DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas.

The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

Laparoscopic cholecystectomy in aged patients.

BACKGROUND/AIM: The life-span of humans increased and the prevalence of gallstones has also increased with age. The aim of this study is to examine the associations between age and clinical outcomes in the patients undergoing elective laparoscopic cholecystectomy (LC). METHODOLOGY: A total of 627 patients receiving LC were categorized into three different age groups. Group I was defined as less than 65 years of age (n = 510), group II as 65 to 79 (n = 100) and group III as more than 80 (n = 17). Clinical characteristics of these patients and surgical outcomes were analyzed. RESULTS: Rates of conversion and major complications were similar among three age groups. Group III had a significantly longer length of perioperative hospital stay compared to groups I or II. However, rates of minor complication appeared to be higher as age progressed (group I: 0.6%; group II: 6.0%; group III: 17.6%). In multivariable-adjusted modeling, groups II and III respectively, had a 7.1-fold (95% CI: 1.3-38.1, p = 0.023) and 34.1 (95% CI: 3.8-310.8, p = 0.002) higher risk of having minor complications than group I patients. CONCLUSION: LC is a safe and accepted procedure in aged patients with uncomplicated gallbladder stones disease, but it may be associated with increased postoperative morbidity.

The impact of body mass index on laparoscopic cholecystectomy in Taiwan: an oriental experience.

BACKGROUND/PURPOSE: The outcome analysis of obese patients undergoing laparoscopic cholecystectomy (LC) in Asia-Pacific countries is rarely reported. This study examined associations between body mass index (BMI) and clinical outcomes of elective LC in Taiwan. METHODS: A total of 627 patients with gallbladder disease due to gallstones undergoing LC were divided into three groups based on BMI: <25.0 kg/m2 (normal, NO; n = 310), 25.0-29.9 kg/m2 (overweight, OW; n = 252), and >30 kg/m2 (obese, OB; n = 65). RESULTS: Both overweight and obesity were not associated with conversion and complication rates. The conversion rates of the three groups were 5.5 (NO), 6.0 (OW), and 4.6% (OB), and the complication rates were 3.2 (NO), 2.4% (OW), and 4.6% (OB), respectively. However, overweight and obesity were related to a trend toward longer operating time (NO 67.4 +/- 31.8; OW 77.8 +/- 35.6; OB 79.0 +/- 37.9 min) (P trend <0.001). One death (BMI 40.6 kg/m2) was due to septic complications. In the multivariable logistic analysis, only acute cholecystitis, but not BMI, was a predictor for conversion and complications. CONCLUSIONS: Based on these results, it appears that BMI was not associated with clinical outcomes and that LC is a safe procedure in obese patients with uncomplicated gallstone disease in Taiwan.

Bacteriology and antimicrobial susceptibility in biliary tract disease: an audit of 10-year's experience.

Cholelithiasis, choledocholithiasis and hepatolithiasis are common biliary tract diseases. These diseases may cause severe infection and/or sepsis. In addition to surgical treatments, prompt administration of appropriate antibiotic is important to control the biliary tract infection. The purpose of this study is to illustrate the bacteriology in biliary tract disease and provide information for antibiotic choices. From Jan 1991 to Aug 2000, 1394 patients including gallbladder (GB) stones, common bile duct (CBD) stones, intrahepatic duct (IHD) stones, GB polyps and biliary malignancy were subjects for this retrospective study. The overall positive rate of bile culture is 36% in this study while it was 25%, 66%, 67% and 9% for GB stones, CBD stones, IHD stones and biliary malignancy, respectively. A significantly higher (p = 0.001) positive culture rate was found for GB stones with acute cholecystits (47%) compared with that without inflammation (17%). Similarly, the culture rate for hepatolithiasis with acute cholangitis was higher than that without cholangitis (75% vs 51%, p = 0.011). Long-term external biliary drainage in biliary malignancy increased the risk of bacterial culture rate. For gallstone diseases, the most common organisms cultured were Gram negative bacteria (74%), in which Escherichia coli (36%) and Klebsiella (15%) were most commonly found, followed by Gram positive (15%) bacteria such as Enterococcus (6%), Staphylcoccus (3%), Streptococcus (2%). Bacteroides (5%) and Clostridium (3%) were occasionally found anaerobes (9%). Polymicrobial infection was encountered in 19%, 31% and 29% for patients with GB stones, CBD stones and IHD stones, respectively; frequency of mixed aerobic and anaerobic infection was 7%, 12% and 9%. In the current study, ampicillin in combination with sulbactam and aminoglycoside is still a suggestive empirical therapy. Antibiotic treatment should be adjusted based on later bacteriological cultures and clinical condition.