Proton beam spot size and position measurements using a multi-strip ionization chamber.

PURPOSE: To develop and characterize a large-area multi-strip ionization chamber (MSIC) for efficient measurement of proton beam spot size and position at a synchrotron-based proton therapy facility. METHODS AND MATERIALS: A 420 mm x 320 mm MSIC was designed with 240 vertical strips and 180 horizontal strips at 1.75 mm pitch. The MSIC was characterized by irradiating a grid of proton spots across 17 energies from 73.5 MeV to 235 MeV and comparing to simultaneous measurements made with a reference Gafchromic EBT3 film. Beam profiles, spot sizes, and positions were analyzed. Short term measurement stability and sensitivity were evaluated. RESULTS: Excellent agreement was demonstrated between the MSIC and EBT3 film for both spot size and position measurements. Spot sizes agreed within ± 0.18 mm for all energies tested. Measured beam spot positions agreed within ± 0.17 mm. The detector showed good short term measurement stability and low noise performance. CONCLUSION: The large-area MSIC enables efficient and accurate proton beam spot characterization across the clinical energy range. The results indicate the MSIC is suitable for pencil beam scanning proton therapy commissioning and quality assurance applications requiring fast spot size and position quantification.

Characterization of an Escherichia coli phage Tequatrovirus YZ2 and its application in bacterial wound infection.

The increasing prevalence of drug-resistant Escherichia coli (E. coli) resulting from the excessive utilization of antibiotics necessitates the immediate exploration of alternative approaches to counteract pathogenic E. coli. Phages, with their unique antibacterial mechanisms, are considered promising candidates for treating bacterial infections. Herein, we isolated a lytic Escherichia phage Tequatrovirus YZ2 (phage YZ2), which belongs to the genus Tequatrovirus. The genome of phage YZ2 consists of 168,356 base pairs with a G + C content of 35.34% and 269 putative open reading frames (ORFs). Of these, 146 ORFs have been annotated as functional proteins associated with nucleotide metabolism, structure, transcription, DNA replication, translation, and lysis. In the mouse model of a skin wound infected by E. coli, phage YZ2 therapy significantly promoted the wound healing. Furthermore, histopathological analysis revealed reductions in IL-1ß and TNF-α and increased VEGF levels, indicating the potential of phages as effective antimicrobial agents against E. coli infection.

Nrdp1-mediated Macrophage Phenotypic Regulation Promotes Functional Recovery in Mice with Mild Neurological Impairment after Intracerebral Hemorrhage.

Neuregulin receptor degradation protein 1 (Nrdp1) is a ring finger E3 ubiquitin ligase involved in some inflammation through ubiquitination, including macrophage polarization following cerebral hemorrhage. However, there is limited understanding regarding the mechanisms through which Nrdp1 modulates macrophage polarization and the potential impact of this modulation on neurological function. Using stereotactic injection and adenoviral transfection techniques, the corresponding animal models were constructed through injecting adenovirus, saline, or blood into the mouse striatum at different periods of time in this research. The alteration in the ratio of various M1/M2 phenotype-associated markers (e.g., CD86, CD206, IL-6, IL-10, etc.) was evaluated through immunohistochemistry, immunofluorescence, western blotting, and elisa assays. Additionally, neurological function scores and behavioral tests were utilized to evaluate changes in neurological function in mice after cerebral hemorrhage. Our results show that overexpression of Nrdp1 promotes the expression of a variety of M2 macrophage-associated markers and enhance transcriptional activity of arginase-1 (Arg1) protein through ubiquitination for early regulation M2 macrophage polarization. Additionally, Nrdp1 promotes hematoma absorption, increases IL-10 expression, inhibits inducible nitric oxide synthase (iNOS), IL-6, and TNF-α production, alleviates neurological impairment and brain edema, and accelerates functional recovery. These findings suggest that modulating macrophage polarization through Nrdp1 could be a therapeutic strategy for neurofunctional impairment in cerebral hemorrhage.

Nanofiber-mediated sequential photothermal antibacteria and macrophage polarization for healing MRSA-infected diabetic wounds.

BACKGROUND: Diabetic wound healing remains a challenge because of its susceptibility to drug-resistant bacterial infection and its persistent proinflammatory state. Switching from proinflammatory M1 macrophages (Mφs) to proregenerative M2 dominant Mφs in a timely manner accelerates wound healing by coordinating inflammatory, proliferative, and angiogenic processes. METHODS: We propose a sequential photothermal antibacterial and subsequent M2 Mφ polarization strategy based on nanofibers (NFs) consisting of polydopamine (PDA) coating on curcumin (Cur) nanocrystals to treat Methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic wounds. RESULTS: The PDA/Cur NFs showed excellent photothermal conversion and antibacterial effects due to the PDA shell under laser irradiation, consequently resulting in the release of the inner Cur with the ability to promote cell proliferation and reinforce the M2 Mφ phenotype in vitro. In vivo studies on MRSA-infected diabetic wounds showed that PDA/Cur NFs not only inhibited MRSA infection but also accelerated the wound regeneration process. Furthermore, the NFs displayed the ability to promote the M2 Mφ phenotype with enhanced collagen deposition, angiogenesis, and cell proliferation. CONCLUSION: Overall, the NFs displayed great potential as promising therapeutics for healing infected diabetic wounds through a sequential photothermal antibacterial and M2 Mφ polarization strategy.

Physicochemical and functional characteristics of polysaccharides from okra extracted by using ultrasound at different frequencies.

In this study, single- (SFU) and dual-frequency (DFU) ultrasounds were used to extract polysaccharides from okra (Abelmoschus esculentus (L.) Moench) pods (OPSs), and the physicochemical characteristics, functional properties, and in vitro biological activities of the OPSs were comparatively evaluated. Results showed that ultrasonic extractions at different frequencies led to remarkable variations in extraction yields, chemical components, monosaccharide compositions, molecular weights (MWs), surface morphologies, and rheological properties of the OPSs but hardly affected their preliminary structural features and thermal stabilities. The OPS obtained through DFU at 40/60 kHz with the lowest MWs (0.85-14.93 × 105 Da) and highest polyphenol content (7.38%) as well as loosest network structures showed superior antioxidant, cholesterol absorption and nitrite ion absorption capacities than the other OPSs, and the OPS extracted through SFU at 20 kHz with the highest carboxylate content (76.08%), MWs (7.28-32.83 × 105 Da) and degree of esterification (30.7%) exhibited higher bile acid-binding capacity than the other OPSs.

Impact of Multiple Beams on Plan Quality, Linear Energy Transfer Distribution, and Plan Robustness of Intensity Modulated Proton Therapy for Lung Cancer.

The increase of proton beam number might provide higher degrees of freedom in the optimization of intensity-modulated proton therapy planning. In this study, we aimed to quantitatively explore the potential benefits of the increased beam number, including dose volume histogram (DVH), linear energy transfer volume histogram, and DVH bandwidth metrics. Twelve patients with lung cancer are retrospectively selected. Four plans were created based on internal target volume (ITV) robust optimization for each patient using the RayStation treatment planning system. Four plans were generated using different numbers (three, five, seven, and nine) of evenly separated coplanar beams. The three-beam plan was considered as the reference plan. Biologically equivalent doses were calculated using both constant relative biological effectiveness (RBE) and variable RBE models, respectively. To evaluate plan quality, DVH metrics in the target [ITV: D2%, CI, HI] and organs-at-risk [Lung: V5Gy[RBE], V20Gy[RBE], V30Gy[RBE]; Heart D2%; Spinal cord D2%] were calculated using both RBE models. To evaluate LET distributions, LET volume histogram metrics [ITV LETmean and LET2%; Lung LETmean and LET2%; Heart LET2%; Spinal cord LET2%] were quantified. To evaluate plan robustness, the metrics using DVH bandwidth [ITV: D2%, D99%; Lung: V5Gy[RBE], V20Gy[RBE], V30Gy[RBE]; Heart D2%; Spinal cord D2%] were also reported. For plan quality, the increase of proton beam number resulted in fewer target hot spots, improved target dose conformity, improved target dose homogeneity, lower median-dose lung volume, and fewer hot spots in spinal cord. As to LET distributions, target mean LET increased significantly as the beam number increased to seven or more. Lung LET hot spots were significantly reduced with the increase of proton beams. With respect to plan robustness, the robustness of target dose coverage, target hot spots, and low-dose lung volume were improved, while the robustness of heart hot spots became worse as the beam number increased to nine. The robustness of cord hot spots became worse using five and seven beams compared to that using three beams. As the proton beam number increased, plan quality and LET distributions were comparable or significantly improved. The robustness of target dose coverage, target dose hot spots, and low-dose lung volume were significantly improved.

PAF1 complex interactions with SETDB1 mediate promoter H3K9 methylation and transcriptional repression of Hoxa9 and Meis1 in acute myeloid leukemia.

The Polymerase Associated Factor 1 complex (PAF1c) is an epigenetic co-modifying complex that directly contacts RNA polymerase II (RNAPII) and several epigenetic regulating proteins. Mutations, overexpression and loss of expression of subunits of the PAF1c are observed in various forms of cancer suggesting proper regulation is needed for cellular development. However, the biochemical interactions with the PAF1c that allow dynamic gene regulation are unclear. We and others have shown that the PAF1c makes a direct interaction with MLL fusion proteins, which are potent oncogenic drivers of acute myeloid leukemia (AML). This interaction is critical for the maintenance of MLL translocation driven AML by targeting MLL fusion proteins to the target genes Meis1 and Hoxa9. Here, we use a proteomics approach to identify protein-protein interactions with the PAF1c subunit CDC73 that regulate the function of the PAF1c. We identified a novel interaction with a histone H3 lysine 9 (H3K9) methyltransferase protein, SETDB1. This interaction is stabilized with a mutant CDC73 that is incapable of supporting AML cell growth. Importantly, transcription of Meis1 and Hoxa9 is reduced and promoter H3K9 trimethylation (H3K9me3) increased by overexpression of SETDB1 or stabilization of the PAF1c-SETDB1 interaction in AML cells. These findings were corroborated in human AML patients where increased SETDB1 expression was associated with reduced HOXA9 and MEIS1. To our knowledge, this is the first proteomics approach to search for CDC73 protein-protein interactions in AML, and demonstrates that the PAF1c may play a role in H3K9me3-mediated transcriptional repression in AML.

[Onset time and efficacy of sublingual immunotherapy with Dermatophagoides farinae drops in children with allergic rhinitis].

OBJECTIVE: To investigate the onset time and efficacy of sublingual immunotherapy (SLIT) with Dermatophagoides farinae drops in children with house dust mites (HDM)-induced allergic rhinitis (AR). METHODS: One hundred and forty three children with perennial moderate to severe HDM-induced AR were treated by SLIT with standardized Dermatophagoides farinae extract. One hundred children who finally completed two years treatment were divided into two groups according to the age: younger children group (aged 4-8 years, n = 52) and older children group (aged 9-14 years, n = 48). Respectively, Each children was assessed before and after 1st, 2nd, 3rd, 6th, 12th, 24th months of the treatment. Total nasal symptom score (TNSS), total medication score (TMS) and visual analogue scale (VAS) were evaluated at each visit. All clinical data were analyzed retrospectively with the SPSS 19.0 software. RESULTS: TNSS, TMS and VAS of two groups decreased significantly after three months of the treatment compared with before (younger children group: Z value was -3.843, -3.534, -3.940, older children group: Z value was -3.938, -3.405, -3.953, all P < 0.05). TNSS and VAS of younger children group decreased significantly after two months of the treatment compared with before (6.4 ± 1.6, 5.3 ± 1.4 vs 8.6 ± 1.2, 7.9 ± 1.6, Z value was -3.843, -3.940, both P < 0.05). Five children (5%) experienced local adverse events and 2 children (2%) experienced mild systemic adverse events. No severe adverse events happened during the treatment. CONCLUSIONS: SLIT with Dermatophagoides farinae drops is an efficient and safe treatment for children with HDM-induced AR. Its onset of action can be observed as early as 3 months after treatment.

[Clinical characteristics of benign paroxysmal positional vertigo secondary to sudden deafness].

OBJECTIVE: To retrospectively analyze the clinical characteristics of the benign paroxysmal positional vertigo (BPPV) secondary to the sudden deafness (SD) and to explore pathogenetic mechanism. METHOD: One hundred and seventy-eight cases of the SD in our department were retrospectively analyzed. They were all treated under the guidance of clinical guidelines. RESULT: (1) In all these patient's with SD, there were 31 cases with BPPV secondary to the SD. There were 26 cases of BPPV of posterior semicircular canal and 5 cases of BPPV of lateral BPPV semicircular canal. All patients with BPPV were diagnosed as the same ears as the SD, including 16 cases on left sides and 15 on right sides. (2) The interval between the onset of SD and BPPV was less than one week in 27 cases, between one week and one month in 3 cases, and between one and three months in 1 case. (3) All patients with BPPV secondary to the SD were cured with Epley maneuver or Barbecue roll maneuver. CONCLUSION: The occurrence of BPPV may follow SD, and the major of BPPV secondary to the SD occurs in the posterior semicircular canal. The canalith repositioning is an effective therapy to the secondary BPPV.

Functional identification of cytokinesis-related genes from tobacco BY-2 cells.

The molecular mechanisms controlling cytokinesis in plant cell division cycle remains largely unknown. In this study, a functional approach was taken to identify genes that may play roles in cytokinesis in tobacco BY-2 cells, using fission yeast as the host organism. A total of 22 BY-2 genes that perturbed the terminal stage of cell division when ectopically expressed in yeast cells were isolated, among which, several encode for uncharacterized genes. Additionally, RT-PCR analysis indicated that four of the isolated genes were expressed in a cell cycle-dependent manner. Our results demonstrate that fission yeast system can be efficiently used to identify the genes that may function, either positively or negatively, in the regulation of cytokinesis. More importantly, the candidate genes we have isolated in this work can provide useful information for unraveling the regulators controlling cell separation at the late stage of BY-2 cell division.

[Expression of telomerase reverse transcriptase and its relationship with expression of c-myc in laryngeal squamous cell carcinomas].

OBJECTIVE: To investigate the expression of human telomerase reverse transcriptase (hTERT) and c-myc and their relationship with clinicopathological parameter in laryngeal squamous cell carcinoma (LSCC). METHOD: The expression of hTERT protein and c-myc protein in 39 LSCC specimens and 10 vocal cord polyp specimens were detected by immunohistochemistry. The correlation between the expression of hTERT protein and c-myc protein and their relationship with clinicopathological parameter were analyzed. RESULT: The positive rate of hTERT protein and c-myc protein expression in 39 LSCC was 84.6% (33/39) and 82.1% (32/39), respectively. The positive rate of hTERT protein and c-myc protein expression in 10 vocal cord polyps was 0 (0/10) and 10.0% (1/10) respectively. Statistical tests showed that hTERT and c-myc protein expression was significantly higher in LSCC than that in vocal cord polyps. Spearman rank correlation analysis revealed that the expression of c-myc protein was great significantly related to that of hTERT protein (correlation coefficient r = 0.541, P < 0.01). No statistically association was observed among the frequency of hTERT expression and TNM stages, degree of differentiation or lymph nodes metastases. CONCLUSION: The activation of hTERT may be a key step in the pathogenesis of LSCC and the expression of hTERT was associated significantly with that of c-myc gene. C-myc is probably an important control factor in the activation and regulation of hTERT expression.

Functional characterization of Gossypium hirsutum profilin 1 gene (GhPFN1) in tobacco suspension cells. Characterization of in vivo functions of a cotton profilin gene.

Cotton fiber is an extremely long plant cell. Fiber elongation is a complex process and the genes that are crucial for elongation are largely unknown. We previously cloned a cDNA encoding an isoform of cotton profilin and found that the gene (designated GhPFN1) was preferentially expressed in cotton fibers. In the present study, we have further analyzed the expression pattern of GhPFN1 during fiber development and studied its cellular function using tobacco suspension cells as an experimental system. We report that expression of GhPFN1 is tightly associated with fast elongation of cotton fibers whose growth requires an intact actin cytoskeleton. Overexpression of GhPFN1 in the transgenic tobacco cells was correlated with the formation of elongated cells that contained thicker and longer microfilament cables. Quantitative analyses revealed a 2.5-3.6 fold increase in total profilin levels and a 1.6-2.6 fold increase in the F-actin levels in six independent transgenic lines. In addition to the effect on cell elongation, we also observed delayed cell cycle progression and a slightly lower mitotic index in the transgenic cells. Based on these data, we propose that GhPFN1 may play a critical role in the rapid elongation of cotton fibers by promoting actin polymerization.