Effect of pH on solubility of white Mineral Trioxide Aggregate and Biodentine: An in vitro study.

Background. The aim of this study was to evaluate the effect of acidic, neutral and alkaline environments on the solubility of white mineral trioxide aggregate (WMTA) and Biodentine (BD). Methods. Thirty-nine ring molds were randomly divided into three groups of A, B, and C (n = 12) with pH values of 7.4, 4.4 and 10.4, respectively, and an empty mold was used as a control. Each group was further divided into two subgroups (1 and 2) according to the material studied. The samples in groups A, B and C were transferred into synthetic tissue fluid buffered at pH values of 7.4, 4.4 and 10.4, respectively, and kept in an incubator at 37°C with 100% humidity. Daily solubility at 1-, 2-, 5-, 14-, 21-, and 30-day intervals and cumulative solubility up to 5-, 14-, and 30-day intervals were calculated. Statistical analysis was carried out with independent-samples t-test, two-way ANOVA and post hoc Tukey tests using SPSS 18. Statistical significance was set at P<0.05. Results. Both WMTA and BD exhibited the highest solubility in acidic pH with 5.4235±0.1834 and 10.7516±0.0639 mean cumulative solubility values at 30-day interval, respectively. At all exposure times, BD was significantly more soluble than WMTA (P<0.001). Conclusion. Acidic periapical environment jeopardized the solubility of both WMTA and BD, affecting their sealing characteristics in clinical applications like perforation repair procedures and blunderbuss canals.

Production of recombinant antibodies using bacteriophages.

Recombinant antibody fragments such as Fab, scFv, diabodies, triabodies, single domain antibodies and minibodies have recently emerged as potential alternatives to monoclonal antibodies, which can be engineered using phage display technology. These antibodies match the strengths of conventionally produced monoclonal antibodies and offer advantages for the development of immunodiagnostic kits and assays. These fragments not only retain the specificity of the whole monoclonal antibodies but also easy to express and produce in prokaryotic expression system. Further, these antibody fragments are genetically stable, less expensive, easy to modify in response to viral mutations and safer than monoclonal antibodies for use in diagnostic and therapeutic applications. This review describes the potential of antibody fragments generated using phage display and their use as diagnostic reagents.

Recombinant human antibody fragment against tetanus toxoid produced by phage display.

Phage display technology is a powerful in vitro method for the identification of specific monoclonal antibodies (antibody fragments) to an antigenic target and allows the rapid generation and selection of high affinity, fully human antibodies directed toward any disease target appropriate for antibody therapy. In the present study, we exploited the phage display technology for the selection of an antigen binding fragment (Fabs) toward tetanus toxoid using human naïve phage antibody library constructed from peripheral blood lymphocytes of naïve human donors. The phages displaying Fab were subjected to three rounds of bio-panning with tetanus toxoid as antigen on a solid phase. The high affinity antibody fragments were expressed in HB2151 strain of Escherichia coli and purified by immobilized metal affinity chromatography. The binding activity and specificity of the antibody fragment was established by its reactivity toward tetanus toxoid and non-reactivity toward other related toxins as determined by enzyme-linked immunosorbent assay and immunoblot analysis. The selected Fab fragment forming the antigen-binding complexes with the toxoid in flocculation assay indicates that the Fab may have a potential neutralizing ability toward antigen.

Development of anti-bovine IgA single chain variable fragment and its application in diagnosis of foot-and-mouth disease.

Recombinant antibody fragments like single chain variable fragments (scFvs) represent an attractive yet powerful alternative to immunoglobulins and hold great potential in the development of clinical diagnostic/therapeutic reagents. Structurally, scFvs are the smallest antibody fragments capable of retaining the antigen-binding capacity of whole antibodies and are composed of an immunoglobulin (Ig) variable light (VL) and variable heavy (VH) chain joined by a flexible polypeptide linker. In the present study, we constructed a scFv against bovine IgA from a hybridoma cell line IL-A71 that secretes a monoclonal antibody against bovine IgA using recombinant DNA technology. The scFv was expressed in Escherichia coli and purified using immobilized metal affinity chromatography (IMAC). The binding activity and specificity of the scFv was established by its non-reactivity toward other classes of immunoglobulins as determined by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. Kinetic measurement of the scFv indicated that the recombinant antibody fragment had an affinity in picomolar range toward purified IgA. Furthermore, the scFv was used to develop a sensitive ELISA for the detection of foot and mouth disease virus (FMDV) carrier animals.

Immobilization of bile salt hydrolase enzyme on mesoporous SBA-15 for co-precipitation of cholesterol.

We describe herein a simple and effective strategy for immobilization of bile salt hydrolase enzyme by grafting glutaraldehyde groups inside channels of APTES functionalized SBA-15. The increase in glutaraldehyde concentration prevents leakage of enzyme but showed a steep decrease in enzyme activity in the immobilized matrix. So the degree of cross-linking should be the minimum possible to ensure sufficient stability without loss of activity. Cross-linking carried out with 0.1% glutaraldehyde concentration showed the highest activity, so this was used in all further experiments. Physico-chemical characterizations of the immobilized enzyme were carried out by XRD, N2 adsorption, TEM, FTIR and (29)Si CP-MAS NMR techniques. Immobilized BSH exhibits enhanced stability over a wide pH (3-11) and temperature range (40-80 °C) and retains an activity even after recycling experiments and six months of storage. From our in vivo research experiment toward co-precipitation of cholesterol, we have shown that immobilized BSH enzyme may be the promising catalyst for the reduction of serum cholesterol levels in our preliminary investigation. Enhancement in pH stability at the extreme side of pH may favor the use of immobilized BSH enzyme for drug delivery purpose to with stand extreme pH conditions in the gastrointestinal conditions.

The efficacy of neem extract on four microorganisms responsible for causing dental caries viz Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis: an in vitro study.

UNLABELLED: HISTORY AND OBJECTIVES: From the ancient time, neem used to be the traditional medicine for many diseases and was mainly used for cleaning the oral cavity. The incidence of dental caries was less a few decades ago but now the incidence of caries is very aggressive. This might be due to change in dietary habits, life style and more tendency toward processed food. The objective of this study is to find out the truth that if the neem is really efficacious against caries-inducing microorganisms, mainly Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis. MATERIALS AND METHODS: The dried neem sticks ground into a coarse powder and weighed into 5, 10 and 50 gm were added to 100 ml of deionized double distilled water. After soaking for 2 days, the water was filtered at 4 °C and the fine filtrate was inoculated onto blood agar plates contains individual species of microorganisms and incubated at 37 °C for 2 days. RESULTS: At maximum concentrations, neem extract has shown the maximum zone of inhibition on Streptococcus mutans. At less concentration, the efficacy of neem has shown some inhibition of growth for all the four species of microorganisms. CONCLUSION: Neem chewing provides the maximum benefits. Hence, the use of chewing sticks of neem can be recommended.

Sciatic nerve division: a cadaver study in the Indian population and review of the literature.

INTRODUCTION: The sciatic nerve is the largest nerve, with a long course in the inferior extremity. Its division into the tibial and common peroneal nerves can occur at any level from the sacral plexus to the inferior part of the popliteal space. These anatomical variations may contribute to clinical conditions such as piriformis syndrome, sciatica and coccygodynia. METHODS: This study was performed on cadavers in order to study the level of sciatic nerve division. The inferior extremities of 43 cadavers were classified into six groups depending on the level of sciatic nerve division in the gluteal region, the upper, middle and lower parts of the back of the thigh, and the popliteal fossa. RESULTS: The highest incidence of sciatic nerve division (40.7 percent) was observed in the lower part of the posterior compartment of the thigh. In 34.9 percent of the specimens, the sciatic nerve was divided into tibial and common peroneal nerves in the popliteal fossa. 16.3 percent of extremities showed sciatic nerve division proximal to its entrance in the gluteal region. CONCLUSION: In sciatic nerve neuropathies, the extent of neurological deficits depends on the level of sciatic nerve division. Sciatic nerve division into tibial and common peroneal components at a higher level can result in the involvement of only one out of the two divisions from sciatic neuropathy. It can also result in a failure of the sciatic nerve block while performing popliteal block anaesthesia.

Palmar dermatoglyphics in carcinoma breast of Indian women.

The present study was planned to assess the relationship of palmar dermatoglyphic patterns of hands in women with breast cancer and or at risk for developing breast cancer. This study was conducted on 100 histopathologically confirmed breast cancer patients in women and their digital dermatoglyphic patterns were studied to assess their association with the type and onset of breast cancer. Simultaneously 100 age-matched controls were also selected with no self or familial history of a diagnosed breast cancer and the observations were recorded. The differences of qualitative (dermatoglyphic patterns) data were tested for their significance using the chi-square test, and Student's t-test was used for quantitative (ridge counts and pattern intensity index) data analysis. The results of the study indicated statistically significant changes in finger ridge count and fingertip pattern in cases of carcinoma breast as compared to the control group. Palmar dermatoglyphics is simple, inexpensive, anatomical and non-invasive and may be used as a reliable indicator for screening of high-risk population in developing country like India, for early detection and early therapy, thus reducing the morbidity and mortality in cases of carcinoma breast.

Influence of silver nanoparticles on 2,3-bis(chloromethyl)anthracene-1,4,9,10-tetraone.

Size effect of silver nano particles on the photophysical properties of 2,3-bis(chloromethyl)anthracene-1,4,9,10-tetraone (BCMAT) have been investigated using optical absorption and fluorescence emission techniques. Silver NPs of different sizes have been prepared by two different methods. Quenching of fluorescence of BCMAT has been found to increase with decrease in the size of the silver NPs. Stern-Volmer quenching constants have also been calculated.

A cadaveric study in the Indian population of the brachialis muscle innervation by the radial nerve.

Radial nerve innervation to the brachialis muscle has been studied previously by different authors in Caucasian, Chinese, and Thai population. Present study was aimed to describe the radial nerve and musculocutaneous nerve contribution to the brachialis muscle and to elucidate racial differences between Indian and other populations. Hundred-forty superior extremities of 70 embalmed cadavers including 29 female and 41 male cadavers were dissected to study the innervation of brachialis muscle by musculocutaneous nerve and branch from the radial nerve. All the specimens were studied for site of penetration, level of distribution and nature of course and pathway of the branch of the radial nerve to the brachialis muscle. The musculocutaneous nerve innervated the brachialis muscle in 100% specimens, whereas the radial nerve in 72.14% specimens. The radial nerve branch to brachialis pierced the muscle in the lower one third of the humerus in 65.71% specimens; on the other hand in the middle one third in 34.29% specimens. The radial nerve branch to brachialis in 50.71% specimens had relatively straighter course before penetration into the muscle, whereas in 49.29% specimens the nerve had relatively curved course and pathway. Aforementioned results regarding brachialis innervation by radial nerve in Indian population is different from studies reported in other populations. These anatomical facts are important for humeral surgery including both the anterior and posterior approaches especially for orthopedic interventions on the Indian population.

Characterization of the smallest dimeric bile salt hydrolase from a thermophile Brevibacillus sp.

A thermophilic microorganism producing bile salt hydrolase was isolated from hot water springs, Pali, Maharashtra, India. This microorganism was identified as Brevibacillus sp. by 16S rDNA sequencing. Bile salt hydrolase (BSH) was purified to homogeneity from this thermophilic source using Q-sepharose chromatography and its enzymatic properties were characterized. The subunit molecular mass of the purified enzyme was estimated to be 28 kDa by SDS-PAGE and, 28.2 kDa by MALDI-TOF analysis. The native molecular mass was estimated to be 56 kDa by gel filtration chromatography, indicating the protein to be a homodimer. The pH and temperature optimum for the enzyme catalysis were 9.0 and 60 degrees C, respectively. Even though BSH from Brevibacillus sp. hydrolyzed all of the six major human bile salts, the enzyme preferred glycine conjugated substrates with apparent K(M) and k(cat) values of 3.08 microM and 6.32 x 10(2) s(-1), respectively, for glycodeoxycholic acid. The NH(2)-terminal sequence of the purified enzyme was determined and it did not show any homology with other bacterial bile salt hydrolases. To our knowledge, this is the first report describing the purification of BSH to homogeneity from a thermophilic source.

Brevibacillus sp: a novel thermophilic source for the production of bile salt hydrolase.

A thermophilic microorganism growing within the temperature range of 40-65 degrees C (optimum at 55 degrees C) was isolated from hot water springs near Konkan, Maharashtra, India. Based on 16S rDNA sequence analysis, it was concluded that the isolate belongs to the genus Brevibacillus. The present paper reports the isolation, identification, and standardization of fermentation conditions for the production of enzyme, bile salt hydrolase (EC 3.5.1.24) which is produced intracellularly at high temperatures. This is the first report regarding the production of bile salt hydrolase from a thermophilic source. Optimization of fermentation conditions resulted in a 2.9-fold enhancement in enzyme production.

Oxidative stress modulates membrane bound ATPases in brain regions of PCB (Aroclor 1254) exposed rats: protective role of alpha-tocopherol.

Polychlorinated biphenyls (PCBs) are a class of widely dispersed and environmentally persistent organic compounds. PCBs exhibit a wide range of toxicological effects including neurotoxicity. Vitamin E (alpha-tocopherol) is an important lipid soluble antioxidant placed in a special region of membranes. Large amounts of energy are required to maintain the signaling activities of the cells in the central nervous system (CNS). Membrane proteins that control ion gradients across organellar and plasma membranes appear to be particularly susceptible to oxidation-induced changes. The aim of this study was to determine the protective role of vitamin E on Aroclor 1254 induced modulation in membrane bound ATPases in brain regions of rats. One group of rats received corn oil as vehicle for 30days as control. The other group of rats were administered Aroclor 1254 at a dose of 2mgkg(-1) bwday(-1) intraperitoneally for 30days. One group of rats received vitamin E (50mgkg(-1) bwday(-1)) orally simultaneously with Aroclor 1254 for 30days. After 30days, the animals were euthanized and the brain was dissected to hypothalamus and hippocampus to determine the following parameters. Hydrogen peroxide (H2O2), Lipid peroxidation (LPO) and the activities of Na+K+-ATPase, Ca2+-ATPase and Mg2+-ATPase were determined. Reduced glutathione (GSH) level was also determined. Activities of all the enzymes were decreased while an increase in H2O2 and LPO were observed in selected brain regions of PCB treated animals. Simultaneous vitamin E treatment in PCB exposed animals restored all the parameters significantly. These results suggest that oxidative stress is involved in the inhibitory effect of PCB (Aroclor 1254) on membrane bound ATPases in selected brain regions. alpha-tocopherol acts against PCB induced neurotoxicity by decreasing oxidative stress.

Rapid in vitro screening of drug-metal ion interactions.

ABSTRACT The toxic side effects of synthetic drugs may, in part, be arising due to their interactions with essential metal ions, especially when the metal ions are administered along with the drug as mineral supplements. In this paper we report the feasibility of establishing such drug-metal ion interactions through in vitro spectrophotometric studies, which are rapid and can be used for routine screening prior to clinical studies. The interaction of the drugs levothyroxine and ranitidine with eight metal ions, copper(II), chromium(III), molybdenum(VI), magnesium(II), calcium(II), iron(II), manganese(II), and zinc(II), commonly used in mineral supplements, was verified through in vitro UV-visible spectrophotometric studies. The experiments were carried out at the physiological pH values 1.5, 7.4, and 8.0 and the concentrations of the drugs and mineral supplements used were comparable to those in their usual doses. These studies indicated interaction between ranitidine and calcium(II), magnesium(II), and iron(II) ions and between levothyroxine and copper(II) and iron(II) ions. A comparison of the results with those reported from clinical studies demonstrated the efficacy of this method.