UMLS:C0027651 - FACTA Search

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)

Several novel macromolecular anticancer agents have fallen short of expectations owing to inadequate and heterogeneous uptake in tumor tissue. In the present work, contrast-enhanced magnetic resonance imaging was used to measure the intertumor and intratumor heterogeneity in the effective microvascular permeability constant, P(eff), of an 82 kDa macromolecule in an attempt to identify possible causes of the inadequate and heterogeneous uptake. Tumors of two human melanoma xenograft lines (A-07 and R-18) were included in the study. Human serum albumin with 30 gadopentetate dimeglumine units per molecule was used as a model molecule of macromolecular therapeutic agents. P(eff) was measured in manually defined regions of interest, corresponding to a whole tumor (ROI(WHOLE)) or to subregions of a tumor (ROIs(SUB)). The P(eff) of the ROI(WHOLE) of individual tumors ranged from 1.4 x 10(-7) cm/s to 2.8 x 10(-7) cm/s (A-07) and from 7.7 x 10(-8) cm/s to 3.2 x 10(-7) cm/s (R-18). P(eff) decreased with increasing tumor volume in R-18, but was independent of tumor volume in A-07. The intratumor heterogeneity in P(eff) exceeded the intertumor heterogeneity in both tumor lines. Some ROIs(SUB) showed P(eff) values that were similar to or slightly higher than the P(eff) values of albumin in normal tissues. Our observations suggest that inadequate and heterogeneous uptake of macromolecular therapeutic agents in tumor tissue is partly a result of low and heterogeneous microvascular permeability. However, the microvascular wall is probably not the major transport barrier to macromolecules in A-07 and R-18 tumors, as most individual tumors and individual tumor subregions showed high P(eff) values, i.e. values that are up to 10-fold higher than those of normal tissues.
...
PMID:Microvascular permeability to macromolecules in human melanoma xenografts assessed by contrast-enhanced MRI--intertumor and intratumor heterogeneity. 1167 31

Neprilysin (CD10) is expressed in both normal and neoplastic liver tissue, where it exhibits a characteristic canalicular pattern (CD10can) similar to the one observed when antibodies cross-react with biliary glycoprotein I (p-CEA). The aim of this retrospective study was to investigate the use of CD10can in differentiating between hepatocellular carcinomas (HCCs; 63 specimens) and nonhepatocellular carcinomas (non-HCCs) metastatic to the liver (non-HCC; 25 specimens). Immunostaining was performed with antibodies directed against CD10, p-CEA, and alpha-fetoprotein (AFP). Albumin mRNA was detected by nonradioactive in situ hybridization (ISHalbumin). In the HCC group a canalicular staining pattern for CD10 was found in 43 (68.3%) specimens. AFP was found in 15 (23.8%) specimens, and a canalicular staining pattern for p-CEA was present in 60 (95.2%) specimens. ISHalbumin was performed in 35 HCC specimens and showed labeling of tumor cells in 30 (85.7%) specimens. In the non-HCC group, CD10can, and p-CEA, immunostaining for AFP and labeling for ISHalbumin were confined to non-neoplastic liver tissue. Sensitivity and specificity were, respectively, 68.3% and 100% for CD10can, 23.8% and 100% for AFP, 95.2% and 100% for canalicular p-CEA, and 86.4% and 100% for ISHalbumin. Our results demonstrate that canalicular staining for CD10 is a highly specific marker of hepatocytic differentiation. Although it does not differentiate between benign and malignant lesions, CD10can is clearly useful in differentiating between HCC and non-HCC.
...
PMID:Canalicular immunostaining of neprilysin (CD10) as a diagnostic marker for hepatocellular carcinomas. 1168 65

We studied the effect of hydralazine on tumor blood volume fraction and microvascular random flow velocity magnitude by IVIM weighted MRI in conjunction with dynamic Gd-DTPA-Albumin enhanced MRI. Blood volume fraction maps were obtained from the dynamic Gd-DTPA-Albumin enhanced MRI measurements. The average blood volume fraction of R3230 AC adenocarcinoma decreased from 0.125 +/- 0.022 (s.d.) ml/g to 0.105 +/- 0.018 (s.d.) ml/g (p < 0.001) after the administration of hydralazine at a dose of 5 mg/kg. The microvascular random flow velocity magnitude maps were obtained from the IVIM weighted MRI signals by utilizing the Gd-DTPA-Albumin measured blood volume fractions as an input in the compartmental modeling analysis of the IVIM weighted MRI signal. The random-directional microvascular flow induced MRI signal attenuation was separated from the molecular diffusion induced signal attenuation. Flow induced attenuation was more significant after the administration of hydralazine. The mean microvascular random flow velocity magnitude increased from 0.52 +/- 0.15 (s.d.) mm/sec to 0.73 +/- 0.23 (s.d.) mm/sec (p < 0.05) in the presence of the above blood volume fraction change.
...
PMID:Effect of vasodilator hydralazine on tumor microvascular random flow and blood volume as measured by intravoxel incoherent motion (IVIM) weighted MRI in conjunction with Gd-DTPA-Albumin enhanced MRI. 1171 Dec 30

The antitrypanosomal and antitumour activities of (2,2':6',2"-terpyridine)platinum(II) complexes have been postulated to be due to their ability to inhibit irreversibly the NADPH/FAD redox enzymes trypanothione reductase and human thioredoxin reductase respectively. Here we show that these platinum(II) complexes metallate recombinant human albumin (rHA) at the single free thiol group (Cys-34). Moreover, the (2,2':6',2"-terpyridine)platinum(II) complex can be transferred from rHA to other thiols, such as 2-hydroxyethanethiol or glutathione. Human serum albumin could therefore provide a natural transport mechanism for the selective delivery of these agents to tumor cells by the enhanced permeability and retention (EPR) mechanism.
...
PMID:Transfer of 4'-chloro-2,2':6',2"-terpyridine platinum(II) between human serum albumin, glutathione and other thiolate ligands. A possible selective natural transport mechanism for the delivery of platinum(II) drugs to tumour cells. 1171 36

Prospective evaluation was performed in 60 in-patients, carriers of ascites of different etiologies, analyzing the validity of the parameters depending on protein and albumin dosage, both in the ascitic serum and fluid, for the discrimination of possible etiological causes of ascites, including in these parameters Protein Concentration in the Ascitic Fluid, the Serum-Ascites Albumin Gradient, the Protein Ascites/Serum Ratio, and the Albumin Concentration in the ascitic fluid. Average age was 46.9 +/- 19.6, all female; 21 cases were associated with Chronic Hepatic Disease, 14 to Tuberculosis, 11 to Malignant Neoplasia, 7 to Nephrotic syndrome, 4 to Congestive Heart Failure, 2 to Collagen Disease, and 1 to a severe Malnutrition case. The evaluation parameters correlate with the oncotic and hydrostatic pressures of the Starling Law, on the basis of what they could be compared with, demonstrating that their sensitivity levels and their specificity may be used as positive or negative predictive values in the discriminative evaluations of ascites in relation to its probable etiological causes. Even though the Serum-Ascites Albumin Gradient may be useful in the separation of ascites cases with portal hypertension, it is also useful for classifying exudates and transudates. However, the other parameters must not be excluded for the evaluation of those cases, aiming at establishing whether the peritoneum has been affected and hence the terms transudates and exudates should still be used on the basis of the high sensitivity value and specificity of theses tests, which do not differentiate them statistically from the Serum-Ascites Albumin Gradient. Using the cut-off points for each parameter, the most adequate for our population would be 1.5 gr/dl for Albumin and 2.5 gr/dl for protein, with the additional lower cost benefit.
...
PMID:[The validity of the proteins concentrations in the ascitic liquid and serum for the differential diagnosis of the ascitis]. 1252 43

The efficacy of structured lipid, a triacylglycerol of medium and long chain fatty acids, as an element of nutritional support therapies in cancer cachexia was investigated. Using the Yoshida sarcoma to induce cachexia, male Sprague Dawley rats (90 g) were injected subcutaneously with tumor cells (n = 17) or sterile saline (n = 16). Seven days later, rats were randomized to two intravenous diets for 3 days at 220 kcal/kg body weight/d, including 2 g nitrogen/kg body weight/d and 39% of total calories as either structured lipid or long chain triglyceride. Nitrogen balance, tumor growth rate, energy metabolism, and plasma albumin and free fatty acid levels were measured, and whole-body protein kinetics and liver, muscle, and tumor fractional protein synthetic rates were evaluated by adding (14)C-leucine to the diet during the last 4 hours of feeding. Nitrogen balance improved (P < .05) in both tumor and control rats receiving structured lipid-enriched total parenteral nutrition, and was also greater in tumor rats compared with controls. There were no differences in tumor growth or protein kinetics between diet groups. Albumin was lower (P < .05) in tumor rats, but significantly higher in both tumor and control rats given structured lipid-enriched total parenteral nutrition. Free fatty acid was significantly higher in tumor rats versus controls. Whole-body protein kinetics were similar among the four groups. Liver weight, liver weight to body weight ratio, and liver protein synthetic rate were higher in tumor rats. Also, liver weight to body weight ratio was lower in tumor and control animals given structured lipid-enriched total parenteral nutrition. Muscle protein synthetic rate was significantly lower in tumor rats, but higher in tumor and control rats given long chain triglyceride-enriched total parenteral nutrition. The nutritional benefits of structured lipid-enriched total parenteral nutrition favor support of host tissue without promoting tumor growth.
...
PMID:Effect of structured lipid-enriched total parenteral nutrition in rats bearing yoshida sarcoma. 1553 64

Decrease in interstitial pH of the tumor stroma and over-expression of low density lipoprotein (LDL) receptors by several types of neoplastic cells have been suggested to be important determinants of selective retention of photosensitizers by proliferative tissues. The interactions of chlorin e6 (Ce6), a photosensitizer bearing three carboxylic groups, with plasma proteins and DOPC unilamellar vesicles are investigated by fluorescence spectroscopy. The binding constant to liposomes, with reference to the DOPC concentration, is 6 x 10(3) M(-1) at pH 7.4. Binding of Ce6 to LDL involves about ten high affinity sites close to the apoprotein and some solubilization in the lipid compartment. The overall association constant is 5.7 x 10(7) M(-1) at pH 7.4. Human serum albumin (HSA) is the major carrier (association constant 1.8 x 10(8) M(-1) at pH 7.4). Whereas the affinity of Ce6 for LDL and liposomes increases at lower pH, it decreases for albumin. Between pH 7.4 and 6.5, the relative affinities of Ce6 for LDL versus HSA, and for membranes versus HSA, are multiplied by 4.6 and 3.5, respectively. These effects are likely driven by the ionization equilibria of the photosensitizer carboxylic chains. Then, the cellular uptake of chlorin e6 may be facilitated by its pH-mediated redistribution within the tumor stroma.
...
PMID:The pH-dependent distribution of the photosensitizer chlorin e6 among plasma proteins and membranes: a physico-chemical approach. 1714 33

Cathepsin B and plasmin are intra- or extracellular proteases that are overexpressed by several solid tumors. In order to exploit both proteases as molecular targets for tumor-specific cleavage of prodrugs, an albumin-binding formulation of methotrexate was developed that incorporated the peptide sequence D-Ala-Phe-Lys as the protease substrate. Albumin is a suitable carrier for cytostatic agents due to passive accumulation in solid tumors. Synthesis was performed by coupling the peptide linker EMC-D-Ala-Phe-Lys(Boc)-Lys-OH (EMC = epsilon-maleimidocaproic acid) to the gamma-COOH group of alpha-tert-butyl protected methotrexate. After cleavage of the protective groups and purification on reverse phase HPLC, a highly water-soluble methotrexate-peptide derivative was obtained that binds rapidly and selectively to human serum albumin. The albumin-bound form of the prodrug was shown to be efficiently cleaved by cathepsin B and plasmin as well as in an ovarian carcinoma homogenate (OVCAR-3) liberating a methotrexate-lysine derivative. In an OVCAR-3 xenograft model, the prodrug at a dose of 4x15 mg/kg methotrexate equivalents demonstrated distinctly superior antitumor efficacy compared to free methotrexate at a dose of 4x100 mg/kg [T/C(%) for MTX = 69; T/C(%) for MTX prodrug = 29]. The data provide a further proof of concept for the development of albumin-binding, enzymatically cleavable prodrugs of anticancer drugs.
...
PMID:Synthesis, cleavage profile, and antitumor efficacy of an albumin-binding prodrug of methotrexate that is cleaved by plasmin and cathepsin B. 1762 30

The results of the administration of the Mini Nutritional Assessment (MNA) of the Elderly to 197 patients (Women: 62.5%; Ages between 60-75 years: 55.4%; Older than 85 years: 9.7%; Whites: 73.7%) consecutively admitted to the Geriatrics Service of the "Hermanos Ameijeiras" Hospital (La Habana, Cuba) are presented. Sixty-nine percent of the patients had between 2 - 7 concurrent health problems. Neoplasms and lymphoproliferative processes (22.8%), heart and blood vessels diseases (15.7%), and infections (12.2%) were prevalent. The state of nutritional anthropometric and biochemical markers was as follows: Body Mass Index < 21 kg x m(-2): 30.9%; Mid-arm Circumference <22 cm: 19.3%; Leg Circumference <31 cm: 42.6%; Serum Albumin <35 g x L(-1): 20.3%. Sixty-eight percent of the patients received scores <24 after administering the MNA. It is to be noticed that 19.3% of the patients was malnourished after receiving scores < 17. MNA scores <24 were concentrated in: Neurological disorders (80.0%), Neoplasms and lymphoproliferative processes (77.8%), heart and blood vessels diseases (74.2%), gastrointestinal disorders (70.6%), infections (69.7%), Diabetes mellitus (66.7%). Patients with the lowest scores also exhibited the lowest values of anthropometric and biochemical markers. MNA score was independent from the patient's sex, skin colour, or number of concurrent health problems. Age had not any influence upon MNA score, although lower scores were observed among the oldest patients. MNA scoring was 80.0% coincident with nutritional diagnosis independently done with anthropometric and biochemical markers used either separately or combined. Aging of the Cuban population, along with increased proportions of elder patients in hospital areas should lead to consider the nutritional status of patients older than 60 years as an important predictor of the success of medical interventions and the quality of medical assistance.
...
PMID:[The Mini Nutritional Assessment of the elderly in the practice of a hospital geriatrics service: inception, validation and operational characteristics]. 1827 4

Albumin fusion proteins have demonstrated the ability to prolong the in vivo half-life of small therapeutic proteins/peptides in the circulation and thereby potentially increase their therapeutic efficacy. To evaluate if this format can be employed for antibody-based imaging, an anticarcinoembryonic antigen (CEA) single-chain antibody(scFv)-albumin fusion protein was designed, expressed and radiolabeled for biodistribution and imaging studies in athymic mice bearing human colorectal carcinoma LS-174T xenografts. The [125 I]-T84.66 fusion protein demonstrated rapid tumor uptake of 12.3% injected dose per gram (ID/g) at 4 h that reached a plateau of 22.7% ID/g by 18 h. This was a dramatic increase in tumor uptake compared to 4.9% ID/g for the scFv alone. The radiometal [111 In]-labeled version resulted in higher tumor uptake, 37.2% ID/g at 18 h, which persisted at the tumor site with tumor: blood ratios reaching 18:1 and with normal tissues showing limited uptake. Based on these favorable imaging properties, a pilot [64 Cu]-positron emission tomography imaging study was performed with promising results. The anti-CEA T84.66 scFv-albumin fusion protein demonstrates highly specific tumor uptake that is comparable to cognate recombinant antibody fragments. The radiometal-labeled version, which shows lower normal tissue accumulation than these recombinant antibodies, provides a promising and novel platform for antibody-based imaging agents.
...
PMID:Biodistribution and tumor imaging of an anti-CEA single-chain antibody-albumin fusion protein. 1831 24

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