TransNet: Transformer-Based Point Cloud Sampling Network

As interest in point cloud processing has gradually increased in the industry, point cloud sampling techniques have been researched to improve deep learning networks. As many conventional models use point clouds directly, the consideration of computational complexity has become critical for practicality. One of the representative ways to decrease computations is downsampling, which also affects the performance in terms of precision. Existing classic sampling methods have adopted a standardized way regardless of the task-model property in learning. However, this limits the improvement of the point cloud sampling network's performance. That is, the performance of such task-agnostic methods is too low when the sampling ratio is high. Therefore, this paper proposes a novel downsampling model based on the transformer-based point cloud sampling network (TransNet) to efficiently perform downsampling tasks. The proposed TransNet utilizes self-attention and fully connected layers to extract meaningful features from input sequences and perform downsampling. By introducing attention techniques into downsampling, the proposed network can learn about the relationships between point clouds and generate a task-oriented sampling methodology. The proposed TransNet outperforms several state-of-the-art models in terms of accuracy. It has a particular advantage in generating points from sparse data when the sampling ratio is high. We expect that our approach can provide a promising solution for downsampling tasks in various point cloud applications.

ESMO Expert Consensus Statements on Cancer Survivorship: promoting high-quality survivorship care and research in Europe

BACKGROUND

The increased number of cancer survivors and the recognition of physical and psychosocial challenges, present from cancer diagnosis through active treatment and beyond, led to the discipline of cancer survivorship.

DESIGN AND METHODS

Herein, we reflected on the different components of survivorship care, existing models and priorities, in order to facilitate the promotion of high-quality European survivorship care and research.

RESULTS

We identified five main components of survivorship care: (i) physical effects of cancer and chronic medical conditions; (ii) psychological effects of cancer; (iii) social, work and financial effects of cancer; (iv) surveillance for recurrences and second cancers; and (v) cancer prevention and overall health and well-being promotion. Survivorship care can be delivered by structured care models including but not limited to shared models integrating primary care and oncology services. The choice of the care model to be implemented has to be adapted to local realities. High-quality care should be expedited by the generation of: (i) focused and shared European recommendations, (ii) creation of tools to facilitate implementation of coordinated care and (iii) survivorship educational programs for health care teams and patients. The research agenda should be defined with the participation of health care providers, researchers, policy makers, patients and caregivers. The following patient-centered survivorship research areas were highlighted: (i) generation of a big data platform to collect long-term real-world data in survivors and healthy controls to (a) understand the resources, needs and preferences of patients with cancer, and (b) understand biological determinants of survivorship issues, and (ii) develop innovative effective interventions focused on the main components of survivorship care.

CONCLUSIONS

The European Society for Medical Oncology (ESMO) can actively contribute in the efforts of the oncology community toward (a) promoting the development of high-quality survivorship care programs, (b) providing educational material and (c) aiding groundbreaking research by reflecting on priorities and by supporting research networking.

In vitro antibacterial effects of non-thermal atmospheric plasma irradiation on Staphylococcus pseudintermedius and Pseudomonas aeruginosa

In the last decade, atmospheric plasma has been used to treating bacterial infections in humans due to its bactericidal effects; however, its efficacy in dogs is unclear. This study evaluated the in vitro bactericidal efficacy of atmospheric plasma on Staphylococcus pseudinter- medius and Pseudomonas aeruginosa, two of the most important bacterial agents isolated from canine pyodermas. Three isolates each of S. pseudintermedius and P. aeruginosa obtained from dogs with pyoderma were subjected to atmospheric plasma. The isolates from the control group were not exposed to plasma, while those from the treatment groups were exposed to plasma for 15 (7.5 J/cm2), 30 (15 J/cm2), 60 (30 J/cm2), or 90 (45 J/cm2) seconds. After each treatment, a reduction in colony formation was observed. Bacterial viability was evaluated using the LIVE/ DEAD® BacLight™ Bacterial Viability Kit. The antibacterial effects were evaluated with Image J software and significance was assessed statistically in comparison to the control group. The bactericidal effect of atmospheric plasma against both bacteria increased significantly in a time-dependent manner. These results demonstrate the bactericidal capacity of atmospheric plasma, and suggest that it could serve as an alternative treatment method for canine pyoderma. Further studies are needed to evaluate the safety and efficacy of atmospheric plasma in dogs.

Toxicological analysis of aerosols derived from three electronic nicotine delivery systems using normal human bronchial epithelial cells

Electronic nicotine delivery systems (ENDS) are a rapidly growing global market advertised as a safer alternative to combustible cigarettes. However, comprehensive investigations of END aerosol physicochemical and toxicological properties have not been fully explored across brands to assess relative safety. In this study, we evaluated aerosols collected from three ENDS - Juul Fruit Medley (5% nicotine), Logic Power (2.4% nicotine), and Mistic (1.8% nicotine). ENDS aerosols were generated using standard machine puffing regimen and collected with a novel fluoropolymer condensation trap. Triple quadrupole-inductively coupled plasma-mass determined the presence of heavy metals in collected aerosols. The toxicological effects of ENDS aerosols on normal human bronchial epithelial cells (NHBE) were investigated using cellular viability, reactive oxygen species, oxidative stress assays, along with DNA damage assessments using the CometChip©. Results indicated the total metal concentrations within collected ENDS aerosols were higher for Mistic and Logic compared to Juul. Logic Power aerosols elicited higher reactive oxygen species levels than Mistic and Juul in NHBE after 24-h exposure. Similar dose-dependent reductions of cellular viability and total glutathione were found for each exposure. However, Logic and Juul aerosols caused greater single stranded DNA damage compared to Mistic. Our study indicates that regardless of brand, ENDS aerosols are toxic to upper airway epithelial cells and may pose a potential respiratory hazard to occasional and frequent users.

0455 Role of Interaction Between Anterior Insula Response to Sleep-Related Pictures and Stress Levels on Sleep Disturbance

Introduction

Literature suggests that stress may play an important role in sleep disturbance. Individuals with higher stress levels often showed hyperarousal to stressful events, possibly leading to sleep disturbance. Hyperarousal is also one of features of stress-related sleep disturbance. Here, we examined the extent to which stress levels interact with neural activity in response to sleep-related information to predict sleep disturbance.

Methods

Forty eight healthy adults (26 females, age = 35.7 ± 10.5) without sleep disorders based on nocturnal polysomnography participated in this study. They were viewing sleep-related pictures (e.g., bedroom and sunset) and non-sleep related, neutral pictures (e.g., kitchen and landscape) during fMRI scanning. They also completed questionnaires assessing stress levels and sleep disturbance using Life Experience Survey (LES) and Pittsburgh Sleep Quality Index (PSQI), respectively. Activity in response to sleep-related pictures compared to neutral pictures was extracted from our region-of-interest (ROI), the anterior insula, and entered into our moderation models. The SPSS macro PROCESS (Hayes, 2013) was used to conduct moderation analyses. Given a significant correlation between age and PSQI scores, age was included as a covariate.

Results

Our moderation analyses showed that interactions between stress levels and anterior insula response to sleep-related pictures significantly predicted sleep disturbance. Simple slope analyses showed that at higher anterior insula response, higher stress levels were associated with greater sleep disturbance, but at lower anterior insula response, stress was not significantly associated with sleep disturbance. These results indicate that individuals with high levels of stress were more likely to experience sleep disturbance if they showed greater anterior insula response to sleep-related pictures (i.e., hyperarousal in response to sleep-related information).

Conclusion

The current findings suggest that interactions between stress levels and neural substrates of hyperarousal, particularly the anterior insula, may play a critical role in sleep disturbance.

Support

Brain Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (Study No.: 2016M3C7A1904338 and NRF-2018R1D1A1B07049704).

0064 Heightened Neural Responses to Negative Words in Shift Workers Using the Stroop Task

Introduction

Shift work is known to have a negative impact on a wide range of health problems such as sleep disturbance, cognitive impairment, and emotional disorders (e.g., anxiety and depression). It is important to understand underlying mechanisms for negative impact of shift work on health problems. This study aimed to investigate psychological and neural mechanisms associated with shift work.

Methods

Thirty six shift workers (28 females, age = 29.9 ± 7.4) and 35 non-shift workers (20 females, age = 30.5 ± 5.5) participated in this study. They were performing the word Stroop task during fMRI scanning. This task included sleep-related words and negative words to investigate neural substrates associated with sleep-related information and emotional information processing. Neutral words were included as control stimuli. The participants also completed questionnaires assessing sleep-related problems such as Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale, and emotion-related problems such as Beck Depression Inventory and Beck Anxiety Inventory. Two-sample t-tests were conducted to find group differences in self-report measures and neural response to sleep-related words and negative words compared to neutral words.

Results

Relative to non-shift workers, shift workers showed greater sleep disturbance (i.e., higher PSQI), but they did not show any evidence of emotion-related problems. Shift workers also demonstrated greater neural response to negative words (vs. neutral words) in several prefrontal regions (e.g., dorsal anterior cingulate cortex and dorsolateral prefrontal cortex), anterior insula and caudate compared to non-shift workers. However, shift workers did not show significantly different neural response to sleep-related words (vs. neutral words) compared to non-shift workers.

Conclusion

The result from this study provides supporting evidence that shift work is associated with subjective sleep disturbance. Shift workers’ heightened neural response to negative information may reflect their increased sensitivity to negative information, that may contribute to sleep disturbance.

Support

Brain Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (Study No.: 2016M3C7A1904338 and NRF-2018R1D1A1B07049704).

Clinical Impact of a Protocolized Kidney Donor Follow-up System

BACKGROUND

Adequate kidney donor management after donation is increasingly emphasized due to concerns of renal function impairment after nephrectomy with increasing life expectancy. In this study, the clinical impact of a protocolized kidney donor follow-up system by nephrologists was evaluated.

METHODS

A total of 427 living kidney donors underwent nephrectomy from January 2010 to December 2014 and were followed for at least 2 years at the Samsung Medical Center. Donors were followed-up by nephrologists after the establishment of a donor clinic with systemized protocols in January 2013. The primary outcomes were incidence of post-donation low estimated glomerular filtration rate (eGFR) and renal function adaptability. Secondary outcomes were changes in compliance and incidence of hyperuricemia and microalbuminuria.

RESULTS

The patients were divided into 2 groups according to the time of nephrectomy: the pre-donor clinic period (n = 182) and the donor clinic period (n = 172). Preoperative eGFR in patients in the pre-donor clinic period was higher than that in patients in the donor clinic period. After donation, poor renal adaptation was less frequent in the donor clinic period compared to the pre-donor clinic period. Low eGFR tended to be less common during the donor clinic period. Shorter mean outpatient clinic visit intervals with more visits within 6 months after donation and earlier detection of de novo hyperuricemia were found during the donor clinic period.

CONCLUSION

A protocolized donor clinic run by nephrologists may improve post-nephrectomy renal outcomes and compliance and facilitate better management of potential risk factors of chronic kidney disease in donors.

Betulinic acid inhibits high-fat diet-induced obesity and improves energy balance by activating AMPK

BACKGROUND AND AIM

Metabolic syndromes are prevalent worldwide and result in various complications including obesity, cardiovascular disease and type II diabetes. Betulinic acid (BA) is a naturally occurring triterpenoid that has anti-inflammatory properties. We hypothesized that treatment with BA may result in decreased body weight gain, adiposity and hepatic steatosis in a diet-induced mouse model of obesity.

METHODS AND RESULTS

Mice fed a high-fat diet and treated with BA showed less weight gain and tissue adiposity without any change in calorie intake. Gene expression profiling of mouse tissues and cell lines revealed that BA treatment increased expression of lipid oxidative genes and decreased that of lipogenesis-related genes. This modulation was mediated by increased AMP-activated protein kinase (AMPK) phosphorylation, which facilitates energy expenditure, lipid oxidation and thermogenic capacity and exerts protective effects against obesity and nonalcoholic fatty liver disease. Overall, BA markedly inhibited the development of obesity and nonalcoholic fatty liver disease in mice fed a high-fat diet, and AMPK activation in various tissues and enhanced thermogenesis are two possible mechanisms underlying the antiobesity and antisteatogenic effects of BA.

CONCLUSIONS

The current findings suggest that treatment with BA is a potential dietary strategy for preventing obesity and nonalcoholic fatty liver disease.

Trends of Colorectal Cancer Incidence in Thailand by Age, Gender, and Region

Background: Colorectal cancer (CRC) is the third most common cancer in the world. While CRC incidence has decreased in many western countries over the last decades, largely thanks to screening, it is increasing in low and middle-income countries, including Thailand. However, it is unclear if these increases are consistent across different regions, gender and age groups. Aim: To understand the age-, gender- and region-specific temporal variation in CRC incidence in Thailand since the 1990s. Methods: We analyzed CRC incidence data from the Thailand National Cancer Network (TCIN) cancer registries, which include Chiang Mai (1990-2012), Lampang (1993-2014), Lopburi (2000-2014), Khon Kaen (1990-2014) and Songkhla (1990-2014) cancer registries. Trends in age-adjusted incidence (measured by annual percentage change (APC)) were assessed using Joinpoint regression. Trends by birth-year and calendar-year were assessed using age-period-cohort models. All analyses were done by region, gender, and age group (30-49, 50-84, 30-84). Results: CRC incidence has been increasing significantly in all regions, gender, and age groups; Overall, the APC was 3.82 for men and 3.84 for women (Chiang Mai, 4.34 for men & 3.26 for women; Khon Kaen, 2.69 for men & 3.68 for women; Lampang, 2.13 for men & 3.37 for women; Lopburi, 5.31 for men & 4.67 for women; Songkhla, 4.67 for men & 4.32 for women). The increase in incidence was higher for ages 50-84 (APC = 3.99 for men & 4.04 for women) compared with ages 30-49 (APC=2.97 for men & 3.09 for women). Test of parallelism suggests that increases are consistent between gender (P-value=0.97). The age-period-cohort analysis suggests that both calendar-year and birth-year are strongly correlated with CRC incidence trends, with a stronger relationship with birth-year than calendar-year for both genders. Conclusion: In contrast to western countries such as the US, CRC incidence is increasing across all age groups in Thailand, with faster increase in older ages. This highlights the needs for establishing population-wide screening programs to reduce the burden and stop the rise of CRC in Thailand and low-middle income countries.

Nanoconfinement effects of chemically reduced graphene oxide nanoribbons on poly(vinyl chloride)

Polymeric nanocomposites with graphene-based nanocarbons (GNCs) have been extensively studied with emphasis on the percolation of nanofillers toward electrical, rheological, and mechanical reinforcement. In this study, we report an unusual indirect reinforcing phenomenon of highly defective GNCs dispersed in the poly(vinyl chloride) (PVC) matrix via densification of the polymer packing originating from nanoscale confinement. Herein, chemically reduced graphene oxide nanoribbons (C-rGONRs) are employed as a nanofiller. The inclusion of defective and oxygen-functionalized C-rGONRs resulted in a dramatic densification of the PVC host with extremely low C-rGONR loading, largely exceeding the theoretical calculation from a rule of mixture. Along with the densification, the glass transition temperature of PVC also increased by 28.6 °C at 0.1 wt% filler loading. Remarkably, the oxygen barrier property and mechanical toughness under tension for the PVC/C-rGONR nanocomposite were the maximum when the greatest densification occurred. The structure-property relationship of the nanocomposites has been discussed with an emphasis on the nanoscale confinement phenomenon.

Electron beam induced tunneling magnetoresistance in spatially confined manganite bridges

Certain manganites exhibit rich and technologically relevant transport properties which can often be attributed to the existence and changes of the intrinsic electronic phase competition within these materials. Here we demonstrate that a scanning electron beam can be used to artificially create domain configurations within La_0.3Pr_0.4Ca_0.3MnO₃ thin film microbridges that results in novel magneto-transport effects. In particular, the electron beam preferentially produces insulating regions within the narrow film and can be used to create a configuration consisting of ferromagnetic metallic domains separated by a potential barrier. This arrangement enables the spin-dependent tunneling of charge carriers and can produce large switching tunneling magnetoresistance effects which were initially absent. Hence, this work describes a new and potentially powerful method for engineering the electronic phase domains in manganites to generate functional transport properties that are important for spintronic devices.

Severity of acute and chronic urticaria correlates with D-dimer level, but not C-reactive protein or total IgE

BACKGROUND

Although various scoring systems for measuring urticaria severity have been introduced, most rely on subjective criteria. Therefore, additional objective criteria such as laboratory markers would be helpful adjuncts in making this assessment.

AIM

To evaluate the usefulness of three laboratory markers [D-dimer, C-reactive protein (CRP), and total IgE] in assessing disease severity of both acute urticaria (AU) and chronic urticaria (CU).

METHODS

We conducted a retrospective analysis of 94 patients with urticaria. Correlations between the aforementioned laboratory markers and the Urticaria Activity Score (UAS) were calculated.

RESULTS

A substantial proportion of patients with urticaria (acute 43.5%; chronic 39.6%) had an increased D-dimer level. Additionally, there was a significant correlation between D-dimer level and UAS (AU r = 0.60, P < 0.001; CU r = 0.37, P < 0.05). However, there was no significant correlation between UAS and either CRP or total IgE.

CONCLUSIONS

D-dimer level could be used as a marker of disease severity for both AU and CU. However, CRP and total IgE are not as reliable in predicting disease severity.

Toward successful migration to computerized physician order entry for chemotherapy

BACKGROUND

Computerized physician order entry (cpoe) systems allow for medical order management in a clinical setting. Use of a cpoe has been shown to significantly improve chemotherapy safety by reducing the number of prescribing errors. Usability of these systems has been identified as a critical factor in their successful adoption. However, there is a paucity of literature investigating the usability of cpoe for chemotherapy and describing the experiences of cancer care providers in implementing and using a cpoe system.

METHODS

A mixed-methods study, including a national survey and a workshop, was conducted to determine the current status of cpoe adoption in Canadian oncology institutions, to identify and prioritize knowledge gaps in cpoe usability and adoption, and to establish a research agenda to bridge those gaps. Survey respondents were representatives of cancer care providers from each Canadian province. The workshop participants were oncology clinicians, human factors engineers, patient safety researchers, policymakers, and hospital administrators from across Canada, with participation from the United States.

RESULTS

A variety of issues related to implementing and using a cpoe for chemotherapy were identified. The major issues concerned the need for better understanding of current practices of chemotherapy ordering, preparation, and administration; a lack of system selection and procurement guidance; a lack of implementation and maintenance guidance; poor cpoe usability and workflow support; and other cpoe system design issues. An additional three research themes for addressing the existing challenges and advancing successful adoption of cpoe for chemotherapy were identified: The need to investigate variances in workflows and practices in chemotherapy ordering and administrationThe need to develop best-practice cpoe procurement and implementation guidance specifically for chemotherapyThe need to measure the effects of cpoe implementation in medical oncology.

CONCLUSIONS

Addressing the existing challenges in cpoe usability and adoption for chemotherapy, and accelerating successful migration to cpoe by cancer care providers requires future research focusing on workflow variations, chemotherapy-specific cpoe procurement needs, and implementation guidance needs.

Novel anti-apoptotic mechanism of A20 through targeting ASK1 to suppress TNF-induced JNK activation

The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of nuclear factor-κB (NF-κB) activation and apoptosis in tumor necrosis factor (TNF) receptor 1 signaling pathway. Although the molecular basis for the anti-NF-κB function of A20 has been well elucidated, the anti-apoptotic function of A20 is largely unknown. Here, we report a novel mechanism underlying the anti-apoptotic function of A20: A20 blocks TNF-induced apoptosis through suppression of c-jun N-terminal kinase (JNK) by targeting apoptosis signal-regulating kinase1 (ASK1). First, the ectopic expression of A20 drastically inhibits TNF-induced JNK activation and apoptosis in multiple cell types including those deficient of NF-κB activation. Unexpectedly, the blunting effect of A20 on TNF-induced JNK activation is not mediated by affecting the TNFR1 signaling complex formation. Instead, A20 interacts with ASK1, an important MAPKK kinase in the JNK signaling cascade. More importantly, overexpression of wild-type A20, but not of mutant A20 (ZnF4; C624A, C627A), promotes degradation of the ASK1 through the ubiquitin-proteasome system. Taken together, the results from this study reveal a novel anti-apoptotic mechanism of A20 in TNF signaling pathway: A20 binds to ASK1 and mediates ASK1 degradation, leading to suppression of JNK activation and eventually blockage of apoptosis.

Patterns of nurse-physician communication and agreement on the plan of care

BACKGROUND

Interdisciplinary communication is critically important to provide safe and effective care, yet it has been inadequately studied for hospitalised medical patients. Our objective was to characterise nurse-physician communication and their agreement on patients' plan of care.

METHODS

During a one-month period, randomly selected hospitalised patients, their nurses and their physicians were interviewed. Nurses and physicians were asked to identify one another, whether communication had occurred, and about six aspects of the plan of care. Two internists rated nurse-physician agreement on aspects of the plan of care as none, partial or complete agreement. Measures included the percentage of nurses and physicians able to identify one another and reporting communication and the percentage of nurse-physician pairs in agreement on aspects of the plan of care.

RESULTS

310 (91%) and 301 (88%) of 342 eligible nurses and physicians completed interviews. Nurses correctly identified patients' physicians 71% of the time and reported communicating with them 50% of the time. Physicians correctly identified the patients' nurses 36% of the time and reported communicating with them 62% of the time. Physicians and nurses showed no agreement on aspects of the plan of care ranging from 11% for planned procedures to 42% for medication changes.

CONCLUSIONS

Nurses and physicians did not reliably communicate with one another and were often not in agreement on the plan of care for hospitalised medical patients.

Role of the M3 muscarinic acetylcholine receptor in beta-cell function and glucose homeostasis

The release of insufficient amounts of insulin in the presence of elevated blood glucose levels is one of the key features of type 2 diabetes. Various lines of evidence indicate that acetylcholine (ACh), the major neurotransmitter of the parasympathetic nervous system, can enhance glucose-stimulated insulin secretion from pancreatic beta-cells. Studies with isolated islets prepared from whole body M(3) muscarinic ACh receptor knockout mice showed that cholinergic amplification of glucose-dependent insulin secretion is exclusively mediated by the M(3) muscarinic receptor subtype. To investigate the physiological relevance of this muscarinic pathway, we used Cre/loxP technology to generate mutant mice that lack M(3) receptors only in pancreatic beta-cells. These mutant mice displayed impaired glucose tolerance and significantly reduced insulin secretion. In contrast, transgenic mice overexpressing M(3) receptors in pancreatic beta-cells showed a pronounced increase in glucose tolerance and insulin secretion and were resistant to diet-induced glucose intolerance and hyperglycaemia. These findings indicate that beta-cell M(3) muscarinic receptors are essential for maintaining proper insulin secretion and glucose homeostasis. Moreover, our data suggest that enhancing signalling through beta-cell M(3) muscarinic receptors may represent a new avenue in the treatment of glucose intolerance and type 2 diabetes.

Polymer confinement and bacterial gliding motility

Cyanobacteria and myxobacteria use slime secretion for gliding motility over surfaces. The slime is produced by the nozzle-like pores located on the bacteria surface. To understand the mechanism of gliding motion and its relation to slime polymerization, we have performed molecular dynamics simulations of a molecular nozzle with growing inside polymer chains. These simulations show that the compression of polymer chains inside the nozzle is a driving force for propulsion. There is a linear relationship between the average nozzle velocity and the chain polymerization rate with a proportionality coefficient dependent on the geometric characteristics of the nozzle such as its length and friction coefficient. This minimal model of the molecular engine was used to explain the gliding motion of bacteria over surfaces.

Synthesis and reactivity of an efficient 1,2-dehydrocarborane precursor, phenyl[o-(trimethylsilyl)carboranyl]iodonium acetate

The reaction of [o-(trimethylsilyl)carboranyl]lithium with IPh(OAc)2 in diethyl ether affords an efficient 1,2-dehydro-o-carborane precursor 4: the facile 2 + 4 cycloaddition of 4 with dienes in the presence of the desilylating agent is reported.

Quadriceps muscle deoxygenation during functional electrical stimulation in adults with spinal cord injury

STUDY DESIGN

Cross-sectional study comparing healthy subjects with age and gender matched subjects with spinal cord injury (SCI, injury levels from C5 to T12).

OBJECTIVES

To compare the acute cardiorespiratory responses and muscle oxygenation trends during functional electrical stimulation (FES) cycle exercise and recovery in the SCI and healthy subjects exercising on a mechanical cycle ergometer.

SETTING

Seven volunteers in each group participated in one exercise test at the Rick Hansen Center, University of Alberta, Edmonton, Canada.

METHODS

Both groups completed a stagewise incremental test to voluntary fatigue followed by 2 min each of active and passive recovery. Cardiorespiratory responses were continuously monitored using an automated metabolic cart and a wireless heart rate monitor. Tissue absorbency, an index of muscle oxygenation, was monitored non-invasively from the vastus lateralis using near infrared spectroscopy.

RESULTS

The healthy subjects showed significant (P<0.05) increases in the oxygen uptake (VO2), heart rate (HR) and ventilation rate (VE) from rest to maximal exercise. The SCI subjects showed a twofold increase in VO2 (P>0.05), a threefold increase in VE (P<0.05) and a 5 beats/min increase in HR (P>0.05) from the resting value. The SCI subjects demonstrated a lesser degree (P<0.05) of muscle deoxygenation than the healthy subjects during the transition from rest to exercise. Regression analysis indicated that the rate of decline in muscle deoxygenation with respect to the VO2 was significantly (P<0.05) faster in the SCI subjects compared to healthy subjects.

CONCLUSIONS

FES exercise in SCI subjects elicits: (a) modest increases in the cardiorespiratory responses when compared to resting levels; (b) lower degree of muscle deoxygenation during maximal exercise, and (c) faster changes in muscle deoxygenation with respect to the VO2 during exercise when compared to healthy subjects.

Enantiomeric separation and discrimination of 2-hydroxy acids as O-trifluoroacetylated (S)-(+)-3-methyl-2-butyl esters by achiral dual-capillary column gas chromatography

An efficient method is described for the simultaneous enantiomeric separation of 18 different racemic 2-hydroxy acids for the determination of their absolute configurations. It involves the conversion of each enantiomer into a diastereomeric O-trifluoroacetylated (S)-(+)-3-methyl-2-butyl ester for the direct separation by achiral dual-capillary column gas chromatography with subsequent identification and determination of its chirality by retention index (I) library matching. The enantiomers of each acid were well separated with high resolution values (R > or = 1.4) on DB-5 and DB-17 columns of different polarity. When temperature-programmed I values of 2-hydroxy acid enantiomers as their diastereomeric derivatives were measured on both columns, the I values were characteristic of each enantiomer. Simple I matching with the reference values was thus useful in cross-checking each acid enantiomer for the identification and chiral discrimination. When applied to urine samples, the present method allowed positive identification of most of the spiked 2-hydroxy acids from normal urine and for endogenous (S)-lactic acid and (S)-2-hydroxybutyric acid from a clinical urine specimen.

Functional electrical stimulation exercise increases GLUT-1 and GLUT-4 in paralyzed skeletal muscle

The study purpose was to determine the effect of functional electrical stimulation (FES)-leg cycle ergometer training (30 minutes on 3 d/wk for 8 weeks) on the GLUT-1 and GLUT-4 content of paralyzed skeletal muscle. Biopsy samples of vastus lateralis muscle were obtained pre- and post-training from five individuals with motor-complete spinal cord injury ([SCI] four men and one woman aged 31 to 50 years, 3 to 25 years postinjury involving C5-T8). Western blot analysis indicated that GLUT-1 increased by 52% and GLUT-4 increased by 72% with training (P < .05). This coincided with an increase in the muscle oxidative capacity as indicated by a 56% increase in citrate synthase (CS) activity (P < .05) and an improvement in the insulin sensitivity index as determined from oral glucose tolerance tests (P < .05). It is concluded that FES endurance training is effective to increase glucose transporter protein levels in paralyzed skeletal muscle of individuals with SCI.