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Biomedical subjects

H Myllärniemi

Publications and source records attributed to H Myllärniemi.

At least 19 recordsLinked to original sources
PubMed1987

Morphology of lysolecithin-induced damage on esophageal mucosa. An experimental light and scanning electron microscopical study.

The morphology of the esophageal mucosal damage induced by lysolecithin was investigated in an experimental model, where an isolated segment of rabbit esophagus was purfused in situ with lysolecithin, alone or in combination with HCl. The results indicate that lysolecithin alone causes no morphological damage to the esophageal mucosa. However, when combined with HCl, lysolecithin causes widening of intercellular spaces and detachment of superficial cells leading ultimately to disclosure of denuded submucosal collagen bundles. This suggests that, in clinical situations lysolecithin refluxed from the duodenum into the stomach and further to esophagus may have importance in the pathogenesis of reflux esophagitis when gastric acid is present, too. In contrast, under unacidic conditions (i.e., in the pathogenesis of alkaline reflux esophagitis) lysolecithin seems to be of minor importance.

Animals↗
PubMed1987

Coronary endothelium and cardioplegic solutions.

Using surface and transmission electron microscopy in eight isolated sheep hearts it was noted that cold crystalloid cardioplegic solution produced coronary endothelial damage which could be prevented if homologous blood or albumin was added into the preservation fluid. Similar endothelial damage was observed in the endothelium of aorto-coronary saphenous vein bypasses and in the endothelium of the proximal aorta after infusion with cold crystalloid cardioplegic fluid. No endothelial changes were seen after infusion of the grafts with cold blood. There was no correlation between the preservation of the high energy phosphates of the myocardium and the endothelial changes of the coronary arteries.

Albumins↗
PubMed1986

Effects of synthetic blood combined with contrast medium on coronary endothelium: an experimental study.

The study described was carried out to evaluate endothelial injury following incubation of coronary material in contrast medium and in contrast medium diluted with fluorocarbon solution. Six porcine hearts were excised and isolated. Immediately thereafter, pieces of the main coronary arteries and ascending aortas were incubated in four different solutions: 1) blood, 2) contrast medium, 3) fluorocarbon solution, 4) fluorocarbon--contrast medium (1:1). Flow surfaces and coronary endothelial morphology were evaluated by scanning electron microscopy (SEM). Porcine blood (at room temperature) preserved endothelial structures intact but, in two samples, small patchy areas of denuded surface were found. Four minutes' immersion in contrast medium resulted in easily visible changes in the endothelial lining and individual cells. Denuded flow surface areas were common, the intact surface morphology was flattened. After 7 minutes, destruction was total. The addition of fluorocarbon solution to contrast medium (1:1) diminished the changes, which also occurred later than after incubation in pure contrast medium. After 7 minutes, separate endothelial cells were still identifiable but the microvilli had disappeared. Fluorocarbon solution preserved the endothelial lining well during a 10-minute follow-up period. The experimental protocol described confirmed the deleterious effect of contrast medium on coronary endothelial lining, which could be reduced to some extent by adding fluorocarbon solution to contrast medium.

Animals↗
PubMed1985

Effects of synthetic blood and crystalloid cardioplegic solutions on coronary endothelium: an experimental scanning electron microscope study.

In an experimental study the effects of Fluosol DA (added with potassium chloride) on the vascular interface and endothelial cells were compared to those of crystalloid potassium cardioplegic solution using scanning electron microscope. Twenty rabbits (10 in each group) were sacrificed, the hearts with ascending aorta were immediately excised, and cold oxygenated solution was infused via a cannula inserted into the cross-clamped aorta. The hearts were left immersed in the perfusion medium for 2 hr. In the Fluosol DA group endothelial cover and endothelial cells were normal or minimal changes were seen in seven cases. Occasional breaking of intercellular attachments, small areas of denuded flow surface, and disappearance of microvilli were seen in three cases. In the crystalloid potassium cardioplegic group 7 of the 10 cases showed moderate or severe damage with large areas of denuded flow surface. The present experimental protocol represented an extreme situation where no collateral coronary blood was present. The coronary endothelial damage was obvious after the crystalloid potassium cardioplegic solution. Similar damage was not found following Fluosol DA infusion.

Animals↗
PubMed1985

A new type of sliding hiatus hernia.

A series of patients showing a previously unrecognized type of sliding hiatus hernia is presented and analyzed. This type of hernia is characterized by reflux of the mucous membrane of the Hiss angle into the lumen of the esophagus. The occurrence of mucosal prolapse is a secondary phase of gastroesophageal reflux. The mucous plug prevents further reflux of the acid contents of the stomach into the esophagus and mouth. After the appearance of mucosal prolapse, the symptoms and signs of esophagitis disappear. The most characteristic complaint of the patients is retrosternal pain on lying and bending down. Endoscopy with provocative tests reveals the mucosal prolapse. Tooth erosions due to previous acid reflux into the mouth are diagnostic. The symptoms of this new subtype of sliding hiatus hernia were cured by the Nissen fundoplication.

Adult↗
PubMed1984

Endothelial cell damage following crystalloid cardioplegic solution infusion. Scanning electron microscope study of coronary bypass grafts.

Scanning electron microscope studies of coronary bypass grafts were carried out in six routine bypass operations. Infusion of the initial crystalloid cardioplegic medium into the aortic root after aortic cross clamping was performed in every case. In two cases, pieces of aorta below and above the cross-clamped site, le, having and not having had contact with the crystalloid cardioplegic medium, were studied. The endothelial lining of the veins showed normal structure following distention with blood. Following infusion with a crystalloid cardioplegic solution, the endothelial cells had almost completely vanished and the flow surface was composed mainly of collagen fibers. The aortic samples taken from below the cross-clamp site showed similar destruction of the endothelium that was observed in vein grafts after crystalloid cardioplegic solution infusion, whereas the aortic samples taken from above the cross-clamp site disclosed normal endothelium.

Aorta↗
PubMed1983

Areae gastricae in gastritis: lack of correlation between size and histology.

The area gastrica patterns of the stomach were studied using surgical specimens. From each of 15 patients, two specimens were obtained: one from the antrum and one from the corpus. These 30 specimens were photographed by stereomicroscope, and the areae gastricae were classified into three groups: none, 1-3 mm in diameter, and 4-6 mm in diameter. The same surgical specimens were studied histologically and the findings were compared with the area gastrica groups. Almost all specimens showed superficial and atrophic gastritis. No correlation between the different sizes of the areae gastricae and the histologic findings was found. The different area gastrica patterns have little value as indication of different types of gastritis.

Gastrectomy↗
PubMed1981

Peritoneal fibrosis due to practolol. Scanning electron microscopical and histological observations.

Three cases of peritoneal fibrosis induced by the beta adrenoceptor blocking agent practolol are presented. Histological and scanning electron microscopical specimens showed a thick layer of loose connective tissue with collagen bundles and fibroblasts. No evidence of mesothelial cells with characteristic microvilli was found. The conclusion is drawn that the basic feature of practolol peritonitis is the destruction of the mesothelial membrane and a slowly progressive formation of loose connective tissue. The reason for the increased formation of connective tissue and the cause of the excessive activity of fibroblasts are discussed.

Aged↗
PubMed1980

Scanning electron microscopy of Crohn's disease and ulcerative colitis of the colon.

12 patients with Crohn's disease (CD) and 9 with ulcerative colitis (UC) affecting the colon were studied by scanning electron microscopy (SEM). The macroscopically unaffected mucosa was distorted in both diseases by irregularities in the normal polygonal units. The individual absorptive cells were disorganized, having lost their pentagonal-hexagonal cell borders. In 7 cases of CD an increase of goblet cells was seen. In 4 cases of UC their number was decreased. One case of UC showed an increased number of goblet cells, the case possibly belonging to the sub-category of indeterminate colitis. The microvilli were normal in CD but affected in many cells from cases of UC. Re-epithelization was followed during conservative treatment in 2 UC patients. It is suggested that with simplified SEM techniques the instrument can be a useful aid in the differential diagnosis of inflammatory colonic diseases.

Colitis↗
PubMed1980

Morphological study of flow surface of glutaraldehyde pre-treated vascular substitutes.

90 grafts were inserted as arterial and shunt conduits in 31 dogs. Human saphenous veins and umbilical veins were either fresh or treated with 0.2% v/v glutaraldehyde. 72 samples from these grafts were studied morphologically. Macroscopic inspection, and light, scanning and transmission microscopy was used. The insertion time of the grafts were kept in place for periods up to 6.0 months. The tanning procedure with glutaraldehyde destroyed all normal endothelial structures. However, the new vascular interface appeared to be quite thrombo-resistant, because only slight changes were found on the flow surface following surgery. Multiple collagen fibres were seen with fibrin like deposits predominating. In those grafts which were thrombosed the thrombus had its origin at the anastomotic site and the graft itself was free of thrombus. No endothelium could be seen in any case studied. Fresh untreated saphenous vein grafts studied as controls showed clear degenerative changes and thrombus accumulation on the inner surface. The same kind of changes were found also in the anastomosing artery.

Animals↗
PubMed1977

Observations by scanning electron microscopy of normal and pathological human gall bladder epithelium.

Thirteen gall bladders presenting normal findings, cholesterolosis, chronic cholecystitis, mucosal hyperplasia and adenomyomatosis were studied by scanning and light microscopy. In the bladder of patients with cholesterolosis the mucosal folds were clearly dilated, but the individual epithelial cells had preserved their normal hexagonal structure. In the gall bladder of one patient with cholesterolosis, goblet-like cells were seen in the epithelium. The greatest changes were seen in material from patients with chronic cholecystitis, in which the mucosal folds were clearly flattened and the cell boundaries indistinct and small polypoid structures were seen on the surface of the epithelium. No special changes were seen in material obtained from patients with adenomyomatosis or mucosal hyperplasia.

Cholecystitis↗
PubMed1977

Solitary diverticulum of the caecum and its complications.

Solitary diverticulum of the caecum is very rare and assumes clinical interest only when inflamed. Preoperatively the condition is virtually impossible to distinguish from acute appendicitis, and even during operation its differentiation from carcinoma is difficult. It is also important to determine whether or not an underlying solitary diverticulum of the caecum is present. In the present series the symptoms and clinical examination as well as laboratory findings pointed to acute appendicitis, which was in fact the preoperative diagnosis in all our patients. In one case the operative findings were strongly suggestive of carcinoma, which was only excluded by inspection and histological examination of the specimen. The wall of the diverticulum was necrotic in all cases. It had already perforated in the previously mentioned case, and right hemicolectomy was performed. An inflamed, but recognizable, solitary diverticulum of the caecum was treated by excision, but the tumour-like mass produced by the diverticulum was removed by resection. In view of the considerable possibility of underlying carcinoma, the authors support an aggressive trend in the treatment of "inflammatory tumours" of the caecal wall.

Adult↗
PubMed1975

Vascular pattern in ileal Crohn's disease.

Angio-, histo- and microangiographic studies were performed on five operative specimens of chronic regional enteritis affecting the ileum. In every patient the vascular pattern differed greatly from that seen in normal ileum and the changes were similar in each investigation. The number of long vasa recta and short vasa recta were increased, but the hypereaemic reaction was limited to the submucosa and mucosa. The long vasa recta arising from the marginal artery arcades were three to five times as close together in the affected regions as normally but their calibre was smaller than normal. The vessels were evenly spaced and ran without variation in their calibre up to the antimesenteric border of the gut. The thicker the mesentery, the wider the angle where the long vasa recta divided to form an anterior and a posterior branch. When the wrapping phenomen occurred this angle exceeded 90 degrees. The short vasa recta branching from the long vasa recta formed a very thin vascular network and thus the affected part of the gut could be easily distinguished from the normal ileum. The vascular changes were limited to the regions that were macroscopically abnormal. The arteries were well organized, but in the most severe cases where the architecture of the gut was destroyed the vascular pattern was also confused. The vascular pattern differed from that seen in malignant disease in two respects: there were no clear changes in the vascular calibres even in the most severe cases and no evidence of open arteriovenous shunts. The vascular changes were regarded as secondary to the fibrotic reaction in chronic regional enteritis and accurately reflected the severity of this reaction.

Adult↗
PubMed1975

Surface electron microscopical changes of the gastric mucosa in experimental porcine stress ulceration.

Gastric mucosal changes in 8 piglets subjected to a transient hypovolaemic shock were studied using scanning electron microscopy (SEM). The mucosal lesions during the shock were characterized by progressive degenerative changes in the mucous membrane of the stomach. These surface changes included flattening or swelling of the individual cells. The flattening of the mucous membrane was later connected with red cell diapedesis through it. These changes were most typical in the areas of haemorrhagic gastritis and preceded the ulcer formation. Following retransfusion, the affected epithelial lining appeared greatly distended over the oedematous lamina propria, with almost complete loss of structural detail. Masses of red blood cells were seen to emerge through the epithelium as an indication of subepithelial haemorrhage. It is possible that the injured epithelium is actually broken down by the pressure of the underlying mucosal haemorrhage and oedema. At later stages, the ulcerated areas showed complete loss of epithelial cells and thus the underlying structureless lamina propria, covered by necrotic cell remnants, blood cells and fibrin, was denuded.

Animals↗