Inter- and intra-laboratory variability of CD4 cell counts in Swaziland

Background. Analytical variability in CD4 enumeration is well known, but few studies from southern Africa have quantified the inter- and intra-laboratory variability in CD4 count measurements. In addition, the possible impact of time lapse after sample collection on CD4 reliability is notwell understood.Methods. A cross-sectional study was conducted at Royal Swaziland Sugar Corporation Hospital and three laboratories, Lab A (comparator), Lab B (national reference) and Lab C (rural hospital). Blood from HIV-infectedindividuals was collected using routine venepuncture into separate specimens for each of the three laboratories. The samples were further subdivided at each laboratory: one was run at 12 hours and the second at 24 hours after venepuncture. The results of absolute CD4 count and CD4percentage testing were compared within (intra-laboratory) and between (inter-laboratory) laboratories.Results. Among 53 participants, the mean CD4 count at 12 hours was 373 cells/ìl, 396 cells/ìl and 439 cells/ìl, and at 24 hours 359 cells/ìl, 389 cells/ ìl and 431 cells/ìl, for laboratories A, B and C, respectively. The coefficientof intra-laboratory variation was 4%, 8% and 20% for CD4 count for laboratories A, B and C, respectively. Comparing 12- and 24-hour measurements, the mean difference (bias) within the laboratories between the two time points (and limits of agreement, LOAs) was 14 (-46 to 73), 8 (-161 to 177) and 7 (20 to 33) cells/ìl for labs A, B and C, respectively.Comparing Lab A versus Lab B, lab A versus Lab C and Lab B versus Lab C, the inter-laboratory bias for the CD4 count at 12 hours was -32, -64 and -38 cells/ìl, respectively. The corresponding LOAs were -213 to 150, -183 to 55, and -300 to 224, respectively. At 24 hours, the biases and LOAs were similar to those at 12 hours.Conclusions. CD4 counts appeared reliable at all three laboratories. Lab B and Lab C were clinically interchangeable with the comparator laboratory, Lab A, but not between themselves. Time to measurement does not affect the interlaboratory agreement within 12 and 24 hours

TAVI pilot outcomes: A South African healthcare funder perspective

BACKGROUND: TAVI (Transcatheter aortic valve implantation) is used to replace the aortic valve in the treatment of aortic stenosis in high-risk, elderly patients who are unable to undergo conventional surgical replacement of the aortic valve (SAVR). However, concerns remain regarding the costs, long-term outcomes and safety of the device. A registry was developed by a healthcare funder to assess utilisation, outcomes and cost of this procedure in their patient population. METHODS: Registry data was collected for a period of 17 months. Clinical entry criteria included high-risk, elderly patients with symptomatic, severe aortic valvedisease who were unsuitable for surgical valve replacement. Clinical outcomes were mortality, readmission and pacemaker requirements post-surgery. Primary outcome measure was all-cause mortality at 30 days.RESULTS: A cohort of 78 patients was enrolled, mean age of 79.53 years. Procedures were performed in 7 centers around the country. Thirty day all-cause mortality was 9 (11.54%) with 5 deaths occurring on the day of the procedure. Eighteen (23.1%) patients were readmitted within 30 days. Average LOS was 5.71 (±4.06SD) days with an average cost of ZAR327 962 per patient. CONCLUSION: Results suggest outcomes are similar toother settings and countries. Ongoing data collection is required to better understand long-term outcomes and costs

Draft Genome Sequences of the Nitrate-Dependent Iron-Oxidizing Proteobacteria <i>Acidovorax</i> sp. Strain BoFeN1 and <i>Paracoccus pantotrophus</i> Strain KS1

The draft genomes of the nitrate-dependent iron-oxidizing bacteria Acidovorax sp. strain BoFeN1 and Paracoccus pantotrophus strain KS1 are presented. These genomes supply supporting data to investigations of the mechanisms underlying this anaerobic form of microbial biogeochemical iron cycling

The Cauchy problem for the 3-D Vlasov-Poisson system with point charges

In this paper we establish global existence and uniqueness of the solution to the three-dimensional Vlasov-Poisson system in presence of point charges in case of repulsive interaction. The present analysis extends an analogeous two-dimensional result by Caprino and Marchioro [On the plasma-charge model, to appear in Kinetic and Related Models (2010)].Comment: 28 page

Human thyroid tumours, the puzzling lessons from E7 and RET/PTC3 transgenic mice

Human rearranged RET/PTC3 (papillary thyroid carcinoma) proto-oncogene and high-risk human papillomavirus (HPV) type 16 E7 oncogene induces in the mouse a neoplastic transformation of thyroid follicular cells. We present a detailed immuno-histological study (170 mouse thyroids: RET/PTC3, E7, wild type, 2- to 10-month-old) with cell cycle proliferation and signalling pathway indicators. The characteristics of both models are different. There is an ‘oncogene dependent' cellular signature, maintained at all studied ages in the E7 model, less in the RET/PTC3 model. During tumour development a large heterogeneity occurred in the Tg-RET/PTC3 model within a same tumour or within a same thyroid lobe. The Tg-E7 model was less heterogeneous, with a dominant goitrous pattern. The solid tumour already described in the RET/PTC3 models associated with cribriform patterns, suggested ‘PTC spindle cell changes' as in humans PTC rather than the equivalent of the solid human PTC. Proliferation and apoptosis in the two thyroid models are related to the causal oncogene rather than reflect a general tumorigenic process. The thyroids of RET/PTC3 mice appeared as a partial and transient model of human PTCs, whereas the Tg-E7 mice do not belong to the usual PTC type

Follicular thyroid lesions: Is there a discriminatory potential in the computerized nuclear analysis?

Background: Computerized image analysis seems to represent a promising diagnostic possibility for thyroid tumors. Our aim was to evaluate the discriminatory diagnostic efficiency of computerized image analysis of cell nuclei from histological materials of follicular tumors. Methods: We studied paraffin-embedded materials from 42 follicular adenomas (FA), 47 follicular variants of papillary carcinomas (FVPC) and 20 follicular carcinomas (FC) by the software ImageJ. Based on the nuclear morphometry and chromatin texture, the samples were classified as FA, FC or FVPC using the Classification and Regression Trees method. Results: We observed high diagnostic sensitivity and specificity rates (FVPC: 89.4% and 100%; FC: 95.0% and 92.1%; FA: 90.5 and 95.5%, respectively). When the tumors were compared by pairs (FC vs FA, FVPC vs FA), 100% of the cases were classified correctly. Conclusion: The computerized image analysis of nuclear features showed to be a useful diagnostic support tool for the histological differentiation between follicular adenomas, follicular variants of papillary carcinomas and follicular carcinomas.This study received financial support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; process number 2014/10028-2), and PIBIC/PROPE-Unesp (process number 33347). The authors thank to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; process number 2014/10028-2), and PIBIC/PROPE-Unesp (process number 33347) for the research support and to Marcos Roberto Franchi and Luiz Fernando Franchi for the help in processing the histological material