Design and implementation of electron diverters for lobster eye space-based X-ray optics

Micropore optics have recently been implemented in a lobster eye geometry as a compact X-ray telescope. Fields generated by rare-earth magnets are used to reduce the flux of energetic electrons incident upon the focal plane detector in such a setup. We present the design and implementation of the electron diverters for X-ray telescopes of two upcoming missions: the microchannel X-ray telescope onboard the space-based multiband astronomical variable objects monitor and the soft X-ray instrument onboard the solar wind magnetosphere ionosphere link explorer. Electron diverters must be configured to conform to stringent limits on their total magnetic dipole moment and be compensated for any net moment arising from manufacturing errors. The two missions have differing designs, which are presented and evaluated in terms of the fractions of electrons reaching the detector, as determined by relativistic calculations of electron trajectories. The differential flux of electrons to the detector is calculated, and the integrated electron background is determined for both designs.

Detection of the Bacteroides fragilis toxin gene in sheep with and without small intestinal adenocarcinoma

Aims: To determine if presence of the Bacteroides fragilis toxin (bft) gene, a molecular marker of colonic carriage of entertoxigenic Bacteroides fragilis (ETBF) in humans, was associated with a finding of small intestinal adenocarcinomas (SIA) in sheep in New Zealand. Methods: Samples of jejunal tissue were collected from the site of tumours and from grossly normal adjacent tissue in 20 sheep, in different consignments, diagnosed with SIA based on gross examination of viscera following slaughter. Two jejunal samples were also collected from a control sheep in the same consignment that had no gross evidence of SIA. A PCR assay was used to detect the presence of the bft gene in the samples. Results: Of the sheep with SIA, the bft gene was amplified from one or both samples from 7/20 (35%) sheep, and in sheep that had no gross evidence of SIA the bft gene was amplified from at least one sample in 11/20 (55%) sheep (RR 0.61; 95% CI = 0.30-1.25; p = 0.34). Of 11 positive samples analysed, ETBF subtype bft-1 was detected in one, bft-2 was detected in 10, and none were bft-3. Conclusions and Clinical Relevance: There was a high prevalence of detection of the bft gene in both SIA-affected and non-affected sheep, but there was no apparent association between carriage of ETBF, evidenced by detection of the bft gene, and the presence of SIA. ETBF are increasingly implicated in the aetiology of human colorectal cancer, raising the possibility that sheep may provide a zoonotic reservoir of this potentially carcinogenic bacterium. Abbreviation: Bft: Bacteroides fragilis toxin; ETBF: Enterotoxigenic Bacteroides fragilis; SIA: Small intestinal adenocarcinoma.

Breast cancer and cytomegalovirus

PURPOSE

To determine whether cytomegalovirus is causally associated with breast cancer and whether cytomegalovirus should be categorised as an oncogenic virus.

METHODS

We undertook a review of published epidemiological and laboratory studies, using established causal criteria: Bradford Hill criteria to determine whether cytomegalovirus is associated with breast cancer; and Evans/Mueller criteria to determine whether cytomegalovirus should be categorised as an oncogenic virus.

RESULTS

Although there are inconsistencies in the findings of published epidemiological and laboratory studies, these may be explained by factors such as: differences in timing of blood samples, differences in selection of cases and controls, or high cytomegalovirus seroprevalence among participants in the epidemiological studies; and, in the laboratory studies, differences in sample preparations, age of sample, whether or not paired breast cancer and normal breast tissue samples were used, differences in the tests, primers and/or antibodies used, differences in histological types of breast cancer studied, and/or features of the virus.

CONCLUSIONS

Overall, the results of published studies of cytomegalovirus and breast cancer suggest cytomegalovirus is a causal factor for at least some types of breast cancer. If the evidence for a link between cytomegalovirus and breast cancer continues to strengthen, further research could lead to: targeted screening; therapy using antiviral drugs; and, perhaps, primary prevention of a significant proportion of breast cancer. Vaccination against viruses has already been shown to be effective in preventing cervix and liver cancer; cytomegalovirus vaccines are already under development.

Multiple Sclerosis impact on employment and income in New Zealand

BACKGROUND AND OBJECTIVES

We investigated the demographic, social and clinical characteristics associated with employment status and income for people with multiple sclerosis (MS) in New Zealand (NZ).

METHODS

The NZ National MS Prevalence study included all persons resident in NZ on census day 2006 diagnosed with MS (96.7% coverage). Factors associated with employment and income status among the working age population (25-64 years) were identified by linear regression.

RESULTS

Over 90% of working age people with MS (n=1727) had a work history, but 54% were not working. Work loss occurred early in the disease course, and at low disability (P<.001). Advancing age, progressive disease, longer disease duration, higher disability levels, partner loss and lower education were associated with work loss (P<.001). Working age people with MS had lower income than the NZ population (P<.0001). Higher qualifications yielded no additional income for MS females and about half the additional income for MS males (P<.0001).

CONCLUSIONS

MS profoundly reduces employment and income early in the disease course, and at low levels of disability, however, unemployment is not entirely accounted for by clinical, social and demographic factors. These findings suggest social supports should be explored early in the disease course to reduce loss of income and unemployment for people with MS.

Parkinson's in the oldest old: Impact on estimates of future disease burden

BACKGROUND

Traditionally the risk of Parkinson's has been considered to increase monotonically with age, although there is evidence that prevalence and incidence may decrease in the oldest old. To examine this further we estimated the national prevalence and incidence of Parkinson's in New Zealand, using drug-tracing methods, to examine the relationship of Parkinson's with sex and age up to 100+.

METHODS

Information on Parkinson's-related medications was extracted from the national pharmaceutical database of community-dispensed medications from 2005 to 2014. Diagnoses for a large subset of individuals were independently determined through national mortality and hospital admissions datasets. We used a Bayesian model, accommodating diagnostic uncertainty and bias, to estimate the number of people with Parkinson's.

RESULTS

The 2013 prevalence of Parkinson's in New Zealand was 210 per 100 000 population (95% uncertainty interval 208-212) with age-standardized prevalence rates higher for males (ratio 1.6:1). Incidence was 31 per 100 000 person-years (95% uncertainty interval 30-32), also higher in males (ratio 1.8:1). Incidence and prevalence by age increased exponentially until 75 years, peaked at 85 years, and then dropped sharply.

CONCLUSIONS

The prevalence of Parkinson's in New Zealand is expected to double over a 25-year period but then increase at a slower rate due to the drop-off in prevalence and incidence in the oldest old. The findings suggest that Parkinson's disease is not an aging-dependent but an age-dependent disorder.

Measures of temperament and character are differentially impacted on by depression severity

BACKGROUND

Cloninger's Temperament and Character Inventory (TCI) is a widely used measure of personality. Two scales of the TCI, harm avoidance (HA) and self directedness (SD), have been shown to be influenced by depressed mood. We examined how the seven TCI scales and their subscales are correlated with depression severity before and after treatment. We also examined whether changes in personality measures could be attributed to changes in depression severity.

METHODS

Two clinical samples of depressed out-patients were recruited for trials to examine predictors of treatment response to antidepressants (N=195) and psychotherapies (N=177). Assessment included the Montgomery-Asberg depression rating scales (MADRS), Hopkins Symptom Checklist (SCL-90) and TCI at baseline and after treatment.

RESULTS

After treatment, in both samples, depression severity correlated significantly with HA and negatively with SD. Multiple regression analysis revealed that changes in SD and HA over treatment were related to improvement in depression. In the psychotherapy trial baseline MADRS scores correlated with low SD and high HA.

LIMITATIONS

The trial results are applicable to mild-moderately depressed out-patients.

CONCLUSIONS

Depression severity influences the total scales and most of the subscale measures of HA and SD. Some personality traits, as measured by the TCI, were not impacted upon by mood. Clinically mood should be taken into account when assessing personality measures of negative affect using the TCI.

Upstream genetic variant near INSIG2, influences response to carnitine supplementation in bipolar patients with valproate-induced weight gain

BACKGROUND

The protein product of INSIG2 is involved in cholesterol and triglyceride metabolism and homeostasis. Variation at rs7566605 near the gene INSIG2 has been associated with increased BMI.

OBJECTIVE

To evaluate the effect of rs7566605/INSIG2 genotype on the ability of valproate-treated bipolar patients (BMI ≥ 25 kg/m2) to lose weight using carnitine supplementation during a 26-week lifestyle intervention study.

DESIGN

Forty-eight bipolar patients with clinically significant treatment emergent weight gain were genotyped at the rs7566605 SNP. Participants were randomised to l-carnitine (15 mg/kg/day) or placebo for 26 weeks in conjunction with a moderately energy restricted, low-fat diet. Weight and body fat percent were measured fortnightly. Waist circumference measurements and dual-energy X-ray absorptiometry were used to assess changes in body composition. Obesity-related biomarkers were measured at baseline and 26 weeks.

RESULTS

There was a significant interaction between rs7566605/INSIG2 genetic status and treatment with carnitine or placebo. Carnitine had no significant effect on body composition measures in G allele homozygous patients who lost between 0.97 and 2.23 kg of fat. However C allele carriers on average gained 2.28 kg when given a placebo. Carnitine supplementation in this group enabled average weight loss of 2.22 kg of fat (p = 0.01). Approximately half of this mass was in the vital truncal compartment (p = 0.002). Bioinformatic analysis detected that the SNP lies in a highly conserved 336 bp sequence which potentially affects INSIG2 gene expression.

CONCLUSIONS

C-carriers at rs7566605, possibly regulating the homeostasis gene INSIG2, lost significantly less weight in this lifestyle intervention study. This effect was reversed by carnitine supplementation.

Polarized fluid movement and not cell death, creates luminal spaces in adult prostate epithelium

There are two predominant theories for lumen formation in tissue morphogenesis; cavitation driven by cell death, and membrane separation driven by epithelial polarity. To define the mechanism of lumen formation in prostate acini we examined both theories in several cell lines grown in 3D Matrigel culture. Lumen formation occurred early in culture and preceded the expression of cell death markers for apoptosis (active caspase 3) and autophagy (LC-3). Active caspase 3 was expressed by very few cells and inhibition of apoptosis did not suppress lumen formation. Despite LC-3 expression in all cells within a spheroid, this was not associated with cell death. However, expression of the prostate secretory protein coincided with lumen formation and subsequent disruption of polarized fluid movement led to significant inhibition of lumen formation. This work indicates that lumen formation is driven by the polarized movement of fluids and proteins in 3D prostate epithelial models and not by cavitation.

Neuroserpin is expressed in the pituitary and adrenal glands and induces the extension of neurite-like processes in AtT-20 cells

Two cDNAs encoding the serine protease inhibitor (serpin) neuroserpin were cloned from a rat pituitary cDNA library (rNS-1, 2922 bp; rNS-2, 1599 bp). In situ hybridization histochemistry showed neuroserpin transcripts in the intermediate, anterior and posterior lobes of the pituitary gland and medullary cells in the adrenal gland. Expression of rNS-1 mRNA was restricted to selected cells in the pituitary gland. Analysis of purified secretory-granule fractions from pituitary and adrenal tissues indicated that neuroserpin was found in dense-cored secretory granules. This result suggested that endocrine neuroserpin may regulate intragranular proteases or inhibit enzymes following regulated secretion. To investigate the function of neuroserpin in endocrine tissues we established stable anterior pituitary AtT-20 cell lines expressing neuroserpin. Cells with increased levels of neuroserpin responded by extending neurite-like processes. Extracellular proteolysis by serine protease plasminogen activators has been suggested to regulate neurite outgrowth. As neuroserpin inhibits tissue plasminogen activator (tPA) in vitro, we measured plasminogen-activator levels. Zymographic analysis indicated that AtT-20 cells synthesized and secreted a plasminogen activator identical in size to tPA. A higher-molecular-mass tPA-neuroserpin complex was also observed in AtT-20-cell conditioned culture medium. tPA levels were similar in parent AtT-20 cells and a stable cell line with increased levels of neuroserpin. There was no accumulation of a tPA-neuroserpin complex. Together these results identify endocrine cells as an important source of neuroserpin. Moreover they suggest that neuroserpin is released from dense-cored secretory granules to regulate cell-extracellular matrix interactions through a mechanism that may not directly involve tPA.

Transvaginal color Doppler in the detection of external iliac vein thrombosis in pregnancy

A case is described where transvaginal color Doppler was used to demonstrate upward external iliac vein extension of thrombus at 26 weeks' gestation. Normally, transabdominal color Doppler can visualize the iliac vessels, but in advanced pregnancy the uterus obstructs the view. This technique is useful in determining of there is a 'high' deep vein thrombosis in pregnancy, and may also prove useful in the obese patient.

Role of balloon dilatation of the aortic valve in pregnant patients with severe aortic stenosis

The outcome of unrelieved severe symptomatic aortic stenosis in pregnancy is poor. Though the valve lesion can be corrected surgically before delivery at a low risk to the mother, cardiopulmonary bypass during pregnancy carries a high risk to the fetus. Two patients in the second trimester of pregnancy were successfully managed with balloon dilatation of the aortic valve. Both delivered healthy infants and were well a year later. Balloon dilatation of the aortic valve is a useful palliative procedure in the management of pregnant women with severe aortic stenosis.

Pregnancy and complicated diabetes

Contemporary management of the insulin-dependent pregnant diabetic is associated with perinatal outcome little different from that in the non-diabetic. Diabetic microangiopathy and its consequences continue to pose a significant threat to the welfare of the diabetic mother and her baby. Pregnancies thus complicated require specialized care by an experienced team.

Fluid balance in severe pre-eclampsia

Women with severe pre-eclampsia are at high risk of pulmonary oedema, especially 12-24 hours postdelivery. Effective vasodilatation with fluid restriction and early diuretic therapy are the cornerstones of preventative therapy.

Emergency mitral valve replacement immediately following caesarean section

Cardiopulmonary bypass immediately post-partum could carry the risk of severe uterine bleeding. We report the case of a woman who successfully underwent emergency replacement of a thrombosed mitral prosthesis immediately after Caesarean section.

Symphysis-fundus height, maternal height, labor pattern, and mode of delivery

Fetal growth was monitored with use of symphysis-fundus charts in 920 consecutive term singleton pregnancies with cephalic presentation. There were 402 primigravid and 518 multigravid patients. The symphysis-fundus charts were divided into four zones and the patients allocated into groups according to the zone of the last symphysis-fundus height measurement before the onset of labor. A highly significant increase was noted in the incidence of abnormal labor and operative delivery in group A primigravid women (symphysis-fundus height above the ninetieth centile), which was even more pronounced when the effect of epidural analgesia was excluded. Conversely, there was a significant progressive increase in the proportion of operative deliveries for fetal distress from group A through group D (symphysis-fundus height below the tenth centile). Similar trends were significant but less pronounced among multigravid women. The relationship between maternal height, symphysis-fundus height, and operative delivery for dystocia in primigravid women was examined. High operative delivery rates were present in group A primigravid patients regardless of maternal height. In groups B and C, however, increased maternal height was associated with lower operative delivery rates.

Relation of haemoglobin levels in first and second trimesters to outcome of pregnancy

The relation between haemoglobin (Hb) concentrations at antenatal booking and subsequent outcome was examined in 54 382 singleton pregnancies. Both high (greater than 13.2 g/dl) and low (less than 10.4 g/dl) Hb values were associated with an adverse outcome. Mothers with a booking Hb in the intermediate range (10.4-13.2 g/dl) fared best. Significant differences emerged in perinatal mortality between those with high and those with intermediate Hb levels at 13-19 weeks' gestation. The frequencies of perinatal death, low birthweight, and preterm delivery were greater with high than with intermediate Hb. There was a striking relation between booking Hb values and the subsequent frequency of hypertension (p less than 0.001). In primiparas, the frequency of subsequent hypertension ranged from 7% at Hb values under 10.5 g/dl to 42% at Hb concentrations over 14.5 g/dl.

New insulating material in maintenance of body temperature

Flectalon, web of aluminised polyvinylchloride fibres, has been formulated to minimise radiant heat losses and to provide conventional insulation. Critical temperature determinations were used to assess the insulating efficacy of this and other swaddling materials in infants. The critical temperature for a baby 2 to 10 days old was 31 degrees C when naked and 23 degrees C when wrapped in a Silver Swaddler or a sheet and two blankets. The use of a quilt made with Thinsulate or Hollofil with a mass per unit area of 160 to 180 g/m2 reduced the critical temperature to 19.5 degrees C, while Flectalon of comparable weight reduced the critical temperature to 13.8 degrees C: Flectalon is thus an efficient insulator. The risk of overheating was studied by monitoring swaddled babies, rectal temperatures at various ambient temperatures. Some forms of swaddling caused increases in rectal temperatures at "normal' hospital temperatures, implying risks from warmer environments and assessments of swaddling materials should, therefore, include medical evaluation of efficiency and safety. Flectalon merits assessment in other groups at risk from hypothermia.

Salivary oestriol in normal and abnormal pregnancies

Profiles of daily salivary oestriol concentrations throughout the third trimester of pregnancy have been constructed for 14 normal and 11 abnormal pregnancies. Day-to-day variations were significantly higher than those reported for unconjugated oestriol in plasma or serum. A sustained decline in salivary oestriol concentrations was observed in one pregnancy in which intrauterine death occurred. Sustained falls were also observed in two pregnancies in which a healthy infant was born at term. In all other patients a normal salivary oestriol profile correlated with a favourable outcome. Salivary oestriol measurements provide similar information to plasma unconjugated oestriol measurements while offering the advantages of a simple, non-invasive sample collection procedure.

Conservative management of pregnancy in diabetic women

In 1979 the obstetric management of pregnancies in diabetic women in Cardiff was changed from elective delivery at 37-38 weeks to delivery at term. This change was facilitated by home monitoring of blood glucose concentrations and improved techniques for assessing fetal wellbeing. There were 35 pregnancies in insulin dependent diabetics in 1972-8 and 45 in 1979-82. The quality of diabetic control during pregnancy was equally good in both periods. The average gestation at final admission to hospital increased from 30 to 37 weeks. Amniocentesis to assess fetal pulmonary maturity was necessary in 26 patients (74%) in the first period of study and in only four (9%) in the second. Gestational age at delivery increased from 37.4 to 39.4 weeks after the change in policy. The proportion of mothers entering spontaneous term labour and delivering vaginally increased from 14.3% to 37.8%. The mean birth weight of live born, singleton infants increased from 3090 g to 3650 g, the feeding pattern improved, and respiratory problems were less common. Morbidity was reduced and perinatal mortality was not increased with conservative management of pregnancy in diabetic women.

Antenatal screening by measurement of symphysis-fundus height

A study was undertaken to assess the value of symphysis-fundus measurement as a screening procedure for intrauterine growth retardation. The reproducibility of this measurement was investigated in two groups of six patients, each measured six times by six different observers. The intraobserver coefficient of variation was 4.6% and the interobserver coefficient of variation 6.4%. There was no evidence that experience aided consistency. A chart of symphysis-fundus measurements derived from Cardiff data was found to be similar to others previously published, and one measurement below the 10th centile identified 64% of pregnancies in which the eventual birth weight was below the 10th centile for gestational age. Symphysis-fundus measurement is a useful screening test; one chart could be used for any Caucasian population and should be incorporated into the maternity services "co-operation card."

Ritodrine in the management of fetal distress

The potential value of a bolus injection of ritodrine in the management of fetal distress was examined in 24 patients. Following the injection of ritodrine, uterine activity measured over a period of 14.7 +/- 6.3 (SD) min was reduced to 22 (+/- 12.4 SD)% of the pre-existing values. The cardiotocographic tracings showed a reversion to a normal or less ominous pattern in 14 of the 16 patients where this could be evaluated. The infants in the ritodrine group took less time to establish regular respirations. The perinatal neurobehaviour in the ritodrine and control groups did not differ. Two mothers who were given ritodrine and who received atropine premedication developed tachycardia and marked systolic hypertension. The administration of a bolus of ritodrine may have a place in the management of fetal distress when caesarean section is unavoidably delayed, but atropine premedication must be avoided as the combination can lead to potentially serious cardiovascular complications.

A six-point scoring system for antenatal cardiotocographs

A six-point scoring system for antenatal cardiotocography based upon baseline fetal heart rate (FHR) ad FHR response to fetal movements and Braxton-Hicks contractions has been described and tested in 89 patients. The 'six-point score' obtained within 24 hours of delivery or death of the fetus (D--1) was shown to be strongly associated both with the one-minute Apgar score and the nutritional status of the infant as reflected by centile birth weight. In 21 patients whose D--1 'six-point score' was 4 or less, analysis ofthe cardiologicographs performed on the previous day (D--2) showed that 14 infants already showed evidence of hypoxia. In the remaining seven patients, however, the previous day's six-point score had been normal (5 or 6); in six of these patients a persistently low daily fetal movement count or placental abruption led to repeat cardiotocography. Hypoxia affected the three components of the score in a progressive manner. Firstly there were alterations in the response of the FHR to Braxton-Hicks contractions followed by changes in the FHR response to fetal movements. Finally, fetal movements ceased and baseline FHR changes occurred mainly in the form of a trachycardia. The method of scoring was simple to use and could standardize reporting.

Response to a Valsalva manoeuvre before and after epidural block

In pregnant patients at term the cardiovascular response to a Valsalva manoeuvre has been evaluated in the lateral and supine positions, before and after epidural block (T8-S5). There was no difference in the pattern of response under these four conditions. After epidural block, there was a tendency to a greater degree of hypotension and a slower recovery. In labour such repeated hypotension could account for the increase in fetal acidosis when the second stage of labour is conducted in the supine position.