Methamphetamine absorption by skin lipids: accumulated mass, partition coefficients, and the influence of fatty acids

Occupants of former methamphetamine laboratories, often residences, may experience increased exposure through the accumulation of the methamphetamine in the organic films that coat skin and indoor surfaces. The objectives of this study were to determine equilibrium partition coefficients of vapor-phase methamphetamine with artificial sebum (AS-1), artificial sebum without fatty acids (AS-2), and real skin surface films, herein called skin oils. Sebum and skin oil-coated filters were exposed to vapor-phase methamphetamine at concentrations ranging from 8 to 159 ppb, and samples were analyzed for exposure time periods from 2 h to 60 days. For a low vapor-phase methamphetamine concentration range of ~8-22 ppb, the equilibrium partition coefficient for AS-1 was 1500 ± 195 μg/g/ppb. For a high concentration range of 98-112 ppb, the partition coefficient was lower, 459 ± 80 μg/g/ppb, suggesting saturation of the available absorption capacity. The low partition coefficient for AS-2 (33 ± 6 μg/g/ppb) suggests that the fatty acids in AS-1 and skin oil are responsible for much high partition coefficients. We predict that the methamphetamine concentration in skin lipids coating indoor surfaces can exceed recommended surface remediation standards even for air concentrations well below 1 ppb.

A Mixed-Methods Evaluation of a Social Paediatrics Block Rotation for Paediatric Residents

BACKGROUND: Poverty and social injustice have a direct link to health outcomes and health care utilization, especially for children. Understanding the complexity of impact of social determinants on health is essential in providing effective, compassionate care to vulnerable populations. Currently, there is a paucity of literature on the impact of various models of advocacy curricula on pediatric residents and future involvement in advocacy. Social Pediatrics is an approach to child health that focuses on the child, in illness, and in health, within the context of their society, environment, school, and family.

OBJECTIVES: 1) To determine if a social pediatrics rotation greater enables residents to become involved in advocacy projects during their residency and interest for career. 2) To identify resident knowledge translation of the social determinants of health and their impact on the pediatric population. 3) To characterize the barriers and enablers, if any, for residents to engage in advocacy.

DESIGN/METHODS: The Social Pediatrics rotation was embedded in the second year of a postgraduate pediatric curriculum. Knowledge and attitudes of resident participants before and after the rotation was assessed with written tests and surveys. A qualitative descriptive study of community partners and resident perspectives was semi-structured interviews, thematic coding and analysis via an inductive-iterative approach.

RESULTS: 21 residents completed pre-and post- written knowledge tests, and 12 residents completed optional attitudinal surveys. Knowledge increased from 68% prior to rotation, to 80% (p < 0.001) following the rotation. All residents completing written surveys indicated increased likelihood of participating in social pediatrics and advocacy in practice following this rotation. Results from 6 resident and 5 community partner interviews included: enhanced knowledge of social determinants of health, residency curricula development with further mental health placements, future practice models involving vulnerable populations, multi-disciplinary learning opportunities, and advocacy projects both at the patient and community level. Community partners shared experiences of residents demonstrating enthusiasm and engagement in placements, some logistical challenges but value in experiences outside hospital environment, particularly in learning from multidisciplinary team.

CONCLUSION: Pediatric residents demonstrate increase in knowledge of social determinants of health and an increased interest in community advocacy initiatives and vulnerable populations following a block rotation in Social Pediatrics. Community partners valued engagement with pediat-ric residents, identifying key learning opportunities in these unique environments and report few barriers to continued involvement. Future directions include impact on advocacy work or career decisions, and multi-centre collaboration.

P18: MULTIPLE DIAGNOSIS OR CONTINUUM OF DISEASE: MULTICENTRIC CASTLEMAN'S DISEASE

Purpose of Study

Multicentric Castleman's disease (MCD) is a rare lymphoproliferative disorder characterized by peripheral lymphadenopathy (LAD), hepatosplenomegaly(HSM), and B symptoms. It is associated with HIV and HHV8 infection.

We report a case of young woman presented with B symptoms, workup suggestive of lupus but lymph node biopsy (BX) was consistent with MCD. Association of SLE with MCD is rare. We report this case to increase awareness of this potential diagnostic and therapeutic dilemma.

Methods Used

Patient is a 27 yr old black woman presented with malaise, fevers, cough, weight loss, arthralgia, alopecia, numbness of extremities and Raynaud's phenomenon. Patient had skin tightness around the mouth, telangiectasia, digital ulcers, HSM, pitting edema, diffuse LAD and moderate pericardial effusion.

Laboratory results consistent with hemolytic anemia with Hb 5.6 g/dl, direct coombs positive, elevated reticulocyte count, LDH and low haptoglobin. Initial RF, ANA, and all infectious work up including HIV were normal. She was transfused cautiously, with inconclusive LN and bone marrow Bx. Patient left hospital against medical advice.

She presented two days later with altered mental status (AMS) and hypotension. CT head and Lumbar puncture were negative. Hypotension responded to fluids, but no response in AMS. Repeat ANA, AntiSSB, AntiSm, AntiRNP, and Antihistone antibodies were positive. Patient met diagnostic criteria for SLE and was subsequently treated for lupus cerebritis with pulse steroids, with moderate improvement in mental status. Repeat LNBX revealed reactive lymphadenitis with features of MCD, HHV8 negative. Patient was treated with IL-6 inhibitor Siltuximab, with significant improvement in mental status.

Summary of Results

MCD is a rare angiolymphoproliferative disorder of unclear etiology. Most cases occur in middle aged men and are associated with immunosuppression where as SLE is common in women of child bearing age. Reported cases of MCD in association with SLE are common in immunocompetent young women. Our patient is a young woman, HIV/HHV8 negative with good response to Siltuximab, favoring MCD.

Conclusions

It is unclear whether this finding of MCD and SLE represents an overlap or a pure association. However, this phenomenon needs further investigation.

Accumulation of gas-phase methamphetamine on clothing, toy fabrics, and skin oil

To better understand methamphetamine exposure and risk for occupants of former residential clandestine methamphetamine laboratories, we measured the dynamic accumulation of methamphetamine in skin oil, cotton and polyester (PE) clothing, upholstery, and toy fabric (substrates) exposed to 15-30 ppb (91-183 μg/m(3)) neutral methamphetamine in air for up to 60 days. The average equilibrium partition coefficients at 30% RH, in units of μg of methamphetamine per gram of substrate per ppb, are 3.0 ± 0.2 for a PE baby blanket, 5.6 ± 3.5 for a PE fabric toy, 3.7 ± 0.2 for a PE shirt, 18.3 ± 8.0 for a PE/cotton upholstery fabric, and 1200 ± 570 in skin oil. The partition coefficients at 60% RH are 4.5 ± 0.4, 5.2 ± 2.1, 4.5 ± 0.6, 36.1 ± 3.6, and 1600 ± 1100 μg/(g ppb), respectively. There was no difference in the partition coefficient for a clean and skin-oil-soiled cotton shirt [15.3 ± 2.1 μg/(g ppb) @ 42 days]. Partition coefficients for skin oil may be sensitive to composition. 'Mouthing' of cloth is predicted to be the dominant exposure pathway [60 μg/(kg body weight*ppb)] for a toddler in former meth lab, and indoor air concentrations would have to be very low (0.001 ppb) to meet the recommended reference dose for children.

PRACTICAL IMPLICATIONS

Gas-phase methamphetamine transfers to and accumulates on clothing, toys and other fabrics significantly increases risk of ingestion of methamphetamine. Current remediation methods should consider measurement of postremediation gas-phase air concentrations of methamphetamine in addition to surface wipe samples.

Higher risk of kidney graft failure in the presence of anti-angiotensin II type-1 receptor antibodies

Reports have associated non-HLA antibodies, specifically those against angiotensin II type-1 receptor (AT1R), with antibody-mediated kidney graft rejection. However, association of anti-AT1R with graft failure had not been demonstrated. We tested anti-AT1R and donor-specific HLA antibodies (DSA) in pre- and posttransplant sera from 351 consecutive kidney recipients: 134 with biopsy-proven rejection and/or lesions (abnormal biopsy group [ABG]) and 217 control group (CG) patients. The ABG's rate of anti-AT1R was significantly higher than the CG's (18% vs. 6%, p < 0.001). Moreover, 79% of ABG patients with anti-AT1R lost their grafts (vs. 0%, CG), anti-AT1R levels in 58% of those failed grafts increasing posttransplant. With anti-AT1R detectable before DSA, time to graft failure was 31 months-but 63 months with DSA detectable before anti-AT1R. Patients with both anti-AT1R and DSA had lower graft survival than those with DSA alone (log-rank p = 0.007). Multivariate analysis showed that de novo anti-AT1R was an independent predictor of graft failure in the ABG, alone (HR: 6.6), and in the entire population (HR: 5.4). In conclusion, this study found significant association of anti-AT1R with graft failure. Further study is needed to establish causality between anti-AT1R and graft failure and, thus, the importance of routine anti-AT1R monitoring and therapeutic targeting.