Optimization of Formaldehyde Fixative Concentration for Individual Blood Cells to Develop a Stabilized Blood Control for Automated Hematology Analyzers.

In a modern haematology laboratory, the complete and differential counts of blood are performed using complex haematology auto analyzers. In order to ensure the accuracy and reliability of test results, various regulatory authorities have prescribed the use of stabilized blood controls. The major pitfalls of these blood controls are their short shelf life. This could be due to the fact that they are prepared by a common cocktail of fixatives which acts on the discrete cells in various ways and would result in either under-fixation or over-fixation of various cells. Thus, in the present study, we have explored and optimized fixative and buffering for individual cells to achieve stable blood control. Blood cells were isolated using the centrifugation technique and were fixed individually with different concentrations of formaldehyde. After fixation, cells were pooled. Analysis of cell count was done till six months. Cells were also analysed morphologically to see the effect of fixation and storage on cell morphology. In the present study we compared the effect of the concentration of formaldehyde fixative for individual cells in the blood and their role in enhancing the shelf life and maintaining the morphology of the cells when suspended in plasma or suitable buffers post-fixation. It was observed that WBCs can be better fixed with 3 and 3.5% formaldehyde in a buffered solution, whereas RBCs and Platelets can be optimally fixed with 2.5% formaldehyde in a buffered solution.

Clinical profile and outcome of endogenous endophthalmitis at a quaternary referral centre in south India.

Purpose: The purpose of this study is to evaluate the clinical profile, visual, anatomical and survival outcome of patients with endogenous endophthalmitis. Methods: Retrospective chart review of consecutive cases with endogenous endophthalmitis presenting from 2009-2016. Results: In our study, 41 eyes of 34 patients were included. Most common co-morbidity associated with endogenous endophthalmitis was Diabetes Mellitus (70.7%) and most common infective foci was UTI (73.2%). Among the culture positive cases, fungi and bacteria were evenly distributed, 76.93% were Gram positive bacteria and 23.07% were Gram negative. Fungal endogenous endophthalmitis was more commonly seen in immunosuppressed state (72.7%) and bilateral cases (66.7%). The mean presenting vision (log MAR) of patients who died during the study were poor compared to those who survived (P = 0.014) Poor mean visual acuity at presentation was associated with more death (P = 0.014). Eyes with poor presenting vision, fungal isolates, culture positivity and immune suppression had poor visual and survival outcome. Poor visual outcome was observed more frequently in eyes with Aspergillus infection (85.7%) compared to Candida (75%) and bacteria (58.3%). Evisceration was done for 5 out of 41 eyes (12.2%). Vitrectomy rate was 53.7% in our study, with 40% of them showing overall improvement in vision. Conclusion: Endogenous endophthalmitis is a sight threatening condition associated with high mortality particularly when caused by Aspergillus spp. in immunocompromised patients. Contrary to the prior published reports of endogenous endophthalmitis outside India, we found an equal distribution of fungal and bacterial organisms among our cases, with predominance of Aspergillus among fungal isolates and Gram-positive organism among bacteria. Fungal infections, especially with Aspergillus spp., resulted in poor visual and survival outcome.

Mycobacterium chelonae infection complicating traumatic and surgical wounds: A case series.

Mycobacterium chelonae is a rapidly growing non-tuberculous mycobacterium. The skin and soft tissue infections due to this organism are steadily on the rise and need to be delineated specifically as most of these are not responsive to routine antituberculosis treatment. Here, we report 3 different presentations caused by Mycobacterium chelonae in traumatic and surgical wounds. Mycobacterium chelonae can complicate surgical or traumatic wounds.This infection may also present as injection site abscesses. Diabetics on insulin injections are especially at risk. A high index of suspicion is necessary in long standing culture negative lesions for clinching the diagnosis. PCR can be helpful in confirming the diagnosis.

Cytogenetic studies on newborns from high and normal level natural radiation areas of Kerala in southwest coast of India.

PURPOSE: To study, characterize and compare chromosome aberrations and karyotype anomalies among newborns from high (> 1.5 mGy/y) and normal (≤ 1.5 mGy/y) level natural radiation areas of monazite-sand bearing southwest coast of Kerala in India. MATERIALS AND METHODS: Cord blood samples from newborns were collected from selected Government hospitals in heparinized vials and cultures were set up employing standard microculture techniques, slides were prepared, coded and stained with giemsa. Well spread metaphases were analyzed for chromosome aberrations and karyotype anomalies. RESULTS: A total of 1,267,788 metaphases from 27,295 newborns of mothers aged 17-45 years (17,298 from high and 9,997 from normal level radiation areas) were analyzed during 1986-2007. Frequencies of dicentrics in high and normal level radiation areas were 1.90 ± 0.14 and 2.01 ± 0.26 per 10,000 cells, respectively (Relative frequency [RF] = 0.94; 95% CI: 0.71-1.26). Karyotype anomalies had a frequency of 5.49‰ and 6.7‰, respectively (RF = 0.82; 95% CI: 0.60-1.12). No dose-related trend was observed in chromosome aberrations or karyotype anomalies. CONCLUSION: Frequencies of chromosomal aberration and karyotype anomalies between the newborns from the high level natural radiation area (HLNRA) and normal level natural radiation areas (NLNRA) were very similar.