10 research outputs found

    Stereotactic Body Radiotherapy Boost with the CyberKnife for Locally Advanced Cervical Cancer: Dosimetric Analysis and Potential Clinical Benefits

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    (1) Aim: To compare the treatment plans of stereotactic body radiotherapy (SBRT) with CyberKnife (CK) and high-dose-rate (HDR) intracavitary/interstitial brachytherapy (IC/ISBT) and examine the feasibility of CK-SBRT as a viable alternative to BT in patients with locally advanced cervical cancer (LACC). (2) Methods: A BT plan of 28 Gy in four fractions delivered previously to 20 patients with LACC was compared with a CK plan based on the same CT images with structures delineation for BT. The SBRT treatment plan was further divided according to two different approaches, with the high-risk planning target volume (HR-PTV) defined by the high-risk clinical target volume (HR-CTV) without and with a 5 mm margin, which were named CK-CTV plan and CK-PTV plan, respectively. The dose distributions and dosimetric parameters of the target volumes and organs at risk (OARs) were recorded and compared for the three boost plans. Radiobiological metrics were calculated based on the EUD for the hybrid plans. Additionally, the relationship between tumor volume and tolerance doses for the OARs in the BT plan and CK-PTV plan was investigated. (3) Results: Target coverage was better with the CK plan than with the BT plan, as the D95%, D98%, HI and CI of the CK-CTV plan and CK-PTV plan were higher than those of the BT plan; an exception was the D50%. Similarly, the TCP of the target was also significantly in favor of the CK hybrid plans (p p < 0.01). (4) Conclusions: CK-based SBRT can achieve better target coverage, dose sparing for the OARs and radiobiological effects compared with the BT plan for tumors that are not excessively large. CK-based SBRT could be an alternative option to administer a radiation boost for patients with LACC

    Characterization of quinoxaline derivatives for protection against iatrogenically induced hearing loss

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    Hair cell loss is the leading cause of hearing and balance disorders in humans. It can be caused by many factors, including noise, aging, and therapeutic agents. Previous studies have shown the therapeutic potential of quinoxaline against drug-induced ototoxicity. Here, we screened a library of 68 quinoxaline derivatives for protection against aminoglycoside-induced damage of hair cells from the zebrafish lateral line. We identified quinoxaline-5-carboxylic acid (Qx28) as the best quinoxaline derivative that provides robust protection against both aminoglycosides and cisplatin in zebrafish and mouse cochlear explants. FM1-43 and aminoglycoside uptake, as well as antibiotic efficacy studies, revealed that Qx28 is neither blocking the mechanotransduction channels nor interfering with aminoglycoside antibacterial activity, suggesting that it may be protecting the hair cells by directly counteracting the ototoxin’s mechanism of action. Only when animals were incubated with higher doses of Qx28 did we observe a partial blockage of the mechanotransduction channels. Finally, we assessed the regulation of the NF-ÎșB pathway in vitro in mouse embryonic fibroblasts and in vivo in zebrafish larvae. Those studies showed that Qx28 protects hair cells by blocking NF-ÎșB canonical pathway activation. Thus, Qx28 is a promising and versatile otoprotectant that can act across different species and toxins

    Rational Metabolic Engineering Combined with Biosensor-Mediated Adaptive Laboratory Evolution for <span style="font-variant: small-caps">l</span>-Cysteine Overproduction from Glycerol in <i>Escherichia coli</i>

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    l-Cysteine is an important sulfur-containing amino acid with numerous applications in the pharmaceutical and cosmetic industries. The microbial production of l-cysteine has received substantial attention, and the supply of the precursor l-serine is important in l-cysteine biosynthesis. In this study, to achieve l-cysteine overproduction, we first increased l-serine production by deleting genes involved in the pathway of l-serine degradation to glycine (serine hydroxymethyl transferase, SHMT, encoded by glyA genes) in strain 4W (with l-serine titer of 1.1 g/L), thus resulting in strain 4WG with l-serine titer of 2.01 g/L. Second, the serine-biosensor based on the transcriptional regulator NCgl0581 of C. glutamicum was constructed in E. coli, and the validity and sensitivity of the biosensor were demonstrated in E. coli. Then 4WG was further evolved through adaptive laboratory evolution (ALE) combined with serine-biosensor, thus yielding the strain 4WGX with 4.13 g/L l-serine production. Moreover, the whole genome of the evolved strain 4WGX was sequenced, and ten non-synonymous mutations were found in the genome of strain 4WGX compared with strain 4W. Finally, 4WGX was used as the starting strain, and deletion of the l-cysteine desulfhydrases (encoded by tnaA), overexpression of serine acetyltransferase (encoded by cysE) and the key enzyme of transport pathway (encoded by ydeD) were performed in strain 4WGX. The recombinant strain 4WGX-∆tnaA-cysE-ydeD can produce 313.4 mg/L of l-cysteine using glycerol as the carbon source. This work provides an efficient method for the biosynthesis of value-added commodity products associated with glycerol conversion

    Liquefaction of kraft lignin over the composite catalyst HTaMoO6 and Rh/C in dioxane-water system

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    A catalytic routine was developed for kraft lignin depolymerization in dioxane-water systems, in which the catalyst HTaMoO6 with strong Bronsted acidity and a hydrogenation catalyst (Rh/C) were employed simultaneously. The performance of the composite catalysts was tested in a series of experiments with various reaction temperatures, reaction time and catalyst ratios. Under the optimized conditions, a higher petroleum ether soluble fraction yield of 58.7% was obtained at 320 degrees C for 24 h. Besides, a higher liquid product yield of 95.6% was achieved at 290 degrees C for 2 h. Specially, the main compositions of the petroleum ether soluble fraction are monomers and dimers, which can be used as liquid fuel. These results demonstrated that the composite catalyst HTaMoO6-Rh/C can effectively catalyze the depolymerization of the kraft lignin into small molecule liquid fuel components

    Optogenetics reveals roles for supporting cells in force transmission to and from outer hair cells in the mouse cochlea

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    Outer hair cells (OHCs) of the organ of Corti (OoC), acting as bidirectional cellular mechanoelectrical- transducers, generate, receive, and exchange forces with other major elements of the cochlear partition, including the sensory inner hair cells (IHCs). Force exchange is mediated via a supporting cell scaffold, including Deiters' (DC) and outer pillar cells (OPC), to enable the sensitivity and exquisite frequency selectivity of the mammalian cochlea and to transmit its responses to the auditory nerve. To selectively activate DCs and OPCs in male and female mice, we conditionally expressed in them a hyperpolarizing halorhodopsin (HOP), a light-gated inward chloride ion pump and measured extracellular receptor potentials (ERPs) and their DC component (ERPDCs) from the Cortilymph, which fills the OoC fluid spaces, and compared the responses with similar potentials from HOP littermates. The compound action potentials (CAP) of the auditory nerve were measured as an indication of IHC activity and transmission of cochlear responses to the CNS. HOP light-activated hyperpolarization of DCs and OPCs suppressed cochlear amplification through changing timing of its feedback, altered basilar membrane (BM) responses to tones at all measured levels and frequencies, and reduced IHC excitation. HOP-activation findings reported here complement recent studies that revealed channelrhodopsin activation depolarized DCs and OPCs and effectively bypassed, rather than blocked, the control of OHC mechanical and electrical responses to sound and their contribution to timed and directed electromechanical feedback to the mammalian cochlea. Moreover, our findings identify DCs and OPCs as potential targets for the treatment of noise-induced hearing loss. Outer hair cells provide electromechanical feedback to the organ of Corti, mediated via a cellular scaffold of Deiters' and outer pillar cells, that enables the sensitivity and fine frequency tuning of the cochlea. The role of this scaffold was explored by expressing the halorhodopsin HOP in Deiters' and pillar cells of male and female mice which became hyperpolarized when illuminated. HOP light-activated hyperpolarization suppressed cochlear amplification, altered basilar membrane responses to tones, including those at levels and frequencies not subject to amplification, and attenuated neural excitation. The findings indicate supporting cells in mediating force transmission between outer hair cells and the organ of Corti and as targets for hearing loss treatments. [Abstract copyright: Copyright © 2023 the authors.

    Nomogram development and external validation for predicting overall survival and cancer-specific survival in patients with primary retroperitoneal sarcoma: a retrospective cohort study

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    Abstract Background Primary retroperitoneal sarcoma (RPS) comprises over 70 histologic subtypes, yet there are limited studies that have developed prognostic nomograms for RPS patients to predict overall survival (OS) and cancer-specific survival (CSS). The objective of this study was to construct prognostic nomograms for predicting OS and CSS in RPS patients. Methods We identified a total of 1166 RPS patients from the Surveillance, Epidemiology and End Results (SEER) database, and an additional 261 cases were collected from a tertiary cancer center. The study incorporated various clinicopathological and epidemiologic features as variables, and prediction windows for overall survival (OS) and cancer-specific survival (CSS) were set at 3, 5, and 7 years. Multivariable Cox models were utilized to develop the nomograms, and variable selection was performed using a backward procedure based on the Akaike Information Criterion. To evaluate the performance of the nomograms in terms of calibration and discrimination, we used calibration plots, coherence index, and area under the curve. Findings The study included 818 patients in the development cohort, 348 patients in the internal validation cohort, and 261 patients in the external validation cohort. The backward procedure selected the following variables: age, French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade, pre-/postoperative chemotherapy, tumor size, primary site surgery, and tumor multifocality. The validation results demonstrated that the nomograms had good calibration and discrimination, with C-indices of 0.76 for OS and 0.81 for CSS. Calibration plots also showed good consistency between the predicted and actual survival rates. Furthermore, the areas under the time-dependent receiver operating characteristic curves for the 3-, 5-, and 7-year OS (0.84, 0.82, and 0.78, respectively) and CSS (0.88, 0.88, and 0.85, respectively) confirmed the accuracy of the nomograms. Interpretation Our study developed accurate nomograms to predict OS and CSS in patients with RPS. These nomograms have important clinical implications and can assist healthcare providers in making informed decisions regarding patient care and treatment options. They may also aid in patient counseling and stratification in clinical trials

    Clinical and genetic study of 12 Chinese Han families with nonsyndromic deafness

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    Abstract Background Nonsyndromic hearing loss is clinically and genetically heterogeneous. In this study, we characterized the clinical features of 12 Chinese Han deaf families in which mutations in common deafness genes GJB2, SLC26A4, and MT‐RNR1 were excluded. Methods Targeted next‐generation sequencing of 147 known deafness genes was performed in probands of 10 families, while whole‐exome sequencing was applied in those of the rest two. Results Pathogenic mutations in a total of 11 rare deafness genes, OTOF, CDH23, PCDH15, PDZD7, ADGRV1, KARS, OTOG, GRXCR2, MYO6, GRHL2, and POU3F4, were identified in all 12 probands, with 16 mutations being novel. Intrafamilial cosegregation of the mutations and the deafness phenotype were confirmed by Sanger sequencing. Conclusion Our results expanded the mutation spectrum and genotype‒phenotype correlation of nonsyndromic hearing loss in Chinese Hans and also emphasized the importance of combining both next‐generation sequencing and detailed auditory evaluation to achieve a more accurate diagnosis for nonsyndromic hearing loss
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