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.

Twenty years of clinical human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) in Hong Kong

OBJECTIVE

To elucidate the development of human immunodeficiency virus (HIV) clinical care and research in Hong Kong.

DATA SOURCES

Articles on clinical HIV and acquired immunodeficiency syndrome (AIDS) published from 1985 to 2004 were identified through four sources: Red Ribbon Centre, Special Preventive Programme, Secretariat of the Scientific Committee on AIDS, and PubMed search. The first three are operated by the Centre for Health Protection, Department of Health, Hong Kong.

STUDY SELECTION

Key words for the literature search were 'AIDS', 'HIV', and 'Hong Kong'.

DATA EXTRACTION

Only papers with original local data were included.

DATA SYNTHESIS

Sixty papers were identified. The contents were catalogued under seven areas: clinical epidemiology, HIV disease course and presentation, specific complications or organ-based manifestations, immunological evaluation and other monitoring, antiretroviral therapy, HIV/AIDS mortality, and HIV in specific groups. Prevalence of HIV has remained low in Hong Kong but new infections continue to occur together with a significant number of late presenters. Three published AIDS patients' series, up to the first 200 reported cases, identified Pneumocystis carinii pneumonia as the most common AIDS-defining illness in Hong Kong. Penicillium marneffei and Mycobacterium tuberculosis were two important specific infections studied most; uniqueness of the former in patients of South-East Asia was evident. Local studies of Kaposi's sarcoma and HIV-associated lymphoma have also been reported. Research on CD4 counts has revealed that it is lower in healthy and HIV-infected Chinese than their western counterparts. Children, pregnant women, and haemophiliac patients infected with HIV are among the specific groups of patients studied. Survival of patients with advanced disease has greatly improved over the years, particularly after the advent of highly active antiretroviral therapy.

CONCLUSION

The clinical presentation and outcome of HIV/AIDS patients in Hong Kong are a mixture of those of western and developing countries. Research on clinical HIV/AIDS in Hong Kong is not only beneficial to the planning of patient care, but also enables the formulation of treatment guidelines and provides a reference for other countries.

Spontaneous pneumomediastinum in a scuba diver

Pneumomediastinum usually occurs following an airleak from the lungs, or from a perforated oesophagus. We report on a 30-year-old man who developed pneumomediastinum after scuba diving. The patient presented with acute onset of throat pain, odynophagia, and hoarseness of voice. The literature is reviewed for this condition.

Clinical utility of genotyping resistance test on determining the mutation patterns in HIV-1 CRF01_AE and subtype B patients receiving antiretroviral therapy in Hong Kong

BACKGROUND

HIV-1 genotypic resistance test (GRT) has been widely used to monitor HIV infection but only few reports revealed the mutation patterns of non-B HIV-1 subtypes.

OBJECTIVE

To evaluate the concordance of GRT and clinical treatment outcomes on different HIV-1 subtypes and monitor the mutation patterns and frequencies.

STUDY DESIGN

Pre- and post-treatment plasma samples from 123 patients (39 treatment naïve and 84 treatment experienced) were tested by ViroSeq HIV-1 Genotyping System followed by analysis using the Stanford HIV database. The mutation patterns and frequencies developed in the pol gene were compared among subtypes.

RESULTS

HIV-1 subtypes among patients in Hong Kong were mainly subtype B and CRF01_AE. Primary mutation was not detected among all pre-treatment samples. For post-treatment samples, primary mutations were only detected in the treatment failure group. The mutation patterns and frequencies were similar between CRF01_AE and subtype B viruses. However, the frequencies of L74V/I and K103N in the reverse transcriptase region were different between CRF01_AE and subtype B viruses. VirtualPhenotype was unable to analyze an in-frame insertion of arginine and isoleucine at protease codon 35 of one CRF01_AE isolate.

CONCLUSIONS

This is the first report to demonstrate the high degree of concordance of longitudinal genotyping data and clinical treatment outcome in patients harboring different HIV-1 subtypes. Our findings shed light to the emergence of resistance mutations and its testing in CRF01_AE, which is relevant to other prevailing places in Asia.

Clinicopathological features and prognostic factors of cutaneous melanoma among Hong Kong Chinese

Cutaneous melanoma is rare among Chinese people. The clinicopathologic features and prognostic factors of 63 Hong Kong ethnic Chinese cases were analysed. We found that the mean age of onset was 65.5 years with a female : male ratio of 1 : 1.33. Forty-two (66.7%) patients had their tumours on their feet. More than 50% had the acral lentiginous histologic subtype. The mean tumour thickness was 5.73 mm with 92.1% (n = 58) having a Clark's level of III or more. Of the tumours, 57.1% were ulcerated. Stage I and II tumours comprised 73% (n = 46) while stage III and IV tumours made up of 26% (n = 17). The 1-, 3- and 5-year survival rates were 75%, 30% and 17%, respectively. Univariate analysis for overall survival showed that advanced clinical staging (stage III and IV), tumour ulceration and thicker tumour (>4 mm) had a significantly poorer prognosis. Multivariate analysis demonstrated that advanced clinical staging was the most decisive prognostic factor followed by tumour ulceration. Our study showed that cutaneous melanoma in Chinese people is a disease predominantly of an older age group with the acral lentiginous histologic type located mainly on the feet. The prognosis depends on clinical staging and ulceration status.

Effects of single nucleotide polymorphisms in the RANTES promoter region in healthy and HIV-infected indigenous Chinese

We determined the occurrence of the single nucleotide polymorphisms (SNPs) -403A/G and -28C/G in the promoter region of RANTES in 1082 Chinese blood donors from northern and southern China and 249 HIV patients from southern China. Compared to healthy adults, Chinese AIDS patients had a significantly higher frequency of the -403G allele and haplotype I, -403G/-28C (P < 0.05), and a lower frequency of the -403A/A genotype (P < 0.01). Symptomatic patients had a higher frequency of the -28G allele and a lower frequency of the -28C/C genotype (P < or = 0.01). The plasma RANTES level was significantly lower in blood donors homozygous for haplotype I than in those who were homozygous for haplotypes II and III (P < 0.05). The frequency of the -403G allele was found to be higher in Chinese than in indigenous Africans, but lower than in Caucasians, Hispanics, and African Americans. The frequency of the -28G allele was comparable in Chinese and Japanese; this allele is rare in other ethnic groups. Results suggest that -403G may be associated with increased susceptibility to HIV infection, while -28G may be associated with advanced disease progression. The impact of SNPs on HIV infection appears to be unique in Chinese.

Optimization of photocatalytic oxidation of 2,2',3,3'-tetrachlorobiphenyl

Polychlorinated biphenyls (PCBs) are wide spread environmental pollutants. This research focused the optimum physico-chemical conditions under which photocatalytic oxidation (PCO) can be used to degrade 2,2',3,3'-tetrachlorobiphenyl (tetra-CB). Among the optimal physico-chemical conditions studied were UV intensity, hydrogen peroxide (H2O2) and titanium dioxide (TiO2) concentrations, initial pH, and possible reaction intermediates were also determined. The results indicate that the optimal physico-chemical conditions necessary for the degradation of tetra-CB by PCO were UV intensity at 3.16 mW/cm2, 30 mM of H2O2 and 100 mg/l of TiO2. In contrast to the results of PCO studies on other organic compounds, the optimum pH for PCO degradation of tetra-CB was 5.5. The removal efficiency was also higher under acidic conditions than alkaline conditions. Although degradation intermediates such as 1,3-bis(1,1-dimethylethyl)benzene, 2,4-bis(1,1-dimethylethyl)phenol, and 3,5-di-tert-butyl-4-hydroxybenzaldehyde were identified at an early stage in the reaction process, they were not completely degraded even after 7h of PCO reaction.

Epidemiology of hepatitis A and hepatitis E infection and their determinants in adult Chinese community in Hong Kong

Current epidemiology of hepatitis A virus (HAV) and hepatitis E virus (HEV) in Hong Kong was evaluated in 936 adult Chinese subjects recruited through a telephone interview in 2001. Some 15% of the subjects had IgG antibodies to both HAV and HEV while 665 (71.0%) and 176 (18.8%) had anti-HAV and anti-HEV, respectively. Age was the most significant independent factor. Six hundred thirty-eight (79.8%) and 165 (20.7%) subjects aged > or =30 had anti-HAV and anti-HEV, respectively, as compared with 27 (19.7%) and 11 (8.0%) in people aged <30. The corresponding adjusted Odds ratio (OR) was 14.94 (95% CI: 9.13-24.44; P<0.001) for anti-HAV positivity and 2.99 (95% CI: 1.58-5.67; P=0.001) for anti-HEV positivity. Subjects born outside Hong Kong were more likely to have anti-HAV (adjusted OR: 3.41; 95% CI: 2.21-5.26; P<0.001) but not anti-HEV. Non-labour work people were less likely to have anti-HAV-adjusted OR, 0.40 (95% CI: 0.26-0.62; P<0.001). Age-specific HAV prevalence right shifted in the last 20 years. Anti-HAV positivity was less frequent, across all age groups, in subjects >21-years-old in the present study than another study done in 1987-89 (P<0.001). HAV prevalence only increased slightly in every 10-year age groups of people aged 21-50 when compared with their corresponding 10-year-younger age groups (P=0.11), suggesting an ageing cohort effect with no major infections in the last decade. For HEV, both the overall and age-specific prevalence decreased over the last decade (P<0.001). The increasing proportion of susceptible population to enterically transmitted viral hepatitis has implications to future prevention and control programmes, including vaccination strategies.

The lack of epidemiological link between the HIV type 1 infections in Hong Kong and Mainland China

Blood samples were collected from 139 newly reported HIV-1 infections in Hong Kong over a 3-year period between 1999 and 2001, representing 22.8% of all reported cases. A majority of the patients were male (85.6%), Chinese (74%), and adult (97.1%) and acquired HIV-1 through sexual transmission (88.2%). The B and CRF01_AE were the major subtypes detected--49.6% and 44.6%, respectively. Over time, the frequency of CRF01_AE subtype increased, the B subtype decreased, and new subtypes of C (4) 2.8%, B' (1) 0.7%, and CRF07_BC (3) 2.2% emerged. The CRF01_AE subtype was commoner in female, Chinese, heterosexuals, and injection drug users whereas B subtype was commoner in male, white, and people with homosexual/bisexual contacts. There was no common source of infection from the analysis except a discernible cluster of Vietnamese injection drug users with the CRF01_AE subtype. The molecular findings did not suggest an epidemiological link between HIV infection in Hong Kong and Mainland China. Hong Kong's longstanding and extensive methadone treatment network may have contributed to the phenomenon.

Recovery of touch after median nerve lesion and subsequent repair

Many techniques have been developed for the evaluation of peripheral nerve function. Consequently, physicians use different techniques in the clinic. This study describes the evaluation of touch after median nerve lesions in the forearm and repair. In order to evaluate touch, 25 patients, aged 11-51 years (mean, 29 years), were evaluated 3-10.5 years (mean, 5 years) after median nerve repair. The evaluation included the moving two-point discrimination test and Semmes-Weinstein monofilaments. We showed that 32% good-excellent results can be obtained with difficult nerve lesions. The results could have been improved if a sensory reeducation regime had been applied.

Determinants of adherence to highly active antiretroviral therapy (HAART) in Chinese HIV/AIDS patients

OBJECTIVE

Drug adherence is crucial to the success of highly active antiretroviral therapy (HAART) in the treatment of HIV disease. Adherence to HAART and its determinants may, however, differ across HIV/AIDS populations.

METHODS

We retrospectively studied drug adherence by self-report in HIV-1 infected Chinese patients who have been on HAART for at least 1 year as at the end of year 2000. HAART is defined as three or more antiretrovirals with at least one protease inhibitor or non-nucleoside analogue reverse transcriptase inhibitor.

RESULTS

The last drug adherence level assessed by self-report in 161 Chinese patients were: grade A (100%) - 130, 80.7%; grade B (95-99%) - 25, 15.5%; grade C (90-94%) - three, 1.9% and grade D (< 90%) - three, 1.9%. Patients with full adherence were more likely to have undetectable (< 500 copies/mL) plasma virus level (adjusted OR, 4.22; 95% CI, 1.75-12.33). Patients' demographics, HIV disease status and antiretroviral regimen did not affect adherence. Partial drug adherence was, however, independently associated with the psychosocial factors of missing clinic appointments (adjusted OR, 3.13; 95% CI, 1.23-8.33), forgetfulness (adjusted OR, 4.55; 95% CI, 1.64-12.5) and a busy work life (adjusted OR, 6.67; 95% CI, 1.75-25).

CONCLUSION

There were similarities and differences in determinants affecting HAART adherence in Chinese compared with other patients. Psychosocial factors rather than HIV disease or treatment were more important factors in our Chinese patients. The relevance of patient populations and care setting for adherence to HAART shall be further studied.