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1.
Brown E. G.; Krouskop R. W.; McDonnell F. E.; Monge C. C.; Winslow R. M. 《Journal of applied physiology》1985,58(4):1383-1389
In hypoxemic high-altitude polycythemic natives whose arterial O2 saturation (SaO2) normally ranges between 70 and 80%, three polyurethane catheters with both optical and polarographic sensors were inserted into the radial artery to measure SaO2 and O2 tension (PaO2), and three thermodilution fiber-optic balloon-tipped catheters were floated into the pulmonary artery to measure mixed venous O2 saturation (SvO2). Correlation of the in vivo SaO2, PaO2, and SvO2 values with the in vitro measurements was high (r = 0.97, 0.99, and 0.98, respectively). Both catheters were inserted in one polycythemic subject before and 4 days after isovolemic hemodilution. Data from the sensors were used to calculate arteriovenous O2 content difference (CaO2 - CvO2) and the O2 half-saturation pressure of hemoglobin (P50). The mean +/- 1 SD of the in vivo and in vitro P50 calculated with the Hill equation was 27.61 +/- 2.15 Torr and 27.35 +/- 1.60 Torr, respectively. The mean +/- 1 SD of the absolute difference between the in vivo and in vitro measurements was 1.16 +/- 1.21 Torr. The in vivo CaO2 - CvO2 correlated well with the in vitro measurements (r = 0.93), and the mean +/- 1 SD of the error in the catheter CaO2 - CvO2 measurements was 0.47 +/- 0.50 ml/dl. This technique appears to provide a useful measurement of blood gas exchange parameters and should be applicable to the study of exercise physiology and clinical regulation of O2 transport. 相似文献
2.
C. Carey O. Dunin-Borkowski F. Leon-Velarde D. Espinoza C. Monge 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1994,163(8):649-656
Oxygen consumption, air cell gases, hematology, blood gases and pH of Puna teal (Anas versicolor puna) embryos were measured at the altitude at which the eggs were laid (4150 m) in the Peruvian Andes. In contrast to the metabolic depression described by other studies on avian embryos incubated above 3700 m, O2 consumption of Puna teal embryos was higher than even that of some lowland avian embryos at equivalent body masses. Air cell O2 tensions dropped from about 80 toor in eggs with small embryos to about 45 toor in eggs containing a 14-g embryo; simultaneously air cell CO2 tension rose from virtually negligible amounts to around 26 torr. Arterial and venous O2 tensions (32–38 and 10–12 toor, respectively, in 12- to 14-g embryos) were lower than described previously in similarly-sized lowland wild avian embryos or chicken embryos incubated in shells with restricted gas exchange. The difference between air cell and arterial O2 tensions dropped significantly during incubation to a minimum of 11 torr, the lowest value recorded in any avian egg. Blood pH (mean 7.49) did not vary significantly during incubation. Hemoglobin concentration and hematocrits rose steadily throughout incubation to 11.5 g · 100 ml-1 and 39.9%, respectively, in 14-g embryos.Abbreviations PO2
partial pressure gradient of O2
- BM
body mass
-
D
diffusion coefficient
-
G
gas conductance (cm3·s-1·torr-1)
-
conductance to water vapor
- IP
internal pipping of embryos
-
P
ACO2
partial pressure of carbon dioxide in air cell
-
P
AO2
partial pressure of oxygen in air cell
-
P
aCO2
partial pressure of carbon dioxide in arterial blood
-
P
aCO2
partial pressure of oxygen in arteries
-
P
H
barometric pressure (torr)
-
PCO2
partial pressure of carbon dioxide
-
P
IO2
partial pressure in ambiant air
-
PO2
partial pressure of oxygen
-
P
VCO2
venous carbon dioxide partial pressure
-
P
VO2
mixed venous oxygen partial pressure
- SE
standard error
-
VO
2
oxygen consumption 相似文献
3.
4.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
5.
6.
Callosobruchus maculatus (F.) is a tropical insect (Coleoptera: Bruchidae) that develops in Vigna unguiculata (Walp) seeds. In this beetle, there are two distinct adult forms that differ in their morphology, physiology and behaviour, the flight form and the flightless form. The development of C. maculatus is analyzed in a traditional store in Niger. During the dry season, 6 to 7 generations of the flightless form develop in the store. When the atmospheric water content increases during the rainy season, adults of the flight form appear and escape from the store. Experimental studies have shown that the adult polymorphism is induced during post-embryonic development and depends on prevailing abiotic factors during this period. The proportion of flight from adults is high when larvae develop in moist seeds (14–15% of water content). Under dry conditions (6–7% of water content) only flightless adult forms emerge from the seeds. Temperatures during development also influence adult polymorphism. In thermoperiodic conditions with 12–13% seed water content, the proportion of flight from adults increases with increasing duration of the thermophase. However, at low temperatures, a high proportion of flightless adult forms emerge, regardless of seed water content. The adaptive importance of these two abiotic factors on polymorphism induction is examined in this study.
Résumé Callosobruchus maculatus (F.) est un Coléoptère Bruchidae tropical qui se développe aux dépens des graines de Vigna unguiculata. Les adultes présentent un polymorphisme; il y a en effet deux formes, la forme voilière et la forme non voilière, distinctes par des critères morphologiques, physiologiques et comportementaux. L'évolution des populations de C. maculatus a été suivie pendant toute la saison sèche et le début de la saison des pluies dans la région de Niamey au Niger (13° LN) à l'intérieur d'un grenier traditionnel. Pendant toute la saison sèche, 6 à 7 générations de C. maculatus de la forme non voilière se succèdent à l'intérieur du grenier. Les adultes de la forme voilière, très actifs, apparaissent surtout au cours de la saison des pluies lorsque la teneur en eau de l'atmosphère et la teneur en eau des graines augmentent. Les études expérimentales réalisées au laboratoire montrent que le polymorphisme imaginal est induit au cours du développement post-embryonnaire et dépend des conditions climatiques dans lesquelles celui-ci a lieu. Le taux d'adultes de la forme voilière est élevé lorsque les larves se développent dans des graines à forte teneur en eau (14 ou 15%). Lorsque la teneur en eau des graines est faible (6 à 7%), il n'y a émergence que d'adultes de la forme non voilière. Lorsque la teneur en eau des graines est comprise entre 12 et 13%, le taux d'adultes de la forme voilière s'accroit et varie avec la durée de la thermophase. A basse température il y a toujours émergence d'adultes de la forme non voilière, quelle que soit la teneur en eau des graines. L'influence de ces deux facteurs abiotiques sur l'induction du polymorphisme imaginal joue probablement un rôle important dans les mécanismes adaptatifs permettant le maintien de cette espèce en zone tropicale.相似文献
7.
Rihab Mohamad Jean‐Paul Monge Marlène Goubault 《Entomologia Experimentalis et Applicata》2013,147(2):99-109
Biological control of bruchid beetles, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae), infesting cowpea seeds, Vigna unguiculata (L.) Walpers (Fabaceae), can be performed via augmentative releases of Dinarmus basalis Rondani (Hymenoptera: Pteromalidae) parasitoid wasps. Females of the latter species are therefore likely to experience intense intraspecific competition: they should encounter numerous previously parasitized hosts but also conspecific competitors, with which they may fight to secure hosts on which to lay their eggs. Such contests might therefore disrupt biological control programs. Here, we studied aggressive behavior that D. basalis females show toward conspecific competitors and subsequent host exploitation strategies. We further investigated factors that classically affect contest intensity and outcomes in animals, such as the effect of ownership status, by manipulating the residency period before the intruder's arrival. In addition, we tested the effect of the size of female reproductive tissue (measured in terms of egg load) and the quality of the habitat previously experienced by females (either rich or poor in hosts). These two factors are expected to influence the value that females place on the host and therefore the costs they are willing to pay to win it. Finally, we discussed the consequences of agonistic behaviors on females' host exploitation strategies. Our results suggest that contest competition may actually enhance host control by favoring parasitoid dispersion, rather than disrupting it. 相似文献
8.
Ignacio Pérez-Valero Alicia González-Baeza Miriam Estébanez María L. Montes-Ramírez Carmen Bayón Federico Pulido José I. Bernardino Francisco X. Zamora Susana Monge Francisco Gaya María Lagarde Rafael Rubio Asunción Hernando Francisco Arnalich José R. Arribas 《PloS one》2013,8(7)
Background
In patients who remain virologically suppressed in plasma with triple-drug ART a switch to protease inhibitor monotherapy maintains high rates of suppression; however it is unknown if protease inhibitor monotherapy is associated to a higher rate of neurocognitive impairment.Methods
In this observational, cross-sectional study we included patients with plasma virological suppression (≥1 year) without concomitant major neurocognitive confounders, currently receiving for ≥1 year boosted lopinavir or darunavir as monotherapy or as triple ART. Neurocognitive impairment was defined as per the 2007 consensus of the American Association of Neurology. The association between neurocognitive impairment and protease inhibitor monotherapy, adjusted by significant confounders, was analysed.Results
Of the 191 included patients - triple therapy: 96, 1–2 years of monotherapy: 40 and >2 years of monotherapy: 55 - proportions (95% CI) with neurocognitive impairment were: overall, 27.2% (20.9–33.6); triple therapy, 31.6% (22.1–41.0); short-term monotherapy, 25.0% (11.3–38.7); long-term monotherapy: 21.4% (10.5–32.3); p = 0.38. In all groups, neurocognitive impairment was mildly symptomatic or asymptomatic by self-report. There were not significant differences in Global Deficit Score by group. In the regression model confounding variables for neurocognitive impairment were years on ART, ethnicity, years of education, transmission category and the HOMA index. Adjusted by these variables the Odds Ratio (95% CI) for neurocognitive impairment of patients receiving short-term monotherapy was 0.85 (0.29–2.50) and for long-term monotherapy 0.40 (0.14–1.15).Conclusions
Compared to triple drug antiretroviral therapy, monotherapy with lopinavir/ritonavir or darunavir/ritonavir in patients with adequate plasma suppression was not associated with a higher rate of asymptomatic neurocognitive impairment than triple drug ART. 相似文献9.
10.