Mg-Doped Hydroxyapatite/Chitosan Composite Coated 316L Stainless Steel Implants for Biomedical Applications

In this investigation, ultrasonication process was used for the synthesis of magnesium doped nano-hydroxyapatite (MH) (0, 1, 2, and 3 mol% of Mg concentration) particles with controlled size and surface morphology. The size of the prepared MH particles was in the range of 20-100 nm with narrow distribution. Increase in the concentration of Mg reduced the particle size distribution from 60 to 40 nm. On incorporation of Mg in HAp lattice, an increase of 20-66 nm in specific surface area was observed in microporous HAp particles. XRF and XRD patterns reveal that the particles possess stoichiometric composition with reduced crystallinity with respect to the Mg concentration. Surface morphology of MH/chitosan (CTS) coated implant was found to be uniform without any defects. The corrosion rate of the implant decreased with increase in Mg concentration. The in vitro formation of bonelike apatite layer on the surface of the MH/CTS coated implant was observed from simulated body fluid studies. The antimicrobial activity of the MH/CTS composites against gram-positive and gram-negative bacterial strains indicated that increasing Mg concentration enhanced antimicrobial properties. Nanoindentation analysis of apatite coated implant surface reveals that the mechanical property depends on the concentration of magnesium in HAp. From the cytotoxicity analysis against NIH 3T3 fibroblast, it was observed that the Mg incorporated HAp/CTS composite was less toxic than the MHO/CTS composite. From this result, it was concluded that the MH/CTS nanocomposites coated implant is the excellent material for implants.

Epidemiology, Clinico-Haematological Profile and Management of Aplastic Anaemia: AIIMS Experience

BACKGROUND

The incidence of aplastic anaemia (AA) is higher in Asia than in the West. The precise incidence of AA in India is not known due to lack of epidemiological study. 20-40% of pancytopenic patients in referral centres are of aplastic anaemia.

PATIENTS AND METHODS

This was an analysis of 1501 patients diagnosed with aplastic anaemia over a period of seven and half years (January 2007- June 2014) attending the Aplastic clinic of department of haematology of All India Institute of Medical Sciences, New Delhi. The details regarding medical history, physical examination, complete blood count, bone marrow aspirate and biopsy, treatment received, were retrieved. Inherited bone marrow failure was screened in patients below 35 years. Treatment response was analysed for various treatment modalities.

RESULTS

1501 patients of AA from 20 different states of India were analysed. The bulk of patients were from Uttar Pradesh (28.7%), Bihar (23.6%), Delhi/NCR (20%) and Haryana (7%).The average number of new aplastic anaemia patients enrolled per year 214 (range: 101 -263). The median age at presentation was 25 years (range 2-83),with M;F - 2.3:1. Severity of AA revealed: severe (SAA): 75%, very severe (VSAA): 15%, non-severe (NSAA): 10%. Inherited bone marrow failure syndromes constituted 5% (75 patients) of all aplastic anaemia patients. The most common clinical presentations were pallor (97%), bleeding manifestations (69.6%) and fever (54%). The haematological parameters showed: median level of haemoglobin level: 5.9 gm/dL, WBC: 2700/mm3, ANC: 380/mm3, platelet: 1 0000/mm3. PNH clone was present in 13.5% of patients. 107 patients (7%) were lost to follow up or expired before any treatment was initiated. Only 69 patients (4.5%) received treatment with HLA-matched sibling stem cell transplantation and another 232 (15.5%) patients received ATG plus cyclosporine as immunosuppressive therapy. Seven hundred thirteenpatients (47.5%) received cyclosporine. The overall response to various treatment modalities was: HLA matched sibling haematopoietic stem cell transplant: 75.3%, Anti-thymocyte globulin plus cyclosporine: 58.7%, cyclosporine plus androgen: 45.6%, cyclosporine alone: 32.2%.

CONCLUSION

Management of AA is a real challenge in developing countries.This is one of the largest case series from a single centre from India. It is our endeavour to reduce the detrimental outcome by increasing awareness among patients and referring physicians to reduce the delay between diagnosis and treatment.

Synthesis, characterization, structural analysis of metal(II) complexes of N'-[(E)-3-Bromo-5-Chloro-2-hydroxybenzidene]-4-hydroxybenzohydrazide-Multisubstituted Schiff base as a F(-) and Cu(2+) ions selective chemosensor

New colorimetric chemosensor, N'-[(E)-3-Bromo-5-Chloro-2-hydroxybenzidene]-4-hydroxybenzohydrazide, containing OH and NH groups as binding sites have been synthesized and characterized by spectral UV, IR, NMR and ESR. The molecular structure of ligand is determined by X-ray crystallography and it has the monoclinic space group P21/c with cell parameters a=15.1058(6), b=14.3433(6), c=17.5800(8)Å and Z=8. The electronic spectral measurements show that Co(2+), Ni(2+) and Zn(2+) complexes have tetrahedral geometry, while Cu(2+) complex has square planar geometry. Magnetic measurements show that Cu(2+), Co(2+) and Ni(2+) complexes have paramagnetic behavior and Zn(2+) complex has diamagnetic behavior. Anion binding studies carried out using (1)H NMR and UV-visible spectrophotometric titrations revealed that these receptors exhibit selective recognition towards F(-) over other halide anions. The selectivity for F(-) among the halides is attributed mainly to the hydrogen-bond interaction of the receptor with F(-). Receptor (5 × 10(-5)M) shows color change from colorless to yellow in the presence of tetrabutylammonium fluoride (TBAF, 1.5 × 10(-3)M). Moreover, F(-)-induced color changes remain the same even in the presence of large excess of Cl(-), Br(-) and I(-). The binding constant is found to be higher towards F(-) ion and this may be due to presence of OH group, which offers extra binding site. Chromogenic receptor undergoes distinct color changes from colorless to green on gradual addition of Cu(2+) can be used as colorimetric probes for spectrophotometric and visual analysis of Cu(2+) in the presence of other transition metal ions such as Co(2+), Ni(2+) and Zn(2+).

In vivo cytotoxicity of MgO-doped nanobioactive glass particles and their anticorrosive coating on Ti–6Al–4V and SS304 implants for high load-bearing applications

Magnesium-doped NBG composites (SiO₂–CaO–P₂O₅–MgO) coated implant is found to be a potential nanocomposite for high load-bearing applications with better anticorrosive property and long-term stability.

Comparative efficacy of live replicating sheeppox vaccine strains in Ovines

In the present study, two sheeppox vaccines made from strains [sheeppox virus-Srinagar (SPPV-Srin) and Ranipet (SPPV-R)] indigenous to India and adapted to Vero cells were compared in terms of their safety, potency, efficacy and antigenic value with the commercial in-use Roumanian Fanar (SPPV-RF) vaccine, a foreign strain adapted in primary lamb testes cells. The safety test indicated that the SPPV (Sri and RF) vaccines were safe while SPPV-R was not completely attenuated and caused excessive adverse reactions at the passage level tested. The immunized animals showed DTH reaction and resisted virulent SPPV challenge, while control animals developed disease. Specific virus could be detected in the controls and animals immunized with lower dilutions of vaccines after challenge but not in any of the sheep immunized with 1 and 100 doses of each vaccine. All vaccines were found potent and the PD(50) was highest for SPPV (Srin and R) followed by RF. The immunized animals were seroconverted following vaccination with sustained antibody responses after challenge. In conclusion, indigenous SPPV-Srin vaccine was found to be as efficacious as SPPV-R and SPPV-RF vaccines. Thus, there is potential benefit in replacing the currently used commercial vaccine SPPV-RF with indigenous SPPV-Srin vaccine for use in India.

(E)-N'-(3-Bromo-5-chloro-2-hy-droxy-benzyl-idene)nicotinohydrazide

There are two independent mol-ecules in the asymmetric unit of the title compound, C(13)H(9)BrClN(3)O(2), in which the dihedral angles between the benzene and pyridine rings are 8.23 (9)° and 52.84 (12)°. Both the mol-ecules exist in an E configuration with respect to the C=N double bond. The two mol-ecules in the asymmetric unit are linked via weak C-H⋯O hydrogen bonds. In both the mol-ecules, an intra-molecular O-H⋯N hydrogen bond generate an S(6) graph-set motif. In the crystal, inter-molecular N-H⋯O and C-H⋯O hydrogen bonds generate bifurcated R(1) (2)(7) ring motifs. The crystal packing is further stabilized by weak inter-molecular N-H⋯O, N-H⋯N, C-H⋯O and π-π [centroid-centroid distance 3.615 (2) Å] inter-actions.

N'-[(1E)-4-Diethyl-amino-2-hy-droxy-benz-idene]benzohydrazide

In the title compound, C₁₈H₂₁N₃O₂, the dihedral angle between the phenyl and benzene rings is 36.85 (10)°. The methyl C atom of one of the ethyl groups is disordered over two positions with site occupancies of 0.810 (8) and 0.190 (8). The mol­ecular structure is stabilized by a classical intra­molecular O—H⋯N hydrogen bond. The crystal structure exhibits weak inter­molecular N—H⋯O, C—H⋯O and C—H⋯π inter­actions.

A randomized controlled study of whether the partner's presence in the operating room during neuraxial anesthesia for cesarean delivery reduces patient anxiety

BACKGROUND

This study compared anxiety in two groups of women undergoing elective cesarean delivery to ascertain if their partner's presence during neuraxial anesthesia placement affected patients' overall anxiety levels.

METHODS

Three hundred fifteen patient-partner dyads were randomized to two groups: group 1 partners were present in the operating room during neuraxial anesthesia placement while group 2 partners remained outside the operating room during placement. Before surgery, all patient-partner dyads completed a survey of demographics, anesthetic experiences and baseline anxiety. Anxiety levels were rated using a visual analogue scale (VAS) and the state portion of the Spielberger State-Trait Anxiety Inventory.

RESULTS

The mean change in anxiety as measured by VAS among patients whose partners were present in the operating room for neuraxial anesthetic placement decreased from before to after the procedure (-4.5+/-25.8; P=0.03; 95% CI -8.55, -0.45); the mean change in anxiety in patients whose partners were not present did not alter significantly (+1.9 +/- 25.3; P=0.34; 95% CI 6.68, 12.12). Anxiety was increased among partners who were not present (+9.4, P<0.001).

CONCLUSION

Although patients whose partners were present in the operating room at the time of neuraxial anesthesia placement reported less anxiety over the time of the study than did patients whose partners were not present, these differences were small and are not considered to be clinically important. Increased anxiety among partners who were not present at neuraxial placements warrants further study.