Relationships of serum haptoglobin concentration with HbA1c and glycated albumin concentrations in Japanese type 2 diabetic patients.

BACKGROUND: The stable fractions of glycated hemoglobin (Hb), particularly HbA(1c), and glycated albumin (GA) were measured to monitor chronic glycemic control. Haptoglobin (Hp) is a Hb-binding protein, which plays a major role in preventing free Hb-induced tissue oxidative damage. The aim of this study was to clarify the relationships of serum Hp concentration with HbA(1c) and GA concentrations. METHODS: A cross-sectional study to determine the relationship of serum Hp concentration with GA and HbA(1c) concentrations was conducted. The subjects were 125 Japanese type 2 diabetic patients with stable HbA(1c) levels for more than 3 consecutive months. Patients with altered albumin and red blood cell turnover, which are observed in those with chronic renal failure, liver cirrhosis, and anemia among others, were excluded from the study. RESULTS: Serum Hp concentration positively correlated with HbA(1c) concentration (r=0.30, p<0.001), but not with GA concentration (r=0.15, p=0.10). There was a weak inverse correlation between serum Hp concentration and GA/HbA(1c) ratio (r=-0.19, p=0.03). Moreover, GA /HbA(1c) ratio inversely correlated with body mass index (BMI) (r=-0.31, p<0.001). In contrast, there was no significant correlation between Hb concentration and HbA(1c) (r=0.01, p=0.88) or GA (r=0.12, p=0.21) concentrations. We also analyzed the correlation of serum Hp concentration with GA and HbA(1c) concentrations in patients with the Hp 2-1 and Hp 2-2 genotypes, separately. Hp concentration positively correlated with HbA(1c) concentration in patients with the Hp 2-1 (r=0.32, p=0.03) and Hp 2-2 (r=0.29, p=0.02) phenotypes. Multiple regression analysis revealed that the observed correlation between Hp and HbA(1c) concentrations was significant after adjustment for age, gender, and BMI. In contrast, there was no significant correlation between GA and Hp concentrations in patients with either phenotype. Then, we analyzed how Hp concentration affects GA/HbA(1c) ratio in patients with these Hp phenotypes. There was an inverse correlation between Hp concentration and GA/HbA(1c) ratio in patients with Hp 2-1 (r=-0.44, p=0.003), but not in those with Hp 2-2 (r=-0.03, p=0.75). Multiple regression analysis revealed that the inverse correlation between Hp concentration and GA/HbA(1c) ratio in patients with Hp 2-1 was independent of age, gender, and BMI. CONCLUSIONS: Hp phenotype and concentration should be considered in interpreting HbA(1c) and GA levels as glycemic control indicators in diabetic patients. We suggest that in type 2 diabetic patients with Hp 2-1 and high Hp concentrations, HbA(1c) level may be overestimated relative to GA level.

Presence and activity of anammox and denitrification process in low ammonium-fed bioreactors.

A combination of anammox and denitrification process was studied for 300 days in low ammonium-fed bioreactors under the support of organic carbon. Nutrient profiles, (15)N-labelling techniques and qualitative fluorescence in situ hybridization (FISH) probes were used to confirm the nitrogen removal pathways and intercompetition among different bacteria populations. About 80% of nitrogen removal was achieved throughout the study period. The results confirmed that anammox bacteria were absent in the bioreactor inoculated with anaerobic granules only but they were present and active in the central anoxic parts of biopellets in the bioreactor inoculated with mixed microbial consortium from activated sludge and anaerobic granules. It also showed that the anammox bacteria were successfully enriched in the low ammonium-fed bioreactors. Results of this study clearly demonstrated that anammox and denitrification processes could coexist in same environment and anammox bacteria were less competitive than denitrifying bacteria.

Nitrogen removal from wastewater using simultaneous nitrate reduction and anaerobic ammonium oxidation in single reactor.

The effects of C/N ratio and total organic carbon (TOC) loading on nitrogen removal through simultaneous nitrate reduction and anaerobic ammonium oxidation in a single reactor were examined. Granular sludge taken from a methane fermentation reactor was placed in an upflow reactor and supplied with synthetic wastewater containing nitrate at a C/N ratio of 1 to grow heterotrophic denitrifying bacteria. When nitrogen removal ratio reached 30%, anammox sludge attached to nonwoven-carrier was added into the same reactor and then ammonia was added to the synthetic wastewater. Nitrogen removal ratio was markedly increased to 80-94%. In this system, nitrogen removal ratio was affected by C/N ratio and TOC loading, not by the amount of granular sludge. A stable isotopic analysis using 15N-labeled nitrate showed that N2 gas was formed by anammox reaction.

Divergent structures of carbazole degradative car operons isolated from gram-negative bacteria.

Southern hybridization analysis of the genomes from the newly-isolated 10 carbazole (CAR)-utilizing bacteria revealed that 8 of the isolates carried gene clusters homologous to the CAR-catabolic car operon of Pseudomonas resinovorans strain CA10. Sequencing analysis showed that two car operons and the neighboring regions of Pseudomonas sp. strain K23 are nearly identical to that of strain CA10. In contrast to strains CA10 and K23, carEF genes did not exist downstream of the car gene cluster of Janthinobacterium sp. strain J3. In the car gene clusters, strains CA10, K23 and J3 have Rieske-type ferredoxin as a component of carbazole dioxygenase, although Sphingomonas sp. strain KA1 possesses a putidaredoxin-type ferredoxin. We confirmed that this putidaredoxin-type ferredoxin CarAc can function as an electron mediator to CarAa of strain KA1. In the upstream regions of the carJ3 and carKA1 gene clusters, ORFs whose deduced amino acid sequences showed homology to GntR-family transcriptional regulators were identified.

Rhizoremediation of dioxin-like compounds by a recombinant Rhizobium tropici strain expressing carbazole 1,9a-dioxygenase constitutively.

A recombinant Rhizobium strain, PBK3-IS, that constitutively expressed the oxygenase component of carbazole 1,9a-dioxygenase from Sphingomonas sp. strain KA1, was constructed. In the water-cultured siratro rhizospheres inoculated with strain PBK3-IS, 48% of the dibenzofuran was removed within 3 days (initial substrate, 25 microg). Similar results were obtained in soil-cultured siratro rhizospheres using sterile vermiculite. When non-sterile field soils were used instead of sterile vermiculite, the inoculated recombinant strain could grow on the siratro root in all soils tested, except for wet paddy field.

Factual analysis of granule flotation in brewery wastewater treatment plants by the fluorescence in situ hybridization method.

The factors that change the microbial distribution and consequently the flotation of brewery granules were investigated using laboratory-scale upflow anaerobic sludge blanket (UASB) reactors and the fluorescence in situ hybridization (FISH) method. The startup operations of laboratory-scale UASB reactors fed with acetate-based synthetic wastewater, in which the loading rate was maintained at 0.1 gCOD/gVSS/d (Run 1) and increased in a stepwise manner from 0.1 gCOD/gVSS/d to 1.0 gCOD/gVSS/d (Run 2), generated methanogen colonies near the granule surface, while the overloading operation at 1.0 gCOD/gVSS/d from the startup (Run 3) resulted in the formation of methanogen colonies deep in the granules. In each run, a proportion of the granules floated when overloaded at 2.0 gCOD/gVSS/d and circulation was stopped. The ratio of floating granules increased as the methanogen-growing region increased. On the other hand, the Bacteria layer on the granule surface, which is also considered as a possible cause of granule flotation, was not formed by the inflow of other organic acids such as propionate and lactate. Glucose caused formation of a 5-microm-thick surface Bacteria layer, but the granules were still resistant to flotation. Interfusing of air under glucose feeding caused the formation of a Bacteria layer over 50 microm thick leading to granule flotation.

Sphingomonas sp. strain KA1, carrying a carbazole dioxygenase gene homologue, degrades chlorinated dibenzo-p-dioxins in soil.

Hybridization analysis showed that a newly isolated carbazole (CAR)-degrading bacterium Sphingomonas sp. strain KA1 did not possess the gene encoding the terminal oxygenase component (carAa) of CAR 1,9a-dioxygenase at high homology (more than 90% identity) to that of another CAR-degrader, Pseudomonas resinovorans strain CA10. However, PCR experiments using the primers for amplifying the internal fragment of the carAa gene (810 bp for strain CA10) showed that a PCR product of unexpected size (1100 bp) was amplified. Sequence analysis revealed that this DNA region contained the portion of two possible ORFs, which showed moderate homology to CarAa and CarBa from strain CA10 (61% and 40% identities at the amino acid level, respectively). Inoculation of strain KA1 into dioxin-contaminated model soil resulted in 96% and 70% degradation of 2-mono- and 2,3-dichlorinated dibenzo-p-dioxin, respectively, after 7-day incubation.

Microbial analyses by fluorescence in situ hybridization of well-settled granular sludge in brewery wastewater treatment plants.

The characteristics of granular sludge from full-scale upflow anaerobic sludge blanket reactors used for the treatment of brewery wastewater were investigated. Fluorescence in situ hybridization (FISH) analyses of settled granules from a reactor that had been treating brewery wastewater stably at COD removal rates of over 90% for more than 6 months showed that a methanogen of the genus Methanosaeta was predominant near the granule surface and that Bacteria were not abundant. The center of the granules was composed of dead or resting cells, or both, which were used as a support for active archaeal and bacterial cells near the surface. Periodic analysis of granules from full-scale plants showed that granules containing methanogens deep within them tended to float. Granules with a Bacteria layer on the surface also tended to float. On the basis of these findings, well-settled granules are considered to have methanogens that develop near the granule surface so that the gases generated during methane fermentation are readily released.