A territory-wide real-world efficacy and toxicity analysis of abiraterone acetate versus docetaxel in 574 Asian patients with metastatic hormone-sensitive prostate cancer

INTRODUCTION

Abiraterone acetate (ABI) or docetaxel (DOC), in addition to androgen-deprivation therapy (ADT), are current treatment options for metastatic hormone-sensitive prostate cancer (mHSPC). No randomized head-to-head trial has compared these 2 mHSPC treatments, and real-world data regarding their outcomes in Asian patients are lacking.

PATIENTS AND METHODS

The medical records of mHSPC patients who began upfront ABI or DOC treatment in addition to ADT at seven public oncology centers in Hong Kong between 2015 and 2021 were reviewed. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), prostate-specific antigen (PSA) response, and toxicities. Kaplan-Meier and multivariate Cox regression analyses were performed.

RESULTS

A total of 574 patients were included, of whom 419 received DOC and 155 received ABI. The median follow-up duration was 22.4 (DOC group: 23.8; ABI group: 17.3) months. The ABI group demonstrated significantly better PFS than the DOC group (not reached vs. 15.1 months: hazard ratio = 0.37; 95% confidence interval = 0.28-0.50; P < .001). No significant OS difference was observed (P = .58). Failure to achieve a ≥ 90% decline in PSA level at 3 months and failure to achieve an undetectable PSA nadir were each associated with unfavorable PFS and OS. Patients who received DOC had a higher rate of febrile neutropenia, whereas those who received ABI had higher rates of grade ≥ 3 hypokalemia and elevated alanine transaminase. Treatment discontinuation due to toxicities was more common in the DOC (3.6%) than the ABI (0.6%) group.

CONCLUSION

In Asian mHSPC patients, upfront ABI + ADT was associated with better PFS than DOC + ADT, with no significant OS difference. PSA kinetics may help stratify the prognosis for treatment intensification. Toxicity profiles were different, with a higher rate of toxicity-related treatment discontinuation in the DOC group.

Imputing missing sleep data from wearables with neural networks in real-world settings

Sleep is a critical component of health and well-being but collecting and analyzing accurate longitudinal sleep data can be challenging, especially outside of laboratory settings. We propose a simple neural network model titled SOMNI (Sleep data restOration using Machine learning and Non-negative matrix factorIzation [NMF]) for imputing missing rest-activity data from actigraphy, which can enable clinicians to better handle missing data and monitor sleep-wake cycles of individuals with highly irregular sleep-wake patterns. The model consists of two hidden layers and uses NMF to capture hidden longitudinal sleep-wake patterns of individuals with disturbed sleep-wake cycles. Based on this, we develop two approaches: the individual approach imputes missing data based on the data from only one participant, while the global approach imputes missing data based on the data across multiple participants. Our models are tested with shift and non-shift workers' data from three independent hospitals. Both approaches can accurately impute missing data up to 24 hours of long dataset (>50 days) even for shift workers with extremely irregular sleep-wake patterns (AUC > 0.86). On the other hand, for short dataset (~15 days), only the global model is accurate (AUC > 0.77). Our approach can be used to help clinicians monitor sleep-wake cycles of patients with sleep disorders outside of laboratory settings without relying on sleep diaries, ultimately improving sleep health outcomes.

Efficient assessment of real-world dynamics of circadian rhythms in heart rate and body temperature from wearable data

Laboratory studies have made unprecedented progress in understanding circadian physiology. Quantifying circadian rhythms outside of laboratory settings is necessary to translate these findings into real-world clinical practice. Wearables have been considered promising way to measure these rhythms. However, their limited validation remains an open problem. One major barrier to implementing large-scale validation studies is the lack of reliable and efficient methods for circadian assessment from wearable data. Here, we propose an approximation-based least-squares method to extract underlying circadian rhythms from wearable measurements. Its computational cost is ∼ 300-fold lower than that of previous work, enabling its implementation in smartphones with low computing power. We test it on two large-scale real-world wearable datasets: [Formula: see text] of body temperature data from cancer patients and ∼ 184 000 days of heart rate and activity data collected from the 'Social Rhythms' mobile application. This shows successful extraction of real-world dynamics of circadian rhythms. We also identify a reasonable harmonic model to analyse wearable data. Lastly, we show our method has broad applicability in circadian studies by embedding it into a Kalman filter that infers the state space of the molecular clocks in tissues. Our approach facilitates the translation of scientific advances in circadian fields into actual improvements in health.

Virological failure and HIV drug resistance among adults living with HIV on second-line antiretroviral therapy in the Asia-Pacific

OBJECTIVES

To assess second-line antiretroviral therapy (ART) virological failure and HIV drug resistance-associated mutations (RAMs), in support of third-line regimen planning in Asia.

METHODS

Adults > 18 years of age on second-line ART for ≥ 6 months were eligible. Cross-sectional data on HIV viral load (VL) and genotypic resistance testing were collected or testing was conducted between July 2015 and May 2017 at 12 Asia-Pacific sites. Virological failure (VF) was defined as VL > 1000 copies/mL with a second VL > 1000 copies/mL within 3-6 months. FASTA files were submitted to Stanford University HIV Drug Resistance Database and RAMs were compared against the IAS-USA 2019 mutations list. VF risk factors were analysed using logistic regression.

RESULTS

Of 1378 patients, 74% were male and 70% acquired HIV through heterosexual exposure. At second-line switch, median [interquartile range (IQR)] age was 37 (32-42) years and median (IQR) CD4 count was 103 (43.5-229.5) cells/µL; 93% received regimens with boosted protease inhibitors (PIs). Median duration on second line was 3 years. Among 101 patients (7%) with VF, CD4 count > 200 cells/µL at switch [odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.17-0.77 vs. CD4 ≤ 50) and HIV exposure through male-male sex (OR = 0.32, 95% CI: 0.17-0.64 vs. heterosexual) or injecting drug use (OR = 0.24, 95% CI: 0.12-0.49) were associated with reduced VF. Of 41 (41%) patients with resistance data, 80% had at least one RAM to nonnucleoside reverse transcriptase inhibitors (NNRTIs), 63% to NRTIs, and 35% to PIs. Of those with PI RAMs, 71% had two or more.

CONCLUSIONS

There were low proportions with VF and significant RAMs in our cohort, reflecting the durability of current second-line regimens.

Atherosclerotic cardiovascular disease screening and management protocols among adult HIV clinics in Asia

OBJECTIVES

Integration of HIV and non-communicable disease services improves the quality and efficiency of care in low- and middle-income countries (LMICs). We aimed to describe current practices for the screening and management of atherosclerotic cardiovascular disease (ASCVD) among adult HIV clinics in Asia.

METHODS

Sixteen LMIC sites included in the International Epidemiology Databases to Evaluate AIDS - Asia-Pacific network were surveyed.

RESULTS

Sites were mostly (81%) based in urban public referral hospitals. Half had protocols to assess tobacco and alcohol use. Protocols for assessing physical inactivity and obesity were in place at 31% and 38% of sites, respectively. Most sites provided educational material on ASCVD risk factors (between 56% and 75% depending on risk factors). A total of 94% reported performing routine screening for hypertension, 100% for hyperlipidaemia and 88% for diabetes. Routine ASCVD risk assessment was reported by 94% of sites. Protocols for the management of hypertension, hyperlipidaemia, diabetes, high ASCVD risk and chronic ischaemic stroke were in place at 50%, 69%, 56%, 19% and 38% of sites, respectively. Blood pressure monitoring was free for patients at 69% of sites; however, most required patients to pay some or all the costs for other ASCVD-related procedures. Medications available in the clinic or within the same facility included angiotensin-converting enzyme inhibitors (81%), statins (94%) and sulphonylureas (94%).

CONCLUSION

The consistent availability of clinical screening, diagnostic testing and procedures and the availability of ASCVD medications in the Asian LMIC clinics surveyed are strengths that should be leveraged to improve the implementation of cardiovascular care protocols.

Early mortality after late initiation of antiretroviral therapy in the TREAT Asia HIV Observational Database (TAHOD) of the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Asia-Pacific

OBJECTIVES

Early mortality among those still initiating antiretroviral therapy (ART) with advanced stages of HIV infection in resource-limited settings remains high despite recommendations for universal HIV treatment. We investigated risk factors associated with early mortality in people living with HIV (PLHIV) starting ART at low CD4 levels in the Asia-Pacific.

METHODS

PLHIV enrolled in the Therapeutics, Research, Education and AIDS Training in Asia (TREAT Asia) HIV Observational Database (TAHOD) who initiated ART with a CD4 count < 100 cells/μL between 2003 and 2018 were included in the study. Early mortality was defined as death within 1 year of ART initiation. PLHIV in follow-up for > 1 year were censored at 12 months. Competing risk regression was used to analyse risk factors with loss to follow-up as a competing risk.

RESULTS

A total of 1813 PLHIV were included in the study, of whom 74% were male. With 73 (4%) deaths, the overall first-year mortality rate was 4.27 per 100 person-years (PY). Thirty-eight deaths (52%) were AIDS-related, 10 (14%) were immune reconstituted inflammatory syndrome (IRIS)-related, 13 (18%) were non-AIDS-related and 12 (16%) had an unknown cause. Risk factors included having a body mass index (BMI) < 18.5 [sub-hazard ratio (SHR) 2.91; 95% confidence interval (CI) 1.60-5.32] compared to BMI 18.5-24.9, and alanine aminotransferase (ALT) ≥ 5 times its upper limit of normal (ULN) (SHR 6.14; 95% CI 1.62-23.20) compared to ALT < 5 times its ULN. A higher CD4 count (51-100 cells/μL: SHR 0.28; 95% CI 0.14-0.55; and > 100 cells/μL: SHR 0.12; 95% CI 0.05-0.26) was associated with reduced hazard for mortality compared to CD4 count ≤ 25 cells/μL.

CONCLUSIONS

Fifty-two per cent of early deaths were AIDS-related. Efforts to initiate ART at CD4 counts > 50 cell/μL are associated with improved short-term survival rates, even in those with late stages of HIV disease.

Diabetes, mortality and glucose monitoring rates in the TREAT Asia HIV Observational Database Low Intensity Transfer (TAHOD-LITE) study

OBJECTIVES

Diabetes is a growing cause of morbidity and mortality in people living with HIV (PLHIV) receiving antiretroviral therapy (ART). We investigated the association between fasting plasma glucose (FPG) levels and mortality, and factors associated with FPG monitoring rates in Asia.

METHODS

Patients from the Therapeutics Research, Education, and AIDS Training in Asia (TREAT Asia) HIV Observational Database Low Intensity Transfer (TAHOD-LITE) cohort were included in the present study if they had initiated ART. Competing risk and Poisson regression were used to analyse the association between FPG and mortality, and assess risk factors for FPG monitoring rates, respectively. FPG was categorized as diabetes (FPG ≥ 7.0 mmol/L), prediabetes (FPG 5.6-6.9 mmol/L) and normal FPG (FPG < 5.6 mmol/L).

RESULTS

In total, 33 232 patients were included in the analysis. Throughout follow-up, 59% had no FPG test available. The incidence rate for diabetes was 13.7 per 1000 person-years in the 4649 patients with normal FPG at ART initiation. Prediabetes [sub-hazard ratio (sHR) 1.32; 95% confidence interval (CI) 1.07-1.64] and diabetes (sHR 1.90; 95% CI 1.52-2.38) were associated with mortality compared to those with normal FPG. FPG monitoring increased from 0.34 to 0.78 tests per person-year from 2012 to 2016 (P < 0.001). Male sex [incidence rate ratio (IRR) 1.08; 95% CI 1.03-1.12], age > 50 years (IRR 1.14; 95% CI 1.09-1.19) compared to ≤ 40 years, and CD4 count ≥ 500 cells/μL (IRR 1.04; 95% CI 1.00-1.09) compared to < 200 cells/μL were associated with increased FPG monitoring.

CONCLUSIONS

Diabetes and prediabetes were associated with mortality. FPG monitoring increased over time; however, less than half of our cohort had been tested. Greater resources should be allocated to FPG monitoring for early diabetic treatment and intervention and to optimize survival.

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.

Cognitive screening in treatment-naïve HIV-infected individuals in Hong Kong - a single center study

Background

HIV-associated neurocognitive disorder (HAND) remains prevalent in the era of combination antiretroviral therapy (cART). The prevalence of HAND in Hong Kong is not known.

Methods

Between 2013 and 2015, 98 treatment-naïve HIV-1-infected individuals were referred to and screened by the AIDS Clinical Service, Queen Elizabeth Hospital with (1) the International HIV Dementia Scale (IHDS), a screening tool that targets moderate to severe HAND, (2) the Montreal Cognitive Assessment (MoCA), a frequently used cognitive screening test and (3) the Patient Health Questionnare-9 (PHQ-9), a 9-item questionnaire that evaluates depression symptoms. Within the study period, 57 of them completed the second set of IHDS and MoCA at 6 months after baseline assessment.

Results

Most participants were male (94%), with a median age of 31 years. At baseline, 38 (39%) and 25 (26%) of them scored below the IHDS (≤10) and MoCA (25/26) cut-offs respectively. Poor IHDS performers also scored lower on MoCA (p = 0.039) but the correlation between IHDS and MoCA performance was weak (r = 0.29, p = 0.004). Up to a third of poor IHDS performers (13/38) showed moderate depression (PHQ-9 > 9). In the multivariable analysis, a lower education level (p = 0.088), a history of prior psychiatric illness (p = 0.091) and the presence of moderate depression (p = 0.079) tended to be significantly associated with poor IHDS performance.

At follow-up, 54 out of 57 were on cART, of which 46 (85%) had achieved viral suppression. Their blood CD4+ T-lymphocytes and IHDS scores were higher at follow-up compared to baseline values (both p < 0.001) but their MoCA performance was similar at both assessments. Of note, 17 participants in this subgroup scored below the IHDS cut-off at both assessments.

Conclusions

Poor IHDS performance, and likely cognitive impairment, was frequently observed in treatment-naïve HIV-infected individuals in our locality. A considerable proportion continued to score below the IHDS cut-off at 6 months after cART. Depression was frequently observed in this vulnerable population and was associated with poor IHDS performance.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3784-y) contains supplementary material, which is available to authorized users.

Cardiovascular disease-related mortality and factors associated with cardiovascular events in the TREAT Asia HIV Observational Database (TAHOD)

OBJECTIVES

With aging of the HIV-positive population, cardiovascular disease (CVD) increasingly contributes to morbidity and mortality. We investigated CVD-related and other causes of death (CODs) and factors associated with CVD in a multi-country Asian HIV-positive cohort.

METHODS

Patient data from 2003-2017 were obtained from the Therapeutics, Research, Education and AIDS Training in Asia (TREAT Asia) HIV Observational Database (TAHOD). We included patients on antiretroviral therapy (ART) with > 1 day of follow-up. Cumulative incidences were plotted for CVD-related, AIDS-related, non-AIDS-related, and unknown CODs, and any CVD (i.e. fatal and nonfatal). Competing risk regression was used to assess risk factors of any CVD.

RESULTS

Of 8069 patients with a median follow-up of 7.3 years [interquartile range (IQR) 4.4-10.7 years], 378 patients died [incidence rate (IR) 6.2 per 1000 person-years (PY)], and this total included 22 CVD-related deaths (IR 0.36 per 1000 PY). Factors significantly associated with any CVD event (IR 2.2 per 1000 PY) were older age [sub-hazard ratio (sHR) 2.21; 95% confidence interval (CI) 1.36-3.58 for age 41-50 years; sHR 5.52; 95% CI 3.43-8.91 for ≥ 51 years, compared with < 40 years], high blood pressure (sHR 1.62; 95% CI 1.04-2.52), high total cholesterol (sHR 1.89; 95% CI 1.27-2.82), high triglycerides (sHR 1.55; 95% CI 1.02-2.37) and high body mass index (BMI) (sHR 1.66; 95% CI 1.12-2.46). CVD crude IRs were lower in the later ART initiation period and in lower middle- and upper middle-income countries.

CONCLUSIONS

The development of fatal and nonfatal CVD events in our cohort was associated with older age, and treatable risk factors such as high blood pressure, triglycerides, total cholesterol and BMI. Lower CVD event rates in middle-income countries may indicate under-diagnosis of CVD in Asian-Pacific resource-limited settings.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Smoking and projected cardiovascular risk in an HIV-positive Asian regional cohort

OBJECTIVES

The aim of the study was to assess the prevalence and characteristics associated with current smoking in an Asian HIV-positive cohort, to calculate the predictive risks of cardiovascular disease (CVD), coronary heart disease (CHD) and myocardial infarction (MI), and to identify the impact that simulated interventions may have.

METHODS

Logistic regression analysis was used to distinguish associated current smoking characteristics. Five-year predictive risks of CVD, CHD and MI and the impact of simulated interventions were calculated utilizing the Data Collection on Adverse Effects of Anti-HIV Drugs Study (D:A:D) algorithm.

RESULTS

Smoking status data were collected from 4274 participants and 1496 of these had sufficient data for simulated intervention calculations. Current smoking prevalence in these two groups was similar (23.2% vs. 19.9%, respectively). Characteristics associated with current smoking included age > 50 years compared with 30-39 years [odds ratio (OR) 0.65; 95% confidence interval (CI) 0.51-0.83], HIV exposure through injecting drug use compared with heterosexual exposure (OR 3.03; 95% CI 2.25-4.07), and receiving antiretroviral therapy (ART) at study sites in Singapore, South Korea, Malaysia, Japan and Vietnam in comparison to Thailand (all OR > 2). Women were less likely to smoke than men (OR 0.11; 95% CI 0.08-0.14). In simulated interventions, smoking cessation demonstrated the greatest impact in reducing CVD and CHD risk and closely approximated the impact of switching from abacavir to an alternate antiretroviral in the reduction of 5-year MI risk.

CONCLUSIONS

Multiple interventions could reduce CVD, CHD and MI risk in Asian HIV-positive patients, with smoking cessation potentially being the most influential.

Impact of hospitalization on medication adherence estimation in claims data

WHAT IS KNOWN AND OBJECTIVE

Pharmacy claims are commonly used to assess medication adherence. It is unclear how different approaches to handling hospitalizations compare to the gold standard of using outpatient and inpatient drug data. This study aimed to compare the impact of different approaches to handling hospitalizations on medication adherence estimation in administrative claims data.

METHODS

We identified β-blocker initiators after myocardial infarction (MI) and statin initiators regardless of hospitalization histories in the population-based, Taiwan database, which includes outpatient and inpatient drug claims data. Adherence to β-blockers or to statins during a 365-day follow-up period was estimated in outpatient pharmacy claims using the proportion of days covered (PDC) in three ways: ignoring hospitalizations (PDC1); subtracting hospitalized days from the denominator (PDC2); and assuming drug use on all hospitalized days (PDC3). We compared these to an approach that incorporated inpatient drug use (PDC4). We also used a hypothetical example to examine variations across approaches in several scenarios, such as increasing hospitalized days.

RESULTS AND DISCUSSION

Mean 365-day PDC was 74% among 1729 post-MI β-blocker initiators (range: 73.1%-74.9%) and 44% among 69 435 statins initiators (range: 43.5%-44.0%), which varied little across approaches. Differences across approaches increased with increasing number of hospitalized days. For patients hospitalized for >28 days, mean difference across approaches was >15%. PDC3 consistently yielded the highest value and PDC1 the lowest.

WHAT IS NEW AND CONCLUSIONS

On average, different approaches to handling hospitalizations lead to similar adherence estimates to the gold standard of incorporating inpatient drug use. When patients have many hospitalization days during follow-up, the choice of approach should be tailored to the specific setting.

Abstract P5-08-20: Breast cancer patient survival prediction based on the signature derived from DNA methylation and mRNA expression

We analyzed a subset in the TCGA breast cancer data set for the samples with both expression and methylation assays. We first used the three Immunohistochemistry (IHC) markers for ER, PR and HER2 to find methylation sites that showed significant association to the IHC markers with Bonferroni adjustments. We obtained 2616 methylation sites in 2148 genes in the union of these significant methylation sites. On the other hand, based on the gene expression of samples, we selected top one percent most variable genes (179 genes). Intersection of the 2616 methylation markers with the 179 genes resulted in 58 methylation markers in 43 genes. We found 339 samples which have both expression and methylation data from which we can compute the correlation between the expression of a gene and the methylation of a marker in this gene. We defined a methylation expression index (MEI) which was a weighted sum of the expression of the 43 genes using the negative Spearman correlations as the weights. The expression index was applied in the survival analysis in three independent data sets GSE6532, NKI and METABRIC using Kaplan-Meier method and found the significant difference between the patient groups with high and low MEI index. Compared to the signature derived from the first principal component, the MEI gave better survival prediction across different data sets. We used Cox proportional hazards regression model to evaluate the hazard ratio of the MEI with adjustment of the other variables including age, grade, tumor size, ER and node and found HR=1.58 for the MEI with 95% confidence interval [1.06, 2.35].

Citation Format: Yang HH, Lee MP. Breast cancer patient survival prediction based on the signature derived from DNA methylation and mRNA expression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-20.

Four-directional stereo-microscopy for 3D particle tracking with real-time error evaluation

High-speed video stereo-microscopy relies on illumination from two distinct angles to create two views of a sample from different directions. The 3D trajectory of a microscopic object can then be reconstructed using parallax to combine 2D measurements of its position in each image. In this work, we evaluate the accuracy of 3D particle tracking using this technique, by extending the number of views from two to four directions. This allows us to record two independent sets of measurements of the 3D coordinates of tracked objects, and comparison of these enables measurement and minimisation of the tracking error in all dimensions. We demonstrate the method by tracking the motion of an optically trapped microsphere of 5 μm in diameter, and find an accuracy of 2-5 nm laterally, and 5-10 nm axially, representing a relative error of less than 2.5% of its range of motion in each dimension.

Dynamic stereo microscopy for studying particle sedimentation

We demonstrate a new method for measuring the sedimentation of a single colloidal bead by using a combination of optical tweezers and a stereo microscope based on a spatial light modulator. We use optical tweezers to raise a micron-sized silica bead to a fixed height and then release it to observe its 3D motion while it sediments under gravity. This experimental procedure provides two independent measurements of bead diameter and a measure of Faxén's correction, where the motion changes due to presence of the boundary.

Prognostic significance of the interval between the initiation of antiretroviral therapy and the initiation of anti-tuberculosis treatment in HIV/tuberculosis-coinfected patients: results from the TREAT Asia HIV Observational Database

OBJECTIVES

We evaluated the effect of the time interval between the initiation of antiretroviral therapy (ART) and the initiation of tuberculosis (TB) treatment on clinical outcomes in HIV/TB-coinfected patients in an Asian regional cohort.

METHODS

Adult HIV/TB-coinfected patients in an observational HIV-infected cohort database who had a known date of ART initiation and a history of TB treatment were eligible for study inclusion. The time interval between the initiation of ART and the initiation of TB treatment was categorized as follows: TB diagnosed while on ART, ART initiated ≤ 90 days after initiation of TB treatment ('early ART'), ART initiated > 90 days after initiation of TB treatment ('delayed ART'), and ART not started. Outcomes were assessed using survival analyses.

RESULTS

A total of 768 HIV/TB-coinfected patients were included in this study. The median CD4 T-cell count at TB diagnosis was 100 [interquartile range (IQR) 40-208] cells/μL. Treatment outcomes were not significantly different between the groups with early ART and delayed ART initiation. Kaplan-Meier analysis indicated that mortality was highest for those diagnosed with TB while on ART (3.77 deaths per 100 person-years), and the prognoses of other groups were not different (in deaths per 100 person-years: 2.12 for early ART, 1.46 for delayed ART, and 2.94 for ART not started). In a multivariate model, the interval between ART initiation and TB therapy initiation did not significantly impact all-cause mortality.

CONCLUSIONS

A negative impact of delayed ART in patients coinfected with TB was not observed in this observational cohort of moderately to severely immunosuppressed patients. The broader impact of earlier ART initiation in actual clinical practice should be monitored more closely.

A multi-modal stereo microscope based on a spatial light modulator

Spatial Light Modulators (SLMs) can emulate the classic microscopy techniques, including differential interference (DIC) contrast and (spiral) phase contrast. Their programmability entails the benefit of flexibility or the option to multiplex images, for single-shot quantitative imaging or for simultaneous multi-plane imaging (depth-of-field multiplexing). We report the development of a microscope sharing many of the previously demonstrated capabilities, within a holographic implementation of a stereo microscope. Furthermore, we use the SLM to combine stereo microscopy with a refocusing filter and with a darkfield filter. The instrument is built around a custom inverted microscope and equipped with an SLM which gives various imaging modes laterally displaced on the same camera chip. In addition, there is a wide angle camera for visualisation of a larger region of the sample.

An unusual cause of oesophageal variceal bleeding in a Chinese human immunodeficiency virus-infected patient

Non-cirrhotic portal hypertension is an unusual but potentially serious liver disorder in human immunodeficiency virus-infected patients with prolonged exposure to didanosine. Due to its rarity, the diagnosis is often delayed. It is postulated that didanosine contributes to obliterative portal venopathy and causes portal hypertension. Affected patients may present with abnormal liver function or signs of portal hypertension, while the diagnosis usually depends on liver biopsy. We report a case of non-cirrhotic portal hypertension in a human immunodeficiency virus-infected patient. The reported histological features include nodular regenerative hyperplasia and hepatoportal sclerosis. Early recognition is important as timely management of severe portal hypertension may prevent potentially fatal gastro-intestinal bleeding.

Optical shield: measuring viscosity of turbid fluids using optical tweezers

The viscosity of a fluid can be measured by tracking the motion of a suspended micron-sized particle trapped by optical tweezers. However, when the particle density is high, additional particles entering the trap compromise the tracking procedure and degrade the accuracy of the measurement. In this work we introduce an additional Laguerre-Gaussian, i.e. annular, beam surrounding the trap, acting as an optical shield to exclude contaminating particles.

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.

Abstract P3-04-04: Novel Genome-Wide DNA Methylation Signatures of Primary Breast Tumor Subtypes

Background: Gene expression signatures can be used to classify breast tumor tissues into distinct categories: luminal, “basal”, and HER2 subtypes, which have distinct clinical prognoses. Since gene expression is largely determined at the level of epigenetic modification, we hypothesize that DNA methylation signatures may also be used to classify breast tumor subtypes and possibly to define new cancer subtypes; thus, such epigenetic signatures can complement gene expression signatures for a better understanding of breast tumorigenesis and in turn, may lead to improvement in clinical diagnosis.

Material and Methods: We used antibodies to 5-methylcytosine to immunoprecipitate DNA enriched for methylation by means of the MeDIP method on 66 breast primary tumors. Then we analyzed the MeDIP-derived DNA by means of the Affymetrix 500K SNP array. We normalized DNA methylation data from the 66 tumors using a modified quantile normalization procedure. The data were generated in two phases, phase 1 consisting of 42 tumors and phase 2 containing 24 tumors, data from the latter being reserved for validation purposes. We concentrated DNA methylation analysis on the SNPs that are located within promoter regions, defined here as +/− 2 kb flanking the transcription start site (TSS), and within CpG islands, since methylation in these regions is especially relevant for gene expression regulation. We searched for DNA methylation signatures that show distinct patterns among tumors with different clinical phenotypes such as histological grade and lymph node involvement. Results: We identified one DNA methylation signature consists of 78 genes that separated the tumors with high grade from those with low-mid grade; we found another DNA methylation signature consists of 42 genes that separated the tumors with lymph node positive status from those with lymph node negative status. We were able to validate these signatures using methylation data obtained from an independent set of 24 tumors. The performance of the signature for predicting lymph node status in the testing samples showed accuracy of 83%, sensitivity of 70%, and specificity of 90%.

Discussion: We have identified DNA methylation signatures that could classify breast tumor subtypes and correlate with clinical phenotypes. We are investigating whether such epigenetic signatures can complement gene expression signatures for a better understanding of breast tumorigenesis and for application in clinical diagnosis and treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-04-04.

Measures of site resourcing predict virologic suppression, immunologic response and HIV disease progression following highly active antiretroviral therapy (HAART) in the TREAT Asia HIV Observational Database (TAHOD)

OBJECTIVES

Surrogate markers of HIV disease progression are HIV RNA in plasma viral load (VL) and CD4 cell count (immune function). Despite improved international access to antiretrovirals, surrogate marker diagnostics are not routinely available in resource-limited settings. Therefore, the objective was to assess effects of economic and diagnostic resourcing on patient treatment outcomes.

METHODS

Analyses were based on 2333 patients initiating highly active antiretroviral therapy (HAART) from 2000 onwards. Sites were categorized by World Bank country income criteria (high/low) and annual frequency of VL (> or = 3, 1-2 or <1) or CD4 (> or = 3 or <3) testing. Endpoints were time to AIDS/death and change in CD4 cell count and VL suppression (<400 HIV-1 RNA copies/mL) at 12 months. Demographics, Centers for Disease Control and Prevention (CDC) classification, baseline VL/CD4 cell counts, hepatitis B/C coinfections and HAART regimen were covariates. Time to AIDS/death was analysed by proportional hazards models. CD4 and VL endpoints were analysed using linear and logistic regression, respectively.

RESULTS

Increased disease progression was associated with site-reported VL testing less than once per year [hazard ratio (HR)=1.4; P=0.032], severely symptomatic HIV infection (HR=1.4; P=0.003) and hepatitis C virus coinfection (HR=1.8; P=0.011). A total of 1120 patients (48.2%) had change in CD4 cell count data. Smaller increases were associated with older age (P<0.001) and 'Other' HIV source exposures, including injecting drug use and blood products (P=0.043). A total of 785 patients (33.7%) contributed to the VL suppression analyses. Patients from sites with VL testing less than once per year [odds ratio (OR)=0.30; P<0.001] and reporting 'Other' HIV exposures experienced reduced suppression (OR=0.28; P<0.001).

CONCLUSION

Low measures of site resourcing were associated with less favourable patient outcomes, including a 35% increase in disease progression in patients from sites with VL testing less than once per year.

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.

High-resolution ultrasound in the evaluation and prognosis of Bell's palsy

INTRODUCTION

Bell's palsy is a commonly encountered paralysis of the facial nerve occurring worldwide. Prognosis for Bell's palsy is good, but the proportion of patients with poor outcomes may reach 30%. Ultrasound (US) may provide a novel approach for evaluating and prognosticating Bell's palsy, in comparison with known electrophysiological techniques.

METHODS

In this study, we measured the diameter of the distal facial (VII) nerve using US in patients with Bell's palsy treated with prednisolone, in comparison with healthy controls. Blink reflex and VII nerve conduction studies were also performed. Studies were prospective and performed within 1 week of disease onset.

RESULTS

Our results have shown that diameter of the distal VII nerve is a good predictor of favorable (positive predictive value: 100%) and bad outcomes (negative predictive value: 77%) in Bell's palsy at 3 months after clinical presentation. Furthermore, we also noted the lack of correlation of VII diameter with conventional VII nerve conduction studies (NCS) and blink reflex studies. US was superior to VII nerve conduction and blink reflex studies in outcome prediction.

CONCLUSIONS

This first study utilizing US in Bell's palsy highlights its role in outcome prediction and contributes to our understanding of recovery processes in this common neurological disorder.

Clinical presentations and outcomes of Penicillium marneffei infections: a series from 1994 to 2004

OBJECTIVES

To describe the clinical presentation, management, and outcomes of patients with Penicillium marneffei infections in a regional hospital in Hong Kong.

DESIGN

Retrospective study.

SETTING

A regional and tertiary human immunodeficiency virus-referral hospital in Hong Kong.

PATIENTS

Those who had penicilliosis during the inclusive period January 1994 to February 2004.

RESULTS

Forty-seven immunocompromised patients (44 being human immunodeficiency virus-positive) with penicilliosis were retrospectively studied. Fever, malaise, and anaemia were the commonest presentations. Most diagnoses were obtained from blood cultures (83%) and lymph node biopsies (34%). Five (11%) died, death being attributable to penicilliosis; four (9%) of them had received no specific antifungal treatment due to late presentation and late diagnosis. The CD4 count of human immunodeficiency virus-infected patients upon diagnosis of penicilliosis was low (median, 20.0 cells/mm3). Most (70%) patients received amphotericin B as an induction treatment, followed by oral itraconazole, although a smaller proportion (21%) received oral itraconazole only. All surviving human immunodeficiency virus-infected patients took highly active antiretroviral treatment and oral itraconazole as secondary prophylaxis after treatment of penicilliosis. The prognosis appeared satisfactory with early diagnosis and administration of appropriate antifungal therapy. Relapse ensued in two (4%) of the patients only.

CONCLUSION

Penicillium marneffei infection in immunocompromised patients is a serious disease with significant mortality if not diagnosed early and treated with appropriate antifungal drugs. Simple investigations like blood culture enable the diagnosis in the majority of cases. Immunocompromised patients who have been successfully treated should receive oral itraconazole as a maintenance therapy to prevent relapse.

Bronchial artery embolisation can be equally safe and effective in the management of chronic recurrent haemoptysis

OBJECTIVE

To examine the efficacy and safety of bronchial artery embolisation in patients with acute major haemoptysis and those with chronic recurrent haemoptysis.

DESIGN

Retrospective review of clinical records.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Clinical records of 70 consecutive patients who had undergone bronchial artery embolisation in Queen Elizabeth Hospital from 1998 to 2003 were reviewed. Altogether 74 bronchial artery embolisation procedures were attempted, 46 (62%) for acute major haemoptysis, and 28 (38%) for chronic recurrent bleeding. Follow-up data were available for 32 patients.

MAIN OUTCOME MEASURES

After bronchial artery embolisation, the Kaplan-Meier method and log-rank tests were used to compare the probability of recurrence in the two patient categories.

RESULTS

Overall immediate control was attained following 99% of the procedures, with a complication rate of 13%; all complications were mild and self-limiting. For the 32 patients (19 having acute major haemoptysis and 13 having chronic recurrent bleeding) with follow-up data available, the overall recurrence rate was 36% (26% in the acute and 47% in chronic group). No statistically significant difference in recurrence probability between the two groups was observed (P=0.24). Presence of active pulmonary tuberculosis was associated with increased risk of recurrence (P=0.005).

CONCLUSION

Bronchial artery embolisation was noted to be effective and safe in both acute major and chronic recurrent haemoptysis.

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.

Illness-related factors, stress and coping strategies in relation to psychological distress in HIV-infected persons in Hong Kong

This study examined the relationships among illness-related factors, stress, coping strategies and psychological distress in HIV-infected persons in Hong Kong (N=118). Multiple regression analyses were used to examine the models of psychological distress as a function of demographic factors, illness-related factors, psychosocial stressors and coping. Results showed that positive thinking was inversely related to psychological distress and avoidance was associated with higher level of anxiety. However, the use of problem solving was found to be inversely related to anxiety. Results are discussed in the context of Chinese culture and the service in Hong Kong.

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.

Benign metastasising leiomyoma: a rare but possible cause of bilateral pulmonary nodules in Chinese patients

We report three cases of benign metastasising leiomyoma, which is a rare cause of multiple lung nodules, in three Hong Kong Chinese females. One patient presented with pleuritic chest pain, another was asymptomatic, while the last presented with haemoptysis. All three patients had previously undergone surgical resection of uterine leiomyomas. Multiple lung nodules mimicking lung metastases were demonstrated on chest radiographs, and all three diagnoses were obtained from lung biopsies. Hormonal therapy was given to two patients with variable responses. To the best of our knowledge, this is the first report of benign metastasising leiomyoma in Hong Kong Chinese population. It highlights the importance of considering this rare and benign disease in premenopausal females presenting with multiple lung nodules.

Corticosteroid therapy in a Chinese patient with nephropathy associated with human immunodeficiency virus infection

A 52-year-old man with 6 years' history of human immunodeficiency virus infection who was receiving highly active antiretroviral therapy presented with acute renal failure and nephrotic syndrome. Renal biopsy revealed features consistent with nephropathy associated with human immunodeficiency virus infection. Treatment consisted of intravenous methylprednisolone followed by oral prednisolone. The patient's renal function improved, although proteinuria persisted. Human immunodeficiency virus-associated nephropathy is very rare in Asian populations and is more common among blacks. To the best of our knowledge, this is the first documented case of nephropathy associated with human immunodeficiency virus infection occurring in Hong Kong.

Short term outcome and risk factors for adverse clinical outcomes in adults with severe acute respiratory syndrome (SARS)

BACKGROUND

Severe acute respiratory syndrome (SARS) was diagnosed in Hong Kong in over 1700 patients between March and early June 2003.

METHODS

115 patients diagnosed with SARS were admitted to Queen Elizabeth Hospital, a large regional hospital in Hong Kong, from March 2003, of whom 100 were either discharged or were dead at 31 May. The patients were prospectively studied after admission to assess their short term outcomes and the risk factors associated with adverse outcomes, defined as death or the need for mechanical ventilation

RESULTS

At the time of writing 18 patients had died, with a crude mortality rate of 15.7% and a 21 day mortality of 10% (standard error 3%). Thirty nine patients (34%) were admitted to the intensive care unit, 30 of whom (26%) required mechanical ventilation. Multivariate analysis showed that age above 60 (hazards ratio (HR) 3.5, 95% CI 1.2 to 10.2; p=0.02), presence of diabetes mellitus or heart disease (HR 9.1, 95% CI 2.8 to 29.1; p<0.001), and the presence of other comorbid conditions (HR 5.2, 95% CI 1.4 to 19.7; p=0.01) were independently associated with mortality. However, only the presence of diabetes mellitus and/or cardiac disease (HR 7.3, 95% CI 3.1 to 17.4; p<0.001) was associated with adverse outcomes as a whole.

CONCLUSION

SARS is a new disease entity that carries significant morbidity and mortality. Specific clinical and laboratory parameters predicting unfavourable outcomes have been identified.

Clinical profiles of human immunodeficiency virus-associated lymphoma in Hong Kong

OBJECTIVE

To identify the clinical and prognostic features of human immunodeficiency virus-associated lymphoma in the local population with a view to designing more effective treatment strategies.

DESIGN

Retrospective review.

SETTING

Referral hospital, Hong Kong.

SUBJECTS AND METHODS

All patients (n=10) with human immunodeficiency virus-associated lymphoma managed at Queen Elizabeth Hospital from January 1995 to December 2001.

RESULTS

All patients were men with a median age of 39 years. The median CD4 cell count at the time of diagnosis of lymphoma was 0.056 x 10(9)/L. All tumours were diffuse large B-cell lymphomas, with the exception of one systemic Burkittlike lymphoma. Systemic lymphoma was diagnosed in seven patients and three had primary central nervous system lymphoma. Combined antiretroviral therapy was continued or given to five of the six patients who received some form of chemotherapy or radiotherapy treatment. Of the two patients with primary central nervous system lymphoma who received whole brain irradiation therapy, one patient survived 41 months in clinical remission after diagnosis and the other patient died of sepsis while in partial remission 19 months after diagnosis. The four patients with systemic lymphoma who received standard- or reduced-dose chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone had a median survival of 3 months.

CONCLUSION

The clinical profiles of these patients were similar to those of patients with human immunodeficiency virus-associated lymphoma in western countries. The overall survival of patients was poor with conventional chemoradiotherapy. Other innovative treatment approaches should be investigated to prolong the survival of this patient group.

Clinical and electrophysiological aspects of distal ulnar neuropathy

OBJECTIVES

To evaluate the use of fixed distance side to side comparison of abductor digiti minimi (ADM) and first dorsal interosseous (FDI) compound muscle action potential (CMAP) studies in the diagnosis of distal ulnar neuropathy.

MATERIALS AND METHODS

Thirty normal controls underwent ADM and FDI CMAP studies bilaterally at a fixed ADM recording to stimulating point distance of 6 cm. Side to side mean latency differences to both muscles were calculated. Twenty patients with suspected unilateral distal ulnar neuropathy from routine nerve conduction studies had positive results when compared with controls.

RESULTS

The upper limit of normal for side to side mean latency difference at 3 SD above the mean was 0.394 and 0.474 ms for ADM and FDI, respectively. All 20 patients had side to side mean CMAP latency difference above 3 SDs in the ADM, FDI or both muscles. Fifty percent of cases had involvement of the superficial sensory branch.

CONCLUSIONS

Fixed distance side to side CMAP latency comparison is a useful electrodiagnostic adjunct for distal ulnar neuropathy. Trauma was the most common aetiology in the 20 reported cases. Correlation was found between aetiological factors and sites of lesions as localized with this method.

Segmental mixed nerve conduction studies in ulnar neuropathy at the elbow

Conventional nerve conduction and electromyography may not be adequate in localizing ulnar neuropathy at the elbow, particularly in longstanding lesions with severe axon loss. Ratios of wrist to elbow and elbow to axilla segmental ulnar mixed nerve amplitudes were determined in 11 patients with ulnar neuropathy at the elbow. In 20 control subjects, the mean ratio was 1.06 +/- 0.25 (standard deviation). All patients had ratios less than two standard deviations of the control mean ratio. This method is a useful adjunct to conventional nerve conduction techniques in the localization of ulnar neuropathy at the elbow.

The use of remifentanil to facilitate the insertion of the laryngeal mask airway

Propofol is often used as an IV induction drug for anesthesia and the insertion of a laryngeal mask airway (LMA). As a sole anesthetic, it may be associated with undesirable airway responses such as coughing and gagging. We conducted a randomized, double-blinded study to compare the conditions during insertion of the LMA in 120 patients who received normal saline (Group P), remifentanil 0.25 microg/kg (Group R1), or remifentanil 0.5 microg/kg (Group R2) before the induction of anesthesia with IV propofol. The addition of remifentanil significantly improved the conditions of insertion; in Group R1, 82.5% (33 of 40 patients), and in Group R2, 85.0% (34 of 40 patients) had excellent insertion conditions as compared with the Control group P, 32.5% (13 of 40 patients). Patients in Group P were apneic for a mean (SD) time of 85 (38) s, 186 (75) s in group R1, and 284 (130) s in group R2. There was a lesser decrease in mean arterial blood pressure in group R1. We conclude that remifentanil 0.25 microg/kg, when administered after IV propofol 2.5 mg/kg, provides excellent conditions for insertion of the LMA with minimal hemodynamic disturbances.

IMPLICATIONS

Small-dose remifentanil can provide excellent conditions for laryngeal mask airway insertion with minimal hemodynamic disturbances.

Targeted disruption of the Kvlqt1 gene causes deafness and gastric hyperplasia in mice

The KvLQT1 gene encodes a voltage-gated potassium channel. Mutations in KvLQT1 underlie the dominantly transmitted Ward-Romano long QT syndrome, which causes cardiac arrhythmia, and the recessively transmitted Jervell and Lange-Nielsen syndrome, which causes both cardiac arrhythmia and congenital deafness. KvLQT1 is also disrupted by balanced germline chromosomal rearrangements in patients with Beckwith-Wiedemann syndrome (BWS), which causes prenatal overgrowth and cancer. Because of the diverse human disorders and organ systems affected by this gene, we developed an animal model by inactivating the murine Kvlqt1. No electrocardiographic abnormalities were observed. However, homozygous mice exhibited complete deafness, as well as circular movement and repetitive falling, suggesting imbalance. Histochemical study revealed severe anatomic disruption of the cochlear and vestibular end organs, suggesting that Kvlqt1 is essential for normal development of the inner ear. Surprisingly, homozygous mice also displayed threefold enlargement by weight of the stomach resulting from mucous neck cell hyperplasia. Finally, there were no features of BWS, suggesting that Kvlqt1 is not responsible for BWS.

Clinical manifestations of tuberculosis in HIV-infected patients

OBJECTIVE

The purpose of the present study was to evaluate the impact of HIV infection on the clinical presentation of tuberculosis.

METHODOLOGY

We retrospectively studied the impact of HIV infection on the clinical presentation of tuberculosis. A total of 60 consecutive patients co-infected with HIV and tuberculosis were identified.

RESULTS

Majority were male (88.3%) and the most common transmission category was heterosexual contact (80%). Most were in the advanced stage of HIV infection; 93% had CD4 cell count less than 200/mm3. Concerning the site of tuberculosis involvement, 37% had pulmonary involvement alone, 13% had extrapulmonary disease involving one single site, 50% had both pulmonary and extrapulmonary involvement. Fifteen (25%) patients also met the criteria of disseminated tuberculosis, who had a significantly lower mean CD4 cell count than those with pulmonary involvement alone (mean 40 vs 102; P = 0.048). Chest radiographs comprised a wide spectrum of manifestations. A considerable proportion had primary pulmonary tuberculosis pattern (38%) and normal radiographs (8.5%).

CONCLUSIONS

Our patients generally had advanced HIV infection; 93% of those had CD4 lymphocyte count < 200/mm3. Extrapulmonary involvement and disseminated disease were common. Radiographic manifestations of pulmonary tuberculosis were often 'atypical' due to the greater proportion of primary tuberculosis among our patients.

Hot-stop PCR: a simple and general assay for linear quantitation of allele ratios

We have developed a simple, quantitative assay for measurement of allele ratios that circumvents the problem of heteroduplex formation skewing the results of restriction endonuclease digestion of PCR products. This assay, 'hot-stop PCR', involves addition of a radiolabelled PCR primer at the final cycle. We applied the assay to analysis of loss of imprinting (LOI) of the insulin-like growth factor II gene (IGF2) in tumours.

Development of a performance assessment capability in the waste management programs of the U.S. Nuclear Regulatory Commission

The U.S. Nuclear Regulatory Commission (NRC) staff has developed a performance assessment capability to address three programmatic areas in nuclear waste management: high-level waste, low-level waste, and decommissioning of licensed facilities (license termination). The NRC capability consists of: (1) methodologies for performance assessment; (2) models and computer codes for estimating system performance; (3) regulatory guidance in various forms, such as regulations, Branch Technical Positions, and Standard Review Plans; and (4) a technical staff experienced in executing and evaluating performance assessments for a variety of waste systems. Although the tools and techniques are refined for each programmatic area, general approaches and similar issues are encountered in all areas.

LIT1, an imprinted antisense RNA in the human KvLQT1 locus identified by screening for differentially expressed transcripts using monochromosomal hybrids

Mammalian imprinted genes are frequently arranged in clusters on particular chromosomes. The imprinting cluster on human chromosome 11p15 is associated with Beckwith-Wiedemann syndrome (BWS) and a variety of human cancers. To clarify the genomic organization of the imprinted cluster, an extensive screen for differentially expressed transcripts in the 11p15 region was performed using monochromosomal hybrids with a paternal or maternal human chromosome 11. Here we describe an imprinted antisense transcript identified within the KvLQT1 locus, which is associated with multiple balanced chromosomal rearrangements in BWS and an additional breakpoint in embryonal rhabdoid tumors. The transcript, called LIT1 (long QT intronic transcript 1), was expressed preferentially from the paternal allele and produced in most human tissues. Methylation analysis revealed that an intronic CpG island was specifically methylated on the silent maternal allele and that four of 13 BWS patients showed complete loss of maternal methylation at the CpG island, suggesting that antisense regulation is involved in the development of human disease. In addition, we found that eight of eight Wilms' tumors exhibited normal imprinting of LIT1 and five of five tumors displayed normal differential methylation at the intronic CpG island. This contrasts with five of six tumors showing loss of imprinting of IGF2. We conclude that the imprinted gene domain at the KvLQT1 locus is discordantly regulated in cancer from the imprinted domain at the IGF2 locus. Thus, this positional approach using human monochromosomal hybrids could contribute to the efficient identification of imprinted loci in humans.

Loss of imprinting of a paternally expressed transcript, with antisense orientation to KVLQT1, occurs frequently in Beckwith-Wiedemann syndrome and is independent of insulin-like growth factor II imprinting

Genomic imprinting plays a fundamental role in cancer and some hereditary diseases, including Beckwith-Wiedemann syndrome (BWS), a disorder of prenatal overgrowth and predisposition to embryonal malignancies such as Wilms tumor. We have previously shown that the KVLQT1 gene on chromosomal band 11p15 is imprinted, with expression of the maternal allele, and that the maternal allele is disrupted in rare BWS patients with balanced germ-line chromosomal rearrangements. We now show that an antisense orientation transcript within KVLQT1, termed LIT1 (long QT intronic transcript 1) is expressed normally from the paternal allele, from which KVLQT1 transcription is silent, and that in the majority of patients with BWS, LIT1 is abnormally expressed from both the paternal and maternal alleles. Eight of sixteen informative BWS patients (50%) showed biallelic expression, i.e., loss of imprinting (LOI) of LIT1. Similarly, 21 of 36 (58%) BWS patients showed loss of maternal allele-specific methylation of a CpG island upstream of LIT1. Surprisingly, LOI of LIT1 was not linked to LOI of insulin-like growth factor II (IGF2), which was found in 2 of 10 (20%) BWS patients, even though LOI of IGF2 occurs frequently in Wilms and other tumors, and in some patients with BWS. Thus, LOI of LIT1 is the most common genetic alteration in BWS. We propose that 11p15 harbors two imprinted gene domains-a more centromeric domain including KVLQT1 and p57(KIP2), alterations in which are more common in BWS, and a more telomeric domain including IGF2, alterations in which are more common in cancer.

Two novel genes in the center of the 11p15 imprinted domain escape genomic imprinting

We previously reported the isolation of a 2.5 Mb tumor-suppressing subchromosomal transferable fragment (STF) from human chromosome 11p15 and the identification of nine known genes and four novel genes within this STF. We now report the isolation of two novel cDNAs, designated here as TSSC4 and TSSC6 (tumor-suppressing STF cDNA 4 and 6), located within the STF. TSSC4 and TSSC6 encode predicted proteins of 329 and 290 amino acids, respectively, with no close similarity to previously reported proteins. TSSC4 and TSSC6 are both located in the center of a 1 Mb imprinted domain, which contains the imprinted genes TSSC3, TSSC5, p57(KIP2), KVLQT1, ASCL2, IGF2 and H19. However, we found that neither TSSC4 nor TSSC6 was significantly imprinted in any of the fetal or extra-embryonic tissues examined. Based on this result, the imprinted gene domain of 11p15 appears to contain at least two imprinted subdomains, between which TSSC4 and TSSC6 substantially escape imprinting, due either to lack of initial silencing or to an early developmental relaxation of imprinting.

Identification and characterization of genes required for hyphal morphogenesis in the filamentous fungus Aspergillus nidulans

In the filamentous fungus Aspergillus nidulans, germination of an asexual conidiospore results in the formation of a hyphal cell. A key feature of spore germination is the switch from isotropic spore expansion to polarized apical growth. Here, temperature-sensitive mutations are used to characterize the roles of five genes (sepA, hypA, podB-podD) in the establishment and maintenance of hyphal polarity. Evidence that suggests that the hypA, podB, and sepA genes are required for multiple aspects of hyphal morphogenesis is presented. Notably, podB and sepA are needed for organization of the cytoskeleton at sites of polarized growth. In contrast, podC and podD encode proteins that appear to be specifically required for the establishment of hyphal polarity during spore germination. The role of sepA and the pod genes in controlling the spatial pattern of polarized morphogenesis in germinating spores is also described. Results obtained from these experiments indicate that the normal pattern of germ-tube emergence is dependent upon the integrity of the actin cytoskeleton.

Strain-dependent developmental relaxation of imprinting of an endogenous mouse gene, Kvlqt1

Genomic imprinting is an epigenetic modification of the gamete or zygote leading to parental origin-specific differential expression of the two alleles of a gene in somatic cells of the offspring. We previously reported that the human KVLQT1 gene is imprinted and disrupted in patients with germline balanced chromosomal rearrangements and Beckwith-Wiedemann syndrome. In human, the gene is imprinted in most fetal tissues except the heart, and KVLQT1 is part of a 1-Mb cluster of imprinted genes on human chromosome 11p15. 5. We sought to determine whether the mouse Kvlqt1 gene is imprinted, by performing interspecific crosses of 129/SvEv mice with CAST/Ei (Mus musculus castaneus). We identified a transcribed polymorphism that distinguishes the two parental alleles in F1 offspring. Examination of embryonic, neonatal, and postnatal tissues revealed that Kvlqt1 is imprinted in mouse early embryos, in both female 129 x male CS and female CS x male 129 offspring, with preferential expression of the maternal allele, like the human homologue. Surprisingly, imprinting was developmentally relaxed, and the developmental stage and tissue specificity of relaxation of imprinting was strain-dependent. To our knowledge, this is the first example of an endogenous gene that shows strain-dependent developmental relaxation of imprinting.

Somatic mutation of TSSC5, a novel imprinted gene from human chromosome 11p15.5

We previously reported the isolation of a 2.5 Mb tumor-suppressing subchromosomal transferable fragment (STF) from 11p15.5 and the identification of nine known genes and four novel genes within this STF. We now report the isolation of a fifth novel cDNA, tumor-suppressing STF cDNA 5, designated TSSC5, located within the STF. TSSC5 encodes a predicted protein of 424 amino acids. Sequence analysis suggests that TSSC5 is a membrane protein with 10 transmembrane segments, and it is located between two imprinted genes, p57KIP2 and TSSC3. Northern blot hybridization revealed a 1.6-kb transcript in multiple adult tissues and in fetal liver and kidney, consistent with a potential role in embryonal tumors. We also found that TSSC5 is imprinted with preferential expression from the maternal chromosome. Reverse transcription-PCR analysis of TSSC5 revealed frequent occurrence of aberrant RNA splicing, which deleted exons 4, 5, and 6 in Wilms' tumors. Mutational analysis of TSSC5 by direct DNA sequencing of exons revealed a base substitution of G1120A in a Wilms' tumor, matched normal kidney, and the patient's mother, changed Arg at codon 309 to Gln. The G1120A substitution thus represents either a rare polymorphism or a tumor-predisposing mutation, because the mutant allele was of maternal origin and preferentially expressed in the patient's tissue. A second base substitution, C892T, was found in a lung cancer, changing Ser at codon 233 to Phe. This substitution was absent from the matched normal tissue and thus represented a somatic mutation. We also found loss of heterozygosity in the lung cancer, suggesting that TSSC5 may be a conventional tumor suppressor gene in the adult human lung and an imprinted tumor suppressor gene in the fetal kidney.