Stools Of Newborns Research Articles

Characterization of newborn gut microbiota according to the pre-gestational maternal nutritional status and delivery mode.

The aim of this study is to characterize the composition of the newborn gut microbiota based on the maternal pre-pregnancy nutritional status and the delivery mode. A biological sample was collected from the anal mucosa of the newborns between 24 and 48h after delivery, as it was not possible to collect a meconium sample at that time. A general data collection questionnaire was administered. The microbiome of the samples was analyzed by next-generation sequencing of the hypervariable regions v3-v4 of the 16S gene. Alpha diversity analyses were performed using the Observed Richness and Shannon diversity index metrics and Beta diversity analyses were conducted using Nonmetric multidimensional scaling with Weighted Unifrac, Differential abundance analysis was performed using a Negative Binomial Wald Test with maximum likelihood estimation for coefficients of Generalized Linear Models. Newborns of obese mothers exhibited lower alpha diversity compared to newborns of mothers with adequate BMI (body mass index). We observed variation in the composition of the microbial community in newborn stool samples, both from mothers with overweight/obesity and those with adequate pre-pregnancy BMI. We observed a visible correlation between the mode of delivery and the newborn's microbiota. We found variation in the overall composition of the microbial community in the stools of newborns, regardless of the delivery mode. The results of our study demonstrate differences in the microbiota of neonates born via cesarean section compared to those born vaginally as well as differences in newborns of mothers with overweight/obesity compared to those with an adequate pre-pregnancy BMI.

Food-Protein-Induced Proctocolitis in Pre-Term Newborns with Bloody Stools in a Neonatal Intensive Care Unit.

The bloody stools of newborns may be a clue for several clinical entities of varying severity, ranging from idiopathic neonatal transient colitis to food-protein-induced allergic proctocolitis (FPIAP) or necrotizing enterocolitis (NEC). Distinguishing among them at an early stage is challenging but crucial, as the treatments and prognoses are different. We conducted a monocentric retrospective study including all pre-term infants with bloody stools admitted to the Neonatal Intensive Care Unit (NICU) of the Vittore Buzzi Children's Hospital (Milan) from December 2022 to May 2024. Patients diagnosed with NEC exhibited significantly lower eosinophil counts and higher procalcitonin levels than both patients with FPIAP and patients with idiopathic neonatal transient colitis, as well as a statistically significant increase in pathological features from abdomen ultrasounds and abdominal X-rays. In contrast, no lab markers or imaging techniques have been demonstrated to be useful in distinguishing between idiopathic neonatal transient colitis and FPIAP. Thus, after excluding a diagnosis of NEC, the only way to confirm FPIAP is through the oral food challenge, which can be performed in premature newborns presenting with bloody stools who are otherwise healthy and under medical supervision, in order to identify infants who may benefit from a cow's-milk-free diet.

Fecal Keratin 8 Is a Noninvasive and Specific Marker for Intestinal Injury in Necrotizing Enterocolitis.

Specific biomarkers of intestinal injury associated with necrotizing enterocolitis (NEC) are needed to diagnose and monitor intestinal mucosal injury and recovery. This study aims to develop and test a modified enzyme-linked immunosorbent assay (ELISA) protocol to detect the total keratin 8 (K8) in the stool of newborns with NEC and investigate the clinical value of fecal K8 as a marker of intestinal injury specifically associated with NEC. We collected fecal samples from five newborns with NEC and five gestational age-matched premature neonates without NEC at the Lucile Packard Children's Hospital Stanford and Washington University School of Medicine, respectively. Fecal K8 levels were measured using a modified ELISA protocol and Western blot, and fecal calprotectin was measured using a commercial ELISA kit. Clinical data, including gestational age, birth weight, Bell stage for NEC, feeding strategies, total white blood cell (WBC) count, and other pertinent clinical variables, were collected and analyzed. Fecal K8 levels were significantly higher in the pre-NEC group (1-2 days before diagnosis of NEC) and NEC group than those in the non-NEC group (p = 0.013, p = 0.041). Moreover, fecal K8 was relatively higher at the onset of NEC and declined after the resolution of the disease (p = 0.019). Results with similar trends to fecal K8 were also seen in fecal calprotectin (p = 0.046), but not seen in total WBC count (p = 0.182). In conclusion, a modified ELISA protocol for the total K8 protein was successfully developed for the detection of fecal K8 in the clinical setting of premature newborns with NEC. Fecal K8 is noted to be significantly increased in premature newborns with NEC and may, therefore, serve as a noninvasive and specific marker for intestinal epithelial injury associated with NEC.

SARS CoV-2 detected in neonatal stool remote from maternal COVID-19 during pregnancy.

BackgroundIn utero transmission of SARS coronavirus 2 (SARS-CoV-2) has not been fully investigated. We investigated whether newborns of mothers with COVID-19 during pregnancy might harbor SARS-CoV-2 in the gastrointestinal tract.MethodsThis cohort study investigated stool from 14 newborns born at 25–41 weeks admitted at delivery to our urban academic hospital whose mothers had COVID-19 during pregnancy. Eleven mothers had COVID-19 resolved more than 10 weeks before delivery. Newborn stool was evaluated for SARS-CoV-2 RNA, Spike protein, and induction of inflammatory cytokines interleukin-6 (IL-6) and interferon-γ (IFN-γ) in macrophages.ResultsDespite negative SARS CoV-2 nasal PCRs from all newborns, viral RNAs and Spike protein were detected in the stool of 11 out of 14 newborns as early as the first day of life and increased over time in 6. Stool homogenates from all 14 newborns elicited elevated inflammatory IL-6 and IFN-γ from macrophages. Most newborns were clinically well except for one death from gestational autoimmune liver disease and another who developed necrotizing enterocolitis.ConclusionsThese findings suggest in utero transmission of SARS-CoV-2 and possible persistent intestinal viral reservoirs in the newborns. Further investigation is required to understand the mechanisms and their clinical implications.Impact SARS-CoV-2 RNAs or Spike protein was detected in the stool of 11 out of 14 preterm newborns born to mothers with resolved COVID-19 weeks prior to delivery despite negative newborn nasal PCR swabs.These novel findings suggest risk of in utero SARS-CoV-2 transmission to the fetal intestine during gestation.The presence of SARS-CoV-2 RNAs and Spike protein in the intestines of newborns may potentially impact the development of the gut microbiome and the immune system; the long-term health impact on the preterm infants should be further investigated.

Implications of Indirect Biomarkers of Intestinal Permeability in the Stools of Newborns and Infants with Perinatal Risk Factors for Intestinal Colonization Disorders and Infant Feeding Patterns.

Background: The intestinal microbiota of pregnant women and factors disturbing the microbial balance of their gastrointestinal tract during the perinatal period may be the cause of dysbiosis and thus intestinal permeability syndrome in their children. The purpose of this study was to analyze the implications of intestinal permeability parameters in the stools of newborns and infants with perinatal risk factors for intestinal colonization disorders (the route of delivery, antibiotic therapy in the neonatal period and the abandonment of breastfeeding). Methods: The study included 100 mother–child pairs. All children were born from uncomplicated and term pregnancies (between 37 and 42 weeks of gestation). In order to determine the parameters of dysbiosis and intestinal permeability, we determined the concentrations of zonulin and occludin in stool samples taken from all children at 0 (i.e., at birth), 3, 6 and 12 months of age. Elevated levels of lipopolysaccharide (LPS) are associated with metabolic diseases and its presence may be indicative of TJ injury and the onset of leaky gut syndrome. To indirectly determine the presence of endotoxemia, the concentrations of lipopolysaccharide were also measured in stool samples taken from all children at 0, 3, 6 and 12 months of age. We analyzed the relationship between the markers studied and perinatal risk factors for impaired intestinal colonization, including the mode of delivery, the method of feeding, and a family history of allergy. Results: During the first 3 months of infant life, higher concentrations of fecal occludin and zonulin were most often accompanied by higher values of fecal LPS. Similarly, higher concentrations of zonulin were accompanied by higher values of occludin. There were no significant differences in the stool concentrations of the studied markers during the first year of life between children born by caesarean section and those born naturally. In addition, the method of feeding had no significant effect on the changes in the concentrations of the determined fractions. Antibiotic therapy was associated only with an increase in the fecal occludin concentration after birth, without any effect on zonulin, occludin or LPS levels. The use of probiotic therapy in infants resulted in a decrease in only LPS concentrations at 3 months of age, with no effect on zonulin or occludin concentrations at 0, 6 and 12 months. Conclusions: Perinatal factors related to intestinal permeability are important during the first 3 months of infant life. However, we found that the mode of delivery had no influence on the parameters of infant intestinal leakage during the first year of life. In addition, the mode of infant feeding—breast or exclusively formula—did not significantly affect the changes in the concentrations of LPS, zonulin or occludin in the stools of children. A short-term increase in occludin concentrations after delivery in the stools of children from mothers undergoing antibiotic therapy indicates a negative but reversible influence of intrapartum antibiotics on the intestinal integrity of children in the perinatal period. Probiotic therapy seems to have a positive effect on reducing endotoxemia in children during the first 3 months of life. The presence of LPS at 3 months did not affect intestinal tightness at any of the later measured periods of the infants’ lives.

Basal Ti level in the human placenta and meconium and evidence of a materno-foetal transfer of food-grade TiO2 nanoparticles in an ex vivo placental perfusion model

BackgroundTitanium dioxide (TiO2) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO2 nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO2-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus. However, no human data are available for pregnant women exposed to food-grade TiO2-NPs and their potential transfer to the foetus. In this study, human placentae collected at term from normal pregnancies and meconium (the first stool of newborns) from unpaired mothers/children were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and scanning transmission electron microscopy (STEM) coupled to energy-dispersive X-ray (EDX) spectroscopy for their titanium (Ti) contents and for analysis of TiO2 particle deposition, respectively. Using an ex vivo placenta perfusion model, we also assessed the transplacental passage of food-grade TiO2 particles.ResultsBy ICP-MS analysis, we evidenced the presence of Ti in all placentae (basal level ranging from 0.01 to 0.48 mg/kg of tissue) and in 50% of the meconium samples (0.02–1.50 mg/kg), suggesting a materno-foetal passage of Ti. STEM-EDX observation of the placental tissues confirmed the presence of TiO2-NPs in addition to iron (Fe), tin (Sn), aluminium (Al) and silicon (Si) as mixed or isolated particle deposits. TiO2 particles, as well as Si, Al, Fe and zinc (Zn) particles were also recovered in the meconium. In placenta perfusion experiments, confocal imaging and SEM-EDX analysis of foetal exudate confirmed a low transfer of food-grade TiO2 particles to the foetal side, which was barely quantifiable by ICP-MS. Diameter measurements showed that 70 to 100% of the TiO2 particles recovered in the foetal exudate were nanosized.ConclusionsAltogether, these results show a materno-foetal transfer of TiO2 particles during pregnancy, with food-grade TiO2 as a potential source for foetal exposure to NPs. These data emphasize the need for risk assessment of chronic exposure to TiO2-NPs during pregnancy.

Group B streptococcal transmission rates as determined by PCR.

Background Group B Streptococcus (GBS) is a common cause of neonatal sepsis. GBS colonization of the newborn gastrointestinal tract (GIT) may be a critical precursor for late-onset infection. Assessment of the rate of neonatal GBS intestinal colonization has generally relied upon culture-based methods. We used polymerase chain reaction (PCR) and culture to determine the rate of GBS transmission to neonates. We hypothesized that PCR may enhance the detection of neonatal GBS colonization of the GIT, and that the rate will be higher when evaluated with PCR as compared to culture. Methods This was a cross-sectional study, in which mothers who were positive for GBS on routine screening and their healthy infants were eligible for recruitment. Newborn stool was collected after 24 h of life and before hospital discharge, and stored at -80°C for culture and PCR targeting the GBS-specific surface immunogenic protein (sip) gene. Results A total of 94 mother-infant pairs were enrolled; of these pairs, stool was collected from 83 infants. Based on PCR, the overall GBS transmission rate was 3.6% (3/83). The transmission rate was 2.4% (1/41) among vaginal deliveries and 4.8% (2/42) among cesarean deliveries. The results of culture-based transmission detection were identical. Conclusion These results indicate that the rate of GBS transmission is low and that detection may not be enhanced by PCR methods.

Development of the Stool Color Card for Early Detection of Biliary Atresia using Multispectral Image

The stool color card for early detection of biliary atresia have been developed using multispectral images of stools of newborns. Color and its spectra were measured and analyzed spectrally first in the world and used to design the stool color card. Representative texture was selected by medical specialists from captured multispectral images and spectral information of the images was replaced and edited according to the result of spectral and chromaticity analysis. The stool color card was placed within the Maternal and Child Health Handbook that was distributed to all pregnant women by their respective local government according to the Maternal and Child Health Law in Japan.

The Influence of Maternal-Foetal Parameters on Concentrations of Zonulin and Calprotectin in the Blood and Stool of Healthy Newborns during the First Seven Days of Life. An Observational Prospective Cohort Study.

Background: It can be hypothetically assumed that maternal and perinatal factors influence the intestinal barrier. Methods: The study was conducted with 100 healthy, full-term newborns breastfed in the first week of life, with similar analyses for their mothers. Zonulin and calprotectin levels were used as intestinal permeability markers. Results: The median (range) zonulin concentrations (ng/mL) were in mothers: serum, 21.39 (6.39–57.54); stool, 82.23 (42.52–225.74); and newborns: serum cord blood, 11.14 (5.82–52.34); meconium, 54.15 (1.36–700.65); and stool at age seven days, 114.41 (29.38–593.72). Calprotectin median (range) concentrations (µg/mL) in mothers were: stool, 74.79 (3.89–211.77); and newborns: meconium, 154.76 (6.93–8884.11); and stool at age seven days 139.12 (11.89–627.35). The use of antibiotics during pregnancy resulted in higher zonulin concentrations in umbilical-cord serum and calprotectin concentrations in newborn stool at seven days, while antibiotic therapy during labour resulted in higher zonulin concentrations in the stool of newborns at seven days. Zonulin concentrations in the stool of newborns (at seven days) who were born via caesarean section were higher compared to with vaginal birth. With further analyses, caesarean section was found to have a greater effect on zonulin concentrations than prophylactic administration of antibiotics in the perinatal period. Pregnancy mass gain >18 kg was associated with higher calprotectin concentrations in maternal stool. Body Mass Index (BMI) increase >5.7 during pregnancy was associated with decreased zonulin concentrations in maternal stool and increased calprotectin concentrations in stool of mothers and newborns at seven days. There was also a negative correlation between higher BMI increase in pregnancy and maternal zonulin stool concentrations and a positive correlation between BMI increase in pregnancy and maternal calprotectin stool concentrations. Conclusion: Maternal-foetal factors such as caesarean section, antibiotic therapy during pregnancy, as well as change in mother’s BMI during pregnancy may increase intestinal permeability in newborns. Changes in body mass during pregnancy can also affect intestinal permeability in mothers. However, health consequences associated with increased intestinal permeability during the first days of life are unknown. Additionally, before the zonulin and calprotectin tests can be adopted as universal diagnostic applications to assess increased intestinal permeability, validation of these tests is necessary.

Detection of intracellular Helicobacter pylori in Candida. SPP from neonate oral swabs.

There is evidence of detection of Helicobacter pylori (H. pylori) in the stool of newborns and in the yeast that colonizes the oral cavity of this age group. However, there is a lack of research to confirm it. This study proposes to determine the existence of the bacteria at an early age, specifically in newborns. To identify intracellular H. pylori in oral yeasts and to detect antigens of the bacteria in newborn stools. Cross-sectional and descriptive study. Samples were obtained from infants (oral swab and meconium). Identification of yeast species was performed using the following techniques: CHROMagar Candida, Germinal Tube Test and API Candida Identification System, then the yeasts were observed by light microscopy and fluorescence. Detection of H. pylori antigen in meconium and PCR were performed to amplify specific genes of the bacterium (rRNA16S, cagA, vacA s1a, vacA s1b, vacA s2, vacA m1, vacA m2 and dupA). Intracellular H. pylori was detected in yeast of the species Candida glabrata (C. glabrata) isolated from an oral swab of a newborn. The results of this study evidenced the existence of intracellular H. pylori in newborns.

Understanding biological mechanisms underlying adverse birth outcomes in developing countries: protocol for a prospective cohort (AMANHI bio-banking) study.

ObjectivesThe AMANHI study aims to seek for biomarkers as predictors of important pregnancy–related outcomes, and establish a biobank in developing countries for future research as new methods and technologies become available.MethodsAMANHI is using harmonised protocols to enrol 3000 women in early pregnancies (8–19 weeks of gestation) for population–based follow–up in pregnancy up to 42 days postpartum in Bangladesh, Pakistan and Tanzania, with collection taking place between August 2014 and June 2016. Urine pregnancy tests will be used to confirm reported or suspected pregnancies for screening ultrasound by trained sonographers to accurately date the pregnancy. Trained study field workers will collect very detailed phenotypic and epidemiological data from the pregnant woman and her family at scheduled home visits during pregnancy (enrolment, 24–28 weeks, 32–36 weeks & 38+ weeks) and postpartum (days 0–6 or 42–60). Trained phlebotomists will collect maternal and umbilical blood samples, centrifuge and obtain aliquots of serum, plasma and the buffy coat for storage. They will also measure HbA1C and collect a dried spot sample of whole blood. Maternal urine samples will also be collected and stored, alongside placenta, umbilical cord tissue and membrane samples, which will both be frozen and prepared for histology examination. Maternal and newborn stool (for microbiota) as well as paternal and newborn saliva samples (for DNA extraction) will also be collected. All samples will be stored at –80°C in the biobank in each of the three sites. These samples will be linked to numerous epidemiological and phenotypic data with unique study identification numbers.Importance of the studyAMANHI biobank proves that biobanking is feasible to implement in LMICs, but recognises that biobank creation is only the first step in addressing current global challenges.

Administration of a Multi-Strain Probiotic Product to Women in the Perinatal Period Differentially Affects the Breast Milk Cytokine Profile and May Have Beneficial Effects on Neonatal Gastrointestinal Functional Symptoms. A Randomized Clinical Trial.

Background: Probiotic supplementation to women during pregnancy and lactation can modulate breast milk composition, with immune benefits being transferred to their infants. Aim: The aim of the study was to evaluate the effect of high-dose probiotic supplementation to women during late pregnancy and lactation on cytokine profile and secretory IgA (sIgA) in breast milk and thus to study if differences in breast milk composition can affect lactoferrin and sIgA levels in stool samples of newborns. The safety of maternal probiotic administration on neonatal growth pattern and gastrointestinal symptoms were also evaluated. Methods: In a double-blind, placebo-controlled, randomized trial, 66 women took either the probiotic (n = 33) or a placebo (n = 33) daily. Levels of interleukins (IL-6, IL-10 and IL-1β), transforming growth factor-β1 (TGF-β1), and sIgA in breast milk; and the level of sIgA and lactoferrin in newborn stool samples were analyzed at birth and then again at one month of life. Antropometrical evaluation and analysis of gastrointestinal events in newborns was also performed. Results: Probiotic maternal consumption had a significant impact on IL6 mean values in colostrum and on IL10 and TGF-β1 mean values in mature breast milk. Fecal sIgA mean values were higher in newborns whose mothers took the probiotic product than in the control group. Probiotic maternal supplementation seems to decrease incidence of infantile colic and regurgitation in infants. Conclusion: High-dose multi-strain probiotic administration to women during pregnancy influences breast milk cytokines pattern and sIgA production in newborns, and seems to improve gastrointestinal functional symptoms in infants.

Analysis of BTEX and chlorinated solvents in meconium by headspace-solid-phase microextraction gas chromatography coupled with mass spectrometry.

Meconium is the earliest stool of newborns, and is a complex matrix that reflects the degree of exposure of the fetus to xenobiotics. To investigate fetal exposure to volatile organic compounds, an analytical method was developed to identify and quantify BTEX (benzene, toluene, ethylbenzene, and o,m,p-xylene) and two chlorinated solvents (trichloroethylene and tetrachloroethylene) in meconium. Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry was selected because it is simple, sensitive, can be automated, and requires no extensive sample preparation. Several extraction variables were optimized (fiber type, incubation time, temperature of fiber, and use of salt). Because meconium is a complex matrix, quantification by SPME was considered carefully because of potential interference, for example competitive adsorption. Calibration in water was compared with calibration in meconium using external and internal methods (with isotope-labeled compounds). In meconium, limits of quantification were determined to be in the range 0.064-0.096ngg(-1) for the investigated compounds. All target compounds were determined in "real-case" meconium samples.

Clostridium Difficile Infection - A Review of Current Treatment Strategies

Clostridium difficile is an anaerobic, gram-positive, spore forming rod-shaped bacillus, spread via the fecal-oral route. The organism was first identified by Hall and O’Toole on 1935 in the stools of newborns, and referred to as Bacillus Difficilis in view of the difficulty in isolation and study [1]. The organism was subsequently renamed Clostridium difficile. The first reported case of toxin-producing Clostridium as a cause of antibiotic associated colitis was in 1978 [2,3].

Live Colonocytes in Newborn Stool: Surrogates for Evaluation of Gut Physiology and Disease Pathogenesis

Studies of gastrointestinal pathophysiology are not feasible by biopsies in human neonates. We examined the utility of live colonocytes in stool in studying cellular markers during early neonatal life. Expression of IgA, IgG, cluster of differentiation-45 cells (CD45), and toll-like receptors-2 and 4 (TLR2 and TLR4) were analyzed by flow cytometry. Colonocyte RNA extracts were used in quantitative real-time PCR (qRT-PCR) to examine the expression of cytokeratin-19, ribosomal protein-24, and tight-junction (Tj) protein zonula occludens-1 (ZO-1). Colonocyte yield varied between 5 × 10⁴ to 2 × 10⁶ cells/g of stool. Meconium samples yielded a highly enriched population of viable cells. Although low, all samples showed CD45-positive cells during the initial weeks of life. Starting as early as d 2, IgA expression was observed in 69% of the cells. Low to moderate expression of IgG was observed with a linear increase as the infants grew. There was an almost total lack of TLR2 staining; however, >55% of the colonocytes showed TLR4 expression. Although high levels of IgA in gut cells may serve as a natural protectant during neonatal period, increased TLR4 may provide a niche for lipopolysaccharide (LPS)-mediated epithelial damage. Use of stool colonocytes can be a valuable noninvasive approach for studying gut pathophysiology in the neonatal period.

A method for isolating and analyzing human mRNA from newborn stool

Efforts to characterize the human transcriptome have largely been limited to blood, urine, and tissue analyses (i.e., normally sterile materials). We report here an extraction protocol using commercially available reagents to obtain high-yield, reverse-transcribable RNA from human stool. Quantitative reverse transcriptase polymerase chain reactions demonstrated minimal intra-specimen but considerable intra-subject variability over time of transcripts for interleukin-6 (IL-6), IL-8, epidermal growth factor (EGF), calprotectin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). This technique now expands opportunities to use the human fecal transcriptome to characterize gastrointestinal pathophysiology.

HPLC detection of fetal blood in meconium: improved sensitivity compared with qualitative methods

We describe an HPLC-based method for the detection and quantification of fetal hemoglobin in stools of newborns. The new procedure is an alternative to the classic qualitative test for adult hemoglobin in meconium based on the differential stability of hemoglobin species in dilute base (Apt test). The HPLC method, based on a commercial device for hemoglobin characterization (Bio-Rad Variant), readily separates fetal and adult hemoglobin from non-hemoglobin components of meconium. To validate the method, blood and meconium were mixed in various proportions and then prepared for analysis with extraction in saline. The HPLC method accurately identified hemoglobin species even when the blood constituted only 5 mL per 100 g of the meconium specimen, and nearly quantitative recovery of hemoglobin was obtained at a blood content of 20 mL per 100 g of the meconium. Analysis time was 6.5 min, and preparation of sample was simple. HPLC detection of fetal blood in stools or other specimens markedly improves detection/characterization of blood in meconium.

Improved quantitative Apt test for detecting fetal hemoglobin in bloody stools of newborns

We devised an improved spectrophotometric method, based on the differential susceptibility of various hemoglobins to alkaline denaturation, to measure the percentage of fetal hemoglobin (HbF) in bloody meconium so as to determine the source of the blood. The oxyhemoglobin of a sample was spectrophotometrically scanned from 450 to 650 nm before and after the addition of sodium hydroxide. With Allen baseline correction, the ratio of absorbance at 576 nm was linearly proportional to the percentage of HbF in the specimen as described by the equation: ratio = 0.01 (%HbF) + 0.0045 (r = 0.9971, Sy/x = 0.047). Preliminary studies on samples containing 10% or 80% HbF revealed that the method was fairly precise. The accuracy of this test was verified by comparing the results (y) with those obtained by radial immunodiffusion (x): y = 0.997x + 2.93 (r = 0.91). This preliminary study demonstrates that the modified test is simple, fast, and free from bilirubin interference. It should be useful for the diagnosis of gastrointestinal bleeding of the newborn on a stat basis.

Heteroimmunization to the capsular polysaccharide of Haemophilus influenzae type b induced by enteric cross-reacting bacteria.

Cross-reacting Escherichia coli strains Easter and 89 and Bacillus pumilis fed to newborn rabbits and E. coli fed to adult rhesus monkeys did not exert untoward reactions. The E. coli regularly colonized the newborns' intestinal tract from 1 to 7 weeks. High doses of E. coli were necessary to colonize adult primates. Colonization occurred in fewer newborn rabbits and lasted only 1 to 3 weeks with B. pumilis. Colonized newborn rabbits and adult rhesus had an active Haemophilus influenzae type b (HITB) immune response. In the rabbit, colonization resulted in accelerated induction of immunoglobulin (Ig) M-. IgA-, and IgG-producing cells in the spleen, mesenteric lymph nodes, and Peyer's patches after HITB challenge. E. coli-fed and control newborn primates were naturally colonized with nasopharyngeal and enteric cross-reacting bacteria and both groups rapidly developed HITB antibodies in the absence of the homologous organisms. Human newborn stool cultures, taken at the time of discharge from the nursery, showed a 0.9% carriage rate for cross-reacting E. coli. These "carrier" infants acquired HITB antibodies more rapidly than their age-matched "noncarrier" controls.

Primary and Secondary Bile Acids in Meconium

Extract: Meconium, newborn stool, and fetal bile were examined for bile acids by the techniques of gas liquid chromatography, thin layer chromatography and colorimetric spectrometry. Cholic, chenodeoxycholic, deoxycholic, and lithocholic acid were detected in meconium. Secondary bile acids were not present in significant amounts in either stool or fetal bile from newborns. During fetal development more cheno-deoxycholate than cholate is formed. The presence of secondary bile acids in meconium is suggestive of maternal-to-fetal transfer via the placenta.Speculation: The number of hydroxyl groups on the basic sterol nucleus may influence bile duct development. Excess quantities of bile acids, particularly lithocholic acid, may alter the developing fetal hepatic stucture.