The effectiveness and cost-effectiveness of minimal access surgery amongst people with gastro-oesophageal reflux disease - a UK collaborative study. The REFLUX trial

OBJECTIVES

To evaluate the clinical effectiveness, cost-effectiveness and safety of a policy of relatively early laparoscopic surgery compared with continued medical management amongst people with gastro-oesophageal reflux disease (GORD) judged suitable for both policies.

DESIGN

Relative clinical effectiveness was assessed by a randomised trial (with parallel non-randomised preference groups) comparing a laparoscopic surgery-based policy with a continued medical management policy. The economic evaluation compared the cost-effectiveness of the two management policies in order to identify the most efficient provision of future care and describe the resource impact that various policies for fundoplication would have on the NHS.

SETTING

A total of 21 hospitals throughout the UK with a local partnership between surgeon(s) and gastroenterologist(s) who shared the secondary care of patients with GORD.

PARTICIPANTS

The 810 participants, who were identified retrospectively or prospectively via their participating clinicians, had both documented evidence of GORD (endoscopy and/or manometry/24-hour pH monitoring) and symptoms for longer than 12 months. In addition, the recruiting clinician(s) was clinically uncertain about which management policy was best.

INTERVENTION

Of the 810 eligible patients who consented to participate, 357 were recruited to the randomised arm of the trial (178 allocated to surgical management, 179 allocated to continued, but optimised, medical management) and 453 recruited to the parallel non-randomised preference arm (261 chose surgical management, 192 chose to continue with best medical management). The type of fundoplication was left to the discretion of the surgeon.

MAIN OUTCOME MEASURES

Participants completed a baseline REFLUX questionnaire, developed specifically for this study, containing a disease-specific outcome measure, the Short Form with 36 Items (SF-36), the EuroQol-5 Dimensions (EQ-5D) and the Beliefs about Medicines and Surgery questionnaires (BMQ/BSQ). Postal questionnaires were completed at participant-specific time intervals after joining the trial (equivalent to approximately 3 and 12 months after surgery). Intraoperative data were recorded by the surgeons and all other in-hospital data were collected by the research nurse. At the end of the study period, participants completed a discrete choice experiment questionnaire.

RESULTS

The randomised groups were well balanced at entry. Participants had been taking GORD medication for a median of 32 months; the mean age of participants was 46 years and 66% were men. Of 178 randomised to surgery, 111 (62%) actually had fundoplication. There was a mixture of clinical and personal reasons why some patients did not have surgery, sometimes related to long waiting times. A total or partial wrap procedure was performed depending on surgeon preference. Complications were uncommon and there were no deaths associated with surgery. By the equivalent of 12 months after surgery, 38% in the randomised surgical group (14% amongst those who had surgery) were taking reflux medication compared with 90% in the randomised medical group. There were substantial differences (one-third to one-half standard deviation) favouring the randomised surgical group across the health status measures, the size depending on assumptions about the proportion that actually had fundoplication. These differences were the same or somewhat smaller than differences observed at 3 months. The lower the REFLUX score, the worse the symptoms at trial entry and the larger the benefit observed after surgery. The preference surgical group had the lowest REFLUX scores at baseline. These scores improved substantially after surgery, and by 12 months they were better than those in the preference medical group. The BMQ/BSQ and discrete choice experiment did distinguish the preference groups from each other and from the randomised groups. The latter indicated that the risk of serious complications was the most important single attribute of a treatment option. A within-trial cost-effectiveness analysis suggested that the surgery policy was more costly (mean 2049 pounds) but also more effective [+0.088 quality-adjusted life-years (QALYs)]. The estimated incremental cost per QALY was 19,000-23,000 pounds, with a probability between 46% (when 62% received surgery) and 19% (when all received surgery) of cost-effectiveness at a threshold of 20,000 pounds per QALY. Modelling plausible longer-term scenarios (such as lifetime benefit after surgery) indicated a greater likelihood (74%) of cost-effectiveness at a threshold of 20,000 pounds, but applying a range of alternative scenarios indicated wide uncertainty. The expected value of perfect information was greatest for longer-term quality of life and proportions of surgical patients requiring medication.

CONCLUSIONS

Amongst patients requiring long-term medication to control symptoms of GORD, surgical management significantly increases general and reflux-specific health-related quality of life measures, at least up to 12 months after surgery. Complications of surgery were rare. A surgical policy is, however, more costly than continued medical management. At a threshold of 20,000 pounds per QALY it may well be cost-effective, especially when putative longer-term benefits are taken into account, but this is uncertain. The more troublesome the symptoms, the greater the potential benefit from surgery. Uncertainty about cost-effectiveness would be greatly reduced by more reliable information about relative longer-term costs and benefits of surgical and medical policies. This could be through extended follow-up of the REFLUX trial cohorts or of other cohorts of fundoplication patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15517081.

The incidence of and risk factors for MRSA bacteraemia in an HIV-infected cohort in the HAART era

OBJECTIVES

To define the incidence and risk factors for methicillin resistant Staphylococcus aureus (MRSA) bacteraemia in an HIV-infected population.

METHODS

From January 1, 2000 to December 31, 2004, we conducted a retrospective cohort study. We identified all cases of Staphylococcus aureus bacteraemia (SAB), including MRSA, among patients enrolled in the Johns Hopkins Hospital out-patient HIV clinic. A conditional logistic regression model was used to identify risk factors for MRSA bacteraemia compared with methicillin-sensitive SAB and no bacteraemia in unmatched (1:1) and matched (1:4) nested case-control analyses, respectively.

RESULTS

Of 4607 patients followed for a total of 11 020 person-years (PY) of follow-up, 216 episodes of SAB occurred (incidence: 19.6 cases per 1000 PY), including 94 cases (43.5%) which were methicillin-resistant. The incidence of MRSA bacteraemia increased from 5.3 per 1000 PY in 2000-2001 to 11.9 per 1000 PY in 2003-2004 (P=0.001). Multivariate analysis demonstrated that independent predictors of MRSA bacteraemia (vs. no bacteraemia) were injection drug use (IDU), end-stage renal disease (ESRD) and CD4 count <200 cells/microL.

CONCLUSIONS

MRSA bacteraemia was an increasingly common diagnosis in our HIV-infected cohort, especially in patients with history of IDU, low CD4 cell count and ESRD.

Substrate-dependent irreversible inactivation of cytochrome P-450: conversion of its haem moiety into modified porphyrins

2-Allyl-2-isopropylacetamide and other drugs containing either an allyl, a vinyl or an ethynyl unsaturated side chain are metabolized by liver cytochrome P-450 to reactive derivatives that irreversibly inhibit the haemoprotein by a suicidal type of inactivation. The main target is the haem moiety of cytochrome P-450 which is converted into abnormal porphyrins. These have been isolated from the liver of treated rats, extensively purified and compared with model porphyrins. The abnormal porphyrins incorporate metal ions in vitro much more readily than does their parent porphyrin, protoporphyrin. They are also much more basic than protoporphyrin, and on titration with a strong acid they readily give rise to a porphyrin monocation which then requires relatively large amounts of acid for conversion to the porphyrin dication. In all these respects and also in the intensity of their bathochromic shifts these abnormal porphyrins closely resemble N-alkylated porphyrins and they markedly differ from porphyrins that are substituted at one of their meso-carbon positions or which bear electron-withdrawing substituents at the beta-positions of the pyrrole rings. This suggests strongly that reactive derivatives of the unsaturated drugs act as electrophilic reagents and alkylate one of the pyrrole nitrogen atoms of cytochrome P-450. A model centred on the apoprotein of cytochrome P-450 is considered for the degradation of liver haem caused by unsaturated drugs. The apocytochrome may accept exchangeable pools of liver haem for degradation, leading to a state of haem depletion and to activation of delta-aminolaevulinate synthase.

High levels of self-efficacy in patients with type 2 diabetes attending a tertiary level clinic

Self-management is a vital element in the care of type 2diabetes patients.  In turn, self-efficacy plays a major role in patients’ self-management. Self-efficacy is the patient’s personal judgement of his/herconfidence in performing aspects of diabetes self-management.  This study investigated the level of self-efficacy of patients attending the Pretoria Academic Hospital Diabetes Clinic, in the light of high levels ofre-admission due to complications, suggesting low self-efficacy levels. Eighty type 2 diabetes patients, mean age of 59 years, completed thepublished IDEA LL baseline questionnaire, to establish a self-efficacyscore.  Relationships between self-efficacy and demographic factors wereinvestigated using the chi-square test. The mean self-efficacy level of thesample population is excellent (mean = 85.44%).A lthough self-reported self-efficacy levels are excellent, in comparison to the Sarkar study (2006) in which participants only scored “fair”, it is speculated that self-efficacy is not transferred to self-management behaviour in thispopulation.  Afrikaans and English speaking participants score significantly better than those from other language categories. There is a positive relationship between self-efficacy and level of education and employment status (tendedtowards significance with p values of 0.06 and 0.07 respectively). A lthough self-efficacy scores of clients at this tertiary level outpatient clinic are excellent, further research is necessary to quantify self-management strategies andto correlate these with self-efficacy levels.

Primary ion fluence dependence in time-of-flight SIMS of a self-assembled monolayer of octadecylphosphonic acid molecules on mica discussion of static limit

By using a self-assembled monolayer of octadecylphosphonic acid molecules, CH3(CH2)17PO(OH)2, on mica as a model of the “soft” materials, such as self-assembled monolayers (SAMs) and multilayers in many biological systems as well as artificially engineered molecular electronic systems, we have examined the effects of primary ion fluence on time-of-flight secondary ion mass spectrometry (TOF-SIMS) of the technologically important model. Our measurements clearly show that although the intensity per unit primary ion fluence of most atomic ions and many small fragment ions do not vary by more than 10% for the fluence range of 1010–1013 cm–2, the intensity of the parent molecular ion can drop by two orders of magnitude in this fluence range. While the changes are different for the primary ion beams of Bi3+ (25 keV, 45°), Bi+ (25 keV, 45°), and Ar+ (8 keV, 45°), they are all substantial, with the damage cross section induced by the Bi3+ beam being the largest (6 000 Å2). Since different secondary ions have quite different intensity changes, the analytical results derived from TOF-SIMS can vary significantly by the time and duration of the measurements in the TOF-SIMS experiment. Therefore, our results suggest that for TOF-SIMS of molecular layers such as SAMs, the primary ion fluence condition should be recorded and reported. In general, the validity of the static condition becomes questionable when the cumulative primary ion fluence exceeds 1 × 1011 cm–2.Key words: SIMS, static SIMS, TOF-SIMS, soft materials, self-assembled monolayer, bilayer, surface of biological materials.

Pre-pregnancy body mass index and pregnancy outcomes

OBJECTIVE

To determine the effect of maternal pre-pregnancy BMI on pregnancy outcomes.

METHODS

Pregnancy cohort recruited pregnancies between 16 and 18 weeks. BMI evaluated underweight, BMI<18.5, normal, BMI 18.5-25, overweight BMI 25-30, and obese BMI>30 women.

RESULTS

Pre-pregnancy BMI classified 331 women as underweight (11.7%), 1982 normal (69.9%), 326 overweight (11.5%), and 188 as obese (6.6%). Obese women were more likely to develop gestational diabetes (p<0.001), hypertension (p<0.001), preeclampsia (p<0.001), need labor induction (p<0.001), cesarean delivery for fetal distress (p<0.001), postpartum hemorrhage (p=0.003), need neonatal resuscitation (p=0.001) and deliver hypoglycemic infants (p=0.007). Being underweight is correlated with fetal growth restriction (p=0.001).

CONCLUSION

Pre-pregnancy obesity is a risk factor for gestational diabetes, preeclampsia, labor induction, cesarean for fetal distress, postpartum hemorrhage and neonatal hypoglycemic and need for resuscitation. Being underweight is risk factor for fetal growth restriction.

Natural history of Canavan disease revealed by proton magnetic resonance spectroscopy (1H-MRS) and diffusion-weighted MRI

Canavan disease is a childhood leukodystrophy caused by mutations in the gene for human aspartoacylase ( ASPA), which leads to an abnormal accumulation of the substrate molecule N-acetyl-aspartate (NAA) in the brain. This study was designed to model the natural history of Canavan disease using MRI and proton magnetic resonance spectroscopy ( (1)H-MRS). NAA and various indices of brain structure (morphology, quantitative T1, fractional anisotropy, apparent diffusion coefficient) were measured in white and gray matter regions during the progression of Canavan disease. A mixed-effects statistical model was used to fit all outcome measures. Longitudinal data from 28 Canavan patients were directly compared in each brain region with reference data obtained from normal, age-matched pediatric subjects. The resultant model can be used to non-invasively monitor the natural history of Canavan disease or related leukodystrophies in future studies involving drug, gene therapy, or stem cell treatments.

Immune responses to AAV in a phase I study for Canavan disease

BACKGROUND

Canavan disease is a rare leukodystrophy with no current treatment. rAAV-ASPA has been developed for gene delivery to the central nervous system (CNS) for Canavan disease. This study represents the first use of a viral vector in an attempt to ameliorate a neurodegenerative disorder.

METHODS

Subjects received intracranial infusions via six cranial burr holes. Adeno-associated virus, serotype 2 (AAV2), mediated intraparenchymal delivery of the human aspartoacylase cDNA at a maximum dose of 1 x 10(12) vector genomes per subject. The immune response and safety profiles were monitored in the follow-up of ten subjects.

RESULTS

Following rAAV2 administration, we found no evidence of AAV2 neutralizing antibody titers in serum for the majority of subjects tested (7/10). In a subset (3/10) of subjects, low to moderately high levels of AAV2 neutralizing antibody with respect to baseline were detected. In all subjects, there were minimal systemic signs of inflammation or immune stimulation. In subjects with catheter access to the brain lateral ventricle, cerebrospinal fluid was examined and there was a complete absence of neutralizing antibody titers with no overt signs of brain inflammation.

CONCLUSIONS

rAAV2 vector administration to the human CNS appears well tolerated. The low levels of immune response to AAV2 detected in 3/10 subjects in this study suggest at this dose and with intraparenchymal administration this approach is relatively safe. Long-term monitoring of subjects and expansion to phase II/III will be necessary in order to make definitive statements on safety and efficacy.

[Potential antinociceptive mechanisms of botulinum toxin]

Botulinum toxin has been used in pain therapy for several years. Its application in migraine and headaches is particularly interesting. Clinical results have not yet been definitely conclusive, and a uniform model of the mode of action has not been established either. Apart from a purely muscular effect, a direct antinociceptive effect of botulinum toxin has been found in patients, in the preclinical model, and in a clinical pain model. This is contradicted by negative observations in the clinical model of pain, which might be related to methodological deficits. Further basics need to be worked out before arriving at any final result. Clinical studies with patients and pain models should then follow. Studying botulinum toxin within the context of pain will also provide many new insights into pain therapy in general. In which pain model botulinum toxin may play a role in the future, has to be awaited.

Functional interactions of antiapoptotic proteins and tumor necrosis factor in the context of a replication-competent adenovirus

Replication-selective oncolytic adenoviruses hold promise, but novel mechanisms must be identified to maximize intratumoral virus persistence, spread and therapeutic transgene-carrying capacity while maintaining safety. One of the main approaches to engineering cancer-selectivity has been to delete a viral gene that is theoretically expendable in cancer cells. Results with this approach have been mixed, however, as evidenced by controversy over Onyx-015 (E1B-55kD(-)) selectivity. We hypothesized that the functional redundancy between viral gene products might limit selectivity and/or potency with this approach. Antiviral immune inducers of apoptosis (eg TNF-alpha) have not been thoroughly investigated in previous studies. We therefore explored whether deletion of functionally redundant viral genes, E1B-19kD and E3B, both independently antagonize TNF-alpha, could lead to enhanced oncolytic potency while maintaining selectivity. Since tumors have numerous blocks in apoptotic pathways, we hypothesized that deletion of one or both gene regions would result in cancer-selectivity in the presence of TNF-alpha. We have previously shown that the E1B-19kD deletion resulted in enhanced viral spread in vitro and in immunocompetent tumor models in vivo. In contrast, the impact of E3B deletion, especially its in vitro selectivity and potency, was not thoroughly characterized, although it resulted in rapid immune-mediated viral clearance in vivo. Furthermore, previous publications indicated that double-deleted mutants have selectivity but unsatisfactory efficacy. We compared the selectivity and potency of E1B-19kD(-), E3B(-) and E1B-19kD(-)/E3B(-) mutants to wild-type adenovirus. In cancer cells, the E1B-19kD(-) mutant had superior replication, spread and cytolysis (+) or (-) TNF-alpha; deletion of both E1B-19kD and E3B was relatively deleterious. In normal cells without TNF-alpha, similar results were obtained. In contrast, all three mutants were significantly inhibited in the presence of TNF-alpha. In immunocompetent mice, all three mutants were significantly inhibited in normal tissue. In tumors, only the E1B-19kD(-) mutant demonstrated enhanced replication, spread and antitumoral efficacy. Therefore, E1B-19kD deletion and E3B retention should be incorporated in oncolytic adenoviruses for enhanced safety and efficacy. In addition, functional redundant viral genes and their biological mediators/targets need to be carefully examined for the next generation of gene-deleted oncolytic viruses.

Effects of AAV-2-mediated aspartoacylase gene transfer in the tremor rat model of Canavan disease

The tremor rat is a spontaneous epilepsy model with a seizure phenotype caused by a deletion in the aspartoacylase (ASPA) gene. The absence of ASPA expression in these animals results in undetectable levels of enzyme activity and the accumulation of the substrate N-acetyl-aspartate (NAA) in brain, leading to generalized myelin vacuolation and severe motor and cognitive impairment. In support of human gene therapy for CD, recombinant adeno-associated viral vector (AAV-2) expressing ASPA was stereotactically delivered to the tremor rat brain and effects on the mutant phenotype were measured. AAV-ASPA gene transfer resulted in elevated aspartoacylase bioactivity compared to untreated mutant animals and elicited a significant decrease in the pathologically elevated whole-brain NAA levels. Assessment of motor function via quantitative rotorod testing demonstrated that rats injected with AAV-ASPA significantly improved on tests of balance and coordinated locomotion compared to animals receiving control vectors. This study provides evidence that AAV-2-mediated aspartoacylase gene transfer to the brain improves biochemical and behavioral deficits in tremor rat mutants (tm/tm) and supports the rationale of human gene transfer for Canavan disease.

Serum vitamin D levels in children with cystic fibrosis

Osteopenia is increasingly recognized in adults with cystic fibrosis (CF), and is potentially related to vitamin D deficiency in both adulthood and childhood. Vitamin D supplements are recommended and prescribed to all pancreatic-insufficient patients. We aimed to ascertain whether vitamin D deficiency in children with CF was prevalent. 25-hydroxyvitamin D (25-OHD) was measured in 290 children attending a specialist pediatric CF clinic for annual assessment. 25-OHD levels were compared with reference values and to other biochemical markers, lung function, and growth. Levels were also analyzed by pancreatic status and by the presence of CF-related liver disease. Median 25-OHD was 65 (range, 9-190) nmol/l. One percent had levels below 15 nmol/l, and 6% had levels less than 25 nmol/l. Levels were lower in adolescents (P < 0.001) and during the "winter" months (P < 0.001). No relationship was found with pancreatic status or liver disease. In conclusion, the majority of children had normal 25-OHD levels. Interpretation is difficult due to a lack of knowledge of optimal levels of 25-OHD required for healthy bone accretion. Lower levels in adolescents may be a precursor to low levels in adulthood, and did not seem to be simply related to poor compliance with supplementation. This may reflect normal physiology.

Investigation into the role of cephalic stimulation of acid secretion on gastric emptying and appetite following a soup meal using the gastric acid inhibitor omeprazole

We previously showed that oral administration of a liquid soup preload was associated with a slower rate of gastric emptying and suppressed appetite more compared with intragastric administration of the same soup [Appetite 31(1998)377]. The present study was designed to investigate whether these results could be explained by the cephalic stimulation of acid secretion induced by oral administration. Eight healthy male subjects took part in a double-blind placebo controlled study comparing the effects of omeprazole and placebo on gastric emptying, appetite ratings and subsequent food intake following the ingestion of a liquid soup. Subjects were administered with a single oral dose of 80 mg omeprazole or placebo 3 h prior to ingesting the radiolabelled soup preload (400 kcal; 425 ml) over 15 min. Ratings of hunger, desire to eat and fullness were recorded over 135 min and gastric emptying was measured by scintigraphy. Food intake was evaluated from a test meal (yoghurt drink) given 120 min after the end of the soup ingestion. Analysis of data showed that there was no significant difference between omeprazole and placebo in gastric emptying, appetite or subsequent energy intake from the test meal. The results suggest that gastric acid secretion is not responsible for the differences in gastric emptying and appetite observed between intragastrically infused and orally administered soup preloads.