Small-angle neutron scattering studies suggest the mechanism of BinAB protein internalization.

Small-angle neutron scattering (SANS) is one of the most widely used neutron-based approaches to study the solution structure of biological macromolecular systems. The selective deuterium labelling of different protein components of a complex provides a means to probe conformational changes in multiprotein complexes. The Lysinibacillus sphaericus mosquito-larvicidal BinAB proteins exert toxicity through interaction with the receptor Cqm1 protein; however, the nature of the complex is not known. Rationally engineered deuterated BinB (dBinB) protein from the L. sphaericus ISPC-8 species was synthesized using an Escherichia coli-based protein-expression system in M9 medium in D2O for 'contrast-matched' SANS experiments. SANS data were independently analysed by ab initio indirect Fourier transform-based modelling and using crystal structures. These studies confirm the dimeric status of Cqm1 in 100% D2O with a longest intramolecular vector (D max) of ∼94 Šand a radius of gyration (R g) of ∼31 Å. Notably, BinB binds to Cqm1, forming a heterodimeric complex (D max of ∼129 Šand R g of ∼40 Å) and alters its oligomeric status from a dimer to a monomer, as confirmed by matched-out Cqm1-dBinB (D max of ∼70 Šand R g of ∼22 Å). The present study thus provides the first insight into the events involved in the internalization of larvicidal proteins, likely by raft-dependent endocytosis.

Novel Furan Coupled Quinoline Diamide Hybrid Scaffolds as Potent Antitubercular Agents: Design, Synthesis and Molecular Modelling.

BACKGROUND: A novel series of 2-[(2-{[2-(furan-2-yl) quinolin-4-yl] carbonyl} hydrazinyl) carbonyl] benzoic acid, -4-oxobut-2-enoic acid and -4-oxobutanoic acids were synthesized and screened for in vitro antitubercular activity. OBJECTIVES: In the present investigation, we describe the synthesis and biological screening of furan C-2 quinoline coupled diamides for antitubercular activity. METHODS: The mycobacterium tuberculai testing was carried out by MABA method and molecular docking studies were done by open-source molecular docking program, Autovina, using Pyrx 0.8 interface. RESULTS: The results revealed that the compounds inhibited the growth of H37Rv strain at concentrations as low as 1.6 to 12 µg/ml. Molecular binding of furan, quinoline and diamide (FQD) derivatives on five targets was good and these compounds fit very well within the binding domain of the target protein. CONCLUSION: The synthesized FQD derivatives exhibited moderate to good inhibition activity especially compounds 5f, 5b and 8a exhibited very good inhibition activity due to the presence of three different scaffolds, such as INH, phenyl ketobutyric acid and fluoroquinolines. Hybridized molecules might have multiple modes of action / inhibit more than one tubercular target and could pave way for novel drug discovery in the field of tuberculosis.

A highly enantioselective asymmetric Darzens reaction catalysed by proline based efficient organocatalysts for the synthesis of di- and tri-substituted epoxides.

A new class of easily available and readily tunable proline based chiral organocatalysts was found to efficiently catalyse an unprecedented highly enantioselective asymmetric Darzens reaction of α-chloroketones and substituted α-chloroketones with various aldehydes, which directly produces optically active di- and tri-substituted chiral epoxides with higher product yields (up to 97%) and excellent ee's (up to 99%) under mild reaction conditions.

Forensic Odontology: A Boon to Community in Medico-legal Affairs.

Forensic odontology is a sub-discipline of dental science which involves the relationship between dentistry and the law. The specialty of forensic odontology is applied in radiographic investigation, human bite marks analysis, anthropologic examination and during mass disasters. Besides the fact that radiographs require pretentious laboratory, it is still claimed to be a facile, rapid, non-invasive method of age identification in the deceased. The budding DNA technology has conquered the traditional procedures and currently being contemplated as chief investigating tool in revealing the hidden mysteries of victims and suspects, especially in hopeless circumstances. Forensic odontology has played a chief role in solving cold cases and proved to be strong evidence in the court of law. Systematic collection of dental records and preservation of the same would marshal the legal officials in identification of the deceased. To serve the forensic operation and legal authorities, dental professionals need to be familiar with the basics of forensic odontology, which would create a consciousness to preserve the dental data. The aim of this paper is to emphasize the vital applications of forensic odontology in medico-legal issues. Conjointly the recent advancements applied in forensic human identification have been updated.

A study on knowledge, attitude and practice regarding voluntary blood donation among medical students in Puducherry, India.

Knowledge, attitude and practice studies have been used to understand the various factors that influence blood donation which is the basis for donor mobilization and retention strategies. Role of youngsters in voluntary blood donation is crucial to meet the demand of safe blood. The present study was aimed to assess the level of knowledge, attitude and practice regarding voluntary blood donation among the health care students. A validated and pre-tested questionnaire on knowledge, attitude and practice on blood donation were assessed among 371 medical students from Sri Lakshmi Narayana Institute of Medical Sciences and Research Institute, Puducherry, India. Result showed that knowledge on blood donation among respondents was 44.8% (1st year 36.7%, 2nd year 42.8% and 3rd year 54.9%). About 62.6% of non-donors (1st year 51%, 2nd year 61% and 3rd year 77%) showed positive attitude by expressing their willingness to donate blood while 22.8%.of the non-donors had negative attitude (1st year 33%, 2nd year 23% and 3rd year 13%). In practice 13.2% of students had donated blood (1st year 10%, 2nd year 13% and 3rd year 24%), in which 2.7% of male students alone donating blood on regular basis. Over all 3rd year student showed significantly higher knowledge compared with 1st years, in attitude and practice section 3rd year student's showed significantly higher positive attitude and practice than that of 1st and 2nd years. The present study reveals that there is a positive association among knowledge, attitude and practice on blood donation, which suggest that positive attitude and practice can be improved by inculcating knowledge on blood donation among college students to recruit and donate blood regularly, which will help to achieve 100% of blood donation on voluntary basis.

Four-part proximal humeral fractures: diagnosis with the 'sunset' sign on anteroposterior radiograph.

INTRODUCTION: Four-part proximal humeral fractures require surgical intervention. However, they can be difficult to diagnose in radiological images. We aim to define a new, easily recognisable, radiological sign as a predictor of four-part fracture of the proximal humerus in a plain anteroposterior radiograph of the shoulder. PATIENTS AND METHODS: We describe our 'sunset' sign as 'articular surface of humeral head pointing away from the glenoid and tilted upwards, in the presence of a displaced greater tuberosity fracture'. We postulate that a patient with proximal humerus fracture showing this sign has four-part fracture until proven otherwise. Between 2002 and 2006, 80 consecutive patients had surgical treatment of their proximal humeral fractures in our unit. Pre-operative radiographs and operative notes of 79 patients were evaluated independently by three blinded observers. The presence of 'sunset' sign was recorded. Findings were then correlated with the operative diagnoses to confirm whether they were four-part fractures or not. With 95% confidence interval, we calculated the sensitivity, specificity, positive and negative predictive values for our diagnostic sign. RESULTS: Of 79 patients, 30 displayed 'sunset' sign in their pre-operative radiograph. Of these, 28 had confirmed four-part fractures operatively. The positive predictive value of 'sunset' sign was 93%. The specificity and sensitivity were 95% and 78%, respectively. The sensitivity was affected by eight patients with four-part fractures with displaced articular head fragment which had dropped either medially or posteriorly. CONCLUSIONS: These results suggest that, in patients with proximal humeral fractures, the presence of 'sunset' sign in the anteroposterior radiograph is a reliable indicator of four-part fracture.

Melatonin enhances the sensitivity of circadian pacemakers to light in the nocturnal field mouse Mus booduga.

The effect of exogenous melatonin (1 mg/kg) on light pulse (LP) induced phase shifts of the circadian locomotor activity rhythm was studied in the nocturnal field mouse Mus booduga. Three phase response curves (PRCs: LP, control, and experimental) were constructed to study the effect of co-administration of light and melatonin at various circadian times (CTs). The LP PRC was constructed by exposing animals free-running in constant darkness (DD) to LPs of 100-lux intensity and 15-min duration, at various CTs. The control and experimental PRCs were constructed by using a single injection of either 50% DMSO or melatonin (1 mg/kg dissolved in 50% DMSO), respectively, administered 5 min before LPs, to animals free-running in DD. A single dose of melatonin significantly modified the waveform of the LP PRC. The experimental PRC had significantly larger areas under advance and delay regions of the PRC compared to the control PRC. This was also confirmed when the phase shifts obtained at various CTs were compared between the three PRCs. The phase delays at three phases (CT12, CT14, and CT16) of the experimental PRCs were significantly greater than those of the control and the LP PRCs. Based on these results we conclude that phase shifting effects of melatonin and light add up to produce larger responses.

Entrainment of circadian locomotor activity rhythm of the nocturnal field mouse Mus booduga using daily injections of melatonin.

In this paper, we report the effects of daily injections of melatonin on the locomotor activity rhythm of the nocturnal field mouse Mus booduga. The locomotor activity rhythm of 45 animals was first monitored in constant darkness (DD) of the laboratory for about 15 days. The animals were then divided into three groups (experimental, vehicle-treated control, and the nontreated control groups) and subjected to three different treatments. The animals from the experimental group (n=19) were administered daily a single subcutaneous (s.c.) injection of melatonin (1 mg/kg) for about 45 days. The vehicle treated controls (n=13) were administered daily injections of 50% dimethyl sulfoxide (DMSO) for about 45 days, and the nontreated controls (n=13) were handled similar to the other two groups without being administered injections. Following the treatments, the animals were maintained in DD for about 20 days, after which the experiments were terminated. A significantly larger percentage of animals from the experimental group either entrained or showed phase control to daily treatments, compared to the animals from the two control groups. These results suggest that externally administered melatonin can influence the phase of the circadian locomotor activity rhythm of M. booduga. The fact that none of the nontreated controls showed any sign of phase control to daily handling, clearly demonstrates that the entrainment or phase control in the melatonin treated group of animals is caused by melatonin alone and not due to handling.

Intensity-dependent phase-adjustments in the locomotor activity rhythm of the nocturnal field mouse Mus booduga.

The locomotor activity rhythm of the nocturnal field mouse Mus booduga was monitored under constant darkness (DD) and free-running periods (tau) were estimated. Following a free-run of about 15 days in DD, the animals were exposed to periodic light pulses (LPs) of various intensities (1 lux, 10 lux, 50 lux, 100 lux, and 1,000 lux) and 15 minutes duration for 65 days at intervals of 24 hours to investigate the influence of intensity of light on the phase-angle-difference (psi) between the onset of locomotor activity and the time of LP administration. The experimentally observed values of psi and tau for a LP of 1,000 lux intensity used for 15 minutes every 24 hr, showed a sigmoid shaped relationship with tau. This relationship was similar to that predicted based on the nonparametric model of entrainment, which uses the tau and the LP phase response curve (PRC) constructed using LP of similar duration and intensity. The functional nature of the relationship between psi and tau was not found to change significantly with increasing intensities of LP used to entrain the locomotor activity rhythm. However, psi was significantly modulated by the intensity of LP. These results suggest that the periodic sensitivity of the circadian pacemaker underlying the locomotor activity rhythm in the nocturnal field mouse M. booduga to LPs plays an important role in maintaining a characteristic psi with the zeitgeber and the psi changes in a light intensity-dependent manner.

Irradiance dependency of UV-A induced phase shifts in the locomotor activity rhythm of the field mouse Mus booduga.

In the nocturnal field mouse Mus booduga, the responsiveness of the circadian system to UV-A light of 2.5 W/m2 and 30 minutes duration is known to be phase dependent. The results of our experiments indicate that the phase shifts evoked by UV-A at the two phases, CT14 (circadian time 14) and CT20 increases nonlinearly with irradiance.

Effects of restricted feeding cycle on the locomotor activity rhythm in the mouse Mus booduga.

The effect of restricted feeding (RF) cycles on the circadian locomotor activity rhythm was studied in the nocturnal field mouse Mus booduga. Mice were presented with a 2-h meal schedule every 24 h in continuous darkness (DD), in continuous light (LL), and in a light-dark (LD) cycle. Additionally, in DD, two groups of mice were subjected to RF cycles of periodicities 22 (T22) and 26 h (T26), respectively, in order to assess the limits of entrainment. The T22 and T26 RF cycles failed to produce any entrainment of the locomotor activity rhythm, whereas some of the animals that had a free-running period (tau) close to 24 h showed stable entrainment or "relative coordination" to daily (T24) RF cycle. In LD, the locomotor activity rhythm phase advanced under the influence of the daily RF cycle when the food presentation preceded the light to dark (L to D) transition by 5-6 h. However, when the timing of food presented in the RF cycle coincided with the L to D transition, locomotor activity rhythm dissociated into two components. Some of the mice whose locomotor activity rhythm disappeared in LL showed prominent meal-AA. These results suggest that RF modifies the expression of the light-entrainable pacemaker (LEP) directly and also that in the absence of the expression of the LEP, RF can induce meal-AA.

Probing the circadian pacemaker of a mouse using two light pulses.

In two separate sets of experiments, the phases of the locomotor activity rhythm of the nocturnal field mouse Mus booduga were probed using two light pulses (LPs). In the first set of experiments, the circadian pacemaker underlying the locomotor activity rhythm was perturbed at circadian time 14 (CT 14) using a resetting light pulse LP1 of 1000 lux intensity and 15 min duration. The phases of the resetting pacemaker were then probed at all even CTs between CT 16 and CT 14 using a PRC probing light pulse LP2 of equal strength. The "LP2 PRC" thus obtained was then compared with the single light pulse PRC in terms of the area under delay (D) and advance (A) zones of the PRCs. The time course and waveform of the two LP PRCs suggest that the LP2 PRC resembled the single LP PRC, displaced by 2 h toward the right. The LP1 PRC had smaller D compared to the single LP PRC (p = 0.007), whereas both the PRCs had A of equal magnitude (p = 0.23). This suggests that the pacemaker phase shifts rapidly after LP perturbations. In the second set of experiments, the LP1 was administered at CT 14. The phase of the pacemaker was then perturbed on day 1 (next cycle after LP1) either 2 h after activity onset (at ca. CT 14 of the transient cycle) or 8 h after activity onset (at ca. CT 20 of the transient cycle) using an LP2 of equal strength. It was observed that the steady-state phase shifts evoked by positioning an LP2, 2 h after activity onset, were positively correlated with the phase shifts observed on day 1. The steady-state phase shifts observed, when the LP2 was positioned, 8 h after activity onset, were negatively correlated with the phase shifts observed on day 1. These results suggest that the transient cycles do not mirror the state of the pacemaker oscillator.

Carboxyl group hydrogen bonding in X-ray protein structures analysed using neutron studies on amino acids.

A method is proposed to make a distinction between ionized and neutral carboxyl groups in X-ray protein structures. This is based on an analysis of the relative hydrogen bonding populations and bond-length bond-valence correlations in high-precision neutron studies of amino acids and small peptides. With the help of this method, four amino acid residues containing carboxyl groups in the refined structure of triclinic hen egg-white lysozyme have been analysed. Two of these, Glu-35 and Asp-52, are involved in lysozyme function, while the other two, Glu-7 and Asp-101, form a protein-protein inter-molecular contact in the triclinic structure.

Fertility trends among acceptors of sterilisation in an urban situation: a socio-demographic explanation.

This report examines the characteristic trends in socioeconomic, demographic, fertility, and marriage patterns of a sample of 48 acceptors of sterilization in an urban situation in India. The sample represents a universe of 211 acceptors out of 1171 eligible couples and 10,000 population. The analysis yields valuable information on the correlation between socioeconomic and demographic variables. Wives' education and residential status are negatively and significantly correlated with family size. The mean ages at vasectomy and tubectomy are 38.3 and 28.1 years respectively. The mean number of living children at the time of tubectomy is 3.4. About 69% of the women have had only live births. The mean number of years of fertile marital union is 12.19. The mean number of conceptions is 4.4. The mean achieved family size is 3.3 living children and the mean ideal family size ranges from 2.13 to 2.5.