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Ashok Kumar

Publications and source records attributed to Ashok Kumar.

At least 55 records · Page 3Linked to original sources
PubMed2006

Synthesis and biological evaluation of some pyrazolinylpyridines and pyrazolylpyridines.

Various new 2-(1'-acetyl-5'-substituted-aryl-2'-pyrazolin-3'-yl)aminopyridines (3a-3e) and 2-(1'-phenyl 5'-substituted aryl-2'-pyrazol-3'-yl)aminopyridines (4a-4e) have been derived from 2-(substituted benzylidenylacetyl)aminopyridines (2a-2e). The structure of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR, mass) analysis. Furthermore, above said compounds were evaluated for their insecticidal, antifungal, and antibacterial activities. Compound 4b 2-[1'-phenyl-5'-(o-chlorophenyl)-2'-pyrazol-3'-yl]aminopyridine, when compared for insecticidal and antifungal activities with parathion and fluconazole, respectively, was found to be the most potent one in this series. It also possessed remarkable antibacterial properties.

Animals↗
PubMed2006

A study of anti-inflammatory activity of some novel alpha-amino naphthalene and beta-amino naphthalene derivatives.

In the present study, some naphthalene derivatives have been synthesized by incorporating azetidinyl and thiazolidinyl moieties at its alpha- or beta-positions such as alpha-(3-chloro-2-oxo-4-substituted)aryl-1-azetidinyl)naphthalenes 6-10, alpha-((substituted)aryl-4-oxo-1,3-thiazolidin-3-yl)naphthalenes 11-15, beta-(3-chloro-2-oxo-4-substituted aryl-1-azetidinyl)naphthalenes 21-25, and beta-(substituted aryl-4-oxo-1,3-thiazolidin-3-yl)naphthalenes 26-30. These compounds have also been screened for acute toxicity and anti-inflammatory and analgesic activities. Compounds which showed better anti-inflammatory and analgesic activities were also examined for their ulcerogenic liability and underwent a cyclooxygenase assay. Two compounds, 12 and 28, were found to exhibit potent anti-inflammatory activity as compared to the standard drugs phenylbutazone and naproxen.

Analgesics↗
PubMed2006

Synthesis of new thiazolylthiazolidinylbenzothiazoles and thiazolylazetidinylbenzothiazoles as potential insecticidal, antifungal, and antibacterial agents.

A series of 2-{[2'-(3''-chloro-2''-oxo-4''-substitutedaryl-1''-azetidinyl)-1',3'-thiazol-4'-yl] thio}benzothiazoles (4a-4e) and 2-{[(2'-(2''-substitutedaryl-4''-thiazolidinon-3''-yl)-1',3'-thiazol-4'-yl]thio}benzothiazoles (5a-5e) have been synthesized from 2-[(2'-substitutedarylidenylimino-1',3'-thiazol-4'-yl)thio]benzothiazoles (3a-3e). The structure of these compounds has been elucidated by elemental (C, H, N) and spectral (IR, (1)H-NMR, Mass) analysis. Furthermore, compounds 3a-3e, 4a-4e, and 5a-5e were screened for insecticidal activity against Periplaneta americana and antifungal, antibacterial activities in vitro against different strains of fungi and bacteria. Out of the fifteen compounds tested, compound 5b, 2-{[2'-(2''-p-hydroxy-m-methoxyphenyl)-4''-thiazolidinon-3''-yl)-1',3'-thiazol-4'-yl]thio}benzothiazole, was found to possess most prominent insecticidal activity.

Animals↗
PubMed2006

Evaluation of chemopreventive action of Ginsenoside Rp1.

We evaluated the chemopreventive properties of Ginsenoside Rp1 on 7,12-Dimethyl benz (a) anthracene (DMBA) skin papillomagenesis in Swiss albino mice. A significant reduction in values of tumor incidence, tumor burden, and cumulative number of papilloma was observed in mice treated orally with Ginsenoside Rp1 continuously at pre-, peri- and post-initiational stages of papillomagenesis as compared to the control group. Chemopreventive potential of Ginsenoside Rp1 was also observed on the skin metabolizing enzymes in Swiss albino mice. Ginsenoside Rp1 produced a significant elevation in the skin microsomal cytochrome p-450 and cytochrome b5, glutathione S-transferase (GST), reduced glutathione (GSH), glutathione peroxidase (GPX), glutathione reductase (GR), DT-diaphorase, superoxide dismutase (SOD) and catalase levels in the group of mice treated with Ginsenoside Rp1 for seven consecutive days. However, there was significant decrease in lipid peroxidation (LPO) level in Ginsenoside Rp1 treated group.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2006

Modulatory effects of Mentha piperita on lung tumor incidence, genotoxicity, and oxidative stress in benzo[a]pyrene-treated Swiss albino mice.

Mentha piperita or peppermint is currently used for alleviating nausea, flatulence, and vomiting. In the present investigation, we evaluated the chemopreventive, antigenotoxic, and antioxidative effects of an aqueous extract of Mentha piperita leaves. One-day-old Swiss albino mice were treated with a single subcutaneous injection of 0.5 mg benzo[a]pyrene (BP) and then given either water or a Mentha extract (ME; 1 g/kg body weight) by gavage starting at 3 weeks of age (weaning). The mice were killed at 9 weeks of age and tested for lung tumor incidence (chemoprevention); bone marrow micronucleus and chromosome aberration frequency (antigenotoxicity); and levels of liver and lung sulfhydral groups, superoxide dismutase (SOD) and catalase (CAT) activity, and lipid peroxidation (LPO) (antioxidative properties). The ME treatment resulted in a significant reduction in the number of lung adenomas from an incidence of 67.92% in animals given only BP to 26.31%, an inhibition of 61.26%. Tumor multiplicity was 1.22 in the BP-alone group and 1.15 in the BP + ME group. In addition, compared with the animals in the BP-alone group, ME reduced the frequency of chromosomal aberrations and micronuclei in bone marrow cells and decreased the levels of LPO and increased reduced glutathione content, and SOD and CAT activities in liver as well as lung. The results of this study indicate that ME is chemopreventive and antigenotoxic when given subsequent to an initiating dose of BP in newborn Swiss albino mice. The chemopreventive action and antigenotoxic effects observed in the present study may be due to the antioxidative properties of ME.

Adenoma↗
PubMed2006

Regulation of phosphatidylinositol 3-kinase (PI3K)/Akt and nuclear factor-kappa B signaling pathways in dystrophin-deficient skeletal muscle in response to mechanical stretch.

Phosphatidylinositol 3-kinase (PI3K)/Akt and nuclear factor-kappa B (NF-kappaB) signaling pathways play a critical role in mediating survival signals. In this study we have investigated how loss of dystrophin (the primary cause of Duchenne muscular dystrophy) modulates the activation of PI3K/Akt and NF-kappaB signaling pathways in skeletal muscle in response to mechanical stimulation. Activation of Akt was significantly higher in diaphragm muscle from dystrophin-deficient mdx mice compared to normal mice at both prenecrotic and necrotic states. Higher activation of Akt was also observed in cultured dystrophin-deficient primary myotubes differentiated in vitro. Application of passive mechanical stretch ex vivo synergistically increased the activation of Akt in diaphragm of mdx mice. Stretch-induced activation of PDK-1 and PI3K were also higher in diaphragm of mdx mice compared to normal mice. Pretreatment of diaphragm with PI3K inhibitor LY294002 blocked the activation of Akt in normal and mdx mice. Higher activation of Akt was associated with increased phosphorylation of its downstream targets glycogen synthase kinase 3beta (GSK3beta), FKHR, and mammalian target of rapamycin (mTOR). Treatment of diaphragm muscle with LY294002 inhibited the stretch-induced activation of IkappaB (IkappaB) kinase (IKK) and NF-kappaB transcription factor in normal and mdx mice. Mechanical stretch also reduced the interaction of HDAC1 with RelA subunit of NF-kappaB in diaphragm muscle. Finally, cellular levels of Bcl-2, cIAP1, and integrin beta1 and activation of integrin linked kinase were higher in diaphragm muscle of mdx mice compared to normal mice. Taken together, our data suggest that loss of dystrophin and/or mechanical stretch results in the up-regulation of P13K/Akt and NF-kappaB signaling pathways in skeletal muscle.

Animals↗
PubMed2006

Case report: Endotracheal tube malposition in a patient with a tracheal bronchus.

PURPOSE: A tracheal bronchus is a congenital abnormality of the tracheobronchial tree, in which a displaced or accessory bronchus arises from the trachea superior to its bifurcation. We report a patient with a tracheal bronchus that was found incidentally during surgery in the prone position, and the potential airway management problems which may have ensued. CLINICAL FEATURES: A 70-yr-old female underwent posterior spinal decompression and fusion in the prone position. Intraoperatively, end-tidal CO2 and airway pressure increased. Fibreoptic bronchoscopy revealed that the endotracheal tube (ETT) was kinked at the 16 cm mark, which was corrected by rotating the patient's head and ETT. When the bronchoscope was advanced beyond the tip of the ETT, a tracheal-bronchial tree trifurcation was identified. Endobronchial intubation was suspected. As the ETT was withdrawn, the endoluminal view remained unchanged. During bronchoscopy, the patient's trachea was nearly extubated in the prone position. Subsequent bronchoscopy of the major bronchial divisions showed that the trifurcation represented left main stem bronchus, bronchus intermedius and right upper lobe bronchus. Once the tracheal bronchus was recognized, the tip of the ETT was repositioned 3 cm above the tracheal trifurcation, and the rest of the case was uneventful. CONCLUSION: This case highlights the diagnostic challenge and airway management implications of one variant of a tracheal bronchus when airway problems are encountered intraoperatively. This knowledge should be applied in the differential diagnosis and management of intraoperative hypoxemia; and in the proper positioning of the ETT.

Aged↗
PubMed2006

Mirizzi syndrome and gallbladder cancer.

BACKGROUND/PURPOSE: Mirizzi syndrome is a rare complication of gallstone disease (GSD). The association of Mirizzi syndrome and gallbladder carcinoma (GBC) is not well understood. We report our experience of gallbladder carcinoma in patients with Mirizzi syndrome. METHODS: We performed a retrospective analysis of the records of patients with Mirizzi syndrome who underwent cholecystectomy at a tertiary care hospital with special emphasis on patients who were found to harbor GBC. Patients with Mirizzi syndrome with associated GBC were compared with those who had Mirizzi syndrome alone and those with uncomplicated GSD. RESULTS: Out of 4,800 cholecystectomies, Mirizzi syndrome was found in 133 (2.8%). Seven (5.3%) patients with Mirizzi syndrome had associated GBC, as compared to only 1% in patients with GSD. GBC was detected on final histology after cholecystectomy in 5 patients, and was detected preoperatively and intraoperatively in 1 patient each. Patients with Mirizzi syndrome with associated GBC were older (60 vs 50 years; P <or= 0.0001) and had a longer duration of symptoms (59 vs 24 months; P = 0.002) as compared to those with Mirizzi syndrome alone. However, presenting clinical features were not different in these two groups. CONCLUSIONS: There was a higher incidence of GBC in patients with Mirizzi syndrome than in patients with uncomplicated GSD. There were no clinical features to differentiate these patients with GBC from those with Mirizzi syndrome alone, except that they were a decade older and had longer duration of symptoms. In the majority, the diagnosis of GBC was made on final histology, after cholecystectomy; hence, this group of patients with GBC are to be treated like any other patients with incidental GBC.

Aged↗
PubMed2006

Organochlorine pesticide residues in milk and blood of women from Anupgarh, Rajasthan, India.

Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk samples were collected from lactating women who were divided into four groups on the basis of different living standards viz residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides in blood ranged from 3.319mg/L-6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence with the reports from other countries.

Adult↗
PubMed2006

Angiotensinogen promoter sequence variants in essential hypertension.

BACKGROUND: Essential hypertension is a complex multifactorial disease caused by ill-defined genetic factors. The angiotensinogen (AGT) gene has been implicated as a risk factor in essential hypertension. METHODS: To assess the role of AGT in hypertension, we evaluated two polymorphisms (A-6G and C-20A) in the 5' region of the gene that have been shown to have a role in transcriptional regulation. A total of 463 subjects were studied: 243 African Americans (26 male and 34 female normotensives, 66 male and 117 female hypertensives) and 220 whites (35 male and 60 female normotensives, 55 male and 70 female hypertensives). African American and white subjects were examined individually, as significant differences in allele and genotype frequencies were observed between these two cohorts. RESULTS: White female hypertensives and normotensives differed significantly in genotype frequency at C-20A (P = .02). No other single site comparisons were significantly different between hypertensives and normotensives in either the white or African American samples. Haplotype frequencies in white males also differed significantly between phenotypic classes (P = .05). To evaluate the data further, we assessed all polymorphic sites simultaneously by the examination of multisite interaction and determined the single best genetic model for each population. A model that included both sites and gender correctly predicted hypertension status in the white population 59.1% of the time (P = .039). The model generated for the African American population was not significant. CONCLUSIONS: Our results suggest that a complex set of genetic factors interact with gender to predispose whites to hypertension.

Adenine↗
PubMed2006

Hemiplegic shoulder pain syndrome: interrater reliability of physical diagnosis signs.

OBJECTIVE: To determine the interrater reliability of shoulder physical diagnosis signs in the acute stroke rehabilitation setting. DESIGN: Prospective inception cohort. SETTING: Academic inpatient stroke rehabilitation service. PARTICIPANTS: People admitted to stroke rehabilitation service. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Neer impingement test, Speed test, acromioclavicular shear test, Rowe shoulder score, and palpation. RESULTS: Two examiners evaluated 46 consecutively admitted participants at 18.9+/-14.1 days after stroke. Percentage agreement was 78% or higher on all tests. The kappa statistic was in the fair to excellent interrater reliability range on all tests except those involving the acromioclavicular joint, for which findings were infrequent. CONCLUSIONS: Most of the shoulder physical diagnosis signs used in this study have sufficient interrater reliability for use in future clinical studies of hemiplegic shoulder pain.

Adult↗
PubMed2006

Predictors of long-term survival in patients with gallbladder cancer.

The aim of this study was to examine the predictors of long-term survival (> 24 months) in patients with gall bladder cancer. A retrospective review of 117 cases of gall bladder cancer resected between 1989 and 2000. The resections included 80 simple cholecystectomies and 37 extended procedures. Patients with survival > 24 months (n = 44) were compared with those having survival < 24 months (n = 73) for 17 prognostic factors. Overall median survival was 16 months with a 5-year survival of 27%. T status (P = .000) and adjuvant chemoradiotherapy (P = .001) were independent predictors of long-term survival. Survival advantage was seen in T3N+ve disease (P = .007) with extended procedures. Complete (R0) resection was attained in 30 patients with a 5-year survival advantage of 30% as compared with incomplete (R1) resection (P = .0002). Adjuvant chemoradiotherapy improved survival in simple cholecystectomy group (P = .0008) but no advantage was seen after extended procedures. Stage III (P = .001) and node-positive disease (P = .0005) had significant benefit with adjuvant therapy. Poor differentiation and vascular invasion were associated with poor long-term survival. R0 resection was associated with prolonged survival. Extended procedures improved survival in patients with T3N+ve disease. Addition of chemoradiotherapy made significant improvement in long-term survival in stage III and node-positive lesions and in patients undergoing simple cholecystectomy. R0 resection predicted long-term survival in gall bladder cancer. T3 N+ve disease had better survival after extended procedures. Adjuvant chemoradiotherapy improved survival in stage III and node-positive disease. Poor differentiation and vascular invasion were adverse predictors of survival.

Adult↗
PubMed2006

CXCR4 physically associates with the T cell receptor to signal in T cells.

SDF-1alpha (CXCL12) signaling via its receptor, CXCR4, stimulates T cell chemotaxis and gene expression. The ZAP-70 tyrosine kinase critically mediates SDF-1alpha-dependent migration and prolonged ERK mitogen-activated protein (MAP) kinase activation in T cells. However, the molecular mechanism by which CXCR4 or other G protein-coupled receptors activate ZAP-70 has not been characterized. Here we show that SDF-1alpha stimulates the physical association of CXCR4 and the T cell receptor (TCR) and utilizes the ZAP-70 binding ITAM domains of the TCR for signal transduction. This pathway is responsible for several of the effects of SDF-1alpha on T cells, including prolonged ERK MAP kinase activity, increased intracellular calcium ion concentrations, robust AP-1 transcriptional activity, and SDF-1alpha costimulation of cytokine secretion. These results suggest new paradigms for understanding the effects of SDF-1alpha and other chemokines on immunity.

Antigens, CD↗
PubMed2006

Analysis of genetic diversity among Staphylococcus aureus isolates from patients with deep-seated and superficial staphylococcal infections using pulsed-field gel electrophoresis.

Molecular typing was performed to reveal the genetic diversity among Staphylococcus aureus strains causing deep-seated versus superficial staphylococcal infections. Pulsed-field gel electrophoresis with cluster analysis, plasmid and antimicrobial susceptibility profiling of 50 S. aureus strains collected from these 2 groups of patients were undertaken. A total of 19 (designated A through S) distinct genotypes were identified by PFGE of Sma I-digested genomic DNA. The most prevalent PFGE type was L, which accounted for 30% of isolates and was detected among superficial isolates only. The second most prevalent PFGE type, type A (18%), was predominant among deep-seated isolates. Remaining PFGE types varied in distribution between the 2 groups. Plasmid profile analysis revealed that deep isolates harbour plasmids more frequently (comprising 64% of isolates) than superficial isolates (4%) and showed 10 and 2 distinct patterns, respectively, with pattern 1 being the dominant among deep isolates. Antimicrobial susceptibility data suggested an increased prevalence of antibiotic resistance among deep isolates with the majority (40%) exhibiting identical antibiograms compared to superficial isolates. No resistance was detected against clindamycin and vancomycin. The results of our study indicate a previously unrecognized dichotomy of S. aureus strains, causing deep-seated and superficial infections.

Adolescent↗
PubMed2006

Radioprotective influence of Mentha piperita (Linn) against gamma irradiation in mice: Antioxidant and radical scavenging activity.

PURPOSE: To evaluate the radiomodulatory influence of a leaf extract of Mentha piperita (Linn) on hepatic antioxidant status and lipid peroxidation in Swiss albino mice. MATERIALS AND METHODS: Animals were given either double distilled water or leaf extract of M. piperita orally (1 g/kg bwt/day) once a day for three consecutive days. Thirty min after the last treatment mice were exposed to 8 Gy of gamma radiation. Mice were autopsied at 30 min post-irradiation. Biochemical parameters were studied to assess the radioprotective effect of leaf extract of M. piperita. RESULTS: Animals pretreated with leaf extract of M. piperita and exposed to 8.0 Gy gamma radiation showed a significant increase in the activities of reduced glutathione content (p < 0.001), glutathione peroxidase (p < 0.005), glutathione reductase (p < 0.001), glutathione S-transferase (p < 0.005), superoxide dismutase (p < 0.005), and catalase (p < 0.005). Irradiated group pretreated with leaf extract of M. piperita showed significant decrease in malondialdehyde (MDA) formation in liver. The leaf extract of M. piperita showed strong radical scavenging activity in both the 1, 1 diphenyl-2-picryl hydrazyl radical (DPPH*) and 2, 2 azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS*+) assays. CONCLUSIONS: The results of the present investigation suggest the antioxidant and free radical scavenging activities of leaf extract of M. piperita are the likely mechanism of radiation protection.

Animals↗
PubMed2006

Role of C825T polymorphism of GNbeta3 gene in preeclampsia.

OBJECTIVE: The main objective of the study was to understand the role of C825T polymorphism that generates a splice variant in the beta3 subunit of heterotrimeric G-protein in preeclampsia. RESULTS: We analyzed genomic DNA of 151 women with preeclampsia (72 Caucasians and 79 African-Americans) and 198 women with normal delivery (102 Caucasians and 96 African-Americans) for C825T polymorphism of GNbeta3 gene. The T-allele frequency in Caucasian women with preeclampsia was 0.42 as compared to 0.25 in normal pregnant women (p = 0.0004) and in African-American women with preeclampsia was 0.82 as compared to 0.68 in normal pregnant women (p = 0.0028). CONCLUSIONS: Results of these experiments show that the allele frequency of C825T polymorphism is significantly different in women with preeclampsia compared with women with normal delivery in Caucasian as well as African-American population.

Adult↗