Search PubMed⌕ Search

Biomedical subjects

A Ohlin

Publications and source records attributed to A Ohlin.

33 records · Page 2Linked to original sources
PubMed1992

Stability of cemented sockets after 3-14 years.

The strength of the mechanical fixation of cemented sockets was studied in 10 pelvic specimens retrieved at autopsy from patients who had had total hip arthroplasty (THA) (group 1). A further 11 sockets, cemented into the acetabulae of fresh cadaver specimens, served as a control group (group 2). The mean twisting torques required to break the sockets loose were 80 Nm and 86 Nm in groups 1 and 2, respectively (no significant difference). However, in all 21 cases the mode of loosening deviated from what is commonly observed in revision operations of loosened THA sockets. The authors conclude that tests of implant stability should not be performed by breaking the implant loose since it is a poor simulation of what seems to occur in vivo.

Aged↗
PubMed1991

Lower-limb vasospasm and renal failure during postoperative thromboprophylaxis. Case report.

In a 73-year-old woman with trimalleolar fracture, secondary acute ischemia of the limb and renal failure developed in association with heparin-dihydroergotamine thromboprophylaxis. Earlier cases of thromboprophylaxis-related angiospasm are briefly reviewed. The condition is infrequent, but trauma of extremities and shock are risk factors. Renal failure is rare.

Acute Kidney Injury↗
PubMed1990

Maternal body weight and relation to birth weight.

In The Stockholm Pregnancy and Weight Development Study the relationships between birth weight and maternal initial body weight as well as weight increase during pregnancy were analysed in 2,295 subjects. As expected, the most important predictor of birth weight was total maternal weight increase, followed by initial maternal body weight. However, in women with an initial BMI value above 24 kg/m2, birth weight did not increase significantly in tact with maternal weight. The frequency of cesarean sections, 12% overall, was not significantly increased with maternal body weight. These data show that birth weight increases with maternal weight only up to the upper normal body weight.

Birth Weight↗
PubMed1990

Failure of the Christiansen hip. Survival analysis of 265 cases.

Totally, 265 primary Christiansen total hip arthroplasties were followed clinically and radiographically for a median of 6 years. The operations were performed for arthrosis in 220 cases, failed fracture in 23, and rheumatoid arthritis in 13. The influence of 11 presumed determinants on the radiographic outcome was studied. In all, 96 hips were exchanged because of aseptic loosening, 35 stems were loose, and 210 sockets were definitely or probably loose at the last radiographic examination. The survivorship analyses revealed the probability of having a radiographically intact stem after 10 years as 67 percent and for the socket 0 percent. None of the 11 determinants influenced the radiographic outcome.

Adult↗
PubMed1990

Loosening of the Lubinus hip. 202 cases followed for 3-6 years.

Survivorship methods were applied to a consecutive series of 202 primary Lubinus total hip arthroplasties followed for 3 to 6 years. After 5 years, the revision rate was 3 percent, and the radiographic loosening rate was 13 percent for the socket and 10 percent for the stem.

Adult↗
PubMed1990

The pathogenesis of loosening of total hip arthroplasties. The production of factors by periprosthetic tissues that stimulate in vitro bone resorption.

The production of factors capable of stimulating bone resorption in the newly formed periprosthetic capsule and in the bone-cement membrane obtained from patients reoperated due to aseptic loosening of cemented total hip prostheses was studied using organ culture techniques. Addition of culture media conditioned by membranes from six patients and bone-cement membranes from two patients to the mouse calvarial cultures resulted in a significantly increased release of calcium. The effect of capsule-conditioned media on calcium release was dose- and time-dependent and significantly reduced by the osteoclast inhibitor of calcitonin. Histologic analysis of bones at the end of the culture period showed that capsule-conditioned media enhanced the breakdown of mineralized bone and increased the number of osteoclasts. The observations showed that newly formed periprosthetic tissues from patients with loose total hip arthroplasties (THAs) can produce one or several factors that stimulate bone resorption in vitro by an osteoclast-mediated mechanism. Not only mechanical failure but also biologic reactions in the periprosthetic tissues eventually lead to osteoclast activation and may contribute to the loosening of THAs.

Adult↗
PubMed1990

Maternal body weight development after pregnancy.

Body weight development during pregnancy was monitored for 2295 women, and up to 1 year post-partum for 1423 of them, at 14 maternity clinics throughout Stockholm. The objective was to find predictors for post-partum weight retention. The mean weight gain after 1 year post-partum compared with the pre-pregnancy body weight (delta-weight) was 1.5 +/- 3.6 kg (P less than 0.001). Of the group 30 per cent lost weight, 56 per cent gained 0 to less than 5 kg and 14 per cent gained greater than or equal to 5 kg. When this result was corrected for possible average underestimation of the self-reported pre-pregnancy weight and weight gain with age, the mean delta-weight was 0.5 kg. The factor with the highest correlation with delta-weight was pregnancy weight gain (r = 0.36, P less than 0.001). Very low r-values, although statistically significant, were obtained for the correlation between the delta-weight and lactation (r = -0.09, P less than 0.01) and age (r = 0.06, P less than 0.05). The delta-weight was not correlated with pre-pregnancy body weight or parity. Women with a delta-weight of greater than or equal to 5 kg had, on average, a higher pre-pregnancy body weight, but initially overweight women had a more variable weight development than lighter women. One in every four women with a weight retention of greater than or equal to 6 kg after a previous pregnancy experienced a high weight gain even after the present pregnancy. Women who stopped smoking had a significantly higher delta-weight than either smokers or non-smokers. Women in the age group greater than or equal to 36 years had a higher mean pre-pregnancy body weight than younger women, and in the age group 26-35 years the pre-pregnancy body weight was increased with increased parity. Thus, post-partum weight development is individual and of the factors studied here only high weight gain during pregnancy and smoking cessation can be considered as predictors for persistent weight gain after 1 year post-partum.

Adolescent↗
PubMed1989

Failed Christiansen total hip arthroplasty. A radiographic and histologic study.

Twenty-two consecutive cases of the Christiansen total hip arthroplasty revised because of aseptic loosening were analyzed with regard to radiographic changes and operative and histopathologic findings. This prosthesis was designed with a socket and a trunnion sleeve made of polyoxymethylene or Delrin. In 18 cases there was isolated socket loosening, in all cases there was obvious bone resorption beneath the collar of the stem, and in 20 cases the socket had migrated. The radiographic socket wear rate averaged 0.4 mm/year. In 18 cases a significant amount of debris material was found in the joint cavity. Light microscopy revealed a severe foreign body reaction with numerous plastic particles, most often engulfed by macrophages. Taken together, these findings indicate that socket wear leading to a foreign body reaction with bone resorption is the main cause of the poor results noted with this particular total hip prosthesis.

Aged↗
PubMed1988

The ultrastructure of the tissue surrounding the Christiansen total hip.

Tissue samples obtained from 24 consecutive Christiansen total hip revision operations were examined with transmission electron microscopy. An abundance of wear particles of plastic, originating from the polyoxymethylene socket, were found in the periprosthetic tissue, where they induced fibrinoid necrosis and macrophage activation. Phagocytosing cells revealed degenerative signs of varying degrees. It seems probable that this strong tissue reaction results in excessive bone resorption and is associated with the disastrous rate of socket loosening recorded with the Christiansen prosthesis.

Aged↗
PubMed1987

Weight reduction with dietary fibre supplements. Results of two double-blind randomized studies.

We report two studies, in which fibre/placebo tablets were added to a weight reduction regimen in the treatment of moderately obese women. In Study I, 60 females were treated for a two-month period with general dietary advice, providing a mean daily energy intake of 1,400 kcal. In addition, the fibre group received a 5 g dietary fibre supplement. In Study II, 45 females were treated for a three-month period with a similar programme, in which the recommended daily energy intake was 1,600 kcal and the fibre supplement 7 g/day. In both groups weight changes, hunger ratings, blood pressure, defecation pattern and possible side-effects were recorded every second week. Before treatment mean body weight was 95.4 kg (Study I) and 99.3 kg (Study II). Six patients dropped out of Study I, and four out of Study II. In Study I mean weight loss, 7.0 kg, in the fibre group was significantly higher (p less than 0.05) than 6.0 kg in the placebo group. In Study II mean weight loss in the fibre group of 6.2 kg was significantly higher than the 4.1 kg in the placebo group (p less than 0.05). No significant difference in hunger feeling between the groups was found. Systolic blood pressure was reduced in all four groups at the end of the treatment, whereas diastolic blood pressure was reduced only in the fibre group in Study II. The results suggest that dietary fibre is of additive value in the treatment of moderately obese patients. The fibre supplement, however, needs to be comparatively high.

Adolescent↗
PubMed1984

Role of disulfide bonding in outer membrane structure and permeability in Chlamydia trachomatis.

The outer membrane of Chlamydia trachomatis can be efficiently solubilized by a variety of mild detergents in the presence of the reducing agent dithiothreitol. This allows purification of the chlamydial major outer membrane protein at high yield in very gentle conditions by using its differential solubility in Sarkosyl and octylglucoside in the presence of dithiothreitol. The major outer membrane protein of the L2 serovar is an acidic protein with a pI of ca. 5. It contains three cysteine residues that allow it to form a disulfide-linked proteinaceous network responsible for the characteristic rigid outer membrane of the elementary body. By the use of an in vitro reconstitution assay developed by Nikaido and his co-workers, it was shown that the outer membrane contains pores with an "exclusion limit" between molecular weights 850 and 2,250. In addition, the "opening-closing" of the pores was shown to be controlled through a simple reduction-oxidation mechanism. A model that outlines the role of disulfide bonding in the physiology of chlamydial development is presented.

Amino Acids↗
PubMed1983

Enzyme-linked immunosorbent assay for immunoglobulin G and M antibodies to Chlamydia trachomatis in human sera.

Microimmunofluorescence methods used for detection of immunoglobulin G and M antibodies to Chlamydia trachomatis are not available to many clinical laboratories. We evaluated a simple enzyme-linked immunosorbent assay in which serotype L2 elementary bodies are used as antigen. The enzyme-linked immunosorbent assay proved satisfactory for the detection of serum IgG. A total of 160 human sera were tested, and the results correlated well with those obtained by microimmunofluorescence. Results for IgM antibody detection were not as successful, and correlation with current methods was poor.

Adult↗
PubMedDate not supplied

Position, orientation and component interaction in dislocation of the total hip prosthesis.

The position, orientation in space and interaction of prosthetic components was determined in 15 patients with known episodes of dislocation after total hip replacement. The same calculations were performed in a reference group of 44 patients without dislocation. In the group with dislocations, there was a significantly decreased femoral anteversion, and a decreased femoral flexion permitted by the prosthetic components. There were no further significant differences of clinical relevance between the groups concerning all other examined parameters of component position, orientation and interaction. It is concluded that the decreased range of flexion, caused by impingement of the prosthetic components with ensuing leverage effect is one cause of dislocation.

Aged↗