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

The authors have used phosphorus magnetic resonance spectroscopy to monitor pH changes in malignant gliomas following treatment with intravenous and intra-arterial 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU). Image-guided, localized phosphorus spectra of human gliomas in situ were obtained using a 1.5-T whole body combined imaging and spectroscopy system. Initial intravenous BCNU treatment was followed by a transient decrease of tumor intracellular pH by 0.15 +/- 0.03 pH units (mean +/- SD). Superselective intra-arterial administration of the same drug was followed by an increase of tumor intracellular pH by 0.15 +/- 0.6 pH units (mean +/- SD). These changes occurred prior to any changes on x-ray, computed tomography (CT), or magnetic resonance imaging (MRI). In addition to enhancing our understanding of the metabolic effects of BCNU, such changes may correlate with drug efficacy or toxicity and may be useful in guiding therapy in the future.
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PMID:Early metabolic changes following chemotherapy of human gliomas in vivo demonstrated by phosphorus magnetic resonance spectroscopy. 260 34

Leiomyomas and leiomyosarcomas were observed in adult laying hens from lines of Japanese quail selected solely (HW) or partly (HW-HP; HW-LP) for increased 4-wk BW and the corresponding randombred control (R1). No neoplasms were observed in a line (LW) selected for decreased 4-wk BW based on observations in one generation. Line R1 served as the base population for Lines HW and LW and was maintained without conscious selection for any trait, Lines HW-HP and HW-LP were sublines of Line HW in which the males were selected for increased 4-wk BW and the females were selected for high or low levels of plasma total phosphorus, respectively. Hens of all lines were necropsied after completing a 120-day production period. A high incidence of neoplasms were found in the dorsal and ventral ligaments of the oviduct in the immediate vicinity of the magnum, and the incidence was much greater in the lines selected for increased growth than in Line R1. These results suggest that selection for increased BW in Lines HW, HW-HP, and HW-LP has resulted in genetic changes that are conducive to neoplastic growth. Based on the results of one generation, it appears that selection for decreased 4-wk BW reduced incidence of neoplasms.
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PMID:Influence of selection for increased body weight on the incidence of leiomyomas and leiomyosarcomas in Japanese quail. 260 12

The effects of localized gamma-irradiation on the in vivo 31P NMR spectra of RIF-1 tumors grown subcutaneously in C3H/HeN mice have been examined before and during the week after treatment. Increases in the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi) and in tumor pH, and decreases in the ratio of Pi to the beta phosphorus resonance of the nucleotide triphosphates (beta NTP) were observed in irradiated tumors. The time course of changes in the 31P spectrum following treatment was the opposite of the pattern during untreated growth, and the magnitude and duration of the changes increased with increasing radiation dose, decreasing clonogenic cell survival and increasing growth delay. To examine the possibility that nontherapeutic systemic effects of the tumor irradiation were responsible for the changes observed, a number of animals bearing two tumors were examined. One tumor on each mouse was selectively irradiated. Changes in tumor volume, Pi/beta NTP, PCr/Pi, the ratio of phosphomonoesters to beta NTP, and tumor pH were all significantly different in the treated compared to the untreated tumor on each animal, indicating that these changes in 31P NMR spectra were a response to radiation therapy and not a systemic response to radiation toxicity.
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PMID:31P NMR spectroscopic study of bioenergetic changes in radiation-induced fibrosarcoma-1 after radiation therapy. 264 98

Disorders of the urinary system are common in geriatric dogs. Common urinary disorders that are seen in older dogs include chronic renal failure, urinary incontinence, bladder tumors, and prostate problems. Therapy for chronic renal failure is aimed at both slowing the progression of the disease and ameliorating the signs of uremia. Therapeutic recommendations for the conservative medical management of chronic renal failure include reducing dietary protein, moderately reducing salt intake, maintaining normal serum phosphorus levels, providing free access to water, avoiding stress, supplementing water soluble vitamins, using anabolic steroids to treat the anemia of chronic renal failure, treating acidosis, and controlling hypocalcemia. Urinary incontinence can often be controlled or eliminated. The appropriate approach to management of this disorder is to identify and remove specific causes. Common causes of urinary incontinence are urethral incompetence, urinary tract infection, and polyuria and polydypsia. Bladder tumors are, fortunately, not a common tumor of dogs, but are more common in geriatric dogs than in the young. The most common bladder tumor is the transitional cell carcinoma. Therapy for this tumor is usually palliative because of its malignant nature and because it is usually located in the neck of the bladder. Its location in the bladder often makes it impossible to resect the tumor completely without removing the entire bladder and diverting the ureters. New chemotherapeutic modalities are being evaluated that may increase life expectancy after diagnosis and, therefore, improve prognosis. Prostate disease is also seen in older dogs. Types of prostate abnormalities seen in dogs include prostatic hyperplasia, cysts, abscesses, acute and chronic infection, and neoplasia. The institution of proper therapy requires an accurate diagnosis; neutering is often recommended as a part of therapy regardless of the type of prostatic disease present.
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PMID:Urologic disorders of the geriatric dog. 264 20

In vivo 31P nuclear magnetic resonance (MR) spectroscopy has shown great promise as a tool for cancer research and the clinical management of solid tumors. It is now possible in some cases to integrate MR spectroscopy with routine MR imaging of the cancer patient, so that tissue identified as tumor on an MR image can be examined biochemically and monitored following treatment. Alterations have been observed in the phosphorus MR spectra of patient tumors after treatment, but the causes and consequences of these alterations are poorly understood. Here we review data obtained from experimental animal tumor models treated with chemotherapy in order to gain insight into the biological events reflected in MR spectroscopic changes, and to determine what information the spectra provide about the success or failure of therapeutic interventions. An attempt is made to relate these experimental findings to the cancer clinic and to analyze the contributions of MR spectroscopy to the understanding of tumor biology.
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PMID:Response of solid tumors to chemotherapy monitored by in vivo 31P nuclear magnetic resonance spectroscopy: a review. 266 40

The mammalian thyroid gland is composed of 2 distinct endocrine cell populations concerned with the synthesis of 2 different classes of hormones. Follicular cells secrete the metabolically active iodothyronines whereas the C-(parafollicular) cells are concerned with the production of calcitonin, a hormone that influences blood levels of calcium and phosphorus, and bone cell metabolism. The synthesis of metabolic thyroid hormones is different than in other endocrine glands because the final assembly of hormone occurs within the follicular lumen. This extracellular synthesis of thyroid hormones is made possible by thyroglobulin, a glycoprotein synthesized by follicular cells. The secretion of thyroid hormones under the influence of pituitary thyrotrophin (TSH) from stores in the luminal colloid is initiated by elongation of microvilli and formation of pseudopods. FD&C Red No. 3 is a tetraiodinated derivative of fluorescein which in lifetime studies increases the incidence of thyroid follicular cell adenomas in male Sprague-Dawley rats. The striking changes in circulating levels of thyroid hormones and morphologic evidence of follicular cell stimulation are the result of alterations in the peripheral metabolism of thyroxine. An inhibition by FD&C Red No. 3 of 5'-deiodinase in the liver and kidney would explain the lower serum triiodothyronine (T3) levels. The pituitary, sensing the lowered circulating levels of T3, increased the secretion of thyroid stimulating hormone which resulted in the morphologic evidence of follicular cell stimulation in the long-term studies. Other xenobiotics increase the incidence of thyroid tumors in rodents by a direct effect on the thyroid gland to disrupt 1 of 3 or more possible steps in the biosynthesis of thyroid hormones. Physiologic perturbations alone, such as iodine deficiency or partial thyroidectomy, can disrupt thyroid hormone economy in rodents and, if sustained, increase the development of thyroid tumors. The wide variety of drugs, chemicals, and physiologic perturbations which increase thyroid tumor development appear to act through a secondary (indirect) mechanism to promote tumor development by causing a long-standing hypersecretion of thyroid stimulating hormone. Nodular and/or diffuse hyperplasia of C-cells occurs with advancing age in many strains of laboratory rats and in response to long-term hypercalcemia in certain animal species and human beings. Focal or diffuse hyperplasia often precedes the development of C-cell neoplasms. Radiation and the feeding of diets high in vitamin D resulting in hypercalcemia have been reported to increase the incidence of C-cell tumors in rats.
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PMID:The effects of xenobiotics on the structure and function of thyroid follicular and C-cells. 267 79

Comparative phosphorus-31 magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) of 15 patients with superficial masses such as sarcoma, carcinoma, lymphoma, adenoma, and tuberculosis revealed significant increased concentrations of phosphomonoester, phosphodiester, and inorganic phosphorus in the lesion, whereas the concentration of the phosphocreatine was lower in comparison to muscle tissue. In nearly all masses, pH showed a slight alkaline shift. Existence of necrotic regions detected by MRI was marked by an increase of inorganic phosphorous in the spectra. Tumor growth was characterized by raised concentrations of phosphomonoester. Follow-up studies in a case of lymphoma showed a six-fold decrease of the tumor, while the spectra indicated a gradual transition of tumor values to muscle values. A follow-up study during irradiation of a squamous cell carcinoma revealed a considerable decrease of inorganic phosphate and a subsequent increase of phosphodiester.
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PMID:31P-spectroscopy of head and neck tumors--surface coil technique. 268 16

Glioma are often histologically heterogenous. As many of these tumors are not removable in toto, due to their localisation, the most malignant part of the tumor may be missed and information for optimum therapeutic management is incomplete. Furthermore, low grade gliomas tend to become more malignant in their development; additional surgical intervention is often not possible. Non-invasive measurement of tumor glucose metabolism with (F-18)-2-fluoro-2-deoxyglucose (FDG) and positron-emission-tomography (PET) may be used to evaluate tumor malignancy. Malignant gliomas (astrocytoma III degree and glioblastoma) frequently showed increased peak metabolic rates (in comparison with normal white matter) and uncoupling of FDG transport and phosphorylation. Preliminary experiences with image-guided localized phosphorus-31 MR spectroscopy (P-31 MRS) demonstrated a decrease of phosphodiesters in malignant gliomas, whereas the phosphomonoesters showed an increase in several cases. The phosphocreatine peak was often reduced. A more active therapy of low grade gliomas might be indicated when signs of hypermetabolism in FDG-PET and alteration of energy-rich phosphates or membrane-phosphates in P-31 MRS are found.
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PMID:[Metabolic studies of gliomas with positron emission tomography and phosphorus 31 MR spectroscopy in diagnosis and treatment planning]. 268 95

An investigation of changes in urine composition, morphology of bladder epithelium, and levels of DNA synthesis following 4 or 8 weeks oral administration of bladder tumor promoters or analogs without promotion potential was performed. The sodium salts of L-ascorbate, o-phenylphenate, and bicarbonate increased the pH value, sodium content, volume, and MgNH4PO4 crystalluria of the urine, while the parent compounds, L-ascorbic acid and o-phenylphenol, which in contrast are not tumor promoters, did not induce these changes. Sodium chloride ingestion caused natriuresis without increasing urinary pH. Diphenyl administration produced only microcalculi consisting of p-phenylphenol. Treatment with the antioxidants butylated hydroxytoluene, butylated hydroxyanisole, and ethoxyquin was also not associated with any changes in urinary pH or Na ions. However, tert-butylhydroquinone did cause an increase in pH. Administration of the strong bladder carcinogens N-butyl-N-(4-hydroxybutyl)nitrosamine and N-ethyl-N-(4-hydroxybutyl)nitrosamine did not result in alteration of urine composition, with the exception of a decrease in phosphorus concentration. However, all the bladder promoters and carcinogens, without exception, brought about an elevation of DNA synthesis in the urothelium and produced morphologic surface alterations such as formation of pleomorphic or short, uniform microvilli and ropy or leafy microridges. Thus, an ability to induce proliferation and cell surface alteration was characteristic of the complete range of bladder promoters investigated. The results suggest that considerable variation in the mechanisms underlying these changes may be involved for different individuals or groups of agents.
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PMID:Changes in urine composition, bladder epithelial morphology, and DNA synthesis in male F344 rats in response to ingestion of bladder tumor promoters. 272 99

The cellular ATP content and the phosphorylation potential, defined as the ATP, ADP and inorganic phosphate (Pi) ratios, of exponentially growing Ehrlich ascites tumour cells were compared with cells at the plateau phase of growth. These phosphorus compounds were measured using 31P-NMR-spectroscopy immediately after removal of the cell material from the host and in their ascites fluid reflecting in vivo growth conditions. Reaching the plateau phase of growth, the ATP content and the phosphorylation potential decreased. Upon addition of glucose, the phosphorylation potential immediately increased. We concluded that the reduced phosphorylation potential was due to a limited availability of glucose in spite of the nearly normal blood glucose concentration found. An increasing diffusion distance from the host to all parts of the tumor is a possible reason for that.
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PMID:31P-NMR-spectroscopy measurements of energy metabolism of in vivo growing ascites tumours following addition of glucose. 273 18


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