Inhibition of nitric oxide generation by 23,24-dihydrocucurbitacin D in mouse peritoneal macrophages.

Nitric oxide (NO) has various physiological functions. However, uncontrolled overproduction of NO can be toxic in many pathologic conditions involving inflammatory tissue damage. In the present study, we examined effects of 23,24-dihydrocucurbitacin D (DHCD) isolated from the root of Bryonia alba L.

Ca2+: a stabilizing component of the transglutaminase activity of Galphah (transglutaminase II).

Galphah (transglutaminase type II; tissue transglutaminase) is a bifunctional enzyme with transglutaminase (TGase) and guanosine triphosphatase (GTPase) activities. The GTPase function of Galphah is involved in hormonal signaling and cell growth while the TGase function plays an important role in apoptosis and in cross-linking extracellular and intracellular proteins. To analyze the regulation of these dual enzymatic activities we examined their calcium-dependence and thermal stability in enzymes from several cardiac sources (mouse heart, and normal, ischemic and dilated cardiomyopathic human hearts).

Antimicrobial performance of alkaline ionic fluid (GC-100X) and its ability to remove Escherichia coli O157:H7 from the surface of tomatoes.

An efficacy test of GC-100X, a noncorrosive alkaline ionic fluid (pH 12) composed of free radicals and supplemented with xylitol, was carried out against six major foodborne pathogens-Staphylococcus aureus FRI 913, Salmonella enterica serovar Enteritidis ATCC 13076, S. enterica serovar Typhimurium DT104 Korean isolate, Vibrio parahaemolyticus ATCC 17803, Escherichia coli O157:H7 ATCC 43894, and Pseudomonas aeruginosa KCTC 1637-at three different temperatures (4, 25, and 36 degrees C) with or without organic load (2% yeast extract). Results revealed a more than 4-log10 (CFU/ml) reduction (1.

Nitric oxide mediates membrane depolarization-promoted survival of rat neuronal PC12 cells.

Membrane depolarization promotes neuronal survival through increases in intracellular calcium. Nitric oxide (NO) is a signaling molecule involved in many neuronal activity-dependent events. Since neuronal NO is generated by NO synthase (NOS) in a calcium-dependent manner and was shown to promote cell survival, we tested whether NO is involved in depolarization-promoted survival in neuronally differentiated PC12 cells.

Emergency physicians' perspectives on smallpox vaccination.

Objective: To evaluate emergency physician (EP) attitudes toward smallpox vaccination, the treatment of patients with suspected smallpox, and the threat of a bioterrorist attack.

Methods: This was a prospective study utilizing a standardized survey instrument that was distributed on November 16, 2002, and collected by February 1, 2003. EPs from a sample of 50 accredited emergency medicine programs were surveyed regarding their perspectives on smallpox vaccination.

Involvement of Ras in survival responsiveness to nitric oxide toxicity in pheochromocytoma cells.

Nitric oxide (NO) plays a key role in attenuation of tumor growth by activated macrophages that generate large amount of cytotoxic/cytostatic free radicals. However, some tumor cells may survive from NO cytotoxicity and continue to proliferate to malignant tumors. Since a protooncogene product Ras was shown to be activated by NO, this study investigated the involvement of Ras in the cell survival in response to NO cytotoxicity in pheochromocytoma (PC12) cells.

The role of nitric oxide in ocular surface diseases.

For the first time, the current series of studies provide a possible pathophysiologic mechanism of NO-induced ocular surface disease. NO is present in tear and aqueous humor and is suspected of having an important physiological role in maintaining normal homeostasis of the ocular surface. NO concentrations are higher in aqueous humor compared to tears, though some variability exists between different species.

The resistance mechanisms of b-lactam antimicrobials in clinical isolates of Acinetobacter baumannii.

Background: Despite increasing importance of Acinetobacter baumannii in nosocomial infections and rapid development of multi-antimicrobial resistance in this strain, the resistance mechanisms of beta-lactam antimicrobials in A. baumannii were not clearly defined. In order to observe the resistance mechanisms against beta-lactams and carbapenem, we characterized the production of beta-lactamases and outermembrane protein (OMP) profiles for the 44 clinical isolates of A.

A case of mediastinal angiomyolipoma.

Angiomyolipoma is a common tumor of the kidney but has rarely been found in the mediastinum. We report a case of angiomyolipoma of the posterior mediastinum in a 62-year-old woman. She experienced exertional dyspnea and intermittent cough at admission.

The role of nitric oxide in ocular surface diseases.

The role of nitric oxide (NO) in ocular surface diseases remains unknown. We investigated the conditions leading to increase NO generation in tears and the main sources of ocular surface tissue. We evaluated the possibility of a dual action (cell survival or cell death) depending on the amount of NO.

Involvement of p38 mitogen-activated protein kinase and apoptosis signal-regulating kinase-1 in nitric oxide-induced cell death in PC12 cells.

Although nitric oxide (NO) plays key signaling roles in the nervous systems, excess NO leads to cell death. In this study, the involvement of p38 mitogen-activated protein kinase (p38 MAPK) and apoptosis signal-regulating kinase-1 (ASK1) in NO-induced cell death was investigated in PC12 cells. NO donor transiently activated p38 MAPK in the wild type parental PC12 cells, whereas the p38 MAPK activation was abolished in NO-resistant PC12 cells (PC 12-NO-R).

Distinct characteristic of Galpha(h) (transglutaminase II) by compartment: GTPase and transglutaminase activities.

Galpha(h) (transglutaminase II) is a bifunctional enzyme possessing transglutaminase and GTPase activities. To better understand the factors affecting these two functions of Galpha(h), we have examined the characteristics of purified Galpha(h) from membrane and cytosol. GTP binding activity of mouse heart Galpha(h) was higher in membrane than that from cytosol.

Evaluation of the physician's ability to recognize the presence or absence of anemia, fever, and jaundice.

Objective: The evaluation of the patient through a comprehensive history and physical examination is considered the cornerstone of medical diagnosis, but many studies suggest that physicians have inadequate physical examination skills. It is unknown whether these skills are reliable and whether they can be adequately acquired through training. The objective of this study was to evaluate the ability of the clinician to detect the presence and discriminate the extent of clinical anemia, fever, and jaundice in an ED or hospitalized patient.

Mutational analysis of the tetrahydrobiopterin-binding site in inducible nitric-oxide synthase.

Inducible nitric-oxide synthase (iNOS) is a hemeprotein that requires tetrahydrobiopterin (H4B) for activity. The influence of H4B on iNOS structure-function is complex, and its exact role in nitric oxide (NO) synthesis is unknown. Crystal structures of the mouse iNOS oxygenase domain (iNOSox) revealed a unique H4B-binding site with a high degree of aromatic character located in the dimer interface and near the heme.

A new member of alpha 1-adrenoceptor-coupled G alpha h (transglutaminase II) family in pig heart: purification and characterization.

We previously reported an identification of a 77-kDa GTP-binding protein that co-purified with the alpha 1-adrenoceptor following ternary complex formation. In the present paper, we report on the purification and characterization of this GTP-binding protein (termed G alpha h5) isolated from pig heart membranes. After solubilization of pig heart membranes with NaCl, G alpha h5 was purified by sequential chromatographies using DEAE-Cellulose, Q-Sepharose, and GTP-agarose columns.

Identification of a distinct molecular mass G alpha(h) (transglutaminase II) coupled to alpha1-adrenoceptor in mouse heart.

Our previous studies on alpha1-adrenoceptor signaling suggested that G alpha(h) family is a signal mediator in different species. To elucidate the species-specificity of G alpha(h) family in molecular mass, we used the solubilized membranes from mouse heart and the ternary complex preparations containing alpha1-agonist/receptor/G-protein. Binding of [35S]GTPgammaS and the intensity of the [alpha-32P]GTP photoaffinity labeled protein resulting from activation of the alpha1-adrenoceptor were significantly attenuated by the antagonist, phentolamine.

Phospholipase C-delta1 and oxytocin receptor signalling: evidence of its role as an effector.

Although the oxytocin receptor modulates intracellular Ca2+ ion levels in myometrium, the identities of signal molecules have not been clearly clarified. Our previous studies on oxytocin receptor signalling demonstrated that 80 kDa Ghalpha is a signal mediator [Baek, Kwon, Lee, Kim, Muralidhar and Im (1996) Biochem. J.

Light-dependent corneal toxicity in streptozocin-treated rats.

Purpose: To find the role of nitric oxide (NO) in streptozocin-induced corneal toxicity in rats.

Methods: Sprague-Dawley rats were injected intraperitoneally with streptozotocin (65 mg/kg). For exposure to light, each rat cage was placed in a box surrounded with aluminum foil and illuminated for 6 hours per day with two 20-W fluorescent lamps at a distance of 50 cm.

Oxytocin receptor couples to the 80 kDa Gh alpha family protein in human myometrium.

One of the primary functions of the oxytocin receptor is to modulate intracellular calcium levels in myometrium. The oxytocin receptor has been purified and cloned. Although it has been suggested that oxytocin receptor couples with a GTP-binding regulatory protein (G-protein), the identity of this G-protein remains unclear.

Chloromethyl ketones block induction of nitric oxide synthase in murine macrophages by preventing activation of nuclear factor-kappa B.

N-alpha-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK), serine protease inhibitors, block many cytotoxic functions of immune cells including superoxide anion production, cytokine release, cell-mediated cytolysis, and nitric oxide (NO)-related macrophage functions. IFN-gamma/LPS-induced NO production from murine peritoneal macrophages was inhibited by TPCK and TLCK in a dose-dependent manner (EC50s: approximately 20 microM for TPCK and approximately 30 microM for TLCK). Viability exceeded 91% with 25 microM TPCK and with 80 microM TLCK.

Nitric oxide generation from streptozotocin.

Streptozotocin (STZ), a diabetogenic agent, is thought to damage pancreatic beta-cells by activating immune mechanisms and by alkylating DNA. In the present study, we demonstrated that STZ can produce nitric oxide (NO), a bioregulatory and cytotoxic molecule. When STZ was dissolved in a sodium phosphate buffer (50 mM, pH 7.

Inactivation of nitric oxide synthase after prolonged incubation of mouse macrophages with IFN-gamma and bacterial lipopolysaccharide.

Large amounts of nitric oxide (NO) are produced by the inducible isoform of NO synthase (iNOS) in many cell types once the iNOS gene is transcriptionally activated. In primary mouse peritoneal macrophages elicited by thioglycolate broth, expression of iNOS follows treatment with IFN-gamma and is synergistically increased by the addition of bacterial LPS. Expression of iNOS is suppressible at transcriptional and translational levels by certain cytokines and microbial products.

Inhibition of tumor cell ribonucleotide reductase by macrophage-derived nitric oxide.

Macrophage-derived nitric oxide (NO) is cytostatic to tumor cells and microbial pathogens. We tested whether one molecular target for the cytostatic action of NO may be ribonucleotide reductase (RR), a rate-limiting enzyme in DNA synthesis. In a concentration-dependent manner, NO gas and lysates of activated macrophages that generated comparable amounts of NO led to the same degree of inhibition of partially purified RR from L1210 mouse lymphoma cells.