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Biomedical subjects

C Hasler

Publications and source records attributed to C Hasler.

At least 19 recordsLinked to original sources

[Pediatric spinal injuries].

Spine injuries during growth are rare, but in comparison to adults they are more often associated with neurologic impairment. They also may occur without visible injuries in X-rays. The problems of conventional radiologic diagnostics include before all the differential diagnosis between synchondrosis, apophysis and fracture lines. MRI is indicated in case of neurologic deficits without radiologic abnormalities. In principle the fracture types correspond to those seen in adults. In addition growth specific injuries of the end-plates (growth plates) or ring apophysis may occur. Stable compression fractures are treated conservatively. The spontaneous remodelling capacity for posttraumatic deformities decreases with age: in children below the age of ten years the remodelling capacity for posttraumatic kyphosis is excellent whereas deformities in the frontal plane show no or only incomplete remodelling. Unstable fractures and injuries with associated compression of neural structures should be treated conservatively.

Accidental Falls↗

[Spondylolysis and spondylolisthesis during growth].

Spondylolysis and Spondylolisthesis present with typical age and activity-related issues: in newborns the pars interarticularis is always intact. Only bipedal ambulators develop spondylolysis, mostly during early childhood. Corresponding to the mechanical etiology, the incidence of spondylolysis is higher in athletes who repeatedly have to hyperextent and rotate their lumbar spine for example gymnasts, javelin throwers etc. Spondylolysis is one of the most frequent diagnosis among adolescents with lumbar back pain. However, most of the people with an interrupted Pars interarticularis (about 6% of the population) never become symptomatic or if they do, they respond very well to conservative treatment (adaptation of physical activity, active physical therapy and bracing). If pain persists in combination with an intact intervertebral disc of the slipped segment, we recommend a direct repair of the Pars interarticularis instead of an intersegmental fusion. Patients with low grade Spondylolisthesis (Meyerding I, II) require repeated radiological follow-up during growth because of the inherent risk of slip progression. If a slip of more than 50% is detected before the end of growth, operative treatment is indicated. High grade olisthesis (Meyerding III, IV) leads to anterior shift of the whole trunk, kyphosis of the slipped vertebra with subsequent compensatory lumbar hyperlordosis and flattening of the thoracic spine. Pelvic flexion is clinically evident. Reduction of the slipped and kyphotic vertebra with correction of the spinal, sacral and pelvic profile is recommended and preferable to simple fusion in situ.

Adolescent↗

[Spontaneous corrections, growth disorders and post-traumatic deformities after fractures in the area of the forearm of the growing skeleton].

Growth phenomena after paediatric forearm fractures are described. The capacity for spontaneous remodelling of malunions should be primarily considered in the treatment of fractures of the growing skeleton. Thus, unnecessary reductions, anaesthesia and posttraumatic deformities can be prevented. Generally speaking, a high remodelling capacity can be expected in cases of enough remaining growth, proximity to a physis with high activity, and if the main deformity lies in the plane of motion of the nearest joint. It is widely accepted that distal radius and/or ulna fractures are fully remodelled up to the age of 11 to 12 years. However, the remodelling capacity of fractures of the proximal and middle third of the shaft is smaller and less well known. Stimulating growth disturbances at the upper extremities are clinically of minor importance. Growth arrests are rare. Their fateful occurrence is not predictable and not closely related to fracture pattern or amount of dislocation.

Bone Remodeling↗

[Screw osteosynthesis in dislocated fractures of the radial condyle of the humerus in the growth period. A prospective long-term study].

UNLABELLED: Pseudoarthrosis and cubitus valgus as main complications following displaced fractures of the radial condyle in children can be prevented by open reduction and fixation by K wires. However, delayed union and stimulation of the radial physis with condylar overgrowth and varisation of the elbow as well as fishtail deformities of the distal end of the humerus are reported nevertheless. To prevent those growth disturbances all primary and secondary (4-day X-ray control) displaced fractures of the radial condyle, i.e. those with a central gap of more than 2 mm, were prospectively treated by open reduction and osteosynthesis with a metaphyseal lag screw beginning 1974. Sixty-six patients (41 boys, 25 girls) with an average follow-up of 10 years (2-22 years) sustained 28 primary and 6 secondary displaced fractures. In 5 cases a K wire fixation was performed in view of the smallness of the fragment. Two children with conservative treatment following overlooked displaced fractures showed condylar overgrowth and varisation of the elbow. Screw osteosynthesis led to symmetric elbow angles and function in all cases, whereas fishtail deformities could be observed in 8 of 27 children, probably as a consequence of the remaining central fracture instability. CONCLUSION: Open reduction and osteosynthesis with a metaphyseal lag screw prevents condylar overgrowth in displaced fractures of the radial condyle by guaranteeing fracture healing in anatomic position within 3-4 weeks. However, fishtail deformity can not be prevented by metaphyseal compression only.

Adolescent↗

[Imported dengue fever following a stay in the tropics].

We report on a tourist returning from Thailand, who presented with classical dengue fever. While in Thailand a 36-year-old Swiss female laboratory assistant suddenly developed fever, devastating headache, retro-ocular pain, myalgia and arthralgia, photophobia, nausea and diarrhea. In addition she suffered from epistaxis, urogenital and skin bleeding, and a morbilliform exanthema. After her return to Switzerland we noted lymphadenopathy and splenomegaly, enanthema and laboratory findings of mild hepatitis, thrombocytopenia and leukopenia. The diagnosis of dengue virus infection was verified serologically. Apart from a long lasting convalescent asthenia we observed restitutio ad integrum within days under symptomatic therapy. Epidemiological clinical and diagnostic aspects of dengue virus infection are discussed.

Adult↗

[Proximal intra-articular tibial fracture in skiers].

56 cases of proximal intraarticular tibia fractures over a 4-year period are reviewed. In every case the patients described a preceding valgus-compression trauma of their knee. Clinically we always found a hemarthrosis combined with a tenderness on pressure at the fractured condyle. Roentgenograms should be performed in 4 projections, eventually followed by conventional tomograms or computed tomography. Frequency of the several fracture types is demonstrated following the classification of the AO working group for osteosynthesis. The Eminentia intercondylaris was concerned in 13 cases as avulsion fracture of the anterior cruciate ligament (ACL) with a double peak distribution in the under 20-years- and over 40-years-age group. In the remaining cases we observed split- and/or compression fractures of the lateral tibial plateau of the 40 to 60 year old skier, in 20% communitive fractures. In 85% of the ACL-avulsion fractures we applied a cast brace as a conservative measure, whereas 75% of the tibia plateau fractures were treated operatively by mean of open reconstruction of the articular surface and internal fixation based on the AO-principles as well as bone graft buttressing in two third of the cases.

Adolescent↗

Proteases and antiproteases related to the coagulation system in plasma and ascites. Prediction of coagulation disorder in ascites retransfusion.

To improve the ability to predict the occurrence of coagulation disorders in ascites retransfusion and, in addition, to better define the nature of the coagulation disorder, several proteases and antiproteases were analyzed in ascites and plasma before ascites retransfusion in 17 patients. Plasminogen, alpha 2-antiplasmin, antithrombin III, and fibrin(ogen) degradation products in ascites were significantly altered in patients who later developed abnormal coagulation as compared to those who did not. Only plasminogen and alpha 2-antiplasmin in ascites achieved a sufficient predictive value for the occurrence of coagulation abnormalities. The pattern of the coagulation abnormalities observed strongly suggests fibrinolysis induced by the infusion of plasminogen activators as the cause of the coagulation disorder in ascites retransfusion procedures.

Antithrombin III↗

Coronary thrombolysis in man with pro-urokinase: improved efficacy with low dose urokinase.

Single-chain urokinase-type plasminogen activator (scu-PA), was given to 20 patients with acute myocardial infarction first alone (group I; n = 9) and then in combination with an initial bolus injection of 200,000 units of urokinase (group II; n = 11). In group I, scu-PA was administered in a dose of 15 mg up to 60 mg as an infusion over one hour. Complete reperfusion was achieved in 3/9 patients after 50 to 60 min and partial reperfusion in an additional 2 patients. In group II, a bolus injection of urokinase and 48 mg of scu-PA over one hour were given. Reperfusion was achieved in 9/11 patients after a mean of 30 +/- 22 min. Fibrinogen, alpha 2-anti-plasmin and plasminogen levels did not change from baseline in group I. In group II, fibrinogen levels decreased slightly from 272 +/- 84 mg% to 178 +/- 82 mg% (p less than 0.05) after two hours. No bleeding complications were encountered. Reocclusion at 24 hours was evaluated in 18 patients and was not seen. It was concluded that an initial bolus of urokinase improves the efficacy and the rate of thrombolysis by scu-PA.

Adult↗

Proteases and antiproteases related to the coagulation system in plasma and ascites--influence of dexamethasone.

Fibrinolysis induced by the infusion of plasminogen activators into the circulation has been shown to cause coagulation disorders in ascites retransfusion. Dexamethasone is known to inhibit the synthesis of plasminogen activators by peritoneal macrophages. We therefore assessed its potential in preventing the occurrence of fibrinolysis by injecting 16 mg dexamethasone intraperitoneally in 10 patients 24 h before ascites retransfusion was performed. In addition, the effect of dexamethasone upon the activity or concentration of several proteases and antiproteases related to coagulation in plasma and ascites was analyzed on 15 occasions. An increase of the activity of plasminogen, alpha 2-antiplasmin, and antithrombin III, and in the concentration of alpha 1-protease inhibitor in ascites was induced by the dexamethasone injection. However, the reaction was not identical in all patients. Those patients having an increase of plasminogen activities of 0.6 CTA U/ml or more did not show signs of fibrinolysis during retransfusion. The results obtained indicate that intraperitoneal injection of dexamethasone decreases the concentration of plasminogen activators in ascites and thereby reduces the risk of coagulation disorders during retransfusion procedures. Since the effect is variable and not sustained, assessment of preoperative plasminogen concentrations is mandatory in order to prevent complications.

Antithrombin III↗