A case series on safety and tolerability of human umbilical cord-derived mesenchymal stem cells on patients in Malaysia.

Umbilical cord-derived mesenchymal stem cells for regenerative therapy are a promising treatment option for chronic illnesses. Umbilical cord-derived mesenchymal stem cells offer several advantages over other sources, which makes them an attractive option in tissue repair and regeneration. This clinical study describes a 1-year follow-up on the safety and tolerance of umbilical cord-derived mesenchymal stem cell therapy on nine patients in Malaysia. Patients were assessed for adverse effects, and liver function tests were carried out on both pre- and post-treatments. Umbilical cord-derived mesenchymal stem cells' effectiveness and safety were assessed by follow-up evaluations. All nine patients responded positively towards umbilical cord-derived mesenchymal stem cell therapy, without any adverse effects. After umbilical cord-derived mesenchymal stem cell therapy, a significant improvement was observed in liver functioning test outcomes, as haematological parameters and tumour markers were stable. The present study concludes that umbilical cord-derived mesenchymal stem cell therapy is well tolerated by Malaysian patients; however, further clinical screening must be done over a large number of patients population.

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production.

A method for facile synthesis of nanostructured catalysts supported on carbon nanotubes with atomically dispersed cobalt and nitrogen dopant is presented herein. The novel strategy is based on a facile one-pot pyrolysis treatment of cobalt (II) acetylacetonate and nitrogen-rich organic precursors under Ar atmosphere at 800 °C, resulting in the formation of Co- and N- co-doped carbon nanotube with earthworm-like morphology. The obtained catalyst was found to have a high density of defect sites, as confirmed by Raman spectroscopy. Here, cobalt (II) nanoparticles were stabilized on the atomically dispersed cobalt- and nitrogen-doped carbon nanotubes. The catalyst was confirmed to be effective in the catalytic hydrolysis of ammonia borane, in which the turnover frequency was 5.87 mol H2·molCo-1·min-1, and the specific hydrogen generation rate was determined to be 2447 mL H2·gCo-1·min-1. A synergistic function between the Co nanoparticle and the doped carbon nanotubes was proposed for the first time in the catalytic hydrolysis of ammonia borane reaction under a mild condition. The resulting hydrogen production with its high energy density and minimal refueling time could be suitable for future development as energy sources for mobile and stationary applications such as road trucks and forklifts in transport and logistics.

Interaction between hydrogenase maturation factors HypA and HypB is required for [NiFe]-hydrogenase maturation.

The active site of [NiFe]-hydrogenase contains nickel and iron coordinated by cysteine residues, cyanide and carbon monoxide. Metal chaperone proteins HypA and HypB are required for the nickel insertion step of [NiFe]-hydrogenase maturation. How HypA and HypB work together to deliver nickel to the catalytic core remains elusive. Here we demonstrated that HypA and HypB from Archaeoglobus fulgidus form 1:1 heterodimer in solution and HypA does not interact with HypB dimer preloaded with GMPPNP and Ni. Based on the crystal structure of A. fulgidus HypB, mutants were designed to map the HypA binding site on HypB. Our results showed that two conserved residues, Tyr-4 and Leu-6, of A. fulgidus HypB are required for the interaction with HypA. Consistent with this observation, we demonstrated that the corresponding residues, Leu-78 and Val-80, located at the N-terminus of the GTPase domain of Escherichia coli HypB were required for HypA/HypB interaction. We further showed that L78A and V80A mutants of HypB failed to reactivate hydrogenase in an E. coli ΔhypB strain. Our results suggest that the formation of the HypA/HypB complex is essential to the maturation process of hydrogenase. The HypA binding site is in proximity to the metal binding site of HypB, suggesting that the HypA/HypB interaction may facilitate nickel transfer between the two proteins.

Prevalence of diabetic retinopathy in patients with recently diagnosed diabetes mellitus.

BACKGROUND: The severity of diabetic retinopathy is well known to have a close association with the duration of diabetes mellitus. Patients with recently diagnosed diabetes should have adequate eye examinations to eliminate the possibility of diabetic retinopathy being present because there is no accurate means of determining the duration of the disease. The prevalence of diabetic retinopathy in type 2 diabetic patients with known duration up to one year was investigated in the present study. METHODS: A centre for diabetic retinopathy screening was set up in a community in Hong Kong. The screening procedures included history taking, visual acuity measurement, anterior ocular health assessment and retinal examination by fundus photography. Fundus photographs were taken in nine different positions of gaze through natural or dilated pupils. Using the criteria recommended by the American Optometric Association the retinopathy was graded in severity. 'Recently diagnosed diabetes mellitus' was defined as having diabetes diagnosed by a physician within the previous year. RESULTS: A total of 12,112 patients having their first visits to the centre were recruited from 2006 to 2009. Among them, 3,510 patients had recently diagnosed diabetes. The mean age of patients was 59.5 years. The prevalence of diabetic retinopathy was 18.2 per cent (639 patients) among the recently diagnosed diabetic patients. Most of the patients had mild non-proliferative diabetic retinopathy. In these 639 patients, approximately seven per cent had sight-threatening retinopathy that included significant macular oedema, all of whom required monitoring. The presence of hypertension or smoking was not significantly associated with the prevalence of diabetic retinopathy in recently diagnosed diabetic patients. CONCLUSIONS: Screening for diabetic retinopathy is important for newly diagnosed diabetic patients. In Hong Kong, the prevalence of diabetic retinopathy was alarmingly high and some patients had already developed sight-threatening retinopathy that included macular oedema. Most of them had no symptoms until the retinopathy progressed and they developed macular oedema. A systematic screening program in the community is needed for early detection and to reduce blindness in diabetic patients.

Low levels of copper reduce the reproductive success of a mobile invertebrate predator.

Marine organisms that occur in urbanised bays can be exposed to low-level chronic pollution that results in sublethal changes to behavior or reproduction. The effects of low levels of copper on the reproductive success of a mobile invertebrate were assessed. Free living flatworms are common predators of bivalves and barnacles. Flatworms (Stylochus pygmaeus) were exposed to low levels of copper ranging from 0 to 25 microg L(-1) in the presence and absence of their barnacle prey (Balanus variegatus). Flatworms laid fewer egg batches when exposed to copper and the hatching success of the eggs was also reduced. Exposure to 25 microg L(-1) copper for 10 d reduced the reproductive success of flatworms by up to 80%. Results were consistent regardless of the presence or absence of prey (barnacles). Barnacles were only moderately affected by copper but exhibited major avoidance behavior (feeding inhibition) in the presence of flatworm predators. This is the first ecotoxicological study on marine flatworms. Experiments are required to quantify the effects of flatworm predator populations on sessile invertebrate community structure in the field.