Blunted nitric oxide regulation in Tibetans under high-altitude hypoxia

Nitric oxide (NO) is an important molecule for vasomotor tone, and elevated NO signaling was previously hypothesized as a unique and adaptive physiological change in highland Tibetans. However, there has been lack of NO data from Tibetans living at low altitude and lowlander immigrants living at high altitude, which is crucial to test this hypothesis. Here, through cross-altitude (1990–5018 m) and cross-population (Tibetans and Han Chinese) analyses of serum NO metabolites (NOx) of 2086 individuals, we demonstrate that although Tibetans have a higher serum NOx level compared to lowlanders, Han Chinese immigrants living at high altitude show an even higher level than Tibetans. Consequently, our data contradict the previous proposal of increased NO signaling as the unique adaptive strategy in Tibetans. Instead, Tibetans have a relatively lower circulating NOx level at high altitude. This observation is further supported by data from the hypoxic experiments using human umbilical vein endothelial cells and gene knockout mice. No difference is detected between Tibetans and Han Chinese for endothelial nitric oxide synthase (eNOS), the key enzyme for circulating NO synthesis, suggesting that eNOS itself is unlikely to be the cause. We show that other NO synthesis-related genes (e.g. GCH1) carry Tibetan-enriched mutations significantly associated with the level of circulating NOx in Tibetans. Furthermore, gene network analysis revealed that the downregulation and upregulation of NOx is possibly achieved through distinct pathways. Collectively, our findings provide novel insights into the physiological and genetic mechanisms of the evolutionary adaptation of Tibetans to high-altitude hypoxia.

Variations of blood glucose in cancer patients during chemotherapy

PURPOSE

The aim of this study was to analyze the blood glucose (BG) variations in cancer patients during chemotherapy according to tumor types and chemotherapeutic regimens.

MATERIALS AND METHODS

Patients were examined from the Department of Medical Oncology of Cancer Hospital and Institute, Chinese Academy Medical Sciences from January 2012 to December 2014. The patients' ages, genders, body mass index, associated disease history, and corresponding BG values were recorded.

RESULTS

Among these 2029 patients, 331 (16.3%) patients encountered high BG during chemotherapy except diabetic patients. Of these patients, 208 (62.8%) were males, and 123 (37.2%) were females, with age ranged from 17 to 84 years. The 331 cases included 23 tumor types and 77 regimens. Totally, BG values increased up to 7.4 ± 1.3 mmol/L during chemotherapy.

CONCLUSIONS

No previous studies in the literature have examined systematically so numerous cases of hyperglycemia during chemotherapy. This study has pointed out possible high-risk chemotherapeutic regimens and tumor types, which should be paid attention to prevent the occurrence of hyperglycemia.

[Potential demand on cancer screening service in urban populations in China: a cross-sectional survey]

Objective: To understand the acceptance and personal demand for cancer screening service among the urban residents who had never been involved in any national level cancer screening programs in China and identify the key factors influencing the sustainability of cancer screening. Methods: A questionnaire survey was conducted among the local people aged 40-69 years selected through convenience sampling in 16 provinces of China to collect the general information about their demands for the screening service and others. Results: A total of 16 394 qualified questionnaires were completed. The average age of the people surveyed was (53.8±8.0) years, and men accounted for 44.6%. Without concerning the cost, 4 831 people (29.5%) had no demands for cancer screening services, the reasons are as follow: they would like to go to see doctors only when they were ill (61.8%); they had already received similar medical examinations (36.8%) and they would like to receive cancer screening directly without pre-health risk assessment (33.0%). Among the people surveyed, 10 795 (65.8%) had demands for cancer screening services, but they had choice on the screening settings, 43.7% wanted to receive the service in a general hospitals, while 36.5% would like to go to cancer-specialized hospitals. As for the level of medical institutes providing cancer screening service, 61.4% of the people surveyed would choose a higher level one, while 36.4% would choose an ordinary one. On screening procedures, 61.5% of the people surveyed would accept the mode of "clinical examination after questionnaire-assessment" . Conclusion: Most people surveyed had demands for cancer screening services and they would like to receive the screening services in higher level medical institutes. It is suggested to spread cancer screening know ledge, and strengthen the capability building of screening in grass root medical institutes to attract more people to receive cancer screening.

[Preference on screening frequency and willingness-to-pay for multiple-cancer packaging screening programs in urban populations in China]

Objective: From an actual cancer screening service demanders' perspective, we tried to understand the preference on screening frequency and willingness-to-pay for the packaging screening program on common cancers and to evaluate its long-term sustainability in urban populations in China. Methods: From 2012 to 2014, a multi-center cross-sectional survey was conducted among the actual screening participants from 13 provinces covered by the Cancer Screening Program in Urban China (CanSPUC). By face-to-face interview, information regarding to preference to screening frequency, willingness-to-pay for packaging screening program, maximum amount on payment and related reasons for unwillingness were investigated. Results: A total of 31 029 participants were included in this survey, with an average age as (55.2±7.5) years and median annual income per family as 25 000 Chinese Yuan. People's preference to screening frequency varied under different assumptions ( " totally free" and "self-paid" ). When the packaging screening was assumed totally free, 93.9% of residents would prefer to take the screening program every 1 to 3 years. However, the corresponding proportion dropped to 67.3% when assuming a self-paid pattern. 76.7% of the participants had the willingness-to-pay for the packaging screening, but only 11.2% of them would like to pay more than 500 Chinese Yuan (the expenditure of the particular packaging screening were about 1 500 Chinese Yuan). The remaining 23.3% of residents showed no willingness-to-pay, and the main reasons were unaffordable expenditure (71.7%) and feeling'no need'(40.4%). Conclusions: People who participated in the CanSPUC program generally tended to choose high-frequency packaging screening program, indicating the high potential acceptance for scale-up packaging screening, while it needs cautious assessments and rational guidance to the public. Although about seven in ten of the residents were willing to pay, the payment amount was limited, revealing the necessity of strengthening individual's awareness of his or her key role in health self-management, and a reasonable payment proportion should be considered when establishing co-compensation mechanism.

[Willingness and preferences of actual service suppliers regarding cancer screening programs: a multi-center survey in urban China]

Objective: From the perspective of actual service suppliers regarding cancer screening, this study aimed to assess the long-term sustainability of cancer screening programs in China. Methods: Based on a Cancer Screening Program in Urban China (CanSPUC), our survey focused on all the hospitals, centers for disease control and prevention (CDC) and community service centers across 16 provinces in China which participated in the programs between 2013 and 2015. All the managers (institutional/department level) and professional staff involved in the program were interviewed using either paper-based questionnaire or online approach. Results: A total of 4 626 participants completed the interview. It showed that the main gains from providing screening service emphasized promotion in social value (63.6%), local reputation (35.9%), and professional skills (30.6%), whereas difficulties encountered included inadequate compensation (30.9%) and discordance among information systems (28.3%). When the service remuneration amounts to about 50 Chinese Yuan per screening item, those professional staff self-reported that they would like to work overtime. More than half (63.7%) of the staff expressed willingness to provide routine screening service, the main expectations were to promote their reputation to the local residents (48.7%) and to promote professional skills (43.1%). Those who were not willing to provide screening services were worried about the potential heavy workload (59.8%) or being interfered with their routine work (49.8%). Further detailed results regarding the different organization types and program roles were presented in the following detailed report. Conclusions: Findings of gains and difficulties showed that if cancer screening is expected to become a long-term running, incentive mechanism from the program, external promotion and advocacy as well as capacity building should be strengthened; furthermore, rewards to staff's screening services should be raised according to the local situations. Results regarding the "willingness to provide service" showed that management of the program should also be strengthened, including information system building and inter-agency and inter-department coordination at the government levels.

General-purpose readout electronics for white neutron source at China Spallation Neutron Source

The under-construction White Neutron Source (WNS) at China Spallation Neutron Source is a facility for accurate measurements of neutron-induced cross section. Seven spectrometers are planned at WNS. As the physical objectives of each spectrometer are different, the requirements for readout electronics are not the same. In order to simplify the development of the readout electronics, this paper presents a general method for detector signal readout. This method has advantages of expansibility and flexibility, which makes it adaptable to most detectors at WNS. In the WNS general-purpose readout electronics, signals from any kinds of detectors are conditioned by a dedicated signal conditioning module corresponding to this detector, and then digitized by a common waveform digitizer with high speed and high precision (1 GSPS at 12-bit) to obtain the full waveform data. The waveform digitizer uses a field programmable gate array chip to process the data stream and trigger information in real time. PXI Express platform is used to support the functionalities of data readout, clock distribution, and trigger information exchange between digitizers and trigger modules. Test results show that the performance of the WNS general-purpose readout electronics can meet the requirements of the WNS spectrometers.

[Health economic evaluation reporting guideline and application status]

Using the guidelines of health economic evaluation reporting is conducive to regulating the contents of this reporting, improving the quality of studies into health economics evaluation. This article summarized the history of the guidelines and specified the instrument used to study " Quality of Health Economic Studies (QHES)" and the checklist about Consolidated Health Economics Evaluation Reporting Standards (CHEERS)-the two specific evaluation contents in this guideline, the article also introduced its present application status of the guideline and its pros and cons. The checklist of CHEERS emphasized the evaluation of this report, while QHES instrument focused on quantitative evaluation on the quality of economic studies. Despite different emphasis, the two guides are actually mutually complemented.

Down-Regulation of EPAS1 Transcription and Genetic Adaptation of Tibetans to High-Altitude Hypoxia

Tibetans are well adapted to the hypoxic environments at high altitude, yet the molecular mechanism of this adaptation remains elusive. We reported comprehensive genetic and functional analyses of EPAS1, a gene encoding hypoxia inducible factor 2α (HIF-2α) with the strongest signal of selection in previous genome-wide scans of Tibetans. We showed that the Tibetan-enriched EPAS1 variants down-regulate expression in human umbilical endothelial cells and placentas. Heterozygous EPAS1 knockout mice display blunted physiological responses to chronic hypoxia, mirroring the situation in Tibetans. Furthermore, we found that the Tibetan version of EPAS1 is not only associated with the relatively low hemoglobin level as a polycythemia protectant, but also is associated with a low pulmonary vasoconstriction response in Tibetans. We propose that the down-regulation of EPAS1 contributes to the molecular basis of Tibetans’ adaption to high-altitude hypoxia.

The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis

Objectives

Osteoporosis has become an increasing concern for older people as it may potentially lead to osteoporotic fractures. This study is designed to assess the efficacy and safety of ten therapies for post-menopausal women using network meta-analysis.

Methods

We conducted a systematic search in several databases, including PubMed and Embase. A random-effects model was employed and results were assessed by the odds ratio (OR) and corresponding 95% confidence intervals (CI). Furthermore, with respect to each outcome, each intervention was ranked according to the surface under the cumulative ranking curve (SUCRA) value.

Results

With respect to preventing new vertebral fractures (NVF), all ten drugs outperformed placebo, and etidronate proved to be the most effective treatment (OR 0.24, 95% CI 0.14 to 0.39). In addition, zoledronic acid and parathyroid hormone ranked higher compared with the other drugs. With respect to preventing clinical vertebral fractures (CVF), zoledronic acid proved to be the most effective drug (OR = 0.25, 95% CI 0.08 to 0.92), with denosumab as a desirable second option (OR = 0.48, 95% CI 0.22 to 0.96), when both were compared with placebo. As for adverse events (AE) and severe adverse events (SAE), no significant difference was observed. According to SUCRA, etidronate ranked first in preventing CVF; parathyroid hormone and zoledronic acid ranked highly in preventing NVF and CVF. Raloxifene was safe with a high rank in preventing AEs and SAEs though performed unsatisfactorily in efficacy.

Conclusions

This study suggests that, taking efficacy and safety into account, parathyroid hormone and zoledronic acid had the highest probability of satisfactory performance in preventing osteoporotic fractures.

Cite this article: G. Wang, L. Sui, P. Gai, G. Li, X. Qi, X. Jiang. The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis. Bone Joint Res 2017;6:452–463. DOI: 10.1302/2046-3758.67.BJR-2016-0292.R1.