摘要:

The associations between serum zinc and copper concentrations and anthropometric variables in 3415 3-, 6-, 9-, 12-, 15-, and 18-y-old Finnish girls and boys were investigated to identify groups with low serum zinc or copper concentrations and retarded growth, possibly suggesting deficiencies. Serum zinc levels and height, wt, body mass index, and skindfold thickness were not strongly related. Serum copper levels were negatively correlated with height and positively with wt, body mass index, and skinfold thickness. These relationships were clearest in both sexes between the ages of 9 and 15 y. Height, wt, body mass index, and skinfold thickness in subjects with very low or high serum values were in agreement with the correlations between these anthropometric variables and serum levels. Groups with clear deficiencies of zinc or copper could not be identified. We conclude that copper levels especially are correlated with stature between the ages of 3 and 18 y. In addition, the results suggest that deficiency states affecting growth are not very likely in healthy Finnish children and adolescents.

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In 19 patients with a deficiency of glucose-6-phosphatase and 1 patient with a deficiency of glucose-6-phosphate translocase, the effect of nocturnal gastric drip feeding (GDF) on growth and plasma lipids and apolipoproteins was studied. The effect on growth was estimated by determining the height standard deviation score (SDS) of the patients and comparing its changes (ΔSDS) over 4-, 2-, and 1-y periods before and 1-, 2-, 5-, and 8-y periods after the institution of GDF. The effect of GDF on plasma lipids and apolipoproteins was investigated by following the concentrations of triglycerides, cholesterol, and apolipoproteins A-I, A-II, B, C-I, C-II, C-III, and E. Growth caught up significantly or remained in the normal range in 14 patients. They were defined as responders to GDF. In the other six patients, growth caught up insufficiently or showed a further deceleration. They were defined as nonresponders to GDF. GDF had only a temporary and marginal effect on plasma lipids and apolipoproteins, but after 5–8 y, the levels of plasma triglycerides, cholesterol, apolipoprotein, B, C-I, C-II, C-III, and E increased further in both responders and nonreponders, whereas apolipoproteins A-I and A-II decreased in nonresponders. There were minor differences in the levels of lipids and apolipoproteins between responders and nonresponders without any discernible trends during the first years of GDF. After 5–8 y, the levels of cholesterol, triglycerides and apolipoproteins B, C-I, C-II, C-III, and E seemed to be higher, and apolipoproteins A-I and A-II lower, in nonresponders than in responders, but the differences were not significant.

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In the male CD-I mouse submandibular gland (SMG) renin activity increases markedly with puberty. We have reported that this is, in part, due to an androgen-mediated increase in renin gene transcription. In this study, we examined whether posttranslational processing is also influenced by androgen. We studied secretion and processing of active renin in the CD-I male mouse SMG which secretes primarily the Ren-2 renin isozyme before and after puberty and also compared findings with the adult female CD-I mouse. Maturation increases renin level and secretion rate in the male SMG but much less in the female, In addition, Western blot analysis of molecular forms of renin in SMG tissue and media shows a predominance of 1-chain intermediate form of renin before puberty but of the 2-chain mature form thereafter. Adult female SMG contains and secretes much less active renin than the male organ. Administration of testosterone to the female CD-I mouse induces an adult male level and pattern of secretion, with high concentrations of active 2-chain renin being secreted. These data suggest that SMG renin is androgen regulated, in part by an androgen-responsive enzyme that processes 1-chain renin to the 2-chain form. (Pediatr Res 25:332-335, 1989)

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Data in the literature concerning atrial natriuretic factor (ANF) physiology in the fetus and newborn, although limited, suggest significant activity during the perinatal period. To characterize further ANF physiology during this time, we documented immunoreactive ANF (IRANF) concentrations in the right and left atria before and immediately after birth as well as in the hearts of immature and adult rats. There was a significant decrease in the concentration of IR-ANF in both right and left atria on the d before birth that persisted for the first 48 h of life [d 20 fetal right 570 (106, 90), left 580 (86, 75); d 21 fetal right 270 (70, 55), left 214 (117, 75); 1 d right 206 (39, 33), left 229 (41, 35); 2-d right 352 (35, 32), left 237 (26, 23) \ geometric mean (upper SE, lower SE) in ng ANF/mg protein \\. Repletion of ANF stores began in the right atrium on d 2 of life and in the left atrium between d 2 and 5. The highest levels of IR-ANF were observed at d 15 [d 5 right 1439 (53, 51), left 1547 (83, 79); d 15 right 2034 (90, 86), left 1943 (108,102); adult right 1380 (119, 109), left 963 (118, 105)]. In contrast to normal adult animals, factors mediating the observed change affect both atria equally during the perinatal period. The concentration of IR-ANF in the right and left atrium of the fetal, newborn, and immature animals was equal. These data document significant alterations in intraatrial IR-ANF concentrations in the perinatal period. The changes in tissue concentration reflect an alteration in the synthesis/release relationship that may be either a response to or evidence of involvement in the modulation of intravascular vol at the initiation of extrauterine life. (Pediatr Res 25:339-341, 1989)

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Blood monocytes produce two well-defined cytokines, tumor necrosis factor/cachenterin (TNF) and 11-1, that have multiple immunologic and inflammatory functions. This study examined the secretion of these cytokines by cord blood monocytes from preterm and term neonates stimulated with or without lipopolysaccharide (LPS). Seventeen samples (eight preterm, nine term) were collected. Supernatant of monocytes were assayed for activities of IL-1 (mitogenesis for mouse thymocytes) and TNF (cytotoxicity for L929 cells). IL-1 and TNF activities were not significant in supernatants of unstimulated monocytes from either preterm or term infants. IL-1 secretion by LPSstimulated monocytes from term and preterm neonates was comparable to IL-1 activity by monocytes from adults, but TNF activity by LPS-stimulated monocytes from preterm neonates was significantly less than that from monocytes of either term or adult groups (p<0.05). TNF activity in supernatants of LPS-stimulated monocytes was neutralized 100% by monoclonal antibody to TNF-a; IL-1 activity was neutralized 80% by polyclonal antiserum to IL-1-/?. Given the multifactorial biologic activities of TNF, the decreased secretion of TNF by monocytes from preterm neonates may be significant in describing mechanisms for the increased susceptibility of the preterm neonate to infection. {PediatrRes 25:342-346, 1989)

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

To investigate further the role of the hypothalamic luteinizing hormone releasing factor (LRF) pulse generator and the pituitary LRF receptor in the regulation of gonadotropin secretion and gonadal steroidogenesis in the ovine (O) fetus and neonatal lamb, we measured the increment (the difference between the concentration of plasma LH at time 0 and peak LH) in oLH (AoLH) and oFSH (AoFSH) responses to a potent LRF agonist, D-Trp6Pro9NEt-LRF (LRF-A), after consecutive daily doses in 17 ovine fetuses (six females, 11 males) and in 15 neonatal lambs (six females, nine males). Seven of the lambs had been studied as fetuses. In addition, plasma concentrations of testosterone (T) and androstenedione (A4A) were measured in nine male fetuses. After a stimulatory response to the first dose of LRF-A, the mean AoLH and AoFSH responses in the 106- to 118-d gestation fetuses of both sexes were significantly suppressed by the fourth dose and in the neonatal lamb by the second dose. Suppression was sustained throughout the duration of LRF-A therapy which included the gestational interval when the fetal pituitary exhibits its greatest responsiveness to an acute dose of synthetic LRF. The duration of oLH and oFSH suppression after cessation of LRF-A therapy was studied by measuring the AoLH and AoFSH responses to LRF before and at intervals after LRF-A therapy. In the fetus, the AoLH and AoFSH responses remained significantly decreased 7-8 d after the agonist was discontinued. No statistical differences were detected in the AoLH and AoFSH responses to LRF in the neonatal lamb at least by the 4th d after discontinuation of LRF-A. Increasing the duration of LRF-A therapy did not prolong the length of recovery of LH and FSH responsiveness to LRF in either fetus or neonate. Mean fetal plasma T levels rose significantly in response to a single dose of LRF or LRFA. Peak T responses to single dose LRF or LRF-A were lower on d 2-4 and d 7 than on the 1st d of LRF-A

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The effect of dexamethasone (0.1, 1, and 5 mg/kg/d given subcutaneously from d 14-18) was tested in infant mice continuously exposed from birth to either humidified air or 80% oxygen. Dexamethasone significantly decreased lung wet wt (p<0.01), lung water (p<0.021), lung dry wt, protein, and DNA (p<0.001) in both airand oxygen-exposed animals. Dexamethasone, however, had no effect on lung compliance measured after animals were killed on d 18. It also had no effect on the increase in the blood-air barrier thickness or decrease in the blood-air exchange surface area seen in the 80% oxygen-exposed mice. Dexamethasone decreased thymus gland wt (p<0.001), body wt gain (p<0.001), brain wt (p<0.001), and lung lymphocytes (p<0.05) in both air- and oxygenexposed animals. The effect of 1 mg/kg and 5 mg/kg of the drug could not be differentiated. During the 4 d of drug administration, one air- and one oxygen-exposed animal died; both received 5 mg/kg/d of dexamethasone; microscopic and culture evidence of infection was not found. If dexamethasone causes similar effects in human infants with bronchopulmonary dysplasia, it should be used with great caution even for short-term clinical management. (Pediatr Res 25:353-359, 1989)

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Despite considerable study, the mechanisms responsible for the transition of the pulmonary circulation from the fetal to newborn life remain obscure. We compared the responses of third and fourth generation pulmonary arteries to norepinephrine, epinephrine, serotonin, and KC1 from lambs 7 d preterm and 1, 7, and 21 d of age to assess differences between age and third and fourth generations of the pulmonary arterial tree during the transitional period. Preterm vessels were significantly smaller in internal diameter than all other aged vessels for both generations. Fourth generation vessel response to KC1 increased with age (94 ± 1 5 mg/mm2, preterm; 259 ± 3 1 mg/mm2, 21 d). Third generation vessel response to KC1 did not change with age (135 ± 15 mg/mm2, preterm; 158 ± 1 8 mg/mm2, 21 d). There were no differences in maximum response to norepinephrine and epinephrine between ages; however, third generation vessel response to these compounds was significantly greater (30-60% of maximum KC1 response) than fourth generation vessel response (0- 10%). Third and fourth generation vessels had the same maximum response to serotonin regardless of age or generation. Third generation vessels were significantly reduced in sensitivity (log molar concentration which produced 50% of the maximum response—EC5o) to norepinephrine at d 1 (5.89 ± 0.12 log molar) and 7 (5.90 ± 0.21) compared to preterm (6.48 ± 0.10) and 21 d of age (6.50 ± .03). Both third and fourth generation vessels were less sensitive to serotonin at d 1 (5.04 ± 0.17, third; 5.61 ± 0.10, fourth) compared to d 7 (5.77 ± 0.13, third; 6.36 ± 0.12, fourth) and 21 d (5.82 ± 0.24, third; 6.50 ± 0.15, fourth). A similar nonsignificant trend occurred in third generation vessels to epinephrine at d 1 and 7 compared to vessels at preterm and 21 d of age. Greater than 75% of fourth generation vessels did not respond to norepinephrine and epinephrine. The small intrapulmonary arteries of the neonate are undergoing dynamic changes in physiologic response which are dependent upon age and generation

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Though bilirubin is reported to affect a variety of cellular functions, the primary target of its toxic effect is still not known. A major problem in understanding this is the wide variation in results reported by different groups. This is probably due to the differences in stability of bilirubin solutions arising from large differences in bilirubin:albumin molar ratios used in experiments. Hence in studying the toxic effects of bilirubin in tissue culture systems, it is important to be certain that the bilirubin is maintained in solution throughout the time of the exposure to bilirubin. Spectrophotometric measurements have shown that bilirubin is stable in Dulbecco's modified Eagle medium solution at bilirubin:albumin molar ratios up to 3. Under these defined conditions, bilirubin was found to affect Na+K+ ATPase, [3H]-thymidine uptake, L-[35S]methionine incorporation into protein and mitochondrial function at bilirubin concentrations up to 125 pM and bilirubin: albumin molar ratio of 1.5. Toxic effects on all parameters measured were evident at bilirubin:albumin molar ratio of 1.5 after a minimum of 2 h of exposure. No effect was evident at a bilirubin:albumin molar ratio below 1. Although it is not possible to identify with certainty the primary target, the effect on mitochondrial function appeared earlier and was more profound than that seen with the other assessed functions

ISSN:0031-3998    

出版商:OVID    

年代:1989

数据来源: OVID