Development and application of HPLC-RI and HPLC-MS/MS based methods for quantification of residual deoxycholate levels in pneumococcal polysaccharides.

The analysis of residual sodium deoxycholate (DOC); a detergent of biological origin used in manufacturing of polysaccharide vaccines is challenging due to complex sample matrices and the lack of suitable methods. Here we report, rapid and sensitive high-performance liquid chromatography-refractive index (HPLC-RI) and tandem mass spectrometry (HPLC-MS/MS) methods for estimation of residual DOC in pneumococcal polysaccharides. For HPLC-RI method, separation was achieved using Luna C18 column and mobile phase compositions of acetonitrile: methanol: 20 mM sodium acetate (60:05:35% v/v). For HPLC-MS/MS method, separation was achieved using a Hypersil BDS C18 column with gradient elution of methanol and water (0.1% formic acid). MS/MS method showed linearity (r2 = 0.997) over the range of 10-320 ng/mL with limits of detection (LOD) and lower limit of quantitation (LOQ) of 3 and 10 ng/mL respectively. Precision (% RSD) and accuracy (% recovery) for both methods were in the range of 0.74-8.29% and 82.33-117.86% respectively. Sample matrices interferences were addressed following novel sample clean-up method based on liquid-liquid extraction. Both methods enabled traceable quantitation of DOC in intermediate and purified pneumococcal polysaccharides of serotypes: 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.

Structural and electrochemical analysis of a novel co-electrodeposited Mn2O3-Au nanocomposite thin film.

In this work we report the fabrication of both pristine Mn2O3 and Mn2O3-Au composite thin films on an indium tin oxide (ITO) substrate by a one-step novel co-electrodeposition technique. From the electron microscopy study, we observed that these two films are morphologically different. The main aim of this study is to understand the effect of the nanostructure and metal integration on the electrochemical charge storage properties of these two films. Since a charge storage mechanism is possible through faradic red-ox reaction and non-faradic double layered process, electrochemical characterization and frequency response analysis indicate better charge storage properties of the composite system over pristine Mn2O3. The Mott-Schottky analysis is used for the charge carrier estimation which provides the electronic properties of both the samples. Besides the mechanism of the co-electrodeposition technique, we also discuss in detail the material characterization of both pristine Mn2O3 and Mn2O3-Au composite samples using XRD, EELS and electron microscopy analysis. To the best of our knowledge, the electrochemical properties of the Mn2O3-Au composite sample are reported here for the first time.

Effect of follicular fluid oxidative stress on meiotic spindle formation in infertile women with polycystic ovarian syndrome.

BACKGROUND: The effect of follicular fluid (FF) oxidative stress (OS) on meiotic spindle (MS) formation in oocytes and subsequent outcome in women with polycystic ovarian syndrome (PCOS) are evaluated in this study. METHODS: 326 oocytes from 35 PCOS women (group A) and 208 oocytes from 32 women with tubal infertility (group B) were visualized for MS using PolScope. FF was analyzed for OS markers including reactive oxygen species (ROS), lipid peroxidation and total antioxidant capacity (TAC). Group A was further classified into groups A1 and A2, and group B into groups B1 and B2 depending upon the presence or absence of MS, respectively. RESULTS: MS formation was absent in a significantly higher number of oocytes in group A compared to group B (p

Evaluation of women seeking sterilisation reversal.

A total of 1120 women attending at Regional Centre of Excellence (RCOE), RG Kar Medical College and Hospital, Calcutta from October, 1989 to July, 1998 with the request for sterilisation reversal (SR) were evaluated step by step for fitness of SR operation on the basis of history, clinical examination, pre-operative investigations, fertility status and laparoscopic findings. One thousand and sixty couples completed their evaluation. Majority of the SR seekers were young (< 30 years) and significant number (8.9%) of women came in late age (> 40 years). Most (85.8%) of the women had one or no child. The main reason for requesting reversal was death of children (91.8%). Only 43.3% were ultimately found fit for SR operation and rest (56.7%) were refused. Presence of 2 or more children in not remarried couple (13.8%), gross pelvic pathology (2.35%), advanced age (8.7%), seminopathy (4.05%), and some medical diseases (3.2%) were important reasons before pre-operative investigations for refusal. Faulty sterilisation technique (11%) was responsible for refusal at laparoscopic evaluation. The need of critical evaluation of all women seeking reversal has been emphasised in this study. Various aspects related with demand for SR and preventive measures to improve the success of this procedure have been critically discussed.