Are ingested plastics a vector of PCB contamination in northern fulmars from coastal Newfoundland and Labrador?

While marine animals are exposed to environmental contaminants via their prey, because plastic pollution in the aquatic environment can concentrate some chemicals, ingested plastics are thought to increase the exposure of biota to contaminants. Currently, in the literature there are contradictory results relating to how higher levels of ingested plastics by birds may lead to higher levels of polychlorinated biphenyl (PCBs). To date none of these have incorporated known Toxic Equivalency Factors (TEFs) for non-ortho and mono-ortho congeners of PCB which is critical to assessing the potential effects from PCBs. We examined northern fulmars (Fulmarus glacialis) from the Labrador Sea region Canada, and the ingested plastics from these same birds for comparative PCB concentrations. We found no significant correlations between the PCB concentrations in the birds and the mass or number of retained ingested plastic pieces in the stomach, this held true when PCBs were considered by a number of different ways, including ∑4PCB, ∑PCB, lower-chlorinated, high-chlorinated, non-ortho PCB, and mono-ortho congeners. PCB concentrations were lower in plastics as compared with livers. We found significant differences in congener profiles between the ingested plastics and seabird livers suggesting that while plastics do not contribute to the PCB concentrations, there may be some interactions between plastics and the chemicals that the birds are exposed to via ingested plastics.

Comparison of two policies for induction of labour postdates.

The objective of this study was to compare maternal and midwifery manpower effects of policies for induction of labour (IOL) postdates, using a retrospective cohort design, in a level two maternity unit in a district hospital in South-West England. Primary outcome measures included mode of delivery, admission-delivery interval, midwifery manpower use. Group I consisted of 124 women who underwent IOL at 40+10. Group II were 104 women who underwent IOL at 42 weeks' gestation and 123 women who laboured spontaneously between 40+10 and 42 weeks' gestation. The nulliparous women had a shorter admission-delivery interval when induction was planned for 42 weeks, compared with 40+10 (p = 0.003), and required less frequent use of syntocinon (p = 0.04) and of continuous fetal monitoring (p = 0.02). The caesarean rate was higher in Group I than in Group II (p = 0.04) for nulliparous women only. The earlier induction policy was associated with a higher midwifery manpower requirement for nulliparae (p = 0.002). For parous women, the only difference was the greater use of oxytocin in labour. There was no difference between the groups in duration of labour, analgesia, Apgar scores, admission to neonatal care and meconium aspiration. In conclusion, delaying planned induction by three days was associated with lower medicalisation of labour and manpower needs for nulliparous women.

The use of contextual learning to teach biochemistry to dietetic students.

This article describes the use of contextualized and "blended" learning to teach biochemistry to dietetic students during the second year of their professional training in a 4-year undergraduate degree (Bachelor of Nutrition and Dietetics). Contextualized content was used to engage students and motivate them to learn biochemistry, which many perceived as a "hard" subject. Contextualized learning presented via problem solving exercises, case-studies, and by the use of virtual subjects in laboratory class introduced content material through real life situations highly relevant to their later clinical practice. A "blended" curriculum where content was presented in a number of different modalities (on-line, on CD, or face-to-face in small/large groups and in tutorials/lectures/laboratory class) further enhanced contextualized learning by providing a range of learning modalities catering to different student learning styles. The on-line and CD material also allowed student self-assessment of learning progress through interactive quizzes in varied assessment formats, where feedback was often immediate. Student responses to this biochemistry course have been positive with 89% finding it intellectually stimulating.

Stereoselective biosynthesis of chloroarylpropane diols by the basidiomycete Bjerkandera adusta.

Previously we have shown that 1-arylpropane-1,2-diols are catabolic products of L-phenylalanine during idiophasic metabolism of B. adusta that are stereoselectively biosynthesized from a C(7)-unit (ring+benzylic carbon) and a C(2)-unit as predominantly erythro 1R, 2S enantiomers.In order to probe the mechanism of 1-arylpropane-1,2-diol formation, the products of the incubation of isotopically labelled aromatic aldehydes as substrates with Bjerkandera adusta (DAOM 215869) have been characterized. The aromatic aldehydes were benzaldehyde (ring D(5)) and 4-methoxy- and 4-hydroxybenzaldehydes (ring 13C(6)). These aldehydes were all stereoselectively incorporated into the corresponding 1-arylpropane-1,2-diols, including the chloro analogues, as well as into the corresponding alpha-ketols (phenyl acetyl carbinols (PAC's) and 2-hydroxy propiophenones (2-HPP's)) the presumed precursors of the diols. Benzoic acid (ring D(5)) was likewise incorporated into the diols, chlorodiols and alpha-ketols. These results lead us to conclude that the aromatic aldehydes benzaldehyde, 4-hydroxybenzaldehyde and 4-methoxybenzaldehyde are likely C(7)-unit precursors in the carboligation reaction(s) that leads to 1-arylpropane-1,2-diol biosynthesis. The metabolic role of the diols remains to be elucidated but they may be important intermediates in CAM (chlorinated anisyl metabolite) aldehyde-alcohol cycling and also act as substrates for the chlorination/hydroxylation enzymes yet to be identified in white rot fungi.

Chlorometabolite production by the ecologically important white rot fungus Bjerkandera adusta.

Two strains of the basidiomycete, Bjerkandera adusta (DAOM 215869 and BOS55) produce in static liquid culture, phenyl, veratryl, anisyl and chloroanisyl metabolites (CAM's) (alcohols, acids and aldehydes) as well as a series of compounds not previously known to be produced by Bjerkandera species: 1-phenyl, 1-anisyl, 1-(3-chloro-4-methoxy) and 1-(3,5-dichloro-4-methoxy) propan-1,2-diols, predominantly as erythro diastereomers with IR, 2S absolute configurations. 1-Anisyl-propan-1,2-diol and 1-(3,5-dichloro-4-methoxy)-propan-1,2-diol are new metabolites for which the names Bjerkanderol A and B, respectively, are proposed. Experiments with static liquid cultures supplied with 13C6- and 13C9-L-phenylalanine showed that all identified aromatic compounds (with the exception of phenol) can be derived from L-phenylalanine. For the aryl propane diols, the 13C label appeared only in the phenyl ring and the benzylic carbon, suggesting a stereoselective re-synthesis from a C7 and a C2-unit, likely aromatic aldehyde and decarboxylated pyruvate, respectively. Other compounds newly discovered to be derived from phenylalanine by this white rot fungus include phenylacetaldehyde and phenylpyruvic, phenylacetic, phenyllactic, mandelic and phenyl glyoxylic (benzoyl formic) acids. For both strains, cultures supplied with Na37Cl showed incorporation of 37Cl in all identified chlorometabolites. Veratryl alcohol and the CAM alcohols, which occur in both strains and can be derived from L-phenylalanine (all 13C-labelled), have reported important physiological functions in this white rot fungus. Possible mechanisms for their formation through the newly discovered compounds are discussed.

Modulation of body temperature, interleukin-6 and leptin by oral contraceptive use.

OBJECTIVES: This study examined the hypothesis that oral contraceptives (OC) influence the production of thermoregulatory cytokines, i.e. interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), soluble glycoprotein 130 (s-gp130) and leptin, and that OC-induced changes in oral temperature (T(oral)) are associated with changes in plasma concentrations of these cytokines. To determine if increases in T(oral) are part of a cytokine-driven inflammatory (acute-phase) response, circulating concentrations of the hepatic acute-phase protein C-reactive protein (CRP) were also measured. METHODS: Morning T(oral) were measured and blood samples were collected from 18 women (19- to 22-years-old) on two occasions: Once during active pill usage (quasi-luteal (QL) phase) and once when no active pills were taken (quasi-follicular (QF) phase). Plasma cytokine and CRP concentrations were measured by immunoassay. RESULTS: T(oral) and plasma leptin were higher during QL phase (36.4 +/- 0.1 degrees C, 9.3 +/- 1.0 ng/ml) than QF phase (36.1 +/- 0.1 degrees C, p < 0.01; 7.5 +/- 0.7 ng/ml, p < 0.01). Increases in T(oral) correlated with increases in plasma leptin (R = 0.55, p = 0.02) and with progestin dose (R = 0.47, p = 0.05) individually as well as with leptin and progestin combined in a multiple regression (R = 0.68, p = 0.01). Plasma IL-6 correlated with progestin dose (R = 0.62, p = 0.006). Although there were no phase-related differences in plasma IL-6, sIL-6R, s-gp130, or CRP, the variation in CRP between individuals correlated with the IL-6 agonist/antagonist ratio combined with progestin dose in a multiple regression (R = 0.71, p = 0.01). CONCLUSIONS: These results (a) implicate leptin in basal thermoregulation; (b) indicate that progestins have a significant influence on circulating IL-6 concentrations, and (c) are consistent with the concept that plasma CRP concentrations depend upon combined influences of progestins and bioavailable IL-6.

Pancreatic xanthomatous neuropathy associated with hyperlipidemia: a cause of abdominal pain mimicking chronic pancreatitis.

"Hyperlipidemic crisis" is a term used to describe episodic abdominal pain in patients with hyperlipidemia. The morphologic correlates of this phenomenon have not been investigated and the etiology of the disorder is uncertain. We report a unique histologic finding in the pancreas of a 34-year-old woman with a 17-year history of episodic abdominal pain, sometimes accompanied by hyperamylasemia. At the age of 18 years, grossly elevated cholesterol and triglyceride levels were documented and type V hyperlipidemia was diagnosed. At the age of 34 years, subtotal pancreatectomy was performed for intractable abdominal pain. Histologic examination identified an increased number of enlarged pancreatic nerves that were infiltrated by foamy macrophages and encircled by fibrous tissue; endoneurial infiltration with macrophages occasionally split nerves into individual fascicles. Otherwise, the pancreas had only minimal fibrosis, nesidioblastosis, mucinous metaplasia of some pancreatic ducts, and scattered small collections of chronic inflammatory cells, subtle features suggesting very mild chronic pancreatitis. We propose that this novel xanthomatous neuropathy mimicked pancreatitis and was one of the underlying pathophysiologic mechanisms of abdominal pain in this patient. Further studies are necessary to document the prevalence of this new entity in patients with hyperlipidemia and to correlate its occurrence with "hyperlipidemic crisis" in those individuals.

Epidural analgesia in labor and fetal hyperthermia.

OBJECTIVE: To assess the effect of epidural analgesia on fetal temperature in labor, contrasting intrauterine with oral thermometry. METHODS: Fetal skin and maternal uterine wall temperatures were measured with an intrauterine probe in 57 laboring women at term. Maternal oral temperatures were measured in the normal way by birth attendants unaware that their measurements would be examined. Maximum recorded fetal, uterine, and oral temperatures were compared. RESULTS: Epidural analgesia resulted in a significant fetal temperature rise compared with other methods of analgesia. Duration of epidural analgesia correlated with the fetal temperature (R = 0.44, P = .012). Oral thermometry underestimated fetal temperature in 95% of the studies. CONCLUSIONS: We estimate that 5% of fetuses reached a core temperature in excess of 40C in this study, all in association with epidural analgesia. We suggest that antipyretic measures be considered after 5 hours of epidural analgesia in ambient temperatures above 24C.

The methyltrienolone binding protein of JEG-3 cells and human placenta is localized within the nucleus and is tightly associated with chromatin.

Human placenta contains the methyltrienolone binding protein (MTBP), an androgen binding protein which is distinct from the androgen receptor. This study demonstrates that the human choriocarcinoma cell line (JEG-3) also contains the MTBP and that in both human placenta and JEG-3 cells the MTBP is located exclusively in the nucleus and in particular is associated with DNase 1 resistant chromatin.

Continuous monitoring of fetal temperature by noninvasive probe and its relationship to maternal temperature, fetal heart rate, and cord arterial oxygen and pH.

The human fetus is normally warmer than its mother. The principal route of fetal heat dissipation is through the placental circulation. We developed a technique that is noninvasive to the fetus to record the fetal skin and maternal uterine wall temperatures, from which we derived the temperature difference. We have established a range of normal values (mean temperature difference 0.24C) and present some preliminary data. The results show a correlation between changing temperature and baseline fetal heart rate (r = 0.628, P less than .001) and the influence of contractions and epidural analgesia on these measurements. Measurement of the fetal-maternal temperature difference during labor may help detect abnormal umbilical-placental blood flow, resulting in fetal distress, and may help distinguish sinister from iatrogenic fetal tachycardias. Our technique provides the first simple means of recording this basic fetal variable.

Measuring fetal and maternal temperature differentials: a probe for clinical use during labour.

The healthy fetus maintains a higher temperature than that of its mother during gestation and labour. This results from the thermal balance between the heat generated by the fetus and the heat loss to its maternal surroundings. The heat loss can be by heat exchange via blood flowing in the umbilical cord and placenta, and via conduction through the fetal skin and amniotic fluid to the maternal wall. The temperature difference between the fetal and maternal tissue may reflect the metabolic state of the fetus and the magnitude and changing patterns of placental blood flow during labour. Physiological changes, such as those induced by epidural analgesia, and fetal infection have been shown to exhibit an increase in the absolute temperature. An intrauterine probe, previously used for non-invasive ECG detection, has been equipped with temperature sensors that measure fetal and maternal skin temperature in utero. Laboratory tests to characterize the performance of the probe reveal that absolute and differential temperatures can be resolved to around 0.01 degree C with a thermal time constant of approximately 9 s. Ideally the probe body should have infinite thermal insulation or thermal shunting across the probe will occur reducing the measured temperature difference. In this initial probe design, a high thermal isolation between sensors has been achieved but is not perfect, resulting in around 85% of the actual temperature difference across the probe being registered. Average feto-maternal differences of 0.2 degrees C have been measured in a clinical investigation.

The methyltrienolone binding protein of human placenta requires nicotinamide adenine dinucleotide cofactor(s) for steroid binding.

The methyltrienolone binding protein (MTBP) found in human placental cytosol was found to require a low molecular weight modulator for steroid binding activity. Purification and characterization of the modulating activity showed that NAD+ is the endogenous substance responsible for activating MTBP to a form capable of steroid binding. The hierarchy of potency of exogenously added nucleotides is NADH greater than NAD+ = NADPH = NADP+. An investigation of the tissue distribution of human MTBP demonstrated that MTBP binding activity was present in placenta and chorion but absent from amnion and umbilical cord. Preliminary studies showed that rat, mouse, and rabbit placenta do not contain MTBP and suggest that MTBP may be a species-specific protein.

Characterisation and covalent labeling of the human placental methyltrienolone binding protein.

Human placental cytosol contains an androgen binding protein which binds the synthetic androgen methyltrienolone (R 1881) with high affinity (Kd 8.7 nM) and with an average binding capacity of 518 fmol/mg cytosol protein. This study provides further evidence that this protein is distinguishable from classical androgen receptors on the basis of steroid specificity and sulphydryl group sensitivity. Covalent labeling studies have shown this protein, which we have called "the methyltrienolone binding protein", to have a mol. wt of 67,000 daltons.

Human placenta contains a high affinity R1881 binding site that is not the androgen receptor.

Human placental cytosol was shown to contain a species that binds the synthetic androgen, methyltrienolone (R1881) with high affinity (Kd 6.5 nM). Major differences were found between this placental androgen binding species and the classical androgen receptor found in human foreskin cytosol. Competitive binding assays in the placental cytosol using [3H]R1881 as tracer showed a 200-fold excess of testosterone to compete poorly, while dihydrotestosterone and the synthetic androgen mibolerone did not compete at all. The placental R1881 binding component was found not to bind to hydroxylapatite, although all classes of steroid receptors are reported to do so. Temperature studies showed that the placental binding site is stable at elevated temperatures with no loss of binding after 4 h at 45 degrees C. Ion exchange chromatography showed that the placental R1881 binding site eluted from DEAE cellulose at a lower salt concentration than foreskin androgen receptors. These results show that R1881 is not entirely specific for androgen receptors and that human placenta contains an androgen binding site that is not the classical androgen receptor.

A system for the partial purification of the human androgen receptor following reversible denaturation.

Androgen receptors from normal human foreskins were partially purified by sequential phosphocellulose chromatography and affinity chromatography resulting in a 28,000-fold purification and an 81% recovery. SDS-electrophoresis of the partially purified receptor preparation demonstrated that binding activity could be recovered and showed two peaks of specific binding mol. wt 35,000-55,000 and 85,000-105,000). This method demonstrates that androgen receptors can withstand harsh denaturation conditions and should prove to be a valuable tool for purifying the human androgen receptor.