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1.
The distribution of methadone between mother and fetus after a single dose and at steady state was determined using the chronic pregnant ewe preparation. Chronic indwelling catheters were placed in the maternal aorta and vena cava, umbilical vein and fetal aorta. Following a single i.v. dose (0.5 mg/kg) to the mother, methadone was rapidly distributed to the fetus, with peak concentration in the umbilical vein occurring within two min. An umbilical venous-arterial gradient existed for 10–15 min after drug administration, indicating uptake of methadone by fetal tissues. Methadone concentration in the fetus was 2–5 times lower than those in the mother even in the post-distribution phase. The terminal half-life of methadone in 4 animals was 57±7.6 (S.E.) min in the mother, and 58.5±10.0 (S.E.) min in the fetus. When methadone was infused at a constant rate to the mother (0.01 mg/kg/min), steady state was achieved in both mother and fetus by 4–5 hrs. In 5 animals, maternal steady state was found to be 203±18.8 (S.E.) ng/ml, and fetal steady state was found to be 29.7±2.9 (S.E.) ng/ml. These studies show that methadone is rapidly distributed to the fetus, but fetal concentration remain lower than maternal concentration at all times.  相似文献   

2.
Most toque macaques give birth to their infants during the night when resting arboreally. Here we report on a birth that occurred in daytime (at 0916 hr) and on the ground. The mother was 7.6 years old; the birth was her second. Prepartum behaviors included lordosis, arching of the back, stretching, squatting, rolling on the ground, and anogenital self-examination. During the birth the female was isolated about 100 m from the rest of her group. The mother stood bipedally during parturition and assisted delivery with her hands. The infant was born within 2 min after first appearing at the vulva. It immediately clung to the mother’s leg and vocalized. The mother licked the infant and oriented it toward her ventrum. She resumed foraging behavior within 20 min after parturition. The infant nursed for the first time 2.25 hr after being born. The mother ate part of the placenta, but the alpha female of the group usurped and also ate a portion of it. Curious group members sniffed and looked at the infant but did not touch it.  相似文献   

3.
An immunofluorescent staining procedure has been developed to identify, with flow cytometry, replicating cells of Saccharomyces cerevisiae after incorporation of bromodeoxyuridine (BrdUrd) into the DNA. Incorporation of BrdUrd is made possible by using yeast strains with a cloned thymidine kinase gene from the herpes simplex virus. An exposure time of 4 min to BrdUrd results in detectable labeling of the DNA. The BrdUrd/DNA double staining procedure has been optimized and the flow cytometry measurements yield histograms comparable to data typically obtained for mammalian cells. On the basis of the accurate assessment of cell fractions in individual cell cycle phases of the asynchronously growing cell population, the average duration of the cell cycle phases has been evaluated. For a population doubling time of 100 min it was found that cells spend in average 41 min in the replicating phase and 24 min in the G2+M cell cycle period. Assuming that mother cells immediately reenter the S phase after cell division, daughter cells spend 65 min in the G1 cell cycle phase. Together with the single cell fluorescence parameters, the forward-angle light scattering intensity (FALS) has been determined as an indicator of cell size. Comparing different temporal positions within the cell cycle, the determined FALS distributions show the lowest variability at the beginning of the S phase. The developed procedure in combination with multiparameter flow cytometry should be useful for studying the kinetics and regulation of the budding yeast cell cycle.  相似文献   

4.
5.
Electron microscopic investigations of secretory ameloblasts from deciduous tooth germs of mini-pig foetuses and investigations of the ability of various fixatives to preserve these cells in tooth germs immersion-fixed in toto 5 min, 10 min, 15 min, 20 min and 40 min after death of the mother gave the following results:
1.  The ameloblasts exhibit ultrastructural characteristics typical of exocrine secretory cells of merocrine type.
2.  The localization of organelles is as in rodent secretory ameloblasts, but differs from the location in the human analogues.
3.  Fixation with 4% formaldehyde invariably gives unacceptable ameloblast preservation.
4.  Fixation with 2.5% glutaraldehyde gives fair preservation of the ameloblasts when the germs are fixed within 10 min of the death of the mother.
5.  Fixation with a fixative mixture 2% formaldehyde — 1.25% glutaraldehyde gives good preservation when the ameloblasts are fixed within 15 min of the death of the mother.
6.  Fixation with a fixative mixture 2% formaldehyde — 1% glutaraldehyde — 1% acrolein gives good ameloblast preservation when the germs are fixed within 15 min of the death of the mother.
  相似文献   

6.
The systematic use of Caesarean section in "double muscled" Belgian Blue cattle can induce ethical concerns. The aims of the following study was to characterise mother-young relationships in such a situation and to assess the effect of parity. Fifteen heifers and 15 cows of the Belgian Blue breed were observed using video recording when isolated with their calf during the 3 days following Caesarean, a rapid surgery with rare occurrence of aggressive behaviour and no sign of cows' discomfort or weakness. All calves were bottle-fed mother's colostrum once before first suckling occurred. Heifers' calves received a supplementary number of three such artificial meals, while cows' calves needed only one. The overall median time to first licking of the calf by the mother was 3.3min without any effect of parity. The mean licking frequency was 29.2+/-15.8 per 24h: heifers licked their calf less frequently than cows, respectively 23.4+/-15.3 per 24h versus 35.1+/-14.5 per 24h (P<0.05). The mean total licking duration was 42.2+/-25.9min per 24h: there was no significant difference between heifers and cows. The overall median time to first suckling was 6.1h, without any effect of parity. The mean suckling frequency was 8.4+/-4.8 per 24h: for half of these suckling bouts, the calf was situated on the left side of the mother, i.e. the side of the scar. The suckling frequency was negatively correlated with the number of artificial meals (r(s)=-0.45,P<0.05). Heifers suckled their calf less often than cows, respectively 6.1+/-3.1 per 24h versus 10.7+/-5.2 per 24h (P<0.01), but the left side proportion was not significantly different. The mean suckling total duration was 35.3+/-21.0min per 24h. The calf was on the left side of the mother during half of this time. Heifers suckled their calf during a shorter time than cows, respectively 26.9+/-20.0min per 24h versus 43.8+/-19.1min per 24h (P<0.05), and the left side proportion was not significantly different. Licking frequency and suckling duration were positively correlated (r=0.43,P<0.05). Only 10% of the mothers (one heifer and two cows) butted their calf and kicking was never observed. Despite the difficult comparison with results of the literature according to various methodologies, mother-young relationships were considered as similar to those reported after natural calving. In our study, cows can be considered as better mothers than heifers.  相似文献   

7.

Background

Haptocorrin (HC) carries cobalamin analogues (CorA), but whether CorA are produced in the body is unknown. All cobalamins (Cbl) to the foetus are delivered by the Cbl-specific protein transcobalamin (TC), and therefore analysis of cord serum for CorA may help to clarify the origin of CorA.

Methods

HC-CorA were quantified in paired samples of cord serum from newborns and serum from mothers (n = 69).

Results

The CorA-concentration was higher in cord serum (median = 380, range: 41–780 pmol/L) than in serum from the mothers (median = 160, range: 64–330 pmol/L), (p<0.0001). HPLC-analysis showed CorA-peaks with retention times of 13.5, 14,5 and 16.5 min in samples from both the mother and cord serum. The peak with retention time 16.5 min constituted 24% (mother) and 45% (cord serum) of the total amount CorA, and eluted as does dicyanocobinamide.

Conclusion

Our results support that CorA in the human body are derived from Cbl.  相似文献   

8.
Six cases of labor and delivery by laboratory-housed patas monkeys (Erythrocebus patas) are described. Five of the births occurred during the daytime, and the sixth occurred just after the usual “lights out” time. Although it was impossible to determine the actual onset of labor, the final 1.5–0.5 hr before parturition were observed in all cases. Throughout labor, females tended to begin a contraction every 2–4 min and contractions usually lasted 35–60 sec. Females did not show common patterns of change in contraction frequency or duration as birth neared. It was not possible to describe patas monkey labor and delivery in terms of “stages.” Postpartum, females typically began cleaning their infants within 90 sec and picked them up within 5 min. Placental delivery times varied among females, as did the extent of placental consumption. One “mother-only” - reared female proved to be an inadequate mother.  相似文献   

9.
The relationships of the first nuclear division during pseudo-mycelial outgrowth in the infectious yeast Candida albicans to pseudo-mycelial length and DNA replication have been investigated. Evidence is presented that the first nuclear division does not occur until the pseudo-mycelium grows to a minimum length equal to or greater than the diameter of the mother cell and until the cells pass through a minimum time period of approx. 150 min which probably reflects the time necessary to complete nuclear DNA replication. Evidence is also presented that pseudo-mycelial outgrowth and nuclear migration occur independently of DNA replication, and that nuclear migration is probably regulated by the length rather than by the volume of the growing pseudomycelium. Similarities to the requirements for nuclear division during budding in Saccharomyces are discussed, and a model for nuclear migration is proposed.  相似文献   

10.
Although the guinea pig is characterized by precocial physical development and minimal active maternal care, studies suggest the presence of the mother can influence neuroendocrine and behavioral activity of offspring even well beyond weaning. Previous results may have been influenced by the procedure of housing weaned subjects with the mother to within 2 days of testing. The present study examined approximately 40-day-old guinea pigs housed apart from the mother for 0 (not rehoused), 2, or 10 days. Rehousing without the mother led to elevations in plasma testosterone (measured in males), progesterone (measured in females), cortisol, and adrenocorticotropin (ACTH) (both measured in males and females). Offspring housed without the mother for 10 days had the highest progesterone, cortisol, and ACTH levels. Testosterone elevations were observed in 2-day-, but not 10-day-, rehoused animals. Regardless of rehousing condition, 60 min isolation in a novel test cage elevated progesterone, cortisol, and ACTH, and reduced testosterone. These effects were all moderated if the subject was tested with the mother or another female. Sexual behavior toward the mother was observed frequently, but only in males housed apart from her prior to testing. Overall, males and females that had been housed apart from the mother interacted with her as they would an unfamiliar female. Our results corroborate previous findings, suggest the effect of housing apart from the mother on male testosterone is transitory, and indicate that continuous housing with the mother past weaning suppresses circulating progesterone in females and cortisol and ACTH in both sexes.  相似文献   

11.
Reports of wild great ape fatalities have been very limited, and only two have described wild orangutan deaths. We found a wounded juvenile female Bornean orangutan on 7 October 2006 in the Danum Valley, Sabah, Malaysia, and observed the individual's behavior for 7 days until her death on 13 October 2006. The 5-6-year-old orangutan, which we had observed since 2004, was wounded in the left brachium, back, and right hand. The individual's behavior changed after injury; the mean nest-nest active time became significantly shorter than before injury (from 12 h 3 min to 9 h 33 min), the mean waking time became significantly later (0552-0629 hours) and the mean bedtime became significantly earlier (from 1747 to 1603 hours). In the activity budget, resting increased significantly from 28.0 to 53.3%. Traveling and feeding decreased significantly from 23.5 to 12.7% and from 45.6 to 32.8%, respectively. The rate of brachiation during traveling and nest making decreased, whereas ground activity increased from 0 to 9%. We observed one vomiting incident and four occurrences of watery diarrhea during the 7 days before the individual died. The results of an autopsy performed by a local veterinarian suggested that the cause of death was septicemia because of Pseudomonas aeruginosa infection of the severely contaminated wounds. The morphology and distribution of the wounds suggested they had been incurred during an attack by a large animal with fangs and/or claws. This juvenile female became independent of its mother at ~4-5 years of age, slightly earlier than average. This individual might have been vulnerable to predatory attack because of her small body size (~5 kg at death) and lack of the mother's protection.  相似文献   

12.
Half-smooth tongue sole (Cynoglossus semilaevis) is an important cultured marine fish as well as a promising model fish for the study of sex determination mechanisms. In the present study, a protocol for artificial gynogenesis of half-smooth tongue sole was developed in order to identify the sex determination mechanism and to generate all-female stock. The optimal UV-irradiation dose for genetically inactivating sea perch spermatozoa was determined to be ≥30 mJ/cm2. The optimal initiation time for cold shock of gynogenetic embryos was determined to be 5 min after fertilization, while the optimal temperature and treatment duration were determined to be 20–25 min at 5°C. Chromosomes from common diploids, gynogenetic haploids, and diploids were analyzed. WW chromosomes were discovered in some of the gynogenetic diploids. The microsatellite marker was applied to analyze gynogenetic diploid fry. Among the 30 gynogenetic diploid fry, 11 fry contained only one allele, while 19 contained two alleles, which had the same genotype as their mother. The female-specific DNA marker was observed in four individuals out of ten gynogenetic diploid fry. Ploidy analysis of 20 putative gynogenetic fry showed them all to be diploid. Thus, a protocol for the induction of artificial gynogenesis has been developed for the first time in half smooth tongue sole, and the sex determination mechanism in the tongue sole was determined to be female heterogametic with the ZW chromosome.  相似文献   

13.
Abnormal oral behaviour in calves is believed to develop when there is a lack of opportunity to suckle, but it is unclear whether they need access to their mother or whether a multiple suckling system will suffice to prevent this behaviour from developing. Therefore, in an initial experiment, the behaviour of calves that suckled their own mother or another cow for 15 min each day was compared with that of artificially-reared calves which had no opportunity to suckle. Cows were mechanically milked twice daily, after which they were either suckled for 15 min by their own calf (Treatment O), multiple-suckled by other cows’ calves (Treatment M) or unsuckled with the calves reared artificially (Treatment A). There was no difference between treatments in the time that calves spent consuming milk, but suckling calves consumed less milk than those reared artificially. The incidence of cross-sucking was greater for non-suckled calves (1.8 events/day) than for suckled calves (0.33 events/day, with no difference between Treatments O and M). In the non-suckled calves, cross-sucking was at its highest frequency 1 min after the end of milk-feeding and declined linearly to negligible levels at 13 min post-milk feeding. For calves in this treatment, most (78%) of the cross-sucking was directed at the inguinal region (especially the udder or scrotum) of other calves, whereas in suckled calves, most of the cross-sucking (81%) was directed at the mouths of other calves. The time spent consuming concentrate feed, and the amount of feed consumed, was greater for artificially-reared calves, compared with suckled calves, suggesting that food ingestion could provide a replacement stimulus. In a second experiment, it was observed that before weaning, the time that calves spent licking their pen or bucket increased until feed intake was sufficient to stimulate significant amounts of rumination, after which it declined. It is concluded that cross-sucking of artificially-reared calves, which is derived from motivation to perform sucking in the inguinal region, can be prevented by providing short access to either the calf’s dam or another cow for two short periods each day. In the absence of a cow to suckle, the calves lick inanimate objects repeatedly until the consumption of solid food stimulates rumination.  相似文献   

14.
Infant development in lion-tailed monkeys was observed during the first eight weeks after birth. A rapid decrease in the time spent in the closest association by the mother and the infant was seen between the first and second weeks. Between the second and fifth week there was a somewhat steady state with only marginal decrease in the time spent by the infant out of lap of the mother. However, during this time, a rapid decline in maternal cradling and restraining behaviour was seen. From the sixth week onwards, there was a rapid increase in the time spent by the infant out of contact with the mother. Independence of the infant during troop progression was seen only towards the eighth week, that too only marginal. Among the troop members the subadult females and the juvenile females showed the maximum interest in the infant. The former spent much more time than the juveniles interacting with the infant. The adult females showed only little interest in the infant while the adult male showed no interest at all. Infant snatching by subadult females and juvenile females was seen on many occasions. The infant remained in the possession of them from less than 1 min to more than 2 hr. This behaviour tended to decrease towards the sixth week.  相似文献   

15.
Individual budding yeast cells, Saccharomyces cerevisiae, enclosedin small culture chambers were observed through two buddingcycles to examine their behavior during growth and division.In the nutrient medium (YHG medium), the duration of the buddingcycles was 77 min for mother cells and 90 min for daughter cells;a 13-min time lag between the two durations. Continuous exposureof cells to 16 or 32 mM hydroxyurea extended the duration ofthe cycles and increased the volume of the cells, resultingin the formation of abnormally large and equal-sized mother-daughterpairs. Each cell of these pairs subsequently produced buds simultaneously.Stained cell nuclei showed simultaneous nuclear division. Thissynchronous budding on mother-daughter pairs was repeated inthe next budding cycle. The coordination of growth with divisionis discussed in relation to these results. (Received August 11, 1979; )  相似文献   

16.
Conflicting data exist on the importance of the father and parental experience during development in rodents. The purpose of this study was to investigate the effects of these two variables on development in Mongolian gerbils. Forty pairs of males and females with a litter size of between 4 and 7 pups were used as subjects. Twenty couples had no experience in raising young. After the birth of their pups, four experimental groups were formed: (I) inexperienced mother and father; (II) inexperienced mother; (III) experienced mother and father and (IV) experienced mother. When the pups reached 10 days of age, pup and parental behavior was recorded in experimental sessions of 15 min on 11 consecutive days. Through the statistical analysis it was found that the presence of the father significantly increased the physical contact between pups and parents and that pups opened their eyes earlier in comparison to the groups without the father. On the other hand, parental experience had a significant influence on the behavior of the pups (locomotion inside and outside the nest, and self-grooming). The results of this study suggest that parental experience and the presence of the father have differentiated effects on development in Mongolian gerbils.  相似文献   

17.
The yeast Candida utilis was continuously synchronized by the phased method of cultivation with the nitrogen source as the growth-limiting nutrient. The doubling time (phasing period) of cells was 6 h. Both cell number and deoxyribonucleic acid synthesis showed a characteristic stepwise increase during the phased growth. The time of bud emergence coincided with the time of initiation of deoxyribonucleic acid synthesis. Size distribution studies combined with microscopic analysis showed that the cells expanded only during the unbudded phase of growth. Usually the cells stopped increasing in size about 30 min before bud emergence, and the arrest of the increase in cell volume coincided with the exhaustion of nitron from the medium. There was no net change in the volume of cells during the bud expansion phase of growth, suggesting that as the bud expanded, the volume of the mother portion of the cell decreased. After division the cells expanded slightly. The postdivision expansion of cells, unlike the growth before bud initiation, occurred in the absence of the growth-limiting nutrient. The newly formed daughter cells were smaller than the mother cells and expanded at a faster rate, so that both types of cells reached maximum size at the same time. Possible reasons for the different rates of expansion of mother and daughter cells are discussed.  相似文献   

18.
19.
Birth is an event that allows the relatively immature marsupial to move from the internal environment of the uterus to the external environment of the pouch. The newborn marsupial passes down from the uterus to the urogenital sinus and then makes its way to the pouch and attaches to the teat at a very early stage of development. From the studies available, there appear to be three methods used by the newborn to move from the uterus to the pouch. In marsupials with a forward pouch such as the red kangaroo, tammar wallaby and the brushtail possum, the mother positions her urogenital sinus below the pouch and the newborn climb upward towards the pouch. The young climb with a swimming motion, moving the head from side-to-side and use the forearms in alternate strokes. In the bandicoot with a backward facing pouch, the mother positions the urogenital sinus above the pouch and the young slither down into the pouch. The young do not have a definite crawl, as seen with the macropodids and possum. The third method of birth has been observed in the marsupials without a definite pouch that have a mammary region that develops as the young grow in size. This type of pouch is observed in the dasyurids. The mother was noted to stand on four legs with her hips raised so that the urogenital sinus was above the pouch and the newborn young crawled downwards from the sinus to the pouch. In all species, birth was completed in 2–4 min.  相似文献   

20.
The transfer of plasma triglyceride fatty acids from mother to fetus was studied in rats. Following i.v. injection of labelled chylomicron and very low density lipoprotein (VLDL) triglycerides into the mother, the time courses of the plasma triglycerides, free fatty acids, and fetal radioactivity were determined. The data were analysed using a mathematical model. From the results the following conclusions were drawn: To cover the need of fetal fatty acids, the placenta utilizes only VLDL triglycerides but not chylomicron triglycerides. Comparison of the amount of VLDL triglyceride fatty acids (0.04 micromoles/min/litter) and of maternal plasma free fatty acids (0.08 micronmoles/min/litter) transferred into the fetus indicates that the maternal plasma triglycerides are a source of fetal fatty acids, that cannot be neglected.  相似文献   

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