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1.
The kidney growth in children is not linear. The aim of this study was to define normal dimensions of kidneys in healthy infants during the first six months of life. A prospective ultrasonographic screening of 1870 kidneys in 935 healthy full-termed infants (476 males, 459 females) was done throughout a 5-year period. Measured kidneys were divided into six age groups according to gender and side. In the first three months of life males had both kidneys longer than same-age females (p < 0.05). In the next three-month-period the difference between sexes was not significant (p > 0.05). Left kidneys were longer than right kidneys in both sexes in the first six months of life (p < 0.01). Four nomograms with normal values of kidney lengths, according to age, sex and side were done in newborns and infants in the first 6-months of life.  相似文献   

2.
The behavioral development of a malformed male infant in a free-ranging Japanese monkey group, whose hands were completely missing and whose hind feet were distorted, was investigated during the first one year of life, by comparison with normal infants. In the first few weeks of life, the malformed infant was not able to move by himself and was almost completely dependent on his mother's help. He gradually became able to creep with his forelimb elbows and distorted hind feet at about the first month of life, and was able to walk bipedally on his hind feet, though unstably, after the sixth month of life. His locomotor ability, however, was essentially inferior to that of normal infants throughout the first one year of life. His social interactions with the group members were different from those of normal infants. Normal infants increased their interactions with sameaged infants or older juveniles through active behavior-like play, whereas the malformed infant developed relations particularly with adults through behavior such as passive body contact. The conditions for survival of the observed malformed infant are discussed.  相似文献   

3.
The aim of this study was to determine the influence of age and ingested food (colostrum and mature milk) on the concentrations of selected blood biochemical components connected with nitrogen and mineral metabolism in dairy calves during their first week of life. The experiment was carried out on 13 Polish Black and White breed dairy calves. The animals were fed colostrum within the first 3 days of postnatal life and thereafter the mature milk of their dams until the end ofthe experiment (7 days). The obtained results showed that intensive catabolic and anabolic changes in nitrogen occur in the first week of life. These changes were particularly intense during the first 24-48 hours of life and may reflect dynamic tissue remodelling. The results of this experiment also show that healthy calves efficiently regulate water and electrolyte homeostasis.  相似文献   

4.
The behaviour in time of labelled nuclear DNA in the hepatocytes of newborn rats was studied using autoradiographic and biochemical techniques in two groups of experiments. In the first group H-3-thymidine was injected to the mothers at the 16th day of pregnancy and the amount of labelled DNA was evaluated in the newborns after delivery. In the second group H-3-thymidine was injected to the newborns two hours after birth and the labelled DNA was studied at the same time intervals as the first group. The amount of labelled thymidine incorporated into the first group of animals remains constant for the first three days of life, thereafter a reduction in specific activity of DNA is observed concomitant with an increase of the percentage of labelled nuclei and a decrease of the number of grains per nucleus. These results show that mitotic divisions, which are absent during the first three days of life, take place between the third and sixth days of life. The decrease of the specific activity is therefore due to dilution and not to loss of labelled DNA. In the second group of experiments the DNA labelled with H-3-thymidine shows a decrease by about 30--40% per day during the first three days of life accompanied by a decrease in the number of grains per nucleus without changes in the percentage of labelled nuclei. These data show that DNA synthesized during the first day after birth is metabolically unstable, unlike that synthesized during foetal life.  相似文献   

5.
Using three mating-treatment groups–pairing with a male for life, pairing with a male from adult emergence to first oviposition, and no pairing (virgin)–of Dysdercus cardinalis females in a laboratory study, the following results were obtained. Most of the virgin females did not lay eggs; those that did oviposited for the first time at a considerably older age than females in the other two groups. In a lifetime, females pairing with a male for life and those pairing with a male up to first oviposition produced essentially the same number of eggs, and this was more than 3.5 times the number of eggs laid by a virgin female. Virgin females produced an average of 1.3 clutches in a lifetime, compared with about 4.5 clutches produced by females in the other two groups. Reproductive span was significantly shorter, and fecundity per day of reproductive span significantly greater, for females pairing with males for life than for those pairing with a male up to first oviposition. Age at death was significantly different amongst females in different mating-treatment groups. Virgin females had the longest life, followed by females pairing with a male up to first oviposition and females pairing with a male for life, in that order. There was a positive correlation between lifetime gross reproduction and age at death for females pairing with a male for life. There was no relationship between these two characters for females pairing with a male up to first oviposition. Both females pairing with a male for life and those pairing with a male to first oviposition exhibited a significant inverse relationship between fecundity per day and age at death. The results obtained indicate that (1) mating is a prerequisite for normal gonadal activity in Dysdercus cardinalis , and (2) repetitive mating increases the rate of reproduction. This would reduce the mean age of parenthood which is inversely related to the intrinsic rate of increase.  相似文献   

6.
In 525 young children the state of intestinal microbiocenosis was studied every month of the first year their life. The study revealed that the process of the microflora formation lasted throughout the first year of their life and was characterized by dysbiotic disturbances. During this period the aggravation of dysbiotic changes in the intestine of these children on months 3, 6-7 and 11-12 was of particular importance. The formation of stable dysbacteriosis led to a decrease in the immunological status of the child, which was manifested by the increased content of such microorganisms as hemolytic cocci, Proteus and a decrease in the quantitative level of bifidobacteria in the total intestinal microbiocenosis by the end of the first year of child's life.  相似文献   

7.
Growth data for grass carp, Ctenopharyngodon idella , in managed small impoundments were examined for density related effects. Ponds ranged in area from 0.02 to 5.0 ha; various species stocking combinations were used. Growth during the first year of life was strongly affected by density. Total standing stock increased and average size decreased with increasing density. This growth–density relationship was more variable among fish in the second year of life, primarily because of differences in availability of preferred food in different ponds. Survival tended to vary during the first year of life depending on the size at stocking but was uniformly high in the second year.  相似文献   

8.
Transient increases in triglycerides and cholesterol were found in rat liver immediately after birth. Plasma VLDL and HDL increased after birth and reached a plateau after one week of life. The content of cholesterol ester was low at birth in all lipoproteins and increased in LDL and HDL during the first week of life. After birth, VLDL became enriched in apolipoproteins C and E, whereas HDL was enriched in apolipoprotein C and depressed in apolipoprotein E. The developmental changes in plasma lipoprotein levels and compositions in rats during the first week of life are comparable to those described in humans.  相似文献   

9.
Abstract— Newborn rats from dams fed on a high fat diet developed increased ketonemia and significant hypertriglyceridemia i.e. "hyperketonemic pups". This perinatal metabolic stress led to an alteration in the developmental pattern of glycolytic intermediates in their brains.
In control rats, the concentration of glucose 6-phosphate (G6P) in the brain was high at birth, and gradually decreased to adult values by the third week of life. In contrast, the fructose-1,6-diphosphate (FDP) concentration was low at birth and increased thereafter. The lactate concentration was also high at birth but decreased to the adult level by the first day of life. In the brains of control pups, lactate and pyruvate concentrations remained relatively constant during the first 3 weeks of life.
In the brains of hyperketonemic pups, the concentration of G6P was the same as in the control animals at birth but decreased significantly during the first days of life. During early development the concentrations of FDP and pyruvate were significantly lower and the concentration of lactate, higher in the hyperketonemic pups as compared to the control group. The alteration in the concentration of these glycolytic intermediates in the brains of hyperketonemic pups indicated a change in the developmental pattern of glycolysis. The ratio of [lactate]/[pyruvate] also suggested an increased cytoplasmic redox potential in the brains of hyperketonemic pups during the first week of life.  相似文献   

10.
To improve the production system, the onset and the termination of reproductive life of C3Hf/HeMsNrs mice mated immediately after weaning and reared for 400 days of life, were studied. From weaning females mated with a full grown male (group A), the first litter was obtained at a mean age of 47 days, suggesting the first copulation at 26 days of age. The age of males at the first copulation was estimated to be at 44 days of age from the age giving the first litters in weanling males mated with weanling (group B) and full grown (group C) females. The sex ratio of litters delivered by young dams tended to be excess in males. The reproductive performance of dams in later life was not affected by the parturition in earlier age. The production efficiency with weaned youngs per pair during the first 200 days after mating was the highest in group A. It was found from these results that the C3H females attained their sexual maturity at 5 to 6 days after weaning, being available for breeding without any deletion in reproductive performance.  相似文献   

11.
Quantitative data on early mother-infant relationships in the Tibetan macaque was collected during the first 23 weeks of infant life in spring, 1987, at Mt. Emei, China. During the first week of life, infants spent 98.3% of their time in ventroventral contact with their mothers. This contact rapidly decreased to 33.8% by the 4th week and thereafter to 0.85% by the 23rd week. Nipple contact decreased relatively slowly from 89.7% to 62.9% within the first 4 weeks of infant life and to 19.8% by the 23rd week. Ventrolateral and ventrodorsal contact appeared by the 2nd week, meanwhile, maternal restraining behavior appeared, and reached a peak by the 3rd week. The mother neither encouraged nor discouraged her infant's independence during 4–8th weeks. Maternal rejection of the infant was first observed when the infant was 11 weeks old and continued thereafter.  相似文献   

12.
Plasma growth hormone, insulin and blood glucose levels were measured longitudinally during the first 60 days of life in 21 premature infants (8 males and 13 females) born between the 6th and 8th month of gestation. When these variables were related to age it was found that insulin and glucose, which are lower than in the prepubertal children and adults, rise simultaneously. Whereas growth hormone, which is higher than in older prepubertal children, decreases during the first 2 weeks of life. The decrease in growth hormone continues during the first 2 months of life, in contrast to the increases in insulin and glucose which do not persist in as long a period.  相似文献   

13.
To elucidate the association between stressful life events and the development of cancer the influence of life stress on relapse in operable breast cancer was examined in matched pairs of women in a case-control study. Adverse life events and difficulties occurring during the postoperative disease free interval were recorded in 50 women who had developed their first recurrence of operable breast cancer and during equivalent follow up times in 50 women with operable breast cancer in remission. The cases and controls were matched for the main physical and pathological factors known to be prognostic in breast cancer and sociodemographic variables that influence the frequency of life events and difficulties. Severely threatening life events and difficulties were significantly associated with the first recurrence of breast cancer. The relative risk of relapse associated with severe life events was 5.67 (95% confidence interval 1.57 to 37.20), and the relative risk associated with severe difficulties was 4.75 (1.58 to 19.20). Life events and difficulties not rated as severe were not related to relapse. Experiencing a non-severe life event was associated with a relative risk of 2.0 (0.62 to 7.47), and experiencing a non-severe difficulty was associated with a relative risk of 1.13 (0.38 to 3.35). These results suggest a prognostic association between severe life stressors and recurrence of breast cancer, but a larger prospective study is needed for confirmation.  相似文献   

14.
Urinary excretion of free noradrenaline and adrenaline during 24 h in 265 individuals was determined and related to sex, age, and hypertension as one indicator of the average sympathetic drive. Noradrenaline was found to correlate positively with age in healthy individuals. Noradrenaline and adrenaline were lower in healthy women than in men during the first half of life expectancy. Catecholamine excretion was similar in men and women in the second half of life expectancy. In hypertensive individuals, catecholamine excretion was slightly higher in the first half, and significantly higher in the second half of life expectancy. We assume that the differences in catecholamine excretion can contribute to the sex-and age-related differences in incidence of cardiovascular diseases, such as hypertension and coronary heart disease.  相似文献   

15.
OBJECTIVE--To assess the relation between breast feeding and subsequent experience of lower respiratory tract illness. DESIGN--Prospective (from well child visits) and retrospective (from maternal recall) study of breast feeding and prospective assessment by paediatricians of lower respiratory tract illness in infants during first year of life. SETTING--Health maintenance organisation. PARTICIPANTS--Over 1000 infants who were healthy at birth and whose parents used the paediatricians of a local health maintenance organisation. MAIN OUTCOME MEASURES--Duration of breast feeding and type of lower respiratory tract illness (wheezing and non-wheezing) at different age intervals during the first year of life. RESULTS--Breast feeding was associated with a decreased incidence of wheezing illnesses only in the first four months of life. Interactions existed between breast feeding and sharing a room, being Mexican American, and being a boy. Multivariate techniques showed that after controlling for a variety of factors children who received minimal breast milk had a greater risk of early wheezing illnesses; the risk was further increased by simultaneous exposure to sharing a room. CONCLUSION--Breast feeding seems to protect against wheezing respiratory tract illnesses in the first four months of life, particularly when other risk factors are present.  相似文献   

16.
Environmental conditions experienced early in life may have long‐term impacts on life history traits and reproductive performance. We investigated whether ambient temperature experienced during the first two to four weeks of life and weather severity during the first two winters affected recruitment age and relative timing of breeding in the year of recruitment in female common goldeneyes Bucephala clangula. Our sample consisted of 141 female recruits hatched in a study population in central Finland between 1985 and 2013 and captured later as breeders. About 56% of the recruited females bred for the first time when two years old (range 2–6 yr). Individuals facing colder ambient temperatures during the first two to four weeks posthatch or more severe winter conditions during the first two winters did not recruit at an older age. Nor did maternal characteristics, relative hatch date or nest site availability affect recruitment age. For females that recruited at two years old, the date of first breeding was usually late relative to the population mean that year (mean difference 6.9 d, range –7 to 21 d). Our results suggest developmental buffering enables female goldeneye ducklings to mitigate the impacts of adverse environmental conditions experienced during the first weeks of life, at least in terms of first breeding.  相似文献   

17.
The survival of common goldeneye Bucephala clangula ducklings during their first week of life was studied in relation to hatching date, brood size, female condition, and weather (temperature and precipitation) during the first week post-hatch by using data from radio-marked females and their broods. Also, age-specific variation in the survival of the young was determined until fledging (over 50 d of age). Survival was lowest in the first week after hatching. Hatching date, brood size, and first week temperature and precipitation were poor predictors of duckling survival during the first week after nest exodus. Instead, the ducklings of females in a better body condition survived better in their first week of life. The results suggest that weather does not have a direct effect on downy ducklings' survival, but the condition of the female seems to be an important determinant of the survival of common goldeneye ducklings.  相似文献   

18.
Hundred eleven children with the congenital toxoplasmosis were treated at the Department of Infectious and Parasitic Diseases in Childhood in 1979-1988. Multi-symptomatic toxoplasmosis has been diagnosed in 35 cases, ocular form in 65, oligosymptomatic in 6, and asymptomatic in 5 cases. Clinical symptoms suggesting congenital toxoplasmosis was seen in the majority of children (63 cases) in the first year of life and the disease was diagnosed in 50% of cases (33 children) at this age. Congenital toxoplasmosis in the group of 78 children has been diagnosed later. The majority of cases was ocular form. Diagnosis of the oligo- and asymptomatic congenital toxoplasmosis is possible in the first year of life, only. A titre of antibodies is exclusively an indicator of the immunologic response, not a severity of infection and does not contribute to the prognosis. Antitoxoplasma drugs were administered to 102 children including 33 under the first year of life. Pyrimethamine, sulphonamides, and spiramycin were used in the treatment. Dosage, duration of therapy, and way of administration have been established individually in dependence of patients age and clinical form of the congenital toxoplasmosis. Two out of 35 children with multi-symptomatic congenital toxoplasmosis died whereas 13 demonstrate psychomotor retardation of significant degree despite the fact that 11 of them were treated in the first year of life.  相似文献   

19.
Culaea inconstans in delta Area, Lake Manitoba matures in the second summer of life, when between 29 and 65 mm in total length and one year of age. Spawning starts at the end of May after migration into the creeks and channels in the marsh. By June 11–12 the yearlings are under 20 mm in total length. The greatest part of growth is completed in the first summer of life. The asymptotic or average maximum length, L was 89.06 mm. Aging of fish was done by reading otoliths and plotting length frequency histograms. Fish set the first ring, a false check, in otoliths within the first month of life and the annual ring is set by the adults on June 1 of the second summer of life. Culaea inconstans was generally found to be an annual fish which died after spawning in the second summer of life. A high positive correlation coefficient was found for body-otolith relationship. The length-weight regression lines were significantly different from one another and from zero, the F-value being significant at 1% level. The condition factor was found to be variable.  相似文献   

20.
The dynamics of the shell convolution diameter with regard to the mollusk age was studied for the river snail Viviparus viviparus. It was found that the diameter of the first (juvenile) convolution remained constant during the ontogenetic development. A weak, but significant increase in the diameter of the second and the third shell convolutions (also juvenile) was observed during the first year of postembryonic development. The forth and the fifth shell convolutions were formed during the first year of mollusk life after hatching; their diameters increased gradually during the second year, and remained constant for the remainder of the life span.  相似文献   

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