ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Lung, liver, kidney, and rib specimens were obtained at autopsy from 66 sudden infant death syndrome (SIDS) infants and 23 infants who died suddenly from other causes between the ages of 4–26 wk. Tissue levels of lead and cadmium were measured by atomic absorption spectroscopy and are expressed as μg/g dry weight. Because these metals are cumulative with age in storage tissues, the levels were corrected for age (adjusted to age 13 wk). The SIDS liver and rib specimens contained significantly more lead than non-SIDS tissues (liver, 1.095 μg/gversus0.761 μg/g,P< 0.05; rib, 1.754 μg/gversus1.041 μg/g,P< 0.01, respectively). There were no significant differences in cadmium concentration between the SIDS and non-SIDS tissues. All four tissues showed significant increases with age in both lead and cadmium concentrations in SIDS. The increase in lung lead concentration with age was significantly greater in SIDS than in non-SIDS cases,P< 0.05. In non-SIDS only kidney cadmium showed an increase with age (P< 0.0001). These data collectively suggest an increased exposure of the SIDS infant to lead either prenatally and/or postnatally. Any physiologic effects of the increased tissue lead levels are unknown. They may be only a marker of the known epidemiology of SIDS.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Deficiencies of various vitamin and mineralsper sehave been suggested as possible causes of sudden infant death syndrome (SIDS). Further, a deficiency of essential minerals may lead to enhanced toxicity of toxic elements, in particular, lead and cadmium. To explore the possibility of mineral deficiencies or interactions with the toxic metals, lead and cadmium, lung, liver, kidney, and rib specimens were obtained at autopsy from 66 SIDS infants and 23 infants who died suddenly from other causes. Tissue copper, zinc, calcium, and magnesium were measured by atomic absorption spectroscopy. No differences were found between SIDS and non-SIDS for any element in any tissue except for more magnesium in the liver (P< 0.0001) and less copper in the lungs (P< 0.02) in the SIDS group. Only sporadic interactions between toxic and essential elements could be found. We found no evidence of any essential mineral deficienciesper seor significant interactions of essential and toxic minerals that might potentiate the effects of toxic metals. The physiologic significance, if any, of the higher liver magnesium and lower lung copper found in SIDS is unclear.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Lipoproteins in newborn plasma were isolated from a minimal sample amount (0.3 ml) by a single-step ultracentrifugation in a density gradient, spanning the density range 1.02–1.20 g/ml. After 66 h ultracentrifugation in a swinging-bucket rotor, the content of the tube was eluted and collected in 0.4 ml fractions. Cholesterol and apoproteins AI, AII, and B were assayed in each fraction yielding both the distribution and composition of the very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL2, and HDL3). Newborn plasma was characterized by a low amount of triglyceride-poor and cholesterol ester-rich VLDL and high content of HDL2and HDL3. The VLDL and LDL concentrations increased drastically between 0 and 7 days together with the triglyceride content of the VLDL.At 30 days the lipid composition of VLDL was similar to that of adults, whereas the lipid/protein content remained low both in VLDL and LDL. The composition of HDL2and HDL3remained constant during this period, the percentage of HDL2being higher in newborns than in adults. These compositional changes were reflected in the microviscosity of the lipoproteins, specially in the VLDL fraction.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Groups of newborn rats were transthoracically inoculated with 1 x 106type III group B streptococci/g body wt, either alone or in combination with 1.5 microgram/g body wt of type-specific antibody derived fom hybridoma cell lines. Ninety-four percent of the animals who received bacteria alone died. In contrast, none of those treated with antibody died (P< 0.005). Kinetic studies suggested that antibody may have offered protection, in part, by facilitating the neutrophil response. Animals who received only bacteria exhibited a marked neutropenia (20 ± 18/mm3, mean ± S.E.M.) whereas infected animals treated with antibody did not (3800 ± 30/mm3,P< 0.001). Furthermore, within 2 h of inoculation, antibody-treated animals mobilized stored neutrophils, whereas significant neutrophil mobilization did not occur in the animals which received bacteria alone until 6 h. In the animals receiving bacteria alone, exhaustion of the neutrophil supply quickly occurred (remaining storage neutrophils at 6 h, 0.2 ± 0.1 x 106cells). In contrast, animals, which received antibody, maintained an adequate supply of stored neutrophils (7.0 ± 0.4 x 106P< 0.001). The migration of neutrophils to the site of inoculation was measured by assaying the lungs' content of myeloperoxidase, a marker enzyme for granulocytes. The right and left lungs of animals not receiving antibody accumulated the same quantity of neutrophils, with peak pulmonary neutrophil accumulation occurring 6 h after the infection. In antibody recipients, however, the inoculated lung accumulated significantly more neutrophils than the opposite lung and peak pulmonary neutrophil accumulation occurred at 2 rather than 6 h.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

We examined neonatal lymphocyte production of the lymphokine, lymphocyte-derived chemotactic factor (LDCF). Supernatants from 10 neonatal lymphocyte cultures were paired with the supernatants from 10 adult lymphocyte cultures. Chemotactic activity was defined as the number of adult monocytes migrating toward phytohemagglutinin-stimulated supernatants minus the number of monocytes migrating toward nonstimulated control supernatants using a blind well chamber assay. Eight of the 10 neonatal lymphocyte cultures produced LDCF and five of the 10 adult lymphocyte cultures showed LDCF activity. The mean number of monocytes migrating toward neonatal supernatants was 13.0 ± 1.5 and toward adult supernatants was 14.1 ± 2.1. To determine if a quantitative difference in LDCF production did exist, six additional experiments were performed assaying multiple dilutions of supernatants. No evidence was found for a quantitative difference in neonatal LDCF production compared to adult production. Our studies show that neonatal mononuclear cells are functionally as competent as adult mononuclear cells to produce LDCF in response to a mitogen challenge.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Behavioral and physiologic indices of arousal to auditory stimuli were examined during the first cycle of sleep in 8–12-year-old hyperactive children and nonhyperactive controls. No behavioral responses or sustained awakenings were obtained for any child during the first cycle of sleep to stimuli at intensities up to 123 dB sound pressure levelre0.0002 dynes/cm2),i.e., at intensities more than 90 dB above waking threshold values. Half of the arousal attempts in stage 2 and a quarter of those in stage 4 elicited a partial or momentary physiologic arousal response (i.e., EEG desynchronization and/or change in skin potential response or respiratory activity rates). These arousals were shortlived, with the subjects returning to sleep even with continuing or increased stimulus intensity. Neither the incidence of partial arousals nor the associated threshold intensities differentiated subject groups. Although increased skin potential response activity and decreased respiratory rates were observed during sleep relative to wakefulness, and a predominance of skin potential response activity was noted in stage 4 sleep, no significant differences in frequency (rate/min) of autonomic response measures were obtained when rates before and during auditory stimulation were compared.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Malnutrition was induced in the immediate postnatal period by expanding newborn litters to 20 rat pups/dam. The reversibility of the effects of malnutrition on the pancreas was evaluated by comparing two different feeding methods. At 21 days of age, pups from the expanded litters exhibited significantly decreased body (P< 0.0005) and pancreatic (P< 0.0025) weights as compared to those from control litters (12 pups/dam). Malnourished pups also had less contents of amylase (P< 0.01), lipase (P< 0.0005) and trypsinogen (P< 0.0025) in their pancreases. The concentrations (specific activities) of amylase (P< 0.05) and lipase (P< 0.0125) were significantly decreased but trypsinogen (P< 0.35) was not affected.Subsequent nutritional rehabilitation by anad libitum(food available 24 h/day) or restricted (food available 2 h/day) feeding regimen failed to allow for “catch-up” in body (P< 0.025) and pancreatic weight (P< 0.05) by 56 days of life. Withad libitumfeedings, enzyme contents and concentrations of amylase and lipase in malnourished animals attained control values by 7 and 14 days, respectively. Restricted feedings, however, delayed the recovery in amylase by an additional 7 days but lipase remained depressed in both content, (P< 0.005) and specific activity (P< 0.0025) for the duration of the experiment (56 days). Changes in pancreatic enzymes in response to malnutrition are readily reversible withad libitumfeedings but changes in somatic and pancreatic weights were not reversed. Restricted feedings have no advantage in promoting the rate of recovery of the pancreas after postnatal malnutrition.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Phototherapy increases the biliary excretion of unconjugated bilirubin. In this form, bilirubin would be subject to enterohepatic circulation, and the true efficacy of phototherapy would be blunted. We tested the hypothesis that sequestration of lumenal unconjugated bilirubin by enteral agar administration would enhance the efficacy of phototherapy in jaundiced infants. Fifty-two infants were studied, 21 control and 31 agar-supplemented. The birth weights, sex distribution, and postnatal age at onset of phototherapy did not differ between the two groups of infants; pre- and postphototherapy bilirubin concentrations also did not differ between the groups. The bile acid concentrations and bilirubin saturation indices were also similar. The rate of declination of the plasma bilirubin concentrations after 24 h of phototherapy was greater and significantly more uniform in the agar-supplemented infants (—1.59 ± 2.3versus−2.51 ± 1.44). Stool frequencies were greater in control infants (5.5versus4.3 per 24 h) whereas fecal bilirubin excretions were greater in agar-supplemented infants during the second day of phototherapy (1.32versus3.29 mg·kg-1·24 h-1). Agar supplementation reduced the duration of phototherapy by 23% (37.6 ± 3.2versus48.1 ± 5.0 h).

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Neutrophil function was studied by nitroblue tetrazotium (NBT) reduction, superoxide anion (O2·) production, chemotaxis, and bactericidal activity in 9 children with HBsAg-positive chronic active hepatitis (CAH). NBT reduction and O2· production were higher in resting neutrophils from the children with CAH than from the controls, but the production of O2· was depressed after stimulation with zymosan. No defect was observed in both random and direct locomotion, whereas a significant decrease was present in bactericidal activity. To evaluate the role of virus components, purified preparations of HBsAg and HBcAg were added to neutrophils from normal children. The incubation with such products inducedin vitrothe same modifications that were observed in the neutrophils from children with CAH. In addition, defects in phagocytosis and killing ofCandida albicansas well as in chemotaxis were demonstrated. The production of O2· was reduced in the neutrophils, stimulated by zymosan and previously opsonized with HBsAg-positive serum.

ISSN:0031-3998    

出版商:OVID    

年代:1983

数据来源: OVID