Heterotopic ossification in the anterior maxilla: a case report and review of the literature

A 13-year-old boy had complained of an asymptomatic swelling in the anterior maxilla for approximately 4 years. The patient reported no local trauma. The intra-oral examination revealed an exophytic lesion in the incisive papilla between the maxillary central and lateral incisor teeth. The radiographies detected no significant findings. Histopathologically, the lesion showed a dense fibrous tissue above the overlying mucosa. Bone ossification lay beneath a partially hypertrophic cartilage showing occasionally pleomorphic chondrocytes. Because of its microscopic aspects, heterotopic ossification may be mistaken for chondrosarcoma or other conditions involving periosteum, such as parosteal osteosarcoma. A case of heterotopic ossification in the anterior maxilla is presented, and clinicopathologic similarities with other osteochondromatous lesions are discussed.     

Is spironolactone safe for dialysis patients?

BACKGROUND: Spironolactone is useful in heart failure, but is not given to dialysis patients for fear of hyperkalaemia. This study evaluated the safety of spironolactone administration in haemodialysis patients. METHODS: Fifteen haemodialysis outpatients with mean serum potassium <5.6 mEq/l over the preceding 4 months were treated with spironolactone 25 mg daily for 28 days. Serum potassium was measured before every haemodialysis during the study. Aldosterone and renin were measured at the beginning and end of the study. Patients were monitored for side effects. Data were examined with a paired t-test, with patients serving as their own controls and P < 0.05 considered significant. A sample size of 14 was required to achieve a power of 0.8 and a P = 0.05 to detect a potassium difference of 0.5 +/- 0.6 mEq/l. All patients were analysed as intention-to-treat. RESULTS: The mean potassium level was 4.6 +/- 0.6 mEq/l at baseline and 4.9 +/- 0.9 mEq/l at study completion (P = 0.14). Thirteen patients completed the trial with no potassium levels >6.0 mEq/l. Four patients had potassium levels between 5.5 and 6.0 mEq/l. One patient was withdrawn at day 20 after developing hyperkalaemia (7.6 mEq/l). Another patient was withdrawn at day 25 after missing a dialysis treatment. There were no differences in either baseline or 28 day aldosterone or renin levels (16.8 +/- 28.8 vs 11.7 +/- 6.1 ng/dl and 3.5 +/- 3.9 vs 3.5 +/- 3.5 ng/ml/h, respectively). Infrequent side effects included dry mouth, nosebleed, pruritis, gynecomastia and diarrhoea. No significant leukopenia or anaemia was noted. CONCLUSIONS: Spironolactone may be considered as a treatment option for selected chronic haemodialysis patients with heart disease.     

Isolated human hepatocytes in culture display markedly different gene expression patterns depending on attachment status

In vitro human hepatocyte cultures are a key tool in the investigation of xenobiotic toxicity and metabolism. In most in vitro hepatocyte studies, the cells are allowed to adhere to an extracellular matrix, such as collagen. Unfortunately, the ability of freshly isolated hepatocytes to adhere to collagen varies from donor to donor. We used microarray analysis to determine what gene expression differences exist between hepatocytes in suspension and hepatocytes attached to collagen. Results from different donors showed a considerable difference in gene expression patterns between the two hepatocyte populations. In addition, we also compared the gene expression profiles of hepatocytes in culture with liver tissue. The results showed that both hepatocytes in suspension and hepatocytes attached to collagen display significant gene expression differences compared with liver tissue. Finally, we show that both populations of hepatocytes are responsive to dexamethasone and regulate some of the same genes. Overall, our results suggest that either significant gene expression changes occur in isolated hepatocytes or that suspended and attached cells represent different populations of hepatocytes found in intact livers.     

Mutational analysis of familial and sporadic hyperekplexia

Hyperekplexia is a rare, autosomal dominant neurological disorder characterized by hypertonia, especially in infancy, and by an exaggerated startle response. This disorder is caused by mutations in the ?1 subunit of the inhibitory glycine receptor (GLRA1). We previously reported two GLRA1 point mutations detected in 4 unrelated hyperekplexia families; both mutations were at nucleotide 1192 and resulted in the replacement of Arg²⁷¹ by a glutamine (R271Q) in one case and a leucine (R271L) in the other. Here, 5 additional hyperekplexia families are shown to have the most common G-to-A transition mutation at nucleotide 1192. Haplotype analysis using polymorphisms within and close to the GLRA1 locus suggests that this mutation has arisen at least twice (and possibly four times). In 2 additional families, a third mutation is also presented that changes a tyrosine at amino acid 279 to a cysteine (Y279C). Five patients with atypical clinical features and equivocal or absent family history of hyperekplexia and 1 patient with a classical presentation but no family history are presented in whom a mutation in the GLRA1 gene was not detected. Thus, only clinically typical hyperekplexia appears to be consistently associated with GLRA1 mutations, and these affect a specific extracellular domain of the protein.     

Significance of diffuse cardiac activity on In-111 labeled leucocyte scans

To assess the significance of diffuse cardiac activity (DCA) seen on In-111 labeled leukocyte scans, we reviewed 87 studies performed over the last 4 years. Inflammatory cardiac conditions were seen as frequently in patients with DCA (15%) as those without (7%, P=0.3). There was a higher ratio of RBC:WBC in the final WBC preparation in the false-positive DCA group than the true positive DCA and no DCA groups. False-positive studies showing DCA are most likely due to residual blood pool activity.Presented in part, 70th annual meeting, Radiological Society of North America, Washington D.C., 25 November 1984     

Sonography of testicular microlithiasis

The sonographic appearance of testicular microlithiasis detected in a patient presenting with torsion is described. A "speckled" pattern of multiple, tiny bright echoes is produced by calcific concretions in the seminiferous tubules and seems to be characteristic of microlithiasis. Although this condition is not treatable, it should be recognized because it is often associated with extratesticular abnormalities and can obscure superimposed testicular disease.     

Use of a T cell-specific monoclonal antibody, T10B9, in a novel allogeneic stem cell transplantation protocol for hematologic malignancy high-risk patients.

To reduce the toxicity of traditional conditioning regimens for allogeneic stem cell transplantation (allo-SCT), we used single-agent chemotherapy conditioning with either busulfan (total cumulative dose, 16 mg/kg) or melphalan (200 to 240 mg/m 2 ), followed by the anti-T cell-specific monoclonal antibody T10B9 (MEDI-500) daily for 3 days. T cell-replete SCT was performed from HLA-identical sibling donors. Acute graft-versus-host disease (aGVHD) prophylaxis consisted of 7 additional days of T10B9 and delayed onset of cyclosporine (ie, on day +4 or +5). Twenty-six high-risk hematologic malignancy patients were entered onto this study. All 24 patients who survived longer than 8 days engrafted, although 1 patient experienced late graft failure. Deaths occurred in 21 of 26 patients because of infection (n = 7), progression/recurrence of primary disease (n = 6), aGVHD (n = 4), regimen-related toxicity (n = 1), and other causes (n = 3). Five of these patients are enjoying disease-free survival with a median survival of 1193 days after allo-SCT. The conditioning regimen induced modulation of surface expression of CD3 (but not CD4 or CD8) and was associated with decreasing tumor necrosis factor-alpha (but not interleukin-6) serum levels. In conclusion, single-agent chemotherapy conditioning with T10B9 produced durable engraftment and long-term survival in some patients who would not have qualified for a traditional allo-SCT.     

CD1a and antitumour immune response

Primary immune response is based on the capacity of local professional antigen-presenting cells (whose prototype is represented by dendritic cells, DCs) to take up and present antigens to selected clones of T cells, but also to non-specific effector cells such as macrophages or natural killer cells. The four CD1 proteins, all of which share a limited homology to class I MHC proteins, are differently expressed in various cell types, of both mesenchymal and, as recently described, epithelial lineage. Regarding the role of CD1 molecules in the anti-tumour response, it has been reported that CD1+ dendritic cells are involved in the first steps of the primary immune response in a number of malignancies. Moreover, the presence of a high number of DCs in the tumoral or peritumoral area, as well as in the draining lymph nodes, has been shown to correlate with a better prognosis. A recent report on the presence of CD1a in metaplastic epithelial cells of Barrett esophagus introduced new questions about CD1a expression patterns. Moreover, the strong correlation between the lack of CD1a+ cells and the malignant evolution of the lesion may indicate a possible role of non-professional APCs in mediating and/or potentiating immune responses to tumours.     

Cyclin alterations in giant cell tumor of bone.

Cyclins play an important role in regulating the passage of dividing cells through critical checkpoints in the cell cycle. Because alterations of several cyclins, especially cyclin D1, have been implicated in the development of many human neoplasms, we examined 32 cases of giant cell tumor of long bones for cyclin D1 gene amplification and protein overexpression using differential polymerase chain reaction and immunohistochemistry, respectively. In addition, the expression of cyclin D3, cyclin B1, and the proliferation-associated antigen Ki-67 (MIB-1) was assessed immunohistochemically. Low-level cyclin D1 gene amplification was detected in 61% of giant cell tumor cases. All tumors showed cyclin D1, cyclin D3, cyclin B1, and Ki-67 (MIB-1) staining; however, the distribution was very characteristic. Cyclin D1 protein expression was seen predominantly in the nuclei of the giant cells, with occasional mononuclear cells staining. There was no correlation between cyclin D1 gene amplification and protein overexpression. Cyclin D3 staining showed a similar distribution, with 88% of cases showing protein overexpression. Cyclin D1 and/or D3 staining in the giant cells was never associated with staining for either cyclin B1 or Ki-67 (MIB-1), as the expression of the latter two proteins was restricted to the mononuclear cells. Cyclin B1 overexpression was seen in 44% of cases. Ki-67 (MIB-1) staining was present in all cases, and between 10 to 50% of the mononuclear cells were positive. These results suggest that alterations in cyclin D1 and/or D3 might play a role in the pathogenesis of giant cell tumor of bone.