Highly Enantioselective Binaphthyl-Based Chiral Phosphoramidite Stabilized-Palladium Nanoparticles for Asymmetric Suzuki C-C Coupling Reactions

The optically pure binaphthyl-based phosphoramidite ligands and their perfluorinated analogs have been first used for the preparation of chiral palladium nanoparticles (PdNPs). These PdNPs have been extensively characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ³¹P NMR, and thermogravimetric analysis techniques. The circular dichroism(CD) analysis of chiral PdNPs exhibited negative cotton effects. Perfluorinated phosphoramidite ligands provided smaller (2.32-3.45 nm) and well-defined nanoparticles, in comparison with the nonfluorinated analog (4.12 nm). The catalytic behavior of binaphthyl-based phosphoramidite stabilized chiral PdNPs has been investigated in the asymmetric Suzuki C-C coupling reactions for the formation of sterically hindered binaphthalene units, and high isolated yields (up to 85%) were achieved with excellent enantiomeric excesses (>99% ee). Recycling studies revealed that chiral PdNPs could be reused over 12 times without significant loss in activity and enantioselectivity (>99% ee). The nature of the active species was also investigated with a combination of poisoning and hot filtration tests and found that catalytically active species is the heterogeneous nanoparticles. These results indicate that the use of phosphoramidite ligands as a stabilizer for developing efficient and unique chiral nanoparticles could open up a field for many other asymmetric organic transformations promoted by chiral catalysts.

A highly sensitive fluorescent sensor for fenamiphos detection in vegetable samples and living cells based-on an enzyme free system

Fenamiphos (Fena), an organophosphorous pesticide, is widely used in agricultural soils to control nematodes and thrips. This nematicide is harmful to fish, birds and humans and, causes several diseases. Therefore, the determination of the nematicide is crucial. Fena has been generally detected by enzyme-based systems which require specific conditions. Herein, we integrated a xanthene moiety and a pyrimidine moiety to obtain an enzyme-free detection system for Fena and, a fluorescent sensor (N-(6-(diethylamino)-9-(pyrimidin-5-yl)-3H-xanthen-3-ylidene)-N-ethylethanaminium hexafluorophosphate(V)) (RosPm) was easily prepared. The colorimetric and spectroscopic properties of RosPm were investigated using the UV-vis and fluorescence spectroscopy. RosPm exhibited a high selectivity and sensitivity to Fena over all the metal ions, the anions and pesticides tested in acetonitrile (ACN)/water (H₂O) (v:v, 1:1) solution. RosPm showed a clear visual change from purple to light-purple resulting fluorescent quenching with Fena. This sensor could be preferred for detecting Fena in vegetable samples such as tomato, pepper, and cucumber, and visualizing Fena in living MFC-7 cells.

A reaction-based system for the colorimetric detection of glyphosate in real samples

Glyphosate is widely used herbicides and causes several diseases in humans. Therefore, the detection of glyphosate is curial and urgent. Studies on the detection of glyphosate in literature are often based on inhibition of the enzyme acetylcholinesterase. In this study, we developed two simple colorimetric sensors, BP-Cl and CP-Cl, by linking 3-chloro-4-methylpyridine with 4-(dimethylamino)cinnamaldehyde or 4-(dimethylamino)benzaldehyde in a one-step reaction. The colorimetric and optical sensing properties of these compounds were investigated by the naked-eye and UV-Vis spectrophotometer in ACN/HEPES buffer (5 mM pH 8.0, 1:1 v/v). The sensors displayed high sensitivity and selectivity for glyphosate by color changes, which ranged from colorless to yellow for BP-Cl and yellow to orange for CP-Cl. The detection limits of BP-Cl and CP-Cl by the naked-eye detection were found as 15 µM and 10 µM. On the other hand, the detection limits of BP-Cl and CP-Cl via UV-Vis measurements were calculated as 0.847 µM and 1.23 µM, respectively. Moreover, the sensors were able to monitor glyphosate in water samples using the naked-eye, UV-Vis spectroscopy, and filter paper strips.

The osseous and dental changes of patients with chronic renal failure by CBCT

OBJECTIVES

The aim of the present study was to evaluate the osseous changes of the jaws of patients with chronic renal failure (CRF) by CBCT.

METHODS

On CBCT scans obtained from 15 patients with CRF and 15 control patients (7 males and 8 females), the mean was calculated for the antegonial index (AI), mental index (MI), panoramic mandibular index (PMI) and mandibular cortical index (MCI). The MI, AI and PMI, pulp chamber size, number of teeth with pulp calcification and lamina dura loss were compared using the paired t-test, and the MCI values were analysed using the χ(2) test.

RESULTS

There were no statistically significant differences in the PMI, MI and AI values in patients with CRF and the control group. With regard to MCI, the cortical margins of the mandible were more porous in patients with CRF than in the control group, and also soft-tissue calcifications, lamina dura loss and radiolucent defects were more common in patients with CRF. There were no statistically significant differences in pulp chamber size and pulp calcifications between patients with CRF and the control group.

CONCLUSIONS

Radiographic changes in the jawbones of patients with CRF may be commonly seen. CBCT is a valuable diagnostic tool for the evaluation of osseous findings, pulp chamber, soft-tissue calcifications and MCIs and allows indices measurement in three dimensions without any superposition.

Serum vanin-1 levels in renal transplant patients

OBJECTIVES

Vascular noninflammatory molecule 1 is a plasma membrane enzyme, also known as pantetheinase. It has been shown that vascular noninflammatory molecule 1 urinary and serum concentrations of vascular noninflammatory molecule 1 increase in nephrotoxicant-induced renal injury before classic markers. Tacrolimus and cyclosporine used as immunosuppressive agents are nephrotoxic drugs. This study sought to investigate alterations of vascular noninflammatory molecule 1 levels after a kidney transplant.

MATERIALS AND METHODS

This study included 28 renal allograft recipients without acute rejection. Before transplant, and the first and sixth months after the transplant, vascular noninflammatory molecule 1 and creatinine levels were measured in renal transplant recipients using enzyme-linked immunosorbent assay and spectrophotometric methods.

RESULTS

During the first month after transplant, we observed a significant increase in vascular noninflammatory molecule 1 levels compared with previous levels (P < .0001). Also, during the sixth month, vascular noninflammatory molecule 1 levels were higher than values previously taken (P < .01), although they were lower compared with the first month values (P = .004). No correlation was found between vascular noninflammatory molecule 1 and creatinine before transplant or during the first and sixth months after transplant. When the patients were divided into subgroups according to the immunosuppressive drugs used, in tacrolimus-treated patients, serum vascular noninflammatory molecule 1 levels were no different from the cyclosporine-administered levels measured at 3 different times.

CONCLUSIONS

We conclude that serum vascular noninflammatory molecule 1 levels may be low in the end-stage renal failure and transiently increase after transplant owing to transient renal function deterioration, which does not lead to elevation of serum creatinine levels in renal transplant patients.

Combined immune thrombocytopenic purpura and immunoglobulin A nephropathy: a similar pathophysiologic process?

IgA nephropathy is one of the most common forms of glomerulopathies. It is an immune complex-mediated glomerulonephritis diagnosed by the presence of mesangial IgA deposits that are often associated with mesangial cell proliferation. The IgG, C3, IgM, or other immunoglobulin light chains may be co-existed with IgA. Its pathogenesis suggested that it is responsible for enhancing the production of proinflammatory cytokines, chemokines, and growth factors. Platelet-derived growth factor (PDGF) has also been implicated as a modulator of disease activity. Immune thrombocytopenic purpura (ITP) is a bleeding disorder caused by thrombocytopenia that is not associated with a systemic disease. Its pathogenesis suggested an autoimmune disease in which IgG is thought to damage megakaryocytes, which are the precursors of platelet cells. Several studies reported that PDGF levels were higher in normal subjects than in patients with ITP. Moreover, ITP is a disease related to the antibody. Thus, our aim is to examine whether a similar pathophysiological relationship exist between ITP and IgAN that may be mediated by PDGF and/or IgG.

Assessment of oral health in peritoneal dialysis patients with and without diabetes mellitus

The incidence of chronic renal failure continues to rise worldwide, and although the oral and dental changes in individuals with this condition have been examined, investigations with diabetic peritoneal dialysis (PD) patients are limited. We therefore examined salivary pH, dry mouth, taste change, and mucosal ulceration in diabetic and nondiabetic uremic patients receiving PD. A total of 49 patients undergoing PD therapy were allocated to either the diabetic or the nondiabetic group. Salivary pH, dry mouth, taste change, and mucosal ulceration were determined for both groups. Salivary flow rate and pH were both lower in the diabetic group. Buffer capacity, dry mouth, taste change, and mucosal ulceration were all increased in that group. These findings were associated with level of glycosylated hemoglobin A1c. Our observations indicate that, compared with nondiabetic PD patients, patients with diabetes exhibit more severe oral uremic symptoms, including dry mouth, burning mouth syndrome, taste change, and mucosal ulcerations. The oral health in these patients should be followed.

Effects of cirrhosis on bone mineral density and bone metabolism

OBJECTIVE

The present study was undertaken to examine the correlation between the severity of liver disease and the presence and severity of bone disease in patients with hepatic cirrhosis.

MATERIALS AND METHODS

Between January 2005 and February 2006, 40 patients with cirrhosis and 22 healthy controls were enrolled in a cross-sectional study. All subjects underwent standard laboratory testing and bone densitometric studies of the lumbar spine and femoral neck using dual X-ray absorptiometry (DEXA).

RESULTS

Cirrhotic patients had lower serum follicle-stimulating hormone (FSH) levels than controls. Male patients had lower serum free testosterone (fT) levels than male controls. 25-hydroxyvitamin D (25-OHD3) levels were significantly higher in the controls as compared to patients with cirrhosis. In the cirrhotic group, 25-OHD3 concentrations did not differ significantly between patients with Child B and C class cirrhosis. As compared to the control group, cirrhotic patients had significantly elevated levels of urinary deoxypyridinoline (DPD). The cirrhotic patients also had a significantly lower mean spinal (SD) bone mineral density (BMD) than the control group. BMD of the lumbar spine (LS) was noted to be significantly lower in the Child C group than in the Child B group. In the cirrhotic patients, there was a positive correlation between the BMD T score of the femoral neck (FN) and albumin levels whereas there was a negative correlation between BMD T scores of the FN and age, bilirubin and prothrombin time (PT).

CONCLUSION

Osteopenia and osteoporosis are highly prevalent in individuals with liver cirrhosis. Cirrhotic patients should undergo routine bone densitometric assessment and, if necessary, be treated for osteoporosis.

Effects of sleep deprivation, nicotine, and selenium on wound healing in rats

Effects of sleep deprivation (SD), nicotine, and selenium (Se) on wound healing were studied in 50 male rats (Sprague-Dawley strain). Full-skin-thickness burns were produced in animals. Then, SD, nicotine, and Se administrations were applied to animals in different groups. Wound healing was assessed by pathological analysis of wound by counting fibroblasts, capillary vessels, polymorphonuclear leucocytes (PNLs), and by measuring radiolabeled immunoglobulin G (IgG) amount in wound area by radio-pharmaceutical and immunoscintigraphic procedures. The number of fibroblasts and capillary vessels were higher in control and Se groups than in sleep deprivation and nicotine groups, and the number of PNLs and the radiolabeled polyvalent IgG levels were higher in SD and nicotine groups than in control and Se groups. The results suggest that SD and nicotine may delay wound healing and that Se supplementation may accelerate wound healing by preventing nicotine-induced oxidative stress and lipid peroxidation.