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PubMed1993

[Energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 3. Chemical composition and energy content of the animal body fractions as well as portions of the animal body fractions of empty body of nonpregnant, pregnant and lactating sows].

The study is based on the results obtained from the slaughter of 5 sows on the first day of pregnancy and the first day of the experiment respectively (pregnant and non-pregnant sows resp.), of 43 pregnant sows on the 56th, 84th, 98th, 105th and 113rd day of gestation as well as 17 lactating sows on the 26th day of lactation. The animal bodies of pregnant sows were divided in 15 fractions and those of non-pregnant and lactating sows in 12 fractions. The investigations were carried out with 3 x 3 variants of litter number (1, 2, 4) and energy supply (120, 100, 80% of requirement recommendation). The chemical composition and the energy content of the animal body fractions as well as their relative portions of the empty body were largely constant during the course of gestation with the exception of the reproductive organs and the conception products. The physiological stage of lactation connected with limited mobilization of body reserves resulted in a reduction in fat content of some body fractions as well as a limited increase of the portions of body organs contrary to the portions of body tissues of the empty body. In comparison with sows of litter numbers 1 and 2 the sows of litter number 4 were characterized by higher portions of bones and meat, valuable parts as well as by smaller portions of depotfat and meat from head and belly of empty body. The raising of the energy supply of the pregnant sows increased the portion of the depotfat and decreased the portion of the meat, valuable parts of the empty body. The chemical composition of the reproductive organs and the conception products as well as the portions of these fractions of the empty body were influenced strongly from the course of the gestation and lactation resp. The portions of the reproductive organs and of the conception products are small (related to energy < or = 5.7 and < or = 2.6% resp.)

Abattoirs↗

PubMed1983

Size fractionation of Trypanosoma brucei DNA: localization of the 177-bp repeat satellite DNA and a variant surface glycoprotein gene in a mini-chromosomal DNA fraction.

We have size-fractionated intact DNA from Trypanosoma brucei into a major large DNA fraction (greater than 350S) and minor middle-sized (60-250S) and small (less than 60S) DNA fractions. Large DNA contains the rRNA genes, the basic copy genes for several variant surface glycoproteins (VSGs), including one which lies near a telomer, and the expression-linked copies of the two VSG genes. The middle-sized DNA contains at least one VSG gene, but the hybridization of this fraction with probes for the conserved repetitive sequences that mark the edges of the transposed segments of VSG genes, suggests that it may contain many VSG genes. The 177-bp repeat satellite DNA is also exclusively found in this fraction.

Animals↗

PubMed1996

Photon-absorbed fractions for cylindrical geometry: a TLD photon-absorbed fraction model.

The purpose of this study is to develop a mathematical model and calculate photon-absorbed fractions in a homogeneous nonradioactive cylinder placed inside off-center and outside a cylindrical homogeneous distribution of activity. In the second case, both the radioactive cylinder and the nonradioactive one are placed in a tissue-equivalent nonradioactive medium. The values of the photon-absorbed fractions are investigated for various geometrical configurations using water as the material filling the cylinders and the medium in between and an isotope commonly used in Nuclear Medicine, 99mTc. The calculations for off-center cylinders allows for modeling inhomogeneous distributions of activity within a tumor by placing several "cold" cylinders of various sizes in a radioactive finite cylinder. This three-dimensional model calculates photon-absorbed fractions for inhomogeneous activity distributions that can be used in quantitative nuclear medicine for self-absorption correction, thus introducing a more realistic correction than the one-dimensional corrections. These calculations are also used to model the response of a cylindrical TLD (thermoluminiscent dosimeter) placed inside a homogeneous radioactive cylinder and outside the homogeneous radioactive cylinder, in an absorbing nonradioactive surrounding medium. The purpose of these calculations is to evaluate the photon-absorbed fraction in the TLD as an instrument of measuring the time-integrated activity of a homogeneous radioactive source versus an inhomogeneous one. The dependence of the TLD-absorbed fraction on the position of the TLD with respect to the radioactive cylinder is investigated.

Biophysical Phenomena↗

PubMed1975

Relative effectiveness of 12-hourly fractionation and a non-uniform x-ray schedule in the optimum fractionation of C3H mouse mammary tumours.

In previous experiments the highest proportions of tumours controlled for 150 days at a particular level of skin reaction were obtained with five or nine fractions of X rays in nine or ten days respectively. Poor results were obtained for the same numbers of fractions given in 4 or 18 days respectively. The present work reports results of three "non-standard" fractionation schedules: two with equal doses given at 12-hour intervals over four or nine days and one with eight decreasing doses given at decreasing intervals over 11 days. The two 12-hour interval schedules gave results which were equal to the best obtained by any other schedule tested. The 8F/11d non-uniform schedule, however, gave mediocre results in spite of being close to the previously optimum overall time. When these results are compared with previously published results from the same tumour system two, phases of optimum fractionation are demonstrated. At short overall times, up to four days, the situation is finely balanced, so that fraction size and interval matter greatly and results of the schedules vary from good to bad. At longer overall times, of nine days or more in these tumours, the response is no longer so variable. Eighteen days (two to three times the average volume doubling time) is too long for any successful treatment with this system, presumably because of proliferation in the tumour.

Animals↗

PubMed2002

[Protein fraction distribution in milling and screened physical fractions of grain amaranth].

The purpose of the study was to establish the protein distribution based on solubility in physical fractions of amaranth flour, in particular between the flour from the germ and that from the perisperm. The protein distribution was obtained applying a series of solvents sequentially utilized in the classical methodology of Osborne & Mendel. The sample of A. cruentus weighing 2000 g was divided into 4 subsamples of 500 g each. One was left as the control while the other 3 were ground individually with a mill. Each flour was screened through 18, 20, 30 and 40 mesh screens, so that 5 fractions were obtained from each of the whole grain flours. Samples of each screened fractions were observed by stereoscopy and analyzed for moisture, fat and protein. This characterization suggested that the fraction above the 30 mesh screen and the flour which passed the 40 mesh screen probably were the perisperm and germ respectively. The 30 mesh sample contained 2.34 fat and 9.05% protein while the 40 mesh contained 16.18% fat and 26.46% protein. The extraction and partitioning of the proteins indicated that the most important fractions in germ and perisperm were the water soluble and glutelins measured by Kjeldahl. The relationship of the water soluble + globulin to glutelins ratio was 2.1 to 1 in the whole grain, 1.9 to 1 in the perisperm and 1.7 to 1 in the germ. The distribution of proteins was very much alike between germ and perisperm. The levels of prolamines were quite low. The protein extraction of the perisperm proteins retained on the 30 mesh screen was low (71.1%) measured by Kjeldahl and 47.4% with the Bradford method to measure protein.

Amaranthus↗

PubMed2000

[Recovery effect of cardiomyopeptidin fractions and fraction addition on cardiac muscle cells in rats damaged by adriamycin].

OBJECTIVE: To investigate the recovery effect of cardiomyopeptidin fractions and fraction addition on the cardiac muscle cells in rats damaged by adriamycin. METHODS: Observing the activity of the succinic dehydrogenase which is at mitochondrion in the cells damaged by adriamycin with MTT. RESULTS: Five fractions have all promoted the activating effect of the enzyme, the action of PI being higher than the others. Fraction addition has also promoted the activating effect of the enzyme, but without additive effect. CONCLUSION: The recovery effect of cardimyopeptidin depends on the interplay among the fractions.

Animals↗

PubMed1981

In vivo studies on the inhibition of coagulation by fractionated heparin and by a heparin analogue. I. Effects of heparin fractions.

High and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

Adult↗

PubMed2005

Size fractionation and characterization of natural colloids by flow-field flow fractionation coupled to multi-angle laser light scattering.

Flow-field flow fractionation (FlFFF) coupled to multi-angle laser light scattering (MALLS) was evaluated for size and shape determination of standard spherical and arbitrarily shaped natural colloids. Different fitting methods for light scattering data retrieved from MALLS were evaluated to determine the particle size of spherical standards and natural colloids. In addition, FlFFF was optimized for best fractionation in connection to MALLS, minimal colloids-membrane interaction, and minimal sample losses. FlFFF, calibrated with standard particles, was used to determine hydrodynamic diameter, or radius (D(h) or R(h)), of the fractionated colloids, whereas the MALLS was used to determine root mean square radius of gyration (R(g)) for fractionated colloids. Combining both results, by calculating the R(g)/R(h) ratio, allows an estimation of colloid deviation from the shape of homogeneous sphere. Accordingly, this study demonstrates that, FlFFF-MALLS is a valuable technique for characterizing heterogeneous and arbitrarily shaped natural colloidal particles in terms of size and shape. To check the usefulness of FlFFF-MALLS in natural colloid studies, the technique was used to investigate the sedimentation behavior of extracted soil colloidal particles. Results illustrate that, in a silty till sample, carbonates function as cement between the colloidal particles, and consequently, change their sedimentation behavior. On the other hand, carbonate dissolution generates a more homogeneous colloidal sample.

Colloids↗

PubMed2004

Pinched inlet split flow thin fractionation for continuous particle fractionation: application to marine sediments for size-dependent analysis of PCDD/Fs and metals.

It is demonstrated that split-flow thin (SPLITT) fractionation, a continuous separation technique for sorting particles or macromolecules, can be utilized for the fractionation of environmental particles to study a size-dependent analysis of pollutants. In this study, focuses are made on the use of a pinched inlet gravitational SPLITT fractionation, a modified form of SPLITT channel formed by reducing the sample inlet thickness of the channel to improve separation efficiency, to separate marine sediments into five different sizes (<1.0, approximately 1.0 to 2.5, approximately 2.5 to 5.0, approximately 5.0 to 10, and approximately 10 to 53 microm). The resulting size fractions are examined with high resolution gas chromatography/high resolution mass spectrometry to determine the size-dependent distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans along with a statistical data treatment and are analyzed with inductively coupled plasma-atomic emission spectrometry and graphite furnace atomic absorption spectrometry to ascertain its major and trace metals. It is shown that the combined analytical methods detailed in this study can be powerfully utilized in such a way as to analyze pollutant distribution and its concentration with regard to particle sizes for an environmental assessment.

Chemical Fractionation↗

PubMed2003

Differences in ICAM-1 and TNF-alpha expression between large single fraction and fractionated irradiation in mouse brain.

PURPOSE: To elucidate the brain molecular response to irradiation. The expression of the intercellular adhesion molecule (ICAM-1) and tumour necrosis factor-alpha (TNF-alpha) in the mouse brain was compared after single-dose and fractionated whole-brain irradiation. MATERIALS AND METHODS: Mice received a single dose of 2, 10 or 20 Gy or a fractionated dose (2 Gy day(-1)) of 10, 20 or 40 Gy. ICAM-1, and TNF-alpha mRNA expression were quantified by the highly sensitive real-time polymerase chain reaction technique. Expression of ICAM-1 protein was quantified by dual-labelled monoclonal antibody assay. RESULTS: After a 20-Gy single dose, there was an increase in ICAM-1 and TNF-alpha mRNA levels (14- and 11-fold, respectively) as well as a significant increase in the level of ICAM-1 protein (p=0.0243). The expression of ICAM-1 and TNF-alpha mRNA increased at the end of the 40-Gy fractionated regimen (3.55- and 2.30-fold, respectively). CONCLUSIONS: The molecular response of the brain to single-dose irradiation was rapid, while its response to fractionated irradiation was slow. This finding is consistent with clinical observations and could be of use when designing strategies to mitigate radiation sequelae.

Animals↗

PubMed1988

Distribution of [3H]dihydrotetrabenazine binding in bovine striatal subsynaptic fractions: enrichment of higher affinity binding in a synaptic vesicle fraction.

[3H]Dihydrotetrabenazine bound to a single class of binding sites in bovine striatal synaptic vesicles with an apparent dissociation constant of 3-9 nM. This is comparable to the inhibitory potency of dihydrotetrabenazine in catecholamine transport assays. In contrast to these results, [3H]dihydrotetrabenazine bound to at least two classes of sites in all other subsynaptic fractions investigated. The higher affinity class of sites was comparable in affinity to that of synaptic vesicles, whereas the lower affinity sites exhibited an apparent dissociation constant of 95-400 nM. Higher affinity sites were most abundant in the synaptic vesicle fraction, and little higher affinity binding was observed in mitochondrial and myelin fractions, or in highly purified synaptic plasma membranes. Lower affinity binding was not enriched in any subsynaptic fraction and was the only class of binding sites detected in homogenates of liver and diaphragm. The distribution of the presynaptic vesicle marker synaptophysin corresponded with that of higher affinity but not lower affinity binding. These results are consistent with the expectation that the higher affinity sites are associated primarily with synaptic vesicles and other neuronal entities that are in communication with these organelles.

Animals↗

PubMed2004

Hypofractionated palliative radiotherapy (17 Gy per two fractions) in advanced non-small-cell lung carcinoma is comparable to standard fractionation for symptom control and survival: a national phase III trial.

PURPOSE: To investigate whether the effect of hypofractionated thoracic radiotherapy (TRT) is comparable to more standard fractionated radiotherapy (RT) in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 421 patients with locally advanced stage III or stage IV NSCLC tumors were included. Inclusion criteria were inoperable, disease too advanced for curative radiotherapy, and chest symptoms or central tumor threatening the airways. Patients were randomly assigned to three arms: A, 17 Gy per two fractions (n = 146); B, 42 Gy per 15 fractions (n = 145); and C, 50 Gy per 25 fractions (n = 130). Four hundred seven patients were eligible for the study; 395 patients (97%) participated in the health-related quality-of-life (HRQOL) study. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and EORTC QLQ-lung cancer-specific module (LC13) were used to investigate airway symptom relief and changes in HRQOL. Assessments were performed before TRT and until week 54. Clinicians' assessments of symptom improvement were at 2, 6, and 14 weeks after completion of TRT. The patients were observed for a minimum of 3 years. Results Baseline prognostic data were equally distributed in the treatment groups. Patient compliance with respect to the HRQOL investigation was minimum 74%. HRQOL and symptom relief were equivalent in the treatment arms. No significant difference in survival among arms A, B, and C was found, with median survival 8.2, 7.0, and 6.8 months, respectively. CONCLUSION: Our data indicate that protracted palliative TRT renders no improvement in symptom relief, HRQOL, or survival when compared with short-term hypofractionated treatment in advanced NSCLC.

Adult↗

PubMed1985

Fractionation of castor bean allergens (CB-1A). Isolation of RC-13, a homogeneous allergenic fraction.

Allergens from castor beans (CB-1A) were fractionated by ion-exchange chromatography both on CM- and SP-Sephadex, employing pH gradient. SP-Sephadex showed better results and fractionated the allergens into 7 components, eluted in a narrow pH range (5.0 - 6.6). An attempt to isolate the major acidic fraction of the group involved successive chromatographic steps on the same gel. RC-13, the isolated fraction, proved homogeneous by rechromatography on SP-Sephadex and isolectric focusing with pH range 3.0 - 10.0 polyacrylamide gel. The pl of RC-13 determined by the latter is approximately 4.2 and allergenic activity was demonstrated by heterologous passive cutaneous anaphylaxis in mice using anti-CB-1A rabbit serum.

Allergens↗

PubMed1981

Fractionation of Marek's disease virus-induced lymphoma by velocity sedimentation and association of infectivity with cellular fractions with and without tumor antigen expression.

Cell suspensions of lymphomas induced by Marek's disease (MD) virus were fractionated by sedimentation at unit gravity on a continuous gradient of bovine fetal serum. Cells in various fractions were examined for MD tumor-associated surface antigen (MATSA) by indirect immunofluorescence, using specific antibody, and for viral infectivity by cocultivating fractionated cells with permissive monolayer cells of duck embryo fibroblasts. Most MATSA-bearing cells in the lymphomas sedimented at a sedimentation velocity of greater than 3.0 mm/hour, whereas smaller, slow-sedimentating cells were generally devoid of MATSA expression. Viral infectivity was associated with MATSA-bearing and MATSA-lacking fractions. Within the limits of the experimental procedures used, this observation provided evidence that presence of MD virus genome in lymphocytes doses not result in concurrent expression of detectable MATSA and that MATSA likely represents another stage of interaction between MD virus and certain lymphocytes.

Animals↗

PubMed1989

Residual haemopoietic damage in the mouse after fractionated gamma-irradiation, down to 0.1 Gy per fraction.

Residual damage in haemopoietic progenitor cell populations, spleen and granulocyte-macrophage colony-forming cells (CFU-S and GM-CFC) was detected in mice after 15 daily fractions where the dose per fraction was as low as 0.1 Gy. The injury was dose-dependent and after higher total fractionated doses of 7.5-10 Gy the CFU-S population recovered to about 50% of control between 2 and 12 months after irradiation. Residual damage was also detected in the stroma, in the form of reduced numbers of fibroblastoid colony-forming cells and of CFU-S in ossicles under the kidney capsule. The response to a second course of 15 fractions, given 3 weeks after the end of the first course, was similar and additive to the response to the first course in the short term. However, in the long term, recovery levels were similar after either one or two courses.

Animals↗

PubMed1984

The influence of fraction size in radiotherapy on the late normal tissue reaction--II: Comparison of the effects of daily and twice-a-week fractionation on human skin.

A comparison of the normal tissue reactions to daily and twice-a-week fractionation over 4 to 6 weeks was performed on postoperatively irradiated parasternal fields in patients with breast cancer. The radiation used was electron beams at 12-13 MeV. We have previously reported that the overall treatment time was of importance for establishment of iso-effect relationships for the acute skin erythema. In this paper we present the degree of telangiectasia after 5 years. Generally, a more pronounced late reaction was found after twice-a-week fractionation than was predicted from the acute reactions. The findings imply that the cumulative radiation effect (CRE) formula has to be modified for both acute and late reactions in certain clinical situations. The main conclusion is that the iso-effect relationship varies significantly over the dose range used in clinical radiotherapy. In the dose range of 30 fractions between 1.6 and 2.1 Gy in 6 weeks, the slope of the curve for iso-effect dose versus number of fractions varies between 0.26 and 0.35, the beta/alpha-ratios between 0.22 and 0.37 Gy-1 and the RBE 2 Fractions/week/5 Fractions/week between 1.97 and 1.82.

Breast Neoplasms↗

PubMed1992

Investigation of red blood cell fractionation by gravitational field-flow fractionation.

Gravitational field-flow fractionation is used for the separation of particles according to their sizes in the range 1-100 microns: larger particles elute before smaller ones. This phenomenon can be explained as a result of the steric exclusion of the particles from the vicinity of the channel walls, and/or hydrodynamic effects supposedly associated with the inertia of the liquid. The method was used for the investigation of red blood cells. The dependence of the retention ratio on the flow-rate, sample volume, concentration of blood and relaxation time was studied. Analysis of fifteen individual fractions by Coulter counter and reinjection of three other fractions were studied in order to verify fractionation of red blood cells.

Cell Separation↗

PubMed2002

Differential fraction-based kinetic model for simulating hydrodesulfurization process of petroleum fraction.

A differential fraction-based kinetic model (DFKM) was proposed to simulate the reaction process in view of the extremely large number of compounds in the petroleum fraction. The results of the simulation experiment on the hydrodesulfurization (HDS) process demonstrated that without considering the exact compounds, DFKM can depict the reaction processes not only of the whole petroleum fraction but of any narrow cut we are interested in. Apparently, this kind of ability, which can be considered as the 'zoom in/out' function, is very useful for the further study on the processing techniques of the petroleum fraction. In the meantime, different methods for obtaining the functions needed in DFKM were investigated and satisfactory results were presented.

Journal Article↗