Changing Narratives and Provoking Dialogue: An Analysis of the HIV Stigma and Faith Summit

GLAAD in partnership with the Gilead COMPASS Initiative® Coordinating Centers conducted a three-day summit to address the HIV epidemic in the Southern region of the United States. The summit featured virtual panel discussions with HIV experts, faith leaders, community advocates, and entertainers to bring about conversation and change around HIV stigma.

Popular Culture and Shaping HIV Perception

The Gilead COMPASS Initiative® used celebrity partnerships to highlight HIV prevalence in the Southern U.S. and support Southern HIV and Lesbian, Gay, Bisexual, Transgender, Queer (LGBTQ) organizations. Using various media platforms, HIV organizations engaged with popular culture in collaboration with national media advocacy and public relations organizations to campaign against stigmatization and raise awareness about HIV.

Intersectional Stigma and Prevention Among Gay, Bisexual, and Same Gender-Loving Men in New York City, 2020: System Dynamics Models

Objectives. To create causal loop diagrams that characterize intersectional stigma experiences among Black, gay, bisexual, same gender-loving, and other men who have sex with men and to identify intervention targets to reduce stigma and increase testing and prevention access. Methods. Between January and July 2020, we conducted focus groups and in-depth interviews with 80 expert informants in New York City, which were transcribed, coded, and analyzed. These qualitative insights were developed iteratively, visualized, and validated in a causal loop diagram (CLD) using Vensim software. Results. The CLD revealed 3 key feedback loops-medical mistrust and HIV transmission, serosorting and marginalization of Black and gay individuals, and family support and internalized homophobia-that contribute to intersectional HIV and related stigmas, homophobia, and systemic racism. On the basis of these results, we designed 2 novel intervention components to integrate into an existing community-level anti-HIV stigma and homophobia intervention. Conclusions. HIV stigma, systemic racism, and homophobia work via feedback loops to reduce access to and uptake of HIV testing, prevention, and treatment. Public Health Implications. The CLD method yielded unique insights into reciprocal feedback structures that, if broken, could interrupt stigmatization and discrimination cycles that impede testing and prevention uptake. (Am J Public Health. 2022;112(S4):S444-S451. https://doi.org/10.2105/AJPH.2022.306725).

Assessing Knowledge of HIV Vaccines and Biomedical Prevention Methods Among Transgender Women in the New York City Tri-State Area

Purpose: To lower the HIV risk of transgender women, it is imperative to understand their unique HIV prevention needs and design biomedical prevention interventions that are responsive to the psychosocial, behavioral, and clinical needs of these communities. Preventive HIV vaccines are an important modality under investigation in diverse study participants. We sought to assess the knowledge of HIV vaccine research and the most common barriers and facilitators to participation in HIV vaccine studies among HIV-negative transgender women living in New York City.

Methods: Six focus groups were conducted among 29 participants recruited in the New York City tri-state area from December 2014 to July 2015. Prefocus group quantitative questionnaire assessed demographic, behavioral information, knowledge of preventive vaccine research, and reasons for potential participation in prevention studies.

Results: Median age of participants was 29 years and 41.4% identified as white. Over half of participants have heard of preventive vaccine research and majority indicated that an important factor in participating in HIV prevention research is to help the community collective effort. Key barriers that emerged were fear of side effects, feelings of exclusion from biomedical research. Facilitators to participation in prevention studies included trusting relationships with providers.

Conclusions: These barriers and facilitators are important to consider in the design of studies inclusive of trans communities and transgender-specific prevention strategies. Barriers may be overcome by disseminating accurate information via social media or health providers.

Impact of a Community-level Intervention on HIV Stigma, Homophobia and HIV Testing in New York City: Results from Project CHHANGE

BACKGROUND

HIV stigma and homophobia are barriers to access to HIV prevention and treatment services. Project CHHANGE, Challenge HIV Stigma and Homophobia and Gain Empowerment, was a multicomponent intervention designed to reduce community-level HIV stigma and homophobia via workshops, space-based events and bus shelter ads delivered to community-based organizations and neighborhood residents in a high HIV prevalence, primarily African-American, Black and/or Afro-Caribbean, neighborhood in New York City (NYC).

METHODS

Serial cross-sectional, street intercept surveys among residents of the invention neighborhood and matched control neighborhood were conducted before and after the intervention. Propensity score matching and generalized estimating equation regression models assessed the impact of CHHANGE on HIV stigma and homophobia. HIV testing service utilization data were assessed and multivariable models of self-reported HIV testing among post-intervention street survey respondents were built.

RESULTS

We did not find a significant treatment effect on HIV stigma and homophobia among residents of the intervention neighborhood as compared with control community residents. However, HIV testing increased by 350% at the testing site in the intervention community after the intervention implementation. Further, lower HIV stigma, attending an HIV stigma workshop and having friends or family living with HIV were independently associated with past six-month HIV testing among post-intervention respondents in both neighborhoods.

CONCLUSIONS

CHHANGE was feasible and acceptable to community residents. Evaluating community-level interventions is challenging. Our triangulated approach yielded somewhat conflicting results, which may be due to design limitations. Further research is needed to understand whether and how CHHANGE affected HIV testing.

Post-exposure Prophylaxis Awareness, Knowledge, Access and Use Among Three Populations in New York City, 2016-17

Post-exposure prophylaxis (PEP) is a cost-effective, but underused HIV prevention strategy. PEP awareness, knowledge, access, and usage was assessed among young men of color who have sex with men (YMSMOC; n = 177), transgender women (TW; n = 182), and cisgender women of color (CWOC; n = 170) in New York City. 59% were aware of PEP: 80% among YMSMOC, 63% among TW and 34% among CWOC (p < 0.001). 13% had ever used PEP. PEP awareness was higher among YMSMOC with a recent HIV test and lower among those with ≥ 4 partners. PEP awareness was lower among TW who anticipated stigma and reported barriers to taking PEP, and higher among TW who exchanged sex for resources. Among CWOC, more barriers to taking PEP reduced the odds of PEP awareness. PEP education and outreach needs to be deliberate about population-specific campaigns, with a need to focus on reducing PEP stigma and other barriers which impede PEP access.

Characteristics and Correlates of Lifetime Suicidal Thoughts and Attempts Among Young Black Men Who Have Sex With Men (MSM) and Transgender Women

This study examined characteristics and correlates of lifetime suicidal thoughts and suicide attempts among HIV-negative young Black men who have sex with men (MSM) and transgender women (transwomen) between 16 and 29 years of age ( N = 161). In our sample, 36.6% of young Black MSM and transwomen reported a history of lifetime suicidal thoughts, while 16.1% reported prior suicide attempts. Using multivariable analysis, a history of intimate partner violence, greater psychological distress, and higher perceived sexuality discrimination were significantly associated with lifetime suicidal thoughts. Childhood sexual abuse history, greater psychological distress, lower score for outness, and higher perceived sexuality discrimination were significantly related to suicide attempts among young Black MSM and transwomen. Efforts to identify and understand factors associated with lifetime suicidal thoughts and attempts are urgently needed to inform the development and implementation of culturally relevant mental health prevention strategies for young Black MSM and transwomen.

Preferences for HIV test characteristics among young, Black Men Who Have Sex With Men (MSM) and transgender women: Implications for consistent HIV testing

BACKGROUND

Promoting consistent HIV testing is critical among young, Black Men Who Have Sex With Men (MSM) and transgender women who are overrepresented among new HIV cases in the United States. New HIV test options are available, including mobile unit testing, one-minute testing, at home or self-testing and couples HIV testing and counseling (CHTC). In the context of these newer options, the objective of this study was to explore whether and how preferences for specific characteristics of the tests acted as barriers to and/or facilitators of testing in general and consistent testing specifically among young Black MSM and transgender women aged 16 to 29.

METHODS

We conducted 30 qualitative, semi-structured, in-depth interviews with young, Black, gay, bisexual or MSM and transgender women in the New York City metropolitan area to identify preferences for specific HIV tests and aspects of HIV testing options. Participants were primarily recruited from online and mobile sites, followed by community-based, face-to-face recruitment strategies to specifically reach younger participants. Thematic coding was utilized to analyze the qualitative data based on a grounded theoretical approach.

RESULTS

We identified how past experiences, perceived test characteristics (e.g., accuracy, cost, etc.) and beliefs about the "fit" between the individual, and the test relate to preferred testing methods and consistent testing. Three major themes emerged as important to preferences for HIV testing methods: the perceived accuracy of the test method, venue characteristics, and lack of knowledge or experience with the newer testing options, including self-testing and CHTC.

CONCLUSIONS

These findings suggest that increasing awareness of and access to newer HIV testing options (e.g., free or reduced price on home or self-tests or CHTC available at all testing venues) is critical if these new options are to facilitate increased levels of consistent testing among young, Black MSM and transgender women. Addressing perceptions of test accuracy and supporting front line staff in creating welcoming and safe testing environments may be key intervention targets. Connecting young Black MSM and transgender women to the best test option, given preferences for specific characteristics, may support more and more consistent HIV testing.

Intervention to Match Young Black Men and Transwomen Who Have Sex With Men or Transwomen to HIV Testing Options (All About Me): Protocol for a Randomized Controlled Trial

Background

HIV testing is a critical component of HIV prevention and care. Interventions to increase HIV testing rates among young black men who have sex with men (MSM) and black transgender women (transwomen) are needed. Personalized recommendations for an individual’s optimal HIV testing approach may increase testing.

Objective

This randomized trial tests the hypothesis that a personalized recommendation of an optimal HIV testing approach will increase HIV testing more than standard HIV testing information.

Methods

A randomized trial among 236 young black men and transwomen who have sex with men or transwomen is being conducted. Participants complete a computerized baseline assessment and are randomized to electronically receive a personalized HIV testing recommendation or standard HIV testing information. Follow-up surveys are conducted online at 3 and 6 months after baseline.

Results

The All About Me randomized trial was launched in June 2016. Enrollment is completed and 3-month retention is 92.4% (218/236) and has exceeded study target goals.

Conclusions

The All About Me intervention is an innovative approach to increase HIV testing by providing a personalized recommendation of a person’s optimal HIV testing approach. If successful, optimizing this intervention for mobile devices will widen access to large numbers of individuals.

Trial Registration

ClinicalTrial.gov NCT02834572; https://clinicaltrials.gov/ct2/show/NCT02834572 (Archived by WebCite at http://www.webcitation.org/6vLJWOS1B)

Informing the Development of a Mobile Phone HIV Testing Intervention: Intentions to Use Specific HIV Testing Approaches Among Young Black Transgender Women and Men Who Have Sex With Men

Background

Regular human immunodeficiency virus (HIV) testing of persons at risk is critical to HIV prevention. Infrequent HIV testing and late diagnosis of HIV infection have been observed among young black men who have sex with men (MSM) and transwomen (transgender women)—two groups overrepresented in the HIV epidemic.

Objective

The objective of this study was to inform the development of a brief mobile phone intervention to increase HIV testing among young black MSM and transwomen by providing a tailored recommendation of an optimal HIV testing approach. We identified demographic, behavioral, psychosocial, and sociostructural factors associated with intentions to use three specific HIV testing approaches: self-testing, testing at a clinic or other provider, and couples HIV testing and counseling (CHTC).

Methods

Individuals were eligible for a Web-based survey if they were male at birth; were between the ages of 16 and 29 years; self-identified as black, African American, Caribbean black, African black, or multiethnic black; were not known to be HIV-infected; and reported insertive or receptive anal intercourse with a man or transwoman in the last 12 months. Recruitment occurred via banner advertisements placed on a range of social and sexual networking websites and apps in New York City and nationally, and via events attended by young black MSM and transwomen in New York City. Intention to test by each testing method was analyzed using logistic regression with best subset models and stepwise variable selection.

Results

Among 169 participants, intention to use a self-test was positively associated with comfort in testing by a friend or a partner at home (Adjusted odds ratio, AOR, 2.40; 95% CI 1.09-5.30), and stigma or fear as a reason not to test (AOR 8.61; 95% CI 2.50-29.68) and negatively associated with higher social support (AOR 0.48; 95% CI 0.33-0.72) and having health insurance (AOR 0.21; 95% CI 0.09-0.54). Intention to test at a clinic or other provider was positively associated with self-efficacy for HIV testing (AOR 2.87; 95% CI 1.48-5.59) and social support (AOR 1.98; 95% CI 1.34-2.92), and negatively associated with a lifetime history of incarceration (AOR 0.37; 95% CI 0.16-0.89). Intention to test by CHTC was negatively associated with higher educational level (Some college or Associate’s degree vs high school graduate or less [AOR 0.81; 95% CI 0.39-1.70]; Bachelor’s degree or more vs high school graduate or less [AOR 0.28; 95% CI 0.11-0.70]).

Conclusions

Unique factors were associated with intention to test using specific testing approaches. These data will be critical for the development of a tailored intervention that shows promise to increase comfort and experiences with a variety of testing approaches among young black MSM and transwomen.

"Just Because It's Out There, People Aren't Going to Use It." HIV Self-Testing Among Young, Black MSM, and Transgender Women

HIV disproportionately affects young black MSM and transgender women in the US. Increasing HIV testing rates among these populations is a critical public health goal. Although HIV self-tests are commercially available, there is a need to better understand access to and uptake of HIV self-testing among this population. Here, we report results of a qualitative study of 30 young black MSM and transgender women residing in the New York City area to understand facilitators of and barriers to a range of HIV testing approaches, including self-testing. Mean age was 23.7 years (SD = 3.4). Over half (54%) had some college or an associate's degree, yet 37% had an annual personal income of less than $10,000 per year. Most (64%) participants had tested in the past 6 months; venues included community health/free clinics, medical offices, mobile testing units, hospitals, emergency departments, and research sites. Just one participant reported ever using a commercially available HIV self-test. Facilitators of self-testing included convenience, control, and privacy, particularly as compared to venue-based testing. Barriers to self-testing included the cost of the test, anxiety regarding accessing the test, concerns around correct test operation, and lack of support if a test result is positive. Participants indicated that instruction in correct test operation and social support in the event of a positive test result may increase the likelihood that they would use the self-test. Alongside developing new approaches to HIV prevention, developing ways to increase HIV self-testing is a public health priority for young, black MSM, and transgender women.

Automated detection of diabetic retinopathy in digital retinal images: a tool for diabetic retinopathy screening

AIMS

To develop a system to detect automatically features of diabetic retinopathy in colour digital retinal images and to evaluate its potential in diabetic retinopathy screening.

METHODS

Macular centred 45 degrees colour retinal images from 1273 patients in an inner city diabetic retinopathy screening programme. A system was used involving pre-processing to standardize colour and enhance contrast, segmentation to reveal possible lesions and classification of lesions using an artificial neural network. The system was trained using a subset of images from 500 patients and evaluated by comparing its performance with a human grader on a test set of images from 773 patients.

RESULTS

Maximum sensitivity for detection of any retinopathy on a per patient basis was 95.1%, accompanied by specificity of 46.3%. Specificity could be increased as far as 78.9% but was accompanied by a fall in sensitivity to 70.8%. At a setting with 94.8% sensitivity and 52.8% specificity, no cases of sight-threatening retinopathy were missed (retinopathy warranting immediate ophthalmology referral or re-examination sooner than 1 year by National Institute for Clinical Excellence criteria). If the system was implemented at 94.8% sensitivity setting over half the images with no retinopathy would be correctly identified, reducing the need for a human grader to examine images in 1/3 of patients.

CONCLUSION

This system could be used when screening for diabetic retinopathy. At 94.8% sensitivity setting the number of normal images requiring examination by a human grader could be halved.

Hysterectomy and ovarian function: levels of follicle stimulating hormone and incidence of menopausal symptoms are not affected by hysterectomy in women under age 45 years

OBJECTIVE

To investigate levels of follicle stimulating hormone (FSH), as a measure of ovarian function and menopausal symptoms prior to and following hysterectomy in women under the age of 45 years.

DESIGN

This was a prospective controlled study.

SAMPLE

A total of 56 hysterectomy patients and 34 controls, up to the age of 42 years, were recruited.

METHODS

Women undergoing hysterectomy were recruited prior to their operation and were matched, where possible, with controls for age, parity and smoking. Five blood samples were taken over 2 years, two before the operation (or at a 1-month interval in the control group) and then at 6 months, 1 year and 2 years. Questionnaires were completed at each sampling to assess symptoms associated with reduced estrogen secretion.

RESULTS

No significant differences in FSH levels between patients and controls were found. Modest differences in FSH levels between different time-points were identified (p = 0.03), but this disappeared if age and smoking were included as covariates. For the questionnaire data, there were no significant differences between the two groups on the somatic and vasomotor scales, but for psychological symptoms the patients scored significantly higher than the controls (p = 0.007), particularly at the pre-operation time-point.

CONCLUSION

The study found no evidence of compromise of ovarian function, as reflected in FSH levels, within 2 years of hysterectomy. Psychological symptoms were higher in women undergoing hysterectomy both before and after the operation.

Automated detection of diabetic retinopathy on digital fundus images

AIMS

The aim was to develop an automated screening system to analyse digital colour retinal images for important features of non-proliferative diabetic retinopathy (NPDR).

METHODS

High performance pre-processing of the colour images was performed. Previously described automated image analysis systems were used to detect major landmarks of the retinal image (optic disc, blood vessels and fovea). Recursive region growing segmentation algorithms combined with the use of a new technique, termed a 'Moat Operator', were used to automatically detect features of NPDR. These features included haemorrhages and microaneurysms (HMA), which were treated as one group, and hard exudates as another group. Sensitivity and specificity data were calculated by comparison with an experienced fundoscopist.

RESULTS

The algorithm for exudate recognition was applied to 30 retinal images of which 21 contained exudates and nine were without pathology. The sensitivity and specificity for exudate detection were 88.5% and 99.7%, respectively, when compared with the ophthalmologist. HMA were present in 14 retinal images. The algorithm achieved a sensitivity of 77.5% and specificity of 88.7% for detection of HMA.

CONCLUSIONS

Fully automated computer algorithms were able to detect hard exudates and HMA. This paper presents encouraging results in automatic identification of important features of NPDR.

Effect of transdermal testosterone treatment on serum lipid and apolipoprotein levels in men more than 65 years of age

PURPOSE

Because the effects of androgen replacement on lipoprotein levels are uncertain, we sought to determine the effect of transdermal testosterone treatment on serum lipid and apolipoprotein levels in elderly men.

SUBJECTS AND METHODS

One hundred and eight healthy men more than 65 years of age who had serum testosterone concentrations >1 SD below the mean for young men were randomly assigned to receive either testosterone (54 men; 6 mg/day) or placebo (54 men) transdermally in a double-blind fashion for 36 months. Serum concentrations of lipids and apolipoproteins were measured, and cardiovascular events recorded.

RESULTS

Serum total cholesterol concentrations decreased in both the testosterone-treated men and placebo-treated men, but the 3-year mean (+/- SD) decreases in the two groups (testosterone treated, -17 +/- 29 mg/dL; placebo treated, -12 +/- 38 mg/dL) were not significantly different from each other (P = 0.4). Similarly, serum low-density lipoprotein (LDL) cholesterol levels decreased in both treatment groups, but the decreases in the two groups (testosterone treated, -16 +/- 24 mg/dL; placebo treated, -16 +/- 33 mg/dL) were similar (P = 1.0). Levels of high-density lipoprotein (HDL) cholesterol, triglycerides, and apolipoproteins A-I and B did not change. Lipoprotein(a) levels increased in both groups by similar amounts (testosterone treated, 3 +/- 9 mg/dL; placebo treated, 4 +/- 6 mg/dL; P = 1.0). The number of cardiovascular events was small and did not differ significantly between the testosterone-treated men (9 events) and the placebo-treated men (5 events) during the 3-year study (relative risk = 1.8; 95% confidence interval: 0.7 to 5.0).

CONCLUSIONS

As compared with placebo, transdermal testosterone treatment of healthy elderly men for 3 years did not affect any of the lipid or apolipoprotein parameters that we measured. The effect of testosterone treatment on cardiovascular events was unclear, because the number of events was small.

Effects of coexpression of the LDL receptor and apoE on cholesterol metabolism and atherosclerosis in LDL receptor-deficient mice

The low density lipoprotein receptor (LDLR) plays a major role in regulation of plasma cholesterol levels as a ligand for apolipoprotein B-100 and apolipoprotein E (apoE). Consequently, LDLR-deficient mice fed a Western-type diet develop significant hypercholesterolemia and atherosclerosis. ApoE not only mediates uptake of atherogenic lipoproteins via the LDLR and other cell-surface receptors, but also directly inhibits atherosclerosis. In this study, we examined the hypothesis that coexpression of the LDLR and apoE would have greater effects than either one alone on plasma cholesterol levels and the development of atherosclerosis in LDLR-deficient mice. LDLR-deficient mice fed a Western-type diet for 10 weeks were injected with recombinant adenoviral vectors encoding the genes for human LDLR, human apoE3, both LDLR and apoE3, or lacZ (control). Plasma lipids were analyzed at several time points after vector injection. Six weeks after injection, mice were analyzed for extent of atherosclerosis by two independent methods. As expected, LDLR expression alone induced a significant reduction in plasma cholesterol due to reduced VLDL and LDL cholesterol levels, whereas overexpression of apoE alone did not reduce plasma cholesterol levels. When the LDLR and apoE were coexpressed in this model, the effects on plasma cholesterol levels were no greater than with expression of the LDLR alone. However, coexpression did result in a substantial increase in large apoE-rich HDL particles. In addition, although the combination of cholesterol reduction and apoE expression significantly reduced atherosclerosis, its effects were no greater than with expression of the LDLR or apoE alone. In summary, in this LDLR-deficient mouse model fed a Western-type diet, there was no evidence of an additive effect of expression of the LDLR and apoE on cholesterol reduction or atherosclerosis.

Hepatic expression of apolipoprotein E inhibits progression of atherosclerosis without reducing cholesterol levels in LDL receptor-deficient mice

Apolipoprotein E (apoE) is a multifunctional protein synthesized by the liver and by tissue macrophages. Plasma apoE (derived primarily from the liver) regulates plasma lipoprotein metabolism, but macrophage-derived apoE was shown to slow the progression of atherosclerosis independent of plasma lipid levels. We utilized liver-directed gene transfer to test the hypothesis that hepatic expression of human apoE would inhibit atherogenesis even in a model in which apoE expression has little effect on plasma lipoproteins. LDL receptor-deficient mice fed a western-type diet for 5 weeks were injected with a second-generation recombinant adenovirus encoding human apoE3 or control virus. Plasma cholesterol levels were not significantly different in the two groups of mice after virus injection. Four weeks after injection, atherosclerosis was examined using three independent assays. Expression of apoE was associated with significantly reduced atherosclerosis compared with control mice in both the aortic arch (decreased by 43%) and the aortic root (decreased by 59%). In summary, hepatic overexpression of apoE inhibited progression of atherosclerosis in LDL receptor-deficient mice without reducing plasma cholesterol levels. This finding indicates that liver-derived plasma apoE can influence early atherogenesis through mechanisms other than modulation of lipoprotein metabolism and that liver-directed gene transfer and overexpression of apoE may be a therapeutic approach to atherosclerosis.

Regression of atherosclerosis induced by liver-directed gene transfer of apolipoprotein A-I in mice

BACKGROUND

The ability of apolipoprotein (apo)A-I to induce regression of preexisting atherosclerotic lesions has not been determined, and a mouse model of atherosclerosis regression has not yet been reported.

METHODS AND RESULTS

LDL receptor-deficient mice were fed a western-type diet for 5 weeks to induce atherosclerotic lesions. A second-generation recombinant adenovirus encoding human apoA-I or a control adenovirus were injected intravenously in order to express apoA-I in the liver. Three days after injection, total apoA-I levels in mice injected with the apoA-I-expressing adenovirus were 216+/-16.0 mg/dL, compared with 68.0+/-3.0 mg/dL in control virus-injected mice (P<0.001). HDL cholesterol levels in mice injected with the AdhapoA-I vector 7 days after injection were 189+/-21.0 mg/dL, compared with 123+/-8.0 mg/dL in control virus-injected mice (P<0.02). Total and non-HDL cholesterol levels did not differ between the 2 groups. Atherosclerotic lesion area was quantified by en face analysis of the aorta and cross-sectional analysis of the aortic root. Compared with baseline mice, atherosclerosis progressed in mice injected with the control adenovirus. In contrast, in mice expressing apoA-I compared with baseline mice, total en face aortic lesion area was reduced by 70% and aortic root lesion was reduced by 46%. Expression of apoA-I was associated with a significant reduction in the fraction of lesions occupied by macrophages and macrophage-derived foam cells.

CONCLUSIONS

Liver-directed gene transfer of human apoA-I resulted in significant regression of preexisting atherosclerotic lesions in LDL receptor-deficient mice as assessed by 2 independent methods.

A PstI polymorphism detects the mutation of serine128 to arginine in CD 62E gene - a risk factor for coronary artery disease

The mutation of serine128 to arginine in the CD 62E gene is a risk factor for coronary artery disease (CAD). We designed a new method to detect this mutation based on the observation that it is due to a transversion of nucleotide A561 to C, which abolishes a PstI recognition site. Two alleles, A and C, are easily typed when genomic DNA is amplified by PCR, digested with PstI, and separated on agarose gels. Among 153 people who underwent an elective, diagnostic arteriography in Johns Hopkins Hospital, we found that the C allele accounts for 19.5% in angiographically documented CAD patients (n = 82). It is significantly higher than the 10.6% frequency observed in normal controls (n = 71, p < 0.05). It indicates that the C allele is associated with early-onset CAD. This new method should facilitate the screening of this mutant allele in large populations and contribute to the understanding of the molecular mechanism underlying the association of this mutation with CAD.

Simian virus 40 large T antigen binds to topoisomerase I

Binding of simian virus 40 (SV40) large T antigen to human and calf thymus topoisomerase I (topo I) was readily detected by using modified enzyme-linked immunosorbent assays and immunoblots. In addition to WT T antigen, binding could also be readily demonstrated with T antigen fragments from the amino-terminal region as well as with fragments missing this region, but much less so with small t antigen or with human p53. Antibody-blocking experiments showed that a monoclonal antibody that binds to the N-terminal region and several antibodies that recognize the central region of T antigen interfere with the binding to topo I. Our data are consistent with the existence of two separate topo I-binding regions in T antigen, one mapping within residues 82 to 246 and an apparently weaker one present after residue 246. By comparing the binding of T antigen to topo I with that of T antigen to DNA polymerase alpha or RPA, a single-stranded DNA-binding protein, it was determined that the T antigen-topo I interaction is much stronger and that the binding sites for topo I and DNA polymerase overlap, whereas the one for RPA differs. Several unwinding-defective mutants of T antigen were partially defective in their binding to topo I, suggesting that the binding to topo I is required for unwinding circular DNA. Finally, immunoprecipitation experiments demonstrated that T antigen can interact with DNA-bound topo I, indicating that such an interaction may take place during SV40 DNA replication.

The low density lipoprotein receptor is not required for normal catabolism of Lp(a) in humans

Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein which is similar in structure to low density lipoproteins (LDL). The role of the LDL receptor in the catabolism of Lp(a) has been controversial. We therefore investigated the in vivo catabolism of Lp(a) and LDL in five unrelated patients with homozygous familial hypercholesterolemia (FH) who have little or no LDL receptor activity. Purified 125I-Lp(a) and 131I-LDL were simultaneously injected into the homozygous FH patients, their heterozygous FH parents when available, and control subjects. The disappearance of plasma radioactivity was followed over time. As expected, the fractional catabolic rates (FCR) of 131I-LDL were markedly decreased in the homozygous FH patients (mean LDL FCR 0.190 d-1) and somewhat decreased in the heterozygous FH parents (mean LDL FCR 0.294 d-1) compared with controls (mean LDL FCR 0.401 d-1). In contrast, the catabolism of 125I-Lp(a) was not significantly different in the homozygous FH patients (mean FCR 0.251 d-1), heterozygous FH parents (mean FCR 0.254 d-1), and control subjects (mean FCR 0.287 d-1). In summary, absence of a functional LDL receptor does not result in delayed catabolism of Lp(a), indicating that the LDL receptor is not a physiologically important route of Lp(a) catabolism in humans.

The inverse association of plasma lipoprotein(a) concentrations with apolipoprotein(a) isoform size is not due to differences in Lp(a) catabolism but to differences in production rate

Lipoprotein(a) (Lp[a]) is an atherogenic lipoprotein which is similar in structure to low density lipoproteins (LDL) but contains an additional protein called apolipoprotein(a) (apo[a]). Apo(a) is highly polymorphic in size, and there is a strong inverse association between the size of the apo(a) isoform and the plasma concentration of Lp(a). We directly compared the in vivo catabolism of Lp(a) particles containing different size apo(a) isoforms to establish whether there is an effect of apo(a) isoform size on the catabolic rate of Lp(a). In the first series of studies, four normal subjects were injected with radio-labeled S1-Lp(a) and S2-Lp(a) and another four subjects were injected with radiolabeled S2-Lp(a) and S4-Lp(a). No significant differences in fractional catabolic rate were found between Lp(a) particles containing different apo(a) isoforms. To confirm that apo(a) isoform size does not influence the rate of Lp(a) catabolism, three subjects heterozygous for apo(a) were selected for preparative isolation of both Lp(a) particles. The first was a B/S3-apo(a) subject, the second a S4/S6-apo(a) subject, and the third an F/S3-apo(a) subject. From each subject, both Lp(a) particles were preparatively isolated, radiolabeled, and injected into donor subjects and normal volunteers. In all cases, the catabolic rates of the two forms of Lp(a) were not significantly different. In contrast, the allele-specific apo(a) production rates were more than twice as great for the smaller apo(a) isoforms than for the larger apo(a) isoforms. In a total of 17 studies directly comparing Lp(a) particles of different apo(a) isoform size, the mean fractional catabolic rate of the Lp(a) with smaller size apo(a) was 0.329 +/- 0.090 day-1 and of the Lp(a) with the larger size apo(a) 0.306 +/- 0.079 day-1, not significantly different. In summary, the inverse association of plasma Lp(a) concentrations with apo(a) isoform size is not due to differences in the catabolic rates of Lp(a) but rather to differences in Lp(a) production rates.

Lipoprotein(a) concentration shows little relationship to IDDM complications in the Pittsburgh Epidemiology of Diabetes Complications Study cohort

OBJECTIVE

To examine the potential associations of lipoprotein(a) and the complications of IDDM and their risk factors.

RESEARCH DESIGN AND METHODS

This report focuses on 186 individuals with IDDM (mean age = 34 yr) participating in a 10-yr prospective study examining various complications. Lp(a) concentrations were evaluated for those with and without complications.

RESULTS

A weak correlation was seen between Lp(a) and HbA1 (r = 0.16, P < 0.05). Lp(a) concentrations were not significantly different for those with or without proliferative retinopathy, overt nephropathy, peripheral vascular disease, or definite myocardial infarction or angina. However, an inverse association (P < 0.05) was seen with distal symmetric polyneuropathy. These results were also confirmed by categorical analyses (i.e., Lp(a) levels < or = 30 vs. > 30 mg/dl).

CONCLUSIONS

These results suggest that any association of Lp(a) concentration with IDDM complications is likely to be weak or nonexistent. However, prospective studies are needed before its full role can be determined.

Variation in lipoprotein(a) concentrations among individuals with the same apolipoprotein (a) isoform is determined by the rate of lipoprotein(a) production

Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein which is similar in structure to, but metabolically distinct from, LDL. Factors regulating plasma concentrations of Lp(a) are poorly understood. Apo(a), the protein that distinguishes Lp(a) from LDL, is highly polymorphic, and apo(a) size is inversely correlated with plasma Lp(a) level. Even within the same apo(a) isoform class, however, plasma Lp(a) concentrations vary widely. A series of in vivo kinetic studies were performed using purified radiolabeled Lp(a) in individuals with the same apo(a) isoform but different Lp(a) levels. In a group of seven subjects with a single S4-apo(a) isoform and Lp(a) levels ranging from 1 to 13.2 mg/dl, the fractional catabolic rate (FCR) of 131I-labeled S2-Lp(a) (mean 0.328 day-1) was not correlated with the plasma Lp(a) level (r = -0.346, P = 0.45). In two S4-apo(a) subjects with a 10-fold difference in Lp(a) level, the FCR's of 125I-labeled S4-Lp(a) were very similar in both subjects and not substantially different from the FCRs of 131I-S2-Lp(a) in the same subjects. In four subjects with a single S2-apo(a) isoform and Lp(a) levels ranging from 9.4 to 91 mg/dl, Lp(a) concentration was highly correlated with Lp(a) production rate (r = 0.993, P = 0.007), but poorly correlated with Lp(a) FCR (mean 0.304 day-1). Analysis of Lp(a) kinetic parameters in all 11 subjects revealed no significant correlation of Lp(a) level with Lp(a) FCR (r = -0.53, P = 0.09) and a strong correlation with Lp(a) production rate (r = 0.99, P < 0.0001). We conclude that the substantial variation in Lp(a) levels among individuals with the same apo(a) phenotype is caused primarily by differences in Lp(a) production rate.

Serum lipoprotein allotypes in inbred strains of rabbits

Serum lipoprotein allotypes were examined for 10 males and 10 female rabbits from each of 16 genetically defined strains. The results suggested that the four allotypes, Lpq 1, Lpq2, Lpq3, and Lpq4, were controlled by three closely linked genes, IpqA, IpqB, and IpqC. Gene IpqA, controlling the expression of the Lpq1 and Lpq2 allotypes, and gene IpqB controlling the expression of the Lpq3 allotype, show limited polymorphisms.

Effect of a low-carbohydrate diet and alcohol on perceptual motor skill

Eleven adults of both sexes ate a low-carbohydrate diet consisting mainly of meat, fish, and eggs for two days. After a low-carbohydrate breakfast on the third day, they operated a Stressalyzer to test their basic perceptual motor skill. Each subject drank 1.5 oz. rye whiskey at hourly intervals from 9:30 A.M. to 12:30 P.M. Blood glucose decreased to below 50 mg. per 100 ml. in three of the eleven subjects; two of the three had decreased perceptual motor skill.

Interaction of P2 bacteriophage with the dnaB gene of Escherichia coli

The dnaB gene product of Escherischia coli is required for multiplication of temperate phage P2. At 37 C in dnaB-ts mutnats, P2 will not plaque and gives a very small burst of progeny. P2 mutants have been isolated which can grow well enough to plaque under these conditions. This type of phage mutant is cis dominant, and one such mutant (P2rlb1) has been mapped near the left end of the early gene B and to the right of the cox4 (excision) mutation. The rlb1 mutation does not lie at the replication origin, but may affect transcription in the early region, which includes the replication origin. It may also represent a site on the P2 DNA which interacts with the dnaB gene product.