Oxidant/antioxidant parameters and their relationship with medical treatment in multiple myeloma

Multiple myeloma (MM) is a neoplastic disorder characterized by monoclonal multiplying of plasma cells. Although radiation, environmental factors, viruses and other factors have been suggested as potential causes of the disease, the aetiopathogenesis of MM is still obscure. This clinical study was designed to investigate the role of reactive oxygen species (ROS) in the aetiopathogenesis of the disease and the possible relationships between treatment and ROS production. For this purpose, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities as well as plasma nitric oxide (NO) and malondialdehyde (MDA) levels were measured in 14 MM patients newly diagnosed at stage III. The relationship between the above-mentioned parameters and vincristine-adriamycin-dexamethasone (VAD) therapy were also investigated in the same patients. All the enzyme activities and the parameters of oxidative stress were found to be significantly reduced after VAD therapy. These findings suggest that ROS may be involved in the aetiopathogenesis of MM. Further investigations with a larger cohort of MM patients are needed to provide definitive data about the role of ROS in MM and the alternative therapeutic approaches to MM.     

Tuftsin-mediated immunoprophylaxis against an isolate of Aspergillus fumigatus shows less in vivo susceptibility to amphotericin B

In the present study, we evaluated the immunopotentiating efficacy of tuftsin against experimental murine aspergillosis in both normal and immunodebilitant BALB/c mice. The animals were challenged with an isolate of Aspergillus fumigatus (1x10(8) cfu/mouse) that was showing less susceptibility to lower doses of amphotericin B in murine animal model. Co-administration of the immunomodulator tuftsin and liposomised-amphotericin B was found to be highly effective in the treatment of systemic infection of A. fumigatus in both immunocompetent and leukopenic mice. Moreover, pre-treatment of mice with liposomised-tuftsin prior to challenging them with A. fumigatus infection and subsequent treatment with tuftsin-bearing liposomised-amphotericin B was found to be extremely efficient in successful elimination of fungal pathogen. In another set of experiments, tuftsin-mediated antigen-specific memory antibody response was also assessed by immunizing the animals with A. fumigatus cytosolic antigen. The animals that received a booster 150 days after the first immunization with tuftsin-liposomes-antigen showed more resistance to A. fumigatus infection in comparison with the na?ve animals.     

Seeing is believing: Applications for nanotechnology in medical imaging and drug discovery

In recent years, progress has been made on in both micro- and nano-sized materials. At the same time, the advances in biology, specifically in genomics, have provided us with a wealth of information that can now be put into research applications and hopefully clinical practice. In our research center in Niskayuna, NY, we have been working on advanced technologies and novel approaches in both areas. Here we show several examples of how we have addressed different topics in our research. In addition, we will show, how we are combining nanotechnology with advanced biology. In particular, we will show examples of using nanoparticles for different applications in vitro and in vivo. We will also show the context for both technology areas and the applications of strategic importance.     

The inhibitory effect of calumenin on the vitamin K-dependent gamma-carboxylation system. Characterization of the system in normal and warfarin-resistant rats

The vitamin K-dependent gamma-carboxylation system is responsible for post-translational modification of vitamin K-dependent proteins, converting them to Gla-containing proteins. The system consists of integral membrane proteins located in the endoplasmic reticulum membrane and includes the gamma-carboxylase and the warfarin-sensitive enzyme vitamin K(1) 2,3-epoxide reductase (VKOR), which provides gamma-carboxylase with reduced vitamin K(1) cofactor. In this work, an in vitro gamma-carboxylation system was designed and used to understand how VKOR and gamma-carboxylase work together as a system and to identify factors that can regulate the activity of the system. Results are presented that demonstrate that the endoplasmic reticulum chaperone protein calumenin is associated with gamma-carboxylase and inhibits its activity. Silencing of the calumenin gene with siRNA resulted in a 5-fold increase in gamma-carboxylase activity. The results provide the first identification of a protein that can regulate the activity of the gamma-carboxylation system. The propeptides of vitamin K-dependent proteins stimulate gamma-carboxylase activity. Here we show that the factor X and prothrombin propeptides do not increase reduced vitamin K(1) cofactor production by VKOR in the system where VKOR is the rate-limiting step for gamma-carboxylation. These findings put calumenin in a central position concerning regulation of gamma-carboxylation of vitamin K-dependent proteins. Reduced vitamin K(1) cofactor transfer between VKOR and gamma-carboxylase is shown to be significantly impaired in the in vitro gamma-carboxylation system prepared from warfarin-resistant rats. Furthermore, the sequence of the 18-kDa subunit 1 of the VKOR enzyme complex was found to be identical in the two rat strains. This finding supports the notion that different forms of genetic warfarin resistance exist.     

Isolated congenital anonychia cases with coincident chromosomal fragility

Isolated anonychia without any associated phenotypical disturbances is one of the rarest anomalies of congenital nail disorders. Some or all fingers of the hands or feet could be affected. Anonychia can be encountered in dermatologic disorders like pemphigus, lichen planus, epidermolysis bullosa; it can also be seen as a component of some syndromes like Nail-Patella and Cooks syndromes. We present a sister couple in whom all fingernails and toenails were lacking without any additional physical sign. A fragile chromosomal site was also encountered in peripheral chromosome analysis in the long arm of the chromosome 10 in both of the cases.     

Differential induction of apoptosis by cigarette smoke extract in primary human lung fibroblast strains: implications for emphysema

Cigarette smoke is the principal cause of emphysema. Recent attention has focused on the loss of alveolar fibroblasts in the development of emphysema. Fibroblasts may become damaged by oxidative stress and undergo apoptosis as a result of cigarette smoke exposure. Not all smokers develop lung diseases associated with tobacco smoke, a fact that may reflect individual variation among human fibroblast strains. We hypothesize that fibroblasts from different human beings vary in their ability to undergo apoptosis after cigarette smoke exposure. This could account for emphysematous changes that occur in the lungs of some but not all smokers. Primary human lung fibroblast strains were exposed to cigarette smoke extract (CSE) and assessed for viability, morphological changes, and mitochondrial transmembrane potential as indicators of apoptosis. We also examined the generation of intracellular reactive oxygen species (ROS), 4-hydroxy-2-nonenal, and changes in glutathione (GSH) and glutathione disulfide (GSSG) levels. Each human lung fibroblast strain exhibited a differential sensitivity to CSE as judged by changes in mitochondrial membrane potential, viability, ROS generation, and glutathione production. Interestingly, the thiol antioxidants N-acetyl-L-cysteine and GSH eliminated CSE-induced changes in fibroblast morphology such as membrane blebbing, nuclear condensation, and cell size and prevented alterations in mitochondrial membrane potential and the generation of ROS. These findings support the concept that oxidative stress and apoptosis are responsible for fibroblast death associated with exposure to tobacco smoke. Variations in the sensitivity of fibroblasts to cigarette smoke may account for the fact that only some smokers develop emphysema.     

An unusual class of PITX2 mutations in Axenfeld-Rieger syndrome

BACKGROUND: Mutations in the PITX2 homeobox gene are known to contribute to Axenfeld-Rieger syndrome (ARS), an autosomal-dominant developmental disorder. Although most mutations are in the homeodomain and result in a loss of function, there is a growing subset in the C-terminal domain that has not yet been characterized. These mutations are of particular interest because the C-terminus has both inhibitory and stimulatory activities. METHODS: In this study we used a combination of in vitro DNA binding and transfection reporter assays to investigate the fundamental issue of whether C-terminal mutations result in gain or loss of function at a cellular level. RESULTS: We report a new frameshift mutation in the PITX2 allele that predicts a truncated protein lacking most of the C-terminal domain (D122FS). This newly reported mutant and another ARS C-terminal mutant (W133Stop) both have greater binding than wild-type to the bicoid element. Of interest, the mutants yielded approximately 5-fold greater activation of the prolactin promoter in CHO cells, even though the truncated proteins were expressed at lower levels than the wild-type protein. The truncated proteins also had greater than wild-type activity in 2 other cell lines, including the LS8 oral epithelial line that expresses the endogenous Pitx2 gene. CONCLUSIONS: The results indicate that the PITX2 C-terminal domain has inhibitory activity and support the notion that ARS may also be caused by gain-of-function mutations.