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PubMed1986

Detection of mucus glycoconjugates in human conjunctiva by using the lectin-colloidal gold technique in TEM. II. A quantitative study in dry-eye patients.

The mucus glycoconjugates produced by conjunctival goblet cells in dry-eye patients were studied by a specific cytochemical reaction in Transmission Electron Microscopy (TEM). Four lectins, proteins of vegetal origin which specifically bind glycosidic residues, (WGA, PNA, SBA and ConA) were used conjugated with colloidal gold as ultrastructural marker. We performed a quantitative analysis by counting the colloidal gold particles present on mucus granules. The results were compared with normal conditions. We found a decrease in sialic acid, N-acetyl-glucosamine, N-acetyl-galactosamine and galactose-N-acetyl-galactosamine and an increase in mannose. The different content of glycoconjugates in goblet cells may reflect in the change of physical and functional properties of mucus. We think these data may be useful in the search for a therapeutic mucomimetic drug.

Carbohydrate Metabolism↗
PubMedDate not supplied

Technetium 99m sulfur colloid scintigraphy to evaluate reticuloendothelial system function in dogs with portasystemic shunts.

In a retrospective study, technetium 99m sulfur colloid scintigraphy was used to evaluate reticuloendothelial system function in 61 dogs with single congenital and 40 dogs with multiple acquired portasystemic shunts. Whole body reticuloendothelial function was measured by calculating the plasma clearance rate constant from a dynamic study of liver uptake of 99mTc sulfur colloid. Relative liver, spleen, and lung uptake, and a ratio of hepatic:extrahepatic uptake were measured on static equilibrium images. Results were compared with those of a group of 26 normal dogs. Compared with values for the group of normal dogs, the plasma clearance rate constant, relative liver uptake, and hepatic:extrahepatic uptake ratio were significantly decreased, and relative spleen and lung uptake were significantly increased in dogs with portasystemic shunts (P < .0001). The only significant difference between dogs with single congenital versus multiple acquired shunts was that the relative splenic uptake was higher in the former group (P < .0002). Based on these results, we concluded that dogs with portasystemic shunts have significantly impaired reticuloendothelial function. The primary cause of this dysfunction is likely a reduction in effective liver blood flow. Increases in spleen and lung reticuloendothelial activity did occur, but only partially compensated for the reduction of liver reticuloendothelial activity. Possible mechanisms for the increased spleen and lung uptake are discussed.

Animals↗
PubMed2004

A molecular rotor as viscosity sensor in aqueous colloid solutions.

BACKGROUND: Molecular rotors exhibit viscosity-dependent quantum yield, allowing non-mechanical determination of fluid viscosity. We analyzed fluorescence in the presence of viscosity-modulating macromolecules several orders of magnitude larger than the rotor molecule. METHOD OF APPROACH: Fluorescence of aqueous starch solutions with a molecular rotor in solution was related to viscosity obtained in a cone-and-plate viscometer. RESULTS: In dextran solutions, emission intensity was found to follow a power-law relationship with viscosity. Fluorescence in hydroxyethylstarch solutions showed biexponential behavior with different exponents at viscosities above and below 1.5 mPa s. Quantum yield was generally higher in hydroxyethylstarch than in dextran solutions. The power-law relationship was used to backcalculate viscosity from intensity with an average precision of 2.2% (range of -5.5% to 5.1%). CONCLUSIONS: This study indicates that hydrophilic molecular rotors are suitable as colloid solution viscosity probes after colloid-dependent calibration.

Blood Viscosity↗
PubMed1960

Neural and hypophyseal colloid deposition in the collared lemming.

Feral and captive lemmings from Churchill, Manitoba, are subject to a unique pathological process in which colloidal material is deposited in bloodvessel walls at scattered points through the central nervous system. Destruction of nervous tissue at these foci is progressive, and colloidal masses in the vascular lumina of the hypothalamus appear to become fixed in the capillaries of the hypophyseal anterior lobe. Inflammatory reactions are never associated with the lesions, and the latter are larger and more numerous in older animals in warmer environments.

Animals↗
PubMed1999

Ordered mesoporous polymers of tunable pore size from colloidal silica templates.

Ordered mesoporous polymers have been prepared by replication of colloidal crystals made from silica spheres 35 nanometers in diameter. The pores in the colloidal crystals were filled with divinylbenzene (DVB), ethyleneglycol dimethacrylate (EDMA), or a mixture of the two. Polymerization and subsequent dissolution of the silica template leaves a polycrystalline network of interconnected pores. When mixtures of DVB and EDMA are used, the pore size of the polymer replicas can be varied continuously between 35 and 15 nanometers because the polymer shrinks when the silica template is removed.

Colloids↗
PubMed1995

Successful treatment of cryptococcal meningitis with amphotericin B colloidal dispersion: report of four cases.

Four patients with cryptococcal meningitis were treated with amphotericin B colloidal dispersion because of nephrotoxicity from prior treatment with conventional amphotericin B. The limited experience presented here suggests that amphotericin B colloidal dispersion is efficacious for the treatment of cryptococcal meningitis, despite being undetectable in cerebrospinal fluid, and offers a potential therapeutic alternative for patients who cannot tolerate conventional amphotericin B.

AIDS-Related Opportunistic Infections↗
PubMed1975

Influence of colloidal iron on the respiration of a species of the genus Acinetobacter.

Washed suspensions of Acinetobacter sp. isolated from water caused the precipitation of iron from a suspension of colloidal ferric iron at pH 6.0 and 7.6. Iron-encrusted cells of the bacterium formed large aggregates. The amount of iron removed from the colloidal preparation in the form of aggregates was from 21 to 52% at pH 7.6 and 49% an pH 6.0 by the bacterial cells. Endogenous respiration rates of the iron-encrusted cells were from 32 to 72% lower than the rates for unencrusted cells. Respiration rates, measured polarographically in the presence of glucose, were also greatly reduced by the coating of iron on the cells.

Acinetobacter↗
PubMed1985

Ultrastructural localization of dipicolinic acid in dormant spores of Bacillus subtilis by immunoelectron microscopy with colloidal gold particles.

The localization of dipicolinic acid in dormant spores of Bacillus subtilis was examined by an immunoelectron microscopy method with colloidal gold-immunoglobulin G complex. The colloidal gold particles were distributed mainly in the core regions of dormant spores and were not observed in those of germinated or autoclaved spores. This result clearly demonstrates that dipicolinic acid is localized in the cores of dormant spores.

Bacillus subtilis↗
PubMed1985

Immunoelectron microscopic double labeling of alkaline phosphatase and penicillinase with colloidal gold in frozen thin sections of Bacillus licheniformis 749/C.

The subcellular distribution of alkaline phosphatase and penicillinase was determined by double labeling frozen thin sections of Bacillus licheniformis 749/C with colloidal gold-immunoglobulin G (IgG). Antipenicillinase and anti-alkaline phosphatase antibodies were used to prepare complexes with 5- and 15-nm colloidal gold particles, respectively. The character of the labeling of membrane-bound alkaline phosphatase and penicillinase was different: the immunolabels for alkaline phosphatase (15-nm particles) were bound to a few sites at the inner surface of the plasma membrane, and the gold particles formed clusters of various sizes at the binding sites; the immunolabels for penicillinase (5-nm particles), on the other hand, were bound to the plasma membrane in a dispersed and random fashion. In the cytoplasm, immunolabels for both proteins were distributed randomly, and the character of their binding was similar. The labeling was specific: pretreating the frozen thin sections with different concentrations of anti-alkaline phosphatase or penicillinase blocked the binding of the immunolabel prepared with the same antibody. Binding could be fully blocked by pretreatment with 800 micrograms of either antibody per ml.

Alkaline Phosphatase↗
PubMed1992

Randomised controlled trial of colloid infusions in hypotensive preterm infants.

Colloid infusions are often given to treat hypotension in preterm infants. The aim of this work was to assess whether it was the amount of protein or the volume of the colloid infused which accounted for the observed increase in blood pressure. Sixty preterm infants were randomised (20 in each group) to receive 5 ml/kg 20% albumin, 15 ml/kg fresh frozen plasma, or 15 ml/kg 4.5% albumin. All infusions were given at a rate of 5 ml/kg/hour in addition to maintenance fluids. The infants were randomised when hypotensive (systolic blood pressure less than 40 mm Hg for two hours). There was no significant difference in the blood pressure of the three groups before or one hour after beginning the infusion. The mean increase in blood pressure one hour after completing the infusion, however, was significantly lower in infants receiving 20% albumin: 9% compared with 17% in the group receiving 4.5% albumin, and 19% in the group receiving fresh frozen plasma. It is concluded that the volume infused rather than albumin load is important in producing a sustained increase in blood pressure.

Albumins↗
PubMed1980

Randomised open controlled trial of colloidal bismuth subcitrate tablets and cimetidine in the treatment of duodenal ulcer.

In a study of 28 outpatients with endoscopically proven duodenal ulcers, 14 patients (with a total of 15 ulcers) were treated with bismuth tablets (colloidal bismuth subcitrate, De-Nol, Gist-Brocades NV) and 14 patients (14 ulcers) were treated with cimetidine (Smith, Kline, and French). Clinical and endoscopic assessments were made after four and six weeks' therapy. After four weeks, 10 of the bismuth treated ulcers (67%) and eight of the cimetidine treated ulcers (57%) were completely healed. After six weeks of therapy, complete healing was seen in 86% of both the bismuth treated and the cimetidine treated ulcers. Twenty of the 24 completely healed ulcer patients (10 of each group) cooperated in a three month follow-up study. Pain recurred in three patients of the bismuth group and four of the cimetidine group and they were examined endoscopically. A recurrent ulcer was found in one of the bismuth treated patients and in three of the cimetidine treated patients. These observations indicate that colloidal bismuth subcitrate was at least as effective as cimetidine in the healing of duodenal ulcer.

Adult↗
PubMed1991

Determinants of atrial natriuretic factor secretion in dogs expanded with isotonic saline or colloid solutions.

Through increments in blood volume and atrial pressure are thought to be the primary stimuli for ANF secretion, plasma levels of this peptide do not always behave as a simple function of volume status. To outline the relationship between the latter and cardiac ANF release, we used five different volume-expansion protocols in anesthetized dogs. A stepwise expansion of plasma volume (PV) was achieved by two consecutive infusions: 0.9% saline followed or preceded by 4 or 25% bovine serum albumin (BSA), 4 or 25% dextran (Dx), or homologous plasma. Saline expansion led to a two- to four-fold increase in arterial plasma ANF level in all five protocols. Both 4 and 25% BSA caused no or very modest increase in plasma ANF, while all other colloid expanders caused the expected ANF release. In all protocols, plasma ANF closely correlated with central venous pressure (CVP). BSA expansion was the only protocol with no correlation between PV and ANF release. Changes in serum Ca2+ could not explain this finding. During BSA expansion, the lack of atrial response was related to the absence of increment (or even fall) in CVP despite the expanded PV. Similarly, urinary Na+ excretion was correlated both with CVP and ANF level but not with PV in BSA expansion. When the dogs were depleted of histamine before BSA infusion, the atrial secretory response was restored, suggesting that this colloid was associated with augmented capillary leakiness and vascular fluid efflux. These results show that the expansion of PV leads neither to ANF release nor to Na+ excretion if it is not accompanied by an expanded central blood volume with elevated atrial pressure.

Animals↗
PubMed2006

The "macromolecular tourist": universal temperature dependence of thermal diffusion in aqueous colloidal suspensions.

By performing measurements on a large class of macromolecular and colloidal systems, we show that thermophoresis (particle drift induced by thermal gradients) in aqueous solvents displays a distinctive universal dependence on temperature. For systems of particles interacting via temperature-independent forces, this behavior is strictly related to the solvent thermal expansivity, while an additional, T-independent term is needed to account for the behavior of "thermophilic" (migrating to the warmth) particles. The former relation between thermophoresis and thermal expansion may be exploited to envisage other fruitful studies of colloidal diffusion in inhomogeneous fluids.

Colloids↗
PubMed2004

Influence of hydrodynamics on many-particle diffusion in 2D colloidal suspensions.

We study many-particle diffusion in 2D colloidal suspensions with full hydrodynamic interactions through a novel mesoscopic simulation technique. We focus on the behaviour of the effective scaled tracer and collective-diffusion coefficients DT(rho)/D0 and DC(rho)/D0 respectively, where D0 is the single-particle diffusion coefficient, as a function of the density of the colloids rho. At low Schmidt numbers Sc - 1, we find that hydrodynamics has essentially no effect on the behaviour of DT (rho)/D0. At larger Sc, DT (rho)/D0 seems to be enhanced at all densities, although the differences compared to the case without hydrodynamics are rather minor. The collective-diffusion coefficient, on the other hand, is much more strongly coupled to hydrodynamical conservation laws and is distinctly different from the purely dissipative case without hydrodynamic interactions.

Colloids↗
PubMed2006

Anisotropic laser trapping in nematic colloidal dispersion.

The interaction between a colloidal particle and a focused laser beam in a nematic liquid crystal reveals an unusual anisotropic Coulomb-like character. Experiments demonstrate two opposite directions in which the particle is attracted to and repelled from the nematic region deformed by the light-induced director reorientation. In this work we present analytical analysis of such behavior and derive the energy of interaction between colloidal particle and deformed director field. The analytical solution is in good agreement with recent results obtained by computer simulation.

Colloids↗
PubMed1975

The prevention of Ehrlich ascites tumor using intraperitoneal colloidal 198Au. Dose vs. size of inoculum.

Previous work has shown that radioactive colloids can cure Ehrlich ascites tumor. In this experiment, the dose of colloidal 198Au needed has been correlated with the number of tumor cells inoculated. On Day 1, varying numbers of Ehrlich cells (10(2), 10(3), 10(4), 10(5), 10(6)) were injected intraperitoneally into 310 BALB/c male mice. Two hours later, varying doses (10, 20, 40, 80, and 160 muCi) of 198Au were injected intraperitoneally. Controls were injected with normal saline. Generally, the lower cell inoculums and higher doses of 198Au yielded better survival rates.

Animals↗
PubMed1975

Further evaluation of 99m-Tc sulfur colloid accumulation in rejecting renal transplants in man and a canine model.

Renal transplant accumulation of 99m-Tc sulfur colloid was evaluated in 41 patients. Ninety-five examinations were performed comparing transplant with bone marrow activity and clinical or pathological diagnosis. 99m-Tc sulfur colloid accumulated in acute or chronic rejection as long as the vascular supply of the grafted kidney was not severely impaired. Accumulation was marked in chronic rejection, slight in acute rejection and absent in normally functioning transplants or in those with acute tubular necrosis. In the 10 dog models, no accumulation was seen in autografted transplants and early accumulation was demonstrated within the hyperacutely rejecting kidneys of allografted dogs.

Angiography↗
PubMed1976

The sensitivity and specificity of 99mTc-sulfur colloid liver imaging in diffuse hepatocellular disease.

The sensitivity and specificity of 99mTc-sulfur colloid liver-spleen imaging in diffuse hepatocellular disease and the significance of image patterns found in these diseases are presented. By visually quantifying the image alterations found in biopsy-proven cases of diffuse hepatocellular disease and analyzing the correlation between the histological diagnosis and the quantified image alteration (individually and by groups), the 99mTc-sulfur colloid liver-spleen image was found to be highly sensitive (83%). Relative discriminatory values were derived for each image finding and a specific image pattern was found in cirrhosis.

Colloids↗

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