Optical feedback training of inhalation with Autohaler and Turbuhaler in COPD patients.

The success of inhalation therapy depends on patients inhalation technique and correct handling of the inhalation device. In this study the effort to train correct handling and optimal inhalation technique of patients using Autohaler and Turbuhaler was assessed. The Bad-Reichenhall-Aerosol-Therapy-Trial (BREATH) was a prospective, randomized, cross-over trial in 200 patients who were not familiar with either of the test systems. The correct handling of Autohaler and Turbuhaler was assessed by means of a checklist (observation score). An optimal inhalation maneuver was used evaluated with the computer-based Inhalation Manager (optical feedback, computer score). The Autohaler reached 6.58 +/- 3.64 (mean +/- SD) out of nine points in the observation score and 66.85 +/- 29.84% in the computer score before training. After training the scores increased significantly to 8.33 +/- 2.08 points and 86 +/- 23.40% respectively. The use of the Turbuhaler also significantly improved from 4.28 +/- 4.24 points and 56.67 +/- 42.97% to 7.78 +/- 2.74 points and 85.80 +/- 27.63%, respectively. The significant improvement of patients inhalation technique after training emphasizes the importance of training in inhalation therapy. In addition, it could be demonstrated that the optical feedback given by the Inhalation Manager was a useful tool for improving the inhalation technique of patients using Autohaler and Turbuhaler.

Mass output and particle size distribution of glucocorticosteroids emitted from different inhalation devices depending on various inspiratory parameters.

Efficient inhalation therapy depends on successful delivery of the drug to the lung. The efficacy of drug delivery is not only influenced by the characteristics of the inhalation device, but also by the patient's handling of the device and by the inspiratory maneuver achieved through the device. We analyzed the output characteristics of three different chlorofluorocarbon (CFC)-free breath-actuated inhalers for inhaled glucocorticosteroids (BUD Turbohaler, FP Diskus/Accuhaler and HFA-BDP Autohaler, respectively). Mass output and particle size distribution of drug aerosol delivered by the inhalers were determined depending on different inhalation parameters in vitro using an Andersen cascade impactor. We found that, beside the peak inspiratory flow (PIF), other factors such as flow acceleration and inhalation volume also have significant effects on aerosol generation with respect to mass output and particle size distribution. Thus, these parameters should be taken into account when a suitable device for an individual patient is to be selected. The dependency on inspiratory parameters was most pronounced for the dry powder inhalers. The Turbohaler showed by far the highest variance in particle output (fine particle fraction ranging from 3.4% to 22.1% of label claim), whereas the Diskus was less dependent on variations in inhalation (10.6% to 18.5% of label claim). The most constant aerosol output was found for the Autohaler, which also released the highest fine particle fraction (43.1% to 56.6% of label claim).

Ribosomal RNA of Nosema algerae and phylogenetic relationship to other microsporidia.

Microsporidia are intracellular parasites that are common in invertebrates. Taxonomic classification is mostly restricted to morphologic and physiologic data. Limited data are available about taxonomic classification using DNA-sequence data for analysis. We examined the small-subunit (SSU) rDNA, the intergenic spacer (ITS) region, and a part of the large-subunit (LSU) rDNA of Nosema algerae, a parasite of mosquitoes, taken from a laboratory colony of Anopheles stephensi. Target gene amplifications were done by polymerase chain reaction (PCR) and, after cloning, DNA fragments were sequenced. The SSU-rDNA sequence obtained was aligned with several other microsporidian SSU-rDNA sequences available from the GenBank or EMBL data bases and was analyzed by different methods. On the basis of the results of our phylogenetic analysis, we suggest that our N. algerae isolate is not closely related to other microsporidia belonging to the genus Nosema.

In vitro replication of Nosema algerae (Microsporidia), a parasite of anopheline mosquitoes, in human cells above 36 degrees C.

Microsporidia form a large and ubiquitous group of obligately intracellular parasitic eukaryotes, increasingly recognized as pathogens in humans. Transmission of invertebrate microsporidia to mammals has been considered impossible because temperature seemed to be a limiting factor for development. Nosema algerae, a microsporidian of anopheline mosquitoes, was cultured in human muscle fibroblasts at temperatures of 31 degrees C and 38 degrees C. This is the first record of an invertebrate microsporidian developing in human cells at a temperature above 36 degrees C. The ultrastructure of N. algerae growing in human muscle fibroblasts is similar to that of Brachiola vesicularum, a microsporidian species previously described in the muscle of an AIDS patient.

Relevant criteria for detecting microsporidia in stool specimens.

By using different staining techniques, 479 stool specimens from 212 diarrheic patients with AIDS were examined for microsporidian spores. Calcofluor fluorescence staining of 119 specimens revealed fluorescent ovoid structures of microsporidian size. Staining of these samples according to the method of Weber et al. (R. Weber, R. T. Bryan, R. L. Owen, C. M. Wilcox, L. Gorelkin, and G. S. Visvesvara, N. Engl. J. Med. 326:161-166, 1992) with trichrome produced six specimens with pinkish spores containing the characteristic microsporidian belt-like structure. The 6 specimens were processed for transmission electron microscopy, as were another 21 specimens which did not present the belt-like structure after trichrome staining but which looked highly suspicious after fluorescence staining. In these 21 samples, only fungal spores and, particularly, bacterial Clostridium spores were demonstrated, whereas in the 6 samples diagnosed positive after trichrome staining, the existence of microsporidia could be verified by electron microscopy. Based on our observations, we propose that the belt-like structure seen with the Weber stains in microsporidian spores corresponds to structures existing in priming-stage spores. The results suggest that routine microscopical fecal diagnosis for microsporidian infection should include a screening by fluorescence staining and, subsequently, a confirmatory viewing of fluorescence-positive samples after trichrome staining.

Morphologic changes in Nosema algerae (Microspora) during extrusion.

As a member of the phylum Microspora, Nosema algerae is a small obligate intracellular parasite. Its free invasive stage is a spore with a characteristic cellular organization, including an apically anchored polar tube that serves as a tool for the transmission of genetic material into the host cell. By detailed electron micrographic documentation of the spore ultrastructure we present the aspects related to the biologic process of spore extrusion. Our ultrastructure findings confirm that the extrusion process of microsporidian spores is based on extreme changes in their organization. This study is the first complete ultrastructural documentation of N. algerae concerning the extrusion process, which can be subdivided into different stages: the breakdown of the microsporidian cellular compartmentation; the filling of a preformed polar tube with modified sporoplasm; the uncoiling of the polar tube, which in this stage has reached its final length; and, finally, its extrusion and screw-like movement.

Opportunistic infections caused by protozoan parasites.

Parasitic protozoa have played a major role in the discovery of the HIV epidemic. It was the occurrence of clustered cases of Pneumocystis pneumonia which caught the attention of the epidemiologists indicating that something unusual was going on. Very recently remarkable progress was made in understanding the epidemiology. Knowledge is evolving that Pneumocystis is host-specific to an extent which seems to justify species rank for the cause of death in AIDS patients for many years. Toxoplasma gondii infections were also recognized very early in AIDS patients. Cerebral toxoplasmosis has now replaced Pneumocystis pneumonia as a fatal infection in many cases. AIDS patients with CD4 cells below 200/microl have a high risk to develop this complication. Cryptosporidium parvum was recognized as the cause of diarrhea in AIDS patients and also in immunocompetent humans where it only leads to a diarrheal episode lasting a few days. In AIDS patients the persisting diarrhea leading to loss of fluid and electrolytes can be life-threatening. Another group of parasites previously unknown to infect humans are the microsporidia, which are wide-spread parasites in nature. Increasing numbers of such infections are observed but many questions regarding pathogenesis and epidemiology are still unclear.

Opportunistic properties of Nosema algerae (Microspora), a mosquito parasite, in immunocompromised mice.

In the last ten years microsporidia have been recognized as opportunistic pathogens in AIDS patients. The sources of infection and the mechanisms of transmission of these organisms in humans are mostly uncertain. Transmission of invertebrate microsporidia to mammals is normally considered impossible, temperature being a limiting factor for development. Mice treated with cortisone acetate and with cyclosporin A, respectively, as well as athymic nice were injected intravenously, intranasally, perorally and subcutaneously with spores of Nosema algerae, a microsporidian species of culicine mosquitoes. No infection could be detected in tissue samples of cortisone acetate and cyclosporin A treated mice. However, the experimental inoculation of spores into the tail and foot of athymic mice caused severe infection in skeletal muscles and the connective tissue. In some tails, nerve tissue and bone marrow were also infected. Vegetative stages and spores were seen in direct contact to host cell cytoplasma. For the first time the prolonged and progressive development of an invertebrate microsporidium in a mammalian host is shown. The possibility of invertebrate microsporidia as a source of human microsporidiosis should now be taken into consideration.