Bioactive, degradable and multi-functional three-dimensional membranous scaffolds of bioglass and alginate composites for tissue regenerative applications.

With a worldwide increase in the aged populace and associated geriatric diseases, there is an enormous need for the regeneration of degenerated organ systems. For this purpose, bioactive glass particulate (nBG) integrated alginate (Alg) composite membrane scaffolds were fabricated by a sol-gel assisted freeze-drying method and validated for their multifunctional utility in regenerative medicine. The presence of the combeite highly crystalline structure of nBG and Alg amorphous broad peaks were confirmed. Repetitive peaks from acids along with stretching confirmed the chemical interactions of the composites. Swelling ability, porosity, and in vitro degradation and biomineralization were analysed for up to 7 days. The results indicated that reduced swelling and degradation enhanced apatite formation. Hemocompatibility and the hemostatic properties on scaffolds were also systematically investigated. Additionally, significant cyto-compatibility and proliferation were noted in a culture with KB3-1. Further 3-D co-cultures with HDF cells and KB3-1 cells exhibited spheroid formation on Alg, nBG/Alg and nBG-Zr/Alg with profound dynamism required to establish organoids of interest. Thus, the results indicate that these 3D hydrogel membranes could offer infinite possibilities in the field of regenerative medicine, notably as an extracellular matrix (ECM) supporting the regeneration of bone, intra-vascularization, and neo-tissue formation, such as cartilage and ligaments.

Enhancing humidity sensing performance of polyaniline/water soluble graphene oxide composite.

The humidity sensing performance of Polyaniline/Water soluble graphene oxide [PWGO] composites have been presented in this work. Various mass ratios of Water soluble graphene oxide [WGO] were mechanically mixed with Polyaniline [PANI] prepared by in-situ polymerization process to form PANI / WGO composites. For the purpose of humidity sensing studies, the samples were structurally characterized by FTIR, Raman, XRD, SEM and TEM techniques and comparatively analyzed. The film of the samples prepared by deposition on ordinary glass substrate using cost effective spin coating technique were tested for their humidity sensing performance in the relative humidity (RH) range of 11-97%. Of the four composites studied, the PWGO-4 composite recorded a good response time of 8 s and a recovery time of 9 s and a very low humidity hysteresis. The mechanism for sensing has been explained on the basis of three sequential steps: chemisorption, physisorption and condensation process. The humidity sensing stability of the composites were tested over a period of 2 months.

The pathogenic role of the coccoid form of Helicobacter pylori.

Adherence of the coccoid forms of Helicobacter pylori to the gastric carcinoma cell line (KATO III) was examined by transmission electron microscopy. Specialized attachment sites such as the 'adhesion pedestal', 'cup-like indentation' and 'abutting adhesion' were seen in the interaction between coccoids and epithelial cells. These adherence patterns were similar to those observed with spiral forms in gastric biopsy specimens in vivo, suggesting a possible pathogenic role for the coccoids of H. pylori. With antigens prepared from both the coccoid and spiral forms, IgG antibodies reactive to H. pylori were detected using ELISA. Patients with gastroduodenal disease accounted for 74% (37/50) ELISA positives. Of the 50 healthy blood donors, 32 and 28% were seroreactive to coccoid and spiral antigens, respectively. These sera were further characterized by Western blot where immunoreactive protein bands of 128, 116, 110, 95, 91, 66, 60, 54, 50 and 33 kD were conserved in both the coccoid and spiral forms. These findings suggest that the coccoids could be a differentiated infective form of H. pylori, and that they could evoke an immune response from the host after invading the cells via specialized attachment sites.

A simple and efficient continuous culture system for Helicobacter pylori.

Helicobacter pylori has been successfully maintained in a continuous culture system. The culture was grown in 0.6 litre of brain heart infusion broth with supplements in a 1 litre fermenter with a flow rate of 25 ml/h, an 80% dilution rate and a specific growth rate of 0.06/h. Unlike the typical growth curve which occurred in batch culture, the growth pattern in continuous culture showed a short lag phase following which growth was maintained in exponential phase with > or = 10-fold increase in viability and the pH was stabilised at 6.95 +/- 0.05. The urease activity remained constant in relation to viability while the urea was completely hydrolysed. The system provides cells with growth characteristics similar to the fresh isolate which are highly adaptable to the in vitro environment. This study shows that continuous culture is a simple and efficient growth system for the cultivation of a 'synchronous' spiral form of H. pylori.

Changing trends in the epidemiology and management of gonococcal ophthalmia neonatorum.

Between June 1985 and December 1988, 58 cases of gonococcal ophthalmia neonatorum were admitted to the neonatal unit at the University Hospital (USM). Of these, 15 (25.9%) cases were due to penicillin-resistant strains of Neisseria gonorrhoea. Of the 58 cases, 56 cases were treated effectively with a single dose of antibiotic given systemically. The mean period of recovery was shorter with spectinomycin in doses of 40 mg/kg than with cefotaxime (100 mg/kg). There was no permanent sequelae in the treated cases. An increasing incidence of infection with penicillin-resistant strains of N. gonorrhoea has been observed in the area of study.

Intestinal helminthiasis and abdominal symptoms in adults.

In a study to test the association between soil transmitted intestinal helminthiasis and abdominal symptoms in a non-paediatric age group, 242 randomly selected patients (137 males, 105 females, median age 45 years) were asked specific questions pertaining to abdominal symptoms at the time of admission to the adult medical wards. Stool examination on all patients revealed a round worm prevalence rate of 21%. A larger proportion of stool positive female patients were symptomatic than stool negative females (68% vs 30%, p = 0.04). There was no significant difference in symptoms between stool positive and stool negative male patients (34.6% vs 31%, p = 0.91). The results suggested an association between intestinal nematode infection and abdominal symptoms in females but not in males.