TK-GFP fusion gene virus vectors as tools for studying the features of HSV-TK/ganciclovir cancer gene therapy in vivo

The fusion gene of herpes simplex virus thymidine kinase and green fluorescent protein (TK-GFP) was shown to be a versatile tool for examining the features of thymidine kinase/ganciclovir gene therapy in vitro. In this study, we used viral vectors carrying the fusion gene to characterize the aspects of this gene therapy form in rodent tumor models. Growth of subcutaneous 9L rat tumors transduced ex vivo with TK-GFP gene was prevented when ganciclovir (GCV) treatment was initiated immediately after tumor inoculation. Established tumors (>100 mm(3)), however, were untreatable despite the initial 55% proportion of TK-GFP positive cells. This was due to a rapid clearance of TK-GFP positive cells, but not GFP positive cells. Propidium iodide staining revealed that TK-GFP lentivirus vector was able to induce apoptosis/necrosis in 9L cells, as opposed to the respective GFP vector. Furthermore, when a subcutaneous nude mouse tumor model was used, the percentage of TK-GFP positive cells in vivo was maintained similarly as in cultured cells, suggesting contribution of a fully functional immune response to the disappearance of fusion gene positive cells. In vivo gene transfer studies: adenovirus TK-GFP vector injections resulted in about 25% gene transfer efficiency to 9L tumors and showed that their growth could be significantly reduced even when the tumor volumes were already >120 mm(3). Part of the effect was shown to be due to cytotoxicity of the vector. In summary, our results demonstrate the utility of TK-GFP fusion gene-carrying viral vectors in animal studies and show that readily detectable therapeutic genes can help us to understand the complicated nature of in vivo cancer gene therapy experiments.     

Analysis of P fimbriae on Escherichia coli O2, O4, and O6 strains by immunoprecipitation.

P fimbriae on Escherichia coli O2, O4, and O6 strains were analyzed by immunoprecipitation. Fimbrial extracts were prepared from a total of 35 strains and tested for precipitation with four anti-P-fimbria sera. The overall fimbrial composition of the strains was related to the O:K:H serotype, and two to three P fimbrial variants per strain were found on most of the O4 and some of the O6 strains. The O2 strains, in contrast, showed only one antigenic variant of P fimbriae per strain, which was serologically unrelated to those of the O4 and O6 strains. The results stress the multiplicity and serological complexity of E. coli P fimbriae.     

Rupture of splanchnic artery aneurysms

The results of surgical therapy for acute ruptured splanchnic artery aneurysms in 6 patients treated at Helsinki University Central Hospital from 1964 to 1984 were analyzed. There were 3 patients with ruptured splenic, 2 with ruptured hepatic and 1 with ruptured superior mesenteric artery aneurysms. The condition remained undiagnosed in all patients preoperatively, and the diagnosis was obtained only at emergency laparotomy performed for severe shock, abdominal pain, and distension. Five of the 6 patients survived, including a pregnant woman, who gave birth to a living baby by ceserean section. The results indicate that immediate, aggressive surgical approach dictated by the clinical condition of the patient affords good survival in patients suffering from acute rupture of splanchnic artery aneurysms.

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Resumen Se analizan los resultados del tratamiento quirúrgico de la ruptura aguda de aneurismas de arterias esplnicas en 6 pacientes manejados en el Hospital Central de la Universidad de Helsinki en el periodo 1964–1984. Se presentaron 3 pacientes con ruptura de aneurismas de la arteria esplénica, 2 de la hepática y 1 de la mesentérica superior. La condición clínica se mantuvo sin diagnóstico durante la fase preoperatoria, y el diagnóstico sólo fue hecho en el curso de la laparotomía, procedimiento que fue realizado por shock severo, dolor abdominal y distensión. Cinco de los 6 pacientes sobrevivieron, incluyendo una mujer embarazada, quien dio a luz un niño vivo mediante sección cesárea. Los resultados indican que el enfoque quirúrgico inicial agresivo indicado por la condición clínica del paciente ofrece una buena oportunidad de supervivencia en pacientes que presentan ruptura de aneurismas de las arterias esplácnicas.

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Résumé Les résultats du traitement chirurgical de 6 ruptures d'anévrysmes des artères splanchniques traités à l'Hôpital Central Universitaire d'Helsinki de 1964 à 1984 sont étudiés par les auteurs. Ils concernent la rupture anévrysmale de 3 artères spléniques, de 2 artères hépatiques, de 1 artère mésentérique. Le diagnostic ne fut porté qu'au moment de l'intervention d'urgence pratiquée en présence d'un état de choc sévère s'accompagnant de douleur et de distension abdominales. Cinq des 6 opérés ont survécu, dont une femme enceinte chez qui une césarienne fut pratiquée avec succès. Ces résultats plaident en faveur de l'action chirurgicale d'urgence.

     

Cumulative biochemical effects of repeated subclinical hydrogen sulfide intoxication in mouse brain

Summary Adult female NMRI mice exposed four times to 100 ppm hydrogen sulfide vapour for 2 h at 4-day intervals showed increasing inhibition of the cerebral cytochrome oxidase activity. Cerebral RNA decreased significantly after the fourth exposure. This change was accompanied by the reduced orotic acid uptake in the RNA fraction. At the same time, 2,3-cyclic nucleotide 3-phosphohydrolase activity used as a marker for glia increased. Acetylcholine esterase activity remained unchanged. The initial exposures also caused an increase in the superoxide dismutase activity and an increase in the glutathione concentration. The latter effects were abolished in the third and fourth exposures. The present data seem to indicate that the biochemical effects of repeated subclinical hydrogen sulfide intoxications are cumulative.     

Intestinal mucosal microdialysis: Histamine release in splanchnic ischemia/reperfusion injury in piglets

Inflammation Research -     

High-resolution CT by diffraction-enhanced x-ray imaging: mapping of breast tissue samples and comparison with their histo-pathology

The aim of this study was to introduce high-resolution computed tomography (CT) of breast tumours using the diffraction-enhanced x-ray imaging (DEI) technique and to compare results with radiological and histo-pathological examinations. X-ray CT images of tumour-bearing breast tissue samples were acquired by monochromatic synchrotron radiation (SR). Due to the narrow beam and a large sample-to-detector distance scattering is rejected in the absorption contrast images (SR-CT). Large contrast enhancement is achieved by the use of the DEI-CT method, where the effects of refraction and scatter rejection are analysed by crystal optics. Clinical mammograms and CT images were recorded as reference material for a radiological examination. Three malignant and benign samples were studied in detail. Their radiographs were compared with optical images of stained histological sections. The DEI-CT images map accurately the morphology of the samples, including collagen strands and micro-calcifications of dimensions less than 0.1 mm. Histo-pathological examination and reading of the radiographs were done independently, and the conclusions were in general agreement. High-resolution DEI-CT images show strong contrast and permit visualization of details invisible in clinical radiographs. The radiation dose may be reduced by an order of magnitude without compromising image quality, which would make possible clinical in vivo DEI-CT with future compact SR sources.