BACKGROUND: Periadventitial gene therapy is a promising alternative for the treatment of stenosis, vessel wall thickening and other complications in vascular surgery. METHODS: We compared lacZ gene transfer efficiency of DOTMA: DOPE (1:1 w/w) plasmid/liposome complexes and adenoviruses in pig carotid arteries using perivascular delivery with either a collagen collar or a wrap of collagen sheet. Safety of the gene transfer was studied by clinical chemistry, tissue pathology and PCR analysis of lung, liver, kidney, spleen, skeletal muscle and gonads. RESULTS: Gene transfer efficiency using the periadventitial collar was fourfold higher than using the collagen wrap with adenovirus at 7 days (10.22 +/- 2.96 vs 2.78 +/- 1.28 positive cells/mm2; p = 0.18) and 4.3-fold at 14 days (13.46 +/- 3.49 vs 3.11 +/- 0.88 positive cells/mm2; p = 0.03). Gene transfer efficiency at 7 days with adenovirus was fivefold higher than with the plasmid/liposome complexes both using the collar (10.22 +/- 2.96 vs 2.07 +/- 0.95 positive cells/mm2; p = 0.01) and the collagen wrap (2.78 +/- 1.28 vs 0.45 +/- 0.35 positive cells/mm2; p = 0.03). No lacZ activity was detected in plasmid/liposome transfected arteries at 14 days. In spite of the local gene delivery methods a moderate systemic distribution of the transgene was detected in the major organs by PCR analysis. CONCLUSIONS: This study shows that: (i) adenovirus delivered with the periadventitial collar or the collagen wrap is well tolerated and may become an efficient new tool in vascular gene therapy, and (ii) gene transfer vector delivered in the periadventitial collar reaches the target tissue more efficiently than the vector in the collagen wrap.

Absorbable Implants↗

PubMedDate not supplied

Evaluation of herpes simplex thymidine kinase mediated gene therapy in experimental pancreatic cancer.

BACKGROUND: Despite of recent improvements in the treatment of many malignant diseases, pancreatic ductal adenocarcinoma is still a disease with an extremely poor prognosis with current modes of treatment. Gene therapy has been suggested as a novel approach also against pancreatic cancer. Previous studies have been carried out predominantly with immunodeficient animal models and with tumors growing in environments other than the pancreas. We have attempted to mimic a more clinically relevant situation and investigated suicide gene therapy strategy for experimental pancreatic cancer in animals with an intact immune system. METHODS: We used herpes simplex virus thymidine kinase (HSV-tk) and ganciclovir (GCV) strategy in both in vitro and in vivo settings. RESULTS: In vitro studies demonstrated that retro- as well as adenovirally transduced HSV-tk-positive DSL-6A/C1 rat pancreatic carcinoma cells were sensitive to low concentrations of GCV when compared with parental, nontransduced cells. In addition, a strong bystander effect was observed. In in vivo studies, subcutaneously transplanted HSV-tk-positive DSL-6A/C1 cells were killed after GCV treatment, whereas parental, HSV-tk-negative cells continued to grow and developed into ductal adenocarcinomas. In in vivo HSV-tk-transduced pancreatic tumors, GCV treatment caused tumor necrosis and the necrosis volume was significantly more extensive when compared with control groups. CONCLUSIONS: HSV-tk gene transfer followed by GCV treatment is efficient in killing pancreatic cancer cells in vitro, in a transduced subcutaneous tumor model, as well as in in vivo transduced pancreatic tumors using an immunocompetent animal model. These results highlight the potential of gene therapy to treat experimental pancreatic cancer.

Adenoviridae↗

PubMedDate not supplied

Effect of clodronate on fracture healing in denervated rats.

The effect of clodronate on healing of the fracture of osteopenic bone was studied in rats. A total of 165 female rats (14 +/- 1 weeks, 216 +/- 2 g) were divided into five fracture groups (n = 30), and a neurectomized group (n = 15). Osteopenia (op) was induced by right sciatic neurectomy 4 weeks before the fracture. Nonosteopenic (nop) rats were not operated. A closed prepinned diaphyseal fracture of the right femur was done by three-point bending method both to op and nop rats, and the left femur served as an unoperated control. All the fracture groups were divided into treatment (clodronate 10 mg/kg/day sc) and control (saline sc) groups, and the administration was continued throughout the study. The op rats were killed 2, 4, 8, and 12 weeks and nop rats 8 weeks after the fracture. Fracture healing was examined by x-ray and bone-bending strength. Neurectomy reduced bone strength (p < 0.01) at 4 weeks. Clodronate did not affect the bending strength of healing callus of op rats at 2, 4, 8, or 12 weeks after fracture, but reduced the strength of healing callus in nop rats (p < 0.05) at 8 weeks. Radiologic callus width increased in clodronate-treated groups both in op (8 and 12 weeks, p < 0.001) and nop rats (8 weeks, p < 0.05) when compared with saline-treated groups. Clodronate did not affect normal bone strength. In conclusion, clodronate did not affect the bending strength of op fracture nor the strength of the control bones. The remodeling of the fracture was delayed with clodronate.

Animals↗

PubMedDate not supplied

Preconditioning hyperthermia inhibits restitution of isolated Guinea pig gastric mucosa.

BACKGROUND: Superficial epithelial injury is followed by restitution which is based on the migration of the surviving mucosal cells to restore the disturbed epithelial continuity. There is previous data that heat-shock (HS) preconditioning may be utilized to enhance the tissue tolerance to injury. Yet, there is little data about the effect of preconditioning on restitution. METHODS: Guinea pig gastric mucosae were mounted and perfused in Ussing chambers. After stabilization, a HS (42 degrees C, 30 min) and concomitant heat-shock protein (Hsp) production was induced. After stabilization and reaching the normothermia, a superficial injury (1.25 mol/l NaCl) was induced. Subsequently, the tissue was allowed to restitute for 3 h. In some sets of experiments, protein synthesis was inhibited either with quercetin or with cycloheximide. During the experiment, transmucosal electrophysiological resistance (R) of the tissue was recorded. After the experiment, the mucosa was prepared for morphologic analysis and for Western blot. RESULTS: HS did not affect mucosal tolerance to hyperosmolar injury, but inhibited significantly restitution after injury and upregulated Hsp70 as well. The levels of Hsp70 correlated inversely with recovery of R and histology. Quercetin and cycloheximide abolished this effect of HS, while quercetin did not completely abolish Hsp70 upregulation. CONCLUSION: Hyperthermic preconditioning inhibits the restitution of gastrointestinal mucosa in correlation with Hsp70 levels. The inhibition of restitution is sensitive to blockades of de novo protein synthesis and of Hsp70 production.

Animals↗

PubMedDate not supplied

Reperfusion but not acute ischemia in pig small intestine induces transcriptionally mediated heat shock response in situ.

BACKGROUND: Although there is data on the cytoprotective role of heat shock proteins in intestinal ischemia-reperfusion, the effects of ischemia and reperfusion per se on the small intestinal heat shock response have been poorly characterized. METHODS: Four female pigs were subjected to 60-min ischemia by superior mesenteric artery occlusion followed by 360-min reperfusion. Systemic and local hemodynamics were monitored. Samples from the jejunal mucosa and muscularis were obtained for histology and for time series molecular biologic analyses of heat shock transcription factor 1 (HSF1), hsp70 mRNA and Hsp70 protein. RESULTS: A 30-min reperfusion of jejunum after a preceding 1-hour ischemia results in a significantly increased DNA-binding activity of HSF1, in a 10-fold increase of hsp70 mRNA in the mucosal and in a 7-fold increase in the muscular layers. Translational activation and accumulation of Hsp70 protein occurs after 60 min of reperfusion in the intestine. Nevertheless, a 60-min ischemia inducing mucosal detachment does not induce the heat shock response at any level analyzed. CONCLUSIONS: Ischemia alone is insufficient to induce the heat shock response, whereas subsequent reperfusion induces the response via transcriptionally mediated induction of Hsp70 synthesis both in the mucosal and muscular layers.

Acute Disease↗

PubMedDate not supplied

Heat shock preconditioning and eicosanoid pathways modulate caspase 3-like activity in superficially injured isolated guinea pig gastric mucosa.

BACKGROUND: After superficial mucosal injury, the disturbed gastric epithelial continuity is restored by cellular migration. Caspase-3 is an enzyme responsible for the execution of stress-induced apoptosis. Interestingly, heat shock proteins (Hsp) including Hsp60 are capable of modulating caspase-3 activity. Interestingly, we have demonstrated that heat shock preconditioning upregulates Hsp synthesis and inhibits restitution and cell proliferation via mechanisms related to de novo protein synthesis and eicosanoid pathways, both of which are crucial in the regulation of apoptosis and gastric mucosal defense systems. AIMS: To assess whether caspase-3 activity is affected by heat shock preconditioning and associated pharmacological modulations after standard superficial injury to allow development of cytoprotective strategies. METHODS: Guinea pig gastric mucosae were mounted and perfused in paired Ussing chambers. After heat shock (HS) preconditioning (42 degrees C) for 30 min, a superficial injury was induced (1.25 mol/l NaCl) followed by 3 h recovery. For mechanistic studies, the mucosa was exposed to 30 micromol/l arachidonic acid (AA) as a substrate for eicosanoid pathways, to 50 micromol/l quercetin (Q) to inhibit lipoxygenases, to 50 micromol/l indomethacin (In) to inhibit cyclo-oxygenases, or to 150 micromol/l cycloheximide (CHX) to inhibit de novo protein synthesis. After the experiment, the mucosa was prepared for analysis of caspase-3 activity. Hsp60 expression was analyzed to monitor the induction of heat shock response. RESULTS: HS upregulated Hsp60 expression, indicating induction of the heat shock response without an effect on basal caspase-3 activity. Superficial injury itself did not affect caspase-3 activity nor Hsp60 synthesis. In all the experiments, exposure to CHX abolished caspase-3 activity and Hsp60 synthesis. AA+Q increased, Q decreased, while In+AA and In+AA+Q abolished caspase-3 activity independent of alterations in Hsp60 synthesis. Upon exposure to In+Q, HS decreased caspase-3 activity and upregulated Hsp60 synthesis. CONCLUSION: Caspase-3 activity in isolated guinea pig gastric mucosa is regulated by mechanisms dependent on de novo protein synthesis and eicosanoid pathways but is not strictly related to Hsp synthesis. Upon modulation of the eicosanoid pathways, HS may be utilized to simultaneously decrease caspase-3 activity and increase Hsp synthesis. Modulations of the eicosanoid pathways may be utilized to reduce caspase-3 activity also upon normothermic conditions suggesting a novel mechanism by which caspase-3 is regulated in the gastric mucosa.

Animals↗

PubMedDate not supplied

Polyamine excretion in depleted patients with gastrointestinal malignancy: effect of perioperative nutrition and tumor removal.

Polyamines, synthesized by all mammalian cells, are involved in protein and energy metabolism. We measured urinary excretion of polyamines, putrescine, spermidine, spermine, and their metabolites N1-acetylspermidine and N8-acetylspermidine, resting energy expenditure, and nitrogen excretion in 12 depleted patients with gastrointestinal malignancy during preoperative and postoperative parenteral nutrition and in 7 patients with multiple trauma receiving similar parenteral nutrition. During preoperative nutrition support, the excretion of putrescine (p less than .05) and total polyamines (p less than .01) increased by 420% and 60%, respectively. Increases in energy balance and resting energy expenditure during nutrition could entirely explain the observed changes in polyamine excretion. Preoperatively, the excretion of N1-acetylspermidine (p less than .05), N8-acetylspermidine (p less than .001) and total polyamines (p less than .05) was higher in patients with a surgically noncurable tumor than in those with a surgically curable tumor. The energy balance and resting energy expenditure could also explain the differences in polyamine excretion between patients with surgically curable and noncurable disease, excluding the increased N8-acetylspermidine. Postoperatively, the excretion of N8-acetylspermidine in patients with multiple trauma without malignancy and in patients with palliative operation was similar, and was higher than in patients with a totally resected malignancy (p less than .01). Our results suggest that the excretion of polyamines reflects the activity of energy metabolism in general and that polyamine excretion is not specific for any particular disease.

Adult↗

PubMedDate not supplied

A prospective study of tissue polypeptide specific antigen (TPS) in breast cancer diagnosis.

The aim of the present study was to evaluate the clinical value of a new tumour marker TPS in sera from patients with breast cancer and patients with benign breast disease. The results for TPS were compared with those for TAG 12, CA 15-3 and MCA. The cutoff levels (90% specificity) determined for each test were 108.0 U/1 for TPS, 57.5 KU/1 for TAG 12, 24.8 KU/1 for CA 15-3 and 9.7 KU/1 for MCA. The diagnostic sensitivity of the TPS test was 0.21, for the TAG 12 test it was 0.2, 0.13 for the CA 15-3 test and 0.12 for the MCA test in detecting breast cancer. TPS, TAG 12, CA 15-3 and MCA tests were tested in a multivariate analysis to find the best combination of independent predictors of breast cancer. The most important predictor of breast cancer was TAG 12 followed by TPS. In order to calculate the contributions of tumour marker tests, a diagnostic score (DS) was developed. The diagnostic score (DS) was: DS = TPS x 0.0085 x TAG 12 x 0.0596 - CA 15-3 x 0.0866 - MCA x 0.2938 + 0.1738. The sensitivity of the DS in detecting breast cancer was 55% with a specificity of 90% and an efficiency of 64%. In conclusion, new tumour markers TPS and TAG 12 may have some value in breast cancer diagnosis. In particular, the results indicate the usefulness of computer assistance and a simple diagnostic score when tumour markers are used in breast cancer diagnosis.

Adult↗

PubMedDate not supplied

A prospective study of the value of imaging, serum markers and their combination in the diagnosis of pancreatic carcinoma in symptomatic patients.

The diagnostic accuracy of ultrasound (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and tumour markers CEA, CA 50 and CA 242 in pancreatic cancer (n = 26) was studied in 113 patients with jaundice, in 20 patients with unjaundiced cholestasis, and in 60 patients with the suspicion of chronic pancreatitis or a pancreatic tumour. The sensitivities of US, CT and ERCP were 61.9%, 95.2% and 82.3%, the specificities 93.9%, 92.9% and 94.1%, and the efficiencies 91.6%, 96.6% and 92.1%, respectively. The sensitivities of CEA, CA 50 and CA 242 were 92.3%, 96.1% and 61.5%, the specificities 59.2%, 58.0% and 95.2%, and the efficiencies 63.7%, 63.2% and 90.6% respectively. The combined use of the imaging methods and tumour markers was also analysed. When either the imaging method or the serum marker test was required to be positive, the sensitivities of the combinations were clearly better than those of US and CA 242 alone, but only slightly better than those of CT, ERCP or the tumour markers CEA and CA 50 alone. When both the imaging test and the marker test were required to be positive, the specificities of the combinations were clearly better than those of CEA and CA 50 alone, but they did not exceed the specificity of the imaging methods or CA 242 alone. We conclude that CT, ERCP and CEA and CA 50 are highly sensitive in the diagnosis of pancreatic cancer in symptomatic patients, while the sensitivity of US and CA 242 is lower. The specificity of the imaging methods and CA 242 is high, but that of CEA and CA 50 is low. Imaging methods and serum tumour markers could be more used in clinical practice in a complementary manner. In patients with jaundice and/or cholestasis or with a suspicion of pancreatic tumour or chronic pancreatitis, the combined use may yield higher sensitivity than US alone and higher specificity than CEA or CA 50 alone.

Antigens, Tumor-Associated, Carbohydrate↗