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At least 451 records · Page 25Linked to original sources
PubMed1980

Contribution of radioisotope CAT to the detection of recurrent tumour in the brain.

Two cases are described showing the value of Radioisotope Computerized Axial Tomography in the early detection of tumour recurrence in the brain. The possibility of recurrence could not be excluded from the information provided by the conventional views since the suspicious areas found could be due to post-operative uptake. In the first case, reliable identification of tumour recurrence was provided by the transverse section scan through the suspicious area. In the second case, the transverse scan showed the uptake to be due to previous craniotomy.

Brain Neoplasms↗
PubMed1976

Trace elements analysis in biological samples by radioisotopic x-ray fluorescence.

The X-ray fluorescence technique, induced by radioisotopic sources, provides a very simple method for the simultaneous analysis of trace elements in biological samples. For blood, serum, platelets, etc., samples of about 0.1 ml were deposited on filter paper disks, dried, and analyzed. In such a way the "thin specimen" approximation is realized, resulting in the following advantages: The X-ray intensity of a given element is a liner function of mass per unit area over several orders of magnitude. Interelement effects became negligible. The ratio of fluorescent X-rays to scattered radiation is increased. The sensitivity of the technique for elements with atomic number ranging from about 20-92 varies from some units to some tens of parts per million by weight in 100 s measuring time, by using a gas proportional counter, and from about some tenths to some parts per million by using an X-ray semiconductor detector, in a measuring time of 10(3)-10(4)s. In such a way and with the described features, the Cl, K, Ca, Fe, Cu, Zn, Br content of several speciments of blood and serum was determined. Measurements were further carried out in order to labelling blood components with stable tracers and to detect their concentration by means of the X-ray fluorescence technique. The life span of platelets was, for example, measured after labelling platelets with stable Selenocystine. The sensitivity of the XRF technique can further be enhanced by about three orders of magnitude by using a pre-enrichment step with ion-exchange resins and liquid volumes not lower than 500 ml. Urine analyses have been carried in such a way, and copper in about 20 ml serum after selective extraction.

Blood Platelets↗
PubMed1976

Radioisotope choroid plexography. A preliminary report.

Radioisotope plexography seems as easy and innocuous as routine brain scanning. An introductory method is given which could be improved. The choroid plexuses of the four ventricles were well visualized in 15 patients. Consideration is given to the possible labeling process. Besides its morphological value, the test could give interesting clues in the dynamic study of hydrocephalus.

Cerebral Ventricles↗
PubMed1975

Measurement of gastric emptying time--a comparative study between nonisotopic aspiration method and new radioisotopic technique.

A comparative study between modified conventional saline load test and the more recently introduced radioisotopic method was run in 8 normal volunteers. Each subject underwent at least three studies by each of the two methods: (1) aspiration method of Goldstein and Boyle incorporating our modification, and (2) an isotopic method employing a gamma camera with a computer. A liquid meal of isotonic saline was used with or without (997) MTc-DTPA. The results indicated that the gastric emptying T 1/2 (8.8 +/- 3.5 min) obtained by saline load test was shorter than that obtained by isotopic method (12 +/- 3 min). This discrepancy was most likely due to inherent error (incomplete aspiration of the gastric fluid) in the former method giving rise to a false faster emptying time. Moreover, the variations in T 1/2 value in the same individual was much more in the aspiration method than it was in the isotopic method.

Adult↗
PubMed1975

Radioisotope cisternography in head-injured patients.

Of 600 patients submitted to radioisotope cisternography carried out with radioiodinated human serum albumin (I131-HSA) a group of 140 had head injuries. Our investigation was intended to study the modifications of CSF circulation and absorption which accompany cranio-cerebral trauma. Of 88 head injured patients who did not undergo operation 44 had transient loss of consciouness, and 44 were in prolonged coma. Fifty-two patients underwent operation. Of these 5 had skull fractures with dural lesions, 7 had extradural haematomas, 19 had subdural haematomas, and 21 had brain contusions. Cisternograms were performed at different time intervals after trauma, and in some instances the test was repeated in order to study the possible long tern alterations of CSF circulation and absorption. Abnormalities of cisternographic pictures are classified into the following groups: 1 degree asymmetric diffusion; 2 degree operative cavity stagnation; 3 degree ventricular reflux; 4 degree associated abnormalities. Cisternographic features are analysed in relation to the corresponding clinical and pneumoencephalographic patterns in the patients examined. These investigations may enable us to recognise possible indications for shunt procedures in the management of CSF absorption defects, which are so frequently apparent after head injury.

Brain Injuries↗
PubMedDate not supplied

Cholecystectomy and drainage: ultrasonographic and radioisotopic evaluation.

Eighty patients undergoing cholecystectomy were either assigned deliberately (n = 30) or randomized (n = 50) to drainage (n = 38) or nondrainage (n = 42). Subhepatic collections were seen on ultrasonography (US) after 48 to 72 hours in 12 of 35 patients with drainage and 24 of 42 patients without drainage (p < 0.05). Only two patients with subhepatic collections were symptomatic, and none required treatment. Postoperative infective complications were seen in 13 of 38 patients with drainage and with a collection, and none of the 18 patients without drainage and without a collection had postoperative infective complications (p < 0.05). Cholecystectomy was then performed in 100 patients without using a drain. BULIDA radioisotope scans revealed a bile leak in only 4 of 34 patients studied. Subhepatic collections were seen on US after 48 to 72 hours in 42 patients. The collection resolved in 22 patients and was smaller in 6 on repeat US. None of the patients with collection was symptomatic, and none required treatment. Postoperative infective complications were seen in 7 of 42 patients with a collection and 5 of 58 patients without a collection (not significant). We conclude that (1) cholecystectomy with drainage is associated with more infective complications than when a drain is not used; (2) cholecystectomy without drainage is safe; and (3) asymptomatic nonbilious subhepatic collections are common after cholecystectomy without drainage but do not require treatment, resolving spontaneously.

Adult↗
PubMed1982

Chronic subdural hematoma: reliability of radioisotope imaging versus computed tomography.

25 surgically verified cases of chronic subdural hematoma (CSH) were examined retrospectively. All the patients had been investigated both with computed tomography (CT) and with radioisotope imaging (RI). RI supplied a correct diagnosis in all cases whilst CT yielded a doubtful diagnosis (generic signs of space-occupying lesion) in 5 cases and normal findings (false negative) in one. The clinical use of the two investigations is discussed. The study shows the reliability of RI in the diagnosis of CSH especially when CT determines the site but not the nature of the lesion (hematoma in the isodense phase).

Chronic Disease↗
PubMed1990

Indications for radioisotope bone scanning in staging of cervical cancer.

The total of 160 patients with newly diagnosed invasive cancer of the cervix had whole body radioisotope bone scanning during staging of their disease. 51 patients had cancer of the cervix stage I, 63 had stage II, 34 stage III and 12 stage IV (FIGO). Only in 8 of 160 patients did the bone scans indicate possible metastases and this was confirmed by X-ray examination in only one patient with stage IV disease and liver metastases. We conclude that patients with stage I and stage II carcinoma of the cervix do not need to have bone scans.

Bone Neoplasms↗
PubMedDate not supplied

Diagnostic value of computer-assisted quantitative radioisotope angiocardiography.

The cardiac cavities and large vessels were studied by radioisotope angiocardiography with 99mTc-labelled albumin, using a gamma-camera linked to Med-II, with subsequent digital scanning and analysis by coloured video unit (VDP2) of the areas of iso-activity. The results are illustrated of 8 cases selected from the aggregate case histories of 78 patients (1 normal, 4 congenital heart disease, 2 rheumatic, 1 cor pulmonale chronicum). The direct observation of the course of the bolus and the activity/time curves in areas of interest in the cardiac cavities and the lungs, together with the representation of the areas of iso-activity, were useful for diagnosis and physiopathological evaluation of the heart conditions in the patients.

Adolescent↗
PubMed1995

Negative radioisotope bone scan in a patient with a fractured neck of femur.

Radioisotope bone scanning is a sensitive and specific method of detecting occult fractures of the femoral neck but may occasionally give false negative results. It would appear that patients with renal failure are more likely to have a false negative test and this is probably related to avascularity of the femoral head.

False Negative Reactions↗
PubMed2003

Ultratrace analysis and isotope ratio measurements of long-lived radioisotopes by resonance ionization mass spectrometry (RIMS).

Resonance Ionization Mass Spectrometry (RIMS) is a sensitive and selective method for ultratrace analysis of long-lived radioisotopes and isotope ratio measurements. It provides extremely high isobaric suppression and good overall efficiency. The experimental limits of detection are as low as 10(6) atoms per sample and isotopic selectivities of 5x10(12) have been obtained. The widespread potential of RIMS, using different experimental arrangements, is demonstrated for the determination of the radiotoxic isotopes Pu-238 to Pu-244 and Sr-89/Sr-90 in various environmental samples as well as for Ca-41 in nuclear reactor components and biomedical samples.

Journal Article↗
PubMed2005

[Therapy with radioisotopes in oncology. Palliative and curative approaches].

For more than 50 years now, nuclear medicine has offered therapeutic procedures in oncology. These comprise bone pain palliation in bone metastases of prostate and breast cancer. For more than 20 years now, metaiodobenzylguanidine (mIBG) has been used to treat neuroendocrine tumors. Ten years ago, somatostatin analogues such as Y-90 Dotatoc became available for the treatment of somatostatin receptor-positive tumors. The intracavitary injection of radiocolloids has been well known for 5 decades now and can be used in malignant effusions. Invasive procedures such as intra-arterial injection of I-131 lipiodol may be applied in multifocal, nonresectable hepatocellular carcinoma. Beyond that, intratumoral injection of radioisotopes may be used in cutaneous metastases. Radioimmunotherapy using labeled tumor antibodies is now also available, especially in patients with non-Hodgkin's lymphoma.

Humans↗
PubMed2003

A new method for enzymatic preparation of isopentenyladenine-type and trans-zeatin-type cytokinins with radioisotope-labeling.

We describe a new enzymatic reaction method for the preparation of the radioisotope-labeled cytokinins isopentenyladenine (iP), trans-zeatin (tZ), and their ribosides. The method is based on the three enzyme activities of an adenylate isopentenyltransferase (IPT; EC 2.5.1.27) from Arabidopsis thaliana, an alkaline phosphatase (EC 3.1.3.1) from calf intestine, and a purine-nucleoside phosphorylase (EC 2.4.2.1) from Escherichia coli. The A. thaliana IPT, AtIPT7, utilized both dimethylallyldiphosphate and 4-hydroxy-3-methyl-2-( E)-butenyl diphosphate as isoprenoid donors. The dual specificity of the substrates enabled us to produce iP-type and tZ-type cytokinins separately in the same system simply by switching the substrates. Our method affords a much higher yield of the labeled products than the chemical reaction methods previously used. These labeled compounds will be useful tools for cytokinin research, such as receptor-ligand assays and cell metabolism studies.

Adenine↗
PubMed1976

Noninvasive diagnosis of a false left ventricular aneurysm with radioisotope gated cardiac blood pool imaging. Differentiation from true aneurysm.

Unlike the true left ventricular aneurysm, false aneurysms have recently been shown to be subject to late rupture. Rarely diagnosed before surgery or autopsy, the false aneurysm has never been identified by noninvasive techniques. We report the first such noninvasive diagnosis employing radioisotope gated cardiac blood pool imaging. Due to the unique and possibly life-threatening clinical course and potential for surgical cure of false left ventricular aneurysm, early noninvasive diagnosis by imaging techniques may be critical. The methods shown here are generally applicable, becoming widely available and may help in evaluation of false left ventricular aneurysm as a cause of sudden death.

Aged↗
PubMed1983

Computed tomographic scanning versus radioisotope imaging in adrenocortical diagnosis.

Referral patterns from internists to departments of nuclear medicine or radiology are important determinants of whether adrenal glands are imaged by computed tomography (CT) or by radioisotope scintigraphy. To assist clinicians in making an informed choice, computed tomographic scans were compared with isotope scintigrams using 131I-19-iodocholesterol (19-IC) and 131I-6 beta-iodomethyl-19-norcholesterol (NP-59). In general, imaging techniques serve to localize diseases that are diagnosed on the basis of biochemical tests of adrenal function. Computed tomographic scanning and NP-59 scanning are of comparable diagnostic accuracy. Both are superior to 19-IC scanning in the diagnosis of Cushing's syndrome and primary aldosteronism. Computed tomographic scanning is faster and less expensive, and involves lower radiation doses to the patient than scintigraphy. Adrenocortical isotope scanning as a routine procedure has been superseded by computed tomographic scanning at the Mayo Clinic.

19-Iodocholesterol↗
PubMed1985

A radioisotope assay for 1-aminocyclopropane-1-carboxylic acid synthase: S-adenosylhomocysteine analogs as inhibitors of the enzyme involved in plant senescence.

A simple and rapid radioisotopic assay for 1-aminocyclopropane-1-carboxylic acid (ACC) synthase was developed, an enzyme involved in the biosynthesis of the plant hormone ethylene. The assay utilizes an AG50W-X4(NH+4) column which separates S-adenosyl-L-[carboxyl-14C]methionine (AdoMet) from the product [14C]ACC, since the latter is not bound to the resin while [14C]AdoMet is. As opposed to other assays, this procedure measures ACC directly and does not require further conversion to ethylene. When an enzyme preparation from ripe tomato fruits (Lycopersicon esculentum Mill). was assayed, an I50 of 2.5 +/- 0.8 microM for sinefungin and a Km of 27 +/- 2 microM for AdoMet were obtained; these values were in good agreement with previous determinations made with a gas chromatographic assay. When other nucleosides were tested as inhibitors, the following order of decreasing activity was found: sinefungin greater than S-adenosylhomocysteine (AdoHcy) greater than AdoHcy sulfoxide greater than S-n-butyladenosine greater than 3-deaza-adenosylhomocysteine greater than S-isobutyladenosine greater than S-isobutyl-1-deazaadenosine. In contrast, S-isobutyl-3-deazaadenosine, S-isobutyl-7-deazaadenosine, 3-deazaadenosine, and adenosine were not inhibitory.

Amino Acids↗
PubMed1990

A radioisotopic assay for polyamine oxidase.

A new radioisotopic assay for polyamine oxidase with N1-acetylspermine as substrate is presented. A modified method for the chemical synthesis of radioactive N1-acetylspermine, which gave a good yield, is also described. The reaction mixture, containing N1-[14C]acetylspermine and tissue homogenate, was incubated for the enzyme reaction and applied to a minicolumn of Amberlite CG-50. The reaction product 3-[14C]-acetamidopropanal did not adsorb to the column, but passed through it; thus the eluate could be directly subjected to liquid scintillation counting. The blank levels were low and relatively constant even with crude tissue homogenates. The detection limit obtained was 0.05 nmol per tube. This method is simple, highly sensitive, and highly specific.

Animals↗