Allylation of intraerythrocytic hemoglobin by raw garlic extracts.

Recent studies have shown that deoxygenated human red blood cells (RBCs) converted garlic-derived polysulfides into hydrogen sulfide, which in turn produced vasorelaxation in aortic ring preparations. The vasoactivity was proposed to occur via glucose- and thiol-dependent acellular reactions. In the present study, we investigated the interaction of garlic extracts with human deoxygenated RBCs and its effect on intracellular hemoglobin molecules. The results showed that garlic extract covalently modified intraerythrocytic deoxygenated hemoglobin. The modification identified consisted of an addition of 71 atomic mass units, suggesting allylation of the cysteine residues. Consistently, purified human deoxyhemoglobin reacted with chemically pure diallyl disulfide, showing the same modification as garlic extracts. Tandem mass spectrometry analysis demonstrated that garlic extract and diallyl disulfide modified hemoglobin's beta-chain at cysteine-93 (beta-93C) or cysteine-112 (beta-112C). These results indicate that garlic-derived organic disulfides as well as pure diallyl disulfide must permeate the RBC membrane and modified deoxyhemoglobin at beta-93C or beta-112C. Although the physiological role of the reported garlic extract-induced allyl modification on human hemoglobin warrants further study, the results indicate that constituents of natural products, such as those from garlic extract, modify intracellular proteins.

Noninvasive monitoring of tissue hemoglobin using UV-VIS diffuse reflectance spectroscopy: a pilot study.

We conducted a pilot study on 10 patients undergoing general surgery to test the feasibility of diffuse reflectance spectroscopy in the visible wavelength range as a noninvasive monitoring tool for blood loss during surgery. Ratios of raw diffuse reflectance at wavelength pairs were tested as a first-pass for estimating hemoglobin concentration. Ratios can be calculated easily and rapidly with limited post-processing, and so this can be considered a near real-time monitoring device. We found the best hemoglobin correlations were when ratios at isosbestic points of oxy- and deoxyhemoglobin were used, specifically 529/500 nm. Baseline subtraction improved correlations, specifically at 520/509 nm. These results demonstrate proof-of-concept for the ability of this noninvasive device to monitor hemoglobin concentration changes due to surgical blood loss. The 529/500 nm ratio also appears to account for variations in probe pressure, as determined from measurements on two volunteers.

Rapid ratiometric determination of hemoglobin concentration using UV-VIS diffuse reflectance at isosbestic wavelengths.

We developed a ratiometric method capable of estimating total hemoglobin concentration from optically measured diffuse reflectance spectra. The three isosbestic wavelength ratio pairs that best correlated to total hemoglobin concentration independent of saturation and scattering were 545/390, 452/390, and 529/390 nm. These wavelength pairs were selected using forward Monte Carlo simulations which were used to extract hemoglobin concentration from experimental phantom measurements. Linear regression coefficients from the simulated data were directly applied to the phantom data, by calibrating for instrument throughput using a single phantom. Phantoms with variable scattering and hemoglobin saturation were tested with two different instruments, and the average percent errors between the expected and ratiometrically-extracted hemoglobin concentration were as low as 6.3%. A correlation of r = 0.88 between hemoglobin concentration extracted using the 529/390 nm isosbestic ratio and a scalable inverse Monte Carlo model was achieved for in vivo dysplastic cervical measurements (hemoglobin concentrations have been shown to be diagnostic for the detection of cervical pre-cancer by our group). These results indicate that use of such a simple ratiometric method has the potential to be used in clinical applications where tissue hemoglobin concentrations need to be rapidly quantified in vivo.

Baby on board: olfactory cues indicate pregnancy and fetal sex in a non-human primate.

Olfactory cues play an integral, albeit underappreciated, role in mediating vertebrate social and reproductive behaviour. These cues fluctuate with the signaller's hormonal condition, coincident with and informative about relevant aspects of its reproductive state, such as pubertal onset, change in season and, in females, timing of ovulation. Although pregnancy dramatically alters a female's endocrine profiles, which can be further influenced by fetal sex, the relationship between gestation and olfactory cues is poorly understood. We therefore examined the effects of pregnancy and fetal sex on volatile genital secretions in the ring-tailed lemur (Lemur catta), a strepsirrhine primate possessing complex olfactory mechanisms of reproductive signalling. While pregnant, dams altered and dampened their expression of volatile chemicals, with compound richness being particularly reduced in dams bearing sons. These changes were comparable in magnitude with other, published chemical differences among lemurs that are salient to conspecifics. Such olfactory 'signatures' of pregnancy may help guide social interactions, potentially promoting mother-infant recognition, reducing intragroup conflict or counteracting behavioural mechanisms of paternity confusion; cues that also advertise fetal sex may additionally facilitate differential sex allocation.

Early growth and adult respiratory function in men and women followed from the fetal period to adulthood

While some studies suggest that poor fetal growth rate, as indicated by lower birth weight, is associated with poor respiratory function in childhood, findings among adults remain inconsistent. A study was undertaken to determine the association between early growth and adult respiratory function.

TRANSIENT LIPOPOLYSACCHARIDE-INDUCED CYTOKINE RESPONSES IN THE MATERNAL AND FETAL GUINEA PIG

The aim of this study was to further investigate the role of pro-inflammatory cytokines in the pathogenesis of fetal cererbral white matter injury associated with chorioamnionitis by charaterizing the time course of the cytokine response in the pregnant guinea pig following a maternal inflammatory insult. Chorioamnionitis increases the risk for fetal brain injury. In the guinea pig, a threshold maternal inflammatory response must be reached for significant fetal brain injury to occur. However, a previous study demonstrated that, by seven days after an acute maternal inflammatory insult, cytokine levels in both maternal and fetal compartments are not different from controls. The purpose of this study, therefore, was to test the hypothesis that a significant cytokine response occurs within the first seven days following an acute maternal inflammatory response. Pregnant guinea pigs (n=34) were injected intraperitoneally with 100µg/kg lipopolysaccharide (LPS) at 70% gestation and euthanized at 24 hours, 48 hours or 5 days following endotoxin exposure. Control animals were euthanized at 70% gestation without exposure. Concentrations of interleukin-6, interleukin 1-β and tumour necrosis factor-α (IL-6, IL-1β, TNF-α) were quantified in the maternal serum and amniotic fluid by enzyme-linked immunosorbent assay. IL-6 and IL-1β concentrations were elevated in the maternal serum at 24 hours and returned to control levels by five days. In the amniotic fluid, IL-6 peaked at 48 hours and IL-1β at 24 hours. TNF-α levels were not significantly increased. A single maternal LPS injection produces transient increases in cytokine concentrations in the maternal serum and amniotic fluid. This further implicates the cytokines as potential mediators of fetal white matter damage. Although this response might not be sufficient to produce the brain injury itself, it may initiate harmful pro-inflammatory cytokine cascades, which could even continue to harm the fetus following delivery. A human diagnostic protocol was developed to assess the use of serial serum biomarkers, including IL-6 and TNF-α, in the prediction of histological chorioamnionitis. Preliminary analysis of the pilot study suggests that certain biomarkers might be worthy of further investigation in a larger-scale study.

Investigation of the effect of intrauterine inflammation and infection on fetal brain injury using human and animal models

In recent years, increased focus has been placed on the role of intrauterine infection and inflammation in the pathogenesis of fetal brain injury leading to neurodevelopmental disorders such as cerebral palsy. At present, the mechanisms by which inflammatory processes during pregnancy cause this effect on the fetus are poorly understood. Our previous work has indicated an association between experimentally-induced intrauterine infection, increased proinflammatory cytokines, and increased white matter injury in the guinea pig fetus. In order to further elucidate the pathways by which inflammation in the maternal system or the fetal membranes leads to fetal impairment, a number of studies investigating aspects of the disease process have been performed. These studies represent a body of work encompassing novel research and results in a number of human and animal studies. Using a guinea pig model of inflammation, increased amniotic fluid proinflammatory cytokines and fetal brain injury were found after a maternal inflammatory response was initiated using endotoxin. In order to more closely monitor the fetal response to chorioamnionitis, a model using the chronically catheterized fetal ovine was carried out. This study demonstrated the adverse effects on fetal white matter after intrauterine exposure to bacterial inoculation, though the physiological parameters of the fetus were relatively stable throughout the experimental protocol, even when challenged with intermittent hypoxic episodes. The placenta is an important mediator between mother and fetus during gestation, though its role in the inflammatory process is largely undefined. Studies on the placental role in the inflammatory process were undertaken, and the limited ability of proinflammatory cytokines and endotoxin to cross the placenta are detailed herein. Neurodevelopmental disorders can be monitored in animal models in order to determine effective disease models for characterization of injury and use in therapeutic strategies. Our characterizations of postnatal behaviour in the guinea pig model using motility monitoring and spatial memory testing have shown small but significant differences in pups exposed to inflammatory processes in utero. The data presented herein contributes a breadth of knowledge to the ongoing elucidation of the pathways by which fetal brain injury occurs. Determining the pathway of damage will lead to discovery of diagnostic criteria, while determining the vulnerabilities of the developing fetus is essential in formulating therapeutic options.

Heightened maternal inflammation is linked to placental oxidative and nitrosative stress associated with fetal growth restriction in the rat

Deficient trophoblast invasion and spiral artery remodeling are associated with pregnancy complications such as pre-eclampsia (PE) and fetal growth restriction (FGR). Using a model in which pregnant Wistar rats are given daily, low-dose, injections of bacterial lipopolysaccharide (LPS; 10 – 40 µg/kg) on gestational days (GD) 13.5 – 16.5, our group has shown that abnormal maternal inflammation is causally linked to shallow trophoblast invasion, deficient spiral artery remodeling, and altered utero-placental hemodynamics leading to FGR/PE; these alterations were shown to be mediated by TNF-a. The present research evaluated certain consequences of decreased placental perfusion; this was accomplished by examining placental alterations indicative of decreased placental perfusion. Additionally, the role of glyceryl trinitrate (GTN) was determined as a potential therapeutic to prevent the consequences of decreased placental perfusion. Results indicated that dams experiencing heightened maternal inflammation showed significantly greater expression of hypoxia-inducible factor-1a (HIF-1a) and nitrotyrosine, both of which are markers of decreased perfusion and oxidative/nitrosative stress. Contrary to expectations, inflammation did not appear to affect nitric oxide (NO) bioavailability, as revealed by a lack of change in placental or plasma levels of cyclic guanosine monophosphate (cGMP). However, continuous transdermal administration of GTN (25 µg/hr) on GD 12.5 – 16.5 prevented the accumulation of HIF-1a and nitrotyrosine in placentas from LPS-treated rats. These results support the concept that maternal inflammation contributes to placental hypoxia and oxidative/nitrosative stress. Additionally, they indicate that GTN has potential applications in the treatment and/or prevention of pregnancy complications associated with abnormal maternal inflammation.

Economic modelling of antenatal screening and ultrasound scanning programmes for identification of fetal abnormalities

Objective Within the framework of a health technology assessment and using an economic model, to determine the most clinically and cost effective policy of scanning and screening for fetal abnormalities in early pregnancy. Design A discrete event simulation model of 50,000 singleton pregnancies. Setting Maternity services in Scotland. Population Women during the first 24 weeks of their pregnancy. Methods The mathematical model was populated with data on uptake of screening, prevalence, detection and false positive rates for eight fetal abnormalities and with costs for ultrasound scanning and serum screening. Inclusion of abnormalities was based on the relative prevalence and clinical importance of conditions and the availability of data. Six strategies for the identification of abnormalities prenatally including combinations of first and second trimester ultrasound scanning and first and second trimester screening for chromosomal abnormalities were compared. Main outcome measures The number of abnormalities detected and missed, the number of iatrogenic losses resulting from invasive tests, the total cost of strategies and the cost per abnormality detected were compared between strategies. Results First trimester screening for chromosomal abnormalities costs more than second trimester screening but results in fewer iatrogenic losses. Strategies which include a second trimester ultrasound scan result in more abnormalities being detected and have lower costs per anomaly detected. Conclusions The preferred strategy includes both first and second trimester ultrasound scans and a first trimester screening test for chromosomal abnormalities. It has been recommended that this policy is offered to all women in Scotland.

Influence of maternal diabetes mellitus on fetal iron status

OBJECTIVE: To determine the effects of maternal diabetes on fetal iron status using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood. METHODS: Iron, ferritin, erythropoietin, STfR and haemoglobin concentration were measured and TfR-F index calculated in 97 maternal/cord blood pairs. Forty-nine women had type 1 diabetes (diagnosed before pregnancy) and these were compared with forty-eight non- diabetic controls. The women with type 1 diabetes were recruited consecutively from attendance at the joint antenatal endocrine clinic while the control group of women was recruited from consecutive attendance at the remaining antenatal clinics. RESULTS: The infants of the diabetic women had significantly lower levels of ferritin (47 vs 169 mug/l; p