Bone aluminum measured in miners exposed to McIntyre powder

A small pilot study was conducted to test whether the technique of in vivo neutron activation analysis could measure bone aluminum levels in 15 miners who had been exposed to McIntyre Powder over 40 years prior. All miners were over 60 years of age, had worked in mines that used McIntyre Powder, and were sufficiently healthy to travel from northern to southern Ontario for the measurements. Individual aluminum levels were found to be significantly greater than zero with 95% confidence (p < 0.05) in 7 out of the 15 miners. The inverse variance weighted mean of the 15 participants was 21.77 ± 2.27µgAl/gCa. This was significantly higher (p < 0.001) than in a group of 15 non-occupationally exposed subjects of a comparable age from Southern Ontario who had been measured in a previous study. The inverse variance weighted mean bone aluminum content in the non-occupationally exposed group was 3.51 ± 0.85µgAl/gCa. Since the use of McIntyre Powder ceased in 1979, these subjects had not been exposed for more than 40 years. Calculations of potential levels at the cessation of exposure in the 1970s, using a biological half-life of aluminum in bone of 10 to 20 years predicted levels of bone aluminum comparable with studies performed in dialysis patients in the 1970s and 1980s. This pilot study has shown that the neutron activation analysis technique can determine differences in bone aluminum between McIntyre Powder exposed and non-exposed populations even though 40 years have passed since exposure ceased. The technique has potential application as a biomarker of exposure in cross-sectional studies of the health consequences of exposure to McIntyre Powder.

Building the body: the resilience of nurturing practices to build the immune system with traditional medicine among Purko Maasai

The benefits of traditional medicine have long been recognized by the World Health Organization. However, as formal education, urbanization, and deforestation increases; the use of traditional medicine has decreased. Within this phenomenon, this paper discusses the continued importance of preventive health practices among the Purko Maasai. Using nurturing as an explanatory framework, qualitative data is analyzed to understand the cultural importance of specific traditional medicine with the goal of building the body with 'engolon' (strength). Results address the importance of nurturing children by administering traditional medicine in order to build the body's immune system. Our data show an interesting gender divide in which both genders play a critical nurturing role, however at different timeframes in the child's life. Findings demonstrate concern with changing frequency of herbal medicine given to children, however there is resiliency within some nurturing components of using preventative traditional medicine to build up children's immune system.

Medical Populism and COVID-19 Testing

This paper uses the lens of medical populism to analyze the impact of biocommunicability on COVID-19 testing through a case study approach. The political efficacy of testing is traced through two mini-case studies: the Philippines and the United States. The case studies follow the approach of populism scholars in drawing from various sources that ‘render the populist style visible’ from the tweets and press releases of government officials to media reportage. Using the framework of medical populism, the case studies pay attention to the ways in which coronavirus testing figured in (1) simplification of the pandemic; (2) spectacularization of the crisis; (3) forging of divisions; and (4) invocation of knowledge claims. Identifying and critically analyzing how knowledge is generated is an essential step to recognizing the impact that political styles have on the COVID pandemic. The political actors in each case study have shaped knowledge of the epidemic, in the way they construct the idea of ‘testing’, and in how they mobilize testing as an ‘evidence-making practice’. Their actions shaped how the pandemic—as well as their responses—is measured. This framework contributes to public policy debates by providing evidence of the impact of medical populism on pandemic response efforts.

The Arcuate Fasciculus and Language Development in a Cohort of Pediatric Patients with Malformations of Cortical Development

BACKGROUND AND PURPOSE

Patients with epilepsy and malformations of cortical development have a high prevalence of language deficits. The purpose of this study was to investigate whether the status of the arcuate fasciculus at diffusion tractography could provide a clinically meaningful marker of language function in patients with cortical malformations.

MATERIALS AND METHODS

Thirty-seven patients 3-18 years of age who had DTI performed at 3T and language evaluation by a pediatric neurologist were retrospectively identified. Twenty-two age-matched children without any neurologic, language, or MR imaging abnormalities who had identical DTI performed for an indication of headache were selected as a control cohort. The arcuate fasciculi were constructed and segmented by deterministic tractography for all subjects.

RESULTS

Twenty-one patients had intact language; 11 had mild-to-moderate and 5, profound language impairment. All patients with normal language and all control subjects had an identifiable left arcuate. The left arcuate was absent in 11 patients; all 11 were language-impaired. Failure to identify the left arcuate was strongly associated with some degree of language impairment (P < .001). Sensitivity, specificity, and positive predictive value for language dysfunction were 65%, 100%, and 100%, respectively. The absence of the arcuate bilaterally was associated with complete failure to develop oral language (P < .015).

CONCLUSIONS

Failure to identify the left arcuate fasciculus at diffusion tractography was a highly specific marker of language dysfunction in a cohort of pediatric patients with malformations of cortical development. Failure to identify the arcuate fasciculus on either side was associated with failure to develop oral language.

Repeatability of quantitative metrics derived from MR diffusion tractography in paediatric patients with epilepsy

OBJECTIVE

To quantify the test-retest repeatability of mean diffusivity (MD) and fractional anisotropy (FA) derived from diffusion tensor imaging (DTI) tractography in a cohort of paediatric patients with localization-related epilepsy.

METHODS

30 patients underwent 2 DTI acquisitions [repetition time/echo time (ms), 7000/90; flip, 90°; b-value, 1000 s mm(-2); voxel (mm), 2 × 2 × 2]. Two observers used Diffusion Toolkit and TrackVis ( www.trackvis.org ) to segment and analyse the following tracts: corpus callosum, corticospinal tracts, arcuate fasciculi, inferior longitudinal fasciculi and inferior fronto-occipital fasciculi. Mean MD and mean FA were calculated for each tract. Each observer independently analysed one of the DTI data sets for every patient.

RESULTS

Segmentation identified all tracts in all subjects, except the arcuate fasciculus. There was a highly consistent relationship between repeated observations of MD (r = 0.993; p < 0.0001) and FA (r = 0.990; p < 0.0001). For each tract, coefficients of variation ranged from 0.9% to 2.1% for MD and from 1.5% to 2.8% for FA. The 95% confidence limits (CLs) for change ranged from 2.8% to 6% for MD and from 4.3% to 8.6% for FA. For the arcuate fasciculus, Cohen's κ for agreement between the observers (identifiable vs not identifiable) was 1.0.

CONCLUSION

We quantified the repeatability of two commonly utilized scalar metrics derived from DTI tractography. For an individual patient, changes greater than the repeatability coefficient or 95% CLs for change are unlikely to be related to variability in their measurement.

ADVANCES IN KNOWLEDGE

Reproducibility of these metrics will aid in the design of future studies and might one day be used to guide management in patients with epilepsy.

Gender and racial differences in treatment process and outcome among participants in the adolescent community reinforcement approach

Increasingly, evidence-based treatments are being implemented by community treatment providers, and it is important to understand whether they can be implemented with similar quality and equivalent effectiveness across gender and racial groups. This study examined whether initiation, engagement, dosage, treatment satisfaction, or outcomes for adolescents who received the Adolescent Community Reinforcement Approach (A-CRA) in a large implementation effort were equivalent by gender or racial group. Analyses of data from 2,141 adolescents representing 33 sites across the United States revealed no significant differences for initiation, engagement, or retention by gender or race. Ninety-six percent of the sample reported being satisfied with treatment; however, male adolescents had significantly higher rates of treatment satisfaction than female adolescents, and African American adolescents had significantly higher rates of treatment satisfaction than Caucasian adolescents. A subset of the initial sample (n = 1,819) was used to investigate outcomes. All racial groups had significant increases in days abstinent from alcohol and other drugs and in the percentage in recovery across the measurement period but did not differ from one another at the six-month follow-up. Female adolescents had a higher percentage of days abstinent from alcohol and other drugs and were more likely to be in recovery at the six-month follow-up than male adolescents. Overall, process indicators suggest the intervention was well implemented across gender and racial groups and equally effective across racial groups, with males having equivalent gains in abstinence and recovery compared with females despite males having greater intake severity and differential outcomes at six months.

Magnetization transfer contrast in MR imaging of the heart

The use of magnetization transfer contrast (MTC) in short-echo-time (TE) cardiac magnetic resonance (MR) imaging was evaluated. For most cardiac MR imaging protocols, either long TE and short repetition time or exogenous intravascular agents are used for generating contrast between the ventricular wall and cavity as well as detecting pathologic conditions of the ventricular wall. The major problem with long-TE images is that the motion of the heart degrades the spatial resolution of the image during the TE period. However, MTC is generated by an off-resonance irradiation during the interpulse delay period that is relatively insensitive to motion artifacts. Short-TE (5-15 msec) gradient-recalled echo sequences were used for imaging the heart with and without MTC. These studies revealed that MTC can be used to greatly improve the contrast between the myocardial wall and blood chamber in short-TE images and may provide useful parameters for tissue characterization in pathologic cardiac muscle.

Levels of lysosomal enzymes in tissues of mice infected with Mycoplasma fermentans

The effects of a toxic dose of Mycoplasma fermentans on levels of lysosomal enzymes in mice were examined. Washed cell suspensions (approximately 10(10) colony-forming units) of a recent isolate of M. fermentans were injected intraperitoneally into 3- to 4-week-old BALB mice, and levels of acid phosphatase and beta-glucuronidase were monitored in liver, spleen, thymus, and serum. Levels of acid phosphatase remained essentially normal, but levels of beta-glucuronidase were markedly evevated in serum and to a lesser extent in liver and thymus. The peak response of serum beta-glucuronidase was noted at 8 h postinjection, with a level of 30 mug of phenolphthalein released per ml per h, representing a six-fold increase over control levels. Pretreatment with BCG did not potentiate the effect as it did with endotoxin. The implication of this increased lysosomal enzyme activity in "lethal toxicity" is that that the increase may be secondary to some other cytotoxic event, or that the affinity of mycoplasmas for biological membranes may be involved. The data suggest that the role of lysosomal enzymes in other models of mycoplasma-induced disease should be evaluated.