[A comparison of current guidelines for the management of intrahepatic cholangiocarcinoma worldwide]

Intrahepatic cholangiocarcinoma (ICC) is the second most common human liver malignancy and its incidence rate has been gradually increasing worldwide over the past decades. Surgical resection (R0 resection) is the preferred potentially curative treatment for ICC patients. However, due to its conceal clinical features and high invasiveness, most patients have lost the opportunity for surgical resection at the time of diagnosis. In recent years, with the rapid development of targeted therapy and immunotherapy, which is represented by immune checkpoint inhibitors, clinicians are expected to provide more effective treatment options for patients with mid-stage or advanced ICC. At present, there are still controversial opinions on different guidelines regarding preoperative biliary drainage, the extent of hepatectomy, the definition of R0 resection, the width of the resection margin, lymph node dissection, postoperative recurrence, adjuvant therapy, etc. In this review, 12 guidelines or expert consensus published worldwide from 2012 to 2022 (including 4 Chinese guidelines, 4 European guidelines, 2 American guidelines and 2 Japanese guidelines) were retrieved. Focusing on sorting and comparing the current views on clinical management of ICC in different guidelines, this review aims to provide reference information for ICC clinical management and decision-making.

Effect of Multicomponent Intervention on Functional Decline in Chinese Older Adults: A Multicenter Randomized Clinical Trial

OBJECTIVES

To confirm whether multicomponent exercise following vivifrail recommendations was an effective method for improving physical ability, cognitive function, gait, balance, and muscle strength in Chinese older adults.

METHODS

This was a multicenter and randomized clinical trial conducted in Jiangsu, China, from April 2021 to April 2022. Intervention lasted for 12 weeks and 104 older adults with functional declines were enrolled. All participants were randomly assigned to a control (usual care plus health education) or exercise group (usual care plus health education plus exercise). Primary outcomes were the change score of Short Physical Performance Battery (SPPB) and activities of daily living (ADL). The secondary outcomes included instrumental activities of daily living, Tinetti scores, Frailty score, short-form Mini Nutritional Assessment, Mini-Mental State Examination, Geriatric Depression Scale-15, the 12-item Short Form Survey, 4-meter gait speed test, 6-min walking distance, grip strength, and body composition analysis.

RESULTS

Among the participants, the average age was 85 (82, 88) years. After 12 weeks of follow-up, the exercise group showed a significant improvement in SPPB, with a change of 2 points (95% confidence interval [0, 3.5], P<0.001) compared to control. In contrast, SPPB remained stable in the control group. Compared to the control group, ADL improved in the exercise group, as did instrumental activities of daily living, Tinetti, Frailty, Short Form Survey, 4-meter gait speed test, and 6-min walking distance. Although there was no significant difference between groups in body composition analysis after post-intervention, the exercise group still improved in soft lean mass (P=0.002), fat-free mass (P=0.002), skeletal muscle mass index (P<0.001), fat-free mass index (P=0.004), appendicular skeletal muscle mass (P<0.001), and leg muscle mass (P<0.001), while the control group had no significant increase. No difference was observed in adverse events during trial period.

CONCLUSIONS

The multicomponent exercise intervention following vivifrail recommendations is an effective method for older adults with functional decline and can reverse the functional decline and improve gait, balance, and muscle strength. Additionally, the 12-week multicomponent exercise method provides guidance for Chinese medical professionals working in the field of geriatrics and is a promising method to improve physical function in the general population.

Intervention effect of Potentilla discolor-Euonymus alatus on intestinal flora of type 2 diabetes mellitus rats

OBJECTIVE

With this study, we aimed at exploring the regulation mechanism of Potentilla discolor-Euonymus alatus on intestinal flora of T2DM (Type 2 Diabetes Mellitus) rats induced by high-fat diet combined with streptozotocin.

MATERIALS AND METHODS

T2DM rats were induced by high-fat diet combined with streptozotocin. There were normal control group, model group, metformin group, high-dose Chinese medicine group and low-dose Chinese medicine group. Each group included 10 rats. Normal control group: normal feeding, no modeling, ordinary feed, and gavage of 0.9% normal saline. Model group: T2DM rats, high-fat diet, and gavage of 0.9% normal saline. Metformin group: T2DM rats, high-fat diet and fed with metformin solution. High-dose Chinese medicine group: T2DM rats, high-fat diet, and gavage of concentrated Chinese medicine at a dose of 6 times the clinical dose. Low-dose Chinese medicine group: T2DM rats, high-fat diet, and gavage of concentrated Chinese medicine at a dose twice the clinical dose. The general situation of T2DM rats was observed, and the changes of intestinal flora were observed with 16SrDNA sequencing.

RESULTS

The T2DM rats induced by high-fat diet combined with streptozotocin were molded. After intervention, at the class level, the ratio of γ-proteobacteria was 22.30% in the model group, 11.97% in the metformin group, 3.24% in the high-dose Chinese herbs group and 1.72% in the low-dose Chinese herbs group; the ratio of Erysipelothrix insidiosa was 4.73% in the model group, 4.68% in the metformin group, 3.93% in the high-dose Chinese herbsgroup and 2.92% in the low dose group; the ratio of Lactinobacillus was 2.30% in the model group, 0.01% in the metformin group, 0.00% in the high-dose Chinese herbs group, and 0.00% low-dose Chinese herbs group; at the portal level, the Firmicutes/Bacteroides was 0.88 in the normal control group, 3.40 in the model group, 1.71 in the metformin group, 2.74 in high-dose Chinese medicine group, and 1.34 in low-dose Chinese medicine group; at the genus level, the relative abundance of Lactobacillus in the model group was 3.28%, that of Akkermansia was 1.99%, that of Shigella coli was 22.08%, and that of Vibrio phaseus was 7.67%. All of them were improved after the intervention of metformin and traditional Chinese medicine.

CONCLUSIONS

Potentilla discolor-Euonymus Alatus could improve the composition and structure of intestinal flora in T2DM rats and regulate the diversity of intestinal flora. The ratio of Firmicutes/Bacteroidetes was adjusted, mainly to increase the number of Bacteroides; the flora related to intestinal barrier was adjusted, mainly to increase the number of Lactobacillus and Akkermansia bacteria.

Antagonistic Cd and Zn isotope behavior in the extracted soil fractions from industrial areas

The remobilization of metals accumulated in contaminated soils poses a threat to humans and ecosystems in general. Tracing metal fractionation provides valuable information for understanding the remobilization processes in smelting areas. Based on the difference between the isotopic system of Cd and Zn, this work aimed to couple isotope data and their leachability to identify possible remobilization processes in several soil types and land uses. For soil samples, the δ^66/64Zn values ranged from 0.12 ± 0.05‰ to 0.28 ± 0.05‰ in Avilés (Spain) and from - 0.09 ± 0.05‰ to - 0.21 ± 0.05‰ in Příbram (Czech Republic), and the δ^114/110Cd ranged from - 0.13 ± 0.05‰ to 0.01 ± 0.04‰ in Avilés and from - 0.86 ± 0.27‰ to - 0.24 ± 0.05‰ in Příbram. The metal fractions extracted using chemical extractions were always enriched in heavier Cd isotopes whilst Zn isotope systematics exhibited light or heavy enrichment according to the soil type and land uses. Coupling Zn and Cd systematics provided a tool for deciphering the mechanisms behind the remobilization processes: leaching of the anthropogenic materials and/or metal redistribution within the soil components prior to remobilization.

Cardiomyocyte stretch mediates the relation between left ventricular amyloid burden and adverse outcomes in light chain amyloidosis: a 18F-florbetapir positron emission tomography study

Background

Patients with light chain (AL) amyloidosis and cardiac involvement have poor prognosis. Mayo stage accounts for severity of plasma cell dyscrasia and cardiac biomarker release, and provides powerful risk stratification. Myocardial amyloid burden can be quantified by 18F-florbetapir positron emission tomography (PET), but its prognostic value is not known.

Purpose

To test our hypothesis that (1) myocardial amyloid burden predicts adverse outcomes and (2) the relationship between amyloid burden and adverse outcomes is mediated by cardiomyocyte stretch and injury. Amyloid burden was estimated by left ventricular 18F-florbetapir retention index (RI) and cardiomyocyte stretch and injury by NT proBNP and troponin T respectively.

Methods

We performed 18F-florbetapir PET (median dose 9.05 mCi) in prospectively enrolled subjects with newly diagnosed AL amyloidosis with abnormal cardiac biomarkers or with normal cardiac biomarkers and normal left ventricular wall thickness (NCT02641145). Left ventricular RI was calculated as the activity concentration between 10 and 30 min. after injection divided by the integral of the left atrial blood time-activity curve from 0 to 20 min. RI was categorized as normal (&lt;0.06/min, based on controls), increased (0.06–0.12/min), or high risk (&gt;0.12/min, based on log-rank statistic maximization). Mayo stages I–IV were based on elevated serum cardiac biomarkers: NT-proBNP ≥1800 pg/ml, troponin T ≥0.025 ng/ml, and difference in free light chains ≥180 mg/l. Adverse outcomes of all-cause death or heart failure hospitalization were evaluated. Survival analysis was performed using Kaplan-Meier and Cox regression including Mayo stage and RI. Mediation analysis was used to elucidate the role of cardiomyocyte stretch (as NT-proBNP) and injury (as troponin T) in the association between amyloid burden estimated by RI and adverse outcomes.

Results

We studied 80 subjects with median age 62 years (IQR 57–67), 46 men (57%), 60 with abnormal cardiac biomarkers (75%), and median RI of 0.10/min (IQR 0.06–0.16). At follow-up (median 15 months), adverse outcomes occurred in 34 subjects (42%), with 17 deaths (21%) and 23 heart failure hospitalizations (29%). The incidence of adverse outcomes increased across Mayo stages from 9% to 44% (log-rank p&lt;0.001), and across RI levels from 29% to 57% (log-rank p=0.037, Figure 1). In multivariable Cox regression, only Mayo stage independently predicted adverse outcomes (HR 2.0 [95% CI 1.4–3.0], p&lt;0.001). Multivariable mediation analysis showed that 83% of the association between RI and adverse outcomes was mediated by NT-proBNP (p&lt;0.001, Figure 2), without contribution from troponin T.

Conclusion

Myocardial amyloid burden estimated by F-18 florbetapir RI predicts adverse outcomes in AL amyloidosis, but not independently of Mayo stage. Cardiomyocyte stretch mediates the relationship between myocardial amyloid burden and adverse outcomes in AL amyloidosis.

Funding Acknowledgement

Type of funding sources: Private company.

LB0002 BARICITINIB IN JUVENILE IDIOPATHIC ARTHRITIS: A PHASE 3, DOUBLE-BLIND, PLACEBO-CONTROLLED, WITHDRAWAL, EFFICACY AND SAFETY STUDY

Background

Baricitinib is a JAK1/2 selective inhibitor approved for the treatment of rheumatoid arthritis. Juvenile idiopathic arthritis (JIA) is a group of diseases characterized by immune mediated chronic arthritis which often requires treatment with conventional synthetic or biologic disease-modifying antirheumatic drugs (cs or b-DMARDs).

Objectives

To investigate baricitinib efficacy and safety in pediatric patients with JIA and an inadequate response to cs or b-DMARDs.

Methods

This Phase 3 multicenter, double-blind, withdrawal, efficacy, and safety study, enrolled patients (pts) age 2 to <18 years with extended oligo- or poly-articular JIA, ERA, or JPsA, per ILAR criteria, and an inadequate response to ≥1 cs and/or b-DMARDs (NCT03773978). There were 3 periods: a 2-week (wk) pharmacokinetic/safety assessment (PKS), a 12-wk open-label lead-in (OLLI), and an up-to 32-wk double-blind withdrawal (DBW). Dosage and safety were confirmed in the PKS and then pts, including those from the PKS, enrolled in the OLLI, receiving age-based, oral, once daily doses of baricitinib. Pts with a JIA-ACR30 response at wk12, end of OLLI, entered the DBW to be randomized 1:1 to continued baricitinib or newly started placebo (PBO) and remained until flare or up to wk32. Primary endpoint was time to flare during the DBW. Secondary endpoints included JIA-ACR30/50/70/90 response rates at wk12, and proportion of pts with a flare during the DBW. Survival curves were estimated using the Kaplan-Meier method.

Results

Of 220 pts enrolled, 29 participated in the PKS, 219 entered the OLLI, and 163 entered the DBW. The JIA-ACR30/50/70/90 response at wk12 was 76.3%/63.5%/46.1%/20.1%, respectively. During the DBW, time of flare was significantly shorter with PBO vs baricitinib (hazard ratio 0.24 [95% CI 0.13,0.45], p<0.001; Figure 1). The proportion of pts with a flare during the DBW was significantly lower for baricitinib vs PBO (14 (17.1%) vs. 41 (50.6%), p<0.001). In the PKS and OLLI periods, 126 (57.3%) pts reported ≥1 treatment emergent adverse event (TEAE), while 6 (2.7%) reported ≥1 serious adverse event (SAE); Table 1. In the DBW, 38 (46.9%) and 54 (65.9%) pts reported ≥1 TEAE for PBO and baricitinib, respectively, whereas those with ≥1 SAE were 3 (3.7%) and 4 (4.9%). The mean wks of exposure was higher in the baricitinib vs PBO group during DBW (26.34 vs 18.91) due to study design. There were no deaths, cardiovascular events or uveitis and 1 case of herpes zoster. Table 1.

Conclusion

Baricitinib significantly reduced time to and frequency of JIA flares in pts with JIA versus PBO, and improved JIA-ACR scores in the majority of pts within 12wks. Safety findings were consistent with the known safety profile in adult rheumatoid arthritis indications. These findings support baricitinib as a treatment for signs and symptoms of JIA with an inadequate response to cs or b-DMARDs.

References

[1]Giannini EH, et. al. Preliminary definition of improvement in juvenile arthritis. Arthritis Rheum 1997; 40: 1202-1209.

[2]Brunner HI, et. al. Preliminary definition of disease flare in juvenile rheumatoid arthritis. J Rheumatol 2002; 29(5):1058-64.

Disclosure of Interests

Athimalaipet Ramanan Consultant of: Eli Lilly and Company, Abbvie, Roche, UCB, Novartis, Pfizer, and Sobi, Grant/research support from: Eli Lilly and Company, Pierre Quartier Consultant of: Eli Lilly and Company, Abbvie, Amgen, BMS, Novartis, Novimmune, Pfizer, Swedish Orphan Biovitrum, SANOFI, Speakers bureau: Abbvie, Novartis, Pfizer, Swedish Orphan Biovitrum, Nami Okamoto Consultant of: Swedish Orphan Biovitrum, Eli Lilly and Company, Speakers bureau: AbbVie, Eli Lilly and Company, Sanofi, Asahi Kasei Medical, Mitsubishi Tanabe Pharma, Bristol Myers Squibb, Pfizer Japan, Ayumi Pharma, Eisai, Torii Pharma, GlaxoSmithKline, Kyorin Pharma, Novartis, Chugai Pharmaceutical, Teijin Pharma, Gabriella Meszaros Employee of: Eli Lilly and Company, Joana Araujo Employee of: Eli Lilly and Company, Zhongkai Wang Employee of: Eli Lilly and Company, Ran Liao Employee of: Eli Lilly and Company, Brenda Crowe Employee of: Eli Lilly and Company, Xin Zhang Employee of: Eli Lilly and Company, Rodney Decker Employee of: Eli Lilly and Company, Stuart Keller Employee of: Eli Lilly and Company, Hermine Brunner Consultant of: AbbVie, Astra Zeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Celgene, Eli Lilly, EMD Serono, Idorsia, Cerocor, Janssen, GlaxoSmithKline, F. Hoffmann-La Roche, Merck, Novartis, R-Pharm, Sanofi, Speakers bureau: Novartis, Pfizer, GlaxoSmithKline, Nicolino Ruperto Consultant of: Eli Lilly and Company, Ablynx, Amgen, Astrazeneca-Medimmune, Aurinia, Bayer, Bristol Myers and Squibb, Cambridge Healthcare Research (CHR), Celgene, Domain therapeutic, Eli-Lilly, EMD Serono, Glaxo Smith and Kline, Idorsia, Janssen, Novartis, Pfizer, Sobi, UCB, Speakers bureau: Eli Lilly and Company, Glaxo Smith and Kline, Pfizer, Sobi, UCB

[Correlation of peritumoral circWDR25 expression with the prognosis of patients with hepatocellular carcinoma after curative resection]

OBJECTIVE

To study the association between the expression of peritumoral circWDR25 (hsa-circRNA-0004310) secreted by hepatic stellate cells (HSCs) and the prognosis of the patients with hepatocellular carcinoma (HCC) after curative resection.

METHODS

HSCs cell line LX-2 was co-cultured separately with 3 liver cancer cell lines (Hep3B, SMMC-7721, and HCCLM3) in Transwell chambers to obtain tumor cell-activated HSCs. The supernatants of HSC cultures were collected to isolate the exosomes, from which total RNA was extracted to detect circRNA expression profile. We also collected specimens of paracancerous liver tissues from 288 HCC patients undergoing radical resection in our department from January, 2014 to October, 2015, and the expression levels of circWDR25 and α-SMA were detected with in situ hybridization. Log-rank test and Cox regression analysis were used for univariate and multivariate analysis of the factors affecting the patients' prognosis, respectively.

RESULTS

Gene expression profiling revealed that the expression of circWDR25 was the most obviously up-regulated in the exosomes isolated from tumor-activated LX-2 cells. The expression of peritumoral circWDR25 was positively correlated with HSCs adjacent to the cancer loci (r=0.156, P=0.008). Multivariate analysis showed that a preoperative AST level >36 g/L, multiple tumors, a tumor diameter >5 cm, HSC>70, and circWDR25>190 were independent risk factors affecting the overall survival of HCC patients after radical resection; a preoperative AST level >36 g/L, multiple tumors, a tumor diameter >5 cm, presence of tumor thrombus, HSC>70, and circWDR25>190 were all independent risk factors for tumor-free survival in patients with liver cancer.

CONCLUSION

Peritumoral circWDR25 and HSCs are factors affecting the prognosis of HCC patients after radical hepatectomy, and their high expression in the adjacent tissues is closely related to a poor prognosis of the patients.

Impaired bone microarchitecture in distal interphalangeal joints in patients with primary hypertrophic osteoarthropathy assessed by high-resolution peripheral quantitative computed tomography

This study aimed to investigate the bone impairment in finger joints in PHO patients by HR-pQCT. Results showed distinguished differences in bone architecture and biomechanics parameters at DIPs between PHO patients and healthy controls using HR-pQCT assessment. Besides, serum PGE2, hsCRP and ESR levels were found negatively correlated with total vBMD.

INTRODUCTION

This study aimed to investigate the bone impairment in finger joints in primary hypertrophic osteoarthropathy (PHO) patients firstly by high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

Fifteen PHO patients and 15 healthy controls were enrolled in this study. Bone erosions in hands at distal interphalangeal joints (DIPs) in both PHO patients and controls were evaluated by X-ray. Bone geometry, vBMD, microstructure parameters, and size of individual bone erosion were also measured at the 3rd DIP by HR-pQCT as well. Blood biochemistry levels between the two groups were also compared.

RESULTS

Compared to X-ray, HR-pQCT assessment were more sensitive for detection of bone erosions, with 14 PHO patients by HR-pQCT versus ten PHO patients by X-ray judged at the 3rd DIP. The average depth, width, and volume of erosions size in PHO patients were 1.38 ± 0.80 mm, 0.79 ± 0.27 mm, and 1.71 ± 0.52 mm³, respectively. The bone cross-areas including total area (+ 25.3%, p ≤ 0.05), trabecular area (+ 56.2%, p ≤ 0.05), and cortical perimeter (+ 10.7%, p ≤ 0.05) at the defined region of interest of 3rd DIP was significantly larger than controls. Total vBMD was 11.9% lower in PHO patients compared with the controls (p ≤ 0.05). Biochemical test results showed the increased levels of inflammatory cytokines, bone resorption markers, and joint degeneration markers in PHO patients. Serum prostaglandin PGE2, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) levels were found negatively correlated with total vBMD.

CONCLUSIONS

This study demonstrated higher sensitivity of the HR-pQCT measurement at DIPs by showing the differences in architecture and biomechanics parameters at DIPs between the PHO patients and healthy controls, which would be of interest clinically to investigate bone deterioration in PHO patients.

Effects of miR-155 on hypertensive rats via regulating vascular mesangial hyperplasia

OBJECTIVE

Vascular smooth muscle cell (VSMC) excessive proliferation is related to hypertension. The cell cycle inhibitory factor (p27) can arrest cell cycle, while its down-regulation is associated with hypertension. It is found that microRNA-155 (miR-155) plays a regulatory role in VSMC proliferation, while its relationship with hypertension is still unclear. Bioinformatics analysis reveals the targeted relationship between miR-155 and the 3'-UTR of p27 mRNA. This study aims to explore the role of miR-155 in regulating p27 expression, VSMC proliferation and apoptosis, and the pathogenesis of hypertension.

MATERIALS AND METHODS

Dual luciferase reporter gene assay confirmed the relationship between miR-155 and p27. MiR-155, p27, α-smooth muscle actin (α-SMA), and Ki-67 expressions in the thoracic aorta media of rat hypertension model were detected. VSMCs were cultured in vitro and divided into five groups, including anti-miR-NC, anti-miR-155, pIRES2-blank, pIRES2-p27, and anti-miR-155 + pIRES2-p27 groups. Cell cycle was evaluated by using flow cytometry. Cell proliferation was detected with EdU staining. Hypertension rats were randomly divided into antagomir-155 and antagomir-control. Caudal artery systolic and diastolic pressures were measured.

RESULTS

MiR-155 targeted suppressed p27 expression. MiR-155 and Ki-67 expressions significantly enhanced, while p27 and α-SMA levels reduced in the tunica media from hypertension rats compared with control. Down-regulation of miR-155 and/or up-regulation of p27significantly declined cell proliferation and arrested cell cycle in G1 phase. Antagomir-155 injection markedly decreased systolic and diastolic pressures, elevated p27 and α-SMA expressions in media, and reduced the thickness of tunica media.

CONCLUSIONS

MiR-155 promoted VSMC proliferation by targeting p27. MiR-155 enhancement was related to hypertension. MiR-155 played a therapeutic effect on hypertension.

[Expression and significance of programmed cell death ligand-1 in neuroblastoma tissues]

Objective: To investigate the relationship between expression of programmed cell death ligand-1(PD-L1) in the tissue of neuroblastoma (NB) and patient's clinical characteristics and prognosis. Methods: Clinical data and surgical tissue paraffin blocks of 100 newly diagnosed NB children at Sun Yat-sen University Cancer Center between January 2000 and December 2015 were collected and the expression level of PD-L1 and its' relationship with pathological parameters and survival rate were analyzed retrospectively. The ratio between groups was compared by chi-square test. Kaplan-Meier method was used for survival analysis and COX regression model was used for multivariate analysis. Results: Among 100 cases, 71 were males and 29 females; there were 5 cases of stageⅠ, 4 cases of stageⅡ, 19 cases of stage Ⅲ, 65 cases of stage Ⅳ and 7 cases of stage Ⅳs. Ten out of 62 cases (16%) were N-MYC amplified; 15 cases were in low-risk group, 18 were in medium-risk group and 67 were in high-risk group. The positive rate of PD-L1 in NB tumor tissue was 57% (57/100), of which 55 were weakly positive, 1 was moderately positive and 1 was strongly positive. The positive rates of PD-L1 expression in tumor tissues without bone metastasis were higher than those with bone metastasis(66%(39/59)vs.44%(18/41), χ(2)=4.864, P=0.027), the positive rates of PD-L1 expression in tumor tissues pathologically diagnosed as neuroblastoma were higher than those pathologically diagnosed as ganglioneuroblastoma (61%(53/87) vs.31%(4/13), χ(2)=4.195, P=0.041), the positive rates of PD-L1 expression in tumor tissues originated from abdominal cavity were higher than those originated from other places (61% (51/83)vs.35%(6/17), χ(2)=3.937,P=0.047).The 4-year event-free survival (EFS) rates of patients with PD-L1 negative and positive were 40% and 33% (χ(2)=0.009, P=0.923), respectively. The 4-year overall survival (OS) rates of patients with PD-L1 negative and positive were 62% and 58% (χ(2)=0.294, P=0.587). Among 33 non-high-risk patients, the 4-year EFS rates of patients with PD-L1 negative and positive were 89% and 78% (χ(2)=0.001, P=0.965), the 4-year OS rates of patients with PD-L1 negative and positive were 100% and 96% (χ(2)=0.500, P=0.480). Among 67 high-risk patients, the 4-year EFS rates of patients with PD-L1 negative and positive were 24% and 11% (χ(2)=1.154, P=0.282), the 4-year OS rates of patients with PD-L1 negative and positive were 48% and 41% (χ(2)=0.692, P=0.405). Multivariate analysis showed that N-MYC gene amplification was an independent adverse prognostic factor for OS and EFS rates of NB patients (RR: 1.726,95%CI:1.209-2.466; RR:1.326,95%CI:1.014-1.736) and advanced clinical stage was an independent adverse prognostic factor for EFS rates of NB patients (RR: 26.498, 95%CI:3.518-199.614). Conclusions: The expression of PD-L1 in NB tumor tissues was correlated with the clinical characteristics of children. However, there were no significant differences in the prognosis of patients with or without PD-L1 expression.

[The study of nomogram based on Ishak inflammation score for recurrence of hepatocellular carcinoma after curative resection]

Objective: To investigate the correlation between Ishak inflammation score and the clinicopathological characteristics and recurrence of patients with hepatocellular carcinoma (HCC) after curative resection, and then set up a recurrence nomogram for HCC. Methods: A total of 326 patients with HCC after curative resection from January 2006 to December 2009 were studied retrospectively as training cohort and 110 HCC patients after surgery from January 2010 to December 2012 were used as validation cohort.Clinical follow-up data and peritumoral Ishak inflammation score in training cohort were used to set up a nomogram predicting recurrence of HCC, which was verified by validation cohort. Kaplan-Meier and Cox proportional hazard regression model were used to analyzed accuracy of model prediction. Results: According to Ishak inflammation score, patients were divided into four subgroups: Grade Ⅰ(1-4 scores), Grade Ⅱ(5-8 scores), Grade Ⅲ (9-12 scores) and Grade Ⅳ(13-18 scores). Ishak inflammation score were associated with aspartate transaminase(median 36.0 U/L, P=0.011), γ-glutamyl transpeptidase(median 54.5 U/L, P=0.005), HBV-DNA load(20.5%>10(6) copies/ml, P=0.015) and microvascular invasion(26.7% positive, P=0.021). Multivariate analysis showed that Ishak inflammation score(P=0.007), HBV-DNA load(P<0.01), tumor size(P=0.001) and microvascular invasion(P=0.001) were related with the recurrence of HCC patients.These four risk factors were incorporated into the nomogram.Calibration curves of the nomogram had good agreement between prediction and observation in the probability of recurrence.Both C-indexes and receiver operating characteristic curve analyses revealed that this nomogram had better predictive abilities than those of the AJCC and Barcelona Clinic Liver Cancer (BCLC) stage systems.These results were verified by the validation cohort. Conclusion: A nomogram based on Ishak inflammation score could accurately predict the recurrence of HCC and contribute to HCC relapse surveillance after curative hepatectomy.

[Analysis of prognostic factors of patients with hepatocellular carcinoma after radical resection]

Objective: To explore the prognostic factors of patients with hepatocellular carcinoma(HCC) after radical resection. Methods: From June 2006 to November 2009, preoperative peripheral blood and the clinicopathological data of 208 patients with HCC after curative resection treated in Department of Hepatobiliary Surgery, the First Affiliated Hospital of Chongqing Medical University, were collected and analyzed, including 173 male and 35 female patients with mean age of 53 years. Univariate analyses were applied by the Kaplan-Meier method, and then, significant clinical factors were used for further multivariate analyses by Cox proportional hazard regression model.The patients were divided into low- lymphocyte-monocyte ratio(MLR) group(MLR≤1.2) and high-MLR group(MLR>1.2) according to preoperative MLR. Results: The enrolled 208 patients with median overall survival time for 38 months(1.5-82.2 months), median recurrence-free survival time for 36 months(1.0-82.0 months). Univariate analyses revealed alanine aminotransferase, serum albumin, tumor differentiation, tumor size, TNM stage and clinical stages and MLR might affect the prognosis significantly(all P<0.05), and multiple analyses showed that TNM stage and MLR could influence patients with HCC after radical resection of overall survival time and recurrence-free survival time(all P<0.05). The overall survival time(42.1 months) and recurrence-free survival time(38.1 months) of low-MLR group were longer than high-MLR group(32.7 months and 25.3 months)(both P<0.01). Conclusions: MLR might be associated with prognosis of patients with HCC after curative resection was significantly negative correlation.TNM stage and MLR might be used as an independent prognostic factors for the prognosis of patients with HCC after curative resection.

Genome-wide genetic variation discovery in Chinese Taihu pig breeds using next generation sequencing

The Chinese Taihu pig breeds are an invaluable component of the world's pig genetic resources, and they are the most prolific breeds of swine in the world. In this study, the genomes of 252 pigs of the six indigenous breeds in the Taihu Lake region were sequenced using the genotyping by genome reducing and sequencing approach. A total of 950 million good reads were obtained using an Illumina Hiseq2000 at an average depth of 13× (for SNP calling) and an average coverage of 2.3%. In total, 122 632 indels, 31 444 insertions, 44 056 deletions and 455 CNVs (copy number variants) were identified in the genomes of the pigs. Approximately 2.3% of these genetic markers were mapped to gene exon regions, and 25% were in QTL regions related to economically important traits. The KEGG pathway or GO enrichment analyses revealed that genetic variants assumed to be large‐effect mutations were significantly overrepresented in 22 SNP, 56 indel, 26 insertion, 28 deletion and three CNV gene sets. A total of 343 breed‐specific SNPs were also identified in the six Chinese indigenous pigs. The findings from this study can contribute to future investigations of the genetic diversity, population structure, positive selection signals and molecular evolutionary history of these pigs at the genome level and can serve as a valuable reference for improving the breeding and cultivation of these pigs.

Scatter to volume registration for model-free respiratory motion estimation from dynamic MRIs

Respiratory motion is one major complicating factor in many image acquisition applications and image-guided interventions. Existing respiratory motion estimation and compensation methods typically rely on breathing motion models learned from certain training data, and therefore may not be able to effectively handle intra-subject and/or inter-subject variations of respiratory motion. In this paper, we propose a respiratory motion compensation framework that directly recovers motion fields from sparsely spaced and efficiently acquired dynamic 2-D MRIs without using a learned respiratory motion model. We present a scatter-to-volume deformable registration algorithm to register dynamic 2-D MRIs with a static 3-D MRI to recover dense deformation fields. Practical considerations and approximations are provided to solve the scatter-to-volume registration problem efficiently. The performance of the proposed method was investigated on both synthetic and real MRI datasets, and the results showed significant improvements over the state-of-art respiratory motion modeling methods. We also demonstrated a potential application of the proposed method on MRI-based motion corrected PET imaging using hybrid PET/MRI.

Genome-wide association study reveals novel variants for growth and egg traits in Dongxiang blue-shelled and White Leghorn chickens

This study was designed to investigate the genetic basis of growth and egg traits in Dongxiang blue-shelled chickens and White Leghorn chickens. In this study, we employed a reduced representation sequencing approach called genotyping by genome reducing and sequencing to detect genome-wide SNPs in 252 Dongxiang blue-shelled chickens and 252 White Leghorn chickens. The Dongxiang blue-shelled chicken breed has many specific traits and is characterized by blue-shelled eggs, black plumage, black skin, black bone and black organs. The White Leghorn chicken is an egg-type breed with high productivity. As multibreed genome-wide association studies (GWASs) can improve precision due to less linkage disequilibrium across breeds, a multibreed GWAS was performed with 156 575 SNPs to identify the associated variants underlying growth and egg traits within the two chicken breeds. The analysis revealed 32 SNPs exhibiting a significant genome-wide association with growth and egg traits. Some of the significant SNPs are located in genes that are known to impact growth and egg traits, but nearly half of the significant SNPs are located in genes with unclear functions in chickens. To our knowledge, this is the first multibreed genome-wide report for the genetics of growth and egg traits in the Dongxiang blue-shelled and White Leghorn chickens.

Real-time 6DoF pose recovery from X-ray images using library-based DRR and hybrid optimization

PURPOSE

Real-time 6 degrees of freedom (6DoF) pose recovery and tracking from X-ray images is a key enabling technology for many interventional imaging applications. However, real-time 2D/3D registration is a very challenging problem because of the heavy computation in iterative digitally reconstructed radiograph (DRR) generation. In this paper, we propose a real-time 2D/3D registration framework using library-based DRRs to achieve high computational efficiency.

METHOD

The proposed method pre-computes a library of canonical DRRs and reconstructs library-based DRRs (libDRRs) during registration without online rendering. The transformation parameters are decoupled to 2 geometry-relevant and 4 geometry-irrelevant ones so that canonical DRRs only need to cover the variation of 2 geometry-relevant parameters, making it practical to be pre-computed and stored. The 2D/3D registration using libDRRs is then solved as a hybrid optimization problem, i.e., continuous in geometry-irrelevant parameters while discrete in geometry-relevant parameters.

RESULTS

On 5 fluoroscopic sequences with 246 frames acquired during animal studies with a transesophageal echocardiography (TEE) probe in the field of view, 6DoF tracking of the TEE probe using the proposed method achieved a mean target registration error in the projection direction (mTREproj) of 0.81 mm, a success rate of 100 % (defined as mTREproj [Formula: see text]2.5 mm), and a registration frame rate of 23.1 fps on a pure CPU-based implementation executed in a single thread.

CONCLUSION

Using libDRRs with a hybrid optimization can significantly improve the computational efficiency (up to tenfold) for 6DoF pose recovery and tracking with little degradation in robustness and accuracy, compared to conventional intensity-based 2D/3D registration using ray casting DRRs with a continuous optimization.

Novel mutations of CLCN7 cause autosomal dominant osteopetrosis type II (ADO-II) and intermediate autosomal recessive osteopetrosis (IARO) in Chinese patients

SUMMARY

Osteopetrosis is a group of genetic bone disorders. Mutations in the chloride channel 7 gene (CLCN7) lead to chloride channel defect, which results in autosomal dominant osteopetrosis type II (ADO-II), autosomal recessive osteopetrosis (ARO), and intermediate autosomal recessive osteopetrosis (IARO). In the present study, we identified seven novel mutations of the CLCN7 gene and reported the first case of IARO with compound heterozygous mutation in Chinese population.

INTRODUCTION

Osteopetrosis is a heritable bone disorder due to the deficiency of or function defect in osteoclasts. Mutations in the CLCN7 lead to chloride channel defects, which result in osteopetrosis with diverse severity ranging from asymptomatic or relatively mild symptoms in ADO-II to the very severe phenotype in ARO. Heterozygous mutations in CLCN7 are associated to ADO-II, while homozygous and compound heterozygous mutations in CLCN7 may result in ARO and IARO. To date, a total of 24 mutations in CLCN7 were identified in ADO-II, and only 3 mutations were identified in IARO. In the present study, we reported seven unrelated ADO-II patients and one IARO patient from Chinese population and elucidated the characteristics of CLCN7 gene mutations in these patients.

METHODS

All 25 CLCN7 exons and exon-intron boundaries from genomic DNA were amplified and sequenced in eight affected individuals suffering from ADO-II/IARO. The clinical, biochemical, and radiographic analysis were evaluated to compare the differences between ADO-II and IARO both in genotype and phenotype.

RESULTS

The results showed that there were seven novel CLCN7 mutations identified in these ADO-II/IARO patients, including six heterozygous missense mutations (p.L224R, p.S290Y, p.R326G, p.G347R, p.S473N, and p.L564P) and a novel splice mutation (p.K691FS).

CONCLUSIONS

The compound heterozygous mutations (p.L224R and p.K691FS) were firstly observed in one IARO patient. The present study would enrich the database of CLCN7 mutations and improve our understanding of this heritable bone disorder.

Genetic diversity and population structure of six Chinese indigenous pig breeds in the Taihu Lake region revealed by sequencing data

The Chinese indigenous pig breeds in the Taihu Lake region are the most prolific pig breeds in the world. In this study, we investigated the genetic diversity and population structure of six breeds, including Meishan, Erhualian, Mi, Fengjing, Shawutou and Jiaxing Black, in this region using whole‐genome SNP data. A high SNP with proportions of polymorphic markers ranging from 0.925 to 0.995 was exhibited by the Chinese indigenous pigs in the Taihu Lake region. The allelic richness and expected heterozygosity also were calculated and indicated that the genetic diversity of the Meishan breed was the greatest, whereas that of the Fengjing breed was the lowest. The genetic differentiation, as indicated by the fixation index, exhibited an overall mean of 0.149. Both neighbor‐joining tree and principal components analysis were able to distinguish the breeds from each other, but structure analysis indicated that the Mi and Erhualian breeds exhibited similar major signals of admixture. With this genome‐wide comprehensive survey of the genetic diversity and population structure of the indigenous Chinese pigs in the Taihu Lake region, we confirmed the rationality of the current breed classification of the pigs in this region.

Outbreak of extrapulmonary tuberculosis infection associated with acupuncture point injection

Mycobacterium tuberculosis infection is rarely reported to be associated with acupuncture practices. We performed a retrospective outbreak investigation of a unique outbreak of 33 extrapulmonary M. tuberculosis infections related to acupuncture point injection therapy (AIT) among clients who visited a private traditional Chinese medicine clinical centre in China. The lumps, abscesses and ulcers occurred mostly on the neck, shoulders, waist, knees and hips, localized at acupuncture point meridian sites. These symptoms appeared from January to November 2011, with a peak cluster of infections in September 2011 (nine cases). M. tuberculosis Beijing strain was isolated and confirmed by DNA sequencing. All diagnosed patients were treated empirically with appropriate antibiotic treatment, and their condition improved. Our study indicated that this outbreak was most likely resulted from contaminated AIT. Drafting standard guidelines for AIT is urgently needed, and routine medical supervision should be provided, including obligating health providers to perform routine physical examinations that include testing for infectious diseases.

ECMO support for right main bronchial disruption in multiple trauma patient with brain injury--a case report and literature review

Extracorporeal membrane oxygenation (ECMO) may offer life-saving treatment in severe pulmonary contusion or acute respiratory distress syndrome when conventional treatments have failed. However, because of the bleeding risk of systemic anticoagulation, ECMO should be performed only as a last resort in multiple trauma victims. Here, we report ECMO as a bridge for right main bronchus reconstruction and recovery of traumatic wet lung in a 31-year-old male multi-trauma patient with right main bronchial disruption, bilateral pulmonary contusion, cerebral contusion and long bone fracture. The patient was discharged without any obvious complication. ECMO support in a traumatic brain injured patient with severe hypoxemia caused by lung contusion and/or tracheal bronchus disruption is not an absolute contraindication.

Folate pathway disruption leads to critical disruption of methionine derivatives in Mycobacterium tuberculosis

In this study, we identified antifolates with potent, targeted activity against whole-cell Mycobacterium tuberculosis (MTB). Liquid chromatography-mass spectrometry analysis of antifolate-treated cultures revealed metabolic disruption, including decreased pools of methionine and S-adenosylmethionine. Transcriptomic analysis highlighted altered regulation of genes involved in the biosynthesis and utilization of these two compounds. Supplementation with amino acids or S-adenosylmethionine was sufficient to rescue cultures from antifolate treatment. Instead of the "thymineless death" that characterizes folate pathway inhibition in a wide variety of organisms, these data suggest that MTB is vulnerable to a critical disruption of the reactions centered around S-adenosylmethionione, the activated methyl cycle.

Mycobacterium tuberculosis Ser/Thr protein kinase B mediates an oxygen-dependent replication switch

Mtb growth and replication are sensitive to altered levels of the Ser/Thr kinase PknB, and this sensitivity increased under hypoxic conditions. Thus, PknB is a critical regulator of the oxygen-dependent replication switch of Mycobacterium tuberculosis.

The majority of Mycobacterium tuberculosis (Mtb) infections are clinically latent, characterized by drug tolerance and little or no bacterial replication. Low oxygen tension is a major host factor inducing bacteriostasis, but the molecular mechanisms driving oxygen-dependent replication are poorly understood. Here, we tested the role of serine/threonine phosphorylation in the Mtb response to altered oxygen status, using an in vitro model of latency (hypoxia) and reactivation (reaeration). Broad kinase inhibition compromised survival of Mtb in reaeration. Activity-based protein profiling and genetic mutation identified PknB as the kinase critical for surviving hypoxia. Mtb replication was highly sensitive to changes in PknB levels in aerated culture, and even more so in hypoxia. A mutant overexpressing PknB specifically in hypoxia showed a 10-fold loss in viability and gross morphological defects in low oxygen conditions. In contrast, chemically reducing PknB activity during hypoxia specifically compromised resumption of growth during reaeration. These data support a model in which PknB activity is reduced to achieve bacteriostasis, and elevated when replication resumes. Together, these data show that phosphosignaling controls replicative transitions associated with latency and reactivation, that PknB is a major regulator of these transitions, and that PknB could provide a highly vulnerable therapeutic target at every step of the Mtb life cycle—active disease, latency, and reactivation.

Exposure to Mycobacterium tuberculosis (Mtb) can result in a latent form of tuberculosis (TB) infection, which can then reactivate and progress to active disease. With 1.8 billion infected persons and no tools to predict who will proceed to active disease, latency and reactivation are among the major challenges of TB treatment and control. Oxygen is one of the environmental triggers affecting the balance between latency and reactivation. Normal oxygen levels promote exponential bacterial growth in culture, but low oxygen levels (hypoxia) inhibit such growth, inducing reversible bacteriostasis. How Mtb regulates this oxygen-dependent replication switch, however, is still unknown. Here we tested the role of serine/threonine protein kinases—signaling molecules that transmit environmental cues into cellular responses—in this process. We found that kinase inhibition led to a bacterial survival defect and we specifically identified the PknB kinase as a critical regulator of the oxygen-dependent replication switch. Mtb growth was sensitive to elevated levels of PknB and this sensitivity increased in hypoxia. Inhibition of PknB activity led to defects in Mtb replication. These data show that signaling through PknB modulates the growth and replication state of Mtb in response to oxygen, suggesting that PknB could be a drug target by which to control both the active replicating and latent nonreplicating forms of Mtb.

Identification of new drug targets and resistance mechanisms in Mycobacterium tuberculosis

Identification of new drug targets is vital for the advancement of drug discovery against Mycobacterium tuberculosis, especially given the increase of resistance worldwide to first- and second-line drugs. Because traditional target-based screening has largely proven unsuccessful for antibiotic discovery, we have developed a scalable platform for target identification in M. tuberculosis that is based on whole-cell screening, coupled with whole-genome sequencing of resistant mutants and recombineering to confirm. The method yields targets paired with whole-cell active compounds, which can serve as novel scaffolds for drug development, molecular tools for validation, and/or as ligands for co-crystallization. It may also reveal other information about mechanisms of action, such as activation or efflux. Using this method, we identified resistance-linked genes for eight compounds with anti-tubercular activity. Four of the genes have previously been shown to be essential: AspS, aspartyl-tRNA synthetase, Pks13, a polyketide synthase involved in mycolic acid biosynthesis, MmpL3, a membrane transporter, and EccB3, a component of the ESX-3 type VII secretion system. AspS and Pks13 represent novel targets in protein translation and cell-wall biosynthesis. Both MmpL3 and EccB3 are involved in membrane transport. Pks13, AspS, and EccB3 represent novel candidates not targeted by existing TB drugs, and the availability of whole-cell active inhibitors greatly increases their potential for drug discovery.

Mycobacterium thermoresistibile as a source of thermostable orthologs of Mycobacterium tuberculosis proteins

The genus Mycobacterium comprises major human pathogens such as the causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), and many environmental species. Tuberculosis claims ~1.5 million lives every year, and drug resistant strains of Mtb are rapidly emerging. To aid the development of new tuberculosis drugs, major efforts are currently under way to determine crystal structures of Mtb drug targets and proteins involved in pathogenicity. However, a major obstacle to obtaining crystal structures is the generation of well-diffracting crystals. Proteins from thermophiles can have better crystallization and diffraction properties than proteins from mesophiles, but their sequences and structures are often divergent. Here, we establish a thermophilic mycobacterial model organism, Mycobacterium thermoresistibile (Mth), for the study of Mtb proteins. Mth tolerates higher temperatures than Mtb or other environmental mycobacteria such as M. smegmatis. Mth proteins are on average more soluble than Mtb proteins, and comparison of the crystal structures of two pairs of orthologous proteins reveals nearly identical folds, indicating that Mth structures provide good surrogates for Mtb structures. This study introduces a thermophile as a source of protein for the study of a closely related human pathogen and marks a new approach to solving challenging mycobacterial protein structures.

Respiratory motion compensation by model-based catheter tracking during EP procedures

In many cases, radio-frequency catheter ablation of the pulmonary veins attached to the left atrium still involves fluoroscopic image guidance. Two-dimensional X-ray navigation may also take advantage of overlay images derived from static pre-operative 3D volumetric data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of static overlay images for catheter navigation. We developed a novel approach for image-based 3D motion estimation and compensation as a solution to this problem. It is based on 3D catheter tracking which, in turn, relies on 2D/3D registration. To this end, a bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3D based on bi-plane fluoroscopy. Phantom data and clinical data were used to assess model-based catheter tracking. Our phantom experiments yielded an average 2D tracking error of 1.4mm and an average 3D tracking error of 1.1mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2D tracking error of 1.0 + or - 0.4mm and an average 3D tracking error of 0.8 + or - 0.5mm. These results demonstrate that model-based motion-compensation based on 2D/3D registration is both feasible and accurate.

Genetic evolution of EGFR and the clonal origin of adenocarcinomas exhibiting various degrees of bronchioloalveolar carcinoma

e22050

Background: EGFR mutations may accumulate during multistage progression of bronchioloalveolar carcinoma (BAC), leading to heterogeneity within the tumor. Moreover, intrapulmonary emersions are the predominant sites of BAC progression in the absence of other distant metastases. In cases of emerging bilateral lung lesions during the follow-up to complete resection, the issue of how to differentiate between lesions originating from multifocal BACs or distant metastases/local recurrence is an important and unresolved issue. This study was performed to determine whether sequential adenocarcinoma with BAC features emerges in the lung field arises from a single clone or multiple clones in the same individual. Methods: Samples of adenocarcinomas exhibiting various degrees of BAC were obtained by thoracotomy. Sequential specimens were obtained on detection of novel lesions in the lung field. Genomic DNA was extracted from the specimens, and the presence of activating mutations in EGFR was analyzed by direct sequencing. Our pathological findings, sequential imaging, and EGFR sequence data were compared to monitor evidence of cancer evolution. Results: Based on an analysis of EGFR in tumor specimens from 428 lung cancer patients, fifteen cases of sequential BAC-related adenocarcinoma obtained by thoracotomy were identified. Together with alterations in BAC/adenocarcinoma components, the EGFR-TKI untreated series with at least one episode of EGFR-activating mutations represented three typical models: no significant EGFR evolution for a single clone, genetic alterations from mutant to wild-type EGFR for multifocal lesions, and a switch from wild-type to mutant EGFR, which might exhibit uncertain circumstances of cancer progression. Conclusions: Genetic analysis in conjunction with pathological and radiological diagnoses can be used to explore the origin of multifocal BAC. The single clone model indicates subsequent disease progression, whereas genetic alterations from mutations to wild-type EGFR are suggestive of secondary primary carcinoma. When additional lesions emerge after radical resection of BAC-related lung cancer, sequential tumor samples should be obtained for further evaluation.

No significant financial relationships to disclose.

Innate immunity is initially effective in killing Mycobacterium tuberculosis (129.20)

Mycobacterium tuberculosis (MTB) is a slow growing pathogen often resulting in lifelong infection. To investigate whether slow replication is an immune evasion strategy for MTB, we developed a replication tracking tool consisting of an unstable plasmid that is lost from replicating MTB at a constant rate. Mice were infected with MTB harboring this plasmid and at various times total and plasmid bearing bacteria in lungs were enumerated. MTB replication and death rates were derived using a mathematical model. Lung bacterial numbers increase for 21 days until antigen specific T cells arrive, after which time they remain constant. Using the unstable plasmid, we observed that replication and death rates were highest early and then slowed during chronic infection. Closer analysis of the acute phase revealed the dynamics of MTB replication and death. High replication and death rates were observed in the first 5 days and then both abruptly slowed. Killing was also observed in Rag1-/- mice indicating that innate immunity is effective in killing MTB. Our studies demonstrate that standard plating methods provide an incomplete picture. Using a replication tracking tool, we found that innate immunity is initially effective in killing MTB but that this is short lived. Which innate immune response mechanisms are at work and why both MTB replication and death so rapidly decrease are topics of ongoing studies.

This work was funded by the Paul G Allen Family Foundation.

Cell therapy for cardiac repair

Cardiovascular diseases remain the leading cause of morbidity and mortality in Western society. Among these diseases, congestive heart failure continues to be a significant health care burden. Recent medical and surgical advances in therapy have improved the quality and quantity of life for patients with heart failure. However, none of these therapies address the fundamental problem of loss of functional cardiomyocytes. Cell regeneration therapies have become an exciting potential treatment for heart failure and other cardiovascular diseases. This emerging therapeutic field has been pursued experimentally with both embryonic-derived stem cells and adult-derived progenitor cells. The identification of resident cardiac progenitor cells has propelled the field of cardiac regenerative biology forward at astonishing rates. This review will examine current findings of various stem and progenitor cells that have been proposed as potential sources for cardiac regeneration, and the recent therapeutic findings from preliminary clinical trials using some of these cell types for cardiovascular repair.

Sensitivity of mouse lung fibroblasts heterozygous for GPx4 to oxidative stress

Phospholipid hydroperoxide glutathione peroxidase (GPx4) is a member of the family of selenium-dependent enzymes that catalyze the reduction of cell membrane-bound phospholipid hydroperoxides in situ and thus protects against membrane damage. Overexpression of GPx4 protects cultured cells from phosphatidylcholine hydroperoxide (PCOOH)-induced loss of mitochondrial membrane potential and blocks cell death induced by treatment with various apoptotic agents. We have generated mice that are heterozygous for a GPx4 null allele (GPx4 +/-); the homozygous null genotype is embryonic lethal. We report that cultured lung fibroblasts (LFs) isolated from adult GPx4 +/- mice had approximately 50% of the GPx4 activity of LFs from GPx4 +/+ mice and were significantly more susceptible to H2O2, cadmium, and cumene hydroperoxide-induced cytotoxicity, as measured by neutral red assay. Both GPx4 +/+ and GPx4 +/- LFs were susceptible to PCOOH-induced cytotoxicity at a high PCOOH concentration. We also found that GPx4 +/- LFs have lower mitochondrial membrane potential, greater cardiolipin oxidation, and lower amounts of reduced thiols relative to GPx4 +/+ LFs, but are more resistant than GPx4 +/+ LFs to further decrements in these endpoints following PCOOH treatment. These results suggest that adult lung fibroblasts deficient in GPx4 may have upregulated compensatory mechanisms to deal with the highly oxidized environment in which they developed.

The enduring hypoxic response of Mycobacterium tuberculosis

Background

A significant body of evidence accumulated over the last century suggests a link between hypoxic microenvironments within the infected host and the latent phase of tuberculosis. Studies to test this correlation have identified the M. tuberculosis initial hypoxic response, controlled by the two-component response regulator DosR. The initial hypoxic response is completely blocked in a dosR deletion mutant.

Methodology/Principal Findings

We show here that a dosR deletion mutant enters bacteriostasis in response to in vitro hypoxia with only a relatively mild decrease in viability. In the murine infection model, the phenotype of the mutant was indistinguishable from that of the parent strain. These results suggested that additional genes may be essential for entry into and maintenance of bacteriostasis. Detailed microarray analysis of oxygen starved cultures revealed that DosR regulon induction is transient, with induction of nearly half the genes returning to baseline within 24 hours. In addition, a larger, sustained wave of gene expression follows the DosR-mediated initial hypoxic response. This Enduring Hypoxic Response (EHR) consists of 230 genes significantly induced at four and seven days of hypoxia but not at initial time points. These genes include a surprising number of transcriptional regulators that could control the program of bacteriostasis. We found that the EHR is independent of the DosR-mediated initial hypoxic response, as EHR expression is virtually unaltered in the dosR mutant.

Conclusions/Significance

Our results suggest a reassessment of the role of DosR and the initial hypoxic response in MTB physiology. Instead of a primary role in survival of hypoxia induced bacteriostasis, DosR may regulate a response that is largely optional in vitro and in mouse infections. Analysis of the EHR should help elucidate the key regulatory factors and enzymatic machinery exploited by M. tuberculosis for long-term bacteriostasis in the face of oxygen deprivation.

Rv3133c/dosR is a transcription factor that mediates the hypoxic response of Mycobacterium tuberculosis

Unlike many pathogens that are overtly harmful to their hosts, Mycobacterium tuberculosis can persist for years within humans in a clinically latent state. Latency is often linked to hypoxic conditions within the host. Among M. tuberculosis genes induced by hypoxia is a putative transcription factor, Rv3133c/DosR. We performed targeted disruption of this locus followed by transcriptome analysis of wild-type and mutant bacilli. Nearly all the genes powerfully regulated by hypoxia require Rv3133c/DosR for their induction. Computer analysis identified a consensus motif, a variant of which is located upstream of nearly all M. tuberculosis genes rapidly induced by hypoxia. Further, Rv3133c/DosR binds to the two copies of this motif upstream of the hypoxic response gene alpha-crystallin. Mutations within the binding sites abolish both Rv3133c/DosR binding as well as hypoxic induction of a downstream reporter gene. Also, mutation experiments with Rv3133c/DosR confirmed sequence-based predictions that the C-terminus is responsible for DNA binding and that the aspartate at position 54 is essential for function. Together, these results demonstrate that Rv3133c/DosR is a transcription factor of the two-component response regulator class, and that it is the primary mediator of a hypoxic signal within M. tuberculosis.

Bilateral central retinal vein occlusions in a Chinese patient with HIV-infection

PURPOSE

To report a case of bilateral nonischemic central retinal vein occlusions as the initial presentation in a Chinese patient with HIV-infection.

METHODS

Complete ophthalmological examination and fundus fluorescein angiography were performed in the eyes of this patient.

RESULTS

Ophthalmic examination and fundus fluorescein angiography revealed bilateral nonischemic central retinal vein occlusions and optic disc edema in a 22-year-old man who was HIV-positive. The findings of fundus examination and fluorescein angiography were similar in both eyes.

CONCLUSION

This case provides additional evidence that central retinal vein occlusion is probably part of the spectrum of HIV retinopathy.

Deletion of RD1 from Mycobacterium tuberculosis mimics bacille Calmette-Guérin attenuation

The tuberculosis (TB) vaccine bacille Calmette-Guérin (BCG) is a live attenuated organism, but the mutation responsible for its attenuation has never been defined. Recent genetic studies identified a single DNA region of difference, RD1, which is absent in all BCG strains and present in all Mycobacterium tuberculosis (MTB) strains. The 9 open-reading frames predicted within this 9.5-kb region are of unknown function, although they include the TB-specific immunodominant antigens ESAT-6 and CFP-10. In this study, RD1 was deleted from MTB strain H37Rv, and virulence of H37Rv:DeltaRD1 was assessed after infections of the human macrophage-like cell line THP-1, human peripheral blood monocyte-derived macrophages, and C57BL/6 mice. In each of these systems, the H37Rv:DeltaRD1 strain was strikingly less virulent than MTB and was very similar to BCG controls. Therefore, it was concluded that genes within or controlled by RD1 are essential for MTB virulence and that loss of RD1 was important in BCG attenuation.