BACKGROUNDRecent studies showed that bone marrow-derived mesenchymal stem cells (BMSCs) had risk of ectopic bone formation. In this study, we aimed to investigate the effect of growth and differentiation factor 6 (GDF-6) on the tenogenic differentiation of BMSCs in vitro, and then combined with small intestine submucous (SIS) to promote tendon regeneration in vivo.

METHODSThe BMSCs were isolated from the green fluorescent protein (GFP) rats, and were characterized by multi-differentiation assays following our previous study protocol. BMSCs cultured with different concentrations of GDF-6, without growth factors served as control. After 2 weeks, mRNA expression and protein expression of tendon specific markers were examined by qRT-PCR and Western blotting to define an optimal concentration of GDF-6. Mann-Whitney U-test was used to compare the difference in relative mRNA expression among all groups; P ≤ 0.05 was regarded as statistically significant. The GDF-6 treated BMSCs combined with SIS were implanted in nude mice and SD rat acute patellar tendon injury model, the BMSCs combined with SIS served as control. After 12 and 4 weeks in nude mice and tendon injury model, the samples were collected for histology.

RESULTSAfter the BMSCs were treated with different concentration of GDF-6 for 2 weeks, the fold changes of the specific markers (Tenomodulin and Scleraxis) mRNA expression were significantly higher in GDF-6 (20 ng/ml) group (P ≤ 0.05), which was also confirmed by Western blotting result. The BMSCs became parallel in orientation after GDF-6 (20 ng/ml) treatment, but the BMSCs in control group were randomly oriented. The GDF-6 (20 ng/ml) treated BMSCs were combined with SIS, and were implanted in nude mice for 12 weeks, the histology showed neo-tendon formation. In the SD rat patellar tendon window injury model, the histology also indicated the GDF-6 (20 ng/ml) treated BMSCs combined with SIS could promote tendon regeneration.

CONCLUSIONSGDF-6 has tenogenic effect on the tenogenic differentiation of BMSCs, and GDF-6 (20 ng/ml) has better tenogenic effect compared to other concentrations. The GDF-6 (20 ng/ml) treated BMSCs combined with SIS can form neo-tendons and promote tendon regeneration.

Animals ; Cell Differentiation ; drug effects ; Growth Differentiation Factor 6 ; pharmacology ; Male ; Membrane Proteins ; genetics ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Mice ; Mice, Nude ; Rats ; Rats, Sprague-Dawley ; Regeneration ; drug effects ; Tendons ; drug effects ; physiology

OBJECTIVE: Several modalities are available for volumetric measurement of the intracranial aneurysm. We discuss the challenges involved in manual segmentation, and analyze the application of alternative methods using automatic segmentation and geometric formulae in measurement of aneurysm volumes and coil packing density. METHODS: The volumes and morphology of 38 aneurysms treated with endovascular coiling at a single center were measured using three-dimensional rotational angiography (3DRA) reconstruction software using automatic segmentation. Aneurysm volumes were also calculated from their height, width, depth, size of neck, and assumed shape in 3DRA images using simple geometric formulae. The aneurysm volumes were dichotomized as "small" or "large" using the median volume of the studied population (54 mm3) measured by automatic segmentation as the cut-off value for further statistical analysis. RESULTS: A greater proportion of aneurysms were categorized as being "small" when geometric formulae were applied. The median aneurysm volumes obtained were 54.5 mm3 by 3DRA software, and 30.6 mm3 using mathematical equations. An underestimation of aneurysm volume with a resultant overestimation in the calculated coil packing density (p = 0.002) was observed. CONCLUSION: Caution must be exercised in the application of simple geometric formulae in the management of intracranial aneurysms as volumes may potentially be underestimated and packing densities falsely elevated. Future research should focus on validation of automatic segmentation in volumetric measurement and improving its accuracy to enhance its application in clinical practice.
Aneurysm ; Angiography ; Intracranial Aneurysm* ; Neck

Calcifying tendinopathy is a tendon disorder with calcium deposits in the mid-substance presented with chronic activity-related pain, tenderness, local edema and various degrees of incapacitation. Most of current treatments are neither effective nor evidence-based because its underlying pathogenesis is poorly understood and treatment is usually symptomatic. Understanding the pathogenesis of calcifying tendinopathy is essential for its effective evidence-based management. One of the key histopathological features of calcifying tendinopathy is the presence of chondrocyte phenotype which surrounds the calcific deposits, suggesting that the formation of calcific deposits was cell-mediated. Although the origin of cells participating in the formation of chondrocyte phenotype and ossification is still unknown, many evidences have suggested that erroneous tendon cell differentiation is involved in the process. Recent studies have shown the presence of stem cells with self-renewal and multi-differentiation potential in human, horse, mouse and rat tendon tissues. We hypothesized that the erroneous differentiation of tendon-derived stem cells (TDSCs) to chondrocytes or osteoblasts leads to chondrometaplasia and ossification and hence weaker tendon, failed healing and pain, in calcifying tendinopathy. We present a hypothetical model on the pathogenesis and evidences to support this hypothesis. Understanding the key role of TDSCs in the pathogenesis of calcifying tendinopathy and the mechanisms contributing to their erroneous differentiation would provide new opportunities for the management of calcifying tendinopathy. The re-direction of the differentiation of resident TDSCs to tenogenic or supplementation of MSCs programmed for tenogenic differentiation may be enticing targets for the management of calcifying tendinopathy in the future.
Animals ; Cell Differentiation ; physiology ; Humans ; Mice ; Rats ; Stem Cells ; pathology ; Tendinopathy ; etiology ; pathology ; Tendons ; pathology

OBJECTIVETo investigate the role of STK15 gene amplification and overexpression to genesis and development of laryngeal squamous cell carcinoma (LSCC).

METHODSSTK15 gene amplification in 40 cases carcinoma tissues and normal tissues as control was detected by differential PCR approach. STK15 mRNA and protein levels were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry method.

RESULTSIn 40 LSCC cases, STK15 gene amplification was found in 14 tumor tissues(35%), mRNA overexpression in 27 tumor tissues(67.5%), and protein upregulated in 29 tumor tissues(72.5%). Statistics analysis showed that STK15 gene amplification and mRNA overexpression were obviously associated to differentiation degree of LSCC, and protein overexpression was closely associated with both differentiation degree and pathological grades of LSCC.

CONCLUSIONThis research results suggest that STK15 gene amplification contributes to its mRNA and protein overexpression through affecting the exact replication of centrosome and separation of chromosomes. STK15 gene thus plays a role in LSCC oncogenesis and malignant progression.

Aurora Kinase A ; Aurora Kinases ; Carcinoma, Squamous Cell ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Laryngeal Neoplasms ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the effects of 4OH-Tamoxifen (OHT) on proliferation and apoptosis of primary cultured prostate stromal cells.

METHODSPrimarily cultured prostate stromal cells in vitro were treated with various concentrations (10(-8) mol/L - 10(-5) mol/L) of estradiol (E2), diethylstilbestrol (DES), OHT and the mixture of E2 (10(-8) mol/L - 10(-6) mol/L) with OHT (10(-7) mol/L) and then MTT and TUNEL were used to detect their proliferation and apoptosis respectively.

RESULTSThere was a significant difference (P < 0.05) between OHT and estrogens in the effects on the apoptosis and proliferation of the primarily cultured prostate stromal cells. OHT suppressed proliferation of the prostate stromal cells at the concentrations from 10(-7) mol/L to 10(-5) mol/L (P < 0.05), and this effect was concentration related (r = -0.383, P = 0.005); OHT (10(-7) mol/L) suppressed the proliferation stimulation effect of E2 at the concentrations from 10(-8) mol/L to 10(-6) mol/L (P < 0.05). OHT induced apoptosis at the concentrations from 10(-8) mol/L to 10(-5) mol/L (P < 0.05), and this effect was concentration related (r = 0.349, P = 0.012). The apoptosis induced by OHT could not be reversed by E2 at the concentrations from 10(-8) mol/L to 10(-5) mol/L (P > 0.05).

CONCLUSIONOHT can obviously suppressed the proliferation and promote the apoptosis of primarily cultured prostate stromal cells, which might not be totally attributed to the competitive inhibition of the estrogen receptor.

Antineoplastic Agents, Hormonal ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Male ; Prostate ; cytology ; Stromal Cells ; cytology ; drug effects ; Tamoxifen ; pharmacology

BACKGROUNDSynovium-derived stem cells (SDSCs) with higher chondrogenic potential are attracting considerable attention as a cell source for cartilage regeneration. We investigated the effect of bone morphogenetic protein 2 (BMP-2) on transforming growth factor beta3 (TGF-β3)-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system.

METHODSThe clonogenicity, stem cell marker expression and multi-differentiation potential of isolated SDSCs were determined by colony forming unit assay, flow cytometry and specific staining including alizarin red S, Oil red O and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium with or without TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type II, sulfated glycosaminoglycan (sGAG) synthesis and mRNA expression of collagen type II, aggrecan, SOX9, link-protein, collagen type X and BMP receptor II.

RESULTSCells isolated under the optimized culturing density (10(4)/60 cm(2)) showed clonogenicity and multi-differentiation potential. These cells were positive (> 99%) for CD44, CD90, CD105 and negative (< 10%) for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Safranin O staining of the extracellular matrix was positive and the expression of collagen type II was detected. Cell pellets treated with TGF-β3 and BMP-2 were larger in diameter and weight, produced more sGAGs, and expressed higher levels of collagen type II and other chondrogenic markers, except COL10A1, than medium with TGF-β3 alone.

CONCLUSIONSSDSCs could be isolated from human osteoarthritic synovium. Supplementation with BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.

Aged ; Bone Morphogenetic Protein 2 ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Chondrogenesis ; drug effects ; Female ; Humans ; Immunohistochemistry ; Male ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Middle Aged ; Synovial Membrane ; cytology ; Transforming Growth Factor beta3 ; pharmacology

BACKGROUNDThe environmental sources associated with community-acquired or nosocomial legionellosis were not always detectable in the mainland of China and Hong Kong, China. The objective of this study was to illustrate the control measures implemented for nosocomial and community outbreaks of legionellosis, and to understand the environmental distribution of legionella in the water system in Hong Kong, China.

METHODSWe investigated the environmental sources of two cases of legionellosis acquired in the hospital and the community by extensive outbreak investigation and sampling of the potable water system using culture and genetic testing at the respective premises.

RESULTSThe diagnosis of nosocomial legionellosis was suspected in a patient presenting with nosocomial pneumonia not responsive to multiple beta-lactam antibiotics with subsequent confirmation by Legionella pneumophila serogroup 1 antigenuria. High counts of Legionella pneumophila were detected in the potable water supply of the 70-year-old hospital building. Another patient on continuous ambulatory peritoneal dialysis presenting with acute community-acquired pneumonia and severe diarrhoea was positive for Legionella pneumophila serogroup 1 by polymerase chain reaction (PCR) testing on both sputum and nasopharyngeal aspirate despite negative antigenuria. Paradoxically the source of the second case was traced to the water system of a newly commissioned office building complex. No further cases were detected after shock hyperchlorination with or without superheating of the water systems. Subsequent legionella counts were drastically reduced. Point-of-care infection control by off-boiled or sterile water for mouth care and installation of water filter for showers in the hospital wards for immunocompromised patients was instituted. Territory wide investigation of the community potable water supply showed that 22.1% of the household water supply was positive at a mean legionella count of 108.56 CFU/ml (range 0.10 to 639.30 CFU/ml).

CONCLUSIONSPotable water systems are open systems which are inevitably colonized by bacterial biofilms containing Legionella species. High bacterial counts related to human cases may occur with stagnation of flow in both old or newly commissioned buildings. Vigilance against legionellosis is important in healthcare settings with dense population of highly susceptible hosts.

Aged ; Aged, 80 and over ; Biofilms ; Community-Acquired Infections ; diagnosis ; epidemiology ; Female ; Hong Kong ; epidemiology ; Humans ; Legionellosis ; diagnosis ; epidemiology ; Male ; Water Microbiology

BACKGROUNDIdentification of hospitalized carbapenem-resistant Enterobacteriaceae (CRE)-positive patient is important in preventing nosocomial transmission. The objective of this study was to illustrate the implementation of proactive infection control measures in preventing nosocomial transmission of CRE in a healthcare region of over 3200 beds in Hong Kong between October 1, 2010 and December 31, 2011.

METHODSThe program included active surveillance culture in patients with history of medical tourism with hospitalization and surgical operation outside Hong Kong within 12 months before admission, and "added test" as an opportunistic CRE screening in all fecal specimens submitted to the laboratory. Outbreak investigation and contact tracing were conducted for CRE-positive patients. Serial quantitative culture was performed on CRE-positive patients and the duration of fecal carriage of CRE was analyzed.

RESULTSDuring the study period, a total of 6533 patients were screened for CRE, of which 76 patients were positive (10 from active surveillance culture, 65 from "added test", and 1 secondary case from contact tracing of 223 patients with no nosocomial outbreak), resulting in an overall rate of CRE fecal carriage of 1.2%. The median time of fecal carriage of CRE was 43 days (range, 13-119 days). Beta-lactam-beta-lactamase-inhibitors, cephalosporins, and fluoroquinolones were associated significantly with high fecal bacterial load when used 90 days before CRE detection, while use of cephalosporins, carbapenems, and fluoroquinolones after CRE detection are significantly associated with longer duration of carriage. The duration of fecal carriage of CRE also correlates significantly with the initial fecal bacterial load (Pearson correlation: 0.53; P = 0.02).

CONCLUSIONProactive infection control measures by enhanced surveillance program identify CRE-positive patients and data obtained are useful for the planning of and resource allocation for CRE control.

Anti-Bacterial Agents ; therapeutic use ; Carbapenems ; therapeutic use ; Cephalosporins ; therapeutic use ; Drug Resistance, Bacterial ; Enterobacteriaceae ; drug effects ; Enterobacteriaceae Infections ; prevention & control ; transmission ; Fluoroquinolones ; therapeutic use ; Humans ; Infection Control ; methods

Background: Insulin-treated patients with long duration of type 2 diabetes mellitus (T2DM) are at increased risk of ketoacidosis related to sodium-glucose co-transporter 2 inhibitor (SGLT2i). The extent of circulating ketone elevation in these patients remains unknown. We conducted this study to compare the serum ketone response between dapagliflozin, an SGLT2i, and sitagliptin, a dipeptidyl peptidase-4 inhibitor, among insulin-treated T2DM patients. Methods: This was a randomized, open-label, active comparator-controlled study involving 60 insulin-treated T2DM patients. Participants were randomized 1:1 for 24-week of dapagliflozin 10 mg daily or sitagliptin 100 mg daily. Serum β-hydroxybutyrate (BHB) levels were measured at baseline, 12 and 24 weeks after intervention. Comprehensive cardiometabolic assessments were performed with measurements of high-density lipoprotein cholesterol (HDL-C) cholesterol efflux capacity (CEC), vibration-controlled transient elastography and echocardiography. Results: Among these 60 insulin-treated participants (mean age 58.8 years, diabetes duration 18.2 years, glycosylated hemoglobin 8.87%), as compared with sitagliptin, serum BHB levels increased significantly after 24 weeks of dapagliflozin (P=0.045), with a median of 27% increase from baseline. Change in serum BHB levels correlated significantly with change in free fatty acid levels. Despite similar glucose lowering, dapagliflozin led to significant improvements in body weight (P=0.006), waist circumference (P=0.028), HDL-C (P=0.041), CEC (P=0.045), controlled attenuation parameter (P=0.007), and liver stiffness (P=0.022). Average E/e’, an echocardiographic index of left ventricular diastolic dysfunction, was also significantly lower at 24 weeks in participants treated with dapagliflozin (P=0.037). Conclusion Among insulin-treated T2DM patients with long diabetes duration, compared to sitagliptin, dapagliflozin modestly increased ketone levels and was associated with cardiometabolic benefits.