Mum In Size Research Articles

Microencapsulation of tumor necrosis factor oligomers: a new approach to proinflammatory cytokine inhibition.

Antisense oligonucleotides offer great therapeutic potential provided adequate intracellular penetration can be achieved. In this study, we evaluated the effectiveness of microencapsulating antisense oligonucleotides to tumor necrosis factor (TNF) in suppressing TNF release in vitro and in vivo. Microencapsulation of TNF oligomers was performed using albumin to produce microcapsules 0.6-1.0 mum in size that target phagocytic cells. Albumin microcapsules containing fluoresceinated TNF oligomers were incubated with U-937 cells to observe uptake. Microcapsules were added to whole blood and stimulated with Escherichia coli endotoxin. Endotoxin was given intravenously (i.v.) to rats along with 100 mug microencapsulated TNF oligomers to determine TNF inhibition and animal survival. E. coli was given intraperitoneally (i.p.) along with gentamicin and microencapsulated TNF oligomers to assess TNF inhibition and animal survival. The duration of microencapsulated antisense TNF oligomers was also determined in vivo. The results demonstrated rapid uptake of the microcapsules by macrophages after 2 h and 4 h incubation. There was improvement in TNF inhibition in vitro and improved animal survival by microencapsulated antisense in both endotoxin (100% survival) and peritonitis models (70% survival) compared with free antisense oligomers in solution. Microencapsulation extended the duration of action of the oligomers to 72 h. Intracellular targeting of macrophages with antisense oligomers to TNF by microencapsules as a delivery system improves TNF inhibition using the models of whole blood endotoxin stimulation and endotoxic shock and peritonitis in rats.

Single-crystal-to-single-crystal transformation of diolefin derivatives in nanocrystals.

Topochemical [2 + 2] cycloaddition polymerization of methyl p-phenylenediacrylate and 2,5-distyrylpyridine in nanocrystals, prepared by the reprecipitation method, were investigated in comparison with those in bulk crystals. The bulk single crystals, larger than 1 mum in size, broke into microcrystals with variety of size and shape in the course of polymerization. Interestingly, however, these nanocrystals show single-crystal-to-single-crystal transformation.

Influence of Bi3+ ions in enhancing the magnitude of positive temperature coefficients of resistance in n-BaTiO3 ceramics

Bi3+ ions substituting at Ba-sites in a limited concentration range with another donor dopant occupying the Ti-sites in polycrystalline BaTiO3 enhanced the positive temperature coefficient of resistance (PTCR) by over seven orders of magnitude. These ceramics did not require normal post sinter annealing or a change to an oxygen atmosphere during annealing. These ceramics had low porosities coupled with better stabilities to large applied electric fields and chemically reducing atmospheres. Bi3+ ions limited the grain growth to less than 8 mum in size, they enhanced the concentration of acceptor-type trap centres at the grain-boundary-layer regions and maintained complete tetragonality at low grain sizes in BaTiO3 ceramics.

DNA-synthesizing cells in human fetal thymus

Fragments and suspensions of human fetal thymus were incubated in the presence of 3H-TdR to permit study of the distribution and morphology of DNA-synthesizing cells. Results of light and EM autoradiography showed that 1. although DNA-synthesizing cells were present in the medulla, the vast majority of these cells were localized in the thymic cortex, 2. cells with the typical EM appearance of small lymphocytes and lymphoid blast cells both synthesized DNA, and 3. cells in S-phase were predominantly 8 to 12 mum in size.

Residues in antibiotic preparations, ii: effect of pH on the nature and level of particulate matter in sodium cephalothin intravenous solutions

The effect of pH on the extent and nature of particulate contamination in sodium cephalothin intravenous solutions was studied. The extent of particulate contamination was determined by microscopic and automatic electronic counting procedures, and the physical nature of the particles was determined using scanning electron microscopy. At low pH values (i.e., 4.9--5.9), an amorphous residue was predominant, while at higher pH values (6.9--7.8), the gelatinous nature of the residue disappeared and small crystalline particulates of varying sizes were predominant. The level of particulate contamination (particles over 10 mum in size) decreased with an increase in pH to a minimum level between pH 7 and 8. Advice is given to practitioners regarding the preparation of sodium cephalothin solutions.

A multipurpose specimen-carrier for handling small biological objects through critical point drying.

A specimen-carrier for safely handling, protecting and drying minute biological specimens down to 1.0 mum in size during the various steps of the critical point drying procedure is described. Free, unattached cells or subcellular fragments can be processed without loss and without risk of unintentional air-drying.

Influence of tubercle aggregate size on severity of adjuvant arthritis in the rat.

Incorporation into Freund's complete adjuvant of tuberculous aggregates smaller than 90 mum in size is essential to produce adjuvant arthritis in the rat, and this correlates with a significantly greater degree of cell-mediated immunity to tuberculous antigens produced by small aggregates (smaller than 90 mum), when compared with large (larger than 90 mum) aggregates. This requirement for small aggregates to render Freund's complete adjuvant arthritogenic is not paralleled by detectable differences in antimycobacterial humoral antibody production nor by a size-dependent requirement for a conventional adjuvant effect.

Sarcocystis fusiformis infection in the coyote (Canis latrans).

Of 150 fecal samples from coyotes from northern Utah and southern Idaho, 21 contained coccidian sporocysts. These were found singly, contained four sporozoites and a granular residuum, and averaged 16.9 x 10.9 mum in size. None of four lambs inoculated with these sporocysts showed clinical signs of disease, and no parasites were found in their tissues. One calf inoculated with 135,000 sporocysts and another inoculated with 720,000 sporocysts eventually became unable to rise from recumbency. One was killed after 43 days; the other died at 50 days. Both calves had a mild mononuclear cell infiltration into the connective tissue adjacent to vessels in the heart, other striated muscles, kidney, and liver, and a moderate lymphoid hyperplasia in the spleen and lymph nodes. Schizonts were observed in a lymph node, and young sarcocysts were observed in skeletal and cardiac muscles. Four coyotes fed bovine heart infected with Sarcocystis passed sporulated sporocysts in their feces that were indistinguishable from those in the fecal samples from Utah and Idaho.

Fine structure of the endogenous stages of Eimeria labbeana. I. The first generation merozoites.

The fine structure of the 1st generation merozoites of Eimeria labbeana from the ileal mucosa of artificially infected pigeons (Columba livia) was investigated and described. The 1st generation merozoites which appeared between 36-48 hr after infection averaged 4.4 times 2.1 mum in size. The 3-membraned pellicle was irregular in texture and harbored a single micropore, and many micropore-like invaginations. Closely apposed to the inner pellicular membrane were seen 22 microtubules, each 22-25 nm in diameter. An apical vesicle, 50 nm in diameter, seen at the anterior extremity, was connected with the common duct of the micronemes. The conoid consisted of 9 spiral elements, each 30 times 25 nm. The paired organelle (rhoptries) varied in length (1.4-2.2 mum), and the ductules (23 nm diameter) were composed of 2 inner tubules, each 6 nm in diameter. A unit membrane enveloped the partially alveolar and differentially osmiophilic interior of the bulbous regions of the rhoptries. The "rod-like structure" was found to be tubular and represented the common duct of the micronemes.

Cytoplasmic inclusions of neurons in the monkey visual cortex (area 19)

Several unusual neuronal inclusions were found in certain cells of the rhesus monkey visual cortex (Area 19): 1. Filamentous bodies, present in the small stellate cells of layer IV, globoid, 0.3-0.6 mum in diameter, consisting of fine 50 A filaments in a hexagonal meshwork. These are often associated with the labyrinthine bodies. 2. Labyrinthine bodies found exclusively in the small stellate cells of layer IV, including certain neurons with dispersed ribosomes. These are 0.4-0.7 mum in diameter and consist of 900 A wide tubes which interconnect with one another. The walls of these tubes are continuous and made up of a sheet or honeycomb lacework of small hexagonal 150 A subunits. 3. This inclusion, an aggregate 0.3-0.7 mum in size, consists of small membrane-bounded vesicles with a single dense granule associated with other non-membrane bound small dense droplets. The inclusions are always associated with the maturing face of the Golgi complex of certain layer IV pyramidal cells; as such, they may be an unusual product of the Golgi apparatus. These observations were confirmed by examination of stereo pairs of electron micrographs. Speculations are made with regard to possible functions for these inclusions.