Differential white cell counts by frequency distribution analysis of cell volumes

Absolute neutrophil and lymphocyte counts on peripheral blood can be made by analysis of the output from a Coulter particle counter, utilizing the difference in the relative cell volume between these two types of cell. A comparison has been made between the results obtained by volume analysis and those obtained by standard microscopical techniques in 10 normal people and 45 patients. The absolute neutrophil count obtained by volume analysis agreed well with values obtained by microscopy; the lymphocyte count did not give such good agreement, since the smaller number of cells counted gave rise to larger sampling errors. The method of volume analysis is suitable for the assessment of absolute neutrophil counts for clinical use

Micro-CT imaging of live insects using carbon dioxide gas-induced hypoxia as anesthetic with minimal impact on certain subsequent life history traits

Abstract Background Live imaging of whole invertebrates can be accomplished with X-ray micro-computed tomography (micro-CT) at 10-100 μm spatial resolution. However, image quality could be compromised by the movement of live subjects, producing image artefacts. We tested the feasibility of using CO2 gas to induce temporary full-immobilization of sufficient duration to image live insects based on their ability to tolerate hypoxic conditions. Additionally, we investigated the effects of these prolonged hypoxic conditions on several life history traits of a lepidopteran species. Methods Live Colorado potato beetle (CPB) and true armyworm (TAW) adults were immobilized under a constant CO2 gas flow (0.5 L/min), and scanned using micro-CT (80 kVp; 450 μA). An L8 (24) orthogonal array (OA) was used to evaluate the effects of prolonged CO2-induced anesthesia on the recovery, longevity, and incidence of mating of TAW adults. The variable factors were age (immature and mature), sex (female and male), exposure time (3 and 7 h), and exposure regime (single and repeated). Results With this method, successful 3D reconstruction and visualizations of CPB and TAW adults were produced at 20 micron voxel spacing at an acceptable radiation dose and image noise level. From the inverse-square relationship found between the radiation doses and image noise levels, the optimal scanning protocol produced an entrance dose of 6.2 ± 0.04 Gy with images of 129.6 ± 5.1 HU noise level during a 2.7 h scan. Independent OA experiments indicated that CO2 gas did not result in death of exposed TAW adults, except when older males were exposed for longer durations. Exposure time and sex were more influential factors affecting recovery, longevity, and mating success than age and exposure regime following CO2 exposure. Conclusion We have demonstrated that using CO2 gas during micro-CT imaging effectively induces safe, repeatable, whole-body, and temporary immobilization of live insects for 3D visualizations without motion artefacts. Moreover, we have shown that exposed TAW individuals made a full recovery with very little impact on subsequent longevity, and mating success post hypoxia. This method is applicable to other imaging modalities and could be used for routine exploratory and time-course studies, for repeated scanning of live and intact individuals

Assessment of ambiguous base calls in HIV-1 pol population sequences as a biomarker to identify recent infections in HIV-1 incidence studies

An increase in the proportion of ambiguous base calls in HIV-1 pol population sequences during the course of infection has been demonstrated in different study populations, and sequence ambiguity thresholds to classify infections as recent or nonrecent have been suggested. The aim of our study was to evaluate sequence ambiguities as a candidate biomarker for use in an HIV-1 incidence assay using samples from antiretroviral treatment-naive seroconverters with known durations of infection (German HIV-1 Seroconverter Study). We used 2,203 HIV-1 pol population sequences derived from 1,334 seroconverters to assess the sequence ambiguity method (SAM). We then compared the serological incidence BED capture enzyme immunoassay (BED-CEIA) with the SAM for a subset of 723 samples from 495 seroconverters and evaluated a multianalyte algorithm that includes BED-CEIA results, SAM results, viral loads, and CD4 cell counts for 453 samples from 325 seroconverters. We observed a significant increase in the proportion of sequence ambiguities with the duration of infection. A sequence ambiguity threshold of 0.5% best identified recent infections with 76.7% accuracy. The mean duration of recency was determined to be 208 (95% confidence interval, 196 to 221) days. In the subset analysis, BED-CEIA achieved a significantly higher accuracy than the SAM (84.6 versus 75.5%, P < 0.001) and results were concordant for 64.2% (464/723) of the samples. Also, the multianalyte algorithm did not show better accuracy than the BED-CEIA (83.4 versus 84.3%, P = 0.786). In conclusion, the SAM and the multianalyte algorithm including SAM were inferior to the BED-CEIA, and the proportion of sequence ambiguities is therefore not a preferable biomarker for HIV-1 incidence testing

Effect of Memantine Treatment and Combination with Vitamin D Supplementation on Body Composition in the APP/PS1 Mouse Model of Alzheimer\u27s Disease following Chronic Vitamin D Deficiency

Background: Vitamin D deficiency and altered body composition are common in Alzheimer\u27s disease (AD). Memantine with vitamin D supplementation can protect cortical axons against amyloid-ß exposure and glutamate toxicity. Objective: To study the effects of vitamin D deprivation and subsequent treatment with memantine and vitamin D enrichment on whole-body composition using a mouse model of AD. Methods: Male APPswe/PS1dE9 mice were divided into four groups at 2.5 months of age: the control group (n=14) was fed a standard diet throughout; the remaining mice were started on a vitamin D-deficient diet at month 6. The vitamin D-deficient group (n=14) remained on the vitamin D-deficient diet for the rest of the study. Of the remaining two groups, one had memantine (n=14), while the other had both memantine and 10 IU/g vitamin D (n=14), added to their diet at month 9. Serum 25(OH)D levels measured at months 6, 9, 12, and 15 confirmed vitamin D levels were lower in mice on vitamin D-deficient diets and higher in the vitamin D-supplemented mice. Micro-computed tomography was performed at month 15 to determine whole-body composition. Results: In mice deprived of vitamin D, memantine increased bone mineral content (8.7% increase, p\u3c0.01) and absolute skeletal tissue mass (9.3% increase, p\u3c0.05) and volume (9.2% increase, p\u3c0.05) relative to controls. This was not observed when memantine treatment was combined with vitamin D enrichment. Conclusion: Combination treatment of vitamin D and memantine had no negative effects on body composition. Future studies should clarify whether vitamin D status impacts the effects of memantine treatment on bone physiology in people with AD