Buried Kirschner wire fixation of the Austin osteotomy-bunionectomy: a preliminary report

Austin bunionectomies were fixated with buried 0.062-inch Kirschner wire. The wires were surgically removed in 7 to 10 weeks, when radiographic union was demonstrated. This approach allows confident early range-of-motion exercises and return to normal footwear. Intermetatarsal angles were reduced 6 to 12 degrees without displacement. The advantages and disadvantages of this technique are discussed.     

Solitary bronchioloalveolar carcinoma: CT criteria

The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.     

Treatment of dural sinus thrombosis using selective catheterization and urokinase

Thrombosis of the cerebral dural venous sinuses, cortical draining veins, and deep cerebral veins is a rare clinical finding. Because of its low incidence and multiple etiologies, the optimum therapy for this condition will only be elucidated by a multicenter, randomized prospective study. At our institution, we favor early and aggressive management of cerebral venous sinus thrombosis with transfemoral, venous intradural infusions of the fibrinolytic agent urokinase. To date, treatment of only 13 patients using this technique has been reported in the English literature. This report adds 12 more such treated patients. Despite the presence of preinfusion infarcts in 5 patients, four of which were hemorrhagic, we incurred no major therapeutic morbidity. Functional sinus patency was achieved in 11 of 12 patients, with our only true failure occurring in an individual with symptoms of at least 2 months' duration. Good to excellent clinical outcome was achieved in 10 of 11 patients (one newborn had inadequate follow-up).     

The involvement of interdigitating (antigen-presenting) cells in the pathogenesis of rheumatoid arthritis.

Macrophage like cells expressing high concentrations of HLA-DR antigen have been identified in situ within the synovium of patients with rheumatoid arthritis. The characteristics of these cells have been determined using immunohistological analysis and combined cytochemical techniques. It was found that the majority (greater than 80%) of these cells were interspersed within the perivascular lymphocytic infiltrates occurring in the synovium. These cells did not stain with antisera against surface immunoglobulin or any Mc Abs to T lymphocyte markers. Further combined staining demonstrated that the HLA-DR + ve cells did stain with an anti-monocyte monoclonal (FMC-17), but could not be stained with a Mc Ab against C3b receptors. The interfacing of cytochemical reactions for acid phosphatase (ACP) and adenosine triphosphatase (ATPase) with immunofluorescence staining for HLA-DR demonstrated that these cells were ACP - ve ATPase + ve. This analysis led to the conclusion that the HLA-DR + ve cells found in abundance in the rheumatoid synovium expressed identical characteristics to the interdigitating cells of the normal lymph node paracortex. The possible significance of the presence of large numbers of such antigen presenting cells in the rheumatoid synovium is discussed.     

The search for a marsupial XIC reveals a break with vertebrate synteny

X-chromosome inactivation (XCI) evolved in mammals to deal with X-chromosome dosage imbalance between the XX female and the XY male. In eutherian mammals, random XCI of the soma requires a master regulatory locus known as the ‘X-inactivation center’ (XIC/Xic), wherein lies the noncoding XIST/Xist silencer RNA and its regulatory antisense Tsix gene. By contrast, marsupial XCI is imprinted to occur on the paternal X chromosome. To determine whether marsupials and eutherians share the XIC-driven mechanism, we search for the sequence equivalents in the genome of the South American opossum, Monodelphis domestica. Positional cloning and bioinformatic analysis reveal several interesting findings. First, protein-coding genes that flank the eutherian XIC are well-conserved in M. domestica, as well as in chicken, frog, and pufferfish. However, in M. domestica we fail to identify any recognizable XIST or TSIX equivalents. Moreover, cytogenetic mapping shows a surprising break in synteny with eutherian mammals and other vertebrates. Therefore, during the evolution of the marsupial X chromosome, one or more rearrangements broke up an otherwise evolutionarily conserved block of vertebrate genes. The failure to find XIST/TSIX in M. domestica may suggest that the ancestral XIC is too divergent to allow for detection by current methods. Alternatively, the XIC may have arisen relatively late in mammalian evolution, possibly in eutherians with the emergence of random XCI. The latter argues that marsupial XCI does not require XIST and opens the search for alternative mechanisms of dosage compensation.     

Evaluation of serotype prediction by cpsA-cpsB gene polymorphism in Streptococcus pneumoniae

New pneumococcal conjugate vaccines covering a limited number of serotypes are likely to come into widespread use over the next few years. It is unknown what effect this will have on the relative importance of different serotypes as causes of pneumococcal infection. Hence, it will be important to monitor serotype prevalence before, during, and after the introduction of new vaccines. We have investigated the ability of a PCR method based on polymorphisms in two genes common to the different capsule loci to predict the serotype of 93 clinical isolates of Streptococcus pneumoniae submitted to the Central Public Health Laboratory in 1997. Of 70 isolates with vaccine serotypes, 65 were predicted to belong to the correct serotype; this number was improved to 69 with the inclusion of two additional patterns to the database. Of 23 isolates with other serotypes, 19 were correctly predicted as non-vaccine serotypes, the discrepancy lying with four isolates of 6A (non-vaccine serotype) that were indistinguishable from isolates of 6B (vaccine serotype). In situations in which culture of the organism is not feasible, this method could potentially be applicable directly to clinical specimens and could be a valuable aid to the surveillance of pneumococcal serotypes.