Serum Fatty Acid Profiles and Neurofilament Light Chain Levels in the General Population.

BACKGROUND: Previous studies have demonstrated associations between fatty acids and neurological disorders. However, no studies have examined the relationship between serum fatty acid levels and serum neurofilament light chain (NfL), a biomarker of neurological disorders. OBJECTIVE: This study aimed to comprehensively investigate the intricate relationship between 30 serum fatty acids and serum NfL levels in a nationally representative sample of U.S. adults, utilizing data from the 2013-2014 National Health and Nutrition Examination Survey. METHODS: Employing a cross-sectional analysis, multivariable linear regression models were utilized to explore the associations between 30 serum fatty acids and serum NfL levels. This analysis involved adjustment for potential confounding variables, including age, sex, race, body-mass index (BMI), smoking status, hyperlipidemia, and diabetes, to clarify the association between serum fatty acids and serum NfL levels. RESULTS: The analysis revealed that certain fatty acids exhibited distinct associations with serum NfL levels. Notably, Docosanoic acid (22:0) and Tricosanoic acid (C23:0) were found to be inversely associated with serum NfL levels (ß = -0.280, 95% CI: -0.525, -0.035; ß = -0.292, 95% CI: -0.511, -0.072). Conversely, Palmitoleic acid (16:1n-7) demonstrated a positive association with serum NfL levels (ß = 0.125, 95% CI: 0.027, 0.222). Notably, these associations remained significant even after adjustment for potential confounders. CONCLUSIONS: Individuals with high relative concentrations of certain saturated fatty acids exhibited decreased serum NfL, whereas those with high relative concentrations of certain monounsaturated fatty acids showed increased serum NfL. These findings contribute to a deeper understanding of the potential impact of serum fatty acids on NfL levels, shedding light on novel avenues for further investigation and potential interventions in the context of neurological health.

Trends of mortality from epilepsy in the United States, 1979-2021.

PURPOSE: The analysis of long-term trends of mortality from epilepsy has not been conducted, which is crucial for estimating the future burden of epilepsy. We therefore aimed to investigate the long-term trends of mortality from epilepsy in the United States from 1979 to 2021. METHODS: The cause-of-death and demographic data were from the National Center for Health Statistics (1979-2021) and population estimates were from the US Census Bureau. We used the joinpoint regression model to analyze secular trends in the mortality of epilepsy spanning from 1979 to 2021. Age-adjusted mortality from epilepsy was assessed based on the year 2000 U.S. population data, stratified by age, sex, and race. RESULTS: The age-adjusted mortality from epilepsy increased from 0.78 per 100,000 population in 1979 to 1.01 per 100,000 population in 2021, with an average annual percent change (AAPC) of 0.58% (95% confidence interval [CI]: 0.45% - 0.72%). The overall age-adjusted mortality of epilepsy had been on the rise between 2011 and 2021. The mortality rate generally increases with age. The mortality of epilepsy was higher in the Afro-American people and men. The mortality of epilepsy in both sexes declined first and then increased, with AAPC 1.02% (95% CI: 0.88%, 1.23%) in women and 0.10% (95% CI: -0.002%, 0.21%) in men. Mortality in all races including White, Afro-American people, and other races individuals fell first and then rose. The AAPC of mortality in White, other races, and Afro-American people were 0.89% (95% CI: 0.79%, 1.02%), -0.87% (95% CI: -1.84%, 0.88%), and -0.31% (95% CI: -0.48%, -0.13%), respectively. CONCLUSION: Although the mortality rate from epilepsy has experienced a period of decline, it is worth noting that the last decade has seen a rapid increase. A comprehensive assessment of long-term trends in mortality from epilepsy holds significance for healthcare prioritization.

Enriched environment during adolescence modulates lipid metabolism and emotion-related behaviors in mice.

Enriched environment (EE) is an important animal experimental paradigm to decipher gene-environment interaction. It is thought to be efficient in aiding recovery from certain metabolism disorders or cognitive impairments. Recently, the effects of EE during adolescence in mice gradually draw much attention. We first established an EE model in adolescent mice, dissected lipid metabolism, and further examined baseline level of anxiety and depression by multiple behavioral tests, including open field test (OFT), elevated zero maze (EZM), tail suspension test (TST), and forced swimming test (FST). EE mice exhibited lower weights, lower cholesterol than standard housing (SH) mice. Behaviorally, EE mice traveled more distance and had higher velocity than SH mice in OFT and EZM. Besides, EE mice showed reduced anxiety levels in OFT and EZM. Furthermore, EE mice also had less immobility time than SH mice in TST and FST. Thus, these results suggest that EE during adolescence has metabolic and behavioral benefits in mice.

Combinatorial targeting of Hippo-STRIPAK and PARP elicits synthetic lethality in gastrointestinal cancers.

The striatin-interacting phosphatase and kinase (STRIPAK) complexes integrate extracellular stimuli that result in intracellular activities. Previously, we discovered that STRIPAK is a key machinery responsible for loss of the Hippo tumor suppressor signal in cancer. Here, we identified the Hippo-STRIPAK complex as an essential player in the control of DNA double-stranded break (DSB) repair and genomic stability. Specifically, we found that the mammalian STE20-like protein kinases 1 and 2 (MST1/2), independent of classical Hippo signaling, directly phosphorylated zinc finger MYND type-containing 8 (ZMYND8) and hence resulted in the suppression of DNA repair in the nucleus. In response to genotoxic stress, the cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) pathway was determined to relay nuclear DNA damage signals to the dynamic assembly of Hippo-STRIPAK via TANK-binding kinase 1-induced (TBK1-induced) structural stabilization of the suppressor of IKBKE 1- sarcolemma membrane-associated protein (SIKE1-SLMAP) arm. As such, we found that STRIPAK-mediated MST1/2 inactivation increased the DSB repair capacity of cancer cells and endowed these cells with resistance to radio- and chemotherapy and poly(ADP-ribose)polymerase (PARP) inhibition. Importantly, targeting the STRIPAK assembly with each of 3 distinct peptide inhibitors efficiently recovered the kinase activity of MST1/2 to suppress DNA repair and resensitize cancer cells to PARP inhibitors in both animal- and patient-derived tumor models. Overall, our findings not only uncover what we believe to be a previously unrecognized role for STRIPAK in modulating DSB repair but also provide translational implications of cotargeting STRIPAK and PARP for a new type of synthetic lethality anticancer therapy.

Correlation of myopia onset and progression with corneal biomechanical parameters in children.

BACKGROUND: Recent epidemiological studies have shown that general eye measurement parameters and corneal biomechanical properties can predict the speed of myopic progression in children. AIM: To investigate the correlation between the onset and progression of myopia and corneal biomechanical parameters in children. METHODS: The study included 102 cases in the emmetropia group, 207 cases in the myopic group, and 109 cases in the hyperopic group. The correlation between the change in corneal biomechanical indexes and the change in general ocular measurement parameters was analyzed. A one-way ANOVA test compared general ocular measurement and corneal biomechanical parameters. Pearson's correlation coefficient was analyzed to correlate corneal biomechanical and general ocular measurement parameters. RESULTS: The general ophthalmometric parameters: Spherical equivalent (SE), intraocular pressure (IOP), and axial length (AL), differed significantly among subjects in myopia, emmetropia, and hyperopic groups. Children's SE positively correlated with corneal biomechanical parameters: Second velocity of applanation (A2V), peak distance (PD), and deformation amplitude (DA) (P < 0.05), and second applanation length (A2L) (P < 0.05). But it was negatively correlated with PD, DA and integral radius (IR) (P < 0.05). Also, IOP was negatively correlated with A2L and IR (P < 0.05). AL positively correlated with A2V and negatively correlated with second applanation time (A2T), highest concavity, and PD. Central corneal thickness positively correlated with first applanation length, first applanation time, first applanation deformation amplitude, A2V, A2L, A2T, second applanation deformation amplitude, central curvature radius at highest concavity (HCR), PD, DA, IR, ambrosia relational thickness-horizontal, first applanation stiffness parameter, corvis biomechanical index, topographic and biomechanics index and the first velocity of applanation. The general ocular Km in children positively correlated with corneal biomechanical parameters DA and IR and negatively correlated with A2L, HCR, and PD. There was a positive correlation between the general ocular measurement parameters ΔSE and corneal biomechanical parameters ΔA2V and ΔA2L, and a negative correlation with ΔIR. The increase in general ocular measurement parameter ΔKm positively correlated with changes in corneal biomechanical parameters, ΔDA and ΔIR, and negatively correlated with ΔHCR and ΔPD. CONCLUSION: Myopia development in children was associated with multiple corneal biomechanical parameters.

Gait monitoring for older adults during guided walking: An integrated assistive robot and wearable sensor approach.

An active lifestyle can mitigate physical decline and cognitive impairment in older adults. Regular walking exercises for older individuals result in enhanced balance and reduced risk of falling. In this article, we present a study on gait monitoring for older adults during walking using an integrated system encompassing an assistive robot and wearable sensors. The system fuses data from the robot onboard Red Green Blue plus Depth (RGB-D) sensor with inertial and pressure sensors embedded in shoe insoles, and estimates spatiotemporal gait parameters and dynamic margin of stability in real-time. Data collected with 24 participants at a community center reveal associations between gait parameters, physical performance (evaluated with the Short Physical Performance Battery), and cognitive ability (measured with the Montreal Cognitive Assessment). The results validate the feasibility of using such a portable system in out-of-the-lab conditions and will be helpful for designing future technology-enhanced exercise interventions to improve balance, mobility, and strength and potentially reduce falls in older adults.

Erratum: Gait monitoring for older adults during guided walking: An integrated assistive robot and wearable sensor approach - ERRATUM.

[This corrects the article DOI: 10.1017/wtc.2022.23.].

The Plasma Levels and Polymorphisms of Vitronectin Predict Radiation Pneumonitis in Patients With Lung Cancer Receiving Thoracic Radiation Therapy.

PURPOSE: Our previous findings have identified vitronectin (VTN) as a potential biomarker for radiation pneumonitis (RP) through proteomics and molecular mechanism studies. In a recent study, we further explored associations of plasma level and single nucleotide polymorphisms of VTN with the risk of RP in patients with lung cancer receiving radiation therapy. METHODS AND MATERIALS: A total of 165 patients with lung cancer were prospectively enrolled with detection of VTN concentration before radiation therapy. VTN reference single nucleotide polymorphisms, rs704 and rs2227721, were genotyped by Taqman probe method. Cox proportional hazard models were performed to identify clinical variables and genotypes associated with the risk of RP on univariate and multivariate analyses, and t tests and analysis of variance were conducted to evaluate the expression level of VTN. RESULTS: The baseline secretion level of VTN in patients with grade ≥3 RP was significantly higher than that in grade <3 RP patients (P < .0001), and elevated levels were observed in patients having the AA genotype compared with GA/GG genotypes of rs704. The VTN rs704 GA/GG and rs2227721 AA/AC genotypes had a significantly lower risk of RP (hazard ratio [HR], 0.448, P = .005; HR, 0.419, P = .008, respectively). In addition, combining cut-off values of mean lung dose (MLD) and VTN plasma level, grade ≥3 RP risk groupings were as follows: high risk: MLD ≥12 Gy and VTN level ≥132 µg/mL (RP rate, 10 of 16 patients, 62.5%); intermediate risk: MLD ≥12 Gy and VTN level <132 µg/mL or MLD <12 Gy and VTN level ≥132 µg/mL (8 of 70 patients, 11.4%); and low risk: MLD <12 Gy and VTN level <132 µg/mL (1 of 79 patients, 1.3%) (P < .0001). CONCLUSIONS: Among patients receiving radiation therapy, relatively high plasma levels of VTN before radiation therapy were associated with the higher incidence of RP, and VTN rs704 and rs2227721 each had a significant effect on predicting RP risk. Combining VTN concentration with MLD appeared to facilitate stratification of patients with lung cancer who received radiation therapy into low-, intermediate-, and high-risk RP groups. This study indicated that VTN may serve as a blood biomarker for susceptibility to RP in patients with lung cancer.

Chidamide combined with paclitaxel effectively reverses the expression of histone deacetylase in lung cancer.

The role of histone deacetylases (HDACs) in lung cancer has been extensively studied. Inhibition of HDAC activities have been used as a new cancer treatment strategy. To date, many HDAC inhibitors have been shown to induce apoptosis and inhibit tumorigenesis. Chidamide (CS055) is a new member of HDAC inhibitors. In China, Chidamide has been approved for the treatment of relapsed or refractory peripheral T-cell lymphoma. However, the efficacy of Chidamide in non-small cell lung cancer remains unclear. In this study, we used lung cancer primary cells and investigated the effects of Chidamide combined with paclitaxel on lung cancer. We found that Chidamide combined with paclitaxel effectively inhibited the expression and activity of HDAC in primary lung cancer cells, induced their apoptosis and blocked cell cycle. Chidamide combined with paclitaxel may therefore provide a new promising therapeutic treatment for lung cancer.

Microcystin-LR ameliorates pulmonary fibrosis via modulating CD206+ M2-like macrophage polarization.

Idiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by myofibroblast proliferation and extracellular matrix deposition with limited treatment options. Based on our previous observation, we hypothesized microcystin-leucine arginine (LR), an environmental cyanobacterial toxin, could potentially suppress pulmonary fibrosis. In this study, we first demonstrated that chronic exposure of microcystin-LR by oral for weeks indeed attenuated the pulmonary fibrosis both on bleomycin-induced rat and fluorescein isothiocyanate-induced mouse models. Our data further indicated that treatment with microcystin-LR substantially reduced TGF-ß1/Smad signaling in rat pulmonary tissues. The experiments in vitro found that microcystin-LR was capable of blocking epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transition (FMT) through suppressing the differentiation of CD206+ macrophages. Mechanically, microcystin-LR was found to bind to glucose-regulated protein 78 kDa (GRP78) and suppress endoplasmic reticulum unfolded protein response (UPRER) signaling pathways. These events led to the modulation of M2 polarization of macrophages, which eventually contributed to the alleviation of pulmonary fibrosis. Our results revealed a novel mechanism that may account for therapeutic effect of microcystin-LR on IPF.

Variants of the ABCA3 gene might contribute to susceptibility to interstitial lung diseases in the Chinese population.

ATP-binding cassette A3 (ABCA3) is a phospholipid carrier that is mainly expressed in the alveolar epithelium. Biallelic mutations of ABCA3 has been associated with fatal respiratory distress syndrome and interstitial lung disease (ILD) in children. However, whether variations in ABCA3 have a role in the development of adult ILD, including idiopathic pulmonary fibrosis (IPF), remains to be addressed. In this study, we screened for germline variants of ABCA3 by exons-sequencing in 30 patients with sporadic IPF and in 30 matched healthy controls. Eleven missense variants, predominantly in heterozygous, were found in 13 of these patients, but only two missenses in 2 healthy controls. We then selected four of the detected missense variants (p.L39V, p.S828F, p.V968M and p.G1205R) to performed cohort analysis in 1,024 ILD patients, containing 250 IPF and 774 connective tissue disease-ILD (CTD-ILD) patients, and 1,054 healthy individuals. Our results showed that the allele frequency of p.G1205R, but not p.L39V, was significantly higher in ILD patients than in healthy controls. However, no additional subject carrying the variant p.S828F or p.V968M was detected in the cohort analysis. These results indicate that the heterozygous ABCA3 gene variants may contribute to susceptibility to diseases in the Chinese population.

High-grade serous ovarian and fallopian tube carcinomas with similar clinicopathological characteristics might originate from serous tubal intraepithelial carcinoma in Chinese women.

AIMS: This study aimed to compare the clinicopathological features, incidence, and prognosis between type II ovarian carcinoma (OC) and fallopian tube carcinoma (FTC) in Chinese women and to analyze the origin of high-grade serous carcinoma (HGSC). METHODS: Three hundreds and seventy-four OC cases and 45 FTC cases were retrospectively studied with histomorphology, tissue microarray, and immunohistochemistry. RESULTS: Our data showed that the characteristics of OC and FTC in Chinese women were younger at diagnosis with worse prognosis. There was no significant difference between type II OC and FTC in the clinicopathological information and survival. Serous tubal intraepithelial carcinoma (STIC) were found in 41.7% (43/103) of ovarian high-grade serous carcinoma (HGSC) and 52.4% (22/42) cases of tubal HGSC, and 26 patients were found with only fallopian tube (FT) mucosal invasive carcinoma. Seventy-eight of 87 cases of ovarian HGSC with tubal lesions (STIC and/or FT mucosal invasive carcinoma) was in advanced stage. There was no significant difference between newly assigned FTC (ovarian HGSC with tubal lesions and FTC) and type II OC without tubal lesions in many clinicopathological parameters, expression of immunohistochemical indicators and survival, but type I OC was quite much different from the former two. CONCLUSIONS: Our data suggested that OC of type II and FTC might be originated from the same organ, and strongly supported the dualistic model of epithelial ovarian cancer. Moreover, this study provided a further clinical basis for the prophylactic salpingectomy to reduce the risk of OC.

Chronic exposure to microcystin-LR affected mitochondrial DNA maintenance and caused pathological changes of lung tissue in mice.

Microcystin-LR (MC-LR), an important variant of cyanotoxin family, was frequently encountered in the contaminated aquatic environment and taken as a potent hepatotoxin. However, a little was known on the association between the long-term MC-LR exposure and lung damage. In this study, we investigated the changes of the pulmonary histopathology, mitochondrial DNA (mtDNA) integrity and the expression of mtDNA encoded genes in the mice with chronic exposed to MC-LR at different concentrations (1, 5, 10, 20 and 40 µg/L) for 12 months. Our results showed that the long-term and persistent exposure to MC-LR disturbed the balance of redox system, influenced mtDNA stability, changed the expression of mitochondrial genes in the lung cells. Notably, MC-LR exposure influenced the level of inflammatory cytokines and resulted in thickening of the alveolar septa. In conclusion, chronic exposure to MC-LR affected mtDNA maintenance, and caused lung impairment in mice.

Effects of chronic exposure to microcystin-LR on hepatocyte mitochondrial DNA replication in mice.

Microcystins (MCs) are produced by cyanobacterial blooms, and microcystin-LR (MC-LR) is the most toxic among the 80 MC variants. Data have shown that the liver is one of the specific target organs for MC-LR, which can cause mitochondrial DNA (mtDNA) damage, resulting in mitochondrial dysfunction. However, the underlying mechanism is still unclear. In the present study, we evaluated the genetic toxicity of MC-LR in mice drinking water at different concentrations (1, 5, 10, 20, and 40 µg/L) for 12 months. Our results showed that long-term and persistent exposure to MC-LR increased the 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels of DNA in liver cells, damaged the integrity of mtDNA and nuclear DNA (nDNA), and altered the mtDNA content. Notably, MC-LR exposure can change the expression of mitochondrial genes and nuclear genes that are critical for regulating mtDNA replication and repairing oxidized DNA. They also further impaired the function of mitochondria and liver cells.

Proton Therapy Facility Planning From a Clinical and Operational Model.

This paper provides a model for planning a new proton therapy center based on clinical data, referral pattern, beam utilization and technical considerations. The patient-specific data for the depth of targets from skin in each beam angle were reviewed at our center providing megavoltage photon external beam and proton beam therapy respectively. Further, data on insurance providers, disease sites, treatment depths, snout size and the beam angle utilization from the patients treated at our proton facility were collected and analyzed for their utilization and their impact on the facility cost. The most common disease sites treated at our center are head and neck, brain, sarcoma and pediatric malignancies. From this analysis, it is shown that the tumor depth from skin surface has a bimodal distribution (peak at 12 and 26 cm) that has significant impact on the maximum proton energy, requiring the energy in the range of 130-230 MeV. The choice of beam angles also showed a distinct pattern: mainly at 90° and 270°; this indicates that the number of gantries may be minimized. Snout usage data showed that 70% of the patients are treated with 10 cm snouts. The cost of proton beam therapy depends largely on the type of machine, maximum beam energy and the choice of gantry versus fixed beam line. Our study indicates that for a 4-room center, only two gantry rooms could be needed at the present pattern of the patient cohorts, thus significantly reducing the initial capital cost. In the USA, 95% and 100% of patients can be treated with 200 and 230 MeV proton beam respectively. Use of multi-leaf collimators and pencil beam scanning may further reduce the operational cost of the facility.

[Preparation process of rutacarpine-hydroxypropyl-beta-cyclodextrin inclusion complex].

Rutaecarpine (Rut) is a type of indole quinazoline alkaloid exracted from Ruticarpum. Studies showed that Rut has a wide range of pharmacological effects, such as anti-hypertension, anticancer, anti-inflammation, anti-thrombus formation. Currently, many scholars are committed to developing it into a new antihypertensive and anti-inflammatory drug with all new mechanisms. But studies found that Rut is a highly fat-soluble drug with low water and oil solubility. Its high insolubility is the main obstacle in its oral absorption and application, which greatly reduced its bioavailability. Therefore, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was used as the inclusion material to prepare Rut-HP-beta-CD inclusion complex in this experiment, in order to increase its water solubility and bioavailability. In this experiment, the inclusion complex was prepared by the stirring-freeze-dry method. The preparation process was optimized by the orthogonal test, with the inclusion rate as the index, and molar ratio between host and guest molecules, inclusion temperature, time and stirring speed as the impacting factors. Moreover, the inclusion complex was verified by detecting the apparent solubility, thin layer chromatography, microscopic identification, melting point detection and dissolution study. The results showed that under the conditions of the molar ratio between Rut and HP-beta-CD of 1: 1, temperature at 60 degrees C, inclusion time of 4h and stirring speed at 600 r x min(-1), the inclusion rate of Rut-HP-beta-CD reached 91.04%. Therefore, the preparation process of Rut-HP-beta-CD inclusion under the optimum conditions is simple and feasible, with a highest inclusion rate and reproducibility, and could significantly improve Rut's solubility and bioavailability, and provide a reliable experimental basis for its clinical application.

A line-profile based double partial fusion method for acquiring planning CT of oversized patients in radiation treatment.

True 3D CT dataset for treatment planning of an oversized patient is difficult to acquire due to the bore size and field of view (FOV) reconstruction. This project aims to provide a simple approach to reconstruct true CT data for oversize patients using CT scanner with limited FOV by acquiring double partial CT (left and right side) images. An efficient line profile-based method has been developed to minimize the difference of the CT numbers in the overlapping region between the right and left images and to generate a complete true 3D CT dataset in the natural state. New image processing modules have been developed and integrated to the Insight Segmentation & Registration Toolkit (ITK 3.6) package. For example, different modules for image cropping, line profile generation, line profile matching, and optimized partial image fusion have been developed. The algorithm has been implemented for images containing the bony structure of the spine and tested on 3D CT planning datasets from both phantom and real patients with satisfactory results in both cases. The proposed optimized line profile-based partial registration method provides a simple and accurate method for acquiring a complete true 3D CT dataset for an oversized patient using CT scanning with small bore size, that can be used for accurate treatment planning.

Dose correction in lung for HDR breast brachytherapy.

PURPOSE: To evaluate the dosimetric impact of lung tissue in Ir-192 APBI. MATERIAL AND METHODS: In a 40 × 40 × 40 cm(3) water tank, an Accelerated Partial Breast Irradiation (APBI) brachytherapy balloon inflated to 4 cm diameter was situated directly below the center of a 30 × 30 × 1 cm(3) solid water slab. Nine cm of solid water was stacked above the 1 cm base. A parallel plate ion chamber was centered above the base and ionization current measurements were taken from the central HDR source dwell position for channels 1, 2, 3 and 5 of the balloon. Additional ionization data was acquired in the 9 cm stack at 1 cm increments. A comparable data set was also measured after replacing the 9 cm solid water stack with cork slabs. The ratios of measurements in the two phantoms were calculated and compared to predicted results of a commercial treatment planning system. RESULTS: Lower dose was measured in the cork within 1 cm of the cork/solid water interface possibly due to backscatter effects. Higher dose was measured beyond 1 cm from the cork/solid water interface, increasing with path length up to 15% at 9 cm depth in cork. The treatment planning system did not predict either dose effect. CONCLUSIONS: This study investigates the dosimetry of low density material when the breast is treated with Ir-192 brachytherapy. HDR dose from Ir-192 in a cork media is shown to be significantly different than in unit density media. These dose differences are not predicted in most commercial brachytherapy planning systems. Empirical models based on measurements could be used to estimate lung dose associated with HDR breast brachytherapy.

Dose monitoring and output correction for the effects of scanning field changes with uniform scanning proton beam.

PURPOSE: The output of a proton beam is affected by proton energy, Spread-Out Bragg Peak (SOBP) width, aperture size, dose rate, and the point of measurement. In a uniform scanning proton beam (USPB), the scanning field size is adjusted (including the vertical length and the horizontal width) according to the treatment field size with appropriate margins to reduce secondary neutron production. Different scanning field settings result in beam output variations that are investigated in this study. METHODS: The measurements are performed with a parallel plate Markus chamber at the center of SOBP under the reference condition with 16 cm range, 10 cm SOBP, and 5 cm air gap. The effect of dose rate on field output is studied by varying proton beam current from 0.5 to 7 nA. The effects of scanning field settings are studied by varying independently the field width and length from 12 x 12 to 30 x 30 cm2. RESULTS: The results demonstrate that scanning field variations can produce output variation up to 3.80%. In addition, larger output variation is observed with scanning field changes along the stem direction of the patient dose monitor (PDM). By investigating the underlying physics of incomplete charge collection and the stem effects of the PDM, an analytical model is proposed to calculate USPB output with consideration of the scanning field area and the PDM stem length that is irradiated. The average absolute difference between the measured output and calculated output using our new correction model are within 0.13 and 0.08% for the 20 and 30 cm snouts, respectively. CONCLUSIONS: This study proposes a correction model for accurate USPB output calculation, which takes account of scanning field settings and the PDM stem effects. This model may be used to extend the existing output calculation model from one snout size to other snout sizes with customized scanning field settings. The study is especially useful for calculating field output for treatment without individualized patient specific measurements.