Parathion: residues in soil and water.
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Animals↗
Biomedical subjects
S Barik
Publications and source records attributed to S Barik.
Visual inspection with acetic acid and cytology in the early detection of cervical neoplasia in Kolkata, India.
Visual inspection of the cervix after application of 3-5% acetic acid (VIA) is a potential alternative to cytology for screening in low-resource countries. The present study evaluated the performance of VIA, magnified visual inspection after application of acetic acid (VIAM), and cytology in the detection of high-grade cervical cancer precursor lesions in Kolkata (Calcutta) and suburbs in eastern India. Trained health workers with college education concurrently screened 5881 women aged 30-64 years with VIA, VIAM, and conventional cervical cytology. Detection of well-defined, opaque acetowhite lesions close to the squamocolumnar junction; well-defined, circumorificial acetowhite lesions; or dense acetowhitening of ulceroproliferative growth on the cervix constituted a positive VIA or VIAM. Cytology was considered positive if reported as mild dysplasia or worse lesions. All screened women (N = 5881) were evaluated by colposcopy, and biopsies were directed in those with colposcopic abnormalities (N = 1052, 17.9%). The final diagnosis was based on histology (if biopsies had been taken) or colposcopic findings, which allowed direct estimation of sensitivity, specificity, and predictive values. Moderate or severe dysplasia or carcinoma in situ (CIN 2-3 disease) was considered as true positive disease for the calculation of sensitivity, specificity, and predictive values of screening tests. 18.7%, 17.7% and 8.2% of the women tested positive for VIA, VIAM, and cytology. One hundred twenty two women had a final diagnosis of CIN 2-3 lesions. The sensitivities of VIA and VIAM to detect CIN 2-3 lesions were 55.7% and 60.7%, respectively; the specificities were 82.1% and 83.2%, respectively. The sensitivity and specificity of cytology were 29.5% and 92.3%, respectively. All the tests were associated with negative predictive values above 98%. VIA and VIAM had significantly higher sensitivity than cytology in our study; the specificity of cytology was higher than that of VIA and VIAM.
Acetic Acid↗
Assessment of the quality of frozen serum by spectrophotometric analysis and sperm bioassay.
Serum is an integral part of media used for in vitro fertilization (IVF) and andrology work. Previous studies showed that the IVF results could benefit if sera were screened for deleterious effects before use. Such screening is impractical when fresh sera are used but may be feasible if the serum is frozen prior to use. This study assessed the impact of freezing on the quality of serum. A total of 158 serum samples, prepared in a university-based andrology-IVF center, were included in the study. The frozen sera were thawed in batches to be used in a series of laboratory experiments. Serum quality was evaluated by spectrophotometric analysis and sperm bioassay under several defined conditions: fresh, frozen, pre- and postfiltration, pre- and postcentrifugation, and the patients' fertility condition. Although all sera were filtered through 0.22-micron filter, more than 10% frozen sera required 0.4- or a combination of 0.8- and 0.4-micron filters before they could be passed through the 0.22-micron filter. Frozen sera that were directly filtrable with a 0.22-micron filter lost 13% turbidity upon filtration. The turbidity of the frozen sera were higher compared to fresh ones as revealed by optical density (OD) and relative light scattering (RLS) spectrophotometry. The freeze/storage-induced spectrophotometric changes did not correlate with the storage time. The centrifugation caused precipitation of sera components. The rate of precipitation of the serum components correlated with the duration of freezing. Spectrophotometric analysis and sperm bioassay did not differentiate the sera of pregnancy-positive and pregnancy-negative subjects. The sperm bioassay failed to detect any biological impact of freezing-induced spectrophotometric changes in the sera, suggesting that the freezing-induced changes did not significantly diminish the serum's capability of supplementing the culture media.
Blood↗
Preconceptional sex selection: past, present, and future.
Predetermination of sex in human and in farm animals is reviewed. Preconceptional sex selection has generated great interest and controversy over the years. Medical and commercial benefits outweigh the ethical issues. Technology has not yet provided a routine method for separating the X- and Y-chromosome-bearing sperm. Flow cytometry is the only technique that produces a clinically significant enrichment of X- or Y-bearing spermatozoa However, concern has been raised about the methodological implications of the flow technique because of the use of DNA stains and UV light. Some other techniques, such as gradient columns, appear to produce a slight enrichment of one type of sperm over the other, but this level of enrichment appears unlikely to affect the sex ratio at birth. It thus remains speculative whether 100% pure preparation of X or Y sperm can be obtained unless a major improvement in methodology is achieved. Fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) are currently the methods of choice for evaluating the validity of the sex selection procedure. In view of the extraordinary pace of the technological and scientific progress, it can be expected that the clinical and commercial application of the technology of preconceptional sex selection by X and Y sperm separation will be a reality in near future.
Animals↗
Lack of significant morphological differences between human X and Y spermatozoa and their precursor cells (spermatids) exposed to different prehybridization treatments.
Human X and Y spermatozoa were previously compared by several nonmolecular techniques. Recent studies show that in many of the previous investigations, the methods used to identify the spermatozoa were nonspecific and thus produced contradictory findings. In the present study, the comparison of the 2 germ cell types, X and Y, were performed following fluorescence in situ hybridization (FISH), which is the most reliable genotyping technique currently available. The FISH technique was performed under 3 different treatments: permeabilization with liquid N2, fixation with Carnoy's, and chromatin decondensation with lithium di-iodosalicylate. Mature and immature germ cells (spermatozoa and spermatids) were compared. Lithium showed higher hybridization efficiency, while liquid N2 and Carnoy's fixative maintained better morphological integrity of cells with lower hybridization. The sperm exhibiting hybridization signals were not different in any of the morphometric or qualitative comparisons from those that did not exhibit signals. No significant deviation of the sex ratio from 1:1 was seen in either the mature or immature germ cell population. The spatial distribution of X and Y chromosome-specific signals in the sperm head were identical. The hybridization treatments did not have any preferential effect on the cells of specific genotype (X or Y). Neither head parameters (length, HL; width, HW; area, HA) nor tail length (TL) significantly differed between X and Y populations of spermatozoa under any of the treatments. Similarly, the haploid, X-specific round cells did not differ from Y-specific ones by their size (diameter) and shape. These results indicate that neither mature sperm nor their precursors possess significant morphological differences between X and Y genotypes.
Cell Separation↗
A preoperative gynaecological clinic.
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Female↗