Oxidant/antioxidant status in blood of patients with malignant breast tumour and benign breast disease

The aim of this study was to investigate the alterations in lipid peroxidation and antioxidant enzyme defences in the blood of patients with malignant breast tumour and benign breast disease. Forty patients with malignant breast tumour, 20 patients with benign breast disease and also 20 healthy control subjects were recruited for the study. Malondialdehyde levels in plasma and erythrocytes, and the activities of erythrocyte CuZn-superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase were measured. Malondialdehyde levels were higher in patients with both benign breast disease and malignant breast tumour compared with control subjects. The activities of all antioxidant enzymes were higher in patients with malignant breast tumour, while only glutathione peroxidase and CuZn-superoxide dismutase activities were higher in patients with benign breast disease. Except for glucose-6-phosphate dehydrogenase, the antioxidant enzymes studied correlated positively with the malondialdehyde levels in patients with malignant breast tumour. On the other hand, only glucose-6-phosphate dehydrogenase activity was increased by the level of malignancy. The activity increases in erythrocyte antioxidant enzymes may be a compensatory upregulation in response to increased oxidative stress especially in patients with malignant breast tumour.     

Rapid deposition of wheat cell wall structural proteins in response to Fusarium-derived elicitors

Two novel cell wall structural proteins of spring wheat (Triticum aestivum L. em Thell.). undergo rapid deposition in the cell wall matrix in a H(2)O(2)-dependent reaction after the elicitation of cultures with Fusarium graminearum (L.)-derived elicitor. The amino acid compositions of these proteins were remarkably similar and indicated that they were highly acidic (pI 3.8). These proteins contained 13--17% each of Gly, Glx and Ser with lesser amounts (6--8%) of Ala, Asx and Thr, and it has been suggested that they are known as glycine- and serine-rich proteins (GSRPs). SELDI-MS ionization spectra demonstrated that these proteins have low molecular masses of 8590 and 4292 Da. These results are discussed in relation to the possible role of these novel proteins in rapid, cell wall defensive reactions to pathogenic attack.     

The role of K+ATP channels in the control of pre- and post-ischemic left ventricular developed pressure in septic rat hearts

Myocardial function is impaired 24 h after the induction of sepsis, however, recovery of left ventricular (LV) function after 35 min of global ischemia is complete. The mechanisms by which this protection occurs are unknown. Ischemic preconditioning, another form of myocardial protection from ischemia/reperfusion (I/R) injury, has been shown to be modulated by ATP-sensitive potassium (K+ATP) channels. To investigate the role of K+ATP channels in the regulation of coronary flow (CF) and protection from I/R injury in septic rat hearts, we assessed the effects of the K+ATP channel antagonist glibenclamide (GLIB) and the agonist cromakalim (CROM) on pre- and post-ischemic CF and left ventricular developed pressure (LVDP). Although GLIB decreased pre-ischemic CF in both control and septic rat hearts, LVDP was unaffected. After I/R, CF was decreased in GLIB-treated control and septic rat hearts and LVDP was more severely depressed in control rat hearts than in septic rat hearts. CROM increased pre-ischemic CF in the septic group although LVDP was unaltered in both groups. After I/R, control rat heart CF was depressed but LVDP completely recovered. Post-ischemic CF in septic rat hearts was elevated compared with vehicle-treated septic rat hearts, but the recovery of LVDP was not improved. These results suggest that K+ATP channels modulate CF in septic rat hearts, but do not mediate cardioprotection as observed in control rat hearts.     

Polystoma macrocnemis n. sp. (Monogenea: Polystomatidae) from the Iranian longlegged wood frog Rana macrocnemis (Ranidae) in Turkey

Polystoma macrocnemis n. sp. (Polystomatidae) is described from the urinary bladder of Rana macrocnemis (Ranidae) in Turkey. Its general morphology is similar to that of other members of the genus, but it is distinguished from closely related species by numerical parameters of the hamuli and also by its host species and geographical range.     

Constituents of the stems of Macrococculus pomiferus and their inhibitory activities against cyclooxygenases-1 and -2

As part of our program directed towards the discovery of new cancer chemopreventive agents from plants, the EtOAc-soluble extract of the stems of M. pomiferus was found to inhibit the enzyme cyclooxygenase-2 (COX-2). Bioassay-directed fractionation of this extract led to the isolation of two dibenzylbutyrolactone lignans, (8R,8'R)-3'-O-demethyl-5-hydroxymatairesinol (1) and (8R,8'R)-3'-O-demethyl-5-methoxymatairesinol (2), as well as seven known compounds, (-)-5'-methoxyyatein (3), blumenol A, (-)-deoxypodophyllotoxin (anthricin), (-)-deoxypodorhizone, 2,6-dimethoxyhydroquinone, 4-hydroxybenzaldehyde, and beta-sitosterol glucoside. The structures of compounds 1 and 2 were determined using spectroscopic data (1D and 2D NMR, and HREIMS), and the 8R and 8'R absolute stereochemistry was established for both 1 and 2 on the basis of their CD spectra. All isolates obtained in the present study were evaluated for their inhibitory effects with both COX-1 and -2. Of these, only 5'-methoxyyatein (3) showed weak activity against COX-2, while all other compounds isolated were inactive. The COX-2 inhibitory activity of the EtOAc extract was also traced to the presence of several common fatty acids by LC-MS.     

Selective and rapid liquid chromatography-mass spectrometry method for the determination of lercanidipine in human plasma

A specific liquid chromatography-mass spectrometric (LC-MS/MS) assay was developed and validated for the determination of lercanidipine, a dihydropyridine calcium channel blocker, in human plasma. Lercanidipine R-D3 was used as internal standard (IS). The drug was extracted from plasma using liquid-liquid extraction technique utilizing hexane: ethyl acetate as extraction solvent. The samples were analyzed using a prepacked Thermo Hypersil C(8) column and a mobile phase composed of a mixture of aqueous acetic acid and triethylamine in methanol. An ion trap mass spectrometer equipped with electrospray ionization (ESI) source operating in the positive ion mode was used to develop and validate the method. The method was proved to be sensitive and specific by testing six different human plasma batches. Linearity was established for the concentration ranges of 0.1-16 ng/ml with a regression factor of 0.9996. The lower limit of quantitation was identifiable and reproducible at 0.1 ng/ml with a precision of 7.2%.     

Cardiac transplantation and resistance artery myogenic tone

Transplantation is an effective treatment for end-stage heart disease; however, most grafts eventually fail by progressive cardiac failure. Primarily, failure is ischemic due to the occlusive nature of transplant vascular disease (TVD). Early after transplantation and preceding TVD, alterations in coronary physiology such as reduced vascular myogenic tone occur. Resistance arteries possess an inherent ability to constrict in response to transmural pressure; this constrictive response (myogenic tone) is important in fluid homeostasis. Recent evidence suggests that a decline in myogenic tone leads to deficits in cardiac contractility. Factors that reduce myogenic tone in transplantation include constitutive nitric oxide synthase and inducible nitric oxide synthase catalyzed, NO-mediated vasodilation as well as deficits in arterial contractile function. Reduced myogenic tone in allograft resistance arteries increases coronary blood flow such that hydrostatic pressure surpasses oncotic pressure, causing cardiac interstitial edema. This generalized edema decreases ventricular compliance leading to heart failure during the course of acute immune rejection of the graft. Cyclosporine A treatment reduces immune mediated dysregulation of myogenic tone, resulting in reduced interstitial edema and improved cardiac function. In this review, we discuss aspects of TVD and myogenic tone signaling mechanisms and how aberrations in myogenic regulation of arterial tone contribute to functional changes observed in cardiac transplant.     

Polyvinyl alcohol--trypsin as a catalyst for amino acid ester synthesis in organic media

The bovine trypsin-catalyzed synthesis of N-alpha-benzoyl-DL-arginine esters from N-benzoyl-DL-arginine were studied in various organic solvents. Trypsin was immobilized to polyvinyl alcohol (PVA) by adsorption from its aqueous solutions. Immobilized enzyme showed higher catalytic activities than free enzyme for amino acid esterification in ethanol. The yield of ester is strongly dependent upon the PVA/trypsin ratio and water content in the reaction medium. The rate and equilibrium constant of the ester formation reaction are also dependent on water content.