Chemical nature of intestinal-type alkaline phosphatase in human kidney.
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Approximately 10% of the alkaline phosphatase activity in human kidney is derived from the intestinal-type alkaline phosphatase isoform, which can be differentiated from adult intestinal alkaline phosphatase by selective reactivity with monoclonal antibodies. The NH2-terminal sequence of the renal intestinal-type alkaline phosphatase was shown to be identical to sequences of the adult and meconial alkaline phosphatases except for the NH2-terminal valine residue, which is missing in the renal intestinal-type enzyme. Incubation of purified meconial alkaline phosphatase with kidney homogenate resulted in removal of the NH2-terminal valine residue, indicating the presence of aminopeptidases in kidney that catalyze this hydrolysis. Furthermore, the oligosaccharide chains of the renal intestinal-type alkaline phosphatase were shown to differ from those of meconial and adult intestinal alkaline phosphatases, as revealed by lectin affinity chromatography. The heterogeneity of the intestinal-type alkaline phosphatase can therefore be generated both by partial peptide bond hydrolysis and differences in glycosylation. (+info)
Use of biomarkers to indicate exposure of children to organophosphate pesticides: implications for a longitudinal study of children's environmental health.
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Because of their history of widespread use in the United States and unknown long-term health effects, organophosphate pesticides (OPs) are being considered as a chemical class of interest in planning for the National Children's Study, a longitudinal study of children's environmental health. The availability and appropriate use of biomarkers to determine absorbed doses of environmental chemicals such as OPs are critical issues. Biomarkers of OP exposure are typically measured in blood and urine; however, postpartum meconium has been shown to be a promising matrix for assessing cumulative in utero exposure to the fetus, and studies are currently in progress to determine the utility of using saliva and amniotic fluid as matrices. In this article, we discuss the advantages and disadvantages of the currently available OP exposure monitoring methods (cholinesterase inhibition in blood, pesticides in blood, metabolites in urine and alternative matrices); study design issues for a large, long-term study of children's environmental health; and current research and future research needs. Because OPs are rapidly metabolized and excreted, the utility of one-time spot measurements of OP biomarkers is questionable unless background exposure levels are relatively stable over time or a specific time frame of interest for the study is identified and samples are collected accordingly. Biomarkers of OP exposure can be a valuable tool in epidemiology of children's environmental health, as long as they are applied and interpreted appropriately. (+info)
Osteopathic manipulative treatment in prenatal care: a retrospective case control design study.
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The use of osteopathic manipulative treatment (OMT) during pregnancy has a long tradition in osteopathic medicine. A retrospective study was designed to compare a group of women who received prenatal OMT with a matched group that did not receive prenatal OMT. The medical records of 160 women from four cities who received prenatal OMT were reviewed for the occurrence of meconium-stained amniotic fluid, preterm delivery, use of forceps, and cesarean delivery. The randomly selected records of 161 women who were from the same cities, but who did not receive prenatal OMT, were reviewed for the same outcomes. The results of a logistic regression analysis were statistically reliable, chi2 (4, N = 321) = 26.55; P < .001, indicating that the labor and delivery outcomes, as a set, were associated with whether OMT was administered during pregnancy. According to the Wald criterion, prenatal OMT was significantly associated with meconium-stained amniotic fluid (Z = 13.20, P < .001) and preterm delivery (Z = 9.91; P < .01), while the use of forceps was found to be marginally significant (Z = 3.28; P = .07). The case control study found evidence of improved outcomes in labor and delivery for women who received prenatal OMT, compared with women who did not. A prospective study is proposed as the next step in evaluating the effects of prenatal OMT. (+info)
Extraction and purification of biologically active intestinal trefoil factor from human meconium.
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Intestinal trefoil factor (TFF3/ITF), a member of trefoil factor family (TFF) domain peptides, is normally expressed by goblet cells and secreted into the lumen of the intestinal tract, and plays an important role in the maintenance and repair of the intestinal mucosal barrier. Significant amounts of TFF3/ITF are present in the meconium of human infants. Here, we describe a relatively simple method for extraction and purification of natural human TFF3/ITF from meconium. The purification methods include acid treatment, ammonium sulfate precipitation, isoelectric precipitation, and iron exchange chromatography. A relatively large amount of natural TFF3/ITF can be purified from meconium of full-term infants and this purified, natural TFF3/ITF is biologically active in an ethanol-induced rat gastric mucosal injury model. (+info)
Placental handling of fatty acid ethyl esters: perfusion and subcellular studies.
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The measurement of fatty acid ethyl esters (FAEE) in neonatal meconium is a novel test to confirm prenatal ethanol exposure. The origin of FAEE in the maternal-placental-fetal unit is not known. The objectives of this study were to investigate whether FAEE are transferred and metabolized by the human placenta. Isolated placental cotyledons were perfused with a mixture of four FAEE (palmitic, stearic, oleic, and linoleic acid ethyl esters) commonly detected in the meconium of neonates exposed to ethanol in utero, and the transfer of FAEE to the fetal unit was investigated in the absence and presence of albumin. The metabolic degradation of FAEE by human placental microsomes was subsequently determined. FAEE disappeared from the maternal circulation but remained undetectable in the fetal unit following perfusions. The addition of albumin had no effect on FAEE transfer. The unrecoverable fraction of individual FAEE in the perfusion system accounted for >50% of the initial amount used, suggesting significant metabolic degradation. Subcellular studies documented the enzymatic degradation of FAEE by placental microsomes (mean Km, 35-95 microM; Vmax, 0.6-1.8 nmol/min/mg for individual FAEE). FAEE at levels found in alcoholics that are originated from the mother are not transferred to the fetus because they are taken up and degraded extensively by the human placenta. Hence, FAEE detected in neonatal matrices are likely produced by the fetus from ethanol that has been transferred to and metabolized by the fetus, rendering FAEE a powerful direct biomarker reflective of true fetal exposure to ethanol in utero. (+info)
Bacterial growth in amniotic fluid is dependent on the iron-availability and the activity of bacterial iron-uptake system.
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In the present study, the relationship among iron-availability, antibacterial activity, role of meconium as an iron source and the activity of bacterial iron-uptake system (IUS) for bacterial growth in amniotic fluid (AF) were investigated. Staphylococcus aureus ATCC 6538 and its streptonigrin-resistant (SR) mutant with defective IUS were used as the test strains. The growth of S. aureus in AF was stimulated dose-dependently by addition of meconium. Bacterial growth stimulated by meconium was re-inhibited dose-dependently by addition of iron-chelator, dipyridyl and apotransferrin. Iron concentration was correlated with the meconium content in AF (r(2)= 0.989, p=0.001). High-affinity IUS of S. aureus was expressed only in AF but not in AF with meconium. The growth of SR strain was more retarded than that of the parental strain in the iron-deficient brain heart infusion (ID-BHI), clear AF and AF containing apotransferrin. The retarded growth of both strains in the ID-BHI and AF was recovered by addition of holotransferrin, hemoglobin and FeCl3. Taken together, the antibacterial activity of AF is closely related with low iron-availability. Bacterial growth in AF considerably depends on the activity of bacterial IUS. Meconium acts as one of the exogenous iron-sources and thus can stimulate bacterial growth in AF. (+info)
Preterm meconium staining of the amniotic fluid: associated findings and risk of adverse clinical outcome.
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BACKGROUND: The incidence of preterm meconium staining of the amniotic fluid (MSAF) is uncertain. It may be an indicator of possible listeriosis. It is unclear how great this risk is or whether preterm MSAF is a risk factor for adverse neonatal outcome. OBJECTIVE: To investigate the incidence of preterm MSAF, the incidence of associated maternal and neonatal infection, and the outcomes of the infants at discharge. DESIGN: Retrospective case-control study. METHODS: Infants < 33 weeks gestation with preterm MSAF born in the Simpson Memorial Maternity Pavilion, Edinburgh between 1 January 1994 and 2 January 2001 were matched with the next infant of the same sex and gestation with clear liquor. Maternal and infant characteristics, culture results, placental histology, and clinical outcomes were compared. RESULTS: Preterm MSAF was observed in 45/1054 (4.3%) infants below 33 weeks gestation. No maternal or infant listeriosis was identified in cases or controls. There was no significant difference in birth weight, Apgar score, or first pH between cases and controls. Preterm MSAF was associated with prolonged rupture of the membranes (odds ratio (OR) 3.34, 95% confidence interval (CI) 1.07 to 10.49), but not maternal hypertension, sepsis, or chorioamnionitis. Severe (grade 3/4) intraventricular haemorrhage was significantly more common in infants with preterm MSAF (OR 2.03, 95% CI 1.62 to 2.53). There was no significant difference in mortality. Early onset sepsis was observed in two cases and three controls. CONCLUSIONS: Preterm meconium staining of the amniotic fluid may be associated with increased risk of intraventricular haemorrhage. It does not appear to be a useful indicator of listeriosis. (+info)
Meconium-stained amniotic fluid and fetal oxygen saturation measured by pulse oximetry during labour.
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BACKGROUND AND AIM OF THE WORK: The high false-positive rate of electronic fetal heart rate monitoring is the major obstacle to the correct prediction and diagnosis of intrapartum fetal distress. Fetal pulse oximetry is a safe and accurate indicator of fetal oxygenation. The aim of this study was to evaluate the clinical use of this technique for the diagnosis of fetal hypoxia and for prevention of fetal metabolic acidosis and asphyxia during labour, in the presence of meconium-stained amniotic fluid with or without abnormal fetal heart rate patterns, using a threshold value of 30% oxygen saturation. METHODS: Fetal blood oxygen saturation levels (SpO2) of 58 term fetuses with non-reassuring fetal status were measured during labour by fetal pulse oximetry. In 35 cases the amniotic fluid was stained with meconium at onset of labour. Mean SpO2 levels at the different stages of labour were matched against fetal heart rate patterns, the amniotic fluid status, and neonatal outcome. The 35 cases with meconium-stained amniotic fluid were compared with a control group of 28 pregnant women at term who had meconium-stained amniotic fluid during labour but were not monitored by pulse oximetry. RESULTS: When the fetal heart rate tracings were abnormal, mean SpO2values were significantly lower in the first 30 minutes of application and in the last 30 minutes of labour or before Cesarean section. Meconium-stained amniotic fluid was associated with lower SpO2values only when fetal heart monitoring showed a "non-reassuring" pattern. No cases were observed with severe neonatal acidosis, with Apgar score <7 at 5 minutes, or with other adverse neonatal events. In patients with meconium-stained amniotic fluid, neonatal outcomes were better in the group monitored by pulse oximetry versus the control group, although the differences were not statistically significant. CONCLUSIONS: Continued monitoring of fetal oxygen saturation combined with fetal heart rate monitoring may improve accuracy in the evaluation of fetal well-being. As a result, labour could be more safely managed in pregnancies with non-reassuring fetal status as measured by conventional methods, especially in the presence of meconium-stained amniotic fluid. (+info)