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G Svensson

Publications and source records attributed to G Svensson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Spinal cord protection by papaverine and intrathecal cooling during aortic crossclamping.

AIM: To extend the safe period of aortic crossclamping in the porcine model by intrathecally dilating the spinal arteries, with cooling of the spinal cord, or using selfoteL METHODS: Experimental design and setting: prospective domestic laboratory pig study. INTERVENTIONS: fifteen animals were assigned to a control group (C, N=5), intrathecal papaverine plus spinal cord cooling group (IP+C, N=5), or selfotel group (S, N=5). In the IP+C group, a lumbar laminectomy was performed and an intrathecal catheter placed for intrathecal injection of papaverine and perfusion with cold Ringer's solution (4 degrees C) prior to aortic crossclamping. In the selfotel group, 20 mg/kg of selfotel was administered 30 minutes before aortic crossclamping. In all 15 animals, the aorta was crossclamped for 60 minutes at normothermia. MEASURES: immediately after the operation and 24 hours later, lower limb function was evaluated. RESULTS: All five control animals were paralyzed; all 5 IP+C animals could stand or walk (p=0.004 versus control); and in the selfotel group, one had paraparesis, three had paraplegia and one died before evaluation (p=n.s.) CONCLUSIONS: The combination of intrathecal papaverine to dilate spinal arteries and prevent spasm from the cold solution plus intrathecally cooling the spinal cord appears to extend the period of safe aortic crossclamping. Selfotel, in this model of extended, severe, spinal cord ischemia, was ineffective.

Administration, Topical↗
PubMed1997

Addition of alpha-ketoglutarate to blood cardioplegia improves cardioprotection.

BACKGROUND: We hypothesized that myocardial content of alpha-ketoglutarate (alpha-KG), an intermediate of the Krebs cycle, can be critically low during heart operations, and that provision of alpha-KG could reduce metabolic abnormalities and lead to improved myocardial protection. METHODS: Twenty-four men aged 46 to 78 years who were undergoing heart operations participated in a prospective, controlled, randomized study. In 13 patients, an average of 28 g of alpha-KG was added to blood cardioplegia. Plasma creatine kinase isoenzyme MB and troponin T, and myocardial extraction of oxygen, substrates, and amino acids were measured. RESULTS: alpha-Ketoglutarate treatment was associated with lower creatine kinase isoenzyme MB (F = 39.6, df = 1.172, p < 0.001) and lower troponin (F = 12.9, df = 1.172, p < 0.001). The values at 4 hours were 31 +/- 2.4 microg/L versus 49 +/- 4.9 microg/L (creatine kinase isoenzyme MB) and 1.1 +/- 0.05 microg/L versus 2.0 +/- 0.34 microg/L (troponin T). Myocardial oxygen extraction was higher during alpha-KG cardioplegia (p < 0.01), but there were no significant differences in myocardial uptake or release of substrates or amino acids. Lactate release was observed in both groups during cardioplegia. Myocardial lactate release had ceased after 30 minutes of reperfusion in nearly half the alpha-KG-treated patients (6 of 13) but remained in all the control patients (11 of 11, p = 0.016). There were no other differences after 30 minutes of reperfusion. CONCLUSION: Provision of alpha-KG during blood cardioplegia improves myocardial protection in patients undergoing coronary operations. This may be linked to enhanced oxidation.

Aged↗
PubMed1996

Occupational dermatoses in a Swedish aircraft plant.

A survey of occupational dermatoses, based on a questionnaire, clinical examination and patch testing, was carried out among 341 workers in an aircraft plant. The questionnaire was answered by 330 workers (96.8%). Present or previous skin disease was reported by 92 employees, who were all subjected to physical examination and patch testing. Patch testing was conducted with a standard series, as well as with a series of substances and products representing the work environment. Occupational contact allergies were established in 12 employees. In total, the figure for occupational skin diseases was 16.1% (55 workers), when calculated for all employees.

Adult↗
PubMed1995

Alpha-ketoglutarate for myocardial protection in heart surgery.

A low myocardial content of alpha-ketoglutarate during heart surgery might aggravate ischaemic injury. 24 men undergoing coronary surgery participated in a randomised controlled study. 28 g alpha-ketoglutarate was added to blood cardioplegia for intermittent antegrade intracoronary perfusion in 13 cases. alpha-ketoglutarate reduced the appearance in blood of the ischaemic markers creatine kinase MB and troponin T (at 4 h after release of aortic cross-clamp; median [95% CI] 49 [37-60] micrograms/L in controls vs 32 [27-37] micrograms/L for creatine kinase MB, 2.0 [1.2-2.8] vs 1.1 [0.8-1.4] micrograms/L for troponin T). These findings signify attenuated ischaemic injury, possibly secondary to enhanced myocardial oxidative capacity.

Aged↗
PubMed1995

Influence of liver transplantation and cyclosporin on bile secretion--an experimental study in the rat.

Bile secretion is reduced after liver transplantation. It has been suggested that this is due either to the effect of cyclosporin or to the damage to the liver graft during preservation and reperfusion. The aim of this study was to explore the influence of cyclosporin as well as of liver transplantation on bile secretion. Bile flow was studied in an experimental model in the rat. In syngeneic liver-transplanted animals, the bile flow was increased compared to the bile flow in the control group (1.29 +/- 0.09 ml/h vs 0.66 +/- 0.03 ml/h; P < 0.01), mainly due to an increased bile acid-independent flow (0.76 ml/h vs 0.50 ml/h; P < 0.01). The findings in the liver-transplanted rats contrasted with those in a group of nontransplanted animals treated with cyclosporin. Cyclosporin treatment resulted in a reduced bile acid-independent fraction (0.37 ml/h vs 0.50 ml/h, P < 0.05) of the bile flow, although no biochemical signs of hepatotoxicity were present. This reduction in the bile acid-independent fraction could, however, not be demonstrated when cyclosporin was given to a group of liver-transplanted rats, although a reduced total bile flow was recorded in the 1st hour measurements. In contrast to previous studies, we found that the cyclosporin vehicle (Cremophor EL), when administered chronically, induced a higher bile flow than that in the control rats. This effect was not seen in the transplanted rats. Our findings in this experimental rat model indicate that cyclosporin will influence and reduce bile secretion and bile acid secretion even if no other signs of liver dysfunction are present. On the other hand, the preservation and reperfusion in this model resulted in an increased bile flow, while bile acid secretion remained constant.

Animals↗
PubMed1995

Hepatocyte and Kupffer cell function after liver transplantation in the rat--in vivo evaluation with dynamic scintigraphy.

In vivo physiological measurements of hepatocyte and Kupffer cell function after liver transplantation are desirable. Orthotopic liver transplantation was performed in 54 rats. Hepatocyte and Kupffer cell function were measured with dynamic liver scintigraphy. Hepatic clearance of 99mTc-Nanocoll (%/min), an albumin colloid phagocytosed by the Kupffer cells, was used to evaluate Kupffer cell function. Hepatic clearance of 99mTc-IODIDA (%/min), an imino-diacetic-acid taken up and secreted by the hepatocytes, was used to evaluate the hepatocyte function. Hepatic clearance in control rats was 27 +/- 2%/min for Nanocoll and 30 +/- 3 %/min for IODIDA. After syngenic liver transplantation, without rejection, there was a rise in Nanocoll clearance (34 +/- 2 %/min p < 0.01) after 3 weeks, but no change in IODIDA clearance (32 +/- 3 %/min N.S.). After syngenic liver transplantation with preservation time prolonged to 16 h, there were no changes in IODIDA or Nanocoll clearance 1 day after transplantation. Both IODIDA (11 +/- 2 %/min) and Nanocoll clearance (22 +/- 2 %/min) were decreased (p < 0.001) during rejection after allogenic transplantation. An in vivo method of measuring the hepatocyte and Kupffer cell function in the transplanted liver is described. Kupffer cell function was increased after syngenic liver transplantation. Kupffer cell and hepatocyte function were decreased during rejection. Dynamic liver scintigraphy seems a suitable procedure for examining liver injury after liver transplantation in the experimental setting.

Alanine Transaminase↗
PubMed1994

Quantitative measurements of collateral arterial blood flow in nonarterialized rat liver grafts.

The early development of arterial blood flow in the grafted liver after orthotopic liver transplantation in the rat without reconstruction of the hepatic artery was studied. Arterial liver blood flow was measured on day 21 after transplantation with NEN-TRAC microspheres (size 15.5 +/- 0.1 microns) and labelled with 103Ru. The arterial liver blood flow in the grafted liver was 0.778 +/- 0.247 ml/min per gram for transplanted rats after 21 days. One day after transplantation, the blood flow was only 0.006 +/- 0.002 ml/min per gram. The results of this study demonstrate that there was no arterial blood flow on day 1 after transplantation, as expected, but that there was a high arterial blood flow in the transplanted liver by day 21. This was also supported by the angiographic findings. The early development of arterial blood flow via collaterals may account for the excellent results that we and others have attained in orthotopic liver transplantation without rearterialization in the rat.

Animals↗
PubMed1994

Effects of immunotherapy with a purified standardized allergen preparation of Dermatophagoides farinae in adults with perennial allergic rhinoconjunctivitis.

Immunotherapy (IT) was performed for 12 months with a purified and standardized preparation of Dermatophagoides farinae. Twenty adults with rhinoconjunctivitis sensitive to house-dust mite were given IT, and a similar group of 11 patients served as open controls. A total of 512 injections were given. Twenty-eight episodes of allergic side-effects occurred, 13 general and 15 local, most of them during the initial incremental dose period. No severe reactions started later than 30 min after the injection. One patient suffered anaphylactic shock. In this patient, specific antibodies fell immediately, followed by an increase within 1 week. The therapy group improved significantly in relation to the open controls in patients' subjective evaluation of symptoms (P < 0.028) and skin (P < 0.0001) and conjunctival (P < 0.001) sensitivity. Specific IgE increased in controls (P < 0.0001) but not in IT-treated patients during the "mite season"; that is, there was a significant difference in change during the observation period (P < 0.0001). There was also a difference in change of specific IgG between the groups during the first 4-5 months and the whole year (P < 0.0001), but not from 4-5 months to 12 months. In contrast to changes in antibody titers (IgG, P = 0.04), changes in conjunctival (P < 0.01) and especially skin sensitivity (P < 0.005) correlated well with subjective improvement. This implies that the skin prick test and the conjunctival test can be recommended for follow-up of IT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Failure of adenine nucleotide and water content of cold-stored rat livers to serve as graft viability indices for transplantation.

A study was undertaken to determine whether the cellular viability of the liver graft and posttransplantation outcome could the assessed by the graft energy status or change in water content prior to the transplantation procedure. These measurements were performed in a rat liver transplantation model. In a first set of experiments, the time for 50% survival of grafts preserved with UW solution or saline solution was determined. Grafts preserved with UW solution could be cold-stored for 19.9 h and grafted with a 50% success rate. The corresponding figure for saline-preserved grafts was 6.2 h. The energy status and water content of liver grafts preserved with UW solution for 19.9 h and livers preserved with saline solution for 6.2 h were compared. There were significant differences between livers preserved with UW solution and saline solution for ATP (p < 0.01), total adenine nucleotides (p < 0.05), ATP/ADP (p < 0.05) and energy charge levels (p < 0.05). ATP concentrations in the donor livers did not decrease significantly during cold storage when the success rate decreased from 100 to 0% after liver transplantation. The livers preserved with NaCl solution took up water during preservation. In contrast, the water content was reduced slightly in the livers preserved with UW solution and the differences were significant at all times. During cold storage using either the UW solution or saline solution for preservation, there were no significant time-related changes in the water content of the liver graft when the posttransplantation success rate decreased from 100 to 0% after liver transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1993

Six-hour preservation of the isolated working rat heart improved with University of Wisconsin solution.

University of Wisconsin (UW) solution was compared with modified St. Thomas cardioplegic solution for 6-hour preservation of isolated working rat hearts. The hearts (9 in each group) were arrested with the respective solution and stored, still cannulated, for 6 hours at 4 degrees C. After retrograde reperfusion for 30 minutes, antegrade perfusion was begun at constant left atrial and aortic pressures. Following 25 minutes of antegrade perfusion the hemodynamic recovery of the UW-preserved hearts was superior to that of the other hearts (cardiac output 46.0 +/- 4.8% of the preischemic control values in the UW group and 10.0 +/- 6.0% in the St. Thomas group, p < 0.01). The adenosine triphosphate content was significantly higher in the UW-preserved hearts (18.8 +/- 0.9 vs. 14.7 +/- 1.6 mumol/g dry weight, p < 0.05). No significant intergroup difference was found in aspartate aminotransferase leak or tissue glycogen. The study demonstrated both better function and enhancement of high-energy phosphates with UW solution vs. modified St. Thomas solution in isolated rat hearts, although without difference in enzyme leakage or tissue glycogen, after 6-hour preservation.

Adenosine↗
PubMed1992

Kupffer cell and hepatocyte function in rat transplanted liver.

The liver consists essentially of two compartments, parenchymal cells (PC) and non parenchymal cells (NPC) i. e. Kupffer cells, endothelial cells, fat storing cells and pit cells. PC remain after transplantation but NPC are eventually exchanged with host cells. Dynamic liver scintigraphy with albumin colloid, extracted by NPC, and IODIDA, extracted by PC, were tested to evaluate function as determined by clearance rates in these two cellular compartments. Experimental liver transplantation was performed in 15 syngeneic rats. Following transplantation, we performed dynamic liver scintigraphy with 0.5 ml 5 MBq 99mTc-Nanocoll and 0.5 ml 20 MBq 99mTc-IODIDA, 10 s per frame, 30 min for each examination. Percentage clearance rate, per minute was calculated from uptake curves over the liver. Uptake curves were nearly exponential and clearance rates could be estimated from a logarithmic plot of uptake versus time. The clearance rate was 25 +/- 4% per min (mean +/- SD) for NPC and 32 +/- 15% per min for PC in controls. After liver transplantation it was 31 +/- 7% per min for NPC and 30 +/- 15% per min for PC. Dynamic liver scintigraphy with 99mTc-Nanocoll and 99mTc-IODIDA alloweds a separate assessment of the function of PC and NPC after experimental liver transplantation in rats.

Animals↗
PubMed1992

Tricuspid valve insufficiency as a complication of endomyocardial biopsy.

The purpose of this study was to investigate the occurrence of major tricuspid insufficiency caused by endomyocardial biopsy in heart transplant recipients. Endomyocardial biopsy was used for the detection of rejection and Doppler echocardiography was performed at regular intervals. Six of 96 heart transplant patients (6.3%) had sudden appearance of large tricuspid regurgitation, all of which were directly related to a preceding biopsy. Chordal tissue was identified histologically in biopsy samples of all six patients. All patients developed symptoms of right ventricular failure which was confirmed by right heart catheterization. Three patients subsequently underwent valvuloplasty for ruptured chordae tendineae of either of the three leaflets. Two of these three patients were free from symptoms during follow-up, but the third patient developed moderate tricuspid regurgitation and clinical symptoms. It is concluded that endomyocardial biopsy, although it is the most useful tool for detection of rejection, should be used with caution with regard to anatomical structures and the risk of damage to the tricuspid valve must not be neglected. It is also concluded that valvuloplasty of the tricuspid valve can be successfully performed in a transplanted heart.

Adolescent↗
PubMed1992

Mantle irradiation in the upright position: a technique to reduce the volume of lung irradiated in patients with bulky mediastinal Hodgkin's disease.

Many patients with mediastinal Hodgkin's disease radiographically show a wider horizontal width of disease in the supine or prone as compared to the upright position. Yet for most patients mantle treatment in the supine/prone position is still preferable. This position allows good patient immobilization and precise matching between the mantle and paraaortic-splenic pedicle fields that would not be possible in the sitting or upright position. Adequate blocking of the lungs and heart remains possible in the supine position since most patients do not have extensive subcarinal Hodgkin's disease. Even when more extensive disease is present, contoured blocks to protect the heart and lungs can be adjusted to protect a greater portion of normal tissues if the mediastinal nodes respond to treatment. But if sizeable mediastinal disease persists, it may be impossible to protect sufficient heart and lung. Under these circumstances, repositioning the patient upright can shift the configuration of the mass, allowing larger lung blocks to be added. We report the use of a chair to facilitate treatment with mantle irradiation in the upright position for patients whose mediastinal disease when supine is too large to allow adequate blocking of heart and lung. Blocks are made from the initial port films and daily treatment films are taken to confirm an accurate set-up. To avoid excessive dose to the spinal cord, patients who are to receive para-aortic irradiation receive a maximum of 15-20 Gy in the upright position and the remainder of the mantle is given in the supine-prone position. The use of the upright technique allows for the use of radiation in patients who would otherwise be unable to receive adequate doses due to potential lung and cardiac toxicity.

Hodgkin Disease↗
PubMed1992

Monitoring of mite Dermatophagoides farinae allergen-specific IgG and IgG subclass distribution in patients on immunotherapy.

House dust mite D. farinae and Der f II-specific IgG and IgG subclass responses were evaluated in 32 adults with perennial rhinitis undergoing immunotherapy for 1 year by means of IgG-RAST and ELISA. The ELISA method, which is based on subclass-specific monoclonal antibodies, could detect 0.5-1.5 ng/ml of specific antibodies. D. farinae and Der f II-specific IgG4 antibodies increased continuously as immunotherapy proceeded, while total IgG and IgG1 antibodies reached a plateau value 6 months after the start of immunotherapy, followed by a slow decrease during maintenance therapy. During the early phase of treatment the concentration of IgG1 and IgG4 antibodies rose, even though the increase of IgG4 antibodies dominated. The positive clinical outcome as measured by the decrease in conjunctival sensitivity was associated with an increased ratio of specific IgG4/IgG1 antibodies as well as the magnitude of the IgG4 subclass response. Quantitation of IgG subclass antibodies in patients undergoing immunotherapy may be of some clinical value, but the clinical usefulness needs to be demonstrated for each type of allergen and possibly also for each assay system.

Adult↗
PubMed1991

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Costs and Cost Analysis↗
PubMed1991

Effect of rearterialization on short-term graft function in orthotopic rat liver transplantation.

The orthotopic liver transplant model in rats has been very useful for immunological studies. However, differing opinions exist as to whether rearterialization of the graft is necessary for such experiments. Therefore, in this study we evaluated the short-term allograft function when rearterialized was compared to restored venous portal flow only and in situ hepatic artery ligation. The technique of orthotopic liver transplantation in the rat with and without rearterialization of the graft is described in detail. In addition, we evaluated the technical feasibility of sutured vascular anastomosis as compared to the traditional cuff technique. Urea synthesis rate was used as a sensitive marker of integrated liver function, including uptake, synthesis and excretion. Standard liver test of bilirubin, plasma aspergine aminotransferase and alanine aminotransferase were measured. We found no significant differences in the biochemical markers between allografts with portal venous flow only compared to the combination with arterial flow. Autopsy was performed after the biochemical studies at day 14. Histopathological analyses revealed no differences between the two groups of transplanted rats. The patency of sutured anastomoses was in our hands found to be superior to that of the cuff technique, with a success rate of more than 90% in rats with portal venous flow. This rat model in which vascular anastomosis is performed with a running suture technique and without rearterialization seems to be excellent for short-term studies of preservation and liver function after orthotopic liver transplantation.

Anastomosis, Surgical↗
PubMed1991

S-erythropoietin levels decrease in patients with chronic hypoxia starting domiciliary oxygen therapy.

Consecutive determinations of erythropoietin in serum (s-Epo) were made in ten patients with chronic hypoxia starting domiciliary long-term oxygen therapy (LTO). After 24 h of supplementary oxygen treatment there was a fall in the median s-Epo level from 11.3 to 4.4 IU.l-1 (p less than 0.01). The initial decrease in s-Epo in conjunction with oxygen treatment was not sustained after one and three months of LTO. S-Epo levels above the reference range (3.3-13.5 IU.l-1) were found in three patients before and during LTO and in another two patients during LTO. Markedly elevated s-Epo levels were found in two patients with hypoxia and hypercapnia at the time of blood sampling. A significant negative relationship was found between the arterial oxygen tension and the log value for the s-Epo level (r = 0.40, p less than 0.005). The s-Epo levels were found to be normal in half of the measurements in patients using oxygen less than 15 h daily, a fact that indicates that s-Epo measurements are probably not suitable as indicators of compliance with LTO.

Aged↗