A high prevalence of chronic gastrointestinal symptoms in adults with cystic fibrosis is detected using tools already validated in other GI disorders

Background

People with cystic fibrosis (CF) report a variety of gastrointestinal (GI) symptoms, independent of pancreatic enzyme insufficiency (PEI), reminiscent of other chronic GI disorders. There are currently no accepted or validated assessment tools and neither the range, frequency nor severity of GI symptoms has been systematically described in CF. We present results of a cross-sectional study using established tools and compare them to current measures of quality of life (QOL).

Methods

Consecutive patients attending specialist CF appointments were asked to complete questionnaires including the GI Symptom Rating Scale (GSRS); Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) and Cystic Fibrosis Questionnaire (CFQ-R). Questionnaire terminology was altered to replace references to 'IBS' with 'GI symptoms'.

Results

In total, 107 patients were recruited (mean age, 27.8 ± 9.6 years; 60 female), and 94 (88%) had PEI. Body mass index was 22.1 ± 3.6 kg/m², forced expiratory volume in one second was 59 + 27.7% predicted. Fifty-three (49.5%) were p.Phe508del homozygous. Overall 69/107 (65%) reported significant GI symptoms independent of PEI or adherence to pancreatic enzyme replacement therapy (PERT), with the four most frequent being attributable to the lower GI tract: bloating/distension, flatulence, abdominal pain and borborygmi (gurgling). There was no numerical correlation between any CFQ-R domain (particularly Digestion domain) and GSRS or SSS.

Conclusion

This is the first systematic study measuring GI symptoms in CF using validated GI tools. Symptoms are not related to PERT or genotype and appear to be captured well by the GSRS. Further research will study longitudinal changes with treatment, and therapeutic trials in CF may use these tools to demonstrate a positive impact on 'non-respiratory' symptoms and QOL.

Simultaneous pelvic exenteration and liver resection for primary rectal cancer with synchronous liver metastases: results from the PelvEx Collaborative

AIM

At presentation, 15-20% of patients with rectal cancer already have synchronous liver metastases. The aim of this study was to determine the surgical and survival outcomes in patients with advanced rectal cancer who underwent combined pelvic exenteration and liver (oligometastatic) resection.

METHOD

Data from 20 international institutions that performed simultaneous pelvic exenteration and liver resection between 2007 and 2017 were accumulated. Primarily, we examined perioperative outcomes, morbidity and mortality. We also assessed the impact that margin status had on survival.

RESULTS

Of 128 patients, 72 (56.2%) were men with a median age of 60 years [interquartile range (IQR) 15 years]. The median size of the liver oligometastatic deposits was 2 cm (IQR 1.8 cm). The median duration of surgery was 406 min (IQR 240 min), with a median blood loss of 1090 ml (IQR 2010 ml). A negative resection margin (R0 resection) was achieved in 73.5% of pelvic exenterations and 66.4% of liver resections. The 30-day mortality rate was 1.6%, and 32% of patients had a major postoperative complication. The 5-year overall survival for patients in whom an R0 resection of both primary and metastatic disease was achieved was 54.6% compared with 20% for those with an R1/R2 resection (P = 0.006).

CONCLUSION

Simultaneous pelvic exenteration and liver resection is feasible, with acceptable morbidity and mortality. Simultaneous resection should only be performed where an R0 resection of both pelvic and hepatic disease is anticipated.

Allergy and infection: understanding their relationship

Sensitization to indoor allergens has long been recognized as a risk factor for asthma and its associated phenotypes. Immunoglobulin E antibody quantification may be used to confirm that a particular sensitization has a role in the development of respiratory symptoms. However, in order to use quantitative information effectively, it is essential to understand the factors that contribute to the deterioration of symptoms and cause exacerbations. One such risk factor is high allergen exposure. Worsening asthma control is also associated with virus infections, in particular rhinovirus infection. Each of these factors in isolation is unlikely to have a major effect on symptoms. However, the combination of respiratory virus infection, allergen sensitization and concurrent high exposure to allergens markedly increases the risk for hospitalization. Further investigation of this synergism could help to understand the mechanisms of asthma exacerbations and lead to the development of strategies for prevention.

Mental health and debt: challenges for knowledge, practice and identity

People with mental health problems (MHPs) in Britain are nearly three times more likely to report debt compared with individuals without similar conditions. With one-in-four respondents with MHPs reporting personal debt, this may be equivalent to eight or nine clients in the recommended national community mental health nurses' (CMHNs) caseload of 35. Although client debt is not a new problem for CMHNs, it can pose significant difficulties for client well-being and nursing practice. This paper reviews the published literature on debt and mental health, then considers three of the challenges that client debt can present to: (1) nursing knowledge--moving away from understandings of client debt based on crisis, and towards those focused on process and prevention; (2) nursing practice--reworking the collaborative relationship between CMHNs and external debt advice agencies; and (3) nursing identity--managing the role conflicts that engaging with client debt can bring. The paper concludes by contending that nurses should raise and monitor debt issues among clients, but cannot be expected to become proxy 'debt advisors', with CMHNs being encouraged to increasingly collaborate with debt advisors (rather than simply referring on clients).

Validation of direct intraabdominal pressure measurement using a continuous indwelling compartment pressure monitor

BACKGROUND

According to recommendations, intraabdominal pressure should be monitored every 8 hours for patients at high risk of abdominal compartment syndrome. Continuous intraabdominal pressure monitoring may be valuable for these patients.

METHODS

For 15 patients undergoing laparoscopic surgery, a pressure monitor was introduced after formation of pneumoperitoneum. During the procedure, the laparoscopic insufflator pressure was varied. The pressure monitor values and the time to equilibrium were recorded.

RESULTS

Altogether, 152 pressure recordings were taken for the patients studied. The measurements from the insufflator and pressure monitor were compared using a Bland-Altman plot. The mean difference between the techniques was 0.04 +/- 3.8, and 95% of the points from the pressure monitor were within two standard deviations of the mean difference. Pressure changes were essentially "real time."

CONCLUSIONS

The intracompartmental pressure monitor provides accurate, rapid, and direct measurement of intraabdominal pressure, and may be a useful tool for continuous intraabdominal pressure measurement among patients at risk of abdominal compartment syndrome.

High-performance liquid chromatographic assay of plasma thalidomide: stabilization of specimens and determination of a tentative therapeutic range for chronic graft-versus-host disease

Thalidomide is now widely used to treat chronic graft-versus-host disease, but its use is associated with non-teratogenic side effects such as peripheral neuropathy. To examine the value of monitoring plasma concentrations of the drug in such patients, we have developed a high-performance liquid chromatographic (HPLC) assay. The method uses 0.5 mL plasma, is linear to 10 mg/L and had a detection limit of 0.2 mg/L. Thalidomide in plasma specimens was unstable at physiological pH but could be stabilized for several weeks by simple acidification. We describe a protocol for monitoring patients treated with thalidomide which permits convenient transportation and storage of specimens and report, provisionally, that plasma concentrations in the range 1-7 mg/L are therapeutically effective in chronic graft-versus-host disease without adverse side effects.

Sudden death and intussusception in infancy and childhood--autopsy considerations

Search of the autopsy files of the Department of Histopathology at the Women's and Children's Hospital (WCH), Adelaide, Australia for cases of intussusception from January 1961 to December 1995 revealed two deaths due to intussusception out of a total of 4,384 autopsies (0.05%). Both cases occurred in infants (aged five months and six months respectively) who had only non-specific and apparently minor manifestations of illness, until precipitate deterioration occurred. The intussusceptions were ileo-ileal and ileocaecal in location, respectively. A total of 204 cases of intussusception were found in a search of 28,123 surgical pathology cases (0.73%) at the WCH over the 20-year period from 1976 to 1995. Mesenteric lymphadenopathy was found in 16 cases (including one with possible Yersinia infection), Meckels diverticulum in 14, isolated gastric/pancreatic heterotopia in two, cystic fibrosis in two and Henoch-Schonlein purpura in one. Although it has been shown that unexpected death is more likely to occur in older children with purely small intestinal intussusception, the current cases demonstrate that unexpected death may occur at any age, with intussusception at any level. The autopsy assessment of deaths due to intussusception requires careful evaluation of cases for evidence of local or systemic disease, particularly given the hereditary nature of certain predisposing conditions. Careful review of the presenting history is also required to assess the quality of care received by the child in the time preceding death.

Hepatic drug metabolism is increased in poorly controlled insulin-dependent diabetes mellitus

In addition to increased glycosylation of hemoglobin, abnormalities of other heme proteins such as cytochrome P-450 might also occur in patients with insulin-dependent diabetes mellitus. Antipyrine is a useful marker drug for cytochrome P-450 dependent hepatic drug metabolism. Antipyrine kinetics and urinary excretion of antipyrine metabolites were measured in 14 patients with insulin-dependent diabetes mellitus in poor metabolic control. Improvement in diabetic control in 9 patients, as measured by more normal HbA1 values, led to normalization of plasma antipyrine half-time (t1/2) and metabolism: the mean antipyrine t1/2 slowed from 4.7 +/- 0.2 (SEM) initially to 7.8 +/- 0.3 h in these 9 patients and was thus nearly identical to that of normal subjects 8.6 +/- 1.0. Antipyrine plasma clearance improved in the 9 diabetic patients whose diabetic control improved. The apparent volume of distribution was normal on both occasions in the diabetic patients. These findings provide a new argument for tight metabolic control in patients with insulin-dependent diabetes mellitus.

Major incident planning in South East Thames Region: a survey of medical staff awareness and training

In order to assess awareness and training of medical staff in major incident planning and disaster medicine, a telephone survey was conducted throughout South East Thames Region. Duty consultants and trainees in anaesthesia, general surgery and orthopaedic surgery from a total of 17 hospitals in the region were included. Accident and emergency (A&E) consultants were also interviewed in order to assess administrative aspects of major incident planning. It was found that major incident plans were updated regularly in all the hospitals that were surveyed. Training exercises had been held in 88% of hospitals and the majority had tested communications only. All consultants and 77% of trainees knew that their hospital had a major incident plan. However, only 39% of trainees had been given any major incident plan related literature and less than a third of all staff had attended a major incident plan orientation session. Over half of all staff expressed confidence in their personal training in disaster medicine, but few had received relevant tuition. Of all non-A&E personnel, 5% had attended an Advanced Trauma Life Support (ATLS) provider course. We conclude that major incident plans are in place and are updated in all the hospitals surveyed. However, all staff lack training in clinical and administrative aspects of major incident planning and disaster medicine. Recommendations to improve this situation are made.

Modelling trajectories of parentally reported and physician-confirmed atopic dermatitis in a birth cohort study

BACKGROUND

In a population-based birth cohort, we aimed to identify longitudinal trajectories of atopic dermatitis (AD) during childhood using data from different sources (validated questionnaires and healthcare records). We investigated the impact of different AD definitions on such trajectories and their relationships with various risk factors.

METHODS

Of the 1184 children born into the study, 1083 had information on current AD for at least three follow-ups from birth to age 11 years and were included in the analysis for parentally reported AD (PRAD). Data were transcribed from healthcare records for 916 of 1184 children for the analysis of doctor-diagnosed AD (DDAD). We also derived a composite definition of AD (CDAD) (at least two of the following: PRAD, DDAD, current use of AD treatment). Using latent class analysis (LCA), we determined longitudinal profiles of AD using the three definitions. Filaggrin (FLG) genotype data were available for 803 white participants.

RESULTS

For PRAD, LCA identified four AD classes ('no AD', 'persistent', 'early-onset remitting' and 'late-onset'). For DDAD and CDAD, the optimal number of phenotypes was three ('no AD', 'persistent' and 'early-onset remitting'). Although AD classes at population level appeared similar in different models, a considerable proportion of children (n = 485, 45%) moved between classes. The association with FLG genotype, atopic diseases and early-life risk factors was inconsistent across different definitions, but the association with oral food challenge-confirmed peanut allergy was similar, with a nine- to 11-fold increase among children in the persistent AD class. In a CDAD model, compared with the early-onset remitting class, those with persistent AD were significantly more likely to have (at age 3 years) moderate/severe AD, polysensitization and current wheeze, and were less likely to have been breastfed.

CONCLUSIONS

Standardized composite definitions of AD may help to define AD cases with more precision and identify more consistent long-term trajectories.

Tooth surface pH during drinking of black tea

OBJECTIVES

To investigate the composition of black tea in terms of its erosive potential. To determine the pH profile at the palatal surface of anterior and posterior sites of the dentition after drinking black tea.

METHODS

Tea solution was analysed for its pH and anion composition to provide information on its acid content. A group of ten healthy subjects, aged 21-23 years were monitored for tooth surface pH on the palatal aspects of the maxillary anterior dentition and the maxillary molar dentition after drinking tea using a micro-pH electrode mounted on a vinyl splint.

RESULTS

The pH of the tea solution was 4.9 and the major anions detected were oxalate and citrate. Tooth surface pH monitoring indicated that only small decreases in pH of less than 1 pH unit were observed after drinking tea and the minimum mean pH reached was 5.45. Maximum decrease in pH was observed after 20-25 seconds and resting pH levels were restored within approximately 2 minutes after drinking.

CONCLUSION

The pH and anion profile of black tea are indicative of low acid composition. The very small pH decreases observed at the tooth surface after drinking tea indicate that it may be safely recommended as a substitute for more acidic drinks as a part of preventive measures for dental erosion.

The avian eye lens protein delta-crystallin shows a novel packing arrangement of tetramers in a supramolecular helix

BACKGROUND

Little is known of the intermolecular organization of crystallins in the protein-packed eye lens. The tetrameric structure of the 200,000 Da avian delta-crystallin, which is closely related to the enzyme argininosuccinate lyase and is characteristic of the accommodating, soft lens of birds, has recently been solved at atomic resolution at acidic pH. To help understand how delta-crystallin remains soluble at the very high concentrations found in the avian lens we have now crystallized turkey delta-crystallin at around neutral pH and examined its intermolecular interactions.

RESULTS

Turkey delta-crystallin has been crystallized around neutral pH. The X-ray structure has been solved at 4.5 A resolution in space group C2 with three and a half tetramers in the asymmetric unit. The symmetrical 222 tetramers have a novel packing arrangement consisting of continuous helices, with 7(3)2 non-crystallographic symmetry, in an approximately hexagonal close-packed array. The internal 222 symmetry of the tetramers allows different polymeric chains to be constructed, based on the tetramer-tetramer association observed in the crystalline helix. It is possible to build a model of a tubule of diameter 212 A that is very similar to observed tubules of bovine argininosuccinate lyase.

CONCLUSIONS

Elements of helical organization may occur in the concentrated solution of the avian eye lens where delta-crystallin is the prominent protein. The symmetry of the tetramer provides a choice in the direction of growth of a helix at each link so that highly hydrated irregular polymers may be formed rather than large compact regular structures that would not be compatible with a transparent lens.

Accidental infant death and stroller-prams

A three-month-old boy and an eight-month-old boy died from accidental positional asphyxia and hanging, respectively, after being placed to sleep unsupervised in stroller-prams. Both infants had moved down towards the fronts of the stroller-prams. The younger infant fell out when the footplate collapsed and he was found hanging from a metal bar on the side. The older infant had partly slipped through the front and was suspended with his head and arms within the stroller-pram and with his face pushed firmly into the mattress by a horizontal metal bar. Stroller-prams are a potentially dangerous sleeping environment unless infants are closely supervised, gaps in the front of stroller-prams closed and upright footplates stabilised.

Perioperative management and anaesthetic considerations in pelvic exenterations using Delphi methodology: results from the PelvEx Collaborative

BACKGROUND

The multidisciplinary perioperative and anaesthetic management of patients undergoing pelvic exenteration is essential for good surgical outcomes. No clear guidelines have been established, and there is wide variation in clinical practice internationally. This consensus statement consolidates clinical experience and best practice collectively, and systematically addresses key domains in the perioperative and anaesthetic management.

METHODS

The modified Delphi methodology was used to achieve consensus from the PelvEx Collaborative. The process included one round of online questionnaire involving controlled feedback and structured participant response, two rounds of editing, and one round of web-based voting. It was held from December 2019 to February 2020. Consensus was defined as more than 80 per cent agreement, whereas less than 80 per cent agreement indicated low consensus.

RESULTS

The final consensus document contained 47 voted statements, across six key domains of perioperative and anaesthetic management in pelvic exenteration, comprising preoperative assessment and preparation, anaesthetic considerations, perioperative management, anticipating possible massive haemorrhage, stress response and postoperative critical care, and pain management. Consensus recommendations were developed, based on consensus agreement achieved on 34 statements.

CONCLUSION

The perioperative and anaesthetic management of patients undergoing pelvic exenteration is best accomplished by a dedicated multidisciplinary team with relevant domain expertise in the setting of a specialized tertiary unit. This consensus statement has addressed key domains within the framework of current perioperative and anaesthetic management among patients undergoing pelvic exenteration, with an international perspective, to guide clinical practice, and has outlined areas for future clinical research.

Exploring the value of mental health nurses working in primary care in England: A qualitative study

WHAT IS KNOWN ON THE SUBJECT?: Primary care and, in particular, general practice (GP) are often first point of access to health care. International evidence suggests that healthcare systems oriented towards primary care may produce better outcomes, at lower costs and with higher user satisfaction. Despite this, there are noted deficiencies and variations in the quality of care in primary care for patients with mental health problems. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: Emerging models of providing mental health services in primary care are poorly understood. This paper evaluates a mental health nurse-led Primary Care Liaison Service (PCLS), developed in 2011 in inner London. The findings suggest that this type of service can improve the quality of care for people presenting with mental health problems within primary care, specifically due to improved integration, clinical effectiveness, patient-centred care, access and efficiency. The study also highlighted challenges such as staff retention within this new role and setting appropriate referral criteria. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This is a relatively new service, and the cost-effectiveness is not yet fully understood; however, commissioners may want to consider the potential benefits of a similar service in their area. The extent to which the findings are transferable will depend on service configuration and local demographics which can vary. Further research within this area could give more detail on the impact of such teams on health outcomes, recovery rates, secondary care referrals and accident and emergency attendances, and its cost-effectiveness.

ABSTRACT

Aims/Question General practice is typically the first point of access to healthcare. This study explores what value a Primary Care Liaison Nurse (PCLN) service, established in 2011, can bring to people with mental health problems in primary care. Method Semi-structured interviews were used to elicit participants' experiences and perspectives on the value of a PCLN service. Participants included ten interviews with seven general practitioners and three senior practitioners working in primary care mental health services. Thematic analysis, based on a 6-phase approach, was used to describe and explore the data collected. Results Five main themes were derived from the thematic analysis of the interviews relating to: integration; clinical effectiveness; patient centred care; access; and efficiency. Discussion The study suggests that the PCLN service can improve the quality of care and is generally highly valued by its stakeholders. The study identifies particularly valued elements of the service, including having a duty worker, as well as aspects which could be improved, such as patient criteria. Implications for practice This is a relatively new service and the cost-effectiveness is not yet fully understood; however, commissioners may want to consider the potential benefits of a similar service in their area.

Healthcare utilization and costs in chronic cough

BACKGROUND

Chronic cough is a common reason for medical consultations and is associated with considerable physical and psychological morbidity. This study investigated healthcare use and cost in chronic cough and assessed its relationship with cough severity, health status, objective cough frequency (CF), and anxiety and depression.

METHODS

This was a prospective study of consecutive patients with chronic cough from a specialist clinic who completed a cough severity visual analogue scale (VAS), cough-specific health status (Leicester Cough Questionnaire; LCQ) and general health status EuroQol EQ-5D-5L, Generalized Anxiety Disorder (GAD7), Patient Health Questionnaire (PHQ9), and 24-hour objective CF monitoring with Leicester Cough Monitor (LCM). Case notes were reviewed for cough-specific healthcare use 12 months before and after the first cough clinic consultation. Resource use included general practitioner and hospital clinic visits, investigations, and treatments. Unit costs for healthcare use were derived predominantly from National Health Service Reference Costs.

RESULTS

One hundred participants with chronic cough were recruited (69% female, median duration 3 years, mean age 58 years). The diagnoses of cough were unexplained (57%), refractory (27%), and other (16%). Cough severity, health status, and CF were: median (IQR) VAS = 59.5 (30-79) mm, mean (SD) LCQ = 11.9 (4.0), mean (SD) EQ-5D-5L = 0.846 (0.178), and geometric mean (SD) CF = 15.3 (2.5) coughs/hr, respectively. The mean (SD) total cost per individual for cough-related healthcare utilization was £1,663 (747). Diagnostic investigations were the largest contributor to cost (63%), followed by cough clinic consultations (25%). In multivariate analysis, anxiety (GAD7) and cough-related health status (LCQ) were associated with increased cost (p ≤.001 and .037).

CONCLUSION

Healthcare cost associated with chronic cough are largely due to diagnostic investigations and clinic consultations. The predictors of costs were health status (LCQ) and anxiety. Further studies should investigate the optimal management protocols for patients with chronic cough.

The Fischer rat thyroid cell line FRTL-5 exhibits a nondiploid karyotype

The FRTL-5 cell line is a stable thyroid cell line derived from the thyroid gland of the Fischer rat under defined culture conditions, which has been widely adopted as a model system for the study of thyroid cell function and for bioassay. While characterizing by flow cytometry FRTL-5 cells that were supplied to this laboratory by ATCC (American Type Cell Collection), we discovered that the cells (ATCC CRL8305) were not diploid, having approximately twofold the DNA content relative to a diploid control. The increase in DNA content also applied to cells originally supplied by the ATCC (described as passage 14) that when counted in metaphase had a modal chromosomal count of 84, indicating tetraploid status, double the expected 42 of a diploid rat cell. In a private communication, the ATCC confirmed these findings which nevertheless are contrary to previous literature reports where they were reported to be diploid. Tetraploid cells are less sensitive to thyrotropin (TSH) as measured by cyclic adenosine monophosphate (cAMP) production, compared with diploid cells (p = < 0.001). Despite similar 3H-thymidine uptake in 0.2% fetal calf serum, tetraploid cells show increased 3H-thymidine uptake in 5% fetal calf serum in the absence of TSH (p = 0.001). The origin of these chromosomal changes is unclear, but these findings must raise doubts regarding the suitability of the tetraploid FRTL-5 cell line as a model for studies of human or animal thyroid physiology.

Relationship between cytokine expression patterns and clinical outcomes: two population-based birth cohorts

BACKGROUND

Models that incorporate patterns of multiple cytokine responses to allergens, rather than individual cytokine production, may better predict sensitization and asthma.

OBJECTIVE

To characterize the patterns of peripheral blood mononuclear cells' (PBMCs) cytokine responses to house dust mite (HDM) allergens among children from two population-based birth cohorts using machine learning techniques.

METHODS

PBMCs collected at 8 years of age from the UK Manchester Asthma and Allergy Study (n = 268) and at 14 years of age from the Australian Raine Study (n = 1374) were cultured with HDM extract (10 μg/ml). Cytokine expression (IL-13, IL-5, IFN-γ, and IL10) was measured in the supernatant. Cytokine patterns were identified using a Gaussian mixture model clustering, and classification stability was assessed by bootstrapping.

RESULTS

A six-class model indicated complex latent structure of cytokine expression. Based on the characteristics of each class, we designated them as follows: 'Nonresponders' (n = 905, 55%); 'IL-10 responders' (n = 49, 3%); 'IFN-γ and IL-13 medium responders' (n = 56, 3.4%); 'IL-13 medium responders' (n = 351, 21.4%); 'IL-5 and IL-13 medium responders' (n = 77, 4.7%); and 'IL-13 and IL-5 high responders' (n = 204, 12.4%). 'IL-13 and IL-5 high responders' were at much higher risk of HDM sensitization and asthma compared to all other classes, with 88% of children assigned to this class being sensitized and 28.5% having asthma.

CONCLUSION

Using model-based clustering, we identified several distinct patterns of cytokine response to HDM and observed interplay between cytokine expression level, cytokine patterns (especially IL-13 and IL-5), and clinical outcomes. 'IL-13 and IL-5 high responders' class was strongly associated with HDM sensitization. However, among HDM-sensitized children, one-third showed no PBMC response to HDM, and the majority of HDM-sensitized children did not have asthma or wheeze. Our findings suggest that positive HDM 'allergy tests' and asthma are associated with a broad range of immunophenotypes, which may have important implications for the use of cytokine-targeted treatment approaches.

Central control of gastric acid secretion by extralateralhypothalamic nuclei

Whether secretion of gastric acid (GAS) is in response to peripheral and/or central administration of chemical or electrical stimuli can be differentiated by vagotomy. GAS has been shown to be controlled by specific lateral hypothalamic (LHA) neurons. Application of 2-deoxy-D-glucose (2-DG) or insulin to the LHA by microinjection or iontophoresis has experimentally induced GAS. The paraventricular nucleus (PVN) has now been found to also affect GAS. GAS was produced more copiously and more quickly by rostral PVN lesion than by lesion of the ventromedial (VMH) or dorsomedial (DMH) nucleus, and nearly as much by caudal PVN lesion. Microinjection of 2-DG into the LHA induced GAS more potently in animals with rostral PVN lesions than in those with caudal PVN, VMH or DMH lesions, or in intact animals. Results indicate that the PVN may be an additional central site from which GAS is affected.

Chronic intermittent toluene inhalation in adolescent rats results in metabolic dysfunction with altered glucose homeostasis

BACKGROUND AND PURPOSE

Abuse of toluene-containing inhalants is an increasing public health problem, especially among adolescents. Abuse during adolescence is associated with emaciation, while industrial exposure leads to altered glycaemic control suggesting metabolic instability. However, the relationship between adolescent inhalant abuse and metabolic dysfunction remains unknown.

EXPERIMENTAL APPROACH

To model human abuse patterns, we exposed male adolescent Wistar rats [postnatal day (PND) 27] to chronic intermittent inhaled toluene (CIT, 10,000 ppm) or air (control) for 1 h·day(-1) , three times a week for 4 weeks. Feeding and body composition were monitored. After 4 weeks, circulating metabolic hormone concentrations and responses to a glucose tolerance test (GTT) were measured. Dietary preference was measured by giving animals access to either a 'western diet' plus standard chow (WC + SC) or standard chow alone during 4 weeks of abstinence. Metabolic hormones and GTT were subsequently measured.

KEY RESULTS

Adolescent CIT exposure significantly retarded weight gain, altered body composition, circulating metabolic hormones and responses to a GTT. While reduced body weight persisted, responses to a GTT and circulating hormones appeared to normalize for animals on standard chow following abstinence. In CIT-exposed WC + SC rats, we observed impaired glucose tolerance associated with altered metabolic hormones. Analysis of hypothalamic genes revealed differential expression profiles in CIT-exposed rats following both the exposure period and abstinence, suggesting a central contribution to inhalant-induced metabolic dysfunction.

CONCLUSION AND IMPLICATIONS

CIT exposure during adolescence has long-term effects on metabolic function, which may increase the risk of disorders related to energy balance and glycaemic control.

Intactness of inhibitory attentional mechanisms following severe closed-head injury

Attentional problems are a common sequelae of closed-head injury (CHI). Research in the area of selective attention has pointed to the role of inhibitory mechanisms in the suppression of irrelevant information. In the current study, a negative priming paradigm was used to assess the inhibitory mechanisms of individuals suffering from a severe CHI. Twenty participants with severe CHIs (greater than 1 year postinjury) and 20 matched controls completed a negative priming task, as well as several other standardized tests of cognitive functioning. Within the negative priming task, 2 conditions were used to elicit information regarding facilitation by attended and ignored information and 1 condition was used to elicit inhibition of ignored information, as compared with a neutral control condition. Despite poorer performances on several tests of attention, there were no significant differences in the amount of inhibition displayed by the CHI participants as compared with the controls. Findings suggest that inhibitory processing deficits may not underlie the selective attention difficulties commonly seen following a severe CHI.

Polymorphisms of endotoxin pathway and endotoxin exposure: in vitro IgE synthesis and replication in a birth cohort

BACKGROUND

Genetic variants in endotoxin signaling pathway are important in modulating the effect of environmental endotoxin on asthma and atopic phenotypes. Our objective was to determine the single nucleotide polymorphisms (SNPs) in the endotoxin signaling pathway that may influence in vitro IgE synthesis and to investigate the relationship between these variants and endotoxin exposure in relation to the development of asthma and atopy in a birth cohort.

METHODS

Peripheral blood mononuclear cells from 45 children with asthma were stimulated with 2 and 200 ng/ml lipopolysaccharide in vitro and IgE was measured in the culture supernatants. Children were genotyped for 121 SNPs from 30 genes in the endotoxin signaling pathway. Variants with a dose-response IgE production in relation to lipopolysaccharide (LPS) were selected for replication in a population-based birth cohort, in which we investigated the interaction between these SNPs and endotoxin exposure in relation to airway hyper-responsiveness, wheeze, and atopic sensitization.

RESULTS

Twenty-one SNPs in nine genes (CD14, TLR4, IRF3, TRAF-6, TIRAP, TRIF, IKK-1, ST-2, SOCS1) were found to modulate the effect of endotoxin on in vitro IgE synthesis, with six displaying high linkage disequilibrium. Of the remaining 15 SNPs, for seven we found significant relationships between genotype and endotoxin exposure in the genetic association study in relation to symptomatic airway hyper-responsiveness (CD14-rs2915863 and rs2569191, TRIF-rs4807000), current wheeze (ST-2-rs17639215, IKK-1-rs2230804, and TRIF-rs4807000), and atopy (CD14-rs2915863 and rs2569192, TRAF-6-rs5030411, and IKK-1-rs2230804).

CONCLUSIONS

Variants in the endotoxin signaling pathway are important determinants of asthma and atopy. The genotype effect is a function of the environmental endotoxin exposure.

The effect of cue-enhancement on consonant intelligibility in noise: speaker and listener effects

Our previous work (Hazan & Simpson, 1998) has shown that increasing the salience of perceptually important regions of nonsense word and sentence materials aids speech perception in noise. This study aimed to extend these findings by investigating the robustness of these enhancement techniques in improving consonant intelligibility for a range of different speakers and for groups of listeners with different language backgrounds. In Experiment 1, nonsense vowel-consonant-vowel (VCV) tokens produced by two female and two male speakers without phonetic training were annotated to highlight segments of the signal corresponding to the consonant constriction/occlusion and vowel onset/offset regions. These regions were selectively amplified to enhance the cues they contained, then combined with speech-shaped noise at 0 dB SNR and presented to normally hearing listeners. Significant improvements in intelligibility were found for all speakers although the extent of the improvement varied across speakers. In Experiment 2, a subset of these stimuli were presented to two groups of learners of English--a Japanese-L1 group and a Spanish-L1 group--and a new group of native-English controls. Results showed a significant effect of enhancement in all listener-groups and similar speaker effects for the non-native and native English listeners. Error patterns were related to the distance between the phonological systems of listeners' L1 and L2.