Evaluation of Corrosion and Tarnishing of Intra-oral Nickel Chromium and Gold-alloy Cast Crown.

Although esthetic factors might limit by the presentation of materials used, all-metal complete cast crown should always be offered to patients requiring restoration of endodontically treated posterior tooth. The complete cast crown has the highest longevity of all fixed restorations. It could be used to rebuild a single tooth or a retainer for a fixed prosthesis. It involves all the axial walls as well as the occlusal surface of the tooth to be restored. All restorations are placed in the oral environment in contact with the gingival tissue. Thus clinicians must choose nontoxic or least toxic metal alloys, since any release of elements that might cause reactions. This study was designed to observe clinical responses of nickel chromium alloy and gold alloy cast crown and provide guidance to ascertain the best alloy for cast metal crown, which serves better functional restoration.

Association of Low Level of High Density Lipoprotein cholesterol with Acute Coronary syndrome.

Incidence of coronary artery disease (CAD) is increasing in developing countries in Bangladesh with improvement of socioeconomic status, urbanization, changes of dietary habits and lifestyle. Dyslipidaemia is one of the major contributors increase CAD risk. This study was aimed to find out the association of low level HDL-C with acute coronary syndrome. This cross sectional study was conducted in the department of cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from August 2009 to May 2010. Sociodemographic characteristics, smoking, hypertension, FBS, serum total cholesterol level, HDL-C, LDL-C, Triglyceride level were important variable considered. A total number of 100 respondents consisted of 50 cases (patient) Group I and 50 healthy people (control) Group II. Investigations included ECG, Troponin-I, FBS and Fasting Lipid Profile. The data was analyzed by computer with the help of SPSS. Chi-square test, T-test, ANOVA test used as test of significance. The mean level in cases of HDL-C 39.3±5.1 and in control level HDL-C 34.2±3.4 statistically significant (p<0.0001). In both group low concentration HDL-C (<40mg/dl) risk for CAD. Un-adjusted odds ratio 95% CI determinants of ACS, HDL-C of OR was 0.2. So, HDL-C is not protective factor. In multivariate logistic regression analysis that adjusted for confounders of HDL-C level (age, sex, smoking, hypertension, TC, LDL-C, TG) associated with ACS. HDL-C was strong predictor of ACS (RR in the highest) compared with lowest quarantile = 0.02; (95% CI=0.003-0.173; P for trend <0.0001). The study reflected that low HDL-C level associated with ACS. Categorization of patients with ACS on the basis HDL-C level may be helpful for risk stratification and management.

Relationship between Triglyceride and HDL-C ratio with Acute Coronary Syndrome.

Cardiovascular diseases (CVD) is the leading cause of death worldwide, responsible for one third of death, coronary artery disease (CAD) is the most common cause. Dyslipidaemiais one of the major contributors increased of CAD risk. This study was aimed to find out the relationship between triglyceride and HDL cholesterol ratio with acute coronary syndrome. This cross sectional study was conducted in the department of Cardiology, Mymensingh Medical College Hospital from August 2009 to May 2010. Smoking, hypertension, serum total cholesterol level, serum HDL-C, LDL-C, triglyceride (TG) level were important variable considered. A total number of 100 respondents consisted of 50 cases (patient) and 50 healthy persons (control). Investigations included ECG, Troponin-I, FBS and lipid profile. The data was analyzed by computer with the help of SPSS; Chi-square test, 't' test, ANOVA test used as test of significance. The mean level in cases of TG 168.2±88.0 vs. HDL 41.3±5.1 in control level TG 141.2±45.3 and HDL 34.2±3.4. TG/HDL ratio cases 4.2±1.7 and control 4.1±1.3. This ratio >4 is atherogenic for CAD. Unadjusted odds ratio TG/HDL ratio level high (>1). In multivariable regression analysis, TG/HDL ratio was strong relation with ACS. The study reflected that high TG/HDL ratio is associated with ACS. Categorization of patient with ACS on the basis of high TG/HDL ratio will be helpful for risk stratification and management.

In silico Identification of Ergosterol as a Novel Fungal Metabolite Enhancing RuBisCO Activity in Lycopersicum esculentum.

RuBisCO (EC 4.1.1.39), a key enzyme found in stroma of chloroplast, is important for fixing atmospheric CO2 in plants. Alterations in the activity of RuBisCO could influence photosynthetic yield. Therefore, to understand the activity of the protein, knowledge about its structure is pertinent. Though the structure of Nicotiana RuBisCO has been modeled, the structure of tomato RuBisCO is still unknown. RuBisCO extracted from chloroplasts of tomato leaves was subjected to MALDI-TOF-TOF followed by Mascot Search. The protein sequence based on gene identification numbers was subjected to in silico model construction, characterization and docking studies. The primary structure analysis revealed that protein was stable, neutral, hydrophilic and has an acidic pI. The result though indicates a 90 % homology with other members of Solanaceae but differs from the structure of Arabidopsis RuBisCO. Different ligands were docked to assess the activity of RuBisCO against these metabolite components. Out of the number of modulators tested, ergosterol had the maximum affinity (E = -248.08) with RuBisCO. Ergosterol is a major cell wall component of fungi and has not been reported to be naturally found in plants. It is a known immune elicitor in plants. The current study throws light on its role in affecting RuBisCO activity in plants, thereby bringing changes in the photosynthetic rate.

Protein-protein and DNA-protein interactions mediate induction of defense genes by fruit extract of Azadirachta indica A. Juss. in Solanum lycopersicum L.

KEY MESSAGE: The present work demonstrates that induction of defense-related genes in tomato by neem extract was mediated by protein-protein and DNA-protein interactions. The induction of elicitor-mediated defense responses in plants is known, but the molecular mechanisms underlying its induction are not well studied. In the present study, third node leaf from the base of aseptically raised tomato plants was treated with aqueous fruit extracts of Azadirachta indica A. Juss. (neem). Samples were collected from the treated node at 24-h intervals for up to 96 h and analyzed for the gene expression of phenylalanine ammonia lyase (PAL), Peroxidase (POX) and Polyphenol Oxidase (PPO), ß-actin (standard). Samples were collected from elicitor-induced node at 5-min interval up to 70 min for analysis of protein-protein and DNA-protein interactions. The results demonstrated the induction of expression of PAL, POX and PPO due to the treatment whereas no change was observed in the expression of ß-actin. There was disappearance of lower molecular weight proteins which cross-linked with other proteins to form complexes. MALDI-TOF MS analysis revealed the interaction of mitogen-activated protein kinases (MAPK). The analysis of proteins interacted with DNA after induction by neem extract indicated the involvement of WRKY transcriptional factors. Neem-elicited defense responses could possibly due to interaction of proteins with other proteins and transcription factors with DNA which might be crucial in enhancing the expression of defense-related genes (PAL, POX and PPO).

Evaluation of a new flow cytometry crossmatch procedure for simultaneous detection of cytotoxicity and antibody binding.

In this study we have evaluated an alternative 96-well format flow cytometry based (FCtox) method which enable simultaneous detection of cytotoxicity and human leukocyte antigen (HLA) antibody binding. Comparable results were obtained in side-by-side comparisons with conventional complement-dependent cytotoxicity (CDC) and flow cytometric crossmatch (FCXM) in terms of sensitivity and specificity. There was 91 and 93% agreement between results obtained by FCtox and CDC for T and B cells, respectively. In addition, comparable results were obtained with FCtox IgG and FCXM IgG for both T and B cells. Furthermore, compared with a recently developed and highly sensitive Luminex based C1q assay we obtained close to 90% method agreement with the FCtox assay. Our alternative cytotoxicity and IgG binding assay which exhibit low intra-and inter-assay variation will improve the workflow and speed up the pre-transplant testing and also allow continuous monitoring of assay performance and proper quality assurance.

Need of dietary energy at critical implantation time when local ovarian hormones are obligatory for conceptus development.

Role of dietary energy and local ovarian hormones in conceptus development in the rat was evaluated by giving ip injections of estrogen and progesterone under diet restricted and/or dextrose supplemented conditions, using the experimental model of ovarian compensatory hypertrophy. Replacement of estrogen on day 2 and progesterone on day 3 was necessary for conceptus development in the ipsilateral uterine horn after unilateral ovariectomy on day 2. Continuation of progesterone injection up to day 9 improved the percentage of conceptus development. Conceptus development was normal when unilateral ovariectomy was performed after day 2 of pregnancy. Compensatory increases in corpus luteum (CL) volume and the activity of delta 5 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD) in contralateral ovary were observed after unilateral ovariectomy on day 2-4 of pregnancy. However, 70% diet restriction reducing the energy intake (from 90 to 27 kcal/rat/day) abolished the single dose hormone therapy effects in ipsilateral horn conceptus development and also reduced the effects of continued progesterone, percentage of contralateral horn conceptus development, compensatory changes in the CL volume and delta 5 3 beta-HSD activity of the contralateral ovary. However, dietary dextrose supplementation (increasing calorie intake from 27 to 56 kcal/rat/day) significantly improved/restored hormone response for conceptus development, compensatory changes of the CL volume and enzyme activity in contralateral ovary. The results suggest that day 2-3 of pregnancy is the critical time when local ovarian supply of estrogen and progesterone are obligatory for establishment and conceptus development in the rat. During this period adequate mobilizable source of energy is necessary for execution of hormonal message.

Hydrogen-1, sodium-23, and carbon-13 MR spectroscopy of cartilage degradation in vitro.

Viable bovine nasal cartilage was examined with magnetic resonance (MR) spectroscopy. Digestion of the proteoglycan matrix by papain or trypsin was accompanied by substantial changes in carbon-13, sodium-23, and hydrogen-1 MR spectra and relaxation parameters, with C-13 MR spectra showing the most pronounced changes. These results indicate the potential of MR spectroscopy (and imaging) for noninvasive evaluation of cartilage disease and monitoring of patients with degenerative joint diseases.

Magnetic resonance imaging of the rabbit knee: detection of cartilage proteoglycan degradation.

Intra-articular (i.a.) injection of papain causes a reversible loss of proteoglycan in intact rabbit knees. Twelve rabbits were scanned with magnetic resonance imaging (MRI) at 0, 24, 48 and 72 hours after 5 units of papain i.a. in a 1.5 Tesla Signa with a three inch surface coil using spin echo sequence. Total cartilage thickness in proton density images was 1.08 +/- 0.09 mm prior to papain injection. The magnetic resonance images showed a reduction in articular cartilage thickness in papain-treated rabbit femurs at 24 hours to 0.69 +/- 0.18 mm and partial restoration by 72 hours to 0.77 +/- 0.21 mm.

The conformational preferences of gamma-lactam and its role in constraining peptide structure.

The conformational constraints imposed by gamma-lactams in peptides have been studied using valence force field energy calculations and flexible geometry maps. It has been found that while cyclisation restrains the psi of the lactam, non-bonded interactions contribute to the constraints on psi of the lactam. The gamma-lactam also affects the (psi, psi) of the residue after it in a peptide sequence. For an L-lactam, the ring geometry restricts psi to about -120 degrees, and psi has two minima, the lowest energy around -140 degrees and a higher minimum (5 kcal/mol higher) at 60 degrees, making an L-gamma-lactam more favourably accommodated in a near extended conformation than in position 2 of a type II' beta-turn. The energy of the psi approximately +60 degrees minimum can be lowered substantially until it is more favoured than the -140 degrees minimum by progressive substitution of bulkier groups on the amide N of the L-gamma-lactam. The (psi, psi) maps of the residue succeeding a gamma-lactam show subtle differences from those of standard N-methylated residues. The dependence of the constraints on the chirality of gamma-lactams and N-substituted gamma-lactams, in terms of the formation of secondary structures like beta-turns is discussed and the comparison of the theoretical conformations with experimental results is highlighted.

A novel beta-turn location in an LHRH antagonist: a combined conformational search and molecular dynamics study.

A 50 pico-second molecular dynamics simulation on a cyclic LHRH antagonist analogue Ac-D-Phe1-D-Phe2-D-Trp3-Ser4-Glu5-D-Arg6-Leu7-Lys8+ ++-Pro9-D-Ala10-NH2 (where the cyclisation is via an amide linkage between the Glu5 and Lys8 side chains), reveals some hitherto unseen conformational features. The LHRH analogue is found to adopt a near beta-sheet type of conformation with the reversal in the chain being brought about by a D-Trp3-Ser4-Glu5-D-Arg6 beta turn. The N- and C-terminal ends of the peptide come close together and interact through a network of hydrogen bonds. Additional hydrogen bonds expected of a sheet type of conformation stabilise the lowest energy minima. A conformational search of all possible cyclic structures of a model system c(Glu-D-Ala-Ala-Lys) which was used to determine the starting structure for the simulation studies of the cyclic LHRH antagonist analogue is also highlighted. The influence of the cyclic part on the conformation of this LHRH analogue is discussed.

Studies on hydrogen bonds. Part V--Hydrogen bonding in energy minimization studies of peptides.

An energy term, representing the N-H...O type of hydrogen bond, which is a function of the hydrogen bond length (R) and angle (theta) has been introduced in an energy minimization program, taking into consideration its interpolation with the non-bonded energy for borderline values of R and theta. The details of the mathematical formulation of the derivatives of the hydrogen bond function as applicable to the energy minimization have been given. The minimization technique has been applied to hydrogen bonded two and three linked peptide units (gamma-turns and beta-turns), and having Gly, Ala and Pro side chains. Some of the conformational highlights of the resulting minimum energy conformations are a) the occurrence of the expected 4----1 hydrogen bond in all of the burn-turn tripeptide sequences and b) the presence of an additional 3----1 hydrogen bond in some of the type I and II tripeptides with the hydrogen bonding scheme in such type I beta-turns occurring in a bifurcated form. These and other conformational features have been discussed in the light of experimental evidence and theoretical predictions of other workers.

Estrogen-induced responses in non-pregnant rats compared with changes in pair-fed & vitamin C treated pregnant rats.

PIP: The effects of continued estradiol-17beta treatment on body and organ weights and the responses of tissue carbohydrates, protein, and nucleic acids were studied in intact nonpregnant rats and pair-fed pregnant rats. Ascorbic acid was administered to protect against the possible loss of pregnancy due to diet restriction. Treatment of intact nonpregnant rats produced an increase in food consumption and protein and nucleic acid levels in the liver and uterus, and decreased blood glucose and glycogen levels in the liver and uterus. These alterations resembled conditions in the pair-fed pregnant animals. Therapeutic doses of ascorbic acid contributed to pregnancy maintenance in animals receiving nonpregnant dietary forms and prevented the depletion of carbohydrate and protein levels in the uterus and liver. Ascorbic acid treatment also reduced appetite in the estrogenized nonpregnant and normal pregnant rats without depleting tissue carbohydrate and protein levels. The results suggest that continued estrogen treatment produces a physiological state in nonpregnant rats resembling pregnancy, and that Vitamin C therapy protects pregnancy in underfed animals and maintains normal metabolic function in fully fed rats by controlling food consumption.^ieng

The effect of an acute dose of biotin at a post-implantation stage and its relation with female sex steriods in the rat.

An acute dose (10 mg/100 g body weight) of biotin at the post-implantation stage (day 14 and 15) inhibited the fetal and placental growth, and in few rats it also caused resorption of fetuses and placentae. The maintenance of pregnancy with normal fetal and placental growth was effected with estrogen therapy, but progesterone failed to correct the biotin-induced effect. The uterine and placental glycogen, RNA and protein levels, as well as, glucose-6-phosphate dehydrogenase activity in the ovary, liver and uterus showed a reduction following biotin treatment. Estrogen therapy under such conditions corrected these adverse effects of biotin overdose, while progesterone had no significant effects. The study suggests that the acute dose of biotin at an advance stage of pregnancy may cause adverse effects on the physiological regulation of gestation, possibly by creating deficiency of estrogen and gestagen. The possible role of estrogen in the fetal and placental growth and regulation of gestagen secretion is discussed.

The effect of an acute dose of biotin at the pre-implantation stage and its relation with female sex steroids in the rat.

An acute dose of biotin (10 mg/100 g body weight) in two subcutaneous injections when given to a rat on day 1 and 2 of pregnancy, caused resorption of fetuses and placentae. Pregnancies under such biotin-treated conditions were maintained by continued estrogen or progesterone therapy. Biotin-treated pregnant rats failed to maintain normal levels of uterine weight, glycogen and protein as well as hepatic protein concomitantly with the loss of pregnancy. Estrogen therapy under such conditions improved all the parameters in these organs including the placenta, but progesterone therapy did not. Glucose-6-phosphate dehydrogenase (G-6-PD) activity in ovary, adrenal, liver and uterus was also reduced following biotin-induced loss of pregnancy which had been improved by estrogen or progesterone therapy. Nevertheless, estrogen was superior to progesterone in stimulating the enzyme activity in these organs excepting the adrenal. As far as the tissue response to biotin, estrogen or progesterone in the nonpregnant rat is concerned, biotin and progesterone exerted a suppressing effect on uterine glycogen and protein and also on liver protein, while estrogen stimulated them. Similarly biotin and progesterone adversely affected G-6-PD activity in all the organs studied except the liver and adrenal. Estrogen stimulated the enzyme activity in all these organs but adrenal. The study suggests that the primary reason for an acute dose of biotin-induced loss of pregnancy is blockage of estrogen production, which probably regulates endogenous progesterone secretion. The associated metabolic derangements are probably secondary to estrogen deficiency and are discussed.