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Biomedical subjects

M Mero

Publications and source records attributed to M Mero.

32 records · Page 2Linked to original sources

Fixation of experimental osteotomies of the distal femur in rabbits with bone cement and cyanoacrylate.

A distal femoral osteotomy was fixed with liquid cyanoacrylate and bone cement in 25 rabbits. Follow-up was done at 1, 3, 6, 12, and 24 weeks. The distal portion of each femur was removed, fixed in alcohol, embedded in methylmethacrylate, sawed to 80 micron thickness for OTC-fluorescence study and microradiography, and cut to 5-micron sections for histological analysis. Radiological and careful microscopic (OTC labeling, microradiographic, and histological) studies showed healing of the osteotomies during the first 6 weeks after operation. However, at 12 and 24 weeks' follow-up only four of ten osteotomies had healed. According to these observations it is obvious that fixation of an osteotomy of the cancellous bone with bone cement and cyanoacrylate does not provide sufficient stability for successful healing.

Adhesiveness↗

Fixation of experimental osteotomies of the distal femur of rabbits with biodegradable material.

Osteotomies of the distal femur in 19 rabbits were operatively fixed with totally biodegradable implants. Radiographic, histological, microradiographic, and oxytetracycline-labeling studies showing healing of the osteotomy within 6 weeks. The fixation proved stable sufficiently during healing of the osteotomized bone. The osteotomies united without delay and malalignment did not occur, although no external support was used and the rabbits were allowed to walk freely after the operation. Successful use of the biodegradable fixation developed in the present study was reported recently for the treatment of fractures of the ankle.

Animals↗

Biodegradable fixation of rabbit osteotomies.

Osteotomies of the tibial diaphysis were operatively fixed with biodegradable implants in 44 rabbits. Polyglycolic acid (PGA)/polylactic acid (PLA) copolymer implants reinforced with 7 per cent carbon fibre and overlaid with gold were used in 24 rabbits. Poly-beta-hydroxy butyric acid (PHBA) with carbon fibre reinforcement and gold surfacing were used in 20 rabbits. No external support was used. Unsatisfactory results were achieved with the PGA/PLA copolymer implants. Better results were achieved in 15 out of 20 rabbits whose osteotomies were fixed with carbon fibre-reinforced PHBA implants.

Animals↗

Serum phospholipase A2, immunoreactive trypsin, and trypsin inhibitors during human acute pancreatitis.

Serum immunoreactive trypsin and phospholipase A2 were analyzed at regular intervals in seven patients hospitalized as a result of acute hemorrhage pancreatitis. alpha 1-Antitrypsin and alpha 2-macroglobulin levels and trypsin-inhibitor capacity of serum were determined simultaneously. Serum trypsin concentrations were markedly raised in all patients. The levels of immunoreactive trypsin remained elevated for longer periods than those of urinary amylase. alpha 1-Antitrypsin and trypsin-inhibitor capacity were also significantly increased as compared with the post-illness values, but alpha 2-macroglobulin decreased considerably, reaching the lowest levels on the 5th day after admission. Consequently, phospholipase and trypsin are released to the circulation during hemorrhagic pancreatitis, but the increase in trypsin is compensated for by an increase in trypsin-inhibitor capacity of serum due to elevated alpha 1-antitrypsin levels. The decrease of alpha 2-macroglobulin in hemorrhagic pancreatitis was one of the most interesting findings, and it is proposed that this inhibitor may be consumed in the elimination of proteases through the reticuloendothelial system. The two patients who died had higher phospholipase values than those who recovered, but the prognosis could not be predicted from the values of the other measured variables.

Acute Disease↗

Changing aetiology of acute pancreatitis.

A retrospective study was undertaken in two groups of patients admitted due to acute pancreatitis in order to obtain information of the relative importance of the main aetiological factors. The first group, consisting of 97 patients, was admitted during 1967--68; the second group of 163 patients during 1977--78. Biliary disease was the main causative factor (53.4%) in the first group of patients with a first-attack of pancreatitis, and alcoholism accounted for only 15.9%. In the second group, ten years later, alcoholism assumed a leading role accounting for 57.5% of the first attack victims as compared to biliary disease with 22.5%. In the total material alcoholism was the aetiological factor in 80.8% of patients with relapsing acute pancreatitis. The absolute and proportional increase of alcohol-induced pancreatitis might be a consequence of a 2.5 fold rise of the consumption of alcohol in Finland during the period of study. Acute alcoholic pancreatitis affected mostly young men and showed a mortality of 7.2% as compared to that of biliary pancreatitis with 13.5% mortality.

Acute Disease↗

Elastic tissue injury in human acute pancreatitis.

Pancreatic vessel wall alterations were studied in tissue material obtained from six patients subjected to resection of the gland for acute necrotizing pancreatitis. Special attention was paid to elastic tissue damage, which was studied using special stains in light and electron microscopy. Vascular wall elastic laminae showed changes varying from fragmentation to complete dissolution. The outer elastic lamina was more consistently affected. Elastic tissue damage was observed in pancreatic areas with minor acinar alterations and in vessels with otherwise relatively well-preserved walls. These observations suggest 1/ an early participation of elastase in the production of tissue damage in human acute pancreatitis and 2/ a primary role for elastic tissue injury in the vascular alterations leading to haemorrhage and tissue necrosis through ischaemia.

Acute Disease↗

Pancreatic acinar ultrastructure in human acute pancreatitis.

Ultrastructural alterations in pancreatic acini from six patients operated for acute necrotizing pancreatitis are described. One of the patients suffered from biliary tract disease, the rest had excessive alcohol intake as the presumed aetiology. Areas of the pancreatic parenchyma showing oedematous inflammation in light microscopy were studied in the electron microscope. Findings in acinar cells included changes in zymogen granules and an increased autophagocytosis in addition to unspecific organelle alterations. Zymogen granules showed increase in size and number, loss or variation of electron-density and peripheral dissolution. Increased autophagic activity was indicated by several autophagic vacuoles and residual bodies. Acinar lumina were dilated showing effacement of microvilli and invaginations in the luminal plasma membrane of the acinar cells. In acinar lumina and in the interstitium fibrillar material was observed, with an increasing frequency in those areas showing severe cellular disintegration. These findings suggest: 1) an increased activity of zymogen granules, 2) an increased autophagocytosis, and 3) penetration of acinar luminal contents into the interstitium.

Acute Disease↗

Serum immunoreactive trypsin and trypsin inhibitors during acute pancreatitis.

Serum trypsin, total trypsin-inhibitor capacity, alpha-1-antitrypsin and alpha-2-macroglobulin were analyzed daily in ten patients hospitalized as a result of acute pancreatitis. Markedly raised serum trypsin concentrations were found in all patients. Alpha-1-antitrypsin and the trypsin-inhibitor capacity were also significantly increased as compared to post-illness values, but alpha-2-macroglobulin tended to decrease during acute pancreatitis. The post-illness values of all these parameters were in the normal range. It is concluded that a deficiency of alpha-1-antitrypsin, trypsin-inhibitor capacity of alpha-2-macroglobulin is not present in patients with acute pancreatitis which could render the pancreas more vulnerable to its own proteases. During acute pancreatitis trypsin is released into the circulation, but it is effectively inactivated by serum protease inhibitors, mainly alpha-1-antitrypsin, which can be seen as an increased trypsin-inhibitor capacity in these patients. The use of protease inhibitors in the treatment of acute pancreatitis seems to be unnecessary against this background. Increased serum trypsin values can be used when confirming the diagnosis of acute pancreatitis.

Acute Disease↗

Alpha 1-antitrypsin and total trypsin-inhibitor capacity in acute pancreatitis.

Twenty three patients with acute pancreatitis were studied to assess the serum alpha 1-antitrypsin levels as well as the total trypsin-inhibitor capacity. These parameters were found to be normal or increased, which is not the case with patients with chronic pancreatitis. The value of protease-inhibitor treatment in acute pancreatitis is doubted.

Acute Disease↗

Hernia through the foramen of Winslow.

An incarcerated internal hernia through the foramen of Winslow is an extremely rare cause of intestinal obstruction and about 105 such cases have been reported. An additional patient, in whom a part of jejunum was incarcerated through the foramen into the lesser sac and who was successfully treated surgically, is reported. The etiology, diagnosis, treatment and prognosis of this rare condition are discussed.

Adult↗

Immunologic observations in canine interstitial nephritis.

Immunofluorescence studies in cases of chronic interstitial nephritis (CIN) in the dog demonstrated deposition of canine IgC and C'3 in the thickened capillary walls of the glomeruli and in the mesangium. Eluates obtained from the nephritic kidneys contained antibodies of IgG type and reacted with autologous or homologous nephritic kidneys but not with normal kidneys or with any normal canine tissue. The staining pattern of fluorescein-conjugated eluates was similar to that obtained with anti-canine IgG or anti-canine C'3. The eluates did not contain leptospiral antibodies. The findings indicate that complement-fixing immune complexes are deposited in the damaged glomeruli in CIN. The nature of the antigen involved in these complexes is unknown, but it does not seem to be a component of normal canine tissue and could thus be viral or bacterial.

Animals↗

Clinical, bacteriological and therapeutic aspects of bovine mastitis caused by aerobic and anaerobic pathogens.

Twenty cows and three heifers with summer mastitis-like signs were included in the study. Forty aerobic and 38 anaerobic bacterial isolates representing 23 different species were isolated from udder secretions, the mean number of species being 3.4/sample. Pathogens most often were recovered in quantities exceeding 10(5) CFU/ml. Growth of pathogenic bacteria in the blood was found in only one case. Most cases occurred in housed animals and had often been preceded by teat injury. No anaerobic growth was found in milk samples of a control group consisting of 29 cows with ordinary acute mastitis. Values of indicators of inflammation in milk (NAGase and plasmin activity) were high, mean values being 914.1 and 1.3 units. The animals with aerobic/anaerobic mastitis were treated using various antimicrobial agents. All but three quarters were lost to milk production. Two animals with complete recovery were given a combination of penicillin G and tinidazole.

Animals↗

The effect of a penetrating biodegradable implant on the epiphyseal plate: an experimental study on growing rabbits with special regard to polyglactin 910.

A polyglactin 910 rod 3.2 mm in diameter and 25 mm in length was driven in a drill hole in the intercondylar portion of the right femur across the central portion of the growth plate in 20 5-week-old rabbits. The follow-up times were 3, 6, 12, and 24 weeks. The distal femoral growth plates of both femurs were analyzed by radiographic, microradiographic, and oxytetracycline fluorescence, histological, and histomorphometric studies. Histomorphometric studies showed clear changes at injury site and appeared to be an excellent means of exact numerical description of the different cellular areas of the growth plate. Six weeks after implantation, a polyglactin 910 implant resulted in a growth disturbance similar to that of a drill hole of equal bore.

Animals↗