The reality of advanced airway management during out of hospital cardiac arrest; why did paramedics deviate from their allocated airway management strategy during the AIRWAYS-2 randomised trial?

Background

AIRWAYS-2 was a large multi-centre cluster randomised controlled trial investigating the effect on functional outcome of a supraglottic airway device (i-gel) versus tracheal intubation (TI) as the initial advanced airway during out-of-hospital cardiac arrest. We aimed to understand why paramedics deviated from their allocated airway management algorithm during AIRWAYS-2.

Methods

This study employed a pragmatic sequential explanatory design utilising retrospective study data collected during the AIRWAYS-2 trial. Airway algorithm deviation data were analysed to categorise and quantify the reasons why paramedics did not follow their allocated strategy of airway management during AIRWAYS-2. Recorded free text entries provided additional context to the paramedic decision-making related to each category identified.

Results

In 680 (11.7%) of 5800 patients the study paramedic did not follow their allocated airway management algorithm. There was a higher percentage of deviations in the TI group (399/2707; 14.7%) compared to the i-gel group (281/3088; 9.1%). The predominant reason for a paramedic not following their allocated airway management strategy was airway obstruction, occurring more commonly in the i-gel group (109/281; 38.7%) versus (50/399; 12.5%) in the TI group.

Conclusion

There was a higher proportion of deviations from the allocated airway management algorithm in the TI group (399; 14.7%) compared to the i-gel group (281; 9.1%). The most frequent reason for deviating from the allocated airway management algorithm in AIRWAYS-2 was obstruction of the patient's airway by fluid. This occurred in both groups of the AIRWAYS-2 trial, but was more frequent in the i-gel group.

Mental health improvements after elective spine surgery: a Canadian Spine Outcome Research Network (CSORN) study

BACKGROUND CONTEXT

Spine patients have a higher rate of depression then the general population which may be caused in part by levels of pain and disability from their spinal disease.

PURPOSE

Determination whether improvements in health-related quality of life (HRQOL) resulting from successful spine surgery leads to improvements in mental health.

STUDY DESIGN/SETTING

The Canadian Spine Outcome Research Network prospective surgical outcome registry.

OUTCOME MEASURES

Change between preoperative and postoperative SF12 Mental Component Score (MCS). Secondary outcomes include European Quality of Life (EuroQoL) Healthstate, SF-12 Physical Component Score (PCS), Oswestry Disability Index (ODI), Patient Health Questionaire-9 (PHQ9), and pain scales.

METHODS

The Canadian Spine Outcome Research Network registry was queried for all patients receiving surgery for degenerative thoracolumbar spine disease. Exclusion criteria were trauma, tumor, infection, and previous spine surgery. SF12 Mental Component Scores (MCS) were compared between those with and without significant improvement in postoperative disability (ODI) and secondary measures. Multivariate analysis examined factors predictive of MCS improvement.

RESULTS

Eighteen hospitals contributed 3222 eligible patients. Worse ODI, EuroQoL, PCS, back pain and leg pain correlated with worse MCS at all time points. Overall, patients had an improvement in MCS that occurred within 3 months of surgery and was still present 24 months after surgery. Patients exceeding Minimally Clinically Important Differences in ODI had the greatest improvements in MCS. Major depression prevalence decreased up to 48% following surgery, depending on spine diagnosis.

CONCLUSIONS

Large scale, real world, registry data suggests that successful surgery for degenerative lumbar disease is associated with reduction in the prevalence of major depression regardless of the specific underlaying diagnosis. Worse baseline MCS was associated with worse baseline HRQOL and improved postoperatively with coincident improvement in disability, emphasizing that mental wellness is not a static state but may improve with well-planned spine surgery.

Maternal mental health and partner delivered massage: a pilot study

Background

Mental health problems place a significant burden on the health system and are an important public health issue. Many pregnant women experience anxiety and depression, which can negatively impact health outcomes for both mother and baby. Partner-delivered massage may provide a cost effective and accessible approach to support the mental wellbeing of pregnant women.

Methods

A feasibility randomised controlled trial was conducted to compare partner-delivered relaxation massage (intervention) with a self-directed stress management program (control), for pregnant women with mild anxiety. Women attended an initial workshop at 28-32 weeks gestation, followed by the completion of either the self-directed massage or stress management program. Qualitative feasibility and acceptability data (primary outcomes) were collected via online participant diaries and post-birth interviews. Anxiety, depression and stress symptoms (secondary outcomes) were assessed using the Depression and Anxiety Stress Scale (DASS-21).

Results

14 women/partner dyads attended the partner- delivered massage group and 13 women attended the self-directed stress management group. Participants from both groups reported the programs were feasible and acceptable. Mean scores on all DASS-21 subscales significantly decreased over time in both the intervention and the control group.

Conclusions

The partner-delivered massage program was feasible and acceptable. Both programs decreased women's symptoms of anxiety, depression and stress, with no significant between-group differences identified. An adequately powered, experimental study is needed to determine the effectiveness of partner-delivered relaxation massage.

Key messages

Many women experience anxiety and depression during pregnancy and this can have a negative impact on both mother and baby. Partner-delivered relaxation massage, at least once a week in the third trimester, may help reduce women’s symptoms of anxiety, depression and stress.

Midwifery leadership, advocacy and action to improve maternal health in PNG

Background

The SDG target for maternal mortality is less than 70 per 100,000 live births; in Papua New Guinea, it is estimated to be 145. PNG will require significant resources and strong leadership to meet the 2030 target. The PNG Midwifery Leadership Buddy Program (Buddy Program), funded and coordinated by Rotary, offers an innovative model to improve maternal health, which may be transferable to other low-middle-income countries.

Objectives

The Buddy Program aims to build midwifery leadership resulting in improved outcomes in PNG. As partners, midwives from PNG and Australia undertake leadership training in Port Moresby and enter a reciprocal peer support relationship. Over 12 months, they support each other in their professional roles and progress a quality improvement project.

Results

Three cohorts of midwives (18 from each country), have participated in the leadership training and the first group has completed 12 months of peer support. Participants have reported increased confidence for leadership, action and advocacy. There has been some communication challenges and variation in expectations, predominately due to cultural differences. The Buddy Program has resulted in a number of tangible projects including the introduction of family planning education at a local school and University, introduction of respectful care in pregnancy charter and increased surveillance and treatment of pregnant women with anaemia. Interestingly, a number of participants have continued to support each other beyond the initial 12-month commitment.

Conclusions

Supportive partnerships that grow midwifery leadership hold significant potential to increase the quality of maternity care and reduce preventable maternal deaths in low-middle-income countries.

Key messages

Midwifery leadership plays a vital role in addressing the SDG targets for maternal health. The Buddy Program offers an innovative model to progress the agenda for universal access to quality maternity care.

Evolving healthcare; nurses’ attitudes towards complementary therapies

Background

Integration of complementary therapies alongside conventional medical treatment is common and affects health behaviour and outcomes. Nurses frequently interact with patients and their attitudes to these therapies may play a significant role in decision-making. This mixed-method study investigated nurses' attitudes and behaviour towards complementary therapies.

Methods

A sequential exploratory design was utilised. Qualitative data were collected via interviews with nurses working in primary and tertiary settings, in all states of Australia. Interview data underwent thematic analysis. Findings from the interviews informed the development of a questionnaire, which was used to conduct a national online survey. Survey data were descriptively analysed using frequency distributions and percentages.

Results

Nineteen nurses were interviewed and 614 responded to the survey. Themes that emerged from the qualitative data were; Promoting safe care, Seeking complementary therapies knowledge; Supporting holistic health care and Integrating complementary therapies in practice. Survey responses revealed most nurses (77.5%) discussed complementary therapies with patients. More than one half (55.5%) would 'sometimes' recommend complementary therapies and 12.0% would 'almost always/always' do so. The majority (91.8%) believed nurses should have some understanding of complementary therapies. There was a lack of agreement regarding integration of these therapies into nursing practice.

Conclusions

Nurses were generally supportive of patients' interest in complementary therapies and want basic education about these therapies.

Key messages

Nurses working in Australia often engage with patients about complementary therapies. Increasing nurses’ complementary therapy knowledge is likely to promote informed decision-making and improve patient safety.

The association between faecal host DNA or faecal calprotectin and feed efficiency in pigs fed yeast-enriched protein concentrate

Gut cell losses contribute to overall feed efficiency due to the energy requirement for cell replenishment. Intestinal epithelial cells are sloughed into the intestinal lumen as digesta passes through the gastrointestinal tract, where cells are degraded by endonucleases. This leads to fragmented DNA being present in faeces, which may be an indicator of gut cell loss. Therefore, measuring host faecal DNA content could have potential as a non-invasive marker of gut cell loss and result in a novel technique for the assessment of how different feed ingredients impact upon gut health. Faecal calprotectin (CALP) is a marker of intestinal inflammation. This was a pilot study designed to test a methodology for extracting and quantifying DNA from pig faeces, and to assess whether any differences in host faecal DNA and CALP could be detected. An additional aim was to determine whether any differences in the above measures were related to the pig performance response to dietary yeast-enriched protein concentrate (YPC). Newly weaned (∼26.5 days of age) Large White × Landrace × Pietrain piglets (8.37 kg ±1.10, n = 180) were assigned to one of four treatment groups (nine replicates of five pigs), differing in dietary YPC content: 0% (control), 2.5%, 5% and 7.5% (w/w). Pooled faecal samples were collected on days 14 and 28 of the 36-day trial. Deoxyribonucleic acid was extracted and quantitative PCR was used to assess DNA composition. Pig genomic DNA was detected using primers specific for the pig cytochrome b (CYTB) gene, and bacterial DNA was detected using universal 16S primers. A pig CALP ELISA was used to assess gut inflammation. Dietary YPC significantly reduced feed conversion ratio (FCR) from weaning to day 14 (P<0.001), but not from day 14 to day 28 (P = 0.220). Pig faecal CYTB DNA content was significantly (P = 0.008) reduced in YPC-treated pigs, with no effect of time, whereas total faecal bacterial DNA content was unaffected by diet or time (P>0.05). Faecal CALP levels were significantly higher at day 14 compared with day 28, but there was no effect of YPC inclusion and no relationship with FCR. In conclusion, YPC reduced faecal CYTB DNA content and this correlated positively with FCR, but was unrelated to gut inflammation, suggesting that it could be a non-invasive marker of gut cell loss. However, further validation experiments by an independent method are required to verify the origin of pig faecal CYTB DNA as being from sloughed intestinal epithelial cells.

Urinary volatile organic compounds and faecal microbiome profiles in colorectal cancer

AIM

Volatile organic compounds (VOCs) are potential biomarkers for diagnosing colorectal cancer (CRC). We characterized urinary VOCs from CRC patients, their spouses/cohabitors (spouses) and first-degree relatives (relatives) to determine any differences. Correlation with stool-derived microbiomes was also undertaken.

METHODS

Urine from 56 CRC patients, 45 spouses and 37 relatives was assayed using liquid chromatography, field asymmetric ion mobility spectrometry (FAIMS), mass spectrometer technology. Analysis was performed using five-fold cross-validation and a random forest classifier. Faecal microbiome 16S rRNA was sequenced using Illumina MiSeq protocols and analysed using UPARSE and QIIME pipelines. VOC and microbiome profiles were also compared before and after cancer treatment.

RESULTS

Urinary VOC profiles of CRC patients were indistinguishable from either spouses or relatives. When spouses and relatives were grouped together to form a larger non-cancer control group (n = 82), their VOC profiles became distinguishable from those of CRC patients (n = 56) with 69% sensitivity and specificity, area under the curve 0.72 (P < 0.001). Microbiome analysis identified > 1300 operational taxonomic units across all groups. The analysis of similarity R value was 0.067 (P < 0.001), with significantly different bacterial abundances in 82 operational taxonomic units (6.2%) by Kruskal-Wallis testing. CRC patients' VOC or stool microbiome profiles were unchanged after treatment.

CONCLUSION

Although CRC patients' urinary VOC profiles cannot be differentiated from those of spouses or relatives they can be differentiated from a larger non-cancer control group. Comparison of the groups' microbiomes confirmed differences in bacterial species abundance. The current FAIMS-based assay can detect a unique, but modest, signal in CRC patients' urinary VOCs, which remains unaltered after treatment.

Eradication of respiratory tract MRSA at a large adult cystic fibrosis centre

INTRODUCTION

The prevalence of MRSA in patients with CF is increasing. There is no consensus as to the optimum treatment.

METHOD

An observational cohort study of all patients with MRSA positive sputum, 2007-2012. All eradication attempts with subsequent culture results were reviewed. Single vs dual antibiotic regimens were compared for both new and chronic infections.

RESULTS

37 patients (median FEV1 58.7 (27.6-111.5)% predicted) were identified, of which 67.6% (n = 25) had newly acquired MRSA. Compared with single regimens, a high proportion of dual regimens achieved MRSA eradication (84.6% vs 50%; p = 0.1) for new infections. Rifampicin/Fusidic acid was associated with high success rates (100% vs 60% for other dual regimens (p = 0.13)). Compared with new infections, chronic MRSA was much less likely to be eradicated (18.2%, p = 0.01).

CONCLUSION

Combined antibiotic therapy, particularly Rifampicin/Fusidic acid, is a well-tolerated and effective means of eradicating MRSA in patients with cystic fibrosis.

Tuning electrospinning parameters for production of 3D-fiber-fleeces with increased porosity for soft tissue engineering applications

Degrapol® and PLGA electrospun fiber fleeces were characterized with regard to fiber diameter, alignment, mechanical properties as well as scaffold porosity. The study showed that electrospinning parameters affect fiber diameter and alignment in an inverse relation: fiber diameter was increased with increased flow rate, with decrease in working distance and collector velocity, whereas fiber alignment increased with the working distance and collector velocity but decreased with increased flow rate. When Degrapol® or PLGA-polymers were co-spun with increasing ratios of a water-soluble polymer that was subsequently removed; fibrous scaffolds with increased porosities were obtained. Mechanical properties correlated with fiber alignment rather than fiber diameter as aligned fiber scaffolds demonstrated strong mechanical anisotropy. For co-spun fibers the Young's modulus correlated inversely with the amount of co-spun polymer. Cell proliferation was independent of the porosity of the scaffold, but different between the two polymers. Furthermore, fibrous scaffolds with different porosities were analyzed for cell infiltration suggesting that cell infiltration was enhanced with increased porosity and increasing time. These experiments indicate that 3D-fiber fleeces can be produced with controlled properties, being prerequisites for successful scaffolds in tissue engineering applications.

Effect of Lipophilicity of Substituted Benzamides on the Dopaminergic Effects in Vivo and in Vitro

The antidopaminergic potencies of some new substituted benzamides related to remoxipride have been studied in the rat using in vitro (3H-spiperone binding) and in vivo techniques (antagonism of apomorphine induced stereotypies). The lipophilicities of the different benzamides were calculated by the addition of the lipophilic contribution (pi value) of the added substituent. It was found that the in vivo potencies of the compounds were not direct proportional to the in vitro potencies. The discrepancies in the potencies in vitro and in vivo (expressed as the ratio) are correlated to the calculated lipophilicities. Certain substituents in the benzene nucleus affect this in vitro--in vivo ratio more than could be expected from the change in lipophilicity caused by the substituent. The type of side chain is also of great importance. The reasons for the discrepancies between in vitro and in vivo antidopaminergic potencies of the studied substituted benzamides are discussed.

A possible association between schizophrenia and GRIK3 polymorphisms in a multicenter sample of Scandinavian origin (SCOPE)

There is considerable evidence of altered glutamatergic signalling in schizophrenia and a polymorphic variant of the GRIK3 glutamate receptor gene on 1p34-33 has previously been associated to this psychotic disorder. We therefore conducted a systematic association study with 30 HapMap-selected tagging SNPs across GRIK3 in three independent samples of Scandinavian origin from the Scandinavian Collaboration of Psychiatric Etiology (SCOPE), including a total of 839 cases with schizophrenia spectrum and 1473 healthy controls. Four markers (rs6671364, rs17461259, rs472188, and rs535620) attained nominally significant P-values in both the genotypic (0.002, 0.02, 0.03, and 0.05, respectively) and allelic (0.001, 0.006, 0.03, and 0.02, respectively) association tests for the combined sample, and 2 additional markers (rs481047and rs1160751) displayed significance for the genotype (P-values: 0.03 and 0.04). Several haplotypes, that all included at least one of the four SNPs implicated by the single marker analysis, remained significant after adjustment for multiple testing using permutations with 10,000 shuffles. In addition we observed an association for two of the four significant GRIK3 markers (rs472188 and rs535620) to scores for negative symptoms on the PANSS scale. The present results, although not robust, support the importance of more extensive investigations of GRIK3, given its potential role in mediating risk for schizophrenia.

Echinacea purpurea and mucosal immunity

This investigation examined the effects of Echinacea purpurea on mucosal immunity and the incidence and duration of upper respiratory tract infection (URTI). 32 subjects completed an exercise protocol known to affect mucosal immunity. Saliva was collected prior to and five minutes after completion of exercise testing. Subjects then took either a placebo (C) or Echinacea supplement (E) for 4 weeks and the testing procedure was repeated. Each time, s-IgA concentrations and saliva flow rate were measured and the secretion rate of s-IgA was calculated. In addition, standard logs indicating symptoms of URTI were completed throughout the study. Both groups demonstrated significant exercise induced reductions in s-IgA (C - 69 %; E - 43 %) and the secretion rate of s-IgA (C - 79 %; E - 53 %) at the beginning of the study (p < 0.05). Following the 4-week intervention, only the control group experienced the post intervention decrease in s-IgA (C - 45 %; E + 7 %) and the secretion rate of s-IgA (C - 45 %; E - 7 %). Further, while there was no significant difference in the number of URTI between groups, the reported duration was significantly different (C 8.6 days vs. E 3.4 days). The results suggest that Echinacea may attenuate the mucosal immune suppression known to occur with intense exercise and reduce the duration of URTI that subjects incur.

NK cells in autoimmune disease

The role of NK cells in autoimmunity has not been extensively studied. Speaking for a disease-promoting role for NK cells in autoimmune diseases are recent results suggesting that IFN-gamma production by NK cells may help adaptive immune responses diverge in the direction of a Th1 response. NK cells may also be involved in direct killing of tissue cells, which could lead to acceleration of autoimmunity. However, NK cells have also been shown to protect from some autoimmune diseases. A possible reason for this discrepancy may lie in the capacity of NK cells also to produce Th2 cytokines, which could downregulate the Th1 responses that are common in autoimmune disorders. Thus there is at present no coherent view on the role of NK cells in autoimmunity, and more work is needed to clarify why NK cells in some cases aggravate disease and in some cases protect from disease.

Kinetics of the reaction of U(vi) with benzene-1,2-diphosphonic acid

The kinetics of the reaction between dioxouranium(VI) and benzene-1,2-diphosphonic acid (BzDPA) has been investigated by stopped-flow spectrophotometry. The rate of reaction of uranyl ions with Arsenazo III (2,7-bis(2,2'-arsonophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid) in 50:50 methanol-water solutions was also determined. Both formation and dissociation rate constants for the 1:1 complex between uranyl-BzDPA in acidic solutions were resolved. To gain insight into the effect of solvation on the progress of the reaction, the system was studied in triply distilled water, in 50:50 methanol-water, 80:20 methanol-water and in 50:50 tert-butanol-water as a function of temperature at pH 1.0. The rates of complex formation and dissociation reactions decrease as methanol substitutes for water in the medium and further decrease as tert-butanol replaces methanol as co-solvent. Activation parameters are most consistent with an associative process governing the progress of both complex formation and dissociation reactions. Introduction of alcoholic co-solvents results in notably more negative activation entropies for both complex formation and dissociation reactions, while the activation enthalpies are only slightly reduced in the mixed methanol-water medium. These results are compared with the kinetic features of other U(VI) systems.

Inhibition of the Proteasome Reduces Transfer-Induced Diabetes in Nonobese Diabetic Mice

Inhibition of the 26S proteasome reduces the severity of several immune-mediated diseases. Here, we report that the proteasome also regulates transfer-induced diabetes in nonobese mice. Treatment of recipient mice with the proteasome inhibitor N(alpha)-benzyloxycarbonyl-l-leucyl-l-leucyl-l-leucinal (MG132) resulted in a 76% reduction in transfer-induced diabetes. The closely related inhibitor carbobenzoxy-l-leucyl-l-leucinal that inhibits calpains but not the proteasome had no protective effect, suggesting that MG132 acted via inhibition of the proteasome. MG132 decreased proliferation of transferred T cells in the pancreatic lymph nodes in vivo and prevented their expansion in a dose-dependent manner in vitro, consistent with a direct effect by MG132 on the T cells. MG132 did not prevent migration of transferred T cells into the islets but reduced the number of mice with severe infiltration. We suggest that MG132 prevents transfer-induced diabetes by directly targeting the autoreactive T cells and lowering their diabetogenic potential.

A laboratory model to evaluate cutout resistance of implants for pertrochanteric fracture fixation

OBJECTIVES

To establish a laboratory model of implant cutout, which can evaluate the effect of implant design on cutout resistance in a clinically realistic "worst case" scenario.

SETTING

Orthopaedic biomechanics laboratory.

DESIGN

Implant cutout was simulated in an unstable pertrochanteric fracture model, which accounted for dynamic loading, osteoporotic bone, and a defined implant offset. For model characterization, lag screw cutout was simulated in human cadaveric specimens and in polyurethane foam surrogates. Subsequently, foam surrogates were used to determine differences in cutout resistance between 2 common lag screws (dynamic hip screw, Gamma) and 2 novel blade-type implant designs (dynamic helical hip system, trochanteric fixation nail).

MAIN OUTCOME MEASURES

Implant migration was continuously recorded with a spatial motion tracking system as a function of the applied loading cycles. In addition, the total number of loading cycles to cutout failure was determined for specific load amplitudes.

RESULTS

Implant migration in polyurethane surrogates closely correlated with that in cadaveric specimens, but yielded higher reproducibility and consistent cutout failure. The cutout model was able to delineate significant differences in cutout resistance between specific implant designs. At any of 4 load amplitudes (0.8 kN, 1.0 kN, 1.2 kN, 1.4 kN) dynamic hip screw lag screws failed earliest. The gamma nail lag screw could sustain significantly more loading cycles than the dynamic hip screw. Of all implants, trochanteric fixation nail implants demonstrated the highest cutout resistance.

CONCLUSIONS

Implant design can significantly affect the fixation strength and cutout resistance of implants for pertrochanteric fracture fixation. The novel cutout model can predict differences in cutout resistance between distinct implant designs.

The serotonin-2A receptor gene locus does not contain common polymorphism affecting mRNA levels in adult brain

The serotonin-2A (HTR2A) receptor is a molecule of particular interest in biological psychiatry, as it is an important target for psychotropic drugs, and altered HTR2A expression has been found in several neuropsychiatric conditions, including depression and schizophrenia. Genetic association has been reported between a synonymous 102T/C polymorphism in the gene encoding HTR2A and a number of clinical phenotypes, including schizophrenia, clozapine response, psychotic symptoms in Alzheimer's disease and certain features of depression. Given that there are no known effects of the 102T/C polymorphism on the structure of the receptor, attention has switched to the possibility that the observations of both altered expression and genetic association point to functional sequence variants that alter expression of the HTR2A gene. Moreover, data have been presented recently suggesting that mRNAs containing the 102T- and C-alleles are differentially expressed. This suggests a direct effect of the variant itself on mRNA levels, or the influence of a distinct regulatory variant, such as the -1438A/G promoter polymorphism, with which it is in perfect linkage disequilibrium. The present study tested this hypothesis by employing a highly accurate quantitative allele- specific primer extension assay to measure the relative expression of brain mRNAs carrying each allele in 23 individuals heterozygous for the 102T/C polymorphism. Comparison between allele ratios derived from genomic DNA and mRNA from several cortical regions revealed that the 102C- and T-alleles are expressed identically. Furthermore, the absence of any interindividual variability in relative mRNA allele ratio suggests that the HTR2A locus is unlikely to contain common polymorphisms or epigenetic modification that alter HTR2A mRNA levels in adult brain, and essentially exclude such phenomena as a potential explanation for the altered expression and genetic associations that have been reported to date.

Pathogenesis of and immunity to a new influenza A (H5N1) virus isolated from duck meat

The outbreak of avian influenza H5N1 in Hong Kong in 1997 raised concerns about the potential for the H5 subtype to cause a human pandemic. In 2001 a new H5N1 virus, A/Duck Meat/Anyang/AVL-1/2001 (A/Dkmt), was isolated from imported duck meat in Korea. The pathogenesis of this virus was investigated in mice. A/Dkmt virus had low infectivity but was lethal for mice at high doses, and at lethal doses, the virus replicated in the brains of infected mice. A/Dkmt virus cross-reacted poorly with ferret antisera raised against human H5N1 viruses, but prior infection with A/Dkmt virus protected mice from death after secondary infection with human H5N1 virus.

Pathogenicity and antigenicity of a new influenza A (H5N1) virus isolated from duck meat

Avian influenza A viruses are the ancestral origin of all human influenza viruses. The outbreak of highly pathogenic (HP) avian H5N1 in Hong Kong in 1997 highlighted the potential of these viruses to infect and cause severe disease in humans. Since 1999, HP H5N1 viruses were isolated several times from domestic poultry in Asia. In 2001, a HP H5N1 virus, A/Duck/Anyang/AVL-1/2001 (Dk/Anyang), was isolated from imported frozen duck meat in Korea. Because of this novel source of HP H5N1 virus isolation, concerns were raised about the potential for human exposure and infection; we therefore compared the Dk/Anyang virus with HP H5N1 viruses isolated from humans in 1997 in terms of antigenicity and pathogenicity for mammals. At high doses, Dk/Anyang virus caused up to 50% mortality in BALB/c mice, was isolated from the brains and lymphoid organs of mice, and caused lymphopenia. Overall Dk/Anyang virus was substantially less pathogenic for mice than the H5N1 virus isolated from a fatal human case in 1997. Likewise, Dk/Anyang virus was apathogenic for ferrets. Dk/Anyang virus was antigenically distinguishable by hemagglutination-inhibition (HI) assay from human H5N1 viruses isolated in 1997 and avian H5N1 viruses isolated in 2001 in Hong Kong. Nevertheless, prior infection with Dk/Anyang virus protected mice from death after secondary infection with HP human H5N1 viruses. These results indicate that compared with HP human H5N1 viruses, Dk/Anyang virus is substantially less pathogenic for mammalian species. Nevertheless, the novel source of isolation of this avian H5N1 virus must be considered when evaluating the potential risk to public health.

Autoradiographic evaluation of [11C]vinpocetine binding in the human postmortem brain

The main objective ofthe study was to evaluate with autoradiographic technique whether or not [11C]vinpocetine, a compound widely used in the prevention and treatment of cerebrovascular diseases (Cavinton, Gedeon Richter Ltd., Budapest), binds to specific sites in the human brain in post mortem human brain sections. Binding was assessed under four conditions: the incubation was performed using Tris-HCl buffer with or without the addition of salts (0.1% (weight/vol) ascorbic acid, 120 mM NaCl, 5 mM KCl, 2 mM CaCl2 and 1 mM MgCl2), with or without the addition of excess (10 microM) unlabelled vinpocetine. Measurements on digitized autoradiograms indicated that [11C]vinpocetine labelled all grey matter areas in the human brain to a similar extent and no significantly heterogeneous binding could be demonstrated among cortical or subcortical regions. The addition of excess unlabelled vinpocetine lowered the binding slightly in all regions. Although these results indicate that [11C]vinpocetine does not bind to human brain transmitter receptors or transporters with a high affinity (Ki < 10 nM), it cannot be ruled out that the compound binds to receptors and/or transporters with lower affinity.

Synthesis, biological and autoradiographic evaluation of a novel Tc-99m radioligand derived from WAY 100635 with high affinity for the 5-HT(1A) receptor and the alpha1-adrenergic receptor

This paper reports the synthesis, biological evaluation, in vitro and ex vivo autoradiography of the first Tc-99m ligand with subnanomolar affinity for the 5-HT(1A) receptor and a remarkably high affinity for the alpha1-adrenergic receptor. The neutral "3+1" mixed-ligand complex combines 4-(6-mercaptohexyl)-1-(2-methoxyphenyl)piperazine as monodentate and 3-(N-methyl)azapentane-1,5-dithiol as tridentate unit with oxotechnetium(V). The analogous rhenium complex was synthesized for complete structural characterization and used in receptor binding assays. In competition experiments both complexes display subnanomolar affinity for the 5-HT(1A) receptor (IC(50)0.24 nM for Re, 0.13 nM for Tc) but also very high affinities for the alpha1-adrenergic receptor (IC(50) 0.05 nM for Re, 0.03 nM for Tc). Biodistribution studies show a brain uptake in rat of 0.22% ID five minutes post injection. In vitro autoradiographic studies in rat brain and postmortem human brain indicate accumulation of the Tc-99m complex in brain areas which are rich in 5-HT(1A) receptors or in alpha1-adrenergic receptors. This in vitro enrichment can be blocked respectively by the 5-HT(1A) receptor agonist 8-OH-DPAT or by prazosin hydrochloride, an alpha1-adrenergic receptor antagonist. Ex vivo autoradiographic studies in rats show a slight accumulation of the Tc-99m complex in 5-HT(1A) receptor-rich areas of the brain, which could not be blocked, as well as in regions rich in alpha1-adrenergic receptors, which could be blocked by prazosin hydrochloride.