Inter-relationship of risk factors and pathways associated with chronic kidney disease in patients with type 2 diabetes mellitus: a structural equation modelling analysis.

OBJECTIVES: Diabetes mellitus is the most common cause of chronic kidney disease (CKD); however, the inter-relationships and pathogenetic mechanisms among risk factors are still largely unknown. Structural equation modelling (SEM) was applied to test a hypothesis of causal pathways related to CKD in patients with type 2 diabetes mellitus (T2DM). STUDY DESIGN: This is a prospective observational study. METHODS: A total of 3395 patients with T2DM were enrolled in this study. A hypothesised SEM was applied to assess associations among demographic data, diabetic self-management behaviours, diabetes control, lifestyle, psycho-social, chronic inflammation factors, anthropometric and metabolic variables simultaneously and the risk of CKD. RESULTS: Demographic data (including education, marital status and mini-mental state examination score) (-0.075), white blood cell count (0.084), high blood pressure (0.144), World Health Organisation (WHO) 5 well-being index (-0.082), diabetes control (0.099), triglyceride (0.091) and uric acid (0.282) levels had direct effects on the risk of CKD. The final model could explain 26% of the variability in baseline CKD status. In addition, the same direct and specific indirect factors at baseline CKD status analysis contributed to the risk of CKD at the 12-month follow-up. The final model could explain 31% of the variability in the risk of CKD at the 12-month follow-up. CONCLUSIONS: This study investigates associations between factors obtained from real-world daily practice and CKD status simultaneously and delineates the potential pathways and inter-relationships of the risk factors that contribute to the development of CKD in patients with T2DM.

Non-alcoholic fatty liver disease increases the prevalence of maintenance haemodialysis in patients with chronic kidney disease.

AIM: To investigate the association between non-alcoholic fatty liver disease (NAFLD) and incidence of maintenance haemodialysis in patients with chronic kidney disease (CKD). METHODS: We enrolled patients diagnosed with CKD between 2001 and 2007. The patients were categorized into two groups based on abdominal ultrasound finding, namely those with NAFLD and those without NAFLD. The disease (maintenance haemodialysis)-free survival rate was estimated using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses was used to evaluate the hazard ratios of covariates for the incidence of maintenance haemodialysis. RESULTS: A total of 161 patients (61 with NAFLD and 100 without NAFLD) were enrolled. The mean age was 69.3 years. The mean follow-up was 7.4 years. The patients with NAFLD had an increased incidence of maintenance haemodialysis (39.3 % vs 24.0 %; p=0.0396) and inferior disease-free survival rate (p=0.006). Furthermore, diabetes (p=0.0126) and proteinuria (p=0.0003) were identified as significant predictors of CKD progression. CONCLUSION: NAFLD was associated with an increased incidence of maintenance haemodialysis and inferior disease-free survival rate. NAFLD may impair renal function and patients with renal impairment should be monitored carefully (Tab. 3, Fig. 1, Ref. 25) Keywords: non-alcoholic fatty liver disease, haemodialysis, chronic kidney disease, proteinuria.

Effects of mutant TDP-43 on the Nrf2/ARE pathway and protein expression of MafK and JDP2 in NSC-34 cells.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons and lacks an effective treatment. The disease pathogenesis has not been clarified at present. Pathological transactive response DNA-binding protein 43 (TDP-43) plays an important role in the pathogenesis of ALS. Nuclear translocation of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) is found in a mutant TDP-43 transgenic cell model, but its downstream antioxidant enzyme expression is decreased. To elucidate the specific mechanism of Nrf2/ARE (antioxidant responsive element) signaling dysfunction, we constructed an ALS cell model with human mutant TDP-43 using the NSC-34 cell line to evaluate the impact of the TDP-43 mutation on the Nrf2/ARE pathway. We found the nuclear translocation of Nrf2, but the expression of total Nrf2, cytoplasmic Nrf2, and downstream phase II detoxifying enzyme (NQO1) was decreased in NSC-34 cells transfected with the TDP-43-M337V plasmid. Besides, TDP-43-M337V plasmid-transfected NSC-34 cells were rounded with reduced neurites, shortened axons, increased levels of intracellular lipid peroxidation products, and decreased viability, which suggests that the TDP-43-M337V plasmid weakened the antioxidant capacity of NSC-34 cells and increased their susceptibility to oxidative damage. We further showed that expression of the MafK protein and the Jun dimerization protein 2 (JDP2) was reduced in TDP-43-M337V plasmid-transfected NSC-34 cells, which might cause accumulation of Nrf2 in nuclei but a decrease in NQO1 expression. Taken together, our results confirmed that TDP-43-M337V impaired the Nrf2/ARE pathway by reducing the expression of MafK and JDP2 proteins, and provided information for further research on the molecular mechanisms of TDP-43-M337V in ALS.

[Application value of whole brain 3D artery spin labeling in diagnosis of intracranial tumors].

Objective: To investigate the perfusion characteristics of arterial spin labeling (ASL) in intracranial tumor and its application value in classification. Methods: The clinical, pathological and imaging data of 44 patients with gliomas confirmed by pathology were analyzed retrospectively, including 9 low grade gliomas, 15 high grade gliomas, 11 cases of meningiomas, 6 cases of neurilemmoma, 3 cases of metastatic tumors.Conventional plain scan, 3D- ASL and MRI dynamic enhanced imaging (DSC-MRI) were performed.The mean maximal cerebral blood flow (CBF) of the solid component of tumor was obtained based on the region of interest.Immunohistochemical staining was performed in 24 patients with glioma.The differences of cerebral blood flow map (CBF) and relative cerebral blood flow (rCBF) in 44 patients with intracranial tumors were compared. The results of paired t test between the tumor area and the contralateral mirror area were measured by the two methods. Results: Taken the normal control-lateral grey matter(GM) as reference to normalize the CBF of tumor, three normalized tumor blood flow (nTBF) acquired by ASL showed statistical difference between low grade and high grade gliomas respectively (P<0.05). While taken the mirror region (M) and normal control-lateral white matter (WM) as reference to normalize the CBF of tumor, it showed no statistical difference (P>0.05). There was no 1p deletion in the cases of ASL perfusion in low-grade glioma group.In the case of 1p deletion in high grade glioma group, ASL was low perfusion, and there was no 1p deletion in the cases of ASL perfusion. Conclusion: 3D ASL can be used to identify high-grade and low-grade gliomas which has important reference value in the qualitative diagnosis of brain tumors and preoperative grading of gliomas.A separate use of 3D-ASL might cause over-or underestimation of tumor diagnosis, therefore a comprehensive analysis is needed.

Anthocyanin contents in the seed coat of black soya bean and their anti-human tyrosinase activity and antioxidative activity.

OBJECTIVE: The seed coat of black soya bean (SCBS) contains high amount of anthocyanins and shows antioxidant and anti-mushroom tyrosinase activities. The objectives of this study were to analyse the anthocyanins in SCBS with different solvents and to find the relationship between anthocyanin profile with anti-human and anti-mushroom tyrosinase activities. METHODS: SCBS was extracted with hot water, 50 and 80% ethanol, 50 and 80% acetone and 50 and 80% acidified acetone. Total phenol and total flavonoid contents in the extracts were determined. Anthocyanins in the extracts were analysed using HPLC and LC/MS/MS. A genetically engineered human tyrosinase was used to evaluate the anti-tyrosinase potential of the extracts from SCBS. RESULTS: 80% acetone extract from SCBS obtained the highest total phenol, total flavonoid and cyanidin-3-O-glucoside (C3G) contents among all the extracts, whereas the hot water extract showed the lowest antioxidant contents. Three anthocyanin compounds were found in all the extracts from SCBS, and the analysis of HPLC and LC/MS/MS indicated that they were C3G, delphinidin-3-O-glucoside (D3G) and peonidin-3-O-glucoside (P3G). The ratios of C3G (2.84 mg g(-1) ), D3G (0.34 mg g(-1) ) and P3G (0.35 mg g(-1) ) in 80% acidified acetone extract were 76.6, 9.1 and 9.3%, respectively. All the extracts from SCBS possessed anti-human tyrosinase activity. Moreover, a good correlation was found between the anti-human tyrosinase activities and C3G contents in the extracts. CONCLUSION: Antioxidants in SCBS also possess anti-human and anti-mushroom tyrosinase activities.

Prognostic significance of p62/SQSTM1 subcellular localization and LC3B in oral squamous cell carcinoma.

BACKGROUND: Autophagy is a programmed cell survival mechanism that has a key role in both physiologic and pathologic conditions. The relationship between autophagy and cancer is complex because autophagy can act as either a tumour suppressor or as a tumour promoter. The role of autophagy in oral squamous cell carcinoma (OSCC) is controversial. Several studies have claimed that either a high or low expression of autophagy-related proteins was associated with poor prognosis of OSCCs. The aims of the study were to compare autophagy in OSCCs, verrucous hyperplasias, and normal oral mucosas, and to inspect the prognostic role of autophagy in OSCCs. METHODS: We used the autophagosome marker, LC3B, and autophagy flux marker, p62/SQSTM1 (p62), by using immunohistochemistry, and examined p62 mRNA by RNA in situ hybridization, to evaluate autophagy in 195 OSCCs, 47 verrucous hyperplasias, and 37 normal oral mucosas. The prognostic roles of LC3B and p62 protein expressions in OSCCs were investigated. RESULTS: We discovered that the normal oral mucosa exhibited limited LC3B punctae and weak cytoplasmic p62 staining, whereas the OSCCs exhibited a marked increase in LC3B punctae and cytoplasmic p62 expression. The expression pattern of LC3B and cytoplasmic p62 of the verrucous hyperplasias were between normal oral mucosas and OSCCs. The normal oral mucosas, verrucous hyperplasias, and OSCCs presented no differences in nuclear p62 expression and the p62 mRNA level. p62 mRNA expression was elevated in a minority of cases. High p62 mRNA expression was associated with high p62 protein expression in the cytoplasm. Increased LC3B punctae, high cytoplasmic p62, and low nuclear p62 expressions in OSCCs were associated with aggressive clinicopathologic features and unfavourable prognosis. In addition, low nuclear p62 expression was an independent prognostic factor for overall and disease-specific survival rates. Furthermore, we disclosed that high cytoplasmic p62 expression accompanied with either a low or high LC3B expression, which indicated autophagy impairment under basal or activated autophagic activity, was associated with aggressive behaviour in advanced OSCCs. CONCLUSIONS: We suggested that autophagy was altered during cancer initiation and progression. Autophagy impairment contributed to cancer progression in advanced OSCCs.

Modified nanoprecipitation method for polysulfone nanoparticles preparation.

Towards developing a more universal and productive nanoprecipitation processes, we focus on the preparation of polysulfone (PSF) nanoparticles through instantaneous solvent displacement in a metal membrane contactor between dimethylformamide (DMF) and water. In the original nanoprecipitation process, cubic nuclei can form instantaneously, but slow growth and aggregation have intensive interactions. Moreover, the reservation of DMF may enhance the adhesive effect between polymeric particles, causing severe particle aggregation. To overcome this difficulty, a modified nanoprecipitation method appending a quenching step was proposed. The well-dispersed PSF nanoparticles are successfully obtained when ethyl acetate is introduced. In this way, DMF can be extracted from water solution, thus facilitating the precipitating of PSF. Furthermore, selecting water as the continuous fluid, the particle size can be adjusted simply by tuning the operating parameters, including the PSF concentration in the dispersed fluid and the ratio of two feeds. Compared with previous reports on the continuous nanoprecipitation process for polymeric nanoparticles preparation, this work shows advantages including expanding the adaptability to more functional polymers, providing better flexibility on process or product development independent of the use of surfactant, and presenting a high throughput and easy-to-scale-up equipment platform.

Retraction Note: Roles of the Nrf2/HO-1 pathway in the anti-oxidative stress response to ischemia-reperfusion brain injury in rats.

The article "Roles of the Nrf2/HO-1 pathway in the anti-oxidative stress response to ischemia-reperfusion brain injury in rats", by L.-J. Jiang, S.-M. Zhang, C.-W. Li, J.-Y. Tang, F.-Y. Che, Y.-C. Lu, published in Eur Rev Med Pharmacol Sci 2017; 21 (7): 1532-1540-PMID: 28429353 has been retracted by the Editor in Chief. Following some concerns raised on PubPeer (link: https://pubpeer.com/publications/4C502B6EB4FCA59AC9F42A8278A3D4), the Editor in Chief has started an investigation to assess the validity of the results as well as possible figure manipulation. The authors have been informed about the journal's investigation but remained unresponsive and have not provided the study's raw data. The journal investigation revealed several figure duplications and manipulations in Figures 3 and 6. Consequently, the Editor in Chief mistrusts the results presented and has decided to retract the article. This article has been retracted. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/12521.

Evaluation of discrepancies between oxacillin and cefoxitin susceptibility in coagulase-negative staphylococci.

The Clinical and Laboratory Standards Institute (CLSI) recommends testing coagulase-negative staphylococci (CoNS) strains to determine resistance against oxacillin by testing for mecA, PBP2a, or with cefoxitin disk. However, discrepant results of resistance to oxacillin and susceptibility to cefoxitin were found. In this study, we aimed to investigate the oxacillin resistance and cefoxitin susceptibility of CoNS in Taiwan. Of 9,017 strains collected from 2005 to 2010, 131 (1.5%) of the isolates were oxacillin-resistant and cefoxitin-susceptible. Species identification was carried out using the Vitek 2 system or 16S ribosomal RNA sequencing. Oxacillin minimum inhibitory concentrations (MICs) were examined by the agar dilution method. The presence of mecA and the activity of ß-lactamase were performed by polymerase chain reaction (PCR) and Cefinase disks, respectively. Overall, 33% (43/129) of the strains carried mecA and 43% (37/86) of mecA-negative isolates tested positive for ß-lactamase. The remaining 49 isolates were negative for both mecA and ß-lactamase, and were mainly Staphylococcus cohnii ssp. urealyticus and S. saprophyticus (oxacillin MICs 0.5-2 µg/ml) obtained from bloodstream and urinary tract infections. Our study suggests that incorrect reporting can be found in CoNS using cefoxitin disk alone to determine the susceptibility to oxacillin, and the strains should be further tested for oxacillin MICs and detection of the mecA gene or ß-lactamase activity.

Evaluation of discrepancies between oxacillin and cefoxitin disk susceptibility for detecting methicillin-resistant Staphylococcus aureus.

The Clinical Laboratory Standards Institute recommends that if both cefoxitin and oxacillin are tested against Staphylococcus aureus and either result is measured as resistant, the organism should be reported as oxacillin resistant. This indicates that discrepancies may be present between oxacillin and cefoxitin sensitivities in S. aureus. In this study, we aimed to investigate the discrepancy between oxacillin and cefoxitin susceptibility in S. aureus clinical isolates. Of 10,980 S. aureus isolates recovered from 2005 to 2010, 27 (0.3%) isolates with discordant results between oxacillin and cefoxitin were collected. Fourteen (oxacillin diameters 10-12 mm) of the 27 strains were susceptible (MICs = 0.5-2 µg/ml) and 13 (6-13 mm) were resistant (4->256 µg/ml) to oxacillin. The cefoxitin MICs of 14 oxacillin-susceptible and 13 oxacillin-resistant strains ranged between 4 and 8 and 8 to 32 µg/ml, respectively. Discrepancies were present between oxacillin and cefoxitin in S. aureus, and these strains should be further tested for oxacillin MICs and for the mecA gene or ß-lactamase activity.

[Advice on the rationalized layout of outpatient clinics in a wound repair department].

According to a document issued by the General Office of National Health Commission, "one person, one diagnosis, and one room" is required in the process of outpatient consultation. However, the patient will need to go to another room for dressing change after the doctor checks the wound if sticking to the conventional layout of current wound repair specialist outpatient clinic in hospitals and following the regulation of "separation of diagnosis and treatment". To allow a patient walking back and forth with the exposed wounds to different clinics or going to another clinic for dressing change with the original dressing reapplied to the wound is against the regulation of nosocomial infection control and the principle of sterility. To ensure that the layout of the outpatient clinic in the wound repair outpatient department not only conforms to the principle of "one person, one diagnosis, and one room", but also meets the characteristics of the diagnosis and treatment process of chronic wounds, this paper proposes the layout of "large space and small partition" in the wound repair clinic.

Tailoring of silver wires and their performance as transparent conductive coatings.

A feasible way to manipulate the scales of Ag wires through the polyol process is presented. By adjusting the amounts of either Pd or Ag precursor used in this process, we demonstrated the ability to control the scale of the wires. The presence of Pd ultrafine particles reduced by EG in advance served as the nuclei for inducing the subsequent formation of Ag wires, and the diameter of the resulting wires was observed to be inversely proportional to the quantity of Pd added. Further, the wire length was demonstrated to be proportional to and highly correlated with the total amount of Ag added, by a linear relationship. A glass plate coated with Ag wire film by the spray method is shown to be both transparent and conductive. The effect of scaling the wires on their performance is also discussed.

Solitary intracranial plasmacytoma located in the spheno-clival region mimicking chordoma: a case report.

Solitary intracranial plasmacytoma (SIP) is very rare. This case report presents serial findings of SIP located in the spheno-clival region in a 54-year old female who presented with an inferior hemianopia in the right eye and an enlarged physiological blind spot in both eyes. Based on the initial diagnosis of a spheno-clival region chordoma, the tumour was partially resected by the nasal-sphenoidal sinus approach. Subsequently, the correct diagnosis of SIP was made based on the pathology and immunohistochemical staining of the tumour. The patient was treated using a whole skull-base radiation therapy protocol with 45 Gy and she was in good physical condition during the subsequent 22 months. The findings of a series of similar case reports documenting SIP in 20 cases published from 1976 to 2008 are also reviewed. Based on these case reports, the key features of SIP, including their clinical manifestations, clinical imaging characteristics, treatment and prognosis, are described.

Hyper-viscoelastic mechanical behavior of cranial pia mater in tension.

BACKGROUND: Cranial pia mater, the innermost layer of the meninges, protects the central nervous system by tightly wrapping the brain and damping the external impact force to the brain. Accurate experimental data of the mechanical property of the cranial pia mater can enhance the theoretical prediction of traumatic brain injury or the scientific surgery design for brain disease. The aim of this study is to characterize the mechanical behavior of the cranial pia mater. METHODS: In vitro tensile and stress-relaxation experiments of ovine cranial pia mater specimens were conducted at eight strain rates to characterize the rate-dependent viscoelastic property. The tensile and stress-relaxation experimental data were fitted by an Ogden hyper-viscoelastic model with a strain rate function to describe the mechanical behavior of the cranial pia mater. FINDINGS: The elastic modulus and the ultimate stress are significantly increased from 5.545 MPa and 0.535 MPa at 0.00167 s-1 to 18.345 MPa and 2.547 MPa at 0.83 s-1 (p < .0001), respectively. The initial stress and the long-term stress (300 s) are also increased significantly with the increasing strain rates (p < .0001). A good fit of the experimental data with the Ogden hyper-viscoelastic model incorporated with a strain rate function was achieved (R2 > 0.93). INTERPRETATION: The cranial pia mater exhibits as a rate-dependent hyper-viscoelastic material in the tensile and stress-relaxation experiments. Compared with the brain, the stiffer nature of the cranial pia mater indicates its essential role in brain protection. The rate-dependent constitutive model provides a proper description of the hyper-viscoelastic characteristics of the cranial pia mater in tension and may provide a basic constitutive relationship for numerical simulations of traumatic brain injury.

Action of the insecticide cyfluthrin on Ca2+ signal transduction and cytotoxicity in human osteosarcoma cells.

Cyfluthrin is a pyrethroid insecticide and common household pesticide. The effect of cyfluthrin on Ca2+-related physiology in human osteosarcoma is unclear. This study investigated the effect of cyfluthrin on cytosolic-free Ca2+ concentrations ([Ca2+]i) and viability in MG63 human osteosarcoma cells. Cyfluthrin concentration-dependently induced [Ca2+]i rises. Cyfluthrin-induced Ca2+ entry was confirmed by the Mn2+-induced quench of fura-2 fluorescence. Cyfluthrin at concentrations of 10-100 µM induced [Ca2+]i rises. Ca2+ removal reduced the signal by approximately 50%. Cyfluthrin (100 µM) induced Mn2+ influx suggesting Ca2+ entry. Cyfluthrin-induced Ca2+ entry was inhibited 50% by protein kinase C (PKC) activator (phorbol 12-myristate 13-acetate) and inhibitor (GF109203X) and also by three inhibitors of store-operated Ca2+ channels: nifedipine, econazole, and SKF96365. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (TG) completely inhibited cyfluthrin-evoked [Ca2+]i rises. Conversely, treatment with cyfluthrin abolished TG-evoked [Ca2+]i rises. Inhibition of phospholipase C (PLC) with 1-[6-[((17ß)-3-methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dion abolished cyfluthrin-induced [Ca2+]i rises. Cyfluthrin at 25-65 µM decreased cell viability, which was not reversed by pretreatment with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester. Together, in MG63 cells, cyfluthrin induced [Ca2+]i rises by evoking PLC-dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ entry. Cyfluthrin also caused Ca2+-independent cell death.

The male sterility and histoincompatibility (mshi) mutation in mice is a natural variant of microtubule-associated protein 7 (Mtap7).

Males homozygous for the mouse male sterility and histoincompatibility (mshi) mutation exhibit small testes and produce no sperm. In addition, mshi generates an "antigen-loss" histoincompatibility barrier, such that homozygous mutants reject skin grafts from wild type co-isogenic BALB/cByJ donors. To facilitate the molecular characterization of the pleiotropic mshi mutation, we genetically mapped mshi into a 0.68 megabasepair region which contains fewer than 10 candidate genes. Complementation testing showed that one of these, Mtap7, is disrupted in mshi mice. Sequence analysis has revealed a 13 kilobasepair deletion in BALB/cByJ-mshi/J mice that begins in Intron 10-11 of Mtap7, and ends less than 2000 base pairs downstream of the wild type gene. Analysis of the mutant cDNA predicts that Mtap7(mshi) encodes a 457 amino acid protein, the first 423 of which are identical to wild type, and the last 34 of which are due to aberrant mRNA splicing with two cryptic exons in the Mtap7 to P04Rik intergenic region. This molecular assignment for the mshi mutation further supports an essential role for microtubule stabilization in spermatogenesis and indicates a new role in allograft transplantation.

Rosette-forming glioneuronal tumour of the fourth ventricle with previous intratumoural haemorrhage: case report and review of the literature.

The case is reported of a rosette-forming glioneuronal tumour of the fourth ventricle (RGTFV) in a 27-year-old male. Symptoms included headache, severe vomiting and clumsy walking that had progressively worsened over 14 days. Computed tomography and magnetic resonance imaging indicated a 3.0 x 2.5 x 2.0 cm solid-cystic mass in the fourth ventricle and obstructive hydrocephalus. The tumour showed evidence of previous intra-tumour haemorrhage, with heterogeneous enhancement after contrast administration. Complete excision of the lesion was performed. Signs of previous intra-tumoural haemorrhage were seen intra-operatively. The detailed clinical, radiological and pathological features in this patient are described and compared with existing literature on this type of tumour. Despite benign histological features and a reported favourable post-operative course, there is still limited clinical experience with this type of tumour, however intratumoural haemorrhage may result in morbidity and mortality. This report will help provide better characterization of this entity, improving the diagnosis and potentially reducing mortality in RGTFV.

A 3D Computational Head Model Under Dynamic Head Rotation and Head Extension Validated Using Live Human Brain Data, Including the Falx and the Tentorium.

We employ an advanced 3D computational model of the head with high anatomical fidelity, together with measured tissue properties, to assess the consequences of dynamic loading to the head in two distinct modes: head rotation and head extension. We use a subject-specific computational head model, using the material point method, built from T1 magnetic resonance images, and considering the anisotropic properties of the white matter which can predict strains in the brain under large rotational accelerations. The material model now includes the shear anisotropy of the white matter. We validate the model under head rotation and head extension motions using live human data, and advance a prior version of the model to include biofidelic falx and tentorium. We then examine the consequences of incorporating the falx and tentorium in terms of the predictions from the computational head model.

Involvement of matrix metalloproteinase-13 in stromal-cell-derived factor 1 alpha-directed invasion of human basal cell carcinoma cells.

Basal cell carcinoma (BCC) is one of the most common skin neoplasms in humans and is usually characterized by local aggressiveness with little metastatic potential, although deep invasion, recurrence, and regional and distant metastases may occur. Here, we studied the mechanism of BCC invasion. We found that human BCC tissues and a BCC cell line had significant expression of CXCR4, which was higher in invasive than non-invasive BCC types. Further, of 19 recurrent tumors among 390 BCCs diagnosed during the past 12 years, 17/19 (89.5%) had high CXCR4 expression. We found that the CXCR4 ligand, stromal-cell-derived factor 1alpha (SDF-1alpha), directed BCC invasion and that this was mediated by time-dependent upregulation of mRNA expression and gelatinase activity of matrix metalloproteinase-13 (MMP-13). The transcriptional regulation of MMP-13 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the AP-1 component c-Jun. Finally, CXCR4-transfected BCC cells injected into nude mice induced aggressive BCCs that co-expressed CXCR4 and MMP-13. The identification of SDF-1alpha/CXCR4 as an important factor in BCC invasiveness may contribute insight into mechanisms involved in the aggressive potential of human BCC and may improve therapy for invasive BCCs.

Melittin-induced [Ca2+]i increases and subsequent death in canine renal tubular cells.

The effect of melittin on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and viability is largely unknown. This study examined whether melittin alters Ca(2+) levels and causes Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Melittin at concentrations above 0.5 microM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 75% by removing extracellular Ca(2+). The melittin-induced Ca(2+) influx was also implicated by melittin-caused Mn(2+) influx. After pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), melittin-induced Ca(2+) release was inhibited; and conversely, melittin pretreatment abolished thapsigargin-induced Ca(2+) release. At concentrations of 0.5-20 microM, melittin killed cells in a concentration-dependent manner. The cytotoxic effect of 0.5 microM melittin was nearly completely reversed by prechelating cytosolic Ca(2+) with BAPTA. Melittin at 0.5-2 microM caused apoptosis as assessed by flow cytometry of propidium iodide staining. Collectively, in MDCK cells, melittin induced a [Ca(2+)](i) rise by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, melittin can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.