Use of Prosthesis-Generated Computed Tomographic Information for Diagnostic and Surgical Treatment Planning

Abstract: Diagnosis, treatment planning, and prediction of a final implant-supported prosthetic outcome require precise noninvasive presurgical information. By combining the use of a clinically verified barium-coated template and interactive computed tomography (SIM/Plant, Columbia Scientific, Inc., Columbia, Maryland), the implant team can determine and address the relevant issues affecting treatment outcomes. Those issues include: implant-prosthesis incompatibility, recognition of anatomic limitations and anomalies, the need for presurgical bone augmentation, implant diameter and distribution, abutment type and angle, bone density, soft tissue augmentation requirements, accurate fee determination, and medicolegal protection. The data collection methodology and format for the Mecall and Rosenfeld prosthesis prediction analysis are discussed as part of case presentation.     

Interaction of troponin-H and glutathione S-transferase-2 in the indirect flight muscles of Drosophila melanogaster

Summary Drosophila indirect flight muscles (IFMs) contain a 35 kDa protein which cross-reacts with antibodies to the IFM specific protein troponin-H isoform 34 (TnH-34). Peptide fingerprinting and peptide sequencing showed that this 35 kDa protein is glutathione S-transferase-2 (GST-2). GST-2 is present in the asynchronous indirect flight muscles but not in the synchronous tergal depressor of the trochanter (jump muscle). Genetic dissection of the sarcomere showed that GST-2 is stably associated with the thin filaments but the presence of myosin is required to achieve the correct stoichiometry, suggesting that there is also an interaction with the thick filament. The two Drosophila TnHs (isoforms 33 and 34) are naturally occurring fusion proteins in which a proline-rich extension of ~250 amino acids replaces the 27 C-terminal residues of the muscle-specific tropomyosin II isoform. The proteolytic enzyme, Igase, cleaves the hydrophobic C-terminal sequence of TnH-34 at three sites and TnH-33 at one site. This results in the release of GST-2 from the myofibril. The amount of GST-2 stably bound to the myofibril is directly proportional to the total amount of undigested TnH. It is concluded that GST-2 in the thin filament is stabilized there by interaction with TnH. We speculate that the hydrophobic N-terminal region of GST-2 interacts with the hydrophobic C-terminal extension of TnH, and that both are close to a myosin cross-bridge. This revised version was published online in August 2006 with corrections to the Cover Date.     

Evaluation of the Dermal Carcinogenic Potential of Tar Sands Bitumen-Derived Liquids

Evaluation of the Dermal Carcinogenic Potential of Tar SandsBitumen-Derived Liquids. MCK.EE, R. H., STUBBLEFIELD, W. A.,LEWIS, S. C, SCALA, R. A., SIMON, G. S., AND DEPASS, L. R. (1986).Fundam Appl. Toxwoi 7, 228–235. The carcinogenic potentialof Athabasca tar sands and six experimental liquids derivedfrom crude bitumen was evaluated utilizing the mouse epidermalcarcinogenesis model. Tar sands, bitumen, and untreated naphthaproduced few, if any, tumors. Three thermally and catalyticallycracked liquids, light (nominal boiling range: 149-316°C)and heavy (nominal boiling range: >316°C) gas oils andgas oil blend (boiling range' >316°C), produced a significantnumber of epidermal neoplasms. A synthetic crude oil, preparedby blending naphtha and light and heavy gas oils, was moderatelycarcinogenic; however, the activity of this sample fell withinthe range of values obtained in studies of crude petroleum samples.Since the bitumen-derived streams do not differ substantiallyin carcinogenic potency from petroleum-denved materials of comparableboiling range and process history, industrial hygiene practiceswhich limit exposures to levels comparable to those observedin the petroleum-refining industry should provide similar measuresof protection.     

Oxacillin-induced Pseudomembranous Colitis

Pseudomembranous colitis has been reported as a complication of therapy with a number of different antibiotics. We present here a case of pseudomembranous colitis following therapy with oxacillin, in which the causative organism and the toxin it produces were isolated from the patient's stool. We believe this is the first documented case of oxacillin-induced pseudomembranous colitis.     

The Radiology Corner

This case serves to illustrate the multiple routes which may occur in the dissemination of carcinoma of the stomach of the large bowel. Spread along the gastrocolic ligament involves the superior aspect of the transverse colon with limitation laterally by the phrenicocolic ligament. Once ascites has developed there is spread along the superior border of the sigmoid and lateral margin of the right side of the colon.     

Effect of Anticoagulant and ABO Incompatibility on Recovery of Transfused Human Platelets

The effects of anticoagulant solutions on the recovery of transfused plateletswere studied. Citrate anticoagulants at pH 7.4 or pH 6.5 were found to beequally effective in preserving the viability of platelets when centrifugationof the cells was not required. When centrifugation is required, as in mostplatelet survival studies, citrate at pH 6.5 gives maximum recoveries. Ethylenediamine tetraacetate (EDTA) caused temporary sequestration of nearly alltransfused platelets and reduced maximum recoveries by about 50 per cent.

Platelet recovery was lowered by ABO-incompatibility between donor platelets and recipient serum, but survival time of remaining platelets was notaltered. Lowest platelet recoveries resulted when group A₁ or A₁ B plateletswere given to group O recipients with high isoagglutinin titers.

It is suggested that ABO-compatible platelets prepared in citrate should beused where possible in the treatment of thromboctyopenic disorders.

Submitted on January 5, 1965 Accepted on March 13, 1965