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1.
G3 (Bethesda) ; 12(4)2022 04 04.
Article in English | MEDLINE | ID: mdl-35143647

ABSTRACT

Shrimp are a valuable aquaculture species globally; however, disease remains a major hindrance to shrimp aquaculture sustainability and growth. Mechanisms mediated by endogenous viral elements have been proposed as a means by which shrimp that encounter a new virus start to accommodate rather than succumb to infection over time. However, evidence on the nature of such endogenous viral elements and how they mediate viral accommodation is limited. More extensive genomic data on Penaeid shrimp from different geographical locations should assist in exposing the diversity of endogenous viral elements. In this context, reported here is a PacBio Sequel-based draft genome assembly of an Australian black tiger shrimp (Penaeus monodon) inbred for 1 generation. The 1.89 Gbp draft genome is comprised of 31,922 scaffolds (N50: 496,398 bp) covering 85.9% of the projected genome size. The genome repeat content (61.8% with 30% representing simple sequence repeats) is almost the highest identified for any species. The functional annotation identified 35,517 gene models, of which 25,809 were protein-coding and 17,158 were annotated using interproscan. Scaffold scanning for specific endogenous viral elements identified an element comprised of a 9,045-bp stretch of repeated, inverted, and jumbled genome fragments of infectious hypodermal and hematopoietic necrosis virus bounded by a repeated 591/590 bp host sequence. As only near complete linear ∼4 kb infectious hypodermal and hematopoietic necrosis virus genomes have been found integrated in the genome of P. monodon previously, its discovery has implications regarding the validity of PCR tests designed to specifically detect such linear endogenous viral element types. The existence of joined inverted infectious hypodermal and hematopoietic necrosis virus genome fragments also provides a means by which hairpin double-stranded RNA could be expressed and processed by the shrimp RNA interference machinery.


Subject(s)
Densovirinae , Penaeidae , Animals , Australia , Densovirinae/genetics , Genome, Viral , Penaeidae/genetics , Polymerase Chain Reaction
2.
Toxicol Mech Methods ; 27(5): 352-362, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28142338

ABSTRACT

Neuroleptic drug molindone hydrochloride is a dopamine D2/D5 receptor antagonist and it is in late stage development for the treatment of impulsive aggression in children and adolescents who have attention deficient/hyperactivity disorder (ADHD). This new indication for this drug would expand the target population to include younger patients, and therefore, toxicity assessments in juvenile animals were undertaken in order to determine susceptibility differences, if any, between this age group and the adult rats. Adult rats were administered molindone by oral gavage for 13 weeks at dose levels of 0, 5, 20, or 60 mg/kg-bw/day. Juvenile rats were dosed for 8 weeks by oral gavage at dose levels of 0, 5, 25, 50, or 75 mg/kg-bw/day. Standard toxicological assessments were made using relevant study designs in consultation with FDA. Treatment-related elevation in serum cholesterol and triglycerides and decreases in glucose levels were observed in both the age groups. Organ weight changes included increases in liver, adrenal gland and seminal vesicles/prostate weights. Decreases in uterine weights were also observed in adult females exposed to the top two doses with sufficient exposure. In juveniles, sexual maturity parameters secondary to decreased body weights were observed, but, were reversed. In conclusion, the adverse effects noted in reproductive tissues of adults were attributed to hyperprolactinemia and these changes were not considered to be relevant to humans due to species differences in hormonal regulation of reproduction. On the whole, there were no remarkable differences in the toxicity profile of the drug between the two age groups.


Subject(s)
Antipsychotic Agents/toxicity , Dopamine D2 Receptor Antagonists/toxicity , Molindone/toxicity , Receptors, Dopamine D3/antagonists & inhibitors , Administration, Oral , Aging/blood , Aging/metabolism , Animals , Antipsychotic Agents/blood , Body Weight/drug effects , Dopamine D2 Receptor Antagonists/blood , Female , Male , Molindone/blood , Organ Size/drug effects , Organ Specificity/drug effects , Prolactin/blood , Rats, Sprague-Dawley , Rats, Wistar , Reproduction/drug effects , Toxicokinetics
3.
Environ Mol Mutagen ; 57(4): 288-98, 2016 May.
Article in English | MEDLINE | ID: mdl-27040600

ABSTRACT

Molindone hydrochloride is a dihydroindolone neuroleptic with dopamine D2 and D5 receptor antagonist activity. As an integral component of its preclinical safety evaluation, molindone hydrochloride was evaluated in a series of in vitro and in vivo genetic toxicology assays. In the bacterial reverse gene mutation assays employing four Salmonella tester strains (TA98, TA100, TA1535, and TA1537) and the E. coli tester strain WP2uvrA, molindone hydrochloride was negative in all strains, except TA100, in which it induced a positive response (up to 3-fold) in the presence of rat liver S9. With human S9, a small (2-fold), but nonreproducible, increase in revertants was observed in TA100 at the highest concentration of molindone tested (5,000 µg/plate). The mutagenicity was completely abrogated by the addition of glutathione and UDP-glucuronic acid to rat liver S9, suggesting detoxification of the mutagenic metabolite(s) by Phase II conjugation reactions, pathways commonly operational in humans. Molindone hydrochloride did not induce chromosomal aberrations in human lymphocyte cultures, did not elicit a positive response in a rat bone marrow micronucleus test for clastogencity/aneugenicity, and did not give a positive response in the rat liver comet assay for DNA damage. Collectively, the weight of evidence from these studies, combined with a large margin of safety and efficient detoxification through Phase II conjugation supports the interpretation that molindone hydrochloride does not pose a genotoxic risk to humans at the anticipated clinical dose levels.


Subject(s)
Dopamine Antagonists/toxicity , Molindone/toxicity , Mutagens/toxicity , Adult , Animals , Bone Marrow/drug effects , Bone Marrow/metabolism , Cell Line , Chromosome Aberrations/chemically induced , Comet Assay , DNA Damage/drug effects , Female , Humans , Liver/drug effects , Liver/metabolism , Lymphocytes/drug effects , Lymphocytes/metabolism , Male , Micronucleus Tests , Mutagenicity Tests , Rats , Salmonella typhimurium/drug effects
4.
Reprod Toxicol ; 58: 73-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26327279

ABSTRACT

The purpose of this study was to better understand the biological effects of increased prolactin levels induced in mice by dopamine D2 receptor antagonist molindone treatment. Toxicokinetics, prolactin levels, and reproductive tissue histology were evaluated in Tg rasH2 wild-type mice treated orally with molindone at 0, 5, 15, and 50mg/kg/day for 6 months, followed by a 2-month posttreatment recovery period. A greater than dose-proportional increase in molindone exposure ([AUC]0‒24) was observed on Day 180 for both sexes. Statistically significant (P<0.01) increases in prolactin levels were observed in most treatment groups compared with controls at 0.5h postdose on Days 1 and 180. Prolactin levels returned to baseline levels during the recovery period. Microscopic changes attributable to hyperprolactinemia, including corpora lutea enlargement and interstitial cell atrophy in the ovaries, and atrophy of the uterus and vagina were observed on Day 180. These changes were reversed during the recovery period in the 5- and 15-mg/kg/day treatment groups. Mice receiving molindone at 50mg/kg/day also showed signs of reversal on histologic examination.


Subject(s)
Dopamine Antagonists , Hyperprolactinemia/pathology , Molindone , Ovary/pathology , Uterus/pathology , Vagina/pathology , Animals , Atrophy , Biomarkers/blood , Disease Models, Animal , Female , Genes, ras , Hyperprolactinemia/blood , Hyperprolactinemia/chemically induced , Hyperprolactinemia/genetics , Male , Mice, Inbred C57BL , Mice, Transgenic , Prolactin/blood , Time Factors
5.
Mol Cell Biochem ; 393(1-2): 223-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24771068

ABSTRACT

Acetaminophen has a reasonable safety profile when consumed in therapeutic doses. However, it could induce hepatotoxicity and even acute liver failure when taken at an overdose. Pioglitazone, PPARγ ligand, is clinically tested and used in treatment of diabetes. PPARγ is a key nuclear hormone receptor of lipid metabolisms and regulates several gene transcriptions associated with differentiation, growth arrest, and apoptosis. The aim of our study was to evaluate the hepatoprotective activity of pioglitazone on acetaminophen-induced hepatotoxicity and to understand the relationship between the PPARγ and acetaminophen-induced hepato injury. For the experiment, Sprague-Dawley rats (160-180 g) were used and divided into four groups. Groups I and II were normal and experimental controls, respectively. Groups III and IV received the pioglitazone 20 mg/kg for 10 days. Hepatotoxicity was induced in Groups II and III on the eighth day with acetaminophen (i.p. 350 mg/kg body weight). The hepatoprotective effect was evaluated by performing an assay of the total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and α-fetoprotein as well as glutathione peroxidase, lipid peroxidation, catalase, superoxide dismutase, and glutathione transferase and liver histopathology. The assay results were presented as mean and standard error of mean for each group. The study group was compared with the control group by one-way ANOVA test. A p value of <0.05 was considered significant. Pioglitazone significantly reduced the elevated level of above serum marker enzymes and also inhibits the free radical formation by scavenging hydroxyl ions. It also restored the level of LPO and significantly elevated the levels of endogenous antioxidant enzymes in acetaminophen-challenged hepatotoxicity. Liver histopathological examination showed that pioglitazone administration antagonized acetaminophen -induced liver pathological damage. Various biochemical estimations of different hepatic markers and antioxidant enzymes and histopathological studies of liver tissues glimpse a support to its significant hepatoprotective activity on acetaminophen -induced hepatotoxicity.


Subject(s)
Acetaminophen/adverse effects , Chemical and Drug Induced Liver Injury/drug therapy , PPAR gamma/metabolism , Thiazolidinediones/administration & dosage , Acetaminophen/therapeutic use , Animals , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/pathology , Lipid Peroxidation/drug effects , Pioglitazone , Rats
6.
Toxicol Mech Methods ; 24(4): 284-93, 2014 May.
Article in English | MEDLINE | ID: mdl-24401039

ABSTRACT

CONTEXT: Caramel coloring chemicals, 2-methylimidazole (2-MI) and 4-methylimidazole (4-MI) have been used extensively in coloring soft drinks. The health effects of these chemicals have been concerned in the recent years. OBJECTIVE: In the present investigation, 2- and 4-MI were subjected to three commonly used structure-activity relationship (SAR) software to understand the utility of such software as a method of alternatives to animal testing in predicting potential genotoxicity and tumorigenicity. MATERIALS AND METHODS: Three SAR software: Osiris, ToxTree and DEREK, were used. Published procedures and/or manuals of respective software were utilized to generate data outputs and the data were evaluated in comparison with available toxicological data on 2- and 4-MI. RESULTS: The results show that these software predicted genotoxic activity in comparison with published genotoxicity for 2- and 4-MI. However, only one of three software used (Osiris) predicted imidazole ring in 4-MI to be tumorigenic; other software predicted them to be negative. DISCUSSION: Based on the weight of evidence of SAR results observed in this study and the genotoxicity and tumorigenicity reported using actual in vitro and in vivo animal testing in literature, it was concluded that the models used are useful for routine screening of chemicals; however, for better prediction, additional models may be employed. Software's ability to predict health effects depends on the type of structural alerts used as knowledgebase in developing such software. CONCLUSION: Three computational software used in this study predicted genotoxic activity of 2- and 4-MI, but did not predict tumorigenicity conclusively when compared to literature reported animal data. Additional mechanistic non-clinical studies may be conducted to better understand reported tumorigenicity.


Subject(s)
Carcinogenicity Tests , Imidazoles/toxicity , Mutagenicity Tests , Software , Imidazoles/chemistry , Structure-Activity Relationship
7.
Mutat Res ; 627(1): 10-30, 2007 Feb 03.
Article in English | MEDLINE | ID: mdl-17157053

ABSTRACT

The in vivo micronucleus assay working group of the International Workshop on Genotoxicity Testing (IWGT) discussed new aspects in the in vivo micronucleus (MN) test, including the regulatory acceptance of data derived from automated scoring, especially with regard to the use of flow cytometry, the suitability of rat peripheral blood reticulocytes to serve as the principal cell population for analysis, the establishment of in vivo MN assays in tissues other than bone marrow and blood (for example liver, skin, colon, germ cells), and the biological relevance of the single-dose-level test. Our group members agreed that flow cytometric systems to detect induction of micronucleated immature erythrocytes have advantages based on the presented data, e.g., they give good reproducibility compared to manual scoring, are rapid, and require only small quantities of peripheral blood. Flow cytometric analysis of peripheral blood reticulocytes has the potential to allow monitoring of chromosome damage in rodents and also other species as part of routine toxicology studies. It appears that it will be applicable to humans as well, although in this case the possible confounding effects of splenic activity will need to be considered closely. Also, the consensus of the group was that any system that meets the validation criteria recommended by the IWGT (2000) should be acceptable. A number of different flow cytometric-based micronucleus assays have been developed, but at the present time the validation data are most extensive for the flow cytometric method using anti-CD71 fluorescent staining especially in terms of inter-laboratory collaborative data. Whichever method is chosen, it is desirable that each laboratory should determine the minimum sample size required to ensure that scoring error is maintained below the level of animal-to-animal variation. In the second IWGT, the potential to use rat peripheral blood reticulocytes as target cells for the micronucleus assay was discussed, but a consensus regarding acceptability for regulatory purposes could not be reached at that time. Subsequent validation efforts, combined with accumulated published data, demonstrate that blood-derived reticulocytes from rats as well as mice are acceptable when young reticulocytes are analyzed under proper assay protocol and sample size. The working group reviewed the results of micronucleus assays using target cells/tissues other than hematopoietic cells. We also discussed the relevance of the liver micronucleus assay using young rats, and the importance of understanding the maturation of enzyme systems involved in the processes of metabolic activation in the liver of young rats. Although the consensus of the group was that the more information with regard to the metabolic capabilities of young rats would be useful, the published literature shows that young rats have sufficient metabolic capacity for the purposes of this assay. The use of young rats as a model for detecting MN induction in the liver offers a good alternative methodology to the use of partial hepatectomy or mitogenic stimulation. Additional data obtained from colon and skin MN models have been integrated into the data bases, enhancing confidence in the utility of these models. A fourth topic discussed by the working group was the regulatory acceptance of the single-dose-level assay. There was no consensus regarding the acceptability of a single dose level protocol when dose-limiting toxicity occurs. The use of a single dose level can lead to problems in data interpretation or to the loss of animals due to unexpected toxicity, making it necessary to repeat the study with additional doses. A limit test at a single dose level is currently accepted when toxicity is not dose-limiting.


Subject(s)
Erythrocytes/drug effects , Hematopoietic System/cytology , Micronucleus Tests/methods , Reticulocytes/drug effects , Animals , Bone Marrow , Cells, Cultured , Dose-Response Relationship, Drug , Image Processing, Computer-Assisted , Rats , Reproducibility of Results , Reticulocytes/cytology
8.
Indian J Physiol Pharmacol ; 50(2): 169-74, 2006.
Article in English | MEDLINE | ID: mdl-17051737

ABSTRACT

Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers antagonists (ARAs) are widely used compounds in various cardiovascular disorders. ACEIs, but not ARAs, inhibit the enzyme dipeptidyl carboxypeptidase which is involved in the conversion of angiotensin I to II and degradation of kinins like bradykinin and substance P. Bradykinin and substance P are potent mediators of inflammation and pain. Hence the study was undertaken to evaluate the effects of captopril (an ACEI) and losartan (an ARA-AT1 receptor antagonist) on thermal and chemical induced nocioception by employing hot plate and acetic acid induced writhing tests respectively in mice. Inbred albino mice weighing between 25-30 g were used and they were divided into two sets, each set containing 7 groups. Control groups received normal saline and the remaining six groups received three doses (0.5, 1 and 2 mg/kg) of captopril and three doses (0.5, 1 and 2 mg/kg) of losartan. Drugs were administered intraperitoneally fifteen minutes before placing the animal over the hot plate or 30 minutes before injecting 0.6% acetic acid. Both drugs dose dependently reduced the reaction time in hot plate method. In chemical induced writhing test, both the drugs reduced the latency of onset of writhing and in captopril pretreated groups, acetic acid induced sustained abdominal contraction without any intermittent relaxation. However, in losartan pretreated animals acetic acid just increased the number of writhings without sustained abdominal contraction. Thus, our study suggests that both drugs have hyperalgesic effects.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/pharmacology , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Captopril/pharmacology , Hyperalgesia/chemically induced , Losartan/pharmacology , Angiotensin II/physiology , Animals , Dose-Response Relationship, Drug , Female , Male , Mice , Reaction Time/drug effects
9.
Basic Clin Pharmacol Toxicol ; 95(3): 144-52, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15447739

ABSTRACT

A-331440 [4'-[3-(3(R)-(dimethylamino)-pyrrolidin-1-yl)-propoxy]-biphenyl-4-carbonitrile], a potent and selective antagonist of histamine H3 receptors, yielded positive results in an in vitro micronucleus assay, predictive of genotoxicity in vivo. Because this compound has highly favourable properties and potential as an antiobesity agent, new compounds of this general chemical class were sought that would retain or improve upon the high potency and selectivity of A-331440 for H3 receptors, but would lack the potential for genotoxicity obtained with that compound. Our working hypothesis was that the biphenyl rings in A-331440 might contribute to interactions with DNA and thereby predispose toward genotoxicity. Toward this end, several analogues were prepared, with substituents introduced onto the biaryl ring to alter the orientation, electronegativity, and polarity of this moiety, and were tested for their radioligand binding potency and selectivity and their propensity to induce genotoxicity in the in vitro micronucleus assay. Using this strategy, novel compounds were discovered that retained or improved upon the potency and selectivity of A-331440 for H3 receptors and were devoid of genotoxicity in vitro. Of these, the simple mono- and di-fluorinated analogues (A-417022 [4'-[3-[(3R)-3-(dimethylamino)-1-pyrrolidinyl]propoxy]-3'-fluoro-1,1'-biphenyl-4-carbonitrile] and A-423579 [4'-[3-[(3R)-3-(dimethylamino)-1-pyrrolidinyl]-propoxy]-3',5'-difluoro-1,1'-biphenyl-4-carbonitrile], respectively) were found to bind to H3 receptors at least as potently as A-331440, while lacking genotoxicity in the micronucleus assay. The reason of the lack of genotoxicity of the fluorinated analogues is unclear, but is especially noteworthy in light of the general principle that fluorine and hydrogen are very similar in size. Therefore, these fluorinated analogues of A-331440 represented the most potent and potentially safest compounds for further evaluation as antiobesity leads. Preliminary findings with one of these examples, A-417022, in a mouse model of obesity are presented.


Subject(s)
Anti-Obesity Agents/pharmacology , Biphenyl Compounds/pharmacology , Histamine Antagonists/pharmacology , Nitriles/pharmacology , Pyrrolidines/pharmacology , Receptors, Histamine H3/metabolism , Animals , Cell Line , Cricetinae , Cricetulus , Disease Models, Animal , Drug Design , Histamine Antagonists/chemical synthesis , Mice , Mice, Inbred C57BL , Micronucleus Tests , Molecular Structure , Radioligand Assay , Structure-Activity Relationship , Weight Loss/drug effects
10.
Indian J Psychiatry ; 45(4): 200-4, 2003 Oct.
Article in English | MEDLINE | ID: mdl-21206858

ABSTRACT

Techniques of psychotherapy commonly used in the west may be difficult to employ in their purest form for Indian patients, especially in those who are not educated and those who are not westernized. Anecdotes from the Ramayana can be used in psychotherapy to show the similarity of the issues facing the patient with the aim of increasing insight. They are powerful examples and can be used to suggest alternate modes of coping. This article discusses anecdotes, themes and possible situations for use in psychotherapy. It also suggests steps in obtaining the necessary permission from patients prior to discussing them in psychotherapy.

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