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Carcinoma of the nasopharynx; treatment with radioactive cobalt.

A method of treatment of carcinoma of the nasopharynx is described, using a bead of radioactive cobalt in a Foley catheter placed through the nose and inside the nasopharynx. As an aid in proper placement of the cobalt bead a portion of the nasal septum is removed first. This method of treatment is to supplement rather than replace other methods of treatment such as external x-ray therapy and surgical excision of lymph nodes in the neck.Twenty-two patients were treated with radioactive cobalt beads and the results indicated that it is a useful method for treating carcinoma in the nasopharynx.

Adult↗

Detection of gastrin mRNA by in situ hybridization using radioactive- and digoxigenin-labelled probes: a comparative study.

The hormone gastrin is mainly produced by the G cells of the antral mucosa and plays a major role in the regulation of digestive mucosal growth. Since it permits identification of cell types containing mRNA, in situ hybridization (ISH) appears to be an interesting method for studying gastrin-producing tissues. In this study, in situ detection of gastrin mRNA has been carried out on frozen sections of four human normal antral mucosa samples and of six colonic carcinomas removed from patients with high levels of plasma gastrin, using a gastrin oligonucleotidic DNA probe. We have compared the results provided respectively by the [35s] labelling and the digoxigenin labelling of the synthetic probe. Positive cells were found in each normal sample analysed with radioactive- as well as digoxigenin-labelled antisense probes. The total number of cells expressing gastrin mRNA appeared slightly higher with the [35s]-labelled probe, while the digoxigenin-labelled probe gave a better definition of positive signals. In contrast, neither radioactive nor cold probes gave positive signals in the six colonic carcinoma samples, although gastrin expression had been demonstrated in these tumours using a reverse transcriptase-PCR method. These results show that, although ISH does not seem sensitive enough to allow the detection of very low levels of gastrin expression, it would appear to be a reliable method for visualizing gastrin mRNA in human antral mucosa.

Base Sequence↗

[Induction of monooxygenase system and incorporation of radioactivity from 2-14C-lysine into proteins of rat liver microsomes under the action of phenobarbital and the background of lysine, methionine, threonine and vitamin A, C and E deficiencies].

The effect of diet on induction of monooxygenases and distribution of radioactivity from 2-14-C-lysine in fractions of liver homogenate, muscle homogenate and blood of male rats treated with phenobarbital (80 mg/kg, three days) was studied. 2-14-C-lysine was injected intraperitoneally 24 h before the first injection of phenobarbital. It was demonstrated that monooxygenase induction, increase of relative liver weight and incorporation of radioactivity from 2-14-C-lysine into fractions of liver homogenate in phenobarbital-treated rats fed diet deficient in lysine, methionine, threonine and vitamins A, C and E were more pronounced as compared with the similarly treated rats which were fed a balanced diet. The possibility of mobilization of deficient essential components to liver from other organs and tissues for maintenance of monooxygenase induction is discussed.

Animals↗

Non-radioactive nucleic acid probes: labelling and detection procedures.

A comprehensive overview is given concerning the in situ hybridization techniques using non-radioactively labelled probes. Details are given on the preparation of the probes with different reporter molecules and on the corresponding revealing assays. The development of non-isotopic labelling methods for nucleic acid probes has facilitated the diffusion of the in situ hybridization techniques to the research as well as to the clinical pathology laboratory. Non-radioactive probes have several advantages over the radiolabelled ones, including cost, shelf-life, safety and, last but not least, resolution of the signal.

2-Acetylaminofluorene↗

Loss of heterozygosity at D14S62 and D14S51 detected by a simple and non-radioactive method in plasma DNA is a potential marker of metastasis and recurrence after curative hepatic resection in hepatocellular carcinoma.

BACKGROUND/AIMS: Recurrence and metastasis in hepatocellular carcinoma remains a major challenge to further improve survival. High frequency of loss of heterozygosity at D14S62 and D14S51 in tumor tissue has been shown to be closely related to metastasis and recurrence in breast cancer. But, loss of heterozygosity on 14q in plasma and tumor tissue DNA of hepatocellular carcinoma patients has not been investigated. To establish a way to predict metastasis and recurrence after curative hepatic resection, we analyzed loss of heterozygosity on 14 q in plasma and tumor tissue DNA of hepatocellular carcinoma patients with curative resection. METHODOLOGY: We used a simple, rapid and non-radioactive method to analyze loss of heterozygosity at D14S62 and D14S51 in paired plasma, lymphocyte and tumor tissue DNA of 85 hepatocellular carcinoma patients with curative resection. RESULTS: From 79 cases informative for D14S62 and 78 cases informative for D14S51 of 85 hepatocellular carcinoma tissue DNA, loss of heterozygosity at D14S62 and D14S51 was present in 45 (57.0%) and 41 (52.6%) cases respectively. And in 96.0% of the tissues which showed loss of heterozygosity we were able to detect loss of heterozygosity in their matched plasma. In matched 85 cases of hepatocellular carcinoma plasma DNA, we detected loss of heterozygosity at D14S62 in 55.7% and at D14S51 in 50.0% of the respective informative DNA samples. The loss of heterozygosity patterns of plasma DNA were almost identical to their corresponding tumor tissues. A comparison of these genetic changes with clinicopathological data of these checked hepatocellular carcinoma patients showed that loss of heterozygosity at D14S62 and D14S51 was adversely correlated significantly with the presence of tumor size, with 35.4% at both the D14S62 and D14S51 locus in the HTMR (high-tendency to metastasis and recurrence) group compared with 72.9% and 59.4% in the LTMR (low-tendency to metastasis and recurrence) group at D14S62 and D14S51, respectively (P = 0.001 and P = 0.027, respectively). CONCLUSION: Our results suggest that loss of heterozygosity at D14S62 and D14S51 plays an important role in the metastasis and recurrence of hepatocellular carcinoma patients following curative resection. Loss of heterozygosity at D14S62 and D14S51 in the plasma DNA of hepatocellular carcinoma patients detected by a simple and non-radioactive method has great potentials to be clinically used to predicate metastasis and recurrence after curative hepatic resection.

Biomarkers, Tumor↗

[The localization of radioactive cesium in bovine muscle tissue].

The form in which radioactive caesium is present in muscular tissue has been investigated. It has been found that protein agents under study do not form stable complexes with radioactive caesium. It is suggested that caesium-137 is partially bound by muscular cell membranes upon meet storage.

Actomyosin↗

[Vilon effect on consequences of repeated radioactive and mercuric impact in small doses].

The purpose of the study was to determine the efficacy of vilon administration in rats after reiterated exposure to ecotoxicants (mercury in concentration near to maximum allowable one and gamma-radiation in small dose). In 24 hours after repeated radioactive and mercuric impact (RMI) and for 30 consecutive days the animals reported lymphopenia. At the same time the indices of DNA leucocytes content and structure did not differ from the parameters of intact animals, this could evidence the development of adaptation reactions. Vilon administration led to the normalization of the lymphocytes number by the 30th day after repeated irradiation (contrary to the radioactive- chemical control), while the number of granulocytes in the test group was higher than that in the intact control group. Study of the survival rate in rats revealed that Vilon reduced morbidity of rats in the course of 15 months after RMI.

Animals↗

[Complex estimation of thyroid gland state in tundra voles, inhabiting the natural radioactive polluted sites].

Behow is presented the complex state of thyroid gland of tundra voles living in high level natural radioactivity conditions (Ukhta region of Komi Republic) by morphological and functional criteria. High sensitivity of thyroid gland under natural chronic irradiation of whole organism is noticed. The essential changes in the morphological structure and in the hormone level of the thyroid gland are found in animals, which live for a long time in the conditions of the radioactive pollution. It is determined, that the inside population processes influence on the structure and on the funcition of the thyroid gland.

Animals↗

[The effect of hydrogen peroxide on the growth of microscopic mycelial fungi isolated from habitats with different levels of radioactive contamination].

The effect of hydrogen peroxide ( 10(-9)-10(-1) M) on the mycelial growth of the fungi Alternaria alternata, Cladosporium cladosporioides, Mucor hiemalis, and Paecilomyces lilacinus has been studied. The growth of fungi isolated from habitats with a background level of radioactive contamination was stopped by H2O2 concentrations equal to 10(-3) and 10(-2) M, whereas the growth of fungi that were isolated from habitats with high levels of radioactive contamination was only arrested by 10(-1) M H2O2. The response of the different fungi to hydrogen peroxide was of three types: (1) a constant growth rate of fungal hyphae at H2O2 concentrations between 10(-9) and 10(-4) M and a decrease in this rate at 10(-3) M H2O2, (2) a gradual decrease in the growth rate as the H2O2 concentration was increased, and (3) an increase in the growth rate as the H2O2 concentration was increased from 10(-7) to 10(2)-5 M. The melanin-containing species A. alternata and C. cladosporioides exhibited all three types of growth response to hydrogen peroxide, whereas the light-pigmented species M. hiemalis and P. lilacinus showed only the first type of growth response. A concentration of hydrogen peroxide equal to 10(-1) M was found to be lethal to all of the fungi studied. The most resistant to hydrogen peroxide was found to be the strain A. alternata 56, isolated from the exclusion zone of the Chernobyl Nuclear Power Plant.

Chernobyl Nuclear Accident↗

[Validation protocol of sentinel node biopsy for breast cancer using radioactive tracer at the Institute of Oncology Bucharest "Prof. Dr. Alexandru Trestioreanu"].

The sentinel ganglion concept originates in the assumption according to which the primary tumor drains into a specific lymph node area and then runs through the lymphatic nodes in an orderly, sequential mode. When neoplastic dissemination along the lymphatic pathway occurs, there is an initial invasion of a specific lymph node (rarely more than one) located on the drainage route. That first lymph node has been identified as the sentinel node, which mirrors the regional lymph node status. In order to establish the indication for lymphadenectomy and avoid the situations in which such a surgical procedure would be of no use (N-), the only correct method consists in the identification and biopsy of the sentinel node which can be performed using vital staining (blue dye), radioactive tracers or both. The technique of sentinel lymph node identification and biopsy by means of radioactive tracing includes: -pre-surgical lymphoscintigraphy, -identification of the sentinel lymph node and its excisional biopsy, -intra-operative histopathological examination, paraffin embedded sections and immunohistochemical stains of the sentinel lymph node. The paper presents the refinement of the technique and the validation of the method for identification and biopsy of the sentinel lymph node in breast cancer with the intra-operative use of NEOPROBE 2000 gamma probe at the "Prof. Dr. Alexandru Trestioreanu" Oncological Institute in Bucharest. It is a prospective study which enrolled 93 patients with breast cancer between September 2003-December 2005, who underwent sentinel node biopsy. Complete axillary dissection (back-up lymphadenectomy) was performed in all cases. By comparing the pathological results of the frozen section of the sentinel node, with the paraffin embedded and immunohistochemical ones of the remaining axillary nodes, we present the following results: sensibility 97,15% (34/35), specificity 100% (93/93), positive predictive value 100% (34/34), negative predictive value 98,3% (58/59).

Axilla↗

[The examination of DNA strand breaks induced by peplomycin-using non-radioactive in situ nick translation method].

In situ nick translation (ISNT) is a method to detect DNA single strand break (nick) at each cellular level. In this study, peplomycin (PEP)-induced DNA strand breaks and its repair were examined using non-radioactive ISNT method. Human fibroblasts were cultured with various concentrations of PEP for different durations, and then DNA strand breaks were evaluated by ISNT method. The signal intensity of DNA strand breaks of the PEP-treated fibroblasts was increased in a dose dependent manner. At the fixed concentration of PEP, it reached to a maximum level after 10 min. of culture and remained unchanged for at least 24 hours. In addition, DNA strand breaks induced by PEP was rapidly repaired in 10 min. after washing. Thus, the non-radioactive ISNT is thought to be a quick, sensitive and specific method not only to detect DNA strand breaks but also to observe its repair.

Bleomycin↗

103Pd radioactive stent inhibits biliary duct restenosis and reduces smooth muscle actin expression during duct healing in dogs.

BACKGROUND: This study was designed to assess the expression of smooth muscle actin (SMA) in the healing process after implanting a (103)Pd radioactive stent in the biliary duct, and to discuss the function and significance of this stent in preventing biliary stricture formation. METHODS: A model of biliary injury in dogs was made and then a (103)Pd radioactive stent was positioned in the biliary duct. The expression and distribution of SMA were assessed in the anastomotic tissue 30 days after implantation of the stent. RESULTS: SMA expression was less in the (103)Pd stent group than in the ordinary stent group. The (103)Pd stent inhibited scar contracture and anastomotic stenosis. CONCLUSION: The (103)Pd stent can reduce the expression of SMA in the healing process and inhibit scar contracture and anastomotic stenosis in the dog biliary duct.

Actins↗

Contrast material iodides: potential effects on radioactive iodine thyroid uptake.

The levels of contaminant, free inorganic iodide and iodine were determined in several commonly used ionic and nonionic intravenous contrast media to gain a better understanding of the roles of these compounds in radioactive iodine uptake inhibition. The method, which involved a reduction-oxidation reaction using sodium nitrite, yielded accurate and precise data for the iothalomate based ionic contrast media as well as the nonionic contrast media. There was no free iodine in any of the contrast media tested. There was considerable variation in free iodide levels, ranging from 1.38 microgram/ml to 20.84 microgram/ml among the different contrast media, although significant differences between the ionic and nonionic media were not found. These levels of contaminant iodide are thought to play a role in the short-term inhibition of radioactive iodine uptake.

Contrast Media↗

[Experimental investigations on the accumulation of radioactive compounds in autochtonal tumors in the rat (author's transl)].

For the first time results of investigations on rats with radioactive compounds in autochtonal tumors of the central nervous system, induced via placenta by Ethyl-Nitrose-Urea (ENU), are reported. In contrast to transplantation tumors the tumors induced by ENU are comparable in regard to the szintigrafic results with human brain tumors. The radiopharmaceuticals 131I-HSA, 99mTc-Pertechnetate, 203Hg-Chlormerodrin and 113m/111In-DTPA are similar to human brain tumors taken up by the ENU-tumors. For these findings it may be important, that the ENU-tumors are of neurogenic origin and do not differ histologically from the human brain tumors. The accumulation of the radioactive substances in ENU-tumors can be explained with the lesion at the blood-brain-barrier and at the blood-nerv-barrier. Therefore, it is discussed that the mechanism of the uptake is similar in human brain neoplasms and in ENU-tumors of the brain. The ENU-tumor model is suitable for testing new radiopharmaceuticals before their application in men.

Animals↗

The effect of xenotransplantation of human thyroid tissue following radioactive iodine-induced thyroid ablation on thyroid function in the nude mouse.

We have attempted to determine whether xenotransplanted human thyroid tissue into nude mice would act as a physiological substitute for the mouse thyroid gland after the mice had been rendered hypothyroid, using radioactive iodine (131I). The dosage of 0.2 millicuries of 131I was given to each mouse. The xenotransplantations of human thyroid tissue, i.e., normal, Graves' and nontoxic multinodular goitre, were carried out three weeks after radioactive ablation. The values of TSH in all mice rose to high levels (71 +/- 15.6 ng/ml, +/- SD) by three weeks after 131I administration. The TSH values in the mice declined rapidly and reached normal levels by 3-5 weeks after xenotransplantation. In addition, the serum T4 values were generally in the euthyroid range by 3-6 weeks after xenotransplantation. There were no marked differences in the changes of serum T4 and TSH when the three groups were compared. These results indicated that the xenografted human thyroid tissue permitted a return to a normal feedback system as reflected by normal serum TSH and T4 values in the animals. The Graves' thyroid tissue reverted to normal physiological function when removed from its human (abnormal) immune environment, signifying that Graves' thyrocytes are mere passive captives to immune events. This model should prove to be useful in the study of human thyroid physiology and pathophysiology.

Animals↗

[Radioactive burden resulting from zirconia implants].

Due to its mechanical properties circonia is an interesting implantation material. However, it may contain a certain amount of radioactive isotopes. The measurement of alpha-emission reveals varying amounts of radiation. As a result, a declaration of radioactivity should be required for circonia implants and only circonia with low emission levels should be used for implantation purposes.

Alpha Particles↗

Nasal distribution of radioactive drug administered using two dosage forms.

The deposition patterns of 99mtechnetium labelled disodium cromoglycate particles administered either from a metered dose aerosol with a conventional nasal adaptor or from a dry powder nasal inhaler were studied using gamma camera. Disodium cromoglycate particles were firstly labelled with 99mTc using the spray drying technique. Both the metered dose aerosol and the dry powder dosage form were formulated using these radioactive drug particles. Seven healthy volunteers inhaled either three aerosol doses or one dry powder dose unit into one nostril. The drug dose reaching nasal cavity after administration from these two dosage forms was about the same. The deposition patterns as well as the changes in distribution due to the mucociliary transport were monitored by a gamma camera equipped with a low energy all purpose collimator. Initially drug doses deposited in a wider area of the nasal cavity when disodium cromoglycate particles were administered as a dry powder dosage form. In addition, retention index (%) which illustrates the movements of drug particles by mucociliary transport from the initial area of application seemed to be slightly higher for a metered dose aerosol than for a dry powder dosage form. At the end of the 30 minutes measuring period the area of the mucosal layer covered by radioactive drug particles was clearly wider for the dry powder dosage form than for the metered dose aerosol. Thus it is well possible to administer drug particles effectively into the nasal cavity as a dry powder dosage form.

Administration, Inhalation↗

[The behavior of radioactive albumin microspheres on administration into the hepatic artery of animals].

A study was made of the behaviour of human serum albumin microspheres--SAM-- (USSR) during intraarterial selective infusion of them in the hepatic artery of rabbits. 125I was used as a radioactive tracing agent. Accumulation of the agent in organs and its excretion were investigated over time by radiometry in vivo and in vitro. Distribution of 125I-SAM in the liver at administration of different amounts of the radioactive drug was also investigated. A mathematical formula of calculation of the optimum amount of administered microspheres was proposed. A conclusion was made of a possibility of the use of the SAM as a carrier of short-lived radionuclides for endovascular radiotherapy of malignant hepatic tumors.

Albumins↗