTS

Young patients presented 11.6% of all patients with STEMI. These patients were predominantly male (92.9% vs 80.3%, P < 0.001), more likely to smoke (75.8% vs 47.2%, P < 0.001), obese (48.2% vs 27.9%, P = 0.002), have higher triglyceride levels (176.9 +/- 153.8 mg/dL vs 140.7 +/- 112.7 mg/dL, P = 0.005), and lower high-density lipoprotein cholesterol (37.1 +/- 7.9 mg/dL vs 42.8 +/- 14.3 mg/dL, P = 0.005) than older patients. Also, younger patients had a shorter hospital stay (7.1 +/- 4.9 d vs 8.5 +/- 6.7 d, P = 0.04), less in-hospital morbidity (29.3% vs 39.7%, P = 0.02), and mortality (3.0% vs 12.3%, P = 0.002). Killip class III or IV could predict in-hospital morbidity and mortality in young patients. Both groups had similar rates of repeated percutaneous coronary intervention (PCI; 45.5% vs 41.5%, P = 0.23) and reinfarction (6.1% vs 3.2%, P = 0.32). Mortality rate during follow-up was significantly lower in younger patients (3.0% vs 19.6%, P < 0.001).

CONCLUSION

Cigarette smoking, obesity, and dyslipidemia were the most important modifiable risk factors in young patients with STEMI. These patients had a better outcome than older patients without differences in repeated PCI and reinfarction between them. Only Killip class III or IV could predict in-hospital morbidity and mortality in young patients with STEMI.

Gastrointestinal bleeding and outcomes after percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Gastrointestinal bleeding is a hemorrhagic complication after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction (STEMI).

OBJECTIVES

To determine predictors of gastrointestinal bleeding and the impact of gastrointestinal bleeding on outcomes in STEMI patients undergoing primary percutaneous coronary intervention.

METHODS AND RESULTS

Gastrointestinal bleeding occurred in 18 (3.5%) of 519 consecutive patients with STEMI undergoing primary percutaneous coronary intervention. Univariate predictors of gastrointestinal bleeding were previous gastrointestinal bleeding (33% vs 4%, P < .001), impaired renal function (89% vs 37%, P<.001), Killip class IV at presentation (61% vs 18%, P<.001), higher peak creatinine kinase level (mean [SD], 3801.6 [3280.2] vs 2721.3 [2286.6] IU/L, P=.05), and mechanical ventilator support (44% vs 12%, P<.001). Coprescription of proton-pump inhibitors did not reduce the risk of gastrointestinal bleeding (22.2% vs 13.4%, P=.22). Multivariate analysis showed an odds ratio (95% confidence interval) for gastrointestinal bleeding of 22.1 (5.6-86.89, P<.001) for previous gastrointestinal bleeding, 6.74 (1.30-34.89, P=.02) for impaired renal function, and 4.68 (1.35-16.2, P=.01) for Killip class IV at presentation. Gastrointestinal bleeding was associated with longer intensive care unit stay (mean [SD], 5.4 [6.7] vs 3.6 [3.6] days, P=.04), and higher in-hospital (44% vs 9%, P<.001) and overall (44% vs 13%, P<.001) mortality rate.

CONCLUSIONS

Although rare, gastrointestinal bleeding in patients with STEMI significantly prolongs intensive care unit stay and increases mortality. Previous gastrointestinal bleeding, impaired renal function, and Killip class IV at presentation are associated with higher incidence of gastrointestinal bleeding.

Diverse cell morphology and intracellular calcium dynamics in pulmonary vein cardiomyocytes

Pulmonary veins (PVs) contain cardiomyocytes with a complex cellular morphology and high arrhythmogenesis. Ca(2+) regulation and Ca(2+) sparks play a pivotal role in the electrical activity of cardiomyocytes. The purpose of this study was to investigate whether the cell morphology can determine the PV electrical activity and Ca(2+) homeostasis. Through confocal microscopy with fluo-3 Ca(2+) fluorescence, Ca(2+) sparks and Ca(2+) transients were evaluated in isolated single rabbit left atria (LA) and PV cardiomyocytes according to the cell morphology (rod, rod-spindle and spindle/bifurcated). Twenty-two (20%) rod, 49 (43%) rod-spindle and 41 (37%) spindle/bifurcated cardiomyocytes were identified in the LA (n = 29) and PV (n = 83) cardiomyocytes. The PV cardiomyocytes with pacemaker activity had a higher incidence of spindle/bifurcated morphology than LA and PV cardiomyocytes without pacemaker activity. As compared to those in the rod or rod-spindle cardiomyocytes, spindle/bifurcated cardiomyocytes had a larger Ca(2+) transient amplitude and higher frequency of the Ca(2+) sparks with larger amplitude and longer duration. In contrast, rod-spindle and rod cardiomyocytes had similar Ca(2+) transients and Ca(2+) sparks. The cell length correlated well with the amplitude of the Ca(2+) transient and Ca(2+) spark duration with a linear regression. In conclusion, cell morphology and cell length play a potential role in the Ca(2+) homeostasis and Ca(2+) spark. The large Ca(2+) transients and high frequency of Ca(2+) sparks in spindle/bifurcated cardiomyocytes may cause a high arrhythmogenesis in the PV cardiomyocytes with pacemaker activity.

Incidence, predictors and outcomes of subacute stent thrombosis following primary stenting for ST-elevation myocardial infarction

BACKGROUND/PURPOSE

Knowledge concerning subacute stent thrombosis (SST) following primary stenting for ST-elevation myocardial infarction (STEMI) is not widely available. We studied the incidence, predictors, and clinical outcomes of SST following STEMI.

METHODS

We analyzed data from 455 consecutive patients who underwent primary stenting for STEMI. Baseline clinical characteristics, coronary angiographic features, medication and outcome were compared in patients with and without SST.

RESULTS

SST occurred in 17 patients, and the incidence was 3.7%. Univariate predictors of SST were being a current smoker (53.0%vs. 82.4%, p = 0.01), Killip class >or= II (38.4%vs. 58.8%, p = 0.05), no coronary re-flow after stenting (6.2%vs. 17.6%, p = 0.05) and lack of coprescription with a statin (39.5%vs. 5.9%, p<0.01). After multivariate analysis, being a current smoker (odds ratio = 4.76; 95% confidence interval 1.20-18.95) and using statin therapy (odds ratio = 0.09; 95% confidence interval = 0.01-0.75) were independent correlates of SST. Patients with SST were associated with higher 30-day mortality (37.5%vs. 3.1%, p<0.01) and all-cause mortality (23.5%vs. 5.3%, p = 0.01) at long-term follow-up.

CONCLUSION

Although SST is rare in patients with STEMI treated by primary stenting, it imparts a significantly higher mortality at short-term and long-term follow-up. Being a current smoker and the lack of co-prescription with a statin were associated with higher incidence of SST. Our results suggest initiation of statin therapy in patients with STEMI should be considered before discharge.

Anti-N-methyl-D-aspartate receptor encephalitis in a young woman with an ovarian tumour

Anti-N-methyl-D-aspartate receptor encephalitis is characterised by psychiatric and neurological abnormalities and occurs in frequent association with ovarian teratoma. We report the first confirmed case of teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis in Hong Kong in a young woman presenting with confusion and prominent dyskinesia, followed by a review of the current literature.

Evolutionary expansion of SPOP and associated TD/POZ gene family: impact of evolutionary route on gene expression pattern

Evolutionary expansion of a gene family may occur at both the DNA and RNA levels. The rat testis-specific Rtdpoz-T2 and -T1 (rT2 and rT1) retrogenes are members of the TD/POZ gene family which also includes the well-characterized SPOP gene. In this study, rT2/rT1 transcriptional activation in cancer cells is demonstrated; the cancer rT2/rT1 transcripts are structurally similar to the embryonic transcripts reported previously in frequent exonization of transposed elements. On database interrogation, we have identified an uncharacterized rT2/rT1-like SPOP paralog, designated as SPOP-like (SPOPL), in the human and rodent genomes. Ka/Ks analysis indicates that the SPOPL genes are under functional constraints implicating biological functions. Phylogenetic analyses further suggest that segmental duplication and retrotransposition events had occurred giving rise to new gene members or retrogenes in the human-rodent ancestors during the evolution of the TD/POZ gene family. Based on this and previous works, a model is proposed to map the routes of evolutionary expansion of the TD/POZ gene family. More importantly, different gene expression patterns of members of the family are depicted: intron-harboring members are ubiquitously expressed whereas retrogenes are expressed in tissue-specific and developmentally regulated manner, and are fortuitously re-activated in cancer cells involving exonization of transposed elements.

Taqman real-time quantitative PCR for identification of western flower thrip (Frankliniella occidentalis) for plant quarantine

Western flower thrip (Frankliniella occidentalis) is a major global pest of agricultural products. It directly damages crops through feeding, oviposition activity or transmission of several plant viruses. We describe a Taqman real-time quantitative PCR detection system, which can rapidly identify F. occidentalis from thrips larvae to complement the traditional morphological identification. The data showed that our detection system targeted on the ribosomal RNA gene regions of F. occidentalis has high sensitivity and specificity. The rapid method can be used for on-site testing of samples at ports-of-entry in the future.

Transcription of the rat testis-specific Rtdpoz-T1 and -T2 retrogenes during embryo development: co-transcription and frequent exonisation of transposable element sequences

Background

Retrotransposition is an important evolutionary force for the creation of new and potentially functional intronless genes which are collectively called retrogenes. Many retrogenes are expressed in the testis and the gene products have been shown to actively participate in spermatogenesis and other unique functions of the male germline. We have previously reported a cluster of retrogenes in the rat genome that encode putative TRAF- and POZ-domain proteins. Two of the genes, Rtdpoz-T1 and -T2 (abbreviated as T1 and T2), have further been shown to be expressed specifically in the rat testis.

Results

We show here that the T1 and T2 genes are also expressed in the rat embryo up to days 16–17 of development when the genes are silenced until being re-activated in the adult testis. On database interrogation, we find that some T1/T2 exons are chromosomally duplicated as cassettes of 2 or 3 exons consistent with retro-duplication. The embryonic T1/T2 transcripts, characterised by RT-PCR-cloning and rapid amplification of cDNA ends, are further found to have acquired one or more noncoding exons in the 5'-untranslated region (5'-UTR). Most importantly, the T1/T2 locus is embedded within a dense field of relics of transposable element (TE) derived mainly from LINE1 and ERV sequences, and the TE sequences are frequently exonised through alternative splicing to form the 5'-UTR sequences of the T1/T2 transcripts. In a case of T1 transcript, the 3'-end is extended into and terminated within an L1 sequence. Since the two genes share a common exon 1 and are, therefore, regulated by a single promoter, a T2-to-T1 co-transcription model is proposed. We further demonstrate that the exonised 5'-UTR TE sequences could lead to the creation of upstream open reading frames resulting in translational repression.

Conclusion

Exonisation of TE sequences is a frequent event in the transcription of retrogenes during embryonic development and in the testis and may contribute to post-transcriptional regulation of expression of retrogenes.

Quantitative effects of an intronic retroviral insertion on the transcription of the tyrosinase gene in recessive white chickens

Recently, we reported the complete association of a retroviral insertion in intron 4 of the tyrosinase gene and the recessive white mutation (c) in chickens. The mutant allele carrying the retroviral insertion produced, in skin samples of 10-week-old chickens, aberrant tyrosinase transcripts that did not contain exon 5. In the present study, we performed serial molecular and statistical analyses on embryos and 10-week-old chickens to characterize the quantitative effect of the retroviral insertion on the expression pattern of tyrosinase in different tissues (skin and retina). By using quantitative real-time RT-PCR, we observed that the expression level of tyrosinase was significantly lower in recessive white chickens than in wild-type coloured chickens, but that this pattern was age- and tissue-dependent. The differential expression in skin was not significant in embryos, whereas it was highly significant in 10-week-old chickens. Furthermore, there was no difference in the expression of tyrosinase in the retinal pigment epithelium of animals with different genotypes; this corresponds to phenotypic data, which show pigmented eyes in both genotypes. These findings show that the retroviral insertion disturbs tyrosinase expression in the recessive white mutant chickens, and suggests that the regulation of tyrosinase expression in chickens differs between embryos and growing animals, as well as between skin and retina.

Transition between icosahedral and cuboctahedral nanoclusters of lead

We have used ab initio methods to study the possible transition between icosahedral (ico) and cuboctahedral (fcc) structures in lead nanoclusters of sizes up to 309 atoms. Spontaneous fcc-to-ico transition in Pb(13) was observed in the ab initio molecular dynamics (MD) simulations at various temperatures. The transition path can be described predominantly by an angular variable s, which can, generally be applied to the similar transitions in clusters of larger sizes and was observed to follow the Mackay model. We have calculated the two-dimensional energy surface that describes the transition in Pb(13) and found a barrierless fcc-to-ico transition path, which is consistent with the observed spontaneous transition in the ab initio MD simulations. The atomic displacements in the transition were identified as one of the vibrational eigenmodes of these two Pb(13) clusters. For clusters of larger sizes (Pb(n), where n = 55, 147, and 309), the possible transitions following similar paths were determined not to be barrierless and the sizes of the barriers were determined by the ab initio elastic band method.

Mechanical stress enhances serotonin 2B receptor modulating brain natriuretic peptide through nuclear factor-κB in cardiomyocytes

OBJECTIVE

Serotonin via serotonin 2B receptors (SR2BR) regulates cardiac embryonic development and adult heart functions. However, the role of SR2BR in the failing heart due to pressure overload is not well understood.

METHODS

Wistar rats of aortic banding and neonatal cardiomyocyte with mechanical stretch were used as cardiomyopathy models.

RESULTS

After two weeks of aortic banding surgery, serum serotonin, mRNA and protein expression of SR2BR increased significantly. The selective SR2BR antagonist, SB215505 (SB), significantly reduced the increase in heart weight, decreased heart wall thickness, left ventricular mass and the expression of the brain natriuretic peptide (BNP) but did not attenuate the up-regulation of SR2BR protein expression in rats after aortic banding for three weeks. After following in vitro mechanical stretch of cardiomyocytes and incubation with serotonin 1 muM, the level of SR2BR and BNP protein increased time-dependently. When transfected by specific siRNA of SR2BR or pretreated with caffeic acid phenethyl ester in cardiomyocytes, the increase of nuclear factor-kappaB (NF-kappaB) translocation and BNP protein induced by serotonin incubation plus mechanical stretch were both reversed.

CONCLUSIONS

SR2BR expression is involved in pressure-induced cardiomyopathy and its downstream signaling may involve NF-kappaB to modulate BNP expression in cardiomyocyte.

Solid-Phase Microextraction Coupled with Liquid Chromatography for Determination of -Carotene in Food

Beta-carotene in vegetables and nutritional products is analyzed using solid-phase microextraction (SPME) coupled with liquid chromatography (LC) to improve the speed of analysis and to reduce the consumption of organic solvents. The relative standard deviations (RSDs) of this analytical method for beta-carotene determinations in vegetables and nutritional products are approximately 10% and 5%, respectively. The amount of beta-carotene was found to vary from 0.35 +/- 0.05 ppm to 76.5 +/- 6.9 ppm for several vegetables in Taiwan. This method was linear over the range of 0.4-40 ppm with correlation coefficients higher than 0.997. The experimentally determined level of beta-carotene in nutritional products varied from 3.8 +/- 0.2 ppm to 24.6 +/- 1.1 ppm following SPME-LC. The recoveries of beta-carotene for these measurements following SPME were all higher than 97% +/- 2% (n = 3). The detection limits of beta-carotene for this method were from 0.027 to 0.054 ppm. Conventional solvent extractions take approximately 4-6 h for extraction and reconcentration but SPME takes approximately 1 h. From several tens to hundreds of milliliters, organic solvents can be saved using SPME. SPME provides better analyses on beta-carotene than conventional solvent extraction for nutritional products in terms of speed, precision, simplicity, and solvent consumption.

Effects of a Na+/Ca2+ exchanger inhibitor on pulmonary vein electrical activity and ouabain-induced arrhythmogenicity

OBJECTIVE

Pulmonary veins (PVs) are the most important focus for generation of atrial fibrillation. The Na(+)/Ca(2+) exchange (NCX) current is important in PV electrical activity and cardiac glycosides-induced arrhythmias. The purpose of this study was to investigate whether KB-R7943, a NCX current blocker with preferential inhibition of the Ca(2+) influx, may alter PV electrophysiological characteristics and reduce glycoside-induced arrhythmogenicity.

METHODS

Conventional microelectrodes were used to record the effects of KB-R7943 on action potentials and contractility in isolated rabbit PV tissue specimens with and without administration of ouabain. The ionic currents and intracellular calcium were studied in isolated single cardiomyocytes before and after KB-R7943 by the whole-cell patch clamp and indo-1 fluorimetric ratio techniques.

RESULTS

KB-R7943 (0, 3, 10, 30 microM) concentration-dependently prolonged APD(50) and APD(90) and decreased the PV firing rates (2.3 +/- 1.2 Hz, 2.1 +/- 1.2 Hz, 1.9 +/- 0.9 Hz, 1.7 +/- 1.1 Hz, n = 7, p < 0.05) and incidences of delayed afterdepolarizations (DADs). KB-R7943 (3, 30 microM) decreased transient inward currents, Ca(2+) transient and sarcoplasmic reticulum Ca(2+) content. Ouabain (0, 0.1, 1 microM) concentration-dependently increased the PV firing rates and DADs in PVs with spontaneous activity (n = 7) and induced nonsustained spontaneous activity (1 microM) in the PVs without spontaneous activity (n = 14). However, in the presence of KB-R7943 (30 microM), ouabain (1 microM) did not increase the PV firing rates or induce spontaneous activity in the PVs without spontaneous activity (n = 7).

CONCLUSIONS

KB-R7943 reduces the PV arrhythmogenic activity and prevents the ouabain-induced arrhythmogenicity. Our findings support the role of the NCX current in the PV electrical activity.

Laparoscopic pyeloplasty: Evolution of a new gold standard

OBJECTIVES

To report our series of laparoscopic dismembered pyeloplasty for the treatment of primary and secondary ureteropelvic junction obstruction and to review the current status of this procedure.

METHODS

A total of 170 consecutive cases of laparoscopic pyeloplasty (156 for primary and 14 for secondary ureteropelvic junction obstruction) were performed or supervised by a single surgeon (C.G.E). A four-port extraperitoneal approach was used in all but 3 cases, which were performed transperitoneally.

RESULTS

The median operative time was 140 minutes. The complication rate was 7.1%, and the conversion rate was 0.6%, with no conversion in the last 161 cases. The median postoperative hospital stay was 3 nights. Crossing vessels were encountered in 42% of cases, and in 11 patients, coexisting renal calculi were successfully removed. At a median follow-up of 12 months, the success rate was 96.2%.

CONCLUSIONS

Laparoscopic dismembered pyeloplasty produces functional results comparable to that of open surgery with the advantages of a minimally invasive procedure. Our results are consistent with previous series and support the view that laparoscopic pyeloplasty is moving rapidly toward replacing open surgery as the gold standard in the treatment of ureteropelvic junction obstruction.

The impact of prostate size in laparoscopic radical prostatectomy

OBJECTIVES

Large prostates can be challenging to remove during open or laparoscopic radical prostatectomy (LRP). Our objective was to critically analyse the impact of prostate volume in LRP.

METHODS

400 cases of LRP were performed. Three hundred and fourteen patients had a small prostate (weight < 75 g) and 86 patients had a large prostate (weight > or = 75 g) on final histology. The following outcomes were assessed: operative time; estimated blood loss (EBL); transfusion rate; length of hospital stay (LOS); length of catheterisation; perioperative and postoperative complications (including incontinence and erectile dysfunction); surgical margin status; and early biochemical recurrence rates.

RESULTS

Patients' age, PSA, Gleason sum and clinical stage were all similar. Larger prostates were associated with a 14 minutes longer mean operating time (p < 0.001), but fewer positive surgical margins (p = 0.01). Blood loss, blood transfusion rate, length of hospital stay, length of catheterisation and complication rate were all similar in both groups.

CONCLUSIONS

Prostate size should not be a factor determining a patient's suitability for LRP. Further follow-up is needed to assess the effect of prostate size on long-term functional and oncological results.

The Impact of Prostate Size in Laparoscopic Radical Prostatectomy

OBJECTIVES

Large prostates can be challenging to remove during open or laparoscopic radical prostatectomy (LRP). Our objective was to critically analyse the impact of prostate volume in LRP.

METHODS

400 cases of LRP were performed. Three hundred and fourteen patients had a small prostate (weight < 75 g) and 86 patients had a large prostate (weight > or = 75 g) on final histology. The following outcomes were assessed: operative time; estimated blood loss (EBL); transfusion rate; length of hospital stay (LOS); length of catheterisation; perioperative and postoperative complications (including incontinence and erectile dysfunction); surgical margin status; and early biochemical recurrence rates.

RESULTS

Patients' age, PSA, Gleason sum and clinical stage were all similar. Larger prostates were associated with a 14 minutes longer mean operating time (p < 0.001), but fewer positive surgical margins (p = 0.01). Blood loss, blood transfusion rate, length of hospital stay, length of catheterisation and complication rate were all similar in both groups.

CONCLUSIONS

Prostate size should not be a factor determining a patient's suitability for LRP. Further follow-up is needed to assess the effect of prostate size on long-term functional and oncological results.

Impurity analysis of 1,4-dioxane in nonionic surfactants and cosmetics using headspace solid-phase microextraction coupled with gas chromatography and gas chromatography–mass spectrometry

1,4-Dioxane impurity in nonionic surfactants and cosmetics were analyzed using solid-phase microextraction (SPME) coupled with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Experimental results show that there is no significant difference using SPME-GC and SPME-GC-MS for analysis of 1,4-dioxane in three types of nonionic surfactants at the 95% confidence level. The relative standard deviation (R.S.D.) values of each analytical method were smaller than 3%. The amount of 1,4-dioxane was found to vary from 11.6 +/- 0.3 ppm to 73.5 +/- 0.5 ppm in 30% of nonionic surfactants from manufacturers in Taiwan. These methods were linear over the studied range of 3-150 ppm with correlation coefficients higher than 0.995. The recoveries of 1,4-dioxane for these nonionic surfactants following SPME were all higher than 96 +/- 1% (n = 3). The detection limits of 1,4-dioxane for these nonionic surfactants following SPME were from 0.06 ppm to 0.51 ppm. The experimentally determined level of 1,4-dioxane in cosmetics from manufacturers in Taiwan varied from 4.2 +/- 0.1 ppm to 41.1 +/- 0.6 ppm in 22% of daily used cosmetics following SPME coupled with GC and GC-MS. Conventional solvent extraction takes around 1 h for extraction and reconcentration but SPME takes only around 10 min. SPME provides better analyses of 1,4-dioxane in nonionic surfactants and cosmetics than conventional solvent extraction and head space pretreatments in term of simplicity, speed, precision, detection limit, and solvent consumption.

Klebsiella pneumoniae fascial space infections of the head and neck in Taiwan: emphasis on diabetic patients and repetitive infections

OBJECTIVES

To assess the epidemiological features, clinical characteristics, treatment, and outcome of head and neck infections caused by Klebsiella pneumoniae.

METHODS

We reviewed records of four common aerobic pathogens isolated by the microbiological laboratory of a teaching hospital in Taiwan from July 1995 to December 1999. Patients aged 14 or older with community-acquired fascial space infections of head and neck were identified by review of medical records and included in the study.

RESULTS

A total of 100 cases were identified, and K. pneumoniae was the most common pathogen of monomicrobial infections (48%), followed by viridans streptococci (15%). Polymicrobial infections were noted in 35 cases. In comparison with patients with infections not caused by K. pneumoniae, those with monomicrobial K. pneumoniae infections were older (P = 0.04) and had a higher prevalence of diabetes mellitus (P < 0.001), a longer duration of antimicrobial therapy (P = 0.007), a longer hospital stay (P = 0.001), and more repetitive infections (P = 0.001). All but one of K. pneumoniae isolates were susceptible to first generation cephalosporins and aminoglycosides.

CONCLUSIONS

K. pneumoniae is an important endemic pathogen of fascial space infections of head and neck in Taiwan, especially among diabetics. Physicians should be aware of the tendency of this organism to cause repetitive infection.

Alternative low-symmetry structure for 13-atom metal clusters

The atomic geometry, electronic structure, and magnetic moment of 4d transition-metal clusters with 13 atoms are studied by pseudopotential density-functional calculations. We find a new buckled biplanar structure with a C(2v) symmetry stabilized by enhanced s-d hybridization. It has a lower energy than the close-packed icosahedral or cuboctahedral structure for elements with more than half-filled d shells. The magnetic moments of this buckled biplanar structure are found to be smaller than those of the icosahedral structure and closer to available experimental results.

Low-affinity nerve growth factor receptor p75NTR immunoreactivity in the myocardium with sympathetic hyperinnervation

INTRODUCTION

We previously demonstrated the relationship between sympathetic nerve density in myocardium and the occurrences of ventricular arrhythmia. Nerve growth factor (NGF) regulates myocardial sympathetic innervation. However, it is unclear whether the NGF high-affinity receptor tyrosine kinase A (TrkA) and the NGF low-affinity receptor p75NTR are altered in the state of sympathetic hyperinnervation in the heart. The aim of this study was to determine the density and location of TrkA and p75NTR in canine ventricles with sympathetic hyperinnervation.

METHODS AND RESULTS

Myocardial sympathetic hyperinnervation was induced by local infusion of NGF into myocardium or left stellate ganglia, or chronic subthreshold electric stimulation to the left stellate ganglia. The results showed that TrkA immunoreactivity was absent in the myocardium. Low-affinity receptor p75NTR immunoreactivity was present in axons, Schwann cells, and interstitial cells of sympathetic nerves, as well as in interstitial cells of the myocardium. The density of p75NTR immunolabeled myocardial interstitial cells at the NGF infusion site was lower than that at the site remote from NGF infusion, yet the sympathetic nerve density was higher at the infusion site than the remote area. The density of p75NTR also was lower in the myocardium with high sympathetic nerve density, induced by NGF infusion or chronic electric stimulation of the left stellate ganglia, compared to control groups.

CONCLUSION

The data indicate that p75NTR may be the main NGF receptor in the myocardium, and p75NTR immunopositive interstitial cells may have a role in regulating sympathetic nerve growth in canine heart.

Induction of atrial fibrillation and nerve sprouting by prolonged left atrial pacing in dogs

The authors hypothesized that rapid electrical stimulation can induce nerve sprouting in canine atria, and that LA pacing is more effective than RA pacing in inducing sustained AF. Chronic rapid (20 Hz) LA epicardial pacing was performed in six dogs. Sustained AF (>48 hours) was induced within 23 +/- 8 days, which was much faster than that with RA endocardial pacing using the same protocol (139 +/- 84 days, P < 0.05). Nerves were identified by immunocytochemical techniques. In all dogs, growth-associated protein 43-positive (sprouting) nerve density was highest near the pacing site, and the rapid LA pacing resulted in differential nerve sprouting among the LA, left superior pulmonary vein (LSPV), interatrial septum (IAS), and RA (5521 +/- 1496, 3154 +/- 2355, 3953 +/- 1164, 1559 +/- 1077 microm2/mm2, respectively, P = 0.0032). Tyrosine hydroxylase-positive (sympathetic) nerve density were not significantly different among groups (2726 +/- 1165, 1586 +/- 558, 2156 +/- 1741, 1509 +/- 1242 microm2/mm2, respectively). The nerves were inhomogeneously distributed. LA epicardial pacing induced sustained AF much faster than RA endocardial pacing and rapid electrical stimulation can induce inhomogeneous nerve sprouting near the pacing site.

Long-term subthreshold electrical stimulation of the left stellate ganglion and a canine model of sudden cardiac death

OBJECTIVES

We sought to develop a high-yield canine model of sudden cardiac death (SCD).

BACKGROUND

Because electrical stimulation is a powerful means to elicit nerve sprouting, we hypothesize that subthreshold electrical stimulation is more effective than nerve growth factor (NGF) infusion in inducing nerve sprouting and SCD in dogs with myocardial infarction (MI) and complete atrioventricular block (CAVB).

METHODS

We gave subthreshold electrical stimulation to the left stellate ganglion (LSG) in six normal dogs for 41 +/- 9 days (protocol 1) and to six dogs with MI and CAVB for 41 +/- 29 days, while continuously monitoring their cardiac rhythm (protocol 2). We also monitored the rhythm of two dogs with MI, CAVB, and NGF infusion to the LSG and determined the ventricular nerve density in six healthy control dogs.

RESULTS

In protocol 1, the hearts from dogs with LSG electrical stimulation had a higher density of nerve fibers immunopositive to tyrosine hydroxylase, synaptophysin, and growth-associated protein-43 than those of normal control dogs (p < 0.01). In protocol 2, there was a high magnitude of cardiac nerve sprouting in all dogs studied. Ventricular tachycardia > or =8 beats and > or =20 beats was more frequent in dogs with electrical stimulation than in dogs with NGF infusion to the LSG (36 +/- 60 and 11 +/- 17 vs. 4.7 +/- 6.1 and 0.1 +/- 0.33 episodes per day, p < 0.05 and p < 0.03, respectively). Four of six dogs in protocol 2 had SCD.

CONCLUSIONS

Subthreshold electrical stimulation of the LSG induces cardiac nerve sprouting and sympathetic hyperinnervation and facilitates the development of a high-yield canine model of ventricular arrhythmia and SCD.