Characterization of a Novel Moderately Thermophilic Solvent-Tolerant Esterase Isolated From a Compost Metagenome Library

A novel esterase, EstCS1, was isolated from a compost metagenomics library. The EstCS1 protein, which consists of 309 amino acid residues with an anticipated molecular mass of 34 kDa, showed high amino acid sequence identities to predicted esterases and alpha/beta hydrolases (59%) from some cultured bacteria and to predicted lipases/esterases from uncultured bacteria. The phylogenetic analysis suggested that the EstCS1 belongs to the hormone-sensitive lipase family of lipolytic enzyme classification and contains a catalytic triad including Ser155–Asp255–His285. The Ser155 residue of the catalytic triad in the EstCS1 was located in the consensus active-site motif, GXSXG. Besides, a conserved HGGG motif placed in an oxyanion hole of the hormone-sensitive lipase family was discovered, too. The EstCS1 demonstrated the highest activity toward p-nitrophenyl propionate (C3) and caproate (C6) and was normally stable up to 60°C with optimal activity at 50°C. In addition, an optimal activity was observed at pH 8, and the EstCS1 possessed its stability within the pH range between 5 and 10. Interestingly, EstCS1 had an outstanding stability in up to 30% (v/v) organic solvents and activity over 50% in the presence of 50% (v/v) acetone, ethanol, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide. The EstCS1 hydrolyzed sterically hindered tertiary alcohol esters of t-butyl acetate and linalyl acetate. Considering the properties, such as the moderate thermostability, stability against organic solvents, and activity toward esters of tertiary alcohols, the EstCS1 will be worthwhile to be used for organic synthesis and related industrial applications.

Enzymatic characterization of a soluble aggregate induced by N-terminal extension to a lipolytic enzyme

A self-assembling peptide (27PEP) was isolated from an open reading frame (ORF). The ORF consisted of an unknown functional domain and a catalytic (lipolytic and phospholipolytic) domain (MPlaG) on metagenomic fosmid clone. This extension of 27 amino acids prior to the N-terminus of the catalytic domain (27PEP-MPlaG), starting at Met₂₆₁, produced an aggregate of high molecular weight (> 700 kDa). Compared with MPlaG, 27PEP-MPlaG showed the same temperature and pH effect for maximum activity but was stable in the presence of inhibitors such as EDTA and PMSF. The 27PEP-MPlaG exhibited lower specific activity than that of MPlaG, but when pre-incubated for 30 min at temperatures between 4 and 100 °C, its activity increased at temperatures greater than 40 °C under alkaline conditions and eventually reached the specific activity level of MPlaG at 60 °C. We experimentally determined that the aggregate caused by 27PEP was dissociated at elevated temperatures resulting in an active catalytic monomer. The 27PEP-indued aggregation may be attractive as application tool for improving or engineering of biocatalysts and biomaterials.

Analysis of efficacy and safety of core-needle biopsy versus fine-needle aspiration cytology in patients with cervical lymphadenopathy and salivary gland tumour

In this study, we compared the diagnostic accuracy and safety of fine-needle aspiration cytology and core-needle biopsy in patients with cervical lymphadenopathy or salivary gland tumour, and provided a basis for selecting the appropriate diagnostic method in clinical situations. A total of 278 patients were included in this study. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 66.7% and 100%, respectively, and negative predictive values were 92.6% and 100%, respectively, for diagnosing malignancy. In diagnosing lymphoma, fine-needle aspiration cytology gave false-negative results in all patients. In diagnosing tuberculous lymphadenopathy, the sensitivities of fine-needle aspiration cytology and core-needle biopsy were 33.3% and 91.15%, respectively, and the negative predictive values were 90.0% and 95.1%, respectively. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 42.9% and 100% in diagnosing malignant salivary gland tumours, and the negative predictive values were 91% and 100%, respectively. The results of this study showed that core-needle biopsy was superior in diagnosing and distinguishing critical diseases such as malignant lymphadenopathy and tuberculosis in patients with cervical lymphadenopathy and salivary gland tumour.

Depression and risk of tuberculosis: a nationwide population-based cohort study

BACKGROUND

Studies on the association between depression and risk of tuberculosis (TB) are lacking.

OBJECTIVE

To determine the association between depression and risk of TB.

METHODS

From a nationwide database, patients with depression were identified to form the exposure cohort between 2003 and 2013. The control cohort comprised an equivalent number of subjects without any mood disorders, with each subject age- and sex-matched to a patient in the exposure cohort. The incidence of TB was identified in the exposure cohort and control cohort between 2003 and 2013. A multivariable Cox proportional hazards model was used to estimate the association between depression and the subsequent risk of TB.

RESULTS

A total of 32 372 patients with depression and the same number of controls were identified. The risk of TB in the depression cohort was 2.63-fold (95%CI 1.74-3.96) higher than in the control cohort. When the depression was classified as 'mild' and 'severe', the risk of TB was proportional to depression severity.

CONCLUSIONS

Patients with depression are at a higher risk for TB, and a dose-response relationship exists between depression and the subsequent risk of TB.

Non-communicable diseases and risk of tuberculosis in Korea

BACKGROUND

It is possible that the increasing burden of non-communicable diseases (NCDs) and their risk factors are an obstacle to the reduction of tuberculosis (TB) incidence in the Republic of Korea.

OBJECTIVE

To estimate population-attributable fractions (PAF) of NCDs and their risk factors related to TB in Korea.

DESIGN

The prevalence of diabetes mellitus (DM), current smoking, heavy drinking and undernutrition was estimated from the Korean National Health and Nutrition Examination Survey (KNHANES) conducted in 2013. Estimates of effect for risk factors were obtained from meta-analyses. The PAF was calculated based on these data.

RESULTS

The PAF of DM, current smoking, heavy drinking and undernutrition was 20.0%, 18.8%, 18.4% and 9.6%, respectively. Current smoking has the highest PAF among men, while undernutrition was the highest among women. Current smoking and heavy drinking were significantly attributed to TB among the younger population, while DM was the most common responsible factor among the older population. Major risk factors such as current smoking and DM were more prevalent in the lower income level population.

CONCLUSION

NCDs and their risk factors play an important role at the population level in TB epidemics in Korea. Collaborative TB and NCD activities in TB control should therefore be intensified.

Development of novel microsatellite markers for conservation genetic studies of Vulpes vulpes (Canidae) by using next-generation sequencing method

The red fox, Vulpes vulpes (Canidae), is the most widely distributed terrestrial carnivore worldwide, but this species is classified as endangered in Korea. In this study, we developed 25 polymorphic microsatellite markers that included 3-13 (mean = 6.32) alleles per locus using 22 red fox individuals. The most polymorphic locus was FR(59)TG (13 alleles) and the least polymorphic loci were FR(70)TG and FR(182)AG (3 alleles each). No significant deviation from Hardy-Weinberg equilibrium (P < 0.05) was observed for the 25 markers. Observed (HO) and expected (HE) heterozygosity varied from 0.182 to 1.000 and from 0.175 to 0.929, respectively. These newly developed microsatellite markers will be useful for investigating the genetic diversity and population genetic structure of V. vulpes and will aid in developing conservation strategies for this species.

Protective role of quercetin against cisplatin-induced hair cell damage in zebrafish embryos

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the protective effects of quercetin on cisplatin-induced hair cell damage in transgenic zebrafish embryos.

MATERIALS AND METHODS

Five days postfertilization zebrafish embryos were exposed to 1 mM cisplatin and quercetin at 10, 50, 100, or 200 μM for 4 h. Hair cells within neuromasts of the supraorbital, otic, and occipital lateral lines were analyzed by fluorescent microscopy (n = 10). Survival of hair cells was calculated as the average number of hair cells in the control group that were not exposed to cisplatin. Ultrastructural changes were evaluated using scanning electron microscopy.

RESULTS

Hair cell damage in neuromasts was decreased by co-treatment of quercetin and cisplatin (quercetin 100 μM: 8.6 ± 1.1 cells; 1 mM cisplatin only: 5.0 ± 0.5 cells; n = 10, p < 0.05); apoptosis of hair cells examined by special stain was also decreased by quercetin. The ultrastructure of hair cells within neuromasts was preserved in zebrafish by the combination of quercetin (100 μM) and cisplatin (1 mM).

CONCLUSION

In conclusion, quercetin showed protective effects against cisplatin-induced toxicity in a zebrafish model. The results of this study suggest the possibility of a protective role of quercetin against cisplatin-induced apoptotic cell death in zebrafish.

Clinical manifestations of hypercalcemia and hypophosphatemia after kidney transplantation

INTRODUCTION

Abnormalities of calcium and phosphorus metabolism in end-stage renal disease patients can persist after transplantation. We investigated their natural courses after transplantation, their risk factors for posttransplantation hypercalcemia and hypophosphatemia, and their impacts on allograft outcomes.

METHODS

We retrospectively analyzed a total of 490 adult patients who underwent kidney transplantations between 2000 and 2009.

RESULTS

The serum calcium continued to increase, and reaching a plateau at around 3 months after transplantation. Thereafter it decreased, reaching a stable level by 2 years. Forty-four patients (9.0%) displayed hypercalcemia within 1 year; it persisted longer than that in 23 subjects (4.7%). Both longer dialysis duration (odds ratio [OR] 1.423; 95% confidence interval [CI], 1.192-1.699) and high intact serum parathyroid hormone (iPTH) level before transplantation (OR 1.002; 95% CI, 1.000-1.003) increased the risk for posttransplantation hypercalcemia. After a significant decrease during the first week, the serum phosphorus level increased, becoming stable between 1 and 6 months after transplantation. Hypophsphatemia occurred in 379 patients (77.3%) with 336 patients displaying hypophosphatemia without hypercalcemia. However, neither hypercalcemia nor hypophosphatemia influenced graft outcomes. Eight patients underwent pretransplantation parathyroidectomy, whereas 4 patients underwent posttransplantation parathyroidectomy. Neither group of patients experienced posttransplantation hypercalcemia.

CONCLUSIONS

Both hypercalcemia and hypophosphatemia are common after renal transplantation, especially among patients with a long history of dialysis before transplantation. Strict control of hyperparathyroidism including parathyroidectomy before transplantation may be the appropriate approach to these abnormalities.

Quantitative analyses of individual sugars in mixture using FRET-based biosensors

Molecular biosensors were developed and applied to measure individual sugars in biological mixtures such as bacterial culture broths. As the sensing units, four sugar-binding proteins (SBPs for allose, arabinose, ribose, and glucose) were selected from the Escherichia coli genome and connected to a cyan fluorescent protein and yellow fluorescent protein via dipeptide linkers (CFP-L-SBP-YFP). The putative sensors were randomized in the linker region (L) and then investigated with regard to the intensity of fluorescence resonance energy transfer on the binding of the respective sugars. As a result, four representatives were selected from each library and examined for their specificity using 16 available sugars. The apparent dissociation constants of the allose, arabinose, ribose, and glucose sensors were estimated to be 0.35, 0.36, 0.17, and 0.18 μM. Finally, the sugar sensors were applied to monitor the consumption rate of individual sugars in an E. coli culture broth. The individual sugar profiles exhibited a good correlation with those obtained using an HPLC method, confirming that the biosensors offer a rapid and easy-to-use method for monitoring individual sugars in mixed compositions.

Cellulophaga geojensis sp. nov., a member of the family Flavobacteriaceae isolated from marine sand

A Gram-stain-negative, aerobic, non-flagellated, non-spore-forming, motile (by gliding) bacterial strain, designated M-M6T, was isolated from marine sand of Geoje island, Korea. Strain M-M6T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain M-M6T fell within the clade comprising Cellulophaga species, forming a coherent cluster with Cellulophaga lytica ATCC 23178T and Cellulophaga fucicola NN015860T, with which it shared 16S rRNA gene sequence similarities of 98.1 and 98.2 %, respectively. Sequence similarities between strain M-M6T and the type strains of other recognized Cellulophaga species were in the range 92.4–93.8 %. Strain M-M6T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH, and C16 : 1ω7c and/or iso-C15 : 0 2-OH as the major fatty acids. The major polar lipids detected in strain M-M6T and the type strains of C. lytica and C. fucicola were two unidentified lipids, one unidentified aminolipid and one unidentified aminophospholipid. The DNA G+C content of strain M-M6T was 35.4 mol%. Levels of DNA–DNA relatedness between strain M-M6T and C. lytica JCM 8516T and C. fucicola JCM 21778T were 33 and 35 %, respectively. Differential phenotypic properties and phylogenetic and genetic distinctiveness distinguished strain M-M6T from all recognized Cellulophaga species. On the basis of the data presented, strain M-M6T is considered to represent a novel species of the genus Cellulophaga , for which the name Cellulophaga geojensis sp. nov. is proposed. The type strain is M-M6T ( = KCTC 23498T = CCUG 60801T).

Algoriphagus namhaensis sp. nov., isolated from seawater

A Gram-staining-negative, non-motile, non-spore-forming bacterial strain, DPG-3T, was isolated from seawater from the South Sea in Korea, and its taxonomic position was investigated using a polyphasic approach. Strain DPG-3T grew optimally at 30 °C and in the presence of 2 % (w/v) NaCl. In a neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain DPG-3T fell within a clade comprising Algoriphagus species and appeared most closely related to Algoriphagus halophilus JC 2051T (96.1 %16S rRNA gene sequence similarity) and Algoriphagus lutimaris S1-3T (96.4 %). The type strains of other Algoriphagus species showed 16S rRNA gene sequence similarities of 92.9–96.0 % with strain DPG-3T. The predominant menaquinone of strain DPG-3T was MK-7. The major fatty acids were iso-C15 : 0 and iso-C15 : 0 2-OH and/or C16 : 1ω7c (summed feature 3). The major polar lipids detected in strain DPG-3T were phosphatidylcholine, phosphatidylethanolamine and an unidentified lipid. The genomic DNA G+C content was 44.8 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain DPG-3T is considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus namhaensis sp. nov. is proposed. The type strain is DPG-3T ( = KCTC 23419T = CCUG 60523T).

Tropicimonas aquimaris sp. nov., isolated from seawater, and emended description of the genus Tropicimonas Harwati et al. 2009

A Gram-staining-negative, aerobic, non-motile and rod-shaped bacterial strain, designated DPG-21T, was isolated from seawater from the South Sea in Korea, and investigated using a polyphasic taxonomic approach. Strain DPG-21T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. In a neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain DPG-21T clustered with Tropicimonas isoalkanivorans B51T (with a sequence similarity of 97.1 %); the novel strain showed lower 16S rRNA gene sequence similarities (<95.4 %) with the other species included in the tree. The mean DNA–DNA relatedness value between strain DPG-21T and T. isoalkanivorans DSM 19548T was 12 %. The predominant ubiquinones of strain DPG-21T were Q-10 and Q-9 while C18 : 1ω7c was the strain’s major fatty acid. The polar lipid profile of strain DPG-21T was similar to that of T. isoalkanivorans DSM 19548T. The genomic DNA G+C content of the novel strain was 69.6 mol%. Some phenotypic properties and the phylogenetic and genetic data indicated that strain DPG-21T was distinct from T. isoalkanivorans and represents a novel species of the genus Tropicimonas, for which the name Tropicimonas aquimaris sp. nov. is proposed. The type strain is DPG-21T ( = KCTC 23424T = CCUG 60524T).

Pseudorhodobacter aquimaris sp. nov., isolated from seawater, and emended description of the genus Pseudorhodobacter Uchino et al. 2002

A Gram-stain-negative, aerobic, motile, ovoid bacterial strain, designated HDW-19T, was isolated from seawater of the west coast of Korea and subjected to a polyphasic taxonomic study. Strain HDW-19T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2–3 % (w/v) NaCl. Bacteriochlorophyll a was not produced by strain HDW-19T. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain HDW-19T clustered with Pseudorhodobacter ferrugineus IAM 12616T, with which it shared 96.4 % similarity. A neighbour-joining phylogenetic tree based on gyrB gene sequences showed that strain HDW-19T also clustered with the type strain of P. ferrugineus, sharing 83.0 % similarity. Strain HDW-19T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, three unidentified aminophospholipids and two unidentified aminolipids. The DNA G+C content of strain HDW-19T was 60.9 mol%. Differential phenotypic properties, together with phylogenetic distinctiveness, showed that strain HDW-19T can be differentiated from P. ferrugineus. On this basis, strain HDW-19T is considered to represent a novel species of the genus Pseudorhodobacter, for which the name Pseudorhodobacter aquimaris sp. nov. is proposed. The type strain is HDW-19T ( = KCTC 23043T  = CCUG 58879T).

Influence of long-term statin use in type 2 diabetic patients on thyroid nodularity in iodine-sufficient area

Statins have marked beneficial effects on lipid profile, but also have pleiotropic actions. A previous study in an iodine-deficient area suggested that statin use is associated with reduced thyroid volume and nodularity. We performed this study to investigate how long-term statin use in type 2 diabetic patients affects thyroid nodularity in iodine-sufficient area.We recruited euthyroid type 2 diabetic patients, receiving statin therapy continuously for at least 5 years (statin group) and, age and sex matched statin-naive type 2 diabetic patients (control group). Subjects with past history of cancer, thyroid disease or treatment with lithium or amiodarone; family history of thyroid cancer; palpable goiter or thyroid nodule, and/or positive thyroperoxidase antibody were excluded. The prevalence, number, and volume of thyroid nodules, size of thyroid were evaluated in all subjects by high resolution ultrasound.Prevalence of non-palpable thyroid nodules of statin group (n=70) and control group (n=98) were 51 and 53%, respectively. There was no difference of prevalence, number, and volume of non-palpable thyroid nodules and size of thyroid between statin and control group. But, the patients aged between 60 and 65 years from statin group showed lower prevalence of non-palpable thyroid nodules than the patients with same age interval from control group (4 out of 12 patients, 33%, statin group; 19 out of 27 patients, 70%, control group; P=0.04).Long-term statin use in elderly type 2 diabetic patients was associated with lesser prevalence of thyroid nodules in an iodine-sufficient area. Our data might support a possible antiproliferative effect of statins on thyroid in old type 2 diabetic patients. But, the effect was not as strong as that in an iodine-deficient area and further studies with enough numbers of subjects and revised design will be needed.

Mucilaginibacter boryungensis sp. nov., isolated from soil

A Gram-stain-negative, non-motile, non-spore-forming bacterial strain, BDR-9T, was isolated from soil collected from Boryung on the west coast of the Korean peninsula, and its taxonomic position was investigated by using a polyphasic study. Strain BDR-9T grew optimally at 25 °C, at pH 6.0–7.5 and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BDR-9T fell within the clade comprising species of the genus Mucilaginibacter within the phylum Bacteroidetes. 16S rRNA gene sequence similarity values between strain BDR-9T and the type strains of species of the genus Mucilaginibacter were in the range 94.0–95.6 %. Strain BDR-9T contained MK-7 as the predominant menaquinone and iso-C15 : 0 and C16 : 1ω7c and/or iso-C15 : 0 2-OH as the major fatty acids. The DNA G+C content was 44.3 mol%. Differential phenotypic properties and phylogenetic distinctiveness of strain BDR-9T demonstrated that this strain is distinguishable from species of the genus Mucilaginibacter. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain BDR-9T is considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter boryungensis sp. nov. is proposed. The type strain is BDR-9T ( = KCTC 23157T  = CCUG 59599T).

Paraperlucidibaca baekdonensis gen. nov., sp. nov., isolated from seawater

A Gram-negative, non-spore-forming, rod-shaped bacterial strain, RL-2T, was isolated from seawater of the East Sea in Korea and was subjected to a polyphasic taxonomic study. Strain RL-2T grew optimally at pH 7.5–8.0, at 20 °C and in the absence of NaCl. Phylogenetic trees based on 16S rRNA gene sequence analysis showed that strain RL-2T forms a cluster with Perlucidibaca piscinae IMCC1704T and various uncultured and unidentified gammaproteobacteria. Strain RL-2T exhibited 16S rRNA gene sequence similarity values of 96.1 % to Perlucidibaca piscinae IMCC1704T and 93.7–99.7 % to the uncultured bacterial clones belonging to the cluster and an unidentified gammaproteobacterium. The fatty acid profile of strain RL-2T was similar to that of Perlucidibaca piscinae IMCC1704T, but the predominant ubiquinone type (Q-11) of strain RL-2T was different from that (Q-8) of Perlucidibaca piscinae IMCC1704T. The DNA G+C content of strain RL-2T was 61.3 mol%. On the basis of phylogenetic, chemotaxonomic and phenotypic data, strain RL-2T is considered to represent a novel species of a new genus in the family Moraxellaceae, for which the name Paraperlucidibaca baekdonensis gen. nov., sp. nov. is proposed. The type strain of Paraperlucidibaca baekdonensis is RL-2T ( = KCTC 23145T  = CCUG 59307T).

A novel family VII esterase with industrial potential from compost metagenomic library

Background

Among the vast microbial genomic resources now available, most microbes are unculturable in the laboratory. A culture-independent metagenomic approach is a novel technique that circumvents this culture limitation. For the screening of novel lipolytic enzymes, a metagenomic library was constructed from compost, and the clone of estCS2 was selected for lipolytic properties on a tributyrin-containing medium.

Results

The estCS2 sequence encodes a protein of 570 amino acid residues, with a predicted molecular mass of 63 kDa, and based on amino acid identity it most closely matches (45%) the carboxylesterase from Haliangium ochraceum DSM 14365. EstCS2 belong to family VII, according to the lipolytic enzyme classification proposed by Arpigny and Jaeger, and it retains the catalytic triad Ser₂₄₅-Glu₃₆₃-His₄₆₆ that is typical of an α/β hydrolase. The Ser₂₄₅ residue in the catalytic triad of EstCS2 is located in the consensus active site motif GXSXG. The EstCS2 exhibits strong activity toward p-nitrophenyl caproate (C6), and it is stable up to 60°C with an optimal enzymatic activity at 55°C. The maximal activity is observed at pH 9, and it remains active between pH 6-10. EstCS2 shows remarkable stability in up to 50% (v/v) dimethyl sulfoxide (DMSO) or dimethylformamide (DMF). The enzyme has the ability to cleave sterically hindered esters of tertiary alcohol, as well as to degrade polyurethanes, which are widely used in various industries.

Conclusions

The high stability of EstCS2 in organic solvents and its activity towards esters of ketoprofen and tertiary alcohols, and in polyurethane suggests that it has potential uses for many applications in biotransformation and bioremediation.

Lysobacter dokdonensis sp. nov., isolated from soil

A Gram-negative, non-motile, rod-shaped bacterial strain, DS-58T, was isolated from a soil sample from Dokdo, an island of Korea, and its taxonomic position was investigated. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-58T fell within the family Xanthomonadaceae. The isolate showed 96.9 % 16S rRNA gene sequence similarity with its closest phylogenetic neighbour, Lysobacter niastensis GH41-7T, and 93.4–95.7 % 16S rRNA gene sequence similarity with other members of the genus Lysobacter. Strain DS-58T contained Q-8 as the predominant ubiquinone and iso-C16 : 0, iso-C15 : 0 and iso-C17 : 1ω9c as the major fatty acids. The DNA G+C content was 68.1 mol%. Strain DS-58T could be distinguished phenotypically from type strains of closely related species of the genus Lysobacter and phylogenetically from all members of the genus Lysobacter. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain DS-58T is considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter dokdonensis sp. nov. is proposed. The type strain is DS-58T ( = KCTC 12822T  = DSM 17958T).

Control of AIF-mediated cell death by antagonistic functions of CHIP ubiquitin E3 ligase and USP2 deubiquitinating enzyme

Apoptosis inducing factor (AIF) is a mitochondrial oxidoreductase that scavenges reactive oxygen species under normal conditions. Under certain stresses, such as exposure to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG), AIF is truncated and released from the mitochondria and translocated into the nucleus, where the truncated AIF (tAIF) induces caspase-independent cell death. However, it is unknown how cells decide to kill themselves or operate ways to survive when they encounter stresses that induce the release of tAIF. Here, we demonstrated that USP2 and CHIP contribute to the control of tAIF stability. USP2 deubiquitinated and stabilized tAIF, thus promoting AIF-mediated cell death. In contrast, CHIP ubiquitinated and destabilized tAIF, thus preventing the cell death. Consistently, CHIP-deficient cells showed an increased sensitivity to MNNG. On the other hand, knockdown of USP2 attenuated MNNG-induced cell death. Moreover, exposure to MNNG caused a dramatic decrease in CHIP level, but not that of USP2, concurrent with cell shrinkage and chromatin condensation. These findings indicate that CHIP and USP2 show antagonistic functions in the control of AIF-mediated cell death, and implicate the role of the enzymes as a switch for cells to live or die under stresses that cause tAIF release.

Roseovarius marinus sp. nov., isolated from seawater

A Gram-stain-negative, non-motile, ovoid- to rod-shaped bacterium, designated HDW-9T, belonging to the class Alphaproteobacteria, was isolated from seawater of the Yellow Sea, Korea. Strain HDW-9T grew optimally at pH 7.0–8.0, at 30 °C and with 2–3 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain HDW-9T clustered with Roseovarius crassostreae CV919-312T, with which it exhibited 95.5 % 16S rRNA gene sequence similarity. Strain HDW-9T exhibited 92.5–94.7 % 16S rRNA gene sequence similarity with the other type strains of species of the genus Roseovarius. Strain HDW-9T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c as the major fatty acid. The DNA G+C content was 58.3 mol%. Differential phenotypic properties distinguished strain HDW-9T from the other members of the genus Roseovarius. Strain HDW-9T is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius marinus sp. nov. is proposed. The type strain is HDW-9T (=KCTC 22805T =CCUG 58403T).

Ruegeria faecimaris sp. nov., isolated from a tidal flat sediment

A Gram-negative-staining, non-motile and rod-shaped bacterial strain, HD-28(T), was isolated from a tidal flat of the Yellow Sea, Korea. Strain HD-28(T) grew optimally at pH 7.0-8.0 and 30 °C in the presence of 2-3 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HD-28(T) was most closely related to species of the genus Ruegeria and exhibited 95.5-96.9 % 16S rRNA gene sequence similarity to the type strains of Ruegeria species. A neighbour-joining phylogenetic tree based on gyrB gene sequences also showed that strain HD-28(T) fell within the cluster comprising recognized species of the genus Ruegeria, showing 77.5-83.9 % sequence similarity. Strain HD-28(T) contained Q-10 as the predominant ubiquinone and C(18 : 1)ω7c as the major fatty acid. The major polar lipids detected in strain HD-28(T) were phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid and two unidentified lipids. The DNA G+C content was 57.9 mol%. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain HD-28(T) could be distinguished from recognized species of the genus Ruegeria. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain HD-28(T) is considered to represent a novel species of the genus Ruegeria, for which the name Ruegeria faecimaris sp. nov. is proposed. The type strain is HD-28(T) ( = KCTC 23044(T) = CCUG 58878(T)).

Jannaschia seohaensis sp. nov., isolated from a tidal flat sediment

A Gram-negative, motile and pleomorphic bacterial strain, SMK-146T, was isolated from a tidal flat sediment of the Yellow Sea, Korea, and its taxonomic position was investigated. Strain SMK-146T grew optimally at pH 7.0–8.0 and 30 °C. It contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c and 11-methyl C18 : 1 ω7c as the major fatty acids. The major polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 68.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SMK-146T belongs to the genus Jannaschia. Strain SMK-146T exhibited 16S rRNA gene sequence similarity values of 95.3–97.0 % to the type strains of the five recognized Jannaschia species. The mean DNA–DNA relatedness value between strain SMK-146T and Jannaschia seosinensis KCCM 42114T, the closest phylogenetic neighbour, was 17 %. Differential phenotypic properties also revealed that strain SMK-146T differs from the recognized Jannaschia species. On the basis of phenotypic, phylogenetic and genetic data, strain SMK-146T represents a novel species of the genus Jannaschia, for which the name Jannaschia seohaensis sp. nov. is proposed. The type strain is SMK-146T (=KCTC 22172T =CCUG 55326T).

Planococcus salinarum sp. nov., isolated from a marine solar saltern, and emended description of the genus Planococcus

A Gram-positive, non-motile and coccoid-, short rod- or rod-shaped bacterial strain, ISL-16(T), was isolated from a marine solar saltern in Korea and its taxonomic position was investigated using a polyphasic taxonomic approach. Strain ISL-16(T) grew optimally at pH 7.0-8.0, at 30 degrees C and in the presence of 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ISL-16(T) joined the cluster comprising species of the genus Planococcus. Its 16S rRNA gene sequence contained the same signature nucleotides as those defined for the genus Planococcus. Strain ISL-16(T) exhibited 16S rRNA gene sequence similarity values of 96.9-98.2 % to the type strains of species of the genus Planococcus. Strain ISL-16(T) contained MK-8 and MK-7 as the predominant menaquinones and anteiso-C(15 : 0), C(16 : 1)omega7c alcohol and anteiso-C(17 : 0) as the major fatty acids. The DNA G+C content was 48.3 mol%. DNA-DNA relatedness values between strain ISL-16(T) and the type strains of species of the genus Planococcus were 15-28 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, enabled strain ISL-16(T) to be differentiated from recognized species of the genus Planococcus. On the basis of the data presented, strain ISL-16(T) is considered to represent a novel species of the genus Planococcus, for which the name Planococcus salinarum sp. nov. is proposed. The type strain is ISL-16(T) (=KCTC 13584(T)=CCUG 57753(T)). An emended description of the genus Planococcus is also given.

Salimicrobium flavidum sp. nov., isolated from a marine solar saltern

A Gram-variable-staining, motile and coccoid-, ovoid- or rod-shaped bacterium, strain ISL-25(T), was isolated from a marine solar saltern of the Yellow Sea, Korea, and its taxonomic position was investigated by means of a polyphasic study. Strain ISL-25(T) grew optimally at pH 7.0-8.0 and 30-37 degrees C. Strain ISL-25(T) contained meso-diaminopimelic acid as the cell-wall peptidoglycan, MK-7 as the predominant menaquinone and anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0) as the major fatty acids. The DNA G+C content was 49.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain ISL-25(T) belongs to the genus Salimicrobium. The similarity values between the 16S rRNA gene sequence of strain ISL-25(T) and those of the type strains of the three currently recognized Salimicrobium species were 97.6-98.3 %. Mean DNA-DNA relatedness values between strain ISL-25(T) and the type strains of the genus Salimicrobium were 9-15 %. Differential phenotypic properties of strain ISL-25(T), together with the phylogenetic and genetic distinctiveness, revealed that this strain could be differentiated from other Salimicrobium species. Therefore, strain ISL-25(T) represents a novel species within the genus Salimicrobium, for which the name Salimicrobium flavidum sp. nov. is proposed. The type strain is ISL-25(T) (=KCTC 13260(T)=CCUG 56755(T)).

Seohaeicola saemankumensis gen. nov., sp. nov., isolated from a tidal flat

A Gram-negative, non-motile and rod-, oval- or coccoid-shaped bacterial strain, SD-15(T), was isolated from a tidal flat of the Yellow Sea, Korea. The novel strain, which was phylogenetically closely related to the genera Phaeobacter, Leisingera and Marinovum, was studied using a polyphasic taxonomic approach. Strain SD-15(T) grew optimally at pH 7.0-8.0 and 30 degrees C in the presence of 2 % (w/v) NaCl. It contained Q-10 as the predominant ubiquinone and C(18 : 1)omega7c and 11-methyl C(18 : 1)omega7c as the major fatty acids. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unidentified lipid. The DNA G+C content was 63.4 mol%. Strain SD-15(T) exhibited the highest 16S rRNA gene sequence similarity values (95.1-96.4 %) to the type strains of species of the genus Phaeobacter, Leisingera methylohalidivorans MB2(T) and Marinovum algicola ATCC 51440(T). Strain SD-15(T) could be differentiated from members of the genera Phaeobacter, Leisingera and Marinovum by differences in the contents of some fatty acids, by the absence of aminolipid and by differences in some phenotypic properties. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain SD-15(T) represents a new genus and novel species, for which the name Seohaeicola saemankumensis gen. nov., sp. nov. is proposed. The type strain of the type species is Seohaeicola saemankumensis SD-15(T) (=KCTC 22175(T)=CCUG 55328(T)).

Novel cold-adapted alkaline lipase from an intertidal flat metagenome and proposal for a new family of bacterial lipases

A new lipase, LipEH166, isolated from an intertidal flat metagenome, showed no amino acid similarity to any known lipolytic enzyme except in the consensus region. This suggested that LipEH166 and its homologues belong to a new family of lipolytic enzymes. Partial characterization indicated that LipEH166 is a novel cold-adapted alkaline lipase.

Fatigue measurement system designed for a chalcogenide-based device using a homemade heater tip

A fatigue measurement system is designed using a homemade tungsten (W) heater tip. This system is composed of a pulse generator and an atomic force microscope with the W heater tip attached. Also included are a parameter analyzer and control devices. The entire measurement process is controlled by a designed program without communication errors. Additionally, a process to fabricate the sharp W heater tip that applies an electrical pulse and evaluates the electrical properties is introduced. The analysis of the tip, carried out by scanning electron microscopy and electron backscattering diffraction, shows that the tip has great thermomechanical stability. Using this fatigue measurement system, the resistance of the Ge(2)Sb(2)Te(5) (GST) cell was successfully measured as a function of the number of set/reset cycles. The specific area (both program area and failure area) was easily observed. It is expected that the expansion of GST is a source of information regarding the fatigue of a GST cell.

Cellular responses and proteomic analysis of Escherichia coli exposed to green tea polyphenols

The purpose of this study was to characterize the cellular response and proteomic analysis of Escherichia coli exposed to tea polyphenols (TPP) extracted from Korean green tea (Camellia sinensis L). TPP showed a dose-dependent bactericidal effect on E. coli. Analysis of cell-membrane fatty acids of E. coli cultures treated with TPP identified unique changes in saturated and unsaturated fatty acids, whereas scanning electron microscopic analysis demonstrated the presence of perforations and irregular rod forms with wrinkled surfaces in cells treated with TPP. Two-dimensional polyacrylamide gel electrophoresis of soluble protein fractions from E. coli cultures exposed to TPP showed 17 protein spots increased or decreased by TPP. Nine upregulated proteins were identified (including GroEL and proteins involved in cellular defense, such as GyrA, RpoS, SodC, and EmrK), whereas the expression of eight proteins was downregulated by exposure to TPP (including proteins involved in carbon and energy metabolism, such as Eno, SdhA, and UgpQ, as well as those involved in amino-acid biosynthesis, such as GltK and TyrB). These results provide clues for understanding the mechanism of TPP-induced stress and cytotoxicity on E. coli.

Characterization of crystallographic properties of SMC poly Si using electron backscattered diffraction

Crystallographic properties of silicide mediated crystallization (SMC) polycrystalline silicon (poly Si) and excimer laser annealing (ELA) poly Si were studied by electron backscattered diffraction. Large-grain sized poly Si with a large fraction of low-angle grain boundaries was acquired by SMC, and small-grain sized poly Si with high-angle grain boundaries especially around 60 degrees was acquired by ELA. The thin film transistor (TFT) device characteristics were investigated in view of short-range crystallinity (pattern quality) and long-range crystallinity (misorientation distribution) of the specimens. Short-range crystallinity did not significantly affect the TFT device characteristics, and long-range crystallinity considering the low energy level of special boundaries could be better related to the TFT device characteristics of poly Si.

Functional tuning of a salvaged green fluorescent protein variant with a new sequence space by directed evolution

We previously reported a method, designated functional salvage screen (FSS), to generate protein lineages with new sequence spaces through the functional or structural salvage of a defective protein by employing green fluorescent protein (GFP) as a model protein. Here, in an attempt to mimic a step in the natural evolution process of proteins, the functionally salvaged mutant GFP-I5 with new sequence space, but showing low fluorescence intensity and stability, was selected and fine-tuned by directed evolution. During a course of functional tuning, GFP-I5 was found to evolve rapidly, recovering the spectral traits to those of the parent GFPuv. The mutant 3E4 from the third round of directed evolution possessed four substitutions; three (F64L, E111V and K166Q) were at the original GFP gene and the other (K8N) at the inserted segment. The fluorescence intensity of 3E4 was approximately 28-fold stronger than GFP-I5, and other spectral properties were retained. Biochemical and biophysical investigations suggested that the fine-tuning by directed evolution led the salvaged variant GFP-I5 to a functionally favorable structure, resulting in recovery of stability and fluorescence. Site-directed mutagenesis of the mutated amino acid residues in both GFPuv and GFP-I5 revealed that each amino acid residue has a different effect on the fluorescence intensity, which implies that 3E4 adopted a new evolutionary path with respect to fluorescence characteristics compared with the parent GFPuv. Directed evolution in conjunction with FSS is expected to be used for generating protein lineages with new fitness landscapes.

Improvement of oxidative and thermostability of N-carbamyl-d-amino Acid amidohydrolase by directed evolution

N-Carbamyl-D-amino acid amidohydrolase (N-carbamoylase), which is currently employed in the industrial production of unnatural D-amino acid in conjunction with D-hydantoinase, has low oxidative and thermostability. We attempted the simultaneous improvement of the oxidative and thermostability of N-carbamoylase from Agrobacterium tumefaciens NRRL B11291 by directed evolution using DNA shuffling. In a second generation of evolution, the best mutant 2S3 with improved oxidative and thermostability was selected, purified and characterized. The temperature at which 50% of the initial activity remains after incubation for 30 min was 73 degrees C for 2S3, whereas it was 61 degrees C for wild-type enzyme. Treatment of wild-type enzyme with 0.2 mM hydrogen peroxide for 30 min at 25 degrees C resulted in a complete loss of activity, but 2S3 retained about 79% of the initial activity under the same conditions. The K(m) value of 2S3 was estimated to be similar to that of wild-type enzyme; however k(cat) was decreased, leading to a slightly reduced value of k(cat)/K(m), compared with wild-type enzyme. DNA sequence analysis revealed that six amino acid residues were changed in 2S3 and substitutions included Q23L, V40A, H58Y, G75S, M184L and T262A. The stabilizing effects of each amino acid residue were investigated by incorporating mutations individually into wild-type enzyme. Q23L, H58Y, M184L and T262A were found to enhance both oxidative and thermostability of the enzyme and of them, T262A showed the most significant effect. V40A and G75S gave rise to an increase only in oxidative stability. The positions of the mutated amino acid residues were identified in the structure of N-carbamoylase from Agrobacterium sp. KNK 712 and structural analysis of the stabilizing effects of each amino acid substitution was also carried out.

Modeling and kinetic analysis of the reaction system using whole cells with separately and co-expressed D-hydantoinase and N-carbamoylase

We developed a kinetic model that describes a heterogeneous reaction system for the production of D-p-hydroxyphenylglycine from D,L-p-hydroxyphenyl-hydantoin using D-hydantoinase of Bacillus stearothermophilus SD1 and N-carbamoylase of Agrobacterium tumefaciens NRRL B11291. As a biocatalyst, whole cells with separately or co-expressed enzymes were used. The reaction system involves dissolution of substrate particles, enzymatic conversion, racemization of the L-form substrate, and transfer of the dissolved substrate, intermediate, and product through the cell membrane. Because the two enzymes have different pH optimum, kinetic parameters were evaluated at different pH for the reaction systems. The model was simulated using the kinetic parameters and compared with experimental data, and it was found that the kinetic model well describes the behavior of the reaction systems using whole cells with separately and co-expressed enzymes. Factors affecting the kinetics of the reaction systems were analyzed on the basis of the kinetic model. In the reaction system with separately expressed enzymes, racemization rate and transport of the reaction intermediate (N-carbamoyl-D-p-hydroxyphenylglycine) were revealed to be the limiting factors at neutral pH, resulting in accumulation of intermediate in the reaction medium. At alkaline condition, on the other hand, inhibition of N-carbamoylase by ammonia was severe, and thereby the reaction rate significantly reduced. In the co-expressed enzyme system, accumulation of intermediate was negligible in the reaction medium, and the improved performance was observed compared to that with separately expressed enzymes. The present model might be applied for the optimization and development of the reaction system using two sequential enzymes.

Directed evolution of N-carbamyl-D-amino acid amidohydrolase for simultaneous improvement of oxidative and thermal stability

Directed evolution of N-carbamyl-D-amino acid amidohydrolase from Agrobacterium tumefaciens NRRL B11291 was attempted in order to simultaneously improve oxidative and thermal stability. A mutant library was generated by DNA shuffling, and positive clones with improved oxidative and thermal stability were screened on the basis of the activity staining method on a solid agar plate containing pH indicator (phenol red) and substrate (N-carbamyl-D-p-hydroxyphenylglycine). Two rounds of directed evolution resulted in the best mutant 2S3 with a significantly improved stability. Oxidative stability of the evolved enzyme 2S3 was about 18-fold higher than that of the wild type, and it also showed an 8-fold increased thermostability. The K(m) value of 2S3 was comparable to that of wild-type enzyme, but k(cat) was slightly decreased. DNA sequence analysis revealed that six amino acid residues (Q23L, V40A, H58Y, G75S, M184L, and T262A) were substituted in 2S3. From the mutational analysis, four mutations (Q23L, H58Y, M184L, and T262A) were found to lead to an improvement of both oxidative and thermal stability. Of them, T262A had the most significant effect, and V40A and G75S only increased the oxidative stability.

Adaptive and cross-protective responses of Pseudomonas sp. DJ-12 to several aromatics and other stress shocks

Pseudomonas sp. DJ-12 cells were subjected to mild treatments of stress such as exposure to biphenyl, 4-chlorobiphenyl (4CB), 4-hydroxybenzoate (4HBA), ethanol, and heat, and then were examined for production of stress-shock proteins and morphological changes. The adapted cells were then subjected to lethal stress conditions such as 200 mm 4CB, 100 mm biphenyl, 10 mm 4HBA, 20% ethanol, and 46 degrees C to examine crossly protective responses to the stresses. Several stress-shock proteins including DnaK and GroEL were newly synthesized in the adapted cells. Some of them were commonly produced by those stresses separately treated. The cells treated with these aromatic hydrocarbons showed destructive openings on the cell envelopes. On the other hand, those cells treated with ethanol or heat displayed irregular rod shapes with wrinkled surfaces. The adapted cells to each stress under sublethal conditions exhibited increased resistance to the same stress of lethal conditions. The cells adapted with 5 mm 4HBA showed greater protection for survival than those adapted by other stresses. In addition, those adapted cells showed increased resistance to other stresses as a cross-protection phenomenon. The cells adapted to 42 degrees C exhibited markedly increased resistance to the lethal stresses of 46 degrees C as well as to 20% ethanol.

Renal biopsy in elderly patients: clinicopathological correlation in 117 Korean patients

AIM

In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease.

PATIENTS AND METHODS

We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease.

RESULTS

85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group.

CONCLUSION

Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease.

A trial for a DNA diagnosis of Plasmodium vivax malaria recently reemerging in the Republic of Korea using microtiter plate hybridization assay

The polymerase chain reaction-based microtiter plate hybridization (PCR-MPH) assay was utilized for a DNA diagnosis of Plasmodium vivax malaria, which has recently reemerged in the Republic of Korea. The subjects were 18 parasite-proven patients and 5 healthy controls. Follow-up blood samples were collected from 4 patients after a standard course of treatment. Polymerase chain reaction and electrophoresis of all the patients' blood showed a prominent band at the 138 base pair area, but not in the controls or after treating the patients. Hybridization of the PCR products with known species-specific probes of the 18S rRNA of various malaria species revealed strong positive reactions against the Plasmodium vivax-specific probe (absorbance 1.30-1.90 at 405 nm) in all of the patients. The absorbance was positively correlated with the degree of blood parasitemia, but with a borderline significance. Sequencing of the probe region of the Korean P. vivax revealed no significant variations from the typical P. vivax. The results show that the PCR-MPH is a highly useful technique for the DNA diagnosis of Korean vivax malaria.

Characterization of strain HY99, a novel microorganism capable of aerobic and anaerobic degradation of aniline

We have characterized a novel microorganism, strain HY99, which is capable of aerobic and anaerobic degradation of aniline. Strain HY99 was found to aerobically metabolize aniline via catechol and 2-hydroxymuconic semialdehyde intermediates, and to transform aniline via p-aminobenzoate in anaerobic environments. Physiological and biochemical tests revealed that strain HY99 was most similar to Delftia acidovorans, but unlike D. acidovorans, strain HY99 was able to metabolize aniline under anaerobic conditions linked with nitrate reduction. Phylogenetic analysis based on 16S rDNA sequencing also revealed that strain HY99 was closely related to D. acidovorans, with 96% overall similarity.

Induction of stress shock proteins DnaK and GroEL by phenoxyherbicide 2,4-D in Burkholderia sp. YK-2 isolated from rice field

The purpose of this work was to investigate the induction of stress shock proteins in Burkholderia sp. YK-2 in response to the phenoxyherbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The stress shock proteins, which contribute to the resistance of the cytotoxic effect of 2,4-D, were induced at different 2,4-D concentrations in exponentially growing cultures of Burkholderia sp. YK-2. This response involved the induction of a 43-kDa DnaK and 41-kDa GroEL proteins, characterized by SDS-PAGE and Western blot by use of the anti-DnaK and anti-GroEL monoclonal antibodies. The total stress shock proteins were analyzed by 2-D PAGE. Survival of Burkholderia sp. YK-2 with time in the presence of different concentrations of 2,4-D was monitored, and viable counts paralleled the induction of the stress shock proteins in this strain.

Isolation of a psychrotrophic Azospirillum sp. and characterization of its extracellular protease

A novel psychrotrophic bacterium secreting a protease was isolated from a mountain soil in Korea. On the basis of a 16S rDNA sequence analysis and physiological properties, the isolate was identified as an Azospirillum sp. The protease purified from the culture supernatant was a monomer in its native form with an apparent molecular mass of 48.6 kDa on SDS-PAGE. The protease was active in a broad pH range around 8.5 and at temperatures up to 40 degrees C and stable at temperatures below 30 degrees C for 3 days. The proteolytic activity was inhibited by iodoacetamide and EDTA. The Mg2+ ion did not activate the enzyme much but reversed the inhibition by EDTA, suggesting that the protease belongs to a cysteine protease stabilized by the Mg2+ ion.

Preparation and characterization of sustained-release microspheres of chlorpromazine

Sustained release microspheres of chlorpromazine were prepared from Eudragit RS 100 by an emulsion-solvent evaporation method using a six-baffled vessel. The morphology of microspheres was characterized by scanning electron microscopy (SEM). In the presence of aluminium tristearate (5%), microspheres were spherical in shape and uniform. The release of chlorpromazine from microspheres was pH-independent. With increasing amount of aluminium tristearate and increasing ratio of Eudragit RS 100/drug from 1:1 to 9:1, the particle size of chlorpromazine microspheres was reduced and the release rate decreased. The microspheres prepared with the polymer/drug ratio of 9:1 produced a 12-h sustained release pattern.

Idiopathic retroperitoneal fibrosis presented as an abdominal mass and nephrotic syndrome

We present a 30-year-old male patient who was initially diagnosed as minimal change nephrotic syndrome, 5 years later, the patient developed a localized form of idiopathic retroperitoneal fibrosis (IRF). An elevated ESR and concomitant nephrotic syndrome in the patient suggested the immunologic nature of IRF, IRF has been reported in association with collagen diseases and rarely with proliferative and nonproliferative glomerulopathies. To our knowledge, the association between minimal change lesion (MC) and IRF has not been reported. Furthermore, the fact that IRF presented itself as an abdominal mass and lacked systemic symptoms was also unusual.

Vertical Banded Gastroplasty and Distal Gastric Bypass as Primary Procedures: A Comparison

BACKGROUND: Comparing primary vertical banded gastroplasty (VBG) and distal gastric bypass (DGBP) patients might assist decision-making based on patient profiles and desired outcomes. METHODS: A prospective study of 81 vertical banded gastroplasty and 60 distal gastric bypass patients. Technical aspects, complications, weight loss, post-op compliance and satisfaction are reported. Length of follow-up is 48 months (VBG) and 36 (DGBP). Lost-to-follow-up 41% (VBG) and 22% (DGBP). Ten per cent of VBGs were revised, with 1% takedown. Three percent DGBPs were converted to proximal GBPs. Demographics are comparable. RESULTS: Operative time was 40 min VBG and 88 DGBP; blood loss 187 cc vs 335 cc; and hospital stay 3 versus 4 days. Exclusive VBG complications include: 1% staple-line leak, 4% intra-abdominal abscess, 1% respiratory failure, 5% pneumonia, 1% intra-abdominal bleed, 1% small bowel obstruction, 2% infected incision, 2% fistula, 2% stenotic or obstructed obstructed stoma, and 1% bezoar. Exclusive DGBP complications include: 2% GI bleed, 12% marginal ulcer, 5% reflux esophagitis, 13% hypocalcemia, 23% hypovitaminosis A and D (12% requiring B12 therapy). Shared complications include hypoproteinemia 6% VBG versus 40% DGBP; excess vomiting (>6 months post-op), 7% versus 10%, excess diarrhea 2% versus 20%, dehydration 1% versus 8%, re-hospitalization 4% versus 15% (hyperalimentation), post-op cholecystectomy 1% versus 5%, weight regain 48% versus 1%. VBG experienced an average of 64% excess weight loss at 36 months versus DGBP 89% excess weight loss. VBG follow-up compliance is generally poor but good for DGBP. Compliance with diet and supplements is equivalent (50%). Satisfaction is 85% and 93% respectively. CONCLUSION: The DGBP provides better long-term weight loss, but nutritional deficiencies occur more often and require close follow-up. The surgery is more complex, but as a primary procedure there are few major complications.