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Biomedical subjects

U Nyman

Publications and source records attributed to U Nyman.

At least 91 records · Page 5Linked to original sources
PubMed1985

DNA replication and H5 histone exchange during reactivation of chick erythrocyte nuclei in heterokaryons.

Fusion of terminally differentiated chick erythrocytes (CE) with replicating quail myoblasts or established L6J1 rat myoblasts results in reactivation of DNA synthesis in the dormant CE nuclei and in suppression of DNA synthesis in the myoblast nuclei. The nuclei of primary quail myoblasts are more effectively inhibited than the nuclei of established rat myoblasts. Inhibition of DNA replication occurs not only by preventing G1 nuclei from entering S-phase but also by blocking nuclei in S-phase and by delaying nuclei in G2 from undergoing mitosis and starting a new DNA replication cycle. No inhibition of DNA synthesis could be observed when mouse erythrocytes, i.e., erythrocytes lacking nuclei, were fused with rat myoblasts to generate mouse-globin-containing L6J1 cybrids.--Reactivation of CE nuclei is associated with a loss of the tissue-specific H5 histone variant. Complete elimination of H5 histone, however, does not seem to be a necessary prerequisite for the initiation or completion of DNA replication in CE nuclei since H5 antigens are found on reactivated G1, S, and G2 nuclei.

Animals↗
PubMed1985

Contrast media for CT. An analysis of the early pharmacokinetics.

Iohexol and meglumine-sodium diatrizoate were injected intravenously into 18 pigs as either a 99:1 or 1:99 mixture. Blood samples were taken for 30 minutes and the concentration of each of the two contrast media was measured by means of a double labeling technique with 125I and 131I. Relative concentrations of iohexol were significantly higher during the first 3 minutes when it was injected as a moderately hyperosmolar (99% iohexol) solution than when it was injected as a very hyperosomolar (99% diatrizoate) solution. The greater intravascular dilution of the 99% diatrizoate solution by extravascular water may explain this finding as well as the significantly longer rapid disposition phase and the slightly lower distribution volume of iohexol.

Animals↗
PubMed1985

Contrast enhancement of the liver and blood. Nonionic versus ionic contrast media in the pig.

The contrast enhancement of low-osmolality (iohexol) and high-osmolality (diatrizoate) contrast media was compared in 18 pigs following intravenous bolus administration. Liver and blood attenuation and blood sample iodine concentration were measured during the first 3 minutes after injection. Iohexol produced a significantly higher contrast enhancement in the blood during the period from 0.5 to 3 minutes after injection. Diatrizoate produced a significantly higher contrast enhancement in the liver during the period from 9 to 30 minutes after injection. The greater contrast enhancement of iohexol during the acute phase should be advantageous in dynamic CT.

Animals↗
PubMed1984

Changes in nuclear antigens during reactivation of chick erythrocyte nuclei in heterokaryons.

Reactivation of dormant chick erythrocyte (CE) nuclei was studied by fusing chick red cells with rat myoblasts, HeLa cells, and chick fibroblasts. Heterokaryons representing different stages of nuclear reactivation were fixed and examined for nuclear antigens using polyclonal patient autoantisera reacting with mammalian (human, mouse, and rat) nuclear envelope, nucleoplasm, and chromatin (DNA) antigens. Reactivation of CE nuclei was associated with marked changes in nuclear antigenicity. In rat myoblast and HeLa heterokaryons the CE nuclei acquired mammalian nucleoplasmic and nuclear envelope antigens in the corresponding nuclear subcompartments. Drastic changes in nuclear antigenicity were noted also in heterokaryons stained with DNA antisera. The compact chromatin of nuclei in mature chick erythrocytes showed little binding of DNA antibodies. Isolated nuclei on the other hand gave a strong immunofluorescence. CE nuclei in heterokaryons were strongly positive during the early stages of nuclear reactivation but then exhibited decreased reactivity. An unexpected finding was a marked reduction in the capacity of mammalian nuclei in heterokaryons to bind DNA-antibodies. This observation is discussed in relation to the previous finding that in CE-heterokaryons these nuclei often show reduced transcription and replication. The present results indicate that in heterokaryons both types of nuclei exchange macromolecules of regulatory importance via the common cytoplasm.

Animals↗
PubMed1984

Computed tomography of malignant lymphoma of the brain.

Correct diagnosis of malignant lymphoma of the brain and differentiation from malignant glioma, metastases, meningeoma and infection is often difficult. With the aim of finding characteristics pointing to the correct diagnosis all CT examinations from 16 patients with primary or secondary lymphoma of the brain were analysed. In 3 of 10 patients with primary lymphoma and 4 of 6 with secondary lymphoma the tumors were multiple. No differences between the CT appearance of primary and secondary lymphoma were found except that secondary lymphomas were generally smaller and more often multiple. The lymphomas were most often well demarcated, had a density equal to or slightly higher than normal brain tissue, were surrounded by no or slight edema and showed a moderate to marked contrast enhancement. The tumors were situated in the basal ganglia, corpus callosum or cerebellum in high frequency and were always in contact with either the ependyma of the ventricles or the superficial subarachnoid space. A tumor with widespread infiltration of the surroundings of the ventricles seen in 6 patients in the material is highly characteristic of lymphoma.

Adult↗
PubMed1984

E-Z-CAT. An oral contrast medium for use in computed tomography of the abdomen.

A new barium sulphate suspension, E-Z-CAT, for use as an oral contrast medium at computed tomography of the abdomen has been compared with the commonly used water-soluble iodinated contrast medium Gastrografin as regards patient tolerance and diagnostic information. The investigation was conducted as an unpaired randomized single-blind study in 100 consecutive patients. E-Z-CAT seems to be preferred because of its better taste, its lesser tendency to cause diarrhoea, and for usage in patients who are known to be hypersensitive to iodinated contrast media. The diagnostic information was the same for both contrast media.

Administration, Oral↗
PubMed1984

Intravenous computed tomographic cholangiography in acute cholecystitis. A comparison with conventional cholangiography.

Forty-nine patients with clinical signs of acute cholecystitis underwent conventional and computed tomographic cholangiography. Among 39 patients with signs of contrast medium in the biliary system at both examinations there was a diagnostic discrepancy in only one patient. Conventional radiography demonstrated cholecystopathy in this patient while contrast medium in the gallbladder and an acute pancreatitis were found at computed tomography. Ten patients with an indeterminate conventional cholangiography had a conclusive computed tomographic examination. Twenty of 30 patients with an abnormal computed tomographic cholangiography underwent cholecystectomy and all had diseased gallbladders. All 17 patients with histopathologically confirmed acute cholecystitis had signs of subserosal edema and/or changes in the omental fatty tissue adjacent to the gallbladder at computed tomography. A layer of tissue of water-density adjacent to the gallbladder and/or changes in omental fatty tissue were also seen in one patient with congestive heart failure and in one with a penetrating duodenal ulcer. None of the 19 patients with a normal computed tomographic cholangiography had a proven acute cholecystitis.

Acute Disease↗
PubMed1984

Tolerance and biochemical effects from intravenous injection of ioxaglate in healthy volunteers.

The influence of intravenous injection of ioxaglate (Hexabrix, 320 mg I/ml) on various biochemical, coagulation and fibrinolytic parameters, fractionated plasma proteins, precordial ECG and blood pressure was prospectively and sequentially studied in 9 healthy volunteers. One ml/kg body weight of the contrast medium was injected within one minute into an antecubital vein. Small, but statistically significant, changes in some of the biochemical parameters were found during the observation period, 2 to 4 days. All values of the biochemical parameters were, however, within the normal reference range for each parameter. No significant alterations were seen in the coagulation parameters. Increased fibrinolysis was recorded in some subjects both before and after the injection. No fibrinolytic degradation products were found indicating that the fibrinolysis was nominal. No significant changes were observed in the fractionated plasma proteins. The heart rate decreased significantly 15 seconds after commencing the injection. No significant changes in blood pressure were recorded. Two participants became nauseated and one of them vomited during the injection. Apart from this, no adverse effects were noted. No clinically significant changes following the injections were found.

Adult↗
PubMed1984

Reversible renal insufficiency after percutaneous transluminal angioplasty (PTA) of renal artery stenosis.

Three patients developed reversible renal insufficiency after successfully performed PTA at the same time as their hypertension was beneficially influenced. The main cause of this complication probably is toxic effects of contrast medium in combination with the temporary occlusion of the renal artery during the PTA of kidneys with previously damaged parenchymal and impaired perfusion. During the phase of renal insufficiency contrast medium retention in the renal cortex was noted at computed tomography.

Acute Kidney Injury↗
PubMed1984

Ultrasonography in complications of renal transplantation.

The reliability of ultrasonography in detecting complications of renal transplantation was investigated by reviewing the ultrasound examination on 78 renal transplants. The results of the ultrasound examinations were correlated with all available clinical, laboratory, radiographic, scintigraphic, and histopathologic data. With the exception of one urine leak no extrarenal complications of clinical significance, such as hydronephrosis, urine leak, lymphocele or hematoma were overlooked at ultrasonography. The exact nature of fluid collections was, however, only seldom accurately assessed unless fine needle biopsy was used. The accuracy in detecting both acute and chronic rejection was high with ultrasonography and a normal ultrasonography of a non-functioning kidney was a strong indication of acute tubular necrosis. Ultrasonography was very sensitive in detecting early acute rejection but was of less value in diagnosing repeated acute rejections with short intervals and in monitoring the response of treatment as the sonographic changes of rejection disappeared slowly.

Acute Kidney Injury↗
PubMed1983

Recognition of gas in gallstones in routine computed tomograms of the abdomen.

In a consecutive group of 1,067 noncholecystectomized patients referred for computed tomography including the upper abdomen, gallstones were seen in 13%. In 4% of the patients with gallstones, gas-containing calculi were found. On reviewing the conventional plain films such stones were revealed in less than one-half of the patients.

Cholelithiasis↗
PubMed1982

Computed tomography in the diagnosis of complications following renal allograft surgery.

Computed tomography was used in a consecutive series of 74 transplantations in the diagnosis of complications to renal allograft surgery. Thirty-nine peritransplant fluid collections were demonstrated, 13 of these were subjected to surgery. A diagnosis of the specific nature of the fluid collection was possible in cases of urine leakage and fresh hematomas. The method was sensitive in defining the size of the renal pelvis though differentiation between postrenal obstruction and large non-obstructed collecting system was not always possible. The cause of postrenal obstruction could be identified in 5 patients out of 10. Renal infarctions were diagnosed in 8 patients. Computed tomography seems to be a highly accurate method in the diagnosis of complications to renal allograft surgery. The method can be used independent of transplant function and the use of contrast medium is necessary only to verify urine leakage and infarction.

Adolescent↗
PubMed1982

Pain and hemodynamic effects in aortofemoral angiography. Clinical comparison of iohexol, ioxaglate and metrizamide.

Two new contrast media, iohexol (non-ionic monomer) and ioxaglate (monoacidic dimer), were compared with the non-ionic metrizamide during aortofemoral angiography in a single blind randomized trial in 2 groups of patients with 20 in each. The degree of heat and pain produced by iohexol and ioxaglate did not differ significantly from that produced by metrizamide, while subsequent injections of metrizoate caused significantly more heat and pain. The hemodynamic effects recorded in 10 patients in each group showed that iohexol and ioxaglate induced a decrease in vascular resistance, decrease in blood pressure and increase in heart rate not differing significantly from that induced by metrizamide.

Aged↗
PubMed1982

Hepatic telangiectasia in Osler's disease treated with arterial embolization. Report of 2 cases.

Hepatic hereditary telangiectasia in 2 females was treated with hepatic artery embolization. In one patient both peripheral and central arterial occlusion was performed; the patient died of massive gastro-intestinal bleeding for 2 months later. Autopsy showed extensive regions with necrosis in the right liver lobe. In the next patient only central occlusion of the right hepatic artery was performed and the arterio-venous shunting in the left liver lobe left remaining. After a long reconvalescence period the patient recovered completely. It is advocated to centrally occlude only that hepatic artery supplying the most affected parts of the liver in Osler's disease. Thus extensive necrosis with possible ensuing death may be avoided.

Adult↗