Vitamin B<Subscript>12</Subscript> Immunoassay on Roche Elecsys 2010: Effects of High Excess Concentration of Serum Vitamin B<Subscript>12</Subscript> in CKD Patients on Parenteral Administration

Vitamin B₁₂ being water soluble is excreted in the urine when administered in excess. The probability of finding an abnormally excess serum concentration would be almost surreal. We report a peculiar clinical situation that may impact the vitamin B₁₂ immunoassay on the Roche Elecsys 2010 due to excess analyte concentration. In separate episodes (Feb and June 2010), the Biochemistry laboratory of a tertiary-care hospital, Kolkata, India, encountered two critically ill patients with background chronic kidney disease (CKD), low urine output, and on cyanocoabalamin supplementation, who had serum vitamin B₁₂ concentrations far exceeding expected values; even post dialysis. The B₁₂ assays (pmol/l) were performed using electrochemiluminiscence immunoassay on Roche Elecsys 2010, the assay validity confirmed by concomitant quality control runs. The immunoassays failed to deliver results, flagged with “signal level below limit”. Biotin therapy was ruled out as a possible interferent. In the first episode, re-assay of a repeat draw yielded same outcome; outsourcing on Immulite provided concentration of >738 pmol/l. Serial dilution gave result of >29520 pmol/l on Elecsys 2010. In the second, we gained from past experience. Vitamin B₁₂ concentration >59040 pmol/l was conveyed to the treating nephrologist the very day. The B₁₂ immunoassay on the Elecsys 2010 employs sequential incubation steps for competitive binding that is compromised in the event of abnormally excess B₁₂ concentration in patient sera akin to the prozone effect. This knowledge may be beneficial while assaying sera of CKD patients to avoid financial loss due unnecessary repeats and delay in turnaround time.     

A study of readability of texts in Bangla through machine learning approaches

In this work, we have investigated text readability in Bangla language. Text readability is an indicator of the suitability of a given document with respect to a target reader group. Therefore, text readability has huge impact on educational content preparation. The advances in the field of natural language processing have enabled the automatic identification of reading difficulty of texts and contributed in the design and development of suitable educational materials. In spite of the fact that, Bangla is one of the major languages in India and the official language of Bangladesh, the research of text readability in Bangla is still in its nascent stage. In this paper, we have presented computational models to determine the readability of Bangla text documents based on syntactic properties. Since Bangla is a digital resource poor language, therefore, we were required to develop a novel dataset suitable for automatic identification of text properties. Our initial experiments have shown that existing English readability metrics are inapplicable for Bangla. Accordingly, we have proceeded towards new models for analyzing text readability in Bangla. We have considered language specific syntactic features of Bangla text in this work. We have identified major structural contributors responsible for text comprehensibility and subsequently developed readability models for Bangla texts. We have used different machine-learning methods such as regression, support vector machines (SVM) and support vector regression (SVR) to achieve our aim. The performance of the individual models has been compared against one another. We have conducted detailed user survey for data preparation, identification of important structural parameters of texts and validation of our proposed models. The work posses further implications in the field of educational research and in matching text to readers.     

A closer look at the Mulliken-Barker test

Qualitative analysis of unknown organic compounds is an essential part of the core curriculum for BSc and MSc students in chemistry. The functional group detection is a significant component of qualitative analysis. The present work describes the reason for the failure of Mulliken-Barker test for nitro compounds having carboxylic acid functionality and suggests a possible remedy.     

Microalbuminuria: An inexpensive,non invasive bedside tool to predict outcome in critically ill patients

This study was conducted to evaluate whether microalbuminuria on admission and after 24 hrs of admission to intensive care unit (ICU) predicts outcome as well as the Acute Physiology and Chronic Health Evaluation (APACHE) II severity illness score, the current accepted method of doing so. The study was carried out in a 20 bed mixed medical-surgical ICU of a tertiary care hospital. Of 525 consecutive adult patients with ICU stay of more than 24 hrs, 238 were included for the study. Patients with pregnancy, menstruation, anuria, macroscopic hematuria, urinary tract infection, marked proteinuria due to renal and post-renal structural diseases, were excluded. Spot urine samples were collected on admission to ICU and 24 hrs thereafter. Urine albumincreatinine ratio (ACR) was measured on ICU admission (ACR1) and after 24 hrs (ACR2) and expressed in mg/g. Patient demographics were noted on admission. For disease severity scoring, APACHE II scores were calculated. Each patient was followed up throughout their ICU stay for a maximum of 28 days and the following outcome data were obtained: ICU length of stay and ICU mortality. Of the 238 patients, 196 survived while 42 patients died in the ICU. Non-survivors had a significantly higher median ACR2 [162.7 mg/g (IQR 69.5–344.3)] in comparison to the survivors who had a median ACR2 = 54.4 mg/g (IQR 19.0–129.1) (P< 0.0001). The median ACR1 [161.0 mg/g (IQR 29.0–369.3)] of non-survivors was higher than the median ACR1 [80.4 mg/g (IQR 35.1–167.6)] of survivors but failed to reach statistical significance (P= 0.0948). In a receiver operating characteristic curve (ROC) analysis, ACR2 emerged as the best indicator of mortality [(area under curve (AUC) of ACR2 = 0.71 > AUC (ACR1) =0.58 > AUC (ΔACR) =0.55] similar to the currently used APACHE II scores (AUC = 0.78) (P=0.3). At a cutoff of 101 mg/g, ACR2 had a sensitivity of 69%, specificity of 67%, positive predictive value of 31% and a negative predictive value of 91% for predicting mortality in the critically ill patients. Absence of significant microalbuminuria at 24 hrs of ICU admission may help to predict survival in the ICU.     

Silicon photonics Silicon Raman lasers

The increased use of optoelectronic devicessuch as TV screens and computer monitors in everyday life, calls for a material on which integration of all circuits may be performed. Silicon, the most widely used material in electronics, has limited application in optoelectronics due to its poor light emission property. In this article, the need for silicon photonics in present day ICs, and communication, the reason for its inefficient light emission, and recent breakthrough in the form of Si Raman laser are discussed.     

Correlation between Apgar score and urinary uric acid to creatinine ratio in perinatal asphyxia

A randomized case control hospital based study was conducted over 12 months time on 31 asphyxiated and 31 normal newborn to see whether urinary uric acid can be used as a marker of perinatal asphyxia and can be correlated with the clinical diagnosis by Apgar score. Uric acid and creatinine were estimated in spot urine within 24 hours after birth in both cases and controls. A ratio between concentrations of uric acid to creatinine was estimated and compared between cases and controls. It was found that the ratios were significantly higher in cases than controls (3.1± 1.3 vs 0.96± 0.54; P < 0.001) and among asphyxia patients, a significant negative linear correlation was found between the uric acid to creatinine ratio and the Apgar score (r = −0.857, P < 0.001). So urinary uric acid to creatinine ratio can be used as an additional non-invasive dispace, easy and at the same time early biochemical marker of birth asphyxia which biochemically supports the clinical diagnosis and severity grading of asphyxia by Apgar score.     

Separation and identification of thyroid autoantibodies in patients with thyroid disorders by hydrophobic column

A method has been developed to separate and identify thyroglobulin autoantibody (TgAb) and thyroid peroxidase autoantibody (TPOAb) in serum obtained from normal and autoimmune thyroid diseases using phenyl Sepharose CL-4B hydrophobic column. The protein peaks obtained from hydrophobic column were identified as TgAb and TPOAb by comparing the elution profile of commercially purified standard thyroid autoantibodies. The similarity of the inhibitory effects of eluted proteins and of standard thyroid autoantibodies on lectin concanavalin A-RBC interaction confirmed the separation of TPO-Ab and TgAb by the hydrophobic, column. The eluted fractions from the hydrophobic column were estimated by the radio immunoassay (RIA) to confirm the presence of both auto-antibodies. This hydrophobic column method offers an advantage of visual inspection of this autoantibodies by graphic representation of peak height along with their estimation in autoimmune thyroid disorders.     

‘But What’s the Use? They Don’t Wear Breeches!’: Montaigne and the pedagogy of humor

Abstract

By virtue of his Essays Montaigne is rightly regarded not only as a radically modern philosopher but also as a transformative educational innovator. He confronted the extent to which pedantry and acculturation can justify cruelty by developing a conception of liberal arts education as the arts of liberation, and at the core of this education he placed the practice of essaying. This article argues that in easing us into essaying practices Montaigne qua educator makes reflexive use of three specific modes of didactic humor: incongruous comparison, subversive superiority, and leveling embodiment. Humor thus emerges as a cognitive disposition and communicative mode especially appropriate to the pedagogical engagement with difference today.