Efficacy and safety of fluticasone propionate 250 microg administered once daily in patients with persistent asthma treated with or without inhaled corticosteroids.

BACKGROUND: Studies have shown fluticasone propionate (FP) 100, 200, and 500 microg administered once daily to be effective in the treatment of asthma. The efficacy of a once daily regimen of FP 250 microg has not been evaluated previously. OBJECTIVE: We sought to evaluate the efficacy and safety of inhaled FP 250 microg administered once daily in patients currently receiving inhaled short-acting beta-agonists (SABA) alone or inhaled corticosteroids (ICS). METHODS: In two separate studies, 408 patients in the SABA study and 401 patients in the ICS study were randomly assigned to receive FP 250 microg or placebo for 12 weeks through the Diskus device (GlaxoSmithKline, Research Triangle Park, NC) each morning. RESULTS: At the study endpoint, SABA patients treated with FP and placebo had mean increases in forced expiratory volume in 1 second from baseline of 0.23 +/- 0.03 L and 0.10 +/- 0.03 L, respectively (P < 0.001). ICS patients treated with FP had a mean increase of 0.08 +/- 0.02 L compared with a decrease in forced expiratory volume in 1 second of -0.08 +/- 0.03 L with placebo (P < 0.001). Changes of similar magnitude in morning peak expiratory flow rates were seen with FP in both the SABA and ICS studies. Fewer FP-treated ICS study patients were withdrawn from the study as a result of predetermined asthma stability criteria and, therefore, those patients had a greater probability of remaining in the study than placebo-treated patients (P < 0.001). CONCLUSIONS: FP 250 microg, once daily, produced greater improvements in pulmonary function and asthma symptom control than placebo. This new treatment regimen provides clinicians with an additional therapeutic option for patients with asthma previously treated with either beta2-agonists alone or ICS.     

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in colorectal cancer.

Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at x 400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31+/-10 vs 19+/-8/0.15 mm2 field, P<0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (P<0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (P<0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (P<0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.     

Phosphorylated KDR is expressed in the neoplastic and stromal elements of human renal tumours and shuttles from cell membrane to nucleus

Vascular endothelial growth factor (VEGF)-A is an important angiogenic factor in establishing the vasculature in renal cell carcinomas (RCCs). Since little is known about VEGF signalling in RCCs, the profile of phosphorylated KDR (pKDR) has been investigated and the intracellular location of the receptor has been examined in the present study. Using two monoclonal antibodies raised against the phosphorylated KDR epitopes (Y1059 and Y1214) known to mediate different VEGF functions, together with a commercial anti-KDR antibody and immunohistochemistry, the expression of pKDR was investigated in a series of normal (n = 25) and neoplastic kidneys (n = 54; clear cell n = 35; papillary n = 10; oncocytomas n = 8). pKDR was present in many tissue elements of both normal and neoplastic renal tissues, with strong expression in the cell membrane, cytoplasm, and nuclei of normal kidney and tumour cells, as well as endothelial cells in tumours of all histological types. Patterns and intensity were similar using both anti-pKDR antibodies. There was no significant correlation in clear cell carcinomas between pKDR expression and age (p = 0.57), tumour size (p = 0.2), gender (p = 0.59), grade (p = 0.2) or histological type (p = 0.36). To delineate further the intracellular processing that might account for the cellular distribution, confocal microscopy was also performed. Antibodies to the different phosphorylated epitopes demonstrated different intracellular staining patterns. This study shows that pKDR is present in a wide variety of renal tumours, suggesting that anti-VEGF therapy might have direct effects on tumour cells. It further suggests that cells traffic pKDR depending on the precise KDR tyrosines that are autophosphorylated in a manner that enables receptor activation to result in different functions.     

Structural organization of the neutrophil NADPH oxidase: phosphorylation and translocation during priming and activation

The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is part of the microbicidal arsenal used by human polymorphonuclear neutrophils (PMNs) to eradicate invading pathogens. The production of a superoxide anion (O2-) into the phagolysosome is the precursor for the generation of more potent products, such as hydrogen peroxide and hypochlorite. However, this production of O2- is dependent on translocation of the oxidase subunits, including gp91phox, p22phox, p47phox, p67phox, p40phox, and Rac2 from the cytosol or specific granules to the plasma membrane. In response to an external stimuli, PMNs change from a resting, nonadhesive state to a primed, adherent phenotype, which allows for margination from the vasculature into the tissue and chemotaxis to the site of infection upon activation. Depending on the stimuli, primed PMNs display altered structural organization of the NADPH oxidase, in that there is phosphorylation of the oxidase subunits and/or translocation from the cytosol to the plasma or granular membrane, but there is not the complete assembly required for O2- generation. Activation of PMNs is the complete assembly of the membrane-linked and cytosolic NADPH oxidase components on a PMN membrane, the plasma or granular membrane. This review will discuss the individual components associated with the NADPH oxidase complex and the function of each of these units in each physiologic stage of the PMN: rested, primed, and activated.     

Dissociation of acetylcholine- and cyclic GMP-induced currents inXenopu oocytes

InXenopus follicular oocytes, activation of muscarinic receptors evokes a slow potassium current (H-response); a similar current is evoked by intracellular injection of cyclic guanosine 3,5-monophosphate, cGMP (Dascal et al. 1984). We have tested the hypothesis that cGMP may be the second messenger that mediates the opening of K channel by acetylcholine (ACh). ACh elevated the intracellular level of cGMP with a time course similar to that of the development of the muscarinic H-response; maximal increase in cGMP concentration above the control was about 0.2 pmole/oocyte. The amount of injected cGMP that produced a detectable K current (threshold dose) varied between 0.5 and 3 pmole/oocyte. At low doses of cGMP, the slope of log dose-log response curve was about 2.5, suggesting involvement of a biochemical process with a positive cooperativity of at least 3. Higher doses of cGMP evoked, in addition to the outward current, an irregular, rapidly developing, long-lasting inward current, that never reached amplitudes comparable to those of ACh-evoked Cl currents. The K current elicited by cGMP was insensitive to elevation or depletion of external Ca. It was potentiated by isobutylmethylxanthine (IBMX). ACh strongly inhibited the cGMP-evoked K current when applied at the plateau of the latter. 4-Phorbol 12,13-dibutyrate (PDBu) (1 M) rapidly and completely inhibited the cGMP response. It is concluded, that most of the results presented in this report contradict the hyothesis that cGMP is the intracellular mediator of ACh-induced changes in membrane conductance in the oocytes.Abbreviations ACh acetylcholine - cAMP cyclic adenosine 3,5-monophosphate - cGMP cyclic guanosine 3,5-monophosphate - EGTA ethylenediaminetetraacetic acid - Hepes N-2-hydroxyethyl-piperazinc-N-2-hydroxypropanesulphonic acid - IBMX 3-isobutyl-l-methylxanthine - IP₃ inositol 1,4,5-trisphosphate - PDBu 4-phorbol 12,13-dibutyrate     

Bloom's syndrome. XIX. Cytogenetic and population evidence for genetic heterogeneity

Cells with abnormally high rates of sister-chromatid exchange (SCE) are uniquely characteristic of Bloom's syndrome (BS). However, in one in five persons a minor population of cells with a low-SCE phenotype circulates in the blood. The origin and significance of the low-SCE cells in BS have never been understood, although they are assumed to arise by somatic mutation. In the present investigation, the enigmatic high-SCE/low-SCE mosaicism was investigated by comparing the incidence in several subpopulations of persons in the Bloom's Syndrome Registry who exhibit the two types of cells, and a striking negative correlation emerged: in persons with BS whose parents share a common ancestor, the case in approximately half of registered persons, low-SCE cells are found only rarely; conversely, the mosaicism occurs almost exclusively in persons with BS whose parents are not known to share a common ancestor. Because those who share a common ancestor are predominantly homozygous-by-descent at the mutated BS locus, the negative correlation is interpreted to mean that the emergence of low-SCE cells in BS in some way depends on the pre-existence of compound heterozygosity. A corollary to this is that BS is genetically heterogeneous.     

Cross-sectional analysis of clinical and environmental isolates of Pseudomonas aeruginosa: biofilm formation, virulence, and genome diversity

Chronic lung infections with Pseudomonas aeruginosa biofilms are associated with refractory and fatal pneumonia in cystic fibrosis (CF). In this study, a group of genomically diverse P. aeruginosa isolates were compared with the reference strain PAO1 to assess the roles of motility, twitching, growth rate, and overproduction of a capsular polysaccharide (alginate) in biofilm formation. In an in vitro biofilm assay system, P. aeruginosa displayed strain-specific biofilm formation that was not solely dependent on these parameters. Compared with non-CF isolates, CF isolates expressed two opposing growth modes: reduced planktonic growth versus efficient biofilm formation. Planktonic cells of CF isolates showed elevated sensitivity to hydrogen peroxide, a reactive oxygen intermediate, and decreased lung colonization in an aerosol infection mouse model. Despite having identical genomic profiles, CF sequential isolates produced different amounts of biofilm. While P. aeruginosa isolates exhibited genomic diversity, the genome size of these isolates was estimated to be 0.4 to 19% (27 to 1,184 kb) larger than that of PAO1. To identify these extra genetic materials, random amplification of polymorphic DNA was coupled with PAO1-subtractive hybridization. Three loci were found within the genomes of two CF isolates encoding one novel homolog involved in retaining a Shigella virulence plasmid (mvpTA) and two divergent genes that function in removing negative supercoiling (topA) and biosynthesis of pyoverdine (PA2402). Together, P. aeruginosa biodiversity could provide one cause for the variation of morbidity and mortality in CF. P. aeruginosa may possess undefined biofilm adhesins that are important to the development of an antibiofilm therapeutic target.     

Novel sequence variants in the TMC1 gene in Pakistani families with autosomal recessive hearing impairment

Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified.