Optimization of a Stacked-design Core-body-temperature Sensor for Long-period Human Trials

We fabricated a wearable sensor that can be attached to the skin surface and continuously measure core body temperature (CBT) wirelessly over a long period. CBT is calculated from skin-surface temperature and heat flux passing through the sensor. Since heat flux is lost to the surroundings of the probe, the slightest change in convection in daily life will degrade the measurement accuracy of the sensor. Accordingly, we previously proposed a heat-flux-path control structure to reduce the absolute amount of heat-flux loss. To make wearable sensors for long-term human trials, we proposed an integrated design in which a sensor probe, a circuit board, and a battery are stacked. We optimized the proposed design by computer simulation and evaluated the fabricated sensor by a phantom experiment in which the convectional state was changed. The evaluation results demonstrate that the sensor has limits of agreement (LOA) of [-0.13; 0.03]°C under 1-m/s-wind convection. Moreover, a preliminary human trial conducted under daily-life conditions (including convectional changes) demonstrated that the sensor has LOA of [-0.18; 0.22]°C. These results demonstrate that the fabricated sensor is suitable for CBT measurement.

Non-invasive and wearable thermometer for continuous monitoring of core body temperature under various convective conditions

We describe the design of a thermometer that can be worn during everyday activities for monitoring core body temperature (CBT) at the skin surface. This sensor estimates the CBT by measuring the heat flux from the body core based on a thermal conductive model. The heat flux is usually affected by the ambient convective conditions (e.g. air conditioner or posture), which in turn affects the model's accuracy. Thus, we analytically investigated heat conduction and designed a sensor interface that would be robust to convection changes. We performed an in vitro experiment and a preliminary in vivo experiment. The accuracy of CBT in an in vitro experiments was 0.1°C for convective values ranging from 0 to 1.2 m/s. The wearable thermometer has high potential as non-invasive CBT monitor.

Extensive "stalagmite" epi-iridic juvenile xanthogranuloma simulating diffuse melanoma in a 16-year-old girl

A 16-year-old girl noted worsening redness and photophobia of the right eye that had previously been treated unsuccessfully with sequential courses of topical antibiotics and topical corticosteroids. Clinical examination revealed diffuse flakelike thickening of the iris surface, pupillary margin, and anterior chamber angle, suggesting diffuse iris melanoma. Anterior segment optical coherence tomography depicted the mass as an epi-iridic deposit with "stalagmite" surface appearance. Fine-needle aspiration biopsy confirmed an atypical histiocytic proliferative disorder consistent with juvenile xanthogranuloma. Aggressive topical corticosteroid treatment was started. There were no systemic findings. Following therapy, the lesion resolved completely.

Humanin Protects RPE Cells from Endoplasmic Reticulum Stress-Induced Apoptosis by Upregulation of Mitochondrial Glutathione

Humanin (HN) is a small mitochondrial-encoded peptide with neuroprotective properties. We have recently shown protection of retinal pigmented epithelium (RPE) cells by HN in oxidative stress; however, the effect of HN on endoplasmic reticulum (ER) stress has not been evaluated in any cell type. Our aim here was to study the effect of HN on ER stress-induced apoptosis in RPE cells with a specific focus on ER-mitochondrial cross-talk. Dose dependent effects of ER stressors (tunicamycin (TM), brefeldin A, and thapsigargin) were studied after 12 hr of treatment in confluent primary human RPE cells with or without 12 hr of HN pretreatment (1-20 μg/mL). All three ER stressors induced RPE cell apoptosis in a dose dependent manner. HN pretreatment significantly decreased the number of apoptotic cells with all three ER stressors in a dose dependent manner. HN pretreatment similarly protected U-251 glioma cells from TM-induced apoptosis in a dose dependent manner. HN pretreatment significantly attenuated activation of caspase 3 and ER stress-specific caspase 4 induced by TM. TM treatment increased mitochondrial superoxide production, and HN co-treatment resulted in a decrease in mitochondrial superoxide compared to TM treatment alone. We further showed that depleted mitochondrial glutathione (GSH) levels induced by TM were restored with HN co-treatment. No significant changes were found for the expression of several antioxidant enzymes between TM and TM plus HN groups except for the expression of glutamylcysteine ligase catalytic subunit (GCLC), the rate limiting enzyme required for GSH biosynthesis, which is upregulated with TM and TM+HN treatment. These results demonstrate that ER stress promotes mitochondrial alterations in RPE that lead to apoptosis. We further show that HN has a protective effect against ER stress-induced apoptosis by restoring mitochondrial GSH. Thus, HN should be further evaluated for its therapeutic potential in disorders linked to ER stress.

Shape matters: Near-field fluid mechanics dominate the collective motions of ellipsoidal squirmers

Microswimmers show a variety of collective motions. Despite extensive study, questions remain regarding the role of near-field fluid mechanics in collective motion. In this paper, we describe precisely the Stokes flow around hydrodynamically interacting ellipsoidal squirmers in a monolayer suspension. The results showed that various collective motions, such as ordering, aggregation, and whirls, are dominated by the swimming mode and the aspect ratio. The collective motions are mainly induced by near-field fluid mechanics, despite Stokes flow propagation over a long range. These results emphasize the importance of particle shape in collective motion.

OCT angiography in healthy human subjects

BACKGROUND AND OBJECTIVE

To noninvasively evaluate the retinal microvasculature in healthy human subjects with optical coherence tomography angiography (OCTA).

PATIENTS AND METHODS

Cross-sectional, observational study of five healthy subjects. OCTA was performed on 3 × 3 mm(2) sections centered on the fovea, nasal macula, and temporal macula. Retinal vasculature was assessed within three horizontal slabs consisting of the inner, middle, and outer retina. The vasculature within each retinal slab was reconstructed using phase-based and intensity contrast-based algorithms and visualized as separate en face images.

RESULTS

OCTA in healthy subjects demonstrates capillary networks consistent with previous histological studies. No retinal vessels were found in the outer retina. OCT angiography of the inner and middle retinal layers showed region-specific vascular patterns that consistently corroborated qualitative findings from past histological studies.

CONCLUSION

OCTA generates high-resolution, noninvasive angiograms qualitatively similar to conventional fluorescein angiography. OCTA may serve as a bridge to assess some features of the retinal microvasculature between conventionally performed angiograms.

MULTIMODAL IMAGING OF GEOGRAPHIC AREAS OF RETINAL DARKENING

PURPOSE

To describe the clinical and multimodal imaging characteristics of a patient with unilateral asymptomatic dark retinal lesions corresponding to ellipsoid zone hyporeflectivity on optical coherence tomography (OCT).

METHODS

The authors report a case of a 35-year-old man with HIV who presents with asymptomatic dark geographic retinal lesions corresponding to ellipsoid zone hyporeflectivity on OCT. Multimodal imaging techniques, including fundus color and widefield photographs, autofluorescence, spectral domain OCT (Spectralis, Heidelberg, Germany), prototype spectral domain OCT (Carl Zeiss Meditec, Dublin, CA) with OCT angiography, and en face images, were performed to evaluate and characterize the morphology of these lesions.

RESULTS

Clinical examination and multimodal imaging reveal geographic darkening of the retina. Optical coherence tomography conveys hyporeflectivity of the ellipsoid zone band, which occurs abruptly and is present only in the areas of geographic retinal darkening. Optical coherence tomographic angiography shows a qualitatively similar appearance of the vasculature from the superficial retina through the avascular retina and the choriocapillaris, on both sides of the demarcation of retinal darkening, and also as compared to the unaffected eye. En face images from spectral domain OCT reveal an abrupt darkening of the tissue that localizes and is limited to the ellipsoid zone, with similar topographic appearance across the demarcation line.

CONCLUSION

Geographic areas of darkening with photoreceptor hyporeflectivity have been described previously as "dark without pressure." In this case, the authors demonstrate photoreceptor hyporeflectivity that localizes to the clinically darkened areas, without topographic qualitative differences on en face spectral domain OCT images. The authors term these dark areas as geographic areas of retinal darkening because of ellipsoid nonreflectivity (GARDEN) spots.

Lateral migration of a spherical capsule near a plane wall in Stokes flow

Lateral migration is the motion of a particle perpendicular to the direction of the surrounding flow. One of the factors leading to the lateral migration of a deformable particle in Stokes flow is the presence of a nearby wall. We numerically investigate the lateral migration of a capsule in a near-wall simple shear flow using a boundary integral method coupled with a finite element method. We find that asymmetrical deformation of the capsule induced by the wall is correlated with a reduction in the lift velocity relative to the lift velocity predicted by a far-field analytical solution. A combination of this asymmetrical deformation, which decreases the lift velocity, and an increase in the value of the capsule stresslet near the wall, which works to increase the lift velocity, leads to a migration velocity that is nearly independent of capillary number and membrane constitutive law at large deformation near the wall.

The oncogenic BRAF kinase inhibitor PLX4032/RG7204 does not affect the viability or function of human lymphocytes across a wide range of concentrations

PURPOSE

PLX4032 (RG7204), an oncogenic BRAF kinase inhibitor undergoing clinical evaluation, has high response rates in early clinical trials in patients with advanced BRAF(V600E) mutant melanoma. Combining PLX4032 with immunotherapy may allow expanding the durability of responses. The effects of PLX4032 on immune cells were studied to explore the feasibility of future combinatorial approaches with immunotherapy for melanoma.

EXPERIMENTAL DESIGN

Peripheral blood mononuclear cells (PBMC) and BRAF(V600E) mutant melanoma cells were exposed to increasing concentrations of PLX4032 and the cell viability, proliferation, cell cycle, apoptosis, and phosphorylation of signaling proteins were analyzed. Effects of PLX4032 on antigen-specific T-cell function were analyzed by specific cytokine release and cytotoxicity activity.

RESULTS

The 50% inhibition concentration (IC(50)) of PLX4032 for resting human PBMC was between 50 and 150 μmol/L compared with an IC(50) below 1 μmol/L for sensitive BRAF(V600E) mutant melanoma cell lines. Activated lymphocytes were even more resistant with no growth inhibition up to concentrations of 250 μmol/L. PLX4032 had a marginal effect on cell-cycle arrest, apoptotic cell changes or alteration of phosphorylated signaling molecules in lymphocytes. Functional analysis of specific antigen recognition showed preserved T-cell function up to 10-μmol/L concentration of PLX4032, whereas the cytotoxic activity of PLX4032 was maintained up to high concentrations of 50 μmol/L.

CONCLUSIONS

The preserved viability and function of lymphocytes exposed to high concentrations of PLX4032 suggest that this agent could be a potential candidate for combining with immunotherapy strategies for the treatment of patients with BRAF(V600)(E) mutant melanoma.

Modulation of cell signaling networks after CTLA4 blockade in patients with metastatic melanoma

Background

The effects on cell signalling networks upon blockade of cytotoxic T lymphocyte-associated antigen-4 (CTLA4) using the monoclonal antibody tremelimumab were studied in peripheral blood mononuclear cell (PBMC) samples from patients with metastatic melanoma.

Methodology/Principal

Findings Intracellular flow cytometry was used to detect phosphorylated (p) signaling molecules downstream of the T cell receptor (TCR) and cytokine receptors. PBMC from tremelimumab-treated patients were characterized by increase in pp38, pSTAT1 and pSTAT3, and decrease in pLck, pERK1/2 and pSTAT5 levels. These changes were noted in CD4 and CD8 T lymphocytes but also in CD14 monocytes. A divergent pattern of phosphorylation of Zap70, LAT, Akt and STAT6 was noted in patients with or without an objective tumor response.

Conclusions/Significance

The administration of the CTLA4-blocking antibody tremelimumab to patients with metastatic melanoma influences signaling networks downstream of the TCR and cytokine receptors both in T cells and monocytes. The strong modulation of signaling networks in monocytes suggests that this cell subset may be involved in clinical responses to CTLA4 blockade.

Clinical Trial Registration

clinicaltrials.gov; Registration numbers NCT00090896 and NCT00471887

The natural history of medical and psychiatric disorders in an American Indian community

In 1969, a Pacific Northwest American Indian community cohort (n = 100) was interviewed for the presence of physical and psychiatric illnesses. The same community was studied again in 1988. This study describes the outcome among the original 100 subjects. The schedule for Affective Disorders and Schizophrenia Lifetime Version (SADS-L) served as the basic interview instrument, supplemented by data from medical records, death certificates, and medical and community informants. Twenty-five subjects had died, 13 from cardiovascular disorders and seven from alcohol-related illnesses. Among the 46 subjects re-interviewed, hypertension, heart disease, and diabetes had become significant sources of medical morbidity. Alcoholism was the most significant cause of psychiatric morbidity, particularly among males. This study indicates that greater attention should be focused upon prevention and treatment of alcoholism, cardiovascular disorders, and diabetes in this community and in other American Indian populations.

Psychiatric epidemiology of an Indian village. A 19-year replication study

This 1988 study reports the point and lifetime prevalence of psychiatric disorders, using DSM-III-R criteria, of a sample (approximately 25%) of adult members of an Indian village previously studied in 1969. The basic instrument was the Schedule for Affective Disorders and Schizophrenia, augmented by available medical information and administered by experienced psychiatrists. Subjects were interviewed and results were weighed for the age- and sex-distributed population. The results indicated a high point prevalence of alcohol dependence (32.8%), with a lifetime prevalence of 72.8%, among males. The lifetime prevalence of affective disorders among women was also high (36.8%), but less so among men (19.3%). When compared with the DSM-III-R diagnoses of the 1969 study, the point prevalence rates of alcohol dependence and abuse disorders fell from 39% to 21%. Also, fewer subjects were judged to be psychiatrically impaired. Even though the prevalence of psychiatric disorders was lower in the current study, the rates for alcohol disorders and affective disorders were still far higher than those reported in Epidemiologic Catchment Area studies. Alcohol dependence (especially among young men) and affective disorder (among women) were major problems.