Novel mouse model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis

Pseudomonas aeruginosa causes a chronic infection in the lungs of cystic fibrosis (CF) patients by establishing an alginate-containing biofilm. The infection has been studied in several animal models; however, most of the models required artificial embedding of the bacteria. We present here a new pulmonary mouse model without artificial embedding. The model is based on a stable mucoid CF sputum isolate (NH57388A) with hyperproduction of alginate due to a deletion in mucA and functional N-acylhomoserine lactone (AHL)-based quorum-sensing systems. Chronic lung infection could be established in both CF mice (Cftr(tmlUnc-/-)) and BALB/c mice, as reflected by the detection of a high number of P. aeruginosa organisms in the lung homogenates at 7 days postinfection and alginate biofilms, surrounded by polymorphonuclear leukocytes in the alveoli. In comparison, both an AHL-producing nonmucoid revertant (NH57388C) from the mucoid isolate (NH57388A) and a nonmucoid isolate (NH57388B) deficient in AHL were almost cleared from the lungs of the mice. This model, in which P. aeruginosa is protected against the defense system of the lung by alginate, is similar to the clinical situation. Therefore, the mouse model provides an improved method for evaluating the interaction between mucoid P. aeruginosa, the host, and antibacterial therapy.     

Adenoviral vectors expressing siRNAs for discovery and validation of gene function

RNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays. To be able to use this technology for genome-wide function screening, a more robust transduction protocol, resulting in a longer duration of the knock-down effect, is required. Here, we describe the validation of adenoviral vectors that express hairpin RNAs that are further processed to siRNAs. Infection of cell lines, or primary human cells, with these viruses leads to an efficient, sequence-specific, and prolonged reduction of the corresponding target mRNA, resulting in a reduction of the encoded protein level in the cell. For knock-down of one of the targets, GalphaS, we have measured inhibition of ligand-dependent, G-protein-coupled signaling. It is expected that this technology will prove to be of great value in target validation and target discovery efforts.     

Effects of enzyme replacement therapy on pain and health related quality of life in patients with Fabry disease: data from FOS (Fabry Outcome Survey)

Background: Fabry disease is an X linked lysosomal storage disease caused by deficiency of the lysosomal enzyme α-galactosidase A. This leads to accumulation of globotriaosylceramide in nearly all tissues, including the blood vessels, kidney, myocardium, and nervous system. Symptoms often begin in childhood and include acroparaesthesia, with burning or tingling pain that spreads from the extremities to more proximal sites.

Aims: This study set out to evaluate pain and its influence on quality of life in patients with Fabry disease receiving enzyme replacement therapy (ERT) with agalsidase alfa.

Methods: Data were obtained from the Fabry Outcome Survey. Pain was measured using the Brief Pain Inventory (BPI), and health-related quality of life (HRQoL) was documented with the European Quality of Life Questionnaire (EQ-5D).

Results: The mean (SD) score for "pain at its worst" on the BPI prior to ERT was 5.1 (2.7). One year after commencement of ERT, this had improved by 0.5, and improved by a further 0.6 after 2 years (p<0.05). Similar statistically significant improvements were seen for "pain on average" and "pain now" after 2 years of ERT. The mean HRQoL utility score prior to ERT was 0.66 (0.32). After 12 months of treatment with agalsidase alfa, this had improved to 0.74 (0.26; p<0.05); this improvement was maintained after 2 years.

Conclusions: ERT with agalsidase alfa significantly reduces pain and improves quality of life in patients with Fabry disease.

     

The Mikulicz Cell in Rhinoscleroma: Light, Fluorescent and Electron Microscopic Studies

The stages in the development of the Mikulicz cell in human rhinoscleroma were studied in biopsy specimens obtained from 10 patients using light, immunofluorescent and electron microscopy. The Mikulicz cell was identified morphologically as a macrophage, not a plasma cell. Acutely inflamed areas of rhinoscleroma presented abundant bacteria with a slime layer. The microorganism was infrequent and the mucopolysaccharide was scanty in rhinoscleromal tissue, where plasma cells predominated, and in cicatricial fibrous tissue. In the granulomatous stage of rhinoscleroma, the mucopolysaccharide was found within the Mikulicz cells. The vacuoles observed in the Mikulicz cells were considered to be phagosomes containing, principally, bacterial mucopolysaccharide and few bacteria and, to a lesser extent, swollen mitochondria. It was concluded that the slime layer of Klebsiella rhinoscleromatis plays an important role in the pathogenesis of the disease. It is postulated that this material is a nondigestible mucopolysaccharide that resides in the phagosomes of macrophages, increases the osmotic pressure and forms multiple hydropic vacuoles that rupture not only the phagosomes but also the cells, resulting in the liberation of the mucopolysaccharide. This would initiate a cycle that would prolong the disease in the absence of the bacteria.     

Retinal projection to the nucleus of the optic tract in the cat as revealed by retrograde transport of horseradish peroxidase

Retrograde transport of horseradish peroxidase injected iontophoretically into the nucleus of the optic tract of cats revealed that the direction-selective cells in this pretectal nucleus receive direct retinal projections from small retinal ganglion cells, the so-called gamma-cells. These cells from a horizontal band on the contralateral retina. Few labeled cells are found in the ipsilateral temporal retina. The input from the contralateral retina is 10 times more numerous than from the ipsilateral one. In both retinae the highest concentration of labeled cells is near the area centralis.     

Light and electron microscopic studies onMyxobolus cotti El-Matbouli and Hoffmann, 1987 infecting the central nervous system of the bullhead (Cottus gobio)

Myxobolus cotti (Myxozoa: Myxosporea) is described as found in the central nervous system of the bullhead (Cottus gobio) caught in the Alpine lake Königssee and in a brook in the Bavarian Forest, Federal Republic of Germany (El-Matbouli and Hoffmann 1987). Aggregations of spores and polysporoblastic trophozoites compressed and replaced large areas of the white and grey matter of the brain and spinal cord. These aggregations may be surrounded by a thin, connective tissue capsule; in a few cases they were associated with loose infiltrates of glial cells. Neither conspicuous tissue reactions nor inflammatory responses were evident. No other organs were seen to be infected withM. cotti. Mature spores are oval, with a tapering anterior end, and the pyriform polar capsules are nearly equal in size. Fresh spores measured 8.9–15.1 m in length (mean, 12.4 m) and 8–12.4 m in width (mean, 9.6 m); polar capsules were 4.3–9 m long (mean, 6.4 m); and 2–3.8 m wide (mean, 2.9 m). Light microscopy, the ultrastructure of pansporoblasts, sporogenesis and mature spores are described.     

Sex- and age-related blood pressure response to dynamic work with small muscle masses

Summary Four groups of subjects of different ages and sex (group I: 20–29 years, women; group II: 20–29 years, men; group III: 30–39 years, women; group IV: 30–39 years, men) undertook dynamic one-hand work (load range 40%–80% of maximum voluntary contraction, at 60 working cycles/min) to allow a study of cardiovascular responses as shown by the resultant changes in blood pressure and heart rate. During fatiguing dynamic one-hand work, there was a large increase in systolic and diastolic blood pressures in both sexes after a few minutes. For all load levels, the systolic blood pressure was found to be higher by about 4 kPa in men (groups II and IV) than in women (groups I and III). Other age-related differences became evident in the diastolic blood pressure changes. The values obtained for the older groups were higher than those in the two younger groups. These differences in blood pressure response are possibly due to sex-related differences in the release of catecholamines, or to age-related organic changes in the vessels.     

Ultrastructure of the gastric mucosa harboring Campylobacter-like organisms

The association between Campylobacter-like organisms (CLOs) and lesions of the gastric mucosa was studied in 59 consecutive biopsies. Hematoxylin and eosin and Warthin-Starry silver stains, as well as high-resolution light microscopy (HRLM) and transmission electron microscopy (TEM), were used. The organisms were found in intimate contact with foveolar cells showing abundant phagolysosomes and alterations of the intercellular complexes. CLOs also were seen in close proximity of parietal cells in resting phase, some of which showed degenerative changes. The findings are discussed in light of recent reports linking CLOs to the cause of gastritis.