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81.
Paul L. Black Hamblin Phillips Henry R. Tribble Robin Pennington Mark schneider James E. Talmadge 《Cancer immunology, immunotherapy : CII》1993,37(5):299-306
The mechanism of therapeutic activity for recombinant murine interferon-(rMu IFN) in the treatment of metastatic disease was investigated by comparing effector cell augmentation with therapeutic activity in mice bearing experimental lung metastases (B16-BL6 melanoma). Effector cell functions in spleen, peripheral blood, and lung (the tumor-bearing organ) were tested after 1 week and 3 weeks of rMu IFN administration (i.v. three times per week). Natural killer (NK), lymphokine-activated killer (LAK), cytolytic T lymphocyte (CTL) activities against specific and nonspecific targets, and macrophage tumoristatic activity were measured. rMu IFN demonstrated immunomodulatory activity in most assays of immune function. The optimal therapeutic protocol of rMu IFN (2.5×106 U/kg, three times per week) prolonged survival and decreased the number of pulmonary metastatic foci. This therapeutic activity was correlated with specific CTL activity from pulmonary parenchymal mononuclear cells (PPMC), but not from spleen or blood. Macrophage tumoristatic activity in PPMC also correlated with therapeutic activity, but activity in alveolar macrophages did not. However, therapeutic activity did not correlate with NK or LAK activity at any site. These results demonstrate that the optimal therapeutic protocol is the same as the optimal immunomodulatory dose for pulmonary CTL and macrophage activities. Furthermore, while immunological monitoring may help to optimize treatment protocols, current monitoring procedures that use readily accessible sites, particularly peripheral blood, may not accurately predict the therapeutic efficacy of biological response modifiers in clinical trials.By acceptance of this article, the publisher or recipient acknowledges the right of the US. Government to retain a nonexclusive, royalty-free license in and to any copyright covering the articleThis research was sponsored by the DHHS, under contract N01-23910 with Program Resources Inc. The contents of this publication do not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government 相似文献
82.
Summary Feeding nutrient to meet demand dilutes slow-growing organisms from continuous culture and greatly favors rapid growth. Doubling times of roughly 10 minutes have been verified in a pH auxostat by viable cell counts and by direct counting with a Petroff-Hausser chamber. Effects of wall attachment were negligible because a fresh reactor was substituted frequently before wall growth could become established. 相似文献
83.
84.
A virus infection is described within the unilocular sporangia of Feldmannia sp., a filamentous brown alga (Phaeophyceae). The alga is easily maintained in culture and vegetative growth is vigorous, but formation of icosahedral virions 150 nm in diameter completely displaces production of zoospores. The viruses, estimated at 1–5 × 106 per sporangium, are eventually released by rupture of the sporangial wall. Deoxyribonucleic acid (DNA) isolated from the viruses can be readily digested with restriction endonucleases and consists of ca. 170 kbp of double-stranded DNA. 相似文献
85.
86.
Henry M. McHenry 《American journal of physical anthropology》1991,86(4):445-454
The “robust” australopithecines are often depicted as having large and powerfully built bodies to match their massive masticatory apparatus, but until 1988 the sample of postcranial remains attributed with certainty to this group was very limited. Almost nothing was known about the body of the East African “robust” australopithecine because taxonomic attribution of the postcrania was so uncertain. The body of the South African “robust” australopithecine had to be reconstructed from about a dozen isolated fragments of postcrania. Now a partial skeleton is attributed with confidence to the East African “robust” group along with several isolated bones. The South African sample has more than tripled. Analyses of this vastly expanded sample reveal that a large portion of postcrania attributed to “robust” australopithecines from Swartkrans Member 1 (35%) are from extraordinarily small-bodied individuals similar in size to a modern Pygmy weighing as little as 28 kg. These small elements include parts from the forelimb, spine, and hindlimb. About 22% of these Swartkrans 1 “robust” australopithecines are about the same size as a modern human weighing about 43 kgs and about 43% are larger than this standard but less than or equal to a 54 kg modern human. Approximately the same pattern is true for the Swartkrans 2 hominids, but taxonomic attribution is less certain. All of the Member 3 specimens are similar in size to the 45 kg standard. The partial skeleton of the East African “robust” australopithecine (KNM-ER 1500) has hindlimb joints that would correspond to a modern human of 34 kgs although the actual weight may be 5 to 10 kgs greater judging from shaft robusticity and forelimb size. The largest postcranial element attributed with some certainty to the East African “robust” australopithecine group (the talus, KNM-ER 1464) is about the same overall size as a modern human of 54 kgs, although its tibial facet is slightly smaller. Although many previous studies have hinted at the possibility that “robust” australopithecines had relatively small bodies, the new fossils provide substantial evidence that these creatures ranged from quite small to only moderate in body size relative to modern humans. These were the petite-bodied vegetarian cousins of our ancestors. Sexual dimorphism in body size appears to be greater than that in modern humans, similar to that in Pan, and less than that in Gorilla or Pongo, although such comparisons are of limited value given the small samples, poorly known body proportions, time averaging, and many other problems. 相似文献
87.
Raymond D. Semlitsch Reid N. Harris Henry M. Wilbur 《Evolution; international journal of organic evolution》1990,44(6):1604-1613
A “common garden” experiment using artifical ponds was performed to test if differences in frequency of paedomorphosis and metamorphosis among six natural populations of the salamander Ambystoma talpoideum resulted from the drying regime of the aquatic habitat acting as an agent of selection. Our experiment supports the hypothesis of genetic differentiation in the propensity to metamorphose among the populations, but gave mixed evidence that pond-drying regime is the selective force directing evolution of this trait. Some populations appear to have evolved phenotypic plasticity whereas others may have a genetic polymorphism in their propensity to metamorphose as ponds dry. 相似文献
88.
Are the characeae able to indicate the origin of groundwater in former river channels? 总被引:2,自引:0,他引:2
The macroscopic algae Characeae are usually assumed to occur in waterbodies supplied by groundwater with low phosphate content, but the indicative value of the species is seldom defined in bibliography. Former braided channels of the Rhône river are supplied with groundwater originating from the main channel (seepage) or from hillslope aquifer. The aim of the present paper was to determine if it possible to use the Characeae as indicators of physicochemical characteristies of water in order to assess the origin of groundwater supplying former river channels. Four former braided channels of the Rhône River colonized by Characeae were investigated, and the physico-chemical characteristics of i) the channels, ii) the groundwater and iii) the river were measured over a period of several months. Species are arranged along a gradient of conductivity, alkalinity, ammonium and phosphate content of the water. Charophyte species can indicate the origin of groundwater, either seepage or hillslope nutrient-poor aquifer, and integrate both the average value of the chemical parameter, and their variations. C. hispida occurs in a nutrient-poor channel mainly supplied by highly calcareous groundwater coming from hillslope aquifer. Chara major has requirements close to those of C. hispida, but is more tolerant to periodic inputs of nutrients. C. vulgaris and N. syncarpa both tolerate mesotrophic waters originating from both hillslope aquifer and seepage, and C. globularis is associated to a channel mainly supplied by mesotrophic to eutrophic river seepage. 相似文献
89.
Evolution of reproductive systems in the genus Silene 总被引:2,自引:0,他引:2
Desfeux C Maurice S Henry JP Lejeune B Gouyon PH 《Proceedings. Biological sciences / The Royal Society》1996,263(1369):409-414
The genus Silene contains both hermaphrodite, gynodioecious and dioecious species, dioecy being represented in three sections of the genus. To locate the events of change of reproductive systems, we compared ITS sequences of 22 species of Silene chosen throughout the whole genus, and four putative outgroup species. Gynodioecy, which is the most common reproductive system within the genus Silene and in closely related genera such as Saponaria and Dianthus, is proposed to be ancestral in the genus. Dioecy has evolved at least twice: once in the section containing S. latifolia, and once in the clade containing S. otites and S. acaulis ssp. bryoides. Evolution towards hermaphroditism, associated with evolution of selfing has also occurred at least twice, in S. gallica and S. comica. 相似文献
90.
Rospars Jean-Pierre Lánský Petr Tuckwell Henry C. Vermeulen Arthur 《Journal of computational neuroscience》1996,3(1):51-72
The coding of odor intensity by an olfactory receptor neuron model was studied under steady-state stimulation. Our model neuron is an elongated cylinder consisting of the following three components: a sensory dendritic region bearing odorant receptors, a passive region consisting of proximal dendrite and cell body, and an axon. First, analytical solutions are given for the three main physiological responses: (1) odorant-dependent conductance change at the sensory dendrite based on the Michaelis-Menten model, (2) generation and spreading of the receptor potential based on a new solution of the cable equation, and (3) firing frequency based on a Lapicque model. Second, the magnitudes of these responses are analyzed as a function of odorant concentration. Their dependence on chemical, electrical, and geometrical parameters is examined. The only evident gain in magnitude results from the activation-to-conductance conversion. An optimal encoder neuron is presented that suggests that increasing the length of the sensory dendrite beyond about 0.3 space constant does not increase the magnitude of the receptor potential. Third, the sensivities of the responses are examined as functions of (1) the concentration at half-maximum response, (2) the lower and upper concentrations actually discriminated, and (3) the width of the dynamic range. The overall gain in sensitivity results entirely from the conductance-to-voltage conversion. The maximum conductance at the sensory dendrite appears to be the main tuning constant of the neuron because it determines the shift toward low concentrations and the increase in dynamic range. The dynamic range of the model cannot exceed 5.7 log units, for a sensitivity increase at low odor concentration is compensated by a sensitivity decrease at high odor concentration. 相似文献