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21.
Wallen L. D.; Murai D. T.; Clyman R. I.; Lee C. H.; Mauray F. E.; Kitterman J. A. 《Journal of applied physiology》1986,60(2):526-531
In fetal sheep, plasma prostaglandin (PG) E2 concentrations are high, and fetal breathing movements (FBM) occur intermittently, primarily during low-voltage fast electrocortical activity (LVFA). There is evidence suggesting that prostaglandins, specifically PGE2, may regulate FBM. To define the physiological role of PGE2 in regulation of FBM, we infused meclofenamate (0.9 mg X kg-1 X h-1), a prostaglandin synthetase inhibitor, into six fetal sheep to suppress endogenous prostaglandin production. Afterward, PGE2 was added in mean doses of 9, 18, 36, and 90 ng X kg-1 X min-1. Meclofenamate decreased PGE2 concentrations and increased FBM, especially during high-voltage slow electrocortical activity (HVSA). Addition of PGE2 reversed the effects of meclofenamate, increasing PGE2 concentrations and decreasing FBM, especially during HVSA. The response to PGE2 was dose dependent; the overall incidence of FBM and incidences of FBM during HVSA and LVFA were inversely correlated with both the infused PGE2 dose and the mean PGE2 concentration. At higher doses of PGE2, FBM occurred intermittently and only during LVFA; thus PGE2 infusion restored the physiological pattern of FBM. These results indicate that PGE2 regulates FBM by inhibiting FBM during HVSA. 相似文献
22.
Koichi Negayama Takako Negayama Kiyomi Kondo 《International journal of primatology》1986,7(4):365-378
Parturitional behavior in 12 caged Macaca fuscatawas analyzed. Wild-caught mothers showed adequate maternal behaviors immediately following the neonate’s expulsion. Parity
differences existed in the behaviors; primiparae were more idiosyncratic than were multiparae. Among multiparae, those with
two or more offspring were uniformly adequate, but those with a single birth experience varied in the adequacy of the maternal
care they provided at parturition. Mothers embraced and licked their neonates and had ventroventral contact with them frequently
immediately after parturition but decreased these behaviors after expulsion of the placenta. In contrast, mothers showed allogrooming
after consuming the placenta. Placentophagy was correlated with the level of orality represented by maternal licking behaviors.
An isolation-reared primipara reacted to her newborn in a basically negative manner, although she showed little actual aggression.
She showed a rapid shift in her negative behavior during the immediate postpartum period. This mother’s newborn sought contact
with her, indicating the neonate’s active role in establishing a stable mother-neonate bond. 相似文献
23.
24.
Nasal mucociliary clearance was measured in both healthy subjects and patients with chronic sinusitis using saccharin granule technique. Nasal mucociliary transit time (ST) was significantly slower in the patients with chronic sinusitis compared with that in controls (p less than 0.005). Nasal mucus collected from each nasal cavity was used for in vitro bullfrog palate clearance studies and compared to the in vivo nasal ST. Mucociliary clearance rate (MTR) on frog palate was 12.5 +/- 2.5 mm/min in the mucus from control subjects, 6.1 +/- 1.5 mm/min in the mucus from the patients. The difference was statistically significant (p less than 0.005). The MTR on frog palate in the patients whose nasal ST was within normal range was significantly slower than that in controls (p less than 0.005), but not significantly different from that in the patients whose nasal ST was over the normal range. These results suggest that the nasal mucous properties which decreased the mucociliary clearance on frog palate did not contribute to the mucociliary clearance of the patients who had a normal one. No significant correlation existed between MTR on frog palate and nasal ST in both control and chronic sinusitis. In chronic sinusitis patients, decelerated nasal ST was recovered significantly by normal saline nebulization compared with the value before the nebulization (p less than 0.01). None of the significant change of ST was observed in control before and after the nebulization. 相似文献
25.
Stereospecific hydroxylation of 3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-trans-and 3-C-cis-(methoxycarbonylmethylene)-α-D-ribo-hexofuranose (2 and 3, respectively), with potassium permanganate in pyridine afforded 3-C-[S- and R-hydroxy-(methoxycarbonyl)methyl]-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose, (6 and 7, respectively), in a combined yield, after chromatography, of 43%. Selective formation of monomethanesulfonates (9a and 10a) and p-toluenesulfonates (9b and 10b), followed by treatment with sodium azide and reduction of the azide, afforded the methyl 2-D-(and 2-L-)(3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-glucofuranos-3-yl)-glycinates (12a and 13a, respectively). Basic hydrolysis of the latter compounds yielded 2-D- and 2-L-(3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-glucofuranos-3-yl)glycine (12b and 13b, respectively). The structures of the glycosyl amino acids were correlated with that of L-alanine by circular dichroism. 相似文献
26.
Koichi Iijima 《Cell and tissue research》1970,103(4):460-474
Summary Detailed histochemical studies have been conducted on the morphology of the Golgi apparatus by applying the thiamine pyrophosphatase technique (Novikoff and Goldfisher, 1961) to the neurons of supraoptic and paraventricular nuclei of normal and dehydrated rabbits. The neurons in both nuclei were classified into five categories on the basis of the morphology of the Golgi apparatus. The number of cells in individual categories were counted to evaluate the percentage of each category in the whole nucleus.Neurons have many vesicles which show the tendency to form clusters. Such clusters are present also in the basal bodies. The Golgi apparatus is localized near one side of the nucleus in many neurons. The neurons indicate phasic activity of resting, anabolic and catabolic stages under normal conditions.During dehydration, the Golgi apparatus went through the three stages of network formation, the increase of the budding-off process and later on disintegration. The supraoptic nucleus reacted to the TPPase test more severely than the paraventricular nucleus, whereas the former went through the stages more slowly than the latter. The paraventricular nucleus also revealed sensitivity to osmotic stress. 相似文献
27.
Summary The effect of competition pressure on the sequential pattern of adult emergence was studied by using the experimental population
of the azuki bean weevil. The density and pattern of emergence curves of the parental adult induced the changes in the shape
of emergence curve of the progeny as well as the number of progeny individuals. In order to explain these changes, a simple
mathematical model which has two independent variables, the population density and the capacity of environment, was introduced.
The model generated basically similar patterns of emergene curves as observed in the present experiments. This means that
the model displayed well the competition pressure which differentially acted upon early-born and late-born individuals in
the populations being at different densities and which were differentially received by individual progeny according to the
sequential distributions of parents. This different severity of competition pressure resulted in the difference of time when
the pressure compelled influences on the sequential distribution of adult emergence. Therefore, early developed individuals
may have good chance to survive, but the competition pressure works as a factor modifying their fundamental superiority, especially
in the scramble type of competition.
Intense crowding of the azuki bean weevil gave rise to the scramble type of competition in the relation between the numbers
of adults emerged in two successive generations. When parental emergence concentrated in a short term and at high density,
the competition becomes intense, resulting in the inferiority of early developed individuals, in the decrease in number at
the next generation and in the increase of duration for emergence. 相似文献
28.
Koichi Fujii 《Population Ecology》1965,7(2):118-125
- A theoretical model for the competition curve, which stands on a few simple assumptions, was proposed.
- Some applications were done to actual data, and during these applications the validity of the present model and its assumptions was discussed.
- From the present model it can be expected that there is a discrete competition mechanism even in the appearently continuous medium.
29.
We compared the removal by solution, the represented count-area method and the beating, for the purpose of estimating the number of the Cryptomeria red mite. Among them the solution procedure provided the smallest standard error as per cent of the mean. 0.25 per cent unheated solution of sodium hydroxide is used for the summer generation, and also 0.25 per cent boiling one for the winter eggs. The mean proportion removed±standard error for the summer eggs and the winter eggs were 0.8770±0.0316 and 0.7920±0.0281 respectively, while 0.9894±0.0050 for the mites. 相似文献
30.
Koichi Fujii 《Population Ecology》1965,7(1):43-51
Experimental studies was made on the interspecies competition between the azuki bean weevil, Callosobruchus chinensis and the southern cowpea weevil, C. macultatus. And the following results were obtained.
- The reverse result of competition between the two species observed under the air-tight condition and the air-free one. That is, the population of the azuki bean weevils destroyedby that of the southern cowpea weevils under the former condition and vice versa under the latter. It is thought that such a reversal is due to the difference of sensibility of each species to the air-tight condition.
- Under the air-free condition, change of the time interval of food-supplying had no effect on the result of competition within the limits of this experiment. The population of the southern cowpea weevils was always destroyed by that of the azuki bean weevils. But there was a certain degree of correlation between the duration of co-existence and the interval of food-supplying.
- From the results, it is possible to say that by changing the degree of air-tightness, or the time interval of food-supplying, the co-existence period and the final result of competition can be changed.
- The different mechanism of competition between two species in the present experiment from the experiments ofUtida (1952) andYoshida (1957) were discussed.
- A difference in the mechanism of interspecies competition and intraspecies competition was expected from the level of total population numbers of two species and the individual weight of C. chinensis.