Psychosocial Syndemic Classes and Longitudinal Transition Patterns Among Sexual Minority men Living with or Without HIV in the Multicenter AIDS Cohort Study (MACS).

Mental health and substance use epidemics interact to create psychosocial syndemics, accelerating poor health outcomes. Using latent class and latent transition analyses, we identified psychosocial syndemic phenotypes and their longitudinal transition pathways among sexual minority men (SMM) in the Multicenter AIDS Cohort Study (MACS, n = 3,384, mean age 44, 29% non-Hispanic Black, 51% with HIV). Self-reported depressive symptoms and substance use indices (i.e., smoking, hazardous drinking, marijuana, stimulant, and popper use) at the index visit, 3-year and 6-year follow-up were used to model psychosocial syndemics. Four latent classes were identified: "poly-behavioral" (19.4%), "smoking and depression" (21.7%), "illicit drug use" (13.8%), and "no conditions" (45.1%). Across all classes, over 80% of SMM remained in that same class over the follow-ups. SMM who experienced certain psychosocial clusters (e.g., illicit drug use) were less likely to transition to a less complex class. These people could benefit from targeted public health intervention and greater access to treatment resources.

"Take It Out on the Floor": Experiences of Violence Among Black LGBT House and Ball Community Youth in a Rust Belt City.

Black, lesbian, gay, bisexual, and transgender (LGBT), individuals experience higher rates of violent victimization compared to their cisgender heterosexual counterparts over their life course. Among Black LGBT people, witnessing and experiencing violence have been related to poor health outcomes, including depression, risky sexual behavior, substance use, and lower engagement in healthcare services. We engaged in research to better understand the effects of violence experienced by the Black LGBT youth community. We conducted a qualitative, phenomenological study focused on the causes of violence occurring in the lives of Black LGBT youth engaged in a recreation-based community health program. The study consisted of four focus groups with Black LGBT youth (N = 24) and in-depth individual interviews with medical and social service providers who work with Black LGBT youth (N = 4). Data analysis presented three themes: (1) causes of violence, (2) the context of intracommunity violence, and (3) solutions to violence. The first theme describes the reasoning, motivation, or explanation for violence experienced by the Black LGBT youth community. The second theme, the context of intracommunity violence, describes how violence occurs specifically within Black LGBT young adult communities. The third theme, solutions to violence, describes the recommendations for addressing, reducing, and/or eliminating violence within the Black LGBT youth community. Our findings highlight the need for safe spaces, culturally-relevant services, and trusted figures for Black LGBT young adults, which can serve as mechanisms for mitigating violence.

Self-Reported Combination HIV Prevention Strategies Enacted by a Prospective Cohort of Midlife and Older Men Who Have Sex with Men in the United States: A Latent Class Analysis.

Insights into combination HIV prevention (CHP) strategies to reduce HIV incidence among midlife and older adult men who have sex with men (MSM) are limited. The current study is a secondary data analysis evaluating CHP in a sample of sexually active midlife and older adult MSM (N = 566) from the Multicenter AIDS Cohort Study Healthy Aging Substudy. Stratified by HIV serostatus, we used latent class analyses to identify CHP classes based on self-reported sociobehavioral and biobehavioral prevention strategies that participants and their male partners used in the prior 6 months. We identified three CHP classes among men living without HIV (MLWOH), including the following: high CHP overall (43.0%), high anal sex abstention (15.0%), and low prevention overall (42.0%). Among men living with HIV (MLWH), we identified four CHP classes, including the following: high CHP overall (20.9%), high CHP/low condom use (27.1%), high condom reliance (22.3%), and low prevention overall (29.7%). There were small differences by sociodemographic characteristics and sexual behavior practices between the classes; however, poppers use was often linked to being in high CHP groups. Our findings support that CHP is not one-size-fits-all for midlife and older adult MSM. There remains a need to scale up clinical providers' sexual health communication practices to assist midlife and older MSM incorporate prevention strategies, particularly biobehavioral prevention strategies that align with their patients' lived experiences.

Short-term binge drinking, marijuana, and recreational drug use trajectories in a prospective cohort of people living with HIV at the start of COVID-19 mitigation efforts in the United States.

BACKGROUND: At the start of the COVID-19 pandemic, HIV experts suggested that an increase in mental health diagnoses and substance use among people living with HIV (PLHIV) may be an unintended consequence of COVID-19 mitigation efforts (e.g., limiting social contact). We evaluated short-term trajectories in binge drinking, marijuana, and recreational drug use in a prospective cohort of PLHIV. METHODS: Data (N = 2121 PLHIV) consist of survey responses on substance use behaviors from two pre-COVID-19 (October 2018-September 2019) and one COVID-19-era (April 2020-September 2020) timepoints within the MACS/WIHS Combined Cohort Study (MWCCS). We conducted group-based trajectory models, triangulated with generalized linear mixed models, to assess changes in binge drinking, daily marijuana use, and recreational drug use at the start of the pandemic. Controlling for age and race/ethnicity, we tested whether trajectories differed by sex and early-pandemic depressive symptoms, loneliness, and social support. RESULTS: Group-based trajectory models yielded two trajectory groups for binge drinking (none vs. any), marijuana (none/infrequent vs. daily), and recreational drug use (none vs. any). Binge drinking and recreational drug use decreased at the beginning of the pandemic. Generalized linear mixed model supported these trends. Consistent with prior research, male sex and having depressive symptoms early pandemic were positively associated with each substance use outcomes. Social support was inversely associated with recreational drug use. CONCLUSIONS: Contrary to hypotheses, problematic substance use behaviors decreased from pre-pandemic to the post-pandemic follow-up in our sample of PLHIV. Ongoing surveillance is needed to assess whether this pattern persists as the pandemic continues.

Negative Perception of Aging Is Associated With Frailty Transitions Within a Cohort of Sexual Minority Men.

BACKGROUND AND OBJECTIVES: Older people have an increased risk of developing frailty, an age-related clinical syndrome associated with worse health outcomes. This study examined the effect of self-perception of aging (ie, age discrepancy-individuals feel younger/older than their chronological age and aging satisfaction) on frailty transitions. RESEARCH DESIGN AND METHODS: We use longitudinal data from 549 HIV-/499 HIV+ sexual minority men aged 50 years or older enrolled in the Multicenter AIDS Cohort Study. To test the association of self-perception of aging on transitions between states of frailty (nonfrail/frail), defined using Fried Frailty Phenotype, a multinomial modeling was used. RESULTS: With remaining nonfrail as the referent group, participants reporting low aging satisfaction (vs moderate aging satisfaction) had increased odds of transitioning from nonfrail to frail (odds ratio [OR]: 2.72; 95% confidence interval [CI]: 1.56-4.74), frail to nonfrail (OR: 3.40; 95% CI: 1.62-7.12), or remaining frail (frail to frail; OR: 6.64; 95% CI: 3.88-11.38). Participants reporting older subjective age (vs no age discrepancy) had increased odds of transitioning from nonfrail to frail (OR: 2.50; 95% CI: 1.11-5.64), frail to nonfrail (OR: 4.47; 95% CI: 1.85-10.81), or remaining frail (frail to frail; OR: 5.68; 95% CI: 3.06-10.56). High aging satisfaction and younger subjective age were not statistically associated with frailty transitions. DISCUSSION AND IMPLICATIONS: Our findings show that negative self-perception of aging (ie, older subjective age and low aging satisfaction) is associated with frailty transitions (nonfrail to frail, frail to nonfrail, and frail to frail) when compared to remaining nonfrail.

Characterizing Experiences of Conversion Therapy Among Middle-Aged and Older Men Who Have Sex with Men from the Multicenter AIDS Cohort Study (MACS).

Conversion therapies are practices that attempt to change an individuals' same-sex attractions through psychotherapeutic and aversive therapeutic techniques. Conversion therapies were developed based on homophobic beliefs that same-sex attractions are a mental illness. We sought to describe the prevalence and characteristics of conversion therapy experienced among middle-aged and older men who have sex with men in the United States. Given associations of homophobic stigma and HIV risk, we hypothesized that HIV-positive men would report higher odds of conversion therapy compared to HIV-negative men. We analyzed data from 1,237 middle-aged and older MSM enrolled in the Multicenter AIDS Cohort Study. Among participants, 17.7% reported lifetime conversion therapy, of which the average start of therapy age was 22.67 (sd = 10.56) years, 25.8% reported therapy durations of 6+ months, 37.7% reported session frequencies 1+ session per week, and 35.9% indicated that undergoing therapy was either a little or not at all their decision. We observed no statistically significant association between reporting lifetime conversion therapy and HIV status. Future efforts should continue to assess the magnitude of harm conversion therapies impose on MSM's health across the life course as well as test potential, indirect associations that may link these practices to HIV.

Marijuana use and pneumonia risk in a cohort of HIV-infected and HIV-uninfected men.

BACKGROUND: The prevalence of marijuana use is increasing in the United States. Marijuana smoking has been shown to impair the microbicidal activity of alveolar macrophages and decrease the number of ciliated epithelial cells in the bronchi with a parallel increase in the number of mucus-secreting surface epithelial cells, which may increase the risk of pneumonia. However, it remains unclear whether there is an association between smoking marijuana and pneumonia. METHODS: Using data from the Multicenter AIDS Cohort Study (MACS), a long-term observational cohort study of men who have sex with men in the United States, we used Cox proportional hazards models to estimate the risk of pneumonia among HIV-infected (n = 2784) and HIV-uninfected (n = 2665) men from 1984 to 2013, adjusted for time-varying and fixed baseline covariates. RESULTS: Weekly or daily marijuana use was not significantly associated with increased risk of pneumonia among HIV-uninfected men (adjusted hazard ratio; 95% confidence limits: 0.83, 0.56-1.23). In the disaggregated dose-response analysis, daily use (0.68, 0.34-1.35) was associated with a lower point estimate than weekly use [0.99, 0.79-1.25]. CONCLUSION: Marijuana smoking was not associated with a significant increase in risk of pneumonia among HIV-infected or HIV-uninfected men.

Lifetime Exposure to Conversion Therapy and Psychosocial Health Among Midlife and Older Adult Men Who Have Sex With Men.

BACKGROUND AND OBJECTIVES: Conversion therapies to minimize same-sex attractions are classified as a dangerous practice by numerous scientific institutions in the United States. These practices may contribute to poor long-term psychosocial health, thereby interrupting processes of healthy aging. Few studies have examined psychosocial differences between persons with and without prior experiences of conversion therapy. We assessed associations between prior conversion therapy experiences and psychosocial health among midlife and older men who have sex with men (MSM; age 40+ years). RESEARCH DESIGN AND METHODS: Participants included a multicity sample of MSM (N = 1,156) enrolled in the Multicenter AIDS Cohort Study who completed health surveys (2016-2019) as part of their biannual study visits. Using multivariable regressions, we investigated the associations of prior conversion therapy with current depressive symptoms, internalized homophobia, post-traumatic stress, and cumulative psychosocial conditions. Using a trait-level measure (e.g., life purpose and perseverance), we tested whether resilience moderated these associations. RESULTS: The full sample was predominantly non-Hispanic white with a mean age of 62.6 years. Fifteen percent of men (n = 171/1,156) reported prior conversion therapy. In multivariable models, men exposed to conversion therapy were more likely to have depressive symptoms and above-average internalized homophobia. Men exposed to conversion therapy had 2-2.5 times the odds of reporting 1 and ≥2 psychosocial conditions, respectively, compared with those who reported 0 conditions. Resilience did not moderate these associations. DISCUSSION AND IMPLICATIONS: Conversion therapies are nonaffirming social stressors for MSM and may compromise critical psychosocial aspects of healthy aging among MSM.

Psychosocial Correlates of HIV Testing Frequency Among Men Who Have Sex with Men in Guangzhou, China.

We examined sociodemographic and psychosocial factors associated with HIV testing patterns in the past 2 years among 492 HIV-negative men who have sex men (MSM) at an HIV testing center in Guangzhou, China. MSM who tested for HIV frequently were more likely to be older, reside in Guangzhou, and have higher monthly income. Compared with MSM who tested frequently, MSM who never tested were less likely to report that their sexual partner(s) had ever received HIV tests or that their good friends had ever received HIV tests, and were less likely to report having an HIV-positive gay friend or ever discussing HIV with sexual partners; they were more likely to report perceiving barriers to HIV testing. Compared with MSM who tested frequently, those who tested irregularly were less likely to report having HIV-positive gay friends or to disclose their sexual orientation to non-gay friends; reported greater barriers to HIV testing; and higher internalized homophobia.

Characterizing the HIV Care Continuum and Identifying Barriers and Facilitators to HIV Diagnosis and Viral Suppression Among Black Transgender Women in the United States.

BACKGROUND: Although black transgender women (BTW) experience high prevalence of HIV in the United States, no characterization of the HIV care continuum exists for this population. This study addresses this gap by (1) characterizing the HIV care continuum, and (2) exploring correlates of HIV diagnosis and viral suppression among a community-based sample of BTW. METHODS: Data came from Promoting Our Worth, Equality, and Resilience (POWER). From 2014 to 2017, POWER recruited BTW who attended Black Pride events in 6 U.S. cities. Participants completed a behavioral health survey and were offered onsite HIV testing. Simple frequencies were used to characterize the HIV care continuum, and multivariable logistic regression analysis was used to identify correlates of HIV diagnosis and viral suppression. RESULTS: A total of 422 BTW provided completed data for our analysis, 45.0% of whom were living with HIV. Over half of the HIV-positive BTW (51.4%) reported being undiagnosed at the time of survey, and 24.5% reported viral suppression. Incarceration and a lack of access to medical care were significantly and positively associated with an undiagnosed HIV-positive status in multivariable models. Incarceration, homelessness, polydrug use, physical assault, intimate partner violence, and current hormone use were significantly and negatively associated with viral suppression in multivariable models. CONCLUSIONS: Developing and implementing interventions that address timely HIV diagnosis may assist in informing the HIV disparity among BTW in the United States. Interventions should address the fundamental causes of poor health in this population.

Associations of osteoprotegerin with coronary artery calcification among women with systemic lupus erythematosus and healthy controls.

Objective We tested the hypothesis that higher circulating levels of osteoprotegerin (OPG) are related to higher levels of coronary artery calcification (CAC) among women with systemic lupus erythematosus (SLE) compared with healthy controls (HCs). Methods Among 611 women in two age- and race-matched SLE case-control studies, OPG was assayed in stored blood samples (HEARTS: plasma, n cases/controls = 122/124, and SOLVABLE: serum, n cases/controls = 185/180) and CAC was measured by electron beam computed tomography. Results In both studies, SLE patients had higher OPG and CAC levels than HCs. Higher OPG was associated with high CAC (>100 vs.100) among SLE, and with any CAC (>0 vs. 0) among HCs. Multivariable-adjusted OR (95% CI) for OPG tertile 3 vs. 1 was 3.58 (1.19, 10.76), p trend = 0.01 for SLE, and 2.28 (1.06, 4.89), p trend = 0.04 for HCs. Associations were attenuated when age-adjusted, but remained significant for HC women aged ≥ 40 and SLE women aged ≥ 50. ROC analyses identified 4.60 pmol/l as the optimal OPG cutpoint for predicting high CAC (>100) among SLE patients with sensitivity = 0.74 and specificity = 0.61, overall, but 0.92 and 0.52, respectively, for SLE patients aged ≥ 50. Conclusion Our cross-sectional results suggest that higher OPG levels are related to higher CAC levels among women with SLE vs. healthy controls.

Psycho-social Correlates of Condom Use and HIV Testing among MSM Refugees in Beirut, Lebanon.

MSM refugees have to deal with personal challenges and social/structural adversaries based on their refugee status on top of their sexual identity. To better customize interventions beside this population, we explored psycho-social and structural correlates of condom use and HIV testing in Lebanon by surveying and testing 150 participants. 67 % self-identified as gay. 84.6 % reported any unprotected anal intercourse (UAI) with men in the prior 3 months. Those who engaged in UAI, were lest comfortable with a doctor, didn't know where to get free HIV testing, experienced discrimination based on their refugee status and spent more time with their refugee peers, were less inclined to have seen a doctor in the past 12 month or knew where to get free HIV testing. Ever having been HIV tested was associated with being comfortable with medical doctors, knowing where to get HIV testing and spending time with other peer refugees. HIV prevention and testing promotion efforts targeting MSM refugees need to account for structural barriers, while fighting discrimination is crucial for a healthy sexual identity development.

HIV Pre-exposure Prophylaxis Indication and Readiness Among HIV-Uninfected Transgender Women in Ho Chi Minh City, Vietnam.

Few studies have considered acceptability of HIV pre-exposure prophylaxis (PrEP) among transgender women in Southeast Asia. We assessed PrEP indications and readiness among a sample of HIV-uninfected transgender women in Ho Chi Minh City, Vietnam. Of 168 HIV-uninfected transgender women, 72.6 % met criteria for PrEP based on United States CDC guidelines. PrEP indication was inversely associated with PrEP interest (76.0 % interested among those for whom PrEP was indicated; 89.1 % among those for whom it was not; aOR 0.16, 95 % CI 0.04-0.67, P = 0.01). PrEP readiness, defined as having heard of, being interested in taking, and believing that PrEP is efficacious, was low (7.7 %). The results of this study indicate potential need for PrEP among transgender women in Ho Chi Minh City, but very low awareness of PrEP in the community. Future PrEP implementation programs should include counseling on HIV risk and eligibility for PrEP to ensure that PrEP is available to those who may benefit the most from it.

HIV and Syphilis Prevalence Among Transgender Women in Ho Chi Minh City, Vietnam.

Globally, transgender women have higher risk for HIV than the general population and men who have sex with men, but there is little data on this population in Vietnam. In 2015 we conducted a biological and behavioral survey of 205 transgender women in Ho Chi Minh City, Vietnam. Factors associated with HIV and syphilis infection were assessed through multivariable logistic regression models. Median age was 25 years (range 18-64). Overall prevalence was 18.0 % for HIV and 17.6 % for syphilis. Factors independently associated with HIV infection included risky alcohol use [adjusted Odds Ratio (aOR) 3.55, 95 % confidence interval (CI) 1.53-8.21], amphetamine stimulant use (aOR 2.90, 95 % CI 1.27-6.61), sex with male sex workers (aOR 4.73, 95 % CI 1.72-13.0), and history of sex with an adult before the age of 18 years (aOR 2.97, 95 % CI 1.06-8.34). Two factors associated with syphilis infection were HIV infection (aOR 2.37, 95 % CI 1.03-5.45) and condomless anal sex with casual partners (aOR 2.27, 95 % CI 1.03-5.00). In order to address the HIV and syphilis epidemics in Vietnamese transgender women, interventions are needed to make HIV and sexually transmitted infection screening and treatment more accessible.

Particle numbers of lipoprotein subclasses and arterial stiffness among middle-aged men from the ERA JUMP study.

We examined the association between serum lipoprotein subclasses and the three measures of arterial stiffness, that is, (i) carotid-femoral pulse wave velocity (cfPWV), which is a gold standard measure of central arterial stiffness, (ii) brachial-ankle PWV (baPWV), which is emerging as a combined measure of central and peripheral arterial stiffness and (iii) femoral-ankle PWV (faPWV), which is a measure of peripheral arterial stiffness. Among a population-based sample of 701 apparently healthy Caucasian, Japanese American and Korean men aged 40-49 years, concentrations of lipoprotein particles were assessed by nuclear magnetic resonance (NMR) spectroscopy, and the PWV was assessed with an automated waveform analyzer (VP2000, Omron, Japan). Multiple linear regressions were performed to analyse the association between each NMR lipoprotein subclasses and PWV measures, after adjusting for cardiovascular risk factors and other confounders. A cutoff of P<0.01 was used for determining significance. All PWV measures had significant correlations with total and small low-density lipoprotein particle number (LDL-P) (all P<0.0001) but not LDL cholesterol (LDL-C) (all P>0.1), independent of race and age. In multivariate regression analysis, no NMR lipoprotein subclass was significantly associated with cfPWV (all P>0.01). However, most NMR lipoprotein subclasses had significant associations with both baPWV and faPWV (P<0.01). In this study of healthy middle-aged men, as compared with cfPWV, both baPWV and faPWV had stronger associations with particle numbers of lipoprotein subclasses. Our results may suggest that both baPWV and faPWV are related to arterial stiffness and atherosclerosis, whereas cfPWV may represent arterial stiffness alone.

Modified Oblique Keller Capsular Interposition Arthroplasty for Hallux Rigidus.

INTRODUCTION: This paper describes the modified oblique Keller capsular interposition arthroplasty, which may be indicated for patients with late-stage hallux rigidus who wish to retain joint motion. STEP 1 EXPOSURE: Make dorsal medial longitudinal incision over MTP joint and retract dorsal cutaneous nerve of great toe laterally. STEP 2 MOBILIZE EXTENSOR HALLUCIS LONGUS TENDON: Separate extensor hallucis longus from dorsal aspect of capsule and extensor hallucis brevis and retract laterally. STEP 3 MOBILIZE DORSAL ASPECT OF CAPSULE AND EXTENSOR HALLUCIS BREVIS TENDON: Leave inferior half of medial aspect of capsule attached to first metatarsal head to prevent late hallux valgus drift; make the capsular flap as long as possible. STEP 4 PERFORM DORSAL CHEILECTOMY AND RESECT PORTION OF BASE OF PROXIMAL PHALANX TO DECOMPRESS JOINT: The greater the preoperative stiffness, the more bone needs to be removed from the phalanx base. STEP 5 INTERPOSE CAPSULE AND SUTURE CAPSULE TO MTP PLANTAR PLATE: Advance the dorsal aspect of the capsule over the metatarsal head and suture it into the plantar plate with absorbable suture in an interrupted fashion. STEP 6 IMBRICATE MEDIAL ASPECT OF CAPSULE: Imbricate the medial aspect of the capsule with absorbable suture to hold the toe in a corrected position. STEP 7 CLOSE WOUND AND APPLY SUPPORTIVE DRESSING: Perform layered closure and apply forefoot compression dressing. STEP 8 POSTOPERATIVE CARE: Patient performs active range-of-motion exercises of great-toe MTP and IP joints, intrinsic muscle strengthening, and scar massage. RESULTS: We compared a cohort of patients who had the modified oblique Keller capsular interposition arthroplasty (MOKCIA) with a group who had an arthrodesis of the first MTP joint. WHAT TO WATCH FOR: IndicationsContraindicationsPitfalls & Challenges.

The modified oblique keller capsular interpositional arthroplasty for hallux rigidus.

BACKGROUND: Hallux rigidus is a common problem characterized by localized osteoarthritis and limited range of motion of the hallux. First metatarsophalangeal joint arthrodesis has been the accepted procedure for the treatment of late-stage disease. Despite the success of arthrodesis, some patients object to the notion of eliminating motion at the metatarsophalangeal joint. For this reason, motion-sparing procedures such as the modified oblique Keller capsular interpositional arthroplasty have been developed. METHODS: We compared a cohort of ten patients (ten toes) who had undergone the modified Keller arthroplasty with a group of twelve patients (twelve toes) who had undergone a first metatarsophalangeal joint arthrodesis at an average of sixty-three and sixty-eight months, respectively. Clinical outcomes were evaluated, and range of motion, great toe dynamometer strength, plantar pressures, and radiographs were assessed. RESULTS: Clinical outcome differences existed between the groups, with the American Orthopaedic Foot and Ankle Society score being significantly higher for the arthroplasty group than for the arthrodesis group. The arthroplasty group had a mean of 54 degrees of passive and 30 degrees of active range of motion of the first metatarsophalangeal joint. The plantar pressure data revealed significantly higher pressures in the arthrodesis group under the great toe but not under the second metatarsal head. CONCLUSIONS: The modified oblique Keller capsular interpositional arthroplasty appears to be a motion-sparing procedure with clinical outcomes equivalent to those of arthrodesis, and it is associated with a more normal pattern of plantar pressures during walking. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Smoking and mouse MCL healing.

Cigarette smoking has been shown to delay soft tissue healing and complicate musculoskeletal recovery. Its deleterious effects have been proven in bone and soft tissue, although to a much more limited fashion in ligament or tendon. We exposed 120 experimental mice to two cigarettes per day for 2 months and then induced a blunt medial collateral ligament (MCL) injury. Mice were assigned to three groups: the first group exposed to two cigarettes per day after injury, the second group exposed to one cigarette per day after injury, and the third group not exposed after injury. A fourth, no-smoking group served as control. The cut and contralateral intact ligaments were biomechanically tested to failure at 7 and 28 days. The ligaments of mice exposed to cigarette smoke were weaker (p = 0.02) and less stiff (p = 0.0004) at 28 days (3.2 N, 3.5 N/mm) compared with those of mice exposed to cigarette smoke for 7 days (3.9 N, 4.7 N/mm). The ligaments of mice exposed to cigarette smoke were weaker (p = 0.02) and less stiff (p = 0.01) at 28 days compared with control mice at 28 days. Between 7 and 28 days, smoking had a deleterious effect on healing manifested as weaker and less stiff ligaments. However, our findings did not support a dose-dependent effect of cigarette exposure on the tensile mechanical properties of ligaments.

Perils of intravascular methylprednisolone injection into the vertebral artery. An animal study.

BACKGROUND: Intravascular injection of particulate steroids during cervical nerve root blocks has been postulated to be a source of catastrophic neurologic complications that might be avoided with the use of non-particulate steroids. The objective of this study was to compare the effects of direct intravascular injection of particulate and non-particulate steroids on the spinal cord and central nervous system. METHODS: Eleven adult pigs underwent direct injection, under fluoroscopic guidance, into the vertebral artery while under general anesthesia. A particulate steroid (methylprednisolone) was injected into four animals (Group 1), whereas seven animals received a non-particulate steroid (dexamethasone in four animals [Group 2] and prednisolone in three [Group 3]). Following injection, the animals were assessed by direct observation of physical activity and with magnetic resonance imaging. After the animals were killed, brain and spinal cord material was retrieved, fixed in paraformaldehyde for one week, and then subjected to histopathologic analysis. RESULTS: All four animals in Group 1 failed to regain consciousness after the injection and required ventilatory support. The animals in Groups 2 and 3 recovered fully and demonstrated no evidence of neurologic injury. Magnetic resonance imaging revealed upper cervical cord and brain stem edema in Group 1, but not in Groups 2 and 3. Histologic analysis showed early evidence of hypoxic and ischemic damage-specifically, early eosinophilic neuronal necrosis, nuclear condensation, white-matter pallor, and extracellular edema-in Group 1 but not in Groups 2 and 3. CONCLUSIONS: These data suggest that one etiology of neurologic complications following cervical nerve blocks may be inadvertent intravascular injection of particulate steroids, as all animals injected with methylprednisolone had neurologic deficits while none of the controls injected with non-particulate steroids were affected. To our knowledge, this study is the first to demonstrate that particulate steroids cause neurologic deficits and to suggest that use of non-particulate steroids might prevent such complications.

Evaluation of zebrafish Danio rerio as a model for enteric septicemia of catfish (ESC).

Zebrafish (also known as zebra danio) Danio rerio were injected intramuscularly with Edwardsiella ictaluri at doses of 6 x 10(3), 6 x 10(4), or 6 x 10(5) colony-forming units per gram (CFU/g) or sterile phosphate-buffered saline (sham) or were not injected. Mortality occurred from 2 to 5 d postinjection (dpi) at rates of 0, 76.6, and 81.3% for the low, medium, and high doses, respectively, and E. ictaluri was isolated from dead fish. Survivors were sampled at 10 dpi and E. ictaluri was not isolated. Sham-injected and noninjected controls did not suffer mortality. Histopathology trials were performed in which zebrafish were injected with 1 x 10(4) CFU/g or sham-injected and sampled at 12, 24, 48, 72, and 96 h postinjection for histological interpretation. Collectively, these zebrafish demonstrated increasing severity of splenic, hepatic, cardiac, and renal interstitial necrosis over time. To evaluate the progression of chronic infection, zebrafish were injected with 1 x 10(2) CFU/g and held for 1 month postinjection. Beginning at 12 dpi and continuing for an additional 2 weeks, zebrafish demonstrated abnormal spiraling and circling swimming behaviors. Histopathology demonstrated necrotizing encephalitis. In immersion trials, zebrafish were exposed to low, medium, and high doses (averaging 1.16 x 10(5), 1.16 x 10(6), and 1.16 x 10(7) CFU/mL of tank water) of E. ictaluri for 2 h. Mortality occurred from 5 to 9 d postexposure at rates of 0, 3.3, and 13.3% for the low, medium, and high doses, respectively; E. ictaluri was isolated from dead fish. Channel catfish Ictalurus punctatus exposed to the medium doses suffered 100% mortality, and E. ictaluri was isolated from these fish. This study demonstrates the potential use of zebrafish as a model for E. ictaluri pathogenesis.