A cross-sectional study of gender differences in quality of life domains in patients with neurofibromatosis type 1

BACKGROUND

There is limited data regarding gender differences in quality of life between women and men with Neurofibromatosis type 1. We aimed to study differences in quality of life domains between women and men with Neurofibromatosis type 1 living in Canada.

METHODS

This is a cross sectional study of adults with Neurofibromatosis type 1 attending a tertiary NF centre at Toronto General Hospital between January 2016 to December 2017. Demographic and clinical data were collected. We compared scores of generic measures (SF-36, EQ-5D-5L, pain interference) and a disease-specific measure (PedsQL-NF1 module) between women and men. We also assessed the relationship between disease visibility scored by an examiner (Ablon's visibility index) and self-reported perceived physical appearance, stratified by gender.

RESULTS

One hundred and sixty-two participants were enrolled, 92 females and 70 males. Ablon's index score 1 was in 43% and score 2 in 44%, while only 13% of patients had a score 3. Women had worse scores on the total PedsQL-NF1 scales, and also in the perceived physical appearance, anxiety and emotional health domains. In women, there was a low but significant correlation between Ablon's index and perceived physical appearance (r = - 0.27, p = 0.01, ANOVA p < 0.001). In men, there was no difference in self-reported physical appearance by Ablon's index. There were no differences between men and women in the SF-36 or EQ-5D-5L scores.

CONCLUSION

Women with NF1 reported worse NF1-related quality of life than men, with worse perceived physical appearance, anxiety, and mental health. Perceived physical appearance does not always correlate to disease visibility; therefore, healthcare providers should inquire about body image, physical appearance concerns, and mental health, especially among women with NF1.

Chronic immunoglobulin maintenance therapy in myasthenia gravis

BACKGROUND AND PURPOSE

Long-term treatment of myasthenia gravis (MG) includes symptomatic and course-modifying therapies that target the immune system. Recently, both intravenous immunoglobulin (IVIG) and subcutaneous immunoglobulin (SCIG) have emerged as viable options for chronic therapy, considering the favourable safety-efficacy profile and possible immunosuppressant sparing properties. The aim was to investigate the outcomes of the long-term care of generalized MG with immunoglobulin (Ig).

METHODS

This is a retrospective, repeated-measures design study. Charts of generalized MG patients, treated with IVIG/SCIG for at least 6 months, from January 2015 to January 2020, were analysed. The primary outcome was the mean change in Myasthenia Gravis Impairment Index (MGII) after treatment with Ig, comparing baseline to IVIG and SCIG treatment periods. Secondary outcomes included the changes in pyridostigmine, immunosuppressive medications and patient-reported outcome 'percentage of normal' (0%-100%).

RESULTS

Thirty-four patients were treated with chronic Ig therapy (30 IVIG/SCIG, three SCIG, one IVIG). The mean durations of IVIG and SCIG periods were 21.8 ± 19.4 (range 3-64) months and 19.5 ± 11.3 (range 5-45) months respectively. There was a significant reduction in MGII scores (27.7 ± 15.7 baseline; 22.0 ± 17.4 IVIG period; 19.5 ± 18.1 SCIG period; F = 17.9; d.f. = 1.7; P < 0.01), pyridostigmine and immunosuppressant use (P = 0.00). The outcome 'percentage of normal' had a significant positive association with both treatments (P = 0.00).

CONCLUSION

Our study results suggest that patients can be successfully transitioned to IVIG and from IVIG to SCIG in the chronic treatment of generalized MG with reductions in impairments and use of other medications and improvement in overall status with Ig therapy. Prospective, randomized studies are needed to clarify costs and comparative effectiveness.

Comparison of the single simple question and the patient acceptable symptom state in myasthenia gravis

BACKGROUND AND PURPOSE

The single simple question (SSQ) is a simple and validated question asking what percentage of normal a patient feels with respect to their myasthenia gravis (MG), with 100% being normal. Patient acceptable symptom states (PASS) are based on a dichotomous 'Yes' or 'No' response, asking whether a patient is satisfied overall with their current status and thus measures holistic satisfaction with their MG state. Both are patient-reported self-assessments but assess different dimensions of MG. The objective was to determine thresholds for the SSQ when patients with MG achieve an acceptable PASS status.

METHODS

A retrospective chart review was performed of consecutive MG patients attending a neuromuscular clinic, and SSQ and PASS responses, demographic, clinical and serological characteristics and disease severity by the MG impairment index were extracted.

RESULTS

One hundred and fifty-seven consecutive patients were identified: 43 (27.4%) patients responded 'No' to the PASS question. Between the PASS 'Yes'/'No' groups, only SSQ (87.5 ± 13.4 vs. 52.3 ± 23.3; P < 0.001) and MG impairment index scores (9.2 ± 10.3 vs. 29.6 ± 16; P < 0.001) were significantly different. The receiver operating characteristic curve for PASS and SSQ had an area under the curve of 0.92 ± 0.024 (confidence interval 0.872-0.965, P < 0.001). An SSQ score ≥72.5% had 84.2% sensitivity and 86% specificity to classify patients as PASS positive.

CONCLUSION

The PASS and SSQ patient-reported outcomes are closely associated and a SSQ threshold ≥72.5% predicts an acceptable MG state. Other demographic and disease-related factors did not influence the PASS response in this study.

OP0164 BLISS-LN: A RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED PHASE 3 TRIAL OF INTRAVENOUS BELIMUMAB IN PATIENTS WITH ACTIVE LUPUS NEPHRITIS

Background:

Lupus nephritis (LN), a serious manifestation of systemic lupus erythematosus (SLE), affects nearly 70% of patients (pts) in high-risk groups. To preserve renal function, LN requires fast and effective treatment. Despite medical advances, progression rates at 15 years to end-stage renal disease (ESRD) remain >40% for pts with diffuse proliferative LN. Belimumab (BEL), approved in pts aged ≥5 years with active SLE, improved renal parameters in pts with baseline renal involvement in apost hocanalysis of Phase 3 trials data.

Objectives:

To assess efficacy and safety of intravenous (IV) BEL vs placebo (PBO), plus standard therapy (ST), in pts with active LN.

Methods:

BLISS-LN is a Phase 3, randomised, double-blind, PBO-controlled, 104-week study (GSK Study BEL114054,NCT01639339). Adults with SLE and biopsy-proven LN (class III, IV, and/or V) were randomised (1:1) to monthly BEL 10 mg/kg IV or PBO, plus ST. Primary endpoint: Primary Efficacy Renal Response (PERR); defined as urine protein creatinine ratio [uPCR] ≤0.7; estimated glomerular filtration rate [eGFR] within 20% of the pre-flare value or ≥60 ml/min/1.73m2; no rescue therapy) at Week (Wk) 104. Key secondary endpoints: Complete Renal Response (CRR; defined as uPCR <0.5; eGFR within 10% of the pre-flare value or ≥90 ml/min/1.73m2; no rescue therapy) at Wk 104; PERR at Wk 52; time to renal-related event (defined as ESRD/doubling of serum creatinine/renal worsening/renal disease-related treatment failure) or death. Other endpoints: time to PERR/CRR sustained through Wk 104; SLEDAI-S2K score <4 points at Wk 104; safety.

Results:

Overall, 448 pts were randomised (efficacy: 223/group; safety: 224/group). Significantly more BEL (43%) than PBO (32.3%) pts achieved PERR at Wk 104 (OR 1.55, 95% CI 1.04, 2.32; p=0.0311). More BEL than PBO pts achieved key secondary and other efficacy endpoints (Table).

Overall, 214 (95.5%) BEL and 211 (94.2%) PBO pts had ≥1 adverse event (AE); 58 (25.9%) BEL and 67 (29.9%) PBO pts had ≥1 serious AE; 29 (12.9%) pts in each group had ≥1 AE resulting in study treatment discontinuation; 4 (1.8%) BEL and 3 (1.3%) PBO pts developed on-treatment fatal AEs.

Conclusion:

In the largest LN study to date, data from BLISS-LN demonstrate that BEL plus ST significantly improves LN renal responses compared with ST alone with a favourable safety profile.

Study funding: GSK.

Table.Endpoint, n (%)PBO(n=223)BEL(n=223)OR/HR (95% CI) vs PBOp-valueCRR at Wk 104*44 (19.7)67 (30.0)OR 1.74(1.11, 2.74)0.0167PERR at Wk 52*79 (35.4)104 (46.6)OR 1.59(1.06, 2.38)0.0245Time to PERR throughWk 104†72 (32.3)96 (43.0)HR 1.46(1.07, 1.98)0.0157Time to CRR throughWk 104†44 (19.7)67 (30.0)HR 1.58(1.08, 2.31)0.0189Time to renal-related event or death†63 (28.3)35 (15.7)HR 0.51(0.34, 0.77)0.0014SLEDAI-S2K score <4 points at Wk 104*41 (18.4)62 (27.8)OR 1.76(1.11, 2.78)0.0164

*PBO and BEL columns represent the n (%) responders

†Data presented as n (cumulative incidence)

Disclosure of Interests:

Richard Furie Grant/research support from: GSK, Consultant of: GSK, Brad H Rovin Grant/research support from: GSK, Consultant of: GSK, Frederic Houssiau Grant/research support from: UCB, Consultant of: GSK, Zahir Amoura Grant/research support from: GSK, Roche, Consultant of: GSK, Astra Zeneca, Amgen, Mittermayer Santiago: None declared, Gabriel Contreras Grant/research support from: Genentech, Merck, Consultant of: Genentech, Merck, Ana Malvar Consultant of: GSK and Roche, chi chiu mok: None declared, Amit Saxena Consultant of: GSK, AZ, BMS, Xueqing Yu: None declared, Y.K. Onno Teng Grant/research support from: GSK, Consultant of: GSK, Aurinia Pharmaceuticals, Novartis, Carly Barnett Shareholder of: GSK, Employee of: GSK, Susan Burriss Shareholder of: GSK, Employee of: GSK, Yulia Green Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Christi Kleoudis Shareholder of: GSK, Consultant of: GSK, Employee of: Parexel, David Roth Shareholder of: GSK, Employee of: GSK

Chronic stress, depression and personality type in patients with myasthenia gravis

BACKGROUND AND PURPOSE

Stress is a known risk factor for the onset and modulation of disease activity in autoimmune disorders. The aim of this cross-sectional study was to determine any associations between myasthenia gravis (MG) severity and chronic stress, depression and personality type.

METHODS

In all, 179 consecutive adult patients with confirmed MG attending the Neuromuscular Clinic between March 2017 and December 2017 were included. At baseline, patients were assessed clinically and they completed self-administered scales for disease severity, perceived stress, depression and personality type.

RESULTS

Higher disease severity [Myasthenia Gravis Impairment Index (MGII)] showed a moderate correlation with depression score (Beck's Depression Inventory, Second Edition, r = 0.52, P < 0.001) and a lower correlation with chronic stress (Trier Inventory for Assessment of Chronic Stress, r = 0.28, P = 0.001). Chronic stress scores were different according to personality types (anova, P = 0.02). The linear regression model with MGII score as the dependent variable showed R² = 0.34, likelihood ratio chi-squared 74.55, with P < 0.0001. The only variables that predicted disease severity were depression scores (P < 0.0001) and female sex (P = 0.003).

CONCLUSIONS

A significant association of MG severity with depression and chronic stress was found, as well as with female gender. These findings should raise awareness that the long-term management of MG should address depression and potential stress and consider behavioural management to prevent stress-related immune imbalance.

EQ-5D-5L and SF-6D health utility index scores in patients with myasthenia gravis

BACKGROUND AND PURPOSE

Health utilities are a preference-based method of valuing health states that are used in healthcare research, such as economic evaluations. There are limited health utility valuation data for patients with myasthenia gravis (MG). The aim of the study was to describe health utilities for patients with MG and different health states, using the EQ-5D-5L and SF-6D utility instruments, and to explore clinical and demographic determinants of utilities in this population.

METHODS

Patients completed the EQ-5D-5L and SF-6D. In addition, patients were assessed with the Myasthenia Gravis Foundation of America classification, Myasthenia Gravis Impairment Index and MG-QOL15 as disease-specific measures, and the Neuro-QoL Fatigue scale. We calculated mean utilities for each Myasthenia Gravis Foundation of America severity class. We built regression models for the EQ-5D-5L and SF-6D to determine the clinical and demographic factors that determine patients' valuation of their health state.

RESULTS

Among 254 patients, mean EQ-5D-5L health utilities were as follows: Remission, 0.94 ± 0.03; Minimal Manifestations, 0.92 ± 0.04; Class I, 0.89 ± 0.06; Class II, 0.78 ± 0.16; Class III, 0.58 ± 0.24 and Class IV, 0.61 ± 0.22. Mean SF-6D health utilities were as follows: Remission, 0.83 ± 0.07; Minimal Manifestations, 0.86 ± 0.14; Class I, 0.82 ± 0.14; Class II, 0.67 ± 0.12; Class III, 0.56 ± 0.11 and Class IV, 0.50 ± 0.10. The limb/axial scores were more highly correlated to health utilities than ocular or bulbar scores.

CONCLUSIONS

We present estimates of health utilities for patients with MG that can be used in cost-utility and decision analyses. Limb/axial symptoms had a higher impact on health utilities than ocular or bulbar symptoms, which might reflect the impact of mobility on health valuation.

[Pharmacological treatment compliance and a description of its associated factors in patients with myasthenia gravis]

INTRODUCTION

Medication adherence is a public health problem and this has not been previously studied in myasthenia gravis patients.

AIM

To determine if patients with myasthenia gravis are adherent to treatment and to describe the clinical factors of patients who are non-adherent to treatment.

PATIENTS AND METHODS

Cross-sectional study of patients with myasthenia gravis followed at Padre Hurtado Hospital, Santiago de Chile, who received their medication through the hospital and therefore were on the pharmacy's list. Patients' participation was voluntary and anonymous. Medication adherence was assessed with the Morisky-Green-Levine survey (4 items). Patients were assessed for myasthenia gravis severity with the Manual Muscle Test, and myasthenia gravis-related quality of life with the MG-QOL15. Finally, patients were screened for depression with the 12-Item General Health Questionnaire.

RESULTS

26 patients were enrolled and 15 (57.7%) were women. Only 10 (38.5%) of patients were adherent to treatment. Patients who were not adherent to medication had more weakness (p = 0.06), worse quality of life (p = 0.008), were taking a greater number of myasthenia gravis drugs (p = 0.003) and had a higher risk of depression (p = 0.03).

CONCLUSIONS

In this cohort of myasthenia gravis patients, three out of five patients were not adherent to treatment. These patients tended to have more weakness, worse quality of life and higher risk of depression. Medication adherence should be assessed routinely in patients with myasthenia gravis.

Toronto Clinical Neuropathy Score is valid for a wide spectrum of polyneuropathies

BACKGROUND AND PURPOSE

The Toronto Clinical Neuropathy Score (TCNS) is a valid and reliable scale for the diagnosis and staging of diabetic sensorimotor polyneuropathy. In this study, we aimed to explore the performance of the TCNS in non-diabetic polyneuropathies.

METHODS

We performed a prospective study from November 2016 to May 2017 of patients with non-diabetic polyneuropathy. Patients had clinical, electrophysiological and functional assessments of their polyneuropathy, and the findings were correlated with the TCNS.

RESULTS

The TCNS correlated with all clinical, electrophysiological and disability measures of polyneuropathy, mostly at a moderate level (e.g. r = -0.58 for sural nerve action potential amplitude). Higher TCNS severity grades were associated with worse polyneuropathy on all measures in the lower limbs, and with worse electrophysiological parameters and vibration perception thresholds in the upper limbs. The scale also showed excellent reliability and accuracy (kappa, 0.92-0.93 for inter- and intra-observer reliability; area under the receiver operating characteristics curve, 0.93).

CONCLUSION

The TCNS is a valid and reliable scale for a wide spectrum of polyneuropathies, and might be useful in clinical practise and research for the diagnosis and staging of polyneuropathy.

Prevalence factors associated with equine herpesvirus type 1 infection in equids with upper respiratory tract infection and/or acute onset of neurological signs from 2008 to 2014

The objective of the present case-control study was to determine prevalence factors associated with the detection of equine herpesvirus type 1 (EHV-1) by quantitative PCR (qPCR) in horses presented to veterinarians with clinical signs related to an upper respiratory tract infection and/or acute onset of neurological disease from March 2008 to December 2014. Nasal secretions and whole blood from 4228 equids with acute onset of fever, respiratory signs and/or neurological deficits were tested by qPCR for EHV-1. Categorical analyses were performed to determine the association between observations and EHV-1. A total of 117/4228 (2.7 per cent) equids tested qPCR-positive for EHV-1, with most of the isolates belonging to the non-neuropathogenic genotype (N752). EHV-1 PCR-positive equids were over-represented in racing horses. Depression, anorexia, nasal discharge and coughing were significantly less frequently reported in the EHV-1 qPCR-positive equids compared with the EHV-1 qPCR-negative cases. Neurological deficits were more frequently reported in the EHV-1 qPCR-positive cases. This study provides contemporary information on the frequency of EHV-1 detection by qPCR in blood and nasal secretions from horses with fever, respiratory signs and neurological deficits.

Voluntary surveillance program for equine influenza virus in the United States from 2010 to 2013

Background

Recent surveillance studies for equine respiratory viruses have shown that equine influenza virus (EIV) continues to be a prevalent respiratory virus of equids throughout the United States and Europe.

Objectives

To gain a better understanding of the prevalence and epidemiology of EIV shed by horses, mules and donkeys in the United States from March 2010 to November 2013.

Animals

2,605 equids.

Methods

Nasal secretions from index cases with acute onset of respiratory disease were tested by qPCR for EIV. Multilevel logistic regression was used to model the association between EIV status and prevalence factors. Furthermore, observations from EIV‐positive study horses were compared to previous data from March 2008 to February 2010.

Results

A total of 230 (9.7%) index cases tested qPCR positive for EIV. A higher‐than‐expected proportion of EIV qPCR‐positive horses occurred in the 1–5, 6–10, and 11–15 age groups when compared to the <1 year of age group. Fever, nasal discharge and coughing were positively associated with EIV‐positive horses. EIV qPCR‐positive study cases were significantly older and more often vaccinated against EIV compared to EIV qPCR‐positive animals from the 2008‐2010 study period.

Conclusions and Clinical Importance

This study provides valuable and contemporary information on the frequency of EIV detected by qPCR in the United States. The results also underscore that older and previously vaccinated horses were susceptible to EIV.

Excessive Daytime Sleepiness in Patients with Myasthenia Gravis

Excessive daytime sleepiness (EDS) has not been investigated using objective tests in myasthenia gravis (MG). We investigated whether objective measurements of somnolence better detected abnormalities compared with sleepiness questionnaires in MG, and determine if MG patients have EDS. Eight patients with mild-to-moderate MG were recruited. Patients completed maintenance of wakefulness, overnight polysomnography, multiple sleep latency tests, Epworth Sleepiness Scale, and fatigue questionnaires. Seven patients demonstrated EDS on objective testing, while Epworth scores were abnormal in two, and the measures showed poor correlation. Our findings highlight that the ESS may be inadequate to diagnose EDS and lead to under-reporting of daytime somnolence in patients with MG.

Patients' satisfaction with fast-track surgery in gynaecological oncology

This study investigates the experience and satisfaction with care of fast-tracked gynaecological patients. The Sydney Gynaecological Oncology Group, New South Wales, Australia, has previously shown the benefits of a fast-track surgery programme for gynaecology patients with both complex benign gynaecological pathology and gynaecological malignancy. The question of whether these benefits translate into a positive experience for fast-tracked patients, in the context of their hospital stay and healthcare team care, has not been previously explored in detail. A self-administered satisfaction questionnaire incorporating the European Organisation for Research and Treatment of Cancer (EORTC) cancer in-patient satisfaction with care measure (INPATSAT-32) questionnaire with additional questions was administered to 106 gynaecology participants at Royal Prince Alfred Hospital. Participants reported high levels of satisfaction with patient care and support received from doctors, ward nurses and the hospital as a service and care organisation, within the context of a fast-track surgical programme. Early hospital discharge after gynaecological surgery results in both enhanced recovery after surgery (ERAS) and high levels of patient satisfaction.

An invitation to contribute to a strategic research agenda in radioecology

With intentions of integrating a portion of their respective research efforts into a trans-national programme that will enhance radioecology, eight European organisations recently formed the European Radioecology ALLIANCE (www.er-alliance.org). The ALLIANCE is an Association open to other organisations throughout the world with similar interests in promoting radioecology. The ALLIANCE members recognised that their shared radioecological research could be enhanced by efficiently pooling resources among its partner organizations and prioritising group efforts along common themes of mutual interest. A major step in this prioritisation process was to develop a Strategic Research Agenda (SRA). An EC-funded Network of Excellence in Radioecology, called STAR (Strategy for Allied Radioecology), was formed, in part, to develop the SRA. This document is the first published draft of the SRA. The SRA outlines a suggested prioritisation of research topics in radioecology, with the goal of improving research efficiency and more rapidly advancing the science. It responds to the question: "What topics, if critically addressed over the next 20 years, would significantly advance radioecology?" The three Scientific Challenges presented within the SRA, with their 15 associated research lines, are a strategic vision of what radioecology can achieve in the future. Meeting these challenges will require a directed effort and collaboration with many organisations the world over. Addressing these challenges is important to the advancement of radioecology and in providing scientific knowledge to decision makers. Although the development of the draft SRA has largely been a European effort, the hope is that it will initiate an open dialogue within the international radioecology community and its stakeholders. This is an abbreviated document with the intention of introducing the SRA and inviting contributions from interested stakeholders. Critique and input for improving the SRA are welcomed via a link on the STAR website (www.star-radioecology.org).

Robot assisted laparoscopic prostatectomy. Striving for Trifecta outcomes in localised prostate cancer

Radical prostatectomy (RP) is the gold standard treatment for localised prostate cancer and its oncological effectiveness has been demonstrated so far. With no doubt though, RP has significant potential morbidity and the selection of patients who will likely benefit from surgery while minimising the side effects of incontinence and erectile dysfunction is fundamental. Robot-assisted radical prostatectomy allows us to achieve oncological control, early continence and preservation of erectile function all in one. Thus, analysing its role is of utmost importance.

No relationship between 18F-fluorodeoxyglucose positron emission tomography and expression of Glut-1 and -3 and hexokinase I and II in high-grade glioma

The purpose of this study was to compare glucose metabolism, measured using 18F-fluorodeoxyglucose positron emission tomography ([18F]FDG-PET), with the expression of Glut-1 and -3 and hexokinase I (Hex I) and II in high-grade glioma. The retrospective study involved 27 patients with WHO classification grade III and IV glioma, with either newly diagnosed or recurrent tumours. Patients underwent dynamic and static [18F]FDG-PET to glucose metabolic rate (MRGlu) and standardised uptake value (SUV), respectively. Tumour biopsies were obtained and stained using immunohistochemistry for the expression of Glut-1, -3, Hex I and II. Relationships between variables were studied using Spearman's rank correlation test. Results showed that the expression of Glut-1, Glut-3, Hex I and Hex II varied between and within the tumour samples. The mean of MRGlu was 0.2 (range 0.09-0.25) micromol/min/ml and that of SUV was 4.2 (range 3.2-5.2). There were no significant relationships among the tumour expression of any of the proteins studied with either MRGlu or SUV (p>0.21 for all). In conclusion, the lack of relationship between the immunohistochemical expression of Glut-1, -3, Hex I or II and glucose metabolism measured using [18F]FDG-PET in patients with high-grade glioma may be due to the tissue heterogeneity and presence of necrosis in high-grade tumours.

Muscle metabolism during sprint exercise in man: influence of sprint training

In order to examine the influence of sprint training on metabolism and exercise performance during sprint exercise, 16 recreationally-active, untrained, men (VO2peak= 3.8+/-0.1 l.min(-1)) were randomly assigned to either a training (n= 8) or control group (n= 8). Each subject performed a 30-sec cycle sprint and a test to measure VO2peak before and after eight weeks of sprint training. The training group completed a series of sprints three times per week which progressed from three 30-sec cycle sprints in weeks 1 and 2, to six 30-sec sprints in weeks 7 and 8. Three mins of passive recovery separated each sprint throughout the training period. Muscle samples were obtained at rest and immediately following the pre- and post-training sprints and analysed for high energy phosphagens, glycogen and lactate; the activities of both phosphofructokinase (PFK) and citrate synthase (CS) were also measured and muscle fibre types were quantified. Training resulted in a 7.1% increase in mean power output (p<0.05), an 8% increase in VO2peak (p< 0.001), a 42% increase (p< 0.01) in CS activity and a 17% increase (p< 0.05) in resting intramuscular glycogen content. In contrast, neither PFK activity nor fibre type distribution changed with training. An increase (p< 0.05) in mean power output and attenuated (p< 0.01) ATP degradation were observed during sprint exercise following training. Glycogen degradation during sprint exercise was unaffected by sprint training. These data demonstrate that sprint training may have enhanced muscle oxidative but not glycolytic capacity.

Patterns of antropyloric motility in fed healthy preterm infants

BACKGROUND

Antropyloric motility is important for regulation of gastric emptying and has not been adequately characterised in premature infants.

AIM

To evaluate fed patterns of antropyloric motility in premature infants.

SUBJECTS

Forty three healthy premature infants, 30-38 weeks of postmenstrual age.

METHODS

Postprandial antropyloric motility was measured using a micromanometric feeding assembly (outer diameter 1.8 mm) incorporating a pyloric sleeve sensor. The occurrence of isolated pyloric pressure waves (IPPWs) and antral pressure wave sequences (PWSs) was characterised. Sequences were further classified as being antegrade, synchronous, antegrade-synchronous, and retrograde according to the direction of propagation.

RESULTS

A total of 7289 pressure wave events were recorded, 48% IPPWs and 52% PWSs (18% antegrade, 12% synchronous, 13% antegrade-synchronous, 2% retrograde, and 7% undefined). IPPWs predominated in the first postprandial hour, peaking at 30-60 minutes. PWSs predominated in the period after one hour postprandially. Mean (SEM) half gastric emptying time was 42 (4) minutes.

CONCLUSIONS

Monitoring of antropyloric motor patterns in healthy premature infants indicates that the neuroregulatory mechanisms responsible for the coordination of antropyloric motility and gastric emptying are well developed by 30 weeks of postmenstrual age.

Cloning and expression of an endocellulase gene from a novel streptomycete isolated from an East African soda lake

Alkaline cellulase-producing actinomycete strains were isolated from mud samples collected from East African soda lakes. The strains were identified as novel Streptomyces spp. by 16S rDNA sequence analysis. A cellulase gene (cel12A) from Streptomyces sp. strain 11AG8 was cloned by expression screening of a genomic DNA library in Escherichia coli. From the nucleotide sequence of a 1.5-kb DNA fragment, an open reading frame of 1,113 nucleotides was identified encoding a protein of 371 amino acids. From computer analysis of the sequence, it was deduced that the Cel12A mature enzyme is a protein of 340 amino acids. The protein contained a catalytic domain, a glycine-rich linker region, and a cellulose-binding domain of 221, 12, and 107 amino acids, respectively. FASTA analysis of the catalytic domain of Cel12A classified the enzyme as a family 12 endoglucanase and the cellulose-binding domain as a family IIa CBD. Streptomyces rochei EglS was determined as nearest neighbor with a similarity of 75.2% and 61.0% to the catalytic domain and the cellulose-binding domain, respectively. The cell2A gene was subcloned in a Bacillus high-expression vector carrying the Bacillus amyloliquefaciens amylase regulatory sequences, and the construct was transformed to a Bacillus subtilis host strain. Crude enzyme preparations were obtained by ultrafiltration of cultures of the Bacillus subtilis recombinant strain containing the 11AG8 cell2A gene. The enzyme showed carboxymethylcellulase (CMCase) activities over a broad pH range (5-10) with an optimum activity at pH 8 and 50 degrees C. The enzyme retained more than 95% of its activity after incubation for 30 min under these conditions.

Age-related accumulation of oxidative DNA damage and alterations in levels of p16(INK4a/CDKN2a), p21(WAF1/CIP1/SDI1) and p27(KIP1) in human CD4+ T cell clones in vitro

T cells in vivo have been shown to accumulate DNA damage with age. To investigate the effects of DNA damage on T cell biology we have utilised an in vitro human CD4+ T cell clone model. Levels and types of DNA damage were determined in 11 independent T cell clones as a function of their in vitro lifespan. Increased levels of reactive oxygen species (ROS) induced DNA damage with increasing age were found in all clones analysed using a modified alkaline comet assay. T cell clones underwent apoptosis at the end of their lifespans. There were no consistent changes in the mRNA levels for the cyclin-dependent kinase inhibitors (CKI) p16, p21, and p27 during the clones' lifespans. It appears that the increased levels of ROS induced DNA damage in the T cells is not the major trigger of apoptosis, via the p53/p21 pathway. In addition, at the end of their lifespans, the T cell clones did not display the CKI phenotype reported for senescent cells (an increase in p16 and p21 levels). Thus, while the T cell clones appear sensitive to ROS-induced DNA damage, the molecular mechanisms through which this influences T cell dysfunction with age remains to be elucidated.

The effects of carnosine on oxidative DNA damage levels and in vitro lifespan in human peripheral blood derived CD4+T cell clones

Carnosine (beta-alanyl-L-histidine), an abundant naturally-occurring dipeptide has been shown to exhibit anti-ageing properties towards cultured cells, possibly due in part to its antioxidant/free radical scavenging abilities. In this paper the results of an investigation on the effects of carnosine, at the physiological concentration of 20 mM, on oxidative DNA damage levels and in vitro lifespan in peripheral blood derived human CD4+ T cell clones are reported. Under the culture conditions used (20% O(2)) long term culture with carnosine resulted in a significant increase in the lifespan of a clone derived from a healthy young subject. No such extension was observed when a T cell clone from a healthy old SENIEUR donor was similarly cultured. Culture with carnosine from the midpoint of each clone's lifespan did not have any effect on longevity, independent of donor age. Oxidative DNA damage levels were measured in the clones at various points in their lifespans. Carnosine acted as a weak antioxidant, with levels of oxidative DNA damage being lower in T cells grown long term in the presence of carnosine. The possibility that carnosine might confer anti-ageing effects to T cells under physiological oxygen tensions would appear to be worthy of further investigation.

Acute gastritis with hypochlorhydria: report of 35 cases with long term follow up

BACKGROUND

Between 1976 and 1987, 35 cases of acute gastritis with hypochlorhydria (AGH) were seen in our research laboratory. The aims of this study were to determine the natural history of AGH and the role of Helicobacter pylori in its pathogenesis.

METHODS

Archived serum and gastric biopsy samples obtained from AGH subjects were examined for evidence of H pylori colonisation. Twenty eight of 33 (85%) surviving AGH subjects returned a mean of 12 years after AGH for follow up studies, including determination of H pylori antibodies, basal and peak acid output, endoscopy, and gastric biopsies. A matched control group underwent the same studies.

RESULTS

Archived material provided strong evidence of new H pylori acquisition in a total of 14 subjects within two months, in 18 within four months, and in 22 within 12 months of recognition of AGH. Prevalence of H pylori colonisation at follow up was 82% (23 of 28) in AGH subjects, significantly (p<0.05) higher than in matched controls (29%). Basal and peak acid output returned to pre-AGH levels in all but two subjects.

CONCLUSIONS

One of several possible initial manifestations of H pylori acquisition in adults may be AGH. While H pylori colonisation usually persists, hypochlorhydria resolves in most subjects.

Mechanism of gastroesophageal reflux in premature infants with chronic lung disease

BACKGROUND/PURPOSE

The aim of this study was to characterize the motor events responsible for gastroesophageal reflux (GER) and esophageal acid clearance in a cohort of preterm infants with chronic lung disease (CLD).

METHODS

Esophageal motility was recorded for 2 to 3 hours postprandially in 14 preterm infants with mild-moderate or moderate-severe CLD at 33 to 39 weeks postmenstrual age using a sleeve-side hole micromanometric assembly into which a pH probe had been installed.

RESULTS

Twenty-six acid GER episodes were recorded by pH probe. Of these, 22 (85%) were associated with transient lower esophageal sphincter (LES) relaxation. Transient LES relaxations were significantly longer in duration than single swallows (13.7 seconds v 4.6 seconds, P < .001) and had lower nadir pressures (1.1 mm Hg v 2.5 mm Hg, P < .001). During periods of esophageal acidification (pH below 4), peristaltic esophageal body pressure wave sequences cleared acid refluxate more effectively than nonperistaltic pressure wave sequences.

CONCLUSIONS

In preterm infants with CLD, transient LES relaxations are the predominant mechanism underlying GER, and esophageal clearance mechanisms are fully functional, which is similar to that seen in healthy preterm infants.

Measurement of upper esophageal sphincter tone and relaxation during swallowing in premature infants

Upper esophageal sphincter (UES) motor function has not been previously evaluated in premature infants. The motor patterns associated with tonic activity and swallow-related relaxation of the UES were recorded for 1 h after completion of gavage feeding in 11 healthy preterm neonates (postmenstrual age 33-37 wk) with a micromanometric assembly, which included a sleeve sensor specifically adapted for UES recordings. A clearly defined UES high-pressure zone was observed in all premature infants studied. Resting UES pressure ranged from 2.3 to 26.2 mmHg and was higher during periods of irritability and apparent discomfort. During dry swallows, UES pressure relaxed from a resting pressure of 28.2 +/- 4.0 mmHg to a nadir of 1.1 +/- 3.3 mmHg. The mean UES relaxation interval (the time from relaxation onset to relaxation offset) was 0. 31 +/- 0.11 s. We conclude that in premature infants >/=33 wk postmenstrual age the motor mechanisms regulating UES resting pressure and the onset of UES relaxation are well developed.

Reproducibility of the 13C-octanoic acid breath test for assessment of gastric emptying in healthy preterm infants

BACKGROUND

The 13C-octanoic acid breath test has been used to measure gastric emptying in preterm infants, but the reproducibility of the test has not been evaluated in this population.

METHODS

Fifty-six paired breath test analyses were performed on 28 healthy preterm infants 1 to 5 days apart using the same food type, volume, and energy content for each paired sample. Breath samples were taken before the feeding, at 5-minute intervals after feeding for 30 minutes, then each 15 minutes for 4 hours. Samples were analyzed using an isotope-ratio mass spectrometer, and 3C recovery was used to calculate values for gastric-emptying coefficient and gastric half-emptying time.

RESULTS

There was no significant difference between test results on different days in the paired samples studied. gastric-emptying coefficients for the first and subsequent samples were 2.6+/-0.1 (mean+/-SEM) and 2.7+/-0.1, respectively, and half-emptying times were 44.5+/-3.7 minutes and 41.4+/-3.2 minutes.

CONCLUSION

The 13C-octanoic acid breath test is a reliable, noninvasive, and reproducible measure of gastric emptying in preterm infants that should have wide application for use in this population.

Mechanisms of gastroesophageal reflux in healthy premature infants

OBJECTIVES

The aim of this study was to characterize the motor events responsible for gastroesophageal reflux (GER) and esophageal acid clearance in a cohort of healthy preterm infants.

STUDY DESIGN

Esophageal motility was recorded for 2 to 3 hours after a feeding in 24 preterm infants, 31 to 38 weeks' postmenstrual age, by using a sleeveside hole micromanometric assembly incorporating a pH probe.

RESULTS

Sixty acid GER episodes were recorded by pH probe, and 133 non-acid GER episodes were recorded manometrically by the presence of esophageal common cavities. Of the 193 GER episodes, 159 (82%) were associated with transient lower esophageal sphincter relaxation (TLESR). TLESRs were significantly longer in duration than single swallows (15.1 seconds vs 5.6 seconds, P < .001) and had lower nadir pressures (0.8 mm Hg vs 2.3 mm Hg, P < .001). A total of 3216 esophageal body pressure waves were analyzed; 70% of swallow-induced pressure waves were peristaltic in sequence compared with 5% of swallow-unrelated pressure waves. During periods of esophageal acidification (pH below 4), peristaltic esophageal body pressure wave sequences cleared acid refluxate more effectively than nonperistaltic pressure wave sequences.

CONCLUSIONS

In healthy preterm infants, TLESRs are the predominant mechanism underlying GER, and esophageal clearance mechanisms are well developed by at least 31 weeks' postmenstrual age.

The relationship between plasma potassium concentration and muscle torque during recovery following intense exercise

The present study investigated the relationship between plasma potassium ion concentration ([K+]) and skeletal muscle torque during three different 15-min recovery periods after fatigue induced by four 30-s sprints. Four males and one female completed the multiple sprint exercise on three separate days; recovery was passive, i.e. no cycling exercise (PRec), active cycling at 30% peak oxygen consumption. VO2peak (30% Rec) and active cycling at 60% VO2peak (60% Rec). Plasma [K+] was measured from blood sampled from an antecubital vein of subjects at rest and at 0, 3, 5, 10 and 15 min into each recovery. Isokinetic leg strength was measured at rest and at 1, 6, 11 and 16 min during each recovery. Following the exhaustive sprints, [K+] increased significantly from an average mean (SEM) resting value of 3.81 (0.07) mmol.l-1 to 4.48 (0.19) mmol.l-1 (P < 0.01). In all recovery conditions, plasma [K+] returned to resting levels within 3 min following the fourth sprint. However, in the two active recovery conditions plasma [K+] increased over the remainder of the recovery periods to 4.36 (0.12) mmol.l-1 in the 30% Rec condition and 4.62 (0.12) mmol.l-1 in the 60% Rec condition, the latter being significantly higher than the former (P < 0.01). The maximum torque measured following the sprints decreased significantly, on average, to 61.1 (8.36)% of peak levels (P < 0.01). After 15 min of recovery, maximum torque was highest in the 30% Rec condition at 92.13 (3.06)% of peak levels (P < 0.01), compared to 85.23 (3.64)% and 85.71 (0.82)% for the PRec and 60% Rec conditions, respectively. In contrast to the significant differences in plasma [K+] across all three recovery conditions, muscle torque recovery was significantly different in only the 30% Rec condition. In summary, recovery of peak levels of muscle torque following fatiguing exercise does not appear to follow changes in plasma [K+].