Repeat administration of DNA/liposomes to the nasal epithelium of patients with cystic fibrosis

The major cause of mortality in patients with cystic fibrosis (CF) is lung disease. Expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene product in the airways is a potential treatment. Clinical studies in which the CFTR cDNA was delivered to the respiratory epithelia of CF patients have resulted in modest, transient gene expression. It seems likely that repeated administration of the gene transfer vector will be required for long-term gene expression. We have undertaken a double-blinded study in which multiple doses of a DNA/liposome formulation were delivered to the nasal epithelium of CF patients. Ten subjects received plasmid DNA expressing the CFTR cDNA complexed with DC-Chol/DOPE cationic liposomes, whilst two subjects received placebo. Each subject received three doses, administered 4 weeks apart. There was no evidence of inflammation, toxicity or an immune response towards the DNA/liposomes or the expressed CFTR. Nasal epithelial cells were collected 4 days after each dose for a series of efficacy assays including quantitation of vector-specific DNA and mRNA, immunohistochemistry of CFTR protein, bacterial adherence, and detection of halide efflux ex vivo. Airway ion transport was also assessed in vivo by repeated nasal potential difference (PD) measurements. On average, six of the treated subjects were positive for CFTR gene transfer after each dose. All subjects positive for CFTR function were also positive for plasmid DNA, plasmid-derived mRNA and CFTR protein. The efficacy measures suggest that unlike high doses of recombinant adenoviral vectors, DNA/liposomes can be successfully re-administered without apparent loss of efficacy.     

Intestinal ischemia-reperfusion-induced acute lung injury and oncotic cell death in multiple organs

Most acute respiratory distress syndrome studies have been focused on the lung injury. Little is known about other organs during the development of acute respiratory distress syndrome. Herein, we investigated the injury and cell death in multiple organs after intestinal ischemia-reperfusion (IIR) in C57BL/6 mice. Terminal transferase dUTP nick end labeling staining was used as a marker of cell death. Caspase 3 and cathepsin B activation as markers of caspase-dependent and caspase-independent apoptosis, respectively, and electron microscopy for ultimate characterization of cell death were used. In comparison with control and sham-operated mice, the IIR group showed interstitial inflammatory infiltrates in the lung and significant increases of lung injury parameters and plasma lactate dehydrogenase and aspartate aminotransferase levels. Terminal transferase dUTP nick end labeling-positive cells and immunostaining for hemeoxygenase 1, an enzyme induced by inflammatory stimuli, were increased in the lung, heart, and kidney, but not in the liver. The number of hemeoxygenase 1-positive cells positively and significantly correlated to the number of terminal transferase dUTP nick end labeling-positive cells. Cell death was not associated with caspase 3 or cathepsin B activation. Electron microscopy showed morphological features compatible with oncotic rather than apoptotic cell death or necrosis, including mitochondrial swelling and cytoplasm disorganization in pulmonary and renal epithelial cells, lung and cardiac endothelial cells, and myocytes. These results indicate that, although lung injury is the most significant manifestation after IIR, oncotic cell death occurs in the lung, heart, and kidney, which may be related to ischemia and inflammation.     

Receptor interactions of imidazolines. IV. Structural requirements for alpha adrenergic receptor occupation and receptor activation by clonidine and a series of structural analogs in rat aorta

Clonidine and a series of nine halogen and alkyl-substituted structural analogs were evaluated for alpha adrenergic receptor agonist activity in rat aorta. Phenylephrine was included for comparison. All the imidazolines were partial agonists with respect to phenylephrine due to the fact that they only weakly activated the receptor. Whereas phenylephrine requires approximately 0.2% receptor occupancy to produce a response 20% of maximum, the imidazolines required from 25 to 100% receptor occupancy to produce the same response. Although clonidine and its structural analogs are from 125 to 500 times weaker activators of the alpha adrenergic receptor than phenylephrine, they have from 2 to 60 times higher affinity for the receptor than phenylephrine. The results support our previous conclusions that a dichotomy exists between the factors that direct receptor occupation and receptor activation since the structural requirements for each of these parameters differ.     

Correlates of endothelial function and their relationship with inflammation in patients with familial hypercholesterolaemia

Atherosclerosis is characterized by a low-grade systemic inflammatory response and endothelial dysfunction. The aim of the present study was to investigate a possible relationship between systemic markers of inflammation, serum markers of endothelial activation and endothelium-dependent vasodilatation in a group of high-risk patients, and to evaluate the effects of intervention with high doses of simvastatin on these parameters. In patients with heterozygous familial hypercholesterolaemia, without atherosclerotic events, flow-mediated vasodilatation (FMD) of the brachial artery was measured after a wash-out period for lipid-lowering drugs (baseline) and after 6 weeks of treatment with simvastatin 80 mg daily. Levels of C-reactive protein (CRP), soluble intercellular cell-adhesion molecule (s-ICAM) and soluble E-selectin (s-E-selectin) were determined at baseline and again after 6 weeks and 12 months of therapy. A total of 35 subjects participated in the study (mean age 42 years; 60% male). When divided into tertiles according to FMD (<3.9%, 3.9-9.0% and >9.0%), no differences in levels of CRP, s-ICAM-1 and/or s-E-selectin were detected between the groups. Moreover, no changes in FMD, levels of CRP or levels of s-ICAM-1 and/or s-E-selectin were found during treatment with simvastatin. We conclude that endothelial function, as reflected by FMD, does not seem to be related to markers of inflammation in familial hypercholesterolaemia subjects at high risk of, but without clinically overt signs of, atherosclerosis. Moreover, aggressive lipid-lowering therapy with simvastatin does not result in improved endothelial function or in a reduction of markers of inflammation in these patients.     

Mortality among maintenance employees potentially exposed to asbestos in a refinery and petrochemical plant

This paper reports the mortality experience from 1948 to 1989 of 2,504 maintenance employees who had a minimum of one year of employment in jobs with potential exposure to asbestos at a Texas refinery and petrochemical plant. For the purposes of this study, “potential exposure” is equated with those jobs or crafts having the greatest direct potential proximity to, or which worked directly with, asbestos-containing materials, especially asbestos-containing thermal insulation. Approximately one-half of the study population had 10 years or longer potential exposure, and 80% had their first potential exposure before 1970. The total population exhibited significantly lower mortality for all causes, the standardized mortality ratio (SMR = 77); and for all cancer (SMR = 85), as compared to residents in the surrounding communities. Statistically significant deficits in mortality were also observed in a number of noncancerous diseases such as heart disease (SMR = 78; 95% CI = 69-88), nonmalignant respiratory disease (SMR = 70; 95% CI = 50-95), and cirrhosis of the liver (SMR = 44; 95% CI = 22-79). Mortality among employees who had 20 years or longer since their first potential exposure was also examined; the pattern of mortality was similar to that exhibited by the total cohort, with a slight increase in the SMR for most of the causes. The only statistically significant excess of mortality found was a fourfold increase in mesothelioma (5 observed and 1.2 expected deaths); the SMR was 428 (95% CI = 139-996) for the total cohort and was 469 (95% CI = 152-1093) for those who had 20 years or more since first potential exposure. In contrast to asbestos industry worker studies, mortality for lung cancer was substantially lower than the general population (SMR = 81; 95% CI = 63-103). The observed number of deaths for cancer of the larynx was virtually the same as expected (3 observed vs. 2.8 expected). This study also showed decreased mortality for cancers of gastrointestinal organs such as the esophagus (SMR = 78), stomach (SMR = 63), large intestine (SMR = 91), rectum (SMR = 55), or pancreas (SMR = 90)—cancers that have been reported to be elevated in studies of various industry workers directly exposed to asbestos. © 1996 Wiley-Liss, Inc.     

Cervical ripening using vaginal misoprostol before hysteroscopy: a double-blind randomized trial

Study ObjectiveThe aim of this study was to evaluate the use of vaginal misoprostol to decrease both the force required to dilate the cervix and the pain experienced during a hysteroscopy.DesignRandomized clinical trial (RCT) (Canadian Task Force classification I).SettingUniversity hospital gynecology clinic.PatientsA total of 101 patients needing a diagnostic hysteroscopy. Fifty patients were randomized to the misoprostol group and 51 to the placebo group. Patient characteristics were similar in the 2 groups.InterventionsSelf-administration of 400 μg of vaginal misoprostol or vaginal placebo 12 to 24 hours before a hysteroscopy.Measurements and Main ResultsThe force needed to dilate the cervix was assessed by a tonometer, and pain was measured by a visual analog scale. The force to dilate the cervix to 6 mm was significantly less in the misoprostol group (5.0 vs 7.5 N, p = .02). Pain-related measurements after dilatation of the cervix to 6 mm were significantly reduced in the misoprostol group (42.1 vs 57.2, p = .004). The main side effect reported with the use of the drug was pelvic cramping.ConclusionThe use of 400 μg of vaginal misoprostol 12 to 24 hours before hysteroscopy reduces the pain and the force needed to dilate the cervix, with only mild side effects.