Patency of permanent vascular access creation in paediatric patients with end stage renal disease

Renal transplant is the first-line therapy in paediatric patients with end-stage renal disease (ESRD). Wong HS and Goh BL reported up to 79% of 1061 paediatric patients still require long-term haemodialysis (HD).1 The lack of deceased and living donors is attributable to the poor awareness, cultural and religious grounds. Permanent vascular access (PVA) in paediatrics therefore, serves more as a long term treatment rather than a bridging therapy. We observed 5 children and an adolescent, all with previous indwelling catheters, who underwent arteriovenous fistula (AVF) creation and report the outcomes. The aim of this report is to determine the factors that influence the longterm patency of paediatric AVF. Factors such as body weight, vessel diameter, preoperative preparations, microsurgical technique and postoperative maintenance are discussed. In addition, considerations on the choice and timing of PVA is highlighted.

Towards label-free distributed fiber hydrogen sensor with stimulated Raman spectroscopy

Hydrogen detection is of great importance in chemical and energy industries. Optical fiber hydrogen sensors show flexibility and compactness, and have the potential for distributed analysis. However, traditional fiber sensors encounter a challenge with light interacting with hydrogen directly because hydrogen only displays weak quadrupole absorption, and metallic palladium and platinum thin-film coatings are typically used as an optically detectable label. Here, based on stimulated Raman spectroscopy in hollow-core photonic crystal fibers, we investigate the label-free optical fiber distributed hydrogen sensors operating in the optical telecommunication band. The approach of distributed Raman measurement represents a new paradigm in fiber sensors, potentially allowing distributed chemical analysis in gas or liquid phase with high sensitivity and selectivity.

Gender differences in body mass index, body weight perception and weight loss strategies among undergraduates in Universiti Malaysia Sarawak

INTRODUCTION

This study was carried out among undergraduate students in Universiti Malaysia Sarawak with the objective of examining gender differences in body mass index (BMI), body weight perception, eating attitudes and weightloss strategies.

METHODS

Subjects consisted of 600 undergraduates (300 males and 300 females) recruited from the various faculties between September 2008 until mid-November 2008. The Original Figure Rating Scale: Body Weight Perception, Body Shape Questionnaire (BSQ) and Eating Attitudes Test-26 (EAT-26) were used as assessment tools.

RESULTS

Overall, 52.8% of students had normal BMI, with approximately an equal number of both sexes. More males than females were overweight (33.7%), while more females were underweight (25.3%). Males were more likely to perceive themselves as overweight, and fail to see themselves as underweight. More than half of the females preferred their ideal figure to be underweight, whereas about 30% males chose an overweight figure as their ideal model. Females were generally more concerned about body weight, body shape and eating than males. They diet more frequently, had self-induced vomiting, and used laxatives and exercise as their weight-loss strategies.

CONCLUSION

Issues pertaining to body weight perception, eating attitudes and weight-loss strategies exist with differences among male and female undergraduates. Thus, in order to correct misperceptions among young adults, a more tailored intervention programme and more in-depth studies into the various factors involved are required.

[Recurrent tick-borne fever: a possible diagnosis in patients returning from Senegal]

In Senegal, tick-borne relapsing fever caused by the spirochetes Borrelia crucidurae is the most common cause of fever after malaria in rural areas. However, this is only rarely diagnosed in France, probably because: i) the diagnosis relies on investigations that are not routinely done; ii) even undiagnosed, borreliosis may be cured with empirical antibiotic treatment. We report four observations of tick-borne relapsing fever in patients returning from Senegal: In two patients, the diagnosis relied on the observation of spirochetes in blood smears; in the other two, the diagnosis relied on typical clinico-biological signs, borreliosis serology and exposure. These four cases diagnosed over a four year period in one institution suggest that relapsing fever is not rare in patients returning from West Africa. Patients who return form Senegal with unexplained fever should be investigated with careful examination of blood smears and PCR on blood samples.

Simple system for optical short-pulse generation in both active mode-locking and self-seeding schemes

A simple system that simultaneously supports active mode-locking and self-seeding schemes for wavelength-tunable optical short-pulse generation is proposed. The system consists of a gain-switched Fabry-Perot laser diode, an erbium-doped fiber amplifier, a tunable optical filter, and two circulators. The mode-locked optical pulses exhibit good stability, a high side-mode suppression ratio of more than 31 dB over a wide wavelength tuning range of 42 nm, and a pulse width of around 35 ps at a repetition frequency of approximately 2.8 GHz.

Variability in physician management of employment during pregnancy

BACKGROUND AND OBJECTIVES

Successful employment outcomes for pregnant women result from a complex interplay between the woman, her employer, her prenatal care provider, laws and other influences.

METHODS

A mail survey about management of employment during pregnancy was sent to directors of US residency programs that train prenatal care providers. Each physician was randomly assigned one of 4 vignette patients whose job involved prolonged standing, rotating shifts and lifting 40 lbs. Half the vignette patients had risk factors for preterm birth and half would have financial difficulty if placed on an unpaid antenatal leave.

RESULTS

The 301 respondents estimated that they provide a written job restriction for 20% of their employed pregnant patients, although in 6 clinics the job restriction rate was 100%. For vignettes with preterm birth risk factors, 62.5% of physicians would always recommend a job restriction, 35.6% would do so sometimes, and 2.2% would rarely do so. When the vignette did not have risk factors for preterm birth, 21.5% of the physicians would always recommend a job restriction, 51.3% would do so sometimes, 25.9% would do so rarely and 1.3% would never do so. Economic factors were not associated with prescribing job restrictions. One in 5 of the residency programs provides no teaching on occupational health issues in pregnancy, and 65.1% provide 2 hours or less.

CONCLUSIONS

Variability in employment recommendations suggests that some women may not obtain the job modifications that they need, whereas others may be restricted unnecessarily. The limited curriculum time devoted to this topic may make it difficult to train physicians about complex employment issues during pregnancy.

Multiplexing of optical fiber gas sensors with a frequency-modulated continuous-wave technique

We report on the use of a frequency-modulated continuous-wave technique for multiplexing optical fiber gas sensors. The sensor network is of a ladder topology and is interrogated by a tunable laser. The system performance in terms of detection sensitivity and cross talk between sensors was investigated and found to be limited by coherent mixing between signals from different channels. The system performance can be improved significantly by use of appropriate wavelength modulation-scanning coupled with low-pass filtering. Computer simulation shows that an array of 37 acetylene sensors with a detection accuracy of 2000 parts in 10(6) for each sensor may be realized. A two-sensor acetylene detection system was experimentally demonstrated that had a detection sensitivity of 165 parts in 10(6) for 2.5-cm gas cells (or a minimum detectable absorbance of 2.1 x 10(-4)) and a cross talk of -25 dB.

The gene expression of the amiloride-sensitive epithelial sodium channel alpha-subunit is regulated by antagonistic effects between glucocorticoid hormone and ras pathways in salivary epithelial cells

The functional expression of the amiloride-sensitive epithelial sodium channel (ENaC) in select epithelia is critical for maintaining electrolyte and fluid homeostasis. Although ENaC activity is strictly dependent upon its alpha-subunit expression, little is known about the molecular mechanisms by which cells modulate alpha-ENaC gene expression. Previously, we have shown that salivary alpha-ENaC expression is transcriptionally repressed by the activation of Raf/extracellular signal-regulated protein kinase pathway. Here, this work further investigates the molecular mechanism(s) by which alpha-ENaC expression is regulated in salivary epithelial Pa-4 cells. A region located between -1.5 and -1.0 kilobase pairs of the alpha-ENaC 5'-flanking region is demonstrated to be indispensable for the maximal and Ras-repressible reporter expression. Deletional analyses using heterologous promoter constructs reveal that a DNA sequence between -1355 and -1269 base pairs functions as an enhancer conferring the high level of expression on reporter constructs, and this induction effect is inhibited by Ras pathway activation. Mutational analyses indicate that full induction and Ras-mediated repression require a glucocorticoid response element (GRE) located between -1323 and -1309 base pairs. The identified alpha-ENaC GRE encompassing sequence (-1334/-1306) is sufficient to confer glucocorticoid receptor/dexamethasone-dependent and Ras-repressible expression on both heterologous and homologous promoters. This report demon- strates for the first time that the cross-talk between glucocorticoid receptor and Ras/extracellular signal-regulated protein kinase signaling pathways results in an antagonistic effect at the transcriptional level to modulate alpha-ENaC expression through the identified GRE. In summary, this study presents a mechanism by which alpha-ENaC expression is regulated in salivary epithelial cells.