Synthesis and Characterization of Calcium Phosphate Ceramic/(Poly(vinyl alcohol)-Polycaprolactone) Bilayer Nanocomposites-A Bone Tissue Regeneration Scaffold.

ß Tricalcium phosphate ceramic was used to reinforce nanofibers in composite mats produced via electrospinning of poly(vinyl alcohol) (PVA), polycaprolactone (PCL) and (PVA: PCL) bilayers. The role of TCP ceramic on morphology of nanocomposites, crystalline structure, functional groups and thermal behaviour of nanocomposites were characterized by SEM, EDAX, XRD, FTIR and DSC analysis. Ultrathin cross-sections of the obtained nanocomposites were morphologically investigated with SEM and all fabricated composites consisted of fibers with average fiber diameter (AFD) around 100 nm except PCL-TCP fibers having AFD in the range of 608 nm. XRD profile presented the main peaks of ß-TCP (JCPDS 090169 and JCPDS 70-2065). The characteristic absorption bands of TCP were also identified by FTIR in all the composites. The thermal stability was enhanced after adding TCP filler particles in all the polymer composites. The porosity of PCL-TCP was found around 63% and (PVA-PCL: TCP) composite was found to be 58%. The biocompatibility of the (PVA-PCL: TCP) composite scaffold has also been investigated by culturing MG-63 osteoblast cells on it; primary results showed that the cells adhered and proliferated well on the composite scaffold.

Preliminary studies of PVA/PVP blends incorporated with HAp and ß-TCP bone ceramic as template for hard tissue engineering.

Polyvinylalcohol (PVA) and Polyvinylpyrrolidone (PVP) blend incorporated with hydroxyapatite (HAp) and ß-tricalcium phosphate (ß-TCP) is electrospun as nanofibrous composite scaffolds to act as suitable template for bone tissue engineering. Microscopic and spectroscopic characterizations confirm uniform integration of the crystalline calcium phosphate ceramics in the scaffolds. PVA-PVP blends are usually amorphous in nature and addition of phosphate ceramic particles specifically HAp elevates its crystalline behavior which is substantiated by XRD details. Further incorporation of ceramics is confirmed using FT-IR as characteristic PO43- groups for HAp and ß-TCP were observed in the distinguished composites. Single glass transition temperature is observed for pure and composite blends indicating the formation of highly miscible blends. Also, addition of these ceramics augments the thermal stability of the blend scaffolds. Biocompatibility of the prepared (PVA: PVP)-HAp and (PVA: PVP)-TCP scaffolds is assessed using MG-63 Osteoblast cell lines in the time interval of 1st, 4th and 7th day. The cell viability percentage for (PVA: PVP)-HAp is high compared to ß-TCP added blend composites, reinforcing the fact that scaffolds with good mechanical strength and enhanced porosity supports better cell adhesion.

Generalized Flows for Optimal Inference in Higher Order MRF-MAP.

Use of higher order clique potentials in MRF-MAP problems has been limited primarily because of the inefficiencies of the existing algorithmic schemes. We propose a new combinatorial algorithm for computing optimal solutions to 2 label MRF-MAP problems with higher order clique potentials. The algorithm runs in time O(2(k)n(3)) in the worst case (k is size of clique and n is the number of pixels). A special gadget is introduced to model flows in a higher order clique and a technique for building a flow graph is specified. Based on the primal dual structure of the optimization problem, the notions of the capacity of an edge and a cut are generalized to define a flow problem. We show that in this flow graph, when the clique potentials are submodular, the max flow is equal to the min cut, which also is the optimal solution to the problem. We show experimentally that our algorithm provides significantly better solutions in practice and is hundreds of times faster than solution schemes like Dual Decomposition [1], TRWS [2] and Reduction [3], [4], [5]. The framework represents a significant advance in handling higher order problems making optimal inference practical for medium sized cliques.

Targeted Busulfan therapy with a steady-state concentration of 600-700 ng/mL in patients with sickle cell disease receiving HLA-identical sibling bone marrow transplant.

Busulfan (BU) has a narrow therapeutic window and the average concentration of BU at steady state (Css) is critical for successful engraftment in children receiving BU as part of the preparative regimen for allogeneic transplants. Sixteen patients with sickle cell disease (SCD) underwent allogeneic bone marrow transplant (BMT) from HLA-identical siblings. The preparative regimen consisted of intravenous BU 0.8-1 mg/kg/dose for 16 doses, cytoxan (CY) of 50 mg/kg daily for four doses and equine anti-thymocyte globulin (ATG) 30 mg/kg daily for three doses. BU levels were adjusted to provide a total exposure Css of 600-700 ng/mL. The median age at the time of transplant was 6.2 years (range 1.2-19.3). Fourteen (87%) patients required adjustment of the BU dose to achieve a median Css of 652 ng/mL (range 607-700). All patients achieved neutrophil and platelet engraftment without significant toxicity. Median donor engraftment at the last follow-up was 100% (range 80-100). None of the patients experienced sickle cell-related complications post transplant. With a median follow-up of 3 years (range 1.3-9), the event-free survival (EFS) and overall survival (OS) are both 100%. We conclude that targeting of BU Css between 600 and 700 ng/mL in this regimen can result in excellent and sustained engraftment in young patients with SCD.

Transport and pharmacodynamics of albitiazolium, an antimalarial drug candidate.

BACKGROUND AND PURPOSE: Choline analogues, a new type of antimalarials, exert potent in vitro and in vivo antimalarial activity. This has given rise to albitiazolium, which is currently in phase II clinical trials to cure severe malaria. Here we dissected its mechanism of action step by step from choline entry into the infected erythrocyte to its effect on phosphatidylcholine (PC) biosynthesis. EXPERIMENTAL APPROACH: We biochemically unravelled the transport and enzymatic steps that mediate de novo synthesis of PC and elucidated how albitiazolium enters the intracellular parasites and affects the PC biosynthesis. KEY RESULTS: Choline entry into Plasmodium falciparum-infected erythrocytes is achieved both by the remnant erythrocyte choline carrier and by parasite-induced new permeability pathways (NPP), while parasite entry involves a poly-specific cation transporter. Albitiazolium specifically prevented choline incorporation into its end-product PC, and its antimalarial activity was strongly antagonized by choline. Albitiazolium entered the infected erythrocyte mainly via a furosemide-sensitive NPP and was transported into the parasite by a poly-specific cation carrier. Albitiazolium competitively inhibited choline entry via the parasite-derived cation transporter and also, at a much higher concentration, affected each of the three enzymes conducting de novo synthesis of PC. CONCLUSIONS AND IMPLICATIONS: Inhibition of choline entry into the parasite appears to be the primary mechanism by which albitiazolium exerts its potent antimalarial effect. However, the pharmacological response to albitiazolium involves molecular interactions with different steps of the de novo PC biosynthesis pathway, which would help to delay the development of resistance to this drug.

Single-step endoscopic ultrasonography-guided drainage of peripancreatic fluid collections with a single self-expandable metal stent and standard linear echoendoscope.

Endoscopic ultrasonography (EUS)-guided drainage of peripancreatic fluid collections (PFCs) is a well described alternative to surgery or percutaneous drainage. However, it is limited by the requirement for a large working channel that allows multiple plastic stent placement, which is only commercially available on therapeutic linear echoendoscopes. Herein, we describe the drainage of PFCs with a single self-expandable metal stent (SEMS) using a single-step technique and standard linear echoendoscope. Seven cases were identified during a retrospective chart review, and included all patients who had undergone EUS-guided drainage of PFCs during a 6-month period. The mean age was 46 years (range 25 - 70 years) and all patients were symptomatic. The mean diameter of PFCs was 8 cm (range 4.1 - 12.5 cm). Previous percutaneous drainage had failed in three patients. A total of 10 PFCs were drained. Three patients had two cysts drained by the same stent and one patient had two separate procedures to drain two distinct cysts. The SEMS was in place for a mean of 13 weeks (range 4 - 34 weeks). Successful placement of SEMS was achieved in all seven cases. Patients were followed for a mean of 18 weeks (range 7 - 35 weeks), and symptom improvement was achieved in all cases. Complete resolution of PFC was achieved in 9 /10 cysts. No complications were encountered. Single-step EUS-guided drainage of PFCs using a single 10-mm SEMS and a standard linear echoendoscope appears to be a feasible endoscopic technique with excellent technical and clinical success rates.

Transcatheter closure of patent ductus arteriosus: report of the first case in Nigeria.

BACKGROUND: Since the first report on device closure of patent ductus arteriosus (PDA) by Porstmann et al in 1967, the procedure has gained wide acceptance and has been used all over the world, including parts of Africa. The advantages when compared to surgical closure include shorter procedure time and hospital stay and no scar being left. This mode of treatment was not available in Nigeria prior to this with patients having to travel abroad to benefit. PATIENT AND METHOD: Cardiac catheterisation laboratory became available in Lagos, Nigeria in 2009 and in October 2010, the laboratory collaborated with Lagos State University College of Medicine (LASUCOM) and Lagos State University Teaching Hospital (LASUTH), to perform a device closure on a 3-year old girl with PDA who had presented to LASUTH with heart failure at the age of 6 months. To the best of our knowledge, this is the first time the procedure has been performed in Nigeria RESULTS: The patient made a successful recovery and is haemodynamically stable, on no medications. CONCLUSION: Device closure of PDA is now safe and available in Nigeria.

Nano-structured nickel oxide based DNA biosensor for detection of visceral leishmaniasis (Kala-azar).

Sol-gel synthesized nickel oxide (NiO) film deposited onto indium tin oxide (ITO) coated glass plate has been utilized for the development of sensitive and stable DNA biosensor and demonstrated for diagnosis of visceral leishmaniasis also known as Kala-azar. Leishmania specific sensor is developed by immobilizing 23mer DNA sequence (oligonucleotide) identified from 18S rRNA gene sequences from Leishmania donovani. Characterization studies like X-Ray Diffraction and Scanning Electron Microscopy revealed the formation of nano-structured NiO, while immobilization of single strand (ss)-DNA of Leishmania was supported by UV-visible, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy techniques. Response studies of ss-DNA/NiO/ITO bioelectrode are carried out using differential pulsed voltammetry in presence of methylene blue redox dye as a redox mediator. A linear response is obtained in the wide concentration range of 2 pg ml(-1) to 2 µg ml(-1) of complementary target genomic DNA (disease DNA) within the variation of 10% for 5 sets of studies. The observed results hold promise not only for diagnosis of Kala-azar patients but also hold enormous potential of the nano-NiO based probe for development of stable and sensitive biosensors.

Cardiac mucormycosis with T-cell immunodeficiency.

We present a case of a 2 year old apparently healthy child who presented with fever and mass on the mitral valve. Excision histopathology of the mass revealed mucormycosis. After 4 months, she had CNS embolisation with recurrence of cardiac lesion when investigations revealed associated T-cell immunodeficiency.

Pulmonary hyalinizing granuloma with ureteric fibrosis: A case report and review of relevant literature.

A 52-year-old, asymptomatic patient presented with bilateral lung nodules on chest radiograph. She was diagnosed to have "pulmonary hyalinizing granuloma" on an open lung biopsy. We review the clinical features of this rare disease.

Parachute tricuspid valve.

Parachute abnormality of mitral valve frequently occurs with left sided obstructive lesions though occasionally may occur as an isolated lesion. Symptoms depend upon the severity of stenosis and associated lesions. Parachute abnormality of the tricuspid valve has rarely been reported and its association with left to right shunts has not been described so far.

Perventricular device closure of muscular ventricular septal defects on the beating heart.

This report describes our initial experience with intraoperative device closure of muscular ventricular septal defects under echocardiographic guidance without cardiopulmonary bypass in two patients.

Clinical profile of neonatal sepsis.

INTRODUCTION: Neonatal Sepsis is a major cause of mortality and morbidity in newborns both in developed and developing countries. OBJECTIVE: This study was to analyse the symptoms and sign of Neonatal Sepsis. MATERIALS AND METHODS: Retrospective hospital based study the date was collected from patient record files of two years (Jan. 2001-Dec.2002). RESULT: 106 Neonates with suspected sepsis were studied out of which 30 were culture positive. The most common organism was E. coli and the most common clinical presentation was the respiratory distress and letharginess. CONCLUSION: Infection in Neonate is an important cause of mortality and morbidity especially in low birth babies.

Case report: Aneurysmal bone cyst of the ethmoid bone.

Aneurysmal bone cysts (ABCs) are benign, slow growing expansile lesions usually found in long bones or vertebrae. Plain radiography reveals expansion of bone and cortical thinning. MRI may assist in diagnosis by virtue of its ability to demonstrate blood-fluid levels, which is a characteristic finding in these lesions. Very few cases of ABC of the paranasal sinuses have been reported in the literature. We present MRI findings of ABC of the ethmoid sinus in a 19-year-old male.

Endovascular stents for coarctation of the aorta: initial results and intermediate-term follow-up.

OBJECTIVES: The aim of this study was to evaluate the use of endovascular stents in native and recurrent coarctation of the aorta (CoA). BACKGROUND: Stents have been used successfully in various locations. Their use in CoA can be an alternative to surgery or balloon angioplasty (BA). METHODS: Thirty-four patients with CoA (13 native and 21 re-coarctation after surgery or BA) with a mean age of 16 +/- 8 years (range 4 to 36 years) underwent attempted stent implantation between 1993 and 1999. Successful outcome was defined as peak systolic pressure gradient after stent implantation < 20 mm Hg. RESULTS: Stents were implanted in 33/34 patients, and successful outcome occurred in 32/33 patients. Peak systolic pressure gradient decreased from 32 +/- 12 mm Hg to 4 +/- 11 mm Hg (p < 0.001). Coarctation site to descending aorta diameter ratio increased from 0.46 +/- 0.16 to 0.92 +/- 0.16 (p < 0.001). Two patients underwent successful stent re-dilation 16 and 21 months after initial implantation. Six patients (18%) developed complications, including two patients who underwent surgery. Follow-up for 29 +/- 17 months (range: 5 to 81 months) demonstrated no evidence of re-coarctation, aneurysm formation, stent displacement or fracture. Systolic blood pressure (SBP) decreased from 136 +/- 21 mm Hg before stent placement to 122 +/- 19 mm Hg at follow-up (p = 0.002). The SBP gradient decreased from 39 +/- 18 mm Hg to 4 +/- 6 mm Hg, and peak Doppler gradient decreased from 51 +/- 26 mm Hg to 13 +/- 11 mm Hg at follow-up (p < 0.001). CONCLUSIONS: Intravascular stent placement for native and recurrent CoA has excellent results in the short and intermediate terms. Long-term outcome remains to be evaluated.

Coronary risk and dyslipidemia in type 2 diabetic patients.

OBJECTIVES: A prospective study was carried out to find out the percentage of dyslipidemia in type 2 diabetics, to study the pattern of dyslipidemia, categorize the levels of LDL, HDL and triglycerides into higher, borderline and lower risk of developing coronary heart disease in type 2 diabetics and to compare the lipid profile with non-diabetics. MATERIAL AND METHODS: Five hundred patients of type 2 diabetes mellitus and 150 age, sex and BMI matched non-diabetic healthy individuals were studied. The labelling of dyslipidemia and the categorization of risk for developing coronary heart disease (CHD) was done according to the guidelines of American Diabetes Association (ADA, 1998). RESULTS: Dyslpidemia was present in 89% of diabetic patients with LDL hyperlipoproteinemia (LDL > 100 mg%) in 76%, HDL dyslipidemia (HDL < 35 mg%) in 58%, hypertriglyceridemia (TG > 200 mg%) in 22% patients. On analysing CHD risk based on lipid profile, it was revealed that in LDL moiety 48% fell in higher risk of CHD (LDL > 130 mg%), 28% in borderline risk (LDL 100-130 mg%) and 24% (LDL < 100 mg%) in lower risk. For HDL 18.5% fell in higher risk (HDL < 35 mg%) and TG only 0.5% fell in higher risk (TG > 400 mg%). The lipid profile was significantly altered in diabetic patients as compared to non diabetics. CONCLUSIONS: The major concern which our study highlights is the high percentage of LDL dyslipidemia majority of whom fell in higher risk of developing CHD. Triglyceride and HDL levels were of lesser significance when newer ADA (1998) criteria for dyslipidemia were applied.