Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The actions of tumor-promoting phorbol esters in smooth muscle excitation-contraction coupling were studied in isolated guinea pig ileum in the presence of various contractile agents. Muscarinic agonists, histamine and bradykinin elicited an initial transient phasic contraction and a subsequent sustained tonic contraction in guinea pig ileum. The Ca2+ channel antagonist nifedipine selectively inhibited the tonic contraction. Phorbol esters, protein kinase C activators, induced immediate muscle relaxation followed by oscillatory contractions when added during the tonic phase of contraction. Phorbol esters, when added in advance, slightly altered the ligand-induced phasic contraction but converted tonic contractions into oscillatory spikes. The amplitude, frequency and shape of the oscillation induced by phorbol esters were dependent upon the dose of phorbol ester: amplitude was increased and frequency was decreased by increasing the doses of phorbol ester. In contrast, the phorbol ester potentiated the tonic contraction induced by high potassium chloride with little effect on the phasic component. It also sensitized the muscles to Bay K 8644. Bay K 8644, which was ineffective in stimulating muscle contraction at 1 nM, became a very effective stimulator in the presence of the phorbol ester. All of these phorbol ester-induced potentiations and oscillations were sensitive to inhibition by staurosporine or nifedipine. These data suggest that in guinea pig ileum, protein kinase C plays a positive regulatory role in Ca2+ channel activation and promotes a complex regulatory effect on Ca(2+)-mobilizing ligand-stimulated Ca2+ channel activity, which results in oscillatory contractile responses to carbachol, methacholine, histamine and bradykinin.
 ...
PMID:Phorbol esters induce oscillatory contractions of intestinal smooth muscles. 172 50

We report a case of an immature teratoma of the third ventricle, which was preoperatively thought to be a choroid plexus papilloma. The diagnosis was made by biopsy since the radiographic (CT, MRI), angiographic and scintigraphic findings ([99mTc]pertechnetate, 99mTc-DTPA, 99mTc-HMPAO brain SPECT) were nonspecific. Disruption of the blood-brain barrier is the mechanism for radionuclidic and contrast tumoral uptake and is demonstrated by marked contrast enhancement on CT and focal concentration on [99mTc]pertechnetate and 99mTc-DTPA images. No suppression of [99mTc]pertechnetate tumor uptake was observed following the administration of potassium perchlorate. Increased concentration of tumor protein is suggested by the increased signal on the T1-weighted magnetic resonance images and high [99mTc]pertechnetate uptake. The tumor's detection on the 99mTc-HMPAO brain SPECT was due to its intraventricular location. A number of potential mechanisms for brain tumor localization of 99mTc-HMPAO are discussed.
 ...
PMID:Radiographic and neuro-SPECT imaging in an immature third ventricle teratoma: case report. 174 Jul 15

Black thyroid discoloration following long-standing use of minocycline has been reported. Morphologic findings of aspiration cytology of these lesions was first reported from The Ohio State University. This abstract describes a second case of black thyroid that was preceded by aspiration cytology. In both cases, thyroidectomies were performed based on "indeterminate" fine-needle aspiration cytology (FNAC). Degenerative changes in follicular epithelial cells in black thyroid causes nuclear hyperchromasia and chromatin clumping, which may be mistaken for neoplasia. Pigment present in follicular epithelial cells and macrophages may be obscured by pigments with similar microscopic appearances, such as hemosiderin. A clinical history of the chronic use of a tetracycline derivative should alert the pathologist to the possibility of black thyroid. Diagnosis may be made by applying special stains on the cell block. The pigment stains with Melanin stain (Fontana) and bleaches with potassium permanganate. In the light of increasing use of FNAC of the thyroid gland and the large number of patients who received tetracycline therapy in the last two decades, it is likely that some practicing cytopathologists may experience this pitfall.
 ...
PMID:Black thyroid: a pitfall for aspiration cytology. 176 97

The effects of the renal tumor promoters; beta-cyclodextrin (beta-C), DL-serine (DL-S), basic lead acetate (LA), trisodium nitrilotriacetate monohydrate (NTA) and potassium bromate (KB), and diethylene glycol (DEG) as a negative control, on early stage of renal carcinogenesis were investigated in unilaterally nephrectomized male Wistar rats after N-ethyl-N-hydroxyethylnitrosamine (EHEN) administration. Wistar male rats were fed 1000 ppm EHEN diet for 2 weeks and the left kidney was removed at week 3, then the animals were divided into 7 groups of 15 rats each. These groups received the following treatments: 1000 ppm LA, 10000 ppm NTA or 500 ppm KB diet for 18 weeks from week 3; 45 mg/100 g body wt./day of beta-C injected sc for 7 days; 100 mg/100 g body wt. of DL-S injected sc biweekly for 6 weeks; 5% DEG in drinking water as a negative control for two days. Five rats in each group were killed at weeks 8, 12 and 20 and their kidneys were examined histologically. At week 20, the average numbers of adenomatous hyperplasias seen as preneoplastic lesions in the beta-C, DL-S, LA, NTA or KB groups were significantly higher than those in the DEG or control groups. Thus within a relatively short period of 20 weeks, promoting effects of chemicals can be detected as a significant increase of adenomatous hyperplasias in this model.
 ...
PMID:Possible application to medium-term organ bioassays for renal carcinogenesis modifiers in rats treated with N-ethyl-N-hydroxyethylnitrosamine and unilateral nephrectomy. 177 62

Specific renin has been identified in the outer layers of the adrenal of rat, mouse and human. Nephrectomy causes a marked elevation of adrenal renin, presumably through hyperkalemia. The subcellular distribution of adrenal renin was investigated by Percoll density gradient. The renin activity in the dense granules from the capsules of nephrectomized rats was 15 times greater than that of intact rats. Most of the active form renin was found in the dense renin granules. Immunohistochemical studies revealed that the dense granules increased in number after bilateral nephrectomy. Immunogold staining of these granules showed unequivocally the presence of renin therein. Adrenal capsules in organ culture were found to release renin at a steady rate. Renin release from bilaterally nephrectomized rat adrenals was 4.6 times greater than from the organs of intact animals. Further, adrenal slices from human adrenocortical tumor tissues which contained specific renin in a sizable quantity were found to release renin in a similar fashion to rats. The mechanism of the control of renin secretion from the adrenal gland was different from the kidney in that the release was stimulated by potassium chloride or angiotensin II but not by ACTH, suggesting stimulation by intracellular calcium. These results provide convincing evidence that the adrenal synthesizes renin, stores it in specific secretory granules, and secretes it in a regulated manner. It is most likely that the adrenal renin plays a role in the production of aldosterone in the adrenal cortex or in the secretion of catecholamines from the adrenal medulla through intra- and/or extracellular formation of angiotensin II.
 ...
PMID:Renin in adrenal: an overview of its synthesis, subcellular localization, and functions. 182 83

Plasma membrane-associated adenosine triphosphatase (ATPase) samples partially purified from the tumor dissections of 15 gastric cancer patients were examined for sensitivity to the synthetic lignan, 2,3-dibenzylbutane-1,4-diol (hattalin), and ouabain in the presence of Mg2+, Na+, and K+. Hattalin was the strongest Na+, K(+)-ATPase inhibitor among the lignans previously examined. The enzyme from normal gastric tissue of the same patient was used as control. The specific activity of ATPase from cancer tissue (C-ATPase) was inhibited by more than 50% by 2.0 mM hattalin, whereas only 33.1% of the specific activity of ATPase from normal gastric mucosa (N-ATPase) was inhibited by 2.0 mM hattalin. There was statistical significance of lignan sensitivity between C- and N-ATPase (p less than 0.02). Ouabain also inhibited C-ATPase in preference to N-ATPase, though not significantly. Hattalin inhibited both C- and N-ATPase more strongly than did ouabain (p less than 0.05). Moreover, the lignan inhibited both C- and N-ATPase in the absence of Na+ and K+. From these data, it is evident that the sensitivity of plasma membrane-associated to lignan increased by gastric canceration. The target ATPase of hattalin is likely to be one other than sodium- and potassium-dependent, ouabain-sensitive ATPase.
 ...
PMID:Differential sensitivity of human gastric cancer ATPase and normal gastric mucosa ATPase to the synthetic mammalian lignan analogue 2,3-dibenzylbutane-1,4-diol (hattalin). 183 Aug 24

Eighty-six colorectal cancer patients who entered the Radioimmunoguided Surgery (RIGS) protocol study were evaluated for 2-, 3-, 4-, and 5-year survival following second-look surgical procedures. Strict preoperative evaluation criteria eliminated patients with extra-abdominal tumor involvement. A saturated potassium iodide preparation was given before the intravenous administration of the B72.3 monoclonal antibody (1 mg) radiolabeled with 2 mCi of iodine-125 by the IODOGEN method. Precordial monitoring of the biologic clearance by the handheld, gamma-detecting probe (Neoprobe 1000 instrument) was conducted at weekly intervals until the average count was less than 20 counts in 2 seconds. Once the drug cleared from the blood, surgery was performed. The mean time interval between injection and operation was 24 days, with a range of 21 to 28 days and a median of 23 days. At surgery the abdomen was explored through the traditional methods of palpation and inspection, and the surgeon committed to a planned procedure. The abdomen was then re-explored with the handheld, gamma-detecting probe and the surgeon stated another intraoperative assessment. After using both traditional and RIGS detection methods, the surgeon stated whether his or her surgical plans changed because of the additional intraoperative information provided by the RIGS system. Fifty-three patients (62%) were deemed resectable by the traditional methods of palpation and inspection, but only 40 (47%) were specified as resectable by RIGS exploration. Two-, three-, four-, and five-year survival data could be gathered for each of the three groups: RIGS resectable (n = 40), traditional nonresectable (n = 33), and RIGS nonresectable (n = 13). At 2 years 95% of the resectable, 36% of the traditional nonresectable, and 53% of RIGS nonresectable patients survived. At 3 years 83%, 7%, and 30% of these patients survived, respectively. For the resectable patients, 74% survived at 4 years and 60% at 5 years, with no survivors from either nonresectable group. Use of the RIGS system increased accurate selection of resectable patients undergoing second-look surgery for recurrent colorectal cancer.
 ...
PMID:Second-look surgery for colorectal cancer. The second time around. 192 12

The contractile effects of the tumor promoter and protein kinase C activator, lyngbyatoxin A, were studied in rabbit aorta rings. Contractions to 1 microM lyngbyatoxin A developed slowly, becoming maximal in approximately 3 hr. Contractions were not altered by 1 microM indomethacin, 1 microM nordihydroguaiaretic acid, or by endothelium removal, indicating that they did not involve contracting or relaxing substances from the epithelium. The contractions were also unaltered by calcium deletion from the medium and by 1 microM verapamil. Removal of adventitia did not alter contractions to lyngbyatoxin A, indicating that they did not involve release of norepinephrine or other neural vasoconstrictors. Previous contraction by norepinephrine in calcium-free medium containing a calcium-sequestering agent did not reduce subsequent lyngbyatoxin A contractions, indicating that they did not utilize the easily depleted intracellular calcium pool utilized by norepinephrine. Partial contraction with lyngbyatoxin A did not prevent contraction of the rings to norepinephrine. Contractions to lyngbyatoxin A in calcium-free medium did not differ from those obtained in calcium-free medium with 80 mM potassium chloride, indicating the contractions involved pharmacomechanical coupling. Contractions to both 1 microM lyngbyatoxin A and to 3 microM norepinephrine were depressed 18 hr after greater than 2 hr exposure to 1 microM lyngbyatoxin A (44 and 27%, respectively). Thus, lyngbyatoxin A contracts the rabbit aorta by an extracellular and intracellular calcium-, endothelium- and neuron-independent mechanism similar to the protein kinase C activating phorbol esters.
 ...
PMID:Effects of lyngbyatoxin A from the blue-green alga Lyngbya majuscula on rabbit aorta contractions. 194 59

Cystic hygromas are large lymphangiomas that are most often found in the posterior triangle of the neck and the axilla in children. They are most frequently found before age 2 and may be massive. After upper respiratory infection, they may become infected and enlarged, causing dysphagia and toxemia. The diagnosis can usually be made by history and physical examination and confirmed by biopsy. Treatment is by surgical excision of small lesions and staged debulking excisions in more severe cases. A patient with a cystic hygroma having many clinical characteristics of a plunging ranula is presented. The cyst fluid was aspirated and analyzed for its amylase, sodium, potassium, chloride, urea nitrogen, glucose, and total protein content. The characteristics of the fluid were also compared with those of lymph and saliva. This report demonstrates the difficulty in determining the diagnosis of a tumor that has the clinical features of a cystic hygroma, as well as a plunging ranula. The necessity of a proper presurgical diagnosis is essential since the form of therapy for each is different and conflicting. A method that distinguishes between the cervical cystic hygroma and a plunging ranula by means of aspirated fluid is discussed.
 ...
PMID:Submandibular cystic hygroma resembling a plunging ranula in a neonate. Review and report of a case. 199 19

Six types of man-made fibers were administered intratracheally (2.0 mg/animal each a week, for 5 weeks; total 10 mg/animal) to female Syrian hamsters that were observed histologically for 2 years after administration. The fibers were rock wool [average diameter (D) = 6.1 microns, average length (L) = 296 microns], fiberglass (D = 0.65 microns, L = 16.8 microns), potassium titanate fiber (D = 0.36 microns, L = 7.17 microns), calcium sulfate fiber (D = 1.0 microns, L = 17.8 microns), basic magnesium sulfate fiber (D = 0.45 microns, L = 22.4 microns), and metaphosphate fiber (D = 2.38 microns, L = 64.1 microns). Tumors were observed in hamsters that had received basic magnesium sulfate fiber (9/20), metaphosphate fiber (6/20), calcium sulfate fiber (3/20), and fiberglass (2/20) but not in the control, rock wool, or potassium titanate fiber groups. The primary sites of the tumors were not only in the pleural cavity but also in the intracelial organs, kidney, adrenal gland, bladder, and uterus. Only a few of the tumors were identified as mesotheliomas by histological examination. In addition to neoplastic lesions, fibrosis, pleural thickening, and chronic inflammatory changes in the lungs were observed in the hamsters, but these changes appeared too mild to foster a pneumoconiosis such as asbestosis.
 ...
PMID:Tumorigenicity of fine man-made fibers after intratracheal administrations to hamsters. 200 37


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>