240 research outputs found
ALTERATIONS OF LIPID PROFILE LEVELS IN 7,12-DIMETHYLBENZ(A)ANTHRACENE INDUCED ULCERATIVE COLITIS RAT MODEL
Objective: Ulcerative colitis is a type of inflammatory bowel disease is a chronic gastrointestinal disorder characterized by intestinal inflammation and mucosal tissue damage. We examined the lipid profile levels in murine model of 7,12 Dimethylbenz(a)anthracene induced ulcerative colitis.Methods: Serum was separated from whole blood and was used to determine the lipid profile such as total cholesterol (TC), phospholipids (PL), triglycerides (TG), free fatty acids, high density lipoprotein (HDL-C) and low density lipoprotein (HDL-C).Results: Ulcerative colitis rats exhibit low level of low density lipoprotein cholesterol and total cholesterol. No significant difference was observed in high density lipoprotein and triglycerides and significant difference was observed in phospholipids and free fatty acid serum levels. This communication highlights the lipid profile that occurs in ulcerative colitis.Conclusion: This study, thus, provides valuable information about the disturbances in the lipids and lipoproteins occur in ulcerative colitis.Keywords: Ulcerative colitis, 7,12-Dimethylbenz(a)anthracene, Lipoprotein, Low-density lipoprotein, Phospholipids
Torque magnetometry study of the spin reorientation transition and temperature-dependent magnetocrystalline anisotropy in NdCo5
We present the results of torque magnetometry and magnetic susceptibility measurements to study in detail the spin reorientation transition (SRT) and magnetic anisotropy in the permanent magnet NdCo5. We further show simulations of the measurements using first-principles calculations based on density-functional theory and the disordered local moment picture of magnetism at finite temperatures. The good agreement between theory and experimental data leads to a detailed description of the physics underpinning the SRT. In particular we are able to resolve the magnetization of, and to reveal a canting between, the Nd and Co sublattices. The torque measurements carried out in the ac and ab planes near the easy direction allow us to estimate the anisotropy constants, K 1, K 2 and K 4 and their temperature dependences. Torque curves, τ(γ) recorded by varying the direction of a constant magnetic field in the crystallographic ac plane show a reversal in the polarity as the temperature is changed across the SRT (240 < T < 285 K). Within this domain, τ(γ) exhibits unusual features different to those observed above and below the transition. The single crystals of NdCo5 were grown using the optical floating zone technique
Tunability of the spin reorientation transitions with pressure in NdCo5
We present pressure-dependent magnetization measurements carried out in the domain of the spin reorientation transitions (SRTs) of a NdCo5 single crystal. The application of a hydrostatic pressure leads to a shift in the SRTs to higher temperatures. This shift is found to be very sensitive to pressure, with the SRT temperatures increasing at a rate of ≈17 K/GPa. To explain the experimental results, we have also performed first-principles calculations of the SRT temperatures for different applied strains, which corroborate the experimental findings. The calculations attribute the pressure dependence of the SRTs to a faster weakening of the Co contribution to the magnetocrystalline anisotropy with pressure compared to the Nd contribution
Single Dose Pharmacokinetics of Efavirenzin Healthy Indian Subjects
Background & Objective: Access to antiretroviral therapy in India is improving. Efavirenz (EFV) is a commonly
used non-nucleoside reverse transcriptase inhibitor used to treat HIV infection. No information is available on
the pharmacokinetics of EFV in Indian subjects. The aim of this study was to obtain information on single dose
pharmacokinetics of efavirenz (EFV) in healthy Indian subjects.
Methods: Sixteen adult healthy volunteers (8 males and 8 females) were administered a single oral tablet of 600
mg EFV after an overnight fast. Blood samples were collected at 1, 2, 3, 4, 5, 6, 10, 24 and 48 hours post
dosing. Plasma EFV concentrations were estimated by HPLC, and certain pharmacokinetic variables were
calculated.
Results: Plasma EFV concentrations were higher in females than males at all the time points, the differences
being significant at 1 (p<0.001) and 2 (p=0.05) hours. Females had significantly higher peak concentration (Cmax)
of EFV than males (p=0.05) (3.11 & 1.90 μg/ml). The inter-individual variability in Cmax and AUC0-48 were 42 and
45% respectively.
Conclusions: This study provides basic information on the pharmacokinetics of EFV in Indian subjects. Females
had higher peak levels of EFV than males. Inter-subject variability was high. Further studies are necessary to
describe the pharmacokinetic profile of EFV under steady state conditions in Indian patients on antiretroviral
treatment
Histogenesis of Peyer’s patches in Ovine foetus (Ovis aries)
Tissue pieces of jejunum and ileum from different prenatal age groups of sheep were collected from Corporation slaughter house, Perambur, Chennai. By three months of foetal age in sheep, the Peyer’s patches appeared as an aggregation of lymphocytes in the propria submucosa of the jejunum and ileum. The lymphocytic aggregation appeared only in the antimesenteric part of the jejunum and ileum. By four months of foetal age, the circumscribed nodular aggregations of lymphocytes were found enlarged giving a follicle-like appearance. The capsular connective tissue was predominated by reticular fibres and a few collagen fibres. The dome area of the follicle consisted of closely packed small-sized lymphocytes which appeared darker than the basal area. The smooth muscle fibres of muscularis mucosae were not continuous throughout and were absent in the follicle having domes. In five months-old foetuses, the jejunal and ileal Peyer’s patches were distinctly observed as follicles. The follicle showed a distinct outer cortex and an inner lighter medulla. Numerous small-sized lymphocytes were observed in the outer cortex and few lymphoblasts, medium sized lymphocytes and reticular cells were observed in the medulla. Keywords: Histogenesis; Peyer’s patches; Ovine foetus
Antidiabetic activity of 3-hydroxyflavone analogues in high fructose fed insulin resistant rats
Synthetic 3-hydroxyflavone analogues (JY-1, JY-2, JY-3, JY-4), were tested for antidiabetic activity in high-fructose-diet-fed (66 %, for 6 weeks) insulin-resistant Wistar rats (FD-fed rats). The fasting blood glucose, insulin, creatinine and AGEs were decreased to near normal upon treatment with test compounds. Insulin resistance markers such as HOMA-IR, K-ITT, plasma triglycerides, lipids, endogenous antioxidant defense and glycogen were restored in FD-fed rats after treatment with 3-hydroxyflavones. It is known that insulin resistance is partly because of oxidative stress and hence antioxidant activity was determined. They exhibited significant in vitro DPPH and ABTS radical scavenging activity (IC50: 10.66-66.63 μM). Test
compounds inhibited ROS and NO production in RAW 264.7 cells (IC50: 10.39–42.63 μM) and they were found as potent as quercetin. Further, the test compounds inhibited lipid peroxidation at low concentrations (IC50: 99.61-217.47 μM). All test compounds at concentrations 100-200 μM protected calf thymus DNA-damage by Fenton reaction. In addition, test compounds inhibited protein glycation in different in vitro
antiglycation assays. JY-2 showed maximum potency in all the stages of glycation which was comparable to the standard quercetin and aminoguanidine. Test compounds also enhanced the glucose uptake by L6 myotubes at an EC50 much lower than that of quercetin. Thus the synthetic 3-hydroxyflavones were found to have good antidiabetic activity by pleotropic and multimodal suppression of insulin resistance and enhancement of glucose uptake by skeletal muscles. These compounds are non-toxic at the doses tested. Further, the combined antioxidant and antiglycation activities of these molecules have complementary benefits in management of diabetes
Urine levels of rifampicin & isoniazid in asymptomatic HIV-positive individuals
Background & objectives: AIDS and its associated gastrointestinal complications may impair the absorption
of anti-tuberculosis (TB) drugs. Impaired absorption of anti-TB drugs could lead to low drug exposure,
which might contribute to acquired drug resistance and reduced effectiveness of anti-TB treatment. The
aim of this study was to obtain information on the status of absorption of rifampicin (RMP) and isoniazid
(INH) in asymptomatic HIV- positive individuals, who are less immunocompromised. The D-xylose
absorption test was also carried out to assess the absorptive capacity of intestive.
Methods: The absorption of RMP, INH and D-xylose was studied in 15 asymptomatic HIV- positive
individuals with CD4 cell counts > 350 cells/mm3 and 16 healthy volunteers, after oral administration of
single doses of RMP (450 mg), INH (300 mg) and D-xylose (5 g). Urine was collected up to 8 h after drug
administration. Percentage dose of the drugs and their metabolites and D-xylose excreted in urine were
calculated.
Results: A significant reduction in the urinary excretion of INH and D-xylose in HIV-positive persons
compared to healthy volunteers was observed. The per cent dose of RMP and its metabolite, desacetyl
RMP was also lower in HIV-positive persons compared to healthy volunteers, but this difference was not
statistically significant.
Interpretation & conclusion: Decreased urinary excretion of D-xylose and INH are suggestive of intestinal
malabsorption in HIV-positive individuals. HIV infection could cause malabsorption of anti-TB drugs
even at an early stage of the disease. The clinical implications of these findings need to be confirmed in
larger studies
Premature Centromere Division and Spontaneous Abortion
Premature Centromere Division (PCD) was observed in the chromosomes of metaphase spreads in a patient with the history of recurrent abortions. Short term leukocyte cultures were set up with blood sample from the woman with a history of recurrent abortions for the past four consequent years. 25 % of the metaphase spreads screened displayed premature centromere division of the chromosomes in each of the cells. This abnormal behavior of the centromeres may predispose the individual to cell division errors due to chromosome instability and the consequences of which may be a spontaneous abortion
Structural and magnetic properties of GdCo5−xNix
GdCo5 may be considered as two sublattices—one of Gd and one of Co—whose magnetizations are in antiparallel alignment, forming a ferrimagnet. Substitution of nickel in the cobalt sublattice of GdCo5 has been investigated to gain insight into how the magnetic properties of this prototype rare earth/transition-metal magnet are affected by changes in the transition-metal sublattice. Polycrystalline samples of GdCo5-xNix for 0 ≤ x ≤ 5 were synthesized by arc melting. Structural characterization was carried out by powder x-ray diffraction and optical and scanning electron microscope imagings of metallographic slides, the latter revealing a low concentration of Gd2(Co,Ni)7 lamellae for x ≤ 2.5. Compensation—i.e., the cancellation of the opposing Gd and transition-metal moments—is observed for 1< x < 3 at a temperature which increases with Ni content; for larger x , no compensation is observed below 360 K. A peak in the coercivity is seen at x ≈ 1 at 10 K coinciding with a minimum in the saturation magnetization. Density-functional theory calculations within the disordered local moment picture reproduce the dependence of the magnetization on Ni content and temperature. The calculations also show a peak in the magnetocrystalline anisotropy at similar Ni concentrations to the experimentally observed coercivity maximum
Study of ABCB1 polymorphism (C3435T) in HIV-1-infected individuals from South India
Studies on P-glycoprotein expression and function have
revealed that a single nucleotide polymorphism (SNP) in
the human ABCB1 gene at 3435 (C > T) results in altered
expression and function of P-glycoprotein [1, 2].There have
been reports of lower nelfinavir and efavirenz (EFV) concentrations
associated with TT genotypes (mutant) of
ABCB1 C3435T polymorphism [3, 4].Frequency distribution
of this polymorphism is known to vary across populations
[3, 5, 6]. We report the genotype distribution of ABCB1
C3435T in 179 individuals (126 HIV-infected and 53
healthy) from South India. The polymorphism was correlated
with plasma 12 h EFV and 2 h nevirapine (NVP) concentrations
in 55 and 71 patients, respectively. Plasma EFV
and NVP were estimated by HPLC [7, 8]. Genotyping was
carried out by PCR-RFLP [9]
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