A comparison between water uptake and root length density in winter wheat: effects of root density and rhizosphere properties.

BACKGROUND AND AIMS: We aim to quantify the variation in root distribution in a set of 35 experimental wheat lines. We also compared the effect of variation in hydraulic properties of the rhizosphere on water uptake by roots. METHODS: We measured the root length density and soil drying in 35 wheat lines in a field experiment. A 3D numerical model was used to predict soil drying profiles with the different root length distributions and compared with measured soil drying. The model was used to test different scenarios of the hydraulic properties of the rhizosphere. RESULTS: We showed that wheat lines with no detectable differences in root length density can induce soil drying profiles with statistically significant differences. Our data confirmed that a root length density of at least 1 cm/cm3 is needed to drain all the available water in soil. In surface layers where the root length density was far greater than 1 cm/cm3 water uptake was independent of rooting density due to competition for water. However, in deeper layers where root length density was less than 1 cm/cm3, water uptake by roots was proportional to root density. CONCLUSION: In a set of wheat lines with no detectable differences in the root length density we found significant differences in water uptake. This may be because small differences in root density at depth can result in larger differences in water uptake or that the hydraulic properties of the rhizosphere can greatly affect water uptake.

Bioaccessibility of Difenoconazole in Rice Following Industry Standard Processing and Preparation Procedures.

For pesticide registration a post application assessment is made on the safety of any residue remaining in the edible portion of the treated crop. This assessment does not typically consider the bioaccessibility of pesticide residues. The effects of this on potential exposure to incurred difenoconazole residues passing through the human gastrointestinal tract were studied, including the impact of commodity processing. It has previously been demonstrated that solvent extraction methods have the potential to overestimate the bioaccessible fraction, so in vitro simulated gut systems may offer a better approach to determine residue bioaccessibility to refine the risk assessment process. The bioaccessibility of difenoconazole residues associated with processed rice samples was assessed using in vitro intestinal extraction and colonic fermentation methods. The mean bioaccessibility following intestinal digestion was 33.3% with a range from 13% to 70.6%. Quantification of the colonic bioaccessible fraction was not possible due to compound metabolism. Mechanical processing methods generally increased the residue bioaccessibility, while chemical methods resulted in a decrease. Both mechanical and chemical processing methods reduced the total difenoconazole residue level by ca. 50%.

Assessment of in vitro human dermal absorption studies on pesticides to determine default values, opportunities for read-across and influence of dilution on absorption.

Dermal absorption is an integral part of non-dietary human safety risk assessments for agrochemicals. Typically, dermal absorption data for agrochemical active substances are generated from the undiluted formulation concentrate and its spray dilutions. European Food Safety Authority (EFSA) guidance, which combines highly conservative default values, very limited opportunities for read-across from existing data and other overly conservative conclusions, was the driver for this assessment. To investigate the reliability of the EFSA guidance, a homogeneous data-set of 190 GLP and OECD guideline compliant in vitro human skin studies, chosen to match the test method preferred by EU data requirements, was evaluated. These studies represented a wide range of active substances, formulation types, and concentrations. In alignment with EFSA guidance on human exposure assessment, a conservative estimate of absorption (95th percentile) was chosen to define defaults, which were also based on the EFSA worst-case assumption that all material in skin, excluding the first two tape strips, is absorbed. The analysis supports dermal absorption defaults of 6% for liquid concentrates, 2% for solid concentrates, and 30% for all spray dilutions, irrespective of the active substance concentration. Relatively high dermal absorption values for organic solvent-based formulations, compared to water-based or solid concentrates, support their use as worst-case surrogate data for read-across to other formulation types. The current review also shows that dermal absorption of sprays does not increase linearly with increasing dilution, and provides a novel, science-based option for extrapolation from existing data.

A 1-year follow-on study from a randomised, head-to-head, multicentre, open-label study of two pandemic influenza vaccines in children.

INTRODUCTION: Pandemic influenza A H1N1 infections occurred worldwide from 2009. Children were particularly vulnerable. Novel vaccines were used during the pandemic. OBJECTIVE: To assess the persistence of antibody to H1N1 influenza 1 year after children aged 6 months to 12 years had been immunised with two doses of either a non-adjuvanted whole-virion H1N1 influenza vaccine or an AS03B-adjuvanted split-virion H1N1 influenza vaccine; and also to assess the immunogenicity and reactogenicity in this population of a single dose of 2010-11 trivalent seasonal influenza vaccine. DESIGN: Multicentre, open-label, follow-on from randomised, head-to-head trial. SETTING: Five UK sites (Southampton, Oxford, Bristol, London and Exeter). PARTICIPANTS: Children who completed last year's head-to-head randomised study were invited to participate. Children who had subsequently received a further dose of H1N1 vaccine, or who had already received a dose of 2010-11 trivalent seasonal influenza vaccine, were excluded. INTERVENTIONS: In the previous study, children were randomised (in a 1 : 1 ratio) to receive two doses, 21 days apart, of either a non-adjuvanted whole-virion H1N1 influenza vaccine or an AS03B-adjuvanted split-virion H1N1 influenza vaccine. In this follow-on study, a blood sample was taken to assess the persistence of antibody 1 year later, followed by administration of one 0.5 ml-dose of trivalent seasonal influenza vaccine. A second blood sample was taken 3 weeks later. MAIN OUTCOME MEASURES: Comparison between vaccines of the percentage of participants with a microneutralisation (MN) titre ≥ 1 : 40 and a haemagglutination titre ≥ 1 : 32, 1 year after vaccination. Immunogenicity of the trivalent seasonal influenza vaccine was assessed 3 weeks after vaccination by both the MN and the haemagglutination inhibition (HI) titres. Reactogenicity data were recorded for 7 days after vaccination. RESULTS: A total of 323 children were enrolled and 318 were included in the analysis of the persistence of antibody. One year after receipt of whole-virion vaccine, the MN titre was ≥ 1 : 40 in 32.4% of those vaccinated when < 3 years old and in 65.9% of those vaccinated when ≥ 3 years old; the HI titre was ≥ 1 : 32 in 63.2% and 79.1% of children in the respective age groups. One year after receipt of the adjuvanted vaccine, the MN titre was ≥ 1 : 40 in 100% of those vaccinated when < 3 years old and in 96.9% of those vaccinated when ≥ 3 years old; the HI titre was ≥ 1 : 32 in 98.4% and 96.9% of children in the respective age groups. Three hundred and two children were given trivalent seasonal influenza vaccination. Three weeks later, sera were obtained from 282 children; 100% had an MN titre ≥ 1 : 40 and HI titre ≥ 1 : 32. Trivalent seasonal influenza vaccine was well tolerated, although in children < 5 years old, fever ≥ 38 °C was reported in 13.6% of those who had previously received whole-virion vaccine, and in 18.3% of those who had received adjuvanted vaccine. CONCLUSIONS: Nearly all children who received two doses of AS03B-adjuvanted split-virion pandemic H1N1 influenza vaccine had titres of antibody deemed protective (HI titre ≥ 1 : 32, MN titre ≥ 1 : 40) 1 year later. Children who received two doses of whole-virion vaccine had lower titres, although many were above the putative protective thresholds. One year after either pandemic vaccine, the 2010-11 trivalent seasonal influenza vaccine produced a marked serological response to the H1N1 component of the vaccine and was well tolerated. We propose to investigate whether or not previous receipt of monovalent influenza vaccines affected serological response to the H3N2 and B components of the 2010-11 seasonal influenza vaccine, using stored sera. TRIAL REGISTRATION: ClinicalTrials.gov NCT01239537. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Rapid high-performance liquid chromatographic method for the separation of hydroxylated testosterone metabolites.

A rapid high-performance liquid chromatography (HPLC) method is described for the quantitation of hydroxytestosterone metabolites. The method combines a Hypersil BDS C18 analytical column (10 cm x 0.46 cm) and a linear mobile phase (1.25 ml/min) gradient of tetrahydrofuran-acetonitrile-water (10:10:80, v/v) changing to tetrahydrofuran-acetonitrile-water (14:14:72, v/v) over 10 min then remaining isocratic for 3 min. The total run time for the chromatographic separation of eight metabolites of testosterone is 15 min. Detection by UV is linear between 300 ng/ml and 10 microg/ml with a limit of detection on column of 300 ng/ml. A method for the direct HPLC analysis of liver microsomal incubates of [14C]testosterone is also briefly described and when combined with the HPLC method, offers a distinct advantage over previously reported methods for the rapid screening of testosterone hydroxylase activity in rat and human liver microsomes.

Indirect fluorescence detection of phenolic compounds by capillary electrophoresis on a glass device.

A micromachined capillary electrophoresis system has been fabricated on a glass device for the separation and indirect fluorescence detection of phenols. Using this device two phenols viz., 2,4-dichlorophenol and pentachlorophenol, were separated within 12 s compared to under 19 min on a conventional capillary electrophoresis system using direct ultraviolet detection. The precision of the glass device ranged from 12.7%-16.7% compared to 0.42%-4.9% for the conventional system. Both systems showed good linearity in the concentration range of 0.8-6.38 mM for the glass device and 5-130 microM for the conventional system. The relationship between temperature and high voltage with baseline drift was also investigated. These results provide a foundation for the development of a miniaturised chemical analysis system for the on-line analysis of phenols in water.

Do abnormal thyroid stimulating hormone level values result in treatment changes? A study of patients on thyroxine in one general practice.

BACKGROUND: Hypothyroidism is a common disorder, easily treated with thyroxine therapy. Thyroid stimulating hormone level assay can detect under- or overtreatment. AIM: A study was carried out in one general practice to discover the number of people on thyroxine therapy, their care, and whether abnormal thyroid stimulating hormone level values resulted in alterations to their thyroxine dose. METHOD: The study was undertaken in a north Suffolk general practice of 7640 patients. A computer search identified patients receiving repeat prescriptions for thyroxine therapy and their notes were studied. A thyroid stimulating hormone level value in the range of 0.3-3.8 mU l-1 was considered to indicate an appropriate thyroxine dose. RESULTS: Thyroxine was being taken by 162 patients (2%), of whom 146 were women. Thyroid stimulating hormone level had been checked within the last year for 127 patients (78%). At their last thyroid stimulating hormone level test, 48 patients (30%) had a value above the normal range, only 21 of whom (44%) had their thyroxine dose increased as a result. The thyroid stimulating hormone level was below 0.3 mU l-1 at the last check in 38 patients (23%), only four of whom (11%) had their thyroxine dose reduced as a result. CONCLUSION: There is often failure to adjust thyroxine dose despite abnormal thyroid stimulating hormone levels. However, more research is needed to determine the ideal thyroid stimulating hormone levels which should be aimed for in these patients, and whether tight control of thyroxine dosage is able to reduce morbidity and mortality among patients with hypothyroidism.

Team approach to working through transference and countertransference in a pediatric/psychiatric milieu.

The principles of transference and countertransference are essential to understanding and working through the intense pain and anger that often dominate the emotional field of the pediatric/psychiatric milieu. Using Winnicott's model of the maternal/infant relationship, this milieu can be seen as a holding environment where transferential phenomena can be expressed, interpreted, and worked through. Anger and pain are common elements of the transference/countertransference relationship matrix of the milieu. Staff often have a strong bias regarding anger and hostility. If they are willing to examine their bias, and are given the forums within which to do so, then patients' anger and hostility can be viewed and interpreted in an adaptive and facilitative manner. Working through in a milieu setting is accomplished by both verbal processing and the lived experience.

Elective hospitalization in the management of twin pregnancies.

We sought to evaluate the effectiveness of a policy of early elective hospitalization on the outcomes of 522 consecutive twin gestations delivered at our institution between 1983-1987. During the first 2 years (1983-1985), 237 twin pregnancies were delivered with a policy of elective hospitalization when twin pregnancy was diagnosed between 24-32 weeks' gestation. When possible, elective hospitalization started at 24 weeks' gestation. Electively admitted women remained hospitalized until 34 weeks' gestation, at which time they were discharged unless complications developed requiring continued hospitalization. During 1985-1987, 285 women with twin gestations were intentionally managed as outpatients unless intercurrent complications required hospitalization. A total of 211 twin pregnancies was excluded from analysis because the women did not present for prenatal care (19%) or were undiagnosed until delivery (22%). Of the remaining 311 pregnancies available for study, 134 were managed when the elective admission policy prevailed and 177 when this policy was not in effect. Although the elective admission policy did result in a small reduction in the incidence of low birth weight among the 58 pregnancies hospitalized electively (mean [+/- SEM] gestational age at elective hospitalization 27.7 +/- 0.3 weeks) compared with outpatient management, this policy did not result in an improvement in prematurity (32 versus 36%; P greater than .05) or perinatal morbidity as reflected by requirement for neonatal intensive care (12 versus 11%; P greater than .05) and mechanical ventilation (8 versus 9%; P greater than .05). Moreover, perinatal mortality was actually higher in the electively hospitalized pregnancies (8 versus 2%; P = .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Individual rights vs institutional rights: nursing imperatives for the provision of aged care services.

This paper offers nurses a legal perspective on some of the major issues arising from the Federal Government's proposal to establish a standard form contract and a charter of residents' rights and obligations for elderly residents in hostels and nursing homes. In emphasising the significance of these proposals it suggests that nurses, individually or collectively, have the potential to make a significant contribution to the continuing user rights debate. The proposed charter and contract and the objectives sought to be achieved by this package are considered. While there are strong and persuasive arguments favouring the concept, it is suggested that as proposed the charter and contract would be largely unworkable and impractical. Progress of the consultation process between Government and other interested bodies and the effect of subsequent drafting changes is discussed. Finally, the manner in which members of the nursing profession with experience and expertise in the provision of aged care services may contribute to the ongoing user rights debate is addressed.

Early pregnancy glycosylated hemoglobin, severity of diabetes, and fetal malformations.

Total percent glycosylated hemoglobin (A1a + b + c) was measured before 16 weeks' gestation in 105 insulin-treated diabetic women enrolled for prenatal care at Parkland Memorial Hospital. Seventy-three of the infants were normal, 14 had malformations, and there were 18 spontaneous abortions. The mean glycosylated hemoglobin level for the entire study group was 9.2%, compared with 9.4% for those pregnancies ending in abortion, 8.9% for those resulting in normal infants, and 10.3% when malformations occurred. The mean glycosylated hemoglobin value for women delivered of normal infants was significantly lower than the mean of those with malformed infants. Ten of the 14 malformations occurred in mothers whose early pregnancy values exceeded the mean of the entire study group. There was also an association between malformations and White classification of maternal diabetes since 10 of the 14 fetal anomalies occurred in women assigned to White Classes C, D, F, H, and R. When the distribution of malformations was analyzed according to both glycosylated hemoglobin level and White Class, there was evidence of an interaction to suggest that hyperglycemia increases the relative risk of fetal malformations when associated with maternal diabetes of longer duration and or with vascular complications.

Continuous subcutaneous insulin infusion during pregnancy.

The development of battery-powered pumps for continuous subcutaneous insulin infusion added new dimensions to control of diabetes during pregnancy. In this report, we describe our experiences with 28 pregnant diabetic women offered participation in an insulin pump program. Fifteen (54%) accepted pump therapy and ten continued usage during their pregnancies. Excluding abortions, eight women continuing pump use are compared to 11 others who declined such therapy and were treated with conventional methods. Although these two groups are small and not strictly comparable, the experiences now reported provide clinical insights into the application of this new technology during pregnancy. Women who successfully used insulin pumps were typically from the private sector and in better glucose control at study entry. The degree of control during pregnancy in women using pumps was not significantly different compared to conventional glucose control methods (mean glucose 120 mg/dl and 142 mg/dl, respectively). Similarly, several indices of pregnancy outcome including length of hospitalization, costs, and perinatal morbidity associated with diabetes were analyzed and no significant differences were observed. We conclude that insulin pumps are not acceptable to all pregnant diabetic women and that such therapy may not necessarily improve pregnancy outcome.

Prediction of discordant twins using ultrasound measurement of biparietal diameter and abdominal perimeter.

Prediction of twin birth weight discordancy was tested in 116 gestations using sonographic measurements of biparietal diameter (BPD) and abdominal perimeter. Abdominal perimeter measurement differences of 20 mm or greater were more sensitive and specific than BPD difference in detecting twins with dissimilar birth weights.

Control of vascular reactivity in pregnancy.

Human pregnancy is characterized by a blunted pressor responsiveness to vasopressor substances. This was first reported by Dieckmann and Michel in 1937 in experiments in which they measured vascular reactivity to the pressor effects of a crude preparation of vasopressin. Recently, this has been reported to occur in response to epinephrine, norepinephrine (NE), and angiotensin II (AII). Gant and associates reported that the increasing vascular sensitivity to infused AII not only was characteristic of women who developed pregnancy-induced hypertension, but in fact preceded the development of pregnancy-induced hypertension. Although a variety of factors may mediate this blunted pressor responsiveness, the most likely candidate appears to be the localized production within endothelium and/or vascular smooth muscle of prostaglandins. Indeed, administration of indomethacin or aspirin results in an increased sensitivity to infused AII in normotensive previously AII-refractory women. Administration of the steroid hormone 5 alpha-dihydroprogesterone reverses this apparent prostaglandin-mediated response. In addition, administration of the phosphodiesterase inhibitor, theophylline, results in a restoration of vascular refractoriness to infused AII in women with pregnancy-induced hypertension or in women destined to develop pregnancy-induced hypertension. Although a variety of known and possibly unknown compounds might also effect the control of vascular reactivity during human pregnancy, the prostinoids appear to play a pivotal role in mediation of control of vascular reactivity during human pregnancy.

Glucose threshold for macrosomia in pregnancy complicated by diabetes.

We analyzed 205 diabetic women treated with insulin during pregnancy to assess the effects of several maternal factors on the development of fetal macrosomia. A total of 95 women were selected for study because they had clearly defined gestational criteria, two or more daytime glucose profiles during the third trimester, and no other complications known to affect fetal growth. The incidence of macrosomia was not found to increase significantly until the mean glucose concentration reached 130 mg/dl; macrosomia occurred in 65% of mothers with glucose values greater than or equal to 130 mg/dl compared with 27% in those with lower values. Other factors strongly associated with fetal macrosomia were maternal weight and insulin dosage. Multiple logistic analysis was performed to control for each risk factor and to obtain estimates of the relative risk for macrosomia. The risk of macrosomia was two times greater in women with mean glucose concentrations greater than or equal to 130 mg/dl, approximately threefold in women whose weight exceeded 80 kg, and one and one half times greater in women with insulin dosages more than 80 units/day. We conclude that several maternal factors in addition to glucose concentration play important roles in the development of fetal macrosomia among diabetic women and that the glucose concentration threshold for macrosomia may exceed 130 mg/dl.

Acute urinary tract infections in pregnancy.

Routine screening for pregnancy ASB followed by adequate therapy and urine culture surveillance are important preventative measures which should be practiced by all obstetric physicians. The considerable maternal morbidity associated with the development of acute pyelonephritis more than justifies the effort and expense necessary to implement screening methods for the detection of ASB. A variety of simplified culture techniques are available for office or clinic use which are inexpensive and correlate well with the more expensive standard bacteriologic methods employed by diagnostic laboratories.

Plasma prostaglandins during the intravenous infusion of angiotensin II in pregnant women.

The possible relation between prostaglandin production and the sensitivity of pregnant women with pregnancy-induced hypertension to the pressor effects of angiotensin II was investigated. Plasma prostaglandin levels were determined in four groups of women before, during, and after intravenous infusion of angiotensin II. Concentrations of the stable metabolites of prostaglandin E2, prostaglandin F2 alpha, and prostaglandin I2 (prostacyclin) were quantified by specific radioimmunoassays in the plasma of nonpregnant women, women pregnant in the late third trimester, and women pregnant in the late third trimester with either pregnancy-induced or chronic hypertension. Plasma prostaglandin concentrations did not change significantly during angiotensin II infusion in any of the four groups of women. Levels of the prostacyclin metabolite, however, were significantly higher in the hypertensive pregnant women than in the normotensive pregnant women.

Fetal lung maturation in twin gestation.

Clear amnionic fluid was collected at cesarean section and the lecithin/sphingomyelin (L/S) ratio was used to evaluate fetal lung maturation in 42 twin gestations. The L/S ratios of twin pairs were usually similar in both numerical value and predictive accuracy except when the greater L/S ratio from one member of a pair indicated borderline lung maturity. Twin fetal lung maturation was found to be independent of sex, zygosity, and birth weight discordance. Comparison of mean L/S ratios in twins to those of uncomplicated singleton pregnancies revealed that fetal lung maturation occurred several weeks earlier in twins.

Respiratory insufficiency associated with pyelonephritis during pregnancy.

A previously unreported complication of acute pyelonephritis during pregnancy is described. Acute respiratory distress accompanied by varying manifestations of liver, kidney, hypothalamic, and hematopoietic dysfunction is chronicled in four women. Because these latter organ system effects are attributable to endotoxin, the authors postulate that endotoxin caused alveolar-capillary injury leading to respiratory failure in these pregnant women with acute renal infection.

Induced delivery prior to surgery for ruptured cerebral aneurysm.

Labor was induced by amniotomy at 34 weeks' gestation because of preeclampsia in a woman with a recent ruptured cerebral aneurysm prior to corrective neurosurgery. Neither labor nor vaginal delivery caused neurologic injury to the mother. Subsequent neurosurgery was successful and both mother and infant continued to do well several months later. These outcomes support management advised in the literature in circumstances not previously reported.