elastin and potassium-hydroxide

It has been inferred from previous work that 40% potassium hydroxide preparations of lower respiratory tract secretions that demonstrate elastin fibers have a 100% specificity and positive predictive value in diagnosing bacterial pneumonia in intubated, mechanically ventilated patients without the adult respiratory distress syndrome (ARDS). Our aim was to assess the specificity of 40% potassium hydroxide preparations in diagnosing bacterial pneumonia in patients with ARDS and suspected pneumonia.. Prospective, case-referral clinical study.. Referral hospital.. Of 24 patients with ARDS who were intubated and mechanically ventilated with suspected bacterial pneumonia, 22 were assessable and evaluated for this report.. Tracheo-bronchial aspirates were obtained from all patients and analyzed for elastin fibers using 40% potassium hydroxide.. Of the 22 assessable patients, ten patients did not have a complicating bacterial pneumonia. Six of these ten patients had potassium hydroxide preparations that demonstrated elastin fibers (false positives). The other four patients had preparations that did not demonstrate elastin fibers (true negatives). Specificity was 40%.. Elastin fiber preparations are not specific for diagnosing bacterial pneumonia in patients with ARDS.

Topics: Adult; Bronchi; Bronchoalveolar Lavage Fluid; Case-Control Studies; Elastin; Humans; Hydroxides; Pneumonia, Bacterial; Potassium Compounds; Predictive Value of Tests; Prospective Studies; Respiration, Artificial; Respiratory Distress Syndrome; Sensitivity and Specificity

The three-dimensional cytoarchitecture of smooth muscle fibers of human cardiac arterial vessels was studied by scanning electron microscopy after removal of extracellular connective tissue matrices with a KOH-collagenase digestion method. Arterioles with an outer diameter of 30-100 microm had a well-developed compact media consisting commonly of circularly oriented smooth muscle fibers. There were also arterioles with oblique or longitudinal muscle fibers in some places. In terminal arterioles with an outer diameter of less than 30 microm, muscle fibers became branched and commonly encircled the endothelial tube. There were some terminal arterioles covered with obliquely arranged smooth muscle fibers. The presence of the regional difference in arrangement of vascular smooth muscle fibers indicates the heterogeneity of blood flows in the level of cardiac microcirculation.

Topics: Aged; Arterioles; Collagen; Collagenases; Coronary Vessels; Elastin; Endothelium, Vascular; Female; Histocytological Preparation Techniques; Humans; Hydroxides; Microscopy, Electron, Scanning; Muscle, Smooth, Vascular; Potassium Compounds

A KOH-collagenase or simple KOH digestion method was employed for scanning electron microscope (SEM) studies of elastin components in the rat thoracic aorta, mouse urinary bladder, and human ductus deferens. Immersion of the fixed tissues in 30% KOH solution for 8-10 min at 60 degrees C, with or without subsequent collagenase treatment, successfully removed collagen fibrils and basal laminae while leaving cellular and elastin elements unchanged at their original shapes and locations. The internal elastic lamina of the rat aorta appeared as a solid sheet formed by elastin fibrils 0.1-0.2 microns thick, while the medial elastic laminae were more fibrous because of the presence of numerous fine elastin fibers on their surface. Adventitial elastin fibers were of a cord-like shape complicatedly entangled among the adventitial fibroblasts. These fibers were seen as bundles of fibrils 0.1-0.2 microns thick. In the mouse urinary bladder, elastin formed a thin lace-like sheet just beneath the serosal covering of the peritoneum. This sheet was composed of small bundles of fine (0.1-0.2 microns thick) fibrils. The external connective tissue of the human ductus deferens was made up of a three-dimensional loose network of elastin fibers 0.1-1.5 microns thick. These fibers also appeared as bundles of the fine fibrils. These findings indicate that the present method is useful for SEM studies of elastin as well as cellular components in various tissues and organs. This study also maintains that elastin fibers and laminae are basically composed of unit fibrils of 0.1-0.2 microns thickness. As elastin components are arranged specific to individual organs and tissues, it is reasonable that these components are concerned in the characteristic mechanical properties of these tissues and organs.

Topics: Animals; Aorta, Thoracic; Elastic Tissue; Elastin; Humans; Hydroxides; Male; Mice; Microbial Collagenase; Microscopy, Electron, Scanning; Middle Aged; Potassium; Potassium Compounds; Rats; Urinary Bladder; Vas Deferens

We have observed five patients for whom the presence of fibers of elastin in potassium hydroxide (KOH) preparations of sputum represented the first evidence of necrotizing pulmonary disease. In four cases, the discovery of elastin fibers in sputum provided additional evidence supporting initiation or modification of antibiotic therapy. Necrotizing disease was confirmed in all cases by autopsy or by the development of cavitation on chest x-ray film. Cytochemical staining, electron microscopy, and elastase digestion all suggest that the refractile fibers seen on KOH wet mount of sputum are elastin. The test, first described in 1846, is simple to perform, requires little experience to read, and may be a valuable adjunct to the chest roentgenogram in the diagnosis of pulmonary parenchymal destruction.

Topics: Adult; Aged; Bronchopneumonia; Elastin; Female; Humans; Hydroxides; Male; Middle Aged; Necrosis; Pneumonia; Potassium; Potassium Compounds; Sputum