Model for a one-step plasma treatment device: feasibility of cholesterol removal

A self-contained plasmapheresis device based on Starling flow has been proposed. A computer model was developed to describe the device performance, and a device using conventional cellulose tri-acetate (CTA) fibers was modeled. Predicted pressure drops and ultrafiltration flow agreed well with measurements using bovine blood in prototype devices made with CTA fibers. The model predicted the expected Starling flow and predicted the observed high hematocrit region near the fiber wall and a layer of packed red cells on the wall. Typically, 15% of the ultrafiltration flow occurred in the first 2-3% of the fiber length where no packed cell layer was present. The entrance header was predicted to cause lower blood pressures in the peripheral fibers, producing a net plasma migration from the central to the peripheral fibers. As an example application for this device, the computer model was used to assess the feasibility of reducing LDL-cholesterol in patients. The use of sequential 1 hour treatments by a modified device was predicted to reduce the cholesterol in a standard man from 200 mg% to 150 mg% in less than 3 hours.     

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients

An analytical method for the rapid isolation and recovery of the homologous series of 2-aminoethanols, a class of organic compounds of importance to wood preservative treatment, is successfully developed. The method is applied to an aqueous solution of copper amine (copper[II] hydroxide complexed monoethanolamine) and to copper-amine-treated sawdust. The method incorporates a gas chromatograph-ion-trap mass spectrometer. A discussion of the secondary equilibrium effects involved when ionizable analytes are extracted from an aqueous phase with respect to organic bases is presented. Using 2-propanol as the extractant coupled to a salt-saturated aqueous phase results in recoveries of 63% for 2-aminoethanol, 51% for N,N-dimethyl-2-aminoethanol, and 56% for N-methyl-2-aminoethanol for a single liquid-liquid extraction. The choice of 2,2,2-trifluoroethanol as an internal standard is found to be quite suitable. A comparison of the precision and accuracy for an external versus an internal mode of instrument calibration demonstrates that the internal standard mode is preferable for this manual injection.     

Control of Leishmania major by a monoclonal alpha beta T cell repertoire

Little is known regarding the diversity of the host T cell response that is required to maintain immunologic control of microbial pathogens. Leishmania major persist as obligate intracellular parasites within macrophages of the mammalian host. Immunity is dependent upon activation of MHC class II-restricted T cells to an effector state capable of restricting growth and dissemination of the organisms. We generated alpha-beta Leishmania-specific (ABLE) TCR transgenic mice with MHC class II-restricted T cells that recognized an immunodominant Leishmania Ag designated LACK. Naive T cells from ABLE mice proliferated in vitro after incubation with recombinant LACK or with Leishmania-parasitized macrophages and in vivo after injection into infected mice. Infected ABLE mice controlled Leishmania infection almost as well as wild-type mice despite a drastic reduction in the T cell repertoire. ABLE mice were crossed to mice with disruption of the TCR constant region alpha gene to create animals with a single alpha beta T cell repertoire. Although mice deficient in all alpha beta T cells (TCR-C alpha 0 mice) failed to control L. major, mice with a monoclonal alpha beta T cell repertoire (ABLE TCR-C alpha 0 mice) displayed substantial control. The immune system is capable of remarkable efficiency even when constrained to recognition of a single epitope from a complex organism.     

Sensitivity of condition indices to changing density in a white-tailed deer population

The ways in which comprehensive condition profiles, incorporating morphometric, histologic, physiologic, and diet quality indices, responded to changes in density of a white-tailed deer (Odocoileus virginianus) population were examined. Changes in these condition indices were monitored in a northeastern Oklahoma deer herd as density declined from peaks of 80 and 72 deer/km2 in 1989 and 1990 (high-density) to lows of 39 and 41 deer/km2 in 1991 and 1992 (reduced-density), respectively. Compared to a reference population (6 deer/km2), deer sampled during high-density exhibited classic signs of nutritional stress such as low body and visceral organ masses (except elevated adrenal gland mass), low fecal nitrogen levels, reduced concentrations of serum albumin, elevated serum creatinine concentrations, and a high prevalence of parasitic infections. Although density declined by one half over the 4-yr study, gross indices of condition (in particular body mass and size) remained largely unchanged. However, selected organ masses, serum albumin and non-protein nitrogen constituents, and fecal nitrogen indices reflected improvements in nutritional status with reductions in density. Many commonly used indices of deer condition (fat reserves, hematocrit, total serum protein, and blood urea nitrogen) were not responsive to fluctuations in density.     

Plasmafunktionalisierung von Textilien und Fasern. Plasma Functionalization of Textiles and Fibers

The future perspectives of the European Textile Industry strongly depend on innovations to add new values to textiles and fibres due to the increasing imports of low‐price products from Asian markets. To functionalize fibers and textiles the plasma technology is of special interest as a dry and versatile process. Mainly due to cost aspects, this technique did not become widely accepted within the textile sector up to now. High‐tech materials (e.g. medicinal devices) or niche products beside classical treatments like dyeing or soil resistance, however, are of economical importance. Possible applications using plasma as well as suitable reactors are presented.     

Predicting nursing home admissions among incontinent older adults: a comparison of residential differences across six years

Whether or not rates of nursing home admissions among elders with urinary incontinence varied by their place of residence was investigated. We also examined whether any observed residential differences could be accounted for by factors other than incontinence that are known to influence rates of institutionalization. Data from the Longitudinal Study on Aging (1984-1990) were used to examine a sample who at baseline lived in community settings and reported problems with urinary incontinence (n = 719). Analyses indicate that residents of less urbanized and thinly populated nonmetropolitan counties were more likely to have a nursing home admission than elders in any other residential context. More importantly, these residential differences persisted in multivariate logistic regression models after controls were introduced for sociodemographic characteristics, measures of health status, and indicators of the social support networks of the elders.     

An in vitro study of apical extrusion of sodium hypochlorite during endodontic canal preparation

One hundred fifty-three single rooted teeth were divided into four groups. Canals were cleaned and shaped using the balanced forces technique. In one group of 50 teeth, irrigation was delivered with the irrigation needle deep within the root canal. In the other group of 51 teeth, the needle was placed passively in the coronal access cavity and the irrigation carried into the root canal during filing. The remaining 52 teeth in the control groups were treated in the same manner using distilled water as the irrigation solution. The concentration of sodium extruded apically was measured by means of atomic emission spectrophotometry, and the volume of sodium hypochlorite extruded was calculated. Significantly more sodium hypochlorite was extruded apically during deep delivery of the irrigation (p<0.05). It is concluded that the use of a reservoir of irrigation in the coronal access cavity results in significantly less apical extrusion of irrigation solution than with deep delivery.