[Histone acetylation in the development and regeneration of craniofacial hard tissue]

Craniofacial hard tissue mainly includes craniofacial bone and tooth, which is one of the important parts of the mouth-jaw system. Congenital aplasia, tumors and trauma can cause large craniofacial hard tissue defects, which are detrimental to the facial appearance and function of patients, and affect the physical and mental health of patients. Histone acetylation modification is the earliest and most widely studied histone modification, which is an epigenetic modification mechanism jointly regulated by histone acetyltransferase and histone deacetylase. In this paper, we will review the research progress of histone acetylation mediated by histone acetyltransferase and histone deacetylase in the development and regeneration of craniofacial hard tissue.

[Analysis of the progress in the field of oral microbiology and regenerative medicine from 2014 to 2023]

Objective: To analyze the trends in literature related to oral microbiology and regenerative medicine from 2014 to 2023. By identifying key research countries, institutions, and their collaboration networks, as well as exploring research hotspots and development directions, the study seeks to provide references for researchers and decision-makers in the field of oral microbiology and regenerative medicine, thereby guiding the direction of future research. Methods: Relevant literature was retrieved using the Web of Science Core Collection database, with data processing and analysis conducted using CiteSpace 6.2.R6 software. Time slicing, node type selection, and the application of the g-index (g-index) were used for filtering, analyzing countries, institutions, authors, journals, and keywords. Results: The volume of literature in the field of oral microbiology and regenerative medicine has steadily increased from 2014 to 2023, with the number of publications first exceeding one hundred in 2020 and reaching 134 in 2022, accompanied by a citation frequency of 3 363 times. China and the United States have been at the forefront in terms of the volume of publications, while the United States and Germany lead in terms of intermediary centrality. The research primarily spans disciplines such as oral medicine, interdisciplinary studies, materials science, and immunology. High-frequency keywords include stem cells, scaffold materials, and gut microbiota, while cluster analysis indicates that inflammation, drug delivery, and antimicrobial activity remain consistent research themes. In recent years, the research heat in "tissue regeneration""gut microbiota " and "maxillofacial surgery" has risen, suggesting these may become focal points of future research. Conclusions: Over the past decade, the volume of literature published in the fields of oral microbiology and regenerative medicine, along with their citation frequencies, has increased annually. The research focus has shifted over time. Understanding the interactions between oral and gut microbiomes is crucial for developing innovative regenerative treatment strategies.

MicroRNA-377-3p exacerbates chronic obstructive pulmonary disease through suppressing ZFP36L1 expression and inducing lung fibroblast senescence

Chronic obstructive pulmonary disease (COPD) is a leading aging related cause of global mortality. Small airway narrowing is recognized as an early and significant factor for COPD development. Senescent fibroblasts were observed to accumulate in lung of COPD patients and promote COPD progression through aberrant extracellular matrix (ECM) deposition and senescence-associated secretory phenotype (SASP). On the basis of our previous study, we further investigated the the causes for the increased levels of miR-377-3p in the blood of COPD patients, as well as its regulatory function in the pathological progression of COPD. We found that the majority of up-regulated miR-377-3p was localized in lung fibroblasts. Inhibition of miR-377-3p improved chronic smoking-induced COPD in mice. Mechanistically, miR-377-3p promoted senescence of lung fibroblasts, while knockdown of miR-377-3p attenuated bleomycin-induced senescence in lung fibroblasts. We also identified ZFP36L1 as a direct target for miR-377-3p that likely mediated its pro senescence activity in lung fibroblasts. Our data reveal that miR-377-3p is crucial for COPD pathogenesis, and may serve as a potential target for COPD therapy.

Evaluation of the Effects of Anti-PD-1 Therapy on Triple-Negative Breast Cancer in Mice by Diffusion Kurtosis Imaging and Dynamic Contrast-Enhanced Imaging

BACKGROUND

The monitoring of immunotherapies is still based on changes in the tumor size in imaging, with a long evaluation period and low sensitivity.

PURPOSE

To investigate the effectiveness of diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the therapeutic efficacy of anti-programmed death-1 (PD-1) therapy in a mouse triple negative breast cancer (TNBC) model.

STUDY TYPE

Prospective.

ANIMAL MODEL

A total of 54 BALB/c mouse subcutaneous 4 T1 transplantation models of TNBC.

FIELD STRENGTH/SEQUENCE

A 3.0-T; turbo spin echo (TSE) T2-weighted imaging, DKI with seven b values (0, 500, 1000, 1500, 2000, 2500, and 3000 sec/mm² ) and T1-twist DCE acquisition series.

ASSESSMENT

DKI and DCE-MRI parameters were evaluated by two radiologists independently. Regions of interest (ROIs) were drawn manually on the maximum cross-sectional area of the lesion; care was taken to avoid necrotic areas. The tumor cell density, the CD45 and CD31 levels were analyzed by two pathologists.

STATISTICAL TESTS

The two-tailed unpaired t-test, Mann-Whitney U test, Fisher's exact test and Pearson correlation coefficient were performed. A P < 0.05 was considered statistically significant.

RESULTS

The apparent diffusion coefficient (ADC), mean diffusivity (MD), K_trans and K_ep values were significantly different between the two groups at each time point after treatment. There were significant differences in the mean kurtosis (MK) and V_e values between the two groups at 5 and 10 days after treatment but no significant differences at 15 days (P = 0.317 and 0.183, respectively). The ADC and MD values were significantly correlated with tumor cell density (ADC, r = -0.833; MD, r = 0.890) and the CD45 level (ADC, r = 0.720; MD, r = 0.718). The K_trans and K_ep values were significantly correlated with the CD31 level (K_trans , r = 0.820; K_ep , r = 0.683).

DATA CONCLUSION

DKI and DCE-MRI could reflect the changes in tumor microstructure and tumor tissue vasculature after anti-PD-1 therapy, respectively.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 4.

[Clinical features and prognostic factors of severe hemophagocytic syndrome in children]

Objective: To explore the clinical characteristics, prognostic risk factors and effective treatment of severe hemophagocytic syndrome (HPS) in children, so as to provide reference for the clinical diagnosis and treatment of the disease. Methods: The clinical data of 83 children with severe HPS admitted in Affiliated Hospital of Zunyi Medical University from January 2014 to April 2021 were collected, and their clinical characteristics, prognosis and prognostic risk factors were analyzed. The children were divided into central nervous system (CNS) dysfunction group and non-CNS dysfunction group according to whether they were accompanied with CNS dysfunction, and were divided into blood purification group and non-blood purification group according to whether they received blood purification, then the survival differences were compared. Results: Among the 83 children, there were 43 males and 40 females, aged[M(Q₁,Q₃)] 36(15,27)months. A total of 51 children were induced by infection, among which 41 children (80.4%) were infected with EB virus. All the children were accompanied by multiple organ dysfunction (MODS), and dysfunction of the blood system (72.3%), liver (71.1%), respiratory system (53.0%) and CNS (37.3%) were common. By the end of follow-up, 40 cases (48.2%) survived, 38 cases (45.8%) died, and 5 cases (6.0%) were lost to follow-up. CNS dysfunction was a risk factor (HR=3.358, 95%CI: 1.445-7.803, P=0.005) and blood purification was a protective factor (HR=0.362, 95%CI: 0.179-0.730, P=0.005) affecting the prognosis of children. The mortality of CNS dysfunction group was statistically higher than that of non-CNS dysfunction group (74.2% vs 28.8%) (P<0.001); The mortality of blood purification group was statistically lower than that of non-blood purification group (31.0% vs 61.0%) (P=0.010). Conclusions: Severe HPS in children was dangerous and had a poor overall prognosis. CNS dysfunction was a risk factor for death. Blood purification could significantly improve the prognosis and improve the survival rate of children.

Performance of radiomics models for tumour-infiltrating lymphocyte (TIL) prediction in breast cancer: the role of the dynamic contrast-enhanced (DCE) MRI phase

OBJECTIVE

To systematically investigate the effect of imaging features at different DCE-MRI phases to optimise a radiomics model based on DCE-MRI for the prediction of tumour-infiltrating lymphocyte (TIL) levels in breast cancer.

MATERIALS AND METHODS

This study retrospectively collected 133 patients with pathologically proven breast cancer, including 73 patients with low TIL levels and 60 patients with high TIL levels. The volumes of breast cancer lesions were manually delineated on T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and each phase of DCE-MRI, followed by 6250 quantitative feature extractions. The least absolute shrinkage and selection operator (LASSO) method was used to select predictive feature sets for the classifiers. Four models were developed for predicting TILs: (1) single enhanced phase radiomics models; (2) fusion enhanced multi-phase radiomics models; (3) fusion multi-sequence radiomics models; and (4) a combined radiomics-based clinical model.

RESULTS

Image features extracted from the delayed phase MRI, especially DCE_Phase 6 (DCE_P6), demonstrated dominant predictive performances over features from other phases. The fusion multi-sequence radiomics model and combined radiomics-based clinical model achieved the highest predictive performances with areas under the curve (AUCs) of 0.934 and 0.950, respectively; however, the differences were not statistically significant.

CONCLUSION

The DCE-MRI radiomics model, especially image features extracted from the delayed phases, can help improve the performance in predicting TILs. The radiomics nomogram is effective in predicting TILs in breast cancer.

KEY POINTS

• Radiomics features extracted from DCE-MRI, especially delayed phase images, help predict TIL levels in breast cancer. • We developed a nomogram based on MRI to predict TILs in breast cancer that achieved the highest AUC of 0.950.

[Microcontact printing and its application prospect in bone tissue engineering]

The application of bone tissue engineering regeneration technology is expected to repair maxillofacial bone tissue defects caused by tumors, trauma, etc. Surface patterning occupies an important position in bone tissue engineering. Microcontact printing is an emerging technology through which the elastic stamp contacts with the substance and materials used as ink can be transferred from stamp to substance to form patterns. The biggest characteristic of the technology is to fabricate high-throughput and high-accuracy patterned surface, making it widely applied. This review summarized the application and optimization of microcontact printing, and prospected its application in bone tissue engineering.

Whole-Lesion Histogram Analysis of the Apparent Diffusion Coefficient as a Quantitative Imaging Biomarker for Assessing the Level of Tumor-Infiltrating Lymphocytes: Value in Molecular Subtypes of Breast Cancer

Purpose

To assess whether apparent diffusion coefficient (ADC) metrics can be used to assess tumor-infiltrating lymphocyte (TIL) levels in breast cancer, particularly in the molecular subtypes of breast cancer.

Methods

In total, 114 patients with breast cancer met the inclusion criteria (mean age: 52 years; range: 29–85 years) and underwent multi-parametric breast magnetic resonance imaging (MRI). The patients were imaged by diffusion-weighted (DW)-MRI (1.5 T) using a single-shot spin-echo echo-planar imaging sequence. Two readers independently drew a region of interest (ROI) on the ADC maps of the whole tumor. The mean ADC and histogram parameters (10^th, 25^th, 50^th, 75^th, and 90^th percentiles of ADC, skewness, entropy, and kurtosis) were used as features to analyze associations with the TIL levels in breast cancer. Additionally, the correlation between the ADC values and Ki-67 expression were analyzed. Continuous variables were compared with Student’s t-test or Mann-Whitney U test if the variables were not normally distributed. Categorical variables were compared using Pearson’s chi-square test or Fisher’s exact test. Associations between TIL levels and imaging features were evaluated by the Mann-Whitney U and Kruskal-Wallis tests.

Results

A statistically significant difference existed in the 10^th and 25^th percentile ADC values between the low and high TIL groups in breast cancer (P=0.012 and 0.027). For the luminal subtype of breast cancer, the 10^th percentile ADC value was significantly lower in the low TIL group (P=0.041); for the non-luminal subtype of breast cancer, the kurtosis was significantly lower in the low TIL group (P=0.023). The Ki-67 index showed statistical significance for evaluating the TIL levels in breast cancer (P=0.007). Additionally, the skewness was significantly higher for samples with high Ki-67 levels in breast cancer (P=0.029).

Conclusions

Our findings suggest that whole-lesion ADC histogram parameters can be used as surrogate biomarkers to evaluate TIL levels in molecular subtypes of breast cancer.

Magnetic Resonance Imaging (MRI) Phenotypes May Provide Additional Information for Risk Stratification for Encapsulated Papillary Carcinoma of the Breast

Background

Encapsulated papillary carcinoma (EPC) of the breast is a rare entity. EPC can be underappreciated on percutaneous biopsy, which may require additional procedures if invasion is not recognized preoperatively. We aimed to investigate the magnetic resonance imaging (MRI) phenotypes correlated with preoperative pathological risk stratification for clinical guidance.

Materials and Methods

The preoperative MRI scans of 30 patients diagnosed with 36 EPCs in multiple centers between August 2015 and February 2020 were reviewed by two breast radiologists. According to the WHO classification published in 2019, EPCs were classified into two pathological subtypes: encapsulated papillary carcinoma and encapsulated papillary carcinoma with invasion. Clinicopathological analysis of the two subtypes and MR feature analysis were performed.

Results

Evaluation of the MRI phenotypes and pathological subtype information revealed that not circumscribed (P=0.04) was more common in EPCs with invasion than in EPCs. There was a significant difference in the age of patients (P=0.05), and the risk increased with age. The maximum diameter of the tumor increased with tumor risk, but there was no significant difference (P=0.36). Nearly half of the EPC with invasion patients showed hyperintensity on T1WI (P=0.19). A total of 63.6% of the EPC with invasion group showed non-mass enhancement surrounding (P=0.85). In addition, 29 patients (96.7%) had no axillary lymph node metastasis, and only one patient with EPC with invasion had axillary lymph node metastasis. Further pathological information analysis of EPCs showed that higher Ki-67 levels were more common in patients with EPCs with invasion (P=0.04). A total of 29 patients (96.7%) had the luminal phenotype, and one patient with EPC with invasion had the Her-2-positive phenotype.

Conclusion

The margin, age and Ki-67 level were the key features for EPC risk stratification. In addition, these MRI signs, including a larger tumor, non-mass enhancement surrounding and axillary lymph node metastasis, may be suggestive of a high-risk stratification. Therefore, MRI phenotypes may provide additional information for the risk stratification of EPCs.

International normalised ratio as an independent predictor of mortality in limb necrotising fasciitis with sepsis

INTRODUCTION

Necrotising fasciitis with sepsis is a life threatening disease. The aim of this study was to analyse the association between international normalised ratio (INR) and mortality in sepsis patients with necrotising fasciitis.

METHODS

A retrospective review was undertaken of 106 patients suffering from necrotising fasciitis with sepsis between November 2007 and December 2016. Data on comorbidities, clinical manifestations, laboratory findings, causative microbiological organisms, APACHE II (Acute Physiology and Chronic Health Evaluation II) score and outcomes were extracted. Logistic regression was carried out to examine the factors affecting mortality.

RESULTS

Forty patients (37.7%) died. There was no significant difference in the white blood count (WBC) for the survivor and non-survivor groups. Non-survivors had a lower mean oxygenation index (OI) (288.7mmHg vs 329.4mmHg, p=0.032) and platelet count (PC) (139.5 vs 214.8 x 10⁹/l, p=0.028), and a higher mean INR (1.9 vs 1.3, p=0.000), activated partial thromboplastin time (APTT) (54.6 vs 44.2 seconds, p=0.005) and serum creatinine (2.3mg/dl vs 1.4mg/dl, p=0.007). Mortality in patients with INR >1.5 was significantly higher than in those with INR <1.5 when all risk factors (WBC, PC, OI, INR, APTT, creatinine) were considered (odds ratio: 4.414, 95% confidence interval: 1.263-15.428, p=0.020). Even after adjusting for age, sex, bacteraemia, diabetes and hepatic disorders, the data still exhibited elevated mortality for patients with INR >1.5 (odds ratio: 5.600, 95% confidence interval: 1.415-22.166, p=0.014).

CONCLUSIONS

INR is a significant independent predictor of mortality in sepsis patients diagnosed with necrotising fasciitis.

The Function of Wnt Ligands on Osteocyte and Bone Remodeling

Bone homeostasis is continually maintained by the process of bone remodeling throughout life. Recent studies have demonstrated that Wnt signaling pathways play a fundamental role in the process of bone homeostasis and remodeling. Intracellular Wnt signaling cascades are initially triggered by a Wnt ligand-receptor complex formation. In previous studies, the blocking of Wnt ligands from different osteoblastic differentiation stages could cause defective bone development at an early stage. Osteocytes, the most abundant and long-lived type of bone cell, are a crucial orchestrator of bone remodeling. However, the role of Wnt ligands on osteocyte and bone remodeling remains unclear. In our present study, we found that, besides osteoblasts, osteocytes also express multiple Wnt ligands in the bone environment. Then, we used a Dmp1-Cre mouse line, in which there is expression in a subset of osteoblasts but mainly osteocytes, to study the function of Wnt ligands on osteocyte and bone remodeling in vivo. Furthermore, we explored the role of Wnt ligands on osteocytic mineralization ability, as well as the regulatory function of osteocytes on the process of osteoblastic differentiation and osteoclastic migration and maturity in vitro. We concluded that Wnt proteins play an important regulatory role in 1) the process of perilacunar/canalicular remodeling, as mediated by osteocytes, and 2) the balance of osteogenesis and bone resorption at the bone surface, as mediated by osteoblasts and osteoclasts, at least partly through the canonical Wnt/β-catenin signaling pathway and the OPG/RANKL signaling pathway.

Size-Switchable Nanoparticles with Self-Destructive and Tumor Penetration Characteristics for Site-Specific Phototherapy of Cancer

The normoxic and hypoxic microenvironments in solid tumors cause cancer cells to show different sensitivities to various treatments. Therefore, it is essential to develop different therapeutic modalities based on the tumor microenvironment. In this study, we designed size-switchable nanoparticles with self-destruction and tumor penetration characteristics for site-specific phototherapy of cancer. This was achieved by photodynamic therapy in the perivascular normoxic microenvironment due to high local oxygen concentrations and photothermal therapy (PTT) in the hypoxic microenvironment, which are not in proximity to blood vessels due to a lack of effective approaches for heat transfer. In brief, a poly(amidoamine) dendrimer with photothermal agent indocyanine green (PAMAM-ICG) was conjugated to the amphiphilic polymer through a singlet oxygen-responsive thioketal linker and then loaded with photosensitizer chlorin e6 (Ce6) to construct a nanotherapy platform (denoted as SNP_ICG/Ce6). After intravenous injection, SNP_ICG/Ce6 was accumulated at the perivascular sites of the tumor. The singlet oxygen produced by Ce6 can ablate the tumor cells in the normoxic microenvironment and simultaneously cleave the thioketal linker, allowing the release of small PAMAM-ICGs with improved tumor penetration for PTT in the hypoxic microenvironment. This tailored site-specific phototherapy in normoxic and hypoxic microenvironments provides an effective strategy for cancer therapy.

[Biomaterials for bone defect repair and bone regeneration]

The treatment of large jaw bone defects remains an urgent clinical problem to be solved. With the development of biomaterials, stem cells and bone tissue engineering, new ideas and hopes for the regeneration of jaw have been offered. In addition to meeting the basic requirements of bone repair materials, scaffolds for the regeneration of large jaw bones require the ability of stem cells to participate in bone regeneration. Methods like optimization of scaffolds composition, design of porous structure and combination of gel and microsphere technology can enhance stem cell delivery in vivo, and the osteogenic differentiation of stem cells can be stimulated through controlled release of drugs, preparation of surface micron/nano topography and modifications of ionic components. Moreover, application of three-dimensional printing and channel structure in large-scale scaffolds fabrication present promising strategies for customized, accurate bone reconstruction and vascularization. It is only through synergistic optimization in all aspects that it is possible to obtain scaffold materials suitable for regeneration of large jaw bones. This article focuses on biological materials regulation, stem cell delivery, survival and differentiation, and their role in bone regeneration.

[Application of negative molds technology based on three-dimensional printing in digital maxillofacial prostheses]

Objective: To explore a digital negative molds technique based on three-dimensional (3D) printing to assist in the manufacture of maxillofacial prostheses, and to improve the deficiency of the current clinical treatment. Methods: Seventeen patients with maxillofacial defects (including nasal defects, orbital defects, cheek defects, auricle defect) were scanned by means of facial optical scanning and computer tomography (CT). The 3D models were then reconstructed and global registration was made to merge the reconstructed models into a new digital model for 3D design. The 3D design of the prostheses was implemented in software. The mechanical connection structure was designed by forward engineering technology for 3 patients with intra-oral defects in maxilla who needed to make removable partial dentures, so that the silicone prostheses and removable partial denture could be combined. The removable partial dentures were made by conventional method and connected with the prostheses. According to the 3D data of the prostheses, the digital negative molds were designed, and the 3D printing technology was used to finish the processing of the resin molds. Silicone for prostheses were filled and cured in the resin molds to fabricate the clinical restorations for the patients. The margin adaptation and retention of the prostheses was detected. Results: Twenty patients with varying degrees of maxillofacial defects were rehabilitated using the courses developed in the study. All patients reported no pain or discomfort during the treatment; and they were satisfied with the final prostheses of the shape, color, retention, stability, etc. Eighteen of the prostheses showed good marginal adaptation, and sixteen of the prostheses showed good retention effect. Conclusions: The digital negative molds technique used in this study could greatly reduce the intensity of manual operation and provided a good therapeutic effect for patients with maxillofacial defects.

[Hand, foot and mouth disease in Hubei province, 2009-2015: an epidemiological and etiological study]

Objective: To clarify the age patterns and types of differences so as to provide reference on prevention and interventions of hand, foot and mouth disease (HFMD) cases, in Hubei province. Methods: We collected the HFMD case information of Hubei province from the Chinese National Notifiable Infectious Disease Reporting System in 2009-2015 while the information on pathogens from the laboratory monitoring system of Center for Disease Control and Prevention at all levels in Hubei province. All the data were stratified by age, disease severity, laboratory confirmation status, and serotypes of enterovirus. Results: There were 495 783 reported HFMD cases from 2009 to 2015, in Hubei province, of which 1 045 were severe with 99 fatal. The annual notification rate was 1 231.0/10(6). HFMD cases were concentrated mainly in 0.5-5 year olds, with highest severity and mortality seen in 6-11 month-olds. The predominated pathogen in mild laboratory-confirmed cases each year, in order during 2009-2015 as: EV71, Cox A16, Cox A16, Cox A16, EV71, Cox A16 and other EV. HFMD showed semiannual peaks in April-June, November-December, and with more cases in the even years than in the odd years. Conclusions: Children aged 0.5 to 5 years with 6 to 11 month-olds in particular, were the focused groups of attention in Hubei province. Our findings provided evidence for the improvement on monitoring program. Targeted intervention approaches should be strengthened to reduce the mortality and morbidity of HFMD in the province.

Surface functionalization of superparamagnetic nanoparticles by an acid-liable polysaccharide-based prodrug for combinatorial monitoring and chemotherapy of hepatocellular carcinoma

For combinatorial monitoring and chemotherapy of liver carcinoma, the macromolecular prodrug based on hyaluronic acid and doxorubicin hydrochloride was prepared by an acid-labile linkage and conjugated with amine-modified iron oxide nanoparticles.

Bioreducible amphiphilic block copolymers based on PCL and glycopolypeptide as multifunctional theranostic nanocarriers for drug delivery and MR imaging

Amphiphilic diblock poly(ε-caprolactone)-b-glycopolypeptides (PCL–SS–GPPs) bearing disulfide bonds were synthesized from a clickable poly(ε-caprolactone)–SS–poly(2-azidoethyl-l-glutamate) diblock copolymer.

Hyaluronan-modified superparamagnetic iron oxide nanoparticles for bimodal breast cancer imaging and photothermal therapy

Theranostic nanoparticles with both imaging and therapeutic abilities are highly promising in successful diagnosis and treatment of the most devastating cancers. In this study, the dual-modal imaging and photothermal effect of hyaluronan (HA)-modified superparamagnetic iron oxide nanoparticles (HA-SPIONs), which was developed in a previous study, were investigated for CD44 HA receptor-overexpressing breast cancer in both in vitro and in vivo experiments. Heat is found to be rapidly generated by near-infrared laser range irradiation of HA-SPIONs. When incubated with CD44 HA receptor-overexpressing MDA-MB-231 cells in vitro, HA-SPIONs exhibited significant specific cellular uptake and specific accumulation confirmed by Prussian blue staining. The in vitro and in vivo results of magnetic resonance imaging and photothermal ablation demonstrated that HA-SPIONs exhibited significant negative contrast enhancement on T2-weighted magnetic resonance imaging and photothermal effect targeted CD44 HA receptor-overexpressing breast cancer. All these results indicated that HA-SPIONs have great potential for effective diagnosis and treatment of cancer.

Association of the programmed cell death-1 PD1.5 C>T polymorphism with cervical cancer risk in a Chinese population

The association of the programmed cell death-1 PD1.5 C>T polymorphism with cervical cancer risk has not been investigated. In this hospital-based case-control study, we analyzed 256 patients with cervical cancer and 250 healthy controls. Pearson chi-square test was used to examine differences in the distribution of genotypes between cases and controls. Association between the polymorphism and the susceptibility to cervical cancer was evaluated using unconditional logistic regression analysis. This revealed that the frequencies of the three genotypes (CC, CT, and TT) in cervical cancer cases and controls were 17.58, 65.23, and 17.19% and 24.80, 40.40, and 34.80%, respectively; the difference between the two groups was significant (P < 0.001). We found that the CT genotype was significantly associated with increased cervical cancer risk (adjusted OR = 2.18; 95%CI = 1.37-6.11; P = 0.009). Moreover, there was significant association between PD-1.5 C/T polymorphism and susceptibility to cervical cancer under dominant model (OR = 1.27, 95%CI = 1.01-2.15, P = 0.047). We conclude that the PD-1.5 C/T polymorphism may be associated with increased risk of cervical cancer. The study also highlights the importance of conducting genetic association studies in different ethnic populations.

Reduction-sensitive amphiphilic dextran derivatives as theranostic nanocarriers for chemotherapy and MR imaging

Reduction-sensitive, amphiphilic dextran derivatives were developed from disulfide-linked dextran-g-poly-(N-ε-carbobenzyloxy-l-lysine) graft polymer (Dex-g-SS-PZLL), and used as theranostic nanocarriers for chemotherapy and MR imaging.

Dimensional schizotypy and social cognition: an fMRI imaging study

Impairment in empathy has been demonstrated in patients with schizophrenia and individuals with psychosis proneness. In the present study, we examined the neural correlates underlying theory of mind (ToM) and empathy and the relationships between these two social cognitive abilities with schizotypy. Fifty-six first-year college students (31 males, 25 females) between 17 and 21 years of age (M = 19.3, SD = 0.9) from a medical university in China participated. All participants undertook a comic strips functional imaging task that specifically examined both empathy and ToM. In addition, they completed two self-report scales: the Chapman Psychosis Proneness scale and the Interpersonal Responsivity Index (IRI). Results showed that both empathy and ToM conditions of the task were associated with brain activity in the middle temporal gyrus, the temporo-parietal junction (TPJ), the precuneus and the posterior cingulate gyrus. In addition, we found positive correlations between negative schizotypy and brain activity in regions involved in social cognition, namely, the middle temporal gyrus, the TPJ, as well as the medial prefrontal gyrus. These findings highlight that different dimensions of schizotypy may show different associations with brain regions involved in social cognitive abilities. More importantly, the positive correlation between brain activity and anhedonia suggests the presence of compensatory mechanisms in high-risk populations.

Increased interhemispheric functional connectivity in college students with non-clinical depressive symptoms in resting state

The underlying neural basis of non-clinical depressive symptoms (nCDSs) remains unclear. Interhemispheric functional connectivity has been suggested as one of the most robust characteristics of brain's intrinsic functional architecture. Here, we investigated the functional connectivity between homotopic points in the brain using the voxel-mirrored homotopic connectivity (VMHC) approach. We performed VMHC analysis on resting-state functional magnetic resonance imaging (rs-fMRI) data from 17 individuals with nCDSs and 20 healthy controls (HCs) who were enrolled from a sample of 1105 college students. We found increased VMHCs in the bilateral posterior cerebellum and fusiform gyrus in nCDSs subjects compared with HCs. Furthermore, receiver operating characteristic (ROC) curves indicated that VMHC values in the posterior cerebellum lobes could use to differente nCDSs from HCs [area under the curve (AUC), 0.756; p<0.01]. We suggest increased VMHCs indicate a possible compensatory mechanism involved in the pathophysiology of nCDSs. VMHC values of the posterior cerebellum lobes might serve as a reliable biomarker for identifying nCDSs.

Glycosaminoglycan-targeted iron oxide nanoparticles for magnetic resonance imaging of liver carcinoma

To develop an efficient probe for targeted magnetic resonance (MR) imaging of liver carcinoma, the surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) was carried out by conjugating a naturally-occurring glycosaminoglycan with specific biological recognition to human hepatocellular liver carcinoma (HepG2) cells. These modified SPIOs have good water dispersibility, superparamagnetic property, cytocompatibility and high magnetic relaxivity for MR imaging. When incubated with HepG2 cells, they demonstrated significant cellular uptake and specific accumulation, as confirmed by Prussian blue staining and confocal microscopy. The in vitro MR imaging of HepG2 cells and in vivo MR imaging of HepG2 tumors confirmed their effectiveness for targeted MR imaging of liver carcinoma.

In vivo assessment of the vascular disrupting effect of M410 by DCE-MRI biomarker in a rabbit model of liver tumor

The present study aimed to prospectively monitor the vascular disrupting effect of M410 by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rabbits with VX2 liver tumors. Twenty-eight rabbits bearing VX2 tumors in the left lobe of the liver were established and randomly divided into treatment and control groups, intravenously injected with 25 mg/kg M410 or sterile saline, respectively. Conventional and DCE-MRI data were acquired on a 3.0-T MR unit at pretreatment, 4 h, 1, 4, 7 and 14 days post-treatment. Histopathological examinations [hematoxylin and eosin (H&E) and CD34 immunohistochemisty staining] were performed at each time point. The dynamic changes in tumor volume, kinetic DCE-MRI parameter [volume transfer constant (Ktrans)] and histological data were evaluated. Tumors grew slower in the M410 group 4-14 days following treatment, compared with rapidly growing tumors in the control group (P<0.05). At 4 h, 1 and 4 days, Ktrans significantly decreased in the M410 group compared with that in the control group (P<0.05). However, Ktrans values were similar in the two groups for the other time points studied. The changes in DCE-MRI parameters were consistent with the results obtained from H&E and CD34 staining of the tumor tissues. DCE-MRI parameter Ktrans may be used as a non-invasive imaging biomarker to monitor the dynamic histological changes in tumors following treatment with the vascular targeting agent M410.

Effects of TiO2 nanotube layers on RAW 264.7 macrophage behaviour and bone morphogenetic protein-2 expression

OBJECTIVES

To investigate behaviour and osteogenic cytokine expression of RAW264.7 macrophages grown on TiO2 nanotube layers.

MATERIALS AND METHODS

The murine macrophage cell line RAW 264.7 was cultured on TiO2 nanotubes of varying diameter; macrophage morphology was examined using scanning electron microscopy. Cell adhesion and viability were assessed with the aid of the MTT method and BMP-2 and TGF-β gene expression were examined by RT-PCR analysis. Levels of BMP-2, TGF-β1 and ICAM-1 proteins secreted into the supernatant were measured by ELISA assay.

RESULTS

Macrophages cultured on nanotube layers had spread out morphology, the largest (120 nm) nanotube layer eliciting an elongation by 24 h. Macrophages adhered significantly less to 120 nm TiO2 nanotubes than to control discs at 4 h after application; after 24 h incubation, macrophages were sufficiently viable (P < 0.05) on 30 and 70 nm nanotube layers. Increasing nanotube diameter led to increased BMP-2 protein secretion and increased BMP-2 mRNA expression.

CONCLUSION

These results demonstrate that nanoscale topography of TiO2 nanotube layers can affect macrophage morphology, adhesion, viability and BMP-2 expression. Macrophages grown on layers of large nanotubes had the highest potential to enhance bone formation during bone healing.

Differentiation of central lung cancer from atelectasis: comparison of diffusion-weighted MRI with PET/CT

OBJECTIVE

Prospectively assess the performance of diffusion-weighted magnetic resonance imaging (DW-MRI) for differentiation of central lung cancer from atelectasis.

MATERIALS AND METHODS

38 consecutive lung cancer patients (26 males, 12 females; age range: 28-71 years; mean age: 49 years) who were referred for thoracic MR imaging examinations were enrolled. MR examinations were performed using a 1.5-T clinical scanner and scanning sequences of T1WI, T2WI, and DWI. Cancers and atelectasis were measured by mapping of the apparent diffusion coefficients (ADCs) obtained with a b-value of 500 s/mm(2).

RESULTS

PET/CT and DW-MR allowed differentiation of tumor and atelectasis in all 38 cases, but T2WI did not allow differentiation in 9 cases. Comparison of conventional T2WI and DW-MRI indicated a higher contrast noise ratio of the central lung carcinoma than the atelectasis by DW-MRI. ADC maps indicated significantly lower mean ADC in the central lung carcinoma than in the atelectasis (1.83±0.58 vs. 2.90±0.26 mm(2)/s, p<0.0001). ADC values of small cell lung carcinoma were significantly greater than those from squamous cell carcinoma and adenocarcinoma (p<0.0001 for both).

CONCLUSIONS

DW-MR imaging provides valuable information not obtained by conventional MR and may be useful for differentiation of central lung carcinoma from atelectasis. Future developments may allow DW-MR imaging to be used as an alternative to PET-CT in imaging of patients with lung cancer.

The influence of bone cement type on production of fretting wear on the femoral stem surface: a preliminary study

BACKGROUND

It has been reported that bone cement correlates with survivorship of cemented total hip replacement. However, little research has been published to investigate the influence of bone cement type on production of fretting wear on the femoral stem.

METHODS

In the present study, we performed six in vitro wear simulations using the same type of femoral stem (polished Exeter V40™) and three different bone cements (Simplex P, Palacos R, and CMW 3).

FINDINGS

Fretting wear was consistently reproduced on the stem surface and the wear locations compared well with the results of retrieval studies. Selected 3D surface parameters were utilised to quantitatively evaluate fretting wear and no significant difference was identified in terms of fretting wear severity between these simulations. The bone cements were all badly damaged in those sites contacting the fretting wear areas on the femoral stem. Additionally, there were plenty of wear debris present on the cement surface, and the energy dispersive X-ray analysis confirmed that it was just cement particles for Simplex P bone cement, whilst it included metallic particles for Palacos R and CMW 3 bone cements.

INTERPRETATION

This preliminary study shed some light on the influence of bone cement type on production of fretting wear on the femoral stem surface but further research is needed to gain a better understanding on this issue.

Clinical features and risk factors of creatine kinase elevations and myopathy associated with telbivudine

With the extensive use of telbivudine, more and more studies reported its association with creatine kinase (CK) elevations and myopathy. However, clinical features of these adverse effects were poorly understood. The aim of the present study was to investigate the clinical features and risk factors of CK elevations and myopathy associated with telbivudine. The serum CK levels of 200 patients who were treated with telbivudine for chronic hepatitis B (CHB) between January 2007 and July 2010 were monitored and analysed along with clinical manifestations. The 3-year cumulative incidence of CK elevations and myopathy was 84.3% and 5%, respectively. CK elevations occurred more frequently in men than in women, and patients aged ≤45 years and with negative HBeAg had higher incidence of CK elevations. There was no difference in CK elevations among patients with different HBV DNA levels. Male, younger age and HBeAg negativity were independent predictors of CK elevations by multivariate Cox regression analysis. There was no association between the occurrence of myopathy and variables including age, sex, HBeAg and HBV DNA. No risk factors of myopathy were identified. CK elevations usually occurred 21 months after starting treatment, and most patients resolved spontaneously without interruption of telbivudine therapy except three patients who had to switch to other agents. In conclusion, CK elevations are common adverse reactions associated with telbivudine therapy, while myopathy is rare. Male, younger age and HBeAg negativity might be risk factors of CK elevations.

Ectopic study of tissue-engineered bone complex with enamel matrix proteins, bone marrow stromal cells in porous calcium phosphate cement scaffolds, in nude mice

OBJECTIVE

This study aimed to investigate the potential of enamel matrix proteins (EMPs) on promoting osteogenic differentiation of porcine bone marrow stromal cells (pBMSCs), as well as new bone formation capabilities, in a tissue-engineered bone complex scaffold of EMPs, pBMSCs and porous calcium phosphate cement (CPC).

MATERIALS AND METHODS

Effects of EMPs on pBMSCs in vitro was first determined by alkaline phosphatase (ALP) activity, von Kossa staining assay and mRNA expression of ALP, bone sialoprotein (BSP) and osteocalcin (OCN) genes. Next, an ectopic new bone formation test was performed in a nude mouse model with four groups: CPC scaffold alone; CPC scaffold + EMPs; CPC scaffold + pBMSCs; and CPC scaffold + EMPs + pBMSCs, for 2 or 4 weeks.

RESULTS

ALP activity, von Kossa assay and mRNA expressions of ALP, BSP and OCN genes were all significantly higher with 150 μg/ml EMP treatment in vitro. In nude mice, new bone formation was detected only in the CPC scaffold + EMPs + pBMSCs group at 2 weeks. At 4 weeks, in the tissue-engineered construct there was significantly higher bone formation ability than other groups.

CONCLUSIONS

EMPs promoted osteogenic differentiation of pBMSCs, and the tissue-engineered complex of EMPs, pBMSCs and CPC scaffold may be a valuable alternative to be used in periodontal bone tissue engineering and regeneration.

In vitro behavior of MC3T3-E1 preosteoblast with different annealing temperature titania nanotubes

OBJECTIVE

Titanium oxide nanotube layers by anodization have excellent potential for dental implants because of good bone cell promotion. It is necessary to evaluate osteoblast behavior on different annealing temperature titania nanotubes for actual implant designs.

MATERIALS AND METHODS

 Scanning Electron Microscopy, X-Ray polycrystalline Diffractometer (XRD), X-ray photoelectron Spectroscope, and Atomic Force Microscopy (AFM) were used to characterize the different annealing temperature titania nanotubes. Confocal laser scanning microscopy, MTT, and Alizarin Red-S staining were used to evaluate the MC3T3-E1 preosteoblast behavior on different annealing temperature nanotubes.

RESULTS

 The tubular morphology was constant when annealed at 450°C and 550°C, but collapsed when annealed at 650°C. XRD exhibited the crystal form of nanotubes after formation (amorphous), after annealing at 450°C (anatase), and after annealing at 550°C (anatase/rutile). Annealing led to the complete loss of fluorine on nanotubes at 550°C. Average surface roughness of different annealing temperature nanotubes showed no difference by AFM analysis. The proliferation and mineralization of preostoblasts cultured on anatase or anatase/rutile nanotube layers were shown to be significantly higher than smooth, amorphous nanotube layers.

CONCLUSION

 Annealing can change the crystal form and composition of nanotubes. The nanotubes after annealing can promote osteoblast proliferation and mineralization in vitro.

Comparison of dental education and professional development between mainland China and North America

Different educational and professional developments within the dental field create different sets of missions, norms, and practices regarding dental diseases and their appropriate treatment. This review has addressed differences in dental education and professional development between mainland China and North America. Many factors influence the choice of model and it is very difficult to predict which model will become predominant. However, there is growing sentiment that the independent faculty model in North America is logical and superior to the model, which 'integrates' dental and medical education in mainland China. Many North America dental schools place a high priority on preclinical and clinical training in the curriculum in order to expose students to patient oral health needs and systemic dental problems much earlier than in mainland China. North America dental schools promote and embrace students self-learning skills by the use of PBL, CRL, and TRAD education methodologies and new e-based technologies and approaches whereby students learn rather than are taught. In mainland China, the traditional lecture-based format is still employed in the majority of dental schools; however, strategies to enhance students self-learning skills is increasingly utilised in most well-known Chinese dental schools. The Chinese dental education model, which treats dentistry as a sub-specialty of medicine, has brought about fundamental differences, with the dentist functioning essentially as a stomatologist. For example, China has built up a large oral and maxillofacial surgery society, and craniofacial surgery is performed to a much broader extent by Chinese dentists than by most North American counterparts. In North America, dentists engage in full-time work, attend continuing training/education programmes, belong to an association, gain legal status, and construct a code of ethics emphasising the quality of care delivered to the public. Currently, continuing dental education in North America is available through a variety of venues involving licensing authorities, universities and private programmes. The concept of professional development in mainland China is relatively new and is still considered primarily in the context of promotion or achieving a higher professional title. Mandatory continuing dental professional education requirements do not guarantee the competence of members of the profession. Today, the Chinese government and society place increasing emphasis upon the accountability of self-regulating professions. Rather than attempting to summarise the current scope of dental education and professional development between mainland China and North America, this paper hopes to enhance mutual understanding, and promote greater academic exchanges in dental education.

[Hepatic metastasis of human colon carcinoma: establishment of a nude mouse model and its magnetic resonance imaging]

OBJECTIVE

To establish a nude mouse model mimicking hepatic metastasis of human colon carcinoma and study its magnetic resonance imaging (MRI) features and the quality of diffusion-weighted images (DWI).

METHODS

Human colon carcinoma SW480 cells were inoculated subcutaneously ((1x10(7)/ml, 0.5 ml) in the costal regions of 2 nude mice, and after successful tumor formation, the generated tumors were harvested and cut into tissue blocks of 1 mm(3). The tissue blocks were subsequently implanted into the liver of 36 nude mice, from which TSE-T1WI, T2WI and EPI-DWI were obtained after tumor growth.

RESULTS

The success rate of intrahepatic tumor implantation was 100% (36/36), and the tumors grown in the liver measured 0.7 to 2 cm in diameter 2 to 6 weeks after implantation. All the tumors were clearly visualized on T1WI and T2WI images, with isointensity on T1WI and hyperintensity on T2WI. Compared with the T2WI, DWI showed conspicuous geometry deformation in 4 mice to cause difficult detection, moderate to slight geometric deformation in 14 mice which remained detectable, and no geometric deformation in 18 mice.

CONCLUSION

The nude mouse model of hepatic metastasis of SW480 colon cancer cell line, with ideal implantation and tumor growth rate, allows convenient tumor observation on MR T1WI, T2WI and DWI, and the MRI findings of the tumor are well consistent with those by pathological examination, suggesting the validity of this model for molecular imaging research of human colon cancer.

Value of multi-slice computed tomography in preoperative "one-station-style" examination for colon cancer

AIM: To assess the value of three-phase contrasted multi-slice computed tomography (MSCT) pneumocolon in preoperative examina-tion of colon cancer.

METHODS: Sixty-three patients with colonic cancer underwent plain MSCT pneumocolon and multiphase contrasted MSCT within 1 week before operation. Contrasted MSCT scans were performed using 16-slices CT system (Toshiba aquilion16) 22 s (phaseⅠ), 37-40 s (phaseⅡ) and 60 s (phase Ⅲ) after intravenous administration of contrast medium. Images were then obtained by CT colonography (CTC), X-ray projection (XRP), multi-planar reformation (MPR), surface shadow display (SSD), CT angiography (CTA) in post-procession workstation. The results were comparatively analyzed with the surgical pathology.

RESULTS: Sixty-four cancer lesions were detected on CT images and in surgery. They located in ascending colon (18 lesions), hepatic flexure of colon (2 lesions), transverse colon (4 lesions), splenic flexure of colon (2 lesions), descending colon (6 lesions), sigmoid (20 lesions, of which 5 lesions in the injunction of sigmoid and rectum), and rectum (12 lesions). Extracolonic diseases were found in 16 patients by MSCT or surgery. On multi-phase contrasted CT images, colon caner lesions demonstrated homogeneous or inhomogenous enhancement, and the absolutely increased peaks in CT density were at phase Ⅱ (30 lesions), phase Ⅱ-Ⅲ (17 lesions), phase Ⅲ (13 lesions) and phaseⅠ-Ⅲ (4 lesions). CTA detected blood-supplying artery of 58 cancer lesions (90.6%). The sensitivity, specificity and positive accuracy were 100%, 64.2%, and 92.1% respectively, for pericolonic fat involvement, and 78.5%, 86.7%, and 86.1% respectively, for abdominal metastasis-positive lymph-nodes.

CONCLUSION: MSCT pneumocolon and preoperative three-phase contrasted CT can provide information about tumor location, number, stage, blood-supplying artery and extracolonic diseases.

[Experimental research of NNB composite in repairing mandibular defects in rabbits]

OBJECTIVE

To study the effects of artificial bone composite of basic fibroblast growth factor(bFGF) with natural non organic bone(NNB)in repairing mandibular defects in rabbits,in order to provide an ideal bone replacement material for clinic.

METHODS

15mm x 6mm bilateral mandibular periosteum bone defects were made surgically in 30 New Zealand adult rabbits and each defect as an experimental unit. The defects were randomly repaired with composite bone, NNB,fresh autogenous bone at 3,6,12 weeks after surgery according to the total random design, blank control group was stayed. Specimens obtained were evaluated with general observation, X-ray as well as computerized histological microscopic analysis.

RESULTS

New bone formed and calcified earlier in composite bone and the bone area was greater in the same period than that in NNB. The new bone area in composite bone was still smaller than that of autogenous bone at 6 weeks, while at 12 weeks they had no significant differences. The blank defects were not repaired even in the end.

CONCLUSION

Composite bone had sound biocompatibility. It was much better than NNB and can be compared with autogenous bone 12 weeks after operation. So it can be an ideal alternative for bone replacement.

Three dimensional measurement of the surface topography of ceramic and metallic orthopaedic joint prostheses

The comprehensive study of surface topography of the orthopaedic joint prostheses has become very important for analysis of the wear mechanism and the performance life of the joint replacement systems. The aim of the study to investigate "best" methods for the three-dimensional (3D) surface metrology of orthopaedic joint prostheses. Characterization techniques for the identification and evaluation of the functional features of the bearing surface topographies has been provided in previous work. This paper concentrates on addressing issues of measurement and application techniques for assessment of the 3D surface topography of the joint replacement systems by using contacting stylus instruments, atomic force microscopes (AFM), and non-contacting measurement supported by focus detection instruments and phase-shifting interferometers. The techniques are discussed according to different analysis requirements of the orthopaedic joint prostheses. This work also discusses the performances of the instruments in terms of the measurement of femoral heads. Finally, recommendations for acceptable measurement techniques and application for analyzing surface topography of orthopaedic joint prostheses are summarized.

[Treatment of nasofacial hemangioma with interventional embolization and pingyungmycin injection]

OBJECTIVE

To investigate a new method with interventional embolization and pingyugmycin injection for treating nasofacial Hemangioma.

METHOD

The fillets and coil were used for interventional embolization facial artery, internal maxillary artery, temporal superficial artery, and pingyungmycin injected for 4 patients.

RESULT

The tumor and vascular beat in this series of 4 patients were disappeared by follow up of one year. There are not nasal obstruction and epistaxis.

CONCLUSION

Treatment with interventional embolization and pingyungmycin injection is a safe and effective method for nasofacial hemangioma.

Three-dimensional surface characterization for orthopaedic joint prostheses

This study attempts to investigate a range of 'better' methods for the characterization of the three-dimensional (3D) surface topography of orthopaedic joint prostheses. In this paper, a new characterization tool for the comprehensive identification and evaluation of functional features of these surface topographies is presented. For identification, the surface topography is investigated in a space-scale space, by employing wavelet analysis. The roughness, waviness and form involved in surface topography are consequently separated and recovered respectively. The multiscalar topographical features are identified and captured. The errors caused as a consequence of three-dimensional measurement methods can be reduced. After identification, the three-dimensional surface assessment techniques previously reported by Stout and co-workers are used for the quantitative evaluation of various surface roughness features of the orthopaedic joint prostheses. Moreover, the functional properties, such as bearing area, material volume and void volume which are significantly effected by large peaks, pits and scratches are studied and the location of isolated peaks, pits and scratches in the different scales is also clearly characterized. In this work, measurement of the femoral heads and acetabular cups is carried out to demonstrate the applicability of the characterization technique for the three-dimensional surface topography of orthopaedic joint prostheses.

High-accuracy wavelength-change measurement system based on a Wollaston interferometer, incorporating a self-referencing scheme

A novel wavelength-difference measurement scheme with a Wollaston prism is presented. By using a suitable reference wavelength, a small variation in the signal wavelength can be converted into a relatively larger change in the modulated wavelength, as a result of the so-called fringe beating effect, resulting in enhanced measurement sensitivity by use of autocorrelation and Gaussian filtering techniques. From the results of a simulation carried out, we observed a wavelength variation of 0.01 nm over 15 nm or 0.1 nm over 60 nm for a typical pair of laser diodes with wavelengths of 785 and 810 nm, and wavelength variations of 0.5 nm over 40 nm or 1 nm over 110 nm for 671-and 785-nm wavelengths. These results were partially verified by the experimental results obtained for which a resolution of 0.01 nm over a range of 2.5 nm for the first pair and 0.5 nm over 4 nm for the second pair of laser diodes was seen. The results have applications to the determination of wavelength variations in a wavelength-division multiplexing system or measurement of the wavelength changes induced in a range of optical sensors.

Portal dosimetry using a liquid ion chamber matrix: dose response studies

Current intensive investigations of electronic portal imaging devices (EPIDs) have prompted their potential application to portal dosimetry. In this paper, the progress made in using a commercial liquid ion chamber matrix EPID for portal dosimetry is discussed. The pixel value of the liquid ion chamber element was calibrated against dose by exposing the imager to 6-MV x-ray beams of various intensities obtained with various thicknesses of lead attenuators and a range of source to detector distances. Absolute dose values were determined using an ion chamber on the central axis at the depth of maximum dose in a solid water phantom. The pixel values of the matrix were determined for various field sizes in order to evaluate the dependence of pixel value on dose at those field sizes. It was confirmed that the pixel value was proportional to the square root of the dose rate and was nearly independent of the field size. The 2D pixel values were converted to 2D dose maps in the water phantom after applying a correction for the effect of horns in the flood calibration field. The flood calibration field was used to obtain the relative sensitivity of each pixel. Good agreement was observed (normally better than 1% in relative standard deviation) between the converted dose distribution obtained from the pixel matrix and the direct dose measurement using an ion chamber scanned in a water phantom in regions of shallow dose gradient. For application to on-line portal dosimetry, both the short- and long-term stability of this EPID system were found to be within 1% relative standard deviation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hepatic hemodynamic changes in liver cancer patients during intrahepatic arterial angiotensin II infusion induced hypertension and chemoembolization]

In this report, hepatic hemodynamics were studied by pulsed ultrasound doppler during the process of intrahepatic arterial angiotensin II infusion induced hypertension and chemoembolization (IHCE) in 20 liver cancer patients. It was found that at 90 seconds after I-HCE, tumor blood supply increased by an average of 1.786 times while the blood flow of proper hepatic artery decreased to an average of 0.5665 times of its original level. At the same time patients' peripheral blood pressure increased by 3.7kPa. It is evidenced that angiotensin II infusion augments blood flow to tumor region while decreases blood supply in healthy tissues.

[In situ detection of EBV DNA in various types of carcinomas derived from the nasopharynx and neighboring regions]

A sensitive and reliable technique for in situ hybridization of DNA-DNA with biotin labelled probe on routine paraffin sections was developed. Using BamH I-W fragment of EBV as probe, a variety of biopsies from nasopharynx and its neighboring regions were examined for EBV distribution. It was discovered that the existence of EBV was related to the histological type and degree of differentiation of carcinomas, but not limited to the nasopharynx region. The EBV DNA positive ratios in (1) poorly, (2) moderately and (3) well differentiated nasopharyngeal squamous cell carcinomas, (4) poorly differentiated nasopharyngeal adenocarcinoma, (5) poorly differentiated squamous cell carcinomas derived from palate and (6) tonsil were 39/41, 1/7, 0/3, 2/8, 3/4 and 2/9 respectively. No EBV DNA was detected in other moderately and well differentiated squamous cell carcinomas or benign tumors of the head and neck. EBV DNA was detected in nearly all malignant cell nuclei of positive sections, whereas all morphologically normal and hyperplastic epithelial cells, stroma cells, infiltrating lymphocytes and epithelium in chronic nasopharyngitis were negative.