Bedaquiline in the treatment of multidrug- and extensively drug-resistant tuberculosis in China

BACKGROUND: Multidrug- and extensively drug-resistant tuberculosis (MDR/XDR-TB) continues to be a challenge in China. Bedaquiline (BDQ) is associated with accelerated sputum culture conversion and favourable treatment outcomes when added to a preferred background regimen. This post-hoc study aimed to assess the outcomes of BDQ treatment in Chinese patients with MDR/XDR-TB.METHODS: Data from 51 Chinese patients who participated in a global Phase 2, open-label, single-arm study (TMC207-C209) were analysed for effectiveness and safety of the BDQ-containing regimen.RESULTS: During the 24-week BDQ treatment, adverse events (AEs) occurred in 48 patients (94.1%), with the most common AE being hyperuricemia. Drug-induced liver injury (DILI) was reported in 13 patients (25.5%); serious DILI was reported in one patient (2.0%). Seven (13.7%) AEs were considered to be possibly related to BDQ by the investigators. Only one Grade 1 QTc prolongation was reported; no QTcF >500 ms was reported. One death occurred after BDQ treatment due to progressive TB. The median time to sputum culture conversion was 85 days based on the 24-week data. The sputum culture conversion rate was 82% at 24 weeks and 78% at 120 weeks; 66% of patients achieved a cure.CONCLUSIONS: BDQ was well-tolerated and effective for treating MDR-TB among Chinese patients.

Radiomics for precision medicine: Current challenges, future prospects, and the proposal of a new framework

The advancement of artificial intelligence concurrent with the development of medical imaging techniques provided a unique opportunity to turn medical imaging from mostly qualitative, to further quantitative and mineable data that can be explored for the development of clinical decision support systems (cDSS). Radiomics, a method for the high throughput extraction of hand-crafted features from medical images, and deep learning -the data driven modeling techniques based on the principles of simplified brain neuron interactions, are the most researched quantitative imaging techniques. Many studies reported on the potential of such techniques in the context of cDSS. Such techniques could be highly appealing due to the reuse of existing data, automation of clinical workflows, minimal invasiveness, three-dimensional volumetric characterization, and the promise of high accuracy and reproducibility of results and cost-effectiveness. Nevertheless, there are several challenges that quantitative imaging techniques face, and need to be addressed before the translation to clinical use. These challenges include, but are not limited to, the explainability of the models, the reproducibility of the quantitative imaging features, and their sensitivity to variations in image acquisition and reconstruction parameters. In this narrative review, we report on the status of quantitative medical image analysis using radiomics and deep learning, the challenges the field is facing, propose a framework for robust radiomics analysis, and discuss future prospects.

Multiple-centre clinical evaluation of an ultrafast single-tube assay for SARS-CoV-2 RNA

OBJECTIVE

To evaluate the performance of an ultrafast single-tube nucleic acid isothermal amplification detection assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA using clinical samples from multiple centres.

METHODS

A reverse transcription recombinase-aided amplification (RT-RAA) assay for SARS-CoV-2 was conducted within 15 minutes at 39°C with portable instruments after addition of extracted RNA. The clinical performance of RT-RAA assay was evaluated using 947 clinical samples from five institutions in four regions of China; approved commercial fluorescence quantitative real-time PCR (qRT-PCR) kits were used for parallel detection. The sensitivity and specificity of RT-RAA were compared and analysed.

RESULTS

The RT-RAA test results of 926 samples were consistent with those of qRT-PCR (330 were positive, 596 negative); 21 results were inconsistent. The sensitivity and specificity of RT-RAA was 97.63% (330/338, 95% confidence interval (CI) 95.21 to 98.90) and 97.87% (596/609, 95% CI 96.28 to 98.81) respectively. The positive and negative predictive values were 96.21% (330/343, 95% CI 93.45 to 97.88) and 98.68% (596/604, 95% CI 97.30 to 99.38) respectively. The total coincidence rate was 97.78% (926/947, 95% CI 96.80 to 98.70), and the kappa was 0.952 (p < 0.05).

CONCLUSIONS

With comparable sensitivity and specificity to the commercial qRT-PCR kits, RT-RAA assay for SARS-CoV-2 exhibited the distinctive advantages of simplicity and rapidity in terms of operation and turnaround time.

Peritonitis in Continuous Ambulatory Peritoneal Dialysis {CAPD): A Multi-Centre Randomized Clinical Trial Comparing the Y Connector Disinfectant System to Standard Systems

sixty-one new continuous ambulatory peritoneal dialysis (CAPD) patients were allocated to a Y connector disinfectant (Amuchina, Italy) and 63 to standard systems (Baxter Systems II & III) in a randomized clinical trial addressing peritonitis rates in 8 CAPD programs in 6 Canadian cities. In the Y connector-disinfectant group, 15 patients experienced 21 episodes of peritonitis in 452 patient-months or 1 per 21.53 patient-months. In the standard systems group, 30 patients experienced 47 episodes of peritonitis in 467 patient-months or 1 per 9.93 patient-months ( p = 0.009). The peritonitis risk reduction was 61% (95% confidence limits 27–79%). Exit-site infections occurred in 36% of each group.

Prior to the development of exit -site infection, the monthly risk for peritonitis was 3.12% for the Y connector disinfectant system and 7.37% for the standard system. After an exit -site infection, these probabilities increased to 6.15% and 15.47%, respectively. Skin organisms were responsible for peritonitis in 8/21 (38%) in the Y connector-disinfectant group and 30/47 (64%) in the standard group. There were 75 days hospitalized for peritonitis in the Y connector-disinfectant group compared to 257 days for the standard group. The Y connector disinfectant system decreases the peritonitis rate through its effect on skin organisms. Exit -site infections are a major source of organisms responsible for peritonitis.

Peritonitis in Continuous Ambulatory Peritoneal Dialysis (CAPD) Patients: A Randomized Clinical Trial of Cotrimoxazole Prophylaxis

A double-blind randomized controlled trial compared the effectiveness of prophylactic oral trimethoprim/sulfamethoxazole (cotrimoxazole) to a placebo in preventing peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients. A daily trimethoprim/sulfamethoxazole dose of 160/800 mg gives a steady state dialysate concentration of 1.07/4.35 mg/L in the final dwell of each dosing interval. Identification of a 40% reduction in peritonitis probability with 80% statistical power and a type 1 error probability of 0.05 required 52 subjects per group. With stratification by previous peritonitis, 56 were allocated to cotrimoxazole and 49 to placebo. For cotrimoxazole there were five deaths and seven catheter losses. For placebo there were three deaths and nine catheter losses. There were 20 withdrawals from cotrimoxazole and 9 from the placebo group. With respect to time to peritonitis, there was no statistically significant difference between cotrimoxazole and placebo groups (p = 0.19). At 6 months, 64.1% of cotrimoxazole and 62.5% of placebo were peritonitis free; at 12 months 41.9% of cotrimoxazole and 35% of placebo were peritonitis free. There was no effect (p > 0.05) of age, sex, catheter care technique, spike or luer, or dialysate additives. Previous peritonitis increased the risk of peritonitis by 2.06 (95% CI, 3.61–1.18) while frequent (six weekly) extension tubing changes increased the risk of by 1.79, (95% CI, 3.04–1.02) when compared to six monthly changes. Cotrimoxazole appears ineffective in prevention of CAPD peritonitis.

Balancing the transesterification reactivity of isosorbide with diphenyl carbonate: preferential activation of exo-OH

Exo-OH on ISB has long been asserted as a highly reactive moiety compared with endo-OH. Herein, we report that the nucleophilic attack surmounts steric hindrance in rendering endo-OH more reactive than exo-OH in case of transesterification with DPC.

The transport of liquids in softwood: timber as a model porous medium

Timber is the only widely used construction material we can grow. The wood from which it comes has evolved to provide structural support for the tree and to act as a conduit for fluid flow. These flow paths are crucial for engineers to exploit the full potential of timber, by allowing impregnation with liquids that modify the properties or resilience of this natural material. Accurately predicting the transport of these liquids enables more efficient industrial timber treatment processes to be developed, thereby extending the scope to use this sustainable construction material; moreover, it is of fundamental scientific value - as a fluid flow within a natural porous medium. Both structural and transport properties of wood depend on its micro-structure but, while a substantial body of research relates the structural performance of wood to its detailed architecture, no such knowledge exists for the transport properties. We present a model, based on increasingly refined geometric parameters, that accurately predicts the time-dependent ingress of liquids within softwood timber, thereby addressing this long-standing scientific challenge. Moreover, we show that for the minimalistic parameterisation the model predicts ingress with a square-root-of-time behaviour. However, experimental data show a potentially significant departure from this [Formula: see text] behaviour - a departure which is successfully predicted by our more advanced parametrisation. Our parameterisation of the timber microstructure was informed by computed tomographic measurements; model predictions were validated by comparison with experimental data. We show that accurate predictions require statistical representation of the variability in the timber pore space. The collapse of our dimensionless experimental data demonstrates clear potential for our results to be up-scaled to industrial treatment processes.

[Survival time and influencing factors in multidrug-resistant tuberculosis patients in Wuhan, 2006-2014]

Objective: To investigate the survival time of multidrug-resistant tuberculosis (MDR-TB) patients and the influential factors in Wuhan. Methods: The relevant information were collected from TB management information system, cause of death reporting system and medical records by trained doctors. The univariate and multivariate Cox proportional hazards model were applied to analyze the factors affecting survival time of patients. Results: A total of 552 patients with MDR-TB were included in the analysis. After the diagnosis of MDR-TB, the cumulative survival rates from the first year to the third year were 0.94, 0.88, and 0.80, respectively. The mortality density of MDR-TB patients was 6.52/100 person-years, and the median survival time was (89.52±1.85) months. Kaplan-Meier analysis showed that the cumulative survival rate of the standardized treatment group was significantly higher than that of the non-standardized treatment group (Log rank=101.070, P<0.001). Compared with the patients aged <30 years, the HR of the patients aged 30-years and ≥60 years were 2.987 (95%CI: 1.268-7.036), 4.957 (95%CI: 1.942-12.653). Compared with the patients with the education level of high school and above, the HR of the patients with education level of junior high school/primary school and below were 1.908 (95%CI: 1.152-3.160), 1.681(95%CI: 1.033-2.735). Compared with the patients without diabetes, the HR of the patients with diabetes was 1.961(95%CI: 1.347-2.854). Compared with the patients without other serious diseases, the HR of the patients with other serious diseases was 2.597 (95%CI: 1.820-3.706). Compared with the patients who had been treated less than one time, the HR of the patients having previous treatment with more than 2 times was 1.611 (95%CI: 1.077-2.409). Compared with patients receiving standard MDR regimen treatment, the HR of the patients receiving no standard MDR regimen treatment was 3.155 (95%CI: 2.132-4.670). Conclusions: The cumulative survival rate of MDR-TB patients without standard treatment was significantly lower than that of patients with standard treatment. Older age, low educational level, diabetes mellitus, other serious diseases, more than two times treatment in the past, and receiving no multi-drug resistance regimen treatment were the risk factors affecting the survival of MDR-TB patients.

Fine-tuning the photosynthetic light harvesting apparatus for improved photosynthetic efficiency and biomass yield

Photosynthetic electron transport rates in higher plants and green algae are light-saturated at approximately one quarter of full sunlight intensity. This is due to the large optical cross section of plant light harvesting antenna complexes which capture photons at a rate nearly 10-fold faster than the rate-limiting step in electron transport. As a result, 75% of the light captured at full sunlight intensities is reradiated as heat or fluorescence. Previously, it has been demonstrated that reductions in the optical cross-section of the light-harvesting antenna can lead to substantial improvements in algal photosynthetic rates and biomass yield. By surveying a range of light harvesting antenna sizes achieved by reduction in chlorophyll b levels, we have determined that there is an optimal light-harvesting antenna size that results in the greatest whole plant photosynthetic performance. We also uncover a sharp transition point where further reductions or increases in antenna size reduce photosynthetic efficiency, tolerance to light stress, and impact thylakoid membrane architecture. Plants with optimized antenna sizes are shown to perform well not only in controlled greenhouse conditions, but also in the field achieving a 40% increase in biomass yield.

Decrease of FGF19 contributes to the increase of fasting glucose in human in an insulin-independent manner

PURPOSE

The ileum-derived fibroblast growth factor 19 (FGF19) plays key roles in hepatic glucose homeostasis in animals in an insulin-independent manner. Here, we analyzed the association of FGF19 with glucose effectiveness (GE, the insulin-independent glucose regulation), as well as hepatic glucose production (HGP) in Chinese subjects.

METHODS

GE was measured by frequently sampled intravenous glucose tolerance test (FSIVGTT) in normal glucose tolerance (NGT), isolated-impaired glucose tolerance (I-IGT), and isolated-impaired fasting glucose (I-IFG) subjects. The oral glucose tolerance test-derived surrogate of GE (oGE) was determined in NGT, I-IFG, combined glucose intolerance (CGI), and type 2 diabetes (T2DM) subjects. HGP was assessed by labeled ([3-³H]-glucose) hyperinsulinemic-euglycemic clamp in NGT subjects. Insulin secretion and sensitivity were calculated by the hyperglycemic and hyperinsulinemic-euglycemic clamps in a subgroup of NGT, I-IGT, and I-IFG subjects. Serum FGF19 levels were determined by ELISA.

RESULTS

FGF19 positively correlated with GE (r = 0.29, P = 0.004) as determined by FSIVGTT. The result was further confirmed by oGE (r = 0.261, P < 0.001). FGF19 was negatively associated with FPG (r = - 0.228, P = 0.025), but the association no longer existed after adjusting for GE (r = - 0.177, P = 0.086). FGF19 was negatively associated with basal HGP (r = - 0.697, P = 0.006). However, the correlation between FGF19 and insulin secretion and sensitivity were not found.

CONCLUSIONS

FGF19 levels are associated positively with GE and negatively with HGP. The increase of FPG in human is at least partially due to the decrease of FGF19 in an insulin-independent manner.