[Retrospective study of diagnosis and treatment of renal oncocytoma]

OBJECTIVE

To summarize the experience of diagnosis and surgical treatment of renal oncocytoma, and to evaluate the surgical results based on follow-up results, in order to find the best strategy.

METHODS

In the study, 21 cases with renal oncocytoma from December 2003 to April 2016 in Peking University Third Hospital were retrospectively analyzed, including 4 males, and 17 females, with 10 cases on the right side and 11 cases on the left side. Their age was between 15 to 80 years (average: 58 years). Ultrasound or CT examination after admission was conducted. Ultrasound examination showed solid nodules. CT manifestations were solid masses with enhancement, and the tumor size was between 1.5 cm to 6.5 cm (average: 3.3 cm). Of the 21 cases, 9 were located in the middle of kidney, 7 were located in the upper pole, and 5 were located in the lower pole. After preoperative examination, according to the size and location of the tumor, laparoscopic partial nephrectomy or laparoscopic nephrectomy was performed, respectively.

RESULTS

All the operations were successful, in which 17 cases underwent laparoscopic partial nephrectomy (including 3 cases which were converted to open surgery), and 4 cases underwent laparoscopic radical nephrectomy. The operation time ranged from 75 to 274 min (mean: 144 min), and the blood loss ranged from 10 to 1 000 mL (mean: 115 mL). The postoperative hospital stay time ranged from 6 to 13 d (average: 8.2 d). The pathological results were all renal oncocytoma. In the study, 17 cases were followed up while 4 cases were lost to follow-up. The follow-up time ranged from 12 to 175 months (mean: 44 months). One case died in 20 months after operation with unknown reason, and there were no recurrence or metastasis in the other 16 cases.

CONCLUSION

Renal oncocytoma is a benign tumor with good prognosis. Enhanced CT is an effective diagnostic method in assistant examination, but it is difficult to differentiate clear cell carcinoma only from the naked eye. It is worthwhile to measure CT value at different stages of the tumor by picture archiving and communication systems (PACS), and to compare with CT value of adjacent kidney tissue may improve the diagnostic efficiency of CT. Laparoscopic surgery is an effective treatment for renal oncocytoma. We recommend laparoscopic partial nephrectomy for the patients with renal oncocytoma as the best choice if conditions permit.

Coupled Pretreatment with Liquid Nitrogen and Ball Milling for Enhanced Cellulose Hydrolysis in Water

A key problem in the conversion of cellulose into chemicals and fuels is the low product yield from cellulose due to its robust structure. In this work, for the first time, cellulose was pretreated with coupling of liquid nitrogen and ball milling (LN-BM) for cellulose hydrolysis. After the LN-BM treatment, the glucose yield from cellulose by HCl in water increased by almost 2 times and yield of formic acid catalyzed by H₂SO₄-NaVO₃ was more than 3-fold that obtained from untreated cellulose. The yields were also much higher than that from the individually ball-milled cellulose. The structure variation of cellulose indicated that reduction of both crystallinity index and molecular weight contributed to improving the conversion efficiency, but the former was the dominant factor. The combination of liquid nitrogen and ball milling developed in this work is an effective and environment-friendly approach for cellulose pretreatment.

Wnt Production in Dental Epithelium Is Crucial for Tooth Differentiation

The Wnt ligands display varied spatiotemporal expression in the epithelium and mesenchyme in the developing tooth. Thus far, the actions of these differentially expressed Wnt ligands on tooth development are not clear. Shh expression specifies the odontogenic epithelium during initiation and is consistently restricted to the dental epithelium during tooth development. In this study, we inactivate Wntless ( Wls), the key regulator for Wnt trafficking, by Shh-Cre to investigate how the Wnt ligands produced in the dental epithelium lineage act on tooth development. We find that conditional knockout of Wls by Shh-Cre leads to defective ameloblast and odontoblast differentiation. Wls^Shh-Cre teeth display reduced canonical Wnt signaling activity in the inner enamel epithelium and the underlying mesenchyme at the early bell stage, as exhibited by target gene expression and BAT-gal staining. The expression of Wnt5a and Wnt10b is not changed in Wls^Shh-Cre teeth. By contrast, Wnt10a expression is significantly increased in response to epithelial Wls deficiency. In addition, the expression of Hedgehog signaling pathway components Shh, Gli1, and Patched1 was greatly decreased in Wls^Shh-Cre teeth. Epithelial Wls loss of function in Shh lineage also leads to aberrant cell proliferation in dental epithelium and mesenchyme at embryonic day 16.5; however, the cell apoptosis is unaffected. Moreover, we find that Decorin and Col1a1, the key markers for odontoblast differentiation that are downregulated in Wls^Shh-Cre teeth, act as direct downstream targets of the canonical Wnt signaling pathway by chromatin immunoprecipitation analysis. Additionally, Decorin and Col1a1 expression can be increased by lithium chloride (LiCl) treatment in the in vitro tooth explants. Taken together, our results suggest that the spatial expression of Wnt ligands within the dental epithelial lineage regulates the differentiation of tooth structures in later stages.

Developing more participatory and accountable institutions for health: identifying health system research priorities for the Sustainable Development Goal-era

Health policy and systems research (HPSR) is vital to guiding global institutions, funders, policymakers, activists and implementers in developing and enacting strategies to achieve the Sustainable Development Goals. We undertook a multi-stage participatory process to identify priority research questions relevant to improving accountability within health systems. We conducted interviews (n = 54) and focus group discussions (n = 2) with policymakers from international and national bodies (ministries of health, other government agencies and technical support institutions) across the WHO regions. Respondents were asked to reflect on challenges and current policy discussions related to health systems accountability, and to identify their pressing research needs. We also conducted an overview of reviews (n = 34) to determine the current status of knowledge on health systems accountability and to identify any gaps. We extracted research questions from the policymaker interviews and focus groups (70 questions) and from the overview of reviews (112 questions), and synthesized these into 36 overarching questions. Using the online platform Co-Digital, we invited researchers from around the world to refine and then rank the questions according to research importance. The questions that emerged amongst the top priorities focused on political factors that mediate the adoption or effectiveness of accountability initiatives, processes and incentives that facilitate the acceptability of accountability mechanisms among frontline healthcare providers, and the national governance reforms and contexts that enhance provider accountability. The process revealed different underlying conceptions of social accountability and how best to promote it, with some researchers and policymakers focusing on specific interventions and others embracing a more systems-oriented approach to understanding accountability, the multiple forms that it can take, how these interact with each other and the importance of power and underlying social relations. The findings from this exercise identify HPSR funding priorities and future areas for evidence production and policy engagement.

Mechanochemical-assisted hydrolysis of pretreated rice straw into glucose and xylose in water by weakly acidic solid catalyst

In this work, carbonaceous materials bearing only weakly acidic COOH and phenolic OH groups were directly prepared by the pyrolysis of lignin and KOH in black liquor generating from rice straw that was pretreated with KOH aqueous solution. The synthesized carbon materials were used for the hydrolysis of cellulose or the alkali pretreated rice straw in water, after mixed ball-milling pretreatment, and provided a high glucose yield of 76.3% for cellulose, high yields of 52.1% glucose and 66.5% xylose for alkali pretreated rice straw, respectively, in 0.015 wt% HCl aqueous solution at 200 °C for 60 min. The weakly acidic catalyst showed good stability and recyclability in the aqueous reaction system. This work provides an efficient process for the hydrolysis of lignocellulose by biomass-derived weakly acidic catalysts in water and should have wide applications in biomass utilization.

[Single-center study of laparoscopic radical nephrectomy with Mayo 0-2 level inferior vena cava thrombectomy]

OBJECTIVE

To investigate the safety and feasibility of laparoscopic treatment for renal carcinoma with Mayo 0-2 level venous thrombosis.

METHODS

From January 2015 to February 2018, 58 renal carcinoma cases with venous thrombus underwent laparoscopic radical nephrectomy with inferior vena cava thrombectomy in Department of Urology, Peking University Third Hospital, of which, 51 cases were male, and 7 female, aged 29-82 years. According to the Mayo grade classification, 20 cases were level 0, 20 cases were level 1, and 18 cases were level 2, with left side being 22 cases, and right side 36 cases. The patients except for those complicated with hemorrhagic diseases, cardiac and pulmonary insufficiency, or those who could not tolerate anesthesia and surgical contraindications, underwent the operation after comprehensive examinations.

RESULTS

The 58 cases of renal tumor with venous tumor emboli were successfully completed with the surgeries, including 50 cases of totally laparoscopic surgery, 8 cases of laparoscopy surgery from convert to open (among the patients who were converted to open surgery, 7 were complicated with grade 2 tumor thrombus and 1 with grade 1 tumor thrombus). The main reasons for converting to open surgery were huge tumors (the largest of which was about 16 cm in diameter), severe adhesion and difficulty of separation. For different patients, different surgical methods and procedures were adopted according to the tumor direction and the different grade of tumor thrombus. Radical nephrectomy combined with vena cava tumor thrombus removal was performed in 55 cases and segmental resection of vena cava in 3 cases. The operation time was 132-557 min, and blood loss was 20-3 000 mL. Post-operative pathological types: 51 cases were clear cell carcinoma, 5 cases were type 2 of papillary carcinoma, 1 case was squamous cell carcinoma, and 1 case was chromophobe cell tumor. In the study, 47 cases were followed up for 1-36 months, and 4 cases died (the survival time was 5-15 months, with an average of 10.2 months).

CONCLUSION

Laparoscopic radical nephrectomy with inferior vena cava thrombectomy is a reasonable choice for renal tumor with Mayo 0-2 level venous thrombosis. For different tumor directions and different grades of tumor thrombus, an appropriate operation plan can give the maxim benefit to the patients with skillful surgeons.

Nitrogen-doped porous carbon derived from chitosan for the enhanced dehydrochlorination of lindane under mild conditions

Dehydrochlorination of lindane is commonly conducted in homogeneous alkaline solutions, possessing a series of problems such as corrosion and poor recyclability. In order to overcome the pervasive problems concerning homogeneous catalysts, heterogeneous catalysts have been increasingly employed in the applications. In this study, nitrogen-doped porous carbons (NPCs) were developed by a simple way in which chitosan and ZnCl₂ were employed as the precursor and activation agent, respectively. NPCs exhibited high surface area (1111-1497 m²/g) and large porosity (0.464-0.621 cm³/g), resulting in a great adsorption affinity to lindane and the by-products. As solid bases, NPCs displayed an enhanced catalytic activity on lindane dehydrochlorination. This was closely related to the amount of pyridinic nitrogen on the pore surface, which could be tuned by the synthesis temperature. The optimal removal efficiency of lindane was up to 99.9% in presence of A800 (a NPC catalyst) at moderate pH (9.0) and mild temperature (45 °C) after incubation for 24 h. The rate constant for A800 suspension was improved by 2-3 orders of magnitude in comparison with that obtained in homogeneous solution at moderate pH (9.0) and mild temperatures (25-45 °C). The reusability of the material was evaluated by cycling for three times without noticeably reduced catalytic activity. This study provides a novel strategy to achieve partial dechlorination of chlorinated organic pollutants.

[Clinicopathological analysis of patients with papillary renal cell carcinoma]

OBJECTIVE

To investigate the clinicopathological features,treatment and prognosis of patients with papillary renal cell carcinoma (PRCC) and PRCC-complicated with tumor thrombus.

METHODS

Single center retrospective analysis of 75 patients with PRCC treated from January 2012 to October 2017 was performed. There were 55 males and 20 females at an age range of 24-82 years. Sixteen PRCC patients were complicated with tumor thrombus. All the patients were with a surgery and had clear pathological diagnosis and detailed follow-up data. The clinicopathological features, prognosis and influencing factors of the patients with PRCC and PRCC complicated with tumor thrombus were analyzed and summarized.

RESULTS

The average age of the 75 patients was(56.05±11.59)years,the average body mass index (BMI) was (26±3) kg/m², and the average tumor maximum diameter was (5.17±3.85) cm. There were significant differences between tumor maximum diameter larger than 7 cm and less than 7 cm (69.6% vs. 94.4%, P<0.001), lymph node metastasis and no lymph node metastasis (<38% vs. 98%, P<0.001), adrenal metastasis and no adrenal metastasis (0% vs. 95.3%, P<0.001), pulmonary metastasis and no pulmonary metastasis (0% vs.90.7%, P<0.001), complicated with and without tumor thrombus (<66.4% vs. 93.5%, P<0.001) on the effect of 3-year survival rate of the PRCC patients. In this study, there were 16 patients with type 2 PRCC complicated with tumor thrombus. There were significant differences in concomitant symptoms (62.5% vs. 22.0%, P=0.005), maximum tumor diameter (68.8% vs.13.3%, P<0.001), adrenal metastasis (18.8% vs. 0.02%, P=0.029), pulmonary metastasis (18.8% vs. 0%, P=0.008), nuclear grade (P<0.001) and pathological type (100% vs. 44.1%, P<0.001) between the PRCC patients with and without tumor thrombus.

CONCLUSION

There were significant differences in tumor diameter,lymph node metastasis,adrenal metastasis, pulmonary metastasis,pathological type, nuclear grade and tumor thrombus in the effect of the 3-year survival rate of PRCC patients. PRCC patients with tumor thrombus were more commonly suffered from type 2 PRCC, for whom the tumor diameter was larger,the nuclear grade was higher,and the distance metastasis happened more easily.

[Retrospective study of young bladder urothelial carcinoma from a single center within 16 years]

OBJECTIVE

To evaluate the clinical and pathological features, treatment and prognosis for bladder urothelial carcinoma in relative young patients under 40 years.

METHODS

A retrospective study involved a total of 43 consecutive patients of bladder urothelial carcinoma, which were under 40 years old from January 2001 to December 2016.

RESULTS

The incidence rate of bladder urothelial carcinoma in the patients under 40 years was 2.2%, and 35 males and 8 females were included. The average age was 33 years (ranging from 23 to 40 years). At initial visit, 62.8% of the patients presented with painless gross hematuria, 9 patients were discovered by routine examination, and 7 patients experienced lower urinary tract symptoms. Solitary tumor occurred in 34 cases whereas multiple carcinomas had been discovered in 9 cases，and all the 9 multiple cases were from 31-40-year-old subgroups. All the patients received proper surgical intervention according to their own clinical stages. Post-operative pathological results showed 29 low-grade urothelial carcinoma and 14 high-grade cases which included 31 Ta cases, with 7 cases of T1, 1 case of T3, and 3 cases of T4 and one case of T1 plus Tis. The total follow-up was from 5 to 165 months, 3 cases were lost. The overall recurrence rate was 12.5% (5 cases from 40). One patient developed distal metastasis, one died of metastasis after 13 months, and the other three received secondary trans-urethral resection of bladder tumors. The average recurrence time was 39 months (ranging from 3 to 105 months). The progression rate was 5% among all the followed-up patients (2 cases from 40). The recurrence rate in multiple lesions group (33%, 3/9) was significantly higher than that (5.9%, 2/34) in solitary lesion group (P=0.000 3).

CONCLUSION

The incidence rate of bladder urothelial carcinoma in young patients under 40 years becomes increasingly higher over years. The major initial presentation is painless gross hematuria among these young patients, but lower urinary tract symptoms should also be noticed for young patients to rule out tumor. Postoperative tumor recurrence might be associated with multiple lesions, which is not related to the tumor size or pathological features.

Catalytic dehydrochlorination of lindane by nitrogen-containing multiwalled carbon nanotubes (N-MWCNTs)

This paper reports a nonreductive dechlorination pathway (dehydrochlorination) of lindane in the presence of N-MWCNTs (CNT-N1 and CNTN2) under environmentally relevant conditions. The enhanced catalytic dehydrochlorination at mild pH values (7.0-9.0) was mainly attributed to the Lewis base nature of nitrogen functional groups on the surface of N-MWCNTs, based on FT-IR spectra, X-ray photoelectron spectroscopy and CO₂-TPD profile. Amine and pyridinic nitrogen species were inferred as the main basic sites that were responsible for the dehydrochlorination of lindane. The concentration of lindane was unchanged in homogenous alkaline aqueous solutions at pH7.0 and 8.0 within 6 d, and up to 89.5% of lindane remained at pH9.0. In sharp contrast, the reaction rate constant (k_obs) increased from 0.024 to 0.876 d^-1 with the increasing pH from 7.0 to 9.0 when CNT-N2 catalyst was used. All lindane was transformed in the presence of CNT-N2 at pH9.0, leading to a much greater k_obs as compared to that obtained in homogenous solution (0.876 vs 0.019 d^-1). Even at neutral pH condition, the k_obs obtained in the presence of CNT-N2 was higher than that observed in weakly alkaline solution (0.024 d^-1 at pH7.0 vs 0.019 d^-1 at pH9.0). γ-1,3,4,5,6-pentachlorocyclohexene and trichlorobenzene isomers were detected as the intermediate and final products, respectively. It might be inferred that amine and pyridinic nitrogen species could attack the hydrogen atom attached to the β‑carbon, and the dehydrochlorination of lindane followed a β-elimination mechanism. This study provides an alternative dechlorination way for making lindane less toxic and better biodegradable under mild conditions, which is beneficial for complete mineralization of lindane when coupled with microbial degradation.

Current progress in black phosphorus materials and their applications in electrochemical energy storage

Recently, a new two-dimensional material, single- or few-layered black phosphorus (BP), has attracted considerable attention for applications in electronics, optoelectronics, and batteries due to its unique properties, including large specific surface area, anisotropy, and tunable and direct band gaps. In particular, contributions to electrochemical energy storage devices, such as lithium and sodium ion batteries and supercapacitors, have emerged. However, critical issues remain to be explored before scaled-up commercial production of BP, such as preparation, stability, and performance. Herein, we present the first review of recent progress in BP-based electrochemical energy storage device. The preparation and electrochemical properties of black phosphorus, recent advances, potential challenges, and relevant perspectives in electrochemical energy storage, and the potential of BP are discussed in this work.

[Ureteroscope can assist risk stratification in upper tract urothelial carcinoma]

OBJECTIVE

To analyze the efficiency of ureteroscope and biopsy in the diagnosis of tumor grade, muscle-invasiveness and multifocality in suspected upper tract urinary carcinoma (UTUC) patients in order to find out whether it can be used in the risk stratification of UTUC patients.

METHODS

A retrospective study of 76 UTUC patients who underwent preoperative ureteroscope and/or biopsy and received radical nephroureterectomy in Peking University Third Hospital during January 2014 to December 2016 was undertaken.

RESULTS

In this study, 76 patients were included. There were 31 males (40.8%), and 45 females (59.2%). The median age was 64.5 years (31-88), and 51 patients had the symptom of hematuresis. The tumor was located in renal pelvis in 39 patients, and in ureter in 37 patients. Post-operative pathology confirmed that all the 76 patients included in this study suffered from UTUC, of whom 21 (21.6%) were of low-grade, 51 (67.1%) were of high-grade, 4 (5.3%) were undetermined, and 47 (61.9%) patients were muscle-invasive, and 27 (35.5%) were not, and 2 (2.6%) were undetermined. Among the 50 patients, in whom the grade of the tumor could be diagnosed by biopsy, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value for low-grade tumor was 88.2%, 69.7%, 76.0%, 60.0% and 92.0%, respectively. Among the 27 patients, in whom the muscle-invasiveness could be diagnosed by biopsy, 5 patients were diagnosed with muscle-invasiveness, all confirmed by pathology after surgery and 22 patients were diagnosed with none muscle-invasiveness, turned out to be 50% muscle-invasive and 50% none-muscle invasive after surgery. The accuracy was 59.3%. The accuracy of ureteroscopic biopsy to diagnosis multifocality was 61.0%. On univariate analysis, biopsy grade was associated with postoperative pathology (P=0.001), while gender, age, side, body mass index (BMI), hematuresis, preoperative estimated glomerular filtration rate (eGFR), hydronephrosis, tumor size, location, multifocality and sessile were not associated with postoperative pathology grade. Biopsy grade (P=0.02), preoperative eGFR<90 mL/(min×1.73 m²)(P=0.025) and tumor located in pelvis (P=0.049) were associated with muscle invasiveness. Gender, age, side, BMI, hematuresis, hydronephrosis, tumor size, multifocality and sessile were not significantly associated with muscle invasiveness.

CONCLUSION

Ureteroscope and biopsy can assist risk stratification in upper tract urothelial carcinoma patients.