A Survey of Laboratory Computers in Psyehophysiology

Since the mid 196O's there has hcen a growing interest in and use of computers in psychophysiology laboratories. There are even a growing number of accepted physiological measures which are fully dependent on computer technology for their derivation. Although minicomputers have been in use for over a decade, recent developments in microcomputer and microprocessor technology have led to rapid acceptance of microcomputers for laboratory work. These rapid advances have produced a need to survey the current state of laboratory computer applications and development. A comprehensive survey was mailed to 301 psychophysiology laboratory groups during the spring and summer of 1979 and completed surveys were received from 61% of the mailing. Sun'ey results are reported on computer hardware and configuration, dependent measures and user satisfaction, and use and cost of engineering and programming support. Developments in computer hardware and user services are also discussed.     

Changes in lymphoid populations of ageing CBA and NZB mice

Changes in subpopulations of lymphoid cells of normal (CBA) and autoimmune (NZB) mice were studied as a function of age, by observing migration patterns of ⁵¹Cr labelled lymph node, spleen and thymus cells from donors aged 8 days to 12 months. The method permits analysis of the proportions and numbers of recirculating and non-recirculating lymphocytes in lymphoid compartments. Changes in the lymphoid populations of CBA mice were found, which could be attributed to the normal processes of maturation and senescence. In NZB mice relative and absolute decreases in the recirculating cell content of lymph node and spleen were observed which coincided with the time of development of autoimmunity. The significance of these results, in relation to altered immunocompetence with age, is discussed.     

Alloactivated long-term cultured human T lymphocytes express both HLA-DR and SB antigens but lack lymphocyte stimulation capacity

Cell populations obtained from mixed leukocyte cultures of 6- or 10-day duration were found specifically to restimulate primed lymphocytes detecting HLA-linked SB as well as HLA-D-associated antigens. After expansion in vitro (9-75 days) with medium containing interleukin 2, the cultured cells expressed the T lymphocyte markers detected in indirect immunofluorescence by monoclonal antibodies Lyt-3, OKT3, OKT4, OKT8, and had high levels of HLA-DR antigens. In addition, they were shown in cell-mediated lymphocytotoxicity specifically to express SB antigens of the donor B cell type. Despite their positivity for DR and SB antigens, such cultured T cells failed to restimulate either SB- or D-specific secondary lymphocyte proliferation. Homogeneous cloned populations of cultured T cells also lacked lymphocyte stimulation capacity. In contrast, B cell lines, which also expressed DR and SB antigens, were potent stimulators of both SB- or D-directed proliferation. These data show that the activated T lymphocytes which express both HLA-DR and SB antigens are by themselves unable to stimulate lymphocyte proliferation.     

Comparison of α-Tocopherol, α-Tocopherol Acetate,and α-Tocopheryl Polyethylene Glycol Succinate 1000 Absorption by Caco-2 TC7 Intestinal Cells

(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p < 0.001); and (iii) significantly lower with the TPGS form (p < 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.     

Public discourse and policy change: Absence of harm from increased oversight and transparency in OPO performance

The Centers for Medicare and Medicaid Services announced changes to the Final Rule for organ procurement organizations (OPOs) in November 2020, after a 23-month period of public debate. One concern among transplant stakeholders was that public focus on OPO underperformance would harm deceased donation. Using CDC-WONDER data, we studied whether donation performance dropped during the era of public debate about OPO reform (December 2018–February 2020). Overall OPO performance as measured relative to cause, age, and location-consistent deaths rose by 12.3% in 2019, compared to a median annual change of 2.5% 2009–2019. Organ recoveries exceeded seasonally adjusted forecasts by 4.2% in the first half of 2019, by 8.1% following the Executive Order issuing a mandate for OPO metric reform, and by 14.1% between the Notice of Public Rule Making and the onset of COVID-19-related systemic disruptions. We describe changes in donor phenotype in the period of increased performance; improvement was greatest for older and donation after cardiac death (DCD) donors, and among decedents who did not have a drug-related mechanism of death. In summary, performance during an era of intense public debate and proposed regulatory changes yielded 692 additional donors over expectations, and no detriment to organ donation was observed.     

Bovine BMP osteoinductive potential enhanced by functionalized dextran-derived hydrogels

This study evaluated functionalized dextran-derived hydrogels as BMP carriers using both in vitro and in vivo models. In vitro release kinetics indicated that dextran-derived hydrogels could retain rhBMP-2 growth factor in a variable manner depending on their functionalization ratio. The potential of these hydrogels when combined with extracted bovine BMP to enhance the bone formation was evaluated in a rat ectopic model. The largest osteoinduction was found when using hydrogels exhibiting the highest growth factor retention capacity. In addition, some implanted hydrogels demonstrated a capacity to induce an in-vivo calcification certainly related to their chemical composition. These properties make these materials interesting osteoconductive BMP carriers, allowing to decrease the amount of implanted factor required for bone regeneration.