Dehiscent temporomandibular joint

The appearance of an acute effusion in a well-pneumatized temporal bone directs attention to the nasopharynx and skull base. Two patients are described in whom dehiscence of the temporomandibular joint allowed herniation of the contents of the joint posteromedically, where they obstructed the middle ear entrance of the eustachian tube, the protympanum. This is, to the authors' knowledge, a previously unreported cause of an acute middle ear and mastoid effusion.     

New hope for children with Kawasaki disease.

Kawasaki disease is now the most common cause of acquired heart disease in America's children. It is an acute febrile illness that may cause coronary artery aneurysm formation in infected children. The results of a multicenter, randomized trial on the effect of intravenous administration of gamma globulin (IVGG) plus aspirin versus aspirin alone upon coronary aneurysm formation show a decrease in coronary aneurysm formation from the usual 20%-30% to 3%. Administration of IVGG presents some unique challenges for nurses. Also, the pediatric nurse must educate parents and children about this disease to prepare them for discharge and long-term follow-up care.     

Five treatment procedures evaluated for the elimination of ascorbate interference in the enzymatic determination of urinary oxalate

We evaluated the efficacies of five treatment procedures for eliminating ascorbate interference in the enzymatic determination of urinary oxalate. Aliquots of urine samples, containing different amounts of added ascorbate and oxalate, were individually subjected to ferric chloride, sodium nitrite, sodium periodate, charcoal, or ascorbate oxidase treatment to eliminate ascorbate interference. Oxalate contents of the urine samples were then determined by a banana oxalate oxidase-horseradish peroxidase-linked assay with 3-methyl-2-benzothiazolinone hydrazone and 3-(dimethylamino)benzoic acid as chromogens. Only those urine samples treated with ascorbate oxidase or charcoal consistently gave recovery of oxalate close to 100%. Treatment with other reagents, though improving the recovery of oxalate, gave inconsistent results. On the basis of these data, we describe procedures for simply and reliably assaying oxalate by using banana oxalate oxidase.     

Magnetic resonance imaging of the pediatric abdomen.

In many ways, MRI of the pediatric abdomen is in its infancy. Motion will be a problem with most of the current pulse sequences, but the problem appears manageable given many of the newer software options for motion suppression. Faster pulse sequences (approaching CT scan times) will serve to improve image quality and reduce the need for sedation. Identification of a reliable enteric contrast agent probably will expand the current utility of MRI beyond evaluation of solid abdominal viscera. Although preliminary results appear promising, controlled comparative studies are necessary to determine the exact role of MRI in diagnosis and staging of common pediatric abdominal malignancies. The addition of MRI intravenous contrast agents and MR spectroscopy are anticipated to add depth and specificity to the diagnostic potential of this exciting modality.     

Multiphase radon generation and transport in porous materials

Radon generation and transport in porous materials involve solid, liquid, and gas phases in the processes of emanation, diffusion, advection, absorption, and adsorption. Oversimplifications, such as representing moist soil systems by air-phase emanation and transport models, cause theoretical inconsistencies and biases in resulting calculations. Detailed Rn rate balance equations for solid, liquid, and gas phases were analyzed and combined using phase equilibrium constants to derive a single diffusive-advective rate balance equation in the traditional form. The emanation, diffusion, and permeability coefficients in the new equation have expanded definitions and interpretations to include Rn phase transfer. Radon adsorption was characterized by an exponential moisture dependence, and diffusion and permeability constants utilized previous moisture relationships. Correct boundary and interface conditions were defined, and the unified theoretical approach was applied to field data from a diffusion-dominated system and to laboratory data from an advection-dominated system. Measured 222Rn fluxes and concentrations validated the modeled values within the measurement variability in both applications.     

Comparative studies of chemotherapy of human tumor cells in vitro by tritiated thymidine uptake inhibition and soft agar clonogenic assay

A rapid nonsterile short-term assay has been investigated in which percent inhibition of incorporation of the DNA precursor (3H)-thymidine is measured following exposure of tumor cells to the test drugs. To evaluate the usefulness of the short-term assay in providing a rapid reliable assessment of chemotherapeutic response, the short-term assay was compared with the soft agar clonogenic assay. Sensitivity to five anticancer drugs was compared using three human tumor cell lines (epidermoid carcinoma of the oral cavity, pancreatic carcinoma, and bladder carcinoma). The short-term assay produced results that were similar to results of the clonogenic assay in two of the three tumors tested, for three drugs (cis-platin, doxorubicin, and BCNU), but did not detect responses to two antimetabolites (5-FU and MTX) in any tumor. Further studies of this short-term assay should focus on alkylating agents and other nonantimetabolites.