The present study was undertaken out of a commercial need for the synthesis of Linezolid with impurity limits within the specification.
(R)-Glycidyl butyrate (RGB) is raw material for the synthesis ...of Linezolid drug substance. This RGB contains (S)-(+)-Glycidyl butyrate (SGB) and SGB appears in same concentration in the final Active Pharmaceutical Ingredient. So, a normal phase high-performance liquid chromatography (HPLC) method has been developed to determine the SGB level in the raw material. RGB and SGB were separated using an HPLC system equipped with quaternary gradient pumps on a Daicel chiralpak AD-H (250 × 4.6 mm) column with a mobile phase consisting 2.0 ml of ethanol in 1 000 ml of n-hexane. A 0.5 ml/minute flow rate and a 10 μl injection volume was used and the compounds were detected at 215 nm.
Method validation parameters demonstrated the same to be reliable, reproducible, and accurate one.
Thus, the present study may be used for regular quality control of RGB to improve commercial feasibility for the synthesis of Linezolid.
Colposcopy: gynecological vision in viewing oral lesions Nayyar, Abhishek Singh; Khan, Mubeen; Bafna, U D ...
Indian Journal of Pathology and Microbiology/Indian journal of pathology and microbiology,
04/2014, Volume:
57, Issue:
2
Journal Article
Peer reviewed
Open access
The diagnosis of malignant and potentially malignant epithelial lesions of the oral mucosa cannot be based solely on clinical findings. The histologic evaluation of a representative biopsy specimen ...thus becomes necessary. The site for biopsy however is always a subjective choice that sometimes raises doubts about its representativeness. So far, no simple and reliable method is available for the selection of the most appropriate area for biopsy. Colposcopy is helpful in the selection of these sites of epithelial dysplasia depending upon the vascular patterns.
This study was planned to assess the role of Colposcopic examination in the selection of biopsy site in patients with varying grades of oral epithelial dysplasia at various sites.
One hundred and eighty patients between the ages of 30 and 60 years clinically diagnosed with leukoplakia and carcinoma buccal mucosa were included in the study.
For each of the subjects, a thorough clinical examination followed by Colposcopic assessment was carried out for the selection of biopsy site from the involved mucosa. The histopathological findings were then compared in the two cases and results analyzed.
The statistical analysis was performed using a paired t-test.
In our study, sensitivity and specificity for the selection of biopsy site by Colposcopic examination was found to be higher for leukoplakia than for carcinoma buccal mucosa.
It was concluded that Colposcopic examination was found to be significant in the selection of biopsy site for leukoplakia while clinical criterion was found to be more appropriate for carcinoma buccal mucosa cases.
PurposeTo determine the disease pathogenesis associated with the frequent ABCA4 variant c.5714+5G>A (p.=,Glu1863Leufs*33). MethodsPatient-derived photoreceptor precursor cells were generated to ...analyze the effect of c.5714+5G>A on splicing and perform a quantitative analysis of c.5714+5G>A products. Patients with c.5714+5G>A in trans with a null allele (i.e., c.5714+5G>A patients; n = 7) were compared with patients with two null alleles (i.e., double null patients; n = 11); with a special attention to the degree of RPE atrophy (area of definitely decreased autofluorescence and the degree of photoreceptor impairment (outer nuclear layer thickness and pattern electroretinography amplitude). ResultsRT-PCR of mRNA from patient-derived photoreceptor precursor cells showed exon 40 and exon 39/40 deletion products, as well as the normal transcript. Quantification of products showed 52.4% normal and 47.6% mutant ABCA4 mRNA. Clinically, c.5714+5G>A patients displayed significantly better structural and functional preservation of photoreceptors (thicker outer nuclear layer, presence of tubulations, higher pattern electroretinography amplitude) than double null patients with similar degrees of RPE loss, whereas double null patients exhibited signs of extensive photoreceptor ,damage even in the areas with preserved RPE. ConclusionsThe prototypical STGD1 sequence of events of primary RPE and secondary photoreceptor damage is congruous with c.5714+5G>A, but not the double null genotype, which implies different and genotype-dependent disease mechanisms. We hypothesize that the relative photoreceptor sparing in c.5714+5G>A patients results from the remaining function of the ABCA4 transporter originating from the normally spliced product, possibly by decreasing the direct bisretinoid toxicity on photoreceptor membranes.
Five impurities in glimepiride drug substance were detected and quantified using a simple isocratic reverse phase HPLC method. For the identification and characterization purpose these impurities ...were isolated from a crude reaction mixture of glimepiride using a normal phase HPLC system. Based on the spectroscopic data like NMR, FTIR, UV and MS these impurities were characterized and used as impurity standards for determining the relative response factor during the validation of the proposed isocratic reverse phase HPLC method. The chromatographic separation was achieved on a Phenomenex Luna C8 (2) 100
Å, 5
μm, 250
mm
×
4.6
mm using a mobile phase consisting of phosphate buffer (pH 7.0)–acetonitrile–tetrahydrofuran (73:18:09, v/v/v) with UV detection at 228
nm and a flow rate of 1
ml/min. The column temperature was maintained at 35
°C through out the analysis. The method has been validated as per international guidelines on method validation and can be used for the routine quality control analysis of glimepiride as active pharmaceutical ingredient (API).
ABCA4-Associated Stargardt Disease Khan, Mubeen; Cremers, Frans P M
Klinische Monatsblatter fur Augenheilkunde
237, Issue:
3
Journal Article
Peer reviewed
Autosomal recessive Stargardt disease (STGD1) is associated with variants in the
gene. The phenotypes range from early-onset STGD1, that clinically resembles severe cone-rod dystrophy, to ...intermediate STGD1 and late-onset STGD1. These different phenotypes can be correlated with different combinations of
variants which can be classified according to their degree of severity. A significant fraction of STGD1 cases, particularly late-onset STGD1 cases, were shown to carry only a single
variant. A frequent coding variant (p.Asn1868Ile) was recently identified which - in combination with a severe
variant - is generally associated with late-onset STGD1. In addition, an increasing number of rare deep-intronic variants have been found and some of these are also associated with late-onset STGD1. The effect of these and other variants on
RNA was tested using
assays in human kidney cells using specially designed midigenes. With stem cells and photoreceptor progenitor cells derived from patient skin or blood cells, retina-specific splice defects can be assessed. With expert clinical examination to distinguish STGD1 cases from other maculopathies, as well as in-depth genomics and transcriptomics data, it is now possible to identify both mutant
alleles in > 95% of cases.
Objective: To study the clinical types and association of psychological factors in patients with Oral Lichen Planus (OLP). Materials and Methods: An analytical age- and sex-matched study involved 30 ...patients with oral lichen planus (group 1) and 30 control subjects (group 2). We applied the following psychometric tests to both groups: General Health Questionnaire (GHQ) and Hospital Anxiety and Depression Scale (HADS). Results: The patients with OLP were found to exhibit statistically significant higher anxiety, insomnia, and social dysfunction with the tests that were used (GHQ 24 and HADS) than the control group (P > 0.05). The study group likewise exhibited greater depression and somatic symptoms. The mean total of the GHQ and HAD scores were found to be higher in the study group than in the controls (P > 0.05). Among the various types of OLP, patients with the erosive type had higher mean scores for anxiety and insomnia, social dysfunction and depression. Conclusion: In most patients psychiatric morbidity was strongly associated with OLP, which could support its role in the etiopathogenesis of the disease. The higher scores of the General Health Questionnaire and Hospital Anxiety and Depression Scale gave an insight into the hypothesis that psychological factors are associated with the causation of OLP.
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