Proton pump inhibitor usage associates with higher risk of first episodes of pneumonia and peritonitis in peritoneal dialysis patients.

BACKGROUND: A large number of studies have shown that proton pump inhibitors (PPIs) are associated with infection events. Therefore, we retrospectively evaluated the association of PPI therapy with the occurrence of first pneumonia and peritoneal dialysis(PD)-related peritonitis events in the maintenance PD patients. METHODS: We collected PD patients in two large hospitals from January 1, 2012 to December 31, 2016, and divided them into the PPI group and the non-PPI group. Multivariate Cox proportional hazards models were applied to evaluate the cumulative incidence and hazard ratios (HRs). Inverse probability of treatment weight (IPTW) method was used to adjust for covariate imbalance between the two groups and further confirm our findings. RESULTS: Finally, 656 PD patients were included for data analysis, and the results showed that PPI usage was associated with an increased risk of pneumonia [HR 1.71; 95% CI 1.06-2.76; p = 0.027] and peritonitis [HR 1.73; 95% CI 1.24-2.40; p = 0.001]. IPTW-adjusted HRs for the association of PPIs with pneumonia and peritonitis were 1.58 (95% CI:1.18-2.12; p = 0.002) and 2.33 (95% CI:1.91-2.85; p < 0.001), respectively. Moreover, the competitive risk model proved that under the conditions of competition for other events(including transfer to hemodialysis therapy, kidney transplant, transfer from our research center, loss to follow-up, and death), the differences in endpoints events between the two groups were still statistically significant (p = 0.009, p < 0.001, respectively). CONCLUSIONS: PPIs was associated with an increased risk of first pneumonia and PD-related peritonitis events in PD patients, which reminds clinicians to be cautious when prescribing acid-suppressing drugs for PD patients.

Territorial Pattern Evolution and Its Comprehensive Carrying Capacity Evaluation in the Coastal Area of Beibu Gulf, China.

Changes in the territorial pattern of the Beibu Gulf, an environmentally sensitive and ecologically fragile area in China, will directly or indirectly affect the regional ecological environment, while profoundly influencing economic development and human well-being. Therefore, it is significant to understand the ecological response in the process of territorial space changes in the Beibu Gulf to promote the coordination between sea and land and sustainable regional development. This paper used remote sensing image interpretation to generate land-use maps in 2000, 2010 and 2020, and then analyzed the spatial and temporal evolution of the territorial pattern of the Beibu Gulf from 2000 to 2020. Finally, this paper proposed a comprehensive carrying capacity evaluation system and explored the spatial functional zones of the coastal areas of the Beibu Gulf. The results showed that the demand for urban development and ecological protection between 2000 and 2020 increased built-up land and forestland by 386.71% and 25.56%, respectively, and reduced farmland by 28.33%. There was significant spatial heterogeneity in various land-use types. Where forestland is mainly distributed in the west, farmland is mainly distributed in the east, wetland is mainly distributed in the south, and orchards are spread throughout the whole area. The evaluation results of land resources, water resources and ecological conditions in the Beibu Gulf area showed that its comprehensive carrying capacity was high in the south and low in the north, and high in the west and low in the east. On this basis, this paper considered the actual situation of natural resources, ecological conditions, socio-economic development, protection and development in coastal areas; divided the study area into four categories: developed areas, priority development areas, ecological reserve areas and coastal reserve areas; and put forward corresponding control suggestions. The results of this paper could provide a scientific basis for regional development and territorial spatial planning in the coastal areas.

System Modeling and Evaluation of a Prototype Inverted-Compound Eye Gamma Camera for the Second Generation MR Compatible SPECT.

We have reported the design of the MRC-SPECT-II system based on the inverted-compound-eye (ICE) gamma camera to offer a > 1% detection efficiency while maintaining a sub-500 µm imaging resolution [1]. One of the key challenges of using the ICE camera for SPECT imaging is whether one could develop an accurate point response function (PRF), given its complex aperture design and low fractionation accuracy of 3D printing. In this work, we will discuss (I) a combined experimental and analytical approach for deriving the precise PRF, and (II) an experimental imaging study to demonstrate the feasibility of using the ICE-camera for acquiring high-quality SPECT images with a sub-500 µm resolution. These studies would help to overcome one of the major hurdles for implement ICE-cameras for practical SPECT imaging.

High Neutrophil/Lymphocyte Ratio as an Independent Risk Factor for the First Occurrence of Stroke in Peritoneal Dialysis Patients.

INTRODUCTION: Though neutrophil/lymphocyte ratio (NLR) level appears to be related with stroke events in general population, its relationship with stroke in peritoneal dialysis (PD) patients is still uncertain. This study aims to investigate the association between NLR and the first occurrence of stroke in PD patients. METHODS: In this retrospective cohort study, 1507 PD patients were enrolled from four centers in China and stratified into tertiles of NLR levels. The incidence of the first occurrence of stroke was analyzed by Kaplan-Meier cumulative incidence curve among different NLR tertiles, competing risk analysis was used to calculate the incidence of the first occurrence of stroke in the presence of competing risk of other events, multivariable COX regression analysis was performed to estimate the hazard ratios (HRs) for the first occurrence of stroke, as well as forest plot was utilized to describe the relationship between NLR and the first occurrence of stroke in different subgroups. RESULTS: During follow-up, 84 new-onset stroke events were recorded. Kaplan-Meier cumulative incidence curves showed significant differences in the incidence of the first occurrence of stroke among three groups (log-rank test: P < .001). In competing risk analysis, the cumulative incidence curves for tertiles of NLR levels were highly significant for the first occurrence of stroke (P < .001), but they were not statistically different for the occurrence of other events. Compared to the lowest tertile of NLR level, the highest tertile was associated with increased risk of the first occurrence of stroke in the adjusted Cox model (HR = 2.39, 95% CI: 1.37 to 4.15; P < .05). As for forest plot, there was no interaction in all subgroups. CONCLUSION: High NLR was an independent risk factor for the first occurrence of stroke in PD patients.

The relationship between neutrophil-to-lymphocyte ratio and the first occurrence of pneumonia in peritoneal dialysis patients.

BACKGROUND: Although neutrophil-to-lymphocyte ratio (NLR) is closely associated with pneumonia in the general population, its relationship is unclear in peritoneal dialysis (PD) patients. METHODS: This is a cohort study consisting of 739 PD patients and dividing into two groups. Kaplan-Meier curves were applied to observe the incidence of the first occurrence of pneumonia, competitive risk analysis was conducted to compare whether there was a significant difference in each NLR group in the presence of other competing events, multivariable COX regression analysis was used to evaluate the hazard ratios (HRs), as well as forest plot was used to analyze the relationship between NLR and the first occurrence of pneumonia in different subgroups. RESULTS: Of all the patients, 116 cases of first-time pneumonia were recorded. The first-time pneumonia incidence rate was 71.67/1000 patient-years in high NLR group, which was markedly higher than that of 45.81/1000 patient-years in low NLR group. Kaplan-Meier curves indicated significant differences in the incidence of the first occurrence of pneumonia between two groups (log-rank test p = 0.015). The competitive risk model suggested a significant difference in the cumulative incidence of first pneumonia between the two groups (p = 0.032). Compared to low NLR group, adjusted Cox model showed that high NLR group was associated with increased risk of pneumonia incidence (HR, 1.51; 95% CI 1.04-2.21; p = 0.031). Forest plot showed no interaction was found in subgroups. CONCLUSIONS: The risk of pneumonia was significantly increasing in PD patients with high NLR, which may have a certain guiding significance for the clinic.

Stationary Computed Tomography for Space and other Resource-constrained Environments.

Computed tomography (CT) is used to diagnose many emergent medical conditions, including stroke and traumatic brain injuries. Unfortunately, the size, weight, and expense of CT systems make them largely inaccessible for patients outside of major hospitals. We have designed a module containing multiple miniature x-ray sources that could allow for CT systems to be significantly lighter, smaller, and cheaper, and to operate without any moving parts. We have developed a novel photocathode-based x-ray source, created by depositing a thin film of magnesium on an electron multiplier. When illuminated by a UV LED, this photocathode emits a beam of electrons, with a beam current of up to 1 mA. The produced electrons are accelerated through a high voltage to a tungsten target. These sources are individually addressable and can be pulsed rapidly, through electronic control of the LEDs. Seven of these sources are housed together in a 17.5 degree arc within a custom vacuum manifold. A full ring of these modules could be used for CT imaging. By pulsing the sources in series, we are able to demonstrate x-ray tomosynthesis without any moving parts. With a clinical flat-panel detector, we demonstrate 3D acquisition and reconstructions of a cadaver swine lung.

Simulation study of the second-generation MR-compatible SPECT system based on the inverted compound-eye gamma camera design.

In this paper, we present simulation studies for the second-generation MRI compatible SPECT system, MRC-SPECT-II, based on an inverted compound eye (ICE) gamma camera concept. The MRC-SPECT-II system consists of a total of 1536 independent micro-pinhole-camera-elements (MCEs) distributed in a ring with an inner diameter of 6 cm. This system provides a FOV of 1 cm diameter and a peak geometrical efficiency of approximately 1.3% (the typical levels of 0.1%-0.01% found in modern pre-clinical SPECT instrumentations), while maintaining a sub-500 µm spatial resolution. Compared to the first-generation MRC-SPECT system (MRC-SPECT-I) (Cai 2014 Nucl. Instrum. Methods Phys. Res. A 734 147-51) developed in our lab, the MRC-SPECT-II system offers a similar resolution with dramatically improved sensitivity and greatly reduced physical dimension. The latter should allow the system to be placed inside most clinical and pre-clinical MRI scanners for high-performance simultaneous MRI and SPECT imaging.

MRC-SPECT: A sub-500 µm resolution MR-compatible SPECT system for simultaneous dual-modality study of small animals.

In this paper, we will report the development of an ultrahigh resolution MR-compatible SPECT system that can be operated inside a pre-existing clinical MR scanner for simultaneous dual-modality imaging of small animals. This system is constructed with 40 small-pixel CdTe detector modules assembled in a fully stationary ring SPECT geometry. We have experimentally demonstrated that this system is capable of providing an imaging resolution of <500 µm when operating inside MR scanners. We will report the design, construction of the MRI-compatible SPECT system, including the detector technology, collimator, system development and so on. The first imaging results obtained with this newly constructed SPECT system will also be reported.