OBJECTIVE: The natural history of asymptomatic (silent) gallstones has been inadequately studied. Existing information derives from studies based on oral cholecystography or relatively small sample sizes. We planned a retrospective cohort study in subjects with gallstones to determine conversion rates from asymptomatic to symptomatic.
METHODS: We extracted data from computerised databases of one government hospital and two private clinics in Malaysia. Files were scrutinised to ensure that criteria for asymptomatic gallstones were fulfilled. Patients were called on telephone, further questioned to confirm that the gallstones at detection were truly asymptomatic, and asked about symptoms that were consistent with previously defined criteria for biliary colic. Appropriate ethical clearances were taken.
RESULTS: 213 (112 males) patients fulfilled the criteria for asymptomatic gallstones and could be contacted. 23 (10.8%) developed pain after an average follow up interval of 4.02 years (range 0.1-11 years). Conversion rates from asymptomatic to symptomatic gallstones were high in the first two years of follow up, averaging 4.03±0.965 per year. Over time the conversion rates slowed, and by year 10 the annual conversion rate averaged only 1.38±0.29. Conversion rates were much higher for females compared to males (F:M hazard ratio 3.23, SE 1.54, p>z 0.014). The lifetime risks for conversion approached 6.15% for males, and 22.1% for females.
CONCLUSION: In conclusion, asymptomatic gallstones are much more likely to convert to symptomatic in females than in males. Males in whom asymptomatic stones are discovered should be advised conservative treatment. Surgery may be preferable to conservative management if the subject is a young female.
m radiology records of Hospital
Study site: Computerised database, Hospital Selayang, Selangor; private clinics, Kuala Lumpur, Malaysia
New technologies rely on the development of new materials, and these may simply be the innovative combination of known components. The structural combination of a polymer hydrogel network with a nanoparticle (metals, non-metals, metal oxides, and polymeric moieties) holds the promise of providing superior functionality to the composite material with applications in diverse fields, including catalysis, electronics, bio-sensing, drug delivery, nano-medicine, and environmental remediation. This mixing may result in a synergistic property enhancement of each component: for example, the mechanical strength of the hydrogel and concomitantly decrease aggregation of the nanoparticles. These mutual benefits and the associated potential applications have seen a surge of interest in the past decade from multi-disciplinary research groups. Recent advances in nanoparticle-hydrogel composites are herein reviewed with a focus on their synthesis, design, potential applications, and the inherent challenges accompanying these exciting materials.
The effect of heat treatment below the gelatinization temperature on the susceptibility of corn, mung bean, sago, and potato starches towards granular starch hydrolysis (35°C) was investigated. Starches were hydrolyzed in granular state and after heat treatment (50°C for 30 min) by using granular starch hydrolyzing enzyme for 24 h. Hydrolyzed heat-treated starches showed a significant increase in the percentage of dextrose equivalent compared to native starches, respectively, with corn 53% to 56%, mung bean 36% to 47%, sago 15% to 26%, and potato 12% to 15%. Scanning electron microscopy micrographs showed the presence of more porous granules and surface erosion in heat-treated starch compared to native starch. X-ray analysis showed no changes but with sharper peaks for all the starches, suggested that hydrolysis occurred on the amorphous region. The amylose content and swelling power of heat-treated starches was markedly altered after hydrolysis. Evidently, this enzyme was able to hydrolyze granular starches and heat treatment before hydrolysis significantly increased the degree of hydrolysis.
Resistant starch type III (RS3 ) was produced from sago (Metroxylon sagu) and evaluated for its characteristics as a prebiotic. Two RS3 samples designated sago RS and HCl-sago RS contained 35.71% and 68.30% RS, respectively, were subjected to hydrolyses by gastric juice and digestive enzymes and to absorption. Both sago RS and HCl-sago RS were resistant to 180 min hydrolysis by gastric acidity at pH 1 to 4 with less than 0.85% hydrolyzed. Both samples were also resistant toward hydrolysis by gastrointestinal tract enzymes and intestinal absorption with 96.75% and 98.69% of RS3 were recovered respectively after 3.5 h digestion and overnight dialysis at 37 °C. Sago RS3 supported the growth of both beneficial (lactobacilli and Bifidobacteria) and pathogenic microbes (Escherichia coli, Campylobacter coli, and Clostridium perfringens) in the range of 2.60 to 3.91 log10 CFU/mL. Hence, prebiotic activity score was applied to describe the extent to which sago RS3 supports selective growth of the lactobacilli and bifidobacteria strains over pathogenic bacteria. The highest scores were obtained from Bifidobacterium sp. FTDC8943 grown on sago RS (+0.26) and HCl-sago RS (+0.24) followed by L. bulgaricus FTDC1511 grown on sago RS (+0.21). The findings had suggested that sago RS3 has the prebiotic partial characteristics and it is suggested to further assess the suitability of sago RS3 as a prebiotic material.