S.-O. Hietala

Impact of gastrointestinal dysfunction on survival after liver transplantation for familial amyloidotic polyneuropathy.

Liver transplantation is the only effective treatment of familial amyloidotic polyneuropathy type I (FAP). The aim of the present investigation was to identify factors at the time of submission for transplantation that had impact on survival, with special reference to gastrointestinal disturbances. All 28 liver-transplanted FAP patients evaluated at Umeå University Hospital were included in the study. A modified body mass index was used to assess nutritional status. Intestinal examinations were performed to diagnose bile acid malabsorption, gastric retention, and bacterial contamination of the small bowel. A significantly improved survival rate was found for patients in a good nutritional state (P=0.002). Peripheral neurological symptoms were unrelated to survival, whereas increased mortality was found for patients with bile acid malabsorption (P<0.05). Bacterial contamination and gastric retention were common complications of the disease. In conclusion, malabsorption and malnutrition have a profound impact on the outcome of liver transplantation for familial amyloidotic polyneuropathy.

Evaluation of single sample clearance calculations in 902 patients : A comparison of multiple and single sample techniques

Purpose: To derive new formulae for the calculation of single sample clearance of the contrast medium iohexol and to compare the formulae to a selection of existing single sample clearance formulae derived for the calculation of 51Cr-EDTA and 99mTc-DTPA clearance. Material and Methods: Glomerular filtration rate (GFR) was calculated from total plasma clearance of iohexol used for urography in 902 patients. Two plasma samples were drawn in each patient. Automated x-ray fluorescence analysis equipment was used for the plasma iodine analysis. Single and multiple sample iohexol clearance values were compared. In 77 patients the multiple sample clearance values were additionally compared to a 51Cr-EDTA clearance performed simultaneously or within 14 days. Results: The precision of the results calculated by the existing single sample clearance formulae and the derived iohexol single sample clearance formulae were essentially the same. The most precise of the derived formulae was that based on the Bak Christensen & Groth formula. The correlation between multiple sample clearance of iohexol and 51Cr-EDTA was high (r=0.918) Conclusion: Iohexol can substitute 51Cr-EDTA for GFR measurement. A valid GFR can be calculated from a single plasma sample determination of iohexol clearance using either the existing formulae or the new formulae derived from the present study.

Systemic, pulmonary and renal haemodynamic effects of intravenously infused iopentol : a comparison in the pig of a new low osmolar non-ionic medium with saline and iohexol

The central, peripheral and renal haemodynamic effects after intravenous infusion (1 ml/s) of high doses (4 mg I/kg) of two low osmolar, chemically and physically similar non-ionic contrast media (iohexol and iopentol) were investigated in 16 pigs. Both contrast media induced a significant increase of mean arterial, mean right atrial, mean pulmonary arterial and mean pulmonary arterial occlusion pressure along with an increase in cardiac output. The systemic vascular and pulmonary vascular resistances were decreased. Renal venous blood flow and renal vascular resistance were not significantly changed after infusion of contrast media. There were no differences in haemodynamic effects between the two media studied.

Scintimetry after total knee arthroplasty. Prospective 2-year study of 18 cases of arthrosis and 15 cases of rheumatoid arthritis.

33 consecutive patients (18 arthrosis, 15 rheumatoid arthritis), operated on with total knee arthroplasty and randomized to cemented (18 knees) or cementless fixation (15 knees), were investigated with scintimetry 3, 6, 12, and 24 months postoperatively. Migration was evaluated with simultaneous roentgen stereophotogrammetric (RSA) examinations. The scintimetric activity in the ipsilateral femoral diaphysis decreased and the activity in the tibial diaphysis increased during the observation period. Constant and low activity was recorded in front of the femoral component. This region was chosen as a reference. Three months after surgery, high activity was noted under the tibial component in knees with a preoperative varus deformity. After 2 years, the activity had decreased to the same level as in the patients with a valgus deformity. Diagnosis and mode of fixation did not influence the activity. Low postoperative activity was recorded in the tibial metaphyses if no rotatory displacement of the tibial component occurred.

Low field magnetic resonance imaging of femoral neck fractures.

Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with 99Tcm-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio <1.0) developed radiographic signs of femoral head necrosis. MR disclosed the definite area of the necrosis at 2 and 12 months after fracture, respectively. In three of the patients with a high scintimetric uptake (femoral head ratio ≥1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several months.

Systemic and pulmonary haemodynamic effects of intravenous infusion of non-ionic isoosmolar dimeric contrast media. An investigation in the pig of two ratio 6 contrast media.

The systemic and pulmonary haemodynamic effects of i.v. infusion (1 ml/s) of high doses (4 ml/kg) of 2 non-ionic, isoosmolar dimeric contrast media (CM) were investigated in 17 female pigs. The 2 CM were iodixanol and iotrolan. Both CM induced a significant increase of the following parameters: mean arterial, mean right atrial, mean pulmonary arterial, mean pulmonary arterial occlusion pressure, cardiac output, stroke volume, and diuresis. The plasma concentration of atrial natriuretic peptide was significantly increased following infusion of the 2 CM. A significant decrease was seen in the systemic and pulmonary vascular resistance.

In Vivo Fluorescence Microscopy of Microcirculation in the Renal Cortex of Mice Part I. An Experimental Model for Contrast Media Studies

An experimental model using in vivo fluorescence microscopy for studies of renal cortical blood flow was tested in 40 mice. The model was suitable for testing a wide variety of hypotheses concerning alterations in renal cortical blood flow, including the possibility of inhomogeneous capillary blood flow distribution in response to i.v. infusions. The experimental model was tested for the effects of i.v. infusion of mannitol (0.3 mol/l). Effects of anesthesia and mechanical kidney fixation on renal cortical blood flow were studied. Neuroleptic analgesia was less hazardous to the animals than pentobarbital. Due to artifacts from respiratory and peristaltic motion, it was not possible to use neuroleptic analgesia without mechanical kidney fixation. A rating scale was designed for evaluating the capillary blood flow. The correlation between repeated ratings by the same observer was 0.806 and between 2 different observers 0.59.

Systemic, pulmonary and renal haemodynamic effects of large intravenous doses of high and low osmolar contrast media: An investigation in the pig of ratio 1.5 and ratio 3 media

The central, peripheral and renal haemodynamic effects of intravenous infusion (1 ml/s) of large doses (4 ml/kg body weight) of non-ionic (iohexol) and ionic (metrizoate and ioxaglate) contrast media were studied in 24 anaesthetized pigs. All contrast media showed marked haemodynamic effects with an increase of mean right atrial pressure, mean pulmonary arterial pressure, mean pulmonary occlusion pressure, cardiac output and stroke volume. The response of the pulmonary circulation to contrast media was a fall rather than a rise in pulmonary vascular resistance. No significant changes were detected in the renal circulation after infusion of contrast media.

Low Dose Pelvimetry with Biplane Digital Radiography

The digital moving slit technique as used by most CT scanners for overview images, was used for antero-posterior and lateral views of the pelvis for pelvimetry. The method was evaluated in phantom experiments and clinical examinations were performed in 23 patients. The method was compared with conventional pelvimetry in 14 patients. Estimated ovarian dose was reduced by a factor of 14.2. The discrepancy in measurements of the pelvic diameters by computed tomography compared with conventional pelvimetry was considered to be without practical importance from an obstetric point of view. Digital pelvimetry is easier for the patient, faster and the need for repeated exposures is eliminated. Based on these facts it is suggested that digital pelvimetry should replace the conventional method whenever possible.

In vivo fluorescence microscopy of microcirculation in the renal cortex of mice. Part II. Effects of mannitol and contrast media infusions.

In vivo fluorescence microscopy was used for experimental studies of renal cortical microcirculation in 46 mice. The cortical circulation was studied after i.v. infusions of mannitol of various osmolalities as well as nonionic low osmolar (iohexol) and ionic high osmolar (metrizoate) contrast media. All infusions produced an increase in the number of capillaries with increased blood flow, significantly more pronounced after the infusion of iohexol, metrizoate and mannitol 1.46 mol/l than after the infusion of mannitol 0.3 mol/l. However, the renal cortical blood flow was inhomogeneous with respect to different capillaries. While the blood flow was increased in some capillaries it was to some extent simultaneously decreased in others, significantly more after infusion of metrizoate than after infusion of mannitol 0.3 mol/l.