Measurement of diffusion in articular cartilage using fluorescence correlation spectroscopy

BACKGROUND

Fluorescence correlation spectroscopy (FCS) provides information about translational diffusion of fluorescent molecules in tiny detection volumes at the single-molecule level. In normal states, cartilage tissue lacks vascularity, so chondrocyte metabolism depends on diffusion for molecular exchanges. The abundant extracellular matrix (ECM) of cartilage is maintained by a limited number of chondrocytes. ECM plays an important role in the regulation of chondrocyte functions. In this study, FCS was used to measure diffusion behaviors of albumin, the major protein of the intra-articular space, using normal and degenerated cartilage. Preliminary investigation of fluorescence dyes including Alexa 488, Rhodamine 6G and Rhodamine 123 was conducted to evaluate their properties in cartilage.

RESULTS

The results indicate that the diffusion behaviors of fluorescently labeled albumin can be observed using FCS in both normal and chemically degenerated cartilage.

CONCLUSIONS

This work demonstrates the capability of FCS for direct measurement of diffusion in cartilaginous ECM. When the diffusion characteristics of fluorescent probes in ECM are clarified using FCS evaluation, FCS will be applicable as a method for early diagnosis of osteoarthritis, which is accompanied by increased abnormalities of ECM and also as tool for evaluating bio-engineered artificial cartilage for autologous chondrocyte implantation.

Detection and characterization of enterovirus associated with herpangina and hand, foot, and mouth disease in Seoul, Korea

BACKGROUND

Human enteroviruses (HEVs) are a major cause of herpangina, HFMD (hand, foot, and mouth disease), and other neurological diseases in Seoul, Korea.

METHODS

A total of 56 specimens from hospitalized patients collected from February to December 2009 (37 females and 19 males) in Seoul were tested for HEV from stool, throat swab, and vesicle swab samples taken from patients with herpangina or HFMD using cell culture and RT-PCR in 2009. By the 1D gene, encoding the VP1 capsid protein, seven different HEV genotypes were detected with Coxsackievirus A2, A4, A5, A9, A16 (CA), Coxsackievirus B1 (CB), and Enterovirus 71 (EV71). The most prevalent genotype was CA16 (6, 10.7%), followed by CA2 (4, 7.1%), CA5 (4, 7.1%), EV71 (2, 3.6%), CA4 (1, 1.8%), CA9 (1, 1.8%), and CB1 (1, 1.8%). The 1D gene sequences of two EV71 strains were closely related with one another (98.5% nucleotide similarity) and belonged to the C4 genotype.

CONCLUSIONS

It is important to continuously survey the genetic characteristics of EV71 and CA16 from patients, which will provide useful data that aids in our understanding of HFMD infections in Seoul, Korea and may contribute to future control.

Effects of joint effusion on proprioception in patients with knee osteoarthritis: a single-blind, randomized controlled clinical trial

OBJECTIVE

To assess the effects of joint effusion on proprioceptive status in patients with knee osteoarthritis (OA).

DESIGN

A single-blind, randomized, controlled clinical trial in 40 female subjects aged 50 years and over with painful knee OA. All subjects were randomly assigned to either the control or experimental group. A volume of 20 mL of normal saline was injected into the knee joint cavity of subjects in the experimental group under ultrasonographic guidance. Proprioceptive acuity was assessed by active repositioning of the lower limb using an electrogoniometer to measure knee joint position sense (JPS) under both non-weight-bearing (NWB) and weight-bearing (WB) conditions twice, with a 20-min rest interval. The experimental group performed the task twice (Test 1 and Test 2) before and within 5 min after joint infusion. The control group also performed Test 1 and Test 2 without joint infusion. The outcome of interest was the absolute angular error (AAE), ignoring the direction of the error, between the randomized target angle and the patient's reproduced angle of JPS values.

RESULTS

Compared with the control group, JPS was significantly compromised in the experimental group in the NWB test after joint infusion (P=0.025). However, no significant differences in the angular error were observed between Test 1 and Test 2 in the control group for the NWB or WB test or in the experimental group for the WB test after infusion (P>0.05).

CONCLUSIONS

This study showed that joint effusion impairs proprioceptive function in osteoarthritic knee joints.

Viral agents associated with acute gastroenteritis in Seoul, Korea

BACKGROUND

The present study was carried out to describe the epidemiologic characteristics of viral gastroenteritis and determine the phylogenetic composition of norovirus strains detected in hospitalized children with acute gastroenteritis in Seoul, Korea.

METHODS AND RESULTS

In total, 10,603 stool samples were collected from 2004 to 2008 and tested by RT-PCR or ELISA. In 4,170 (39.3%) samples at least one viral pathogen was present. Rotavirus (RoV) (1,864, 17.5%) was found to be the causative agent followed by norovirus (NoV) (1,845, 17.4%), human adenovirus (HAdV) (266, 2.5%), human astrovirus (HAstV) (194, 1.8%), and sapovirus (SV) (1, 0.009%). Five GI genotypes (GI-1, GI-3, GI-4, GI-8, and GI-9) and eight GII genotypes (GII-2, GII-3, GII-4, GII-6, GII-7, GII-12, GII-16, and GII-17) of NoV were identified in acute gastroenteritis patients in 2008.

CONCLUSIONS

The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen from acute gastroenteritis patients may give potentially effective data for epidemiological studies in Seoul, Korea.

Abstract P6-13-05: Differences of Clinical Manifestations and Therapeutic Outcomes in Leptomeningeal Metastases (LM) According to Breast Cancer Subtypes

Backgrounds: Breast cancer is the solid tumor most commonly associated with leptomeningeal metastases (LM). Therapeutic modalities include intrathecal and systemic chemotherapy, radiotherapy and other palliative modality including placement of a ventricular reservoir. The aim of this study is to characterize clinical feature and outcomes of LM according to breast cancer subtypes in conjunction with whole CNS metastases.

Methods: A retrospective study was performed on breast cancer patients with LM who received palliative management at Samsung Medical Center between 1994 and 2008. Among 281 metastatic breast cancer patients, 71 breast cancer patients with LM were identified. They were divided into three biological subgroups. The propensity of biological subtypes for LM, clinical manifestation including recursive partitioning analysis of Radiation Therapy Oncology Group (RPA RTOG) prognostic class, and therapeutic outcomes were assessed.

Results: The median age was 48 (range 26-70) years. The rates of the patients with triple negative breast cancer (TNBC), human epidermal growth factor receptors 2 (HER2)-positive and hormone receptor (HR)- positive subtype breast cancer were 26 (44%), 15 (25%) and 18 (31%), respectively. Sixty-four patients (90%) had metastatic disease at sites other than LM. TNBC were more common in RPA RTOG prognostic class III than those in HER2 and HR-positive subtypes (61% vs 39% vs 0%, P<0.0001). CNS including LM was the first site of distant metastasis in 65% of the TNBC patients. Treatment includes intrathecal chemotherapy (IT), whole brain radiotherapy (WBRT), and systemic chemotherapy. The median survival duration from the diagnosis of LM to death (OS-LM) was 4.5 months (range 0.2-26.4 months). Main causes of death were deterioration of neurologic sequelae associated with LM (55%), systemic disease progression (27%), and et cetera (18%). Death rates related with LM at each subtype were 64% for TNBC, 36% for HER2-positive, and 0% for HR-positive patients (p=0.060). In the univariate analysis, RPA RTOG classification (p=0.003), systemic disease control at LM (p=0.041), cytologic negative conversion to IT (p=0.001), systemic chemotherapy after LM diagnosis (p=0.002), and combined modality for LM treatment (p=0.005) were singled out as having prognostic value for OS-LM. Cox-regression multivariate analysis showed that RPA class (HR (Hazard Ratio) 1.8, p=0.022), cytologic negative conversion to IT (HR 0.4, p=0.043), and systemic chemotherapy (HR 0.24, p=0.004) are identified as independent prognostic factors.

Conclusion: TNBC and HER2-positive breast cancer appeared to have special predilection for LM as well as brain parenchymal metastases. High RPA class of TNBC may reflect more aggressive tumor biology in this sanctuary area. OS-LM depended on RPA class, cytologic negative conversion, and the use of systemic chemotherapy. The role of systemic chemotherapy and active local treatment modalities according to subtypes should be defined to improve dismal prognosis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-13-05.

Identification and analysis of QTLs controlling cold tolerance at the reproductive stage and validation of effective QTLs in cold-tolerant genotypes of rice (Oryza sativa L.)

Low temperature or cold stress is one of the major constraints of rice production and productivity in temperate rice-growing countries and high-altitude areas in the tropics. Even though low temperature affects the rice plant in all stages of growth, the percent seed set is damaged severely by cold and this reduces the yield potential of cultivars significantly. In this study, a new source of cold-tolerant line, IR66160-121-4-4-2, was used as a donor parent with a cold-sensitive cultivar, Geumobyeo, to produce 153 F(8) recombinant inbred lines (RILs) for quantitative trait locus (QTL) analysis. QTL analysis with 175 polymorphic simple sequence repeat (SSR) markers and composite interval mapping identified three main-effect QTLs (qPSST-3, qPSST-7, and qPSST-9) on chromosomes 3, 7, and 9. The SSR markers RM569, RM1377, and RM24545 were linked to the identified QTLs for cold tolerance with respect to percent seed set using cold-water (18-19 degrees C) irrigation in the field and controlled air temperature (17 degrees C) in the greenhouse. The total phenotypic variation for cold tolerance contributed by the three QTLs was 27.4%. RILs with high percent seed set under cold stress were validated with linked DNA markers and by haplotype analysis that revealed the contribution of progenitor genomes from the tropical japonica cultivar Jimbrug (Javanica) and temperate japonica cultivar Shen-Nung89-366. Three QTLs contributed by the cold-tolerant parent were identified which showed additive effect on percent seed set under cold treatment. This study demonstrated the utility of a new phenotyping method as well as the identification of SSR markers associated with QTLs for selection of cold-tolerant genotypes to improve temperate rice production.

Dominance specific visual extinction associated with callosal disconnection

Callosal disconnection signs are closely related to asymmetric hemispheric specialization of cognitive functions. Although extinction is more commonly associated with the right parietotemporal lesion, it may occur following lesions of the corpus callosum. After an infarction involving the left splenium, a 58-year-old right-handed man had no disconnection symptoms that had been reported earlier, but showed visual extinction with left or right visual hemifield dominant stimuli. Our results suggest that dominance specific visual extinction might be another disconnection sign associated with splenial lesion.

Bacterial adhesion, cell adhesion and biocompatibility of Nafion films

We investigated bioadhesion (bacterial and cell adhesion) and biocompatibility of poly(tetrafluoroethylene-co-perfluoro-3,6-dioxa-4-methyl-7-octenesulfonic acid) (Nafion) and compared the results with those obtained with poly(vinylidene fluoride-co-hexafluoropropylene) (PVFHFP). When incubated with bacteria for 4 h to 7 days, Nafion film exhibited scarce bacterial adhesion at 6 h, after which the adhesion gradually increasing to relatively low levels. In contrast, significant bacterial adhesion to PVFHFP film was observed at 4 h, and much higher adhesion levels were shown thereafter. Although HEp-2 human cells adhered normally to both films, reaching confluence in 7-8 days, the cells adhered to Nafion appeared more lively and stable than those to PVFHFP. Subcutaneous implantation in mice revealed that Nafion elicited a mild acute inflammatory reaction without chronic inflammation or tissue necrosis, indicating excellent biocompatibility in mice. PVFHFP, however, provoked a moderate and prolonged acute inflammatory response. These differences in the biological characteristics of Nafion and PVFHFP films may be attributable to the differences in the chemical and physical natures of these polymer films. Nafion film provided a sufficiently solid support, expressing a high surface charge density and good water-wettability. In summary, Nafion is suitable for use in biomedical applications that require biocompatibility with a reduced possibility of post-operative infections.

Celecoxib induces hepatic stellate cell apoptosis through inhibition of Akt activation and suppresses hepatic fibrosis in rats

BACKGROUND AND AIMS

Activated hepatic stellate cells (HSCs) but not quiescent HSCs express cyclo-oxygenase-2 (COX-2), suggesting that the COX-2/prostanoid pathway has an active role in hepatic fibrogenesis. However, the role of COX-2 inhibitors in hepatic fibrogenesis remains controversial. The aim of this study was to investigate the antifibrotic effects of celecoxib, a selective COX-2 inhibitor.

METHODS

The effects of various COX inhibitors-that is, ibuprofen, celecoxib, NS-398 and DFU, were investigated in activated human HSCs. Then, the antifibrotic effect of celecoxib was evaluated in hepatic fibrosis developed by bile duct ligation (BDL) or peritoneal thioacetamide (TAA) injection in rats.

RESULTS

Celecoxib, NS-398 and DFU inhibited platelet-derived growth facor (PDGF)-induced HSC proliferation; however, only celecoxib (> or =50 microM) induced HSC apoptosis. All COX inhibitors completely inhibited prostaglandin E(2) (PGE(2)) and PGI(2) production in HSCs. Separately, PGE(2) and PGI(2) induced cell proliferation and extracellular signal-regulated kinase (ERK) activation in HSCs. All COX inhibitors attenuated ERK activation, but only celecoxib significantly inhibited Akt activation in HSCs. Celecoxib-induced apoptosis was significantly attenuated in HSCs infected with adenovirus containing a constitutive active form of Akt (Ad5myrAkt). Celecoxib had no significant effect on PPARgamma (peroxisome proliferator-activated receptor gamma) expression in HSCs. Celecoxib inhibited type I collagen mRNA and protein production in HSCs. Oral administration of celecoxib (20 mg/kg/day) significantly decreased hepatic collagen deposition and alpha-SMA (alpha-smooth muscle actin) expression in BDL- and TAA-treated rats. Celecoxib treatment significantly decreased mRNA expression of COX-2, alpha-SMA, transforming growth factor beta1 (TGFbeta1) and collagen alpha1(I) in both models.

CONCLUSIONS

Celecoxib shows a proapoptotic effect on HSCs through Akt inactivation and shows antifibrogenic effects in BDL- and TAA-treated rats, suggesting celecoxib as a novel antifibrotic agent of hepatic fibrosis.

A Newly Developed Immunoisolated Bioartificial Pancreas with Cell Sheet Engineering

The term “immunoisolation” refers to the encapsulation of a graft in a selectively permeable membrane. Encapsulation of cellular grafts may provide a way to protect the graft from immune attack without the need for immunosuppressive agents. Although numerous types of artificial materials have been used for encapsulating membranes, their incomplete biocompatibility causes foreign body reaction against the membranes. A new technique has been developed, called cell sheet engineering using temperature-responsive culture dishes, that allows the use of living cells as an immunoisolating membrane in this study. Using this method, the cultured cells can be easily harvested in the shape of a sheet by a simple change of the temperature without the use of proteolytic enzymes. A cell sheet can be created with three-dimensional structure by making multiple cell sheet layers. In this study, a new technique of macroencapsulation (bioartificial organs) has been developed using chondrocyte sheets. Among the various candidate cells, pancreatic islet cells were selected for a bioartificial organ in this study. A chondrocyte sheeting immunodelusive immunoisolated bioartificial pancreas (CSI-BAP) was manufactured by means of cell sheet engineering. An auricular cartilage, which is a histologically elastic cartilage from dogs (beagle), was used as a source of immunoisolating membrane. CSI-BAP was made by multilayering the chondrocyte sheets, and the donor's islets were located between each sheet. Islets were isolated and prepared from the dog (ALLO-model) and Brown Norway (BN) rat (XENO-model). The CSI-BAP was cultured for 83 days and the cultured medium was collected every 24 h to measure the insulin concentrations. The CSI-BAP was examined histologically using hematoxyhin and eosin (H&E), and azan dye staining. In addition, immunohistochemical staining was performed to demonstrate the insulin production of CSI-BAP. Insulin secretion of CSI-BAP on day 16 was reduced to 21.4% of the insulin secretion level of day 10, which was the start point of measurement. Although a gradual reduction was observed, insulin secretion was maintained for 3 months. The CSI-BAP was capable of secreting insulin to the culture medium during the observation period. Histological evaluations demonstrated the good viability of the islets, and immunohistochemistry showed the positive staining of insulin. This novel technology may be used for other kinds of endocrine cells or hepatocytes, which may become the models for immunoisolated bioartificial organs in the near future.

Expression and serological application of a capsid protein of an iridovirus isolated from rock bream, Oplegnathus fasciatus (Temminck & Schlegel)

Iridoviruses infect a wide variety of wild and cultured fish. Those iridoviruses belonging to the genus Ranavirus, in the Iridoviridae family, cause systemic disease in infected animals with a high morbidity and mortality. This paper reports the cloning, sequencing, and expression of the rock bream iridovirus (RBIV) major capsid protein (MCP) in an Escherichia coli expression system for subsequent immunological studies. The completeness of the expressed protein was confirmed by peptide mass fingerprinting (PMF) analysis using MALDI-TOF MS. The recombinant MCP (rMCP)-specific mouse polyclonal antibody reacted with the viral 52 kDa protein, indicating that this rMCP induces an immunological response. Fish antibodies induced against iridovirus infection were also detected using ELISA when rMCP was used as an antigen. As a result, it was found that many cultured rock bream (92.5%) were naturally infected with iridovirus and that the rMCP might be useful for serological tests.

Limits on interactions between weakly interacting massive particles and nucleons obtained with CsI(Tl) crystal detectors

The Korea Invisible Mass Search (KIMS) experiment presents new limits on the weakly interacting massive particle (WIMP)-nucleon cross section using data from an exposure of 3409 kg.d taken with low-background CsI(Tl) crystals at the Yangyang Underground Laboratory. The most stringent limit on the spin-dependent interaction for a pure proton case is obtained. The DAMA signal region for both spin-independent and spin-dependent interactions for the WIMP masses greater than 20 GeV/c2 is excluded by the single experiment with crystal scintillators.

A biocompatibility study of a reinforced acrylic-based hybrid denture composite resin with polyhedraloligosilsesquioxane

Acrylic-based denture materials have several common weak points, such as shrinkage after curing, lack of strength and toxicity. In order to solve these problems, we adapted a hybrid system using acrylic polymer and polyhedraloligosilsesquioxane (POSS). The aim of the study was to investigate the biocompatibility of a reinforced acrylic-based hybrid denture composite resin with POSS. Specimens of a novel polymeric denture base resin, in which POSS was used to partially replace the commonly used base monomer, were fabricated. In order to examine changes in biocompatibility with time, fresh specimens, along with specimens soaked in distilled water for 24 and 72 h were fabricated. Three other types of acrylic denture base resins were used to prepare the resin specimens. Biocompatibility (as measured by a metabolic assay, an agar overlay test, and a mutagenesis assay) of the composites was tested. The metabolic and mutagenesis assays were conducted with pure culture medium as a control. In this study, the reinforced acrylic-based hybrid denture composite resin with POSS showed improved biocompatibility and lower mutagenicity than the control. Statistical examinations showed the cell metabolic activity of the novel polymeric denture base resin in the 72-h immersion case as having almost the same inclination as the control. We hope that these results might aid in the development of a reinforced acrylic-based denture resin.

Internal Pallidal Neuronal Activity During Mild Drug-Related Dyskinesias in Parkinson's Disease: Decreased Firing Rates and Altered Firing Patterns

The neuronal basis of hyperkinetic movement disorders has long been unclear. We now test the hypothesis that changes in the firing pattern of neurons in the globus pallidus internus (GPi) are related to dyskinesias induced by low doses of apomorphine in patients with advanced Parkinson's disease (PD). During pallidotomy for advanced PD, the activity of single neurons was studied both before and after administration of apomorphine at doses just adequate to induce dyskinesias (21 neurons, 17 patients). After the apomorphine injection, these spike trains demonstrated an initial fall in firing from baseline. In nine neurons, the onset of on was simultaneous with that of dyskinesias. In these spike trains, the initial fall in firing rate preceded and was larger than the fall at the onset of on with dyskinesias. Among the three neurons in which the onset of on occurred before that of dyskinesias, the firing rate did not change at the time of onset of dyskinesias. After injection of apomorphine, dyskinesias during on with dyskinesias often fluctuated between transient periods with dyskinesias and those without. Average firing rates were not different between these two types of transient periods. Transient periods with dyskinesias were characterized by interspike interval (ISI) independence, stationary spike trains, and higher variability of ISIs. A small but significant group of neurons demonstrated recurring ISI patterns during transient periods of on with dyskinesias. These results suggest that mild dyskinesias resulting from low doses of apomorphine are related to both low GPi neuronal firing rates and altered firing patterns.