Early use of oral cholera vaccines as a prime control measure during outbreaks: Necessary but not sufficient.

INTRODUCTION: Despite being a preventable and treatable disease, cholera remains a public health problem in Sudan. The objective of the outbreak investigation was to identify associated risk factors that would help institute appropriate control measures. MATERIAL AND METHODS: A case control study design was chosen to identify the risk factors for cholera in Gadarif State. RESULTS: Multi-variate analysis of identified two risk factors and three preventive factors for cholera in Gadarif City. RISK FACTORS: Buying foods or drinks from street vendors (OR = 71.36), 95 % CI: 16.58-307.14), living in an urban setting (Gadarif City) (OR = 5.38), 95 % CI: 2.10-13.81); and the preventive factors were: Washing hands with water after defecation but without soap (OR = 0.16), 95 % CI: 0.04-0.63) or with soap (OR = 0.01), 95 % CI: 0.00-0.03), washing hands before eating (OR = 0.15), 95 % CI: 0.05-0.51) and taking Oral Cholera Vaccine (OCV) (OR = 0.19, 95 % CI: 0.08-0.44). The effectiveness of OCV (VE) was (Unadjusted VE: 80 %, 95 % CI: 69 %-87 %) or (Adjusted VE = 81.0 %, 95 % CI: 56.0 %-92.0 %). DISCUSSION: Cholera outbreaks, especially in the setting of a complex humanitarian crises, can spread rapidly, resulting in many deaths, and quickly become a public health crisis. Implementation of a community-wide vaccination campaign using OCV as early as possible during the outbreak while implementing other control measures to target hotspots and at-risk populations would expedite halting outbreaks of cholera and save lives.

Synthesis, structural characterization and in vivo anti-diabetic evaluation of some new sulfonylurea derivatives in normal and silicate coated nanoparticle forms as anti-hyperglycemic agents.

Series of new sulfonylurea derivatives (gliclazide analogues) was synthesized and characterized. Thus, p-tolylsulfonylisocyanate was left to react with different amino derivatives under mild conditions to afford the desired sulfonylurea derivatives 1-5. The molecular structure of the compound N-(2,6-Dichlorophenylcarbamoyl)-4-methylbenzenesulfonamide, 1c has been elucidated by single crystal X-ray diffraction. Anti-diabetic properties of the synthesized compounds relative to anti-diabetic drug (gliclazidem MR60) were carried out, where most of the tested compounds showed significant activity for reducing the blood glucose level. The results revealed that compounds 1c and 5 showed better anti-diabetic activities compared with gliclazide. Activity of the most potent derivatives of sulfonylurea compounds namely 1c and 5 were increased using coated nanostructure tetraethyl orthosilicate (TEOS) as a modified release (MR) agent. The effect of the prepared sulfonylurea compounds against the diabetic condition was investigated using specific selected biomarkers as of liver enzyme activities as transaminases (AST, ALT) and alkaline phosphatase (ALP), lipids profiles; total cholesterol (TC), triacylglycerols (TG) and total lipid (TL). The antioxidants, oxidative stress biomarkers and histological examination were also examined and discussed.

Preparation and Histological Study of Multi-Walled Carbon Nanotubes Bone Graft in Management of Class II Furcation Defects in Dogs.

BACKGROUND: The main target of periodontal disease and alveolar bone defeat treatment is the regeneration of the lost structures. AIM: This work deals with the evaluation of the effect of functionalised multi-walled carbon nanotubes (MWCNTs), as grafting material in the management of furcation defects created in dogs. MATERIAL AND METHODS: Potential cytotoxicity of the grafting material was assessed. Scanning electron microscope (SEM) and energy dispersive x-ray (EDX) analysis after incubation of the grafting material in simulated body fluid (SBF) at pH 7.4 and 37°C for one week was done. In six healthy mongrel dogs' full-thickness mucoperiosteal flaps were raised on the buccal aspects to create two walls intrabony defects at the furcation areas. The mandibular premolar area received the grafting material. Histological evaluation was carried out at 1, 2- and 3-months' period. RESULTS: Cytotoxicity results proved the safety of grafting material application. The prepared material exhibited good Ca-apatite crystal patterns at the surface revealed by SEM and high calcium content showed by EDX results. Good bone formation ability was also apparent histologically. CONCLUSION: The prepared grafting material (MWCNTs) can serve as a delivery vehicle for osteogenic cells and osteogenic growth factor proteins in the bone development process.

Conducting cellulose/TiO2 composites by in situ polymerization of pyrrole.

Cellulose/polypyrrole and cellulose/polypyrrole-TiO2 composites were prepared via in situ oxidative chemical polymerization of pyrrole using FeCl3 as oxidant. The concentration effect of pyrrole on the structure and properties of prepared matrix has been investigated. Furthermore, the structure of the prepared materials was characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Thermal gravimetrical analysis (TGA). The results exhibited that the addition of cellulose and TiO2 increase the thermal stability of the polypyrrole system. Moreover, dielectric properties of the obtained composites were studied over frequency range from 42Hz to 5MHz. The electrical measurements including dielectric constant, ε'(ω), dielectric loss, ε''(ω), loss tangent, tan δ and ac conductivity, σac were carried.

Cellulosic fabrics printing with multifunctional encapsulated phthalocyanine pigment blue using phase separation method.

Aqueous dispersions of citric-acrylate (CAC) oligomer encapsulating C.I. Pigment Blue 15:3 (PB15:3) in the presence of glutaraldhyde were formulated using the phase separation method. FT-IR spectroscopy and centrifuge sedimentation are performed to confirm the encapsulation of pigment into CAC oligomer. The prepared capsules were characterized using thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). The results revealed that the encapsulated pigment had a profound multifunctional impact and minimized the driving force of pigment printing on the cellulosic fabrics. Besides, the encapsulated pigment accelerated the pigment fixation on cellulosic fabrics without drying in one step and reduced the required amount of the binder, compared with the control sample. Furthermore, the printed fabrics exhibited good antibacterial performance against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The presence of the crosslinker could be stabilized the encapsulated pigment on the cellulosic fabrics. Moreover, the light and washing fastness for the printed fabrics using encapsulated pigment are higher than that in case of using control samples.

Synthesis and in vitro release study of ibuprofen-loaded gelatin graft copolymer nanoparticles.

OBJECTIVE: This work deals with the preparation, characterization and in vitro release study of IBU-loaded gel graft copolymer nanoparticles. METHOD: Gelatin (Gel) graft copolymer nanoparticles were prepared using styrene (Sty) and/or 2-hydroxyethyl methacrylate (HEMA) monomers in the presence of potassium persulfate and glutaraldehyde as an initiator and cross-linker, respectively. The prepared nanoparticles as sustained release drug carriers were investigated using the nonsteriodal anti-inflammatory model drug, ibuprofen (IBU). RESULTS: The prepared nanoparticles as sustained release drug carriers were investigated using the nonsteriodal anti-inflammatory model drug, IBU. The prepared Gel/HEMA and Gel/Sty nanoparticles exhibited particles size ranging from 15 to 17 nm and from 0.42 to 5 mm, respectively. The dissolution of IBU in phosphate buffer, pH 7.4, at 37°C from the prepared nanoparticles was evaluated using UV spectroscopy. In addition, the prepared nanoparticles were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), transmitting electron microscope (TEM) and zeta potential/particle size analyzer. In vitro dissolution study showed that the dissolution rates of the crosslinked nanoparticles were retarded relative to the uncrosslinked ones. Moreover, the released amount constantly decreases with increasing gluteraldehyde content in the gel nanoparticles. CONCLUSION: Crosslinked gel-based graft copolymers exhibited slow IBU release within six hours. Furthermore, results from different characterization techniques such as TEM, particles size and zeta potential measurements confirmed the formation of pH-responsive gel-graft copolymer nanoparticles.

In vitro biological study of gelatin/PLG nanocomposite using MCF-7 breast cancer cells.

This work aimed to evaluate new materials to be carried out as scaffolds using breast cancer cells MCF-7. These new nanocomposites were prepared through blending of gelatin with poly (DL-lactide-co-glycolide) (PLG) in presence of titanium nanowires (TiO2 ) and cartilage powder (CP). The prepared nanomaterials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and transmitting electron microscope. Moreover, the MCF-7 cells were in vitro tested with apoptosis/necrosis assay, micronucleus test, and DNA fragmentation and MMT assay. TiO2 nanowires and CP particles have diameters around 28-128 and 17-20 nm, respectively. These were coated with gelatin matrix. Seeding of MCF-7 cells with the prepared nanomaterials revealed high cell attachment to their surfaces and they were viable after 72 h. It has been shown that the prepared nanocomposites did not induce necrotic effects on MCF-7 cells; however, they induced a significant DNA fragmentation in comparison with the nontreated control cells.

Novel multi walled carbon nanotubes/ß-cyclodextrin based carbon paste electrode for flow injection potentiometric determination of piroxicam.

A novel carbon paste electrode based on functionlized multi-walled carbon nanotubes/ß-cyclodextrin composite (FMWCNTs/ß-CD-CPE) is described for potentiometric determination of piroxicam (PXM). Improved sensitivity and selectivity was achieved by application of CDs as molecular host-guest recognition elements and MWCNTs. The electrochemical performance of carbon paste electrodes incroporated with FMWCNTs/ß-CD composite was compared to those incroporated with MWCNTs and free CDs. Matrices compositions of each electrode are optimized on the basis of nature and content of the modifier, ionic sites and selected plasticizer. CPEs containing FMWCNTs/ß-CD composite, hyamine (Hy) and 2-fluorophenyl 2-nitrophenyl ether (f-NPE) as electrode plasticizer, work satisfactory in the concentration range from 10(-6) to 10(-2) mol L(-1) with Nernstain compliance (58.7±0.9 mV decade(-1) activity) with fast response time of about 2s and exhibit adequate operational lifetime (16 weeks). The developed electrodes have been applied for the potentiometric determination of PXM in pharmaceutical formulation under batch and flow injection analysis (FIA). FIA allows the analysis of 120 samples h(-1) with the advantage of simplicity, accuracy and automation feasibility.

Preparation and antimicrobial activity of poly (vinyl chloride)/gelatin/montmorillonite biocomposite films.

The aim of this study was using a novel antimicrobial thermoplastic plasticizer based on aliphatic anhydride derivative dodecenyl succinic anhydride (DSA) for blending poly (vinyl chloride), PVC, with gelatin in presence of montmorillonite (MMT) using Brabender via polymer melting technique. This anhydride-based plasticizer blended the membrane ingredients homogenously under melting process. The used plasticizer exhibited high performance antimicrobial potency for some biomedical and industrial applications. The prepared biocomposite films were evaluated for antimicrobial activity using agar disc diffusion method against gram-positive and gram-negative bacteria such as: Staphylococcus aureus (S. aureus), Klebsiella pneumonia (K. pneumonia), Bacillus cereus (B. cereus), Bacillus subtilis (B. subtilis) and Escherichia coli (E. coli). The majority of these biocomposites, except the plasticized PVC with DOP, have shown inhibitory effect at different concentrations (1.0-20) mg/ml against all above mentioned bacteria. However, C. albicans and A. niger were the most resistant strains.

Synthesis and in vitro evaluation of gelatin/hydroxyapatite graft copolymers to form bionanocomposites.

The combination of gelatin (Gel) with a bioactive component hydroxyapatite (HA) and cartilage powder (CP) to form biocomposites takes advantage of the osteoconductivity and osteoinductivity properties. The studies on bionanocomposites containing HA, CP fillers and Gel are still being conducted. In this present study, the bioactive fillers were loaded onto poly(hydroxylethylmethacrylate) and poly(hydroxylethylmethacrylate-co-methyl methacrylate) grafted gelatin copolymers to produce novel bionanocomposites having osteoconductive and osteoinductive properties. The resulting bionanocomposites were assessed by ATR-IR and SEM-EDX techniques to prove the interaction between different matrices. In vitro behavior of these bionanocomposites was performed in SBF for 21 days at pH 7.4 to verify formation of the apatite layer on the surfaces and its enhancement. The results confirmed the formation of thick plentiful aggregated (hexagonal or spherical) nanoparticles with a bright color (apatite layer) containing carbonate ions onto the surface of composites especially these containing CP and P(HEMA-co-MMA) having bone cement formation in their structure. These novel bionanocomposites have unique bioactivity that can be applied in bone implants as scaffolds and tissue engineering in future.

Preparation, characterization and in vitro biological study of biomimetic three-dimensional gelatin-montmorillonite/cellulose scaffold for tissue engineering.

This work focused on studying the effect of blending gelatin (Gel) with Cellulose (Cel), in the presence of montmorillonite (MMT), on the swelling behavior, in vitro degradation and surface morphology. Additionally, the effect of the prepared biocomposites on the characteristics of the human osteosarcoma cells (Saos-2), including proliferation, scaffold/cells interactions, apoptosis and their potential of the cells to induce osteogenesis and differentiation was evaluated. The crosslinked biocomposites with glutaraldehyde (GA) or N,N-methylene-bisacrylamide (MBA) was prepared via an intercalation process and freeze-drying technique. Properties including SEM morphology, X-ray diffraction characterization and in vitro biodegradation were investigated. The successful generation of 3-D biomimetic porous scaffolds incorporating Saos-2 cells indicated their potential for de novo bone formation that exploits cell-matrix interactions. In vitro studies revealed that the scaffolds containing 12 and 6% MMT crosslinked by 5 and 0.5% GA seem to be the two most efficient and effective biodegradable scaffolds, which promoted Saos-2 cells proliferation, migration, expansion, adhesion, penetration, spreading, and differentiation, respectively. MMT improved cytocompatibility between the osteoblasts and the biocomposite. In vitro analysis indicated good biocompatibility of the scaffold and presents the scaffold as a new potential candidate as suitable biohybrid material for tissue engineering.