A study on alkaline heat treated Mg-Ca alloy for the control of the biocorrosion rate

To reduce the biocorrosion rate by surface modification, Mg-Ca alloy (1.4wt.% Ca content) was soaked in three alkaline solutions (Na(2)HPO(4), Na(2)CO(3) and NaHCO(3)) for 24h, respectively, and subsequently heat treated at 773K for 12h. Scanning electron microscopy and energy-dispersive spectroscopy results revealed that magnesium oxide layers with the thickness of about 13, 9 and 26microm were formed on the surfaces of Mg-Ca alloy after the above different alkaline heat treatments. Atomic force microscopy showed that the surfaces of Mg-Ca alloy samples became rough after three alkaline heat treatments. The in vitro corrosion tests in simulated body fluid indicated that the corrosion rates of Mg-Ca alloy were effectively decreased after alkaline heat treatments, with the following sequence: NaHCO(3) heated<Na(2)HPO(4) heated<Na(2)CO(3) heated. The cytotoxicity evaluation revealed that none of the alkaline heat treated Mg-Ca alloy samples induced toxicity to L-929 cells during 7days culture.

Occupational risk of lung cancer among lifetime non-smoking women in Shanghai, China

OBJECTIVES

Occupational lung carcinogens have been primarily studied in men. The aim of this study was to investigate occupational lung cancer risk in a cohort of Chinese non-smoking women.

METHODS

In 1996-2000, 71 067 non-smoking women who had held a job outside the home were interviewed for the prospective Shanghai Women's Health Study in China. Exposure to lung carcinogens was assessed by matching occupation and industry titles from lifetime occupational histories with lists of jobs identified by the International Agency for Research on Cancer to have potential exposure to: (1) known (A-list); or (2) suspected (B-list) carcinogens. In addition, similar occupational titles were grouped independent of the a priori defined lists. Relative risks (RRs) were calculated using Cox proportional hazards regression.

RESULTS

During follow-up through 2005, 219 incident lung cancer cases were diagnosed. Jobs on the A-list and B-list were held by 0.8-6.7% and 2.7-9.4% of the cohort, respectively. Overall, ever holding any job on the A-list or B-list was not associated with lung cancer incidence. Indications of excess risk were found for two subgroups: painters (A-list) and rubber workers (B-list) (RR = 2.0 and 1.7, respectively, p<or=0.1). An exploratory analysis of 35 occupational categories independent of the lists showed significantly increased risks for leather products/shoes, wood/paper products and miscellaneous production/transportation. The former two of these categories were similar to subgroups of the B-list, but broader than the specific a priori defined jobs.

CONCLUSIONS

Significantly elevated lung cancer risk was associated with employment in some broad occupational categories that also included jobs with potential exposure to suspected carcinogens (B-list). The results suggest that although similar exposures to those described on the B-list may play a role in this cohort of Chinese women, carcinogenic exposure may not be restricted only to the jobs on the B-list.

Evaluation of AGR2 and AGR3 as candidate genes for inflammatory bowel disease

Linkage analyses have implicated chromosome 7p21.3 as a susceptibility region for inflammatory bowel disease (IBD). Recently, the mouse phenotype with diarrhea and goblet cell dysfunction caused by anterior gradient protein 2 dysfunction was reported (European patent WO2004056858). The genes encoding for the human homologues AGR2 and AGR3 are localized on chromosome 7p21.3. The gene structures were verified and mutation detection was performed in 47 IBD patients. A total of 30 single nucleotide polymorphisms (SNPs) were tested for association to ulcerative colitis (UC, N = 317) and Crohn's disease (CD, N = 631) in a German cohort and verified in a UK cohort of 384 CD and 311 UC patients. An association signal was identified in the 5' region of the AGR2 gene (most significant SNP hcv1702494, nominal P(TDT) = 0.011, P(case/control) = 0.0007, OR = 1.34, combined cohort). The risk haplotype carried an odds ratio of 1.43 in the German population (P = 0.002). AGR2 was downregulated in UC patients as compared to normal controls (P < 0.001) and a trend toward lower expression was seen in carriers of the risk alleles. Luciferase assays of the AGR2 promoter showed regulation by the goblet cell-specific transcription factors FOXA1 and FOXA2. In summary, AGR2 represents an interesting new avenue into the etiopathophysiology of IBD and the maintenance of epithelial integrity.

ZNT7 and Zn2+ are present in different cell populations in the mouse testis

The aim of the present study was to investigate the relation of the spatial distribution between ZNT7 and chelatable zinc ions in the mouse testis. Immunohistochemical results demonstrated a wide distribution of ZNT7 in both seminiferous tubules and interstitial tissues of the testis. The spermatocytes and spermatids in the seminiferous tubules showed strong ZNT7 immunoreactivity whereas zinc autometallographic (AMG) staining was absent. Spermatozoa showed a high level of free zinc, but were void of ZNT7 immunoreactivity. No ZNT7 immunoreactivity and AMG grains were found in spermatogonia. Both ZNT7 and chelatable zinc were detected in Sertoli and Leydig cells. Furthermore, double immunofluorescence study demonstrated that the ZNT7 staining overlapped with that of TGN38 (a trans-Golgi marker), suggesting that ZNT7 was localized in the Golgi apparatus in the ZNT7-positive cells. In conclusion, ZNT7 and chelatable zinc were distributed in different cell populations except for Sertoli and Leydig cells in the mouse testis. ZNT7 may be involved in zinc transportation into the Golgi apparatus for protein packaging in the mouse testis.

Regulation of non-AU-rich element containing c-fms proto-oncogene expression by HuR in breast cancer

The role of RNA-binding proteins in cancer biology is recognized increasingly. The nucleocytoplasmic shuttling and AU-rich RNA-binding protein HuR stabilizes several cancer-related target mRNAs. The proto-oncogene c-fms, whose 3'untranslated region (3'UTR) is not AU-rich, is associated with poor prognosis in breast cancer. Using a large breast-cancer tissue array (N=670), we found nuclear HuR expression to be associated with nodal metastasis and independently with poor survival (P=0.03, RR 1.45), as well as to be co-expressed with c-fms in the breast tumors (P=0.0007). We described c-fms mRNA as a direct target of HuR in vivo, and that HuR bound specifically to a 69-nt region containing 'CUU' motifs in 3'UTR c-fms RNA. Overexpressing or silencing HuR significantly up- or down-regulated c-fms RNA expression, respectively. We also found that known glucocorticoid stimulation of c-fms RNA and protein is largely dependent on the presence of HuR. HuR, by binding to the 69-nt wild type, but not mutant, c-fms sequence can regulate reporter gene expression post-transcriptionally. We are the first to describe that HuR can regulate gene expression by binding non-AU-rich sequences in 3'UTR c-fms RNA. Collectively, our findings suggest that HuR plays a supportive role for c-fms in breast cancer progression by binding a 69-nt element in its 3'UTR, thus regulating its expression.

Effect of sequential surface irrigations on field-scale emissions of 1,3-dichloropropene

A field experiment was conducted to measure subsurface movement and volatilization of 1,3-dichloropropene (1,3-D) after shank injection to an agricultural soil. The goal of this study was to evaluate the effect of sprinkler irrigation on the emissions of 1,3-D to the atmosphere and is based on recent research that has shown that saturating the soil pore space reduces gas-phase diffusion and leads to reduced volatilization rates. Aerodynamic, integrated horizontal flux, and theoretical profile shape methods were used to estimate fumigant volatilization rates and total emission losses. These methods provide estimates of the volatilization rate based on measurements of wind speed, temperature, and 1,3-D concentration in the atmosphere. The volatilization rate was measured continuously for 16 days, and the daily peak volatilization rates for the three methods ranged from 18 to 60 microg m(-2) s(-1). The total 13-D mass entering the atmosphere was approximately 44-68 kg ha(-1), or 10-15% of the applied active ingredient This represents approximately 30-50% reduction in the total emission losses compared to conventional fumigant applications in field and field-plot studies. Significant reduction in volatilization of 1,3-D was observed when five surface irrigations were applied to the field, one immediately after fumigation followed by daily irrigations.

Liver metastasis in a case of adenoid cystic carcinoma of the Bartholin's gland: a rare presentation

INTRODUCTION

Adenoid cystic carcinoma of the Bartholin's gland accounts for a minority of all Bartholin's gland malignancies. Although local recurrences commonly occur distant metastasis is rare.

CASE REPORT

We present the first reported case of Adenoid cystic carcinoma of the Bartholin's gland with metastasis to the liver.

DISCUSSION

There is no consensus on the treatment of adenoid cystic carcinoma of the Bartholin's gland. Wide local excision and/or vulvectomy and radiotherapy are advocated for treatment of this cancer. There is not much data on treatment of metastasis and it varies according to site.

Adhesive growth of pancreatic islet cells on a polyglycolic acid fibrous scaffold

BACKGROUND

The use of cultured pancreatic islet cells for diabetes treatment offers several advantages. In theory, cultured cells show greater purity and lower immunogenicity. However, cultured islet cells display a low survival rate in vitro. In the present study we grew islet cells on a polyglycolic acid (PGA) fibrous scaffold to promote cell adhesion, growth, and viability during prolonged culture.

METHODS

Islets isolated from Wistar rat pancreata were digested with collagenase and purified by the Ficoll method. Cells were grown in culture with or without PGA scaffolds. Islet cell purity was determined using a dithizone stain; viability and survival rates were determined using an AO-PI stain. The insulin-secretion index was detected using radioimmunodetection and the growth on an adhesive scaffold analyzed using an inverted microscope and scanning electron microscope (SEM).

RESULTS

In contrast to the scaffold-free control group, cells cultured on PGA scaffolds exhibited improved morphology, less cell death, and prolonged survival times. Cell viability and survival rates were significantly increased in scaffolded cells when compared to control cells (P < .05). Increased insulin secretion was observed in the culture solution of scaffolded cells following stimulation with low glucose (5.6 mmol/L) versus high glucose (16.7 mmol/L). The secretion indices of the two groups were significantly different (P < .05). Islet cell growth, as observed under SEM, was tightly circumvolute, adhesive, and three-dimensional.

CONCLUSIONS

The present results demonstrated that islet cells can successfully grow and survive in culture on a PGA scaffold. These cells exhibited enhanced viability, survival, and insulin secretion.

New method to determine the total carbonyl functional group content in extractable particulate organic matter by tandem mass spectrometry

A functional group analysis method was developed to determine the quantitative content of carbonyl functional groups in atmospheric particulate organic matter (POM) using constant neutral loss scanning-tandem mass spectrometry (CNLS-MS/MS). The neutral loss method consists in monitoring the loss of a neutral fragment produced by the fragmentation of a precursor ion in a collision cell. The only ions detected are the daughter ions resulting from the loss of the neutral fragment under study. Then, scanning the loss of a neutral fragment characteristic of a functional group enables the selective detection of the compounds bearing the chemical function under study within a complex mixture. The selective detection of carbonyl functional groups was achieved after derivatization with pentafluorophenylhydrazine (PFPH) by monitoring the neutral loss of C(6)F(5)N (181 amu), which was characteristic of a large panel of derivatized carbonyl compounds. The method was tested on 25 reference mixtures of different composition, all containing 24 carbonyl compounds at randomly determined concentrations. The repeatability and calibration tests were satisfying as they resulted in a relative standard deviation below 5% and a linear range between 0.01 and 0.65 mM with a calculated detection limit of 0.0035 mM. Also, the relative deviation induced by changing the composition of the mixture while keeping the total concentration of carbonyl functional groups constant was less than 20%. These reliability experiments demonstrate the high robustness of the developed procedure for accurate carbonyl functional group measurement, which was applied to atmospheric POM samples.

CFTR and its key role in in vivo resting and luminal acid-induced duodenal HCO3- secretion

BACKGROUND AND AIMS

We investigated the role of the recently discovered, villous-expressed anion exchanger Slc26a6 (PAT1) and the predominantly crypt-expressed cystic fibrosis transmembrane regulator (CFTR) in basal and acid-stimulated murine duodenal HCO(3)(-) secretion in vivo, and the influence of blood HCO(3)(-) concentration on both.

METHODS

The proximal duodenum of anaesthetized mice was perfused in situ, and HCO(3)(-) secretion was determined by back-titration. Duodenal mucosal permeability was assessed by determining (51)Cr-EDTA leakage from blood to lumen.

RESULTS

Compared with wild type (WT) littermates basal duodenal HCO(3)(-) secretory rates were slightly reduced in Slc26-deficient mice at low ( approximately 21 mm), and markedly reduced at high blood HCO(3)(-) concentration ( approximately 29 mm). In contrast, basal HCO(3)(-) secretion was markedly reduced in CFTR-deficient mice compared with WT littermates both at high and low blood HCO(3)(-) concentration. A short-term application of luminal acid increased duodenal HCO(3)(-) secretory rate in Slc26a6-deficient and WT mice to the same degree, but had no stimulatory effect in the absence of CFTR. Luminal acidification to pH 2.5 did not alter duodenal permeability.

CONCLUSIONS

The involvement of Slc26a6 in basal HCO(3)(-) secretion in murine duodenum in vivo is critically dependent on the systemic acid/base status, and this transporter is not involved in acid-stimulated HCO(3)(-) secretion. The presence of CFTR is essential for basal and acid-induced HCO(3)(-) secretion irrespective of acid/base status. This suggests a coupled action of Slc26a6 with CFTR for murine basal duodenal HCO(3)(-) secretion, but not acid-stimulated secretion, in vivo.

From anesthetic mechanisms research to drug discovery

The ability to render patients insensible and amnesic to remarkably invasive procedures that are uncomfortable to watch, let alone experience, has been rightly designated as one of the greatest medical discoveries of all time. General anesthesia, introduced formally in the mid-nineteenth century, is now delivered to approximately 40 million patients every year in the United States alone. Given its central role in health care, it is indeed extraordinary how poorly we understand anesthesia and anesthetics. In fact, definitions are at best operational and convey little understanding of the underlying neurobiology, while the hypothetical mechanisms are surprisingly superficial. Worse, there is growing concern that the anesthetic drugs in current use, especially the inhaled anesthetics, have durable adverse effects on cognition.

Phenotypic analysis of Dlx5 overexpression in post-natal bone

Dlx5 plays an important role in the embryonic development of mineralized tissues. We hypothesized that Dlx5 also functions in regulating post-natal bone formation in mice. To prove this hypothesis, we infected 5-day-old bone sialoprotein (BSP)/avian retroviral receptor gene (TVA) transgenic mice with replication-competent retroviral vectors expressing wild-type Dlx5 (RCAS-Dlx5WT) and mutated Dlx5 at arginine (R) 31 of its homeodomain (RCAS-Dlx5RH). Immunohistochemistry indicated that RCAS-Dlx5WT increased BSP and osteopontin (OPN) expression, whereas it decreased that of osteocalcin (OC). RCAS-Dlx5RH mediated opposite effects. Semi-quantitative RT-PCR confirmed these results. Ex vivo overexpression of RCAS-Dlx5WT in BSP/TVA calvarial cells promoted, whereas that of RCAS-Dlx5RH inhibited, mineralized nodule formation as compared with that in control cells. Our results suggest that Dlx5 promotes expression of early markers of osteogenic differentiation and increases mineralization post-natally.