Efficacy and Safety of Bepirovirsen in Chronic Hepatitis B Infection

BACKGROUND

Bepirovirsen is an antisense oligonucleotide that targets all hepatitis B virus (HBV) messenger RNAs and acts to decrease levels of viral proteins.

METHODS

We conducted a phase 2b, randomized, investigator-unblinded trial involving participants with chronic HBV infection who were receiving or not receiving nucleoside or nucleotide analogue (NA) therapy. Participants were randomly assigned (in a 3:3:3:1 ratio) to receive weekly subcutaneous injections of bepirovirsen at a dose of 300 mg for 24 weeks (group 1), bepirovirsen at a dose of 300 mg for 12 weeks then 150 mg for 12 weeks (group 2), bepirovirsen at a dose of 300 mg for 12 weeks then placebo for 12 weeks (group 3), or placebo for 12 weeks then bepirovirsen at a dose of 300 mg for 12 weeks (group 4). Groups 1, 2, and 3 received loading doses of bepirovirsen. The composite primary outcome was a hepatitis B surface antigen (HBsAg) level below the limit of detection and an HBV DNA level below the limit of quantification maintained for 24 weeks after the planned end of bepirovirsen treatment, without newly initiated antiviral medication.

RESULTS

The intention-to-treat population comprised 457 participants (227 receiving NA therapy and 230 not receiving NA therapy). Among those receiving NA therapy, a primary-outcome event occurred in 6 participants (9%; 95% credible interval, 0 to 31) in group 1, in 6 (9%; 95% credible interval, 0 to 43) in group 2, in 2 (3%; 95% credible interval, 0 to 16) in group 3, and 0 (0%; post hoc credible interval, 0 to 8) in group 4. Among participants not receiving NA therapy, a primary-outcome event occurred in 7 participants (10%; 95% credible interval, 0 to 38), 4 (6%; 95% credible interval, 0 to 25), 1 (1%; post hoc credible interval, 0 to 6), and 0 (0%; post hoc credible interval, 0 to 8), respectively. During weeks 1 through 12, adverse events, including injection-site reactions, pyrexia, fatigue, and increased alanine aminotransferase levels, were more common with bepirovirsen (groups 1, 2, and 3) than with placebo (group 4).

CONCLUSIONS

In this phase 2b trial, bepirovirsen at a dose of 300 mg per week for 24 weeks resulted in sustained HBsAg and HBV DNA loss in 9 to 10% of participants with chronic HBV infection. Larger and longer trials are required to assess the efficacy and safety of bepirovirsen. (Funded by GSK; B-Clear ClinicalTrials.gov number, NCT04449029.).

The 111 Study: A Single-arm, Phase 3 Trial Evaluating One Cycle of Bleomycin, Etoposide, and Cisplatin as Adjuvant Chemotherapy in High-risk, Stage 1 Nonseminomatous or Combined Germ Cell Tumours of the Testis

BACKGROUND

Standard management in the UK for high-risk stage 1 nonseminoma germ cell tumours of the testis (NSGCTT) is two cycles of adjuvant bleomycin, etoposide (360 mg/m2), and cisplatin (BE360P) chemotherapy, or surveillance.

OBJECTIVE

To test whether one cycle of BE500P achieves similar recurrence rates to two cycles of BE360P.

DESIGN, SETTING, AND PARTICIPANTS

A total of 246 patients with vascular invasion-positive stage 1 NSGCTT or combined seminoma + NSGCTT were centrally registered in a single-arm prospective study.

INTERVENTION

One cycle comprising bleomycin 30000 IU on days 1, 8, and 15, etoposide 165 mg/m2 on days 1-3, and cisplatin 50 mg/m2 on days 1-2, plus antibacterial and granulocyte colony stimulating factor prophylaxis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was 2-yr malignant recurrence (MR); the aim was to exclude a rate of ≥5%. Participants had regular imaging and tumour marker (TM) assessment for 5 yr.

RESULTS AND LIMITATIONS

The median follow-up was 49 mo (interquartile range 37-60). Ten patients with rising TMs at baseline were excluded. Four patients had MR at 6, 7, 13, and 27 mo; all received second-line chemotherapy and surgery and three remained recurrence-free at 5 yr. The 2-yr MR rate was 1.3% (95% confidence interval 0.3-3.7%). Three patients developed nonmalignant recurrences with localised teratoma differentiated, rendered disease-free after surgery. Grade 3-4 febrile neutropenia occurred in 6.8% of participants.

CONCLUSIONS

BE500P is safe and the 2-yr MR rate is consistent with that seen following two BE360P cycles. The 111 study is the largest prospective trial investigating one cycle of adjuvant BE500P in high-risk stage 1 NSGCTT. Adoption of one cycle of BE500P as standard would reduce overall exposure to chemotherapy in this young population.

PATIENT SUMMARY

Removing the testicle fails to cure many patients with high-risk primary testicular cancer since undetectable cancers are often present elsewhere. A standard additional treatment in Europe is two cycles of chemotherapy to eradicate these. This trial shows one cycle has few adverse effects and comparable outcomes to those seen with two cycles.

BOXIT-A Randomised Phase III Placebo-controlled Trial Evaluating the Addition of Celecoxib to Standard Treatment of Transitional Cell Carcinoma of the Bladder (CRUK/07/004)

BACKGROUND

Non-muscle-invasive bladder cancer (NMIBC) has a significant risk of recurrence despite adjuvant intravesical therapy.

OBJECTIVE

To determine whether celecoxib, a cyclo-oxygenase 2 inhibitor, reduces the risk of recurrence in NMIBC patients receiving standard treatment.

DESIGN, SETTING, AND PARTICIPANTS

BOXIT (CRUK/07/004, ISRCTN84681538) is a double-blinded, phase III, randomised controlled trial. Patients aged ≥18 yr with intermediate- or high-risk NMIBC were accrued across 51 UK centres between 1 November 2007 and 23 July 2012.

INTERVENTION

Patients were randomised (1:1) to celecoxib 200mg twice daily or placebo for 2 yr. Patients with intermediate-risk NMIBC were recommended to receive six weekly mitomycin C instillations; high-risk NMIBC cases received six weekly bacillus Calmette-Guérin and maintenance therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was time to disease recurrence. Analysis was by intention to treat.

RESULTS AND LIMITATIONS

A total of 472 patients were randomised (236:236). With median follow-up of 44 mo (interquartile range: 36-57), 3-yr recurrence-free rate (95% confidence interval) was as follows: celecoxib 68% (61-74%) versus placebo 64% (57-70%; hazard ratio [HR] 0.82 [0.60-1.12], p=0.2). There was no difference in high-risk (HR 0.77 [0.52-1.15], p=0.2) or intermediate-risk (HR 0.90 [0.55-1.48], p=0.7) NMIBC. Subgroup analysis suggested that time to recurrence was longer in pT1 NMIBC patients treated with celecoxib compared with those receiving placebo (HR 0.53 [0.30-0.94], interaction test p=0.04). The 3-yr progression rates in high-risk patients were low: 10% (6.5-17%) and 9.7% (6.0-15%) in celecoxib and placebo arms, respectively. Incidence of serious cardiovascular events was higher in celecoxib (5.2%) than in placebo (1.7%) group (difference +3.4% [-0.3% to 7.2%], p=0.07).

CONCLUSIONS

BOXIT did not show that celecoxib reduces the risk of recurrence in intermediate- or high-risk NMIBC, although celecoxib was associated with delayed time to recurrence in pT1 NMIBC patients. The increased risk of cardiovascular events does not support the use of celecoxib.

PATIENT SUMMARY

Celecoxib was not shown to reduce the risk of recurrence in intermediate- or high-risk non-muscle-invasive bladder cancer (NMIBC), although celecoxib was associated with delayed time to recurrence in pT1 NMIBC patients. The increased risk of cardiovascular events does not support the use of celecoxib.

Clinical and patient-reported outcomes of SPARE - a randomised feasibility study of selective bladder preservation versus radical cystectomy

OBJECTIVES

To test the feasibility of a randomised trial in muscle-invasive bladder cancer (MIBC) and compare outcomes in patients who receive neoadjuvant chemotherapy followed by radical cystectomy (RC) or selective bladder preservation (SBP), where definitive treatment [RC or radiotherapy (RT)] is determined by response to chemotherapy.

PATIENTS AND METHODS

SPARE is a multicentre randomised controlled trial comparing RC and SBP in patients with MIBC staged T2-3 N0 M0, fit for both treatment strategies and receiving three cycles of neoadjuvant chemotherapy. Patients were randomised between RC and SBP before a cystoscopy after cycle three of neoadjuvant chemotherapy. Patients with ≤T1 residual tumour received a fourth cycle of neoadjuvant chemotherapy in both groups, followed by radical RT in the SBP group and RC in in the RC group; non-responders in both groups proceeded immediately to RC following cycle three. Feasibility study primary endpoints were accrual rate and compliance with assigned treatment strategy. The phase III trial was designed to demonstrate non-inferiority of SBP in terms of overall survival (OS) in patients whose tumours responded to neoadjuvant chemotherapy. Secondary endpoints included patient-reported quality of life, clinician assessed toxicity, loco-regional recurrence-free survival, and rate of salvage RC after SBP.

RESULTS

Trial recruitment was challenging and below the predefined target with 45 patients recruited in 30 months (25 RC; 20 SBP). Non-compliance with assigned treatment strategy was frequent, six of the 25 patients (24%) randomised to RC received RT. Long-term bladder preservation rate was 11/15 (73%) in those who received RT per protocol. OS survival was not significantly different between groups.

CONCLUSIONS

Randomising patients with MIBC between RC and SBP based on response to neoadjuvant chemotherapy was not feasible in the UK health system. Strong clinician and patient preferences for treatments impacted willingness to undergo randomisation and acceptance of treatment allocation. Due to the few participants, firm conclusions about disease and toxicity outcomes cannot be drawn.

The UK HeartSpare Study (Stage II): Multicentre Evaluation of a Voluntary Breath-hold Technique in Patients Receiving Breast Radiotherapy

AIMS

To evaluate the feasibility and heart-sparing ability of the voluntary breath-hold (VBH) technique in a multicentre setting.

MATERIALS AND METHODS

Patients were recruited from 10 UK centres. Following surgery for early left breast cancer, patients with any heart inside the 50% isodose from a standard free-breathing tangential field treatment plan underwent a second planning computed tomography (CT) scan using the VBH technique. A separate treatment plan was prepared on the VBH CT scan and used for treatment. The mean heart, left anterior descending coronary artery (LAD) and lung doses were calculated. Daily electronic portal imaging (EPI) was carried out and scanning/treatment times were recorded. The primary end point was the percentage of patients achieving a reduction in mean heart dose with VBH. Population systematic (Σ) and random errors (σ) were estimated. Within-patient comparisons between techniques used Wilcoxon signed-rank tests.

RESULTS

In total, 101 patients were recruited during 2014. Primary end point data were available for 93 patients, 88 (95%) of whom achieved a reduction in mean heart dose with VBH. Mean cardiac doses (Gy) for free-breathing and VBH techniques, respectively, were: heart 1.8 and 1.1, LAD 12.1 and 5.4, maximum LAD 35.4 and 24.1 (all P<0.001). Population EPI-based displacement data showed Σ =+1.3-1.9 mm and σ=1.4-1.8 mm. Median CT and treatment session times were 21 and 22 min, respectively.

CONCLUSIONS

The VBH technique is confirmed as effective in sparing heart tissue and is feasible in a multicentre setting.

111: A single-arm trial evaluating one cycle of BEP as adjuvant chemotherapy in high-risk, stage 1 non-seminomatous or combined germ cell tumors of the testis (NSGCTT)

400

Background: The standard post-orchiectomy treatment for UK patients (pts.) presenting with high-risk stage 1 NSGCTT is 2 cycles of bleomycin, etoposide (360mg/m2) & cisplatin (BE360P) chemotherapy or surveillance with BEPx3 at recurrence. 111 (CRUK/09/011) investigates whether BE500P x1 would achieve recurrence rates similar to BE360P x2. Methods: Pts aged ≥16 yrs post-orchiectomy for vascular invasion positive stage 1 NSGCTT or combined seminoma + NSGCT, with normalised tumour markers, received 1 cycle of bleomycin30000IU day 1, 8 & 15, etoposide165mg/m2 day 1, 2 & 3, &cisplatin50mg/m2day 1 & 2. All pts received a prophylactic antibacterial & GCSF. Pts were assessed for tumour markers q2m, q3m, q4m in years (yrs) 1, 2, 3, respectively and q6m in yrs 4 & 5. CT scan of chest, abdo and pelvis was performed at 6, 12, 24 & 60months (m) with chest x-ray at other visits. Toxicity was assessed using NCI CTCAE v3. Recurrences were independently reviewed. A sample size of 236 pts excludes a 2-yr recurrence rate of ≥5% if ≤6 recurrences were observed (80% power, 5% α). Results: Between 18/2/2010 and 31/7/2014 246 pts. were recruited at 33 UK centres; 54% with NSGCTT, 46% with combined GCT. Median follow-up was 39.1m (IQR 30.0-50.8). Four patients had malignant recurrences at 5, 8, 12 and 27m. 2 yr recurrence rate in 236 treated pts = 1.3% (95% CI: 0.4 to 4.0%). All 4 pts with recurrences were treated with 2ndline chemotherapy +/- surgery, 3 are alive and free from disease, 1 died at 9m with refractory disease. In addition there were 3 non-malignant recurrences at 7, 10 and 13m with teratoma differentiated in retroperitoneal nodes (3, 4 and 4.4cm). All these pts are disease-free post RPLND surgery. 41% pts had grade 3-4 CTCAE at end of treatment (neutropenia: 31% and febrile neutropenia: 7%). The 2 yr overall survival is 99.2% (95% CI: 96.7, 99.8%). Conclusions: BE500P is safely deliverable & 2 yr recurrence rate is similar to that seen with 2 cycles BE360P. The adoption of BE500P x1 as standard would reduce overall exposure to chemotherapy in this young pt population. 111 is the biggest formal, prospective trial to date investigating adjuvant BEPx1 in high-risk stage 1 NSGCTT. Clinical trial information: ISRCTN37875250.

Wide versus narrow excision margins for high-risk, primary cutaneous melanomas: long-term follow-up of survival in a randomised trial

BACKGROUND

The necessary margin of excision for cutaneous melanomas greater than 2 mm in thickness is controversial. At a median follow-up of 5 years, findings from our previously published randomised trial of narrow (1 cm) versus wide (3 cm) excision margins in patients with thick cutaneous melanomas showed that narrow margins were associated with an increased frequency of locoregional relapse, but no significant difference in overall survival was apparent. We now report a long-term survival analysis of that trial.

METHODS

We did a randomised, open-label multicentre trial in 59 hospitals--57 in the UK, one in Poland, and one in South Africa. Patients with one primary localised cutaneous melanoma greater than 2 mm in Breslow thickness on the trunk or limbs (excluding palms or soles) were randomly assigned (1:1) centrally to receive surgery with either a 1 cm or 3 cm excision margin following an initial surgery. The randomisation lists were generated with random permuted blocks and stratified by centre and extent of initial surgery. The endpoints of this analysis were overall survival and melanoma-specific survival. Analyses were done in the intention-to-treat population. This trial was not registered because it predated mandatory trial registration.

FINDINGS

Between Dec 16, 1992, and May 22, 2001, we randomly assigned 900 patients to surgery with either a 1 cm excision margin (n=453) or a 3 cm excision margin (n=447). At a median follow-up of 8·8 years (106 months [IQR 76-135], 494 patients had died, with 359 of these deaths attributed to melanoma. 194 deaths were attributed to melanoma in the 1 cm group compared with 165 in the 3 cm group (unadjusted hazard ratio [HR] 1·24 [95% CI 1·01-1·53]; p=0·041). Although a higher number of deaths overall occurred in the 1 cm group compared with the 3 cm group (253 vs 241), the difference was not significant (unadjusted HR 1·14 [95% CI 0·96-1·36]; p=0·14). Surgical complications were reported in 35 (8%) patients in the 1 cm excision margin group and 65 (15%) patients in the 3 cm group.

INTERPRETATION

Our findings suggest that a 1 cm excision margin is inadequate for cutaneous melanoma with Breslow thickness greater than 2 mm on the trunk and limbs. Current guidelines advise a 2 cm margin for melanomas greater than 2 mm in thickness but only a 1 cm margin for thinner melanomas. The adequacy of a 1 cm margin for thinner melanomas with poor prognostic features should be addressed in future randomised studies.

FUNDING

Cancer Research UK, North Thames National Health Service Executive, Northern and Yorkshire National Health Service Executive, British United Provident Association Foundation, British Association of Plastic Surgeons, the Meirion Thomas Cancer Research Fund, and the National Institute for Health and Research Biomedical Research Centre at The Royal Marsden NHS Foundation Trust.

Hyperbaric oxygen for patients with chronic bowel dysfunction after pelvic radiotherapy (HOT2): a randomised, double-blind, sham-controlled phase 3 trial

BACKGROUND

Hyperbaric oxygen has been used as a therapy for patients experiencing chronic intestinal syndromes after pelvic radiotherapy for decades, yet the evidence to support the use of this therapy is based almost exclusively on non-randomised studies. We aimed to provide conclusive results for the clinical benefits of hyperbaric oxygen in patients with chronic bowel dysfunction after radiotherapy for pelvic malignancies.

METHODS

HOT2 was a double-blind, sham-controlled, phase 3 randomised study of patients (≥18 years) with chronic gastrointestinal symptoms for 12 months or more after radiotherapy and which persisted despite at least 3 months of optimal medical therapy and no evidence of cancer recurrence. Participants were stratified by participating hyperbaric centre and randomly assigned (2:1) by a computer-generated list (block size nine or 12) to receive treatment with hyperbaric oxygen therapy or sham. Participants in the active treatment group breathed 100% oxygen at 2·4 atmospheres of absolute pressure (ATA) and the control group breathed 21% oxygen at 1·3 ATA; both treatment groups received 90-min air pressure exposures once daily for 5 days per week for a total of 8 weeks (total of 40 exposures). Staff at the participating hyperbaric medicine facilities knew the allocated treatment, but patients, clinicians, nurse practitioners, and other health-care professionals associated with patients' care were masked to treatment allocation. Primary endpoints were changes in the bowel component of the modified Inflammatory Bowel Disease Questionnaire (IBDQ) score and the IBDQ rectal bleeding score 12 months after start of treatment relative to baseline. The primary outcome was analysed in a modified intention-to-treat population, excluding patients who did not provide IBDQ scores within a predetermined time-frame. All patients have completed 12 months of follow-up and the final analysis is complete. The trial is registered with the ISRCTN registry, number ISRCTN86894066.

FINDINGS

Between Aug 14, 2009, and Oct 23, 2012, 84 participants were randomly assigned: 55 to hyperbaric oxygen and 29 to sham control. 75 (89%) participants received 40 pressure exposures, all participants returned the IBDQ at baseline, 75 (89%) participants returned the IBDQ at 2 weeks post-treatment, and 79 (94%) participants returned the IBDQ at 12 months post-start of treatment. Patients were excluded from analyses of co-primary endpoints if they had missing IBDQ scores for intestinal function or rectal bleeding at baseline or at 12 months. In an analysis of 46 participants in the active treatment group and 23 participants in the control group, we found no significant differences in the change of IBDQ bowel component score (median change from baseline to 12 months of 4 (IQR -3 to 11) in the treatment group vs 4 (-6 to 9) in the sham group; Mann-Whitney U score 0·67, p=0·50). In an analysis of 29 participants in the active treatment group and 11 participants in the sham group with rectal bleeding at baseline, we also found no significant differences in the change of IBDQ rectal bleeding score (median change from baseline to 12 months of 3 [1 to 3] in the treatment group vs 1 [1 to 2] in the sham group; U score 1·69, p=0·092). Common adverse events in both groups were eye refractive changes (three [11%] of 28 patients in the control group vs 16 [30%] of 53 patients in the treatment group), increased fatigue (three [11%] vs two [4%]), and ear pain (six [21%] vs 15 [28%]). Eight serious adverse events were reported in eight patients: two were reported in two patients in the control group (tonsillitis requiring surgery [grade 3]; recurrent cancer of the vulva [grade 4]) and six serious adverse events were reported in six patients in the treatment group (malignant spinal cord compression requiring surgery [grade 3]; malignant paraortic lymph node involvement requiring surgery [grade 3]; recurrence of vomiting and dehydration [grade 3]; diarrhoea and fever associated with Campylobacter infection [grade 3]; recurrence of abdominal pain, bloating, diarrhoea, and urinary tract infection [grade 3]; aneurysm [grade 4]), none of which were deemed treatment-related.

INTERPRETATION

We found no evidence that patients with radiation-induced chronic gastrointestinal symptoms, including those patients with rectal bleeding, benefit from hyperbaric oxygen therapy. These findings contrast with evidence used to justify current practices, and more level 1 evidence is urgently needed.

FUNDING

Cancer Research UK and National Health Service (NHS) funding to the National Institute of Health Research Biomedical Research Centre at The Royal Marsden and the Institute of Cancer Research.

Phantom hand and wrist movements in upper limb amputees are slow but naturally controlled movements

After limb amputation, patients often wake up with a vivid perception of the presence of the missing limb, called "phantom limb". Phantom limbs have mostly been studied with respect to pain sensation. But patients can experience many other phantom sensations, including voluntary movements. The goal of the present study was to quantify phantom movement kinematics and relate these to intact limb kinematics and to the time elapsed since amputation. Six upper arm and two forearm amputees with various delays since amputation (6months to 32years) performed phantom finger, hand and wrist movements at self-chosen comfortable velocities. The kinematics of the phantom movements was indirectly obtained via the intact limb that synchronously mimicked the phantom limb movements, using a Cyberglove® for measuring finger movements and an inertial measurement unit for wrist movements. Results show that the execution of phantom movements is perceived as "natural" but effortful. The types of phantom movements that can be performed are variable between the patients but they could all perform thumb flexion/extension and global hand opening/closure. Finger extension movements appeared to be 24% faster than finger flexion movements. Neither the number of types of phantom movements that can be executed nor the kinematic characteristics were related to the elapsed time since amputation, highlighting the persistence of post-amputation neural adaptation. We hypothesize that the perceived slowness of phantom movements is related to altered proprioceptive feedback that cannot be recalibrated by lack of visual feedback during phantom movement execution.

Cascading effects of a highly specialized beech-aphid-fungus interaction on forest regeneration

Specialist herbivores are thought to often enhance or maintain plant diversity within ecosystems, because they prevent their host species from becoming competitively dominant. In contrast, specialist herbivores are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa) colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator), ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia). A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently and repeatedly colonized the same large beech trees, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid-fungus interaction has the potential to negatively impact local forest regeneration via a cascade of indirect effects.

High-intensity interval training alters ATP pathway flux during maximal muscle contractions in humans

AIM

High-intensity interval training (HIT) results in potent metabolic adaptations in skeletal muscle; however, little is known about the influence of these adaptations on energetics in vivo. We used magnetic resonance spectroscopy to examine the effects of HIT on ATP synthesis from net PCr breakdown (ATPCK ), oxidative phosphorylation (ATPOX ) and non-oxidative glycolysis (ATPGLY ) in vivo in vastus lateralis during a 24-s maximal voluntary contraction (MVC).

METHODS

Eight young men performed 6 sessions of repeated, 30-s 'all-out' sprints on a cycle ergometer; measures of muscle energetics were obtained at baseline and after the first and sixth sessions.

RESULTS

Training increased peak oxygen consumption (35.8 ± 1.4 to 39.3 ± 1.6 mL min(-1) kg(-1) , P = 0.01) and exercise capacity (217.0 ± 11.0 to 230.5 ± 11.7 W, P = 0.04) on the ergometer, with no effects on total ATP production or force-time integral during the MVC. While ATP production by each pathway was unchanged after the first session, 6 sessions increased the relative contribution of ATPOX (from 31 ± 2 to 39 ± 2% of total ATP turnover, P < 0.001) and lowered the relative contribution from both ATPCK (49 ± 2 to 44 ± 1%, P = 0.004) and ATPGLY (20 ± 2 to 17 ± 1%, P = 0.03).

CONCLUSION

These alterations to muscle ATP production in vivo indicate that brief, maximal contractions are performed with increased support of oxidative ATP synthesis and relatively less contribution from anaerobic ATP production following training. These results extend previous reports of molecular and cellular adaptations to HIT and show that 6 training sessions are sufficient to alter in vivo muscle energetics, which likely contributes to increased exercise capacity after short-term HIT.

Treatment of canine parvoviral enteritis with interferon-omega in a placebo-controlled field trial

The clinical efficacy of a recombinant feline interferon (IFN) (type omega) was evaluated under field conditions for the treatment of dogs with parvoviral enteritis. In this multicentric, double-blind, placebo-controlled trial, 94 dogs from one to 28 months old were randomly assigned to two groups which were treated intravenously either with IFN (2.5 million units/kg) or placebo once a day for three consecutive days, and monitored for clinical signs and mortality for 10 days. Each dog received individual supportive treatment The data from 92 interpretable cases (43 IFN-treated and 49 placebo) showed that the clinical signs of the IFN-treated animals improved significantly in comparison with the control animals, and that there were only three deaths in the IFN group compared with 14 deaths in the placebo group (P = 0.0096) corresponding to a 4.4-fold reduction. Alternative analyses of the data taking into account the prior vaccination status of the dogs against canine parvovirus suggested that the IFN therapy resulted in a 6.4-fold reduction in mortality (P = 0.044) in the unvaccinated cohort, a significant reduction when compared with the vaccinated cohort.

Field efficacy of a 10 per cent pyriproxyfen spot-on for the prevention of flea infestations on cats

The clinical application of a new method for using the insect growth regulator, pyriproxyfen, for controlling flea populations in cat-owning homes is evaluated for the first time. In a multicentric, controlled and randomised trial, 107 flea-infested cats were treated with a minimum dose of 10 mg/kg bodyweight pyriproxyfen as a 10 per cent spot-on application on two occasions, with a three-month interval between doses. For comparison, 99 cats received lufenuron suspension orally, once a month, for six months. Flea counts decreased significantly over time in each group and were significantly lower in the pyriproxyfen group than in cats treated with the reference product. The percentage of 'zero-flea' cats increased from 49 per cent on day 30 to 88 per cent on day 180 in the pyriproxyfen group and from 30 to 71 per cent in the lufenuron group at the same time points (P<0.05). Appropriately timed topical applications of pyriproxyfen, therefore, offer a method of flea control in the domestic environment.

Therapeutic doses of oral methylphenidate significantly increase extracellular dopamine in the human brain

Methylphenidate (Ritalin) is the most commonly prescribed psychoactive drug in children for the treatment of attention deficit hyperactivity disorder (ADHD), yet the mechanisms responsible for its therapeutic effects are poorly understood. Whereas methylphenidate blocks the dopamine transporter (main mechanism for removal of extracellular dopamine), it is unclear whether at doses used therapeutically it significantly changes extracellular dopamine (DA) concentration. Here we used positron emission tomography and [(11)C]raclopride (D2 receptor radioligand that competes with endogenous DA for binding to the receptor) to evaluate whether oral methylphenidate changes extracellular DA in the human brain in 11 healthy controls. We showed that oral methylphenidate (average dose 0.8 +/- 0.11 mg/kg) significantly increased extracellular DA in brain, as evidenced by a significant reduction in B(max)/K(d) (measure of D2 receptor availability) in striatum (20 +/- 12%; p < 0.0005). These results provide direct evidence that oral methylphenidate at doses within the therapeutic range significantly increases extracellular DA in human brain. This result coupled with recent findings of increased dopamine transporters in ADHD patients (which is expected to result in reductions in extracellular DA) provides a mechanistic framework for the therapeutic efficacy of methylphenidate. The increase in DA caused by the blockade of dopamine transporters by methylphenidate predominantly reflects an amplification of spontaneously released DA, which in turn is responsive to environmental stimulation. Because DA decreases background firing rates and increases signal-to-noise in target neurons, we postulate that the amplification of weak DA signals in subjects with ADHD by methylphenidate would enhance task-specific signaling, improving attention and decreasing distractibility. Alternatively methylphenidate-induced increases in DA, a neurotransmitter involved with motivation and reward, could enhance the salience of the task facilitating the "interest that it elicits" and thus improving performance.

Resting brain metabolic activity in a 4 tesla magnetic field

MRI is a major tool for mapping brain function; thus it is important to assess potential effects on brain neuronal activity attributable to the requisite static magnetic field. This study used positron emission tomography (PET) and (18)F-deoxyglucose ((18)FDG) to measure brain glucose metabolism (a measure of brain function) in 12 subjects while their heads were in a 4 T MRI field during the (18)FDG uptake period. The results were compared with those obtained when the subjects were in the earth's field (PET scanner), and when they were in a simulated MRI environment in the PET instrument that imitated the restricted visual field of the MRI experiment. Whole-brain metabolism, as well as metabolism in occipital cortex and posterior cingulate gyrus, was lower in the real (4 T) and simulated (0 T) MRI environments compared with the PET. This suggests that the metabolic differences are due mainly to the visual field differences characteristic of the MRI and PET instruments. We conclude that a static magnetic field of 4 T does not in itself affect this fairly sensitive measure of brain activity.

Management of children with potential anaphylactic reactions in the community: a training package and proposal for good practice

BACKGROUND

The increase in potentially dangerous food allergic reactions (e.g. to peanuts and nuts) in children had lead to an increase in the prescription of adrenaline, including adrenaline for self- or parent-injection. This raises problems in the management of these children in schools. Our experience in response to this is described.

OBJECTIVE

To develop a training package to ensure that each child can continue at school but receive optimum emergency treatment in a safe environment. To provide education, training and support to school staff, and to support parents.

METHODS AND RESULTS

This paper describes a model of good practice in the support of children with potentially fatal anaphylactic reactions. The following points are emphasized. Children with a history of anaphylactic reactions should be expertly assessed prior to the prescription of adrenaline injection. A written treatment plan is essential. Parents need expert support in managing the child. Schools need training and support. Children should lead a normal life, and not be stigmatized or labelled by their problem. Close liaison between primary care, acute services, community services and education services are essential for the successful management of this problem. Data from a questionnaire showed the training package was of benefit, with considerable reduction in anxiety in school staff and parents.

CONCLUSION

A broad training package is essential: training in administration of adrenaline is only one aspect, and emphasis is placed on education, recognition of allergic reactions and prevention. The presence of children in school needing access to adrenaline is no longer perceived as a problem in our area. We recommend other health authorities provide a similar service.