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971.
Dale C. Garell 《The Western journal of medicine》1967,106(5):368-371
Obesity constitutes a major health problem in the United States. Hypertension, atherosclerosis, coronary artery disease, diabetes and gout are often associated with obesity and may be a direct result of persistent obesity in adult life.Obesity frequently has its beginnings in childhood and adolescence. Unfortunately, obesity which develops in early life is a progressive problem. Eighty per cent of overweight children and adolescents will continue to be overweight as adults.12 Furthermore, adults with a history of obesity in childhood are the most resistant to treatment.Recent studies have shown there is more than one body constitutional type among obese adolescents. Obese adolescents tend to eat less than non-obese controls. While obesity may be found to have many different causative factors, efforts to control this disease may be most successful in the area of primary prevention. 相似文献
972.
Summary
Vitreoscilla contained a homodimeric bacterial hemoglobin (VtHb). The purification of this protein yielded VtmetHb which exhibited electronic and electron paramagnetic resonance (EPR) spectra, showing that it existed predominantly in a high-spin ferric form, both axial and rhombic components being present. The preparations also contained variable amounts of low-spin components. There was no evidence that these high-spin and low-spin forms were in equilibrium. The former were reducible by NADH catalyzed by the NADH-metVtHb reductase, and the latter were not. High ionic strength and high pH led to the formation of low-spin metVtHb; both treatments were reversible. Cyanide and imidazole liganded to VtHb resulted in the conversion of high-spin to low-spin ferric heme centers, each with characteristic electronic and EPR spectra. Some preparations of VtHb exhibited EPR signals consistent with a sulfur ligand bound to the ferric site. When VtHb was treated with NADH plus the reductase in the presence of oxygen, the intensity of the high-spin EPR signals decreased significantly. No reduction occurred in the absence of oxygen, suggesting a possible role for the superoxide anion. Dithionite treatment of VtHb resulted in a slow reduction, but the main product of the reaction of dithionite-reduced VtHb with oxygen was VtmetHb, not VtHbO2. EPR spectra of whole cells ofVitreoscilla exhibited a variety of intense signals at low and high magnetic field, theg-values being consistent with the presence of high-spin ferric heme proteins, in addition to an iron-containing superoxide dismutase (FeSOD) and iron-sulfur proteins. EPR spectra of the cytosol fraction ofVitreoscilla showed the expected resonances for VtmetHb and FeSOD.Abbreviations
A
absorbance
- DEAE
diethylaminoethyl
- EDTA
ethylenediamine tetraacetate
- EPR
electron paramagnetic resonance
- HiPIP
high-potential iron protein
- SDS
sodium dodecyl sulfate
- SOD
superoxide dismutase
- VtHb
Vitreoscilla hemoglobin
- VtmetHb
oxidizedVitreoscilla hemoglobin
- VtHbO2
oxygenatedVitreoscilla hemoglobin 相似文献
973.
Abstract. The traditional approach to the analysis of species association within a community, based upon co-occurrence in sampling units such as quadrats, has been to test all pairs of species, using a 2 × 2 contingency table for each pair. It has long been recognised that all these tests are not independent of each other, but there is an additional problem in that the association between any particular pair may depend on the combination of the other species that are present or on the environmental factors that determine that combination. We use a 2k contingency table to examine this problem and find that pairwise associations are not independent of the other species. The second problem that we consider is the effect of spatial autocorrelation in the data which makes the statistical tests too liberal. In the absence of a derived solution for a deflation factor to correct the test statistic calculated from a 2k table, we describe a Monte Carlo approach that provides an approximate solution to this problem. In our data the amount of deflation that is necessary for a 2k table is small compared to the amount required for the 2 × 2 tables used to test pairwise association. 相似文献
974.
Scheherazade Sadegh-Nasseri Dale E. Kipp Benjamin A. Taylor Alexander Miller Eli Sercarz 《Immunogenetics》1984,20(5):535-546
Genes outside of the mouse major histocompatibility complex (H-2) were found to be capable of specifically reversing the previously described nonresponsiveness to hen egg-white lysozyme (HEL) owing to H-2
b
immune response (Ir) genes. C3H.SW, BALB.B, and C57L, all of the H-2
b
haplotype, showed responsiveness to HEL, but not to human lysozyme (H UL). Mapping of the reversing gene(s) was attempted by testing H-2
b
recombinant inbred (RI) strains of mice carrying C3H, BALB, and C57L non-H-2
b
genes. Analysis of the strain distribution pattern of responsiveness with both CXB and BXH RI strains was consistent with the location of the responsible site within the H-3 region on chromosome 2. The anti-HEL proliferative responsiveness in two H-3 congenic strains of mice, B10.C(28NX)
SN
and B10.C-H-3
cH-3
a
, that have BALB/c genes within the H-3 region confirmed the mapping, as well as localized the reversing gene(s) near the Ir-2 gene. The data are discussed with regard to the site of expression of the reversing gene(s) and its mechanism of action.Abbreviations used in this paper MHC
major histocompatibility complex
- HEL
hen egg-white lysozyme
-
Ir
immune response gene
- HUL
human lysozyme
- SDP
strain distribution pattern
- PFC
plaque-forming cells;
2
m,
2-microglobulin
- CFA
complete Freund's adjuvant
- PT-LN
parathymic lymph nodes
- RI
recombinant inbred mice 相似文献
975.
Phencyclidine and Analogues: Effects on Brain Protein Synthesis 总被引:1,自引:1,他引:0
Abstract: Phencyclidine and four analogues were tested for their capacity to inhibit total protein synthesis in a brain homogenate. At 1.0 m M they were all found to be potent inhibitors with values ranging from 36% to 96% inhibition. At this high concentration two of the analogues were equal to or more effective than the classic protein synthesis inhibitors cycloheximide and emetine. At lower concentrations the inhibition dropped off sharply to 18% at 1.0 × 10−4 M and 9% at 1.0 × 10−5 M for phencyclidine. If the inhibition observed in the brain homogenate occurs in vivo it may account for the high incidence of memory loss reported with phencyclidine use. 相似文献
976.
Glutamine Oxidation by Dissociated Cells and Homogenates of Rat Brain: Kinetics and Inhibitor Studies 总被引:4,自引:3,他引:1
The rates of [U-14C]glutamine oxidation to 14CO2 were determined under a variety of experimental conditions using whole homogenates and dissociated cells from rat brain. The pattern of glutamine oxidation by homogenates differed from that by dissociated brain cells in several respects. The rates of glutamine oxidation by dissociated brain cells showed saturation kinetics with an apparent Km of 0.30 mM. Lineweaver-Burk plots of glutamine oxidation by homogenates revealed two linear segments with two apparent Km values (0.58 mM and 3.0 mM). In the presence of aminooxyacetate, however, the Lineweaver-Burk plots for homogenates were linear with a single Km of 0.47 mM. The oxidation of glutamine by homogenates was inhibited by both rotenone and antimycin A (80-85%), as were glutamate and glucose oxidation, suggesting that a significant amount of glutamine is oxidized via the tricarboxylic acid cycle. In the presence of aminooxyacetate, glutamine oxidation was inhibited less than 40%, whereas the oxidation of glutamate was inhibited 75%; in contrast, glucose oxidation was enhanced 50%. The rates of glutamine oxidation by homogenates were highest in the presence of high levels of potassium (50 mM) and low levels of sodium (2.5 mM). Varying ionic composition, however, had little or no effect on the rates of glutamine oxidation by dissociated brain cells. Measurements of glutamine oxidation by homogenates prepared from 2-, 10-, 15-, 25-, and 90-day-old rats revealed little or no age-dependent difference. In contrast, the oxidation by dissociated brain cells from 2-day-old animals was significantly less than that obtained for animals 10 days or older (7.76 vs. 15.6 nmol/h/mg).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
977.
Concentrations of phorbol myristate acetate and the calcium ionophore, A23187, which by themselves are minimally effective in stimulating superoxide generation in human neutrophils show marked mutual potentiation when given together. This supports the hypothesis that synergism between cytosolic calcium and protein kinase C is involved in the stimulus/activation coupling of the respiratory burst in the neutrophil. 相似文献
978.
Development of the eyelids and cornea in repeated epilation (Er/Er) mice is characterized by fusion of the tarsal conjunctiva to the epithelia of the bulbar conjunctiva and cornea. We investigated the ultrastructural features of this malformation and tested for abnormal expression of filaggrin by immunofluorescence. Heterozygous (Er/+) breeding stock were mated and 13,14,15, and 19-day-old embryos were studied by light and electron microscopy. Fusion occurred in all Er/Er specimens and was associated with abnormal migration of surface ectodermal cells onto the cornea. Immunofluorescence studies with antimouse filaggrin antibody on day 13 and day 15 revealed the presence of filaggrin precursors in the fused epithelia of mutants, but not in normal corneal or conjunctival epithelia. The results suggest defective regulation of the synthesis of cellular proteins and altered cell surface properties in the Er/Er ocular epithelia. 相似文献
979.
The virus PBCV-1, which replicates in a Chlorella-like green alga, has a dsDNA genome. The DNA was mapped for BamHI, HindIII, and PstI restriction sites. The resulting map has a size of 333 kbp and is circular—indicating either covalently closed circular DNA or circularly permuted linear DNA. Several regions of repetitive DNA were also identified and located on the restriction map. 相似文献
980.
Six hundred patients with chronic leg ulcers were studied by detailed history and examination as part of a population survey. In 22% ulceration began before the age of 40, and in this group the sex incidence was equal. Over age 40 there was an increasing preponderance of women. Ulcers were significantly more common in the left leg in women but not in men. The site of 26% of ulcers did not include the classical medial goiter area. The median duration of the ulceration at the time of the survey was nine months and 20% had not healed in over two years. The great majority of patients had had recurrence, 66% having had episodes of ulceration for more than five years. Healing of ulcers is a serious problem, but preventing recurrence is the greater challenge. 相似文献