Comparison of Cotrel-Dubousset pedicle screws and hooks in the treatment of idiopathic scoliosis

Eighty-two patients with idiopathic scoliosis were treated by Cotrel-Dubousset instrumentation between 1987 and 1991. Twenty were treated with hooks only, 47 with screws and hooks, and 15 with screws only. The methods were compared and the findings showed that screw fixation can be used in the thoracic spine without neurological complications. The screws provided immediate stability with rigid fixation, together with better correction of frontal, sagittal and rotational deformity. There is less loss of correction, a shorter fusion and less risk of neurological complications because of the placement outside the spinal canal and the rigid fixation in derotation. The technique was simpler and the operating time shorter than with the other methods.

Salvage of neglected unstable intertrochanteric fracture with cementless porous-coated hemiarthroplasty

A cementless porous-coated femoral prosthesis with a long stem was implanted in seven patients who had untreated comminuted unstable intertrochanteric fractures of the femur associated with a posterior dislocation of the femoral head. The average age of the patients was 35 years (range, 25-52 years). The length of follow-up observation averaged 45 months (range, 23-60 months). The hip rating at the final follow-up examination ranged from 82 to 100 points (average, 96 points). The follow-up roentgenographs of these patients revealed complete consolidation of the fracture site and no evidence of subsidence or loosening of the prosthesis. There was no indication of detrimental bone remodeling phenomenon in this series. Hemiarthroplasty with a cementless, porous-coated, long-stem prosthesis can be effective treatment for this complex fracture dislocation.

Isolation of leukocyte-free platelets from standard platelet concentrates by centrifugation

We evaluated centrifugation techniques to isolate leukocyte-free platelets from standard platelet concentrates. Among various settings of centrifugation force and time, we found the setting at 300 X g for 10 minutes or 370 X g for 5 minutes to be efficient and reproducible for recovering sufficient quantities of platelets free of leukocytes.

Lymphocytotoxic donor-specific response to fresh and stored blood. An experiment in immunosuppressed rhesus monkies (brief communication)

Transfusion of stored blood has been found to decrease the rate of antibody formation. Antigen immunogenicity and the recipient's immunoresponsiveness have a major role in the fate of the allograft. The combined effect of low immunogenicity and depressed responsiveness has been studied.

Association between HLA-BW38 and peripheral psoriatic arthritis

The frequency distribution of HLA antigens was studied in a group of psoriatic patients with and without arthritis. HLA-BW38 was found significantly increased in the group with peripheral psoriatic arthritis. There were no differences in the clinical features of the arthritis in the BW38 positive (+) and BW38 negative (-) individuals. It is suggested that BW38 is a genetic marker and/or an indicator of peripheral joint involvement in psoriatic patients.

Prognostic use of preoperative and immediate postoperative carcinoembryonic antigen determinations in colonic cancer

Preoperative and postoperative carcinoembryonic antigen (CEA) concentrations are useful in predicting the likelihood of recurrence in patients undergoing curative operations for cancer of the colon. The incidence of recurrence was studied in three groups of patients followed for 6 to 18 months after such an operation: 36 patients (group 1) had preoperative and postoperative plasma CEA concentrations less than 2.5 ng/ml; 11 patients (group 2) had a preoperative CEA value above but a postoperative value below 2.5 ng/ml; and 11 patients (group 3) had preoperative and postoperative concentrations greater than 2.5 ng/ml. Cumulative rates of recurrence at 6, 12 and 18 months after operation were as follows: 0, 3 and 17% in group 1; 0, 9 and 21% in group 2; and 27, 79 and 79% in group 3. Statistically there was no difference in the recurrence rate between groups 1 and 2, but the rate was significantly lower in group 2 compared with group 3. The data show that patients in whom the immediate postoperative CEA concentration returns to normal have a much lower incidence of recurrent cancer of the colon than patients whose CEA concentration remains elevated.

Diseases associated with specific HL-A antigens

Significantly increased prevalences of particular HL-A antigens have been reported for many human diseases. The correlation is particularly striking in ankylosing spondylitis, Reiter's syndrome, psoriasis and some immunopathic disorders, so that HL-A typing may be of great value in diagnosis. The possible mechanisms whereby these associations may occur suggest the cause of certain disorders, and further investiatation will likely help in the understanding of the pathogenesis of many diseases.

Kinetics of uric acid transport and its production in rat small intestine

Segments of the middle third of rat small intestine were incubated at 30 °C for 1 hour in the model of Crane and Wilson. When comparison was made between the uric acid contained in unincubated segments and that in both incubated segments and their incubation media, the latter was found to exceed the former nearly fivefold. This indicates that the small intestine is a major site of uric acid production in the body. The rate of uric acid-14C transport across the intestinal wall was studied with the same model, and found to be linearly proportional to its initial concentration gradient in both directions. This rate was not altered by hypoxanthine or uricosuric agents, which have been shown to influence uric acid transport in other systems. It is concluded, therefore, that uric acid transport across the wall of the small intestine is by passive diffusion.

The effects of rapid hemodialysis on brain tissues and cerebrospinal fluid of dogs

The effects of hemodialysis on cerebral tissue and cerebrospinal fluid constituents and on intracranial pressure were investigated in dogs. It was shown that the potassium content of the cerebral cortical gray matter is decreased in uremic brain. In uremic animals the urea concentration of cerebral tissues was found to be in equilibrium with that of plasma whereas the urea concentration of cerebrospinal fluid was significantly lower. Hemodialysis for 60 minutes with a Kolff twin-coil artificial kidney rapidly decreased the urea concentration in the plasma and caused a considerable but slower decrease in the urea content of cerebral tissues. The urea level in cerebrospinal fluid was only slightly altered. Consequently, a significant transient difference developed between the urea concentrations in brain and plasma. The difference between the concentration of urea in cerebrospinal fluid and plasma was always more pronounced and of longer duration after hemodialysis. Swelling of cortical gray matter was demonstrated in 50% of dialyzed uremic animals and of white matter in 75%. A rapid rise in cerebrospinal fluid pressure occurred during dialysis in all cases. Similar effects were observed when a concentration gradient for sodium between plasma and the central nervous system was produced in normal animals by dialysis against a hyposmotic, low-sodium bath fluid. It was concluded that, in experimental uremia, hemodialysis results in increased cerebrospinal fluid pressure owing to an osmotically induced increase in cerebrospinal fluid volume and, to a variable extent, to osmotically induced cerebral tissue swelling. Osmotically induced cerebral swelling was shown to be a different phenomenon from cerebral edema associated with trauma.