Search PubMed⌕ Search

Biomedical subjects

S Nielsen

Publications and source records attributed to S Nielsen.

At least 343 records · Page 19Linked to original sources
PubMed1985

Long-term outcome of 151 cases of anorexia nervosa. The Copenhagen Anorexia Nervosa Follow-Up Study.

One hundred and fifty-one patients (140 females - 11 males) with anorexia nervosa (AN) from three departments (child psychiatry, psychiatry, and internal medicine) were re-examined 4-22 years (average 12.5 years) after their first contact with the Rigshospital in Copenhagen. During the years 1960-76 the number of referrals was on the increase, and relatively more patients were treated in the psychiatric departments at the end than at the beginning of the period. Mean age was 16.6 years at onset, 19.0 years at primary contact. Mean weight loss was 32%. Mean duration of treatment was 12 months. Differences between the three departments concern especially age, sex, and duration of treatment. Mean age at follow-up was 31.0 years (range 16-63 years) for surviving probands. Follow-up information originated from semi-structured personal interviews (in 80% of surviving probands) together with register data on all probands, supplemented by extensive hospital data. Nine patients (6%), including six who committed suicide, died on the average 7.3 years after primary contact (average age 27.1 years). The mortality rate was 0.5% per year. At follow-up one fourth of the surviving probands had AN and one fourth suffered from other psychiatric disorders, while one half were free from mental illness. There were no significant differences in outcome between the three departments. As a whole, the group experienced a social decline. It is concluded that a substantial part of this group of AN patients had a poor prognosis with a tendency towards chronicity, despite relatively long and intensive treatment, but, on the other hand, about one half of the probands seemed to be healthy and well functioning.

Adolescent↗
PubMed1985

Contribution of the cortex to epiphyseal strength. The upper tibia studied in cadavers.

Non-destructive measurements of compressive stiffness were carried out on 20 proximal tibial autopsy specimens. The tibial epiphyses were first loaded through a template covering all but the peripheral 2 mm of the subchondral resection surface, then through the whole resection surface, and finally, after removal of the peripheral shell. A slight increase of the stiffness coefficient resulted from peripheral contact. Stiffness increased significantly after removal of the shell, but several potential sources of systematic error in this part of the investigation raise questions as to the validity of this finding. The area-corrected stiffness showed a decrease as a result of peripheral contact; this result indicates that the peripheral rim of bone has a lower area-corrected stiffness than the central bone, a finding which is incompatible with the concept of a true cortical shell at the epiphyseal level.

Cadaver↗
PubMed1985

Prosthesis position in shoulder arthroplasty. A cadaver study of the humeral component.

In six cadaver shoulder joints, the external rotation was measured applying a constant external torque to the humerus before and after insertion of a non-constrained shoulder joint prosthesis at different degrees of retroversion. At 35-45 degrees of retroversion there was no difference between the external rotation of the inserted prosthesis and the external rotation of the joint before arthroplasty.

Biomechanical Phenomena↗
PubMed1985

Unicompartmental arthroplasty of the knee. Cadaver study of the importance of the anterior cruciate ligament.

The tibiofemoral articulation on horizontal and 10 degrees tilted tibial components was examined radiographically in 20 cadaver knees after lateral arthroplasty, and after cutting the anterior cruciate ligament in 10 knees with medial and 10 with lateral arthroplasty. Articulation took place more posteriorly on the horizontal components at any degree of flexion examined; a correlation was found between the operation-induced change in the inclination of the lateral tibial plateau and the point of articulation. Based on the regression equations, the expected point of articulation on an arbitrarily chosen component placement could be calculated for any degree of flexion provided the preoperative inclination was known. Cutting the anterior cruciate ligament caused articulation to move posteriorly on the tibial component at both medial and lateral arthroplasty. We concluded that it was possible to estimate the tilt of the tibial component that was required to avoid marginal articulations when the preoperative slope of the tibial plateau was known. Absence of the anterior cruciate ligament seems to contraindicate unicompartmental arthroplasty.

Biomechanical Phenomena↗
PubMed1985

Stability of the shoulder joint. Cadaver study of stabilizing structures.

In 10 cadaver shoulder joints, the increments in external rotation were measured after successive cutting of the anterior stabilizing structures while a constant external torque was applied to the humerus, abducted in the scapula plane. The subscapularis muscle prevented anterior subluxation in the lower range of abduction. As abduction increased, the lower part of the capsule was the most important stabilizing structure. The findings suggest that it may be possible to perform more selective repairs in the treatment of recurrent anterior instability.

Biomechanical Phenomena↗
PubMed1985

Instability of knees with ligament lesions. Cadaver studies of the anterior cruciate ligament.

We studied the importance of the two parts of the anterior cruciate ligament (ACL), the medial collateral ligament (MCL), and the posterior medial capsule (PMC) to translatory and spontaneous axial rotatory instability in 15 osteoligamentous knee preparations. Instability was recorded continuously from zero to 90 degrees of flexion with application of a constant force to the tibia. Isolated cutting of the ACL caused a moderate anterior translatory movement, which increased if the MCL was also cut. Transection also of the PMC resulted in an even larger range of anterior translatory movement. Combined lesions to the MCL and the PMC and the posterolateral part of the ACL did not cause such instability provided the anteromedial part of the ACL was intact. Application of a valgus moment to specimens with injured ACL and medial structures induced a spontaneous anteromedial subluxation of the tibia in a semiflexed position. When flexion was increased to 70-80 degrees, a sudden reduction was observed.

Humans↗
PubMed1985

Trabecular bone strength profiles at the ankle joint.

The mechanical strength of trabecular bone at the ankle joint was studied in ten amputation specimens by means of multiple penetration tests. Tibial bone was considerably weaker than talar bone (40% on average). An area of peak bone strength located posteriorly and medially to the center of the joint was found in most joints. The variation of bone strength with the depth from the surface was studied by comparing five successive 2-mm levels. At the tibia there was a statistically significant decrease of bone strength from the first to the second level. At the talus, bone strength increased at first, then decreased significantly. The absolute values of strength recorded suggest that in a substantial number of the joints studied, the resection surfaces--especially at the tibial side--might be too weak to support the loads imposed by current prosthetic designs.

Ankle Joint↗
PubMed1984

Rotatory instability of cadaver knees after transection of collateral ligaments and capsule.

The importance of the medial and lateral compartment ligaments of the knee in relation to valgus-varus and axial rotation instability was investigated. Mobility patterns were drawn from 20 osteoligamentous knee preparations after successive transections of the structures. Cutting of the medial collateral ligament resulted only in slight valgus instability and modest anteromedial instability. When the medial posterior joint capsule was also cut, both types of instability increased, and moreover, the knee became posteromedially unstable. Cutting of the lateral collateral ligament produced only a little varus instability and anterolateral rotatory instability, but varus instability increased considerably when the posterior lateral capsule was also transected. In this latter situation, even marked posterolateral rotatory instability was found. Isolated transection of the medial or lateral collateral ligament did not cause any major valgus or varus instability, but when the posterior capsule was also transected, a considerable degree rotatory instability could be found even though the cruciate ligaments were intact.

Biomechanical Phenomena↗
PubMed1984

The anterior cruciate ligament of the knee: an experimental study of its importance in rotatory knee instability.

The importance of the anterior cruciate ligament (ACL) in relation to valgus-varus and axial rotation stability in the knee joint was investigated. Mobility patterns were drawn from ten osteoligamentous preparations after successive transection of the two parts of the ACL and the medial (MCL) and lateral collateral ligaments (LCL). The knee joint remained grossly stable after partial injury of the ACL, while sectioning of the entire ACL caused an increase in internal rotation in the extended-semiflexed position. Combined lesions to the ACL and the MCL caused considerable valgus instability increasing with flexion, the joints remaining stable in extension. Moreover, marked anteromedial instability occurred, while only slight posteromedial instability was found. Combined lesions to the ACL and the LCL caused varus instability, worst in the semiflexed position, and a consistent pivot shift in applying a valgus torque in flexion was noted. Moreover, moderate posterolateral instability was found, at its maximum in the semiflexed position. External rotatory stability is secured primarily by the MCL, secondarily by the posterior medial capsule, and finally by the ACL. The existence of lateral pivot shift is proof of damage to the ACL.

Humans↗
PubMed1984

Antibiotic treatment of pneumonia and bronchiolitis. A prospective randomised study.

Routine administration of antibiotics in the treatment of pneumonia and bronchiolitis in infants and small children was evaluated in an open randomised prospective trial. From 1979-82 136 children between the age of 1 month and 6 years were allocated to one of two treatment groups shortly after their admission to a paediatric ward. Group A patients were to be given antibiotics but those in group B were not. None of the children had received antibiotics before hospital admission. A viral infection was diagnosed in 38 of the 72 patients from group A and in 34 of the 64 patients from group B. Respiratory syncytial virus was detected in 84% of these patients. Samples of tracheal secretions showed no differences between the groups in respect of cytology and bacterial flora. Nor were there any significant differences in the course of acute disease, the frequency of fever relapse and pulmonary complications. Fifteen patients from group B were subsequently treated with antibiotics: two of these developed secondary purulent infections of the middle ear and one showed a slight pleural effusion. These results do not support the routine use of antibiotics in infants and small children admitted to hospital with pneumonia and bronchiolitis.

Anti-Bacterial Agents↗
PubMed1984

Bacterial infections of the CNS in neutropenic patients.

In neutropenic patients, fever and mental status changes are frequently the only overt clinical manifestations of bacterial infections of the CNS. Prominent headache and meningeal signs are exceptional. CNS infections may occur even in patients receiving large doses of broad-spectrum antibiotics. CSF culture and Gram's stain are required to establish or exclude the diagnosis and are often positive, even in patients receiving antibiotics for other indications. The CSF cell counts and chemistries are helpful if abnormal, but, when normal, provide no assurance that infection is not present. The CSF glucose can be lowered in the absence of pleocytosis, but a low CSF glucose is neither sensitive (27% in this series) nor specific. Lumbar puncture is hazardous in many neutropenic patients because of simultaneous thrombocytopenia; lumbar puncture should be performed by an experienced physician after platelet transfusions. The outcome of CNS infection depends on the underlying clinical disorder and on bone marrow recovery. The use of third-generation cephalosporins, new semisynthetic penicillins, and intrathecal administration of aminoglycosides may improve outcome.

Agranulocytosis↗
PubMed1984

Instability of cadaver knees after transection of capsule and ligaments.

The importance of the medial collateral ligament and the anterior cruciate ligament of the knee in relation to valgus and varus instability was investigated. Mobility patterns were drawn from ten osteoligamentous knee preparations after successive transections of the structures. Cutting the entire collateral medial ligament caused only slight valgus instability, even when the knee was flexed. Further transection of the anterior cruciate ligament increased the instability considerably, but the knee remained stable in extension. The valgus instability after the transections was maximal at about 60 degrees of flexion.

Biomechanical Phenomena↗
PubMed1984

Total condylar knee arthroplasty. Prosthetic component positioning and radiolucent lines.

Prosthetic positioning and overall postoperative alignment were studied in 138 consecutive total knee replacements, using the Insall/Burstein total condylar knee system. Overall alignment was within 7 +/- 5 degrees of valgus in 63 per cent of the knees, while tibial component positioning was within 4 degrees of tilt in any direction in 53 per cent of the knees. A radiolucency index incorporating width and extent of radiolucent zones at the tibia was shown to progress from 3 months to 2 years postoperatively. The radiolucency index 2 years postoperatively was higher with postoperative varus alignment in the rheumatoid arthritis group; a tibial component tilt of more than 4 degrees in any direction increased the radiolucency index in both treatment groups.

Adult↗
PubMed1983

Progressive multifocal leukoencephalopathy: a burnt-out case.

A patient with Hodgkin's disease developed progressive multifocal leukoencephalopathy (PML), documented by brain biopsy to be associated with JC virus infection. His disease progressed over several months, resulting in severe neurological deficit, but then stabilized with little or no further clinical progression during the remaining year of his life. Histopathological evaluation of the brain at autopsy supported the clinical impression that brain infection was arrested. Whereas the brain biopsy exhibited the histological features of active PML including giant bizarre astrocytes, at postmortem examination brain lesions appeared inactive, with regression of astrocytic changes and elimination of oligodendroglial inclusions. Similarly, JC virus antigen, present in the brain biopsy, was not detected in the autopsied brain. This case provides further evidence that PML is not invariably fatal and that clinical and cytological remission can occur.

Adult↗