Effect of High Fructose Corn Syrup (HFCS) Intake on the Female Reproductive Organs and Lipid Accumulation in Adult Rats.

High-fructose corn syrup (HFCS) is widely used as sweetener, and its overconsumption is become a major health problem. In the present study, we used adult female rats and applied a 28 days HFCS feeding model to monitor the estrous cycle and changes in tissue weights and histology. Adult female rats were divided into three groups. Animals were fed with ad libitum normal chow and (1) 24 hours tap water (Control group), (2) 12 hours HFCS access during dark period and 12 hours tap water (12H group), and (3) 24 hours HFCS only access (24H group). Total exposure period was 28 days. There is no significant change in body weight between control and HFCS-fed animals. Both absolute and relative weights of ovary in 24H animals were significantly heavier than those in control or 12H animals. The absolute and relative weights of the kidney and liver in 24H groups were significantly heavier than those in control or 12H animals. The estrous cycles of the 24H animals were significantly longer. Histological analyses revealed that 24H ovaries were relatively bigger and possessed more corpus lutea than control ovaries. Uterine sections of 12H and 24H animals showed a well-developed stratum vasculare between inner and outer myometrial layers. The number of endometrial glands were decreased in 12H uteri, and recovered in 24H uteri compared to control. Numbers of convoluted tubule in distal region increased in 12H and 24H kidney samples. Liver specimens of 12H and 24H showed the increased number of fat containing vacuoles. In conclusion, our study demonstrated that HFCS treatment for 28 days could induce (1) changes in length of estrous cycle with extended estrous and diestrous stages, (2) altered ovarian and uterine histology, and (3) liver and renal lipid accumulation. These findings reveal the adverse effects of HFCS drinking on the reproductive function and lipid metabolism of female rats.

Acinetobacter sp. isolates from emergency departments in two hospitals of South Korea.

A total of 114 Acinetobacter sp. isolates were collected from patients in the emergency departments (EDs) of two Korean hospitals. Most isolates belonged to the Acinetobacter baumannii complex (105 isolates, 92.1 %). Imipenem resistance was found in 39 isolates (34.2 %) of the Acinetobacter sp. isolates, and 6 colistin-resistant isolates were also identified. Species distribution and antimicrobial-resistance rates were different between the two hospitals. In addition, two main clones were identified in the imipenem-resistant A. baumannii isolates from hospital B, but very diverse and novel genotypes were found in those from hospital A. Many Acinetobacter sp. isolates, including the imipenem-resistant A. baumannii, are considered to be associated with the community. The evidence of high antimicrobial resistance and different features in these Acinetobacter sp. isolates between the two EDs suggests the need for continuous testing to monitor changes in epidemiology.

Molecular cloning and characterization of active truncated dextransucrase from Leuconostoc mesenteroides B-1299CB4.

The open reading frame of dsrE563, a dextransucrase gene obtained from a constitutive mutant (CB4-BF563) of Leuconostoc mesenteroides B-1299, consists of 8,511 bp encoding 2,836 amino acid residues. DsrE563 contains two catalytic domains (CD1 and CD2). Two truncated derivative mutants DsrE563ΔCD2ΔGBD (DsrE563-1) and DsrE563ΔCD2ΔVR (DsrE563-2) of DsrE563 were constructed and expressed using the pRSETC vector in Escherichia coli. The derivatives DsrE563-1 (deletion of 1,620 amino acids from the C-terminus) and DsrE563-2 (deletion of 1,258 amino acids from the C-terminus and 349 amino acids from the N-terminus) were expressed as active enzymes. Both enzymes synthesized less-soluble dextran, mainly containing α-1,6 glucosidic linkage. The synthesized less-soluble dextran also had a branched α-1,3 linkage. DsrE563-2 showed 4.5-fold higher dextransucrase activity than that of DsrE563-1 and showed higher acceptor reaction efficiency than that of dextransucrase from L. mesenteroides 512 FMCM when various mono or disaccharides were used as acceptors. Thus, the glucan-binding domain was important for both enzyme expression and dextransucrase activity.

Acinetobacter species isolates from a range of environments: species survey and observations of antimicrobial resistance.

Acinetobacter species isolates from a range of environments, including soil, were investigated. We determined 16S rRNA and rpoB gene sequences for species identification and performed tests of antimicrobial resistance susceptibility. Twenty-nine of the isolates (8 from soil and 21 from life environment) belonged to the genus Acinetobacter. Fourteen Acinetobacter species were identified among 29 isolates: 4 A. baumannii, 3 A. calcoaceticus, 1 A. nosocomialis, 2 A. pittii, and 2 Acinetobacter gen. sp. 'close to 13TU' as A. calcoaceticus-baumannii complex. Three Acinetobacter species isolates were identified as novel species candidates. Three Acinetobacter species isolates were resistant to imipenem: 1 A. parvus and 2 novel species candidates of Acinetobacter. Eight isolates showed resistance to colistin: all Acinetobacter gen. sp. 'close to 13TU' (2 isolates) and A. parvus isolates (3 isolates) were resistant to colistin. Although the genotypes of A. baumannii isolates from various natural environments were different from those of clinical isolates, the presence of clinically important and antimicrobial resistant Acinetobacter species in the natural environment may represent a threat to public health.

Construction, expression and characterization of fusion enzyme from Arthrobacter oxydans dextranase and Klebsiella pneumoniae amylase.

An artificial fusion protein of Arthrobacter oxydans dextranase and Klebsiella pneumoniae alpha-amylase was constructed and expressed in Escherichia coli. Most of the expressed protein existed as an insoluble fraction, which was solubilized with urea. The purified fusion enzyme electrophoretically migrated as a single protein band; M = 137 kDa, and exhibited activities of both dextranase (10.8 U mg(-1)) and amylase (7.1 U mg(-1)), which were lower than that of reference dextranase (13.3 U mg(-1)) and alpha-amylase (103 U mg(-1)). The fusion enzyme displayed bifunctional enzyme activity at pH 5-7 at 37 degrees C. These attributes potentially make the fusion enzyme more convenient for use in sugar processing than a two-enzyme system.

Maximization of dextransucrase activity expressed in E. coli by mutation and its functional characterization.

A novel dextransucrase gene, DSRN, was obtained by ultrasoft X-ray treatment of the DSRB742 gene. The DSRN gene was further mutated via site-directed mutagenesis producing four mutants: DSRN1 (F196S), DSRN2 (Y346N), DSRN3 (K395T) and DSRN4 (P980T). Dextransucrases derived from DSRB742 and its mutants were expressed in E. coli and affinity-purified using dextran to give 80% purity. They had specific activities of 0.6-17 U/mg with Km values of 18-88 mM. DSRB742 had the lowest (0.02 s(-1) x mM(-1)) and DSRN1 had the highest (0.13 s(-1) x mM(-1)) Kcat/Km values. DSRN3 had the highest enzymatic transglycosylation efficiency with maltose (63% of theoretical), gentiobiose (39%), or salicine (40%).