PubMed Health⌕ Search

Biomedical subjects

U Stenram

Publications and source records attributed to U Stenram.

At least 19 recordsLinked to original sources
PubMed2005

Resistance to tumour challenge after tumour laser thermotherapy is associated with a cellular immune response.

Previous studies in our laboratory have shown that interstitial laser thermotherapy (ILT) of an experimental liver tumour is superior to surgical excision, at least partly due to a laser-induced immunological effect. The aim of the present study was to investigate the time-response relationship of the ILT-induced immunisation and the cellular response of macrophages and lymphocytes. A dimethylhydrazine-induced adenocarcinoma was transplanted into the liver of syngeneic rats. Rats with tumour were treated 6-8 days later (tumour size 0.25-0.40 cm(3)) with ILT of tumour or resection of the tumour-bearing lobe. Two groups of rats without tumour were treated with resection of a normal liver lobe or ILT of normal liver. A challenging tumour was implanted into the liver of each rat 2, 5 or 10 weeks after primary treatment. Rats were killed 6, 12 and 48 days (or earlier due to their condition) after challenge (n = 8 in all groups). Immunohistochemical techniques were used to determine lymphocytes (CD8, CD4) and macrophages (ED1, ED2) in rats having had treatment of a primary tumour. Interstitial laser thermotherapy of the first tumour was followed by eradication of challenging tumour and absence of tumour spread. This contrasted with rapid growth and spread of challenging tumour in the other groups. In the challenging vital tumour tissue and in the interface between the tumour and surroundings, the number of ED1 macrophages and CD8 lymphocytes was higher in rats having been treated with the ILT of tumour than in those having undergone resection of the tumour-bearing lobe. The number of ED2 macrophages and CD4 lymphocytes was low and did not vary between these two groups. Interstitial laser thermotherapy elicited an immune response that eradicated a challenging tumour and was associated with increased numbers of tumour-infiltrating macrophages and CD8 lymphocytes.

Adenocarcinoma↗
PubMed2003

Local infusion of the nitric oxide donor Sin-1 after angioplasty. Effects on intimal hyperplasia in porcine coronary arteries.

PURPOSE: To investigate the development of intimal hyperplasia in response to percutaneous transluminal coronary angioplasty (PTCA) followed by local delivery of the nitric oxide (NO) donor 3-morpholino-sydnonimine (SIN-1). MATERIAL AND METHODS: Overdilation PTCA was performed in coronary arteries in 20 healthy pigs. One of the dilated segments was additionally treated with local delivery of SIN-1 for 10 min. Segments distal to the treated part of the arteries served as controls. Arteries were radiographically depicted and analyzed after 1 and 8 weeks for actin, myosin and intermediate filaments (IF), nitric oxide synthetase (NOS) and histological evaluation. RESULTS: Segments treated with PTCA+SIN-1 showed a significantly (p=0.03) larger luminal diameter compared with PTCA only treated segments. The luminal loss after SIN-1 was not significant compared with the diameter prior to treatment. Endothelial NOS content was significantly lower in the PTCA+SIN-1 group compared with the PTCA group after 1 (p=0.03) and 8 weeks (p=0.013). IF/actin ratio after 1 week was significantly increased in PTCA-treated segments compared with untreated controls (p=0.004), and compared with PTCA+SIN-1-treated segments (p=0.004). CONCLUSION: PTCA-induced intimal hyperplasia was potently inhibited by local delivery of the NO donor SIN-1. Momentary events at the time of injury play a significant role in the development of intimal hyperplasia and long-lasting down-regulation of the endothelial NOS expression after SIN-1 exposure is suggested. The IF/actin ratio can be useful as an early marker of intimal hyperplasia.

Angioplasty, Balloon, Coronary↗
PubMed2002

Percutaneous fine-needle aspiration cytology in the diagnosis and management of liver tumours.

BACKGROUND: The aim of the study was to investigate the value of percutaneous fine-needle aspiration cytology (FNAC) in the diagnosis and management of liver tumours. METHODS: FNAC followed by histopathological examination was carried out in 216 patients with suspected liver tumours. The final diagnosis was primary liver cancer in 106, colorectal metastases in 51, non-colorectal metastases in 46, benign tumour in nine and no tumour in four patients. RESULTS: Cytology resulted in correct classification of the lesion as benign or malignant in 87 per cent of patients, correct discrimination between primary and secondary malignancy in half of the patients, and a correct diagnosis of tumour type in one-third of patients. The tumour was erroneously classified as benign or malignant in 22 patients (11 per cent) and four patients (2 per cent) respectively. When FNAC showed malignancy, the predictive value was 98 per cent, whereas the predictive value was 27 per cent when it did not. FNAC guided investigations and treatment in one-quarter of patients. Implantation metastases were recorded in seven patients (3 per cent), including five (10 per cent) of 51 patients with colorectal liver metastases, and caused major local problems and death in four patients. CONCLUSION: FNAC was valuable in about a quarter of patients with liver tumour. The risks of implantation metastases and a false-negative finding do not justify its use in candidates for curative therapy of liver tumours.

Adult↗
PubMed2000

Acute taurodeoxycholate-induced pancreatitis in the rat is associated with hyperCCKemia.

BACKGROUND: Cholecystokinin (CCK) has been suggested to be involved in the development and course of acute pancreatitis. In the present study we measured plasma CCK concentrations in acute experimental pancreatitis (AEP) in the rat, and evaluated the role of circulating CCK levels on the initial pancreatic damage in pancreatitis. METHODS: Endogenous hyperCCKemia was induced by surgical biliodigestive shunt (BDS) and exogenous hyperCCKemia by infusion of CCK-8S. The CCK-A receptor antagonist devazepide was used to antagonize the effect of CCK. Pancreatitis was induced by pancreatic duct infusion of sodium taurodeoxycholate 4 wk after the BDS operation or 1 wk after the start of the infusions. Nonpancreatitic sham- and BDS-operated rats, respectively, were used as control animals as were groups of otherwise untreated rats with pancreatitis. The animals were sacrificed 6 h after induction of pancreatitis. Concentrations of CCK were determined in plasma as were protein and amylase levels in the pancreas and peritoneal exudates. The extent of pancreatic necroses was assessed microscopically. RESULTS: Pancreatitis caused an 11-20-fold increase of circulating CCK as measured after 6 h. In pancreatitic rats with induced hyperCCKemia, there was a further marked increase of plasma CCK. Pancreatic weight and edema, protein and amylase contents, and extent of necroses were the same regardless of the level of plasma CCK. Devazepide had no influence on the studied pancreatic parameters. CONCLUSION: We conclude that acute taurodeoxycholate-induced pancreatitis in the rat is associated with elevated plasma CCK concentrations. There seems, however, not to be any correlation between the degree of hyperCCKemia and the extent of initial pancreatic damage.

Acute Disease↗
PubMed1999

Cytogenetic analyses of secondary liver tumors reveal significant differences in genomic imbalances between primary and metastatic colon carcinomas.

To investigate if karyotypic features of secondary liver tumors may provide diagnostic information and if the cytogenetic patterns of primary and metastatic colorectal carcinomas (CRC) are different, 33 liver metastases were analyzed: 25 CRC, 4 small intestine carcinoids, 1 ovarian carcinoid, 1 lobular breast cancer, 1 head-and-neck squamous cell carcinoma, and 1 uveal malignant melanoma. Chromosomal aberrations were detected in 24 cases, whereas 5 had normal karyotypes and 4 were uninformative due to lack of mitoses. Trisomy 12 was detected in 2 small intestine carcinoids, suggesting that +12 may be of pathogenetic importance in this tumor type. The breast and head-and-neck carcinomas and the uveal melanoma displayed aberrations previously reported as characteristic in primary tumors, e.g., der(1;16) and deletion of 3p in the breast cancer, losses of 3p and 8p and partial gain of 8q in the head-and-neck carcinoma, and monosomy 3 and i(8)(q10) in the uveal melanoma, indicating that cytogenetic investigations provide important diagnostic information in secondary liver tumors. In the 18 CRC metastases with chromosomal abnormalities, the cytogenetic findings agreed well with previously reported primary CRC. Common numerical abnormalities included gains of chromosomes 7, 11, 13, and 20, and losses of Y, 4, 18, 21, and 22. Structural rearrangements most often affected chromosome bands 1p13, 1q10, 3p21, 5q10, 5q11, 7q10, 8q10, 8q11, 12q13, 16p13, 17p11, 20p13, 20p11, and 20q10, and frequently resulted in losses of 1p, 8p, and 17p, and gains of 5p, 6p, 7p, 8q, and 20q. Comparing the present cases with primary CRC previously analyzed in our department revealed that additional gains of 6p, 6q, 7p, and 20q, and losses of 1p, 4p, 4q, 8p, 18p, 18q, and 22 were more common (P < 0.05) in the metastases, suggesting that these genomic sites harbor genes of importance in the metastatic process of CRC.

Adult↗
PubMed1999

Immunohistochemical expression of metallothionein in resected hepatic primary tumors and colorectal carcinoma metastases.

Metallothionein is a protein with affinity for metals and is present in several tumors. We examined its immunohistochemical expression in 37 resected primary liver tumors and 117 colorectal metastases. The reaction was intense in the two fibrolamellar hepatocellular carcinomas and in many of the hepatocytes of the pseudotumor case of focal nodular hyperplasia. The reaction was low or moderate in 5 of 17 ordinary hepatocellular carcinomas and in 4 of 14 cholangiocellular carcinomas. There was no reaction in one case each of spindle cell hepatocellular carcinoma, oncocytic adenoma and hemangioendothelial sarcoma. In the metastases, the reaction was low or moderate in 14 cases and negative in 103. Surrounding hepatocytes and stromal cells were more or less positive in all cases.

Carcinoma, Hepatocellular↗
PubMed1998

Resection of colorectal liver metastases: 25-year experience.

The aim of this retrospective study was to analyze survival and prognostic factors in 111 consecutive patients undergoing curative resection of liver metastases from colorectal cancer. In addition, the time periods 1971-1984 and 1985-1995 were compared; criteria for first liver resection did not change with time, whereas the attitude toward re-resection was more aggressive during the latter period. Operative mortality was 6% during 1971-1984 and 0% during 1985-1995 (3.6% for all patients). The crude 5-year actuarial survivals were 19% and 35% for patients operated during 1971-1984 and 1985-1995, respectively (25% for the whole period). Relapse at any site was observed in 52 patients (81%) operated during the first period and in 29 patients (67%) operated during the second period; re-resection was performed in 12 (23%) and 15 (52%) of these patients, respectively. Five-year survival after hepatic re-resection was 29% (no operative mortality). In the univariate analysis, significant determinants for long-term survival were, in descending order, a clear resection margin, high degree of fibrosis around the tumor, absence of extrahepatic metastases (including metastases to the liver hilum), use of an ultrasound dissector, low preoperative serum carcinoembryonic antigen (CEA) level, year of resection (1985-1995), and low/moderate grade of liver tumor. There were no 5-year survivors when extrahepatic metastases were present, the liver tumor(s) had a low differentiation or satellites, or the resection margin was involved with tumor. In the multivariate analysis, the determinants were grade of liver tumor, absence of extrahepatic tumor, few intraoperative blood transfusions, low preoperative serum CEA level, and year of resection (1985-1995). It is concluded that: (1) an increased rate of hepatic re-resection was partly responsible for the improved outcome after liver resection for colorectal metastases during recent years; (2) patients with extrahepatic metastases did not benefit from liver resection; and (3) surgery should be performed with a clear resection margin and minimal blood loss.

Adult↗
PubMed1998

Comparison between interstitial laser thermotherapy and excision of an adenocarcinoma transplanted into rat liver.

The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was transplanted (implanted if not stated otherwise) into the left lateral lobe of the rat liver, and treatment was performed 8 days later. In the main experiment, rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46 degrees C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection of the tumour-bearing lobe, with no difference in local control. Metastatic spread after resection of the median liver lobe was similar to that observed after sham procedures for thermotherapy or resection, suggesting that the advantage of thermotherapy was not due to a difference in surgical trauma. Additional studies showed that laser thermotherapy reduced intraperitoneal spread when treatment was suboptimal or in a tumour inoculation model and suggested that immunological mechanisms might be involved. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour compared with resection.

Adenocarcinoma↗
PubMed1998

Electrolytic stent in the normal bile duct. An experimental study.

PURPOSE: To evaluate and compare changes in the bile-duct wall after the insertion of electrolytic and nonelectrolytic stents. MATERIAL AND METHODS: The electrolytic stents were composed of 3 different layers (iron, isolating polyethylene and tantalum) and were implanted surgically in the bile duct of 8 healthy pigs. The nonelectrolytic stents were also composed of 3 layers (2 layers of tantalum and an isolating layer of polyethylene) and were implanted surgically in the bile ducts of 9 healthy pigs. After an observation time of 8 weeks, the pigs were killed and the bile ducts were excised and sent for histopathological examination. RESULTS: One pig was killed after the procedure owing to postoperative complications; all the other pigs survived without complications. Migration of the stent to the bowel occurred in 4 pigs. A slight inflammatory reaction was seen at histopathological examination in 6 pigs with the electrolytic stent and in 6 pigs with the nonelectrolytic stent. There was no difference in the specimens from pigs with electrolytic and nonelectrolytic stents. CONCLUSIONS: The electrolytic stents did not cause more changes in the normal bile-duct wall than the nonelectrolytic stents.

Animals↗
PubMed1997

Hepatic inflow occlusion increases the efficacy of interstitial laser-induced thermotherapy in rat.

Interstitial laser-induced thermotherapy (ILT) destroys tumors thermally. ILT was performed for treatment of liver tumors in rats to investigate the effect of hepatic inflow occlusion on temperature distribution and lesion size. Tumors were irradiated for 20 min with near-infrared light from a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. The laser light at a power of 1.5 W was delivered through a plane-cut optical fiber, the tip of which was placed in the tumor. Rats in group I received ILT without interruption of hepatic blood flow. Those in group II received ILT during hepatic inflow occlusion. Liver temperatures were measured during treatment. After 3 days the animals were sacrificed and the size of the lesions was measured. Occlusion of the hepatic inflow during ILT increased the maximum lesion diameter, as measured at the liver surface, by 47%. Linear interpolation between the temperatures measured at 6 and 12 mm distance from the fiber tip revealed that the temperature at the necrotic border just before the end of treatment was approximately 45 degrees C in both the occluded and nonoccluded groups, indicating that the hepatic inflow occlusion caused no increase in tissue thermal sensitivity. This study shows that occlusion of the hepatic inflow during interstitial laser-induced thermotherapy causes a significant increase in lesion size, which could have implications for the treatment of hepatic tumors.

Animals↗
PubMed1997

Incorporation of 5-fluorouracil into hepatoma and normal tissue RNA at protein depletion in the rat.

BACKGROUND AND OBJECTIVES: 5-fluorouracil (5-FU) exerts its effects mainly by its incorporation into RNA and inhibition of DNA synthesis. Its toxicity may therefore be estimated by measuring its incorporation into RNA. Protein malnutrition has been considered to increase the toxicity of 5-FU. METHODS: Rats with a hepatoma implanted into the liver were fed on either a 25% or a 0% casein diet for 1 week. On the last day, they were infused via the hepatic artery with a therapeutic dose of 3H-5-FU. Its incorporation into RNA was measured in hepatoma and several normal tissues. RESULTS: Protein deprivation increased the incorporation of 5-FU into liver and intestinal RNA. Incorporation into hepatoma RNA did not increase significantly, but the ratio, liver/hepatoma RNA incorporation, remained unchanged. CONCLUSIONS: Protein deprivation might increase the toxicity of 5-FU on liver and intestine.

Animals↗
PubMed1997

Proliferative response in smooth muscle cells after angioplasty or insertion of self-expanding stents. An experimental study in pigs.

PURPOSE: Evaluation of the early proliferative reaction of smooth muscle cells (SMC) in the media of the artery following percutaneous transluminal angioplasty (PTA), compared with the reaction on insertion of self-expandable stents. MATERIAL AND METHODS: In 6 healthy pigs, one iliac artery was overdilated with an 8-mm diameter angioplasty balloon. A self-expanding Nitinol stent, OD 8 mm, was inserted into the contralateral iliac artery without previous dilatation. The nuclei of the proliferating SMC in the media of the artery were labelled by intravenous administration of 5-bromo-2-deoxy-uridine and cells in S-phase counted 24 h after the procedure. RESULTS: The mean number of proliferating nuclei of the SMC increased significantly more after PTA (p < 0.05) than after the insertion of a stent. CONCLUSION: Early proliferative reaction of the SMC is more pronounced after PTA than after insertion of the self-expanding stent.

Alloys↗
PubMed1997

Sclerosing peritonitis in a case of benign cystic ovarian teratoma. A case report.

A 52-year old woman with regular menstruation presented with ascites and abdominal swelling and pain. Bilateral salpingo-oophorectomy, hysterectomy and excision of a few peritoneal nodules was performed. The omentum was firm, giving the impression of carcinoma. The ovaries were enlarged, each containing a non-ruptured cyst with thick yellowish fluid. Microscopy revealed a sclerosing peritonitis in the omentum and nodules. There was a benign cystic teratoma in the left ovary, a corpus luteum in the right ovary. Follow-up has been uneventful for 26 months. The sclerosing peritonitis is considered to be secondary to the ovarian changes, most probably the teratoma.

Female↗
PubMed1997

Adenomyoma of the ampulla of Vater: an uncommon cause of bile duct obstruction.

Adenomyomas of the bile ducts are extremely rare. They are most likely often overlooked also when situated in the ampulla of Vater and obstructing bile flow. Of 3,131 endoscopic retrograde cholangiograms, four patients with ampullary adenomyoma and signs of biliary obstruction have been diagnosed. When recognized they can be treated effectively by endoscopic means. However, their radiologic and endoscopic appearances were found difficult to interpret and led to unnecessary endoscopic sessions in one patient and surgery in another. Thus, increased awareness of this entity is important to avoid overlooking or misdiagnosing it.

Adenomyoma↗
PubMed1997

Interstitial laser thermotherapy of adenocarcinoma transplanted into rat liver.

OBJECTIVE: To examine the effect of different temperatures and exposure times in interstitial laser thermotherapy. DESIGN: Controlled laboratory study. SETTING: University hospital, Sweden. MATERIAL: 48 male Wistar FU rats with dimethylhydrazine-induced adenocarcinoma transplanted into the liver. INTERVENTION: Treatment was given with an Nd:YAG laser and a feedback system for temperature regulation. Light was delivered into the centre of the tumour and the feedback thermistor probe was placed 3 mm from the tumour margin. Rats were treated at steady-state temperatures at the feedback thermistor of 43, 46, or 50 degrees C for 30 minutes, and at a steady-state temperature of 46 degrees C at the feedback thermistor also for 10 and 20 minutes. MAIN OUTCOME MEASUREMENT: Tumour control as assessed 6 days after treatment using light microscopical examination including immunohistochemical determination of bromodeoxyuridine (BrdU) incorporation into DNA as a measure of cell viability. RESULTS: Complete tumour necrosis was achieved in all rats treated for 30 minutes, in 6/8 rats treated for 10 minutes and in 6/8 rats treated for 20 minutes at 46 degrees C. During steady-state thermotherapy, temperatures at the tumour margin were about 11 degrees higher than at the feedback thermistor (range 54-61 degrees C). The surrounding liver tissue also became necrotic so that the total necrosis volume exceeded the pretreatment tumour volume. CONCLUSION: Interstitial laser thermotherapy at temperatures ranging from 54-61 degrees C at the tumour margin ensures total necrosis of a transplanted rat liver carcinoma provided that treatment is given for 30 minutes.

Adenocarcinoma↗