Effect of cyanate on nitrate reduction by Rhizobium meliloti SU47

Effect of cyanate on nitrate reduction by Rhizobium meliloti SU47 was studied. In the presence of cyanate assimilatory nitrate reduction activity appeared in the culture after a long lag and a conspicuously low level of nitrite was accumulated. Dissimilatory nitrate reduction activity was low in the intact cells precultured in KCNO of KNO₃ as compared to that in the control. Dissimilatory nitrate reductase activity in the extracts of cells precultured in KCNO was also compared to be low. In the extracts, dissimilatory nitrate reductase activity assayed with increasing concentrations of KCNO confirmed that KCNO acts as an inhibitor of the enzyme.     

Perceptions of Home Dialysis Training and Experience Among US Nephrology Fellows

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Frequent Alterations of MCPH1 and ATM are Associated with Primary Breast Carcinoma: Clinical and Prognostic Implications

Background

MCPH1 is a proximal regulator of DNA damage response pathway that is involved in recruitment of phosphorylated ATM to double-stranded DNA breaks.

Methods

To understand the importance of MCPH1 and ATM in deregulation of DNA damage response pathway in breast carcinoma, we studied m-RNA expression and genetic/epigenetic alterations of these genes in primary breast carcinoma samples.

Results

Our study revealed reduced expression (mRNA/protein) and high alterations (deletion/methylation) (96 %, 121 of 126) of MCPH1 and ATM. Mutation was, however, rare in inactivation of MCPH1. In immunohistochemical analysis, reduced protein expression of MCPH1, ATM and p-ATM were concordant with their molecular alterations (P = 0.03–0.01). Alterations of MCPH1 and deletion of ATM were significantly high in estrogen/progesterone receptor–negative than estrogen/progesterone receptor–positive breast carcinoma samples compared to early or late age of onset tumors, indicating differences in pathogenesis of the molecular subtypes (P = 0.004–0.01). These genes also showed differential association with tumor stage, grade and lymph node status in different subtypes of breast carcinoma (P = 0.00001–0.01). Their coalterations showed significant association with tumor progression and prognosis (P = 0.003–0.05). Interestingly, patients with alterations of these genes or MCPH1 alone had poor outcome after treatment with DNA-interacting drugs and/or radiation (P = 0.01–0.05).

Conclusions

Inactivation of MCPH1-ATM-associated DNA damage response pathway might have an important role in the development of breast carcinoma with diagnostic, prognostic and therapeutic implications.

     

Immune correlates of talactoferrin alfa in biopsied tumor of relapsed/refractory metastatic non-small cell lung cancer patients

Context: Talactoferrin alfa (TLF) is a unique recombinant form of human lactoferrin. The hypothesized mechanism of action involves TLF binding to the intestinal endothelium inducing dendritic cell maturation and cytokine release leading to infiltration of tumor with monocytes and T-lymphocytes and inhibition of tumor growth.

Objective: Based on promising phase II trial results, this correlative study was undertaken to examine immune mechanism of action of TLF in metastatic non-small cell lung cancer (NSCLC) patients.

Methods: Talactoferrin was administered orally at 1.5?g bid weeks 1–12 with 2 weeks off on a 14-week cycle. Enrolled patients had a pathologic diagnosis of NSCLC previously treated with at least two lines of systemic treatment. Patients had core biopsy of tumor before initiation of talactoferrin and at week 7 on TLF. Flow cytometry and quantitative immunohistochemistry for immune correlates were performed on the biopsied specimens.

Results: Four patients with metastatic NSCLC were enrolled. The trial was halted pre-maturely in light of negative phase III trial results. For the two patients who had repeat on-treatment tumor biopsies, a consistent increase in monocytes as a percentage of total immune cells was observed. Otherwise, no clear trend of increase or decrease was observed in any other immune cell parameters compared to matched patient pre-treatment biopsies.

Conclusion: Repeat biopsies for immune correlates by flow cytometry and quantitative immunohistochemistry in NSCLC patients are feasible. In the few patients sampled before trial closure, increased monocytes as a total percentage of the immune cell population within tumor was observed in response to TLF.     

A novel DPP IV-resistant C-terminally extended glucagon analogue exhibits weight-lowering and diabetes-protective effects in high-fat-fed mice mediated through glucagon and GLP-1 receptor activation

Aims/hypothesis

Modification of the structure of glucagon could provide useful compounds for the potential treatment of obesity-related diabetes.

Methods

This study evaluated N-acetyl-glucagon, (d-Ser²)glucagon and an analogue of (d-Ser²)glucagon with the addition of nine amino acids from the C-terminal of exendin(1-39), namely (d-Ser²)glucagon-exe.

Results

All analogues were resistant to dipeptidyl peptidase IV degradation. N-Acetyl-glucagon lacked acute insulinotropic effects in BRIN BD11 cells, whereas (d-Ser²)glucagon and (d-Ser²)glucagon-exe evoked significant (p?d-Ser²)glucagon-exe stimulated cAMP production (p?GLP-1-receptor (GLP-1R)-transfected cells but not in glucose-dependent insulinotropic polypeptide-receptor-transfected cells. In normal mice, N-acetyl-glucagon and (d-Ser²)glucagon retained glucagon-like effects of increasing (p?d-Ser²)glucagon-exe was devoid of hyperglycaemic actions but substantially (p?d-Ser²)glucagon-exe reduced the glycaemic excursion (p?p?d-Ser²)glucagon-exe. Twice-daily administration of (d-Ser²)glucagon-exe to high-fat-fed mice for 28 days significantly (p?p?p?2 consumption and locomotor activity were (p?p?p?p?p?Conclusions/interpretation This study emphasises the potential of (d-Ser²)glucagon-exe for the treatment of obesity-related diabetes.     

Human fibrocytes coexpress thyroglobulin and thyrotropin receptor

Thyroglobulin (Tg) is the macromolecular precursor of thyroid hormones and is thought to be uniquely expressed by thyroid epithelial cells. Tg and the thyroid-stimulating hormone receptor (TSHR) are targets for autoantibody generation in the autoimmune disorder Graves disease (GD). Fully expressed GD is characterized by thyroid overactivity and orbital tissue inflammation and remodeling. This process is known as thyroid-associated ophthalmopathy (TAO). Early reports suggested that in TAO, both Tg and TSHR become overexpressed in orbital tissues. Previously, we found that CD34(+) progenitor cells, known as fibrocytes, express functional TSHR, infiltrate the orbit, and comprise a large subset of orbital fibroblasts in TAO. We now report that fibrocytes also express Tg, which resolves as a 305-kDa protein on Western blots. It can be immunoprecipitated with anti-Tg Abs. Further, (125)iodine and [(35)S]methionine are incorporated into Tg expressed by fibrocytes. De novo Tg synthesis is attenuated with a specific small interfering RNA targeting the protein. A fragment of the Tg gene promoter fused to a luciferase reporter exhibits substantial activity when transfected into fibrocytes. Unlike fibrocytes, GD orbital fibroblasts, which comprise a mixture of CD34(+) and CD34(-) cells, express much lower levels of Tg and TSHR. When sorted into pure CD34(+) and CD34(-) subsets, Tg and TSHR mRNA levels become substantially higher in CD34(+) cells. These findings indicate that human fibrocytes express multiple "thyroid-specific" proteins, the levels of which are reduced after they infiltrate tissue. Our observations establish the basis for Tg accumulation in orbital GD.     

Periodontal findings in patients with oral submucous fibrosis and comet assay of affected gingival epithelial cells

Background: Oral submucous fibrosis (OSF) involves large sections of population and is related to certain chewing practices that involve direct exposure of the gingiva to noxious chemicals and additives. The impact of such practices, although studied extensively in relation to the cheek mucosa, is not elucidated as far as gingival tissues are concerned. The possible DNA damage on affected gingiva is also one of the objectives of the present study. Methods: One hundred cases of individuals with OSF and 89 without OSF were examined for periodontal parameters and compared. Biopsies of gingival tissue from both categories were examined with conventional hematoxylin and eosin staining for epithelial, connective tissue, and inflammatory changes. Comet assay of epithelial cells obtained from scraping the gingival surface of both patients with OSF and control individuals was performed . Results: Patients with OSF had poorer oral hygiene and greater loss of attachment, probing depth, and recession compared with controls. Significant histopathologic changes in the form of loss of rete ridges with gingival epithelium reduced to a flattened surface was observed. All the patients with OSF showed comet cells in larger numbers. The controls also showed comet cells but in fewer numbers, and the number of individuals showing comet cells was significantly less. Conclusion: OSF showed significant changes in affected gingiva, and the presence of comet cells in all the patients with OSF is a significant indicator of possible pathognomonic developments.