Low Levels Of Testing Research Articles

Effects of COVID-19 restriction measures in Indonesia: A comparative spatial and policy analysis of selected urban agglomerations

With higher densities, urban agglomerations account for the fastest rates of COVID-19 transmission. In Indonesia, one of the most rapidly urbanizing regions in the world, the national government issues overall policy on the pandemic. However, implementation is often contingent on local governments. Many policies aim to stem the spread of infection by controlling people's mobility or regulating their daily activities. Urban agglomerations are a strategic site of investigation in this light, because they consist of interconnected communities governed by various levels and jurisdictions. This paper analyzes the effects of policy interventions relative to confirmed cases in the seven major urban agglomerations in Indonesia (totaling 30 municipal/district governments). Data were collected from confirmed and fatality trends from March to mid-October 2020, which were contrasted with corresponding policies for each jurisdiction. By sorting the indicators of the spread of the pandemic and its corresponding control measures, we reach conclusions about which dimensions served to curb or trigger the surge of COVID-19 clusters. The analysis unsurprisingly shows that within each agglomeration, the main cities continue to represent the highest number of confirmed cases despite variations between them. This study also highlights two key findings. First, the effectiveness of distancing measures depends considerably on the capacity of governments to implement restrictions. For example, budget limitations resulted in uneven implementation of national mandates by decentralized authority. Facilities and services at different locations also influence our understanding of disease transmission. Second, people's ability and willingness to engage with a policy regime is contingent upon personal values or economic constraints. The study shows that viewing the spatial distribution of COVID-19 at the scale of urban agglomerations helps to explain key aspects of transmission and policy, pointing to recommendations about pursuing certain protocols. Nevertheless, key challenges remain to meet the full potential of this analytical approach, due to relatively low levels of testing and inadequate data collection measures in Indonesia.

Laboratory-Based Comparison for the Effects of Environmental Stressors Supports Field Evidence for the Relative Importance of Pollution on Life History and Behavior of the Pond Snail, Lymnaea stagnalis.

Biodiversity is declining at an alarming rate globally, with freshwater ecosystems particularly threatened. Field-based correlational studies have "ranked" stressors according to their relative effects on freshwater biota, however, supporting cause-effect data from laboratory exposures are lacking. Here, we designed exposures to elicit chronic effects over equivalent exposure ranges for three ubiquitous stressors (temperature: 22-28 °C; pollution [14 component mixture]: 0.05-50 μg/L; invasive predator cue [signal crayfish, Pacifasticus leniusculus]: 25-100% cue) and investigated effects on physiological end points in the pond snail (Lymnaeastagnalis). All stressors reduced posthatch survival at their highest exposure levels, however, highly divergent effects were observed at lower test levels. Temperature stimulated hatching, growth, and reproduction, whereas pollution delayed hatching, decreased growth, reduced egg number/embryo viability, and induced avoidance behavior. The invasive predator cue stimulated growth and reduced embryo viability. In agreement with field-based ranking of stressors, pollution was identified as having the most severe effects in our test system. We demonstrate here the utility of laboratory studies to effectively determine hierarchy of stressors according to their likelihood of causing harm in the field, which has importance for conservation. Finally, we report negative impacts on life-history traits central to population stability (survival/reproduction) at the lowest pollution level tested (0.05 μg/L).

Speech comprehension across multiple CI processor generations: Scene dependent signal processing.

ObjectivesIn clinical practice, characterization of speech comprehension for cochlear implant (CI) patients is typically administered by a set of suprathreshold measurements in quiet and in noise. This study investigates speech comprehension of the three most recent cochlear implant sound processors; CP810, CP910, and CP1000 (Cochlear Limited). To compare sound processor performance across generations and input dynamic range changes, the state‐of‐the art signal processing technologies available in each sound processor were enabled. Outcomes will be assessed across a range of stimulation intensities, and finally analyzed with respect to normal hearing listeners.MethodsIn a prospective study, 20 experienced postlingually deafened CI patients who received a Nucleus CI in the ENT department of the University Hospital of SH in Kiel were recruited. Speech comprehension was measured in quiet at 40, 50, and 65 dBSPL with monosyllabic words as well as by speech reception threshold for two‐digit numbers. In noise, speech reception thresholds were measured with the adaptive German matrix test with speech and noise in front.ResultsWe found that high levels of open‐set speech comprehension are achieved at suprathreshold presentation levels in quiet. However, results at lower test levels have remained mostly unchanged for tested sound processors with default dynamic range. Expanding the lower limit of the acoustic input dynamic range yields better speech comprehension at lower presentation levels. In noise the application of ForwardFocus improves the speech reception. Overall, a continuous improvement for speech perception across three generations of CI sound processors was found.ConclusionsFindings motivate further development of signal pre‐processing, an additional focus of clinical work on lower stimulation levels, and automation of ForwardFocus.Level of evidence2.

COVID-19 in African Countries versus other World Regions: A Review.

This review examines the spread of COVID-19 (coronavirus) in Africa. By May 15, 2020, while the COVID-19 infections were 1,741,129 in Europe, 1,632,167 in North America, 757,924 in Asia, 401,072 in South America, there were only 79,780 infections in Africa, a continent with 1.34 billion people. During this same date, of the total COVID-19 deaths of 308,154 worldwide, Europe accounted for 160,482 (52.1%) deaths; North America accounted for 99,633 (32.3%) deaths; Asia accounted for 23,963 (7.8%) deaths; South America accounted for 21,303 (6.9%) deaths; and Africa accounted for only 2,639 (0.9%) deaths. Among the factors cited for this phenomenon (Africa's low figures) are: low volumes of international tourism to most African nations; a relatively young African population, with 533.5 (39.8%) million under the age of 15; low obesity rates in Africa; low rates of urbanization in most African nations; hot or high temperatures and high humidity in most African nations; low levels of testing, which continues to be the case in countries all across the world and proactive measures by African governments and people to slow the spread of the coronavirus. It is recommended that African countries continue to pursue proactive measures such as use of facemasks, hand sanitizers, regular hand washing and immediate partial or full lockdown when necessary.

A model comparing the value of broad next-gen sequencing (NGS)-based testing to single gene testing (SGT) in patients with nonsquamous non-small cell lung cancer (NSCLC) in the United States.

9529 Background: Patients (pts) with nonsquamous (ns) NSCLC should be tested for actionable driver oncogenes (ADOs), and highly effective treatments (tx) may be available for these pts. Although EGFR and ALK single gene testing (SGT) is relatively common (>80%) in the US, testing for less common ADOs is rare. Unidentified pts with ADOs have survival comparable to pts without alterations. We interrogate plausible testing configurations and discuss their implications for the US population. Methods: Simulation was used to evaluate various levels of testing with SGT or NGS on the basis of life years gained (LYG) as well as cost per LYG. Expected prevalence of ADOs among nsNSCLC pts as well as the survival distribution of pts in the presence versus absence of an ADO tx strategy were calibrated based on current literature. Survival duration for each simulated pt was generated from Weibull distributions fit to statistical estimates of median and 5-year survival. With appropriate match between ADO and targeted tx, the Weibull distribution offered a median additional 2 years of life. ADOs included in NGS: EGFR, ALK, ROS1, BRAF, RET, MET, NTRK. SGT: EGFR and ALK. Results: Each incremental 10% increase in NGS instead of SGT produces 2630 additional LYG and a cost savings per LYG between -$49 to -$109. At the current 80% testing rate, replacing SGT with NGS would result in an additional 21,019 LYG with reduced cost per LYG of -$599. Increasing testing from 80% to 100% of eligible pts would increase LYG by 15,017 over the current state. If 100% of eligible pts were tested with NGS and every identified pt received tx, the cost per LYG of this strategy would be $16,641.57. Conclusions: In a hypothetical model where highly effective tx is available to all identified pts with ADOs, broad NGS testing compared to SGT for EGFR/ALK leads to large gains in life years at reduced cost per LYG compared to SGT, supporting universal NGS testing of all advanced nsNSCLC pts. Conversely, lower levels of testing or only testing for common ADOs (as is the current state) result in large numbers of pts being unidentified and not experiencing these benefits. [Table: see text]

Network Structure of COVID-19 Spread and the Lacuna in India’s Testing Strategy

We characterize the network of COVID-19 spread in India and find that the transmission rate is 0.43, with daily case growth driven by individuals who contracted the virus abroad. We explore the question of whether this represents exponentially decaying dynamics or is simply an artefact of India’s testing strategy. Testing has largely been limited to individuals travelling from high-risk countries and their immediate contacts, meaning that the network reflects positive identifications from a biased testing sample. Given generally low levels of testing and an almost complete absence of testing for community spread, there is significant risk that we may be missing out on the actual nature of outbreak. India still has an apparently low current caseload, with possibly a small window of time to act, and should therefore aggressively and systematically expand random testing for community spread, including for asymptomatic cases. This will help understand true transmission characteristics and plan appropriately for the immediate future.

Variations in Testing for HIV and Other Sexually Transmitted Infections Across Gender Identity Among Transgender Youth.

Purpose: Transgender youth are at high risk for human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs), but their rates of screening are unknown. This study sought to quantify HIV and other STI testing levels and to examine variations in testing levels across three categories of gender identity: transgender men, transgender women, and nonbinary individuals.Methods: Between June 2017 and June 2018, 186 transgender youth aged 15–24 years were recruited into a randomized trial of home HIV testing supplemented with telehealth-based counseling. Information on sociodemographics, health care utilization, sexual activity, stress and resilience, and history of HIV and other STI testing was obtained. Multivariable logistic regression models were formulated to identify variations in testing for HIV and other STIs across gender identities.Results: Twenty-eight of 186 participants (15.1%) reported testing for HIV in the past year, and 42 (22.6%) reported testing for other STIs. Transgender women were less likely to have been tested for HIV (adjusted odds ratio [aOR]: 0.15, 95% confidence interval [CI]: 0.03–0.78) and other STIs (aOR: 0.33, 95% CI: 0.11–0.99), but nonbinary individuals were equally likely to have been tested compared with transgender men. Participants who agreed that their health care provider is knowledgeable about transgender health issues were thrice as likely to have been tested for HIV (aOR: 3.29, 95% CI: 1.36–7.97) and other STIs (aOR: 3.05, 95% CI: 1.40–6.63) compared with those who disagreed.Conclusion: Low levels of testing among transgender youth highlight the exigency of improving gender- and age-appropriate HIV and other STI prevention services. Given that provider knowledge of transgender health issues was strongly associated with testing, training health care providers in transgender-related care could prove beneficial.

Geographic and population-level disparities in colorectal cancer testing: A multilevel analysis of Medicaid and commercial claims data.

Morbidity and mortality from colorectal cancer (CRC) can be attenuated through guideline concordant screening and intervention. This study used Medicaid and commercial claims data to examine individual and geographic factors associated with CRC testing rates in one state (Oregon). A total of 64,711 beneficiaries (4516 Medicaid; 60,195 Commercial) became newly age-eligible for CRC screening and met inclusion criteria (e.g., continuously enrolled, no prior history) during the study period (January 2010-December 2013). We estimated multilevel models to examine predictors for CRC testing, including individual (e.g., gender, insurance, rurality, access to care, distance to endoscopy facility) and geographic factors at the county level (e.g., poverty, uninsurance). Despite insurance coverage, only two out of five (42%) beneficiaries had evidence of CRC testing during the four year study window. CRC testing varied from 22.4% to 46.8% across Oregon's 36 counties; counties with higher levels of socioeconomic deprivation had lower levels of testing. After controlling for age, beneficiaries had greater odds of receiving CRC testing if they were female (OR 1.04, 95% CI 1.01-1.08), commercially insured, or urban residents (OR 1.14, 95% CI 1.07-1.21). Accessing primary care (OR 2.47, 95% CI 2.37-2.57), but not distance to endoscopy (OR 0.98, 95% CI 0.92-1.03) was associated with testing. CRC testing in newly age-eligible Medicaid and commercial members remains markedly low. Disparities exist by gender, geographic residence, insurance coverage, and access to primary care. Work remains to increase CRC testing to acceptable levels, and to select and implement interventions targeting the counties and populations in greatest need.

Incidence of Fragile X syndrome in Ireland.

Described as the commonest single gene cause of learning disability internationally, the incidence of Fragile X syndrome (FXS) has never previously been determined in Ireland. The aim of this work was to determine the observed incidence of FXS in the island of Ireland; the Republic of Ireland (ROI) and Northern Ireland (NI) separately and combined. Ascertainment was achieved for a cross-sectional study by a retrospective, clinical and laboratory database review of positive FXS cases, born in either ROI or NI, between years 2000-2009 inclusive. The observed incidence of FXS per 10,000 live births in the island of Ireland in males was 0.94 (95%CI: 0.75-1.13) or ∼1:10,600 and in females was 0.23 (95%CI: 0.14-0.32) or ∼1:43,000. Comparable testing rates for FXS are present in ROI and NI, with on average 1.48% (1.30% in ROI, 1.96% in NI) of live male births and 0.4% (0.35% in ROI, 0.55% in NI) of live female births undergoing analysis which is comparable to other centres internationally. This study demonstrates the observed incidence of FXS in the island of Ireland is (i) approximately half the estimated worldwide incidence in males and is not explained by low levels of testing, and (ii) approximately one quarter the estimated worldwide incidence in females which may be explained by low levels of testing. © 2017 Wiley Periodicals, Inc.

Men Who Have Sex with Men in Kampala, Uganda: Results from a Bio-Behavioral Respondent Driven Sampling Survey.

We report on the results of a respondent-driven sampling survey among men who have sex with men (MSM) in Kampala, Uganda, where same-sex behavior is criminalized and highly stigmatized. We enrolled 608 MSM aged 18+years and residing in greater Kampala from June 2012-November 2013. Anonymous data were collected through audio-computer assisted self-interviews; blood was tested for HIV-1 antibodies, CD4+T cell counts, and viral load. Estimated HIV prevalence was 12.2% (95% confidence interval [CI] 8.0-16.1), increasing with age. One in five (19.6%) stated knowing their HIV-positive status and a similar proportion of HIV-infected MSM were virally suppressed (19.3%; 95% CI 3.3-33.1). HIV-related risk behaviors included unprotected anal sex (35.8% at last sex act), selling sex (38.5%), having multiple steady (54.3%) or casual (63.6%) partners, and ever injecting drugs (31.6%). Forty percent experienced homophobic abuse; 44.5% ever experienced suicide ideation. HIV prevalence among MSM remains high whereas knowledge of seropositive status and suppression of viral load remains low. MSM report a wide range of high risk behaviors, frequent homophobic abuse, poor mental health, as well as low levels of testing and treatment. Better access to tailored prevention and treatment services to improve population-level viral load suppression are warranted.

The Influences of Health Insurance and Access to Information on Prostate Cancer Screening among Men in Dominican Republic.

Objectives. Although research demonstrates the public health burden of prostate cancer among men in the Caribbean, relatively little is known about the factors that underlie the low levels of testing for the disease among this population. Study Design. A cross-sectional study of prostate cancer testing behaviours among men aged 40–60 years in Dominican Republic using the Demographic and Health Survey (2013). Methods. We use hierarchical binary logit regression models and average treatment effects combined with propensity score matching to explore the determinants of prostate screening as well as the average effect of health insurance coverage on screening. The use of hierarchical binary logit regression enabled us to control for the effect of unobserved heterogeneity at the cluster level that may affect prostate cancer testing behaviours. Results. Screening varied significantly with health insurance coverage, knowledge of cholesterol level, education, and wealth. Insured men were more likely to test for prostate cancer (OR = 1.65, p = 0.01) compared to the uninsured. Conclusions. The expansion and restructuring of Dominican Republic universal health insurance scheme to ensure equity in access may improve health access that would potentially impact positively on prostate cancer screening among men.

What Prevents Men Aged 40-64 Years from Prostate Cancer Screening in Namibia?

Objectives. Although a growing body of evidence demonstrates the public health burden of prostate cancer in SSA, relatively little is known about the underlying factors surrounding the low levels of testing for the disease in the context of this region. Using Namibia Demographic Health Survey dataset (NDHS, 2013), we examined the factors that influence men's decision to screen for prostate cancer in Namibia. Methods. We use complementary log-log regression models to explore the determinants of screening for prostate cancer. We also corrected for the effect of unobserved heterogeneity that may affect screening behaviours at the cluster level. Results. The results show that health insurance coverage (OR = 2.95, p = 0.01) is an important predictor of screening for prostate cancer in Namibia. In addition, higher education and discussing reproductive issues with a health worker (OR = 2.02, p = 0.05) were more likely to screening for prostate cancer. Conclusions. A universal health insurance scheme may be necessary to increase uptake of prostate cancer screening. However it needs to be acknowledged that expanded screening can have negative consequences and any allocation of scarce resources towards screening must be guided by evidence obtained from the local context about the costs and benefits of screening.

Analysis of laboratory testing results collected in an enhanced chlamydia surveillance system in Australia, 2008-2010.

BackgroundChlamydial infection is the most common notifiable disease in Australia, Europe and the US. Australian notifications of chlamydia rose four-fold from 20,274 cases in 2002 to 80,846 cases in 2011; the majority of cases were among young people aged less than 29 years. Along with test positivity rates, an understanding of the number of tests performed and the demographics of individuals being tested are key epidemiological indicators. The ACCESS Laboratory Network was established in 2008 to address this issue.MethodsThe ACCESS Laboratory Network collected chlamydia testing data from 15 laboratories around Australia over a three-year period using data extraction software. All chlamydia testing data from participating laboratories were extracted from the laboratory information system; patient identifiers converted to a unique, non-reversible code and de-identified data sent to a single database. Analysis of data by anatomical site included all specimens, but in age and sex specific analysis, only one testing episode was counted.ResultsFrom 2008 to 2010 a total of 628,295 chlamydia tests were referred to the 15 laboratories. Of the 592,626 individual episodes presenting for testing, 70% were from female and 30% from male patients. In female patients, chlamydia positivity rate was 6.4% overall; the highest rate in 14 year olds (14.3%). In male patients, the chlamydia positivity rate was 9.4% overall; the highest in 19 year olds (16.5%). The most common sample type was urine (57%). In 3.2% of testing episodes, multiple anatomical sites were sampled. Urethral swabs gave the highest positivity rate for all anatomical sites in both female (7.7%) and male patients (14%), followed by urine (7.6% and 9.4%, respectively) and eye (6.3% and 7.9%, respectively).ConclusionsThe ACCESS Laboratory Network data are unique in both number and scope and are representative of chlamydia testing in both general practice and high-risk clinics. The findings from these data highlight much lower levels of testing in young people aged 20 years or less; in particular female patients aged less than 16 years, despite being the group with the highest positivity rate. Strategies are needed to increase the uptake of testing in this high-risk group.

Young Men’s Views Toward the Barriers and Facilitators of Internet-Based Chlamydia Trachomatis Screening: Qualitative Study

BackgroundThere is a growing number of Internet-based approaches that offer young people screening for sexually transmitted infections.ObjectiveThis paper explores young men’s views towards the barriers and facilitators of implementing an Internet-based screening approach. The study sought to consider ways in which the proposed intervention would reach and engage men across ages and socioeconomic backgrounds.MethodsThis qualitative study included 15 focus groups with 60 heterosexual young men (aged 16-24 years) across central Scotland, drawn across age and socioeconomic backgrounds. Focus groups began by obtaining postcode data to allocate participants to a high/low deprivation category. Focus group discussions involved exploration of men’s knowledge of chlamydia, use of technology, and views toward Internet-based screening. Men were shown sample screening invitation letters, test kits, and existing screening websites to facilitate discussions. Transcripts from audio recordings were analyzed with "Framework Analysis".ResultsMen’s Internet and technology use was heterogeneous in terms of individual practices, with greater use among older men (aged 20-24 years) than teenagers and some deprivation-related differences in use. We detail three themes related to barriers to successful implementation: acceptability, confidentiality and privacy concerns, and language, style, and content. These themes identify ways Internet-based screening approaches may fail to engage some men, such as by raising anxiety and failing to convey confidentiality. Men wanted screening websites to frame screening as a serious issue, rather than using humorous images and text. Participants were encouraged to reach a consensus within their groups on their broad design and style preferences for a screening website; this led to a set of common preferences that they believed were likely to engage men across age and deprivation groups and lead to greater screening uptake.ConclusionsThe Internet provides opportunities for re-evaluating how we deliver sexual health promotion and engage young men in screening. Interventions using such technology should focus on uptake by age and socioeconomic background. Young people should be engaged as coproducers of intervention materials and websites to ensure messages and content are framed appropriately within a fast-changing environment. Doing so may go some way to addressing the overall lower levels of testing and screening among men compared with women.

Lantz et al. Respond

Conrath and Pawel’s response does not acknowledge the growing evidence that current radon control efforts are not as effective or efficient as they could be for optimal public health benefit.1 We are not against a comprehensive approach. However, the strong interaction between radon and tobacco exposure cannot be ignored; the Environmental Protection Agency (EPA) itself estimates that 86% of radon-induced lung cancer deaths are among current and former smokers.2 Given stalled radon control efforts and limited resources, we argue that residential radon policy should have a much stronger focus on smokers and should also create synergies with evidenced-based tobacco control efforts.1,3 Conrath and Pawel take issue with our assertion that there has been limited tailored communication with smokers about radon risk. The EPA’s main educational product, A Citizen’s Guide to Radon, does provide some risk information for smokers along with the pithy message to smokers in homes above the action level to both “stop smoking and fix your home.”4 This simple informational approach to behavior change, however, cannot be considered a tailored or sophisticated communication strategy.5 Furthermore, at the state and local level, radon-related messaging to smokers is mostly buried within general educational materials. Our review of state government Web sites about residential radon revealed that very few explicitly or prominently communicate that smokers are at significantly higher risk.3 The fact that there are low levels of testing and remediation in the general population and that smokers remediate at an even lower rate strongly indicates that current efforts are lacking.1,6 We agree that this type of risk communication is not easy and that more research regarding effective educational interventions is needed. The EPA’s 1992 cost-effectiveness analysis is cited to justify the current recommended approach to remediation.7 However, since this analysis was conducted, smoking rates in the United States have fallen from near 30% to 19%, which decreases the cost-effectiveness ratio because smokers carry the majority of the residential radon burden.8 Furthermore, given normal residential mobility, Warner et al. demonstrated that current radon exposure is a poor indicator of lifetime risk, and that for typical individuals living in high radon homes, the lifetime risk is likely much lower than what EPA analyses have assumed.9 We maintain that reducing smoking in the general population and special efforts to target current and former smokers with tailored radon testing and remediation messages are the most cost-effective approaches to reducing the public health burden of radon.

HIV/AIDS-Related Stigmatizing and Discriminatory Attitudes and Recent HIV Testing Among Men Who Have Sex With Men in Beijing

This study assessed the correlates of recent HIV testing and HIV/AIDS-related stigmatizing and discriminatory attitudes among men who have sex with men (MSM) in Beijing, China. A cross-sectional study probed demographics, sexual and drug use behaviors, HIV testing, and prevention services. Of 500 participants, 39.3% recently received a test for HIV. Recent testing was independently associated with expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes, more male sex partners, no female sexual partners and knowing HIV status of their last male partner. Expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes was independently associated with recent testing, younger age, and knowing HIV status of their last male partner. This study revealed that HIV/AIDS-related stigmatizing and discriminatory attitudes were common and inversely associated with recent HIV testing. Low levels of testing highlighted the urgent needs to reduce HIV/AIDS-related stigma and discrimination and expand HIV testing among MSM in Beijing.

Evidence of direct smooth muscle relaxant effects of the fibrate gemfibrozil

Fibrates are commonly employed to treat abnormal lipid metabolism via their unique ability to stimulate peroxisome proliferator-activated receptor alpha (PPARalpha). Interestingly, they also decrease systemic arterial pressure, despite recent evidence that PPAR alpha may contribute to expression of renin and related hypertension. Yet, mechanisms responsible for their potential antihypertensive activity remain unresolved. Rapid decreases in arterial pressure following bolus intravenous injections of bezafibrate strongly suggest they may relax arterial smooth muscle directly. But since bezafibrate is highly susceptible to photodegradation in aqueous media, it has never been critically tested for this possibility in vitro with isolated arterial smooth muscle preparations. Accordingly, we tested gemfibrozil which is resistant to photodegradation. We examined it over a therapeutically-relevant range (50-400 microM) for both acute and delayed relaxant effects on contractions of the isolated rat tail artery; contractions induced by either depolarizing its smooth muscle cell membranes with high potassium or stimulating its membrane-bound receptors with norepinephrine and arginine-vasopressin. We also examined these same gemfibrozil levels for effects on spontaneously-occurring phasic rhythmic contractile activity, typically not seen in arteries under in vitro conditions but commonly exhibited by smooth muscle of uterus, duodenum and bladder. We found that gemfibrozil significantly relaxed all induced forms of contraction in the rat tail artery, acutely at the higher test levels and after a delay of a few hours at the lower test levels. The highest test level of gemfibrozil (400 microM) also completely abolished spontaneously-occurring contractile activity of the isolated uterus and duodenum and markedly suppressed it in the bladder. This is the first evidence that a fibrate drug can directly relax smooth muscle contractions, either induced by various contractile agents or spontaneously-occurring. These findings are particularly relevant to both the recently renewed concern over the impact of fibrates on hypertension and a new understanding of their gastrointestinal side effects.

Risk factors associated with hepatocellular carcinoma notified to the Anti-Cancer Council of Victoria in 1991-1992.

The study aimed to estimate the prevalence of risk factors for liver disease, particularly hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, in a population-based series of hepatocellular carcinoma, and to assess the feasibility of retrospective surveys in determining risk factors for hepatocellular carcinoma. A survey of all cases of hepatocellular carcinoma diagnosed in 1991 and 1992 documented the high contribution of alcoholic cirrhosis, particularly in Australian-born men. Low levels of testing for HBV and HCV made their contribution to hepatocellular carcinoma uncertain. No cases of hepatocellular carcinoma due to HBV or HCV were reported in Australian-born subjects. Higher rates of HBV carriage in those tested were found in Asian and Mediterranean immigrants. Testing for HCV was known to have occurred for less than a quarter of subjects, and assessment for multiple aetiological risk factors was rare. The burgeoning epidemic of HCV will require improved surveillance for the sequelae of long-term infection. Satisfactory surveillance will require cooperation from clinicians in regard to the completeness of medical records and adequate resources for cancer registries to supplement their passive reporting system with exposure data.

Color appearance under chromatic adaptation varied along theoretically significant axes in color space.

Changes in color appearance caused by chromatic adaptation were measured with a wide range of adapting fields. Observers viewed a 39'-55' annular test field composed of an admixture of lights from the red phosphor and the green phosphor of a CRT. The annular mixture field was centered and superimposed upon a 4.7 degrees steady, circular background field. After the observer was completely adapted to the background, the luminance of the red phosphor in the test was held fixed while the observer adjusted the luminance of the green phosphor until the test appeared neither reddish nor greenish. Twenty-two equiluminant backgrounds (4.5 cd/m2, approximately 50 Td) were systematically selected along two axes in Judd chromaticity space. One axis was along tritanopic confusion lines, with middle-wavelength-sensitive- (M-) and long-wavelength-sensitive- (L-) cone stimulation held constant. The other axis maintained constant short-wavelength-sensitive- (S-) cone stimulation. The results show that adapting backgrounds that were varied along tritanopic confusion lines do not have a differential effect on color appearance at high test levels (well above the adapting level). At lower test levels there is a systematic change in color appearance of the test light, which is quantitatively described by additive redness. Along constant S-cone-stimulation lines, adapting backgrounds differentially affect color appearance in a systematic way, reflecting changes in receptoral gain and the additive contribution. The measurements taken with adapting fields throughout color space are described by the two-process model of chromatic adaptation.