All that Glitters is Not Gold: Examining Cost Effectiveness Analyses in Radiation Oncology

PURPOSE/OBJECTIVE(S)

Cost effectiveness analyses (CEA) provide data for health policy decisions in resource constrained environments. These are important in Radiation Oncology as infrastructure and delivery costs increase and indications expand. The purpose of this study was to systematically review methodologic quality and trends in CEAs involving radiotherapy (RT).

MATERIALS/METHODS

A systematic review was performed on cost effectiveness/utility studies involving RT, querying PubMed and Embase from inception to September 2020. Non-English, reviews, abstracts and cost-only studies were excluded. Independent reviewers screened and abstracted study demographics, economic parameters and methodological details.

RESULTS

After screening 1652 abstracts, 214 met criteria. The first publication was in 1995, and more than half (n = 113, 53%) were published after 2014. Author institutions were from North America (n = 128, 60%), Europe (n = 49, 23%) and Asia (n = 30, 14%) with most reporting in US$ (n = 143, 67%). A majority utilized a decision model (n = 164, 77%), healthcare payer perspective (n = 171, 80%) and a finite time horizon (n = 108, 50%). Publications spanned 96 unique journals, most commonly International Journal of Radiation and Oncological Biology and Physics (n = 35, 16%). Treatment intent was curative in 171 studies. Disease sites included breast (n = 34, 16%), genitourinary (n = 31, 14%), and gastrointestinal (n = 31, 14%). RT was mostly used as primary treatment (n = 144, 67%), followed by adjuvant (n = 70, 33%) and neoadjuvant (n = 10, 5%). Emerging topics included stereotactic RT (n = 45, 21%), immunotherapy (n = 6, 3%), oligometastasis (n = 4, 2%), and heavy particles (n = 23, 11%). RT was compared to other RT (n = 136, 64%), surgery (n = 43, 20%), drugs (n = 14, 7%) and observation (n = 31, 17%). Incomplete reporting was common. Missing elements included analysis perspective (n = 13, 6%), time horizon (n = 38, 18%), discounting of utilities (n = 71, 33%) or costs (n = 54, 25%), and willingness-to-pay threshold (n = 59, 28%). Furthermore, 27 studies did not perform sensitivity analyses, 36 did not evaluate incremental cost-effectiveness ratio and only 60 explicitly utilized recognized reporting guidelines. Conflict of interest statements were found in 63%, with sponsor statements in 59%; 25% were industry sponsors. Outcome parameters were obtained from primary (author institution/trial data) sources in 33%, including randomized trials (RCTs) (n = 20, 9%), retrospective data (n = 20, 9%) and population data (n = 9, 4%). The remainder utilized secondary sources including RCTs (n = 71, 33%), retrospective data (n = 35, 16%) or meta-analyses (n = 11, 5%). Outcomes included quality adjusted life years (n = 158, 74%), life-years (n = 30, 14%) or toxicity (n = 26,12%). 31% utilized author generated utilities; of literature derived only 49% were matched to disease and clinical context.

CONCLUSION

While CEAs are increasingly common in RT, reporting and methodologic rigor must improve. Greater use of published guidelines will improve data quality for decision makers.

Facial expression of patients with Graves' orbitopathy

PURPOSE

Patients with Graves' orbitopathy (GO) have characteristic facial expressions that are different from those of healthy individuals due to the combination of somatic and psychiatric symptoms. However, the facial expressions of GO patients have not yet been described and analyzed systematically. Thus, the present study aimed to present the facial expressions of GO patients and explore their applications in clinical practice.

METHODS

Facial image and clinical data of 943 GO patients were included, and 126 patients answered quality of life (GO-QOL) questionnaires. Each patient was labeled for one facial expression. Then, a portrait was drawn for every facial expression. Logistic and linear regression was performed to analyze the correlation between facial expression and clinical indicators, including QOL, disease activity and severity. The VGG-19 network model was utilized to discriminate facial expressions automatically.

RESULTS

Two groups, i.e., the non-negative emotion (neutral, happy) and the negative emotion (disgust, angry, fear, sadness, surprise), and seven expressions of GO patients were systematically analyzed. Facial expression was statistically associated with GO activity (P = 0.002), severity (P < 0.001), QOL visual functioning subscale scores (P = 0.001), and QOL appearance subscale score (P = 0.012). The deep learning model achieved satisfactory results (accuracy 0.851, sensitivity 0.899, precision 0.899, specificity 0.720, F1 score 0.899, and AUC 0.847).

CONCLUSIONS

As a novel clinical sign, facial expression holds the potential to be incorporated into GO assessment system in the future. The discrimination model may assist clinicians in real-life patient care.

[Changes of the World Health Organization 2022 classification (5th edition) of salivary glands tumors]

Pathological diagnosis of salivary gland tumors is one of the most challenging areas in all head and neck surgical pathology. The classification of salivary gland tumors was updated in the 5th edition of the World Health Organization Classification of Head and Neck Tumours, most of which were based on their molecular pathological characteristerics. This new classification features a description of several new entitiesamong benign and malignant neoplasms, salivary gland tumors with updated naming or diagnostic criteria, and lesions deleted from this section, etc.This present review focuses on the updates and changes in the new classification of salivary gland tumors, and provides some reference for head and neck surgeons and pathologists.

[Etiological and epidemiological characteristics of Vibrio cholerae in Beijing, 2015-2021]

Objective: To analyze the etiological and epidemiological characteristics of Vibrio cholerae in Beijing during 2015-2021 and provide evidence for the prevention and control of cholera. Methods: The V. cholerae strains isolated in Beijing during 2015-2021 were analyzed by serotyping and virulence genes detection. Pulsed field gel electrophoresis (PFGE) was performed for the molecular typing of the strains. Based on the collected epidemiological and clinical data of cholera cases,the epidemiological characteristics of cholera were analyzed by descriptive epidemiology method. Results: A total of 76 Vibrio cholerae O1 strains were isolated in Beijing during 2015-2021, including 61 strains from human, 10 strains from environment and 5 strains from seafood. The 76 strains consisted of 68 Ogawa strains and 8 Inaba strains. Six Ogawa strains isolated from sporadic cases carried ctxAB. After NotⅠ digestion, 76 strains were divided into 33 PFGE patterns. From 2015 to 2021, a total of 38 cholera epidemics were reported in Beijing, most of them were sporadic ones, accounting for 92.11% (35/38). A total of 45 cases were reported, and the cases occurred during June-September accounted for 97.78% (44/45). Cholera cases occurred in 9 districts of Beijing, and the cases reported in Chaoyang district accounted for 42.22% (19/45) and in Changping district accounted for 31.11% (14/45). The age of the cholera cases ranged from 19 to 63 years. Except for one case with unknown clinical symptoms, 44 cases had diarrhea symptoms with 84.09% (37/44) of the cases reporting diarrhea (3-9 times/day), followed by yellow watery stool (95.45%, 42/44), abdominal pain (68.18%, 30/44), nausea and vomiting (40.91%, 18/44) and fever (36.36%, 16/44). Conclusion: Vibrio cholerae strains isolated in Beijing during 2015-2021 were mainly O1 serotype Ogawa,most of which were non-toxigenic. The PFGE of the strains varied. Cholera epidemics occurred in 9 districts of Beijing, but most were sporadic ones with incidence peak during June-September.

Anti-Inflammatory and Anti-Oxidant Activity of Ultra-Short Wave Diathermy on LPS-Induced Rat Lung Injury

We studied the lung-protective effect and mechanisms of the anti-inflammatory and antioxidant effects of ultra-short-wave diathermy (USWD) in a rat model of LPS-induced acute lung injury. Histological examination of the lung tissues was performed and the levels of oxidative stress-related factors and inflammatory cytokines were measured. It was shown that the lung injury score, the lung wet-to-dry weight ratio (W/D), oxidative stress-related factors malondialdehyde and acyl-CoA synthetase long-chain family member 4 (ACSL4), and inflammatory cytokines were increased after LPS administration, while USWD treatment reduced these parameters. In addition, superoxide dismutase and glutathione peroxidase 4 were decreased in rats with LPS-induced acute lung injury, while USWD therapy up-regulated the expression of these enzymes. Thus, USWD could antagonize lung injury by inhibiting oxidative stress and inflammatory response in rats with acute lung injury. USWD can be a promising adjunctive treatment to counter oxidative stress and inflammation and a potential therapeutic candidate for the treatment of patients with this pathology.

[Analysis on epidemiological characteristics of multidrug-resistant Salmonella Kentucky in Beijing, 2010-2020]

Objective: To investigate the epidemiological, drug resistance and molecular characteristics of Salmonella (S.) Kentucky strains isolated from diarrheal patients in Beijing. Methods: The drug susceptibility of 22 S. Kentucky strains isolated in Beijing during 2010-2020 was tested by using the micro broth dilution method. The multilocus sequence typing (MLST), drug resistance genes and Salmonella genomic island (SGI) identifications of the strains were performed by whole-genome sequencing (WGS).The pulsed field gel electrophoresis (PFGE) was performed to analyze the molecular epidemiological characteristics of the isolates. Results: The 22 strains were highly resistant to 8-22 kinds of antibiotics, especially to ciprofloxacin, cephalosporins and azithromycin, etc., showing a super high level of multidrug resistance and 21 strains were positive for extended-spetrum beta-lactamase (ESBL). The WGS analysis revealed that all the isolates belonged to ST198, carrying SGI1-K. The drug resistance genes tetA, sul1 and qacE were identified in all strains and Quinolone resistance-determining regions (QRDRs) showed 2 mutations in gyrA (S83F, D87 N) and 3 mutations in the parC gene (T57S, S80I, T255S). The resistance genes associated with β-lactam antibiotics (blaCTX-M-55, blaCTX-M-14b, blaTEM-141, blaTEM-206, blaTEM-209, blaTEM-214, blaTEM-1B), resistance genes associated with aminoglycosides [aac(3)-Id, aac(3)-IId, aac(6')-Iaa, aadA7, aadA17, aph(3')-Ia, aph(3'')-Ib, aph(6)-Id,rmtB] as well as floR, dfrA14, mphA and qnrS1 had significant differences in the strains of different years, which were highly consistent with the drug-resistant phenotype. Furthermore, phylogenetic analysis showed that the similarity of the 22 strains was more than 85%, and the strains were highly homologous to CIP-resistant ST198-X1 circulating in the world. In the process of spread, the drug resistance and PFGE spectrums had changed, two clusters had formed. Conclusions: The S. Kentucky strains isolated in Beijing shared high homology with the multidrug-resistant strain ST198-X1-SGI-1K isolated in the world, which has maintained a low level of spread since 2016, causing sporadic infections and clusters of diarrhea, and has serious resistances to fluoroquinolones, ESBLs and azithromycin. The surveillance for multidrug-resistant S. Kentucky should be strengthened.

Comparative Study on Temperature Response of Hydropower Development in the Dry-Hot Valley

Due to the specific hydrothermal conditions of dry-hot valleys, temperature changes caused by the development of large-scale hydropower projects may be more extreme than they are in other regions. In this study, we analyzed these temperature changes at four hydropower stations in both dry-hot and non-dry-hot valleys. Based on the calculated relative temperatures of the downstream river and the areas surrounding the reservoirs, we employed two indices to quantify the influence of the reservoirs on the temperatures of these two regions: the downstream river temperature change and the reservoir effect change intensity. Our results are as follows: (a) In the downstream rivers, the temperature regulation effect was more pronounced in the wet season; in the regions surrounding the reservoirs, the temperature regulation effect was more pronounced in the dry season. (b) The downstream river temperature in both the dry-hot and wet-hot valleys exhibited noticeable warming in both the wet and dry seasons, while the cold-dry valley was characterized by cooling in the dry season and warming in the wet season. With the exception of the Liyuan station (where the influence of the reservoir on the downstream temperatures only extended to a distance of 9 km from the dam) during the dry season, the existence of the hydropower stations affected the temperatures of the entire downstream region. (c) For the areas surrounding the reservoir, the presence of a hydropower station mainly caused the temperatures in the dry-hot valleys to rise and the temperatures in the non-dry-hot valleys to decrease.

Distributions of serum thyroid-stimulating hormone in 2020 thyroid disease-free adults from areas with different iodine levels: a cross-sectional survey in China

PURPOSE

The aim of the present study was to describe the distributions of serum thyroid- stimulating hormone (TSH) levels in thyroid disease-free adults from areas with different iodine levels in China. Meanwhile, we aimed to evaluate the influence of age and gender on the distribution of TSH, assess the relationship between concentrations of TSH and free thyroxine (FT₄), and analyze the factors that may affect TSH levels.

METHODS

2020 adults were included from April 2016 to June 2019. Urinary iodine concentration, serum iodine concentration, serum TSH, FT₄, free triiodothyronine, thyroid peroxidase antibodies and thyroglobulin antibodies were measured, and thyroid ultrasonography was performed.

RESULTS

The median of TSH in iodine-fortification areas (IFA), iodine-adequate areas (IAA), iodine-excessive areas (IEA) were 2.32, 2.11 and 2.34 mIU/L, respectively. Serum TSH concentrations were significantly higher in IFA and IEA than that in IAA (p = 0.005 and < 0.0001). The TSH values of most adults were distributed within the range of 1.01-3.00 mIU/L with the same trend in three groups. In our study, TSH levels did not change with age, and the TSH level of females was higher than that of males (p < 0.0001). There was a negative correlation between FT₄ and TSH in IAA (r = - 0.160, p < 0.0001) and IEA (r = - 0.177, p < 0.0001), but there was no correlation between FT₄ and TSH in IFA (r = - 0.046, p = 0.370). BMI, smoking status, education levels, and marital status were associated with TSH.

CONCLUSION

Our study provides a basis for establishing the reference intervals of TSH in different iodine level areas.

FOXK1 promotes malignant progression of breast cancer by activating PI3K/AKT/mTOR signaling pathway

OBJECTIVE

The aim of this study was to investigate the expression characteristics of forkhead box K1 (FOXK1) in breast cancer (BCa). Meanwhile, its relationship with clinicopathology and prognosis of patients with BCa was also explored.

PATIENTS AND METHODS

The expression level of FOXK1 in 65 paired BCa tissues and para-cancerous tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between FOXK1 expression and BCa pathological parameters as well as the prognosis of patients was analyzed. Meanwhile, the expression of FOXK1 in BCa cells was detected by qRT-PCR. Subsequently, FOXK1 knockdown and overexpression models were constructed by lentivirus transfection in BCa cell lines (including MCF-7 and SKBR3). The effect of FOXK1 on the biological functions of BCa cells was analyzed using Cell Counting Kit-8 (CCK-8), cell cloning assay and flow cytometry, respectively. Finally, whether the role of FOXK1 was achieved via the PI3K/AKT/mTOR signaling pathway was explored.

RESULTS

The qRT-PCR results showed that FOXK1 expression in BCa tissues was significantly higher than that of adjacent tissues. Compared with patients with low expression of FOXK1, the pathological grading was markedly higher in those with high expression. Meanwhile, the overall survival rate was remarkably lower in patients with high expression. In addition, compared with the negative control group, the proliferation ability of cells in FOXK1 knockdown group was significantly decreased, while cell apoptosis was markedly up-regulated. Besides, Western blot results revealed that silencing FOXK1 could reduce the levels of key proteins in the PI3K/AKT/mTOR signaling pathway, thereby promoting the malignant progression of BCa. Finally, PI3Kα/mTOR-IN-1, which was the inhibitor of the PI3K/AKT/mTOR signaling pathway, significantly reversed the proliferative capacity of cells in FOXK1 overexpression group, as well as enhanced anti-apoptotic ability.

CONCLUSIONS

FOXK1 expression was remarkably increased both in BCa tissues and cells. Meanwhile, it was markedly associated with pathological stage and poor prognosis of patients. Besides, FOXK1 might promote the malignant progression of BCa by inhibiting the PI3K/AKT/mTOR signaling pathway.

The accuracy of three-dimensional rapid prototyped surgical template guided anterior segmental osteotomy

Background

Surgical guiding templates provided a reliable way to transfer the simulation to the actual operation. However, there was no template designed for anterior segmental osteotomy so far. The study aimed to introduce and evaluate a set of 3D rapid prototyping surgical templates used in anterior segmental osteotomy.

Material and Methods

From August 2015 to August 2017, 17 patients with bimaxillary protrusions were recruited and occlusal-based multi-sectional templates were applied in the surgeries. The cephalometric analysis and 3D superimposition were performed to evaluate the differences between the simulations and actual post-operative outcomes. The patients were followed-up for 12 months to evaluate the incidence rate of complications and relapse.

Results

Bimaxillary protrusion was corrected in all patients with no complication. In radiographic evaluations, there was no statistically significant difference between the actual operations and the computer-aided 3D simulations (p >0.05, the mean linear and angular differences were less than 1.32mm and 1.72° consequently, and 3D superimposition difference was less than 1.4mm). The Pearson intraclass correlation coefficient reliabilities were high (0.897), and the correlations were highly significant (P< 0.001).

Conclusions

The 3D printed surgical template designed in this study can safely and accurately transfer the computer-aided 3D simulation into real practice.

Key words:CAD/CAM; anterior segmental osteotomy; surgical guiding templates; bimaxillary protrusion; virtual surgery simulation.

[Pathogenic surveillance and related factors on bacillary dysentery in Beijing, 2008-2017]

Objective: To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing, 2008-2017, to provide evidence for the practices of diagnosis, treatment and prevention of the disease. Methods: Analysis was conducted on surveillance data of bacillary dysentery, collected from the surveillance areas of national bacillary dysentery in Beijing. Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella, diagnostic accordance rate and resistance were computed on data from the surveillance programs. Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection. Results: Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend, from 2008 to 2017. The accordance rate of bacillary dysentery was only 7.80% (111/1 423). Shigella sonnei was the most frequently isolated strain (73.95%, 159/215) followed by Shigella flexnery. Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs. routine test of stool positive (OR=1.863, 95%CI: 1.402-2.475), onset from July to October vs. other months'time (OR=7.271, 95%CI: 4.514-11.709) temperature ≥38 ℃vs. temperature <38 ℃(OR=4.516, 95%CI: 3.369-6.053) and age from 6 to 59 years old vs. other ages (OR=1.617, 95%CI: 1.085-2.410), presenting higher positive detection rates of Shigella from the stool tests. The resistant rates on ampicillin and nalidixic acid were 97.57% (201/206) and 94.90% (186/196), both higher than on other antibiotics. The resistant rates on ciprofloxacin (16.33%, 32/196), ofloxacin (9.57%, 11/115) and on amoxilin (15.05%, 31/206) were relatively low. The resistant rate appeared higher on Shigella flexnery than on Shigella sonnei. The proportion of strains with resistance on 3 more drugs, was 30.00%(21/70). Conclusions: The diagnostic accordance rate of bacillary dysentery in Beijing was low, with severe resistance of Shigella. Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history, clinical symptom and testing results for diarrhea patients.

Lives and Economic Loss in Brazil Due to Lack of Radiotherapy Access in Cervical Cancer

Background: Cervical cancer collects the highest survival benefit from radiotherapy (RT) among all malignancies. A large gap between oncological demand and RT availability exists for cervical cancer in Brazilian Public Health System (BPHS). Aim: To evaluate cost-effectiveness of universal access to RT and chemo-radiation (CRT) for untreated cervical cancer patients in the BPHS. Methods: The incremental cost was calculated based on the direct medical cost from a payer's perspective and the proportion of new cases with unmet RT/CRT needs in 2016. The incremental effectiveness was evaluated by life-year (LY) gain based on life expectancy, cervical cancer incidence and the number of cancer deaths due to lack of RT/CRT access as previously described. The incremental cost-effectiveness ratio (ICER) was calculated from direct medical costs and LYs. The indirect costs from mortality-related productivity loss (MRPL) were estimated based on life expectancy, wage and labor force participation rate. The MRPL was compared with direct medical cost. All costs and effectiveness were age-adjusted based on 2016 Brazilian data and discounted at 3% per year. Costs were adjusted to 2016 U.S. dollars. One-way sensitivity analysis was performed to assess the robustness of the model. Results: The annual cost to close RT gap was $14.3 million, with additional cost of $4.1 million to close the CRT gap. The average years of potential life lost per death was 20.5. Cost per life saved was $10,820 for RT alone (ICER: $528/LY) and $18,919 for CRT (ICER: $584/LY), respectively. The MRPL due to shortage of RT/CRT were 70/81 million respectively. Conclusion: Providing universal access to RT/CRT for cervical cancer patients in the BPHS will incur low cost per life-year saved and provide large economical gain by saving thousands of lives.

The physiological differentiation along the midgut of Bombyx mori - inspirations from proteomics and gene expression patterns of the secreted proteins in the ectoperitrophic space

The ectoperitrophic space (EcPS) between the insect midgut epithelial cells and the peritrophic matrix is an unexplored, clean resource for concentrated proteins secreted by the midgut epithelial cells, which offers an ideal opportunity to uncover the midgut functions. In this study, we used Bombyx mori as a model organism and performed comparative proteomic analyses of the secreted proteins in the EcPS at the feeding and wandering stages. A total of 372 proteins were identified from both stages and 70 proteins were predicted to be secreted. Amongst these proteins, 17 secreted digestive proteins were identified and their temporal and spatial transcriptional expression patterns demonstrated that all these proteins were up-regulated at the feeding stage and differentially expressed in different parts of the midgut. Proteins with nutrient reservoir activity and defence activity were found to be up-regulated at the wandering stage. This work is the first to show the presence of digestive enzymes in the EcPS of the insect midgut using a proteomic approach, which provides evidence that suggests a physiological functional differentiation of the insect midgut. It is very clear that the EcPS undergoes dynamic changes in its composition of proteins in response to the changing needs of the insect at different developmental stages.

A regulatory circuit HP1γ/miR-451a/c-Myc promotes prostate cancer progression

Heterochromatin protein 1γ (HP1γ) has been implicated in carcinogenesis of various cancer types. However, the role of HP1γ in prostate cancer (PCa) progression and the underlying molecular mechanisms remain largely unknown. We found that HP1γ is upregulated in PCa and elevated levels of HP1γ in PCa predict poor outcome. In addition, depletion of HP1γ in PCa cells not only repressed proliferation and induced apoptosis but also impaired tumorigenicity. We also found that c-Myc was capable of upregulating HP1γ by directly binding to the E-box element in the first intron of HP1γ gene, and the upregulated HP1γ, in turn, repressed the expression of miR-451a by enhancing H3K9 methylation at the promoter region of miR-451a. Furthermore, reduction of miR-451a significantly reversed HP1γ loss-induced PCa cell apoptosis, whereas miR-451a overexpression repressed cell survival by targeting and downregulating c-Myc. The association among c-Myc, HP1γ and miR-451a was further confirmed in human clinical samples. Therefore, we propose that an HP1γ/miR-451a/c-Myc regulatory circuitry exists in PCa cells and this circuit has a crucial role in PCa progression.

Studies on the chitin/chitosan binding properties of six cuticular proteins analogous to peritrophin 3 from Bombyx mori

Chitin deacetylation is required to make the cuticle rigid and compact through chitin chain crosslinking. Thus it is presumed that specialized proteins are required to bind deacetylated chitin chains together. However, deacetylated-chitin binding proteins have not ever been reported. In a previous work, six cuticular proteins analogous to peritrophin 3 (CPAP3s) were found to be abundant in the moulting fluid of Bombyx mori. In this study, these BmCPAP3s (BmCPAP3-A1, BmCPAP3-A2, BmCPAP3-B, BmCPAP3-C, BmCPAP3-D1 and BmCPAP3-D2) were cloned and expressed in Escherichia coli and purified using metal-chelating affinity chromatography. Their binding activities demonstrated that although all of the BmCPAP3s showed similar binding abilities toward crystalline chitin and colloidal chitin, they differed in their affinities toward partially and fully deacetylated chitin. Amongst them, BmCPAP3-D1 exhibited the highest binding activity toward deacetylated chitin. The gene expression pattern of BmCPAP3-D1 was similar to BmCPAP3-A1 and BmCPAP3-C at most stages except that it was dramatically upregulated at the beginning of the pupa to adult transition stage. This work is the first report of a chitin-binding protein, BmCPAP3-D1, which exhibits high binding affinity to deacetylated chitin.

Reduced miR-490-3p expression is associated with poor prognosis of Helicobacter pylori induced gastric cancer

OBJECTIVE

Helicobacter pylori (HP) infection has been demonstrated to be a risk factor accounting for the initiation and development of gastric cancer (GC). The aim of the present study was to investigate the clinical significance of miR-490-3p in HP associated GC.

PATIENTS AND METHODS

We measured the expression level of miR-490-3p in human GC tissues by quantitative Real-time PCR (qPCR). Then the association between miR-490-3p and clinical features of GC was further investigated.

RESULTS

Our results showed that miR-490-3p levels exhibited a progressive downregulation in gastritis, intestinal metaplasia, HP negative GC and HP positive GC. In addition, miR-490-3p expression was significantly correlated with various clinicopathological parameters such as lymph node metastasis and clinical stage in HP-positive GC. Moreover, GC patients with lower miR-490-3p had a shorter 5 years overall/disease free survival time in the HP positive cohort. Finally, multivariate analysis showed that low miR-490-3p was an independent risk factor for HP associated GC.

CONCLUSIONS

miR-490-3p is downregulated in HP-positive GC and associated with poor clinical outcome, indicating that miR-490-3p is a promising prognostic biomarker for HP positive GC.

Sensing the delivery and endocytosis of nanoparticles using magneto-photo-acoustic imaging

Many biomedical applications necessitate a targeted intracellular delivery of the nanomaterial to specific cells. Therefore, a non-invasive and reliable imaging tool is required to detect both the delivery and cellular endocytosis of the nanoparticles. Herein, we demonstrate that magneto-photo-acoustic (MPA) imaging can be used to monitor the delivery and to identify endocytosis of magnetic and optically absorbing nanoparticles. The relationship between photoacoustic (PA) and magneto-motive ultrasound (MMUS) signals from the in vitro samples were analyzed to identify the delivery and endocytosis of nanoparticles. The results indicated that during the delivery of nanoparticles to the vicinity of the cells, both PA and MMUS signals are almost linearly proportional. However, accumulation of nanoparticles within the cells leads to nonlinear MMUS-PA relationship, due to non-linear MMUS signal amplification. Therefore, through longitudinal MPA imaging, it is possible to monitor the delivery of nanoparticles and identify the endocytosis of the nanoparticles by living cells.

The critical role of membralin in postnatal motor neuron survival and disease

Hitherto, membralin has been a protein of unknown function. Here, we show that membralin mutant mice manifest a severe and early-onset motor neuron disease in an autosomal recessive manner, dying by postnatal day 5–6. Selective death of lower motor neurons, including those innervating the limbs, intercostal muscles, and diaphragm, is predominantly responsible for this fatal phenotype. Neural expression of a membralin transgene completely rescues membralin mutant mice. Mechanistically, we show that membralin interacts with Erlin2, an endoplasmic reticulum (ER) membrane protein that is located in lipid rafts and known to be important in ER-associated protein degradation (ERAD). Accordingly, the degradation rate of ERAD substrates is attenuated in cells lacking membralin. Membralin mutations or deficiency in mouse models induces ER stress, rendering neurons more vulnerable to cell death. Our study reveals a critical role of membralin in motor neuron survival and suggests a novel mechanism for early-onset motor neuron disease.

DOI:http://dx.doi.org/10.7554/eLife.06500.001

As new proteins are built inside a cell, many will pass into a structure called the endoplasmic reticulum for processing. There, the proteins are folded into the specific three-dimensional shapes that allow them to carry out their respective jobs. Sometimes the folding process goes awry, leading to a build-up of unfolded proteins that stress the endoplasmic reticulum and can kill the cell. Brain cells are particularly vulnerable to death from endoplasmic reticulum stress. To combat a deadly build-up of unfolded proteins, each cell has systems that respond when the endoplasmic reticulum is under stress.

Unchecked stress on the endoplasmic reticulum has been linked to diseases like amyotrophic lateral sclerosis (called ALS for short). In diseases like ALS, the nerve cells that control muscle movements gradually die off, causing a loss of muscle control and eventually death. Scientists suspect that these nerve cells (called motor neurons) are particularly sensitive to endoplasmic reticulum stress because they are highly active. Drugs that help counteract stress on the endoplasmic reticulum extend the lives of mice with motor neuron disease, suggesting this may be a useful strategy for treating such diseases in humans.

Now, Yang, Qu et al. identify a new protein that appears necessary for a healthy endoplasmic reticulum. Mice that lack the gene for a protein called membralin die within five or six days after birth because their motor neurons die off. Further experiments showed that re-introducing membralin in their nervous system can rescue these membralin-deficient mice.

Yang, Qu et al. found that membralin interacts with another protein that helps eliminate poorly folded or unfolded proteins in the endoplasmic reticulum, and thus relieves stress on the cell. Mutations in this endoplasmic reticulum stress response protein have previously been linked to motor neuron diseases. The motor neurons in membralin-deficient mice show signs of endoplasmic reticulum stress and are extra vulnerable to chemicals that induce protein misfolding. Together, the experiments show membralin plays an important role in mitigating stress on the endoplasmic reticulum. More studies of mice lacking membralin may help explain why the endoplasmic reticulum stress increases in motor neuron diseases and may point to possible treatments.

DOI:http://dx.doi.org/10.7554/eLife.06500.002

Use of dual-energy CT and virtual non-calcium techniques to evaluate post-traumatic bone bruises in knees in the subacute setting

OBJECTIVE

The purpose of this study was to determine the ability of dual-energy computed tomography (DECT) and virtual non-calcium (VNCa) imaging to detect magnetic resonance imaging (MRI)-demonstrated bone bruises several weeks after unilateral knee injury.

MATERIALS AND METHODS

Patients with unilateral knee injury and MRI-confirmed bone bruises who had undergone a DECT scan of both knees were retrospectively identified. Two radiologists evaluated VNCa images for bruises in four regions per knee without knowing the MRI results. The mean CT numbers were calculated for the lesion-positive and lesion-negative regions of the injured knee, and the contralateral knee.

RESULTS

Fourteen patients with a total of 36 regions positive for bone bruises on MRI were identified. The median delay between injury and DECT was 37 days (range, 11-99 days). The mean CT numbers in VNCa images for lesion-positive and lesion-negative regions were -7.6 ± 24.9 HU and -58.2 ± 19.5 HU, respectively. There were no significant differences in mean CT number between the lesion-negative regions in the injured knee and the contralateral knee. No resolution of bruising was seen before week 5, and bone bruising was still identifiable in one out of the two patients scanned at 10 weeks following injury.

CONCLUSIONS

DECT and VNCa images can identify bone bruising for at least 10 weeks after injury.

Reduction and the intracellular translocation of EphB2 in Tg2576 mice and the effects of β-amyloid

AIMS

EphB2 is a member of receptor tyrosine kinases (RTKs) family that is essential for the cell adhesion, neural crest migration, axon guidance and synaptogenesis in the nervous system. Recent studies show that preservation of EphB2 in a transgenic mouse model of Alzheimer's disease (AD) rescues the cognitive deficit, suggesting a crucial role of EphB2 in AD. However, the expression and distribution profiles of EphB2 in the early stage of AD have not been reported.

METHODS

Immunohistochemistry, immunoblot and immunofluorescence were used to analyse the level of EphB2 in Tg2576 mice at different ages and in cultured neurones with Aβ treatment at different times.

RESULTS

EphB2 was reduced in an age-dependent manner in the olfactory bulb and the hippocampus of Tg2576 mice. The decrease of EphB2 appeared earlier in the olfactory bulb than the hippocampus, and reduction of EphB2 appeared earlier than that of MAP2, a dendritic cytoskeleton marker. In the cortex, EphB2 displayed a significant translocation from the neuronal processes to the cell bodies with ageing. In primary hippocampal neuronal cultures, Aβ42 treatment also induced the decrement of EphB2 that was prior to the decline of MAP2.

CONCLUSIONS

Our findings provide the first evidence for an age- and region-dependent reduction and intracellular translocation of EphB2 in Tg2576 mice, and the foremost decrement of EphB2 in the olfactory bulb may represent an early sign of AD.

Differentiating calcium oxalate and hydroxyapatite stones in vivo using dual-energy CT and urine supersaturation and pH values

RATIONALE AND OBJECTIVES

Knowledge of urinary stone composition can guide therapeutic intervention for patients with calcium oxalate (CaOx) or hydroxyapatite (HA) stones. In this study, we determined the accuracy of noninvasive differentiation of these two stone types using dual-energy CT (DECT) and urine supersaturation (SS) and pH values.

MATERIALS AND METHODS

Patients who underwent clinically indicated DECT scanning for stone disease and subsequent surgical intervention were enrolled. Stone composition was determined using infrared spectroscopy. DECT images were processed using custom-developed software that evaluated the ratio of CT numbers between low- and high-energy images. Clinical information, including patient age, gender, and urine pH and supersaturation profile, was obtained from electronic medical records. Simple and multiple logistic regressions were used to determine if the ratio of CT numbers could discriminate CaOx from HA stones alone or in conjunction with urine supersaturation and pH.

RESULTS

Urinary stones (CaOx n = 43, HA n = 18) from 61 patients were included in this study. In a univariate model, DECT data, urine SS-HA, and urine pH had an area under the receiver operating characteristic curve of 0.78 (95% confidence interval [CI] 0.66-0.91, P = .016), 0.76 (95% CI 0.61-0.91, P = .003), and 0.60 (95% CI 0.44-0.75, P = .20), respectively, for predicting stone composition. The combination of CT data and the urinary SS-HA had an area under the receiver operating characteristic curve of 0.79 (95% CI 0.66-0.92, P = .007) for correctly differentiating these two stone types.

CONCLUSIONS

DECT differentiated between CaOx and HA stones similarly to SS-HA, whereas pH was a poor discriminator. The combination of DECT and urine SS or pH data did not improve this performance.

Dynamic CT technique for assessment of wrist joint instabilities

PURPOSE

To develop a 4D [three-dimensional (3D) + time] CT technique to capture high spatial and temporal resolution images of wrist joint motion so that dynamic joint instabilities can be detected before the development of static joint instability and onset of osteoarthritis (OA).

METHODS

A cadaveric wrist was mounted onto a custom motion simulator and scanned with a dual source CT scanner during radial-ulnar deviation. A dynamic 4D CT technique was utilized to reconstruct images at 20 equidistant time points from one motion cycle. 3D images of carpal bones were generated using volume rendering techniques (VRT) at each of the 20 time points and then 4D movies were generated to depict the dynamic joint motion. The same cadaveric wrist was also scanned after cutting all portions of the scapholunate interosseus ligament to simulate scapholunate joint instability. Image quality were assessed on an ordinal scale (1-4, 4 being excellent) by three experienced orthopedic surgeons (specialized in hand surgery) by scoring 2D axial images. Dynamic instability was evaluated by the same surgeons by comparing the two 4D movies of joint motion. Finally, dose reduction was investigated using the cadaveric wrist by scanning at different dose levels to determine the lowest radiation dose that did not substantially alter diagnostic image quality.

RESULTS

The mean image quality scores for dynamic and static CT images were 3.7 and 4.0, respectively. The carpal bones, distal radius and ulna, and joint spaces were clearly delineated in the 3D VRT images, without motion blurring or banding artifacts, at all time points during the motion cycle. Appropriate viewing angles could be interactively selected to view any articulating structure using different 3D processing techniques. The motion of each carpal bone and the relative motion among the carpal bones were easily observed in the 4D movies. Joint instability was correctly and easily detected in the scan performed after the ligament was cut by observing the relative motion between the scaphoid and lunate bones. Diagnostic capability was not sacrificed with a volume CT dose index (CTDI(vol)) as low as 18 mGy for the whole scan, with estimated skin dose of approximately 33 mGy, which is much lower than the threshold for transient skin erythema (2000 mGy).

CONCLUSIONS

The proposed dynamic 4D CT imaging technique generated high spatial and high temporal resolution images without requiring periodic joint motion. Preliminary results from this cadaveric study demonstrate the feasibility of detecting joint instability using this technique.

Urinary stone differentiation in patients with large body size using dual-energy dual-source computed tomography

OBJECTIVE

To evaluate the ability of 100/Sn140 kV (Sn, tin filter) dual-energy computed tomography (CT) to differentiate urinary stone types in a patient cohort with a wide range of body sizes.

METHODS

Eighty human urinary stones were categorised into four groups (uric acid; cystine; struvite, oxalate and brushite together; and apatite) and imaged in 30-50-cm-wide water tanks using clinical 100/Sn140 kV protocols. The CT number ratio (CTR) between the low- and high-energy images was calculated. Thresholds for differentiating between stone groups were determined using receiver operating characteristics (ROC) analysis. Additionally, 86 stones from 66 patients were characterised using the size-adaptive CTR thresholds determined in the phantom study.

RESULTS

In phantoms, the area under the ROC curve for differentiating between stone groups ranged from 0.71 to 1.00, depending on phantom size. In patients, body width ranged from 28.5 to 50.0 cm, and 79.1 % of stones were correctly characterised. Sensitivity and specificity for correctly identifying the stone category were 100 % and 100 % (group 1), 100 % and 95.3 % (group 2), 85.7 % and 60.9 % (group 3), and 52.6 % and 92.5 % (group 4).

CONCLUSION

Dual-energy CT can provide in vivo urinary stone characterisation for patients over a wide range of body sizes.

KEY POINTS

• Dual-energy CT helps assessment of urinary stone composition in vivo. • 100/Sn140 kV DECT differentiates among four stone types with 79.1 % accuracy. • In vivo diagnostic test achievable in patients with many body sizes.

Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

OBJECTIVE

To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium.

METHODS

Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium.

RESULTS

The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml.

CONCLUSION

The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms.

KEY POINTS

Computed tomography is widely used to assess renal tract calculi. Dual-energy CT can assess stone composition and provide virtual unenhanced images. However, iodinated contrast medium affects the volume estimation for urinary stones. CTR of stones is altered by the surrounding iodine in CT urograms. The region-growing method improves the identification of uric acid stones.

Physiological significance of alternatively spliced exon combinations of the single-copy gene class A chitin synthase in the insect Ostrinia furnacalis (Lepidoptera)

Insect chitin synthase is an essential enzyme involved in chitin biosynthesis in insects. Chitin synthase A (CHSA) is expressed in different insect tissues during different developmental stages. CHSA contains alternative-splicing exons that allow tissue- and development-specific chitin synthesis. Here, we report that OfCHSA from the lepidopteran Ostrinia furnacalis contains two alternative-splicing exons, exons 2a and 2b and exons 19a and 19b. Although four combinations of these exons are theoretically possible, we found that transcripts containing exon 2a were dominant during most developmental stages, including embryonic development, larval-larval moulting, the larval-pupal transition and pupal-adult metamorphosis. Unexpectedly, 2b-containing transcripts were much more responsive to 20-hydroxyecdysone regulation than 2a-containing ones, suggesting that although OfCHSA isoforms encoded by 2b-containing transcripts are normally expressed at very low levels, they play unique roles. Spliced exons 2a and 2b have also been observed in Bombyx mori; therefore, this work provides new insights into the regulation of insect chitin synthase, particularly in lepidopteran insects.

Kidney stone volume estimation from computerized tomography images using a model based method of correcting for the point spread function

PURPOSE

We propose a method to improve the accuracy of volume estimation of kidney stones from computerized tomography images.

MATERIALS AND METHODS

The proposed method consisted of 2 steps. A threshold equal to the average of the computerized tomography number of the object and the background was first applied to determine full width at half maximum volume. Correction factors were then applied, which were precalculated based on a model of a sphere and a 3-dimensional gaussian point spread function. The point spread function was measured in a computerized tomography scanner to represent the response of the scanner to a point-like object. Method accuracy was validated using 6 small cylindrical phantoms with 2 volumes of 21.87 and 99.9 mm(3), and 3 attenuations, respectively, and 76 kidney stones with a volume range of 6.3 to 317.4 mm(3). Volumes estimated by the proposed method were compared with full width at half maximum volumes.

RESULTS

The proposed method was significantly more accurate than full width at half maximum volume (p <0.0001). The magnitude of improvement depended on stone volume with smaller stones benefiting more from the method. For kidney stones 10 to 20 mm(3) in volume the average improvement in accuracy was the greatest at 19.6%.

CONCLUSIONS

The proposed method achieved significantly improved accuracy compared with threshold methods. This may lead to more accurate stone management.

Synthesis of axially chiral oxazoline-carbene ligands with an N-naphthyl framework and a study of their coordination with AuCl·SMe(2)

Axially chiral oxazoline–carbene ligands with an N-naphthyl framework were successfully prepared, and their coordination behavior with AuCl·SMe₂ was also investigated, affording the corresponding Au(I) complexes in moderate to high yields.

PROX1 is a predictor of survival for gliomas WHO grade II

Background:

The clinical course of World Health Organisation grade II gliomas remains variable and their time point of transformation into a more malignant phenotype is unpredictable. Identification of biological markers that can predict prognosis in individual patients is of great clinical value. PROX1 is a transcription factor that has a critical role in the development of various organs. PROX1 has been ascribed both oncogenic and tumour suppressive functions in human cancers. We have recently shown that PROX1 may act as a diagnostic marker for high-grade gliomas. The aim of this study was to address the prognostic value of PROX1 in grade II gliomas.

Methods:

A total of 116 samples were evaluated for the presence of PROX1 protein. The number of immunopositive cells was used as a variable in survival analysis, together with established prognostic factors for this patient group.

Results:

Higher PROX1 protein was associated with poor outcome. In the multivariate analysis, PROX1 was identified as an independent factor for survival (P=0.024), together with the presence of mutated isocitrate dehydrogenase 1 R132H protein, and with combined losses of chromosomal arms 1p/19q in oligodendrocytic tumours.

Conclusion:

PROX1 is a novel predictor of survival for grade II gliomas.

Enhanced pulsed magneto-motive ultrasound imaging using superparamagnetic nanoclusters

Recently, pulsed magneto-motive ultrasound (pMMUS) imaging augmented with ultra-small magnetic nanoparticles has been introduced as a tool capable of imaging events at molecular and cellular levels. The sensitivity of a pMMUS system depends on several parameters, including the size, geometry and magnetic properties of the nanoparticles. Under the same magnetic field, larger magnetic nanostructures experience a stronger magnetic force and produce larger displacement, thus improving the sensitivity and signal-to-noise ratio (SNR) of pMMUS imaging. Unfortunately, large magnetic iron-oxide nanoparticles are typically ferromagnetic and thus are very difficult to stabilize against colloidal aggregation. In the current study we demonstrate improvement of pMMUS image quality by using large size superparamagnetic nanoclusters characterized by strong magnetization per particle. Water-soluble magnetic nanoclusters of two sizes (15 and 55 nm average size) were synthesized from 3 nm iron precursors in the presence of citrate capping ligand. The size distribution of synthesized nanoclusters and individual nanoparticles was characterized using dynamic light scattering (DLS) analysis and transmission electron microscopy (TEM). Tissue mimicking phantoms containing single nanoparticles and two sizes of nanoclusters were imaged using a custom-built pMMUS imaging system. While the magnetic properties of citrate-coated nanoclusters are identical to those of superparamagnetic nanoparticles, the magneto-motive signal detected from nanoclusters is larger, i.e. the same magnetic field produced larger magnetically induced displacement. Therefore, our study demonstrates that clusters of superparamagnetic nanoparticles result in pMMUS images with higher contrast and SNR.

Imaging evaluation and treatment of nephrolithiasis: an update

Advances in radiology have led to improvements in care for patients with urinary tract stones. One of the most promising imaging techniques is dual-energy CT, which enables more accurate characterization of stone disease than other imaging techniques and helps direct therapy at the time of the initial imaging evaluation. Improvements in percutaneous therapy have led to less-invasive and less-costly treatments for nephrolithiasis. This article describes some of these new approaches to diagnosing and caring for patients with renal stone disease.

Molecular genetic and epigenetic analysis of NCX2/SLC8A2 at 19q13.3 in human gliomas

AIM

Loss of heterozygosity at 19q13.3 is a common genetic change in human gliomas, indicating yet unknown glial-specific tumour suppressor genes in this chromosome region. NCX2/SLC8A2 located on chromosome 19q13.32 encodes a Na(+)/Ca(2+) exchanger, which contributes to intracellular Ca(2+) homeostasis. Its expression is restricted to brain, and it is present neither in other normal tissues nor in gliomas at any significant level. The aim of this study was to investigate if NCX2 might be a tumour suppressor gene involved in glioma.

METHODS

We performed a systematic analysis of NCX2 in 42 human gliomas using microsatellite analysis for evaluation of loss of heterozygosity at 19q, DNA sequencing and DNA methylation analysis.

RESULTS

Except for three known intragenic single nucleotide polymorphisms, rs12459087, rs7259674 and rs8104926, no NCX2 sequence variations were detected in any of the tumour samples. Furthermore, a CpG island in the 5' promoter region of NCX2 was unmethylated. Interestingly, the CpG sites of three gene-body CpG islands located in exon 2, intron 2-3 and exon 3 and of a 5' CpG-rich area relevant to so-called CpG island shore of NCX2 were methylated in all eight glioma samples and in three established glioma cell lines tested. Surprisingly, NCX2 could be activated by addition of the DNA methylation inhibitor 5-aza-2'-deoxycytidine to glioma cell lines in which NCX2 was completely silent.

CONCLUSION

Results indicate that DNA methylation may play a key role in the transcriptional silencing of NCX2.

Radiation dose reduction in computed tomography: techniques and future perspective

Despite universal consensus that computed tomography (CT) overwhelmingly benefits patients when used for appropriate indications, concerns have been raised regarding the potential risk of cancer induction from CT due to the exponentially increased use of CT in medicine. Keeping radiation dose as low as reasonably achievable, consistent with the diagnostic task, remains the most important strategy for decreasing this potential risk. This article summarizes the general technical strategies that are commonly used for radiation dose management in CT. Dose-management strategies for pediatric CT, cardiac CT, dual-energy CT, CT perfusion and interventional CT are specifically discussed, and future perspectives on CT dose reduction are presented.

Cartilage-like phenomenon in the anterior cruciate ligamenta

OBJECTIVE

To detect histological characteristic of anterior cruciate ligament (ACL) and medial collateral ligament (MCL).

METHODS

In each of 20 skeletally mature male mongrels and 4 men, the ACL and MCL were examined by standard hematoxylin-eosin procedure and toluidine blue staining for histologic observation.

RESULTS

The fibroblasts in medial collateral are elongated to spindle shape and aligned in a row between the bundles of collagenous fibers. Toluidine blue staining is negative. The anterior cruciate ligament demonstrated more heterogenous cell types and arrangement. It had three major cell forms: spindle, round and ovoid type, which were shorter but greater than the cells in medial collateral ligament. Toluidine blue staining was positive in anterior cruciate ligament. Most cells in anterior cruciate ligament were enclosed within lacunae.

CONCLUSION

This study suggests that the ACL has different histological characteristics from MCL, and is more cartilage-like in nature.

Expression of collagen type I, II and III in loose body of osteoarthritis

The expression of collagen type I, II, and III was investigated to evaluate phenotypic change in chondrocytes in loose bodies related to osteoarthritis. We assessed collagen type I, II, and III production in loose bodies from knee joints of ten osteoarthritic patients, using an immunohistochemical method with monoclonal antibodies. Collagen type III expression was identified in all ten loose bodies and was mainly located in cartilage, including chondrocytes and matrices, as well as in a layer of fibroid tissue on the surface. No positive signal for collagen type III was observed in necrotic osteocytes. There was weakly positive staining for collagen type I in chondrocytes. No positive staining for collagen type II could be seen in the cartilage of loose bodies. Cartilage from the non-osteoarthritic knee joints of four people was negative for the expression of collagen type I and III, and positive for the expression of collagen type II. Collagen type I and III expression suggested the dedifferentiation status of chondrocytes in loose bodies.