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Biomedical subjects

O Laitinen

Publications and source records attributed to O Laitinen.

16 recordsLinked to original sources
PubMed1992

Mechanical properties of biodegradable ligament augmentation device of poly(L-lactide) in vitro and in vivo.

To evaluate the mechanical properties of absorbable braided poly(L-lactide) (PLLA) fibre implants, 2.0 and 3.2 mm in diameter, maximum load defined as tensile load carrying capacity, elongation and axial rigidity were investigated after immersion in phosphate-buffered distilled water at 37 degrees C and pH 6.1 and after subcutaneous implantation in rabbit. The results confirm earlier indications that PLLA degrades faster in vivo than in vitro. The non-sterilized 2.0 mm implants lost 69% of initial tensile load carrying capacity in 46 wk in vitro. In vivo the loss of tensile load carrying capacity of the 2.0 and 3.2 mm implants was most marked between 6 to 12 wk. After 48 wk in vivo 2.0 and 3.2 mm implants retained 3 and 4% of initial tensile load carrying capacity respectively. Both in vitro and in vivo, elongation diminished in the same way as the maximum load. In vitro, mean axial rigidity of unsterilized 2.0 mm implants was 64 N during the first 34 wk but fell to 31 N at 46 wk. In vivo the initial mean axial rigidity of the 2.0 and 3.2 mm implants was 29 and 95 N respectively. At 24 wk the mean axial rigidity was 2 N in both implants.

Animals↗
PubMed1978

Electrocardiographic findings in patients with connective tissue disease.

ECG changes in 49 patients with rheumatoid arthritis, 18 with ankylosing spondylitis, 47 with systemic lupus erythematosus, 17 with dermatomyositis, 21 with scleroderma and 7 with polyarteritis nodosa were compared with ECG changes in 106 control subjects. The classification of ECG findings was based mainly on the Minnesota Code. Compared with control subjects, pathological Q--QS, ST segment and T wave patterns were more common in all patient groups--including dermatomyositis, in which cardiac involvement has rarely been reported. P terminal force (PTF) was higher in the patient group. Conduction defects were probably more common in connective tissue diseases, whereas differences in ectopic beats, arrhythmias, QRS duration and QRS axis and R wave amplitude were not significant. The only significant difference between the steroid-treated patients and those without such treatment was the higher frequency of ST changes in the steroid-treated group. The results imply that heart affection is common in all connective tissue diseases. The several mechanisms underlying the cardiac involvement are reflected in many ways in the electrocardiograms of these patients, including an increased frequency of ECG changes mimicking those met in coronary heart disease.

Adult↗
PubMed1977

Relation between HLA-B27 and clinical features in patients with yersinia arthritis.

A study of 74 yersinia arthritis patients implied that the clinical picture of the disease may be modified by genetic background associated with the histocompatibility antigen B27 (HLA-B27). Sixty-six percent of patients were B27 positive. Joint symptoms were somewhat more severe in B27+ patients. Iritis, conjunctivitis, carditis, signs of urologic inflammation, and complete Reiter's triad occurred only in the B27 + group, whereas erythema nodosum was more common in B27 - group. Several B27 + patients also had "B27 + rheumatic diseases," such as ankylosing spondylitis or Reiter's disease, in their history.

Adult↗
PubMed1977

Bone, calcium, and hydroxyproline metabolism in hyperparathyroidism and after removal of parathyroid adenoma.

Several laboratory parameters have been followed before and after surgery in a 69-year-old woman with parathyroid adenoma and severe skeletal involvement. High preoperative levels of immunoreactive parathyroid hormone rapidly decreased postoperatively, accompanied by a similar fall in the peptide-bound hydroxyproline (HP) excretion in the urine. Renal clearance of free HP was high both pre- and postoperatively, probably because of renal damage associated with the disease. The high serum alkaline phosphatase levels increased slightly after the operation. The patient developed severe postoperative hypocalcaemia, and prolonged calcium supplement therapy was necessary. The results imply a clear correlation between the changes in Ca homeostasis and the breakdown rate of bone collagenous matrix. Postoperative hypocalcaemia was mainly due to the rapid change in the rates of bone formation and destruction.

Adenoma↗
PubMed1977

Rubella antibodies and acute viral hepatitis.

High antibody titres against rubella and measles viruses have recently been associated with certain chronic disorders such as chronic active hepatitis and occasionally with acute hepatitis. The present study was designed to evaluate the frequency of this association with acute hepatitis. Haemagglutination inhibition (HI) and complement fixation (CF) antibodies to rubella, measles and influenza A viruses were determined in 97 consecutive patients with acute viral hepatitis and in 97 control persons matched by sex and age. In patients, particularly in those over 30 years of age, a small but statistically significant increase in rubella HI titres was seen. In 3 hepatitis cases the rubella HI titres were very high (greater than or equal to 2 560). The antibody levels against measles and influenza A viruses did not differ from the controls. The present data indicate that a small proportion of acute hepatitis patients show a transient strong humoral immune response to rubella virus. The reason for this is not known.

Acute Disease↗
PubMed1977

HLA phenotypes in patients with rheumatic fever, rheumatic heart disease, and Yersinia arthritis.

HLA phenotypes were determined in 109 patients with rheumatic fever (RF), 48 patients with Yersinia arthritis (YA), 86 patients with chronic rheumatic heart disease (RHD), and 326 controls. There was an increased frequency of Bw35 in RF as compared to controls (Pc less than 0.01), while B18 was more common in patients with acute carditis than in those without (P less than 0.02). HLA frequencies in RHD did not differ significantly from those in controls. A significant correlation between B27 and YA was observed (Pc less than 0.001). Carditis or iritis occurred in 10 of 31 B27 positive YA patients but in none of 17 B27 negative patients. Eleven of 31 B27 carriers had signs of urological inflammation vs one of 17 B27 negative patients. In the B27 positive YA group, there were three men with previous ankylosing spondylitis and one with Reiter's syndrome (RS). Also, four patients developed RS during Yersinia infection. This simultaneous occurrence of three B27 positive rheumatic diseases suggests that a patient with one "B27 positive rheumatic disease" is more susceptible to other diseases or symptoms known to be associated with the B27 antigen.

Adult↗
PubMed1976

Relation to osteoporosis of age- and hormone-induced changes in the metabolism of collagen and bone.

Experimental evidence is presented which suggests that age-induced changes in the collagenous matrix, the main constituent of the organic portion of bones, are at least partially responsible for age-induced physiological osteoporotic changes in the skeleton. In particular, there seems to be a labile fraction of recently synthesized collagen in bones, which loses its metabolic activity rapidly with advancing age. Experimental and clinical hormonal disorders and disturbances in calcium metabolism also cause changes in skeletal metabolism; these changes seem to be largely mediated through changes in the collagenous matrix. In experimental hyperthyroidism and hyperparathyroidism, the rate of degradation of the collagenous matrix appears to act as a moderator or "final messenger" in hormone-induced bone resorption. In conditions with altered calcium metabolism, such as malabsorption associated with hypocalcemia, altered bone metabolism may be due to osteomalacia or hypocalcemia-induced hyperparathyroidism. An increase in the rate of bone destruction in relation to the rate of bone formation is probably also the cause of postmenopausal osteoporosis. At present there is no optimal form of hormonal treatment for age-induced or post menopausal osteoporosis. Estrogen replacement therapy may be the best available treatment for postmenopausal osteoporosis, but slowing down the already low rate of bone catabolism in elderly subjects by estrogen or other therapeutic means requires long periods of treatment before pronounced increases in the total mass of bones take place and prophylactic administration of estrogen may produce better results.

Aging↗
PubMed1975

Rheumatic fever and Yersinia arthritis. Criteria and diagnostic problems in a changing disease pattern.

A study of rheumatic fever (RF) in Finland and Sweden was carried out by examining (a) the patients with RF in two hospitals in Helsinki, Finland during the years 1969-72, (b) the case reports of RF patients in Uppsals hospital region (UHR) in Sweden during the years 1968-69. In Helsinki there were 22 and 2n UHR 16 patients with an acceptably certain diagnosis of RF. Of the five "major manifestations" according to Jones' revised criteria (Circulation, 32: 664, 1965), carditis and polyarthritis were the most valuable diagnostic criteria, whereas only 8 cases of the whole material had erythema marginatum. The two remaining criteria, chorea and subcutaneous nodules, have lost their diagnostic value, since they are extremely rare nowadays. The diagnosis of RF was substantially influenced by arthritis associated with Yersinia enterocolitica infection. Some of the patients with YA met completely the Jones revised criteria for the diagnosis of RF. The symptomatology of Yersinia arthritis (YA) and that of RF are similar in some cases it is impossible to separate then even on the basis of serological tests. Diagnostic criteria should therefore be viewed against the geographical distribution of the disease. In addition to the required Jones' criteria, we concluded that at least in Sweden and Finland, in order to be categorized under RF, a patient must demonstrate clinical and serological evidence of acute streptococcal infection and, furthermore, Yersinia infection must be excluded.

Adolescent↗
PubMed1975

Rheumatic fever in adult patients.

A study of rheumatic fever in adult patients (diagnosed according to the Jones revised criteria; Circulation 36: 664, 1965) was performed by examining 26 patients during the acute phase of the disease, and by re-examining 22 of them from 6 months to 64 months later (mean 33 months). Polyarthritis and carditis were the most common major manifestations. 23 patients had polyarthritis and 3 monoarthritis. 18 patients had signs of acute cardiac involvement. Carditis appeared to be rather benign: at the acute stage no patient developed congestive heart failure or any other serious complication. Five patients had erythema marginatum, but we saw no chorea or subcutaneous nodules. Of the 22 patients examined in the follow-up study, 4 had persistent signs of cardiac involvement and 15 showed chronic joint manifestations. Yersinia enterocolitica infection was by far the most difficult differential diagnostic problem, since polyarthritis and carditis associated with this enteric infection were very similar to those in patients with rheumatic fever. Current literature on rheumatic fever and the results of this series suggest that the diagnostic criteria of rheumatic fever (Jones) should be re-evaluated, at least in industrial countries.

Acute Disease↗
PubMed1975

Pulmonary involvement in patients with rheumatoid arthritis.

Vital capacity (VC) and single-breath diffusing capacity for carbon monoxide of the lungs (Dco) were measured and chest X-ray evaluated in 129 patients with rheumatoid arthritis (RA). 123 of them represented average RA patients, either hospitalized (84 patients, Group I) or outpatient material (39 patients, Group II). The remaining six patients (Group III) represented cases with marked changes in chest X-ray detected in an earlier study. Deviating findings in the 123 cases of Groups I and II were observed as follows: in one the lung function tests or X-ray examinations, 35%; abnormal X-rays, 18%; reduced VC or Dco, 28%; simultaneously low VC and Dco, 7%; and pathological findings in all three tests, 2%. Group III showed extremely low VC and Dco values. Changes in respiratory function involved restrictive impairment and diffusion defects, and the results further implied that restrictive changes develop early, whereas decreased diffusing capacity is associated with more advanced "rheumatoid lung". The disparity abnormal findings in chest X-ray changes and in lung function tests suggests that in examining pulmonary manifestations in patients witu RA, both radiographic methods and pulmonary function tests should be used for relevant evaluation.

Adult↗