Benign osteoblastoma of the occipital bone: Case report and literature review

We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation.     

Direct assessment of the role of NK cells in autoimmune diabetes.

Considerable indirect evidence implicates participation of natural killer cells (NK) in the pathogenesis of diabetes in BB rats. The most convincing evidence derives from studies showing that anti-CD8 antibody effectively prevents both primary disease onset and autoimmune damage to transplanted islets. However, anti-CD8 treatment depletes both NK and cytotoxic T cells (CTL) since both cell types express the CD8 marker. To study directly the role of NK in diabetic BB rats we used MCA 3.2.3, a monoclonal antibody which selectively depletes normal Lewis rats of NK cells but not CTL. A regimen of ip injected antibody achieved rapid reduction of NK cells in diabetic and nondiabetic BB rats by FACS analysis. NK cell activity remained low in rats treated weekly as evidenced by YAC tumor cell killing. We next studied the effect of NK depletion on disease incidence in diabetes-prone BB rats of which about one half are expected to develop diabetes. Onset and incidence of diabetes in 3.2.3-treated and control antibody-treated aged matched litter mates were equal. These studies suggest that NK cells are not necessary for autoimmune islet destruction in spontaneously diabetic BB rats and support a role for CTL in pathogenesis of the disease.     

Enhanced endothelialization of expanded polytetrafluoroethylene grafts by fibroblast growth factor type 1 pretreatment.

BACKGROUND. Biomaterial pretreatment with endothelial cell mitogens may enhance endothelialization. METHODS. Modified fibrin glue (FG) containing 1 ng/cm2 recombinant 125I-labeled fibroblast growth factor type 1 (125I-FGF-1), 20 micrograms/cm2 heparin, 2.86 mg/cm2 fibrinogen, and 2.86 x 10(-2) units/cm2 thrombin was pressure perfused into expanded polytetrafluoroethylene (ePTFE) grafts. Grafts were interposed into infrarenal aortas of 24 New Zealand white rabbits and explanted after 0, 5, 30, and 60 minutes and 1, 7, 14, and 30 days. Residual radioactivity was determined by gamma-counting. Remaining 125I-FGF-1 is expressed as percent of value at time 0. To determine the effect of the FG/FGF-1 on graft healing, three groups of 50 x 4 mm 60 microns internodal-distance nonreinforced ePTFE grafts were implanted in the aortoiliac position of 12 dogs. Group I (n = 12) contained the complete modified FG, group II (n = 6) contained FG with heparin but no FGF-1, and group III (n = 6) contained untreated identical ePTFE. Tritiated thymidine (0.5 microCi/kg) was injected intramuscularly 10 hours before explantation after 7 and 28 days for light and electron microscopy and en face autoradiography. RESULTS. Retention of 125I-FGF-1 showed rapid initial loss (delta %/delta min = -24.1) followed by slow loss after 1 hour (delta %/delta min = -0.03), with 13.4% +/- 6.9% remaining at 1 week and 3.8% +/- 1.1% at 30 days. Every FG/FGF-1 graft at 28 days showed extensive capillary ingrowth and confluent endothelialized luminal surfaces, not seen in any specimen of the other two groups. Autoradiography revealed a significant increase (p less than 0.05) in 3H-thymidine incorporation in the FG/FGF-1 grafts at 28 days versus all groups as a function of time and graft treatment. CONCLUSIONS. Pressure perfusion of an FGF-1/FG suspension into 60 microns internodal-distance ePTFE grafts promotes endothelialization through capillary ingrowth and increased endothelial cell proliferation.     

Localization and developmental expression of a novel protein kinase C delta gene.

The expression and localization of a novel protein kinase C delta (nPKC delta) mRNA were investigated using Northern blotting and in situ hybridization in the developmental process of mouse brain. In adult mice, nPKC delta was abundantly expressed in the thalamus, moderately in the pons and the cerebellum, but faintly in the cerebral cortex and the spinal cord. By in situ hybridization, the signals were observed specifically at the sensory and motor relay nuclei of the thalamus, the dorsal cochlear nuclei of the pons, and the molecular layer of the cerebellum. When developmental changes in the expression of nPKC delta gene were analyzed by in situ hybridization, it was not detectable in embryonic and neonatal brains, very weakly expressed in the thalamus in the first week, and highly expressed at two weeks of age. These results suggest that the gene expression of nPKC delta is strictly controlled by both the cell type and the developmental process.     

Case report 487

The opinions or assertions contained herein are the private views of the authors and are not to be construed as official nor as reflecting the views of the United States Air Force     

RBC improved survival due to recombinant human erythropoietin explains effectiveness of less frequent, low dose subcutaneous therapy.

Effectiveness of less frequent, once weekly, low dose subcutaneous recombinant human erythropoietin (rHuEPO) in maintaining 35% hematocrit in patients with chronic renal failure, predialysis and ESRD receiving dialysis, is dependent on rHuEPO induced prolonged RBC survival. One year of weekly rHuEPO doses to 7 patients originally part of the National Cooperative Protocol were evaluated for a total of 372 weeks for an average of 53 weeks per patient. The original 8 to 12 week dosage was directed by protocol for units per dose at 3 doses per week (4 IV, 3 subcutaneous). Thereafter, all doses were subcutaneous. Units/dose and doses/week were titrated to keep hematocrit at 35-38%. Dosage reduction of rHuEPO was determined by two investigators at the time of each examination. Statistical correlation was performed on effect of rHuEPO on 51Cr T1/2 RBC survival changes and changes of rHuEPO weekly doses. Patients evaluated at specific time points in the study were compared to themselves as their own controls by paired t-test analysis. The long-term increased RBC count correlated with prolonged RBC survival by 51Cr T1/2 rather than reticulocytosis. A relatively increased ease of sustaining the target hematocrit of 35% was demonstrated from the 8th week to 1 year. Thirty-two percent of the expanded RBC mass was older at 12 weeks and 22% was older at 1 year. rHuEPO dosage was reduced to 27% at weeks 8-12, to 21% at weeks 20-24, and to 38% at 1 year corresponding to prolonged RBC survival. 51Cr T1/2 increased from 21.6 days control to 28.6 days at 12 weeks and 26.3 days at 1 year.(ABSTRACT TRUNCATED AT 250 WORDS)