Mechanochemical Synthesis of α-halo Alkylboronic Esters.

α-halo alkylboronic esters, acting as ambiphilic synthons, play a pivotal role as versatile intermediates in fields like pharmaceutical science and organic chemistry. The sequential transformation of carbon-boron and carbon-halogen bonds into a broad range of carbon-X bonds allows for programmable bond formation, facilitating the incorporation of multiple substituents at a single position and streamlining the synthesis of complex molecules. Nevertheless, the synthetic potential of these compounds is constrained by limited reaction patterns. Additionally, the conventional methods often necessitate the use of bulk toxic solvents, exhibit sensitivity to air/moisture, rely on expensive metal catalysts, and involve extended reaction times. In this report, a ball milling technique is introduced that overcomes these limitations, enabling the external catalyst-free multicomponent coupling of aryl diazonium salts, alkenes, and simple metal halides. This approach offers a general and straightforward method for obtaining a diverse array of α-halo alkylboronic esters, thereby paving the way for the extensive utilization of these synthons in the synthesis of fine chemicals.

Accelerated partial breast irradiation: Current evidence and future developments.

Whole breast irradiation after breast-conserving surgery for early breast cancer has become one of the standard treatment modes for breast cancer and yields the same effect as radical surgery. Accelerated partial breast irradiation (APBI) as a substitute for whole breast irradiation for patients with early breast cancer is a hot spot in clinical research. APBI is characterised by simple high-dose local irradiation of the tumour bed in a short time, thus improving convenience for patients and saving costs. The implementation methods of APBI mainly include brachytherapy, external beam radiation therapy, and intraoperative radiotherapy. This review provides an overview of the clinical effects and adverse reactions of the main technologies of APBI and discusses the prospects for the future development of APBI.

External Quality Assessment (EQA) scheme for serological diagnostic test for SARS-CoV-2 detection in Sicily Region (Italy), in the period 2020-2022.

OBJECTIVES: Since December 2019, worldwide public health has been exposed to a severe acute respiratory syndrome caused by Coronavirus-2. Serological testing is necessary for retrospective assessment of seroprevalence rates, and the determination of vaccine response and duration of immunity. For this reason, it was necessary to introduce a panel of tests able to identify and quantify Covid-19 antibodies. METHODS: As a Regional Reference Centre, the CRQ Laboratory (Regional Laboratory for the Quality Control) developed and conducted an External Quality Assessment (EQA) panel of assays, to evaluate the quality of various methods, that were used by 288 Sicilian laboratories, previously authorized on behalf of the Public Health Service. RESULTS: The performance test was based on pooled samples with different levels of concentration of antibodies. 97 , 98, and 95 % of the participating laboratories tested all samples correctly in 2020, 2021, and 2022 respectively. The best performance was observed in the test of total Ig. The general performance of laboratories improved over the years. CONCLUSIONS: The incorrect diagnosis had and could still have important implications on vaccination cycles. Only through the effort of laboratory professionals, and the extension of the EQA scheme, a better harmonization of methods, protocols, and thus results, to guarantee a better healthcare system, will be possible.

Evaluating the Commutability of Reference Materials for α-Fetoprotein: Accurate Value Assignment With Multiple Systems and Trueness Verification.

Background: The accurate measurement of α-fetoprotein (AFP) is critical for clinical diagnosis. However, different AFP immunoassays may yield different results. Appropriate AFP reference materials (RMs) were selected and assigned accurate values for applications with external quality assessment (EQA) programs to standardize AFP measurements. Methods: Forty individual clinical samples and six different concentrations of candidate RMs (Can-RMs, L1-L6) were prepared by the Beijing Center for Clinical Laboratories. The Can-RMs were assigned target values by performing five immunoassays, using WHO International Standard 72/225 as a calibrator, and sent to 45 clinical laboratories in Beijing for AFP measurements. The commutability of all RMs was assessed based on CLSI and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) approaches. Analytical performance was assessed for compliance based on accuracy (total error, TE), trueness (bias), and precision (CV). Results: The Can-RMs were commutable for all immunoassays using the CLSI approach and for 6 of 10 assay combinations using the IFCC approach. RMs diluted in WHO RM 72/225 were commutable among all assays with the CLSI approach, except for serum matrix (Autolumo vs. Roche analyzer) and diluted water matrix (Abbott vs. Roche/Mindray analyzer), whereas some inconclusive and non-commutable results were found using the IFCC approach. The average pass rates based on the TE, bias, and CV were 91%, 81%, and 95%, respectively. Conclusions: The commutability of the RMs differed between both evaluation approaches. The Can-RMs exhibited good commutability with the CLSI approach, suggesting their suitability for use with that approach as commutable EQA materials with assigned values and for monitoring the performance of AFP measurements.

A staging table of Balkan crested newt embryonic development to serve as a baseline in evolutionary developmental studies.

There is an increased interest in the evolution and development of newts from the genus Triturus because: (1) morphological differentiation among the nine constituent species largely corresponds to different ecological preferences, (2) hybridization between different species pairs has various evolutionary outcomes in terms of life history traits and morphology, and (3) the genus expresses a balanced lethal system that causes arrested growth and death of half of the embryos. These features provide natural experimental settings for molecular, morphological, and life-history studies. Therefore, we produce a staging table for the Balkan crested newt (T. ivanbureschi). We provide detailed descriptions of 34 embryonic stages based on easily observable and interpretable external morphological characters, to ensure reproducibility. Compared with previous staging tables for Triturus, we include a vastly increased sample size and provide high-resolution photographs in lateral, ventral, and dorsal view, complemented by videos of specific developmental periods, and accompanied by detailed explanations on how to delineate the specific stages. Our staging table will serve as a baseline in comparative studies on Triturus newts: an emerging model system in evolutionary and developmental studies.

Impact of Reduced Acidic Earwax pH and Earwax-Determinant Genotypes in Acquired Middle Ear Cholesteatoma.

OBJECTIVE: The development of acquired middle ear cholesteatoma is associated with a single nucleotide polymorphism, 538G>A, in the human adenosine triphosphate-binding cassette transporter C11 (ABCC11) gene, which is a determinant of the earwax morphotype, such as wet- and dry-type earwax; however, the mechanism underlying this association is unclear. We focused on the earwax pH and aimed to elucidate the mechanism between ABCC11 genotypes and acquired middle ear cholesteatoma. STUDY DESIGN: Prospective observational study. SETTING: Single-center, academic hospital. METHODS: We recruited 40 patients with acquired middle ear cholesteatoma who underwent surgery and 115 controls with no history of middle ear cholesteatoma. We assessed the earwax pH and ABCC11 genotypes in all participants. Clinical information was collected from the patients with cholesteatoma. RESULTS: The earwax pH was significantly less acidic in patients with cholesteatoma and those carrying wet earwax genotypes (ABCC11 538G/G or 538G/A) than in the controls and those carrying the dry earwax genotype (ABCC11 538A/A), respectively. Furthermore, earwax pH was significantly positively correlated with high preoperative cholesteatoma stages in the patients with cholesteatoma. CONCLUSION: Our results show that the less acidic earwax pH was significantly related to the development and progression of acquired middle ear cholesteatoma. The less acidic earwax pH may play an important role in the mechanism underlying the association between acquired middle ear cholesteatoma and the ABCC11 gene at site 538.

How does the data element-driven industry affect corporate cash holdings? Evidence from Chinese listed companies.

The data element-driven industry (DEDI) generates large amounts of data, thereby mitigating information asymmetry. Does this affect corporate cash holdings? On the basis of theoretical analysis, this study empirically analyzes the impact of DEDI on enterprises' cash holdings and its transmission path using data of Chinese cities and A-share listed enterprises from 2008 to 2020. First, the results indicate that the DEDI reduces corporate cash holdings. As the development level of the DEDI improves, the corporate cash holdings gradually decrease. Second, the DEDI indirectly affects corporate cash holdings by influencing debt-financing and external credit supply capacities. Specifically, the DEDI increases the upstream corporate debt-financing and downstream corporate external credit supply capacities. Improvements in debt-financing and the external credit supply capacities can reduce corporate cash holdings. Third, the DEDI has a heterogeneous impact. For enterprise with CEO duality, small and medium-sized, and information technology enterprises, the impact of DEDI in reducing cash holdings is greater.

A new approach to comparing the demands of small-sided games and soccer matches.

To improve soccer performance, coaches should be able to replicate the match's physical efforts during the training sessions. For this goal, small-sided games (SSGs) are widely used. The main purpose of the current study was to develop similarity and overload scores to quantify the degree of similarity and the extent to which the SSG was able to replicate match intensity. GPSs were employed to collect external load and were grouped in three vectors (kinematic, metabolic, and mechanical). Euclidean distance was used to calculate the distance between training and match vectors, which was subsequently converted into a similarity score. The average of the pairwise difference between vectors was used to develop the overload scores. Three similarity (Simkin, Simmet, Simmec) and three overload scores (OVERkin, OVERmet, OVERmec) were defined for kinematic, metabolic, and mechanical vectors. Simmet and OVERmet were excluded from further analysis, showing a very large correlation (r > 0.7, p < 0.01) with Simkin and OVERkin. The scores were subsequently analysed considering teams' level (First team vs. U19 team) and SSGs' characteristics in the various playing roles. The independent-sample t-test showed (p < 0.01) that the First team presented greater Simkin (d = 0.91), OVERkin (d = 0.47), and OVERmec (d = 0.35) scores. Moreover, a generalized linear mixed model (GLMM) was employed to evaluate differences according to SSG characteristics. The results suggest that a specific SSG format could lead to different similarity and overload scores according to the playing position. This process could simplify data interpretation and categorize SSGs based on their scores.

Survival after resection of malignant peripheral nerve sheath tumors: Introducing and validating a novel type-specific prognostic model.

Background: This study aimed to assess the performance of currently available risk calculators in a cohort of patients with malignant peripheral nerve sheath tumors (MPNST) and to create an MPNST-specific prognostic model including type-specific predictors for overall survival (OS). Methods: This is a retrospective multicenter cohort study of patients with MPNST from 11 secondary or tertiary centers in The Netherlands, Italy and the United States of America. All patients diagnosed with primary MPNST who underwent macroscopically complete surgical resection from 2000 to 2019 were included in this study. A multivariable Cox proportional hazard model for OS was estimated with prespecified predictors (age, grade, size, NF-1 status, triton status, depth, tumor location, and surgical margin). Model performance was assessed for the Sarculator and PERSARC calculators by examining discrimination (C-index) and calibration (calibration plots and observed-expected statistic; O/E-statistic). Internal-external cross-validation by different regions was performed to evaluate the generalizability of the model. Results: A total of 507 patients with primary MPNSTs were included from 11 centers in 7 regions. During follow-up (median 8.7 years), 211 patients died. The C-index was 0.60 (95% CI 0.53-0.67) for both Sarculator and PERSARC. The MPNST-specific model had a pooled C-index of 0.69 (95%CI 0.65-0.73) at validation, with adequate discrimination and calibration across regions. Conclusions: The MPNST-specific MONACO model can be used to predict 3-, 5-, and 10-year OS in patients with primary MPNST who underwent macroscopically complete surgical resection. Further validation may refine the model to inform patients and physicians on prognosis and support them in shared decision-making.

Limb salvage versus amputation: Experience of a young patient at a university hospital.

Decision-making regarding limb amputation represents a significant clinical challenge, especially when the initial evaluation does not coincide with the criteria established in scales used worldwide, as is the case of the MESS scale. This article presents the case of a 24-year-old female patient who was transferred to a university hospital after a road traffic accident with severe and large lesions in the left lower limb. Despite a poor initial prognosis and in-hospital complications, including multiple surgical procedures and foot drop, a favorable recovery was achieved with complete anatomical salvage of the limb at risk. The multidisciplinary approach and intensive rehabilitation were instrumental in achieving a satisfactory functional recovery. This case highlights the importance of considering factors beyond amputation scale scores, as well as the need for comprehensive care to improve outcomes in patients with complex extremity injuries.

Recent update of proton beam therapy for hepatocellular carcinoma: A systematic review and meta-analysis.

Backgrounds/Aims: Although access to proton beam therapy (PBT) is limited worldwide, its use for the treatment of hepatocellular carcinoma (HCC) is gradually increasing with the expansion of new facilities. Therefore, we conducted a systematic review and meta-analysis to investigate the updated evidence of PBT for HCC. Methods: The MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched for studies that enrolled patients with liver-confined HCC that were treated with PBT for a cure up to February 2024. Results: A total of 1858 HCC patients receiving PBT from 22 studies between 2004 and 2023 were selected for this meta-analysis. The median proportion of Child-Pugh class A was 86% (range: 41-100%), and the median tumor size was 3.6 cm (range: 1.2-9 cm). The median total dose ranged from 55 GyE to 76 GyE (median, 69 GyE). The pooled rates of 3- and 5-year local progression-free survival after PBT were 88% (95% confidence interval [CI], 85-91%) and 86% (95% CI, 82-90%), respectively. The pooled 3- and 5-year overall rates were 60% (95% CI, 54-66%) and 46% (95% CI, 38-54%), respectively. The pooled rates of grade 3 hepatic toxicity, classic radiation-induced liver disease (RILD), and non-classic RILD were 1%, 2%, and 1%, respectively. Conclusions: The current study supports PBT for HCC and demonstrates favorable long-term survival and low hepatic toxicities compared with other published studies on other radiotherapy modalities. However, further studies are needed to identify the subgroups that will benefit from PBT.

The Neural Representation of Binaural Sound Localization Cues Across Different Subregions of the Chicken's Inferior Colliculus.

The sound localization behavior of the nocturnally hunting barn owl and its underlying neural computations is a textbook example of neuroethology. Differences in sound timing and level at the two ears are integrated in a series of well-characterized steps, from brainstem to inferior colliculus (IC), resulting in a topographical neural representation of auditory space. It remains an important question of brain evolution: How is this specialized case derived from a more plesiomorphic pattern? The present study is the first to match physiology and anatomical subregions in the non-owl avian IC. Single-unit responses in the chicken IC were tested for selectivity to different frequencies and to the binaural difference cues. Their anatomical origin was reconstructed with the help of electrolytic lesions and immunohistochemical identification of different subregions of the IC, based on previous characterizations in owl and chicken. In contrast to barn owl, there was no distinct differentiation of responses in the different subregions. We found neural topographies for both binaural cues but no evidence for a coherent representation of auditory space. The results are consistent with previous work in pigeon IC and chicken higher-order midbrain and suggest a plesiomorphic condition of multisensory integration in the midbrain that is dominated by lateral panoramic vision.

Comparison of the therapeutic effects of three minimally invasive approaches for laparoscopic cholecystectomy combined with common bile duct exploration-- a 5-year retrospective analysis.

OBJECTIVE: The aim of this retrospective study was to explore the indications for three minimally invasive approaches-T-tube external drainage, double J-tube internal drainage, and primary closure-in laparoscopic cholecystectomy combined with common bile duct exploration. METHODS: Three hundred eighty-nine patients with common bile duct stones who were treated at the Second People's Hospital of Hefei between February 2018 and January 2023 were retrospectively included. Patients were divided into three groups based on the surgical approach used: the T-tube drainage group, the double J-tube internal drainage group, and the primary closure group. General data, including sex, age, and BMI, were compared among the three groups preoperatively. Surgical time, length of hospital stay, pain scores, and other aspects were compared among the three groups. Differences in liver function, inflammatory factors, and postoperative complications were also compared among the three groups. RESULTS: There were no significant differences among the three groups in terms of sex, age, BMI, or other general data preoperatively (P > 0.05). There were significant differences between the primary closure group and the T-tube drainage group in terms of surgical time and pain scores (P < 0.05). The primary closure group and double J-tube drainage group differed from the T-tube drainage group in terms of length of hospital stay, hospitalization expenses, and time to passage of gas (P <0.05). Among the three groups, there were no statistically significant differences in inflammatory factors or liver function, TBIL, AST, ALP, ALT, GGT, CRP, or IL-6, before surgery or on the third day after surgery (P > 0.05). However, on the third day after surgery, liver function in all three groups was significantly lower than that before surgery (P<0.05). In all three groups, the levels of CRP and IL-6 were significantly lower than their preoperative levels. The primary closure group had significantly lower CRP and IL-6 levels than did the T-tube drainage group (P < 0.05). The primary closure group differed from the T-tube drainage group in terms of the incidences of bile leakage and electrolyte imbalance (P < 0.05). The double J-tube drainage group differed from the T-tube drainage group in terms of the tube dislodgement rate (P < 0.05). CONCLUSION: Although primary closure of the bile ducts has clear advantages in terms of length of hospital stay and hospitalization expenses, it is associated with a higher incidence of postoperative complications, particularly bile leakage. T-tube drainage and double J-tube internal drainage also have their own advantages. The specific surgical approach should be selected based on the preoperative assessment, indications, and other factors to reduce the occurrence of postoperative complications.

Ultrasound-Guided External Oblique Intercostal Block as Part of Multimodal Analgesia for Unplanned Open Cholecystectomy.

We present the case of a 56-year-old female with a significant medical history of cholelithiasis and recurrent choledocholithiasis. Following an elective cholecystectomy, an obstructing gallstone in the common bile duct led to a series of interventions, including endoscopic retrograde cholangiopancreatography and stent placement. The patient was scheduled for a robot-assisted laparoscopic common bile duct exploration. Due to severe adhesions, the procedure was converted to open with a large right upper quadrant incision. Intraoperative continuous external oblique block and catheter placement were performed at the end of surgery in the OR. Peripheral nerve blocks have become an integral part of multimodal pain management strategies. This case report describes the successful implementation of an ultrasound-guided right external oblique intercostal block and catheter placement for postoperative pain control and minimization of opioids. This case highlights the efficacy and safety of ultrasound-guided peripheral nerve blocks for postoperative pain management. Successful pain control contributed to the patient's overall postoperative recovery.

Biomechanical analysis of the tandem spinal external fixation in a multiple-level noncontiguous lumbar fractures model: a finite element analysis.

Objective: This study aimed to investigate the biomechanical characteristics of the tandem spinal external fixation (TSEF) for treating multilevel noncontiguous spinal fracture (MNSF) using finite element analysis and provide a theoretical basis for clinical application. Methods: We constructed two models of L2 and L4 vertebral fractures that were fixed with the TSEF and the long-segment spinal inner fixation (LSIF). The range of motion (ROM), maximum stresses at L2 and L4 vertebrae, the screws and rods, and the intervertebral discs of the two models were recorded under load control. Subsequently, the required torque, the maximum stress at L2 and L4 vertebrae, the screws and rods, and the intervertebral discs were analyzed under displacement control. Results: Under load control, the TSEF model reserved more ROM than the LSIF model. The maximum stresses of screws in the TSEF model were increased, while the maximum stresses of rods were reduced compared to the LSIF model. Moreover, the maximum stresses of L2 and L4 vertebrae and discs in the TSEF model were increased compared to the LSIF model. Under displacement control, the TSEF model required fewer moments (N·mm) than the LSIF model. Compared to the LSIF model, the maximum stresses of screws and rods in the TSEF model have decreased; the maximum stresses at L2 and L4 in the TSEF model were increased. In the flexion condition, the maximum stresses of discs in the TSEF model were less than the LSIF model, while the maximum stresses of discs in the TSEF model were higher in the extension condition. Conclusion: Compared to LSIF, the TSEF has a better stress distribution with higher overall mobility. Theoretically, it reduces the stress concentration of the connecting rods and the stress shielding of the fractured vertebral bodies.

Consideration of the conversion factor from air dose rates to individual external dose per hour after the Fukushima accident - Individual external dose measurements of a TEPCO employee in Fukushima prefecture over a 9 year Period.

The accident at Fukushima Daiichi Nuclear Power Plant (FDNPP) in 2011 resulted in the dispersion of radioactive materials throughout the surrounding area and an increase in the air dose rate was even confirmed in Fukushima City, which is located approximately 60 km northeast of FDNPP. A Tokyo Electric Power Company (TEPCO) Holdings employee, who has lived and worked in Fukushima City since the FDNPP accident, measured individual external doses, GPS data, and his activities in Fukushima Prefecture over a 9 year period beginning in 2014. This data provides valuable information about the area. The data show the following results.  Comparison of the air dose rate at the home location to the individual external dose per hour at the home shows that the average conversion factor has increased over the 9 years and exceeded 0.3 since 2019, indicating an overall relatively good correlation.  Individual external doses measured in the office on the fourth floor of a concrete structure in Fukushima City have not changed significantly from 2014 to 2022, when air dose rates showed a decrease.  Outdoor individual external doses, such as those measured when commuting on foot, have a relatively strong correlation with air dose rates from airborne monitoring with the conversion factor of about 0.6. The conversion factor do not differ significantly from 2014 to 2022. In this study, the individual external dose data is applicable to the TEPCO measurer and is not necessarily representative of all residents of Fukushima City. However individual external dose data for 9 consecutive years will be useful for estimating individual external doses from air dose rates, and estimating annual additional exposure doses, if even some of them are applicable to similar life patterns and lifestyles.

Longitudinal evaluation of external quality assessment results for CA 15-3, CA 19-9, and CA 125.

Background: Tumor markers are established laboratory tools that help to diagnose, estimate prognosis, and monitor the course of cancer. For meaningful decision-making in patient care, it is essential that methods and analytical platforms demonstrate high sensitivity, specificity, precision, and comparability. Regular participation at external quality assessment (EQA) schemes is mandatory for laboratories. Here, a longitudinal evaluation of EQA data was performed to assess the performance of tumor marker assays over time. Methods: Longitudinal data of the cancer antigens (CA) 15-3 (n = 5,492), CA 19-9 (n = 6,802), and CA 125 (n = 5,362) from 14 INSTAND EQAs conducted between 2019 and 2023 were evaluated. A median of 197, 244 and 191 laboratories participated at the EQAs for CA 15-3, CA 19-9 and CA 125, respectively. Data evaluation encompasses intra- and inter-manufacturer specific variations over time, assay precision, and adherence to the EQA limits of ±24% for CA 15-3, ±27% for CA 19-9 and ±36% for CA 125. Results: The study showed median manufacturer-dependent differences of up to 107% for CA 15-3, 99% for CA 125, and even 549% for CA 19-9 between the highest and the lowest methods over the studied period. Regarding the normalized median of all methods, the values of the most deviant methods were 0.42 for CA 15-3, 7.61 for CA 19-9, and 1.82 for CA 125. Intra-manufacturer variability was generally low, with median coefficients of variation (CV) below 10%. As the methods were evaluated according to method-specific consensus values, most participants passed the EQAs within the acceptance criteria. When the criteria were consistently set at 24%, the central 90% of participants passed the EQAs in 78.6%-100% for CA 15-3 (with exception of AX), 89.3%-100% for CA 125, and 64.3%-100% for CA 19-9. Conclusion: While intra-method precision of most analytical platforms is acceptable for all three tumor markers, considerable inter-method variability was observed over the whole studied period demonstrating the necessity for better standardization and harmonization of the methods, development of international reference materials, and comprehensive commutability studies with patient samples.

External Oblique Intercostal Plane Block: A Case Report and Review of Literature.

Chronic low back pain (CLBP) and post-laminectomy syndrome (PLS) can pose significant therapeutic challenges, often refractory to conservative management. We present a case of a 52-year-old male with refractory CLBP and PLS who underwent spinal cord stimulation (SCS) lead placement, and subsequently developed chronic right anterior chest wall and upper abdominal pain. Despite using SCS and opioid therapy, the pain persisted until an ultrasound-guided external oblique intercostal plane block (EOIPB) was administered, resulting in complete pain relief. This case highlights the efficacy of EOIPB in managing chronic post-surgical neuropathic pain, underscoring its potential as a valuable intervention in such cases.

Teacher-assigned grades and external exams: sources of discrepancy.

Modest correlations between teacher-assigned grades and external assessments of academic achievement (r = .40-.60) have led many educational stakeholders to deem grades subjective and unreliable. However, theoretical and methodological challenges, such as construct misalignment, data unavailability and sample unrepresentativeness, limit the generalisability of previous findings. We overcome these challenges by exploiting rich, population-wide data from the National Registries in Norway (n = 511,858), where state regulations require close construct alignment between grades and external exams. Correlations between lower-secondary education final grades and external exam results (r = .64-.86) suggest that grades are better measures of academic achievement than previously acknowledged. Dominance analyses and multivariate regression analyses indicate that external exam results are the best predictor of grades in the same subject. However, our results also indicate that state regulations and quality assurance systems cannot completely eradicate potential sources of discrepancy.

Investigating Ras homolog gene family member C (RhoC) and Ki67 expression following external beam radiation therapy show increased RhoC expression in relapsing prostate cancer xenografts.

Ras homolog gene family member C (RhoC) is a GTPase involved in cell migration, implicated in epithelial-mesenchymal transition and treatment resistance and metastasis of cancer. For example, RhoC has been shown to be involved in resistance to radiation in cervical carcinoma. Here, the effect of X-ray irradiation on RhoC expression in prostate cancer (PCa) xenografts was investigated in both xenografts in regression and relapse. Male BALB/cAnNRj-Foxn1nu/nu mice were inoculated with 4-6 million LNCaP-FGC cells and established xenografts were irradiated with X-rays (200 kV, 1 Gymin-1), 5, 10 or 15 Gy using a Gulmay Medical X-ray system. Expression of RhoC and Ki67, a known proliferation marker, was investigated in xenografts, given 15 Gy, 7 days (midst response as measured by size) or 3 weeks (relapse) post irradiation. Staining was quantified using the Halo software (v2.3.2089.34) with the Indica Labs - cytonuclear v1.6 algorithm. RhoC and Ki67 staining was divided into weak, medium, and strong staining and the percentage of cells stained, single and dual staining, was quantified. The HALO software was further used to classify the tissue in each section so that analysis of RhoC and Ki67 expression in cancer cells, stroma and necrotic areas could be done separately. The results showed that RhoC expression in cancer and stroma cells was significantly higher in relapsed xenografts than in those in regression. This was not seen for Ki67 staining, where the percentage of stained cells were the same in regressing and relapsing tumors. RhoC could be a useful biomarker to confirm relapse following external beam radiation therapy.