Browsing by Author "Srinivasan, MR"
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ArticleItem Open Access A Comparative Study on Staining Techniques for Vaginal Exfoliative Cytology of Rat(2017-07) Srinivasan, MR; Sabarinathan, A; Geetha, A, et al.,; TANUVASThis study describes the suitable vaginal exfoliative cytology staining technique for the study of various stage of estrus cycle. Two staining techniques namely Crystal violet and Papanicolaou stains were compared and evaluated for various types of cells during the four stage of estrous cycle in rats. The study revealed that the Papanicolaou staining is a better method over crystal violet staining technique, because the Papanicolaou staining is polychromatic, hence it yields clear nuclear and cytoplasmic details of vaginal exfoliativecells. This study concludes that the Papanicolaou staining technique can be utilized for vaginal exfoliative cells staining for the determination various cell stages in estrous cycle in rats.ArticleItem Open Access Genotoxicity assessment of andrographolide in Ames mutagenicity assay and in vitro chromosomal aberration assay(2021) Srinivasan, MR; Preetha, SP; Sudhakar Rao, GV, et al.,; TANUVASAbstract Andrographis paniculata (Burm.f.) Nees. is a medicinal herb widely used in various traditional medicines for the treatment of various ailments particularly related to viral fever, respiratory tract infections, and other pharmacological properties. Andrographolide is a diterpene present as a major active ingredient responsible for various pharmacological activities. This study was conducted to assess the mutagenicity and clastogenicity potential of the andrographolide by Ames mutagenicity and in vitro chromosomal aberration studies, respectively. Materials and Methods: Ames Mutagenicity assay was performed using Salmonella typhimurium strains, TA100, TA1535, TA102 and TA98 and TA1537 and in vitro chromosomal aberration study was performed in CHO-K1 cell line. Both these studies were conducted following the procedure mentioned in the OECD guidelines no. 471 and 473 for Ames and in vitro chromosomal aberration studies, respectively. Results: Andrographolide was found to be non-mutagenic in Ames mutagenicity assay and non-clastogenic in the in vitro chromosomal aberration study in the CHO-K1 cell line.ArticleItem Open Access Non-Invasive Fecal Based PCR Assays for Detection of Mouse Parvo Virus and Minute Virus of Mice in Laboratory Mice(2021-11) Srinivasan, MR; Vijay, K; Karuppannan, AK, et al.,; TANUVASABSTRACT Background: Murine parvoviruses are a few of the most common pathogens of laboratory mice posing potential threats to mice colonies and experiments conducted in mice. We initiated this study to develop the fecal based PCR assays as an alternative to serology and to check its feasibility to detect the infections in mice caused by Mouse Parvo Virus (MPV) and Minute Virus of mice (MVM). Methods: Primers targeting the VP2 gene of MPV and MVM were selected and their sensitivity was analysed in tenfold serially diluted gene template in the presence of negative mouse fecal DNA. Selected thirty-seven mice at the age of 6 to 18 weeks randomly and collected blood samples for serology and fecal samples for PCR assays. Result: PCR assays of MPV and MVM detected as low as 0.4 fg of the target plasmid DNA. PCR assays in fecal samples of mice detected the presence of natural infections of MPV and MVM and their respective prevalence was 24% and 30%. Diagnostic sensitivity of MPV and MVM were 74% and 76% respectively. Our findings indicate that the fecal-PCR assay may be a useful, non-invasive and sensitive diagnostic tool in the ante-mortem detection of MPV and MVM in the health monitoring program.ArticleItem Open Access The pharmacokinetic disposition of Enrofloxacin in zebrafish by aquarium water exposure, oral and intraperitoneal administration(2021) Sakthivel, D; Srinivasan, MR; Karthik Venkatesh, P; TANUVASZebrafish (Danio rerio) is an emerging alternative animal model used for screening pharmacological effects and safety studies. One of the bottlenecks for the lack of PK data in zebrafish is the inability to collect the volume of blood required for bioanalysis. To make zebrafish a suitable alternative animal model to mammalian species to study the PK profile of a drug, we have used the skeletal muscles as an alternative to blood for bioanalysis based on the assumption that they may exhibit an equilibrium with the concentration of drug in blood and it is easy to collect muscle after euthanasia. Hence the current study was undertaken to assess the comparative pharmacokinetic profile of enrofloxacin administered by oral route, intraperitoneal (IP) route, and mixed in aquarium water. The fishes were euthanized and the skeletal muscle was collected at various time points. An assay of Enrofloxacin in skeletal muscle was done using a validated HPLC method. The AUC (μg/g.h) values for oral, intraperitoneal and exposed water routes are 2.82, 2.91 and 4.34 respectively, Cmax (μg/g) values are 0.71, 0.64 and 0.30 respectively. The results revealed that the oral and intraperitoneal (IP) route showed a better PK profile than mixed in water for enrofloxacin. The results show that the PK of enrofloxacin administered by oral and intraperitoneal route showed the typical absorption and elimination phase, whereas enrofloxacin mixed in water did not show the absorption and elimination phase. Hence it is reasonable to conclude that zebrafish can be used as an alternative model to mammals for understanding the PK of a drug. However further studies are required to ascertain their utility as an alternative to studying PK or TK of drugs.ArticleItem Open Access Rapid and Sensitive Faecal based PCR Assays for the Detection of Parvoviruses in Laboratory Rats(2020-08) Srinivasan, MR; Vijay, K; Ramesh, S; Karuppannan, AK; Krishnamohan Reddy, Y; TANUVASHealth status of laboratory rats indicates its suitability for the researches. They are prone to develop viral infections of subclinical nature caused by parvoviruses, which affects the research results adversely; Hence Implementation of health monitoring protocol is essential at the level of breeding colony itself. This study was intended to develop rapid and sensitive fecal-PCR assays to detect infections of multiple species of Parvoviruses affecting rats namely, Rat Minute Virus, Toolan’s Parvo Virus, Rat Parvo Virus and Kilham’s Rat Virus as an alternate approach to serology based health monitoring in a lab animal breeding unit. All the primers detected only in the presence of the respective templates. PCR assays of RMV and TPV consistently amplified as little as 40 fg and that of RPV and KRV consistently amplified as little as 4 fg of plasmid DNA. Specificity and sensitivity assays indicate that the PCR assays may be useful as diagnostic tools for rapid detection of natural acute viral infections. Further analysis of the primers in the positive laboratory animal colony is essential.ArticleItem Open Access RT-PCR Assay for Detection of Enterotropic Strains of Mouse Hepatitis Virus in Faecal Samples(2020) Srinivasan, MR; Vijay, K; Karuppannan, AK, et al.,; TANUVASABSTRACT Background: Mouse Hepatitis Virus (MHV) is one of the most important and common viral infections of laboratory mice, due to its highly contagious and subclinical nature, posing threat to the research outcomes. Periodic screening of laboratory mice for MHV is mandatory. Hence, this study was intended to develop sensitive faecal based RT-PCR assays to detect active infection of enterotropic MHV in laboratory mice. Methods: Primers targeting N-gene of MHV were selected and their sensitivity was analysed in tenfold serially diluted gene template in the presence of negative mouse faecal cDNA. Thirty-six weaned mice at the age of 6 to 18 weeks were randomly selected at different periods and the blood and faecal sample were collected for serology and RT-PCR assay respectively. RT-PCR assay in colon samples was carried out for comparison. Result: PCR assay of MHV detected as low as 4 fg of plasmid DNA. Seroprevalence of MHV is very high than the prevalence by RTPCR assay showing its retrospective nature and also seroprevalence includes both enterotropic and polytropic strain. RT-PCR results in faecal samples are analogous with that of the colon samples, showing the reliability of antemortem testing of mice for enterotropic strain of MHV.ArticleItem Open Access கால்நடைத் தீவனம் மற்றும் உணவுப் பாதுகாப்பிற்கான ஆய்வகத்தின் சேவைகள் பற்றிய விளக்கம்(2021-08) Raghu, D; Srinivasan, MR; Jayakanth, CM; TANUVAS