[Investigation of the immune profile of multiple myeloma patients achieving long-term survival after autologous stem cell transplantation]

Objective: To identify the characteristics of the bone marrow immune microenvironment associated with long-term survival in multiple myeloma (MM) patients. Methods: In the follow-up cohort of patients with newly diagnosed MM and who received "novel agent induction therapy and subsequent autologous stem cell transplantation and immunomodulator maintenance therapy" in the First Affiliated Hospital of Sun Yat-sen University, a cross-sectional study was carried out between August 2019 and May 2020. Using NanoString technology, the RNA expression of 770 bone marrow immune-related markers was compared between 16 patients who had progression-free survival ≥5 years and 5 patients with progressive disease. Among the 16 patients who achieved long-term survival, 9 achieved persistent minimal residual disease (MRD) negative while the other 7 had persistent positive MRD. The functional scores of each kind of immune cells were calculated based on the expression level of characteristic genes, so as to indirectly obtained the proportion of each immune cell subset. The Mann-Whitney U test and the Kruskal Wallis test were used for statistical analysis. Results: The proportion of neutrophils was significantly higher in long-surviving MM patients than in patients with progressive disease [functional scores, 13.61 (13.33, 14.25) vs. 12.93 (12.58, 13.38); Z=2.31, P=0.021]. Among long-surviving patients, those who were MRD-positive had a significantly greater number of mast cells compared with those who were MRD-negative [functional scores, 7.09 (6.49, 8.57) vs. 6.03 (5.18, 6.69); H=2.18, P=0.029]. Compared with patients with progressive disease, four genes (CTSG, IFIT2, S100B, and CHIT1) were significantly downregulated and six (C4B, TNFRSF17, CD70, IRF4, C2, and GAGE1) were upregulated in long-surviving patients. Among long-surviving patients, only gene CMA1 was significantly upgraded, 10 genes (ISG15, OAS3, MX1, IFIT2, DDX58, SIGLEC1, CXCL10, IL1RN, SERPING and TNFSF10) were significantly downregulated in the MRD-positive group compared with that in the MRD-negative group, the first 5 of which are related to the interferon response pathway. Conclusions: The increased neutrophil and mast cell numbers may be related to long-term survival in MM. Interferon signaling activation may be a key bone marrow immune profiling feature for MRD-negative, long-surviving patients with MM.

[Clinical application of split liver transplantation: a single center report of 203 cases]

Objective: To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application. Methods: This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis. Results: The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group (χ2=5.560,P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group (χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion: SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

Development of the Static and Dynamic Gene Expression Regulation Toolkit in Pseudomonas chlororaphis

The advancement of metabolic engineering and synthetic biology has promoted in-depth research on the nonmodel microbial metabolism, and the potential of nonmodel organisms in industrial biotechnology is becoming increasingly evident. The nonmodel organism Pseudomonas chlororaphis is a safe plant growth promoting bacterium for the production of phenazine compounds; however, its application is seriously hindered due to the lack of an effective gene expression precise regulation toolkit. In this study, we constructed a library of 108 promoter-5'-UTR (PUTR) and characterized them through fluorescent protein detection. Then, 6 PUTRs with stable low, intermediate, and high intensities were further characterized by report genes lacZ encoding β-galactosidase from Escherichia coli K12 and phzO encoding PCA monooxygenase from P. chlororaphis GP72 and thus developed as a static gene expression regulation system. Furthermore, the stable and high-intensity expressed PMOK_RS0128085UTR was fused with the LacO operator to construct an IPTG-induced plasmid, and a self-induced plasmid was constructed employing the high-intensity PMOK_RS0116635UTR regulated by cell density, resulting in a dynamic gene expression regulation system. In summary, this study established two sets of static and dynamic regulatory systems for P. chlororaphis, providing an effective toolkit for fine-tuning gene expression and reprograming the metabolism flux.

[Prognostic value of the Second Revision of the International Staging System in patients with newly diagnosed transplant-eligible multiple myeloma]

Objective: To verify the predictive value of the Second Revision of the International Staging System (R2-ISS) in newly diagnosed patients with multiple myeloma (MM) who underwent first-line autologous hematopoietic stem cell transplantation (ASCT) in a new drug era in China. Methods: This multicenter retrospective cohort study enrolled patients with newly diagnosed MM from three centers in China (Beijing Chao-Yang Hospital, Capital Medical University; the First Affiliated Hospital, Sun Yat-Sen University, and the Second Affiliated Hospital of Naval Medical University) from June 2008 to June 2018. A total of 401 newly diagnosed patients with MM who were candidates for ASCT were enrolled in this cohort, all received proteasome inhibitor and/or immunomodulator-based induction chemotherapy followed by ASCT. Baseline and follow-up data were collected. The patients were regrouped using R2-ISS. Progression-free survival (PFS) and overall survival (OS) were analyzed. The Kaplan-Meier method was used to analyze the survival curve and two survival curves were compared using the log-rank test. Cox regression analysis were performed to analyze the relationship between risk factors and survival. Results: The median age of the patients was 53 years (range 25-69 years) and 59.5% (240 cases) were men. Newly diagnosed patients with renal impairment accounted for 11.5% (46 cases). According to Revised-International Staging System (R-ISS), 74 patients (18.5 %) were diagnosed with stage Ⅰ, 259 patients (64.6%) with stage Ⅱ, and 68 patients (17.0%) with stage Ⅲ. According to the R2-ISS, the distribution of patients in each group was as follows: 50 patients (12.5%) in stage Ⅰ, 95 patients (23.7%) in stage Ⅱ, 206 patients (51.4%) in stage Ⅲ, and 50 patients (12.5%) in stage Ⅳ. The median follow-up time was 35.9 months (range, 6-119 months). According to the R2-ISS stage, the median PFS in each group was: 75.3 months for stage Ⅰ; 62.0 months for stage Ⅱ, 39.2 months for stage Ⅲ, and 30.3 months for stage Ⅳ; and the median OS was not reached, 86.6 months, 71.6 months, and 38.5 months, respectively. There were statistically significant differences in PFS and OS between different groups (both P<0.001). Multivariate Cox regression analysis showed that stages Ⅲ and Ⅳ of the R2-ISS were independent prognostic factors for PFS (HR=2.37, 95%CI 1.30-4.30; HR=4.50, 95%CI 2.35-9.01) and OS (HR=4.20, 95%CI 1.50-11.80; HR=9.53, 95%CI 3.21-28.29). Conclusions: The R2-ISS has significant predictive value for PFS and OS for transplant-eligible patients with MM in the new drug era. However, the universality of the R2-ISS still needs to be further verified in different populations.

Evaluation of a Deep-Learning Auto-Segmentation Model of Cardiac Substructures

PURPOSE/OBJECTIVE(S)

Increasing evidence has suggested that limiting dose not only to the whole heart but also to cardiac substructures can potentially reduce cardiac toxicities. Manual contouring of cardiac substructure can be challenging and time-consuming. To address this concern, we developed a deep learning (DL) model, trained on convolutional neural network algorithms in large external datasets, for auto-segmentation of cardiac substructures. This study aimed to evaluate the quality of the cardiac substructure contours generated by the DL algorithm.

MATERIALS/METHODS

We identified 28 patients with esophagus or gastroesophageal junction cancer from a single institution who received radiation to the esophagus between January 2017 and December 2022. For each case, the DL-generated cardiac substructures (4 heart chambers - left/right atrium [L/RA] and L/R ventricle [L/RV], 4 coronary arteries - L common [LCA], L anterior descending [LAD], L circumflex [LCx], and R common [RCA], and great vessels - ascending aorta [AA], pulmonary artery [PA], and superior vena cava [SVC]) were modified by two radiation oncologists (RO) using the contouring atlas developed by Duane et al. Spatial overlapping of the contours were then assessed using the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD-95), and normalized surface dice at 2 mm tolerance (NSD-2).

RESULTS

The mean values of DSC, HD-95, and NSD-2 are shown in Table 1. Overall, the mean DSC, HD-95, and NSD-2 for the heart chambers ranged from 0.82 to 0.92, 0.40 cm to 1.52 cm, and 0.68 to 0.85, respectively. Ranges of the mean DSC, HD-95, and NSD-2 for the coronary vessels were 0.41 to 0.74, 0.18 cm to 0.98 cm, and 0.66 to 0.77, respectively. Lastly, comparison of the great vessel contours yielded the following ranges for mean DSC, HD-95, and NSD-2 respectively: 0.72 to 0.92, 0.30 cm to 1.64 cm, and 0.65 to 0.83.

CONCLUSION

Our study demonstrates that auto-segmentation of cardiac substructures by DL-powered models can be comparable to manual contours for certain cardiac substructures, namely the four heart chambers and great vessels. Further improvement of the DL on contouring of coronary vessels would be needed prior to the autosegmentation model being widely adopted.

Patterns of Care for Patients with Locally Advanced Rectal Cancer Treated with Total Neoadjuvant Therapy between 2016-2020: An NCDB Analysis

PURPOSE/OBJECTIVE(S)

Treatment for locally advanced rectal cancer (LARC), defined as T3/4 or any T with N+ disease, typically requires multi-modality management consisting of radiation (RT), chemotherapy (CHT), and surgery. Despite emerging evidence that total neoadjuvant therapy (TNT) is the preferred treatment of LARC, it remains unknown what proportion of patients are receiving TNT in the United States. Our objective was to (1) determine the proportion of patients with LARC receiving TNT over time, (2) determine the most common method in which TNT is being delivered, and (3) determine what factors are associated with a lower likelihood of receiving TNT in the United States.

MATERIALS/METHODS

Retrospective data was obtained from the National Cancer Database (NCDB) for patients diagnosed with rectal cancer between 2016-2020. Patients were excluded if they had M1 disease, T1-2 N0 disease, incomplete staging information, non-adenocarcinoma histology, received RT to a non-rectum site, or received a non-definitive RT dose. Patients were determined to have received TNT if they (1) received RT and multi-agent (MA)-CHT prior to surgery, (2) had an interval of >180 days from the onset of neoadjuvant therapy to surgery if they received long course (LC)-chemoradiation (CRT) (based on 35 days for LC-CRT + 112 days for 8 cycles of MA-CHT + 30 days to surgery), or (3) had an interval of >150 days from the onset of neoadjuvant therapy to surgery if they received short course (SC)-RT (based on 5 days for SC-RT + 112 days for 8 cycles of MA-CHT + 30 days to surgery). Data were analyzed using linear regression, Chi-square test, and binary logistic regression.

RESULTS

Of the 26,375 patients included, the median age was 60 (range 21-90) years, with the majority of patients being <65 years old (65.6%), male (62.1%), and non-Hispanic white (77.0%). A total of 5,003 (19.0%) patients received TNT, and 21,372 (81.0%) patients received classical combined modality therapy (CMT). The proportion of patients receiving TNT increased significantly over time, from 6.1% in 2016, 9.0% in 2017, 15.3% in 2018, 25.8% in 2019, to 34.6% in 2020 (slope = 7.36, 95% CI 4.58-10.15, R2 = 0.96, p = 0.040). The most common TNT regimen was MA-CHT followed by LC-CRT (73.2% of cases from 2016-2020). The proportion of patients receiving SC-RT as part of TNT significantly increased from 2.8% in 2016, 1.7% in 2017, 4.6% in 2018, 7.3% in 2019, to 13.7% in 2020 (slope = 2.74, 95% CI 0.37-5.11, R2 = 0.82, p = 0.035). On multivariate analysis, factors associated with a lower likelihood of TNT use included age >65 (OR 0.66, 95% CI 0.61-0.71, p<0.001), female gender (OR 0.92, 95% CI 0.86-0.98, p = 0.014), Black race (OR 0.87, 95% CI 0.77-0.98, p = 0.024), and T3 N0 disease (OR 0.60, 95% CI 0.52-0.70, p<0.001).

CONCLUSION

TNT utilization rates have significantly increased in recent years, from 6.1% in 2016 to 34.6% in 2020. The observed trend appears to be in line with the recent National Comprehensive Cancer Network (NCCN) guidelines recommending TNT as the preferred approach.

Dosimetric Evaluation of Cardiac Substructures in Irradiation of Esophagus

PURPOSE/OBJECTIVE(S)

Due to the anatomic proximity of the heart, cardiac toxicity is a major concern in radiation treatment (RT) of esophageal cancer. Historically, the entire heart is considered an organ at risk. However, more recent studies have demonstrated that dose to cardiac substructures may better predict cardiac toxicities. We retrospectively reviewed patients (pts) who had RT to the distal esophagus and evaluated the dose-volume constraints (DVCs) of the cardiac substructures and the whole heart. We hypothesized that the majority of the treatment plans would not meet the DVCs to cardiac substructures noted in the current literature, albeit meeting commonly accepted whole heart DVCs.

MATERIALS/METHODS

We identified 27 pts with esophagus or gastroesophageal junction cancer who received RT to the esophagus between January 2017 and December 2022. For each case, the cardiac substructures (4 heart chambers - left/right atrium [L/RA] and left/right ventricle [L/RV], 4 coronary arteries - left common [LCA], left anterior descending [LAD], left circumflex [LCx], and right common [RCA], and great vessels - ascending and descending aorta [A/DA], pulmonary artery [PA], and superior vena cava [SVC]) were contoured based on the contouring atlas developed by Duane et al. DVCs based on existing literature for the whole heart and each cardiac substructure were reviewed and retrospectively analyzed for each treatment plan (Table 1).

RESULTS

Eighteen (66.7%) pts received 50 Gy/25 fractions, and nine (33.3%) pts received 50.4 Gy/28 fractions. The dose-volume constraints for the whole heart and each cardiac substructure are shown in Table 1. When considering the heart as a whole organ, all the treatment plans met the V45 and V40 objectives, with a mean V45 of 7.1% and V40 of 10.8%. All the cases also met the constraints for RV and PA. However, none of the cases met the DVCs for RA or LV. Only 6 (22.2%) of cases met the constraint for LCx or AA.

CONCLUSION

We found that despite all the treatment plans meeting the whole heart V45 and V40 constraints, none of the cases met the dose constraints to all cardiac substructures. This suggests that dosimetric evaluation of the whole heart alone may not be sufficient in minimizing cardiac toxicities from RT, and thus further supports the importance of defining the cardiac substructures. Future studies will be needed to standardize the dose constraints to these substructures to ensure patient safety.

[Predictive factors for sequelae of bronchitis obliterans in refractory Mycoplasma pneumoniae pneumonia]

Objective: To investigate the predictive factors for bronchitis obliterans in refractory Mycoplasma pneumoniae pneumonia (RMPP). Methods: A restrospective case summary was conducted 230 patients with RMPP admitted to the Department of No.2 Respiratory Medicine of Beijing Children's Hospital, Capital Medical University from January 2013 to June 2017 were recruited. Clinical data, laboratory results, imaging results and follow-up data were collected. Based on bronchoscopy and imaging findings 1 year after discharge, all patients were divided into two groups: one group had sequelae of bronchitis obliterans (sequelae group) and the other group had not bronchitis obliterans (control group), independent sample t-test and nonparametric test were used to compare the differences in clinical features between the two groups. Receiver operating characteristic (ROC) curve to explore the predictive value of Bronchitis Obliterans in RMPP. Results: Among 230 RMPP children, there were 115 males and 115 females, 95 cases had sequelae group, the age of disease onset was (7.1±2.8) years;135 cases had control group, the age of disease onset was (6.8±2.7) years. The duration of fever, C-reative protein (CRP) and lactate dehydrogenase (LDH) levels, the proportion of ≥2/3 lobe consolidation, pleural effusion and the proportion of airway mucus plug and mucosal necrosis were longer or higher in the sequelae group than those in the control group ((17±9) vs. (12±3) d, (193±59) vs. (98±42) mg/L,730 (660, 814) vs. 486 (452, 522) U/L, 89 cases (93.7%) vs. 73 cases (54.1%), 73 cases (76.8%) vs.59 cases (43.7%), 81 cases (85.3%) vs. 20 cases (14.8%), 67 cases (70.5%) vs. 9 cases (6.7%), t=5.76, 13.35, Z=-6.41, χ²=14.64, 25.04, 22.85, 102.78, all P<0.001). Multivariate Logistic regression analysis showed that the duration of fever ≥10 days (OR=1.200, 95%CI 1.014-1.419), CRP levels increased (OR=1.033, 95%CI 1.022-1.044) and LDH levels increased (OR=1.001, 95%CI 1.000-1.003) were the risk factors for sequelae of bronchitis obliterans in RMPP. ROC curve analysis showed that CRP 137 mg/L had a sensitivity of 82.1% and a specificity of 80.1%; LDH 471 U/L had a sensitivity of 62.7% and a specificity of 60.3% for predicting the development of bronchitis obliterans. Conclusions: The long duration of fever (≥10 d), CRP increase (≥137 mg/L) may be used to predict the occurrence of sequelae of bronchitis obliterans in RMPP. It is helpful for early recognition of risk children.

[New agents-based induction chemotherapy followed by autologous stem cell transplantation and maintenance treatment strategy for multiple myeloma: a single center retrospective study of 300 cases]

Objective: To examine the survival and influential factors of an integrated approach of novel agents, autologous hematopoietic stem cell (auto-HSCT) , and maintenance therapy in patients with multiple myeloma (MM) patients from a single center over the past 15 years. Methods: In our center, 300 MM patients who received an integrated strategy of new agents, auto-HSCT, and maintenance therapy over 15 years were retrospectively and prospectively analyzed. Results: The complete remission rates (CR) and ≥very good partial remission rates (VGPR) following induction therapy, transplantation, and maintenance therapy were respectively 35.3% and 55.2% , 72.4% and 80.0% , 89.2% , and 93.4% . When compared to patients receiving double-drug induction, the ≥VGPR and ORR of patients receiving triple-drug induction were improved. No difference existed in CR, ≥VGPR, and ORR between the PAD (bortezomib + liposome doxorubicin+ dexamethasone) and RAD (lenalidomide + liposome doxorubicin + dexamethasone) regimens, but the benefits speed differed. The negative rate of flow minimal residual disease following induction, transplantation, and maintenance was 18.8% (54 cases) , 41.4% (109 cases) , and 58.7% (142 cases) , respectively. The median time to progress (TTP) was 78.7 months and the median overall survival (OS) was 109 months. The median TTP for RISS-Ⅰ-Ⅲ patients were 111.8 months, 77.4 months, and 30.6 months, and the median OS was 118.8 months, 91.4 months, and 48.5 months, respectively. At various points during treatment, the TTP and OS of patients obtaining CR and MRD negative were longer than those of patients who did not obtain CR and MRD negative. TTP was noticeably shorter in high-risk cytogenetic patients compared to standard-risk patients even when CR was acquired during induction. There was no difference in TTP between patients with high-risk cytogenetics and those with standard-risk cytogenetics if MRD negative was acquired during induction. According to a multivariate analysis, the R-ISS stage was a poor predictor of TTP and OS at various treatment intervals. Therapeutic effectiveness was a newly independent prognostic factor following treatment. Conclusion: A median survival of almost 10 years is possible for MM patients who receive an integrated strategy of induction regimens followed by auto-HSCT and maintenance therapy, which significantly improves prognosis. However, this approach did not significantly benefit high-risk cytogenetic MM patients.

[Clinical features of children with post-primary tuberculosis]

Objective: The aim of this study was to summarize the clinical and imaging characteristics of post-primary tuberculosis in children, so as to improve the early identification and diagnosis of post-primary tuberculosis. Methods: This was a retrospective study which enrolled children who were admitted to the Department No.2 of Respiratory Medicine, Beijing Children's Hospital Affiliated to Capital Medical University between January 2015 to December 2020 and with a diagnosis of post-primary tuberculosis. Results: A total of 30 patients were enrolled, including 10 males and 20 females. The age on admission were 13.0 (12.0, 13.3) years. Their common symptoms were cough and fever, there were 26 cases (87%) with cough and 23 cases (77%) with fever, but only 4 cases (13%) had other toxic symptoms (night sweat, weakness or weight loss) of tuberculosis other than fever. Blood examination showed that the white blood cell count was (10±3)×10⁹/L, accompanied by elevated proportion of neutrophils (0.69±0.11) and increased level of C-reactive protein (31 (15,81) mg/L). The common radiographic findings of CT were nodular or mass shadow with cavitation (19 cases (63%)), consolidation (13 cases (43%)), bronchogenic spread (12 cases (40%)), hilar or mediastinal lymphadenopathy (5 cases (17%)) in this cohort. The affected locations included the right upper lobe (21 cases (70%)), the left lower lobe (17 cases (57%)) and the right lower lobe (15 cases (50%)). Acid-fast bacillus smears and mycobacterial cultures were attempted for all cases, resulting in 33% (10/30) with smear positivity and 50% (15/30) with culture positivity. Conclusions: Post-primary tuberculosis in children has no specific clinical manifestations. Imaging of chest CT is mainly manifested as nodular shadow with cavitation, consolidation or bronchogenic spread. Accurate identification of post-primary tuberculosis is crucial for preventing the spread and early treatment of tuberculosis.

[Clinical features and early diagnostic clues of chronic granulomatous disease]

Objective: To explore the early clinical clues for diagnosis of chronic granulomatous disease (CGD). Methods: One hundred and thirty-nine children with CGD seen in Beijing Children's Hospital from January 2007 to October 2020 were included in this study. The clinical features including age of onset, first presentations, reason for being hospitalized, etiology, imaging features, clues for early diagnosis of all patients were evaluated retrospectively. According to the time of diagnosis, the patients were divided into two groups, cases diagnosed before 2015 and after 2015 and 2015. The time of diagnosis, the length of stay and the hospital charges were compared between the two groups. T test and χ² test were used for statistical analyses. Results: One hundred and nineteen of the cases were males and 20 were females. The age of onset was 4 months (8 d to 14 years), and 103 cases (74.1%) had onset before 1 year of age. The age at diagnosis was 1.8 years (21 d to 14.7 years), and the time of diagnosis delay was 1 year (7 d to 13.7 years). One hundred and thirty-five cases (97.1%) had pulmonary infection as the main reason for hospitalization, of whom 76 cases (56.3%) had positive pulmonary etiology. One hundred and thirty-six patients (97.8%) were referred cases, of whom 5 were suspected of CGD before referral, and the misdiagnosis rate was as high as 96.3% (131/136). Eight early clues for diagnosis were found, the frequency from high to low, large bacillus Callmette-Guer scar in 99 cases (70.5%), left axillary lymphadenopathy or calcification in 73 cases (52.5%), skin or other lymph node infections in 58 cases (41.7%), skin scars in 50 cases (36.0%), multiple lung nodules in 42 cases (30.2%), perianal abscess in 35 cases (25.2%), pulmonary Aspergillus infection in 26 cases (18.7%) and pulmonary Burkholderia infection in 15 cases (10.8%). A total of 120 cases of CGD were diagnosed by respiratory burst test during hospitalization, including 55 cases diagnosed before 2015 and 65 cases diagnosed after 2015. After using these 8 early diagnosis clues, the cases diagnosed after 2015 had shorter time of diagnosis and the length of stay and lower hospitalization charge than cases diagnosed before 2014, and the difference was statistically significant ((25±7) vs. (10±5) d, (29±7) vs. (18±6) d, (3.7×10⁴±1.2×10⁴) vs. (3.2×10⁴±1.2×10⁴) Yuan, t=13.763, 9.262, 2.381, all P<0.05). Conclusions: Patients with CGD are younger at onset and the diagnosis is delayed. Pulmonary infections are the most common. Large BCG scar, left axillary lymphadenopathy or calcification, skin or other lymph node infections, skin scars, multiple lung nodules, perianal abscesses, pulmonary Aspergillus infection and Burkholderia infection can help early diagnosis of CGD.

[A multicenter retrospective study on the etiology of necrotizing pneumonia in children]

Objective: To investigate the etiology of necrotizing pneumonia (NP) in children and the clinical characteristics of NP caused by different pathogens in China. Methods: A retrospective, case-control study was performed in children with NP who were admitted to 13 hospitals in China from January 2008 to December 2019. The demographic and clinical information, laboratory data, etiological and radiological findings were analyzed. The data were divided into three groups based on the following years: 2008-2011, 2012-2015 and 2016-2019, and the distribution characteristics of the pathogens in different period were compared. Meanwhile, the pathogens of pediatric NP in the southern and northern China were compared. And the clinical characteristics of the Mycoplasma pneumoniae (MP) NP and the bacterial NP were also compared. T-test or Mann-Whitney nonparametric test was used for comparison of numerical variables, and χ² test was used for categorical variables. Results: A total of 494 children with NP were enrolled, the median ages were 4.7 (0.1-15.3) years, including 272 boys and 222 girls. Among these patients, pathogens were identified in 347 cases and the pathogen was unclear in the remaining 147 cases. The main pathogens were MP (238 cases), Streptococcus pneumoniae (SP) (61 cases), Staphylococcus aureus (SA) (51 cases), Pseudomonas aeruginosa (13 cases), Haemophilus influenzae (10 cases), adenovirus (10 cases), and influenza virus A (7 cases), respectively. MP was the most common pathogen in all three periods and the proportion increased yearly. The proportion of MP in 2016-2019 was significantly higher than that in 2012-2015 (52.1% (197/378) vs. 36.8% (32/87), χ²=6.654, P=0.010), while there was no significant difference in the proportion of MP in 2012-2015 and that in 2008-2011 (36.8% (32/87) vs. 31.0% (9/29), χ²=0.314, P=0.575).Regarding the regional distribution, 342 cases were in the southern China and 152 in the northern China. Also, MP was the most common pathogen in both regions, but the proportion of MP was higher and the proportion of SP was lower in the north than those in the south (60.5% (92/152) vs. 42.7% (146/342), χ²=13.409, P<0.010; 7.9% (12/152) vs. 14.3% (49/342), χ²=4.023, P=0.045). Comparing the clinical characteristics of different pathogens, we found that fever and cough were the common symptoms in both single MP and single bacterial groups, but chest pain was more common (17.0% (34/200) vs. 6.1% (6/98), χ²=6.697, P=0.010) while shortness of breath and wheezing were less common in MP group (16.0% (32/200) vs. 60.2% (59/98), χ²=60.688, P<0.01; 4.5% (9/200) vs. 21.4% (21/98), χ²=20.819, P<0.01, respectively). The white blood cell count, C-reactive protein and procalcitonin in the bacterial group were significantly higher than those in the MP group (14.7 (1.0-67.1)×10⁹/L vs. 10.5 (2.5-32.2)×10⁹/L, 122.5 (0.5-277.3) mg/L vs. 51.4 (0.5-200.0) g/L, 2.13 (0.05-100.00) μg/L vs. 0.24 (0.01-18.85) μg/L, Z=-3.719, -5.901 and -7.765, all P<0.01). Conclusions: The prevalence of pediatric NP in China shows an increasing trend during the past years. MP, SP and SA are the main pathogens of NP, and the most common clinical symptoms are fever and cough. The WBC count, C-reactive protein and procalcitonin in bacterial NP are significantly higher than those caused by MP.

Altered resting-state functional connectivity between subregions in the thalamus and cortex in migraine without aura

BACKGROUND AND PURPOSE

Migraine is a complex and disabling neurological disorder, the exact neurological mechanisms of which remain unclear. The thalamus is considered to be the hub of the central processing and integration of nociceptive information, as well as the modulation of these processes.

METHODS

A total of 48 migraineurs without aura (MWoAs) during the interictal phase and 48 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. We utilized masked independent component analysis and seed-based functional connectivity (FC) to investigate whether MWoAs exhibited abnormal FC between subregions in the thalamus and the cortex regions.

RESULTS

The MWoAs showed significantly weaker FC between the anterior dorsal thalamic nucleus and left precuneus. Additionally, MWoAs exhibited significantly reduced FC between the ventral posterior nucleus (VPN) and left precuneus, right inferior parietal lobule (R-IPL) and right middle frontal gyrus. Furthermore, the FC Z-scores between the VPN and R-IPL were negatively correlated with pain intensity in MWoAs. The disease duration of patients was negatively correlated with the FC Z-scores between the VPN and R-IPL.

CONCLUSION

These altered thalamocortical connectivity patterns may contribute to multisensory integration abnormalities, deficits in pain attention, cognitive evaluation and pain modulation. Pain sensitivity and disease duration are closely tied to abnormal FC between the VPN and R-IPL. Remarkably, recurrent headache attacks might contribute to this maladaptive functional plasticity closely related to pain intensity.

[High dose melphalan (HDM) is superior to cyclophosphamide plus etoposide and busulfan (CVB) as the conditioning regimen in autologous stem cell transplantation for multiple myeloma]

目的

比较大剂量美法仑（HDM）和环磷酰胺、依托泊苷联合白消安（CVB）预处理方案应用于新诊断多发性骨髓瘤（NDMM）患者自体造血干细胞移植（ASCT）的安全性、近期及远期疗效。

方法

回顾性分析2011年1月至2017年8月期间接受PAD（硼替佐米+脂质体阿霉素+地塞米松）方案诱导治疗序贯ASCT的NDMM患者共123例，按接受预处理方案分为CVB组（82例）和HDM组（41例）。

结果

①非血液学不良反应方面两者无显著区别。②CVB组中性粒细胞植入和血小板植入较HDM组快，中性粒细胞植入时间为第10（9~35）天对第11（9~12）天（z=−3.433，P=0.001）；血小板植入时间为11（7~55）d对HDM组13（10~35）d（z=−3.506，P<0.001）；但CVB组也更早进入粒细胞缺乏（粒缺）及显著血小板减少，最终粒缺及显著血小板减少持续时间两组间尚未显示出差别；但CVB组的发热持续时间以及相应抗生素使用时间显著延长。③CVB组经过移植后获得传统疗效进步的患者比例显著低于HDM组（9/46对14/28，P=0.021）；而且移植后3个月CVB组的微小残留病（MRD）阴性率有低于HDM组的趋势（31.7%对48.8%，P=0.065）。④无论单因素还是多因素分析均显示两种预处理方案并不影响接受PAD诱导序贯ASCT及维持治疗的NDMM患者的至进展时间（TTP）（P= 0.619）及总生存（OS）时间（P=0.295）。

结论

HDM预处理方案血液学不良反应、减低MM肿瘤负荷以及使用方便性方面较CVB方案具有优势，但采用两种预处理方案的ASCT治疗MM的TTP和OS未见明显差异。

[Clinical analysis of methylmalonic acidemia and hyperhomocysteinemia with diffuse lung disease as an initial or main presentation]

Objective: To improve the awareness of methylmalonic acidemia and hyperhomocysteinemia with diffuse lung disease as an initial or main presentation. Methods: A retrospective analysis of the clinical manifestations, radiological features, laboratory tests, genetic variations, treatments and prognoses was conducted in six children presented with diffuse lung disease and finally diagnosed with methylmalonic acidemia and hyperhomocysteinemia in Ward 2 of Department of Respiratory Diseases, Beijing Children's Hospital, from August 2017 to November 2018. Results: Six children were included in this study. Two children were male and four were female. The average age of onset was 28 months. The mean age at diagnosis was 34 months. The average interval from onset to diagnosis was 6 months. Four children who underwent genetic tests were found to have variants of gene MMACHC and diagnosed with CblC type. All children had respiratory symptoms and signs as initial or main presentation, which were tachypnea (5 cases), exercise intolerance (5 cases), cough (4 cases), cyanosis (4 cases), clubbing (4 cases), dyspnea (3 cases) and retractions (3 cases). Pulmonary arterial hypertension was found in all six children. Pericardial effusion (4 cases), kidney involvement (3 cases), nervous system involvement (3 cases), gastrointestinal system involvement (3 cases) and anemia (2 cases) also coexisted. The high resolution computed tomography (HRCT) features included dilated pulmonary artery (6 cases), ground-glass opacities (4 cases), diffuse poorly defined ground-glass centrilobular nodules (3 cases), pleural effusion (3 cases), thickening of interlobular septum (2 cases), etc. All children had an elevated concentration of methylmalonic acid in urine and homocysteine in plasma. Genetic tests were performed in four patients, and MMACHC genetic mutations were found in all of them. Clinical manifestations, HRCT features and pulmonary arterial hypertension turned better in five children after treatment. One patient who was not regularly followed-up died. Conclusions: Pulmonary involvement including diffuse lung disease and pulmonary arterial hypertension could coexist with methylmalonic acidemia and hyperhomocysteinemia, which may have respiratory symptoms and signs as the initial or main presentation. Characteristic HRCT features were found in some patients. Plasma homocysteine test is a quick method for screening the disease in children with diffuse lung disease and (or) pulmonary arterial hypertension. Both diffuse lung disease and pulmonary arterial hypertension may turn better after treatment.

[Bortezomib-based induction chemotherapy followed by autologous hematopoietic stem cell transplantation and maintenance in 200 patients with multiple myeloma: long-term follow-up results from single center]

Objective: To study the efficacy, safety and long-term outcomes of integrated strategy of bortezomib-based induction regimens followed by autologous hematopoietic stem cell (ASCT) and maintenance therapy in Chinese multiple myeloma (MM) patients. Methods: 200 MM patients receiving integrated strategy of bortezomib--based induction regimens followed by ASCT and maintenance therapy were retrospectively and prospectively analyzed from December 1. 2006 to April 30. 2018. Results: The complete remission rates (CR) and better than very good partial remission rates (VGPR) after induction therapy, transplantation and maintenance therapy were respectively 31% and 75.5%, 51.8% and 87.7%,73.6% and 93.4%. There was no difference between 4 cycles and more than 5 cycles induction chemotherapy. The negative rate of MRD detection by flow cytometry was 17.6% and 38.2% respectively after induction and 3 months after transplantation. The negative rate of MRD gradually increased during the maintenance therapy. The success rate of high dose CTX combined with G-CSF mobilization was 95.5% and transplantation related mortality (TRM) was zero. The median time to progress (TTP) was 75.3 months and the median overall survival (OS) was 99.5 months. TTP of patients obtaining CR and negative MRD after induction were longer that those of no CR and positive MRD. TTP and OS of patients receiving triple-drug induction and ASCT in early stage were longer than those of double-drug induction and ASCT in late stage. LDH≥240 U/L, high risk cytogenetics, ISS II+III stage and HBsAg positive were prognostic factors at diagnosis. However, only MRD and high risk cytogenetics were independent prognostic factors after transplantation and maintenance therapy. The clinical characteristics of patients of TTP ≥6 years were listed below: light-chain type M protein, ISS I stage, normal level of hemoglobin and platelet, normal LDH, HBsAg negative, chromosome 17p-negative, good response and sustained good response. Conclusions: Integrated strategy of bortezomib-based induction regimens followed by ASCT and maintenance therapy can significantly improve the short-term and long-term efficacy. The prognostic factors of TTP in different disease stages were different. Response to treatment, especially MRD, played a more important role in prognostic factors.

Ultra-narrow linewidth quantum dot coherent comb lasers with self-injection feedback locking

We have used an external cavity self-injection feedback locking (SIFL) system to simultaneously reduce the optical linewidth of over 39 individual wavelength channels of an InAs/InP quantum dot (QD) coherent comb laser (CCL). Linewidth reduction from a few MHz to less than 200 kHz is observed. Measured phase noise spectra clearly indicate a significant decrease in phase noise in the frequency range above 2 kHz. The RF beating signal between two adjacent channels also shows a substantial reduction in 3-dB linewidth from 10 kHz to 300 Hz with the SIFL system, and a corresponding drop in baseline level (-27 dB to -50 dB).

High performance InAs/InP quantum dot 34.462-GHz C-band coherent comb laser module

We have developed an InAs/InP quantum dot (QD) C-band coherent comb laser (CCL) module with actively stabilized absolute wavelength and power, and channel spacing of 34.462 GHz with ± 100 ppm accuracy. The total output power is up to 46 mW. The integrated average relative intensity noise (RIN) values of the lasing spectrum and a filtered single channel at 1540.19 nm were -165.6 dB/Hz and -130.3 dB/Hz respectively in the frequency range from 10 MHz to 10 GHz. The optical linewidth of the 45 filtered individual channels between 1531.77 nm to 1543.77 nm ranged from 850 kHz to 2.16 MHz. We have also analyzed the noise behaviors of each individual channel.

[Clinical and genetic analysis for activated PI3K-δ syndrome by PIK3CD gene mutation]

OBJECTIVE

To analyze clinical and genetic features of activated PI3K-δ syndrome (APDS), a new form of immunodeficiency disease caused by PIK3CD gene mutation.

METHOD

Data of two patients diagnosed as APDS at Second Department of Respiratory Medicine of Beijing Children's Hospital Affiliated to Capital Medical University in 2015 were retrospectively reviewed. Pathogenetic genes were screened by whole exome sequencing, and identified by first generation sequencing. The identified pathogenetic genes were further verified in patients' parents. Then the gene sequencing results were analyzed.

RESULT

Both patients were females, aged 2 years and 4 months and 5 years respectively. The main clinical features of both cases were recurrent respiratory infections, enlargement of lymph node, hepatosplenomegaly, cytomegalovirus (CMV) or Epstein-Barr virus (EBV) viremia, decreased number of native CD4(+) T cell, inverted CD4(+) /CD8(+) T cell ratio and increased IgM. Patient 1 has decreased IgA and IgG. Patient 2 showed wide follicular hyperplasia of the airway mucosa. Both patients had de novo mutation in c. 3061G>A(E1021K)of PIK3CD gene, which was homozygous in patient 1 and heterozygous in patient 2. Both were treated with 500 mg/kg dose of gamma globulin intravenously at 4-weeks interval. Patient 1 started oral rapamycin therapy at the dose of 1 mg/(m(2)·d) and discontinued the treatment after 2 weeks. Patient 2 was given low dose of oral prednisone. The two patients were followed up for 2 months. The number of respiratory infection in both patients was decreased. Hepatosplenomegaly was subsided, while respiratory tract damage was not improved in patient 2.

CONCLUSION

The clinical manifestations of APDS include recurrent respiratory tract infection, enlargement of lymph nodes, hepatosplenomegaly, and CMV or EBV infection. The immunophenotype is decreased native CD4(+) T cell, inverted CD4(+) /CD8(+) T cell ratio, increased IgM and decreased IgA/IgG for some patients. c. 3061G>A(E1021K)of PIK3CD gene is a common de novo mutation in APDS patients.

[Clinical features and therapy of persistent bacterial bronchitis in 31 children]

OBJECTIVE

To investigate the clinical features and therapy of persistent bacterial bronchitis (PBB).

METHOD

A retrospective review of 31 patients with PBB from Octorber 2010 to May 2014 in Department 2 of Respiratory Diseases in Beijing Children's Hospital was undertaken.

RESULT

(1) The patients (17 boys and 14 girls) were 6 months to 3 years old. The main complaint was chronic wet cough (>4 weeks); 13 cases had fever and 25 cases had wheezing. Rattle was heard on auscultation in all patients. (2) Chest X ray showed an increase in bronchovascular markings in all cases, accompanied by patchy infiltration in 6 cases. The high resolution computed tomography (HRCT) demonstrated bronchial wall thickening in 25 cases, associated with peri-bronchial patchy infiltration in 18 cases, with organized pneumonia in 7 cases ( atelectasis in 5 cases). Centrilobular nodules and ground-glass opacity were observed in the remaining 6 patients. (3) Purulent secretion was seen in endobronchial cavity by bronchoscopy. Streptococcus pneumoniae was isolated from sputum culture or bronchoalveolar lavage fluid culture in 16 patients. (4)Patients recovered completely after over 2 weeks'treatment with amoxicillin-clavulanate or the second and third generation cephalosporin (including enzyme inhibitors) in 28 cases, carbapenems, teicoplanin , linezolid in 1 case respectively.

CONCLUSION

PBB often occurred in 3 years old or younger patients and had chronic wet cough for more than 4 weeks, fever and wheezing. HRCT may reveal bronchial wall thickening, respiratory secretions culture may reveal Streptococcus pneumoniae. Most of patients recovered completely after over 2 weeks'treatment with amoxicillin-clavulanate or the second or third generation cephalosporins (including enzyme inhibitors).

[Clinical analysis of two cases with diffuse pulmonary lymphatic disease]

OBJECTIVE

To analyze the clinical characteristics and diagnosis of 2 cases with diffuse pulmonary lymphatic disease.

METHOD

Clinical manifestations of the children were retrospectively analyzed. Two patients were both from Beijing Children Hospital in 2013 and 2014.Diffuse pulmonary lymphatic disease was diagnosed by pathology of pleura in case 1 and by lymphoscintigraphy in case 2.

RESULT

The first patient was a male aged 10-year-5-month who presented with a history of pleural effusion for 2 years. Examination revealed chylothorax and pericardial effusion. After pleural decortications and ligation of thoracic duct was performed, he still had recurrent chylothorax. Pathology of pleura revealed lymphangioma. Physical examination showed diminished breath sound and heart sounds. A bronchoscope revealed too much white viscous secretions. Thorax ultrasound revealed lymphangioma in bilateral lower thoracic cavity and post inferior mediastinum. Chest computed tomography showed diffuse thickening of the interlobular septa and bronchovascular bundle in both lungs, many punctate calcification in the lower field. Abdomen ultrasound revealed a small quantity seroperitoneum. Lymphoscintigraphy revealed radioactivity enhancement in bilateral thoracic cavity. The second patient was a female aged 6 years and 9 months, who presented with a history of recurrent cough for 2 years and 9 months. Physical examination showed normal result. Pulmonary function showed mixed ventilation function disturbance. A bronchoscopy showed extensive viscous secretions. Mediastinum, heart and abdomen were normal on ultrasound. Chest computed tomography showed diffuse thickening of the interlobular septa and bronchovascular bundle in both lungs and bilateral pleural thickening. Lymphoscintigraphy revealed diffuse lymphangiectasis in both lungs. Both patients received a diagnosis of diffuse pulmonary lymphatic disease. Case 1 who had died was diagnosed with diffuse pulmonary lymphangiomatosis. Case 2 had no exacerbation after 9 months' treatment with prednisone.

CONCLUSION

Diffuse pulmonary lymphatic disease might present with cough and shortness of breath and result in diffuse interstitial disease with thickening of the interlobular septa, refractory chylothorax, multiple lymphangioma in mediastinum, pericardial effusion and seroperitoneum. It could be diagnosed by pleura or lung tissue pathology and lymphoscintigraphy.

E-selectin expression induced by Porphyromonas gingivalis in human endothelial cells via nucleotide-binding oligomerization domain-like receptors and Toll-like receptors

Porphyromonas gingivalis, an important periodontal pathogen, has been proved to actively invade cells, induce endothelial cell activation, and promote development of atherosclerosis. Innate immune surveillance, which includes the activity of nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and Toll-like receptors (TLRs), are essential for the control of microbial infections; however, the roles of receptor families in P. gingivalis infections remain unclear. Here, we examined the roles of NLRs and TLRs in endothelial cell activation caused by P. gingivalis. Live P. gingivalis and whole cell sonicates were used to stimulate endothelial cells, and both showed upregulation of E-selectin as well as NOD1, NOD2, and TLR2. In addition, silencing of these genes in endothelial cells infected with P. gingivalis led to a reduction in E-selectin expression. Porphyromonas gingivalis also induced nuclear factor-κB (NF-κB) and P38 mitogen-activated protein kinase (MAPK) activity in endothelial cells, whereas small interfering RNA targeting NOD1 significantly reduced these signals. Moreover, inhibition of either NOD2 or TLR2 inhibited NF-κB significantly, but had only a weak inhibitory effect on P38 MAPK signaling. Direct inhibition of NF-κB and P38 MAPK significantly attenuated E-selectin expression induced by P. gingivalis in endothelial cells. Taken together, these findings suggest that NOD1, NOD2, and TLR2 play important, non-redundant roles in endothelial cell activation following P. gingivalis infection.

An L-band monolithic InAs/InP quantum dot mode-locked laser with femtosecond pulses

We have developed an InAs/InP quantum dot (QD) gain material using a double cap growth procedure and GaP sublayer to tune QDs into the L-band. By using it, a passive L-band mode-locked laser with pulse duration of 445 fs at the repetition rate of 46 GHz was demonstrated. The 3-dB linewidth of the RF spectrum is less than 100 KHz. The lasing threshold injection current is 24 mA with an external differential quantum efficiency of 22% and an average output power of 27 mW. The relationship between pulse duration and 3-dB spectral bandwidth as a function of injection current was investigated.

Identification of yeasts and evaluation of their distribution in Taiwanese Kefir and Viili starters

The objective of the present study was to investigate yeast communities in kefir grains and viili starters in Taiwan through conventional microbiological cultivation and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The DNA sequencing was used as a validity technique to ensure that all isolates within each group belonged to just one species, and to confirm the identified results of PCR-DGGE. Results indicated that a combination of conventional microbiological cultivation with PCR-DGGE and sequencing could successfully identify 4 yeast species from both types of cultures in Taiwan. Kluyveromyces marxianus, Saccharomyces turicensis, and Pichia fermentans were found in Taiwanese kefir grains with a distribution of 76, 22, and 2%, respectively, whereas Klu. marxianus, Saccharomyces unisporus and P. fermentans were identified in viili starters corresponding to 58, 11, and 31% of the total cell counts, respectively. Furthermore, the culture-independent method was applied to identify the yeast species using DGGE. Only 2 yeast species, Klu. marxianus and S. turicensis, were found in kefir grains and 2, Klu. marxianus and P. fermentans, in viili starters. These results suggest that in samples containing multiple species, PCR-DGGE may fail to detect some species. Sequences of yeast isolates reported in this study have been deposited in the GenBank database under accession nos. DQ139802, AF398485, DQ377652, and AY007920.

312-fs pulse generation from a passive C-band InAs/InP quantum dot mode-locked laser

For the first time, we report femtosecond pulses from a passive single-section InAs/InP quantum-dot (QD) mode-locked laser (MLL) with the active length of 456 microm and ridge width of 2.5 microm at the C-band wavelength range. Without any external pulse compression, the transform-limited Gaussian-pulses are generated at the 92 GHz repetition rate with the 312 fs pulse duration, which is the shortest pulse from any directly electric-pumping semiconductor MLLs to our best knowledge. The lasing threshold injection current and external differential quantum efficiency are 17.2 mA and 38%, respectively. We have also investigated the working principles of the proposed QD MLLs.

Evaluation of an intestinalLactobacillus reuteristrain expressing rumen fungal xylanase as a probiotic for broiler chickens fed on a wheat-based diet

1. This study was conducted to evaluate the feasibility of using a transformed Lactobacillus reuteri Pg4 strain harbouring a rumen fungal xylanase gene as a probiotic supplement in a wheat-based poultry diet. 2. A total of 400 broiler chicks was allocated to two treatment groups with or without supplementation with 10(6) colony forming units (cfu)/g of transformed L. reuteri Pg4 in a wheat-based regimen to investigate the performance, intestinal microflora populations, digesta viscosity and excreta ammonia concentrations in these broiler chickens. 3. Supplementation of the wheat-based diet with transformed L. reuteri Pg4 decreased intestinal viscosity, caecal coliform population, and increased body weight gain and ileal villus height and crypt depth from 0 to 21 d of age. It also decreased excreta ammonia concentrations, and increased the caecal total volatile fatty acid (VFA) and lactic acid concentrations from 0 to 21 d and 22 to 37 d of age. 4. Further, it was demonstrated that 40% of the Lactobacillus cells randomly isolated from the digesta of the ileum and caecum of the supplemented group possessed xylanase secretion capability. 5. It appears reasonable to assume, therefore, that the derived benefit is a result of the organism surviving, and the associated performance of some function in the intestinal tract which benefits gut health.

The impact of reduced phosphorus levels on microbial floc properties during biological treatment of pulp and paper wastewaters

The effect of limiting P in activated sludge was investigated in laboratory scale sequencing batch reactors (SBRs) fed effluent from a container board mill. Floc characterization included measurement of hydrophobicity, surface charge, and analysis of extracellular polymeric substances (EPS). Reactor performance was assessed by monitoring COD and inorganic P removal, MLSS, and sludge settleability (SVI and batch settling flux) over a period of eight months. Control reactors (BOD:N:P of 100:5:1) were compared to reactors run under P-limited conditions (100:5:0.3; 100:5:0.1). Reactor performance at lower temperatures (14 degrees C; control = 26 degrees C) was also studied to assess the impact of P-limitation. Changes in floc structure and the composition of EPS occurred within 1 to 3 days following a reduction in P levels. There was an insignificant increase in SVI; however, gravitational settling velocity and batch settling flux values for low P floc were consistently higher than for floc generated under control conditions. Lower temperatures (14 degrees C) resulted in a deterioration in floc settling properties at a BOD:N:P of 100:5:1. This impact on settling was significantly reduced at a BOD:P of 100:0.1. Reducing P concentrations in the wastewater treatment system has the potential to improve sludge settleability and reduce final P discharges.

Effect of phosphorus limitation on microbial floc structure and gene expression in activated sludge

The effect of limiting phosphorus (P) in activated sludge was investigated in laboratory-scale sequencing batch reactors (SBRs). Correlative microscopy revealed that P-limitation (COD:N:P = 100:5:0.05) leads to morphological changes in floc structure and the composition of extracellular polymeric substances (EPS). This was found to be accompanied by expression of quorum-sensing in an acyl homoserine lactone bioassay. Differential gene expression in relation to P-limitation was examined in a global profile using the Affymetrix Escherichia coli antisense genomic microarray. Three separate experiments were conducted where the impact of P-limitation was examined under batch conditions and in SBRs at stable operating conditions and within 3-7 days following a down-shift in P. Significant changes in open reading frames (ORF) and intergenic regions based on the E. coli microarray were observed. Several genes associated with cell structure, including slt, wbbH, fimH, amB, rfaJ and slp were found to be expressed. Quorum regulated genes were also found to be expressed including psiF which is known to be induced by P-starvation (92% confidence level; 1.45 log ratio).

Apoptosome dysfunction in human cancer

Apoptosis is a cell suicide mechanism that enables organisms to control cell number and eliminate cells that threaten survival. The apoptotic cascade can be triggered through two major pathways. Extracellular signals such as members of the tumor necrosis factor (TNF) family can activate the receptor-mediated extrinsic pathway. Alternatively, stress signals such as DNA damage, hypoxia, and loss of survival signals may trigger the mitochondrial intrinsic pathway. In the latter, mitochondrial damage results in cytochrome c release and formation of the apoptosome, a multimeric protein complex containing Apaf-1, cytochrome c , and caspase-9. Once bound to the apoptosome, caspase-9 is activated, and subsequently triggers a cascade of effector caspase activation and proteolysis, leading to apoptotic cell death. Recent efforts have led to the identification of multiple factors that modulate apoptosome formation and function. Alterations in the expression and/or function of these factors may contribute to the pathogenesis of cancer and resistance of tumor cells to chemotherapy or radiation. In this review we discuss how disruption of normal apoptosome formation and function may lead or contribute to tumor development and progression.

Taxonomic discrimination of flowering plants by multivariate analysis of Fourier transform infrared spectroscopy data

Fourier transform infrared spectroscopy (FTIR) provides biochemical profiles containing overlapping signals from a majority of the compounds that are present when whole cells are analyzed. Leaf samples of seven higher plant species and varieties were subjected to FTIR to determine whether plants can be discriminated phylogenetically on the basis of biochemical profiles. A hierarchical dendrogram based on principal component analysis (PCA) of FTIR data showed relationships between plants that were in agreement with known plant taxonomy. Genetic programming (GP) analysis determined the top three to five biomarkers from FTIR data that discriminated plants at each hierarchical level of the dendrogram. Most biomarkers determined by GP analysis at each hierarchical level were specific to the carbohydrate fingerprint region (1,200-800 cm(-1)) of the FTIR spectrum. Our results indicate that differences in cell-wall composition and structure can provide the basis for chemotaxonomy of flowering plants.

Plant regeneration from hairy-root cultures transformed by infection with Agrobacterium rhizogenes in Catharanthus roseus

Hypocotyl explants of Catharanthus roseus produced hairy roots when cultured on Murashige and Skoog (MS) basal medium after infection by Agrobacterium rhizogenes. Explants gave rise to adventitious shoots at a frequency of up to 80% when cultured on MS medium supplemented with 31.1 microM 6-benzyladenine and 5.4 microM alpha-naphthaleneacetic acid. There was a significant difference in the frequency of adventitious shoot formation for each hairy-root line derived from a different cultivar. Plants derived from hairy roots exhibited prolific rooting and had shortened internodes. Approximately half of the plants had wrinkled leaves and an abundant root mass with extensive lateral branching, but otherwise appeared morphologically normal. Plants with hairy roots that were derived from the cultivar Cooler Apricot developed flowers with petals that were white in the proximal region, whereas the wild-type flower petals are red. PCR and Southern blot analyses revealed that plants derived from hairy roots retained the Ri TL-DNA.

Plant regeneration from hairy-root cultures transformed by infection with Agrobacterium rhizogenes in Catharanthus roseus

Hypocotyl explants of Catharanthus roseus produced hairy roots when cultured on Murashige and Skoog (MS) basal medium after infection by Agrobacterium rhizogenes. Explants gave rise to adventitious shoots at a frequency of up to 80% when cultured on MS medium supplemented with 31.1 microM 6-benzyladenine and 5.4 microM alpha-naphthaleneacetic acid. There was a significant difference in the frequency of adventitious shoot formation for each hairy-root line derived from a different cultivar. Plants derived from hairy roots exhibited prolific rooting and had shortened internodes. Approximately half of the plants had wrinkled leaves and an abundant root mass with extensive lateral branching, but otherwise appeared morphologically normal. Plants with hairy roots that were derived from the cultivar Cooler Apricot developed flowers with petals that were white in the proximal region, whereas the wild-type flower petals are red. PCR and Southern blot analyses revealed that plants derived from hairy roots retained the Ri TL-DNA.

Dicistronic expression of the green fluorescent protein and antibiotic resistance genes in the plastid for selection and tracking of plastid-transformed cells in tobacco

A plastid transformation vector was constructed for dicistronic expression of the aminoglycoside 3'-adenyltransferase (aadA) and green fluorescent protein (gfp) genes under the control of the plastid rrn promoter. Gold particles coated with the vector DNA were bombarded onto tobacco leaf explants using a particle delivery system. Leaf explants produced adventitious shoots when cultured on shoot-inducing medium containing 500 mg l(-1) spectinomycin. Shoots that exhibited green fluorescence under UV light were selected. Southern blot analysis detected the presence of the aadA and gfp genes between trnA and trnI in the plastid genome. Northern blot analysis revealed that the aadA and gfp genes were both properly transcribed into a dicistronic transcriptional unit. The expression of the gfp gene in the plastid enabled separation of transformed chloroplasts from wild-type chloroplasts in the protoplast under a fluorescent microscope. The overall results indicate that dicistronic expression of the aadA and gfp genes in the plastid simplifies gene manipulation, facilitating selection and tracking of plastid-transformed cells.

N-(4-hydroxyphenyl) retinamide (4HPR) enhances TRAIL-mediated apoptosis through enhancement of a mitochondrial-dependent amplification loop in ovarian cancer cell lines

The majority of ovarian cancer cells are resistant to apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Subtoxic concentrations of the semisynthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) enhanced TRAIL-mediated apoptosis in ovarian cancer cell lines but not in immortalized nontumorigenic ovarian epithelial cells. The enhancement of TRAIL-mediated apoptosis by 4HPR was not due to changes in the levels of proteins known to modulate TRAIL sensitivity. The combination of 4HPR and TRAIL enhanced cleavage of multiple caspases in the death receptor pathway (including the two initiator caspases, caspase-8 and caspase-9). The 4HPR and TRAIL combination leads to mitochondrial permeability transition, significant increase in cytochrome c release, and increased caspase-9 activation. Caspase-9 may further activate caspase-8, generating an amplification loop. Stable overexpression of Bcl-xL abrogates the interaction between 4HPR and TRAIL at the mitochondrial level by blocking cytochrome c release. As a consequence, a decrease in activation of caspase-9, caspase-8, and TRAIL-mediated apoptosis occurs. These results indicate that the enhancement in TRAIL-mediated apoptosis induced by 4HPR is due to the increase in activation of multiple caspases involving an amplification loop via the mitochondrial-death pathway. These findings offer a promising and novel strategy for the treatment of ovarian cancer.

Taxonomic discrimination of higher plants by pyrolysis mass spectrometry

Pyrolysis mass spectrometry (PyMS) is a rapid, simple, high-resolution analytical method based on thermal degradation of complex material in a vacuum and has been widely applied to the discrimination of closely related microbial strains. Leaf samples of six species and one variety of higher plants (Rosa multiflora, R. multiflora var. platyphylla, Sedum kamtschaticum, S. takesimense, S. sarmentosum, Hepatica insularis, and H. asiatica) were subjected to PyMS for spectral fingerprinting. Principal component analysis of PyMS data was not able to discriminate these plants in discrete clusters. However, canonical variate analysis of PyMS data separated these plants from one another. A hierarchical dendrogram based on canonical variate analysis was in agreement with the known taxonomy of the plants at the variety level. These results indicate that PyMS is able to discriminate higher plants based on taxonomic classification at the family, genus, species, and variety level.

Discovery of genes for ginsenoside biosynthesis by analysis of ginseng expressed sequence tags

Expressed sequence tags (ESTs) provide a valuable tool that can be used to identify genes in secondary metabolite biosynthesis. Ginseng (Panax ginseng C.A Meyer) is a medicinal plant that accumulates ginsenosides in roots. We sequenced 11,636 ESTs from five ginseng libraries in order to create a gene resource for biosynthesis of ginsenosides, which are thought to be the major active component in roots. Only 59% of the ginseng ESTs exhibited significant homology to previously known polypeptide sequences. Stress- and pathogen-response proteins were most abundant in 4-year-old ginseng roots. ESTs involved in ginsenoside biosynthesis were identified by a keyword search of BLASTX results and a domain search of ginseng ESTs. We identified 4 oxidosqualene cyclase candidates involved in the cyclization reaction of 2,3-oxidosqualene, 9 nine cytochrome P450 and 12 glycosyltransferse candidates, which may be involved in modification of the triterpene backbone.

The "Nostocoida limicola" story: resolving the phylogeny of this morphotype responsible for bulking in activated sludge

On the basis of 16S rRNA sequence analyses of several isolates of "Nostocoida limicola" from activated sludge plants in Australia and other countries, it is clear that "N. limicola" I, II and III are not three morphological variants of a single bacterium but at least three phylogenetically different bacteria. Data show that "N. limicola" I are members of at least two genera in the low mol% G+C gram-positive bacteria, while some isolates of "N. limicola" II belong to the high mol% G+C gram positive bacteria, and "N. limicola" III is a member of the Planctomycetales. Design and application of 16S rRNA targeted probes for each to biomass samples suggests that their phylogeny is more diverse than pure culture studies would suggest.

Design and application of oligonucleotide probes for fluorescent in situ identification of the filamentous bacterial morphotype Nostocoida limicola in activated sludge

16S rRNA targeted probes, designed using sequence data from pure cultures of the three morphotypes of the filamentous bulking bacteria Nostocoida limicola I, II and III and their successful application to the in situ identification of these bacteria in activated sludge biomass samples are described here. Two probes were required to detect all the sequenced N. limicola II isolates. Results from fluorescent in situ hybridization suggest that the morphotypes N. limicola I and II contain at least two phylogenetically unrelated bacteria. The N. limicola II filaments that did not respond to the probes designed in this study fluoresced instead with the probes previously designed for the alpha-Proteobacteria. The data also suggest that both N. limicola I and III can exist in activated sludge as single, paired or clumped cells and thus in a form not recognizable microscopically as this morphotype. Some N. limicola II filaments which responded to the probes designed here were much thinner than the filaments conventionally 'identified' as this morphotype and better fitted the descriptions often used in the literature for N. limicola I.

Phylogeny of the filamentous bacterium 'Nostocoida limicola' III from activated sludge

Five strains of the filamentous bacterium 'Nostocoida limicola' III were successfully isolated into pure culture from samples of activated sludge biomass from five plants in Australia. 16S rRNA gene sequence analyses showed that all isolates were members of the Planctomycetales, most closely related to Isosphaera pallida, but they differed phenotypically from this species in that they did not glide and were not thermotolerant. The ultrastructure of these 'N. limicola' III isolates was also consistent with them being Planctomycetales, in that they possessed complex intracellular membrane systems compartmentalizing the cells. However, the arrangements of these intracellular membranes differed between isolates. These data confirm that 'N. limicola' III is phylogenetically unrelated to both 'N. limicola' I and 'N. limicola' II, activated sludge filamentous bacteria which share morphological features in common with 'N. limicola' III and which have been presumed historically to be the same or very similar bacteria.

The filamentous bacterial morphotype 'Nostocoida limicola' I contains at least two previously described genera in the low G+C gram positive bacteria

Isolates of eight bacterial filaments fitting the published morphological description of 'Nostocoida limicola' I were obtained from the mixed liquor of four different Australian and one Czech Republic activated sludge plants by micromanipulation. On the basis of their near complete (Ben 200 and Ben 201), or partial (Ben 77, Ben 78, Ben 202, Ben 203, Ben 204 and Ben 205) 16S rRNA gene sequences, six of these isolates were 99.3-100% similar to Lactosphaera pasteurii and Trichococcus flocculiformis, a bulking filament only reported previously in Germany. The other two (Ben 203 and Ben 204) were 99.9% similar to Streptococcus suis. Hence, all are in the low mol % G+C gram-positive bacteria division of the Bacteria. On this evidence 'N. limicola' I is phylogenetically unrelated to 'Nostocoida limicola' II, which is now known to be in the Actinobacteria, even though these two filamentous bacteria appearing in activated sludge systems have been considered to be closely related to each other historically.

Presence of multiple cDNAs encoding an isoform of ADP-glucose pyrophosphorylase large subunit from sweet potato and characterization of expression levels

Three cDNAs (iAGPLI-1, iAGPLI-2, and iAGPLI-3) encoding an isoform of AGPase large subunit were isolated from a sweet potato cDNA library constructed from tuberous root tissue. iAGPLI-1 was 2,161 bp in length and contained an open reading frame of 517 amino acids with a calculated molecular mass of 57,689 Da. iAGPLI-2 and iAGPLI-3 were 1,804 and 1,524 bp in length, respectively, and contained partial open reading frames of 490 and 385 amino acids. Deduced amino acid sequence comparison analysis showed that iAGPLI-1 has sequence identity with iAGPLI-2 (97.9) and iAGPLI-3 (98.7%) while iAGPLI-2 and iAGPLI-3 have 96.8% sequence identity. iAGPLI-1 had the highest sequence identity of 77.8% with potato AGPase (sAGPL1). Steady-state levels of iAGPLI-1 transcripts were expressed predominantly in the stem, and moderately in the tuberous root, but not in either the roots or leaves. However, AGPase activity was present in all tissues. The expression level in the stem declined dramatically after a 12 h incubation in the dark to nearly 3% of the value under light, although the activity under a dark condition remained at half the levels in light. The activity levels were not correlated with the transcript levels. iAGPL transcripts in leaves were induced by sucrose feeding but not by glucose or fructose. Therefore, the expression of iAGPLI-1 is regulated in stem tissue preferentially and by sucrose. Southern blot analysis showed that the sweet potato genome contained several copies of iAGPLI gene probably due to polyploidy.

Polymeric diaquatetra-mu;-thiocyanato-manganese(II)mercury(II) bis(N,N-dimethylacetamide) solvate

In the title complex, ¿[MnHg(SCN)(4)(H(2)O)(2)].2C(4)H(9)NO¿(n), each Mn atom is octahedrally coordinated to four equatorial thiocyanate N atoms and two axial water O atoms. The Mn atom and two O atoms lie on a twofold axis. Two kinds of crystallographically independent Hg atoms (denoted Hg1 and Hg2) are tetrahedrally coordinated with four thiocyanate S atoms and each Hg atom lies on a -4 axis. N,N-Dimethylacetamide molecules are connected to coordinated water molecules through hydrogen bonds. Each pair of Mn and Hg atoms is bridged via one thiocyanate ion. An Mn(2)Hg1Hg2(SCN)(4) 16-membered ring is formed as a unit and the four metal atoms are in a chair-form tetrahedral arrangement. The units are linked with one another and form infinite two-dimensional networks.