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61.
The natural 13C abundance (13C value) of the field-grown leguminousplants (soybean, kidney bean, pea, azuki bean, mung bean, peanutand cowpea) was investigated by mass spectrometry with a precisionbetter than %0.2 for 13C. Among organs of premature plants,the leaves had the most negative values, and the nodules generallyhad the least negative values, and other organs, fruits, stemsand roots, showed intermediate values. In the soybeans so farinvestigated, the grains of nodulating plants exhibited higher13C values than nonnodulating lines. The 13C values of the grainsvaried depending on the species: peanuts showed the most negativevalues. Possible causes underlying these variations are discussed. (Received March 2, 1983; Accepted May 27, 1983) 相似文献
62.
63.
Does New Guinea cannibalism have nutritional value? 总被引:1,自引:0,他引:1
This paper examines the question of the nutritional value of cannibalism. Although other authors have concluded that the practice does not have such value, we argue that this cannot properly be determined except in the context of the total subsistence economy and local human ecology. The paper also presents a format for the empirical investigation of foodgetting and new ethnographic information about New Guinea cannibalism. Our major conclusion is that this practice does have nutritional value for certain human groups, specifically tropical peoples living at lowmedium population densities and exploiting a diverse range of animal foods. 相似文献
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65.
Evidence for a Reductive Pathway for the Anaerobic Metabolism of Benzoate 总被引:18,自引:6,他引:12 下载免费PDF全文
Evidence is presented for a reductive pathway for the anaerobic metabolism of benzoate by Rhodopseudomonas palustris. 相似文献
66.
This investigation was undertaken to study heat stress and dehydration effects on 1) plasma lactic acid (LA) concentration and 2) plasma LA effect on plasma volume conservation during thermal dehydration. Experiments were performed on conscious nonacclimated and heat-acclimated laboratory rats subjected to various levels of heat stress and/or dehydration (37-42 degrees C with and without drinking water). During the exposures, rectal temperature (Tre), plasma LA pyruvic acids, and hematocrit were measured. From these data, excess LA, indicative of anaerobic metabolism, was calculated. In separate experiments, transvascular protein efflux (half time of Evans blue-labeled albumin) was measured before and after plasma LA elevation, either by LA infusion or thermal dehydration. The results show that elevation of plasma LA was associated with a rise in Tre, with accelerated elevation within a Tre range of 41-42 degrees C. LA concentrations were similar for the same Tre in all experimental groups. In nonacclimated rats, this rise was accompanied by a significant rise in excess LA. In acclimated rats, only a minor rise in excess LA was observed. A positive correlation was found between plasma LA elevation and the increase in plasma protein efflux. It is concluded that there is a temperature threshold for the rise in plasma LA. In nonacclimated rats, local hypoxia may contribute to this rise. The data also suggest that, in nonacclimated rats, lactacidemia accelerates plasma protein and fluid loss, leading to circulatory failure during acute thermal dehydration. 相似文献
67.
68.
Mark Phillippe Trevania Saunders Shrikar Bangalore 《In vitro cellular & developmental biology. Plant》1990,26(4):369-378
Summary The following studies were undertaken to develop a cultured uterine myocyte model which would allow further clarification
of the adrenergic signal transduction mechanisms utilized by these myocytes. After mechanical removal of the endometrium,
rabbit uterine myoctes were isolated by an overnight enzymatic disaggregation using collagenase and DNase I. The isolated
myocytes were maintained in culture in 75-cm2 flasks containing Waymouth's MB 751/1 medium-10% fetal bovine serum along with 10−8
M estradiol, penicillin, streptomycin, and Fungizone. The phase contrast and electron micrographic appearance of these cells
was consistent with that previously reported for smooth muscle myocytes in culture. Immunocytochemical studies utilizing monoclonal
anti-alpha-smooth muscle actin antibodies confirmed the presence of smooth muscle actin in these cultured myocytes. Western
blot studies similarly confirmed the presence of alpha-smooth muscle actin in rabbit myometrial tissue and the cultured myocytes,
both the primary and F1 generation. After prelabeling the myocytes with [3H]inositol, adrenergic stimulation experiments demonstrated alpha-1 receptor mediated stimulation of inositol phosphates.
Beta receptor stimulation experiments confirmed cAMP production in these cultured myocytes, and the ability of clonidine,
an alpha-2 agonist, to inhibit forskolin stimulated cAMP production confirmed the presence of functional alpha-2 adrenergic
receptors in these myocytes. In conclusion, these cultured rabbit uterine myocytes have provided an in vitro model which can
be utilized to further clarify the adrenergic receptor signal transduction mechanisms in genital tract smooth muscle.
This research was supported by grant HD-22063 from the National Institutes of Health, Bethesda, MD. 相似文献
69.
70.
Benjamin B. Roa Frank Greenberg Preethi Gunaratne Christine M. Sauer Mark S. Lubinsky Chahira Kozma Jeanne M. Meck R. Ellen Magenis Lisa G. Shaffer J. R. Lupski 《Human genetics》1996,97(5):642-649
Autosomal dominant Charcot-Marie-Tooth type-1A neuropathy (CMT1A) is a demyelinating peripheral nerve disorder that is commonly
associated with a submicroscopic tandem DNA duplication of a 1.5-Mb region of 17p11.2p12 that contains the peripheral myelin
gene PMP22. Clinical features of CMT1A include progressive distal muscle atrophy and weakness, foot and hand deformities, gait abnormalities,
absent reflexes, and the completely penetrant electrophysiologic phenotype of symmetric reductions in motor nerve conduction
velocities (NCVs). Molecular and fluorescence in situ hybridization (FISH) analyses were performed to determine the duplication
status of the PMP22 gene in four patients with rare cytogenetic duplications of 17p. Neuropathologic features of CMT1A were seen in two of these
four patients, in addition to the complex phenotype associated with 17p partial trisomy. Our findings show that the CMT1A
phenotype of reduced NCV is specifically associated with PMP22 gene duplication, thus providing further support for the PMP22 gene dosage mechanism for CMT1A.
Received: 3 May 1995 / Revised: 1 August 1995 相似文献