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121.
Naegleria fowleri, which produces a fatal meningoencephalitis in humans, is also able to produce a progressive and fatal disease in mice. The course of the disease in DUB/ICR mice is dependent upon the infecting dose of organisms, whether administered intraperitoneally (i.p.) or intravenously (i.v.). All of the mice receiving 10(7) trophozoites/mouse i.v. or 4.85 X 10(7) trophozoites/mouse i.p. were killed within 10 days. Escherichia coli O26:B6 lipopolysaccharide, administered at a dose of 1 mg/kg 24 h prior to N. fowleri, afforded some protection for several days after challenge, but by day 8 there was no difference in survival of untreated and endotoxin-treated mice. No significant protection was afforded by a complex of lipid A with concanavalin A (ConA) or bovine serum albumin (BSA) or by dimethylmyristamide-BSA, dimethylmyristamide, BSA, beta-hydroxymyristic acid-ConA, beta-hydroxymyristic acid, ConA, myristic acid-BSA, or myristic acid. Mice surviving primary i.v. or i.p. challenge doses of N. fowleri, 5 X 10(6) and 10(7) trophozoites/mouse, respectively, were highly resistant to rechallenge with an i.v. dose of organisms (5 X 10(6) Naegleria/mouse) that produced uniformly fatal disease in untreated control mice. 相似文献
122.
Gaye?T?Adams Harold?Snieder Virgil?C?McKie Betsy?Clair Donald?Brambilla Robert?J?Adams Ferdane?Kutlar Abdullah?KutlarEmail author 《BMC medical genetics》2003,4(1):6
Background
The phenotypic heterogeneity of sickle cell disease is likely the result of multiple genetic factors and their interaction with the sickle mutation. High transcranial doppler (TCD) velocities define a subgroup of children with sickle cell disease who are at increased risk for developing ischemic stroke. The genetic factors leading to the development of a high TCD velocity (i.e. cerebrovascular disease) and ultimately to stroke are not well characterized. 相似文献123.
The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry 总被引:8,自引:1,他引:8
Nistico L; Buzzetti R; Pritchard LE; Van der Auwera B; Giovannini C; Bosi E; Larrad MT; Rios MS; Chow CC; Cockram CS; Jacobs K; Mijovic C; Bain SC; Barnett AH; Vandewalle CL; Schuit F; Gorus FK; Tosi R; Pozzilli P; Todd JA 《Human molecular genetics》1996,5(7):1075-1080
Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus
is determined by a combination of environmental and genetic factors, which
include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin
gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2
cannot explain the clustering of type 1 diabetes in families, and a role
for other genes is inferred. In the present report we describe linkage and
association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte
associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong
candidate gene for T cell- mediated autoimmune disease because it encodes a
T cell receptor that mediates T cell apoptosis and is a vital negative
regulator of T cell activation. In addition, we provide supporting evidence
that CTLA-4 is associated with susceptibility to Graves' disease, another
organ- specific autoimmune disease.
相似文献
124.
Post-exercise ketosis and the glycogen content of liver and muscle in rats on a high carbohydrate diet 总被引:1,自引:0,他引:1
Summary Post-exercise ketosis is known to be suppressed by physical training and by a high carbohydrate diet. As a result it has often
been presumed, but not proven, that the development of post-exercise ketosis is closely related to the glycogen content of
the liver. We therefore studied the effect of 1 h of treadmill running on the blood 3-hydroxybutyrate and liver and muscle
glycogen concentrations of carbohydrate-loaded trained (n=72) and untrained rats (n=72). Resting liver and muscle glycogen levels were 25%–30% higher in the trained than in the untrained animals. The resting
3-hydroxybutyrate concentrations of both groups of rats were very low: <0.08 mmol·1−1. Exercise did not significantly influence the blood 3-hydroxybutyrate concentrations of trained rats, but caused a marked
post-exercise ketosis (1.40±0.40 mmol·1−1 1 h after exercise) in the untrained animals, the time-course of which was the approximate inverse of the changes in liver
glycogen concentration. Interpreting the results in the light of similar data obtained after a normal and low carbohydrate
diet it has been concluded that trained animals probably owe their relative resistance to post-exercise ketosis to their higher
liver glycogen concentrations as well as to greater peripheral stores of mobilizable carbohydrate. 相似文献
125.
Turrisi R Hillhouse J Heavin S Robinson J Adams M Berry J 《Journal of behavioral medicine》2004,27(4):393-412
The research evaluated an intervention strategy designed to prevent skin cancer in young adolescents. The intervention used parents as change agents to effectively communicate the risks of skin cancer and encourage their children to avoid high-risk sun-related behaviors while increasing positive sun-safe behaviors. Three hundred and forty parents in two regions of the United States were educated about the dangers of risky sun behaviors and how to convey information about skin cancer prevention to their children. Parents were then encouraged to talk with their children about these issues over a 1-month period prior to the onset of summer. Following this time period, children whose parents received and implemented the intervention materials were compared with a control sample of 129 children. These two groups were matched on age, gender, and school on number of sunburns and sunburn severity, attitudes and beliefs, and sunbathing behavior. Children in the treatment condition differed significantly from controls in the predicted directions on all outcome variables. The findings are discussed in terms of reducing skin cancer risk behaviors of children via parent-based intervention approaches. 相似文献
126.
127.
Vivek Kapur Joanne T. Maffei Rebecca S. Greer Ling-Ling Li Gerald J. Adams James M. Musser 《Microbial pathogenesis》1994,16(6)
Virtually all clinical isolates of group A streptococci secrete a highly conserved extracellular cysteine protease that cleaves human fibronectin and vitronectin, and converts IL-1β precursor to biologically active IL-1β. Based on the high degree of gene conservation within the species and its role in host pathogenicity, it was postulated that antibodies to the cysteine protease would confer protective immunity against S. pyogenes infection. To test this hypothesis, Swiss CD1 mice were intraperitoneally administered either saline, rabbit IgG, or IgG from rabbits immunized with the protease, and challenged with a highly virulent (minimum lethal dose 10 cfu) clinical isolate of S. pyogenes expressing a heterologous cysteine protease. The results indicate that mice administered IgG from rabbits immunized with purified cysteine protease had significantly enhanced survival when compared with mice given either non-specific rabbit IgG (log rank test; χ2; p = 0.0195) or saline (log rank test; χ2; p = 0.0002). Moreover, mice actively immunized with the cysteine protease had a significantly longer time to death than the control group (log rank test; χ2; p = 0.0418). The results show that the cysteine protease elicits non-type-specific immunity to challenge with heterologous S. pyogenes. 相似文献
128.
Plant virus transmission by plasmodiophorid fungi is associated with distinctive transmembrane regions of virus-encoded proteins 总被引:1,自引:0,他引:1
Summary. Computer analysis of published sequence data has consistently identified two complementary transmembrane domains in the coat
protein readthrough domains of benyviruses, furoviruses and pomoviruses and in the P2 proteins of bymoviruses. These viruses
differ in genome organisation but are all transmitted by plasmodiophorid fungi. The second domain is absent or disrupted in
naturally-occurring deletion mutants that cannot be fungally-transmitted. In a non-transmissible substitution mutant of Beet necrotic yellow vein virus [Tamada et al. (1996) J Gen Virol 77: 1359–1367], the alignment of the helices is disrupted. From conserved patterns detected
in transmembrane helix sequences and calculated relative helix tilts, structural arrangements consistent with tight packing
of transmembrane helices were identified. These included ridge/groove arrangements between the two helices and strong electrostatic
associations at the interfacial regions of the membrane. The data strongly suggest that these transmembrane helices facilitate
the movement of virus particles across the fungal membrane.
Accepted November 9, 2000 Received June 30, 2000 相似文献
129.
Gastrointestinal graft-versus-host disease in recipients of autologous hematopoietic stem cells: incidence, risk factors, and outcome. 总被引:2,自引:0,他引:2
Leona Holmberg Kaoru Kikuchi Ted A Gooley Kristina M Adams David M Hockenbery Mary E D Flowers H Gary Schoch William Bensinger George B McDonald 《Biology of blood and marrow transplantation》2006,12(2):226-234
Graft-versus-host disease (GVHD) is seen in skin, intestinal mucosa, and liver after autologous stem cell transplantation. We reviewed 681 consecutive patients to estimate the probability of gastrointestinal (GI) GVHD, response to treatment, risk factors for development, and effect on survival. GI GVHD was defined by persistent symptoms, mucosal abnormalities at endoscopy, and histology showing apoptotic crypt cells with or without lymphoid infiltrates. The proportion of patients with GI GVHD was 90/681 (13%). Nausea and vomiting occurred in 90% and diarrhea in 40%. The mean time to developing symptoms was day +15, that to histologically proven diagnosis was day +42, and that to starting prednisone treatment was day +45 after stem cell infusion. Treatment with a short course of prednisone effected durable responses in 79% of patients, and an additional 18% responded to a second course of prednisone. A multivariable logistic regression model demonstrated that the combined factor of a diagnosis of breast cancer or hematologic malignancy and female sex was statistically significantly associated with the probability of GI GVHD (P = .003). Survival in patients with GI GVHD was not statistically different than that in those without GVHD. We conclude that women with breast cancer or hematologic malignancy are more likely to develop GI GVHD after autologous transplantation, and that treatment with prednisone was effective. 相似文献
130.
The present study was conducted to test Brener's calibration theory of visceral learning. It was hypothesized that training in discrimination of cephalic vasomotor responses would enhance acquisition of voluntary and biofeedback control of cephalic vasomotor response. Four groups were given discrimination training to detect either constriction, dilation, both constriction and dilation, or given false feedback. All groups were then given biofeedback training in constriction. All groups were assessed on discrimination accuracy, acquisition of biofeedback control of constriction, and voluntary control of dilation and constriction. The results indicated that discrimination of cephalic vasomotor responses can be learned and that this skill facilitates the acquisition of biofeedback and voluntary control of vasomotor responses. This facilitation occurs only if discrimination training is given for the specific response to be learned. The data suggest that discrimination of the relevant response is a necessary but not sufficient condition for acquisition of voluntary control in biofeedback learning. 相似文献