Cell cycle analysis and synchronization of pluripotent hematopoietic progenitor stem cells

Hematopoietic stem cells purified from mouse bone marrow are quiescent with less than 2% of Lin- Hoechst(low)/Rhodamine(low) (Lin- Ho(low)/Rho(low)) and 10% to 15% of Lin-/Sca+ cells in S phase. These cells enter proliferative cycle and progress through G1 and into S phase in the presence of cytokines and 5% heat-inactivated fetal calf serum (HI-FCS). Cytokine-stimulated Lin- Ho(low)/Rho(low) cells took 36 to 40 hours to complete first division and only 12 hours to complete each of 5 subsequent divisions. These cells require 16 to 18 hours to transit through G0/G1 period and 28 to 30 hours to enter into mid-S phase during the first cycle. Up to 56% of Lin- Rho(low)/Ho(low) cells are high-proliferative potential (7 factor-responsive) colony-forming cells (HPP-CFC). At isolation, HPP-CFC are quiescent, but after 28 to 30 hours of culture, greater than 60% are in S phase. Isoleucine-deprivation of Lin- Ho(low)/Rho(low) cells in S phase of first cycle reversibly blocked them from entering into second cycle. After the release from isoleucine-block, these cells exhibited a G1 period of less than 2 hours and entered into mid-S phase by 12 hours. Thus, the duration of G1 phase of the cells in second cycle is 4 to 5 times shorter than that observed in their first cycle. Similar cell cycle kinetics are observed with Lin-/Sca+ population of bone marrow cells. Stem cell factor (SCF) alone, in the presence of HI-FCS, is as effective as a cocktail of 2 to 7 cytokines in inducing quiescent Lin-/Sca+ cells to enter into proliferative cycle. Aphidicolin treatment reversibly blocked cytokine-stimulated Lin-/Sca+ cells at G1/S boundary, allowing their tight synchrony as they progress through first S phase and enter into second G1. For these cells also, SCF alone is sufficient for their progression through S phase. These studies indicate a very short G1 phase for stem cells induced to proliferate and offer experimental approaches to synchronize murine hematopoietic stem cells.     

Transfection of the gene for B7-1 but not B7-2 can induce immunity to murine malignant mesothelioma

A 56-year-old female with rheumatoid arthritis was admitted because of bilateral hip pain. In a few months of her hospitalization, a relatively abrupt renal dysfunction was emerged besides complement breakdown, and renal biopsy revealed crescentic glomerulonephritis. Immunofluorescence study showed peripheral granular deposits of IgG, IgM, and C3 in the glomeruli. Cresents were predominantly composed of macrophages and glomerular epithelial cells. Amyloid nephropathy, renal vasuculitis, and association of other collagen vascular diseases were negligible for the causative factor. It was suggested that immune complexes were formed in the glomeruli, in which both humoral and cellular immune responses were to be induced, that brought cescents formation in the lesions. Crescentic glomerulonephritis in patients with rheumatoid arthritis is rare and a possible pathogenetic mechanisms involved in the development of renal dysfunction are discussed with the special reference to immune complex-induced inflammation.     

Limits on a bent waveguide for a wedge display

Wedge displays seem immune to slight bends even though they are likely to be introduced by the physical limits of the tools used for wedge manufacture. We show how the maximum angular error which can be introduced by a bend of constant curvature is determined by its thickness, radius of curvature, and the angle of the ray before entry into the bend. The maximum change in angle therefore depends on the number of bounces through the bend, not on how the ray enters. For a 500 lines VGA image of 20 mm thick curved part, the minimum acceptable radius of curvature is about 51.6 m. That Wedge panels seem able to tolerate more than this is probably because through a real bend, the radius of curvature varies.     

Snowboarding injuries

Snowboarding is a popular winter sport that involves riding a single board down a ski slope or on a half-pipe snow ramp. Compared with injuries resulting from traditional alpine skiing, snowboarding injuries occur more frequently in the upper extremities and ankles and less frequently in the knees. Different types of snowboard equipment, rider stance and snowboarding activity tend to result in different types of injury. Snowboarder's ankle, a fracture of the lateral talus, must be considered in a snowboarder with a "severe ankle sprain" that has not responded to treatment. Risk of injury may be lowered by using protective equipment, such as a helmet and wrist guards.     

Attracting nurses to long-term care

1. A major issue facing nursing, and society as a whole, is the longstanding and continuing nursing shortage in long-term care. 2. The demand for RNs in nursing homes will continue to intensify into the next century as the population of older adults with complex care needs continues to grow. 3. The findings of this study suggest that RN recruitment needs in long-term care include having enough qualified and dedicated staff, supportive and competent administration; competitive salaries and benefits; functional, attractive facilities; improved professional and public image; a caring, supportive environment; realistic regulations; decreased paperwork; progressive nurse practice models; and opportunities for educational advancement and career growth.     

Eye movements induced by lateral acceleration steps. Effect of visual context and acceleration levels

Different extracellular matrix (ECM) molecules, when presented to hippocampal neurons in culture in a substrate-bound form, exert strikingly similar effects on the establishment of neuronal polarity, i.e., the growth of axon-like major neurites is favored, whereas extension of dendrite-like minor neurites is inhibited. To gain insight into the underlying signal transduction processes, we have investigated the effects of modulators of protein kinase activity on the morphology of neurons cultured on tenascin-R, tenascin-C, and laminin-entactin substrates. We found differential effects of broad-spectrum protein kinase inhibitors: H-7 promoted the growth of minor neurites, whereas H-8 reduced the growth of major neurites on ECM but not control substrates. In contrast, chelerythrine, a specific inhibitor of protein kinase C, selectively affected growth of both minor and major neurites on control, but not on ECM substrates. Finally, reagents which elevate intracellular cAMP levels facilitated growth of minor neurites and inhibited growth of major neurites and thus interfered with the establishment of a polarized phenotype on both ECM and control substrates. Our results suggest that protein kinases mediate the effects of ECM molecules on neuronal polarity and that different kinases control extension of axons and dendrites.     

Cytotoxicity of curcuminoids and some novel compounds from Curcuma zedoaria

Bioassay-directed fractionation of an EtOH extract of Curcuma zedoaria led to isolation of an active curcuminoid, which was identified as demethoxycurcumin (2) by comparison of its 1H and 13C NMR spectra with literature data and by direct comparison with synthetic material. Curcumin (1) and bisdemethoxycurcumin (3) were also obtained. Curcuminoids (1-3) were synthesized and demonstrated to be cytotoxic against human ovarian cancer OVCAR-3 cells. The observed CD50 values of 1, 2, and 3 were 4.4, 3.8, and 3.1 microg/mL, respectively. Three additional novel compounds, 3, 7-dimethylindan-5-carboxylic acid (4), curcolonol (5), and guaidiol (6), were also isolated from the EtOH extract. The structures and relative stereochemistry of 4-6 were determined by spectroscopic methods and X-ray crystallographic analysis.     

Reducing pregnancy and induced abortion rates in China: family planning with husband participation

OBJECTIVES: This study assessed the effectiveness of a family planning intervention with and without husband's participation in reducing pregnancy and abortion rates in Shanghai, China. METHODS: In this 3-arm randomized trial among 1800 nonsterilized married women, educational interventions targeting both spouses and targeting the wife only were compared with usual family planning care. RESULTS: Among women not using intrauterine devices (IUDs), the intervention with husband's participation had an effect in reducing pregnancy rates (adjusted odds ratio [OR] = 0.36, 95% confidence interval [CI] = 0.12, 1.1) and abortion rates (adjusted OR = 0.29, CI = 0.09, 0.94) compared with control subjects, and a significant effect in reducing pregnancy rates (adjusted OR = 0.29, CI = 0.10, 0.85) and abortion rates (adjusted OR = 0.24, CI = 0.07, 0.77) compared with wife-only subjects. CONCLUSIONS: Family planning interventions involving husbands may reduce pregnancy and abortion rates among non-IUD users.     

Treatment of cutout of a lag screw of a dynamic hip screw in an intertrochanteric fracture

Sixteen consecutive patients with cutout of a lag screw of a dynamic hip screw fixation in an intertrochanteric fracture were treated with reinsertion of a lag screw, bone cement supplementation in the neck-trochanter, and subtrochanteric valgus osteotomy. Postoperatively, patients were permitted to ambulate with protected weight-bearing. Fourteen patients were followed-up for at least 1 year (median 2 years; range 1-3 years), and all had a solid union. The union period took a median of 5 months, with a range of 3-7 months. Usually, union of an intertrochanteric fracture was faster than that of subtrochanteric osteotomy (P < 0.01). There were no complications of wound infection, loss of reduction, cutout of a lag screw, or osteonecrosis of the femoral head. From clinical and theoretical considerations, we conclude that despite cutout of a lag screw of a dynamic hip screw fixation being difficult to treat, out technique still can provide an excellent outcome. Therefore, we strongly recommend its wide use.