Biomedical subjects
G Gadeholt
Publications and source records attributed to G Gadeholt.
[Podophyllin. Systemic poisoning after intracutaneous injection in plantar warts].
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The changing scene of radiology: value of urography as initial examination in infectious and hypertensive disease, hematuria and malignant disease.
Four to 20% positive findings were found in a review of 1913 excretory urographics. Possibly relevant findings were 20% in patients referred for infectious disease, 10% in hypertensive disease, 6% in hematuria and 4% in neoplasms. Urography influenced treatment mainly in the 2 groups with few positive findings. The costs for positive findings may be acceptable in patients with hematuria or suspicion of neoplasms, but are too high in the other groups. Until ultrasonography can replace intravenous urography as the first screening method in upper urinary tract disease, the patient selection for urography in infectious and hypertensive disease should be improved.
Percutaneous fine needle biopsy of abdominal and pelvic lesions: passes necessary for secure diagnosis with fluoroscopy and CT-guidance.
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Percutaneous antegrade dilatation of distal ureteral strictures and obstructions.
Since the first ureteral dilatations in experimental dogs were performed, the technique in human has been accepted and improved over the years. Balloon dilatation has been successful, but it has been very difficult or impossible to force the guide wires through long total strictures, especially those localized distally. In order to recanalize very narrow strictures or total occlusions located in the distal ureter, a modified angiographic technique was developed and tested in 12 ureters in 10 patients.
The cranial base and calvaria index methods applied to Australian aborigine skulls.
Cranial base and calvaria indices were calculated on lateral skull radiographs of Australian aborigines, and compared with the values of one mummy, 4 prehistoric (fossil), and modern Scandinavian skulls. The aborigines had thicker calvarian bone and a lower forehead profile than the mummy and the modern skulls, but a higher frontal calvarium than the fossils. The aborigines may developmentally represent a link between prehistoric and modern man (including the mummy).
A quality study of 35 mm, miniaturization of full-size radiographic film.
Twenty-one radiologists with 6 months--25 years experience judged the quality and the possibilities for the routine use of miniaturized full-size radiographic films for long time archiving. Twenty-eight examinations on full-size radiographs were photographed on 35 mm. film. After mounting in transparent jackets, the miniaturized films were read with enlarging equipment and diagnoses and quality noted. Comparison was later made with the originals. The consensus was that the quality of the miniaturized film was good enough to permit their use for long-term archiving purposes and subsequent comparison with future full-size radiographs. The use of reading equipment was not considered tedious.
Identification of opiates in urine by capillary column gas chromatography of two different derivatives.
A capillary gas chromatographic method is described for the identification and confirmation of morphine, codeine, ethylmorphine and 6-monoacetylmorphine in urine. The method was useful for forensic purposes, as morphine and 6-monoacetylmorphine could be measured together with the legal drugs codeine and ethylmorphine. The legal non-prescription drug pholcodine could be detected together with the metabolites normorphine and norcodeine. After extraction and evaporation the opiates were derivatized with either N,O-bis(trimethylsilyl)trifluoroacetamide or pentafluoropropionic anhydride, and both types of derivative were chromatographed on a non-polar capillary column with a nitrogen-phosphorus selective detector. The use of two chemically different derivatives was found to be necessary for the unequivocal identification of all opiates of interest, which were not all separated as a single derivative. If a mixture of opiates was subjected to the two different derivatization agents, the derivatives were eluted in a different order. This improved considerably the selectivity of opiate analysis in urine. Particularly difficult samples would require mass spectrometric confirmation.
CT staging of early rectal carcinoma.
Of 43 rectal carcinomas, initially presumed to be modified Dukes' stage A or B-1, 42 were examined with computed tomography (CT) prior to endocavitary treatment or surgery in 40 cases. The CT correctly showed 28 patients to have early stages and incorrectly showed 2 to have perirectal extension. Three patients had anal neoplasms. The remaining 10 patients had disease stage B-2 or higher and CT was not good for staging them. A CT scan can fairly accurately stage rectal carcinomas stage A and B-1 grouped together, and is doing better in predicting the prognosis than digital palpation when histologic sections show well or moderately well-differentiated adenocarcinoma of the rectum.
Computed tomographic enhancement of liver and spleen in the dog with iodipamide ethyl ester particulate suspensions.
Particulate suspensions have been developed for use as contrast agents to aid in the detection of hepatic lesions by CT. In several previous rodent studies, the toxicity and tissue concentrations of iodipamide ethyl ester (IDE) particles have been evaluated. The purpose of this study was to determine the pharmacokinetics of IDE in three dogs by evaluation of CT enhancement. Serum chemistry and hematologic parameters after intravenous administration were also followed. A dose of 75 mgI/kg IDE caused an increase of 40-60 Hounsfield units (HU) in liver attenuation, which persisted from 5 minutes to ten hours postinfusion. No enhancement of tissues other than liver and spleen was observed. IDE was completely eliminated from the liver within seven days. A mild transient elevation of liver enzymes may be attributable to the use of barbiturates rather than IDE. A transient depression of the white blood count was the only biochemical or hematologic change that was clearly in response to the infusion of IDE particulates.
Spectral interaction between 4-methylphenol and beta-oestradiol on hepatic microsomal cytochrome P-450: difference between ethanol and phenobarbital pretreatment.
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[Preoperative computed tomography of abdominal aortic aneurysm].
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Complications and results of repeated renal artery doxorubicin infusion in rabbits with VX-2 kidney carcinoma.
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European Congress of Radiology--necessity or luxury?
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Percutaneous fine needle biopsy of abdominal and pelvic lesions. Passes necessary for secure diagnosis with fluoroscopy and CT-guidance.
The number of passes performed at each occasion of biopsy of abdominal and pelvic lesions was recorded in 296 patients. In 178 patients the percutaneous fine needle-biopsy was guided by fluoroscopy (FL), in 118 by computed tomography (CT). At FL correct results were obtained in 73% of the patients, at CT in 91%. The highest accuracy was obtained at biopsy of adrenals, kidneys, ureter and soft tissue masses and the lowest accuracy in the pancreas. 59% of the correct diagnoses were obtained at the first pass at FL, the corresponding figure at CT was 81%. At least 3 passes were necessary for obtaining diagnostic material of the pancreas while for other organs and soft tissue masses 2 passes often were sufficient. In most patients with false negative/inconclusive diagnoses or with non-representative material only 2 passes had been performed.
Mechanisms behind the inhibitory effect of ethanol on the conjugation of morphine in rat hepatocytes.
Liver microsomes were isolated by calcium aggregation, and isolated hepatocytes from male Wistar rats were prepared according to a two-step Ca++-free collagenase perfusion method. With the hepatocytes maximal inhibition of glucuronidation (about 40%) was reached at 10 mM ethanol after incubation at 37 degrees C for 60 min. UDP-glucuronic acid concentration and energy charge in the hepatocytes also did decrease maximally (about 90 and 50%, respectively) and the amount of UDP-glucose was tripled in the presence of 10 mM and higher concentrations of ethanol. The alcohol dehydrogenase inhibitor 4-methylpyrazole abolished ethanol-induced inhibition of morphine glucuronidation in the hepatocytes. Acetaldehyde (250-50 microM) and the pH decrease induced by ethanol did not reduce morphine-3-glucuronide formation by the cells. Cellular uptake of morphine and excretion of morphine metabolites were similar in the absence and presence of ethanol. Ethanol (60 mM) did not affect the glucuronidation of morphine (1.7 mM added) during a 30-min incubation at 37 degrees C with the microsomes (UDP-glucuronic acid, 5 mM). When the concentration of UDP-glucuronic acid in the microsomes was lowered from 1 to 0.1 mM, the decrease in morphine-3-glucuronide formation was similar to that observed in cells. The data indicate that the inhibition by ethanol of morphine glucuronidation was due to decreased levels of UDP-glucuronic acid. The mechanism is likely to be inhibition of UDP-glucose dehydrogenase activity by ethanol from increased intracellular NADH/NAD ratio accompanying ethanol oxidation.
Interstitial fluid pressure and hemodynamics in a sarcoma implanted in the rat tail.
To investigate the influence on tumor blood flow of changes in interstitial fluid pressure (IFP) and tumor perfusion pressure, 0.1 ml of sarcoma cell suspension containing 10(6) cells obtained from ascites fluid was injected in the tail of Lister rats. Experiments were performed 10-35 days after implantation in tumors weighing 0.25-1.5 g. The hydrogen gas washout technique was used for flow measurements in tumor and normal tail tissue, while IFP was measured with the wick-in-needle technique. Control tumor blood flow averaged 0.18 ml/min . g (SD 0.15, N = 21), which was similar to tail skin. The corresponding tumor IFP was 26.6 mm Hg (SD 11.5, N = 21). Interstitial fluid pressure was increased by inflating a cuff at the tail root to 30 and 55 mm Hg and/or by plasma volume expansion by a 5% solution of bovine serum albumin, the latter resulting in a two- to threefold increase in tumor and tail skin blood flow. When the tail cuff was inflated to 55 mm Hg in control rats, mean IFP in tumor rose to 37.6 mm Hg and blood flow in tumor and tail skin fell by 45-70%. Inflating the cuff to 55 mm Hg in plasma volume expanded rats resulted in a rise in mean tumor IFP to 50.5 mm Hg and a reduction of tumor and tail skin blood flow by 40-56%. No change in tumor blood flow was observed after reduction of tail arterial pressure by 25 mm Hg. The experiments show that a high interstitial fluid pressure does not seem to affect tumor perfusion more than the host organ.
11-Deoxycortisol induces hepatic tryptophan oxygenase in rats.
11-Deoxycortisol (cortexolone) has previously been used as a glucocorticoid antagonist in vitro and in adrenalectomized rats. Antiglucocorticoid properties of 11-deoxycortisol in intact rats were examined by studying the effect of 11-deoxycortisol on the induction of hepatic tryptophan oxygenase (TO) by corticosterone. No antiglucocorticoid effect was observed. When 11-deoxycortisol was injected into rats, the TO activity increased. This was probably mainly caused by an elevation of the serum corticosterone level. The induction of TO by 11-deoxycortisol was inhibited by metyrapone. However, 11-deoxycortisol (100 mg/kg) was still not a glucocorticoid antagonist even in presence of metyrapone.