Paroxysmal atrial tachycardia and frontal lobe tumor

We describe a patient who experienced repeated episodes of paroxysmal atrial tachycardia. He was found to have an epileptogenic focus within the right frontal lobe adjacent to a frontal lobe glioma. Subsequent to excision of the tumor, no further attacks have occurred.     

Isolation of a spontaneous CHO amino acid transport mutant by a combination of tritium suicide and replica plating

A spontaneous transport mutant of Chinese hamster ovary cells, CHY-1, was isolated by a combination of [3H]proline suicide and replica plating. The mutant took up less tritium than the parent, resulting in a lower killing rate during storage. Transport by four separate amino acid transport systems (A, ASC, L, Ly+) was examined. The CHY-1 mutant exhibited normal uptake via the ASC, L, and Ly+ systems. By contrast, uptake of the most specific substrate of the A system, 2-(methylamino)-isobutyric acid, was significantly reduced at low, but not high, concentrations, due to a 3.5-fold increase in Km and a 1.5-fold increase in Vmax. Taken together, these data suggest that the CHY-1 mutation may be in the structural gene coding for the A transport protein. The tritium suicide procedure is discussed, and general equations are derived to predict the maximum storage time for the survival of one mutant cell and the optimum size of the cell population for maximum mutant enrichment.     

T-cell regulation in murine and human autoimmune diabetes: the role of TH1 and TH2 cells

Insulin-dependent diabetes mellitus (IDDM) results from the destruction of pancreatic insulin-secreting cells by a T-cell-mediated autoimmune reaction. Distinct types of T helper cells (TH1 and TH2) have been characterised based on their cytokine secretion profiles following activation. Evidence from animal models favours the hypothesis that autoimmune diabetes is a TH1 response. However, there is no clear indication that a primary imbalance between protective TH2 and deleterious TH1 cells at early stages can trigger the autoimmune process. Protective CD4 + cells detected in nondiabetic young non-obese diabetic mice have not been shown to work through TH2 cytokines. In humans, there is little evidence that IDDM results from a TH1 response. Indeed, efficient experimental systems are lacking in humans to study the regulation of the autoimmune response in vitro. Interestingly, several immunotherapy strategies have aimed at inducing a TH2 response, even though TH2 cells have not been implicated in spontaneous disease development. However, recent ongoing trials in humans using oral administration of insulin to prevent diabetes are based on a protective mechanism which seems to depend essentially on transforming growth factor-beta. This cytokine is not dependent on TH1/TH2 dichotomy. Thus, although several attempts have been made to induce a TH1/TH2 switch to obtain a protective effect, a different and more complex mechanism probably (and paradoxically) accounts for the oral protection actually tested in animal models and humans.     

Video-assisted thoracoscopic surgery (VATS). Endoscopic thoracoplasty technique

STUDY DESIGN: The study of two patients whose rib deformity was treated using a new endoscopic thoracoplasty technique is reported. OBJECTIVES: To report a new endoscopic thoracoplasty technique for the treatment of rib deformities associated with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Thoracoplasty has traditionally been performed as an open procedure, often necessitating additional incisions and/or tissue dissection. METHODS: Two children with significant rib humps associated with idiopathic scoliosis were treated with a new endoscopic thoracoplasty technique. RESULTS: Both children showed dramatic cosmetic improvement of their rib deformity. CONCLUSIONS: The indications for the use of video-assisted thoracoscopic surgery in the treatment of pediatric spinal deformity are expanding. We have extended our video-assisted thoracoscopic surgery repertoire to include endoscopic thoracoplasty for treatment of rib deformities associated with idiopathic scoliosis. The technique for endoscopic thoracoplasty is discussed, and illustrative cases are presented.