New avenues for residual stress analysis in ultrathin atomic layer deposited free-standing membranes through release of micro-cantilevers

The fabrication of thinnest, yet undeformed membrane structures with nanometer resolution is a prerequisite for a variety of Microelectromechanical systems (MEMS). However, functionally relevant thin films are susceptible to growth-generated stress. To tune the performance and reach large aspect ratios, knowledge of the intrinsic material properties is indispensable. Here, we present a new method for stress evaluation through releasing defined micro-cantilever segments by focused ion beam (FIB) milling from a predefined free-standing membrane structure. Thereby, the cantilever segment is allowed to equilibrate to a stress-released state through measurable strain in the form of a resulting radius of curvature. This radius can be back-calculated to the residual stress state. The method was tested on a 20 nm and 50 nm thick tunnel-like ALD Image 1 membrane structure, revealing a significant amount of residual stress with 866 MPa and 6104 MPa, respectively. Complementary finite element analysis to estimate the stress distribution in the structure showed a 97% and 90% agreement in out-of-plane deflection for the 20 nm and 50 nm membranes, respectively. This work reveals the possibilities of releasing entire membrane segments from thin film membranes with a significant amount of residual stress and to use the resulting bending behavior for evaluating stress and strain by measuring their deformation.

The importance of triple panel testing for hepatitis B and the burden of isolated anti-hepatitis B core antibodies within a community sample

Within the United States (US), 2.4 million individuals are living with chronic hepatitis B, but less than 20% are diagnosed. Isolated anti-hepatitis B core (iAHBc) antibodies indicate serology in an individual that is positive for anti-HBc antibodies, while negative for surface antigen (HBsAg) and surface antibodies (anti-HBs). A result of iAHBc could indicate a chronic occult bloodstream infection, necessitating further testing. This study assesses the prevalence and risk factors associated with anti-HBc and iAHBc within community high-risk screening in Greater Philadelphia. Participants (n = 177) were screened for HBsAg, anti-HBs, and anti-HBc during community screening events in 2022. Chi-square tables and Firth logistic regression were used to describe the data and to assess the odds of iAHBc. The findings indicate that there was an iAHBc prevalence of 7.3% (n = 13) within our study. The odds of anti-HBc were increased for immigrants from the Western Pacific (4.5%) and Africa (11.9%). Individuals born in Africa had 7.93 greater odds for iAHBc than those born in the Americas, and these odds are multiplied by 1.01 for every 1-year increase in age. Our data show a high burden of iAHBc within high-risk and often hard-to-reach communities. Triple panel screening should be incorporated into all HBV screening programs, in accordance with current Centers for Disease Control and Prevention (CDC) universal screening recommendations, to ensure a comprehensive picture of the disease burden and reduce the risk of missing people with occult hepatitis B and those at risk for viral reactivation or liver complications.

Performance of an automated deep learning algorithm to identify hepatic steatosis within noncontrast computed tomography scans among people with and without HIV

PURPOSE

Hepatic steatosis (fatty liver disease) affects 25% of the world's population, particularly people with HIV (PWH). Pharmacoepidemiologic studies to identify medications associated with steatosis have not been conducted because methods to evaluate liver fat within digitized images have not been developed. We determined the accuracy of a deep learning algorithm (automatic liver attenuation region-of-interest-based measurement [ALARM]) to identify steatosis within clinically obtained noncontrast abdominal CT images compared to manual radiologist review and evaluated its performance by HIV status.

METHODS

We performed a cross-sectional study to evaluate the performance of ALARM within noncontrast abdominal CT images from a sample of patients with and without HIV in the US Veterans Health Administration. We evaluated the ability of ALARM to identify moderate-to-severe hepatic steatosis, defined by mean absolute liver attenuation <40 Hounsfield units (HU), compared to manual radiologist assessment.

RESULTS

Among 120 patients (51 PWH) who underwent noncontrast abdominal CT, moderate-to-severe hepatic steatosis was identified in 15 (12.5%) persons via ALARM and 12 (10%) by radiologist assessment. Percent agreement between ALARM and radiologist assessment of absolute liver attenuation <40 HU was 95.8%. Sensitivity, specificity, positive predictive value, and negative predictive value of ALARM were 91.7% (95%CI, 51.5%-99.8%), 96.3% (95%CI, 90.8%-99.0%), 73.3% (95%CI, 44.9%-92.2%), and 99.0% (95%CI, 94.8%-100%), respectively. No differences in performance were observed by HIV status.

CONCLUSIONS

ALARM demonstrated excellent accuracy for moderate-to-severe hepatic steatosis regardless of HIV status. Application of ALARM to radiographic repositories could facilitate real-world studies to evaluate medications associated with steatosis and assess differences by HIV status.

Hepatitis B care cascade among people with HIV/HBV coinfection in the North American AIDS Cohort Collaboration on Research and Design, 2012-2016

A care cascade is a critical tool for evaluating delivery of care for chronic infections across sequential stages, starting with diagnosis and ending with viral suppression. However, there have been few data describing the hepatitis B virus (HBV) care cascade among people living with HIV infection who have HBV coinfection. We conducted a cross-sectional study among people living with HIV and HBV coinfection receiving care between January 1, 2012 and December 31, 2016 within 13 United States and Canadian clinical cohorts contributing data to the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). We evaluated each of the steps in this cascade, including: 1) laboratory-confirmed HBV infection, 2) tenofovir-based or entecavir-based HBV therapy prescribed, 3) HBV DNA measured during treatment, and 4) viral suppression achieved via undetectable HBV DNA. Among 3,953 persons with laboratory-confirmed HBV (median age, 50 years; 6.5% female; 43.8% were Black; 7.1% were Hispanic), 3,592 (90.9%; 95% confidence interval, 90.0-91.8%) were prescribed tenofovir-based antiretroviral therapy or entecavir along with their antiretroviral therapy regimen, 2,281 (57.7%; 95% confidence interval, 56.2-59.2%) had HBV DNA measured while on therapy, and 1,624 (41.1%; 95% confidence interval, 39.5-42.6) achieved an undetectable HBV DNA during HBV treatment. Our study identified significant gaps in measurement of HBV DNA and suppression of HBV viremia among people living with HIV and HBV coinfection in the United States and Canada. Periodic evaluation of the HBV care cascade among persons with HIV/HBV will be critical to monitoring success in completion of each step.

1774. Impact of Dalbavancin as Step-Down or Salvage Therapy on Duration of Hospitalization Among People Who Inject Drugs

Background

A well-known clinical dilemma complicating the management of infections in people who inject drugs (PWID) is the restriction of outpatient parenteral antimicrobial therapy. As a result, PWID experience prolonged hospitalizations to complete parenteral antimicrobial courses inpatient. This strategy is also associated with increased rates of patient-directed discharge (PDD). Dalbavancin, a long-acting lipoglycopeptide, serves two unique roles in this population: step-down therapy to decrease inpatient length of stay once clinically stable and salvage therapy in the setting of imminent PDD.

Methods

This retrospective review of PWID from November 2019 through October 2021 identified patients in which on- or off-label dalbavancin could be considered. Day of hypothetical dalbavancin administration was determined when both ≥7 days of therapy and ≥48 hours of clinical stability (non-critical unit, afebrile, resolved leukocytosis, and source control or negative blood cultures) were completed. Included patients had ≥7 days of therapy remaining at time of hypothetical dalbavancin administration. A one-time dalbavancin dose was considered to provide up to 14 days of antimicrobial coverage. Patients were included in either the step-down cohort (completed entire parenteral antimicrobial course inpatient) or salvage therapy cohort (PDD prior to completing course). The number of potentially preventable inpatient days with dalbavancin and readmissions due to infection progression were assessed in each cohort, respectively.

Results

Nineteen patients were identified as potential dalbavancin candidates. In the step-down cohort (n=11) a one-time dalbavancin dose prevented a maximum of 146 inpatient days. In the salvage cohort (n=8), hypothetical dalbavancin administration at time of PDD could have prevented six readmissions due to infection progression, associated with 36 additional inpatient days.

Conclusion

Inpatient administration of dalbavancin may bridge treatment disparities experienced by PWID by reducing unnecessary inpatient days for parenteral antibiotic administration and by preventing hospital readmissions attributable to inadequate antimicrobial course.

Disclosures

All Authors: No reported disclosures.

The Hepatitis C Care Cascade During the Direct-Acting Antiviral Era in a United States Commercially-Insured Population

Background

Periodic surveillance of the hepatitis C virus (HCV) care cascade is important for tracking progress toward HCV elimination goals, identifying gaps in care, and prioritizing resource allocation. In the pre-direct-acting antiviral (DAA) era, it was estimated that 50% of HCV-infected individuals were diagnosed and that 16% had been prescribed interferon-based therapy. Since then, few studies utilizing nationally representative data from the DAA era have been conducted in the United States.

Methods

We performed a cross-sectional study to describe the HCV care cascade in the United States using the Optum de-identified Clinformatics® Data Mart Database to identify a nationally representative sample of commercially insured beneficiaries between January 1, 2014 and December 31, 2019. We estimated the number of HCV-viremic individuals in Optum based on national HCV prevalence estimates and determined the proportion who had: (1) recorded diagnosis of HCV infection, (2) recorded HCV diagnosis and underwent HCV RNA testing, (3) DAA treatment dispensed, and (4) assessment for cure.

Results

Among 120,311 individuals estimated to have HCV viremia in Optum during the study period, 109,233 (90.8%; 95% CI, 90.6%–91.0%) had a recorded diagnosis of HCV infection, 75,549 (62.8%; 95% CI, 62.5%–63.1%) had a recorded diagnosis of HCV infection and underwent HCV RNA testing, 41,102 (34.2%; 95% CI, 33.9%–34.4%) were dispensed DAA treatment, and 25,760 (21.4%; 95% CI, 21.2%–21.6%) were assessed for cure.

Conclusions

Gaps remain between the delivery of HCV-related care and national treatment goals among commercially insured adults. Efforts are needed to increase HCV treatment among people diagnosed with chronic HCV infection to achieve national elimination goals.

Clinic screening for adverse childhood experiences in people living with HIV to Improve Care Delivery

Adverse childhood experiences (ACEs) are associated with negative health outcomes; however, screening for ACEs is not routinely performed among people living with HIV (PLWH). We conducted a single-center, cross-sectional pilot study to define the (1) prevalence of ACEs in PLWH and (2) acceptability of ACEs screening in routine out-patient clinical care. One hundred participants completed screening: median age of participants was 49 years (interquartile range: 38.5-59.5), 73% male, 66% Non-Hispanic Black/African American, and 47% gay/lesbian. Clinically significant ACEs score, defined as ≥4, was reported in 51%. High ACEs score was more common among participants <50 years old (64.7% vs. 36.7%; p < 0.01), but the prevalence of ACEs ≥4 did not differ by gender, race, ethnicity, or sexual orientation. Among participants with ≥4 ACEs, 44.4% screened negative on both PHQ-9 and PC-PTSD screens. The majority of participants (89%) reported a positive experience with ACEs screening. The prevalence of clinically significant ACEs in this clinic population of PLWH was more than twice that reported in the general population. Routine ACEs screening can improve delivery of trauma-informed care in the HIV primary care setting.

Effect of a Default Order vs an Alert in the Electronic Health Record on Hepatitis C Virus Screening Among Hospitalized Patients: A Stepped-Wedge Randomized Clinical Trial

IMPORTANCE

Hepatitis C virus (HCV) screening has been recommended for patients born between 1945 and 1965, but rates remain low.

OBJECTIVE

To evaluate whether a default order within the admission order set increases HCV screening compared with a preexisting alert within the electronic health record.

DESIGN, SETTING, AND PARTICIPANTS

This stepped-wedge randomized clinical trial was conducted from June 23, 2020, to April 10, 2021, at 2 hospitals within an academic medical center. Hospitalized patients born between 1945 and 1965 with no history of screening were included in the analysis.

INTERVENTIONS

During wedge 1 (a preintervention period), both hospital sites had an electronic alert prompting clinicians to consider HCV screening. During wedge 2, the first intervention wedge, the hospital site randomized to intervention (hospital B) had a default order for HCV screening implemented within the admission order set. During wedge 3, the second intervention wedge, the hospital site randomized to control (hospital A) had the default order set implemented.

MAIN OUTCOMES AND MEASURES

Percentage of eligible patients who received HCV screening during the hospital stay.

RESULTS

The study included 7634 patients (4405 in the control group and 3229 in the intervention group). The mean (SD) age was 65.4 (5.8) years; 4246 patients (55.6%) were men; 2142 (28.1%) were Black and 4625 (60.6%) were White; and 2885 (37.8%) had commercial insurance and 3950 (51.7%) had Medicare. The baseline rate of HCV screening in wedge 1 was 585 of 1560 patients (37.5% [95% CI, 35.1%-40.0%]) in hospital A and 309 of 1003 patients (30.8% [95% CI, 27.9%-33.7%]) in hospital B. The main adjusted model showed an increase of 31.8 (95% CI, 29.7-33.8) percentage points in test completion in the intervention group compared with the control group (P <. 001).

CONCLUSIONS AND RELEVANCE

This stepped-wedge randomized clinical trial found that embedding HCV screening as a default order in the electronic health record substantially increased ordering and completion of testing in the hospital compared with a conventional interruptive alert.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04525690.

Protease inhibitor-based direct-acting antivirals are associated with increased risk of aminotransferase elevations but not hepatic dysfunction or decompensation

BACKGROUND & AIMS

Cases of acute liver injury (ALI) have been reported among chronic HCV-infected patients receiving protease inhibitor (PI)-based direct-acting antiviral (DAA) regimens, but no analyses have compared the risk of ALI in patients receiving PI- vs. non-PI-based DAAs. Thus, we compared the risk of 3 ALI outcomes between patients (by baseline Fibrosis-4 [FIB-4] group) receiving PI-based or non-PI-based DAAs.

METHODS

We conducted a cohort study of 18,498 patients receiving PI-based DAA therapy (paritaprevir/ritonavir/ombitasvir±dasabuvir, elbasvir/grazoprevir, glecaprevir/pibrentasvir) matched 1:1 on propensity score to those receiving non-PI-based DAAs (sofosbuvir/ledipasvir, sofosbuvir/velpatasvir) in the 1945-1965 Veterans Birth Cohort (2014-2019). During exposure to DAA therapy, we determined development of: i) alanine aminotransferase (ALT) >200 U/L, ii) severe hepatic dysfunction (coagulopathy with hyperbilirubinemia), and iii) hepatic decompensation. We used Cox regression to determine hazard ratios (HRs) with 95% CIs for each ALI outcome within groups defined by baseline FIB-4 (≤3.25; >3.25).

RESULTS

Among patients with baseline FIB-4 ≤3.25, those receiving PIs had a higher risk of ALT >200 U/L (HR 3.98; 95% CI 2.37-6.68), but not severe hepatic dysfunction (HR 0.67; 95% CI 0.19-2.39) or hepatic decompensation (HR 1.01; 95% CI 0.29-3.49), compared to those receiving non-PI-based regimens. For those with baseline FIB-4 >3.25, those receiving PIs had a higher risk of ALT >200 U/L (HR, 2.15; 95% CI 1.09-4.26), but not severe hepatic dysfunction (HR, 1.23 [0.64-2.38]) or hepatic decompensation (HR, 0.87; 95% CI 0.41-1.87), compared to those receiving non-PI-based regimens CONCLUSION: While risk of incident ALT elevations was increased in those receiving PI-based DAAs in both FIB-4 groups, the risk of severe hepatic dysfunction and hepatic decompensation did not differ between patients receiving PI- or non-PI-based DAAs in either FIB-4 group.

LAY SUMMARY

Cases of liver injury have been reported among patients treated with protease inhibitor-based direct-acting antivirals for hepatitis C infection, but it is not clear if the risk of liver injury among people starting these drugs is increased compared to those starting non-protease inhibitor-based therapy. In this study, patients receiving protease inhibitor-based treatment had a higher risk of liver inflammation than those receiving a non-protease inhibitor-based treatment, regardless of the presence of pre-treatment advanced liver fibrosis/cirrhosis. However, the risk of severe liver dysfunction and decompensation were not higher for patients treated with protease inhibitor-based regimens.

Risk of HCC With Hepatitis B Viremia Among HIV/HBV-Coinfected Persons in North America

BACKGROUND AND AIMS

Chronic HBV is the predominant cause of HCC worldwide. Although HBV coinfection is common in HIV, the determinants of HCC in HIV/HBV coinfection are poorly characterized. We examined the predictors of HCC in a multicohort study of individuals coinfected with HIV/HBV.

APPROACH AND RESULTS

We included persons coinfected with HIV/HBV within 22 cohorts of the North American AIDS Cohort Collaboration on Research and Design (1995-2016). First occurrence of HCC was verified by medical record review and/or cancer registry. We used multivariable Cox regression to determine adjusted HRs (aHRs [95% CIs]) of factors assessed at cohort entry (age, sex, race, body mass index), ever during observation (heavy alcohol use, HCV), or time-updated (HIV RNA, CD4+ percentage, diabetes mellitus, HBV DNA). Among 8,354 individuals coinfected with HIV/HBV (median age, 43 years; 93% male; 52.4% non-White), 115 HCC cases were diagnosed over 65,392 person-years (incidence rate, 1.8 [95% CI, 1.5-2.1] events/1,000 person-years). Risk factors for HCC included age 40-49 years (aHR, 1.97 [1.22-3.17]), age ≥50 years (aHR, 2.55 [1.49-4.35]), HCV coinfection (aHR, 1.61 [1.07-2.40]), and heavy alcohol use (aHR, 1.52 [1.04-2.23]), while time-updated HIV RNA >500 copies/mL (aHR, 0.90 [0.56-1.43]) and time-updated CD4+ percentage <14% (aHR, 1.03 [0.56-1.90]) were not. The risk of HCC was increased with time-updated HBV DNA >200 IU/mL (aHR, 2.22 [1.42-3.47]) and was higher with each 1.0 log₁₀ IU/mL increase in time-updated HBV DNA (aHR, 1.18 [1.05-1.34]). HBV suppression with HBV-active antiretroviral therapy (ART) for ≥1 year significantly reduced HCC risk (aHR, 0.42 [0.24-0.73]).

CONCLUSION

Individuals coinfected with HIV/HBV on ART with detectable HBV viremia remain at risk for HCC. To gain maximal benefit from ART for HCC prevention, sustained HBV suppression is necessary.

HIV RNA, CD4+ Percentage, and Risk of Hepatocellular Carcinoma by Cirrhosis Status

BACKGROUND

Despite increasing incidence of hepatocellular carcinoma (HCC) among HIV-infected patients, it remains unclear if HIV-related factors contribute to development of HCC. We examined if higher or prolonged HIV viremia and lower CD4+ cell percentage were associated with HCC.

METHODS

We conducted a cohort study of HIV-infected individuals who had HIV RNA, CD4+, and CD8+ cell counts and percentages assessed in the Veterans Aging Cohort Study (1999-2015). HCC was ascertained using Veterans Health Administration cancer registries and electronic records. Cox regression was used to determine hazard ratios (HR, 95% confidence interval [CI]) of HCC associated with higher current HIV RNA, longer duration of detectable HIV viremia (≥500 copies/mL), and current CD4+ cell percentage less than 14%, adjusting for traditional HCC risk factors. Analyses were stratified by previously validated diagnoses of cirrhosis prior to start of follow-up.

RESULTS

Among 35 659 HIV-infected patients, 302 (0.8%) developed HCC over 281 441 person-years (incidence rate = 107.3 per 100 000 person-years). Among patients without baseline cirrhosis, higher HIV RNA (HR = 1.25, 95% CI = 1.12 to 1.40, per 1.0 log10 copies/mL) and 12 or more months of detectable HIV (HR = 1.47, 95% CI = 1.02 to 2.11) were independently associated with higher risk of HCC. CD4+ percentage less than 14% was not associated with HCC in any model. Hepatitis C coinfection was a statistically significant predictor of HCC regardless of baseline cirrhosis status.

CONCLUSION

Among HIV-infected patients without baseline cirrhosis, higher HIV RNA and longer duration of HIV viremia increased risk of HCC, independent of traditional HCC risk factors. This is the strongest evidence to date that HIV viremia contributes to risk of HCC in this group.

Improving stress corrosion cracking behavior of AZ31 alloy with conformal thin titania and zirconia coatings for biomedical applications

Magnesium and its alloys have been widely studied as materials for temporary implant devices. However, corrosion-assisted cracking phenomena such as stress corrosion cracking (SCC) continue to prevent their mainstream use. For the first time, we explore the SCC susceptibility of Atomic Layer Deposition (ALD) coated AZ31 alloys in Simulated Body Fluid (SBF). Conformal 100 nm coatings of titania and zirconia were deposited on standard dogbone specimens and subjected to slow strain rate tests at 3.5 10^-6 s^-1 and a temperature of 37 °C. Remarkably, the SCC susceptibility index I_UTS was reduced by 6% and 40% and the I_ε was reduced by more than 70% and 76% with a titania and zirconia coating, respectively. Potentiodynamic polarization, hydrogen evolution and fracture behavior of the samples revealed the drastic corrosion reduction to be the main reason for the susceptibility reduction. We discuss the observed SCC behavior of our samples in light of the coatings' electrochemical activities, wettabilities, surface integrities and mechanical properties. This straightforward conformal surface treatment can be useful as a workaround for one of the major bottlenecks of biomedical Mg based implants and hence provides a possible pathway for making them more commonplace in the field.

1268. Clinic Screening for Adverse Childhood Experiences among Persons with HIV: A Pilot Project

Background

Childhood trauma has long-lasting implications for adult health as prior work in the general population linked ≥4 adverse childhood experiences (ACEs) to multiple negative health outcomes in adulthood. History of childhood trauma is prevalent in people living with HIV (PLWH); however, screening for history of childhood trauma is not routinely performed in HIV clinical care.

Methods

We conducted a single-center, cross-sectional quality improvement pilot project to (1) define the prevalence of ACEs in PLWH engaged in care and (2) improve linkage with mental health resources. We hypothesized the prevalence of ≥4 ACEs in PLWH would be >21%, the prevalence previously reported in the local, general population. Patients were approached in the course of routine clinical care at an urban, academic HIV outpatient clinic between October 2018 and April 2019 and offered screening for ACEs, depression, and post-traumatic stress disorder (PTSD) using previously validated tools.

Results

Forty-nine patients completed the screening. Median age was 48 years [IQR: 37–55]; 69% were male and 53% were gay or bisexual. Most patients identified as black/African American (75%) and white (12%). Median ACEs score was 4 [IQR 1–6], with 51% (95% CI: 36–66%) reporting ≥4 ACEs (Figure 1), and most common ACE being guardian substance abuse (57%) (Figure 2). When compared with men, women had a higher median ACEs score (5 vs. 3, P = 0.04), history of childhood sexual abuse (67% vs. 26%, P <0.001), parent incarceration (53% vs. 24%, P = 0.04), and parental divorce or separation (73% vs. 41%, P = 0.04). Patients with ≥4 ACEs were more likely to have positive PTSD screens (56% vs. 21%, P = 0.02), moderate depression or greater (37% vs. 11%, P = 0.002), and were more likely to accept on-site mental health referral after screening (36% vs. 8%, P = 0.04). Acceptability of screening was deemed “very good” by patients, with median acceptability score 5 [IQR: 4–5] on a 5-point scale.

Conclusion

Over half of HIV+ patients screened in our clinic reported ≥4 ACEs, more than twice the prevalence of the general population. ACEs screening facilitated linkage of patients with high ACEs scores to mental healthcare. These results highlight the potential value of routine ACEs screening to enhance delivery of trauma-informed HIV primary care.

Disclosures

All authors: No reported disclosures.

Differences in Pathology, Staging, and Treatment between HIV+ and Uninfected Patients with Microscopically Confirmed Hepatocellular Carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) is substantially higher among HIV-infected (HIV⁺) than uninfected persons. It remains unclear if HCC in the setting of HIV infection is morphologically distinct or more aggressive.

METHODS

We evaluated differences in tumor pathology in a cohort of HIV⁺ and uninfected patients with microscopically confirmed HCC in the Veterans Aging Cohort Study from 2000 to 2015. We reviewed pathology reports and medical records to determine Barcelona Clinic Liver Cancer stage (BCLC), HCC treatment, and survival by HIV status. Multivariable Cox regression was used to determine the hazard ratio [HR; 95% confidence interval (CI)] of death associated with HIV infection after microscopic confirmation.

RESULTS

Among 873 patients with HCC (399 HIV⁺), 140 HIV⁺ and 178 uninfected persons underwent liver tissue sampling and had microscopically confirmed HCC. There were no differences in histologic features of the tumor between HIV⁺ and uninfected patients, including tumor differentiation (well differentiated, 19% vs. 28%, P = 0.16) and lymphovascular invasion (6% vs. 7%, P = 0.17) or presence of advanced hepatic fibrosis (40% vs. 39%, P = 0.90). There were no differences in BCLC stage (P = 0.06) or treatment (P = 0.29) by HIV status. After adjustment for risk factors, risk of death was higher among HIV-infected than uninfected patients (HR = 1.37; 95% CI, 1.02-1.85).

CONCLUSIONS

We found no differences in HCC tumor characteristics or background hepatic parenchyma by HIV status, yet HIV was associated with poorer survival. Of note, pathology reports often omitted these characteristics.

IMPACT

Systematic evaluation of HCC pathology by HIV status is needed to understand tumor characteristics associated with improved survival.

Enhancement of stress corrosion cracking of AZ31 magnesium alloy in simulated body fluid thanks to cryogenic machining

Magnesium and its alloys have recently attracted great attention as potential materials for the manufacture of biodegradable implants. Unfortunately, their inadequate resistance to the simultaneous action of corrosion and mechanical stresses in the human body have hampered their use as implant materials. This work aims at evaluating the Stress Corrosion Cracking (SCC) susceptibility of the AZ31 Mg alloy after being machined under cryogenic cooling. The SCC behaviour was evaluated by means of Slow Strain Rate Tests (SSRTs) in Simulated Body Fluid (SBF) at 37 °C. Prior to testing, a full characterization of the machined surface integrity, including microstructural observations, residual stress, nano-hardness measurements and surface texture analysis was carried out together with the assessment of the corrosion properties through potentiodynamic polarization curves. In addition, the morphology of the fracture surfaces after SSRTs was analysed by means of 3D optical profiler and Scanning Electron Microscopy (SEM). The improved corrosion resistance due to the increased extension of the nano-surface layer and to the compressive residual stresses represents the reason of the reduced SCC susceptibility of cryogenically machined AZ31 samples as compared to dry machined ones.

Impact of Efavirenz Metabolism on Loss to Care in Older HIV+ Africans

BACKGROUND AND OBJECTIVE: Efavirenz is commonly used in Africa and is frequently associated with neurocognitive toxicity, which may compromise clinical outcomes. Older individuals are at increased risk for drug toxicity and clinical outcomes may be worse in older age, particularly among those individuals with cytochrome P450 (CYP) 2B6 polymorphisms associated with slower efavirenz metabolism. The aim of this study was to determine if the CYP2B6 polymorphisms differentially impacts loss to care in older people.

METHODS

We conducted a prospective cohort study of 914 treatment-naïve HIV+ adults initiating efavirenz-based antiretroviral treatment at public HIV clinics in Gaborone, Botswana between 2009 and 2013. Older age, defined as age ≥ 50 years, was the primary exposure and loss to care at 6 months was the primary outcome. Interaction between age and CYP2B6 516G>T and 983T>C polymorphisms, defined as extensive, intermediate, and slow metabolism, was assessed. Neurocognitive toxicity was measured using a symptom questionnaire. Age-stratified logistic regression was performed to identify factors associated with loss to care.

RESULTS

Older age was associated with loss to care (OR 1.95, 95% CI 1.30-2.92). Age modified the effect of CYP2B6 genotype on loss to care with older, slow metabolizers at over four-fold higher risk when compared to older, intermediate metabolizers (OR 4.06 95% CI 1.38-11.89); neurocognitive toxicity did not mediate this risk. CYP2B6 metabolism genotype did not increase risk of loss to care in younger participants.

CONCLUSION

Older age was associated with loss to care, especially among those with slow efavirenz metabolism. Understanding the relationship between older age and CYP2B6 genotype will be important to improving outcomes in an aging population initiating efavirenz-based ART in similar settings.

Comparison of the prevalence, severity, and risk factors for hepatic steatosis in HIV-infected and uninfected people

Background

Hepatic steatosis is prevalent in Western countries, but few studies have evaluated whether the frequency and severity of steatosis are greater in the setting of HIV infection. We compared the prevalence and severity of hepatic steatosis between HIV-infected (HIV+) and uninfected persons and identified factors associated with greater steatosis severity within both groups.

Methods

We performed a cross-sectional study among participants without cardiovascular disease who participated in a substudy of the Veterans Aging Cohort Study. Hepatic steatosis was defined by noncontrast computed tomography (CT) liver-to-spleen (L/S) attenuation ratio < 1.0. Multivariable linear regression was used to: 1) evaluate the association between HIV infection and severity of hepatic steatosis, as measured by absolute liver attenuation, and 2) identify factors associated with greater severity of steatosis, by HIV status.

Results

Among 268 participants (median age, 55 years; 99% male; 79% black; 23% obese; 64% HIV+ [91% on antiretroviral therapy]), the overall prevalence of steatosis was 7.8% and was similar between HIV+ and uninfected individuals (13 [7.6%] versus 8 [8.2%], respectively; p = 0.85). Participants with HIV, the majority of whom received antiretroviral therapy, had a higher mean absolute liver attenuation (mean difference, 5.68 Hounsfield units; p < 0.001), correlating with lesser hepatic steatosis severity, compared to uninfected participants. After adjusting for covariates, only advanced hepatic fibrosis was associated with greater severity of steatosis in HIV+ persons (p = 0.03) and uninfected individuals (p < 0.001).

Conclusions

In this sample of participants without cardiovascular disease, the prevalence of hepatic steatosis by noncontrast abdominal CT was not different by HIV status. Increasing severity of steatosis was independently associated with advanced hepatic fibrosis in both groups.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0969-1) contains supplementary material, which is available to authorized users.

Cognitive dysfunction and health-related quality of life after a cardiac arrest and therapeutic hypothermia

BACKGROUND

Evidence-based treatment protocols including therapeutic hypothermia have increased hospital survival to over 50% in unconscious out-of-hospital cardiac arrest survivors. In this study we estimated the incidence of cognitive dysfunctions in a group of cardiac arrest survivors with a high functional outcome treated with therapeutic hypothermia. Secondarily, we assessed the cardiac arrest group's level of cognitive performance in each tested cognitive domain and investigated the relationship between cognitive function and age, time since cardiac arrest and health-related quality of life (HRQOL).

METHODS

We included 26 patients 13-28 months after a cardiac arrest. All patients were scored using the Cerebral Performance Category scale (CPC) and Mini-Mental State Examination (MMSE). Twenty-five of the patients were tested for cognitive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB). These patients were tested using four cognitive tests: Motor Screening Test, Delayed Matching to Sample, Stockings of Cambridge and Paired Associate Learning from CANTAB. All patients filled in the Short Form-36 for the assessment of HRQOL.

RESULTS

Thirteen of 25 (52%) patients were classified as having a cognitive dysfunction. Compared with the reference population, there was no difference in the performance in motor function and delayed memory but there were significant differences in executive function and episodic memory. We found no associations between cognitive function and age, time since cardiac arrest or HRQOL.

CONCLUSION

Half of the patients had a cognitive dysfunction with reduced performance on executive function and episodic memory, indicating frontal and temporal lobe affection, respectively. Reduced performance did not affect HRQOL.

Molecular epidemiology of pleural and other extrapulmonary tuberculosis: a Maryland state review

BACKGROUND

Limited information exists about the current epidemiological characteristics of extrapulmonary tuberculosis. However, pleural tuberculosis is usually considered to be a manifestation of primary tuberculosis. Our objective was to use molecular epidemiological techniques to describe the occurrence of pleural and other extrapulmonary tuberculosis in Maryland, a state with moderate tuberculosis incidence.

METHODS

We surveyed tuberculosis cases reported with a single site of disease in Maryland from 1996 through 2001. Genotyping of Mycobacterium tuberculosis isolates was performed with an IS6110-based restriction fragment-length polymorphism analysis. DNA clustering of strains with >5 IS6110 bands, with supporting epidemiologic information on patients, served as a proxy for recent transmission.

RESULTS

A total of 1811 patients with tuberculosis were reported (incidence, 5.9 cases per 100,000 population). Of 1411 patients (77.9%) with cultures positive for M. tuberculosis, 1246 (88.3%) had a single site of disease, with 934 (75.0%) of these isolates having >5 IS6110 bands. Of the 934 patients included in the analyses, 729 (78.0%) had pulmonary tuberculosis, and 205 (22.0%) had extrapulmonary tuberculosis; of the latter group, 46 patients had pleural disease, and 159 patients had nonrespiratory disease. In multivariate analyses, patients with pleural tuberculosis were not significantly associated with clustered strains, compared with patients with nonrespiratory or pulmonary tuberculosis disease. Having a DNA-clustered strain was negatively associated with nonrespiratory tuberculosis, compared with pulmonary disease (adjusted odds ratio, 0.48; P = .003).

CONCLUSIONS

Nonrespiratory extrapulmonary tuberculosis is less likely than pulmonary tuberculosis to be a result of recent infection. Pleural tuberculosis is not an appropriate indicator for recent transmission among our population.

Gene-Gun-Mediated Transfer of Reporter Genes to Somatic Zebrafish (Danio rerio) Tissues

We describe the use of gene-gun-mediated transfer of luciferase and green fluorescent protein (GFP) reporter genes in zebrafish (Danio rerio). Optimization of DNA transfer parameters indicated highest overall luciferase expression in epidermis and dermis using 1-μm microcarriers and 1 μg of pCMVL plasmid DNA at a delivery pressure of 200 psi. Time course studies revealed luciferase activity peaking at 18 hours and decreasing to 30% of the maximum at day 8 after DNA transfer. Onset of reporter gene (GFP) expression was detected at 13 minutes after DNA delivery, and by 65 minutes approximately 100% of the cells in the target area exhibited GFP expression. No germline association or integration events were detected in a screen of approximately 250,000 zebrafish sperm cells by fluorescence in situ hybridization at 15 or 30 days after delivery of 1 μg of pCMVL DNA, suggesting incidental male germline integration should not be considered as a risk factor when using the biolistic DNA delivery parameters and target tissues described.

Lethality and bone alterations in chicken embryos and newly hatched chickens given bone-active agents

Studies were undertaken to assess the chicken embryo and newly hatched chicken as models for studying the effects of bone-active agents. Initially, 1,25-dihydroxycholecaliferol (1,25[OH]2D3), sodium fluoride (NaF), parathyroid extract, epidermal growth factor, and prostaglandin E2, were tested for lethality over a broad dose range. One or 3 injections of 1,25(OH)2D3 into the yolk sac of chicken embryos resulted in death of embryos given greater than or equal to 0.1 ng/injection, whereas 0.01 ng was tolerated by the embryos. Administering 1,25(OH)2D3 intraperitoneally to newly hatched chickens as a single injection or weekly for 3 weeks resulted in no deaths at doses up to 50 ng. One or 3 IV injections of 800 micrograms of NaF were lethal to embryos, whereas injections of less than or equal to 400 micrograms were tolerated by the embryo. Giving chickens feed and water containing 2.4 g of NaF/kg was lethal, but no deaths occurred when chickens were given feed containing less than or equal to 1.2 g of NaF/kg. Mortality associated with the administration of epidermal growth factor to embryos was inconsistent, in that death occurred in embryos given a single injection of greater than or equal to 250 ng, but no deaths occurred in embryos given 3 injections at similar doses. Parathyroid extract and prostaglandin E2 were not lethal when administered to embryos and chickens in a single-injection or multiple-injection regimen. Overall, lethality in chicken embryos given a particular agent reflected the dose of bone-active agent injected, rather than the number of injections. Three of the bone-active agents were selected to characterize their microscopic bone effects in chicken embryos and chickens.(ABSTRACT TRUNCATED AT 250 WORDS)