Copy number variation prevalence in known asthma genes and their impact on asthma susceptibility

BACKGROUND

Genetic studies have identified numerous genes reproducibly associated with asthma, yet these studies have focussed almost entirely on single nucleotide polymorphisms (SNPs), and virtually ignored another highly prevalent form of genetic variation: Copy Number Variants (CNVs).

OBJECTIVE

To survey the prevalence of CNVs in genes previously associated with asthma, and to assess whether CNVs represent the functional asthma-susceptibility variants at these loci.

METHODS

We genotyped 383 asthmatic trios participating in the Childhood Asthma Management Program (CAMP) using a competitive genomic hybridization (CGH) array designed to interrogate 20 092 CNVs. To ensure comprehensive assessment of all potential asthma candidate genes, we purposely used liberal asthma gene inclusion criteria, resulting in consideration of 270 candidate genes previously implicated in asthma. We performed statistical testing using FBAT-CNV.

RESULTS

Copy number variation in asthma candidate genes was prevalent, with 21% of tested genes residing near or within one of 69 CNVs. In six instances, the complete candidate gene sequence resides within the CNV boundaries. On average, asthmatic probands carried six asthma-candidate CNVs (range 1-29). However, the vast majority of identified CNVs were of rare frequency (< 5%) and were not statistically associated with asthma. Modest evidence for association with asthma was observed for 2 CNVs near NOS1 and SERPINA3. Linkage disequilibrium analysis suggests that CNV effects are unlikely to explain previously detected SNP associations with asthma.

CONCLUSIONS AND CLINICAL RELEVANCE

Although a substantial proportion of asthma-susceptibility genes harbour polymorphic CNVs, the majority of these variants do not confer increased asthma risk. The lack of linkage disequilibrium (LD) between CNVs and asthma-associated SNPs suggests that these CNVs are unlikely to represent the functional variant responsible for most known asthma associations.

Photochemical activation of TRPA1 channels in neurons and animals

Optogenetics is a powerful research tool because it enables high-resolution optical control of neuronal activity. However, current optogenetic approaches are limited to transgenic systems expressing microbial opsins and other exogenous photoreceptors. Here, we identify optovin, a small molecule that enables repeated photoactivation of motor behaviors in wild-type zebrafish and mice. To our surprise, optovin's behavioral effects are not visually mediated. Rather, photodetection is performed by sensory neurons expressing the cation channel TRPA1. TRPA1 is both necessary and sufficient for the optovin response. Optovin activates human TRPA1 via structure-dependent photochemical reactions with redox-sensitive cysteine residues. In animals with severed spinal cords, optovin treatment enables control of motor activity in the paralyzed extremities by localized illumination. These studies identify a light-based strategy for controlling endogenous TRPA1 receptors in vivo, with potential clinical and research applications in nontransgenic animals, including humans.

The anti-viral effect of sorafenib in hepatitis C-related hepatocellular carcinoma

BACKGROUND

Sorafenib is currently the only approved systemic therapy shown to have efficacy in the treatment of advanced hepatocellular carcinoma (HCC). Recent studies suggest that hepatitis C (HCV)-related HCC patients derive more clinical benefit from sorafenib than other subgroups, but the mechanism for this effect is unknown. In vitro data suggest that sorafenib may exert anti-viral properties, and thus our aim in this study was to evaluate potential anti-viral activity of sorafenib in patients with HCV-related HCC.

AIM

To evaluate potential anti-viral activity of sorafenib in patients with HCV-related HCC.

METHODS

We prospectively enrolled patients with HCV-related HCC treated with sorafenib for up to 6 months. Baseline clinical, viral and oncologic data were collected. Patients' HCV viral loads were obtained at various time points, and compared with their baseline viral levels. No patients received any known anti-viral therapy during this time.

RESULTS

Thirty-three patients were identified with baseline and subsequent HCV levels available for analysis. Six patients completed 6 months of full dose sorafenib, and comparisons of their HCV viral loads showed no significant change at week 24 (difference of means = 0.3500, CI: -0.1799-0.8799, P = 0.150), or the interim time points. Similarly, the HCV viral loads of all patients who received sorafenib and the viral loads of those patients who had tumour response to sorafenib showed no significant changes at any time point.

CONCLUSION

Despite preclinical data and previous subgroup analyses suggesting that sorafenib has an anti-viral effect against HCV, this study suggests that sorafenib lacks significant anti-viral activity in HCV patients with HCC.

Primary care physicians' knowledge of and experience with pharmacogenetic testing

It is anticipated that as the range of drugs for which pharmacogenetic testing becomes available expands, primary care physicians (PCPs) will become major users of these tests. To assess their training, familiarity, and attitudes toward pharmacogenetic testing in order to identify barriers to uptake that may be addressed at this early stage of test use, we conducted a national survey of a sample of PCPs. Respondents were mostly white (79%), based primarily in community-based primary care (81%) and almost evenly divided between family medicine and internal medicine. The majority of respondents had heard of PGx testing and anticipated that these tests are or would soon become a valuable tool to inform drug response. However, only a minority of respondents (13%) indicated they felt comfortable ordering PGx tests and almost a quarter reported not having any education about pharmacogenetics. Our results indicate that primary care practitioners envision a major role for themselves in the delivery of PGx testing but recognize their lack of adequate knowledge and experience about these tests. Development of effective tools for guiding PCPs in the use of PGx tests should be a high priority.

Survey of genetic counselors and clinical geneticists' use and attitudes toward pharmacogenetic testing

Pharmacogenetic (PGx) testing aims to improve therapeutic outcomes through tailoring treatment based on a patient's genetic risk for non-response and/or an adverse event. Given their expertise, geneticists could facilitate the use of PGx testing; however, the preparedness and perceived role of the clinical genetics community is unclear. To assess the attitudes, preparedness, and perceived roles of geneticists in the delivery of PGx testing, we conducted a survey of 1500 randomly selected board-certified genetic counselors and clinical geneticists in the United States [response rate: 37.8% (n = 516)]. Twelve percent of genetic counselors and 41% of clinical geneticists indicated that they had ordered or coordinated patient care for PGx testing, a seemingly high proportion at this early stage of adoption. Almost all respondents had some education on pharmacogenetics, although only 28% of counselors and 58% of clinical geneticists indicated they felt well-informed about PGx testing. About half of counselors (52%) and clinical geneticists (46%) felt they would play 'some' role in the delivery of PGx testing; 17 and 19%, respectively, felt that they would play 'no' or 'a little' role. At this early stage of PGx testing, the role of geneticists and genetic counselors is unclear. However, their experience may aid in readying PGx testing and informing delivery strategies into clinical practice.

Do patient-reported outcomes have a role in the management of patients with cystic fibrosis?

BACKGROUND

Health-related quality of life (HRQoL) is a rapidly growing area of expertise and the most commonly used patient-reported outcome (PRO). The impact of cystic fibrosis (CF) on HRQoL is liable to be great, making CF patients ideal candidates for the application of HRQoL instruments. The aims of this study were to assess the affect of CF on HRQoL, to ascertain the reliability and validity of the United Kingdom Sickness Impact Profile (UKSIP) and the Cystic Fibrosis Quality of Life Questionnaire (CFQoL) in the adult CF population, and to examine their role in the management of patients.

METHODS

Seventy participants were recruited from the All Wales Adult Cystic Fibrosis Centre at Llandough Hospital, UK. There were two stages to the study: self-report of the UKSIP and CFQoL; and completion of the same two questionnaires 7-10 days later.

RESULTS

The areas of HRQoL most impaired by CF were employment and concerns regarding the future. The UKSIP and CFQoL showed high internal consistency (rα = 0.89-0.93) and test-retest reliability (r(s) = 0.57-0.94, p < 0.005) in the CF population. Validity was variable with the UKSIP showing discrimination across socio-demographic factors, whilst the CFQoL showed increased sensitivity to clinical variables. Many parameters influenced patient-reported HRQoL, with the greatest correlations seen with the Borg score (p < 0.005). The use of a HRQoL instrument in CF annual reviews is recommended to provide holistic patient care. The results of this study underpin the value of HRQoL as a patient-reported outcome measure in the management of adult CF.

A child presenting with a bullet in the middle ear: case report

Introduction

Foreign bodies in the external auditory canal are common in both adults and children. Removal of the foreign body requires skill, but is usually successfully performed in the emergency department. We report a case of a child with a bullet in ear canal which was pushed into the middle ear during an attempt to remove it.

Case Presentation

A 6-year-old Thai boy went to the community hospital with his parents, who reported that their child had pushed a bullet into his ear. Otoscopic examination revealed a metallic foreign body in his external auditory canal. The first attempt to remove the foreign body failed and the child was referred to an otolaryngologist. We found that the tympanic membrane was ruptured, with granulation tissue in the middle ear and the bullet was located in the hypotympanum. The foreign body was removed via a post-auricular approach.

Conclusion

Removal of a foreign body from external auditory canal is an essential skill for physicians. Careful removal can prevent further trauma and complications. When the first attempt fails, referral to an otolaryngologist is recommended.

A micropower miniature piezoelectric actuator for implantable middle ear hearing device

This paper describes the design and development of a small actuator using a miniature piezoelectric stack and a flextensional mechanical amplification structure for an implantable middle ear hearing device (IMEHD). A finite-element method was used in the actuator design. Actuator vibration displacement was measured using a laser vibrometer. Preliminary evaluation of the actuator for an IMEHD was conducted using a temporal bone model. Initial results from one temporal bone study indicated that the actuator was small enough to be implanted within the middle ear cavity, and sufficient stapes displacement can be generated for patients with mild to moderate hearing losses, especially at higher frequency range, by the actuator suspended onto the stapes. There was an insignificant mass-loading effect on normal sound transmission (<3 dB) when the actuator was attached to the stapes and switched off. Improved vibration performance is predicted by more firm attachment. The actuator power consumption and its generated equivalent sound pressure level are also discussed. In conclusion, the actuator has advantages of small size, lightweight, and micropower consumption for potential use as IMHEDs.

Preliminary assessment of remote photoelectric excitation of an actuator for a hearing implant

Sound modulated infrared (IR) light, as an alternative signal (and energy) transmission method, was evaluated for remote powering of a hearing implant via an implanted photodiode receiver. One human cadaveric temporal bone was used to test this concept by locating an IR source (LED) in the ear canal 4 mm away from the eardrum and a photodiode in the middle ear cavity. The photodiode output was directly used to drive a piezo-ceramic disc actuator which was located externally for facilitating the test. The displacement frequency response of the actuator was measured by a laser vibrometer. It was found that, at a LED current of 8.6 mA, the actuator displacement was about 22.4 nm, equivalent to a stapes displacement from about 91 dB sound-pressure-level (SPL) stimulation at the eardrum. The IR light transmittance through the eardrum (compared to through an air path) was about 67%. The LED optical power was 0.77 mW (its maximal irradiance was about 3.95 mW/cm2) which is a safe to the human body. Current consumption can be reduced by a factor of 3-5 by using a more efficient LED and photodiode.

Is routine urine cytology useful in the haematuria clinic?

INTRODUCTION

The objective of this study was to determine the value of routine urine cytology in the initial evaluation of patients presenting to a one-stop haematuria clinic.

PATIENTS AND METHODS

A total of 1000 consecutive patients who attended the haematuria clinic between June 2003 and November 2004 were studied prospectively. A standard protocol was used to investigate these patients. This included urine cytology, upper tract imaging and flexible cystoscopy.

RESULTS

Overall, 986 samples of urine were sent for cytology. In 126 patients, the report was abnormal; of these, 71 patients were found to have bladder transitional cell carcinoma by flexible cystoscopy and a further 3 had upper tract transitional cell carcinoma diagnosed radiologically. The remaining 52 patients with abnormal cytology were not found to have cancer on further investigations. The total cost for urine cytology and additional investigations was pound50,535.

CONCLUSIONS

In this study of the initial evaluation of patients with haematuria, no case of urothelial malignancy was diagnosed on the basis of urine cytology alone. Therefore, urine cytology need not be used routinely in the initial diagnostic work-up for haematuria.