Search PubMed⌕ Search

Biomedical subjects

N Schwarz

Publications and source records attributed to N Schwarz.

At least 73 records · Page 4Linked to original sources
PubMed1988

Pressure-volume ratio in human cadaver hip joints.

In postmortem examinations 26 hip joints of 23 adult individuals were filled with Ringer's solution in order to furnish data on the relationship between intra-articular pressure, capsular content, and joint position. A tube system was connected to an 18-gauge needle and to a pressure transducer. After instillation of 2.5, 5.0, 7.5, and 10.0 ml of Ringer's solution, intra-articular pressure was recorded in six different joint positions (extension, 45 degrees and 90 degrees flexion, 40 degrees internal and 40 degrees external rotation, and 45 degrees abduction in extension). Intra-articular pressure depends mainly on the position of the joint, with highest values in external and internal rotation and lowest values in 45 degrees flexion. In this last position, the pressure was zero in two of four cases after injection of 10 ml, whereas with external rotation and instillation of 2.5 ml almost 60 kPa was recorded. In extension and after filling with 10 ml the pressure exceeded the level of normal systolic blood pressure in all cases. Under pathologic conditions intra-articular pressure of the hip joint can rise well above arterial pressure and thus eventually compromise vascular supply to the femoral head, even in the presence of only minimal intra-articular effusion.

Aged↗
PubMed1988

[Abduction fractures of the femur neck in adolescents].

Valgus fractures of the femoral neck during growth are a rarity. Four cases are reported, and, in addition, one patient from the literature. Three were treated by bed rest, two by primary screw fixation. Clinical results were good; there was no necrosis. In accordance with the experience with similar fractures in adults primary osteosynthesis is recommended in all cases to prevent secondary displacement. Decompression of the hip joint by aspiration should be done for diagnosis and for decompression of tension haemarthrosis.

Adolescent↗
PubMed1988

Irradiation-sterilization of rat bone matrix gelatin.

Bone matrix gelatin induces bone formation in muscle, and when implanted orthotopically it improves bone repair. Co-60 sterilization of bone gelatin impairs the protein-bound induction mechanisms. Gelatin samples nonirradiated or irradiated by 25 or 50 kGy were implanted into a pouch in the abdominal wall of Sprague-Dawley rats, as well as into a 7-mm calvarial defect. Evaluation was done by histologic studies, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. Gelatin irradiated with 50 kGy was absorbed in the muscle bed without evidence of any specific host reaction. Irradiation of 25 kGy led to histologically confirmed ectopic bone formation, but the wet weight of the explants was only half that of the nonirradiated control samples. Alkaline phosphatase activity was equal in both of these groups. With orthotopic implantation, neither a histologic nor a morphometric effect was seen with 25 kGy. Loss of osteoinduction with 25-kGy irradiation is apparently masked by osteoconductive mechanisms with orthotopic implantation.

Alkaline Phosphatase↗
PubMed1988

Inferior acromioclavicular separation. Report of an unusual case.

An inferior acromioclavicular separation occurred in a 33-year-old man. Diagnosis was based on plain roentgenograms and a computed axial tomographic scan. There were no fractures and no vascular or nerve damage. Open reduction was performed 48 hours after injury followed by tension wire fixation of the acromioclavicular joint and repair of torn ligaments. Clinical outcome four months after injury was perfect.

Acromioclavicular Joint↗
PubMed1987

Experimental osteoinduction in rats: collagen-apatite versus osteogenin-containing gelatine.

An experimental study in rats was done to investigate the bone-regenerating properties of collagen apatite (Collapat) and to compare it with osteoinduction dependent on osteogenin-containing gelatine (OCG). The test substances were implanted orthotopically (calvarial defect--7 mm in diameter) and heterotopically (paravertebral muscles, abdominal muscles). The results were evaluated histologically and enzymatically (alkaline phosphatase). Collapat caused neither osteoinduction in the heterotopic site nor healing of the bone defects. Foreign body reaction without new bone formation was encountered. OCG implantation leads to new bone formation in the muscles within 3 weeks, associated with a significant increase in alkaline phosphatase activity, and to extensive new bone formation in the calvarial defect within 4 weeks. The defects did not heal if left empty. The value of clinical application of Collapat appears to be doubtful. Osteoinduction with OCG requires further experimental investigation.

Animals↗
PubMed1986

[Technic and results of clavicular medullary wiring].

Pseudo-arthrosis was recorded from 13 per cent of patients whose clavicular fractures had been treated by wire fixation. Too short fragmental splinting, postoperative diastasis, use of too thin wires (2 mm in diameter) or intricate shapes of fracture (fragmental) were causes of poor results. Neither parallel nor sagittal skin incision was cosmetically acceptable. Kirschner's wire fixation, when applied to short fractures in the central third of the clavicula--has proved to be a simple and promising method of stabilisation.

Adolescent↗
PubMed1986

[Fragment dislocation and surgical indications in segmental fractures of the radial head].

The aim of this study was to evaluate the influence of primary displacement of fragments of the radial head on the clinical result after conservative therapy, also to see whether the extent of displacement could give valuable indications for operation. In non-displaced fractures the results are slightly but significantly better than in displaced fractures. On the other hand, the amount of displacement must be considered to be of minor importance. In 64 percent of conservatively treated patients the results were good despite displacement and the results were similar after primary open reduction. It has to be assumed that undiagnosed lesions of the joint capsule and ligaments are the most important cause of residual functional deficits.

Bone Screws↗
PubMed1986

[Mood and social information processing in depressive disorders].

Informative and directive functions of mood in judgments of well-being were explored in both depressed and non-depressed subjects by using the weather as a natural mood manipulation. Non-depressives reported higher well-being on sunny than on rainy days. The reverse was true for depressives, who tended to report higher well-being, and were more optimistic about their future well-being, on rainy than on sunny days. That is, depressives tended to report lower well-being when they felt bad "despite" salient positive situational influences (sunny weather), and higher well-being when they could attribute their negative feelings to the weather. These results are consistent with a social information processing approach to depression. In contrast to purely cognitive models of depression this framework provides an account for naturally occurring mood swings and recognizes the contribution of mood to the maintainance of depression.

Arousal↗
PubMed1984

[Failures of clavicular intramedullary wire fixation and their causes].

The fixation of fractures of the clavicle by intramedullary Kirschner wires is a semirigid method. External fixation of the arm after operation is, therefore, necessary. 25 out of 38 fresh fractures in our series healed in ideal position of the fragments. Another eight fragments healed under angulation of 10 degrees to 35 degrees. Five patients developed pseudarthrosis, three of whom had multiple fragmentation. Only two of a total of eight multiple fractures healed in good position. The causes for negative results are multiple fragmentation or technically insufficient fixation--mainly perforation of the corticalis of the medial fragment by the wire and therefore improper position of fragments and K-wires or too short intramedullary run of the wire in the medial fragment. Wires of less than 2.0 mm in diameter are not strong enough to withstand the bending forces. The intramedullary wire fixation gives adequate results in transverse or short oblique fractures of the middle third of the clavicle if good reposition is obtained and if the thickest possible wire or, better, two wires are introduced. In all other cases and especially in multiple fragmentation higher stability has to be achieved by plate fixation.

Adolescent↗
PubMed1983

[Conservative therapy of isolated radius head fracture--immobilization or early functional movement treatment?].

We reviewed 95 patients with isolated fractures of the radial head. 33 of them were treated by plaster cast fixation for three weeks, 62 by immediate active motion. No difference in frequency of arthrosis and periarticular ossification in both groups could be observed. Examination of the patients two to four years after trauma showed excellent functional results in 61% of the 33 patients and in 77% of the 62 patients. The average duration of treatment is shorter by two weeks in the group of immediate active motion. The clinical results of this group, although not statistically significant, seem to be better than after immobilization.

Adolescent↗