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.     

Endovascular thrombolysis in deep cerebral venous thrombosis.

We present two cases of acute thrombosis of the internal cerebral veins, vein of Galen, and straight sinus without sagittal sinus involvement. Both patients had hydrocephalus and severe edema of the basal ganglia and thalami, one with hemorrhagic infarction of the thalamus. Because both patients rapidly deteriorated to a comatose state, endovascular thrombolysis was performed with urokinase infusion of the deep venous structures. Thrombolysis was continued until a patent channel with brisk flow in the venous structures was achieved. Both patients survived with minimal neurologic deficits.     

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.

     

Tumor vascular signals in renal masses: detection with Doppler US

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.     

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.