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Biomedical subjects

A Kristoffersson

Publications and source records attributed to A Kristoffersson.

At least 19 recordsLinked to original sources
PubMed2005

Reduction of abdominal wall blood flow by clamping or carbon dioxide insufflation increases tumor growth in the abdominal wall: an experimental study in rats.

BACKGROUND: We have previously demonstrated that there is a reduction of blood flow in the abdominal wall in rats insufflated with air concomitant with an increase in tumor growth. The present study was designed to examine whether a reduction of blood flow achieved by clamping or insufflation with carbon dioxide (CO(2)) would increase tumor growth in the abdominal wall. METHODS: In the first part of the experiments, laser Doppler blood flow of both rectus muscles was measured in 16 Wistar Fu rats. The left rectus muscle was clamped to reduce blood flow, and 5 x 10(4) adenocarcinoma cells were injected into both rectus muscles. Clamping was maintained for 45 min. In the second part, 22 rats had 5 x 10(4) adenocarcinoma cells injected into the rectus muscle and blood flow was measured. The experimental group (n = 11) was insufflated with CO(2) at 10 mmHg for 45 min; the control group (n = 11) was not insufflated. After 9 days, tumor weight and volume were analyzed. RESULTS: Clamping caused a 69% reduction of blood flow (p < 0.001), whereas no reduction was registered on the nonclamped side. Tumor weight (p = 0.028) and volume (p = 0.030) were increased on the clamped side. The insufflation of CO(2) caused a 71% reduction of blood flow, whereas no reduction was registered in the control group. Tumor weight (p = 0.006) and volume (p = 0.006) were increased in the insufflated group. CONCLUSION: Clamping, as well as CO(2) insufflation, causes a significant reduction of blood flow in the abdominal wall, which seems to increase tumor growth at the same site.

Abdominal Neoplasms↗
PubMed2004

Platelet serotonin 5-HT2A receptor binding in patients with carcinoid tumor.

BACKGROUND: As carcinoid tumors produce and secrete serotonin, various serotonin markers in blood, plasma and urine have been used as diagnostic tools, and quantification of the urinary excretion of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) is the method most frequently used. METHODS: [3H]lysergic acid diethylamide ([3H]LSD) binding to the platelet serotonin 5-HT2A receptor was investigated in nine patients with carcinoid tumors. The possible effect of serotonin-rich food on the receptor binding was also investigated. RESULTS: B(max) for [3H]LSD binding was significantly lower in the carcinoid group than in the control group (mean +/- SD: 17.6 +/- 1.3 vs. 23.9 +/- 5.2 fmol/mg protein; p = 0.007). Kd for [3H]LSD binding was significantly higher in the carcinoid group than in the control group (median: 1.14 vs. 0.71 nmol/L; p = 0.03). B(max) was inversely related to the urinary 5-HIAA excretion, but the correlation did not reach statistical significance (r(s) = -0.57; p = 0.14). Intake of five bananas per day for one week had no effect on B(max) or Kd in healthy volunteers. CONCLUSIONS: The results are consistent with a down-regulation of the 5-HT2A receptor as a response to the high serotonin levels found in patients with carcinoid tumors. Intake of serotonin-rich food does not affect the receptor characteristics. Further studies are needed to determine whether the platelet 5-HT2A receptor status can be used as a supplement to urinary 5-HIAA and other biochemical variables in carcinoid tumors.

Aged↗
PubMed2003

Pneumoperitoneum impairs blood flow and augments tumor growth in the abdominal wall.

BACKGROUND: Despite several clinical and experimental studies, the mechanisms behind the development of port site metastases in laparoscopic surgery have remained largely unknown. The current study was designed to investigate the effect of pneumoperitoneum on blood flow in the abdominal wall and its possible effects on tumor growth at this site. METHODS: A total of 40 Wistar Fu rats had a laser Doppler probe placed on their left rectus muscle and a suspension of 50,000 adenocarcinoma cells was injected into their right rectus muscle. The experimental group (n = 20) was insufflated with air at 10 mmHg for 45 min while abdominal blood flow was registered before and during insufflation and after exsufflation. The control group (n = 20) was not insufflated but the blood flow was recorded in the same manner. After 9 days, all animals were killed and the occurrence of tumor was observed. The tumors were analyzed with respect to weight and volume. RESULTS: The insufflation caused an 82% reduction in blood flow in the experimental group (p < 0.001). No reduction in blood flow was registered in the control group. Tumor nodules developed significantly more often in the insufflated group (20/20) compared to the controls (14/20) (p = 0.016). Tumor weight (p = 0.003) and volume (p < 0.001) were significantly increased in the insufflated group. CONCLUSIONS: Pneumoperitoneum seems to enhance tumor growth. It also causes a significant reduction in blood flow in the abdominal wall, which may contribute to the increased susceptibility of tumor take.

Adenocarcinoma↗
PubMed2001

Open versus laparoscopic cholecystectomy for gallbladder carcinoma.

Laparoscopic surgery has replaced conventional open cholecystectomy for benign gallbladder disease. A major concern is how to handle gallbladder cancer in the laparoscopic era, since there are numerous case reports of port site metastases from gallbladder cancer after laparoscopic cholecystectomy. There are also many experimental studies favoring the opinion that the laparoscopic technique implies a higher risk of spreading malignant disease. This opinion has gained wide acceptance despite little previous clinical effort to determine the risk of tumor dissemination and the lack of comparisons between open and laparoscopic surgery. This report is a short summary of our own studies and present knowledge with special respect to the clinical aspects of the development and incidence of abdominal wall metastases. Among 270 patients with verified gallbladder carcinoma in whom 210 had open surgery and 60 a laparoscopic cholecystectomy, 12 patients (6.5%) in the open cholecystectomy group and 9 (15%) in the laparoscopic group developed incisional metastases. Although the sparse clinical documentation does not unavoidably mean that laparoscopic cholecystectomy has an increased risk of disseminating tumor cells, we recommend open surgery in cases of known or suspected gallbladder carcinoma.

Abdominal Neoplasms↗
PubMed2000

Wound recurrence from gallbladder cancer after open cholecystectomy.

BACKGROUND: Reports of port site recurrences from gallbladder cancer after laparoscopic cholecystectomy have raised considerable concern as to whether the laparoscopic technique implies an increased risk of metastatic disease. In a previous study of gallbladder cancer and laparoscopic cholecystectomy, we reported a frequency of 16% port site metastases. The purpose of the present study was to determine the frequency of wound metastases from gallbladder cancer after open cholecystectomy. METHODS: The registers from the Swedish Oncological Centers and the National Board of Health and Welfare were checked for reported cases of gallbladder cancer and surgical classification codes for open cholecystectomy from 1991 to 1994. The study included all 8 university and 24 county hospitals in Sweden. The files from all patients with gallbladder cancer who had an open cholecystectomy were retrospectively reviewed. RESULTS: The study included 270 patients who had a cholecystectomy, of which 215 were classified as open and 55 as laparoscopic. Of the 215 patients, 11 patients were excluded because of an incorrect or deficient histopathologic or surgical classification. In 186 patients (91%), sufficient data were obtained for follow-up. Twelve patients (6.5%) had wound metastases from their gallbladder cancer. All patients with wound metastases died with a median survival of 10 months (range, 3 to 65 months). CONCLUSIONS: Wound metastases from gallbladder cancer after open cholecystectomy may be more common than previously assumed.

Aged↗
PubMed2000

Positive effect of radiotherapy and surgery on hormonally active pulmonary metastases of primary parathyroid carcinoma.

OBJECTIVE: Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. Surgery is the primary treatment in recurrent or metastatic disease. Radiotherapy has been used as an adjuvant to control subclinical local disease but is otherwise considered ineffective. DESIGN: We report on a patient with parathyroid carcinoma with hypercalcaemia and pulmonary metastases, treated with pamidronate and radiotherapy and later with surgery. METHODS: The treatment was evaluated using serial analysis of serum parathyroid hormone (PTH) and calcium, clinical evaluation and chest radiographs. RESULTS: Intravenous pamidronate alone had limited effect on hypercalcaemia. Following irradiation of the pulmonary lesions (34 Gy in ten fractions), serum levels of calcium and PTH decreased and pamidronate could be discontinued. The patient's general condition improved parallel to a radiological response. At clinical relapse 18 months following radiotherapy, the pulmonary metastases were resected and serum PTH was normalised. CONCLUSIONS: The results indicate that parathyroid carcinoma can be radiosensitive. Thus radiotherapy may be an alternative to palliate symptoms of hypercalcaemia in patients not suited for surgery.

Antineoplastic Agents↗
PubMed1999

Port site metastases from gallbladder cancer after laparoscopic cholecystectomy. Results of a Swedish survey and review of published reports.

OBJECTIVE: To investigate the incidence of port site metastases from unsuspected gallbladder cancer after laparoscopic cholecystectomy. DESIGN: Retrospective national multicentre study, 1991-94. SETTING: All 8 university and 24 central hospital, Sweden. SUBJECTS AND INTERVENTIONS: All 32 hospitals were interviewed by means of a written questionnaire. The registers of all Swedish Oncological Centres and the registers of the National Board of Health and Welfare were checked for reported cases of gallbladder cancer and surgical classification codes for cholecystectomy. To detect laparoscopic interventions incorrectly registered as open operations, all cholecystectomies registered as open were matched against the Swedish Registry of Laparoscopic Cholecystectomy for the years 1991-93 and all patients records for 1994 were scrutinised. RESULTS: Replies were obtained from 30/32 clinics (94%) and 11976 laparoscopic cholecystectomies were done. Of 447 patients with verified gallbladder carcinoma 270 had their gallbladders removed, 55 (20%) laparoscopically. 9 of these (16%) developed port site metastases and 6 died from their disease at a median of 18 months (range 5-22). Two patients are alive, 54 and 45 months after cholecystectomy. One patient has been lost to follow-up. CONCLUSIONS: Port site metastases from gallbladder cancer may be more common than previously thought. A laparoscopic procedure should not be done if cancer of the gallbladder is suspected.

Adult↗
PubMed1998

Effective of pneumoperitoneum induced by carbon dioxide and air on tumor load in a rat model.

Laparoscopic surgery for malignant disease is highly controversial mainly due to the large number of abdominal wall metastases being reported. Previous experimental studies have particularly studied CO2 pneumoperitoneum and its effect on tumor development. The purpose of this study was to compare CO2- and air-induced pneumoperitoneum with regard to intraperitoneal tumor growth. Altogether 39 rats were injected intraperitoneally with 10(5) colonic tumor cells and randomly allocated into three groups: 13 rats had a pneumoperitoneum created with CO2, 13 with air, and 13 served as controls. Tumor development was determined semiquantitatively by a peritoneal cancer index scale after 12 days. CO2 and air pneumoperitoneum equally increased intraperitoneal tumor growth compared to controls. Pneumoperitoneum induced by CO2 and air seems to increase tumor load, but the mechanisms are not established. This finding supports the hypothesis that insufflation not only by causing tumor cell movements but in fact pneumoperitoneum per se and the used gas are involved in the development of abdominal wall metastases after laparoscopic surgery.

Abdominal Muscles↗
PubMed1997

Effects of moderate endurance exercise on calcium, parathyroid hormone, and markers of bone metabolism in young women.

We investigated the short-term (1 hour-3 days) effects of a 45 minute run on calcium, parathyroid hormone, the carboxyterminal propeptide of type I procollagen (PICP), and the immunoactive carboxyterminal telopeptide of type I collagen in serum (ICTP) in young females. Fourteen healthy young women, aged 25.2 +/- 0.6 years (mean +/- SEM) with regular menstruations, participated. The test was outdoor jogging for 45 minutes at an intensity of 50% of VO2 max. Blood samples were collected 15 minutes before the test and 1, 24, and 72 hours after the test. The measured values were adjusted for changes in plasma volume. A significant decrease of ionized calcium was observed at 1 hour (P < 0.001) and 72 hours (P < 0.05) and a significant increase of parathyroid hormone (PTH) was noted 24 (P < 0.01) and 72 hours (P < 0.05) after the test. A significant decrease of PICP at 1 hour (P < 0.05) was followed by an increase after 24 (P < 0.01) and 72 hours (P < 0.001) and a significant increase in ICTP was noted at 24 and 72 hours (P < 0.05). A strong positive correlation was found between serum levels of PICP and ICTP (r = 0. 55-0.84; P < 0.05) throughout the experiment. In conclusion, young females showed biochemical signs of increased bone collagen turnover and altered homeostasis of calcium and PTH after a single bout of moderate endurance exercise.

Adult↗
PubMed1997

von Willebrand factor mediates increased platelet retention in recurrent thrombotic thrombocytopenic purpura.

The plasma cryoprecipitate of two brothers with recurrent thrombotic thrombocytopenic purpura (TTP) was previously found to mediate increased platelet retention and contain ultra-large von Willebrand factor (vWF) multimers during remissions. We conducted this study to examine if vWF is involved in the increased platelet retention in TTP. Platelet retention decreased when the patients' plasma was incubated with a monoclonal antibody directed to the vWF epitope which interacts with the platelet receptor glycoprotein Ib or when incubated with a Fab-fragment directed to the platelet receptor glycoprotein IIb/IIIa. Replacement of patient vWF with an equivalent concentration of a factor VIII/vWF concentrate containing no ultra-large vWF multimers was accompanied by a normalization of platelet retention. These results indicate that vWF is involved in the increased platelet retention. Analysis of polymorphic markers in the vWF gene demonstrated that a recessive mutation in this gene is unlikely.

Adolescent↗
PubMed1996

The effects of brisk walking on markers of bone and calcium metabolism in postmenopausal women.

Weight-bearing exercise has been shown to maintain or increase bone mass in younger as well as older individuals but the mechanisms by which mechanical loading affects bone metabolism are not known in detail. Twelve postmenopausal women participated in a single bout of brisk walking (50% of VO2 max) for 90 minutes. Calciotropic hormones and markers of type I collagen formation (PICP) and degradation (ICTP) were measured before the exercise, and 1, 24, and 72 hours following the exercise. Total body bone mineral content (BMC) and density (BMD) were measured by dual energy X-ray absorptiometry (DXA). Brisk walking did not induce any significant changes in the concentrations of ionized calcium, parathyroid hormone (PTH), calcitonin, or osteocalcin. A significant increase of PICP was noted 24 and 72 hours (P < 0.01) after exertion and a significant decrease in the concentration of serum ICTP at 1 hour (P < 0.05) was followed by an increase at 72 hours (P < 0.001). There was no significant difference between the increases in the concentrations of PICP and ICTP at 72 hours. Strong inverse correlations between the basal levels of PTH and BMD (r = -0.78; P < 0.01) as well as between osteocalcin and BMD (r = -0.83; P < 0.01) were noticed. The changes in serum levels of bone collagen markers indicate an altered bone collagen turnover due to this moderate endurance exercise. The results also support the fact that serum levels of PTH as well as those of osteocalcin are associated with total body BMD in postmenopausal women.

Aged↗
PubMed1995

Effects of short-term maximal work on plasma calcium, parathyroid hormone, osteocalcin and biochemical markers of collagen metabolism.

Physical activity is most probably an important factor to increase bone mass. The exact mechanisms by which this takes place are not completely understood. During the last years methods have become available making it possible to study the metabolism of type I collagen in bone in more detail. In this study seven male athletes were studied before and after a short-term maximal work (a modified Wingate test at a retardation of 7.5% of body weight) during 30 seconds. Blood samples were drawn before the test and 5 and 60 minutes after. Serum concentrations of type I procollagen carboxyterminal propeptide (PICP) and carboxyterminal telopeptide of type I collagen (ICTP) were measured, as were serum calcium, parathyroid hormone and osteocalcin. Serum PICP and ICTP reflect synthesis and degradation of type I collagen, respectively and mainly bone collagen metabolism. A significant increase of ionized calcium and lactate was noted while PTH and total serum calcium did not change. No significant alterations of either ICTP, PICP or osteocalcin were registered. We conclude from this study that the short-term maximal work performed by means of the modified Wingate test failed to show any significant changes in bone metabolism (osteocalcin and metabolites of type I collagen). A short experimental period and lactacidosis might contribute to the unaltered bone metabolism. The results mainly indicate that there is no pool of bone biochemical markers in young athletic males that is washed out by short bursts of intense exercise.

Acidosis, Lactic↗
PubMed1994

Preoperative local infiltration with ropivacaine for postoperative pain relief after cholecystectomy.

In a randomized, double-blind, placebo-controlled trial, we evaluated the use of preoperative local anesthesia with regard to postoperative pain. Before surgery in 66 patients scheduled for cholecystectomy, the abdominal wall along the proposed line of incision was infiltrated with 70 mL of 0.25% ropivacaine, 70 mL of 0.125% ropivacaine, or 70 mL of saline. Wound pain at rest, wound pain during mobilization, and pressure exerted to reach maximum pain tolerance were assessed after 6, 26, 50, and 74 h and after 7 days. Consumption of analgesics was recorded. At the 6-h assessment, there was a statistically significant dose-related decrease in wound pain during mobilization (P = 0.001) and an increase of pressure exerted to reach maximum pain tolerance (P < 0.001). The tests were two-tailed and performed at a significance level of P < 0.05. There were no significant differences between the groups at later pain control assessments. The median time to first request for postoperative analgesics was significantly shorter (P = 0.014) in the saline group than in the ropivacaine 0.25% group. These effects are suggested to be a residual anesthetic effect of ropivacaine. The study gives no support to the hypothesis that preoperative local anesthetics dampen the inflammatory response and ensuing hyperalgesia.

Acetaminophen↗
PubMed1992

Muscle strength is improved after parathyroidectomy in patients with primary hyperparathyroidism.

Fatigue and muscular weakness are prevalent symptoms in patients with primary hyperparathyroidism. This study examined muscular strength before and after operation in a group of eight patients with hyperparathyroidism and in a control group of seven patients with benign thyroid lesions. The maximum power grip, pronation and supination, and endurance for the same muscular movements, were studied by means of a computer program. Patients with hyperparathyroidism had impaired muscular strength compared with the controls but 12 months after operation a significant improvement of all muscular performance was observed. No such improvement was detectable among the controls. There was no correlation between the levels of serum calcium and parathyroid hormone and the measurements recorded before and after operation. Muscular impairment in hyperparathyroidism is measurable by an objective technique. Improvement occurs after surgery.

Adult↗
PubMed1991

Plasma and urinary amino acids as indicators of proximal tubular function in primary hyperparathyroidism.

Nineteen patients with histologically confirmed parathyroid adenomas were studied immediately before and 12 months after operation. The concentrations of 37 amino acids were estimated by chromatography in plasma and urine. In addition, proximal tubular function was studied by measuring the excretion of beta 2-microglobulin. No general aminoaciduria was registered either before or after operation but there were variations between preoperative and postoperative values in the plasma and urinary concentrations of a few amino acids. There were no correlations between preoperative and postoperative concentrations of calcium, parathyroid hormone or the various amino acids in plasma or urine. Nor was there any between the fall in serum calcium and the concentrations of the amino acids. There was no correlation between glomerular filtration rate and the amount of the different amino acids filtered. beta 2-Microglobulin excretion was normal both before and after operation in all but one patient. Aminoaciduria does not seem to be present in primary hyper-parathyroidism. Plasma and urinary concentrations of amino acids were unchanged after parathyroidectomy and proximal tubular function, assessed by measuring concentrations of amino acids in plasma and urine and urinary excretion of beta 2-microglobulin does not seem to be affected in primary hyperparathyroidism.

Adult↗