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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We consider animal bioassay experiments with variable dosing regimens in which groups of animals are dosed beginning at different ages and for varying durations. Two response models are discussed and then applied to data from an experiment on vinyl chloride exposure of F-344 rats, B6C3F1 and Swiss CD-1 mice, and Syrian Golden hamsters. The multistage model of Armitage and Doll, as extended by Whittemore, Day and Brown, and Crump and Howe, is used to estimate the dose effect on the ordered stages of tumor development. The data for all endpoints and species/strains examined consistently indicate a predominant effect on the first stage, suggesting that vinyl chloride is primarily a tumor initiator. This is consistent with evidence from two-stage experiments on this chemical. The second response model, new to this article, adjusts for survival nonparametrically. It is used to test for an age difference in susceptibility, to evaluate alternative exposure durations, and to compare the effectiveness of alternative dosing regimens for detecting carcinogenicity.
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PMID:Statistical modeling of animal bioassay data with variable dosing regimens: example--vinyl chloride. 361 85

Brown adipose tissue plays a thermoregulatory role influencing energy balance in experimental animals and possibly also in humans. In the present study we have reevaluated whether brown adipose tissue may contribute to the development of cancer cachexia in non-growing mice bearing an isogeneic tumor. Interscapular brown adipose tissue mass decreased by 20% in freely-fed sarcoma-bearing mice housed at room temperature. Increased mitochondrial density and increased oxidation rate of acetate at low acetate concentrations were found in brown fat from sarcoma-bearing mice, while the oxidation capacity was unchanged compared with that of freely-fed controls. Metabolic and morphologic changes in brown fat from sarcoma-bearing mice were similar to those found in weight-paired controls, which had experienced the same loss of body weight as the tumor-bearing mice. Selective and non-selective B-receptor blockade and surgical removal of interscapular brown fat before tumor implantation did not influence the nutritional state of freely-fed tumor-bearing mice. Injections of noradrenaline caused a proportionately lower increase in oxygen uptake in tumor-bearing animals than in freely-fed controls. Exposure to cold (+5 degrees C) doubled food intake and led to hypertrophy of brown fat in both sarcoma-bearing mice and control animals. Tumor growth was lower although not statistically different in animals housed at +5 degrees C compared with animals housed at +25 degrees C. It is concluded that brown adipose tissue from sarcoma-bearing mice could not account quantitatively for the host wasting in tumor-bearing mice housed at room temperature.
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PMID:Metabolic and morphologic changes in brown adipose tissue from non-growing mice with an isogeneic sarcoma. Evaluation with respect to development of cachexia. 369 34

Specific activity of glycerol-3-phosphate dehydrogenase, estimated in direct and reverse reactions, was decreased, as compared with normal state, without any alterations in the ratio of activities, in muscle homogenates of rabbits with Brown-Pearce carcinoma. The enzymatic activity was decreased by an order of magnitude in homogenates of the tumor as compared with muscle homogenates of the tumor-bearing animals simultaneously with relative stimulation of the reverse reaction. Specific activity of the crystalline enzyme from muscles of tumor-bearing animals was decreased as compared with normal tissues but the ratio of activities was 2-fold increased due to the reverse reaction. In the carcinoma activity of one of the three enzyme fractions, obtained after isoelectrofocusing, was similar to the control values; in the second fraction the ratio of activities was decreased due to inhibition of the direct reaction, the third fraction was inactive. Amino acid composition of crystalline glycerol-3-phosphate dehydrogenase, isolated from tumor-bearing animals, was different in content of 5 amino acids from the enzyme amino acid composition of controls, thus suggesting the structural differences of the proteins from these fractions.
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PMID:[Properties of muscle glycerol-3-phosphate dehydrogenase in rabbits with Brown-Pearce carcinoma]. 370 12

Brown tumors, focal bony lesions of hyperparathyroidism, result from the direct effect of parathyroid hormone on bone. While such lesions are not uncommon in primary hyperparathyroidism, brown tumors have been associated less frequently with secondary hyperparathyroidism and have rarely been described as involving the orbital bones. We have found only four such cases previously reported in the ophthalmic literature. We report a case of orbital involvement by brown tumor in a child with chronic renal failure and secondary hyperparathyroidism. Use of long-term hemodialysis has increased the life span of individuals with chronic renal failure and produced an increased population of patients with secondary hyperparathyroidism and resultant bony changes. The ophthalmologist should consider brown tumor in the differential diagnosis of a patient with chronic renal failure and ocular symptomatology.
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PMID:Brown tumor of the orbit. Case report and review of the literature. 374 Dec 52

Site-specific modification of monoclonal antibodies at their oligosaccharide had previously been demonstrated to produce excellent 111In imaging in a xenograft model using a Brown Norway (BN) rat lymphoma and a rat anti-BN MHC monoclonal antibody [Lee C. et al. Fed. Proc. Abstr. 43 3014 (1984)]. These results are due, in part, to lack of liver uptake, so we wanted to evaluate the extent of hepatic uptake observed with different monoclonal antibodies in normal mice. Biodistribution data were obtained for four monoclonal antibodies by first modifying each antibody at its carbohydrate with a diethylenetriaminepentaacetic acid (DTPA) derivative. The antibodies were then labelled with 111In and injected into normal mice. Images were obtained 24 h post-injection, and at 48 h the mice were dissected and the tissue-to-blood (T:B) ratios determined. T:B ratios were approximately 1 (or less) for every organ evaluated, indicating minimal non-specific uptake into these organs. Data is also presented for the BN-rat system which shows excellent localization into the tumor xenograft and low non-specific organ uptake. These data indicate that modification of antibodies site-specifically at their oligosaccharide results in minimal non-specific uptake into non-target tissues and enhanced localization into the tumor target, and that this may represent a preferred method for production of 111In labelled antibodies.
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PMID:Site-specifically modified 111In labelled antibodies give low liver backgrounds and improved radioimmunoscintigraphy. 379 88

We undertook this study to determine whether radiation (10 Gray, single dose) or water bath hyperthermia (41 degrees C, 45 min) could enhance binding of 111In-labeled anti-p97a monoclonal antibody (MAb) to human melanoma tumors transplanted subcutaneously into nude mice. Sixty animals were given injections of 1-2 X 10(7) Brown C5513 melanoma cells. At 1-2 weeks postinjection, two-thirds of the mice were treated (one-third served as controls). Within 3 hours after treatment, each animal was given iv 2 muCi 111In-anti-p97a MAb. At 24 and 48 hours thereafter, whole-body scans were done with the use of a MaxiCamera 300 A/M unit, and the ratio of activity at the tumor and liver was determined. Some animals were kept for 7 days posttreatment, whereas others were taken after the 48-hour scan for determination of biodistribution of the radiolabeled complex. Enhancement of MAb binding was demonstrated by either modality, although enhancement was more consistent with radiation. The therapeutic efficacy of MAb may be enhanced with increased binding of radioactive MAb complexes through single dose radiation or hyperthermia.
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PMID:Enhancement of monoclonal antibody binding to melanoma with single dose radiation or hyperthermia. 382 18

High linoleic acid (C18:2) (group I; 17.7 cal%) and low C18:2 (group II; 3.3 cal%) diets were given to groups of inbred Brown Norway virgin female rats (100 animals/group), during their whole life-span. A total of 140 tumors were found in group I and 123 tumors in group II; the median survival times of the 2 groups were 124.2 and 118.5 weeks, respectively. Total spontaneous tumor incidence and median survival times were not significantly different. However, significant differences were found in the incidences of some specific tumors: The numbers of reticuloendothelial tumors and adrenocortical carcinomas were significantly higher in the group of animals receiving the low-C18:2 diet. A high incidence of tumor multiplicity, however, resulted in a significantly greater number of mammary tumors in the high-C18:2 diet group.
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PMID:Spontaneous tumor incidence in female brown Norway rats after lifelong diets high and low in linoleic acid. 385 59

Sym 1,2-dimethylhydrazine (DMH)-induced colon tumorigenesis was studied in immunologically different strains of rat: the Brown--Norway which is known to be immunologically a low-responder and the Fischer a high-responder. Brown--Norway rats received a total dose of 75, 150 or 225 mg DMH/kg or vehicle and Fischer rats received 150 mg DMH/kg or vehicle over a 3-week period. Rats were killed 5 months after the final treatment. Lymphocytes were isolated from the spleen and colon from rats treated with 150 mg DMH/kg or vehicle. Natural killer (NK) cell activity and the autologous mixed lymphocyte response (AMLR) as well as colon tumor incidence were compared between the two strains. Splenic and colonic intraperithelial lymphocytes (IEL) from the Brown--Norway strain demonstrated low NK activity and reduced splenic T lymphocyte proliferation in response to autologous non-T lymphocytes. As well, colonic lamina propria lymphocyte (LPL) proliferation was low and Brown--Norway rats had a low incidence of DMH-induced colon neoplasms (7%). In comparison, the Fischer rats had more effective splenic and IEL NK killing, enhanced splenic AMLR, enhanced LPL proliferation and a higher incidence of colon tumors (20%).
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PMID:Comparison of immune status and 1,2-dimethylhydrazine induced tumorigenesis in brown--Norway and Fischer rats. Emphasis on splenic and colonic lymphocyte function. 387 59

Brown-Roberts-Wells stereotactic instruments were used for CT guided stereotactic surgery in 54 cases (65 operations). Stereotactic biopsy was done in 9 cases and successive regional chemotherapy was done in 3 cases. Stereotactic drainage was done in 2 cases of bacterial abscess, 3 cases of cystic neoplasm and 33 cases (43 operations) of intracerebral hematoma. CT guided stereotactic procedure was valuable for the correct cannulation to the center of the cavity. We tried to utilize CT image for the selection of targets for stereotactic functional neurosurgical procedures in 6 cases. In the cases of thalamotomy, the information derived from CT made the operation safer than that by contrast ventriculography alone. In all cases of electrode implantation for deep brain stimulation, accurate and precise electrode placement was achieved from CT images alone. This rapid and easy surgical technique was useful also for poor risk patients.
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PMID:[CT-guided stereotactic neurosurgery]. 389 16

Experience with computed tomogram-guided stereotactic biopsy is described with special reference to technical considerations important to the application of the Brown-Roberts-Wells system in pediatric patients. Eleven procedures were performed in 9 patients aged 9 months to 16 years of age. In all cases, the lesion was either deep seated or related to deficit prone areas making open biopsy hazardous. Since the stereotactic frame may interfere with intubation, it is important to apply it only after the patient has been anesthetized and intubated. In very small children, special attention is required to avoid over tightening of the fastening pins and to avoid excessive pressure when making the calvarial opening. In an effort to reduce the risk of hemorrhage, vasculature at the entry site was visualized and avoided by making a standard burr hole opening. Improved imaging of the vasculature at the deep biopsy site was obtained in most cases by intra-arterial contrast enhancement. No complications of the procedure were encountered and a diagnosis was obtained in all cases, although in 2 cases the procedure was repeated before adequate tissue was obtained. In 3 cases the procedure was therapeutic as well as diagnostic in that a tumor cyst or abscess could be drained.
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PMID:Computed tomogram-guided stereotactic brain biopsy in the pediatric patient. 390 29


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