Association between beta-blocker use and obesity in Hong Kong Chinese elders: a post-hoc analysis.

INTRODUCTION: Studies of Caucasian populations have shown that beta-blockers may exacerbate weight gain, a risk factor for many chronic diseases. Still, beta-blockers are the most prescribed antihypertensives in the Chinese population in Hong Kong. We aimed to explore the association between beta-blocker use, hypertension, and weight status of this population. METHODS: A post-hoc analysis regarding body mass index (BMI) and the use of beta-blockers was performed based on the medication profile of community-dwelling older adults. Participants' BMI, hypertension diagnosis, name, dose, frequency, route of administration of beta-blockers, and other drugs that may alter body weight were recorded. RESULTS: Of 1053 Chinese individuals aged ≥65 years (mean age 76.9±7.2 years, 80% female) from 32 elderly centres in Hong Kong, 18% (185/1053) of them consumed beta-blockers. That group also had a significantly larger proportion of obese individuals (45.9% vs 32.1%, P=0.002). After adjusting for other weight-altering drugs, beta-blockers remained a significant predictor of overweight and obesity (P=0.001). As the hypertensive population had significantly higher BMI than the normotensive population (24.3±3.6 vs 22.9±3.5, P<0.001), a sub-analysis on those with hypertension diagnosis confirmed that only the hypertensive population taking atenolol had a significantly larger population of obese individuals (BMI ≥25) compared with those who took metoprolol (58.9% vs 38.5%, P=0.03) and those who did not take any beta-blockers (58.9% vs 38.4%, P=0.007). CONCLUSIONS: Our findings taken together with other guideline reservations cast doubt on whether beta-blockers, particularly atenolol, should be the major drug prescribed to older adults with hypertension.

A pilot external quality assurance programme for line-probe assay detection of anti-tuberculosis drug resistance.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB; resistance to isoniazid and rifampicin) is difficult to detect and control. Line-probe assays (LiPA) are widely used for the rapid detection of MDR-TB. OBJECTIVE: To ensure the quality of the test, a pilot external quality assurance (EQA) programme was initiated to assess the feasibility of running such a programme and the possibility of improving the proficiency of TB laboratories in performing the test. DESIGN: Prepared filter-paper-based Mycobacterium tuberculosis DNA samples were shipped to participant laboratories for LiPA EQA. The tests were performed blind, and the results were returned to the organising laboratory for comparison and analysis. RESULTS: A total of four rounds of EQA samples were dispatched to five laboratories in four countries. Overall inter- and intra-laboratory reproducibility was respectively 97% and 96%. The strengths and weaknesses of the participant laboratories in performing the test were discussed. CONCLUSION: A LiPA EQA programme can ensure quality and improve the performance of TB laboratories. This is a critical step during the initial stages at the time of setting up this method of testing.

Effects of spectral manipulation on nonindividualized head-related transfer functions (HRTFs).

BACKGROUND: Directional sounds simulated using nonindividualized head-related transfer functions (HRTFs) often result in front-back confusion. OBJECTIVE: This study was designed to examine how manipulating these nonindividualized HRTF spectra can reduce front-back confusion in headphone-simulated directional sounds. METHOD: HRTFs of six ear-level directions were studied (angles of 0 degrees, 45 degrees, 135 degrees, 180 degrees, 225 degrees, and 315 degrees). The HRTF gains in each of six frequency bands (200 to 690 Hz, 690 to 2400 Hz, 2400 to 6500 Hz, 6500 to 10000 Hz, 10000 to 14000 Hz, and 14000 to 22000 Hz) were amplified or attenuated by 0, 12, or 18 dB. Each manipulated HRTF generated a directional sound stimulus. For this study, 32 participants were invited to localize the randomly ordered stimuli. RESULTS: The results indicate that a 12- or 18-dB manipulation of five of the six frequency bands produced significantly better directional accuracy, with significantly less front-back confusion. A reduction of up to 70% in localization error was obtained, along with 66% less front-back confusion. Significant interactions were found between the manipulation level and frequency. CONCLUSION: A 12-dB spectral manipulation of selected HRTF frequency bands produces better directional accuracy. APPLICATION: The results of this research could be applied to the development of tunable nonindividualized HRTFs for audio products.

Endoscopic submucosal dissection versus local excision for early rectal neoplasms: a comparative study.

BACKGROUND: Transanal local excision (LE) is a well-established treatment option for early rectal neoplasms not amenable to complete colonoscopic removal. Endoscopic submucosal dissection (ESD) has been introduced recently as a novel procedure that enables en bloc resection of large rectal neoplasms. To date, no report comparing the two approaches can be found in the literature. This study aimed to compare the short-term clinical outcomes between ESD and LE for early rectal neoplasms. METHODS: Between 2007 and 2010, 14 patients with early rectal neoplasms deemed not feasible for en bloc endoscopic resection using conventional techniques underwent ESD. They were compared with a matched cohort of 30 patients who had early rectal neoplasms and underwent LE between 2000 and 2009. Short-term clinical outcomes including postprocedure recovery and morbidity were compared between the two groups. RESULTS: The mean lesion size was comparable between the ESD and LE groups (2.9 vs 2.6 cm; P = 0.423), but the mean distance of the lesions from the anal verge was greater in the ESD group (8.6 vs 5.0 cm; P = 0.001). En bloc resection was achieved for 12 patients (85.7%) in the ESD group and for all the patients in the LE group. The ESD group exhibited a trend toward a longer operative time (77.5 vs 50.0 min; P = 0.081) but lower morbidity (7.1 vs 33.3%; P = 0.076). The time to full ambulation was shorter in the ESD group (0 vs 1 day; P = 0.005), but the hospital stay was similar in the two groups (2.5 vs 4.0 days; P = 0.129). CONCLUSION: For the treatment of early rectal neoplasms, ESD offers better short-term clinical outcomes in terms of faster recovery and possibly lower morbidity than LE. Further prospective studies with a larger sample are needed to validate the benefits of rectal ESD.

Usefulness of resistant gene markers for predicting treatment outcome on second-line anti-tuberculosis drugs.

AIM: Mutations in rrs [nucleotide (nt) 1401], gyrA gene (codons 90, 91 or 94), tlyA, ethA and thyA genes of Mycobacterium tuberculosis (MTB) were evaluated for their usefulness in predicting treatment outcome of kanamycin (KM), capreomycin (CPM), ofloxacin (OFX), ethionamide (ETH) and para-aminosalicylic acid (PAS). METHODS AND RESULTS: DNA sequence analyses of these genes were performed against 188 MTB isolates obtained from patients put on second-line anti-TB drugs (SLDs) with well-documented clinical history and treatment outcome. Mutations in rrs and gyrA have 100% positive predictive value (PPV) in predicting treatment failure for KM and OFX, while 88·9 and 80% were obtained, respectively, when tlyA and rrs mutations were considered in CPM. For ETH and PAS, the PPV of using ethA and thyA mutations to predict treatment failure was 82·5 and 89·3%, respectively. CONCLUSIONS: Our study demonstrated high specificities of gene mutations in predicting poor treatment outcome; however, further technical advancement is required to make the molecular detection of resistances to other SLDs feasible in clinical laboratories. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to correlate different polymorphisms of major SLD resistance gene markers with predicted treatment outcome, using an international set of well-documented clinical MTB strains.

Toward orthogonal non-individualised head-related transfer functions for forward and backward directional sound: cluster analysis and an experimental study.

Individualised head-related transfer functions (HRTFs) have been shown to accurately simulate forward and backward directional sounds. This study explores directional simulation for non-individualised HRTFs by determining orthogonal HRTFs for listeners to choose between. Using spectral features previously shown to aid forward-backward differentiation, 196 non-individualised HRTFs were clustered into six orthogonal groups and the centre HRTF of each group was selected as representative. An experiment with 15 listeners was conducted to evaluate the benefits of choosing between six centre-front and six centre-back directional sounds rather than the single front/back sounds produced by MIT-KEMAR HRTFs. Sound localisation error was significantly reduced by 22% and 65% of listeners reduced their front-back confusion rates. The significant reduction was maintained when the number of HRTFs was reduced from six to five. This represents a preliminary success in bridging the gap between individual and non-individual HRTFs for applications such as spatial surround sound systems. STATEMENT OF RELEVANCE: Due to different pinna shapes, directional sound stimuli generated by non-individualised HRTFs suffer from serious front-back confusion. The reported work demonstrates a way to reduce front-back confusion for centre-back sounds generated from non-individualised HRTFs.

Development of a simple and low-cost real-time PCR method for the identification of commonly encountered mycobacteria in a high throughput laboratory.

AIMS: To facilitate efficient identification of commonly encountered mycobacteria species (Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium fortuitum complex, Mycobacterium chelonae/abscessus, Mycobacterium kansasii, Mycobacterium gordonae) in high throughput laboratories, a 16s rDNA sequence based real-time PCR assay was developed and evaluated. METHODS AND RESULTS: Oligonucleotide primers and hybridization probes were designed based on sequence differences of the mycobacterial 16S rDNA gene. This assay was evaluated with 1649 suspected non-tuberculosis mycobacterial isolates. Apart from 3 out of 40 M. avium isolates that showed false signal with M. intracellulare specific probe, 100% specificity was obtained for all tested probes. Assay sensitivity varied from 88.9 to 100% depending on species. Average cost for obtaining a definite identification was only USD 1.1 with an average turn around time of less than 3 days. CONCLUSIONS: A rapid, simple and inexpensive real-time PCR assay was developed for the identification of common encountered mycobacteria in a high throughput laboratory setting. SIGNIFICANCE AND IMPACT OF THE STUDY: With this assay, more than 80% of the clinically isolated nontuberculous mycobacteria could be identified in a highly cost effective manner. This helped to save resources for other laboratory activities especially in high throughput mycobacterial laboratories.

Use of the Interact Short Form as a tool to evaluate emotion of people with profound intellectual disabilities.

BACKGROUND: One of the essential purposes of intervention programmes for people with profound intellectual disabilities (ID) is to enhance the desirable mood and behaviour and decrease the undesirable ones through stabilizing their emotion. There is lack of validated instrument to offer a comprehensive measure that covers the mood and behaviour, both desirable and undesirable, appropriate for people with profound ID. METHOD: This study aimed to examine the validity and reliability of the Interact Short Form for evaluating the mood and behaviour of people with profound ID, and at the same time, review their emotional profile using the Interact Short Form. Both content validity using expert panel review and construct validity by means of factor analysis were investigated. A total of 75 people with profound ID were recruited. Inter-rater reliability was tested. The results of the Interact Short Form were described to reflect the emotional profile of this group of participants. RESULTS: Using the results of expert panel review and those from factor analysis, we found three subscales representing the mood and behaviour of people with profound ID. They were: 'emotional expression', 'interests towards tasks' and 'behaviours to environment'. All three subscales were found to be internally consistent (alpha = 0.71-0.88). The Interact Short Form- People with profound ID version also showed good inter-rater reliability (mean = 0.72). The results of the Interact Short Form showed that this group of participants had fairly stable emotion under the structured setting and activities in the residential institutions where data were collected. CONCLUSIONS: The Interact Short Form- People with profound ID version serves as a helpful tool for both clinical and research use in assessing the mood and behaviour of people with profound ID in a simple, comprehensive and systematic way.

Laparoscopic total colectomy for colorectal cancers: a comparative study.

BACKGROUND: No previous report could be found in the literature comparing laparoscopic and open total colectomy for colorectal cancers, especially synchronous colorectal cancers. This study aimed to compare the short-term clinical outcomes and oncologic results of laparoscopic and open total colectomy or proctocolectomy for colorectal cancers. METHODS: Between July 1997 and January 2005, six patients with colorectal cancers underwent elective laparoscopic total colectomy or proctocolectomy at the authors' institution. Clinical data for 12 patients who underwent elective open total colectomy or proctocolectomy for colorectal cancers during the same period were prospectively collected and compared. RESULTS: The median follow-up periods were 43.9 months for the laparoscopic group and 48.2 months for the open group. Conversion to open procedure was required for one patient (16.7%) in the laparoscopic group because of bleeding. The median operative time was significantly longer in the laparoscopic group (427.5 min; range, 280-480 min vs 172.5 min; range, 90-260 min; p = 0.001). The patients in the laparoscopic group required a significantly shorter duration of parenteral analgesia (3 vs 5 days; p = 0.01), but there were no differences in time to first bowel motion, time to resumption of diet, time to full ambulation, and duration of hospital stay between the two groups. Perioperative morbidity rates were comparable between the two groups, and there was no operative mortality. The oncologic results, including number of lymph nodes removed, recurrence rates, and survival rates, were similar in the two groups. CONCLUSIONS: Laparoscopic total colectomy has short-term clinical outcomes (postoperative recovery and perioperative morbidity and mortality rates) and oncologic results similar to those of open surgery for treating patients with colorectal cancers. Our study has shown that the only advantage of laparoscopic over open surgery is a shorter duration of analgesic requirement, but at the expense of a longer operative time.

Denaturing HPLC for high-throughput screening of rifampicin-resistant Mycobacterium tuberculosis isolates.

OBJECTIVE: To evaluate the use of denaturation high-performance liquid chromatography (dHPLC) as a rapid method to detect rifampicin (RMP) resistance based on mutations in the rpoB gene in a high-volume laboratory setting. METHODS: A total of 132 RMP-resistant Mycobacterium tuberculosis strains with different rpoB mutation were used to optimise the running condition of dHPLC as a pilot study. A blind correlation study was subsequently done between dHPLC and in vitro RMP susceptibility tests on 3167 M. tuberculosis strains in a high-throughput clinical setting. RESULTS: In the pilot study, rpoB mutation could be detected on 116/132 (87.9%) RMP-resistant strains by dHPLC. In the second phase of the study, 84/3107 (2.7%) clinical M. tuberculosis isolates were RMP-resistant. The sensitivity and specificity of dHPLC in the prediction of RMP resistance were 70/84 (83.3%) and 70/77 (91.0%), respectively. The specificity became 100% when 511 Leu to Pro mutation was excluded from the RMP resistance-related genetic changes. CONCLUSION: In the detection of RMP resistance in a high-throughput laboratory setting, dHPLC has been demonstrated to be rapid, simple, workable, automatable and inexpensive in terms of running costs and the labour involved.

A low cost, non-individualized surround sound system based upon head related transfer functions: an ergonomics study and prototype development.

This paper reports on the types and magnitudes of localization errors of simulated binaural direction cues generated using non-individualized, head-related transfer functions (HRTFs) with different levels of complexity. Four levels of complexity, as represented by the number of non-zero coefficients of the associated HRTF filters (128, 64, 32, 18 non-zero coefficients), were studied. Experiment 1 collected 1728 data runs that were exhaustive combinations of the four levels of complexity, nine simulated directions of sound (no direction (i.e., diotical-mono), 0 degrees , 45 degrees , 90 degrees , 135 degrees , 180 degrees , 225 degrees , 270 degrees , and 315 degrees azimuth angles at 0 degrees elevation), two repetitions, and 24 participants). Binaural cues generated from HRTFs of reduced complexity (from 128 to 18 non-zero coefficients) produced significantly higher localization errors for the directions of 45 degrees , 135 degrees , 225 degrees , and 315 degrees azimuth angles (p<0.01). From the directions of 0 degrees , 90 degrees , and 270 degrees azimuth angles, the cues produced by HRTFs with reduced complexity did not affect the localization error (p>0.2). Surprisingly, cues produced by HRTFs of 128 non-zero coefficients did not have the lowest number of errors. From 45 degrees , 135 degrees , 225 degrees , and 315 degrees , the lowest numbers of errors were obtained from cues produced by HRTFs of 64, 32, 32, and 64 non-zero coefficients, respectively. Based on these findings, a prototype virtual headphone-based surround-sound (VHSS) system was developed. A double-blind usability experiment with 32 participants indicated that the prototype VHSS system received significantly better surround-sound ratings than did a Dolby stereo system (p<0.02). This paper reports results from an original ergonomics study and the application of these results to the design of a consumer product.

Prediction of vocational outcome of people with brain injury after rehabilitation: a discriminant analysis.

Due to advancements in emergency evacuation procedures and neurosurgical techniques, more patients with brain injury (BI) can survive cerebral injury and regain a satisfactory degree of recovery through rehabilitation. Their improvement in physical and cognitive functions can facilitate their reintegration into the community, especially their return to work (RTW). Different factors were reported to affect this rate of RTW in previous studies. This retrospective study thus aimed to investigate the role of demographic data, the severity of injury, residual physical deficits, activities of daily living, and cognitive function using a stepwise discriminant function analysis (DFA). Data sets for 79 persons with BI were retrieved so as to identify predictors of their vocational outcomes upon discharge and during a follow-up period. The stepwise DFA revealed that the discharge score on the Disability Rating Scale (DRS), the attention-subtest of the Neurobehavioral Cognitive Status Examination (NCSE) or Cognistat, and pre-morbid occupation were significant predictors that correctly classified 65.8% of the subjects.

Over-expression of Bcl-2 against Pteris semipinnata L-induced apoptosis of human colon cancer cells via a NF-kappa B-related pathway.

Ent-11 alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), an antitumor component, is a chemical compound isolated from Pteris semipinnata L (PsL), a Chinese traditional herb. We examined whether 5F could affect apoptosis in human colon cancer HT-29 cells, and test whether and how the over-expression of Bcl-2 and Bcl-xL could offset the effect of 5F on cell growth. The result demonstrated that 5F significantly induced apoptosis of HT-29, as shown by MTT assay and DNA fragmentation measurement. Treatment of HT-29 with 5F increased both p38 and iNOS levels, suggesting these two molecules may contribute to the apoptotic effect of 5F. Over-expression of Bcl-2 or Bcl-xL attenuated the increase of p38 and iNOS induced by 5F. The cells with Bcl-2 or Bcl-xL over-expression showed an elevation of nuclear factor kappa B (NF-kappa B) activity, accompanying a significant reduction of 5F-induced apoptosis. Furthermore, inhibition of NF-kappa B by I k B alpha SR, which is a powerful inhibitor of NF-kappa B, restored the ability of 5F to induce apoptosis in the cells transfected with Bcl-2. These data strongly indicated that the apoptotic effect of 5F on HT-29 was closely associated with the activity of NF-kappa B, which was up-regulated by Bcl-2 and Bcl-xL. In conclusion, 5F induced apoptosis in HT-29 cells and this apoptotic effect was associated with the high level of p38 and iNOS expression. The apoptotic effect of 5F could be significantly offset by over-expression of either Bcl-2 or Bcl-xL. Bcl-2, and to the less extent, Bcl-xL, were able to increase the activity of NF-kappa B, which was a known anti-apoptotic molecule in human colon cancer cells.

Feasibility study of using air as a contrast medium in MR colonography.

AIM: To evaluate the feasibility of using air as intraluminal contrast medium in magnetic resonance (MR) colonography. MATERIALS AND METHODS: Twenty-two patients underwent MR colonography (MRC) using air before colonoscopy. All patients were imaged in prone and supine positions. Each colon was divided into five segments. Two radiologists reviewed the images for the degree of colonic distension, image quality and colonic lesions. The colonic lesions identified using MR were compared with those identified on colonoscopy. RESULTS: Eight men and 14 women with mean age of 55.5 years were studied. All patients completed the MR examination. One hundred and five out of 110 (95.5%) colonic segments were well distended in both prone and supine positions. Image quality was good in all cases. Colonoscopy detected 16 lesions: three > or = 1 cm, one 7 mm lesion and 12 lesions < or = 5 mm. All lesions 1 cm or larger were detected by MRC. CONCLUSION: MRC using air and the single-shot half-Fourier rapid acquisition with refocused echoes (RARE) technique is feasible. But in this small pilot study, it had low sensitivity for the detection of polyps less than 1 cm in diameter.

Lymphocyte subsets and natural killer cell cytotoxicity after laparoscopically assisted resection of rectosigmoid carcinoma.

BACKGROUND: Laparoscopically assisted resection of colorectal carcinoma is technically feasible and minimally invasive. Postoperative immunosuppression also may be reduced. This study compared the lymphocyte subsets and natural killer (NK) cell cytotoxicity in patients after laparoscopically assisted resection with those after open resection of rectosigmoid carcinoma. METHODS: In this study, 40 patients with rectosigmoid carcinoma, but no evidence of metastasis, were randomized to receive either laparoscopically assisted or conventional open resection of the tumor. Blood was collected before the operation, then 24 h, 72 h, and 8 days after the operation for studies of lymphocyte subsets and NK cell cytotoxicity. RESULTS: The lymphocyte subsets and NK cell cytotoxicity of both groups showed typical suppression after surgery. The suppression of T cell activation and NK-like T cells was significantly less after laparoscopically assisted resection than in after open resection, whereas the difference in other lymphocyte subsets and NK cell cytotoxicity was not significant. CONCLUSION: This study showed that some cellular components of the immune system are less suppressed after laparoscopically assisted than after conventional open resection of rectosigmoid carcinoma. This may have implications for tumor recurrence and long-term patient survival.

Synchronous laparoscopic-assisted right hemicolectomy and right adrenalectomy.

In recent years, minimally invasive surgery has been increasingly employed for the treatment of colorectal and adrenal tumors. We report an 82-year-old woman with synchronous right-sided colonic tumor and right adrenal tumor requiring resection. Preoperative workup showed a 6-cm primary right adrenal tumor with no evidence of invasion to adjacent structures. Laparoscopic removal of the two tumors was achieved with the use of a hand-port device, which assured safe retraction of the liver and meticulous dissection of the adrenal tumor, as well as port site protection during retrieval of the specimens. The whole operation lasted 270 min and our patient made an uneventful recovery.

Construction of the Chinese University Prognostic Index for hepatocellular carcinoma and comparison with the TNM staging system, the Okuda staging system, and the Cancer of the Liver Italian Program staging system: a study based on 926 patients.

BACKGROUND: The current TNM staging system for patients with hepatocellular carcinoma (HCC) does not include liver function parameters and does not provide a precise prognosis for patients in different risk groups. The objectives of this study were to construct a new prognostic index for patients with hepatocellular carcinoma, the Chinese University Prognostic Index (CUPI), and to compare it with existing staging systems in terms of their ability to classify patients into different risk group. METHODS: From 1996 to 1998, 926 ethnic Chinese patients who were diagnosed with HCC (mainly hepatitis B-associated) at a single institution were recruited prospectively into this study. A multivariate analysis on 19 patient characteristics was performed using a Cox regression model to identify independent prognostic factors. Weights were derived from the regression coefficients of various factors to construct the CUPI. Patients were classified according to different staging systems. Survival curves were plotted with the Kaplan-Meier method and were compared by using a log-rank test. RESULTS: Both the TNM staging system and the Okuda staging system had prognostic significance, but the significance was lower for the Cancer of the Liver Italian Program (CLIP) prognostic score among the patients in the study population. The CUPI was constructed by adding the following factors into the TNM staging system: total bilirubin, ascites, alkaline phosphatase, alpha fetoprotein, and asymptomatic disease on presentation. The new CUPI characterized three risk groups with highly significant differences in survival during the whole period of follow-up (P < 0.00001) and was more discriminant than the other systems. CONCLUSIONS: In the study population of patients with mainly hepatitis B-associated HCC, the CUPI was more discriminant than the TNM staging system, the Okuda staging systems, or the CLIP prognostic score in classifying patients into different risk groups and was better at predicting survival. The CUPI needs to be validated by different cohorts of patients before it can be recommended for general use.