Remote ultrasound diagnostics disrupting traditional military frontline healthcare delivery

Accurate and reliable diagnostic capability is essential in deployed healthcare to aid decision-making and mitigate risk. This is important for both the patient and the deployed healthcare system, especially when considering the prioritisation of scarce aeromedical evacuation assets and frontline resources. Novel ultrasound tele-guidance technology presents a valuable diagnostic solution for remotely deployed military clinicians. This report discusses the first use of a consultant radiologist guiding a clinician, untrained in ultrasound, to perform an ultrasound scan via a live tele-guidance feed in the deployed environment using the Butterfly iQ+ tele-guidance system. Distance scanning provided a diagnostic quality report when compared with locally performed imaging to improve patient care and maintain operational output. This example demonstrates feasibility of remote point-of-care imaging systems in provision of location-agnostic high-quality diagnostic capability. Future opportunities to develop care pathways using bedside tele-diagnostics will democratise access, drive efficiency and improve patient care experience and outcomes.

Ancestry-specific hereditary cancer panel yields: Moving toward more personalized risk assessment

Healthcare disparities in genomic medicine are well described. Despite some improvements, we continue to see fewer individuals of African American, Asian, and Hispanic ancestry undergo genetic counseling and testing compared to those of European ancestry. It is well established that variant of uncertain significance (VUS) rates are higher among non-European ancestral groups undergoing multi-gene hereditary cancer panel testing. However, pathogenic variant (PV) yields, and genomic data in general, are often reported in aggregate and derived from cohorts largely comprised of individuals of European ancestry. We performed a retrospective review of clinical and ancestral data for individuals undergoing multi-gene hereditary cancer panel testing to determine ancestry-specific PV and VUS rates. An ancestry other than European was reported in 29,042/104,851 (27.7%) of individuals. Compared to Europeans (9.4%), individuals of Middle Eastern ancestry were more likely to test positive for one or more pathogenic variants (12.1%, p = .0025), while African Americans were less likely (7.9%, p < .0001). Asian and Middle Eastern individuals were most likely (34.8% and 33.2%, respectively) to receive a report with an overall classification of VUS, while individuals of Ashkenazi Jewish and European ancestry were least likely (17.1% and 20.4%, respectively). These data suggest that in addition to higher VUS rates, there may be ancestry-specific PV yields. Providing aggregate data derived from cohorts saturated with European individuals does not adequately reflect genetic testing outcomes in minority groups, and interrogation of ancestry-specific data is a step toward a more personalized risk assessment.

Age-adjusted association of homologous recombination genes with ovarian cancer using clinical exomes as controls

Background

Genes in the homologous recombination pathway have shown varying results in the literature regarding ovarian cancer (OC) association. Recent case-control studies have used allele counts alone to quantify genetic associations with cancer.

Methods

A retrospective case-control study was performed on 6,182 women with OC referred for hereditary cancer multi-gene panel testing (cases) and 4,690 mothers from trios who were referred for whole-exome sequencing (controls). We present age-adjusted odds ratios (OR_Adj) to determine association of OC with pathogenic variants (PVs) in homologous recombination genes.

Results

Significant associations with OC were observed in BRCA1, BRCA2, RAD51C and RAD51D. Other homologous recombination genes, BARD1, NBN, and PALB2, were not significantly associated with OC. ATM and CHEK2 were only significantly associated with OC by crude odds ratio (OR_Crude) or by OR_Adj, respectively. However, there was no significant difference between OR_Crude and OR_Adj for these two genes. The significant association of PVs in BRIP1 by OR_Crude (2.05, CI = 1.11 to 3.94, P = 0.03) was not observed by OR_Adj (0.87, CI = 0.41 to 1.93, P = 0.73). Interestingly, the confidence intervals of the two effect sizes were significantly different (P = 0.04).

Conclusion

The lack of association of PVs in BRIP1 with OC by OR_Adj is inconsistent with some previous literature and current management recommendations, highlighted by the significantly older age of OC onset for BRIP1 PV carriers compared to non-carriers. By reporting OR_Adj, this study presents associations that reflect more informed genetic contributions to OC when compared to traditional count-based methods.

Electronic supplementary material

The online version of this article (10.1186/s13053-019-0119-3) contains supplementary material, which is available to authorized users.

Clinical validity assessment of genes frequently tested on hereditary breast and ovarian cancer susceptibility sequencing panels

PURPOSE

Several genes on hereditary breast and ovarian cancer susceptibility test panels have not been systematically examined for strength of association with disease. We employed the Clinical Genome Resource (ClinGen) clinical validity framework to assess the strength of evidence between selected genes and breast or ovarian cancer.

METHODS

Thirty-one genes offered on cancer panel testing were selected for evaluation. The strength of gene-disease relationship was systematically evaluated and a clinical validity classification of either Definitive, Strong, Moderate, Limited, Refuted, Disputed, or No Reported Evidence was assigned.

RESULTS

Definitive clinical validity classifications were made for 10/31 and 10/32 gene-disease pairs for breast and ovarian cancer respectively. Two genes had a Moderate classification whereas, 6/31 and 6/32 genes had Limited classifications for breast and ovarian cancer respectively. Contradictory evidence resulted in Disputed or Refuted assertions for 9/31 genes for breast and 4/32 genes for ovarian cancer. No Reported Evidence of disease association was asserted for 5/31 genes for breast and 11/32 for ovarian cancer.

CONCLUSION

Evaluation of gene-disease association using the ClinGen clinical validity framework revealed a wide range of classifications. This information should aid laboratories in tailoring appropriate gene panels and assist health-care providers in interpreting results from panel testing.

Germline pathogenic variants identified in women with ovarian tumors

OBJECTIVE

The recognition of genes implicated in ovarian cancer risk beyond BRCA1, BRCA2, and the Lynch syndrome genes has increased the variety of testing options available to providers and patients. We report the frequency of pathogenic variants identified among individuals with ovarian cancer undergoing clinical genetic testing via a multi-gene hereditary cancer panel.

METHODS

Genetic testing of up to 32 genes using a hereditary cancer panel was performed on 4439 ovarian cancer cases, and results were analyzed for frequency of pathogenic variants. Statistical comparisons were made using t-tests and Fisher's exact tests.

RESULTS

The positive yield was 13.2%. While BRCA1/2 pathogenic variants were most frequent, one third (33.7%) of positive findings were in other homologous recombination genes, and accounted for over 40.0% of findings in endometrioid and clear cell cases. Women with a personal history of breast cancer (22.1%), who reported a family history of ovarian cancer (17.7%), and/or serous histology (14.7%) were most likely to harbor a pathogenic variant. Those with very early onset (<30 years) and late onset (≥70 years) ovarian cancer had low positive yields.

CONCLUSIONS

Our study highlights the genetic heterogeneity of ovarian cancer, showing that a large proportion of cases are not due to BRCA1/2 and the Lynch syndrome genes, but still have an identifiable hereditary basis. These findings substantiate the utility of multi-gene panel testing in ovarian cancer care regardless of age at diagnosis, family history, or histologic subtype, providing evidence for testing beyond BRCA1/2 and the Lynch syndrome genes.

Germline pathogenic variants in patients with pheochromocytoma

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Background: Approximately 25% of pheochromocytomas (PCC) have a hereditary basis, and germline variants in the SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, VHL, FH, RET, MEN1, and NF1 genes have been associated with a predisposition to PCC and paraganglioma (PGL). Multi-gene hereditary cancer panel testing for PCC has become increasingly more common than single-gene testing algorithms. Identification of a pathogenic or likely pathogenic variant (PV/LPV) in one of these genes has important implications for surveillance in patients and their family members. Here we describe the spectrum of PV/LPV variants identified in individuals with PCC. Methods: We performed a retrospective review of clinical and molecular data for all individuals diagnosed with PCC who underwent panel testing through BioReference Laboratories that included at least SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, VHL, FH, RET, MEN1, and NF1 between January 2016 and February 2017. Results: Seventy-nine individuals underwent testing due to a personal (n = 76) or family (n = 3) history of PCC. The positive yield was 14% (11/79). The majority of PV/LPV were in SDHB (n = 4; 36%), followed by RET (n = 2, 18%), with the remaining variants being identified in SDHA (1), SDHC (1), VHL (1), TMEM127 (1), and MAX (1). Approximately half (6/11) of those with a PV/LPV had a non-syndromic presentation of a unilateral PCC with no reported family history of PCC or PGL. The average age at tumor diagnosis was lower for probands testing positive than those without PV/LPV (34y±14 vs 44y±16). Conclusions: Our data support previous recommendations that patients with apparently sporadic, non-syndromic PCC be considered for genetic testing. Panel testing is a useful tool for identifying individuals with hereditary PCC.

Male breast cancer in BRCA1 and BRCA2 mutation carriers: pathology data from the Consortium of Investigators of Modifiers of BRCA1/2

BACKGROUND

BRCA1 and, more commonly, BRCA2 mutations are associated with increased risk of male breast cancer (MBC). However, only a paucity of data exists on the pathology of breast cancers (BCs) in men with BRCA1/2 mutations. Using the largest available dataset, we determined whether MBCs arising in BRCA1/2 mutation carriers display specific pathologic features and whether these features differ from those of BRCA1/2 female BCs (FBCs).

METHODS

We characterised the pathologic features of 419 BRCA1/2 MBCs and, using logistic regression analysis, contrasted those with data from 9675 BRCA1/2 FBCs and with population-based data from 6351 MBCs in the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

Among BRCA2 MBCs, grade significantly decreased with increasing age at diagnosis (P = 0.005). Compared with BRCA2 FBCs, BRCA2 MBCs were of significantly higher stage (P for trend = 2 × 10(-5)) and higher grade (P for trend = 0.005) and were more likely to be oestrogen receptor-positive [odds ratio (OR) 10.59; 95 % confidence interval (CI) 5.15-21.80] and progesterone receptor-positive (OR 5.04; 95 % CI 3.17-8.04). With the exception of grade, similar patterns of associations emerged when we compared BRCA1 MBCs and FBCs. BRCA2 MBCs also presented with higher grade than MBCs from the SEER database (P for trend = 4 × 10(-12)).

CONCLUSIONS

On the basis of the largest series analysed to date, our results show that BRCA1/2 MBCs display distinct pathologic characteristics compared with BRCA1/2 FBCs, and we identified a specific BRCA2-associated MBC phenotype characterised by a variable suggesting greater biological aggressiveness (i.e., high histologic grade). These findings could lead to the development of gender-specific risk prediction models and guide clinical strategies appropriate for MBC management.

Degarelix: a review of its use in patients with prostate cancer

Degarelix (Firmagon(®); Gonax(®)) is a gonadotropin-releasing hormone receptor antagonist that is approved for the treatment of advanced (hormone-dependent) prostate cancer in the US and EU and the treatment of prostate cancer in Japan. In a pivotal randomized, controlled, 12-month phase III study, degarelix (initial subcutaneous dose of 240 mg followed by monthly dosages of 80 mg) was noninferior to leuprolide (monthly intramuscular dosages of 7.5 mg) in patients with prostate cancer of any stage for which endocrine treatment was indicated (except neoadjuvant hormonal therapy) with regard to suppression of testosterone to castration levels (i.e. ≤0.5 ng/mL). Suppression of testosterone and prostate-specific antigen (PSA) levels was faster with degarelix than with leuprolide, and no testosterone surges or microsurges were seen in degarelix recipients. Suppression of testosterone and PSA levels was maintained for the 12-month study duration and continued for up to 5 years in an extension to the main trial (including in patients switching from leuprolide to degarelix in the extension). The drug was generally well tolerated, with most adverse events being mild to moderate in severity. Injection-site reactions and events reflecting the expected effects of testosterone suppression (e.g. hot flushes, weight increase) were the most common treatment-emergent adverse events. Thus, degarelix is a useful option for the treatment of prostate cancer in patients for whom endocrine treatment is indicated.

Regorafenib: a review of its use in previously treated patients with progressive metastatic colorectal cancer

Regorafenib (Stivarga) is an inhibitor of multiple protein kinases, including those involved in oncogenesis, tumour angiogenesis and maintenance of the tumour microenvironment. The drug is approved as monotherapy for the treatment of metastatic colorectal cancer (mCRC) in patients who have previously received all standard systemic anticancer treatments (US, EU and Canada) or in patients with unresectable, advanced or recurrent colorectal cancer (Japan). In the randomized, controlled COloRectal cancer treated with REgorafenib or plaCebo after failure of standard Therapy (CORRECT) trial, regorafenib 160 mg once daily for the first 3 weeks of each 4-week cycle plus best supportive care (BSC) was associated with a significantly longer median overall survival than placebo plus BSC in patients with previously treated, progressive mCRC. The drug was also associated with significantly longer progression-free survival and better disease control rates than placebo, although objective response rates were similar in both treatment groups. Regorafenib did not appear to compromise health-related quality of life over the study duration and had a generally acceptable tolerability profile. The introduction of regorafenib expands the currently limited range of effective treatment options in patients with previously treated, progressive mCRC.

Rivaroxaban: a review of its use in the prevention of stroke and systemic embolism in patients with atrial fibrillation

Rivaroxaban (Xarelto(®)), a direct factor Xa inhibitor, is approved for the prevention of stroke and systemic embolism in patients with atrial fibrillation (AF) in Canada or those with nonvalvular AF (NVAF) in the EU, US and Japan. It is administered at a fixed oral dose and generally does not require routine monitoring of coagulation parameters. In the ROCKET AF trial in patients with NVAF and a moderate to high risk of stroke, oral rivaroxaban 20 mg once daily (15 mg once daily in patients with moderate renal impairment) was noninferior to oral dose-adjusted warfarin once daily in preventing primary endpoint events (i.e. stroke and systemic embolism) in the per-protocol population (primary noninferiority analysis) and superior in the on-treatment safety population (primary superiority analysis). Several ROCKET AF subgroup analyses indicated that the treatment effect of rivaroxaban was consistent across patient subgroups stratified according to baseline factors, including the presence or absence of previous stroke or transient ischaemic attack. Patients with moderate renal impairment receiving the reduced rivaroxaban dosage (15 mg once daily) showed a treatment effect consistent with that seen with rivaroxaban 20 mg once daily in patients with normal renal function. The tolerability profile of rivaroxaban was generally acceptable in ROCKET AF, with no significant difference between rivaroxaban and warfarin in the incidence of major or nonmajor clinically-relevant bleeding events (primary safety endpoint). In the Japanese ROCKET AF trial, rivaroxaban 15 mg once daily (10 mg once daily in patients with moderate renal impairment) was noninferior to oral dose-adjusted warfarin once daily in the incidence of major or nonmajor clinically-relevant bleeding (primary study outcome). Thus, rivaroxaban is a reasonable alternative to warfarin for the prevention of stroke and systemic embolism in patients with NVAF.

Multicomponent meningococcal serogroup B vaccine (4CMenB; Bexsero(®)): a review of its use in primary and booster vaccination

Multicomponent meningococcal serogroup B vaccine (4CMenB; Bexsero(®)) is a unique vaccine containing four main immunogenic components: three recombinant proteins combined with outer membrane vesicles derived from meningococcal NZ98/254 strain. After three doses of 4CMenB (administered at 2, 3, and 4 months or 2, 4, and 6 months of age) in vaccine-naive infants, the majority of infants had seroprotective human complement serum bactericidal assay (hSBA) antibody titers against the meningococcal serogroup B test strains selected to be specific for the vaccine antigens in randomized, open-label or observer-blind, multicenter, phase IIb or III trials. In extensions to the phase III trial, two doses of 4CMenB administered between 12 and 15 months of age in vaccine-naive infants, and a single booster dose of 4CMenB administered at 12 months of age in vaccine-experienced infants, also elicited robust immunogenic responses. In a phase IIb/III trial, the majority of adolescents (aged 11-17 years) achieved seroprotective hSBA antibody titers against meningococcal serogroup B test strains after two doses of 4CMenB, and a third dose did not appear to add any extra protection. In adults who were potentially at an increased risk of occupational exposure to meningococcal isolates, seroprotection rates were high after one dose of 4CMenB and increased further after two or three doses in a small noncomparative, two-center, phase II trial. The reactogenicity of 4CMenB was generally acceptable in clinical trials. However, the vaccine was associated with more solicited systemic adverse events (particularly fever) in infants when coadministered with routine infant vaccines than when these vaccines were administered alone. In conclusion, 4CMenB effectively elicited immune responses against meningococcal serogroup B test strains selected to be specific for the vaccine antigens in infants, adolescents, and adults.

Bilastine: in allergic rhinitis and urticaria

Bilastine is an orally administered, second-generation antihistamine used in the symptomatic treatment of seasonal or perennial allergic rhinoconjunctivitis and urticaria. In two well designed phase III trials, 14 days' treatment with bilastine was associated with a significantly lower area under the effect curve (AUEC) for the reflective total symptom score (TSS) than placebo in patients with symptomatic seasonal allergic rhinitis. Additionally, reflective nasal symptom scores were significantly lower in bilastine than placebo recipients in patients with a history of seasonal allergic rhinitis who were challenged with grass pollen allergen in a single-centre, phase II study. Neither bilastine nor cetirizine was effective in the treatment of perennial allergic rhinitis with regard to the mean AUEC for reflective TSS in another well designed phase III trial. However, results may have been altered by differences in some baseline characteristics and placebo responses between study countries. In another well designed phase III trial, compared with placebo, bilastine was associated with a significantly greater change from baseline to day 28 in the mean reflective daily urticaria symptom score in patients with chronic urticaria. There were no significant differences in primary endpoint results between bilastine and any of the active comparators used in these trials (i.e. cetirizine, levocetirizine and desloratadine). Bilastine was generally well tolerated, with a tolerability profile that was generally similar to that of the other second-generation antihistamines included in phase III clinical trials.

Live attenuated influenza vaccine (Fluenz™): a guide to its use in the prevention of seasonal influenza in children in the EU

Live attenuated influenza vaccine (LAIV).[Fluenz™] has a convenient intranasal route of administration. In the EU, it is indicated for the prevention of influenza disease caused by the influenza virus strains contained in the vaccine in children and adolescents aged 2 years to <18 years. The vaccine elicits a high immunogenic response, is protective against seasonal influenza infection and is associated with the development of herd immunity. LAIV is generally well tolerated, with the safety of the vaccine in the approved pediatric population generally considered to be similar to that of placebo based on clinical trials and extensive experience involving more than 39 million vaccine doses.

Pirfenidone: in idiopathic pulmonary fibrosis

Pirfenidone is an orally administered pyridine that has orphan designation for the treatment of mild to moderate idiopathic pulmonary fibrosis (IPF) in the EU. Pirfenidone 2403 mg/day for 72 weeks administered to patients with IPF was associated with a significantly lower mean decline in the percent predicted forced vital capacity than placebo (primary endpoint) according to data from one of two randomized, double-blind, multinational trials (studies 004 and 006 [also known as the CAPACITY trials]), and data from a pooled analysis of both trials. In another randomized, double-blind, multicentre Japanese trial, the adjusted mean in the change in vital capacity from baseline to week 52 was significantly lower in patients with IPF who received pirfenidone 1800 mg/day (considered to be comparable to the 2403 mg/day dose in studies 004 and 006 on a weight-normalized basis) than in those who received placebo (primary endpoint). Pirfenidone had an acceptable tolerability profile in clinical trials, with most adverse events being mild to moderate in severity.

Live attenuated influenza vaccine (FluMist®; Fluenz™): a review of its use in the prevention of seasonal influenza in children and adults

Live attenuated influenza vaccine (LAIV) is an intranasally administered trivalent, seasonal influenza vaccine that contains three live influenza viruses (two type A [H1N1 and H3N2 subtypes] and one type B). LAIV was effective in protecting against culture-confirmed influenza caused by antigenically matched and/or distinct viral strains in children aged ≤71 months enrolled in three phase III trials. LAIV was superior to trivalent inactivated influenza vaccine (TIV) in protecting against influenza caused by antigenically-matching viral strains in a multinational phase III trial in children aged 6-59 months. LAIV was also significantly more effective than TIV in decreasing the incidence of culture-confirmed influenza illness in two open-label studies (in children with recurrent respiratory tract illnesses aged 6-71 months and in children and adolescents with asthma aged 6-17 years). LAIV did not differ significantly from placebo in preventing febrile illnesses in adults (primary endpoint) enrolled in a phase III trial. However, LAIV significantly reduced the incidence of febrile upper respiratory tract illnesses (URTI), severe febrile illnesses, febrile URTI-related work absenteeism and healthcare provider use. In another well designed trial in adults, LAIV significantly reduced the incidence of symptomatic, laboratory-confirmed influenza compared with placebo (but not intramuscular TIV). LAIV was generally well tolerated in most age groups, with the majority of adverse events being mild to moderate in severity, and runny nose/nasal congestion being the most common. In a large phase III trial, LAIV, compared with TIV, was associated with an increased incidence of medically significant wheezing in vaccine-naive children aged <24 months and an increased incidence of hospitalization in children aged 6-11 months; LAIV is not approved for use in children <24 months. LAIV was not always associated with high rates of seroconversion/seroresponse, particularly in older children and adults, or in subjects with detectable levels of haemagglutination-inhibiting antibodies at baseline. However, LAIV did elicit mucosal (nasal) IgA antibody responses and strong cell-mediated immunity responses. Only one confirmed case of LAIV virus transmission to a placebo recipient (who did not become ill) occurred in a transmission study conducted in young children. The immunogenic response to LAIV in young healthy children was not affected by concomitant administration with other commonly administered childhood vaccines. In conclusion, intranasal LAIV seasonal influenza vaccine is effective and well tolerated in children, adolescents and adults. LAIV was more effective than TIV in children, although this advantage was not seen in adults. In the US, LAIV is indicated for the active immunization of healthy subjects aged 2-49 years against influenza disease caused by virus subtypes A and type B contained in the vaccine.

OROS hydromorphone prolonged release: a review of its use in the management of chronic, moderate to severe pain

OROS hydromorphone prolonged release (OROS hydromorphone) [Jurnista] is a once-daily formulation of the opioid agonist hydromorphone that utilizes OROS (osmotic-controlled release oral delivery system) technology to deliver the drug at a near constant rate, thereby providing consistent analgesia over a 24-hour period. It is indicated for use in patients with severe pain and contraindicated in those with acute or post-operative pain. In several, randomized, multicentre, phase III trials, oral OROS hydromorphone administered once daily for up to 52 weeks was generally effective in the treatment of patients with chronic, moderate to severe cancer or nonmalignant/noncancer pain with regard to improvements from baseline to endpoint in patient-assessed measures of pain intensity, pain relief and/or functional impairment. Pharmacoeconomic analyses suggest that OROS hydromorphone provides greater cost utility than other opioids in this patient population. In addition, OROS hydromorphone was generally well tolerated in clinical trials, with most adverse events being mild to moderate in severity and similar to those seen with other opioids. Thus, OROS hydromorphone is an effective and useful alternative to other opioids for the treatment of patients with severe pain.

Bosentan: in pediatric patients with pulmonary arterial hypertension

Bosentan is a dual endothelin-1 (ET-1) receptor antagonist that has affinity for ET-1 receptors A and B. In the EU, oral bosentan (Tracleer) is indicated to improve exercise capacity and symptoms in patients with pulmonary arterial hypertension (PAH) of WHO functional class III; benefits have also been seen in patients with WHO functional class II PAH. Bosentan is available as film-coated tablets, and a new dispersible formulation of bosentan has also recently been approved in the EU for the treatment of PAH in children aged > or =2 years. A noncomparative, multicenter, phase III trial (FUTURE-1), which was primarily designed to investigate the pharmacokinetics of dispersible bosentan in pediatric patients, demonstrated that increasing the dosage of bosentan from 2 to 4 mg/kg twice daily was unlikely to result in increased exposure to bosentan. Exploratory measures of efficacy in FUTURE-1 demonstrated that target dosages of twice-daily dispersible bosentan 4 mg/kg (in patients weighing <30 kg) or 120 mg (in patients weighing > or =30 kg) for 12 weeks were beneficial in pediatric patients (aged > or =2 to <12 years) with WHO functional class II or III PAH. Film-coated bosentan 31.25, 62.5, or 125 mg (in pediatric patients weighing 10-20, >20-40, or >40 kg, respectively) twice daily for 12 weeks significantly (p < 0.05) improved the majority of hemodynamic measures evaluated as an exploratory measure in pediatric patients (aged 3-15 years) with WHO functional class II or III PAH in another noncomparative, multicenter, pharmacokinetic trial (BREATHE-3). However, there was no significant change in peak oxygen consumption or mean walk distance in those patients capable (i.e. children aged > or =8 years) of performing the 6-minute walk test. Bosentan was generally well tolerated in clinical trials of pediatric patients with PAH, with most adverse events being mild or moderate in severity and resolving with continued treatment.

Micafungin: a review of its use in the prophylaxis and treatment of invasive Candida infections in pediatric patients

Intravenous micafungin (Mycamine; Funguard) is an echinocandin indicated in Japan and the EU for the treatment of pediatric patients (including neonates) with invasive candidiasis and as prophylaxis against Candida infection in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). In the EU, micafungin is also indicated in pediatric patients who are expected to have neutropenia for >/=10 days. In Japan, children may also receive micafungin for the treatment of, or as prophylaxis against, invasive Aspergillus infection. Micafungin is not currently approved for use in pediatric patients in the US. Micafungin has very good antifungal activity against a wide range of Candida spp. in vitro. It has a favorable pharmacokinetic profile allowing for once-daily administration, has few drug-drug interactions, and reports of resistance are rare. The results of pediatric substudies indicate that intravenous micafungin is effective in a majority of patients for the treatment of candidemia and other types of invasive candidiasis, and provides effective prophylaxis against invasive fungal infections in pediatric patients undergoing HSCT. The tolerability profile of micafungin in pediatric patients was generally acceptable. In the EU, micafungin is indicated for use when other antifungal medications are not appropriate. Therefore, micafungin provides an alternative to other antifungal agents used in the management of candidemia and invasive candidiasis in pediatric patients, or as prophylaxis against fungal infections in pediatric patients undergoing HSCT.

Duloxetine: a review of its use in the treatment of generalized anxiety disorder

Duloxetine (Cymbalta(R)) is a potent serotonin and noradrenaline (norepinephrine) reuptake inhibitor (SNRI) in the CNS. It is indicated for the treatment of generalized anxiety disorder (GAD) as well as other indications. In patients with GAD of at least moderate severity, oral duloxetine 60-120 mg once daily was effective with regard to improvement from baseline in assessments of anxiety and functional impairment, and numerous other clinical endpoints. Longer-term duloxetine 60-120 mg once daily also demonstrated efficacy in preventing or delaying relapse in responders among patients with GAD. In addition, duloxetine was generally well tolerated, with most adverse events being of mild to moderate severity in patients with GAD in short- and longer-term trials. Additional comparative and pharmacoeconomic studies are required to position duloxetine among other selective serotonin reuptake inhibitors and SNRIs. However, available clinical data, and current treatment guidelines, indicate that duloxetine is an effective first-line treatment option for the management of GAD. Duloxetine is a potent and selective inhibitor of serotonin and noradrenaline transporters, and a weak inhibitor of dopamine transporters. It has a low affinity for neuronal receptors, such as alpha(1)- and alpha(2)-adrenergic, dopamine D(2), histamine H(1), muscarinic, opioid and serotonin receptors, as well as ion channel binding sites and other neurotransmitter transporters, such as choline and GABA transporters. It does not inhibit monoamine oxidase types A or B. The pharmacokinetics of duloxetine in healthy volunteers were dose proportional over the range of 40-120 mg once daily. Steady state was typically reached by day 3 of administration. Duloxetine may be administered without regard to food or time of day. Duloxetine is highly protein bound and is widely distributed throughout tissues. It is rapidly and extensively metabolized in the liver by cytochrome P450 (CYP) 1A2 and 2D6, and its numerous metabolites, which are inactive, are mainly excreted in the urine. The mean elimination half-life of duloxetine is approximately 12 hours. Duloxetine is a substrate for CYP1A2 and CYP2D6 and a moderate inhibitor of CYP2D6. Concomitant use of duloxetine and potent CYP1A2 inhibitors should be avoided and duloxetine should be used with caution in patients receiving drugs that are extensively metabolized by CYP2D6, particularly those with a narrow therapeutic index. Duloxetine was effective in the short-term treatment of patients with primary GAD of at least moderate severity. In four randomized, double-blind, placebo-controlled, multicentre, phase III trials, duloxetine 60-120 mg once daily for 9 or 10 weeks was significantly more effective than placebo with regard to the primary endpoint of mean change in Hamilton Anxiety Rating Scale (HAM-A) total score from baseline to study endpoint. In addition, all other endpoints were generally improved from baseline to a greater extent with duloxetine 60-120 mg once daily than with placebo. Duloxetine also improved patient role functioning (assessed using Sheehan Disability Scale global impairment functioning scores), health-related quality of life and patient well-being compared with placebo. Duloxetine was effective in patients with GAD who were aged >/=65 years. Pooled results of data from the two short-term efficacy trials that also included an active comparator arm showed that the mean change in HAM-A scores with duloxetine relative to placebo were of the same magnitude as those with venlafaxine extended release versus placebo. Duloxetine 60-120 mg once daily was also more effective than placebo in preventing or delaying relapse in responders to duloxetine in a longer-term study. In this study, patients with GAD received duloxetine during a 26-week, open-label, acute treatment phase and responders were then randomized to continue on duloxetine or receive placebo during a 26-week, double-blind, continuation phase. Time to relapse was significantly longer in duloxetine recipients than in placebo recipients. In addition, significantly fewer duloxetine recipients than placebo recipients relapsed during the double-blind phase of the trial and more duloxetine recipients achieved remission. Short- (9-10 weeks) and longer-term (52 weeks) treatment with duloxetine 60-120 mg once daily was generally well tolerated in patients with GAD, with the majority of adverse events being of mild to moderate severity. Nausea, dry mouth, headache, constipation, dizziness and fatigue were among the most common treatment-emergent adverse events. The adverse event profile of duloxetine did not differ with dose or treatment duration. Significantly more patients receiving short-term duloxetine than placebo discontinued treatment because of an adverse event, with nausea being the only event that resulted in significantly more treatment discontinuations in duloxetine recipients than in placebo recipients. Serious adverse events were uncommon with both short- and longer-term duloxetine treatment. Two episodes of attempted suicide and one episode of completed suicide occurred in duloxetine recipients during the 24-week open-label phase of a longer-term trial. No deaths or suicides were reported in any of the short-term trials. Discontinuation-emergent adverse events, most commonly nausea and dizziness, occurred in up to one-third of duloxetine recipients in the short-term trials.

Prepandemic influenza vaccine H5N1 (split virion, inactivated, adjuvanted) [Prepandrix]: a review of its use as an active immunization against influenza A subtype H5N1 virus

Although rare, influenza pandemics are a recurrent event, and influenza A/H5N1 is generally considered to be the most likely causative agent of the next pandemic. Vaccines are widely considered to be the first line of defense for protecting populations in advance of an influenza pandemic. Because it is not known beforehand which strain of influenza A/H5N1 virus could give rise to a pandemic, prepandemic vaccines that impart broad cross-reactive immunogenicity are required. In addition, low doses of H5 hemagglutinin are preferable in order to make antigen supplies go further towards meeting global demands for prepandemic vaccines.Prepandemic influenza vaccine H5N1 [Prepandrix(trade mark); AS03-H5N1 vaccine] is a split virion, inactivated vaccine containing H5 hemagglutinin antigen adjuvanted with a novel 10% oil-in-water emulsion-based adjuvant system (AS03). It is approved in the EU for use as an active immunization against H5N1 subtype influenza A virus (influenza A/H5N1 virus) in adults aged 18-60 years. The recommended dosage in this population is two doses of 0.5 mL containing 3.75 microg of H5 hemagglutinin, administered > or =21 days apart. Adjuvantation of H5N1 vaccine with AS03 allows for a reduction in the H5 hemagglutinin dose required to elicit an adequate immune response, and administration of two doses of the adjuvanted vaccine met all criteria for the licensure of influenza vaccines set out in European Committee for Proprietary Medicinal Products (CPMP) and US FDA documents. In two clinical trials, two doses of AS03-H5N1 vaccine containing 3.75 microg of H5 hemagglutinin induced an immune response in healthy volunteers aged 18-60 years against the homologous, clade 1 vaccine strain, A/Vietnam/1194/2004, and the heterologous, drifted, clade 2 nonvaccine strains, A/Anhui/1/2005, A/Indonesia/5/2005, and A/turkey/Turkey/1/2005. This cross-clade response persisted for > or =6 months following administration of the first vaccine dose in the majority of vaccine recipients. In addition, AS03-H5N1 vaccine protected against lethal challenge with A/Vietnam/1194/2004 or A/Indonesia/5/2005 in animal studies. The vaccine was generally well tolerated and adverse events were transient and predominantly of mild to moderate severity.AS03-H5N1 vaccine has demonstrated antigen dose-sparing properties and cross-clade reactive immunity in clinical trials and challenge studies in animal models. As a result, stockpiling AS03-H5N1 vaccine has the potential to protect populations against a pandemic caused by an influenza A/H5N1 virus and may represent an important measure in pandemic preparedness.

Spotlight on enoxaparin in ST-segment elevation myocardial infarction

Enoxaparin (enoxaparin sodium; Lovenox) is a low-molecular-weight heparin (LMWH) that has recently been approved by the US FDA for use in patients with medically managed ST-segment myocardial infarction (STEMI), or STEMI with subsequent percutaneous coronary intervention. It binds to and potentiates the action of antithrombin, and inhibits coagulation factors XIa, IXa, Xa, and IIa (thrombin), thereby preventing formation of blood clots. Unfractionated heparin (UFH) has long been regarded as the antithrombotic agent of choice in the adjunctive treatment of patients with STEMI. However, compared with UFH, enoxaparin has many advantages in terms of its pharmacodynamic profile and, potentially, also its efficacy. Enoxaparin was significantly more effective than UFH in patients presenting with STEMI who underwent fibrinolytic therapy in terms of the 30-day combined incidence of all-cause mortality plus recurrent nonfatal myocardial infarction (MI) [primary endpoint], and all-cause mortality plus recurrent nonfatal MI plus urgent revascularization (secondary endpoint) in the ExTRACT-TIMI 25 trial. The significant difference in the incidence of the composite primary endpoint between these two groups was maintained at the 1-year follow-up. Although bleeding was reported more frequently with enoxaparin than with UFH in the ExTRACT-TIMI 25 trial, enoxaparin was associated with a net clinical benefit relative to UFH. Patients in this trial received enoxaparin as an initial 30 mg intravenous bolus, followed by 1 mg/kg subcutaneously within 15 minutes and then every 12 hours for up to 8 days; the first two subcutaneous dosages were not to exceed 100 mg. Patients > or =75 years of age did not receive the initial bolus of enoxaparin and the 12-hourly dosages were reduced to 0.75 mg/kg; the dose was also reduced to 1 mg/kg every 24 hours in patients of any age who had an estimated creatinine clearance of <30 mL/min. Data from several earlier randomized, multicentre, phase III trials support these results.

Trabectedin : a review of its use in the management of soft tissue sarcoma and ovarian cancer

Trabectedin (Yondelis); ET-743) is an antineoplastic agent that was originally derived from the Caribbean marine tunicate Ecteinascidia turbinata and is now produced synthetically. It binds to the minor groove of DNA, disrupting the cell cycle and inhibiting cell proliferation. Intravenous trabectedin administered once every 3 weeks is approved as monotherapy in Europe for use in patients with advanced soft tissue sarcoma (STS) after failure of standard therapy with anthracyclines or ifosfamide, or who are unsuited to receive these agents. It also has orphan drug status in STS in the US and in ovarian cancer in the US and Europe, and is under investigation as combination therapy in patients with recurrent ovarian cancer. In clinical trials, trabectedin showed efficacy in the treatment of patients with advanced or metastatic STS, especially those with leiomyosarcoma or liposarcoma, as well as in women with platinum-sensitive advanced or recurrent ovarian cancer. In addition, its tolerability profile was generally manageable. The introduction of trabectedin expands the currently limited range of effective treatment options for patients with advanced or metastatic STS; trabectedin also has the potential to be a beneficial treatment for advanced or recurrent ovarian cancer.

Maraviroc

Maraviroc is a specific, slowly reversible, noncompetitive, small-molecule antagonist of the CCR5 chemokine receptor, which also serves as an HIV-1 coreceptor. By acting as an antagonist at the CCR5 coreceptor, maraviroc inhibits HIV-1 from entering host cells. Clinical data for maraviroc are available from two large, well designed, ongoing phase IIb/III trials (MOTIVATE-1 and MOTIVATE-2) conducted in patients infected with R5-tropic HIV-1 who had previously received at least one agent from three of the four classes of antiretroviral drugs and/or were triple-class resistant. According to 24-week interim results of the MOTIVATE-1 and -2 trials, a significantly greater reduction in viral load occurred in patients receiving maraviroc 150 or 300mg (depending on optimised background therapy [OBT]) twice daily plus OBT compared with placebo plus OBT. This significant difference was maintained at 48 weeks in MOTIVATE-1. In the MOTIVATE-1 and -2 trials, a significantly greater proportion of patients receiving maraviroc plus OBT achieved an HIV-1 RNA level <400 and <50 copies/mL compared with those receiving placebo plus OBT. In addition, the CD4+ cell count was increased to a significantly greater extent with maraviroc plus OBT compared with placebo plus OBT. The 48-week results of MOTIVATE-1 also report a significant difference in favour of maraviroc for all these endpoints. In general, maraviroc at dosages of up to 300mg twice daily was well tolerated in treatment-experienced patients infected with R5-tropic HIV-1.

Human Plasma von Willebrand Factor/Factor VIII Complex (Haemate?? P/Humate-P??)

Haemate P/Humate-P is a pasteurised human plasma-derived concentrate containing coagulation factor VIII and a near-normal spectrum of von Willebrand factor multimers, including high-molecular weight multimers, for intravenous use in patients with von Willebrand disease or haemophilia A. Extensive clinical experience over the past 25 years has shown that Haemate P/Humate-P provides effective haemostatic control for the prevention and treatment of bleeds in patients with these conditions, with no confirmed cases of viral or prion transmission occurring during this time. In small prospective and retrospective noncomparative studies, Haemate P/Humate-P provided effective haemostatic control for the prevention and treatment of bleeding episodes in the vast majority of paediatric and adult patients with von Willebrand disease. Haemate P/Humate-P was generally well tolerated in patients with von Willebrand disease or haemophilia A.

Mechanics of the kinesin step

Kinesin is a molecular walking machine that organizes cells by hauling packets of components directionally along microtubules. The physical mechanism that impels directional stepping is uncertain. We show here that, under very high backward loads, the intrinsic directional bias in kinesin stepping can be reversed such that the motor walks sustainedly backwards in a previously undescribed mode of ATP-dependent backward processivity. We find that both forward and backward 8-nm steps occur on the microsecond timescale and that both occur without mechanical substeps on this timescale. The data suggest an underlying mechanism in which, once ATP has bound to the microtubule-attached head, the other head undergoes a diffusional search for its next site, the outcome of which can be biased by an applied load.

Comparison of a sprayable pheromone formulation and two hand-applied pheromone dispensers foruse in the integrated control of oriental fruit moth (Lepidoptera: Tortricidae)

The efficacy of integrated programs using a sprayable pheromone formulation or one of two hand-applied pheromone dispensers, and a conventional oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) control program, was compared using 4-5-ha blocks of peach orchard at three Niagara Peninsula farms during 2000-2002. In the integrated programs, chlorpyrifos and mating disruption with 3M Sprayable Pheromone, Isomate OFM Rosso, or Rak 5 hand-applied dispensers were used to control first-generation larvae, and mating disruption alone was used to control second- and third-generation larvae. In the conventional program, chlorpyrifos was used to control first-generation larvae, and pyrethroid insecticides were used to control larvae of the later generations. All programs were effective at maintaining fruit infestation by G. molesta below the industry tolerance level of 1%. An integrated program using sprayable pheromone required the use of more supplementary insecticide applications to control second- and third-generation larvae than a program using hand-applied dispensers. The elimination of insecticide sprays from integrated program blocks did not result in an increase in damage by plant bugs, Lygus spp. (Hemiptera: Miridae) or by the plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae).

99mTc-SnF2 colloid "LLK": particle size, morphology and leucocyte labelling behaviour

99mTc-SnF2 colloid (Radpharm LLK) leucocyte labelling agent is used in whole blood, exploiting phagocytosis. The objectives of this work were to optimize leucocyte labelling in leucocyte-enriched plasma, and to investigate: (i) the effect of temperature and other factors on labelling efficiency; (ii) the selectivity for different leucocyte types; (iii) the viability of the labelled cells and efflux of the radiolabel; and (iv) the physical characteristics of the colloid. Density gradient centrifugation was used to investigate the labelling efficiency, cell selectivity and efflux, Trypan blue to study the viability, and laser scattering, electron microscopy and membrane filtration to investigate particle size and morphology. Particles appeared as loose, coiled, chain-like aggregates of much smaller particles (<0.05 microm). The aggregate diameter ranged from <0.1 to >5 microm and increased with time. The distribution of radioactivity amongst the particle sizes varied widely. The labelling efficiency in leucocyte-rich plasma was enhanced at 37 degrees C compared to room temperature, and by centrifuging during labelling. The selectivity for different leucocyte types varied markedly between batches and blood samples, in some cases showing preference for mononuclear cells and in others for granulocytes. Viability was excellent and comparable with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO)-labelled cells. A significant fraction of radiolabel, comparable to that observed with 99mTc-HMPAO, was lost from leucocytes during incubation in vitro over 4 h. Thus, 99mTc-SnF2 is a convenient, efficient labelling agent for leucocytes, but shows variable cell selectivity which may be linked to particle size variability, and there is significant efflux of radioactivity from labelled cells.

Imaging of abdominal infection using 99m Tc stannous fluoride colloid labelled leukocytes

Radiolabelling of leukocytes using labelled phagocytosed technetium-99m (99mTc) colloidal radiopharmaceuticals has been reported as a method for imaging infection. This in vivo study compares the use of leukocytes labelled using 99mTc stannous fluoride colloid with leukocytes labelled using indium-111 (111In) oxinate. A total of 26 patients (10 male, 16 female; mean age 52 years, range 23-88 years) referred for the investigation of possible infection were studied using both leukocyte labelling methods simultaneously. Images were acquired 4h and 24h after re-injection of the labelled cells. The images were evaluated qualitatively by two nuclear medicine physicians. The results show a high degree of concordance between the techniques: 11 of the 28 images showed a focus of leukocyte accumulation with both techniques at 24h, and 13 out of 28 showed a normal appearance at 24h with both methods. In four cases the results were discordant; the 99mTc stannous fluoride colloid labelled leukocytes gave a false positive appearance at 24h in three patients and a false negative in one. In conclusion, colloid labelling of leukocytes offers a sensitive method for the detection of infective foci coupled with the high resolution imaging offered by 99mTc. It has the advantage over other in vitro labelling methods of being a simpler, non-labour-intensive procedure employing whole blood, and its use should be considered by departments that have limited facilities for in vitro leukocyte labelling.

Integrated control of oriental fruit moth (Lepidoptera: Tortricidae) in peach orchards using insecticide and mating disruption

The efficacy of an integrated and a conventional oriental fruit moth, Grapholita molesta (Busck), control program was compared using 4-ha blocks of peach at three Niagara Peninsula farms during 1997-1999. In the integrated program, chlorpyrifos was used to control first-generation larvae and mating disruption using Isomate M100 pheromone dispensers was used to control the second and third generations. In the conventional program, chlorpyrifos was used to control first-generation larvae and pyrethroids were used to control larvae of the later generations. The average release rate of pheromone was 23.7-26.4 mg/ha/h over a period of 86-91 d. The pheromone treatment reduced the capture of moths in pheromone-baited traps on average by 98%, suggesting a high level of disruption. The integrated program provided control of oriental fruit moth similar to the control provided by a conventional program. The mean percentage of peach shoots infested with first- and second-generation larvae, and fruit infested with third-generation larvae was not significantly greater in the integrated-program blocks during the 3-yr study. The elimination of insecticide sprays from the integrated-program blocks did not result in an increase in damage caused by plant bugs. The incidence of damage caused by other pests was negligible in both the integrated and conventional blocks.

The conformational cycle of kinesin

The stepping mechanism of kinesin can be thought of as a programme of conformational changes. We briefly review protein chemical, electron microscopic and transient kinetic evidence for conformational changes, and working from this evidence, outline a model for the mechanism. In the model, both kinesin heads initially trap Mg x ADP. Microtubule binding releases ADP from one head only (the trailing head). Subsequent ATP binding and hydrolysis by the trailing head progressively accelerate attachment of the leading head, by positioning it closer to its next site. Once attached, the leading head releases its ADP and exerts a sustained pull on the trailing head. The rate of closure of the molecular gate which traps ADP on the trailing head governs its detachment rate. A speculative but crucial coordinating feature is that this rate is strain sensitive, slowing down under negative strain and accelerating under positive strain.

A one-hour walk-in service for wrist trauma imaging

We investigated the feasibility of rapid imaging of wrist trauma following casualty presentation and any subsequent effect on image quality and interpretability. All patients referred for wrist imaging were injected with 370 MBq 99Tcm-hydroxymethyl diphosphonate (HDP) and imaged 1, 2 and 3 h later. Palmar images were acquired on a 256 x 256 x 16 matrix using a high-resolution collimator, 140 keV photopeak and a 20% window. The images were scored qualitatively by four qualified observers in three categories: image quality, lesion detection and lesion localization. Statistical analysis indicated a significant improvement in scan quality with time, the mean difference (+/- standard error of the mean) between the 1 and 3 h scans being 0.81 +/- 0.07 (P = 0.001). No significant differences were seen in lesion detection (0.05 +/- 0.08; P = 0.51) or localization (0.14 +/- 0.08; P = 0.10). We conclude that imaging of wrist trauma is possible as early as 1 h post-injection of 99Tcm-HDP, although negative studies at 1 h require a 3 h image to maintain diagnostic accuracy.

Microbiological and radioactive contamination from radioaerosol ventilation scanning: is there a problem?

Radioaerosol lung imaging may result in (a) microbiological contamination of nebulizer circuits (a potential hazard to patients if the circuit is re-used), and (b) radioaerosol contamination of the atmosphere (a hazard to staff, particularly if inhaled, ingested or both). Altogether, 138 circuits were assessed for bacteriological contamination, 93 of which had been used for ventilation perfusion studies and 45 for lung permeability studies in human immunodeficiency virus (HIV) positive patients. The circuits used for ventilation/perfusion (V/Q) studies were re-used over a period of 1-5 days. The mouthpiece and Y-piece were changed between patients. The circuits used for permeability studies were changed in toto for each patient. Organisms belonging to normal respiratory flora were isolated from the Y-piece, mouthpiece or both in 9 of 138 cases. An additional case (from one of the HIV-positive patients) demonstrated a growth of methicillin-resistant Staphylococcus. We also demonstrated bacteriological growth, most likely of patient origin, in circuit tubing in 11 cases at the end of the first day's use and 9 cases by day 5. None of the circuits used for HIV-positive cases were culture-positive. Airborne radioactive contamination was assessed during radioaerosol inhalation with and without an air extractor device (Nederman) during 40 ventilation studies. The 20 studies with air extraction showed a large decrease in room air contamination. Nebulizer circuits can, and occasionally do, become contaminated with patients' organisms; this represents a potential infection control hazard and therefore re-use is contraindicated. The use of an air extractor will significantly reduce airborne radioaerosol contamination.

Evaluating the Swirler nebulizer: a user's perspective

The change from multi-use to single-use nebulizer systems could potentially result in greatly increased expense for aerosol ventilation imaging and a larger waste disposal problem. We have therefore investigated a new compact single-use nebulizer system, the Swirler (Amici), for ventilation lung imaging using 99Tcm-DTPA aerosol. Seventy-five patients requiring lung ventilation/perfusion imaging were studied. The ventilation imaging was assessed using three different fills: Group 1, 1000 MBq in 2 ml; Group 2, 1000 MBq in 4 ml; and Group 3, 2000 MBq in 4 ml. The nebulization times to give 1200 counts s-1 on the posterior ventilation image were similar for Groups 1 and 3 (mean 4 min) but slower for Group 2 (mean 6 min). Room contamination was very low when performed in a room with an extractor device. The mean room air contamination was 117.0 Bq l-1 min-1 for Group 1 amd 27.6 Bq l-1 min-1 for Group 2, comparable to previous nebulizers we have used. Dose rates measured at the surface of the lead shielded nebulizer were 6.8 microSv h-1 for 1000 MBq in 2 ml and 10.9 microSv h-1 for 2000 MBq in 4 ml. The mass median diameter (span) without the extension tubing was 1.39 microns (1.85) and with a small extension tube reduced to 1.11 microns (1.70). Qualitative and quantitative assessment of image quality showed good peripheral airways penetration of particles with no uninterpretable scans, comparable with other systems we have used. In practical terms, the device is much more compact than other systems and therefore generates a much smaller volume of waste. It is an easy device to use. However, when ventilating patients supine or erect, we found that it was necessary to use the small extension tube.

Ventilation and perfusion lung imaging--which nebulizer?

Three commercially available 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol delivery nebulizers for lung ventilation imaging were investigated. Two were air-jet systems, 'Optimist' (Medicaid) and 'Microcirrus' (Amersham), and one was an ultrasonic device (Europlus). Altogether, 112 consecutive patients were scanned, 37 using the Optimist, 40 using the Microcirrus and 35 the Europlus. The age mix, FEV1, FVC and PEFR measurements of the patients in each group were similar. Each contained a proportion of patients with poor respiratory function, with PEFR rates ranging from 30 to 582 l min-1 for patients studied with all systems. Ease of use, image quality and cost were evaluated as well as radioactive and microbiological contamination. The Optimist system gave the best combination of image quality and cost, and was associated with the lowest level of radioactive contamination. It also proved the most popular. Airborne contamination for all nebulizers was lower than previously reported and was largely dependent on patient compliance. With poorly compliant patients, the contamination levels are sufficient to warrant an extraction device. There was no evidence of bacterial contamination of the nebulizers or tubing on repeated use over 5 days.

Radiation dose rates from paediatric patients undergoing 99Tcm investigations

Infants or children undergoing nuclear medicine investigations may subsequently come into close contact with nurses or parents responsible for their care. In order to estimate the radiation dose to these individuals, and to formulate appropriate recommendations, dose rates were measured at distances of 0.1, 0.5 and 1.0 m from 148 paediatric patients who had undergone one of 12 99Tcm studies. The maximum dose rates of 70, 14 and 5 microSv h-1 at these distances were not greater than the corresponding maximum values found in an earlier study of adult patients. However, the maximum dose rates per unit activity of 0.5, 0.2 and 0.1 microSv h-1 MBq-1 were greater than the corresponding maximum 99Tcm adult values, consistent with a general increase of dose rate per unit activity with decrease of body weight observed in the paediatric measurements. A parent caring for and feeding a young infant is most unlikely to receive a dose equivalent of 1 mSv, and a nurse attending to one young radioactive patient is most unlikely to receive a dose equivalent in a working day of 60 microSv. The data obtained should allow radiation doses to be estimated and appropriate recommendations to be formulated for other circumstances, including any future legislative changes in dose limits or derived levels.

Rapid preparation of 123I-labelled methylene blue and toluidine blue: potential new agents for parathyroid scintigraphy

Methylene blue and toluidine blue are phenothiazinium dyes used to localize parathyroid glands visually during surgery. For the purpose of assessing the potential of radiolabelled analogues for scintigraphic localization of parathyroids, a rapid and convenient method has been developed for covalently labelling the dyes with iodine-123. Treatment of aqueous methylene blue or toluidine blue with 123I-sodium iodide in the presence of potassium iodate and hydrochloric acid at 100 degrees C for 1 h results in incorporation of 80-90% of the radioiodine into the dye. The chemical and radiochemical impurities are readily removed by passage through a disposable sample preparation column. Using the optimized protocol, a sterile, pyrogen-free multi-dose solution of radioiodinated dye (pH 7, specific activity greater than or equal to 37 MBq mg-1, radioactivity concentration congruent to 37 MBq ml-1, radiochemical purity greater than 99%, overall activity yield available for injection 60-70%) can be prepared within 1.5 h.