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Biomedical subjects

N Catsimpoolas

Publications and source records attributed to N Catsimpoolas.

At least 19 recordsLinked to original sources
PubMed1989

Omental angiogenic lipid fraction and bone repair. An experimental study in the rat.

A lipid material extracted from the omentum has previously been shown to contain a potent angiogenetic activator (20), capable of creating intense vasoproliferation in traumatized tissues (19). This study was undertaken to analyze the efficacy of local administration of this omental lipid fraction on osseous vascularization and bone repair. An osteoperiosteal segmental femoral defect in the rat was replaced by a demineralized allogenic bone graft exposed to continuous local delivery of omental lipid via an implanted miniosmotic pump. Saline solution delivered in the same way served as a control. Neovascularization and bone formation in the transplant were quantitatively evaluated by means of dynamic radioisotopic bone imaging, radiographic photodensitometry, microangiography, and biomechanical testing. Compared with the control group, the omental lipid angiogenic fraction-treated specimens showed an 80% overall increase (p less than 0.001) in bone density as well as a twofold increase (p less than 0.001) in regional blood perfusion, maximal at 2 weeks following surgery. At 12 weeks, biomechanical testing demonstrated significantly higher union rate (p less than 0.05) and strength (p less than 0.01) in the treated specimens as compared with the controls. These data demonstrate that the omental lipid fraction factor has potent angiogenic properties that enhance bone blood perfusion and bone regeneration.

Absorptiometry, Photon↗
PubMed1987

Characterization of feline omentum lipids.

Feline omental lipid extracts, previously reported to be angiogenic in the cornea of rabbits, were fractionated and the major lipid components characterized. Approximately 97% of the chloroform/methanol extract consisted of triglycerides containing primarily 16:0, 18:0, 18:1 and 18:2 fatty acids. Trace quantities of free fatty acids, cholesterol, di- and monoglycerides were also detected. The phospholipid fraction, obtained by solvent partition and Unisil column chromatography and characterized by high performance liquid chromatography (HPLC)-mass spectrometry, was found to consist of phosphatidylcholine, sphingomyelin, phosphatidylethanolamine and phosphatidylserine. The neutral glycolipids, isolated by solvent partition and Unisil column chromatography and identified by high performance thin layer chromatography and HPLC of their perbenzoylated derivatives, were found to consist of glucosyl- and galactosylceramides, galabiosylceramide, lactosylceramide, globotriaosylceramide and globotetraosylceramide. The complex glycolipid fraction, obtained from Folch upper phase solvent partition, was found to consist primarily of Forssman glycolipid and gangliosides GM3 and GD3. Smaller amounts of GM1 and other unidentified gangliosides were also present.

Animals↗
PubMed1986

Increased vascular perfusion after administration of an omental lipid fraction.

Recently, it has been reported that a lipid material is present within the omentum which has potent angiogenic activity. In the report being presented herein, the omental material was injected intramuscularly in the area of a standardized wound and at a site distant from the wound. Control animals were injected in a comparable manner using saline solution. The omental lipid material resulted in increased vascular perfusion in the wound regardless of whether the material was injected locally or remotely as measured by in vivo nuclear imaging techniques using tagged erythrocytes labeled with Technetium (Tc-99m). The ability to demonstrate that an omental lipid fraction can cause increased vascular perfusion has become possible because the omental lipid material is abundant in supply and relatively simple to prepare in large quantities.

Angiogenesis Inducing Agents↗
PubMed1984

Lipid angiogenic factor from omentum.

Placing the omentum on the brain surface by surgical transposition or transplantation will result in the development of numerous neovascular connections between these two structures. This phenomenon occurs even in the absence of cerebral ischemia, which raised the question as to whether an angiogenic factor was causing the response. A lipid material obtained from the omentum contains a potent angiogenic factor extractable in a chloroform-methanol solvent mixture. Angiogenesis created by this material was observed in the rabbit cornea after only a single injection of the substance. The angiogenic material obtained from the omentum is abundant in supply. This important characteristic offers promise for the purification and identification of its structure, which should allow for extensive animal and clinical studies dealing with the development or inhibition of angiogenesis.

Adipose Tissue↗
PubMed1983

Measurement of the distribution of indium-111 on human plasma proteins using immunoprecipitation.

The distribution of radioactivity on plasma proteins labeled by addition of [111In]oxine to citrated plasma was investigated. Analyses of plasma proteins separated on Sephadex G-200 columns showed that 23-36% of the 111In was associated with proteins with molecular weight greater than 200,000 daltons and the remaining 111In was associated with proteins with molecular weight less than 100,000 daltons, presumably transferrin. Affinity chromatography experiments showed that less than 2% of the radioactivity was associated with albumin. Further identification of the labeled proteins and quantitation of associated radioactivity was performed by precipitating specific proteins with antibodies. These studies showed that the 111In was distributed on transferrin (54-76%), fibrinogen (11-24%), IgM (8-20%), C3 (10-21%), and haptoglobin (3-8%). 111In associated with fibrinogen, IgM, and haptoglobin was over-estimated in some experiments due to binding of 111In-labeled C3 to the antigen-antibody precipitates.

Blood Proteins↗
PubMed1983

Alteration of the electrophoretic mobility of human peripheral blood mononuclear cells following treatment with dimethyl sulfoxide.

Studies have been conducted to determine the effects of DMSO and freezing on the electrophoretic distribution of peripheral blood mononuclear cells. Sodium [51Cr]chromate was used to label the cells, and the distributions of cell number and cell-associated radioactivity were determined. Cells treated with DMSO had a narrower distribution of electrophoretic mobilities when compared with those not treated. DMSO-treated cells also demonstrated a more homogeneous distribution of radioactivity relative to the cell distribution than did the nontreated cells. The freezing of DMSO-treated cells did not result in any additional alteration of electrophoretic pattern compared to DMSO treatment alone. Analysis by linear categorization techniques indicated that the DMSO-treated and nontreated cells were completely distinguished by their electrophoretic behavior.

Blood Preservation↗
PubMed1981

Sedimentation behavior of activated human granulocytes. Aggregation and volume effects.

Human peripheral blood granulocytes (PMNs) obtained from normal adults were studied by an analytical gravity sedimentation system. Exposure of PMNs to endotoxin-activated serum (EAS) in a Ficoll density gradient containing Hank's balanced salt solution with calcium and magnesium produced significantly different sedimentation patterns compared to those from granulocytes exposed to normal serum under the same conditions. Experiments were performed to determine whether changes in granulocyte density, volume, shape, or aggregation were responsible for the sedimentation pattern of granulocytes exposed to EAS. The altered gravity sedimentation behavior of endotoxin-activated granulocytes was abolished when calcium and magnesium were not present in the Ficoll density gradient. Granulocyte aggregation was inhibited by the absence of calcium and magnesium in the medium during granulocyte stimulation, whereas the changes in granulocyte shape and volume associated with granulocyte stimulation were not affected. The data indicate that the altered granulocyte sedimentation pattern in the presence of EAS and calcium and magnesium was produced by granulocyte aggregation and not by changes in granulocyte volume or shape.

Adult↗
PubMed1981

51Cr and DF32P labeling of human blood cells in leukocyte-rich plasma.

Cell-rich plasma from human peripheral blood was labeled with disodium chromate (51Cr) and diisopropylfluorophosphate (DF32P), and the uptake and distribution of the radionuclides by granulocytes, lymphocytes, monocytes, and erythrocytes were studied. Velocity sedimentation through a 1-2% albumin gradient and electrophoresis in a Ficoll-sucrose gradient demonstrated that granulocytes migrated the fastest, followed by monocytes, and then by the mixture of lymphocyte-red cell populations. Monocytes accumulated four to five times as much 51Cr as the other leukocytes or the red blood cells. Erythrocytes showed a greater uptake of 51Cr than did granulocytes or lymphocytes. Granulocytes were preferentially labeled in vitro by DF32P, and the uptake of DF32P by lymphocytes was about one-third that by granulocytes. No measurable DF32P labeling of monocytes and only slight labeling of erythrocytes was observed by liquid scintillation counting of the labeled cells. These data have implications in the interpretation of in vivo survival studies of radiolabeled leukocytes.

Blood Cells↗
PubMed1980

Density gradient electrophoresis of mouse spleen lymphocytes: age-related differences. A critical thymus-dependent event during development in the young adult mouse.

T and B BALB/c mouse spleen lymphocytes have been separated by preparative density gradient electrophoresis from animals of different ages. Significant age-related differences in the frequency of occurrence of cells exhibiting different mobility were observed in the young adult mouse. In the 6.5-week-old animals, the frequency of occurrence of the high (T lymphocytes) and low (B lymphocytes) mobility cells was changed, so that these lymphocytes exhibit an electrophoretic distribution profile different (essentially unimodal) from younger (3.5--5.5 weeks) or older (7.5--17 weeks) animals. In the latter two, bimodal electrophoretic distributions were observed. However, differences were also found in the frequency of occurrence of high and low mobility cells. The mobility distributions, representing individual cell types, were reproducible. Furthermore, the age-related changes were independent of the method of cell preparation and appeared in all mouse strains examined. Lymphocytes from animals thymectomized at the 5th week of age did not exhibit these changes (i.e. unimodal distribution) by the 6th week of age. Their electrophoretic distributions at the 6th week and thereafter were similar to those obtained from younger (3.5--5.5 weeks old) animals. It is concluded that the observed changes in the electrophoretic distributions of mouse spleen lymphocytes during development are thymus dependent and may be related to thymus involution.

Aging↗
PubMed1980

Gravity sedimentation analysis of human blood leukocytes.

A new method of sedimentation analysis of human blood leukocytes is described. Platelets, lymphocytes, monocytes, and polymorphonuclear cells isolated from normal human peripheral blood have been analyzed alone and in mixture by gravity sedimentation, employing a computerized scanning instrument. All four classes could be clearly resolved from each other exhibiting sedimentation velocities of 0.06 +/- 0.00, 1.04 +/- 0.11, 1.27 +/- 0.15 and 1.89 +/- 0.21 x 10(-4) cm/s, respectively, at 37 degrees C in a 2.5--6.25% Ficoll gradient in Medium 199. Less than 10(6) cells can be used for analysis. Possible applications of the method are discussed.

Blood Platelets↗
PubMed1980

Density gradient electrophoresis of mouse spleen lymphocytes. Differential mobilities of macrophages, responding and stimulating cells in mixed lymphocyte culture.

Preparative density gradient electrophoresis has been employed for the separation of BALB/c mouse spleen T and B lymphocytes, on the basis of their surface charge. The high mobility cells were found to be predominantly T lymphocytes, whereas the low mobility cells were B lymphocytes. One way mixed lymphocyte cultures were prepared using electrophoretically separated BALB/c lymphocytes, either as responding or stimulating cells and unfractionated CBA/H/T6j mouse spleen lymphocytes, in the appropriate combination. The responding lymphocytes were found only among the high mobility cells which are primarily T lymphocytes. In contrast, the stimulating cells were found in the intermediate and low mobility fractions which contain the B lymphocytes and macrophages. Minimal stimulation in mixed lymphocyte culture was observed by T cells in this allogeneic system. Ia-positive cells were found only in the intermediate and low mobility fractions, which exhibited the capacity to stimulate allogeneic cells in MLC. Macrophages, identified by nonspecific esterase staining, exhibited intermediate electrophoretic mobility, their peak height coinciding with the maximum observed stimulation.

Animals↗
PubMed1979

Cytotaxins after the sedimentation behavior of human granulocytes.

Human granulocytes from the peripheral blood of healthy donors were subjected to transient gravity sedimentation analysis in Ficoll density gradient columns (37 degrees C) containing different concentrations of Escherichia coli endotoxin-activated serum and medium 199. A dramatic serum concentration-dependent dispersion of the cells based on changes in sedimentation velocity was observed as a function of time, using a new optical scanning instrument. The phenomenon was virtually abolished in the presence of cytochalasin B, a known inhibitor of cellular chemotaxis. The width (second statistical moment) of the sedimenting cell distribution increased in a sigmoid fashion as a function of time regardless of cytotaxin concentration. This indicates that a slow and nonlinear response of the granulocytes to the cytotaxins occurs. This new kinetic method should be useful in examining an alternate manifestation of the chemoresponsiveness of phagocytic cells and of cell interactions in general.

Bacterial Toxins↗
PubMed1979

Separation of T and B lymphocytes from various mouse strains by density gradient electrophoresis.

T and B mouse spleen lymphocytes were separated by density gradient electrophoresis on the basis of their surface charge. In all strains examined, the T lymphocytes were found in the high mobility fractions and the B in the low. The T and B cells were separated completely in most fractions, with some overlapping in the middle. Significant differences were found in the electrophoretic distribution profiles between the strains: C57BL/6j, C57BL/10j, (BALB/cXC57BL/6j)F1, and all the following: B6.C-H-2d/cBy (congenic to C57BL/6j), BALB/c, CBA/H/T6j, C57BL/10Sn, and C3H. The C57BL/6j and the (BALB/cXC57BL/6j)F1 cells appear more heterogeneous as far as electrophoretic mobility is concerned. Almost all the other strains give two major peaks. Moreover, the high mobility areas are less populated in the C57BL/6j and the (BALB/cXC57BL/6j)F1 animals than in all the others. The above differences were found consistently when cells prepared by different methods were electrophoresed. It is concluded that the surface charge of lymphocytes may be genetically determined. Possible dependency on the H-2 complex or non-H-2 areas is discussed.

Animals↗
PubMed1979

Separation of rat T and B lymphocytes by density gradient electrophoresis.

Density gradient electrophoresis has been employed for the preparative separation of T and B lymphocytes from rat spleen and peripheral blood. The high mobility cells were found to be predominantly T lymphocytes, as determined by their response to phytohemagglutinin and the relative absence of immunoglobulin-positive cells. The low mobility cells were predominantly B cells, as determined by the high percentage of immunoglobulin-positive cells and the total lack of response to PHA, an exclusive T cell mitogen. A better separation of peripheral blood T and B lymphocytes was achieved than with spleen T and B cells.

Animals↗
PubMed1977

Structural features of rat cardiac ferritins.

Ferritin extracted from rat heart containes two species separable by gel electrophoresis. These were purified and examined for structural characteristics. As in gel electrophoresis, cardiac ferritin preparations yielded only two bands on isoelectric focusing in gels, with pI values of 4.6 and 4.8. After separation by preparative electrophoresis, the two species were found to have a different amino acid composition from each another and from liver ferritin. Similarly, peptide maps showed several components not found in liver ferritin. On dissociation and electrophoresis with sodium dodecyl sulfate, heart ferritins were found to contain subunits of the same sizes as in other rat ferritins but also some larger components. Since cardiac ferritins have apparent molecular weights greater than those of other ferritins, it is concluded they probably contain more subunits, and possibly some of larger size not present in ferritins of other tissues.

Amino Acids↗