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.

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.

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.

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.

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.

Laparoscopic-assisted resection of rectosigmoid carcinoma. Immediate and medium-term results.

BACKGROUND: The technique of laparoscopic-assisted resection of colorectal carcinoma has been established. However, whether such a procedure is beneficial to patients is uncertain. OBJECTIVE: To review the immediate and medium-term results of laparoscopic-assisted resection in patients with rectosigmoid carcinoma. PATIENTS AND INTERVENTIONS: We attempted laparoscopic-assisted sigmoid colectomy or anterior resection in 50 patients with rectosigmoid carcinoma (ie, the study group). The results were compared with those of 50 matched patients who underwent conventional open resection in the immediate prelaparoscopic era (ie, the control group). RESULTS: The median follow-up times for the study and control groups were 32.8 and 39.1 months, respectively. The operating time was significantly longer (P < .001, Student t test), while the analgesic requirement was significantly less (P < .001, Mann-Whitney U test) and the duration of hospitalization was significantly shorter (P = .001, Mann-Whitney U test), in the study group than in the control group. The oncological clearance (ie, the number of lymph nodes removed and the distal resection margin), the complication rate, the disease-free rate, and the survival rate were comparable in the 2 groups. CONCLUSION: The immediate and medium-term results of laparoscopic-assisted resection of rectosigmoid carcinoma are promising.

Spontaneous rupture of hepatocellular carcinoma: conservative management and selective intervention.

HYPOTHESIS: A conservative approach using selective intervention is better than an aggressive approach using nonselective intervention for ruptured hepatocellular carcinoma. DESIGN: Nonrandomized controlled trial. SETTING: A university hospital. PATIENTS AND INTERVENTIONS: From 1984 to 1990, an aggressive approach was adopted in which 29 and 8 of a total of 40 patients underwent surgical intervention or attempted transarterial embolization (TAE), respectively. From 1991 to 1997, a more conservative approach was used. The initial treatment for 72 patients was conservative with close monitoring. Additional hemostatic procedures consisting of TAE (n = 13) or surgical intervention (n = 9) were given, depending on the clinical progress, disease status, and liver function of the patients. MAIN OUTCOME MEASURES: In-hospital mortality, survival. RESULTS: In-hospital mortality rate was 62% (25 of 40 patients) in the first period and 51% (37 of 72 patients) in the second period. The respective median survival times were 7 and 12 days. If 36 patients with end-stage malignant neoplasms were excluded, the in-hospital mortality rate became 60% (18 of 30 patients) in the first period and 35% (16 of 46 patients) in the second period (P = .03, chi2 test). The respective median survival times became 8 and 72 days (P = .02, log rank test). In the second period, 7 (54%) of 13 patients who underwent TAE and 1 (11%) of 9 patients who underwent surgical intervention died within the same hospital admission (P = .07, Fisher exact test). CONCLUSIONS: Selective intervention was cost-effective and gave better results than an aggressive approach. When intervention was indicated for hemostasis, surgery seemed better than TAE although the difference was not statistically significant.

Predicting mortality and morbidity of patients operated on for perforated peptic ulcers.

HYPOTHESIS: Since the early 1990s, the laparoscopic technique has been increasingly used for the treatment of perforated peptic ulcer. It is important to validate a risk scoring system that can stratify patients into various risk groups before comparing the treatment outcome of laparoscopic repair against that of conventional open surgery. The scoring system should be able to predict the likelihood of mortality and morbidity. Boey score and APACHE II (Acute Physiology and Chronic Health Evaluation II) score may be of use in patient stratification. DESIGN: Retrospective review of relevant case notes by one reviewer. SETTING: A teaching hospital treating 0. 5 million to 1 million patients during the study period. PATIENTS: Patients operated on for perforated peptic ulcer between January 1989 and December 1998. Patients treated conservatively were excluded. MAIN OUTCOME MEASURES: Mortality and postoperative complications (morbidity). RESULTS: A total of 436 patients (365 male and 71 female) with a mean +/- SD age of 51.5 +/- 18.3 years (range, 14-92 years) were studied. Duodenal perforation accounted for 344 (78.9%) of 436 cases. The mortality rate was 7.8% (34/436), and 89 patients had postoperative complications. Multivariate analysis demonstrated that only the APACHE II score predicted both mortality and morbidity. Although the Boey score predicted mortality, it failed to predict morbidity. However, the Boey score predicted the chance of conversion in patients undergoing laparoscopic repair. CONCLUSIONS: The APACHE II score may be a useful tool for stratifying patients into various risk groups, and the Boey score might select appropriate patients for laparoscopic repair.

Obstructive jaundice secondary to hepatocellular carcinoma.

This prospective study aimed to identify different groups of patients with the rare pathology of biliary obstruction caused by hepatocellular carcinoma (HCC). Patients were evaluated with blood tests, chest radiography, ultrasound of the liver and endoscopic retrograde cholangiopancreatography/percutaneous transhepatic cholangiography. Patients who were potentially operable were further assessed with selective hepatic angiography and computed tomography (CT). Of the 38 patients with obstructive jaundice secondary to HCC, the levels of obstruction were extrahepatic in 19 patients and intrahepatic in 19 patients. The clinical presentations and blood biochemistry were similar in these two groups of patients. "Curative' resection was significantly more common in extrahepatic obstruction (8/19) than in intrahepatic obstruction (0/19) (chi 2 with Yates correction P = 0.001). All non-resectable tumours, except in four patients with terminally ill disease, were palliated with stents. Survival in patients who had "curative' liver resection was significantly better than in those who had no resection (median survival 25.3 vs. 2.1 months, log-rank test P = 0.004). Patients with extrahepatic biliary obstruction secondary to HCC had a better chance of being treated by liver resection, which resulted in a significantly improved survival rate compared to patients with intrahepatic obstruction.

Cytoreductive surgery for hepatocellular carcinoma.

A prospective study was conducted on 26 patients for cytoreductive surgery of inoperable hepatocellular carcinoma. These patients underwent cytoreduction with liver resection, cryosurgery, microwave tissue coagulation and/or absolute alcohol injection. In-hospital mortality was 7.7%. The symptomatic relief and quality of survival were excellent. The median survival of patients after cytoreduction was 10.0 months and the survival was much better than those of 26 patients matched by sex, age, tumour size, Child-Pugh grading and Karnofsky scores who received systemic chemotherapy during the same period of the study (log rank test, P = 0.0001). There was no statistical difference between the survival curves of those patients who received (19 patients) and those who did not receive (7 patients) additional treatment by chemotherapy or selective internal radiation therapy after cytoreduction. This suggests that the gained survival benefit could have been derived mainly from the cytoreductive surgery rather than the additional treatments.

An unusual case of breast metastasis from an anorectal melanoma.

An unusual case of solitary breast metastasis from a primary anorectal melanoma in a 59-year-old post-menopausal woman is reported. The course and management of melanotic breast metastases is discussed.

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.

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.

Laparoscopic-assisted abdominoperineal resection for low rectal adenocarcinoma.

BACKGROUND: Laparoscopic-assisted resection for colorectal lesions is feasible, but most reported series are heterogeneous and noncomparative. The aim of this study was to investigate whether laparoscopic-assisted resection was better than open abdominoperineal resection for low rectal adenocarcinoma. METHODS: Twenty-five (study group) of 59 consecutive patients who were considered suitable were selected for laparoscopic-assisted abdominoperineal resection based on the availability of informed consent, laparoscopic instruments, and experienced surgeons. The results in these patients were compared with the other 34 patients operated on by the open method (control group). RESULTS: The median follow-up times for the study and control groups were 30.1 and 28.3 months, respectively. The operation time was significantly longer (t-test, p < 0.001), while operative blood loss (Mann-Whitney U test, p = 0.02), postoperative analgesic requirement (Mann-Whitney U test, p = 0.02), time to resume normal diet (Mann-Whitney U test, p = 0.04), and total hospital stay (Mann-Whitney U test, p = 0.02) were significantly less in the study than in the control group. The oncological clearance, complication rate, disease-free interval, and survival were comparable in the two groups. CONCLUSIONS: Laparoscopic-assisted abdominoperineal resection allowed earlier postoperative recovery, with equal oncological clearance, morbidity, mortality, disease-free interval, and survival.