Insight into the reactions of antimonite with manganese oxides: Synergistic effects of Mn(III) and oxygen vacancies.

Manganese oxides (MnxOy) are critical for determining the environmental behaviors and fate of antimonite (Sb(III)). However, little is known about the qualitative/quantitative connection between MnxOy structures and Sb(III) fate. Herein, the reactions of Sb(III) and six MnxOy with different structures were systematically investigated. The initial oxidation rates of Sb(III) (rinit) on six MnxOy decreased in the order of γ-MnO2>δ-MnO2>α-MnO2>γ-MnOOH>Mn3O4>ß-MnO2 (pHinitial=7.0), from 0.32 ± 0.04 to 11.17 ± 1.61 mmol/min/mol-Mn. The amounts of antimony retained (i.e., the sum of Sb(III) and antimonate (Sb(V))) on these MnxOy followed the same trend as that of oxidation. Oxidation of Sb(III) released Mn(II) and created more sites for adsorption. Outwardly, MnxOy with higher reduction potential (E0) and specific surface area (SSA) favored faster Sb(III) oxidation. Inwardly, Mn(III) and oxygen vacancies (Ov) exhibited a synergistic effect on Sb(III) oxidation. Mn(III) can easier accept electron than Mn(IV) based on the change in Gibbs free energy calculation. Ov can adsorb free oxygen to form surface oxygen (Osur) which is much more reactive than lattice oxygen (Olatt). Moreover, Ov is in close proximity to Mn(III) in high-valent MnxOy which facilitated the reactions between Sb(III) and Mn(III) through the enhancement of Sb(III) adsorption and electron transfer. Ov in low-valent MnxOy is adjacent to Mn(II), thus it showed weaker enhancement than that in high-valent MnxOy. Part of δ-MnO2 and almost all Mn3O4 were converted to γ-MnOOH during their reaction with Sb(III), while the other four MnxOy were barely changed. The results obtained provide mechanistic insight into the reactions occurring within Sb(III) and MnxOy, which are helpful for better understanding and prediction of the fate of Sb(III) in Mn-rich environments.

The role of organic and inorganic substituents of roxarsone determines its binding behavior and mechanisms onto nano-ferrihydrite colloidal particles.

The retention and fate of Roxarsone (ROX) onto typical reactive soil minerals were crucial for evaluating its potential environmental risk. However, the behavior and molecular-level reaction mechanism of ROX and its substituents with iron (hydr)oxides remains unclear. Herein, the binding behavior of ROX on ferrihydrite (Fh) was investigated through batch experiments and in-situ ATR-FTIR techniques. Our results demonstrated that Fh is an effective geo-sorbent for the retention of ROX. The pseudo-second-order kinetic and the Langmuir model successfully described the sorption process. The driving force for the binding of ROX on Fh was ascribed to the chemical adsorption, and the rate-limiting step is simultaneously dominated by intraparticle and film diffusion. Isotherms results revealed that the sorption of ROX onto Fh appeared in uniformly distributed monolayer adsorption sites. The two-dimensional correlation spectroscopy and XPS results implied that the nitro, hydroxyl, and arsenate moiety of ROX molecules have participated in binding ROX onto Fh, signifying that the predominated mechanisms were attributed to the hydrogen bonding and surface complexation. Our results can help to better understand the ROX-mineral interactions at the molecular level and lay the foundation for exploring the degradation, transformation, and remediation technologies of ROX and structural analog pollutants in the environment.

Nano-ferrihydrite colloidal particles mediated interfacial interactions of arsenate and cadmium: Implications for their fate under iron-rich geological settings.

Arsenic (As) and cadmium (Cd) often coexist in paddy soils. Nano-ferrihydrite colloidal particles (NFPs) are ubiquitous at redox active interfaces of the paddy system and are well-known to play a critical role in controlling the solubility and bio-availability of As and Cd. However, the mutual interaction between As and Cd on NFPs remains elusive. Herein, batch experiments and in-situ spectroscopic techniques were used to investigate the effects of the interaction pattern (sequential reaction) of Cd(II) and As(V) on their respective adsorption on the surfaces of NFPs. Two scenarios were designed: Cd(II) pre-saturated NFPs and As(V) pre-saturated NFPs. Adsorption of Cd(II) was increased by 1.67, 4.08, and 5.21 times in As(V)-saturated NFPs, but only by 1.05, 1.11, and 1.15 times for As(V) in Cd(II)-saturated NFPs. Further, we determined the pH-dependent mutually beneficial cooperation pathways as mediated by the surface of NFPs. At lower pH (5), As(V) tended to promote Cd(II) adsorption, whereas Cd(II) tended to enhance As(V) adsorption at higher pH (> 5.5). X-ray photoelectron spectroscopy (XPS) indicated that both pre-saturated Cd(II) and As(V) altered the local coordination environment of their counterpart ions. Furthermore, results from in-situ attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR) and second derivative peak shape fitting revealed two types of ternary surface complexes, namely Cd(II)-bridged and As(V)-bridged complexes, which were responsible for the distinct Cd(II) and As(V) co-adsorption behavior on the surface of NFPs under different conditions. These findings help us understand how co-presence Cd and As behave in an iron-rich geological setting and will aid in the development of related restoration technologies.

Efficient removal of pefloxacin from aqueous solution by acid-alkali modified sludge-based biochar: adsorption kinetics, isotherm, thermodynamics, and mechanism.

In this paper, one kind of acid-alkali modified sludge-based biochar (ASBC) was synthesized, characterized, and employed as adsorbent for the removal of pefloxacin. The characterization results showed that the specific surface area (SSA) of ASBC (53.381 m2/g) was significantly higher than that of SBC (24.411 m2/g). ASBC had a rougher surface, larger particle distribution, lower zero point charge, and richer functional groups (e.g., C-O and O-H) than SBC. The adsorption capacity of ASBC was 1.82 times than that of SBC. After 8 adsorption cycles in reuse experiment, the adsorption capacity of ASBC for pefloxacin still reached 144.08 mg/L, indicating that ASBC has good reusability. Static experiments showed that the optimal pH value was 6.0 in the adsorption of pefloxacin on SBC and ASBC. The result of adsorption kinetics indicated that the pseudo-second-order model could describe well the adsorption process. The Freundlich model was better than the Langmuir model to describe the adsorption of pefloxacin by ASBC, indicating that the adsorption process was mainly multilayer adsorption. Thermodynamic result showed that the adsorption of pefloxacin by ASBC was spontaneous and endothermic. The removal mechanism of pefloxacin by ASBC is mainly the substitution reaction and π-π EDA interaction. In summary, acid-alkali modified biochar is an effective adsorbent for pefloxacin in aqueous solution, and has great application prospects.

Simultaneous removal of iron and manganese from acid mine drainage by acclimated bacteria.

A bacterial consortium for efficient decontamination of high-concentration Fe-Mn acid mine drainage (AMD) was successfully isolated. The removal efficiencies of Fe and Mn were effective, reaching 99.8 % and 98.6 %, respectively. High-throughput sequencing of the 16S rRNA genes demonstrated that the microbial community had changed substantially during the treatment. The Fe-Mn oxidizing bacteria Flavobacterium, Brevundimonas, Stenotrophomonas and Thermomonas became dominant genera, suggesting that they might play vital roles in Fe and Mn removal. Moreover, the pH of culture increased obviously after incubation, which was benefit for depositing Fe and Mn from AMD. The specific surface area of the biogenic Fe-Mn oxides was 108-121 m2/g, and the surface contained reactive oxygen functional groups (-OH and -COOH), which also improved Fe and Mn removal efficiency. Thus, this study provides an alternative method to treat AMD containing high concentrations of Fe and Mn.

Simultaneous adsorption and oxidation of antimonite onto nano zero-valent iron sludge-based biochar: Indispensable role of reactive oxygen species and redox-active moieties.

The nano zero-valent iron sludge-based biochar (nZVI-SBC) was prepared in this study to eliminate Sb(III) from aqueous solutions, which was characterized by BET, SEM, XRD, TEM, FTIR, XPS. Our results proved that the incorporated nZVI on SBC matrix could significantly enhance eliminating Sb(III), and the max-adsorption capacity (160.40 mg g-1) can be achieved at pH = 4.8 ± 0.2 and temperature of 298 K. The effect of co-existing anions and natural organic matters on the Sb(III) adsorption efficiencies were systematically investigated. The surface complexation is the possible adsorption mechanisms by FTIR and XPS. Furthermore, mechanistic investigation revealed that •OH and hydroquinone radical (H-SQ•-) could be the primary oxidants for the transformation of Sb(III) under oxic conditions, while 9,10-phenanthrene quinone radical (P-SQ•-) were responsible under anoxic conditions. Thus, the enhanced elimination of Sb(III) from aqueous solution was ascribed to the combined adsorption and oxidation. The potential engineering application of nZVI-SBC can be proved through three actual water matrix experiments, including lake water, river water and acid mine drainage. Our present findings proved that nZVI-SBC could be a potential adsorbent, given the excellent performance in the adsorption processes, as well as the toxicity alleviating ability and economic advantages, especially under sub-surface water.

Mechanistic insights into the enhanced removal of roxsarsone and its metabolites by a sludge-based, biochar supported zerovalent iron nanocomposite: Adsorption and redox transformation.

Roxarsone is a phenyl-substituted arsonic acid comprising both arsenate and benzene rings. Few adsorbents are designed for the effective capture of both the organic and inorganic moieties of ROX molecules. Herein, nano zerovalent iron (nZVI) particles were incorporated on the surface of sludge-based biochar (SBC) to fabricate a dual-affinity sorbent that attracts both the arsenate and benzene rings of ROX. The incorporation of nZVI particles significantly increased the binding affinity and sorption capacity for ROX molecules compared to pristine SBC and pure nZVI. The enhanced elimination of ROX molecules was ascribed to synergetic adsorption and degradation reactions, through π-π* electron donor/acceptor interactions, H-bonding, and As-O-Fe coordination. Among these, the predominate adsorption force was As-O-Fe coordination. During the sorption process, some ROX molecules were decomposed into inorganic arsenic and organic metabolites by the reactive oxygen species (ROS) generated during the early stages of the reaction. The degradation pathways of ROX were proposed according to the oxidation intermediates. This work provides a theoretical and experimental basis for the design of adsorbents according to the structure of the target pollutant.

Elevated expression of interleukin-33 in myasthenia gravis patients.

Myasthenia gravis (MG) is an archetypal autoimmune disorder of the neuromuscular junction. The imbalance of inflammatory cytokines are involved in the pathogenesis of MG. IL-33, a member of the IL-1 family, plays a key immune-modulation role in several autoimmune disease. However, its regulatory role in MG remains unclear. Here, we demonstrated that IL-33 expression in the serum of MG patients was significantly increased. We further proved that the serum levels of IL-33 were significantly negative correlated with the expression levels of TSLP. Increased serum IL-33 levels positively correlated with the upregulation of IL-17A levels and the quantitative myasthenia gravis (QMG) score in MG patients. Our findings indicate that IL-33 plays a potent immuno- enhancing role in the pathogenesis of MG by downregulating TSLP, consequently affecting the development of Th17 cells in MG.

Mitigating arsenic accumulation in rice (Oryza sativa L.) from typical arsenic contaminated paddy soil of southern China using nanostructured α-MnO2: Pot experiment and field application.

Manganese oxides are naturally occurring powerful oxidants and scavengers, which can control the mobility and bioavailability of arsenic (As). However, the effect of synthetic nanostructured manganese oxides on the mobilization and transportation of As at actual paddy soils are poorly understood, especially in soils with low or medium background Mn concentration. In the present study, a novel nano manganese oxide with superior reactivity and surface area has been synthesized. A 90-d soil incubation experiment combined with pot and field rice cultivation trials were designed to evaluate the effectiveness of exogenous α-MnO2 nanorods on the mobilization and transportation of As in soil-rice systems. Our results proved that the addition of α-MnO2 nanorods can effectively control the soil-to-solution partitioning of As under anaerobic conditions. After treatment with different amounts of α-MnO2 nanorods, the content of effective As decreased, offset by an increase in residual As and insoluble binding As (Ca-As and Fe-As). Enhancing the oxidation of As(III) into As(V), the α-MnO2 nanorods increased the adsorption of As onto indigenous iron (hydr)oxides which greatly reduced the soil porewater As content. In addition, pot experiments and field applications revealed that the influx of As into the aerial parts of rice plants (stems, husk and leaves) was strictly prohibited after treatments with different amount of α-MnO2 nanorods; more interestingly, significantly negative correlations have been observed between As and Mn in rice, which indicated that as Mn is increased in soil, As in brown rice decreases. Our results demonstrated that the use of α-MnO2 nanorods in As polluted paddy soil containing low levels of background Mn oxides can be a promising remediation strategy.

Biochar-based functional materials in the purification of agricultural wastewater: Fabrication, application and future research needs.

Nowadays, agricultural contamination is becoming more and more serious due to the rapid growth of agricultural industry, which discharged antibiotics, pesticides or toxic metals into farmlands. A large number of researchers have applied biochar-based functional materials to the treatment of agricultural wastewater contamination. Meanwhile, biochar has also proved to be a very promising and effective technology in water purification field due to its various beneficial properties (e.g., cost effective, high specific surface area, and surface reactive groups). The focus of this review is to highlight the fabrication methods and application of biochar-based functional materials with the removal of different agricultural contaminants, and discuss the underlying mechanisms. However, the application of biochar-based functional materials is currently under its infancy, with the main hindrance is identified as the gap between laboratory scale and field application, immaturity of engineered biochar production technologies, and lack of quality standards. In order to fill these knowledge gaps, more efforts should be made to pay for the relevant research in future studies.

Enhanced flocculation and sedimentation of trace cadmium from irrigation water using phosphoric fertilizer.

Suspended substrate (SS) in natural waters controls the interaction, transportation, and biological effects of heavy metals in water bodies. The large amount of cadmium (Cd) carried by SS is an important source of Cd pollution in irrigation water. In this study, a novel procedure to remove trace Cd coexisting with SS from irrigation water by fertilizer flocculation was investigated. Four common fertilizers (K2HPO4, (NH4)2HPO4, KH2PO4, and K2SO4) were used as flocculants. Batch experiments with various fertilizers revealed that the removal efficiency followed the order: K2HPO4>(NH4)2HPO4>KH2PO4>K2SO4. When levels of K2HPO4 higher than 0.75g/L were applied, the total Cd decreased from 20 to 3.8µg/L after 12h of flocculation, i.e., the removal efficiency reached 80%. The mechanism analysis(Zeta potential, multi-element analysis) results demonstrated that the aggregation of SS and its sedimentation by K2HPO4 were due to the combined effect of the oxidation of Fe2+ to Fe3+ and cation binding behavior towards SS, as a result of charge neutralization and electric double layer compression. This method of Cd removal from irrigation water is simple and has the potential to be applied in agricultural production.

Long-term efficacy and side effects of low-dose tacrolimus for the treatment of Myasthenia Gravis.

The study evaluated the efficacy of low-dose tacrolimus for treating Myasthenia Gravis (MG). Data were collected from 97 patients treated with low-dose tacrolimus from February 2011 to April 2015. Metabolic analysis was performed to determine more accurate tacrolimus dosing and patients were followed-up within clinic every 6 months for up to 4 years. The myasthenia gravis-specific activities of daily living scale was used to assess MG symptoms and their effects on patients' daily activities. All side effects and adverse reactions were thoroughly documented. At the end of follow-up, 6 patients were in complete stable remission, 17 patients were in pharmacological remission, 26 patients were in minimal manifestation status, 32 patients were improved, 2 patients were unchanged, 11 patients had worsening symptoms, and 3 patients died. Side effects were reported and/or observed in 24 patients, of which 7 patients experienced elevated blood glucose, 2 patients developed neoplasms, 3 patients developed gastrointestinal symptoms, 3 showed mild increases in aminotransferases, 3 patients suffered from bone marrow suppression, 2 patients suffered from skin rashes and erythema, and 1 patient required discontinuation of therapy. Transient renal insufficiency was also observed in 1 patient and 3 other patients had minor miscellaneous side effects. This study adds some knowledge on the efficacy and side effects of low-dose tacrolimus in the treatment of MG. Tacrolimus immunotherapy is a valid option for the management of MG, and can be gradually reduced in dose once symptoms are improved until complete withdrawal is achieved.

Aberrant decrease of microRNA19b regulates TSLP expression and contributes to Th17 cells development in myasthenia gravis related thymomas.

Myasthenia gravis (MG) is an organ-specific autoimmune disease. The imbalance of T helper type 17 cells (Th17) plays a key role in the pathogenesis of thymomatous MG. But the regulatory mechanism for Th17 cell development in MG-related thymoma remains undefined. Here we demonstrated that thymic stromal lymphopoietin (TSLP) is significantly decreased in thymomas. We also proved that TSLP was post-trancriptionally regulated by microRNA-19b. The expression of microRNA-19b was negatively correlated with the expression of TSLP mRNA and protein in thymomas. This study indicated that the elevation of microRNA-19b suppressed TSLP expression and then influenced T cell development in thymomatous MG.

[The clinical outcomes of thymectomy combined with radiotherapy or cyclophosphamide treatment for myasthenia gravis patients with thymoma].

OBJECTIVE: To evaluate the therapeutic effects of thymectomy in myasthenia gravis (MG) patients with thymoma. METHODS: A total of 178 MG patients with thymectomy between July 2008 and December 2010 were included. All the subjects were received either cyclophosphamide alone or in combination with radiotherapeutic treatment after surgery. The MG absolute and relative clinical scores were used to assess the effectiveness of long-term treatments. Clinical evaluations were conducted before, and at 1 , 6, 12 and 24 months after operation. A comparative analysis on the inter-relationships among MG clinical presentation, WHO histology and Masaoka stage was also conducted. RESULTS: (1) Of the 178 thymoma-patients, 103 were male and 75 were female, with a mean age of (43.7 +/- 12.5)-years old. One hundred and twelve cases were taken cyclophosphamide, and 58 cases with invasive thymoma (stages II , III and IV or WHO type B3 ) were taken cyclophosphamide in combination with radiotherapy. Five patients refused cyclophosphamide or radiotherapy and 3 did not finish treatment. (2) The muscular strength improved obviously in 32.8% (58/177) of the patients after 1 month after thymectomy, and 59.8% (101/169), 69.7% (115/165) and 81.5% (132/162) after 6 months, 1 year and 2 years, respectively with MG score for disease severity decreased significantly with time. (3) No significant differences of the improvement rates were observed in patients within different WHO histology category. However, the rates were much higher in patients with Masaoka stage I (91.4%) and stage I (89.8%) than those in patients with stage III (45.5%) and IV (28.6%) (all P < 0.001) . CONCLUSIONS: The remission rate of MG patients with thymomas increase after thymectomy plus cyclophosphamide or in combination with radiotherapy and reached 81.5% after 2 years. The remission rate is associated with Masaoka stage, but not with WHO histology.

[The clinical efficacy and safety of tacrolimus in patients with myasthenia gravis].

OBJECTIVE: To evaluate the efficacy and safety of tacrolimus in patients with generalized myasthenia gravis (MG). METHODS: A total of 69 cases admitted to our hospital were given 2-6 mg/day tacrolimus (FK506) for 12 months. The MG absolute and relative clinical scores were used to monitor the efficacy of tacrolimus. Clinical evaluation was conducted at month 1, 3, 6, and 12, while the serum concentration of FK506 was measured at one month after administration of tacrolimus for one month. RESULTS: The therapeutic response presenting as improved muscular strength showed within one month after administration of tacrolimus. The overall response rates (MG relative clinical score ≥ 25%) at month 1, 3, 6 were 81.2%, 87.6%, 92.2% respectively. It reached 93.8% by the final visit at month 12. MG score to evaluate disease severity decreased significantly as the subjects continued to take tacrolimus. Statistic analysis suggested that the serum concentration of FK506 was correlated with its therapeutic effect. Serum trough levels in remission and response groups [(7.1 ± 3.9) µg/L and (6.3 ± 3.8) µg/L, respectively] were significantly higher than that of no response group [(3.4 ± 1.3) µg/L]. The most common adverse effects included hyperglycemia (5 cases), myelosuppression (3 cases), and dizziness tinnitus (3 cases), majority of which were temporary and manageable. CONCLUSIONS: Our study has shown that tacrolimus significantly improved muscular strength of generalized MG patients. The treatment is well tolerated. The therapeutic effect of tacrolimus is observed within 1 month after initial use. Adverse events were manageable and not common.

A cohort study on myasthenia gravis patients in China.

Clinical classification and age distribution in myasthenia gravis (MG) cases seem different between Oriental and Caucasian populations, but there have rarely been any clinical studies on MG patients from mainland China. The goal of the current study was to perform a comprehensive survey of myasthenia gravis in a hospital in China, establishing contemporary cohort data and clinical features. 1,108 unselected patients with MG attending the 309th Hospital of PLA, Beijing, China were studied during a 36-month period from July 2008 to June 2011. The sex ratio was 1:1 (F:M). 62.5 % of patients presented as adolescents and adults. Ocular MG cases accounted for 65.6 % childhood MG patients. A positive response was observed in 96.8 % of the patients for neostigmine tests, whereas a positive decremental response to low frequency repetitive nerve stimulation (RNS) was observed in 77.4 % of the patients. The highest stimulating positive rate was 65.3 % in stimulated facial nerve. Thymoma was significantly increased in those patients with severe MG, especially in the cohort involving the respiratory muscles (p < 0.001). The study revealed higher frequency of ocular and childhood MG compared to other studies in USA and European countries, which can be a result of optimum case ascertainment, increased disease duration, or application of complex diagnostic tests. The relative increase in the prevalence of ocular myasthenia can be attributed to the impact of an aging population.

[The clinical characteristics of patients with thymoma-associated myasthenia gravis].

OBJECTIVE: To investigation the clinical characteristics in myasthenia gravis (MG) patients with thymomas. METHODS: A total of 856 MG patients admitted to the department during 2008.7 - 2010.12 were reviewed retrospectively. The patients with MG were divided into two groups based on thymic pathology, which were 162 cases with thymoma and 694 cases without thymoma. We compared the different clinical features including the gender, age of onset, MG symptoms and the incidence rate of myasthenia crisis. And the relationship between the WHO types, Maosaoka stages of thymoma and the severe of MG was also studied. RESULTS: The percentage of thymoma-associated MG patients was 18.9 percent of hospitalized MG patients at the same period. Of the 162 thymoma-associated patients, 94 were male and 68 were female, with a ratio of 1.38:1 and a mean age of (42.9 ± 12.4) years old. Thymoma was more frequent in middle-old aged patients than in children. Compared with non-thymoma MG, more thymomatous patients showed generalised MG, but not only ocular muscles weakness (90.1% vs 62.4%, P < 0.001). There were significant differences of the incidence rate of myasthenic crisis in the two groups (14.8% vs 2.3%). (2) WHO type B2 and Maosaoka I, II thymoma were the commonest types among all potentially MG-associated thymoma. No differences of Osserman MG classification was found in thymomatous patients with different pathologic changes. CONCLUSIONS: The thymomatous MG patients had its distinctive clinical features: thymomas occurred in about 19.7% of MG patients with more men than women, more common in generalized, higher incidence of myasthenia crisis, with B2 type thymic pathology and Maosaoka I, II stages. No correlation was found between pathologic and clinical stages.

[Thymoma T helper type 17 cells and related cytokines in myasthenia gravis].

OBJECTIVE: To investigate the immunoregulatory role of Th17 cell and the related cytokines in myasthenia gravis. METHODS: Totally 51 myasthenia gravis (MG) patients were divided into MG with thymomas (TM group) and the MG with normal thymus (NT group), as well as 22 healthy subjects as controls. Th17 cells from peripheral blood mononuclear cells were measured by flow cytometry. Th17 related cytokines were detected by ELISA and real-time quantitative-PCR. RESULTS: The quantity of Th17 cells in MG patients with thymomas (1.53 ± 0.59)% were significantly increased compared with that of healthy control (0.94% ± 0.32%, P < 0.05). There was no significant difference in the number of Th17 cells between healthy controls and NT group. The expression levels of IL-17 mRNA (23.7 ± 4.5) were up-regulated significantly versus those in healthy controls (13.4 ± 3.2, P < 0.01). The levels of mRNA expression of IL-1ß, IL-6 and IL-23 were up-regulated significantly in TM group. The mean concentration of IL-17 was up-regulated significantly in TM group (30.4 ± 7.3) ng/L versus healthy controls [(19.2 ± 4.9) ng/L, P < 0.05]. Serum levels of IL-23 and IL-1ß were always increased in TM group versus healthy controls. CONCLUSION: The elevated levels of IL-17 and other Th17 related cytokines in thymomas may aggravate the autoimmunity disorder.

Three cases of myasthenia gravis from one family with variations in clinical features and serum antibodies.

Myasthenia gravis, an autoimmune disorder affecting neuromuscular transmission, is mainly sporadic while familial cases are very rare. Usually familial myasthenia gravis cases have uniform clinical symptoms as well as serum anti-acetylcholine receptor antibodies. Interestingly, in our cases varying clinical types of myasthenia gravis and seropositive/seronegative anti-acetylcholine receptor antibodies coexisted in the same family. The mother and her daughter both had ocular myasthenia gravis, detectable anti-acetylcholine receptor antibodies and non-detectable anti-muscle-specific kinase antibodies, and good responses to medications. The son displayed ocular symptoms at the onset, and then progressed into a generalized form after 1 year. His serum anti-acetylcholine receptor antibodies and anti-muscle-specific kinase antibodies were both negative. Neither corticosteroids nor thymectomy alleviated his symptoms. Human leukocyte antigen DQA1*0301 allele sharing by the three patients may be involved in their genetic susceptibility to myasthenia gravis, and subtle differences in human leukocyte antigen DQB1 alleles may be associated with their variations in clinical features and serum antibodies.

Effect of automatic versus fixed continuous positive airway pressure for the treatment of obstructive sleep apnea: an up-to-date meta-analysis.

PURPOSE: This study was made to evaluate the effect of automatic continuous positive airway pressure (auto-CPAP) versus fixed continuous positive airway pressure (fixed CPAP) in reducing the apnea-hypopnea index (AHI) and the mean therapy pressure, improving subjective sleepiness, sleep architecture, patient compliance, and preference in patients with obstructive sleep apnea. METHODS: We searched the electronic databases MEDLINE, EMBASE, the Cochrane Library, and Google Scholar. Randomized controlled trials comparing auto-CPAP with fixed CPAP were reviewed. Continuous variables were presented as mean difference (MD), and dichotomous data as odds ratio (OR), both with 95% confidence intervals (CI). RESULTS: We identified 19 studies consisting of 845 patients. Compared to fixed CPAP, the use of auto-CPAP reduced mean therapy pressure (MD -1.64; 95% CI -2.46 to -0.82), improved patient compliance (MD 0.23; 95% CI 0.06 to 0.39), increased the percentage of total sleep time (TST) in slow wave sleep (MD 5.11; 95% CI 1.34 to 8.88), and decreased the percentage of TST in stage 2 sleep (MD -4.75; 95% CI -9.38 to -0.11). Moreover, more patients preferred auto-CPAP therapy (OR 3.65; 95% CI 1.27 to 10.53). There were nonsignificant trends towards better outcomes with auto-CPAP for AHI and Epworth Sleepiness Scale (MD -0.43; 95% CI -1.10 to 0.23, and MD -0.24; 95% CI -0.74 to 0.25, respectively), though these are of questionable clinical significance. CONCLUSIONS: There are some aspects of clinical care, such as a mild improvement in compliance, patient preference, and sleep architecture that appear to favor the use of auto-CPAP compared to fixed CPAP. The clinical relevance of these findings requires further study.