Synthesis and biological evaluation of sialylmimetics as rotavirus inhibitors

Rotaviruses cause severe gastroenteritis in infants and are estimated to be responsible for over 600 000 deaths annually, primarily in developing countries. The development of potential inhibitors of this virus is therefore of great interest, particularly since the safety and efficacy of rotaviral vaccines has recently been questioned. This study describes the synthesis of a variety of compounds that can be considered as mimetics of N-acetylneuraminic acid thioglycosides and the subsequent in vitro biological evaluation of these sialylmimetics as inhibitors of rotaviral infection. Our results show that readily accessible carbohydrate-based compounds have the potential to act as inhibitors of rotaviral replication in vitro, presumably through inhibition of the rotaviral adhesion process.

Synthesis of novel sialylmimetics as biological probes

Glycomimetics are increasingly being recognised as powerful tools in the search for novel compounds that possess useful biological properties. This paper describes our preliminary efforts towards the development of novel mimetics of sialic acid thioglycosides. These sialylmimetics are readily prepared and have been shown, in some instances, to have biological properties similar to sialic acid thioglycosides.

Morphological and Mechanical Properties of Thermoplastic Elastomers Based on Recycled High Density Polyethylene and Recycled Natural Rubber

In this work, thermoplastic elastomers (TPE) are produced by melt mixing of recycled high-density polyethylene (RHD) with two types of off-the-road (OTR) ground tire rubber (GTR). Non-regenerated (NR) and regenerated (RR) rubbers are used to investigate the effect of GTR concentration and regeneration on the blends properties containing up to 90 wt.% GTR. The blend morphology is studied by scanning electron microscopy (SEM) to show incompatibility and low interfacial adhesion between RHD and GTR (NR and RR) especially above 40 wt.% RR. This behavior is attributed to the GTR regeneration process and agglomeration of RR particles with lower surface area and affinity toward RHD compared with NR. In all the compounds, the mechanical properties in tension of RR blends were lower than for NR blends, which is attributed to the degradation of the GTR backbone chains lowering the molecular weight (MW) during the regeneration process. Also, NR has a more important effect on impact strength improvement due to its higher crosslinked structure making the particles more deformable/elastic to absorb the mechanical energy before crack initiation. The experimental results also show that 80 wt.% GTR is the optimum concentration for the production of low cost and eco-friendly TPE based on recycled materials.

Factors associated with cognitive impairment in patients with Parkinson disease: an urban study

BACKGROUND AND AIMS

Parkinson disease (PD) is the second most prevalent neurodegenerative disorder after Alzheimer disease. Besides motor presentations, cognitive impairment is among the other likely complications as the illness progresses. This study aimed to determine the prevalence of cognitive impairment in PD and the factors associated with the cognitive impairment.

MATERIALS AND METHODS

A cross-sectional, descriptive study was conducted on all PD patients at different stages of their illness, in two major tertiary hospitals in Malaysia with their caregivers, over a three month period in 2002. Patients' cognitive functions were tested using the Mini Mental State Examination (MMSE). Important sociodemographic data and relevant clinical information of the patients as well as caregivers' information on income, duration of care-giving, relationship with the patient, and other relevant variables were gathered. Patients' level of functioning was assessed using the Activities of Daily Living (ADL) index. Staging of illness was done based on the Hoehn and Yahr Scale.

RESULTS

Out of 115 eligible patients, 35% were in the 60-69 age group with 57% in stage 2 of illness, A total of 29% of patients experienced various degrees of cognitive impairment , with almost half (47%) in the stage 3 and 4 exhibiting MMSE scores <24. Factors which were significantly associated with impaired cognitions were race, educational level and stage of illness.

CONCLUSION

Cognitive impairment was fairly common in PD and the severity of impairment in cognition and physical functioning increased with the advancement of the illness.

[Studies of Yersinia pestis in wild animals captured in Ankara, Konya and Nevsehir]

No Yersinia pestis could be isolated, by culturing and by inoculations to 1212 guinea-pigs and 150 mice; from 623 citellus, 41 Mus musculus, 55 Microtus, 442 Meriones, 70 Rattus rattus, 56 turtle, 89 hare, 1 hamster, 1 hedgehog, 1 sea snake, altogether 790 dead, 589 alive, i.e. 1379. wild animals captured in Ankara, Konya (Karapinar), Urfa (Akçakale) and in Nevşehir. In 141 sera taken from citellus captured alive, and in 174 sera taken from guinea-pigs inoculated with spleen, liver and kidney suspensions of wild animals, 1/20 - 1/80 agglutination titers (one of the sera from a guinea-pig inoculated with hare organ suspension) were obtained. These findings, probably were due to Yersinia pseudotuberculosis, because this organism was isolated from citellus captured in Ankara and Konya.