ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractThe intermediates of the glycolytir pathway were investigated in erythroeytes of children with Down's syndrome and the results achieved were compared with those obtained from healthy children of the same age. In the acid-soluble fraction obtained from the erythroeytes, the levels of the intermediates of the glycolytic pathway were determined. The adenine and guanine nucleotides, coenzymes, and inorganic phosphate (Pi) and some other intermediates were examined. The adenine nucleotides: adenosine 5'-monophosphate (AMP), adenosine o'-diphosphate (ADP), adenosine o'-triphosphate (ATP) and the guanine nucleotide: guanosine fZ-triphosphate (GTP) were determined. The nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), two glycolytic pathway coenzymes, were examined. Hexose diphosphate (HDP) and 2,3-diphosphoglyceric acid (2,3-DPG) were tested.Three groups were distinguished after the determination of the karyotype in the children examined: group I, seven children with Down's syndrome and trisomy G (karyotype 47,XX,G+ or 47,XY,G +); group II, two children (siblings) with Down's syndrome and G/G translocation (karyotype 46,XX,G —, t(GqGq) +mat or 46,XY, G —, t(GqGq) +mat); and group III, healthy children with a normal karyotype, corresponding to the sex. The results of the biochemical investigations in all of the three groups were compared.Taking the values obtained for the healthy children as standard, a considerable decrease in the levels of ATP and 2,3-DPG and an increase in the levels of AMP, GTP, NAD, NADP, Pi, and HDP were noticed in the group of children with Down's syndrome and trisomy G. The ADP concentration was the same as in the control group. The values of some intermediates obtained for the group of mongols with unbalanced translocation G/G were approximately the same as the values obtained for the group of mongols with trisomy G. The 2,3-DPG level was just as low as in the mongol group with trisomy G.The results of the calculations, developed by means of the Student test, are statistically significant.SpeculationThe levels of the glycolytic pathway intermediates in erythroeytes of children with Down's syndrome deviate from normal. The differences which were observed may reflect disturbances of enzymatic activity. It is also possible that these differences are aresult of nutritional disturbances or are caused by the incidence of a population of atypical erythrocytes.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractDaily urinary excretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in one premenarchial and four postmenarchial girls was determined over a 3-month collection period. Samples were collected overnight and a 24-hr excretion was extrapolated. Gonadotropins were acetone-precipitated and assessed by using the Second International Reference Preparation of Human Menopausal Gonadotropin (2nd IRP-HMG).Excretion of LH and FSH in the premenarchial girl followed no constant pattern, but average levels were comparable to postmenarchial and adult levels for FSH and early postmenarchial levels for LH. During the 3-month observation period, two simultaneous spikes of LH to 55 international units (IU)/24 hr and FSH to 60 IU/24 hr, occurring 6 days apart, were observed. These were of the magnitude of low normal adult midcyclc peak values.In all postmenarchial girls, simultaneous midcycle surges of FSII to as high as 70 IU/24 hr and LH to 43–155 IU/24 hr were observed in all cycles. During the earliest postmenarchial cycles, peak levels were less than those observed during cycles of girls who were postmenarchial for a longer period of time. Some characteristics of adult cycles, such as follicular phase FSH elevations and higher follicular than luteal phase levels of both gonadotropins, were observed during cycles occurring only 1–4 months after menarche. Other characteristics of adult cycles, such as late luteal phase FSH rises, were seen only in the girl who was 3 years postmenarchial.SpeculationPremenarchial and early postmenarchial girls have gonadotropin surges similar to adult midcycle ovulatory peaks. They presage evolution of the adult gonadotropin pattern in the subsequent postmenarchial years.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractThe median vitamin A level in plasma of patients with cystic fibrosis of the pancreas (CFP) (18 μg/100 ml) was less than half that of a control group (39 μg/100 ml), whereas the median vitamin A level in liver (57 μg/g) was nearly 3.5 times higher (Table II.). Concentrations of vitamin E in both the plasma and the liver of the patients were less than one-third those of the control group. The data suggest that vitamin A-supplemented children with CFP are unable to maintain normal circulating levels of vitamin A because of a defect in mobilization or transport from storage tissue, rather than because of tissue depletion. Low blood levels of vitamin E, however, reflect tissue depletion and not defective transport.SpeculationThe cause of the apparent defect in ability to mobilize or transport vitamin A from the liver in children with CFP may be due to a limited ability to synthesize transport proteins or to a reduced activity of hepatic retinyl ester hydrolase enzymes These alternatives are under investigation.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractLean body mass (LBM) was estimated by40K counting in 609 normal boys and girls 7.5–20.5 years of age. This component of the body is shown to be related to stature, but the quantitative nature of the relation varies with age and sex.Boys have a higher LBM/height ratio in adolescence than do girls, and the slope of the LBM-height regression is also greater, whereas before adolescence there is no appreciable sex difference. Age also affects LBM independently of stature. This effect is first seen during adolescence, and it is more pronounced in boys.When the entire age span for this group of subjects is considered, the relation between LBM and height is exponential, LBM = b.ek.ht, b and k being constants. This means that the relative, or percentage, growth in LBM is a linear function of height growth at this time of life.SpeculationThe relations developed from these data emphasize the need to gear nutritional requirements to the speed of height growth. On the average, the adolescent boy has greater needs than does the girl, merely to satisfy the demands of the growth process. The changing pattern of the LBM-height relation during adolescence lends support to the concept that androgens facilitate the growth of the LBM with its large component of muscle.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractNormal and undernourished 3-week-old rats were examined for activity of crude mitochondrial acetylcholinesterase (a marker for nerve-ending particles) in four brain areas. Littermates of these animals were used for determination of four other brain enzymes which are known to increase in activity during rat brain growth. Significant deficits (in units per gram wet weight) in crude mitochondrial acetylcholinesterase activity were found in the forebrain (normal = 2085, malnourished = 1444), brainstem (normal = 709, malnourished = 536), and olfactory lobes (normal = 74, malnourished = 46) of undernourished animals. When enzyme activities were expressed in terms of tissue wet weight, whole brain butyrylcholinesterase, fumarate hydratase, and β-galactosidase were found to be unaffected by undernutrition, whereas 5'-nucleotidase activity was higher in undernourished (730 units/g dry weight) than in control animals (660 units/g dry weight). The results lend support to the hypothesis that those constituents of the brain which show a large increase in concentration during brain growth are those most likely to be affected by growth retardation in early life.SpeculationUndernutrition during the period of rat brain growth when interneuronal connectivity is being established may result in a deficit in the number of nerve-ending particles in the brain. This could imply that an impaired formation of synaptic connections may account for some of the functional changes which result from growth restriction at this time.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ExtractCalcium ion activity was measured in plasma obtained by venous or arterial puncture using a calcium-selective flow-through electrode. Mean level of ionized calcium in umbilical venous plasma was 2.48 ± 0.04 mEq/liter. Within 30 hr after birth, the values decreased in sick infants to 1.35 ± 0.11 mEq/liter. Total calcium concentra tions were in the normal adult range at birth (5.20 ± 0.08 mEq/liter), showing a subsequent decline to subnormal values (3.47 ± 0.28 mEq/liter at age 30–40 hr). A calcium ion activity of less than 1.4 mEq/liter was associated with total calcium level at or below 3 mEq/liter in 80% of patients. Symptoms and signs attributable to hypocalcemia (ionized fraction) or hypomagnesemia, or both, were found only in infants in whom plasma levels of both divalent cations were below the lower limit of normal. Administration of NaHGO3for acidosis caused a slight rise in pH (from 7.20 to 7.28 mEq/liter) and a decrease in plasma calcium ion activity (from 1.68 to 1.51 mEq/liter). During exchange transfusion with acid-citrate-dextrosc (ACD)-Tham buffered blood, calcium ion activity decreased significantly from 1.90 ± 0.08 to 1.20 ± 0.09 mEq/liter, whereas total calcium levels increased consistently (from 4.22 ± 0.13 to 5.33 ± 0.15 mEq/liter).SpeculationThe temporary hypocalcemia, observed in sick newborn infants, may also occur in healthy newborns. It is thought to initiate normal calcium homeostasis by stimulating parathormone secretion and by bringing into play the two feedback mechanisms for calcitonin and parathormone secretion.

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1972

数据来源: OVID