Transplant data: sources, collection and research considerations, 2004

The process of collecting and analyzing transplant data is complex. Familiarity with how these data are collected is crucial to a thorough understanding of the information. This article focuses on available OPTN-SRTR data and the continuing evolution of data collection mechanisms; how that data collection system is improving the data quality and reducing the data collection burden; how additional ascertainment of outcomes both completes and validates existing data; and caveats that remain for researchers. This year's article focuses further on research considerations related to cohort choice, timing of data submission, and potential biases in follow-up data. Ongoing improvements in data collection timeliness and scope are covered. The impact of extra ascertainment of outcomes, particularly for post-transplant kidney graft failure from Medicare data, are also examined. A section on graft failure reporting among different sources traces the steps by which the SRTR reconciles different data sources in its analyses. It is important that those reading and conducting transplant research understand the origin, structure, and scope of the available data. All of these issues should be carefully considered when choosing cohorts and data sources for analysis.     

Small-animal PET of tumor angiogenesis using a (76)Br-labeled human recombinant antibody fragment to the ED-B domain of fibronectin.

The aim of this study was to image the extra domain B (ED-B) of fibronectin, an angiogenesis-related target, in solid tumors using small-animal PET. Toward this aim, an ED-B fibronectin-binding human antibody derivative (L19-SIP) was labeled with (76)Br via an enzymatic approach. Biodistribution and imaging studies were performed in human teratoma-bearing mice for up to 48 h after injection. METHODS: L19-SIP was labeled with (76)Br using bromoperoxidase/H(2)O(2). The stability of the labeled antibody was tested both in vitro and in vivo. Biodistribution and small-animal imaging studies (PET and CT) were performed in F9-bearing 129/sv mice (n = 3 or 4). RESULTS: The enzymatic radiobromination approach afforded the labeled antibody in high yield (>55%) under mild reaction conditions. (76)Br-L19-SIP stability in mouse serum proved to be similar to that of the (125)I-labeled analog (>80% of intact material at 48 h after injection). Fast and specific in vivo targeting was obtained in tumors and other organs expressing ED-B fibronectin (i.e., ovaries and uterus). However, slow renal clearance and persistent activity predominately in blood and stomach suggests partial (76)Br-L19-SIP debromination in vivo. This debromination was confirmed in a metabolism study in normal mice. The F9 tumors were clearly imaged by small-animal PET at each considered time point, starting at 5 h up to 48 h after injection. CONCLUSION: (76)Br-L19-SIP specifically accumulated at the target site, enabling detailed small-animal PET of tumor neovasculature. Therefore, targeting the angiogenesis-associated expression of ED-B fibronectin can be a valuable tool for tumor detection using molecular imaging with PET.     

Recurrent stroke associated with thymoma and anticardiolipin antibodies

A 44-year-old woman developed recurrent thrombotic cerebral cortical infarctions. IgG and IgM anticardiolipin antibodies were found, as was a thymoma. To our knowledge, these antiphospholipid antibodies, which may inhibit prostacyclin formation and alter platelet function, have not been previously associated with this thymic neoplasm, an association we believe is not coincidental.     

Limitations of a thermal camera in measuring surface temperature of laser-irradiated tissues

Thermal cameras are used in research laboratories to measure tissue temperature during laser irradiation. This study was an evaluation of the accuracy of a 3-5 microns thermal camera and two 8-12 microns cameras in detecting the maximum temperatures of small targets. The size of the targets was within the range of laser spot diameters which are used for vessel welding, angioplasty, and dermatology. The response to a sharp thermal edge was measured and analyzed for the three cameras, which had a scanning rate of 30 frames per second. The response of the 3-5 microns camera to reference black body targets of different sizes was also studied. It was found that the detector system required an average of 2.44 microseconds to reach 90% of maximum step response for the 8-12 microns system and 5.85 microseconds for the 3-5 microns system. With a 3 x telescope and a 9.5 inch focal distance close-up lens, the 3-5 microns camera underestimated the temperature of targets smaller than 2.0 mm because of its slow detector response. Although the 8-12 microns camera provides more accurate measurements due to its faster detector response, it still underestimates the temperature of targets smaller than 900 microns, when similar magnification and focal distance are used. Methods to compensate for the inaccuracies are discussed, including empirical correction factors and the inverse filtering technique.     

Transport and cellular uptake of polychlorinated biphenyls (PCBs)--I. Association of individual PCB isomers and congeners with plasma lipoproteins and proteins in the pigeon

Polychlorinated biphenyls (PCBs) are abundant and persistent pollutants in the ecosystem. Commercial mixtures (e.g. Aroclor 1254) can contain up to 80 different isomers and congeners, many of which accumulate in biological systems by the ingestion of PCB-contaminated lipid components of food chains. PCBs are lipophilic and lipid-rich lipoproteins provide an excellent system to transport PCBs to tissues. We report here the distribution of PCBs between plasma fractions in the pigeon. Twenty-four hours after injection, [14C]4-monochlorobiphenyl and [14C]2,2',5,5'-tetrachlorobiphenyl were associated with the protein-rich HDL fraction and the lipoprotein-poor fraction (predominantly albumin), rather than with the lipid-rich VLDL and LDL fractions. Five days after injection with the commercial PCB mixture Aroclor 1254, there was a distinctive distribution between the plasma fractions of the 41 congeners detected. Avian species have a poorly developed lymphatic system and dietary lipids are secreted into the portal vein. To emphasize this route of entry, the lipoprotein particles formed are termed portomicrons rather than chylomicrons. The most striking result was that the lipid-rich portomicron and the VLDL fraction was associated almost exclusively with only one congener (2,2',4,4'5,5'-hexachlorobiphenyl), whereas the other isomers and congeners were distributed amongst the LDL, HDL and the lipoprotein-poor (predominantly albumin) fractions. Thirteen of the congeners detected accounted for 74, 53 and 54%, respectively, of the total amount of PCBs in the LDL, HDL and lipoprotein-poor protein fractions. Five congeners that are highly toxic were enriched in the latter fraction. The distribution of PCBs is more complex than can be explained solely by their solubility in the lipid components of plasma fractions, and may suggest a complex association with apolipoproteins and plasma proteins that are important in transporting PCB to tissues. The identification of individual PCBs in lipoprotein fraction provides evidence for their role in the transport of lipophilic xenobiotics in blood and it is suggested that PCBs associated with lipoproteins are taken up by cells as lipoprotein-PCB complexes.     

Acute volvulus of the right colon: An analysis of 69 patients

Sixty-nine patients with acute volvulus of the right colon have been analyzed; the overall mortality was 19%. Nonviable colon was present in 20 patients; the mortality rate in these patients was 40%. When the cecum is viable, a combination of simple cecopexy and tube cecostomy was as effective as resection in preventing long-term recurrence. Cecopexy alone was followed by recurrence in 20%. In the presence of cecal perforation or a large area of confluent gangrene, resection with the formation of an ileostomy and a distal mucous fistula is the procedure of choice; resection with primary anastomosis should be avoided. When the gangrene is patchy, resection and primary anastomosis appears to be a safe procedure.

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Resumen El vólvulo agudo del colon derecho es una emergencia quirÚrgica no comÚn, la cual representa menos del 2% de todos los casos de obstrucción intestinal en el adulto. El manejo operatorio es motivo de controversia; varios autores favorecen la resección, mientras otros abogan por el tratamiento que no implique resección. Muchas de las series previamente publicadas han estudiado pequeños nÚmeros de pacientes sin seguimiento adecuado. Sesenta y nueve pacientes con vólvulo agudo del colon derecho admitidos a cuatro hospitales docentes de Escocia e Irlanda del Norte en el curso de 12 años fueron analizados. La mortalidad global fue de 19%. Colon no viable fue hallado en 20 pacientes; la mortalidad en ellos fue de 40%. Cuando el ciego aparece viable, la combinación de la simple cecopexia con cecostomía de tubo probó ser un procedimiento tan efectivo como la resección en cuanto a prevenir recurrencias a largo plazo. La cecopexia realizada como Único procedimiento resultó en una tasa de recurrencia de 20%. En presencia de perforación cecal o de una extensa área de gangrena confluente, el procedimiento de elección es la resección con ileostomía y fístula mucosa distal; debe evitarse la resección con anastomosis primaria. Cuando la gangrena se presenta en parches, la resección con anastomosis primaria parece ser un procedimiento seguro.

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Résumé Les auteurs rapportent une série de 69 volvulus aigus du colon droit qu'ils ont observés. La mortalité globale a été de 19%. Chez 20 malades le colon n'était pas viable; la mortalité a été de 40%. Quand le caecum est viable la coecopexie associée à la coecotomie sur drain donne des résultats identiques à ceux de la résection mais elle est suivie de récidive dans 20% des cas. En présence d'une perforation caecale ou d'une large zone de sphacèle du colon la résection suivie d'une iléostomie est de la mise à la peau de l'extrémité colique d'aval représente l'opération de choix. C'est seulement lorsque la zone sphacélée est limitée que la résection suivie du rétablissement immédiat de la continuité constitue une méthode dénuée de danger.

     

The blast path: theoretical basis, experimental data and clinical application

Use of the "blast path" may be helpful in patients where positioning for ESWL treatments is difficult. Good pressures are maintained along the blast path and an alternate fracture mechanism may be in effect. The rate of fragmentation, assessed using model material, decreases with distance beyond F2.