In vitro and in vivo Studies of the Extent of Electrothrombotic Deposition of Blood Elements on the Surface of Electrolytically Detachable Coils.

SUMMARY: Endovascular treatment of intracranial aneurysms with electrolytically detachable coils is often claimed to be based on electrothrombosis, i.e. intra-aneurysmal thrombus formation through applied direct current. Despite the fact that this concept was described more than a century ago, the significance of electrothrombosis in the endovascular treatment of aneurysms remains debatable. Apart from electrothrombosis, mechanical obliteration of the aneurysmal lumen might be one of the many possible mechanisms to explain why and how detachable coils are effective in preventing aneurysms from (re-)rupture. The purpose of this experimental study was to investigate to what extent direct current comparable to that used for coil detachment would influence the adhesion of cellular and liquid blood components to the surface of electrolytically detachable platinum coils. For the in vitro study, electrolytically detachable platinum coils of various types were exposed to stagnant heparinised blood for a total of 16 h, without or with applied direct current for 30 or 90 s (1 mA, 4-6 V, coil as anode). For the in vivo study, electrolytically detachable platinum coils were exposed to flowing blood for 180 s, without or with applied direct current (2 mA, 4-6 V, coil as either anode or cathode), without anti-coagulation and after intravenous administration of 5000 U Heparin and again after the intravenous administration of 500 mg Aspisol in addition to Heparin. After exposure to blood according to these different experimental protocols, the coils were fixed in formalin solution, gold coated and examined by scanning electron microscopy. Thrombus formation on the surface of all unfibred coils was thin and highly variable both from coil to coil, and on different areas of any given coil. The application of direct current minimally enhanced thrombus formation in stagnant blood in vitro, but not in vivo. The cellular and fibrin adhesions on the coil surfaces without and with applied current did not effectively increase the diameter or volume of unfibred coils. Coils with attached nylon fibres, however, proved to be highly thrombogenic without or with application of current. In fibred coils, surface adhesions without and with applied current were voluminous enough to effectively increase the diameter of the coil, potentially important for the process of endosaccular aneurysm occlusion. Electrothrombosis plays no role in the endovascular treatment of intracranial aneurysms with electrolytically detachable coils. This explains why platinum coils with non-electrolytic detachment mechanisms show a similar efficiency and recurrence rate.

Detection of Chlamydia pneumoniae in unexplained pulmonary hypertension.

The pathogenesis of primary pulmonary hypertension is still unclear. The case of a 68-yr-old female patient who complained of recurrent dizzy spells and collapses over a period of 6 weeks and died of global cardiac failure is presented. Autopsy revealed severe pulmonary hypertension, slight chronic bronchitis, and bronchiolitis as well as intra-alveolar accumulation of macrophages. Chlamydiae were detected within the pulmonary arteries and in intramural and intra-alveolar macrophages by immunofluorescence, confocal laser scanning microscopy, scanning and transmission electron microscopy. Nested-polymerase chain reaction (PCR) and nonradioactive deoxyribonucleic acid (DNA) hybridization of PCR products from pulmonary arteries revealed Chlamydia pneumoniae DNA. Chlamydia pneumoniae has already been detected in atherosclerosis and in pulmonary emphysema. It can induce proliferation of smooth muscle cells. Chlamydia pneumoniae might be relevant in aggravation of primary pulmonary hypertension and might perhaps be a trigger factor in some cases.

Detection of Chlamydophila pneumoniae in mouse respiratory ciliated epithelium using targeted sections of the lung tissue.

Chlamiophila pneumoniae were detected in targeted sections of mouse lung tissue by means of transmission electron microscopy and immunofluorescent staining. Incorporation of microorganisms into the axonemal matrix of cilia was observed 24 h after infection. The ciliary axoneme was characterized by pronounced swelling. At the late stages Chlamiophila pneumoniae were present in cytoplasmic vacuoles. Structural abnormalities and dysfunction of mucociliary clearance followed by incorporation of Chlamiophila pneumoniae into the cytoplasm of epitheliocytes were revealed in the early stage of infection. The proposed method allows studying the very early events of Chlamiophila pneumoniae infection.

Infection of murine precision cut lung slices (PCLS) with respiratory syncytial virus (RSV) and chlamydophila pneumoniae using the Krumdieck technique.

The Krumdieck technique allows the investigation of the so-called precision cut lung slices (PCLS) with a special microtome. It is thus possible to evaluate morphologic changes over a longer period of time using only a small group of animals. Chlamydophila pneumoniae (Cp) and respiratory syncytial virus (RSV) proved to be important causes of pneumonia, rhinitis and exacerbations of asthma bronchiale, as well as of lower respiratory tract infections in young children. PCLS should be tested for their suitability as an in vitro model for these infections. The PCLS were infected with Cp and RSV over different periods of time. Investigations were carried out by light and transmission electron microscopy (TEM). Furthermore, immunofluorescence (IF) studies with antibodies against bacterial or viral proteins and cell-specific markers were done using confocal laser scanning microscopy (CLSM). Non-infected and infected PCLS showed a well-preserved morphology up to 72 hours. After short infection intervals, typical inclusions of Cp or RSV were detected in vacuoles of different cell types. Infection and cell types could be verified using IF. Cytopathic effects were not prominent. Ciliary beat was detectable up to 96 hours after infection. This in vitro technique offers the possibility of studying mechanisms and effects of bacterial and viral infections on viable tissue complexes.

The role of chlamydia in the pathogenesis of pulmonary emphysema. Electron microscopy and immunofluorescence reveal corresponding findings as in atherosclerosis.

Chlamydia pneumoniae has been detected in atherosclerotic plaques by various means. Chlamydiae are able to cause persistent infections. Serologically elevated antibody titers are found in severe chronic obstructive pulmonary disease. In atherosclerosis and pulmonary emphysema, inflammatory reactions can be seen by means of light microscopy. Specimens from patients with obliterative arteriosclerosis undergoing thrombendarteriectomy and with advanced emphysema undergoing lung volume reduction surgery were examined using scanning (SEM) and transmission (TEM) electron microscopy, and using immunofluorescence with monoclonal antibodies and antiserum against chlamydiae. SEM shows spherical bodies (SBs) with a diameter from 0.3 microm to 0.6 microm on the surface of the alveoli and bronchioles, as well as in atherosclerotic plaques. In atherosclerosis and emphysema, SBs reveal a double membrane, adherence to collagen fibers, tissue destruction, as well as intracellular and interstitial localization in TEM. They show in parts a densely packed central structure. SBs are seen both in alpha-1-antitrypsin deficiency emphysema and smoker's emphysema. Using immunofluorescence microscopy, spots are seen in corresponding distributions to the SBs. Morphological findings are typical for aberrant chlamydiae seen in persistent infections. Chronic infection and bacterial colonization associated with progressive disease seems to be relevant not only in atherosclerosis but also in pulmonary emphysema.

[Calcifying granulomatous peritendinitis after local dexamethasone treatment]. / Kalzifizierende granulomatöse Peritendinitis nach lokaler Dexamethasonbehandlung.

In this article we report on a 43-year-old man, who had been treated with two cortisone injections containing soja bean oil for epicondylitis humeri radialis. Four weeks after the second injection necrotized fat which had been extracted surgically was sent to us for histological examination. We could show a calcifying collagen fibre necrosis being cleared by a granulomatous reaction and resorbed by granulation tissue. The calcifying necrosis of collagen fibres might have been induced by soja bean oil which were used as carrier of the drug.