Evaluating the effects of grass management technologies on the physical, environmental, and financial performance of Irish pasture-based dairy farms

Grass management technologies (grass measuring devices and grassland management decision support tools) have been identified as important tools to improve the performance of pasture-based dairy farms. They have the potential to significantly improve the efficiency and sustainability of dairy systems by increasing milk production through enhanced pasture growth and utilization, which would reduce the need for supplementary feeds, along with increased output, therefore increasing farm profitability and environmental sustainability. Despite the several potential benefits of grass management technologies, there is a lack of empirical research around the effects of these technologies on the performance of pasture-based dairy systems. The current study aimed to fill this knowledge gap by using a 2018 nationally representative survey of Irish dairy farms and a propensity score matching approach to determine the effects of adopting grass management technologies on the physical, environmental, and financial performance of Irish pasture-based dairy farms. The findings showed that dairy farms utilizing grass management technologies had, on average, higher farm physical, environmental, and financial performance (in terms of grazed pasture use, total pasture use, length of the grazing season, milk yield, milk solids, greenhouse gas emissions per kilogram of fat- and protein-corrected milk, gross output, and gross margin) compared with dairy farms not utilizing these technologies. However, when controlling for selection bias, we can only attribute a positive causal effect of grass management technology adoption on the use of grazed pasture per cow, grazing season length, milk yield per cow, and milk solids per cow. This might be due to dairy farmers not yet using the technologies to their full potential, 2018 being an unusual year in terms of weather (and therefore not being able to capture the full range of farm performance benefits), or because grass management technologies need to be adopted in association with other technologies and practices to achieve their expected performance outcomes. Future research should include updated farm-level data to capture the weather and learning effects and so be able to determine the impact of grass management technologies on a wider range of performance indicators.

Phase separation in surfactant-containing amorphous solid dispersions: Orthogonal analytical methods to probe the effects of surfactants on morphology and phase composition

Amorphous-amorphous phase separation (AAPS) is an important phase transition process for amorphous solid dispersion (ASD) performance both in terms of drug release as well as physical and chemical stability during storage. Addition of surfactants to ASD systems can impact both of these processes. One possible mechanism through which surfactants affect ASD performance is via their impact on AAPS. Unfortunately, despite their increasing usage in ASD formulations, the effect of surfactant on AAPS is still poorly understood, and there are limited analytical techniques that provide microstructural and composition information about phase separated ASDs. In this study, the impact of four surfactants (sodium dodecyl sulfate, Tween 80, Span 20 and Span 85) on water-induced phase separation in ASDs formulated with ritonavir and polyvinylpyrrolidone/vinyl acetate (PVPVA) was investigated using a variety of orthogonal analytical methods. Transparent films of ASDs with different compositions were prepared by spin coating. Fluorescence confocal microscopy in combination with an in situ humidity chamber was used to monitor the kinetics and morphology of phase separation following exposure to high relative humidity. Optical photothermal IR analysis of phase separated films enabled characterization of domain composition and surfactant distribution. Liquid-liquid phase separation concentration, zeta potential and solution nuclear magnetic resonance spectroscopy measurements enabled interpretation of interaction with and partition of surfactants into the drug-rich phase. It was found that phase separation kinetics and morphology were notably changed by the surfactants. Further, the surfactants showed different affinities for the drug-rich versus the aqueous/polymer-rich phases. The employed analytical techniques were found to be complementary in providing insight into surfactant location in phase separated systems. This study highlights the complexity of phase separation, especially in the presence of surfactants, and provides a foundation to understand the impact of AAPS on ASD performance.

Micro to Nano: Multiscale IR Analyses Reveal Zinc Soap Heterogeneity in a 19th-Century Painting by Corot

Formation and aggregation of metal carboxylates (metal soaps) can degrade the appearance and integrity of oil paints, challenging efforts to conserve painted works of art. Endeavors to understand the root cause of metal soap formation have been hampered by the limited spatial resolution of Fourier transform infrared microscopy (μ-FTIR). We overcome this limitation using optical photothermal infrared spectroscopy (O-PTIR) and photothermal-induced resonance (PTIR), two novel methods that provide IR spectra with ≈500 and ≈10 nm spatial resolutions, respectively. The distribution of chemical phases in thin sections from the top layer of a 19th-century painting is investigated at multiple scales (μ-FTIR ≈ 10² μm³, O-PTIR ≈ 10^-1 μm³, PTIR ≈ 10^-5 μm³). The paint samples analyzed here are found to be mixtures of pigments (cobalt green, lead white), cured oil, and a rich array of intermixed, small (often ≪ 0.1 μm³) zinc soap domains. We identify Zn stearate and Zn oleate crystalline soaps with characteristic narrow IR peaks (≈1530-1558 cm^-1) and a heterogeneous, disordered, water-permeable, tetrahedral zinc soap phase, with a characteristic broad peak centered at ≈1596 cm^-1. We show that the high signal-to-noise ratio and spatial resolution afforded by O-PTIR are ideal for identifying phase-separated (or locally concentrated) species with low average concentration, while PTIR provides an unprecedented nanoscale view of distributions and associations of species in paint. This newly accessible nanocompositional information will advance our knowledge of chemical processes in oil paint and will stimulate new art conservation practices.

Orientation Matters: Polarization Dependent IR Spectroscopy of Collagen from Intact Tendon Down to the Single Fibril Level

Infrared (IR) spectroscopy has been used for decades to study collagen in mammalian tissues. While many changes in the spectral profiles appear under polarized IR light, the absorption bands are naturally broad because of tissue heterogeneity. A better understanding of the spectra of ordered collagen will aid in the evaluation of disorder in damaged collagen and in scar tissue. To that end, collagen spectra have been acquired with polarized far-field (FF) Fourier Transform Infrared (FTIR) imaging with a Focal Plane Array detector, with the relatively new method of FF optical photothermal IR (O-PTIR), and with nano-FTIR spectroscopy based on scattering-type scanning near-field optical microscopy (s-SNOM). The FF methods were applied to sections of intact tendon with fibers aligned parallel and perpendicular to the polarized light. The O-PTIR and nano-FTIR methods were applied to individual fibrils of 100–500 nm diameter, yielding the first confirmatory and complementary results on a biopolymer. We observed that the Amide I and II bands from the fibrils were narrower than those from the intact tendon, and that both relative intensities and band shapes were altered. These spectra represent reliable profiles for normal collagen type I fibrils of this dimension, under polarized IR light, and can serve as a benchmark for the study of collagenous tissues.

Establishing nationally representative benchmarks of farm-gate nitrogen and phosphorus balances and use efficiencies on Irish farms to encourage improvements

Agriculture faces considerable challenges of achieving more sustainable production that minimises nitrogen (N) and phosphorus (P) losses and meets international obligations for water quality and greenhouse gas emissions. This must involve reducing nutrient balance (NB) surpluses and increasing nutrient use efficiencies (NUEs), which could also improve farm profitability (a win-win). To set targets and motivate improvements in Ireland, nationally representative benchmarks were established for different farm categories (sector, soil group and production intensity). Annual farm-gate NBs (kg ha^-1) and NUEs (%) for N and P were calculated for 1446 nationally representative farms from 2008 to 2015 using import and export data collected by the Teagasc National Farm Survey (part of the EU Farm Accountancy Data Network). Benchmarks for each category were established using quantile regression analysis and percentile rankings to identify farms with the lowest NB surplus per production intensity and highest gross margins (€ ha^-1). Within all categories, large ranges in NBs and NUEs between benchmark farms and poorer performers show considerable room for nutrient management improvements. Results show that as agriculture intensifies, nutrient surpluses, use efficiencies and gross margins increase, but benchmark farms minimise surpluses to relatively low levels (i.e. are more sustainable). This is due to, per ha, lower fertiliser and feed imports, greater exports of agricultural products, and for dairy, sheep and suckler cattle, relatively high stocking rates. For the ambitious scenario of all non-benchmark farms reaching the optimal benchmark zone, moderate reductions in farm nutrient surpluses were found with great improvements in profitability, leading to a 31% and 9% decrease in N and P surplus nationally, predominantly from dairy and non-suckler cattle. The study also identifies excessive surpluses for each level of production intensity, which could be used by policy in setting upper limits to improve sustainability.

Optical Photothermal Infrared Microspectroscopy with Simultaneous Raman - A New Non-Contact Failure Analysis Technique for Identification of <10 μm Organic Contamination in the Hard Drive and other Electronics Industries

Optical Photothermal Infrared (O-PTIR) spectroscopy is a new technique for measuring submicron spatial resolution IR spectra with little or no sample preparation. This speeds up analysis times benefiting high-volume manufacturers through gaining insight into process contamination that occurs during development and on production lines. The ability to rapidly obtain far-field non-contact IR spectra at high spatial resolution facilitates the chemical identification of small organic contaminants that are not possible to measure with conventional Fourier transform infrared (FT-IR) microspectroscopy. The unique pump-probe system architecture also facilitates submicron simultaneous IR + Raman microscopy from the same spot with the same spatial resolution. With these unique capabilities, O-PTIR is finding utilization in the high-volume and high-value industries of high-tech componentry (memory storage, electronics, displays, etc.).

Lorentz contact resonance spectroscopy for nanoscale characterisation of structural and mechanical properties of biological, dental and pharmaceutical materials

Scanning probe microscopy has been widely used to obtain topographical information and to quantify nanostructural properties of different materials. Qualitative and quantitative imaging is of particular interest to study material-material interactions and map surface properties on a nanoscale (i.e. stiffness and viscoelastic properties). These data are essential for the development of new biomedical materials. Currently, there are limited options to map viscoelastic properties of materials at nanoscale and at high resolutions. Lorentz contact resonance (LCR) is an emerging technique, which allows mapping viscoelasticity of samples with stiffness ranging from a few hundred Pa up to several GPa. Here we demonstrate the applicability of LCR to probe and map the viscoelasticity and stiffness of 'soft' (biological sample: cell treated with nanodiamond), 'medium hard' (pharmaceutical sample: pMDI canister) and 'hard' (human teeth enamel) specimens. The results allowed the identification of nanodiamond on the cells and the qualitative assessment of its distribution based on its nanomechanical properties. It also enabled mapping of the mechanical properties of the cell to demonstrate variability of these characteristics in a single cell. Qualitative imaging of an enamel sample demonstrated variations of stiffness across the specimen and precise identification of enamel prisms (higher stiffness) and enamel interrods (lower stiffness). Similarly, mapping of the pMDI canister wall showed that drug particles were adsorbed to the wall. These particles showed differences in stiffness at nanoscale, which suggested variations in surface composition-multiphasic material. LCR technique emerges as a valuable tool for probing viscoelasticity of samples of varying stiffness's.

Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens

Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.

Correlation of Campylobacter bacteriophage with reduced presence of hosts in broiler chicken ceca

Campylobacter jejuni and Campylobacter-specific bacteriophage were enumerated from broiler chicken ceca selected from 90 United Kingdom flocks (n = 205). C. jejuni counts in the presence of bacteriophage (mean log(10) 5.1 CFU/g) were associated with a significant (P < 0.001) reduction compared to samples with Campylobacter alone (mean log(10) 6.9 CFU/g).

Longitudinal study of Campylobacter jejuni bacteriophages and their hosts from broiler chickens

A longitudinal study of bacteriophages and their hosts was carried out at a broiler house that had been identified as having a population of Campylobacter-specific bacteriophages. Cloacal and excreta samples were collected from three successive broiler flocks reared in the same barn. Campylobacter jejuni was isolated from each flock, whereas bacteriophages could be isolated from flocks 1 and 2 but were not isolated from flock 3. The bacteriophages isolated from flocks 1 and 2 were closely related to each other in terms of host range, morphology, genome size, and genetic content. All Campylobacter isolates from flock 1 were genotypically indistinguishable by pulsed-field gel electrophoresis (PFGE). PFGE and multilocus sequence typing indicated that this C. jejuni type was maintained from flock 1 to flock 2 but was largely superseded by three genetically distinct C. jejuni types insensitive to the resident bacteriophages. All isolates from the third batch of birds were insensitive to bacteriophages and genotypically distinct. These results are significant because this is the first study of an environmental population of C. jejuni bacteriophages and their influence on the Campylobacter populations of broiler house chickens. The role of developing bacteriophage resistance was investigated as this is a possible obstacle to the use of bacteriophage therapy to reduce the numbers of campylobacters in chickens. In this broiler house succession was largely due to incursion of new genotypes rather than to de novo development of resistance.

Catecholamines in human saliva

Catecholamines are readily detectable in human saliva but their origin is unclear. Norepinephrine (NE) was stable in saliva stored at 4 degrees for 2 hours but 11 +/- 3% degraded after storage at 25 degrees for 1 hour. We intravenously infused 3H-NE into humans and measured levels of 3H-NE and its metabolites in both saliva and forearm venous plasma (a site whose plasma NE levels reflect both local uptake and release of NE). 3H-NE levels in saliva continued to rise for 1 hour even though forearm plasma levels had plateaued by 5 min. By 65 min into the infusion the ratio of 3H-NE:non-radioactive NE was similar in saliva and forearm venous plasma. The ratio of NE:epinephrine (E) was similar in saliva and forearm venous plasma at all time points. Chewing induced salivation, and at least tripled the amount of NE, E and 3H-NE released into saliva per minute, but decreased their concentration in saliva by as much as one half. Saliva NE level was unaltered after 15 min of standing but was increased by 31% after 1 hour of upright posture. Our data imply that the NE present in human saliva comes from both the bloodstream and from salivary sympathetic nerves. The finding that diffusion of blood NE into saliva takes roughly 1 hour to complete suggests that NE in saliva is a poor index of acute changes in sympathetic activity.

Congenital diaphragmatic herniation: antenatal detection and outcome

201 fetuses and babies with a congenital diaphragmatic herniation or eventration (referred to collectively as CDH) were notified to the Northern Region Congenital Abnormality Survey (NorCAS) in the 13-year period from 1985 to 1997, an incidence of 0.25 per 1000 births. The 1-year survival of all pregnancies associated with CDH was 37%. The 1-year survival of livebirths was 50%. Antenatal scan detected the diaphragmatic defect or associated structural abnormality in 50%. Another major structural abnormality was present in 62 (31%); one of these babies survived and 26 pregnancies were terminated. This group contained four of the six antepartum stillbirths, all three intrapartum stillbirths and four of the five spontaneous miscarriages. Non-isolated CDH occurred in association with Fryns (5), Goldenhar (1) and de Lange (1) syndromes, and in 16 of 17 with a chromosome anomaly. 53% of the 139 fetuses with isolated CDH survived to 1 year of age, and 59% of the 124 liveborn survived. Of 37 fetuses with isolated CDH detected before 25 weeks gestation, 12 pregnancies were terminated. There were 11 survivors among the 25 continuing pregnancies (44%). The overall survival of babies with CDH is very poor but, when a defect is identified by ultrasound before 25 weeks gestation, chromosome analysis and a careful ultrasound scan may suggest which fetuses have an isolated diaphragmatic abnormality and a greater chance of survival.

Serologic markers for Chlamydia pneumoniae in asthma

BACKGROUND

Chlamydia pneumoniae infection has been reported as a possible etiologic agent in asthma, which in primary care settings often appears to be initiated by acute respiratory infections.

OBJECTIVE

To determine if serologic markers for C. pneumoniae are associated with adult asthma that first became symptomatic after an acute respiratory illness (asthma associated with infection: AAWI).

METHODS

Serum samples from 164 primary care outpatients, mean age 44 years, (68 with AAWI; 36 with atopic, occupational or exercise-induced asthma (non-AAWI); 16 nonasthmatic patients with acute bronchitis; and 44 asymptomatic nonasthmatic controls) were tested for the presence of C. pneumoniae-specific IgG and IgA antibodies. Levels of chlamydial heat shock protein 60 (CHSP60) antibody were also measured. Those positive for CHSP60 were tested for C. pneumoniae-specific IgE antibodies by immunoblotting.

RESULTS

Statistically significant differences in IgG and IgA seroreactivity were noted between groups: acute bronchitis and AAWI had the highest levels (93% to 94% IgG seroreactivity, 69% to 75% IgA seroreactivity) whereas non-AAWI and asymptomatic controls had the lowest levels (61% to 84% IgG seroreactivity, 31% to 43% IgA seroreactivity, P < .02 after adjustment for age, sex and smoking). CHSP60 antibodies were significantly more prevalent in AAWI than in non-AAWI (19% versus 3%, P = .02). IgE antibodies against C. pneumoniae 60, 62, and/or 70 kD antigens were detected in 5 of 13 CHSP60 positive AAWI patients. Persistent IgG, IgA, and CHSP60 seroreactivities were noted in all seropositive asthma patients with serial serum samples.

CONCLUSIONS

Serologic markers of C. pneumoniae infection were associated with acute bronchitis and with asthma that first became symptomatic following respiratory illness. Serologic responses to C. pneumoniae may be useful in the classification and diagnosis of asthma.

Congenital anterior abdominal wall defects in the north of England, 1986-1996: occurrence and outcome

The aim was to describe trends in prevalence, maternal age-specific prevalence, associated anomalies, clinical outcomes and the sensitivity of antenatal diagnosis of congenital anterior abdominal wall defects (in particular gastroschisis and exomphalos). Data were identified from a population-based register of major congenital abnormalities in the Northern health region of England, the Northern Congenital Abnormality Survey (NorCAS), between 1986 and 1996. 296 cases were notified; there were 133 cases of gastroschisis, 98 exomphalos, 30 limb-body wall defects and 23 other anterior abdominal wall defects. 12 cases could not be classified. In 19 (6 per cent) the initial diagnosis was changed following case review. 30 (30.6 per cent) cases of exomphalos were associated with a chromosomal anomaly compared with 1 (0.8 per cent) case of gastroschisis. The total prevalence for the 11 years was 6.33 (95 per cent CI=5.57-7.08) per 10 000 live births, still births and terminations of pregnancy, and the overall birth prevalence was 4.30 (95 per cent CI=3.68-4.93) per 10 000 live births and still births. For gastroschisis, there was a significant increase over the study period in both the total prevalence (1.48 in 1986 to 5.29 per 10 000 in 1996; chi(2)=8.41, p=0.00433) and the birth prevalence (1.48 in 1986 to 4.72 per 10 000 in 1996; chi(2)=7.42, p=0.00644), but there was no such significant increase for exomphalos (total prevalence chi(2)=2.29, p=0.13055; birth prevalence chi(2)=0.16, p=0.69348). The maternal age-specific prevalence was highest in the 11-19 year age group for gastroschisis but in the 35-39 year age group for exomphalos. Fewer pregnancies with gastroschisis resulted in a termination and a greater proportion of cases were alive at one year compared with exomphalos. The sensitivity of abnormality detection by ultrasonography was 75 per cent and 77.3 per cent for gastroschisis and exomphalos, respectively. Antenatal diagnosis improved from 47.4 per cent during 1986-91 to 80 per cent between 1992-96 for gastroschisis (chi(2)=5.7, p=0.00169), and from 55.6 per cent to 68.8 per cent for isolated exomphalos, although this increase was not significant. Total and birth prevalence of gastroschisis increased in the Northern region between 1986 and 1996. For exomphalos, there was a trend towards an increase in total prevalence and towards a decrease in birth prevalence. This decreasing trend has been accompanied by improvements in antenatal detection and subsequent termination of cases of exomphalos associated with other anomalies.

A 10 year audit of antenatal ultrasound detection of renal disease

During a 10 year period, a renal tract anomaly was suspected on antenatal ultrasound in 125 fetuses, an incidence of five per 1000 births. 107 live births resulted. Three of six babies with renal failure were stented antenatally. A chromosome anomaly was present in three fetuses (2.4%). No live birth resulted in 14 pregnancies associated with oligohydramnios and no visible fetal bladder. Of those with renal agenesis or bilateral cystic dysplasia, one had a chromosome defect and a further four had extrarenal anomalies. Nine fetuses demonstrated isolated parenchymal hyperechogenicity and trisomy occurred in two of four with bilateral change in enlarged kidneys. All 14 babies with unilateral renal cysts had normal renal function postnatally, but only three of the cystic kidneys showed function. Antenatally, typical multicystic change was seen in 10, and smaller unevenly distributed cysts in four kidneys. Contralateral parenchymal echogenicity and/or pelvicalyceal distension indicating dysplasia was identified in four fetuses. Of 78 fetuses with isolated pelvic with or without calyceal distension the outcome was completely normal in 59% with unilateral, and in 48% with bilateral changes. One baby with unilateral and three with bilateral changes required dialysis or renal transplantation. One of four babies with antenatal ureteric distension had renal failure. Only one of six fetuses with bladder distension is alive in renal failure after in utero stenting.

L-selectin expression affects T-cell circulation following isoproterenol infusion in humans

beta-Adrenergic receptor agonists have been shown to affect leukocyte migration. This study examined the expression of cellular adhesion molecules on lymphocyte, monocyte, and granulocyte distribution following an infusion of isoproterenol (20 and 40 ng/kg/min for 15 min each) in 12 healthy subjects. Leukocyte populations and adhesion molecule expression were determined via flow cytometry. Isoproterenol led to an expected lymphocytosis and leukocytosis. L-selectin expression varied across leukocytes and influenced cell trafficking in response to isoproterenol. Approximately 60% of CD8+ T-cells expressed L-selectin (CD8+CD62L+) and these cells showed no appreciable response to isoproterenol. In contrast, CD8+CD62L- cells showed a robust increase in number and distribution of approximately 100% over baseline (p's < .001). Across CD4+ T-helpers, L-selectin was expressed on approximately 86% of cells. CD4+CD62L+ cells decreased in number and distribution (p's < .001) with isoproterenol, while CD4+CD62L- cells showed a modest increase (p's < or = .05). In contrast to lymphocytes, nearly all monocytes and granulocytes expressed L-selectin; these cells increased and decreased respectively in response to isoproterenol (p's < or = .05). CD11a (the beta 2-integrin LFA-1) was expressed on > 95% of all leukocytes and these data were thus similar to the overall leukocytosis data. CD54 (ICAM-1) was expressed on approximately 60% of mixed lymphocytes and was unchanged in response to isoproterenol. The findings indicate that L-selectin expression influences T-cell trafficking in response to beta-adrenergic stimulation and help further illuminate catecholamine-mediated sympathetic and immune interactions.

The antenatal diagnosis of fetal abnormalities: a 10 year audit of influencing factors

During the 10 years 1984-1993, a total of 438 fetuses and children with a congenital abnormality, identified antenatally or in the first year of life, were registered from the North Tees Health District with the Northern Region Congenital Abnormality Survey (NorCAS). This represented an abnormality rate of 2% of all births. In total, 252 structural abnormalities (57.5%) were detected by antenatal ultrasound examination. In spite of a targeted education programme, identification of cardiac lesions remained poor. The detection of structural abnormality by antenatal scan rose from 52% in 1984 to 85% in 1993, due mainly to improvements in image quality and resolution of ultrasound equipment. Also important was audit, based both on review of images and feedback from a comprehensive central register (NorCAS).

Race and sex differences in cardiovascular recovery from acute stress

To evaluate the effects of race and gender on recovery, i.e. the relative return to baseline after a stress challenge, cardiovascular and catecholamine measures were examined before, during and after two standardized laboratory stressors (a speaking and a mirror tracing task) in a group of 85 Black and White men and women (mean age 35.6 years, range 20 to 52). For the speech task, White men showed the least systolic (p < 0.025) and diastolic (p < 0.05) blood pressure recovery as compared to Black men and women. For the mirror star tracing task, total peripheral resistance (p < 0.03) recovery was least for Whites as compared to Blacks and heart rate (p < 0.04) recovery was least for White women as compared to Black women and men. There were no significant group effects in terms of catecholamine recovery from either task. The findings extend prior studies on race and gender by suggesting that these same characteristics affect recovery from stressors.

Psychologic characteristics associated with acute stressor-induced leukocyte subset redistribution

This study examined relationships between psychologic characteristics and enumerative immune responses to an acute laboratory stressor. Lymphocyte subsets were measured in 104 subjects at rest and following a 6-minute laboratory naturalistic speaking stressor. Multiple linear regression was utilized to assess relationships between immune reactivity (change scores) and anger expression, hostility, anxiety, depression, and stress. The task resulted in significant increases over baseline in WBC (p < 0.001), T-suppressor/cytotoxic CD8 cells (p = 0.010) natural killer CD56 cells (p < 0.0001), and CD57 (p < 0.0001) cells, and significant decreases in T-cells (p = 0.012), T-helper cells (p = 0.003), B-cells (p < 0.001), and the T-helper/suppressor ratio (p < 0.001). In general, the regression suggested that moderate associations exist between certain psychologic attributes and acute subset redistribution. For example, the increase in natural killer cell subsets was significantly negatively associated with anger expression, hostility, and depression. Suppressor/cytotoxic (CD8) cell reactivity was associated with baseline as well as with the task-induced changes in anxiety. B-cell (CD19) responses were related to the subject's age, expression of anger, and depression scores. As with the cardiovascular reactivity literature, these findings suggest that a relationship exists between certain psychologic characteristics such as anger and anxiety and immune reactivity to acute stress.

Menstrual cycle effects on catecholamine and cardiovascular responses to acute stress in black but not white normotensive women

This study examined cardiovascular and catecholamine responses to two standardized laboratory stressors in 33 healthy age- and weight-matched black and white normotensive women (mean age, 32 years) during two phases of the menstrual cycle. Subjects were studied in a randomized order at the same time of day on two separate occasions approximately six weeks apart, once during the follicular phase (days 7 to 10 after menses) and once during the luteal phase (days 7 to 10 after the leutenizing hormone surge) of the menstrual cycle. Black women has higher systolic (P=.01) and diastolic (P=.01) pressures compared with white women. Black women showed greater diastolic pressure (P <.01) and plasma epinephrine (P <.05) responses to stress during the follicular compared with the luteal phase of the menstrual cycle; white women showed no significant changes in these variables. The findings extend the literature on race differences in responsivity to stress and indicate that in contrast to white women, reproductive hormones do influence cardiovascular and catecholamine responsivity to stress in black women.

The antenatal diagnosis and management of abdominal wall defects: the northern region experience

One hundred and twenty abdominal wall defects were notified to the Northern Region Fetal Abnormality Survey in the five years 1988 to 1992. Gastroschisis occurred in 56, exomphalos in 43, amnion rupture in 11, ectopia vesicae in seven and ectopia cordis in three. Ultrasound failed to identify gastroschisis in 14 and incorrectly diagnosed exomphalos in eight. There was no associated chromosome abnormality and the survival rate, excluding first trimester loss, was 87%. Ultrasound failed to identify exomphalos in ten and incorrectly diagnosed gastroschisis in two. Another structural abnormality was present in 40% and a chromosome anomaly in 28%. Excluding spontaneous first trimester loss, the survival rate was 34%. Delivery of babies away from the regional paediatric surgical centre did not adversely affect the outcome in gastroschisis or exomphalos although closure was delayed, on average, by 2 h. There was one survivor of 11 fetuses with amnion rupture sequence. Six of the seven babies with ectopia vesicae and two of the three with ectopia cordis survived.

A technique for improved blood sampling during sleep studies

Research protocols often require that blood samples be drawn during sleep. This study compares the efficacy of obtaining nocturnal blood samples using a standard heparinized intravenous setup versus the same intravenous setup used in conjunction with a small chemical heating pad. The chemical heating pad significantly improved the number of blood samples obtained and the maintenance of intravenous patency. The use of a chemical heating pad is an economical way to resolve the frustration of lost blood samples while maintaining a reasonable environment to monitor sleep.

Effects of chronic stress on beta-adrenergic receptors in the homeless

This study examined the role of chronic life stress (homelessness), coping style, and hypertension on beta-adrenergic receptors in a sample of homeless men. Sixteen healthy normotensive subjects and nine untreated hypertensive subjects were studied. Life stress was measured with the Brown and Harris categorization; coping style was measured with the Ways of Coping Scale. Lymphocyte beta-adrenergic receptors were characterized in terms of receptor density (Bmax). Individuals with high life stress had lower Bmax (p < .005). In multiple regression analyses, 50% of the variance in Bmax was accounted for by life stress and coping style (p = .01). Receptor measures may be useful for characterizing the physiological response to continuing life adversity.

Case report: the antenatal ultrasound diagnosis of megalourethra

The antenatal ultrasound findings in a fetus which postnatally had fusiform megalourethra, rectal agenesis, recto-vesical fistula and unilateral renal hypoplasia are described. At 16 weeks gestation a cystic area was seen arising from the perineum. It later became evident that this was the urethra. Initially, an echogenic mass was noted in the pelvis, but by the second trimester, fluid-filled loops of bowel were evident. This combination of developmental abnormalities though rare is well defined. Only one previously recorded case has been suspected antenatally.

Antenatal detection of congenital diaphragmatic hernias: the northern region experience

This study analyses 7 years of data relating to congenital diaphragmatic herniation in the Northern Region. Ninety-nine confirmed cases were notified to the Northern Region Fetal Abnormality Survey between 1985 and 1991, which is an incidence of 0.35 per 1000 births. A specific diagnosis of CDH was made by antenatal ultrasound in 21 fetuses. The rate of detection improved from 6% to 41% but this had no impact on survival; severe pulmonary hypoplasia was found in the majority dying in the first 48 h. Another structural abnormality occurred in 29% and was the primary antenatal scan diagnosis in 11 fetuses. No other reliable indicator of outcome was identified, including the gestation when detected. The incidence of chromosomal abnormality was 5% and Fryns' syndrome 4%.

Does reactivity testing in the laboratory reflect blood pressure changes elsewhere?

This study examines whether reactivity testing in a laboratory setting might identify individuals whose blood pressure (BP) fluctuates excessively outside of the laboratory. Eighty-eight normotensive and untreated hypertensive patients were studied. Patients' BPs were obtained repeatedly on two separate screening occasions. They were subsequently admitted to a research ward, and 4 days later their BPs were measured at resting baseline and in response to a series of stressful tasks. Blood pressure declined by 14/11 mm Hg +/- 1.2/1.1 mm Hg (SE) from screening to the in-patient resting baseline. The four stressful tasks all led to increases in BP over the in-patient resting baseline level. Individuals with increased amounts of task-induced reactivity in the laboratory were also more likely to be those whose BP declined the most from out-patient screening to hospitalized baseline. The average correlation between the drop in BP associated with hospitalization and the BP reactivity to each stressor task was r = 0.33 for systolic BP (p < 0.01) and r = 0.24 for diastolic BP (p < 0.05). Reactivity responses in a laboratory setting may convey information about blood pressure fluctuation in the real world.

Noise-induced stress as a predictor of burnout in critical care nurses

In this study we found that, for 100 critical care nurses, noise-induced occupational stress was positively related to burnout as measured by Jones's Staff Burnout Scale for Health Professionals (r = 0.369, p less than 0.001) and the emotional exhaustion subscale of Maslach's Burnout Inventory (r = 0.300, p less than 0.01). Hierarchical multiple regressions confirmed these results once variance in burnout linked with life stressors and other occupational stressors was accounted for. Furthermore, an interaction term, noise-induced stress X intrinsic sensitivity to noise in the person, did not account for significant variance in burnout once independent variance linked with noise-induced stress was identified. That is, nurses with intrinsic sensitivity to noise were no more at risk for burnout linked with noise-induced stress than were less sensitive nurses. This result is discussed as evidence that there are exceptionally high levels of noise in critical care units. The critical care unit noises that are most distressing to nurses are identified and discussed in terms of stress theory.

The stress interview as a tool for examining physiological reactivity

Most studies of cardiovascular reactivity utilize tasks that are highly standardized and controlled. However, there is some concern whether the information obtained from these tasks is relevant to understanding the cardiovascular responses to behavioral stimuli encountered in real life. Historically, various forms of a stress interview have been used to examine physiological concomitants of emotional arousal. However, these tools fell into disuse because of ethical concerns, their intensive time requirements, and the perception that the interviews could not be standardized. We have developed a short (16-minute) interview that is not aversive or threatening. In studies on 24 normotensives and 19 hypertensives, the interview elicited greater blood pressure elevations than those elicited by mathematical calculations or cold pressor (p less than 0.0001). The interview increased systolic and diastolic pressures by 38/32 mm Hg in hypertensives and 31/24 mm Hg in normotensives. The variance in BP elicited by this interview is not appreciably greater than that found in highly structured tasks such as mathematical calculations. The test-retest stability of the interview is comparable to that of resting baseline blood pressure and is superior to that of mathematical calculations or cold pressor. Techniques such as the interview may be at least as useful as highly standardized tasks and possibly more valid as models for examining cardiovascular reactivity.

Ultrasonography, HIDA scintigraphy or both in the diagnosis of acute cholecystitis?

The benefit of early surgery for patients with acute cholecystitis is now accepted but rapid accurate pre-operative diagnosis is important and the single best investigation has not yet been clearly established. All 47 patients with suspected acute cholecystitis admitted to a district general hospital during a 6 month period underwent ultrasonic examination and scintigraphy with HIDA within 48 h of admission. In 23 patients acute cholecystitis was proven. Ultrasound correctly diagnosed this in 21 patients but in 2, changes attributed to chronic cholecystitis only were detected. Two false positive ultrasound results also occurred, one in a patient with adenomyomatosis and acute pancreatitis, the other in a case of duodenitis. HIDA scan was diagnostic in 19 patients but in the remaining 4 the presence of abnormal liver function tests accounted for non-visualization of the biliary tree (a non-diagnostic result). In the absence of jaundice a HIDA scan is the more specific test for confirming acute cholecystitis.

Low-frequency voltage noise in a mammalian bone cell clone

Measurements were made of plasma membrane voltage noise in cells of a bone cell clone. The measurements were made under conditions intended to approximate in vivo conditions more closely than in previous electrical measurements on small mammalian cells. Mononucleate cells of normal size, imbedded in a collagen matrix, were used. The electrical state of the cell membrane under normal conditions was characterized by low-frequency random fluctuations (noise) of high magnitude. Hyperpolarizing spikes were observed in some cells. Power spectrum analysis revealed that the random fluctuations were actually a sum of incoherent spike patterns, with spikes of the same time width as those seen in the clearly spiking patterns. This analysis, combined with similar measurements in a high [K+], low [Na+] medium, showed that the fluctuation/spiking phenomenon resulted from modulation of K+ and Na+ transport by a control process at a level higher than that of the individual channels. This process persisted when the membrane potential was depolarized. These results indicate that the membrane potential is not part of the feedback loop producing the fluctuation/spiking phenomenon.

High bile duct cancer: incidence and pattern of investigation in the General Hospital setting

Between 1 April 1977 and 30 November 1979, 16 cases of high bile duct carcinoma presented at North Tees District Hospital, giving an incidence of one per 40000 population per annum for Teesside. Results of this prospective study emphasize the potential accuracy of preoperative assessment using techniques which should be available in a district general hospital. Ultrasound revealed the site of obstruction in every patient in whom it was used (n = 13), and often indicated a neoplastic aetiology (n = 10). Percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiography (ERC) correctly demonstrated the site of obstruction in each patient and suggested a primary bile duct carcinoma in 12 patients. Although intraoperative cholangiography gave additional information in some patients, it was not sufficiently reliable to dispense with either PTC or ERC. Histological proof of a primary bile duct carcinoma was obtained in 15 patients. In the 10 patients without obvious metastatic disease frozen section analysis was positive in 7, but was negative in 3 patients with multiple strictures where malignant cells were relatively infrequent and were found in the perineural lymphatics on paraffin sections. In this difficult group of patients the approach described eliminates the possibility of a false negative laparotomy, enables careful planning of the necessary surgical technique and also the consideration of nonoperative management.

The diagnosis of primary bile duct carcinoma (cholangiocarcinoma) in the jaundiced patient

One hundred and ten patients with obstructive jaundice were investigated in the established manner; an initial abdominal ultrasonic B scan was followed by fine needles percutaneous transhepatic cholangiography (PTC) and/or endoscopic retrograde cholangiography (ERC). This yielded 15 cases of histologically proven primary bile duct carcinoma (cholangiocarcinoma), which is an incidence of 13.6%. Primary bile duct carcinoma is suggested on ultrasonic examination by: (i) Attenuation of the ultrasound beam in the bile duct area especially if the shadowing is multiple and/or from the intrahepatic ducts. (ii) Delineation of a mass associated with the bile ducts. (iii) A high level of duct obstruction with a normal pancreatic appearance. On direct cholangiography a stricture of the duct system which is branched, short, multiple or tapering also suggests primary bile duct malignancy. It is possible to diagnose primary bile duct carcinoma on ultrasonic examination alone once this condition is recognised as occurring with significant frequency. PTC and ERC aid delineation of the extent of the tumour and exclude biliary duct stone as the cause of jaundice.

The role of upper abdominal ultrasonography in suspected acute cholecystitis

Ultrasonic investigation of the upper abdomen was performed as an initial imaging procedure in 117 consecutive patients regarded on clinical examination as probably suffering from acute cholecystitis. All patients were studied within 72 h and the majority within 48 h of admission. All were followed up for a minimum of 12 months and the ultimate clinical diagnosis recorded and compared with the initial ultrasonic diagnosis. Despite the clinical suspicion at referral, only about half were ultimately found to have biliary tract or closely related pathology. In a further 10% totally unexpected and unrelated causes for the symptoms were detected. 87% of gallstones were detected on the initial ultrasonic examination, which compares well with previously reported series. In all cases where there was a right upper quadrant mass at presentation, the organ from which this arose was demonstrated. The results of this initial study indicate that upper abdominal ultrasonic examination is a valuable inital screening procedure in patients presenting with acute right upper abdominal symptoms.

The role of diagnostic radiology in the diagnosis and management of rhabdomyosarcoma in young persons

Rhabdomyosarcoma is a rare tumour of mesenchyme-like tissue in which differentiation of rhabdomyoblasts has occurred. It is found mainly in infants and children. The prognosis, until recent years very grave, has been improved by a combination of chemotherapy and radiotherapy occasionally with surgery. Survival depends on the extent of the disease at the time of diagnosis. Diagnostic radiology has an important role to play in the demonstration of this, illustrations of which are given from a series of seven cases. The primary tumour has no pathognomonic appearances and is demonstrated essentially as a soft tissue mass lesion which displaces adjacent soft tissue structures such as arteries, veins, bladder and colon, or erodes adjacent bones whether in the extremities or the skull. The main role of diagnostic radiology is the detection of metastases. Chest radiography and skeletal survey are mandatory. Lymphangiography may reveal filling defects in regional lymph nodes but these are indistinguishable from any other metastases. Arteriography as well as revealing displacement of larger vessels, may show typical tumour neovascularity in the lesion. Serial skeletal radiographs are of help in assessing response of metastases to therapy.