Nitrofen interferes with trophoblastic expression of retinol-binding protein and transthyretin during lung morphogenesis in the nitrofen-induced congenital diaphragmatic hernia model

Background  

Retinoids play a key role in lung development. Retinoid signaling pathway has been shown to be disrupted in the nitrofen model of congenital diaphragmatic hernia (CDH) but the exact mechanism is not clearly understood. Retinol-binding protein (RBP) and transthyretin (TTR) are transport proteins for delivery of retinol to the tissues via circulation. Previous studies have shown that pulmonary retinol levels are decreased during lung morphogenesis in the nitrofen CDH model. In human newborns with CDH, both retinol and RBP levels are decreased. It has been reported that maternal RBP does not cross the placenta and the fetus produces its own RBP by trophoblast. RBP and TTR synthesized in the fetus are essential for retinol transport to the developing organs including lung morphogenesis. We hypothesized that nitrofen interferes with the trophoblastic expression of RBP and TTR during lung morphogenesis and designed this study to examine the trophoblastic expression of RBP and TTR, and the total level of RBP and TTR in the lung in the nitrofen model of CDH.     

Assessment of vitamin A status of preschool children in Indonesia using plasma retinol-binding protein

Although plasma retinol-binding protein (RBP) has been proposed as an indicator of vitamin A status of populations in less technologically developed settings, potential factors which could influence this indicator include inflammation and protein energy status. Plasma RBP, retinol, alpha1-acid glycoprotein (AGP), C-reactive protein (CRP), and albumin were measured in a study of 236 preschool children in Bandung, Indonesia. Spearman correlation coefficient between plasma RBP and retinol concentrations was 0.55 (p < 0.0001). By linear regression, 0.70 pmol/l retinol was equivalent to 0.69 micromol/l RBP. With these cut-off points for defining vitamin A deficiency and plasma retinol as the standard for comparison, RBP had a sensitivity and specificity of 75.0 per cent and 63.2 per cent, respectively. The correlation between RBP and retinol was not affected by plasma AGP, CRP, or albumin concentration. Measurement of plasma RBP by radial immunodiffusion is simple and inexpensive, and this test can be used as a simple surrogate measure for vitamin A concentrations in large field studies.     

Comparison of the pulmonary vasculature in newborns and stillborns with congenital diaphragmatic hernia

The purpose of this study was to compare structural changes in the pulmonary vasculature in newborns with congenital diaphragmatic hernia (CDH) complicated by persistent pulmonary hypertension (PPH) and stillborns with CDH. Victorian blue van Gieson (VVG) staining and immunostaining with anti-alpha smooth-muscle actin (ASMA) was performed on lung tissue obtained at autopsy from 23 newborns with CDH complicated by PPH, 7 stillborns with CDH, and 11 age-matched controls with sudden infant death syndrome (SIDS). The degrees of adventitial and medial thickness and area were measured in pulmonary arteries with an external diameter (ED) of <75 μm, 75–100 μm, 100–150 μm, 150–250 μm, 250–500 μm, and >500 μm by image analyzer and compared statistically. The degrees of adventitial and medial thickness and area were measured in pulmonary veins with an ED of <100 μm, 100–200 μm, and >200 μm by image analyzer and compared statistically. In order to determine whether the characteristic structural changes were size-related, each was related to ED. There was a significant increase in adventitial thickness and area in arteries of all sizes in both newborns and stillborns with CDH compared to SIDS patients (P < 0.05). The degree of medial thickness in newborns and stillborns with CDH was significantly increased compared to SIDS patients (P < 0.01). The degree of medial area was significantly increased for arteries with ED less than 100 μm (P < 0.05) in newborns and stillborns with CDH compared with SIDS patients. There was a significant increase in adventitial thickness and area in veins of all sizes in newborns with CDH compared to stillborns with CDH and SIDS (P < 0.05). The degree of adventitial thickness and area of pulmonary veins were similar in stillborns with CDH and SIDS. There were no significant differences in medial thickness of veins between the three groups. The presence of abnormally thick-walled pulmonary arteries in stillborns with CDH suggests that the intrapulmonary arteries in CDH may become excessively muscularized during fetal life, becoming unable to adapt normally at birth. The absence of structural changes in pulmonary veins in stillborns with CDH suggests that the pulmonary venous changes observed in newborns with CDH complicated by PPH occur after birth as a result of increases in transvascular pressure or a response to release of peptide growth factors. Accepted: 10 March 1998     

Serum retinol in post‐partum mothers and newborns from an impoverished South African community where liver is frequently eaten and vitamin A deficiency is absent

Serum retinol was assessed in mothers and newborns from an impoverished South African community where liver is frequently eaten and vitamin A deficiency known to be absent. Paired cord and maternal blood (n = 201) were collected after delivery and analysed for serum retinol and C‐reactive protein (CRP). Liver intake during pregnancy and intention to breastfeed were also assessed. Mean serum retinol was 1.03 µmol/L ± 0.40 in mothers and 0.73 ± 0.24 µmol/L in newborns, with 21.4% and 49.3% having serum retinol <0.70 µmol/L (<20 µg/dL), respectively. Raised CRP was found in 59.9% of mothers, with a significant negative correlation between serum retinol and CRP (r = ?0.273; p < 0.0001). Liver was eaten by 87.6% of mothers, and 99% indicated their intention to breastfeed. Despite consumption of liver, serum retinol was low in both the mother and the newborn. The conventional cut‐off for serum retinol, i.e. <0.70 µmol/L may therefore not apply for the mother and newborn in the period immediately after delivery. Serum retinol may be influenced by factors other than vitamin A status, e.g. the haemodilution of pregnancy, as well as the acute phase response induced by the birth process, as suggested by raised CRP in 60% of mothers. In the newborns, the low serum retinol is likely to increase rapidly, as liver is frequently eaten by mothers and practically all of them intended to breastfeed. Our results confirm the need for better indicators of vitamin A status or alternative cut‐off values during this period.     

Retinol binding protein status in relation to ocular surface changes in patients with cystic fibrosis treated with daily vitamin A supplements

Cystic fibrosis (CF) is an autosomal recessive disease characterised by increased viscosity of mucus secretions and high chloride concentration in exocrine secretions. Clinically, the patients suffer from chronic pulmonary changes, chronic pancreatic deficiency, and an obstruction of the gastrointestinal tract. The disease affects all secretory epithelia including the eye. The influence of nutritional status on long-term survival and quality of life of CF patients is well documented. Steatorrhea, a consequence of decreased fat digestion and absorption may be associated with vitamin deficiences, including vitamin A. The aim of this study was to document plasma retinol binding protein (RBP) status, a specific plasma transport protein for vitamin A, and ocular surface changes in children and adolescents with CF. The patients were recruited at the 3rd Department of Paediatric Diseases, Medical University of Bialystok, Poland. All patients were regularly seen by a CF specialist dietitian. A group of 15 patients had the following investigations: plasma RBP, visual acuity, physical examination, tear film break-up time, fluorescein staining and Schirmer tear test. A group of 15 age- and sex-matched controls without CF or ocular pathology were also recruited. Plasma RBP concentrations were significantly lower in patients with CF than in the control group. CF patients showed a statistically significant increase in the incidence of clinical blepharitis. Five of the CF patients had clinical evidence of dry eyes. Conclusion:Low plasma retinol binding protein levels frequently occur in clinically stable and retinol supplemented cystic fibrosis patients, of whom five had dry eyes. We recommend monitoring of plasma retinol binding protein levels and evaluation of ocular surface changes, especially those with dry eye symptoms in all cystic fibrosis patients.     

Maternal-neonatal serum vitamin A concentrations

Prevention of neonatal vitamin A deficiency is related to the adequacy of maternal vitamin A stores. In this study we investigated maternal and cord serum vitamin A and retinol-binding protein (RBP) values in an Indian population including, for the first time, clinically vitamin A-deficient mothers. Twenty-eight maternal-neonatal pairs were selected from maternal cohorts of high socioeconomic status without clinical evidence of vitamin A deficiency (group I) and low socioeconomic status with conjunctival xerosis and Bitot's spots (group II). Maternal education, caloric and vitamin A intakes, weight, height, hemoglobin, and birth weight were significantly lower in group II. Serum vitamin A levels were significantly higher in group I mothers and newborns as were RBP levels in group I mothers. However, a significant difference between groups I and II in cord blood RBP was not observed. Upon correlation of maternal vitamin A levels with cord blood vitamin A levels, a logarithmic relationship was revealed, suggesting saturable transplacental transport of vitamin A.     

Comparison of enteral and intramuscular vitamin A supplementation in preterm infants.

Vitamin A deficiency associated with preterm delivery is not readily reversible using the recommended supplement of 1500 IU per day. It has been reported that 2000 IU of intramuscular vitamin A administered on alternate days for 28 days will correct the deficiency. The objective of this study was to compare this regime with the practice in our nursery of giving 5000 IU of vitamin A per day with the early introduction of feeds. The vitamin A status of ten preterm infants (mean gestation 30.5 weeks) who received intramuscular vitamin supplementation was compared with that of nine infants (mean gestation 30.7 weeks) given enteral vitamin A. Vitamin A status was evaluated on the 32nd day of life using plasma retinol and retinol-binding protein (RBP) concentrations and a modified relative dose response (RDR) test. Plasma retinol and RBP concentrations were similar in the two groups shortly after birth revealing vitamin A deficiency. By the 32nd day of life, plasma retinol and RBP concentrations had risen significantly in both groups and in 70% the modified RDR was normal. Differences between the groups were not observed irrespective of the method of vitamin A administration. None of the infants developed clinical or biochemical vitamin A toxicity. In most preterm infants who tolerate feeds, vitamin A deficiency can be corrected safely by supplementing the feeds with 5000 IU of vitamin A per day.     

Vitamin A nutritional status in high- and low-income postpartum women and its effect on colostrum and the requirements of the term newborn

Objective

To evaluate the vitamin A status in serum and colostrum of postpartum women with different socioeconomic status, comparing the colostrum retinol supply with the vitamin A requirement of the newborn.

Altered regulation of retinoic acid synthesis in nitrofen-induced hypoplastic lung

Retinoids are a group of molecules derived from vitamin A, which play an important role in lung development. Within the cell, retinol can either be oxidized to retinal or esterified to retinyl esters by lecithin : retinol acyltransferase (LRAT) for storage. Retinal is then oxidized to an active metabolite of vitamin A, retinoic acid (RA) by retinal dehydrogenase (RALDH). RA is the active metabolite of vitamin A. Cyp26 (a1,b1, and c1), which is a member of the cytochrome P450 family, acts by reducing the activity of RA. Cyp26 type b1 is the predominant subtype expressed in the murine lung. Several studies have suggested that nitrofen may interfere with the retinoid pathway resulting in congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia. Recently, it was reported that nitrofen may act by inhibiting RALDH2. The aim of this study was to examine the pulmonary expression of Cyp26b1, LRAT, and RALDH2, the key enzymes involved in the synthesis of RA, in order to understand the mechanisms underlying pulmonary hypoplasia in the nitrofen CDH model. Pregnant rats were exposed to either olive oil or 100 mg of nitrofen on day 9 of gestation (D9). Fetal lungs were harvested at D15, D17, D19, and D21. D17, D19, and D21 lungs were divided into three groups: control, nitrofen without CDH and nitrofen with CDH, whereas D15 lungs were divided into only two groups; control and nitrofen as the diaphragm is not fully formed yet at this stage. Real- time PCR was performed to evaluate the relative level of Cyp26b1, LRAT, and RALDH2 expression in the lung. Relative levels of Cyp26b1 mRNA were significantly decreased in the lungs of nitrofen with CDH (D17;0.19 ± 0.09, D19;0.70 ± 0.20, D21;0.40 ± 0.36) and nitrofen without CDH (D17;0.14 ± 0.06, D19;0.54 ± 0.42, D21;0.51 ± 0.56) compared to controls (D17;0.35 ± 0.16, D19;1.15 ± 0.48, D21;1.28 ± 0.78) (P < 0.05). LRAT expression was also significantly decreased in nitrofen with CDH (D17; 19.3 ± 7.8, D19; 4.3 ± 1.1, D21; 3.3 ± 1.6) and nitrofen without CDH (D17; 21.2 ± 11.1, D19; 4.5 ± 3.6, D21; 4.1 ± 1.6) compared to controls (D17; 153.7 ± 29.8, D19; 26.8 ± 16.8 D21; 10.1 ± 3.8) (P < 0.05). There was no significant difference in the relative levels of Cyp26b1 and LRAT between nitrofen with CDH and nitrofen without CDH. There were no significant differences in RALDH2 expression among the groups at any stages. Down-regulation of Cryp26b1 and LRAT demonstrates that RA content is decreased in nitrofen induced hypoplastic lungs compared to controls. The finding that RALDH2 expression in the hypoplastic lung is not altered suggests that nitrofen may act by interfering with the retinoid metabolism during the early stage of the retinoid signaling pathway.     

Relationship between the dietary intake,serum, and breast milk concentrations of vitamin A and vitamin E in a cohort of women over the course of lactation

This study evaluated the nutritional status of lactating women with regard to vitamins A and E and the relationship between dietary intake and concentrations in serum and milk. A longitudinal study was conducted with 43 women at a hospital in northeastern Brazil. Blood and milk samples and food intake recalls were obtained at three moments during the breastfeeding period. Retinol and alpha‐tocopherol were analysed by high‐performance liquid chromatography. Dietary inadequacy was analysed according to the estimated average requirement, with intrapersonal variation adjusted by the multiple source method. Food intake was classified by quartiles of consumption. Serum retinol was 1.65 μmol/L, with 5% of low concentrations (<0.7 μmol/L) at the first collection. Serum alpha‐tocopherol decreased from 30.18 to 25.49 μmol/L at the third collection (P = 0.008), with an increase in the percentage frequency of deficiency (<12 μmol/L). Both vitamins maintained stable concentrations in milk at the different collection times, and the overall dietary inadequacy of vitamins A and E was 58% and 100%, respectively. There was a correlation only between vitamin A intake and serum retinol (r = 0.403, P = 0.007), and higher retinol concentrations were found in women classified in the highest consumption quartile (P = 0.031). Over the course of lactation, there was a high degree of inadequacy in vitamin intake and a reduction in serum alpha‐tocopherol, whereas its concentrations in milk remained unchanged. Dietary intake of vitamin A has been shown to influence serum retinol, which underscores the importance of adequate nutrition and monitoring of vitamin deficiency during lactation.     

Accounting for the influence of inflammation on retinol‐binding protein in a population survey of Liberian preschool‐age children

Vitamin A deficiency (VAD) is an important contributor to child morbidity and mortality. The prevalence of VAD, measured by retinol‐binding protein (RBP) or retinol, is overestimated in populations with a high prevalence of inflammation. We aimed to quantify and adjust for the effect of inflammation on VAD prevalence in a nationally representative survey of Liberian children 6 to 35 months of age. We compared five approaches to adjust RBP for inflammation and estimate VAD prevalence (defined as RBP < 0.7 µmol/L): (1) ignoring inflammation; (2) excluding individuals with inflammation (C‐reactive protein (CRP) >5 mg/L or alpha1‐acid glycoprotein (AGP) >1 g/)L; (3) multiplying each individual's RBP by an internal correction factor; (4) by an external correction factor; and (5) using regression (corrected RBP = exp(InRBP – β₁(lnCRP_obs‐lnCRP_ref) – β₂(lnAGP_obs‐lnAGP_ref)). Corrected RBP was based on a regression model where reference lnCRP and lnAGP were set to the maximum of the lowest decile. The unadjusted prevalence of VAD was 24.7%. Children with elevated CRP and/or AGP had significantly lower RBP concentrations than their apparently healthy peers (geometric mean RBP 0.79 µmol/L (95% CI: 0.76, 0.82) vs. 0.95 µmol/L (95% CI: 0.92, 0.97), P < 0.001). Using approaches 2–5 resulted in a prevalence of VAD of 11.6%, 14.3%, 13.5% and 7.3%, respectively. Depending on the approach, the VAD prevalence is reduced 10–17 percentage points when inflammation is taken into account. Further quantification of the influence of inflammation on biomarkers of vitamin A status from other national surveys is needed to compare and recommend the preferred adjustment approach across populations.     

Increased levels of circulating adhesion molecules in neonates with congenital diaphragmatic hernia complicated by persistent pulmonary hypertension

The aim of this study was to determine circulating levels of adhesion molecules in serum from patients with congenital diaphragmatic hernia (CDH) to investigate the relationship between soluble ICAM-1, ELAM-1, and VCAM-1 liberated by activated vascular endothelium and the development of persistent pulmonary hypertension (PPH) in patients with CDH. We measured serum levels of ICAM-1, ELAM-1, and VCAM-1 in 20 high-risk neonates with CDH at the time of diagnosis (11 with PPH and 9 without PPH) and 7 age-matched controls using ELISA system. We further examined the lungs of 5 patients with CDH complicated by PPH who died during resuscitation and stabilization, and three control lung specimens for the expression of adhesion molecules using immunohistochemistry. The mean serum ICAM-1 levels in CDH patients with PPH (227.0±98.9 ng/ml) were increased compared with levels in CDH patients without PPH (140.29±37.4 ng/ml; p<0.05) and controls (130.0±23.8 ng/ml; p<0.05). Mean serum ELAM-1 levels in CDH patients with PPH (116.5±19.2 ng/ml) were significantly increased compared with levels in CDH patients without PPH (79.3±27.9 ng/ml; p<0.01) and controls (58.4±14.5 ng/ml; p<0.001). Mean serum VCAM-1 levels in CDH patients with PPH (1596.9±460.4 ng/ml) were significantly higher compared with levels in CDH patients without PPH (1069.3±444.6 ng/ml; p<0.01) and controls (838.0±171.2 ng/ml; p<0.001). But serum adhesion molecule levels in CDH patients without PPH were no different from controls statistically. Pulmonary vascular endothelial cells from CDH lung with PPH had strong expression of adhesion molecules compared with controls. Up-regulated expression of adhesion molecules on the endothelium of pulmonary vessels and high circulating levels of adhesion molecules in CDH patients with PPH suggest that adhesion molecules may play a role in the development of PPH in CDH.     

Nitrofen increases total retinol levels in placenta during lung morphogenesis in the nitrofen model of congenital diaphragmatic hernia

Background

It has been shown that pulmonary retinol level is decreased during lung morphogenesis in the nitrofen-induced PH in congenital diaphragmatic hernia (CDH). Placenta has a major role in the retinol homeostasis in fetal life. Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. Placenta is the main fetal retinol store where retinol is stored in retinyl-ester formation. Trophoblasts have to produce its own retinol-binding protein (RBP) for retinol transport from placenta to fetus. Recently, we demonstrated that trophoblastic RBP expression is decreased in the nitrofen model of CDH. The aim of this study was to investigate the retinol transfer from mother to the placenta in nitrofen model of CDH.

Methods

Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal placenta harvested on D21 and divided into two groups: control (n = 11) and nitrofen with CDH (n = 11). Retinoid levels in placenta were measured using HPLC. Immunohistochemistry was performed to evaluate trophoblastic expression of main RSP genes.

Results

Total retinol levels in the placenta were significantly increased in CDH placenta compared to control placenta. The retinyl-ester levels were significantly increased in CDH placenta compared to control placenta. Markedly, decreased immunoreactivity of retinoid signaling pathway was observed in trophoblast cells in CDH compared to control placenta.

Conclusions

Increased placental retinol levels show that retinol is transferred from mother to placenta and stored in the placenta in nitrofen model of CDH during lung morphogenesis. Nitrofen may disturb the mobilization of retinol from placenta to fetal circulation causing PH in CDH.     

Plasma protein Z levels in healthy and high-risk newborn infants

AIM: To evaluate plasma protein Z (PZ) levels in healthy and high-risk newborn infants. METHODS: A longitudinal observational study was conducted. Inclusion criteria were: healthy term and preterm newborns normal for gestational age and newborns belonging to one of the following groups: newborns small for gestational age (SGA), newborns affected by respiratory distress syndrome (RDS), newborns from mothers with pre-eclampsia. Newborns with sepsis, congenital malformation or haemorrhagic disorders were excluded. Plasma PZ levels, protein C (PC) concentration, PC activity and protein-induced vitamin K absence levels were measured. RESULTS: 53 newborns were enrolled into the study. PZ and PC antigen levels varied significantly among analysed subgroups on day 1 (p < 0.01): lower levels of these inhibitors were found in RDS newborns (group C), newborns from mothers affected by pre-eclampsia (group D) and SGA newborns (group E) than in healthy term and preterm newborns (groups A and B). CONCLUSION: PZ deficiency occurs in newborns affected by severe RDS, in newborns from pre-eclamptic mothers and in SGA newborns, probably owing to activated coagulation in the first two conditions and to reduced PZ synthesis in the last condition.     

Serum Vitamin B12 and Folate Concentrations and the Effect of the Mediterranean Diet on Vulnerable Populations

Low vitamin B12 and folate levels in expectant mothers may lead to low stores in babies. The aim of this study was to determine the frequencies of vitamin B12 and folate deficiencies in pregnant women and neonates, and to assess the effect of maternal vitamin status on babies’ vitamin levels in the Aegean region of Turkey, where the Mediterranean diet (mainly fresh fruits and vegetables) is adopted. We studied 72 pregnant women and their singleton-term babies. Venous blood samples of expectant mothers were collected 1 h before delivery and cord blood of babies were obtained at birth. The mean vitamin B12 in maternal and cord blood serum was 163.1 ± 72.0 pg/mL and 146.2 ± 102.5 pg/mL, and the mean folate, 9.8 ± 4.8 ng/mL and 15.8 ± 3.8 ng/mL, respectively. There were statistically significant correlation between maternal and cord blood serum vitamin B12 (r = 0.61, P = .04) and folate levels (r = 0.65, P < .001). 70.8% of the mothers and 83.9% of the babies were vitamin B12 deficient (<200 pg/mL). Neither group showed folate deficiency. The mean level of vitamin B12 in mothers significantly varied by the type of diet (241.6 (72.1) pg/mL versus 155.9 (68.2) pg/mL; P = .012). Vitamin B12 deficiency in pregnant women and neonates may be a public health problem in our community. The Mediterranean diet in these vulnerable groups may be an aggravating factor for vitamin B12 deficiency. Prenatal screening of all expectant mothers, prenatal supplementation of vitamin B12, and an increase in animal-source food intake may improve expectant mother's vitamin B12 level.     

Vitamin A deficiency and nocturnal vision in teenagers with cystic fibrosis

The aim of this study was to document plasma retinol status and nocturnal vision in ten eutrophic adolescents with cystic fibrosis (CF) receiving daily retinol supplementation. Plasma retinol, α and β carotenes and retinol binding protein were measured in ten clinically stable CF patients (mean age: 14.3 years; Shwachman score: 80–100). Nocturnal vision evaluation was performed with a Beyne optometer. Plasma retinol (mean 0.42 ± 0.16 mg/l), α carotene and β carotene levels were below the lower limit of normal in all but one patient. Five out of ten patients with normal standard opthalmological examination presented a poor (n=3 patients) or a pathological (n=2) dark adaptation test. These two patients showed a dramatic increase in nocturnal vision after 1 year of adapted retinol supplementation. Conclusion Low vitamin A levels occur frequently in clinically stable, eutrophic and retinol supplemented CF adolescents. Since vitamin A deficiency is asso-ciated with poor nocturnal vision and since this pattern can be reversed by adapted retinol supplementation, we recommend monitoring plasma vitamin A levels in CF patients and evaluation of dark adaptation in retinol deficient patients. Received: 6 December 1996 / Accepted in revised form: 18 June 1997     

A comparison of three vitamin A dosing regimens in extremely-low-birth-weight infants

OBJECTIVE: Vitamin A supplementation reduces bronchopulmonary dysplasia (BPD)/death in extremely low birth weight neonates. It was hypothesized that compared with the standard regimen of 5000 IU 3 times per week for 4 weeks, (1) a higher dose (10,000 IU 3 x per week) would increase serum retinol and retinol binding protein (RBP) and lower relative dose responses (RDR), and (2) once-per-week dosing (15,000 IU once per week) would lead to equivalent levels, RBP, and RDR. STUDY DESIGN: Extremely low birth weight neonates (n = 120) receiving O(2)/mechanical ventilation at 24 hours were randomly assigned to (1) standard, (2) higher dose, or (3) once-per-week regimens. Measures of vitamin A deficiency were serum retinol <20 microg/dL, RBP <2.5 mg/dL, and/or RDR >10% on day 28. BPD was defined as O(2)/mechanical ventilation at 36 weeks' postmenstrual age. RESULTS: Groups were similar at enrollment (median gestational age, 25 weeks; birth weight, 689 g). Possible toxicity was seen in <5%. The higher dose regimen did not increase retinol or RBP, decrease RDR, or improve outcomes. Infants in the once-per-week regimen had lower retinol levels and higher RDR without an effect on outcomes. CONCLUSIONS: Compared with the standard regimen, once-per-week dosing worsened, and higher doses did not reduce, vitamin A deficiency. Therefore, the standard regimen is recommended.     

Maternal-neonatal retinol and alpha-tocopherol serum concentrations in Greeks and Albanians

BACKGROUND: Vitamin A and E are required in physiological processes such as pregnancy and growth. AIM: To evaluate retinol and alpha-tocopherol serum levels in Greek and Albanian mothers and in their newborns. METHODS: Data concerned 1125 Greek and 898 Albanian mothers along with their newborns. Immediately after delivery, blood from the umbilical cord and from the mothers was collected into light-protected tubes. Retinol and alpha-tocopherol serum levels were measured with a reversed-phase HPLC method. A 60-d dietetic diary was kept by each woman during the last 2 mo of pregnancy. RESULTS: Retinol (1.3 +/- 0.1 micromol/l) and alpha-tocopherol (32.9 +/- 9.5 micromol/l) levels were estimated to be normal in Greek mothers and in most of their offspring (0.9 +/- 0.1 and 18.5 +/- 3.4 micromol/l, respectively). In contrast, in Albanian mothers, retinol concentration was found to be low (0.6 +/- 0.1 micromol/l), and in 1/3 significantly low (<0.45 micromol/l). Consequently, the vitamin was evaluated to be very low in their newborns (0.4 +/- 0.1 micromol/l), and in 1/2 extremely low. However, in 12% of the Albanian cord blood samples, retinol level was determined to be higher as compared with that of their mothers. alpha-Tocopherol was evaluated to be normal in most of the immigrant mothers (20.0 +/- 8.8 micromol/l) and low (<7.5 micromol/l) in 15% of their newborns. Vitamin A intake was found to be extremely low and vitamin E low (p < 0.05) in the Albanians. CONCLUSIONS: (a) The decreased vitamin A and vitamin E intake, and their low blood status in the Albanian mothers and in their newborns, could be due to their low socio-economic and nutritional status. (b) Immigrant Albanians, during their pregnancy, and their newborns should be "followed up", being at risk of developing symptoms from the very low levels of these lipid-soluble vitamins.     

The tracheobronchial tree is abnormal in experimental congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia (CDH) have other malformations that contribute to the high mortality. The nitrofen rat model allows experimental study of these anomalies. This study examines whether the tracheobronchial tree is also abnormal in this model. Time-mated rats received 100 mg nitrofen on gestational day 9.5; 90 fetuses were harvested on day 21 (near full term) and dissected. The trachea and bronchi were stained with alcian blue-alizarin red and their anatomy was examined by transillumination under a microscope. The findings were compared with those of 11 suitable controls. Control pups had no malformations. Those with CDH (n = 57) had significantly decreased numbers of tracheal rings in comparison with controls (22.9 ± 1.9 vs 26 ± 1.9, P < 0.05) and 40/57 had fragmented rings (0 in controls). Twelve CDH animals had, in addition, tracheal stenoses of variable severity, sometimes related to vascular rings. Nitrofen fetuses without CDH (n = 33) had only short tracheas and 4 had mild stenoses. Nitrofen-exposed fetuses have, in addition to lung hypoplasia and sometimes CDH, severe tracheobronchial anomalies that suggest the involvement of pathogenetic mechansims capable of acting on various tissue components. The genetic control of organogenesis is most probably disturbed by the teratogen.     

The influence of maternal smoking on maternal and newborn oxidant and antioxidant status

Background  Maternal smoking has been suggested as a source of oxidant stress in pregnant women and in newborns exposed in utero. The aim of this study was to determine the influence of maternal smoking on oxidant status and antioxidant vitamins of mother–infant pairs. Materials and methods  Socioeconomic and diet characteristics were recorded from 20 smoker and 20 non-smoker pregnant women of 36 weeks’ gestation. On the day of delivery, venous blood samples of the women and cord bloods were taken. On postpartum day 7, milk and infant urine samples were collected. Plasma and milk β-carotene, retinol, α-tocopherol and cotinine levels, plasma malondialdehyde levels, and urine cotinine levels were measured. Results  Milk α-tocopherol levels of smoking mothers were lower than those of non-smoking mothers. In smokers, there were no correlations between maternal vitamin A intakes and milk levels of retinol, and between maternal plasma levels and milk levels of β-carotene. Conclusions  Maternal smoking may lead to decreased milk levels of vitamin E, as a result of making use of this antioxidant in order to limit lipid peroxidation, as well as may lead to a possible limitation on the transfer of lipophilic antioxidants including vitamin A from blood plasma to milk. Further investigations conducted in large populations will be needed to assess the effects of maternal smoking on the oxidant and antioxidant status of breast milk.