Does the extent of neck surgery based on preoperative calcitonin level influence survival in medullary thyroid carcinoma: a retrospective tertiary centre experience

INTRODUCTION

Medullary thyroid carcinoma (MTC) is a rare thyroid cancer arising from the calcitonin-secreting parafollicular cells. Previous studies suggested a preoperative calcitonin level >200ng/l is an indication for prophylactic lateral neck dissection (LND) to remove micrometastases and improve survival outcomes.

METHODS

This retrospective single-centre study assessed the efficacy of preoperative calcitonin levels as a marker for determining need for prophylactic LND in MTC. Data were obtained on demographics, preoperative calcitonin levels, size and laterality of index tumour, type of neck dissection (central neck dissection (CND), LND), nodes removed, levels with involved nodes, number of nodes histologically involved, mortality, adjuvant therapy and locoregional recurrence.

RESULTS

A total of 33 patients were identified from St George's University Hospitals NHS Foundation Trust between 1 January 2001 and 19 August 2021; 8 were excluded for data quality issues. Of the 18 classified with a high preoperative calcitonin level (>200ng/l), 10 (56%) had a LND and 8 (44%) had a CND. In the low-calcitonin group, three (43%) patients had a CND only and four (57%) had a LND. There was no difference in absolute or disease-free survival between the low and high groups (p=0.960, p=0.817), or between those who had a CND and LND in the high-calcitonin group (p=0.607, hazard ratio (HR) 0.55; p=0.129, HR 8.78).

CONCLUSION

There was no statistically significant difference in outcomes between high and low calcitonin groups. A selective approach to performing LND in MTC patients based on clinical and imaging findings suggesting disease presence in the lateral neck should be explored further.

The real-world impact of the COVID-19 pandemic on patients with cancer: a multidisciplinary cross-sectional survey

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented disruptions to cancer care worldwide. We conducted a multidisciplinary survey of the real-world impact of the pandemic, as perceived by patients with cancer.

METHODS

A total of 424 patients with cancer were surveyed using a 64-item questionnaire constructed by a multidisciplinary panel. The questionnaire examined patient perspectives regarding COVID-19-related effects (eg, social distancing measures) on cancer care delivery, resources, and healthcare-seeking behaviour, along with the physical and psychosocial aspects of patient well-being and pandemic-related psychological repercussions.

RESULTS

Overall, 82.8% of respondents believed that patients with cancer are more susceptible to COVID-19; 65.6% expected that COVID-19 would delay anti-cancer drug development. Although only 30.9% of respondents felt that hospital attendance was safe, 73.1% expressed unaltered willingness to attend scheduled appointments; 70.3% of respondents preferred to receive chemotherapy as planned, and 46.5% were willing to accept changes in efficacy or side-effect profile to allow an outpatient regimen. A survey of oncologists revealed significant underestimation of patient motivation to avoid treatment interruptions. Most surveyed patients felt that there was an insufficient amount of information available concerning the impact of COVID-19 on cancer care, and most patients reported social distancing-related declines in physical, psychological, and dietary wellness. Sex, age, education level, socio-economic status, and psychological risk were significantly associated with patient perceptions and preferences.

CONCLUSION

This multidisciplinary survey concerning the effects of the COVID-19 pandemic revealed key patient care priorities and unmet needs. These findings should be considered when delivering cancer care during and after the pandemic.

Dabrafenib and Trametinib Therapy for Advanced Anaplastic Thyroid Cancer - Real-World Outcomes From UK Centres

AIMS

Anaplastic thyroid cancer (ATC) is a rare but aggressive form of thyroid cancer with a median survival of 4 months. Recent advances in molecular profiling have shown that up to half of ATCs harbour the BRAF-V600E mutation. The aim of this study was to provide real-world data and experience on the use of combination therapy dabrafenib and trametinib in patients with BRAF-V600E-mutated advanced ATC.

MATERIALS AND METHODS

We retrospectively evaluated patients with confirmed BRAF-V600E-mutated ATC, defined as patients with locally advanced or metastatic ATC with no locoregional, radical treatment options. Outcomes measured were overall survival, progression-free survival, response rate, discontinuation rate, dose reduction rate and toxicity data.

RESULTS

Seventeen patients were evaluated and the mean age was 68 years. Ten patients died by the time of censoring. The median duration of follow-up was 12 months (3-43 months). The estimated median overall survival was 6.9 months (95% confidence interval 2.46 months - upper confidence interval not reached) and the median progression-free survival was 4.7 months (95% confidence interval 1.4-7.8 months). Dose interruptions and/or reductions were common, but none of the patients had to permanently discontinue treatment because of toxicities. Severe toxicities (grades 3 and 4) were uncommon.

CONCLUSIONS

This study supports the indication of dabrafenib and trametinib in BRAF-V600E-mutated ATC as an effective and well-tolerated treatment in an historically difficult to treat cancer.

Update on the Recommendations on Breast Cancer Screening by the Cancer Expert Working Group on Cancer Prevention and Screening

Breast cancer (BC) is the most common cancer among women in Hong Kong. The Food and Health Bureau commissioned The University of Hong Kong (HKU) to conduct the Hong Kong Breast Cancer Study (HKBCS) with the aim of identifying relevant risk factors for BC in Hong Kong and developing a locally validated BC risk assessment tool for Hong Kong Chinese women. After consideration of the most recent international and local scientific evidence including findings of the HKBCS, the Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) has reviewed and updated its BC screening recommendations. Existing recommendations were preserved for women at high risk and slightly changed for women at moderate risk. The following major updates have been made concerning recommendations for other women in the general population: Women aged 44 to 69 with certain combinations of personalised risk factors (including presence of history of BC among first-degree relative, a prior diagnosis of benign breast disease, nulliparity and late age of first live birth, early age of menarche, high body mass index and physical inactivity) putting them at increased risk of BC are recommended to consider mammography screening every 2 years. They should discuss with their doctors on the potential benefits and harms before undergoing mammography screening. A risk assessment tool for local women (eg, one developed by HKU) is recommended to be used for estimating the risk of developing BC with regard to the personalised risk factors described above.

Cranial neuropathies in advanced nasopharyngeal carcinoma: Neurological recovery after modern radiotherapy and systemic chemotherapy

OBJECTIVES

Cranial neuropathy is a common presenting symptom of advanced T4 nasopharyngeal carcinoma (NPC). Data on neurological outcomes after modern intensity-modulated radiotherapy (IMRT) and chemotherapy are scarce.

MATERIALS AND METHODS

Case records of consecutive T4 NPC patients who received definitive IMRT in two tertiary oncology centers in 2004-2019 were reviewed. Patterns of cranial neuropathies at disease presentation were recorded. Time to neurological recovery and the rate of subsequent re-palsy were estimated by the Kaplan-Meier method. Clinical predictors were analyzed using multivariable Cox regression.

RESULTS

During the study period, 257 T4 NPC patients presented with 504 individual cranial neuropathies. The median time from neuropathy onset to NPC diagnosis was two months (IQR, 1-4 months). Cranial nerves (CN) VI (56.4%), V2 (47.9%), and V3 (29.2%) were most frequently involved. At a median follow-up of 6.4 years, the crude partial and full recovery rates of neuropathies were 111 (22%) and 289 (57.3%), respectively. CN III, IV, and VI had the highest 5-year full recovery rate (72.7%), followed by CN V1-3 (60.3%), XII (48.6%), and II (18.2%) (p < 0.001). Positive smoking history, optic nerve involvement, and longer duration of neuropathy were independent negative predictors for neurological recovery. After full recovery, re-palsy was observed in 6.9% (20/289) of the nerves, 60% of which co-occurred with local NPC recurrences.

CONCLUSION

Durable recovery of most cranial neuropathies in advanced T4 NPC was observed in the era of modern IMRT and effective systemic chemotherapy. Both patient and disease factors affected the chance of neurological recovery. Re-palsy of recovered nerves should prompt careful evaluation for local recurrence.

Clinical outcomes of patients with ductal carcinoma in situ in Hong Kong: 10-year territory-wide cancer registry study

BACKGROUND

Incidence of ductal carcinoma in situ (DCIS) has increased in recent decades because of breast cancer screening. This study comprised a long-term survival analysis of DCIS using 10-year territory-wide data from the Hong Kong Cancer Registry.

METHODS

This study included all patients diagnosed with DCIS in Hong Kong from 1997 to 2006. Exclusion criteria were age <30 years or ≥70 years, lobular carcinoma in situ, Paget's disease, and co-existing invasive carcinoma. Patients were stratified into those diagnosed from 1997 to 2001 and those diagnosed from 2002 to 2006. The 5- and 10-year breast cancer-specific survival rates were evaluated; standardised mortality ratios were calculated.

RESULTS

Among the 1391 patients in this study, 449 were diagnosed from 1997 to 2001, and 942 were diagnosed from 2002 to 2006. The mean age at diagnosis was 49.2±9.2 years. Overall, 51.2% of patients underwent mastectomy and 29.5% received adjuvant radiotherapy. The median follow-up interval was 11.6 years; overall breast cancer-specific mortality rates were 0.3% and 0.9% after 5 and 10 years of follow-up, respectively. In total, 109 patients (7.8%) developed invasive breast cancer after a considerable delay. Invasive breast cancer rates were comparable between patients diagnosed from 1997 to 2001 (n=37, 8.2%) and those diagnosed from 2002 to 2006 (n=72, 7.6%).

CONCLUSION

Despite excellent long-term survival among patients with DCIS, these patients were more likely to die of breast cancer, compared with the general population of women in Hong Kong.

Abstract 6073: The lipogenic regulator SREBP induces Transferrin in circulating melanoma cells, suppressing their susceptibility to ferroptosis

Circulating tumor cells (CTCs) are shed by cancers into the bloodstream, where a viable subset overcomes oxidative stress to initiate metastatic outgrowth. Clonally derived cultured CTCs from patients with BRAF-mutant melanoma reveal upregulation of lipogenesis and iron homeostasis pathways, correlated with their baseline and acquired drug resistance. In CTCs, the lipogenesis regulator SREBP directly induces transcription of the iron carrier Transferrin (TF), thereby reducing intracellular reactive oxygen species (ROS) and lipid peroxidation, and conferring resistance to BRAF inhibitors and inducers of ferroptosis. Knockdown of endogenous TF impairs tumorigenesis by melanoma CTCs; their associated soft agar clonogenic defect is rescued by the lipophilic anti-oxidants Ferrostatin-1 or Vitamin E, and by cholesterol. Single cell RNA-seq of patient-derived melanoma CTCs identifies a subset with high lipogenic, iron metabolic and proliferative signatures, correlated with adverse clinical outcome. Together, the coordinated regulation of these SREBP-driven pathways contributes to cancer progression, drug resistance and metastasis.

Citation Format: Xin Hong, Whijae Roh, Ryan J. Sullivan, Keith H. Wong, Ben S. Wittner, HongShan Guo, Taronish D. Dubash, Moshe Sade-Feldman, Ben K. Wesley, Genevieve M. Boland, Dieuwke L. Marvin, Todd Bonesteel, Chenyue Lu, Elad Horwitz, François Aguet, Samuel S. Freeman, Katherine Calhoun, Michelle K. Jewett, Linda T. Nieman, Nir Hacohen, Anders M. Näär, David T. Ting, Mehmet Toner, Shannon L. Stott, Gad Getz, Shyamala Maheswaran, Daniel A. Haber. The lipogenic regulator SREBP induces Transferrin in circulating melanoma cells, suppressing their susceptibility to ferroptosis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6073.

Diurnal changes in central blood pressure and pulse pressure amplification in patients with obstructive sleep apnoea

STUDY OBJECTIVES

Recent evidence suggests that compared to peripheral blood pressure (BP), central BP may be more strongly associated with target organ damage and cardiovascular morbidity and mortality. Technological advances now allow the ambulatory measurement of peripheral and central BP over 24 ​h. For the first time, we set out to characterise the diurnal profile of central BP and pulse pressure amplification (PPA) in patients with obstructive sleep apnoea (OSA).

METHODS

In this observational study, patients with moderate to severe OSA underwent 24 ​h central and peripheral BP testing before and after at least 4 weeks of CPAP therapy. Concurrent actigraphy was performed to confirm sleep and wake times.

RESULTS

36 patients were screened, 31 had successful testing (mean (SD) age 45 ​± ​10 years, AHI 58 ​± ​27 events/hr, Office BP 136/89 ​± ​10.7/9.5 ​mmHg, 32% on anti-hypertensives, 77% dippers), 21 completed testing post CPAP. Central systolic and diastolic BP followed the same nocturnal dipping profile as peripheral BP, however the peripheral pulse pressure (PP) narrowed in sleep (-3.2 ​mmHg, p ​< ​0.001), whereas the central PP remained unchanged (0.124 ​mmHg, NS), causing a significant reduction in PPA overnight (-10.7%, p ​< ​0.001). The magnitude of dip in central systolic pressure was less than peripheral systolic pressure (by 2.3 ​mmHg, p ​< ​0.001). After treatment with CPAP, the PPA reduction overnight was attenuated (by -3.3%, p ​= ​0.004).

CONCLUSIONS

In moderate to severe OSA, central BP and PPA reduce overnight during sleep. Further randomised controlled studies are needed to quantify the differential effects of CPAP and anti-hypertensives on central versus peripheral BP.

Recommendations on prevention and screening for colorectal cancer in Hong Kong

Colorectal cancer is the commonest cancer in Hong Kong. The Cancer Expert Working Group on Cancer Prevention and Screening was established in 2002 under the Cancer Coordinating Committee to review local and international scientific evidence, assess and formulate local recommendations on cancer prevention and screening. At present, the Cancer Expert Working Group recommends that average-risk individuals aged 50 to 75 years and without significant family history consult their doctors to consider screening by: (1) annual or biennial faecal occult blood test, (2) sigmoidoscopy every 5 years, or (3) colonoscopy every 10 years. Increased-risk individuals with significant family history such as those with a first-degree relative diagnosed with colorectal cancer at age ≤60 years; those who have more than one first-degree relative diagnosed with colorectal cancer irrespective of age at diagnosis; or carriers of genetic mutations associated with familial adenomatous polyposis or Lynch syndrome should start colonoscopy screening earlier in life and repeat it at shorter intervals.

Risk factors associated with 1-year mortality among patients with HIV-associated tuberculosis in areas with intermediate tuberculosis burden and low HIV prevalence

INTRODUCTION

Data are limited regarding risk factors for mortality among patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) in areas with low HIV prevalence and intermediate TB burden, such as the Western Pacific region. This study aimed to assess such risk factors in Hong Kong, which has an intermediate TB burden and low HIV prevalence.

METHODS

We conducted a retrospective cohort analysis of adult patients reported to the Hong Kong TB-HIV Registry between 2006 and 2015. Baseline characteristics were compared with Kaplan-Meier estimates. Cox proportional hazards regression modelling was used to identify factors associated with mortality.

RESULTS

Of 299 patients studied, 21 (7.0%) died within 12 months of anti-TB treatment (median [interquartile range], 7.5 [3.8-10] months). The median age of death was 54 (interquartile range, 40.5-75.0) years. The cause of death was TB in five and unrelated to TB in the remaining 16. Cox proportional hazards regression showed that older age (adjusted hazard ratio=4.5; 95% confidence interval [CI]=1.4-14.9), history of drug addiction (4.6; 95% CI=1.6-13.0), and low baseline CD4 cell count of <50/μL (2.9; 95% CI=1.1-7.7) were independent risk factors for death within 12 months.

CONCLUSION

This study complements previous studies by providing information regarding risk factors associated with mortality among patients with HIV-associated TB in areas with intermediate TB burden and low HIV prevalence. The results from our study may guide targeted measures to improve survival in other areas with intermediate TB burden and low HIV prevalence, such as the Western Pacific region.

Are we mis-estimating chemotherapy-induced peripheral neuropathy? Analysis of assessment methodologies from a prospective, multinational, longitudinal cohort study of patients receiving neurotoxic chemotherapy

Background

There are inconsistencies in the literature regarding the prevalence and assessment of chemotherapy-induced peripheral neuropathy (CIPN). This study explored CIPN natural history and its characteristics in patients receiving taxane- and platinum-based chemotherapy.

Patients and methods

Multi-country multisite prospective longitudinal observational study. Patients were assessed before commencing and three weekly during chemotherapy for up to six cycles, and at 6,9, and 12 months using clinician-based scales (NCI-CTCAE; WHO-CIPN criterion), objective assessments (cotton wool test;10 g monofilament); patient-reported outcome measures (FACT/GOG-Ntx; EORTC-CIPN20), and Nerve Conduction Studies.

Results

In total, 343 patients were recruited in the cohort, providing 2399 observations. There was wide variation in CIPN prevalence rates using different assessments (14.2–53.4%). Prevalence of sensory neuropathy (and associated symptom profile) was also different in each type of chemotherapy, with paclitaxel (up to 63%) and oxaliplatin (up to 71.4%) showing the highest CIPN rates in most assessments and a more complex symptom profile. Peak prevalence was around the 6-month assessment (up to 71.4%). Motor neurotoxicity was common, particularly in the docetaxel subgroup (up to 22.1%; detected by NCI-CTCAE). There were relatively moderately-to-low correlations between scales (r_s = 0.15,p < 0.05-r_s = 0.48 p < 0.001), suggesting that they measure different neurotoxicity aspects from each other. Cumulative chemotherapy dose was not associated with onset and course of CIPN.

Conclusion

The historical variation reported in CIPN incidence and prevalence is possibly confounded by disagreement between assessment modalities. Clinical practice should consider assessment of motor neuropathy for neurotoxic chemotherapy. Current scales may not be all appropriate to measure CIPN in a valid way, and a combination of scales are needed.

Recommendations on prevention and screening for breast cancer in Hong Kong

In Hong Kong, breast cancer is the most common cancer among women and poses a significant health care burden. The Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) was set up in 2002 by the Cancer Coordinating Committee to review and assess local and international scientific evidence, and to formulate recommendations for cancer prevention and screening. After considering the local epidemiology, emerging scientific evidence, and local and overseas screening practices, the CEWG concluded that it was unclear whether population-based breast cancer screening did more harm than good in local asymptomatic women at average risk. The CEWG considers that there is insufficient evidence to recommend for or against population-based mammography screening for such individuals. Women who consider breast cancer screening should be adequately informed about the benefits and harms. The CEWG recommends that all women adopt primary preventive measures, be breast aware, and seek timely medical attention for suspicious symptoms. For women at high risk of breast cancer, such as carriers of confirmed BRCA1/2 deleterious mutations and those with a family history of breast cancer, the CEWG recommends that they seek doctor's advice for annual mammography screening and the age at which the process should commence. Additional annual screening by magnetic resonance imaging is recommended for confirmed BRCA1/2 mutation carriers or women who have undergone radiation therapy to the chest between the age of 10 and 30 years. Women at moderate risk of breast cancer should discuss with doctors the pros and cons of breast cancer screening before making an informed decision about mammography screening every 2 to 3 years.

Normal Tissue Complication Probability (NTCP) Modelling of Severe Acute Mucositis using a Novel Oral Mucosal Surface Organ at Risk

AIMS

A normal tissue complication probability (NTCP) model of severe acute mucositis would be highly useful to guide clinical decision making and inform radiotherapy planning. We aimed to improve upon our previous model by using a novel oral mucosal surface organ at risk (OAR) in place of an oral cavity OAR.

MATERIALS AND METHODS

Predictive models of severe acute mucositis were generated using radiotherapy dose to the oral cavity OAR or mucosal surface OAR and clinical data. Penalised logistic regression and random forest classification (RFC) models were generated for both OARs and compared. Internal validation was carried out with 100-iteration stratified shuffle split cross-validation, using multiple metrics to assess different aspects of model performance. Associations between treatment covariates and severe mucositis were explored using RFC feature importance.

RESULTS

Penalised logistic regression and RFC models using the oral cavity OAR performed at least as well as the models using mucosal surface OAR. Associations between dose metrics and severe mucositis were similar between the mucosal surface and oral cavity models. The volumes of oral cavity or mucosal surface receiving intermediate and high doses were most strongly associated with severe mucositis.

CONCLUSIONS

The simpler oral cavity OAR should be preferred over the mucosal surface OAR for NTCP modelling of severe mucositis. We recommend minimising the volume of mucosa receiving intermediate and high doses, where possible.

The phenomenon of missing doses in a cohort of HIV patients with good adherence to highly active antiretroviral therapy

A self-administered questionnaire survey was conducted in a specialist HIV clinical service in Hong Kong. A total of 76 male Chinese patients who had been on highly active antiretroviral therapy for over one year were enrolled. All except one had undetectable viral load at the time of the assessment. Though a majority (76%) scored 100% in self-reporting adherence rating, one-third of these had in fact missed at least one dose in the preceding four-week period. Men having sex with men had a lower tendency of missing dose than heterosexuals (13.6% versus 42%, P = 0.019). There was no association between missing doses and clinical staging or the regimens. The study revealed that missing doses may occur despite report of almost complete adherence, which, in the long run, could be a cause for concern.

Management of health care workers following occupational exposure to hepatitis B, hepatitis C, and human immunodeficiency virus

INTRODUCTION

Needlestick injury or mucosal contact with blood or body fluids is well recognised in the health care setting. This study aimed to describe the post-exposure management and outcome in health care workers following exposure to hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) during needlestick injury or mucosal contact.

METHODS

This case series study was conducted in a public clinic in Hong Kong. All health care workers with a needlestick injury or mucosal contact with blood or body fluids who were referred to the Therapeutic Prevention Clinic of Department of Health from 1999 to 2013 were included.

RESULTS

A total of 1525 health care workers were referred to the Therapeutic Prevention Clinic following occupational exposure. Most sustained a percutaneous injury (89%), in particular during post-procedure cleaning or tidying up. Gloves were worn in 62.7% of instances. The source patient could be identified in 83.7% of cases, but the infection status was usually unknown, with baseline positivity rates of hepatitis B, hepatitis C, and HIV of all identified sources, as reported by the injured, being 7.4%, 1.6%, and 3.3%, respectively. Post-exposure prophylaxis of HIV was prescribed to 48 health care workers, of whom 14 (38.9%) had been exposed to known HIV-infected blood or body fluids. The majority (89.6%) received HIV post-exposure prophylaxis within 24 hours of exposure. Drug-related adverse events were encountered by 88.6%. The completion rate of post-exposure prophylaxis was 73.1%. After a follow-up period of 6 months (or 1 year for those who had taken HIV post-exposure prophylaxis), no hepatitis B, hepatitis C, or HIV seroconversions were detected.

CONCLUSIONS

Percutaneous injury in the health care setting is not uncommon but post-exposure prophylaxis of HIV is infrequently indicated. There was no hepatitis B, hepatitis C, and HIV transmission via sharps or mucosal injury in this cohort of health care workers.

Treatment outcomes after early initiation of antiretroviral therapy for human immunodeficiency virus-associated tuberculosis

OBJECTIVE

To evaluate the optimal timing for initiating antiretroviral therapy in patients with human immunodeficiency virus (HIV)-associated tuberculosis in Hong Kong.

DESIGN

Historical cohort. SETTING. Tuberculosis and Chest Service and Special Preventive Programme, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong.

PATIENTS

Consecutive patients with HIV-associated tuberculosis in a territory-wide TB-HIV registry encountered from 1996 to 2009.

RESULTS

Of the 260 antiretroviral therapy-naïve patients with HIV-associated tuberculosis, 32 (12%) had antiretroviral therapy initiated within 2 months after starting anti-tuberculosis treatment (early antiretroviral therapy). Early antiretroviral therapy was associated with a more favourable outcome (cure or treatment completion without relapse) at 24 months (91% vs 67%; P=0.007) than those with antiretroviral therapy started later or not initiated, and remained an independent predictor of a favourable outcome after adjustment for potential confounders. Adverse effects from anti-tuberculosis drugs tended to occur more frequently in patients with early antiretroviral therapy (13/32 or 41%) compared with the remainder (59/228 or 26%; P=0.08). A significantly higher proportion of patients in the former group experienced immune reconstitution inflammatory syndrome than in the latter group (7/32 or 22% vs 9/228 or 4%; P<0.001). There was no death attributable to immune reconstitution inflammatory syndrome.

CONCLUSIONS

Early initiation of antiretroviral therapy is associated with more favourable tuberculosis treatment outcomes in patients with HIV-associated tuberculosis with a low CD4 count (<200/µL). Drug co-toxicity and immune reconstitution inflammatory syndrome that may be increased by earlier initiation of antiretroviral therapy does not undermine tuberculosis treatment outcomes to a significant extent.

Tuberculin sensitivity testing and treatment of latent tuberculosis remains effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong

OBJECTIVE

To evaluate whether a policy to treat latent tuberculosis identified by annual tuberculin sensitivity testing is effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong.

DESIGN

Historical cohort study.

SETTING

Integrated Treatment Centre, Department of Health, Hong Kong.

PATIENTS

Patients infected with human immunodeficiency virus without a history of tuberculosis were offered annual tuberculin sensitivity testing, coupled with treatment of latent tuberculosis if they tested positive. All such patients were followed for new tuberculosis.

RESULTS

In all, 1154 patients on antiretroviral therapy, contributing to 5587 patient-years of observation, were analysed; 1032 patients (89%) received annual tuberculin sensitivity testing. Their baseline characteristics, including CD4 counts and other risk factors for tuberculosis, did not differ significantly from those who declined testing. The overall incidence rate of tuberculosis was 0.59 case per 100 patient-years. It was lower in those who received annual tuberculin sensitivity testing than those who did not (0.41 vs 3.85 per 100 patient-years; P<0.0001). Only a low baseline CD4 count and a history of tuberculin sensitivity testing were shown to be significant indicators of incident tuberculosis using multivariate analysis. The hazard ratio was 0.36 (95% confidence interval, 0.16-0.85; P=0.02) for those with a baseline CD4 count of 100/mm3 or above, and 0.26 (95% confidence interval, 0.08-0.77; P=0.016) for those who received annual tuberculin sensitivity testing. The incidence of tuberculosis was highest within 90 days of antiretroviral therapy initiation.

CONCLUSION

The established policy continues to be effective. The high risk of tuberculosis during the early period of antiretroviral therapy supports early use of tuberculin sensitivity testing. Alternatively, the strategy of universal isoniazid preventive therapy at antiretroviral therapy initiation could be studied for those with very low baseline CD4 counts.

Accelerating prevention of mother-to-child transmission of HIV: ten-year experience of universal antenatal HIV testing programme in a low HIV prevalence setting in Hong Kong

Hong Kong has a low prevalence of HIV infection at less than 0.01%. Universal Antenatal HIV Testing Programme (UATP) was launched in all public antenatal units in September 2001. In 2008, voluntary rapid HIV testing was introduced in all public labour units to fill up the gap for pregnant women without HIV testing during the antenatal period. This study evaluated the performance of UATP and rapid HIV testing with indicators. From September 2001 to December 2011, process and outcome indicators for monitoring and evaluation were collected from the service providers in the form of monthly return of workload statistics and case-based statistics of each identified HIV-positive pregnancy via reporting forms. A total of 479,160 antenatal HIV tests and 2,675 rapid tests were performed in the study period. The acceptance rate for UATP and rapid HIV testing was 98% and 80.4% respectively. With the implementation of rapid HIV testing in January 2008, the proportion of pregnant women with HIV status discerned before delivery increased from 84.9% in 2006 to over 99.5% since 2008. The HIV prevalence in UATP and rapid HIV testing was 0.02% and 0.1% respectively. Fifty-three (68%) out of 78 HIV-infected pregnant women identified from the programme have delivered locally. Forty-three (81%) of them delivered by caesarean section and 50 (94%) of them were given antiretrovirals for intervention. Only three children born before the implementation of rapid HIV testing were HIV-infected. In conclusion, UATP and its rapid HIV testing component have been highly accepted and effective in the prevention of perinatal HIV transmission in Hong Kong.

Use of methylphenidate for the management of fatigue in Chinese patients with cancer

REASON FOR THE STUDY: Studies on methylphenidate for cancer-related fatigue showed conflicting results. This prospective study aims to determine whether methylphenidate is useful for relieving fatigue in Chinese patients with cancer. Chinese Version of Brief Fatigue Inventory (BFI-C) was administered on days 1, 8, and 29. Methylphenidate dose on day 1 was 5 mg daily then adjusted after day 8 according to response and side effects tolerance.

MAIN FINDINGS

Only 48% of the 25 recruited patients were on methylphenidate by day 29. Overall, no significant improvement in fatigue level was observed after methylphenidate, though benefits were shown in subgroups with age ≤ 65 and higher baseline BFI-C values.

PRINCIPAL CONCLUSIONS

Methylphenidate may be useful for management of cancer-related fatigue in selected Chinese patients.

The pentacyclic triterpenoids in herbal medicines and their pharmacological activities in diabetes and diabetic complications

Pentacyclic triterpenoids including the oleanane, ursane and lupane groups are widely distributed in many medicinal plants, such as Glycyrrhiza species, Gymnema species, Centella asiatica, Camellia sinensis, Crataegus species and Olea europaea, which are commonly used in traditional medicine for the treatment of diabetes and diabetic complications. A large number of bioactive pentacyclic triterpenoids, such as oleanolic acid, glycyrrhizin, glycyrrhetinic acid, ursolic acid, betulin, betulinic acid and lupeol have shown multiple biological activities with apparent effects on glucose absorption, glucose uptake, insulin secretion, diabetic vascular dysfunction, retinopathy and nephropathy. The versatility of the pentacyclic triterpenes provides a promising approach for diabetes management.

Incidence, mortality, and survival trends of ovarian cancer in Hong Kong, 1997 to 2006: a population-based study

OBJECTIVES

To assess the incidence and mortality of ovarian cancer, and the survival patterns of the invasive epithelial ovarian carcinoma in Hong Kong based on population-based cancer registry data.

DESIGN

Historical cohort study.

SETTING

Hong Kong.

PATIENTS

All patients with ovarian cancer diagnosed between 1997 and 2006 were included. Patients eligible for survival analysis were followed up until 31 December 2007.

MAIN OUTCOME MEASURES

Age-standardised incidence and mortality rates with their estimated annual percent changes were determined. Cumulative observed and relative survival rates were estimated using a period approach.

RESULTS

During the study period, in Hong Kong there was a steadily increasing ovarian cancer incidence rate (1.4% annually) but a steadily decreasing mortality rate (1.9% annually). The improvement in mortality was mainly in the age-group of 50-69 years (4.7% annually). Invasive epithelial ovarian carcinoma accounted for 79.6% of the study cohort. The 2-year and 5-year relative survival rates were 75.8% and 63.1%, respectively. Those diagnosed in the period 2002 to 2006 had significantly better survival than those diagnosed in the period 1997 to 2001 (65.3% vs 60.7%; P=0.008); a significant improvement was evident for patients with stage II disease and in the age-group of 50-69 years. Multivariate analyses confirmed that age, histological subtype, FIGO stage, and the period of diagnosis were independent prognostic indicators of invasive epithelial ovarian carcinoma.

CONCLUSION

In Hong Kong, invasive epithelial ovarian carcinoma showed an increasing incidence and an improving survival trend over the period 1997 to 2006. The survival data derived from this study provides a baseline from which to monitor the effectiveness of ovarian cancer treatment in Hong Kong.

In-house human immunodeficiency virus-1 genotype resistance testing to determine highly active antiretroviral therapy resistance mutations in Hong Kong

OBJECTIVE

To determine the frequency of highly active antiretroviral therapy resistance mutations in the viral pol gene of human immunodeficiency virus-1 (HIV-1) genotypes that circulate in Hong Kong, by means of an in-house HIV-1 genotyping system.

DESIGN

Retrospective study.

SETTING

Two HIV clinics in Hong Kong.

PATIENTS

A modified in-house genotyping resistance test was used to sequence the partial pol gene in 1165 plasma samples from 965 patients. The performance of our test was cross-compared with the US Food and Drug Administration-approved ViroSeq HIV-1 genotyping system. The results of genotyping were submitted to the Stanford HIV-1 drug resistance database for analysis.

RESULTS

The cost-effective in-house genotypic resistance test (US$40) demonstrated comparable performance to the US Food and Drug Administration-approved ViroSeq system. The detection limit of this in-house genotypic resistance test could reach 400 copies/mL for both HIV-1 subtype B and CRF01_AE, which were the predominant genotypes in Hong Kong. Drug resistance mutations were detected only in post-treatment samples from treatment-failure patients. However, there was no significant difference in the frequency of drug resistance mutations between subtype B and CRF01_AE.

CONCLUSION

Our cost-effective in-house genotypic resistance test detected no significant difference in drug resistance-related mutations frequencies between HIV-1 subtype B and CRF01_AE in Hong Kong. A drug resistance-related mutations database for different HIV-1 genotypes should be established in Hong Kong to augment guidance for HIV treatment.

The use of self-expanding metallic stents (SEMS) is effective in symptom palliation from recurrent tumor after esophagogastrectomy for cancer

The efficacy of using self-expanding metallic stent (SEMS) for palliation of symptoms because of tumor recurrence after prior esophagogastrectomy has not been properly assessed despite the well recognized use of SEMS in patients without prior surgery. The aim of this study is to evaluate the efficacy and safety of using SEMS in patients who had prior esophagogastrectomy. The study group included 35 patients with carcinoma of esophagus or cardia documented to have loco-regional recurrence after esophagogastrectomy and in whom SEMS were placed for palliation. The median age was 67 (ranged 41-85). The indications for stenting were dysphagia caused by recurrence at the esophageal anastomosis (n= 4) and in the esophageal remnant (n= 5), or extrinsic compression from mediastinal nodal disease (n= 7); gastric outlet obstruction produced by extrinsic tumor compression (n= 13); and tracheo-esophageal fistulae (n= 6). Forty-three stenting procedures were performed, and the technical success rate was 97.6%. The dysphagia score improved from 4.66 to 2.54 (P < 0.001). All patients with tracheo-esophageal fistula had their symptoms successfully palliated. The immediate complication rate was 14% (n= 5); two patients had stent malpositioning, two had inadequate opening of their stents, and one had a failed stenting procedure. On follow-up, 15 (42.8%) patients required a total of 22 re-intervention procedures for various reasons: endoscopic dilatation (five dilatations in three patients), removal of foreign bodies (nine procedures in four patients), and insertion of a second SEMS related to tumor growth (eight stents in eight patients). There was no procedure-related mortality. The median survival was short at 42 days (range 5-290 days), mostly related to advanced disease stage. SEMS in patients with recurrent tumor after esophagogastrectomy is safe and effective.

Antigens of mycobacterial cell walls

Three antigenic fractions from the cell walls of eight strains of mycobacteria were studied. Isolation and purification of these antigens were effected by enzymatic digestions, differential and sucrose gradient centrifugations, dialyses, and column chromatography. Two of the fractions were termed cell wall tuberculins (CWT-1, solubilized with lipase; CWT-2, solubilized with lysozyme); the third was termed "C" (cross-reacting) antigen. All appeared to be lipopolysaccharides. The CWT antigens, as compared with purified protein derivatives (human), were relatively species (group)-specific in both double immunodiffusion and guinea pig skin tests; in the latter, the reactions resembled those of delayed hypersensitivity. The C antigens reacted heterologously in double immunodiffusion and skin tests; the latter were the "immediate" type of reaction.

The epidemiology and clinical manifestations of human immunodeficiency virus-associated tuberculosis in Hong Kong

OBJECTIVE

To evaluate the epidemiology and clinical manifestations of human immunodeficiency virus-associated tuberculosis in Hong Kong.

DESIGN

Retrospective study.

SETTING

Tuberculosis and Chest Service and Special Preventive Programme, Public Health Services Branch, Centre for Health Protection, Department of Health, Hong Kong Special Administrative Region.

PATIENTS

Cases reported to the TB/HIV Registry jointly kept by the Tuberculosis and Chest Service and Special Preventive Programme from 1996 to 2006 were reviewed. The Registry includes cases of human immunodeficiency virus-associated tuberculosis diagnosed in the two services, and cases referred from regional hospitals under the Hong Kong Hospital Authority and the private sector.

RESULTS

Tuberculosis has become an increasingly important acquired immunodeficiency syndrome-defining illness in Hong Kong, and overtook Pneumocystis jiroveci pneumonia for the first time as the most common primary acquired immunodeficiency syndrome-defining illness in 2005 (accounting for 39% and 31% of all such illnesses, respectively in that year). The presentation of human immunodeficiency virus-associated tuberculosis is often atypical. In these patients moreover, there was a slightly higher rate of multidrug-resistant tuberculosis (2%) than in the general population (range, 0.7-1.5%).

CONCLUSIONS

Programmes for the provider-initiated human immunodeficiency virus testing policy to reduce diagnostic delays should continue and be enhanced. Continual surveillance of both conditions is imperative, especially in view of a possible link between human immunodeficiency virus and multidrug-resistant tuberculosis.

Profiling advanced disease in an Asian clinical human immunodeficiency virus cohort: comparison of two definitions for acquired immunodeficiency syndrome

OBJECTIVE

To compare advanced human immunodeficiency virus disease defined immunologically and clinically by evaluating the characteristics of human immunodeficiency virus patients in Hong Kong.

DESIGN

Retrospective observational study.

SETTING

A human immunodeficiency virus cohort database established at a university and the major human immunodeficiency virus specialist services in Hong Kong.

PATIENTS

Patients diagnosed with acquired immunodeficiency syndrome at the study centres between 1985 and 2006 were included.

MAIN OUTCOME MEASURES

Comparison of advanced human immunodeficiency virus disease defined (a) clinically as World Health Organization stage IV, and (b) immunologically as a CD4 count lower than 350/microL.

RESULTS

Between 1985 and 2006, a total of 1317 patients, a majority of whom Chinese, were evaluated. Of these, 914 (69%) and 335 (25%) fulfilled the criteria for immunologically and clinically defined advanced disease, respectively. The mean age of the study population was 38 years and male-to-female ratio 4:1. There were two peaks in the frequency distribution of CD4 counts, one at a low count of less than 100/microL and the other between 200 and 400/microL. All except four with clinically defined advanced disease had CD4 counts lower than 350/microL on presentation. Of those with immunologically defined advanced disease, men having sex with men accounted for a lower proportion in the clinically advanced category, and Pneumocystis pneumonia was the commonest advanced disease at presentation.

CONCLUSIONS

Both clinical and immunological definitions provide a consistent means for assessing advanced disease, the implications of which are different. Such profiling has been made possible through the operation of a standardised cohort database, which is useful in (1) enhancing human immunodeficiency virus epidemiology studies, and (2) evaluating the performance of public health services.

Photocatalytic oxidation of polycyclic aromatic hydrocarbons: intermediates identification and toxicity testing

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic pollutants and their low water solubility limits their degradation in aqueous solution. The presence of water-miscible solvent such as acetone can increase the water solubility of PAHs, however acetone will also affect the degradation of PAH. In this study the effects of acetone on the photocatalytic degradation efficiency and pathways of 5 selected PAHs, namely naphthalene (2 rings), acenaphthylene (3 rings), phenanthrene (3 rings), anthracene (3 rings) and benzo[a]anthracene (4 rings) were investigated. The Microtox toxicity test was used to determine whether the PCO system can completely detoxify the parental PAHs and its intermediates. The addition of 16% acetone can greatly alter the degradation pathway of naphthalene and anthracene. Based on intermediates identified from degradation of the 5 PAHs, the location of parental PAHs attacked by reactive free radicals can be correlated with the localization energies of different positions of the compound. For toxicity analysis, irradiation by UV light was found to induce acute toxicity by generating intermediates/degradation products from PAHs and possibly acetone. Lastly, all PAHs (10 mg l(-1)) can be completely detoxified by titanium dioxide (100 mg l(-1)) within 24h under UVA irradiation (3.9 mW cm(-2)).

Degradation of Acid Orange 7 using magnetic AgBr under visible light: the roles of oxidizing species

AgBr was creatively immobilized on a magnetic substrate (SiO(2)-coated Fe(3)O(4) nanoparticle, SFN) to achieve magnetic separation after visible light-driven photocatalytic oxidation (PCO). The resulted Ag/AgBr/SFN was characterized by TEM, vibrating sample magnetometer and other techniques. It is found that the average diameter of the Ag/AgBr/SFN particle is less than 20 nm. The typical superparamagnetic behavior of Ag/AgBr/SFN implies that the catalyst can be magnetically separated. The physicochemical features of the used Ag/AgBr/SFN after visible light irradiation were not dramatically changed by X-ray diffraction, UV-Vis diffuse reflectance spectra and Fourier transform-infrared analysis. SiO(2) interlayer was proven to slightly increase the degradation efficiency for an azo dye Acid Orange 7. UV-Vis spectra and HPLC analysis indicated that the dye was oxidized and decomposed. The photoactivity of Ag/AgBr/SFN was partly maintained after successive PCO under visible light. In order to evaluate the roles of e(-)-h(+) pairs and reactive oxygen species, the quenching effect was examined by employing Ag/AgBr/SFN and commercial TiO(2) (P-25) under visible light (lambda>400 nm) and UV-A irradiation, respectively. Active h(+) and the resulting (*)OH played the major roles for degradation. The effect of active h(+) and (*)OH were proven to be highly dependent on the concentration of photocatalysts. The effect of (*)OH was more obvious for P-25, while that of active h(+) was more predominant for Ag/AgBr/SFN.

Comparison of assessment tools to score recovery of function after repair of traumatic lesions of the median nerve

In this paper the recovery after repair of the median nerve has been used to compare different assessment tools for evaluation of peripheral nerve function: touch (moving 2-point discrimination (2PD); Semmes-Weinstein (SW) monofilament, motor (Medical Research Council (MRC) scale), combined motor and sensory (Dellon modification of the Moberg pick up test; Moberg Recognition test), and pain (visual analogue scale; pinprick-test). The mean (SD) age of our 28 patients was 28 (12) years. The mean (SD) follow-up period was 5 years, 2 months (2 years, 8 months). On the operated side three patients (11%) had a moving 2PD of less than 4 mm. The results of the moving 2PD were compared with those of the SW monofilaments, but with a poor correlation. The MRC score correlated well with opposition movement of the thumb and muscle wasting (p<0.01). We recommend a number of tests to evaluate (the chronological return of) peripheral nerve function.

Blue-shift and intensity enhancement of photoluminescence in lead-zirconate-titanate-doped silica nanocomposites

Transparent PbZr(0.52)Ti(0.48)O(3) (PZT)-doped silica nanocomposites were fabricated via a modified sol-gel process. The nanocomposites were annealed at different temperatures between 740 and 800 °C in order to produce PZT crystallites with different particle sizes. X-ray diffraction analysis indicated that the embedded PZT nanoparticles were crystallized with a perovskite structure while the SiO(2) matrix was still in an amorphous state. Transmission electron microscopy confirmed that the PZT particles were of nanosize with perovskite structure and dispersed within the SiO(2) matrix. Photoluminescence spectra of the samples were measured between 10 and 290 K. The pure silica matrix showed an emission band at 3.20 eV and a weak emission band at 2.65 eV. They were noticeably suppressed in the PZT/SiO(2) nanocomposites. An additional emission band at ∼2.30 eV, due to transition within the PZT crystallites, was identified. This emission band showed a large blue-shift with decreasing PZT crystallite size and a substantially enhanced intensity as compared with that of bulk PZT ceramics. Our studies demonstrate the typical quantum size effect of ferroelectric-doped nanocomposites and the large influence of the silica matrix on the PL intensity of the embedded PZT particles.

Universal antenatal human immunodeficiency virus (HIV) testing programme is cost-effective despite a low HIV prevalence in Hong Kong

OBJECTIVE

To evaluate the cost-effectiveness of universal antenatal human immunodeficiency virus (HIV) testing in Hong Kong.

DESIGN

Cost-effectiveness analysis from the health care provider's perspective.

SETTING

Public antenatal clinics in Hong Kong.

PARTICIPANTS

All pregnant women who gave birth in Hong Kong during the inclusive period 1 September 2001 and 31 December 2004.

MAIN OUTCOME MEASURES

The primary endpoints were (i) the cost per HIV infection avoided and (ii) the cost per life-year gained.

RESULTS

From 2001 to 2004, a total of 160,878 deliveries were recorded in Hong Kong; and 75% of the corresponding women had HIV testing before delivery. In all, 28 women tested HIV-positive and gave birth to 15 babies, one of which was HIV-positive. The mother of the infected baby presented late in labour, without her HIV status being diagnosed and thus missed the opportunity for prompt intervention. Assuming a natural transmission rate of 25%, it was estimated that six out of seven anticipated HIV infections among the newborns had been avoided. The cost for implementation of the programme for the first 3 years was HKD12 227 988. Hence, the average costs per HIV infection averted and per discounted life-year gained were HKD2 037 998 and HKD79 099, respectively. Sensitivity analysis showed that both the coverage and the loss-to-follow-up rate were the major determinants of the cost-effectiveness of the universal antenatal testing programme in Hong Kong.

CONCLUSION

The universal antenatal testing programme in Hong Kong is largely efficient. In view of the low prevalence of HIV infection, high rates of HIV testing and uptake of antiretroviral prophylaxis are crucial to the success of the programme.

Evaluation of an in-house genotyping resistance test for HIV-1 drug resistance interpretation and genotyping

INTRODUCTION

The human immunodeficiency virus type 1 (HIV-1) genotyping resistance test (GRT) has been considered essential for HIV-1 drug resistance monitoring. However, it is not commonly used in some developing countries in Asia and Africa due to its high running cost.

OBJECTIVE

This study aims to evaluate a new low-cost in-house GRT for both subtype B and non-B HIV-1.

STUDY DESIGN

The in-house GRT sequenced the entire protease and 410 codons of reverse transcriptase (RT) in the pol gene. Its performance on drug resistance interpretation was evaluated against the FDA-approved ViroSeq HIV-1 Genotyping System. Particularly, a panel of 235 plasma samples from 205 HIV-1-infected patients in Hong Kong was investigated. The HIV-1 drug resistance-related mutations detected by the two systems were compared. The HIV-1 subtypes were analyzed through the REGA HIV-1 Genotyping Tool and env phylogenetic analysis.

RESULTS

Among the 235 samples, 229 (97.4%) were successfully amplified by both in-house and ViroSeq systems. All PCR-negative samples harbored viral RNA at <400 copies/mL. The in-house and ViroSeq system showed identical drug resistance-related mutation patterns in 216 out of 229 samples (94.3%). The REGA pol genotyping results showed 93.9% (215/229) concordance with the env phylogenetic results including HIV-1 subtype A1, B, C, D, G, CRF01_AE, CRF02_AG, CRF06_cpx, CRF07_BC, CRF08_BC, CRF15_01B and other recombinant strains. The cost of running the in-house GRT is only 25% of that for the commercial system, thus making it suitable for the developing countries in Asia and Africa.

CONCLUSIONS

Overall, our in-house GRT provided comparable results to those of the commercial ViroSeq genotyping system on diversified HIV-1 subtypes at a more affordable price which make it suitable for HIV-1 monitoring in developing countries.

Profiling of HIV clinic patients to determine the prevalence and characteristics of recent infections

Patients newly attending the government HIV clinic in Hong Kong were studied for the prevalence and characteristics of recent HIV infection, which was defined as having a negative HIV antibody test and/or seroconversion illness within one year of a first positive antibody result. Fifty-nine (12.0%) of 492 HIV-positive patients first seen from 2001 to 2004 were determined to be recently infected. This likely represented the lower bound of the real situation. Compared with non-recent infections on univariate analysis, recent cases were more likely to be men who have sex with men (OR 2.23; 95%CI, 1.23-4.05), never married (OR 1.96; 95%CI, 1.03-3.89), had tertiary or above education (OR 3.93; 95%CI, 1.65-10.09) and with a baseline CD4>=500 cells/ul (OR 3.65; 95%CI, 1.87-6.93). Upon multivariate analysis, tertiary or above education (adjusted OR 4.23; 95%CI, 1.76-10.16) and CD4>=500 cells/ul at diagnosis (adjusted OR 3.58; 95%CI, 1.88-6.84) remained independent variables. HIV clinics are feasible settings for collecting epidemiological information of on-going infection. Differences in the profile between recent and non-recent cases may shed light on targeting efforts to prevent new HIV infections.

Adsorption of copper ion on magnetite-immobilised chitin

The adsorption of Cu2+ from aqueous solution by magnetite-immobilised chitin (MC) was studied in batch mode. Two conventional adsorbents, cation exchange resin (CER) and activated carbon (AC) were used for the comparison. The physicochemical parameters including pH, concentration of adsorbent, temperature and initial Cu2+ concentration were optimised. Under the optimised conditions, the removal efficiencies of Cu2+ for MC, CER and AC were 91.67, 93.36 and 89.16%, respectively. In addition, the removal capacities of Cu2+ for MC, CER and AC were 56.71, 74.84 and 6.55 mg/g, respectively. The adsorption isotherm studies indicated that the adsorptive behaviour of Cu2+ on three adsorbents could be well described by the Langmuir model. The maximum adsorption capacities (qmax) for MC, CER and AC were 53.19, 89.29 and 5.82 mg/g, respectively. The applicability of the kinetic model has been investigated for MC. Experimental results indicated that a pseudo-second-order reaction model provided the best description of the data with a correlation coefficient 0.999 for different initial Cu2+ concentrations. The rate constants were also determined. Various thermodynamic parameters such as standard free energy (DeltaG 0), enthalpy (DeltaH 0) and entropy (DeltaS 0) were calculated for predicting the adsorption nature of MC. The results indicated that this system was a spontaneous and endothermic process.

Photocatalytic degradation of di(2-ethylhexyl)phthalate adsorbed by chitin A

Di(2-ethylhexyl)phthalate (DEHP) is a ubiquitous environmental contaminant due to its extensive use as a plasticiser and its persistence. Currently, there is no cost-effective treatment method for its removal from industrial wastewater. In a previous study, DEHP was effectively adsorbed from aqueous solution by biosorption onto chitinous materials. Biosorption can pre-concentrate DEHP from the aqueous phase for further treatment. As biosorption cannot degrade DEHP, in this study the degradation (and detoxification) of DEHP adsorbed onto chitinous material by photocatalytic oxidation (PCO) is attempted. PCO relies on hydroxyl radical (.OH), which is a strong oxidising agent, for the oxidative degradation of pollutants. It is a non-selective process which can degrade DEHP adsorbed onto chitinous material. The first part of this study is the optimisation of the degradation of adsorbed DEHP by PCO. Adsorption was carried out in the physicochemical conditions optimised in the previous study, with 500 mg/L chitin A and 40 mg/L DEHP at initial pH 2, 22+/-2 degrees C and 150 rpm agitation for 5 min. After optimisation of PCO, a 61% removal efficiency of 10 mg/L of DEHP was achieved within 45 min under 0.65 mW/cm2 of UV-A with 100 mg/L TiO2, and 10 mM of H2O2 at initial pH 12. The optimisation study showed that UV-A and TiO(2) are essential for the degradation of DEHP by PCO. The degradation intermediates/products were identified by GC-MS analysis. GC-MS results showed that the di(2-ethylhexyl) side chain was first degraded, producing phthalates with shorter side chains. Further reaction produced phathalic anhydride and aliphatic compounds such as alkanol and ester. The toxicities of parental and degradation intermediates in the solution phase and on chitinous materials were followed by the Microtox test. Results indicated that toxicity can be removed after 4 h treatment by PCO. Thus the decontamination of DEHP by integrating biosorption and PCO is feasible.

Evaluation of NucliSens EasyQ™ HIV-1 assay for quantification of HIV-1 subtypes prevalent in South-east Asia

BACKGROUND

Monitoring anti-retroviral therapy requires that viral load assays for human immunodeficiency virus type 1 (HIV-1) be applicable to diverse HIV-1 subtypes.

OBJECTIVES

To evaluate NucliSens EasyQ HIV-1 assay for quantitation of common HIV-1 subtypes prevalent in South-east Asia.

STUDY DESIGN

One hundred and nineteen plasma samples collected in Hong Kong and Cambodia were used to compare the performance of NucliSens EasyQ HIV-1 and COBAS Amplicor HIV-1 Monitor version 1.5 assays. Viral RNA extracted from the NucliSens MiniMAG was also used for HIV-1 subtyping.

RESULTS

Performance of NucliSens EasyQ correlated well with COBAS Amplicor (r=0.777, p<0.001) and the small mean difference (0.0462log(10)IU/mL) obtained in the Bland and Altman model indicated good agreement between two assays. The NucliSens EasyQ assay demonstrated a 95% sensitivity at 500IU/mL and 100% specificity. Reproducibility of this assay was within log(10)2-4IU/mL and had a coefficient of variation between 2.3% and 10.4%. Among the 109 specimens included in the analysis, HIV-1 subtyping identified 64 CRF01_AE, 38 subtype B, 3 subtype C, 3 CRF07_BC and 1 subtype G viruses.

CONCLUSIONS

Performance of NucliSens EasyQ was comparable to COBAS Amplicor for HIV-1 viral load monitoring. RNA extracts from NucliSens MiniMAG could be used for HIV-1 viral load monitoring, subtyping and drug resistance mutations detection. Our findings highlight the versatility of both NucliSens EasyQ and COBAS Amplicor in monitoring prevalent subtypes and rare circulating recombinant forms (CRFs) in the South-east Asia region.

Universal decline in mortality in patients with advanced HIV-1 disease in various demographic subpopulations after the introduction of HAART in Hong Kong, from 1993 to 2002

OBJECTIVE

Reductions in HIV/AIDS mortality associated with highly active antiretroviral therapy (HAART) have mainly been reported from Western countries. We studied the impact on survival of patients with advanced HIV disease after the introduction of HAART in Hong Kong.

METHODS

The mortality pattern in a government clinic cohort of 511 adult HIV-1-infected patients with AIDS or CD4 count <200 cells/microL from 1993 to 2002 was examined. The number of deaths, the crude mortality rate (CMR) and the death rate per 1000 person-months were recorded.

RESULTS

Despite an increase in the patient population, 36 deaths occurred in the HAART era (1997-2002) as compared with 56 deaths in the pre-HAART era (1993-1996). The overall annual CMR fell significantly from a high, fluctuating level of 10.8-30.4 per 100 mid-year patient population pre-HAART to a low, steady level of 0.8-6.9 per 100 mid-year population in the HAART era (P=0.004, 1996 vs 1998; P<0.001, 1996 vs 2000; P<0.001, 1996 versus 2002). A fall in CMR was observed in all demographic subpopulations, categorized by sex, ethnicity, HIV exposure risk and age (P ranged from 0.012 to<0.001). Longitudinal tracking until mid-2003 revealed a death rate of 9.2 events/1000 person-months (52 deaths with 5661.5 person-months follow up) among patients first diagnosed as having advanced disease during 1993-1996, and a lower death rate of 2.4 events/1000 person-months (25 deaths with 10551.8 person-months follow up) in patients first diagnosed as having advanced disease during 1997-2001 (rate ratio 3.9; 95% confidence interval 2.4-6.2).

CONCLUSION

There was dramatic temporal decline in mortality in patients with advanced HIV disease in all demographic subpopulations with the advent of HAART. Notwithstanding confounding variables, one reason for the universal decline may be that there was no major disparity in access to HIV care across community groups.