A population-based characterization study of anti-mitochondrial M2 antibodies and its consistency with anti-mitochondrial antibodies.

OBJECTIVE: This study aims to estimate the prevalence of anti-mitochondrial antibody subtype M2 (AMA-M2) and assess its consistency with AMA in a general population. METHODS: A total of 8954 volunteers were included to screen AMA-M2 using enzyme-linked immunosorbent assay. Sera with AMA-M2 >50 RU/mL were further tested for AMA using an indirect immunofluorescence assay. RESULTS: The population frequency of AMA-M2 positivity was 9.67%, of which 48.04% were males and 51.96% were females. The AMA-M2 positivity in males had a peak and valley value of 7.81% and 16.88% in those aged 40 to 49 and ≥70 years, respectively, whereas it showed a balanced age distribution in females. Transferrin and immunoglobulin M were the risk factors for AMA-M2 positivity and exercise was the only protective factor. Of 155 cases with AMA-M2 >50 RU/mL, 25 cases were AMA-positive, with a female-to-male ratio of 5.25:1. Only 2 people, with very high AMA-M2 of 760 and >800 RU/mL, met the diagnostic criteria of primary biliary cholangitis (PBC), making the prevalence of PBC 223.36 per million in southern China. CONCLUSION: We found that AMA-M2 has a low coincidence rate with AMA in the general population. A new decision-making point for AMA-M2 is needed to improve consistency with AMA and diagnostic accuracy.

[Levels of fat-soluble vitamins A, D, and E and their influencing factors in children with obesity]. / è‚¥èƒ–ç—‡å„¿ç«¥è„‚æº¶æ€§ç»´ç”Ÿç´ A、D、Eæ°´å¹³åŠå ¶å½±å“å› ç´ .

OBJECTIVES: To investigate the levels of fat-soluble vitamins A, D, and E in children with obesity and their influencing factors. METHODS: A total of 273 children with obesity who attended the Department of Clinical Nutrition, Xi'an Children's Hospital, from January 2019 to April 2021 were enrolled as the obesity group. A total of 226 children with normal body weight who underwent physical examination during the same period were enrolled as the control group. Anthropometric parameters and body composition were measured for both groups, and the serum concentrations of vitamins A, D, and E were also measured. RESULTS: Compared with the control group, the obesity group had significantly higher serum levels of vitamin A [(1.32±0.21) µmol/L vs (1.16±0.21) µmol/L, P<0.001] and vitamin E [(9.3±1.4) mg/L vs (8.3±1.2) mg/L, P<0.001] and a significant reduction in the level of 25-hydroxyvitamin D [(49±22) nmol/L vs (62±24) nmol/L, P<0.001]. In the obesity group, the prevalence rates of marginal vitamin A deficiency, vitamin D deficiency/insufficiency, and vitamin E insufficiency were 5.5% (15/273), 56.8% (155/273), and 4.0% (11/273), respectively. After adjustment for body mass index Z-score and waist-to-height ratio, serum vitamin A level was positively correlated with age (P<0.001), while vitamins E and 25-hydroxyvitamin D levels were negatively correlated with age in children with obesity (P<0.001). After adjustment for age, the serum levels of vitamin A, vitamin E and 25-hydroxyvitamin D were not correlated with degree of obesity, percentage of body fat, and duration of obesity in children with obesity, while the serum levels of vitamins A and E were positively correlated with waist-to-height ratio (P<0.001). CONCLUSIONS: There are higher serum levels of vitamins A and E in children with obesity, especially in those with abdominal obesity, while serum vitamin D nutritional status is poor and worsens with age. Therefore, vitamin D nutritional status should be taken seriously for children with obesity, and vitamin D supplementation should be performed when necessary.

Thalidomide-based Pt(IV) prodrugs designed to exert synergistic effect of immunomodulation and chemotherapy.

Combination of immune- and chemo-therapy has become a new trend in cancer treatment. Food and Drug Administration (FDA)-approved immune-modulatory agent, thalidomide, can modulate the related proteins of upstream signaling pathway of programmed cell death-ligand 1 (PD-L1), including nuclear transcription factor κB (NF-κB), hypoxia inducible factor-1α (HIF-1α), epidermal growth factor receptor (EGFR), and signal transducer and activator of transcription 3 (STAT3), all acting as key antitumor target proteins. In this work, we conjugated thalidomide with oxidized cisplatin to construct multi-functional Pt(IV) prodrugs, named thaliplatins 4-6, to investigate the anti-tumor effect of immuno- and chemo-therapy. Among them, thaliplatin 6 exerted remarkable cytotoxicity against the tested cancer cell lines, showing 15-26 and 9-20 times higher IC50 values than those of single cisplatin or the combination of cisplatin + thalidomide, respectively. Moreover, thaliplatin 6 could rapidly accumulated into cells, markedly triggered DNA damage, and induced cell S phase arrest and apoptosis, as well as inhibited cell migration and invasion in breast carcinoma cell line (MCF-7). Fluorescent confocal and western blotting experiments proved that 6 significantly regulated NF-κB, EGFR, HIF-1α and phosphor-signal transducer and activator of transcription 3 (p-STAT3), and simultaneously inhibited PD-L1 expression to interrupt programmed cell death 1 (PD-1)/PD-L1 signaling pathway, suggesting a synergistic action of cisplatin and thalidomide. Most strikingly, in vivo tests indicated that 6 effectively decreased tumor growth with no observable systemic toxicity, being superior to the anticancer efficacy of cisplatin.

Treatment of lower part of glenoid fractures through a novel axillary approach: A case report.

BACKGROUND: Based on the location and size of the fracture block, open reduction and internal fixation can be employed or assisted for shoulder arthroscopy in the treatment of glenoid fractures. However, the treatment of lower part of glenoid fractures through a novel axillary approach has not been reported so far. CASE SUMMARY: A 22-year-old right-handed man was transferred to our outpatient clinic because of right shoulder injury during a traffic accident. X-ray examination after admission suggested the fracture of the lower part of the right glenoid and an ipiselial proximal humeral fracture. Three-dimensional (3D) computed tomography (CT) further suggested that the size of the fracture block of the lower part of the right glenoid was 3.4 mm × 16.2 mm. The patient was diagnosed as the fracture of the lower part of the glenoid, also known as bony Bankart lesion without shoulder dislocation. After general anesthesia, the patient was surgically treated with the open reduction internal fixation through a novel axillary approach. 3D CT and shoulder joint function were reexamined at 12 mo of follow-up, showing acceptable recovery. CONCLUSION: This case report describes a novel axillary approach adopted in an open reduction with cannulated screw and wire anchor internal fixation. After a follow-up for more than 12 mo, 3D CT and shoulder joint function examinations display a good recovery.

Performance Evaluation of Antiphospholipid Antibodies on INOVA Quanta Flash System.

BACKGROUND: The diagnosis of antiphospholipid syndrome (APS) relies predominantly on the laboratory measurement of antiphospholipid antibodies (aPLs). We attempt to verify the analytical performance of anticardiolipin antibodies (aCL) IgA/IgG/IgM and anti-ß2-glycoprotein I antibodies (aß2GPI) IgA/IgG/IgM on a high-throughput automated immunoassay platform. METHODS: Limit of blank (LOB), limit of detection (LOD), imprecision, and linearity were calculated according to the corresponding Clinical and Laboratory Standards Institute (CLSI) guidelines protocols. The biological reference intervals (RIs) were verified in healthy individuals. RESULTS: The LoB of aCL IgA/IgG/IgM and aß2GPI IgA/IgG/IgM were 0.000, 1.200, 0.200, and 0.400, 1.250, 0.100, respectively. The LoD were 0.093, 1.715, 0.337 and 0.547, 2.174, 0.185 CU, respectively. All the within-run CVs and total CVs were less than the criterion at 10%. The linear analysis showed a good correlation between the predictive values and observed values with correlation coefficients greater than 0.99. CONCLUSIONS: The BIO-FLASH automated chemiluminescent analyzer performed well in measuring aPLs.

Ketoplatin in triple-negative breast cancer cells MDA-MB-231: High efficacy and low toxicity, and positive impact on inflammatory microenvironment.

Triple-negative breast cancer (TNBC) shares the molecular features facilitating epithelial-to-mesenchymal transition (EMT), which contributed to tumor invasion and metastasis. A platinum(IV) conjugate ketoplatin deriving from FDA-approved drugs cisplatin and ketoprofen was designed and prepared to enhance antitumor activity and suppress EMT in TNBC via positive impact on inflammatory microenvironment by modulating COX-2 signal. As a prodrug, ketoplatin afforded 50.26-fold higher cytotoxicity than cisplatin against TNBC mesenchymal-stem cell-like MDA-MB-231 cells, partly attributing to its dramatic increase of cellular uptake and DNA damage. More importantly, EMT progress in MDA-MB-231 was markedly restrained by ketoplatin, resulting from the suppression of vimentin and N-cadherin mediated by down-regulated COX-2. Further in vivo investigation exhibited that ketoplatin effectively inhibited tumor growth and reduced systemic toxicity compared to cisplatin. Overall, ketoplatin possessed high antitumor activity and low toxicity against TNBC MDA-MB-231 in vitro and in vivo.

Oxidative Stress Induces Chondrocyte Apoptosis through Caspase-Dependent and Caspase-Independent Mitochondrial Pathways and the Antioxidant Mechanism of Angelica Sinensis Polysaccharide.

INTRODUCTION: Chondrocyte apoptosis is considered one of the pathogenic factors of osteoarthritis (OA), but its importance in the pathogenesis of OA remains unclear. Recent research adds progress to the knowledge that the mitochondrial signaling pathway mediates chondrocyte apoptosis in OA. METHOD: Rat chondrocyte exposed to H2O2 was used as the experimental oxidative stress model. Chondrocyte viability was tested by cell counting kit-8 (CCK-8) assay. Cell apoptosis and ROS were tested by flow cytometry. Contents of malondialdehyde (MDA), catalase (CAT), caspase-3, caspase-9, cytochrome C, superoxide dismutase (SOD)-2, and adenosine triphosphate (ATP) were evaluated by biochemical detection. The expressions of related genes and proteins were assessed by quantitative polymerase chain reaction (qPCR) and western blot. RESULTS: H2O2 provokes oxidative stress and decreases the viability of chondrocyte, which leads to the release of cytochrome C and inhibition of SOD-2 activity. The damage of mitochondrion disturbs the energy metabolism of chondrocyte and eventually induces chondrocyte apoptosis through the mitochondrial pathway. Furthermore, pretreated with anglicasinensis polysaccharide (ASP) or caspase inhibitors increase the expression of Bcl-2 and Bcl-xL but do not work for the expression of Bax and Bad. CONCLUSION: Oxidative stress induces chondrocyte apoptosis through caspase-dependent and caspase-independent mitochondrial pathways. ASP protects chondrocyte from H2O2-induced oxidative stress and subsequent cell injury through its antioxidant effect by inhibiting the caspase pathway.

[Activating Efficiency of Iron-copper Bimetallic Organic Framework MIL-101(Fe,Cu) Toward H2 O2 for Degradation of Dyes].

Practical use of heterogeneous Fenton-like catalysis is inhibited by poor mass transfer and slow conversion of Fe(Ⅲ) to Fe(Ⅱ). In this study, we prepared a novel iron-copper bimetallic organic framework (MIL-101 (Fe,Cu)) using the solvothermal method, and carefully investigated its interfacial characters, catalytic efficacy toward dyes with methylene blue as a model pollutant, and the catalytic activating mechanisms involved in it. The MIL-101(Fe,Cu) exhibited a three-dimensional octahedral shape with a complete crystal structure. The specific BET surface area and average pore size were determined to be as high as 667.2 m2 ·g-1 and 1.9 nm, respectively. These characteristics benefits the exposure of the reactive sites and accelerates mass transfer accordingly. The MIL-101(Fe,Cu)/H2 O2 exhibited promising efficiency toward the degradation of methylene blue in a wide pH range; moreover, at a pH value of 5, the removal efficiency observed was as high as 100% after 20 min of reaction, which was 43.1% and 88.9% higher than that of MIL-101(Fe)/H2 O2 and H2 O2, respectively. Hydroxyl radical ( ·OH) is a dominant active species involved in the degradation of methylene blue using MIL-101(Fe,Cu)/H2 O2 as indicated in radicals quenching experiments. The results of species transformation in Fe and Cu indicated that Cu(Ⅱ) doping provided more active sites, and the Cu(Ⅱ)/Cu(Ⅰ) and Fe(Ⅲ)/Fe(Ⅱ) cycles synergistically facilitated ·OH generation to improve the Fenton-like catalytic efficiency accordingly. The MIL-101(Fe,Cu) as a novel heterogeneous Fenton-like catalyst achieved good performance without any significant pH adjustment and is practically viable for industrial wastewater treatment.

Anticancer Melatplatin Prodrugs: High Effect and Low Toxicity, MT1-ER-Target and Immune Response In Vivo.

Multitargeted therapy could rectify various oncogenic pathways to block tumorigenesis and progression. The combination of endocrine-, immune-, and chemotherapy might exert a highly synergistic effect against certain tumors. Herein, a series of smart Pt(IV) prodrugs 3-6, named Melatplatin, were rationally designed not only to multitarget DNA, MT1, and estrogen receptor (ER) but also to activate immune response. Melatplatin, conjugating first-line chemotherapeutic Pt drugs with human endogenous melatonin (MT), significantly enhanced drug efficacy especially in ER high-expression (ER+) cells, among which 3 presented the most potent cytotoxicity toward ER+ MCF-7 with nanomolar IC50 values 100-fold lower than cisplatin. Melatplatin could bind well to melatonin receptor (MT1) according to molecular docking. Besides, 3 evidently increased intracellular accumulation and DNA damage, upregulated γH2AX and P53, and silenced NF-κB to induce massive apoptosis. Most strikingly, 3 effectively inhibited tumor growth and attenuated systemic toxicity compared to cisplatin in vivo, promoting lymphocyte proliferation in spleen to achieve immune modulation.

[Catalytic Degradation of Rhodamine B by FeOCl Activated Hydrogen Peroxide].

The wide application of traditional Fenton reactions was firmly restricted by the requirement for harsh acid conditions, as well as the inevitable generation of iron slurry. The FeOCl nanosheets, prepared by the chemical vapor transformation method, were used to degrade RhB via activation of H2O2. The FeOCl was characterized by a field emission scanning electron microscope (FE-SEM) and X-Ray Diffractometer (XRD), the results showed that FeOCl exhibited a fine crystal structure and nanosheet-like morphology, which was favorable for exposure of active sites. The results of degradation experiments showed that the RhB was totally removed within 15 min under the conditions of[H2O2]=1.67 mmol·L-1 and[FeOCl]=200 mg·L-1. The initial pH plays a negative role in RhB degradation, and the initial pH increased from 3 to 7 as the RhB removal efficiency decreased from 100% to 84%. Typically, when the initial pH was 9, the RhB degradation sharply decreased to 57.6%. Compared with traditional Fenton reactions, the FeOCl/H2O2 system widened the pH range, which resulted in superior organics removal even under a mild-acidic to medium pH condition. The quenching experiments demonstrated that the·OH was the major reactive oxygen species. Additionally, Electron Paramagnetic Resonance (EPR) results showed that intense DMPO-HO·signals were detected in the FeOCl/H2O2 system, which further demonstrated the important role of·OH in RhB degradation.

[Metabolic Functional Analysis of Dominant Microbial Communities in the Rapid Sand Filters for Drinking Water].

Rapid sand filter (RSF) is widely used in drinking water treatment plants. Rapid filtration is always considered a physicochemical process, but the effect of the microorganisms that attach to the filter media remain inadequately investigated. In order to understand the composition and functional characteristics of microbial communities in RSFs, influent water, effluent water, and filter materials from eleven RSFs in eight Chinese cities were sampled and analyzed. After filtration, dissolved organic carbon (DOC) showed a slight but significant removal due to the growth of heterotrophic microbes. The activity of ammonia-oxidizing microbes and nitrite-oxidizing microbes promoted a significant decrease in ammonia nitrogen (NH4+-N) and a significant increase in nitrate nitrogen (NO3--N) in water. No significant changes in total nitrogen (TN) were observed, indicating that denitrification and anammox were weak in the RSFs. The composition and function of the microbial communities of RSFs were assessed using metagenomic methods. Genera in the top 10% with respect to relative abundance (14 genera in total) were identified as the dominant genera, including the two ammonia-oxidizing bacteria Nitrospira and Nitrosomonas. Functional gene information for the dominant genera was also extracted for analysis. The dominant genera exhibited higher relative abundances of carbohydrate, nitrogen, sulfur, and xenobiotic metabolic pathways. Aeromonas had the highest relative abundance of carbohydrate metabolic genes, and Bradyrhizobium had the highest relative abundance of nitrogen, sulfur, and xenobiotics metabolic genes, indicating that these two genera play an important role in the transformation of substances in drinking water. Finally, the metabolic potential of the dominant genera on xenobiotics was evaluated, and the results showed that Bradyrhizobium, Sphingomonas, Methyloglobulus, Sphingopyxis, and Klebsiella were the key bacterial genera for the removal of micropollutants in RSFs.

Fuplatin: An Efficient and Low-Toxic Dual-Prodrug.

As FDA-approved chemotherapeutic agents, cisplatin, oxaliplatin, and 5-fluorouracil are widely used in clinic but limited by severe side-effects. To ameliorate their respective defects, a series of "dual-prodrug" by linking oxoplatin and 5-FU were designed and synthesized. The assembled compounds 10-17, named Fuplatin, exhibited much higher cytotoxicity against the tested cancer cells while lower cytotoxicity toward the human normal lung cells than free drugs or their combinations. Among them, 14 enhanced cellular accumulation with 62- and 825-fold amount of oxaliplatin and 8 at 9 h, respectively, significantly induced DNA damage and cell apoptosis, and inhibited migration and invasion in HCT-116 cells. Compound 14 arrested the cell cycle at S and G2 phases and up-regulated thymidylate synthase and p53, consistent with the results of the combination, suggesting 14 adopted a collaborative mode of 5-FU and oxaliplatin to kill cancer cells. In vivo, compound 14 showed high antitumor effect and no observable toxicity in NOD/SCID mice bearing HCT-116 tumors.

[Principle and techniques for fluoride pollution control in drinking water]. / 饮用水氟污染控制原理与技术.

Long-term natural geochemical processes result in wide occurrence of fluoride contamination in underground water and fluoride exposure via drinking water for over 500 million people glo-bally. The control of fluoride pollution and fluorosis is one of the most important issues for drinking water safety. In the past several decades, many initiatives failed in defluoridation of water. Better understanding of fluoride occurrence mechanisms in underground water chemistry and the prediction of high-risk areas by geographic information and remote sensing are of crucial importance to minimize fluorosis occurrence. The use of alternative source water or blending should be considered as priority option. Much efforts should be devoted to the fundamental studies on defluoridation reagents and innovative materials, and to the development of highly-efficient, economic, easy-to-handle and stable technologies and integrated instruments. Furthermore, the design, construction, operation, and supervision of defluoridation facilities should be carefully evaluated and strengthened to achieve stable benefits as much as possible.

TNFAIP3 gene rs10499194, rs13207033 polymorphisms decrease the risk of rheumatoid arthritis.

Accumulating evidences suggested that tumor necrosis factor alpha inducible protein 3 (TNFAIP3) gene rs10499194, rs13207033 polymorphisms may be associated with the risk of rheumatoid arthritis (RA). However, these studies yielded contradictory findings. To clarify convincing associations, we conducted a comprehensive meta-analysis by searching in PubMed, Embase, and the China Knowledge Resource Integrated Database. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by using fixed-effect or random-effect models. A total of 13 case-control studies for rs10499194 polymorphism and 6 studies for rs13207033 polymorphism were included. Our data indicated that TNFAIP3 gene rs10499194, rs13207033 polymorphisms were associated with the decreased risk of RA. Stratification analyses of ethnicity indicated rs10499194, rs13207033 polymorphisms decreased the risk of RA among Caucasian populations, but not among Asian populations. In conclusion, this meta-analysis indicates that TNFAIP3 gene rs10499194, rs13207033 polymorphisms decrease the risk of RA, especially among Caucasian populations.

The associations between MDM4 gene polymorphisms and cancer risk.

Considerable studies have investigated the associations between MDM4 gene polymorphisms and cancer risk recently, but with contradictory results. The aim of this meta-analysis was to evaluate the associations between MDM4 gene polymorphisms and cancer risk. Relevant studies were identified by a systematic search of PubMed, Embase, and CNKI databases. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe the strength of the associations. Fifty-six studies published in 11 publications involving 18,910 cases and 51,609 controls were included in this meta-analysis. Five MDM4 gene polymorphisms were evaluated: rs4245739, rs1563828, rs11801299, rs10900598, and rs1380576. Our analyses suggested that the rs4245739 polymorphism was significantly associated with overall cancer risk. Furthermore, stratification analyses of ethnicity indicated that rs4245739 decreased the risk of cancer among the Asian population, and stratification analyses of smoking status indicated that rs4245739 decreased the risk of cancer among nonsmokers. However, stratification analyses of cancer type and sex suggested that rs4245739 was not related to cancer risk. There were no associations of rs1563828, rs11801299, rs10900598, or rs1380576 with overall cancer risk. In conclusion, our analyses indicated that rs4245739 polymorphism in the MDM4 gene may play an important role in the etiology of cancer.

Association of IL12B Gene Polymorphisms with Rheumatoid Arthritis: A Meta-analysis.

BACKGROUND AND AIMS: Currently published papers regarding the relationship between interleukin (IL)-12B gene polymorphisms and rheumatoid arthritis (RA) are contradictory. The aim of this meta-analysis was to evaluate the associations between the IL-12B gene polymorphisms (rs3122227 and rs6887695) and RA risk. METHODS: We searched PubMed, Embase, the Cochrane Library and the China Knowledge Resource Integrated Database. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess associations between IL12B gene polymorphisms and RA. RESULTS: A total of eight publications (4,409 cases and 5,591 controls) were included in this meta-analysis. The results demonstrated that rs3122227 and rs6887695 were not associated with RA risk based on current included studies. However, stratification analyses indicated rs6887695 was associated with RA in Asian patients. Rs3122227 was not related with RA in Asian or Caucasian patients. CONCLUSIONS: Our data indicated that IL-12B gene polymorphisms were not related with RA. However, rs6887695 was associated with RA in Asian patients. Further larger-scale studies are urgently needed to identify the association between IL-12B gene polymorphisms and RA in Asian populations.

Is It Time to Phase Out the Austin Moore Hemiarthroplasty? A Propensity Score Matched Case Control Comparison versus Cemented Hemiarthroplasty.

We compared the Austin Moore hemiarthroplasty versus cemented hemiarthroplasties using a propensity score matched cased control study. For a consecutive cohort of 450 patients with displaced intracapsular neck of femur fractures, 128 matched cases in each group were selected based on age, gender, walking status, nursing home residency, delays in surgery, ASA score, and the Charlson comorbidity score. At a mean follow-up of 16.3 months, we evaluated their outcomes. Significantly more patients with AMA experienced thigh pain (RR = 3.5, 95% CI: 1.67-7.33, p = 0.000), overall complications (RR = 4.47, 95% CI: 1.77-11.3, p = 0.000), and implant loosening (RR = 8.42, 95% CI: 2.63-26.95, p = 0.000). There were no definite cement related deaths in this series. There was no significant difference in mortality, walking status, and the number of revisions between the groups. We support the routine use of cemented hemiarthroplasty instead of the Austin Moore for treating elderlies with displaced intracapsular neck of femur fractures.

Re: "PICALM Gene rs3851179 Polymorphism Contributes to Alzheimer's Disease in an Asian Population".

Liu et al. have carried out a meta-analysis of case-control studies to investigate the association between PICALM gene rs3851179 polymorphism and Alzheimer's disease in an Asian population. However, several important issues should be noted.

[Characterization of manganese oxidation by Pseudomonas sp. QJX-1].

A manganese-oxidizing bacteria (QJX-1) was isolated from the soil of a manganese mine. It was identified as Pseudomonas sp. QJX-1 by 16S rDNA sequencing. Experimental results showed that the Pseudomonas sp. QJX-1 has a multi-copper oxidase gene CumA, which is an essential component for manganese oxidation by Pseudomonas sp. Under the condition of low initial inoculum level (D600, 0.020), 5.05 mg x L(-1 Mn2+ could be oxidized by QJX-1 within 48 h with a conversion rate of as high as 99.4%. In comparison with the eutrophic conditions, the oligotrophic condition dramatically increased the biological manganese oxidation rate. Biofilm formation by employing the quartz sand could further improve the oxidation rate of Mn2+. Based on these results, it is speculated that biological manganese oxidation in underground water treatment is comparatively high.