Antioxidant, anticlastogenic and radioprotective effect of Coleus aromaticus on Chinese hamster fibroblast cells (V79) exposed to gamma radiation

Coleus aromaticus (Benth, Family: Laminaceae), Indian Oregano native to India and Mediterranean, is well known for its medicinal properties. A preliminary study was undertaken to elucidate in vitro free radical scavenging potential and inhibition of lipid peroxidation by C.aromaticus hydroalcoholic extract (CAE). Anti-clastogenic and radioprotective potential of CAE were studied using micronucleus assay after irradiating Chinese hamster fibroblast (V79) cells. CAE at 10, 20, 40, 60, 80, 100 and 120 mug/ml resulted in a dose-dependent increase in radical scavenging ability against various free radicals viz., 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide anion (O(2)(*-)), hydroxyl (OH(*)) and nitric oxide (NO(*)) generated in vitro. A maximum scavenging potential was noticed at 100 mug/ml and a saturation point was reached thereafter with the increasing doses of CAE. The free radical scavenging potential of the extract was in the order of DPPH > ABTS > Superoxide > Hydroxyl > Nitric oxide. CAE also exhibited a moderate inhibition of lipid peroxidation in vitro, with a maximum inhibition at 60 mug/ml (33%), attaining saturation at higher doses. The extract also rendered protection against radiation induced DNA damage, as evidenced by the significant (P < 0.05) decrease in the percentage of radiation-induced micronucleated cells (MN) and frequency of micronuclei (total). A maximum anticlastogneic effect/ radioprotection was noticed at a very low concentration i.e., 5 mug/ml of CAE, treated 1 h prior to 2 Gy of gamma radiation. A significant (P < 0.0001) anticlastogenic/radioprotective effect was also observed when the cells were treated with an optimum dose of CAE (5 mug/ml) 1 h prior to 0.5, 1, 2 and 4 Gy of gamma radiation compared with the respective radiation control groups. Overall, our results established an efficient antioxidant, anticlastogenic and radioprotective potential of CAE, which may be of great pharmacological importance.

Crystallographic identification of an ordered C-terminal domain and a second nucleotide-binding site in RecA: new insights into allostery

RecA protein is a crucial and central component of the homologous recombination and DNA repair machinery. Despite numerous studies on the protein, several issues concerning its action, including the allosteric regulation mechanism have remained unclear. Here we report, for the first time, a crystal structure of a complex of Mycobacterium smegmatis RecA (MsRecA) with dATP, which exhibits a fully ordered C-terminal domain, with a second dATP molecule bound to it. ATP binding is an essential step for all activities of RecA, since it triggers the formation of active nucleoprotein filaments. In the crystal filament, dATP at the first site communicates with a dATP of the second site of an adjacent subunit, through conserved residues, suggesting a new route for allosteric regulation. In addition, subtle but definite changes observed in the orientation of the nucleotide at the first site and in the positions of the segment preceding loop L2 as well as in the segment 102-105 situated between the 2 nt, all appear to be concerted and suggestive of a biological role for the second bound nucleotide.

Spectrophotometric estimation of functional groups on microslides for preparation of biochips

A universal reagent 1-O-(4,4'-dimethoxytrityl)-6-aminohexanol (DTAH) is described for the estimation of surface-bound functionalities (epoxy, aldehyde, and carboxyl) required for preparation of oligonucleotide arrays (biochips). The method involves the reaction of universal reagent DTAH with surface-bound functionality under microwaves for 10 min, followed by washings to remove the excess reagent. In the subsequent step, a weighed amount of DTAH-treated surface is exposed to acid to liberate 4,4'-dimethoxytrityl cation, which is measured at 505 nm to determine the functional group loading on the surface.

Predicting cubitus varus in supracondylar fractures of the humerus by Baumann's angles in post reduction X-rays

OBJECTIVES

The present study presents the technique to predict cubitus varus by post reduction Affected Side and Normal Side Baumann's angle difference (ASBA and NSBA) respectively. It intends to correlate the Baumann's angle to the final carrying angle of the injured elbow and presents the relevant mathematical clinical rule along with its prediction test characteristics.

MATERIAL AND METHODS

Total 57 patients of 6.5+/-1.67 yrs, 22 were males and 8 females with 19/30 having left side injury. Isolated closed supracondylar fractures of humerus up to 5 days duration included and previous trauma, pathological fracture, other injury, elbow disease were excluded .30/57 completed >1 year follow-up.

RESULTS

The Mean NSBA was 74.4+/-4.14 masculine. The mean normal side carrying angles (NSCA) were 9.56 +/- 2.2 masculine. The NSCA IQR (Inter Quartile Range) was 8.8-10 masculine. The ASBA was 79.9+/-9.1 masculine and affected side carrying angles (ASCA) was 0.20+/-8.7 masculine. The ASCA was best predicted by the difference between ASBA-NSBA (ASCA=3.87-0.65(ASBA- NSBA; F=15.91). At a cut off of 8.8 masculine (the lower limit of IQR for NSCA), a value >0 masculine for ASBA- NSBA was 80% predictive of cubitus varus. With pre test probability of varus at 70%, sensitivity was 0.94 and specificity 0.42.

DISCUSSION

A prediction rule to predict the final carrying angle from ASBA NSBA difference is presented with a positive predictive value 0.80, specificity of 0.42, and sensitivity of 0.94 at a pre test probability of 0.70.When the diagnosis of cubitus varus is ASCA<8.8 masculine (Lower limit of the IQR for NSCA).

CONCLUSION

If affected side Baumann's Angle - Normal Side Baumann's Angle is equal to or greater than 0 then there was 80% probability of having cubitus varus.

Sero-epidemiological study of kala-azar in a village of Varanasi district, India

OBJECTIVE

To evaluate five kala-azar serological tests for field use.

METHOD

Serological survey in Pandit Ka Purva village in Varanasi district, India, using Sia water test, aldehyde test, direct agglutination test (DAT), micro-enzyme-linked immunosorbent assay (ELISA) and dot-ELISA.

RESULTS

The total population of the village was 518, 67 of whom showed typical clinical and parasitological features of kala-azar, including seven who died. The age distribution of kala-azar cases showed significant differences, being highest among the 45-54-year age group. The disease was more prevalent among males. Serum samples were collected from 498 persons (96% of total population) including 67 kala-azar cases and 40 disease controls (malaria, TB, leprosy, typhoid). Ten 10 serum samples from healthy controls living in endemic area were also collected. The test sensitivities were: Sia water test, 85.0%; aldehyde test, 62.7%; DAT, 94.0%; micro-ELISA, 91.0% and dot-ELISA, 97.0%. The test specificities were: Sia water test 92.5%, aldehyde test, 93.2%, DAT, 96.7; micro-ELISA, 97.6% and dot-ELISA, 98.4%.

CONCLUSION

The dot-ELISA is highly sensitive and specific, cheap, and easy to interpret with the naked eye, making it a powerful screening test for the surveillance and diagnosis of Indian kala-azar at field level.

A new synthetic protocol for labeled oligonucleotides, using a chemically cleavable universal linker

A two-step general method for labeling of synthetic oligonucleotides is described. The protocol employs a cleavable universal linker, 5'-O-(4,4'-dimethoxytrityl)-3'-O-benzoyl-2'-O-(2-cyanoethyl-N,N-diisopropyl)-uridine phosphoramidite, to effect coupling to polymer-bound oligonucleotide chains. Sequentially, coupling with commercially available phosphoramidite reagent of an appropriate label (Biotin, HEX etc.) in an automated DNA synthesizer is carried out. The labeled oligomers, obtained after cleavage and deprotection reactions, are analyzed on RP-HPLC. A distinctive feature of this protocol is the recovery of free oligomers from their labeled analogs under mild conditions. The oligomers obtained are comparable to the corresponding standard oligonucleotides (HPLC).

Histology, Immunohistochemistry and Ultrastructure of the Tonsil of the Soft Palate of the Horse

The tonsil of the soft palate was an oval, flat structure located centro-rostrally on the oral surface of the soft palate. Its stratified squamous non-keratinized epithelium was perforated by holes or small crypts the deeper parts of which were loosely spongiform inter-digitated with lymphoid tissue. These unusual features have not previously been reported in tonsils of any species. Crypts and reticulated epithelium as found in the lingual and palatine tonsils were not observed. Lectins showed varying affinities for specific layers of the epithelium. M cells were not observed. A few Langerhans cells were distributed among surface epithelial cells. Lymphoid tissue was arranged loosely and in isolated lymphoid follicles in the subepithelial lamina propria mucosae. Although IgA+ cells and macrophages were proportionately more numerous the amount of lymphoid tissue was much less than in the lingual and palatine tonsils. Most of the follicular germinal centres lacked a darkly stained corona. CD4 positive were more numerous than CD8+ lymphocytes and were distributed in the parafollicular and inter-follicular areas. Large clusters of mucus acini positive for glycogen, acidic and neutral mucopolysaccharides separated lymphoid tissue from deeply placed striated muscle. Only a few high endothelial venules were observed in the parafollicular and inter-follicular areas. These had relatively few vesiculo vacuolar or other organelles in their high endothelial cells and few lymphocytes attaching to their walls.

The cooperative transforming effects of PAX3-FKHR and IGF-II on mouse myoblasts

Alveolar rhabdomyosarcoma (ARMS) cells express high levels of PAX3-FKHR and IGF-II. In this study, we have investigated the effects of PAX3-FKHR and IGF-II on the expression of muscle regulatory factors (myf5, MyoD and myogenin), and platelet derived growth factor-B (PDGF-B) and vascular endothelial growth factor (VEGF) in mouse C2C12 myoblasts in vitro. PAX3-FKHR induced cell cycling of C2C12 cells and promoted proliferation whilst blocking myogenesis. IGF-II inhibited their differentiation without influencing proliferation. Western blotting showed that PAX3-FKHR and IGF-II blocked the expression of myogenin and MyoD respectively. Since MyoD affects early myogenesis and myogenin controls terminal differentiation, a combination of PAX3-FKHR and IGF-II synergistically blocks myogenesis at several different stages in differentiation. We have also shown that the major survival and angiogenic cytokines, PDGF-B and VEGF, were induced by IGF-II and PAX3-FKHR respectively. A combination of PAX3-FKHR and IGF-II could synergistically up regulate the expression of PDGF-B and VEGF and stabilize their high expression levels. Our results suggest that high expression of PAX3-FKHR and IGF-II in ARMS synergistically play a key role in oncogenesis and tumour progression of ARMS.

Samarium-153 ethylenediamine tetramethylene phosphonate therapy for bone pain palliation in skeletal metastases

BACKGROUND

Systemic therapy with radionuclides may be used for the treatment of patients with painful skeletal metastases owing to its efficacy, low cost and low toxicity. Imported radionuclides for pain palliation, like Strontium-89 are expensive; particularly for developing countries. In the Indian scenario, Samarium-153 (Sm-153) is produced in our own reactors and as a result, it is readily available and economical.

AIM

We undertook this study to determine the efficacy and toxicity of single-dose Sm-153 ethylenediamine tetramethylene phosphonate as a palliative treatment for painful skeletal metastases.

MATERIALS AND METHODS

Eightysix patients with painful skeletal metastases from various primaries, were treated with Sm-153 EDTMP at a dose of 37 MBq/kg. The effects were evaluated according to change in visual analogue pain score, analgesic consumption, Karnofsky performance score, mobility score and blood count tests, conducted regularly for 16 weeks.

STATISTICS

Repeated measures analysis.

RESULTS

The overall response rates were 73%, while complete response was seen in 12.4%. Reduction in analgesic consumption with improvement in Karnofsky performance score and mobility score, was seen in all responders. Response rates were 80.3 and 80.5% in breast and prostate cancer, respectively. One case, each of Wilms tumor, ovarian cancer, germ cell tumor testis, multiple myeloma, primitive neuroectodermal tumor and oesophageal cancer, did not respond to therapy. No serious side-effects were noted, except for fall in white blood cell, platelet and haemoglobin counts, which gradually returned to normal levels by six-eight weeks.

CONCLUSION

Sm-153 EDTMP provided effective palliation in 73% patients with painful bone metastases: the major toxicity was temporary myelosuppression.

Tolerability and safety of HIV protease inhibitors in adults

Antiretroviral drugs are associated with both short-term and long-term adverse events. Like other HIV drugs, protease inhibitors (PIs) may affect metabolic processes influencing body shape and body tissue composition, appearance, bone integrity, and cardiovascular status. However, numerous confounding variables including age, cigarette smoking, body mass index (BMI), duration of HIV infection, degree of immunodeficiency, concomitant antiretroviral agents, extent of previous treatment, and duration of treatment all blur the relationship between PI use and adverse events. Recent data suggest that the early PIs appear to have greater effects on such surrogate markers of disease risk as insulin resistance and cholesterol and triglyceride levels than the recently developed PIs. These data also suggest that evaluation of PIs as a class should be reconsidered and that it is probably not appropriate to extrapolate safety data obtained from individuals treated with first-generation agents in the era of potent combination antiretroviral therapy to those treated with recently developed PIs. Because PIs remain a critical component of successful antiretroviral therapy, evaluation of potential long-term complications with prolonged PI use is essential, as is delineation of the significant differences in safety profiles among individual PIs.

Tuberculous meningitis in BCG vaccinated and unvaccinated children

BACKGROUND

A modified clinical presentation of tuberculous meningitis (TBM) in children vaccinated with BCG has been described in the literature. However, most reports are old and not based on actual comparisons and tests of significance. Also, neuroimaging features were not compared. With large scale BCG coverage, it becomes pertinent to describe the "modified" presentation and identify any significant differences between vaccinated and unvaccinated children with TBM.

METHODS

A total of 150 consecutive hospitalised children (96 unvaccinated, 54 vaccinated) were enrolled. They all satisfied predefined criteria for diagnosis of TBM. Clinical and radiological features of children with/without a BCG scar were compared.

RESULTS

Univariate analysis revealed that the vaccinated children with TBM had significantly lower rates of altered sensorium (68.5% v 85.4% unvaccinated; OR 2.2 (1.1 to 6.2); p = 0.019) and focal neurological deficits (20.3% v 39.5% unvaccinated; OR 2.6 (1.1 to 6.0); p = 0.016), and higher mean (SD) Glasgow Coma Scale score (10.2 (3.4) v 8.76 (2.7) unvaccinated; p = 0.010) and cerebrospinal fluid cell count (210.9 v 140.9 unvaccinated; p = 0.019). No significant radiological differences were seen. Short term outcome was significantly better in the vaccinated group with 70% of the total severe sequelae and 75% of the total deaths occurring in the unvaccinated group (p = 0.018).

CONCLUSION

Children with TBM who have been vaccinated with BCG appear to maintain better mentation and have a superior outcome. This may in part be explained by the better immune response to infection, as reflected in the higher CSF cell counts in this group in the present study.

The afterglow of GRB 050709 and the nature of the short-hard gamma-ray bursts

The final chapter in the long-standing mystery of the gamma-ray bursts (GRBs) centres on the origin of the short-hard class of bursts, which are suspected on theoretical grounds to result from the coalescence of neutron-star or black-hole binary systems. Numerous searches for the afterglows of short-hard bursts have been made, galvanized by the revolution in our understanding of long-duration GRBs that followed the discovery in 1997 of their broadband (X-ray, optical and radio) afterglow emission. Here we present the discovery of the X-ray afterglow of a short-hard burst, GRB 050709, whose accurate position allows us to associate it unambiguously with a star-forming galaxy at redshift z = 0.160, and whose optical lightcurve definitively excludes a supernova association. Together with results from three other recent short-hard bursts, this suggests that short-hard bursts release much less energy than the long-duration GRBs. Models requiring young stellar populations, such as magnetars and collapsars, are ruled out, while coalescing degenerate binaries remain the most promising progenitor candidates.

Preparation of the hypoxia imaging PET tracer [18F]FAZA: reaction parameters and automation

18F-labeling of the nitroimidazole nucleoside analogue 1-(5-fluoro-5-deoxy-alpha-D-arabinofuranosyl)-2-nitroimidazole (FAZA) was developed to use this tracer in PET for detection of hypoxia. Parameters for labeling and hydrolysis were optimized with regard to amount of precursor, temperature and time. Labeling yields reached a maximum of 62+/-4% at 100 degrees C within 5 min using 5 mg of precursor. Hydrolysis was best performed with 1 mL of 0.1 N NaOH at 20 degrees C for 2 min. Transfer of these conditions to an automated synthesizer resulted in an overall radiochemical yield of 20.7+/-3.5%. Absolute yields at EOS were 9.8+/-2.3 GBq of [18F]FAZA ready for injection (n=21; 50 min after EOB; irradiation parameters: 35 microA, 60 min). Thus, a convenient approach suitable for large-scale production of [18F]FAZA was developed by an automated process.