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Biomedical subjects

G Nylander

Publications and source records attributed to G Nylander.

At least 127 records · Page 7Linked to original sources
PubMed1980

Kinetics of 51CrEDTA in the rat.

The kinetics of 51Cr EDTA in the rat has been analysed. A single bolus injection after an equilibration period of 30 min, resulted in a steep monoexponential plasma clearance (T 1/2 = 40.8 +/- 4.3 min). To facilitate estimation of the EDTA space, renal clearance was eliminated by renal vascular ligation. The extrarenal clearance of EDTA was very slow (T 1/2 approximately 800 min) according to a linear function. The EDTA space was 25.7 +/- 1.8 ml/100 g body weight. The EDTA space is considered to measure the extracellular fluid volume.

Animals↗
PubMed1980

Experimental colon cancer in the absence of intestinal contents in Sprague-Dawley rats.

The proximal and distal ends of the transverse colons of 16 noninbred Sprague-Dawley rats were severed and stitched to their abdominal walls. The ascending and descending colons were anastomosed end-to-end. The disarticulated colon loop was rinsed 30 times over 15 days to remove all traces of dimethylhydrazine (21 mg/kg body wt) for 27 weeks. When rats were killed 3 weeks later, 4 had invasive carcinomas and 2 had tubular adenomas in the end-to-end anastomosed (function-isolated) colons. Three rats developed invasive carcinomas in the isolated (defunctionalized) colon loops. The carcinogen probably reached the isolated colon loop through the circulation and induced (independently of bile acids) mucosal changes that led to invasive carcinoma.

Adenocarcinoma↗
PubMed1980

Effects of dehydration on plasma water and extracellular fluid volumes in the rat.

Dehydration was induced in rats by depositing 3 ml of hyperosmolar glucose (1670 mOsm/kg) in a closed small bowel loop. The plasma water and extracellular fluid volumes of the whole animal and selected tissues were subsequently studied with 125I human serum albumin and 51Cr EDTA. The fluid accumulation in the bowel was equivalent to 122% of the plasma water volume. The plasma water volume of the whole animal was significantly reduced by 31%, while the extracellular fluid volume reduction by 8% was not statistically significant. The regional extracellular fluid volumes decreased in the lung (9%), the liver (34%), the gastric antrum (15%) and the omental fat (24%). The results show regional differences in tissue response to dehydration.

Animals↗
PubMed1980

Combined radionuclide phlebography and lung scanning in patients operated on for scoliosis with the Harrington procedure.

Iliac vein thrombosis is an uncommon type of deep vein thrombosis (DVT) that occurs in young patients following surgical procedures for scoliosis. The symptomatology is diffuse and this type of DVT carries a risk for fatal pulmonary embolism as well as the development of a postphlebitic syndrome. Combined radionuclide phlebography and lung scanning were performed in 16 patients operated on for scoliosis with the Harrington procedure. In three patients with diffuse pain in the inguinal region, iliac vein thrombosis was easily visualized in the radionuclide phlebogram and confirmed by conventional phlebography in two cases. Six patients without lung symptoms had perfusion defects typical for pulmonary embolism. It is concluded that radionuclide phlebography can be recommended as a diagnostic procedure for iliac vein thrombosis in patients with diffuse symptoms in the inguinal region or the lower abdomen after scoliosis surgery. Advantages include the ease of performance, good patient acceptance and low radiation dose compared with conventional phlebography. Asymptomatic pulmonary embolism as diagnosed by the perfusion lung scan was an unexpected finding which raised clinical considerations that require further investigations.

Adolescent↗
PubMed1980

Retrocaval ureter.

A case of retrocaval ureter is reported taking especially the diagnostic procedure and the therapeutic alternatives into account.

Humans↗
PubMed1979

Deep vein thrombosis after total hip replacement: a clinical and phlebographic study.

Two hundred and forty-seven phlebograms (113 bilateral and 21 unilateral) were performed in 134 patients 10--14 days after total hip replacement. Fifty-eight per cent of the patients were found to have deep vein thrombosis. The patients with DVT were significantly older than patients without DVT, but there was no difference regarding sex, type of hip prosthesis, side of operation or day of mobilization. No difference was found in the duration of operation and anaesthesia, the operative haemorrhage and the amount of bank blood transfused in patients with and without DVT. Fifty per cent of the thrombi were confined to the calf veins. Ninety-seven per cent of these thrombi were asymptomatic and were as frequent on the operated as on the non-operated side. The remaining 50 per cent of the thrombi engaged the thigh with or without simultaneous calf vein involvement. These thrombi produced symptoms in 23 per cent of the cases and were significantly more common on the operated than on the non-operated side. It is concluded that DVT after hip replacement can be of two different types: thrombosis caused by stasis and the general effects of trauma and thrombosis caused by local factors involving the thigh veins of the operated leg.

Aged↗
PubMed1979

The mechanism of lysine-vasopressin hemostasis in bleeding esophageal varices.

The effect of vasopressin on the blood flow through experimentally induced esophageal varices and on the musculature of the lower end of the esophagus has been studied. The blood flow was measured by 85Kr injection into the portal vein and selective recording of the radioactivity of the blood flow through the varices. Simultaneous portography and recording of the portal and arterial blood pressure were performed. Following i.v. administration of vasopressin, there was seen a decrease in portal pressure and transient increase in arterial blood pressure. Simultaneously there was observed a decrease in blood flow through the varices, which were no longer visible at portography, while intra-esophageal pressure was increased. It is concluded that there is a dual mechanism of the effect of vasopressin on bleeding from esophageal varices. It reduces the portal pressure and it contracts the esophageal musculature with resultant compression of the afferent radicles to the submucosal esophageal varices.

Animals↗
PubMed1978

Dynamic radionuclide phlebography. A clinical study in patients after total hip replacement.

Dynamic radionuclide phlebography was performed in 50 consecutive patients after total hip replacement to evaluate the diagnostic value of the method compared to contrast phlebography. The investigation was limited to the diagnosis of iliofemoral thrombi. A special injection technique was developed and flow curves, mean transit time and distribution of flow were recorded with a scintillation camera interfaced to a digital computer. Three principally different types of flow curves were observed. Mean transit time was of value in differentiating particle flow in the superficial veins from passage through the deep veins. Out of 15 legs with thrombi in the iliofemoral region, the distribution of flow was significantly changed in 12. Deep vein thrombosis in the lower leg did not influence mean transit time or distribution of flow in the iliofemora region. Extensive collateral flow was rare. Ninety per cent of the thrombi were asymptomatic. The method compares favorably with the 125 I fibrinogen method and cuff impedance phlebography, in diagnosing iliofemoral thrombi after total hip replacement.

Hip Joint↗
PubMed1978

Localized arterial occlusions in patients treated with pelvic field radiation for cancer.

Five patients, previously treated with pelvic irradiation for cancer of the cervix uteri, ovaries or bladder are presented. They developed occlusions of the distal aorta and/or the iliac arteries 2 to 6 years after irradiation. The presenting symptoms caused by the vascular obstructions were claudication or rest pain. All patients were operated upon with revascularization procedures and thereby relieved from their symptoms. One vascular graft occluded but reoperation was successful. The mechanism by which radiation causes atherosclerosis is discussed. All patients were heavy cigarette smokers. The patients with signs of atherosclerosis outside the irradiated area were the ones with the shortest time interval between radiation and symptoms of ischaemia. It is proposed that irradiation acts synergistically to other atherogenetic factors and this should be kept in mind when radiation therapy is planned in patients with high risk of developing atherosclerosis.

Arteriosclerosis↗
PubMed1978

Experimental studies on fluid pathophysiology in small intestinal obstruction in the rat. I. Effects of intraluminal hyperosmolality.

An experimental model is described which is intended to simulate and accentuate the movement of fluids across the intestinal mucosa resulting from simple small intestinal obstruction as well as to provide a means for measuring these fluid shifts. Working on the hypothesis that the increase in fluid in the obstructed small intestine is a consequence of increased osmolality resulting from enzymatic breakdown of the intestinal contents, a solution of high osmolality was introduced into an intestinal segment of known size and position. Under these conditions the intestinal mucosa functioned in the manner of a semipermeable membrane and permitted only fluids of low osmolality to enter the intestinal lumen, thus tending to normalize its hyperosmolal contents. The process of dilution followed a simple dilution curve. At the same time hemoconcentration and increased serum osmolality reflected the mobilization of fluids from the extravascular and vascular compartments. The transfer of fluids into the intestinal lumen continued throughout the test period, despite the fact that there was a linear increase in intraluminal pressure to a relatively high level, indicating increased smooth muscle tone probably due to the hyperosmolal provocation. The observed accumulation of fluid was well reproducible and associated with predictable effects on the vascular and extra-vascular compartments.

Animals↗
PubMed1978

Experimental studies on fluid pathophysiology in small intestinal obstruction in the rat. II. Effects of intraluminal hyperosmolality and simultaneous intravenous infusions.

Using an experimental model in rats a hyperosmolal glucose solution was introduced into the intestinal lumen to simulate and magnify the accumulation of fluid seen in simple small intestinal obstruction. Efforts to modify the extent and rate of this fluid flux by administering parenteral solutions of varying osmolality produced no result. When hypoosmolal or iso-osmolal infusion solutions were used, the intraluminal dilution process displayed mathematical characteristics in agreement with those of a simple dilution process, while at the same time normal blood volume was maintained. On the other hand, when a hyperosmolal glucose solution was infused, very great demands were made on the extravascular compartment, because a severe diuresis equal in volume to the fluid given parenterally took place, while at the same time there was marked hemodilution. Despite this the organism delivered as much fluid to the intestine as when hypo-osmolal or iso-osmolal infusions were given. Thus in principle the flow of fluid into the intestinal lumen could not be modified by giving parenteral solutions of any osmolality.

Animals↗
PubMed1978

Experimental studies on fluid pathophysiology in small intestinal obstruction in the rat. IV. Effects of intraluminal hyperosmolality and simultaneous intravenous infusions on mucosal micromorphology.

A hyperosmolal glucose solution was introduced into a loop of small intestine of specified length and position while intravenous infusions of varying osmolality were given at the same time. The hyperosmolal solution in the lumen caused damage primarily to the tips of the villi where sloughing of the epithelial cells was frequently seen. These defects were repaired by an increase in surface coverage by neighboring epithelial cells, which thus were reduced in height. A varying degree of edema was generally seen in the epithelial cells. The severity of these lesions was modified by intravenous infusions in inverse relationship to the osmolality of the infusions. Thus the defence mounted by the intestinal mucosa against the hyperosmolal solution in the lumen was impaired by the infusion of hypo-osmolal solutions and improved by hyperosmolal solutions. In the latter cases the mucosa maintained a practically normal histological picture.

Animals↗
PubMed1978

Experimental studies on fluid pathophysiology in small intestinal obstruction in the rat. III. Effects of intraluminal iso-osmolality and simultaneous intravenous infusions.

The introduction of a hyperosmolal glucose solution in the intestinal lumen in an experimental model using rats resulted in the accumulation of large quantities of fluid in the lumen, resembling the situation in simple obstruction of the small intestine. To establish whether the osmotic strength of the glucose solution caused this influx of fluid, or whether the volume of the fluid per se is a contributory factor, an identical amount of an iso-osmolal and largely non-resorbable substance was introduced in place of the hyperosmolal glucose solution. No influx of fluid into the intestinal lumen could be demonstrated even when large infusions of varying osmolality were given intravenously. The osmolality of the intestinal contents remained unchanged as well as the intraluminal pressure. Despite the massive infusion of fluids, the hematocrit remained relatively stable, thus indicating stable blood volume and demonstrating the enormous storage capacity of the extravascular compartment.

Animals↗
PubMed1978

Experimental studies on fluid pathophysiology in small intestinal obstruction in the rat. V. Effects of intraluminal hyperosmolality and simultaneous intravenous infusions on the experimentally obstructed and decompressed small intestine.

An influx of fluid into the lumen of the intestine similar to that seen in simple obstructional ileus may be provoked by introducing a hyperosmolal glucose solution into the bowel. In the otherwise intact small intestine the effect of this influx of fluid will be in accordance with a simple dilution curve. The intestinal mucosa thus functions in the manner of a semipermeable membrane permitting only hypo-osmolal fluids to enter the intestinal lumen and in amounts independent of parenteral fluid infusions, regardless of osmolality. This relationship persists even after the intestine has been totally obstructed for 3 days. The influx of fluid has the same principal characteristics, and the only limiting factor on the magnitude of this fluid shift to the intestine is the lack of fluids resulting from the marked dehydration of the organism due to ileus. Prerequisites for this are normal epithelial function and normal mucosal circulation. Thus it is clear that the organism in general and the small intestine in particular, even when exposed to prolonged obstruction, are still able to counteract intraluminal hyperosmolality by dilution with hypo-osmolal fluid.

Animals↗
PubMed1977

Renal revascularization after splenic artery implantation into the kidney. Consecutive serial angiographic study in the dog.

29 mongrels were subjected to splenic artery implantation into the left kidney. Consecutive angiographies showed that this procedure regularly was followed by an initial thrombus formation in the implanted artery and an early recanalization of this thrombus. After creation of stenosis and eventually occlusion of the left renal artery, newly formed intrarenal vessels could be demonstrated next to the implanted artery. These vessels formed communications between the splenic and intrarenal arteries. At angiography of the implanted splenic artery the constrast medium was seen to pass over to the newly formed vessels and to intrarenal arteries followed by contrast medium opacification of the renal parenchyma and the renal vein and excretion to the pelvis and ureter. The experimental animals survived contralateral nephrectomy and ligature of the ipsilateral renal artery provided that a slowly progressing stenosis of this artery was created.

Animals↗