The Immunogenicity of a Foot-and-Mouth Disease Virus Serotype O Vaccine in Commercial and Subsistence Cattle Herds in Zambia

The recent introduction of foot-and-mouth disease (FMD) virus serotype O (O/EA-2 topotype) in Southern Africa has changed the epidemiology of the disease and vaccine requirements of the region. Commercial and subsistence cattle herds in Zambia were vaccinated with an FMD virus serotype O Manisa vaccine according to a double- or single-dose vaccination schedule. Heterologous antibody responses induced by this vaccine against a representative O/EA-2 virus from Zambia were determined. Virus neutralisation tests (VNTs) showed double-dosed cattle had a mean reciprocal log virus neutralisation titre of 2.02 (standard error [SE] = 0.16, n = 9) for commercial herds and 1.65 (SE = 0.17, n = 5) for subsistence herds 56 days after the first vaccination (dpv). Significantly lower mean titres were observed for single-dosed commercial herds (0.90, SE = 0.08, n = 9) and subsistence herds (1.15, SE = 0.18, n = 3) 56 dpv. A comparison of these results and those generated by solid-phase competitive ELISA (SPCE) tests showed a statistically significant positive correlation by Cohen's kappa coefficient. Therefore, SPCE might be used in assessing the immunogenicity of vaccines in place of VNT. Furthermore, for this vaccine and field strain, a vaccination regime employing a two-dose primary course and revaccination after 4-6 months is likely to be appropriate.

Comparison of vaccination schedules for foot-and-mouth disease among cattle and sheep in Mongolia

Vaccines are a critical tool for the control strategy for foot-and-mouth disease (FMD) in Mongolia where sporadic outbreaks regularly occur. A two-dose primary vaccination course is recommended for most commercial vaccines though this can be logistically challenging to deliver among nomadic pastoralist systems which predominate in the country. Although there is evidence that very high potency vaccines can provide prolonged duration of immunity, this has not been demonstrated under field conditions using commercially available vaccines. This study compared neutralizing titres to a O/ME-SA/Panasia strain over a 6-month period following either a two-dose primary course or a single double-dose vaccination among Mongolian sheep and cattle using a 6.0 PD50 vaccine. Titers were not significantly different between groups except in sheep at six-months post vaccination when the single double-dose group had significantly lower titers. These results indicate the single double-dose regimen may be a cost-effective approach for vaccination campaigns supporting FMD control in Mongolia.

Evaluating serological tests for foot-and-mouth disease while accounting for different serotypes and uncertain vaccination status

Controlling foot-and-mouth disease (FMD) by vaccination requires adequate population coverage and high vaccine efficacy under field conditions. To assure veterinary services that animals have acquired sufficient immunity, strategic post-vaccination surveys can be conducted to monitor the coverage and performance of the vaccine. Correct interpretation of these serological data and an ability to derive exact prevalence estimates of antibody responses requires an awareness of the performance of serological tests. Here, we used Bayesian latent class analysis to evaluate the diagnostic sensitivity and specificity of four tests. A non-structural protein (NSP) ELISA determines vaccine independent antibodies from environmental exposure to FMD virus (FMDV), and three assays measuring total antibodies derived from vaccine antigen or environmental exposure to two serotypes (A, O): the virus neutralisation test (VNT), a solid phase competitive ELISA (SPCE), and a liquid phase blocking ELISA (LPBE). Sera (n = 461) were collected by a strategic post-vaccination monitoring survey in two provinces of Southern Lao People's Democratic Republic (PDR) after a vaccination campaign in early 2017. Not all samples were tested by every assay and each serotype: VNT tested for serotype A and O, whereas SPCE and LPBE tested for serotype O, and only NSP-negative samples were tested by VNT, with 90 of them not tested (missing by study design). These data challenges required informed priors (based on expert opinion) for mitigating possible lack of model identifiability. The vaccination status of each animal, its environmental exposure to FMDV, and the indicator of successful vaccination were treated as latent (unobserved) variables. Posterior median for sensitivity and specificity of all tests were in the range of 92-99 %, except for the sensitivity of NSP (∼66%) and the specificity of LPBE (∼71 %). There was strong evidence that SPCE outperformed LPBE. In addition, the proportion of animals recorded as having been vaccinated that showed a serological immune response was estimated to be in the range of 67-86 %. The Bayesian latent class modelling framework can easily and appropriately impute missing data. It is important to use field study data as diagnostic tests are likely to perform differently on field survey samples compared to samples obtained under controlled conditions.

Development of anti-Crimean-Congo hemorrhagic fever virus Gc and NP-specific ELISA for detection of antibodies in domestic animal sera

Crimean-Congo hemorrhagic fever (CCHF) is a priority emerging disease. CCHF, caused by the CCHF virus (CCHFV), can lead to hemorrhagic fever in humans with severe cases often having fatal outcomes. CCHFV is maintained within a tick-vertebrate-tick cycle, which includes domestic animals. Domestic animals infected with CCHFV do not show clinical signs of the disease and the presence of antibodies in the serum can provide evidence of their exposure to the virus. Current serological tests are specific to either one CCHFV antigen or the whole virus antigen. Here, we present the development of two in-house ELISAs for the detection of serum IgG that is specific for two different CCHFV antigens: glycoprotein Gc (CCHFV Gc) and nucleoprotein (CCHFV NP). We demonstrate that these two assays were able to detect anti-CCHFV Gc-specific and anti-CCHFV NP-specific IgG in sheep from endemic CCHFV areas with high specificity, providing new insight into the heterogeneity of the immune response induced by natural infection with CCHFV in domestic animals.

A COVID-19 vaccine candidate using SpyCatcher multimerization of the SARS-CoV-2 spike protein receptor-binding domain induces potent neutralising antibody responses

There is need for effective and affordable vaccines against SARS-CoV-2 to tackle the ongoing pandemic. In this study, we describe a protein nanoparticle vaccine against SARS-CoV-2. The vaccine is based on the display of coronavirus spike glycoprotein receptor-binding domain (RBD) on a synthetic virus-like particle (VLP) platform, SpyCatcher003-mi3, using SpyTag/SpyCatcher technology. Low doses of RBD-SpyVLP in a prime-boost regimen induce a strong neutralising antibody response in mice and pigs that is superior to convalescent human sera. We evaluate antibody quality using ACE2 blocking and neutralisation of cell infection by pseudovirus or wild-type SARS-CoV-2. Using competition assays with a monoclonal antibody panel, we show that RBD-SpyVLP induces a polyclonal antibody response that recognises key epitopes on the RBD, reducing the likelihood of selecting neutralisation-escape mutants. Moreover, RBD-SpyVLP is thermostable and can be lyophilised without losing immunogenicity, to facilitate global distribution and reduce cold-chain dependence. The data suggests that RBD-SpyVLP provides strong potential to address clinical and logistic challenges of the COVID-19 pandemic.

Evaluation of the immunogenicity of prime-boost vaccination with the replication-deficient viral vectored COVID-19 vaccine candidate ChAdOx1 nCoV-19

Clinical development of the COVID-19 vaccine candidate ChAdOx1 nCoV-19, a replication-deficient simian adenoviral vector expressing the full-length SARS-CoV-2 spike (S) protein was initiated in April 2020 following non-human primate studies using a single immunisation. Here, we compared the immunogenicity of one or two doses of ChAdOx1 nCoV-19 in both mice and pigs. Whilst a single dose induced antigen-specific antibody and T cells responses, a booster immunisation enhanced antibody responses, particularly in pigs, with a significant increase in SARS-CoV-2 neutralising titres.

Immunogenicity of imported foot-and-mouth vaccines in different species in Mongolia

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FMD vaccines were independently assessed using published international guidelines.

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Highest titres were seen with oil-adjuvanted vaccines with a 2 dose primary course.

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Lower titres were seen with aqueous vaccines requiring a boost after 3 months.

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It is unknown how the lower titres observed in camels correlate with protection.

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The results have important implications for vaccine policy in Mongolia.

Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used in control. Mongolia has regular incursions of FMD virus that are typically limited to the eastern region although large epidemics are occasionally reported in the normally disease-free western areas. Vaccines are imported and form an important component of the control strategy. In 2015, post-vaccination monitoring guidelines were published by the FAO-OIE recommending approaches for assessing the appropriateness of imported vaccines including small-scale immunogenicity studies. This study used these recommended approaches to guide the use of vaccine adjuvant type and the need for a one or two dose primary course in the national control programme considering cattle, sheep and Bactrian camels and also whether these vaccines were appropriate for the FMD virus lineages considered high risk to Mongolia (A/ASIA/Sea-97; O/SEA/Mya-98; O/ME-SA/PanAsia; O/ME-SA/Ind-2001). The results of these immunogenicity studies indicated that in cattle and sheep, oil-adjuvanted vaccines led to higher and more persistent neutralisation titres that were satisfactory against the target lineages if a two-dose primary course was utilised. In contrast, aqueous-adjuvanted vaccines were associated with lower titres that likely required a booster after 3 months. Levels of antibodies in Bactrian camels were significantly lower although it is unknown how these may correlate with protection under experimental or field exposure conditions. The results of this study have implications for vaccine policy in Mongolia and suggest further studies on the role of Bactrian camels in the epidemiology of FMD are necessary to indicate if further research on FMD vaccines are needed in this species.

Efficacy of a high-potency multivalent foot-and-mouth disease virus vaccine in cattle against heterologous challenge with a field virus from the emerging A/ASIA/G-VII lineage

In 2015, outbreaks of foot-and-mouth disease (FMD) in the Middle East were discovered to be caused by a viral lineage (A/ASIA/G-VII), which has recently emerged from the Indian sub-continent. In vitro vaccine matching data generated by the World Reference Laboratory (WRLFMD) indicated that A/ASIA/G-VII field viruses were poorly matched with vaccines (A-SAU-95, A22 IRQ and A-IRN-05) that are already used in the region. In order to assess the likely performance of one of these commercially available FMD vaccines, sixteen cattle were vaccinated with a polyvalent vaccine which contained two serotype A components (A-SAU-95 and A-IRN-05) with a homologous potency of at least 6PD50, and two cattle were left unvaccinated as controls. Twenty-one days later, all 18 cattle were challenged by tongue inoculation with an FMDV field isolate A/IRN/22/2015 from the A/ASIA/G-VII lineage, in line with the European Pharmacopeia PPG test conditions. The two control animals developed generalised FMD, and 7/16 vaccinated animals developed at least one foot lesion, thus only 56.3% were defined as protected. For the vaccine components, there was a significant increase in the probability of protection with increasing serological titres for A-SAU-95 (p = 0.03), but not for A-IRN-05 (p = 0.42). Analysis of FMDV in blood and nasal swabs suggested that vaccination reduced shedding and potential onward spread of FMD virus even if the animal developed foot lesions. In summary, the results from this study suggest that whilst this vaccine would not be appropriate for use in an emergency situation (in previously FMD-free countries), it may be partially effective in the field in endemic countries where repeat prophylactic vaccination is practiced. For emergency reactive vaccination, the findings from this study support the idea that a new vaccine strain should be developed that is tailored to the A/ASIA/G-VII lineage.

Time to question diabetes self-management support for Arabic-speaking migrants: exploring a new model of care

AIM

The objective of this study was to explore a new model for diabetes self-management support in Arabic-speaking migrants.

METHODS

Two qualitative methods were used: face-to-face semi-structured individual interviews and focus groups. Interviews were audio-taped, transcribed verbatim and coded thematically. Arabic-speaking migrants with Type 2 diabetes were recruited from several primary, secondary and tertiary healthcare settings in metropolitan Melbourne, Australia. These settings were purposefully selected to obtain a diverse group of participants. Data collection continued until saturation was reached. This is the first study that involved members of Arabic-speaking communities in Australia in a formal process of consumer and public involvement to inform research design and recruitment in order to provide evidence for a new model of diabetes self-management for Arabic-speaking migrants.

RESULTS

No self-management support was offered to Arabic-speaking migrants beyond the initial diagnosis period. Significant knowledge gaps and skills deficits in all self-management domains were evident. The provision of tailored self-management support was considered crucial. When asked about preferred structure and delivery modalities, a strong preference was reported for face-to-face storytelling interactions over telephone- or internet-based interventions. Gender-specific group education and self-management support sessions delivered by Arabic-speaking diabetes health professionals, lay peers or social workers trained in diabetes self-management were highly regarded.

CONCLUSIONS

A patient and public involvement approach allows genuine engagement with Arabic-speaking migrants with diabetes. There is urgent need for a new model for self-management support among Arabic-speaking migrants. Findings yielded new recommendations for diabetes health professionals working with these migrant communities to support behaviour change.

Direct modulation of a tuneable slotted Fabry-Pérot laser with adaptive modulation OFDM

Next generation optical access networks will require low cost lasers in conjunction with network flexibility and higher data rates. This work presents the direct modulation of a low cost tuneable slotted Fabry-Pérot laser (tuneable over 14 nm) with AM-OFDM. Characteristics of this dual section laser are presented and transmission of 10 Gb/s over 50 km is achieved with this device.

Evaluation of two different swab transport systems in the detection of avian influenza virus excretion from infected Pekin ducks (Anas platyrhynchos)

The role of wild birds in the epidemiology and ecology of influenza A viruses has long been recognised (Alexander, 2007a). As a result of the emergence of a H5N1 highly pathogenic avian influenza (HPAI) virus and the apparent role of wild birds in its spread across Asia, Europe and Africa, avian influenza (AI) wild bird surveillance has been implemented in many countries including, since February 2006, a mandatory programme in the European Union (CEC, 2006a). In the present study the detection of virus excreted from Pekin ducks (Anas platyrhynchos) infected experimentally with A/mallard/England/2126/07 (H3N6) was investigated over a fourteen day period post-infection using cloacal and oropharyngeal swabs, with (wet) and without (dry) viral transport medium which were collected from each duck in alternating order. For influenza A virus matrix gene RNA detection, wet oropharyngeal swabs were significantly more sensitive than dry oropharyngeal on days 4-5 after infection. For cloacal samples, dry swabs were equivalent or superior to wet swabs throughout the study. Although differences in detection between dry and wet swabs were observed, the qualitative bird-level results were unaffected, meaning that the infection status of individual birds was correctly determined.

Pharmacological characterization of GSK1004723, a novel, long-acting antagonist at histamine H(1) and H(3) receptors

BACKGROUND AND PURPOSE

Preclinical pharmacological characterization of GSK1004723, a novel, dual histamine H(1) and H(3) receptor antagonist.

EXPERIMENTAL APPROACH

GSK1004723 was characterized in vitro and in vivo using methods that included radioligand binding, intracellular calcium mobilization, cAMP production, GTPγS binding, superfused human bronchus and guinea pig whole body plethysmography.

KEY RESULTS

In cell membranes over-expressing human recombinant H(1) and H(3) receptors, GSK1004723 displayed high affinity, competitive binding (H(1) pKi = 10.2; H(3) pKi = 10.6). In addition, GSK1004723 demonstrated slow dissociation from both receptors with a t(1/2) of 1.2 and 1.5 h for H(1) and H(3) respectively. GSK1004723 specifically antagonized H(1) receptor mediated increases in intracellular calcium and H(3) receptor mediated increases in GTPγS binding. The antagonism exerted was retained after cell washing, consistent with slow dissociation from H(1) and H(3) receptors. Duration of action was further evaluated using superfused human bronchus preparations. GSK1004723 (100 nmol·L(-1) ) reversed an established contractile response to histamine. When GSK1004723 was removed from the perfusate, only 20% recovery of the histamine response was observed over 10 h. Moreover, 21 h post-exposure to GSK1004723 there remained almost complete antagonism of responses to histamine. In vivo pharmacology was studied in conscious guinea pigs in which nasal congestion induced by intranasal histamine was measured indirectly (plethysmography). GSK1004723 (0.1 and 1 mg·mL(-1) intranasal) antagonized the histamine-induced response with a duration of up to 72 h.

CONCLUSIONS AND IMPLICATIONS

GSK1004723 is a potent and selective histamine H(1) and H(3) receptor antagonist with a long duration of action and represents a potential novel therapy for allergic rhinitis.

Performance improvement of 10 Gb/s direct modulation OFDM by optical injection using monolithically integrated Discrete Mode lasers

Performance improvement of a directly modulated 10 Gb/s OFDM system by optical injection of monolithically integrated lasers is shown experimentally over differing fibre lengths. The modulation and optical injection is performed using monolithically integrated Discrete Mode lasers. It is shown that optical injection with this device reduces third order inter-modulation distortion by up to 10dB and this results in an improvement in system performance from above a forward error correction BER threshold of 1 × 10(-3) to significantly below it.

Linkage and association study of late-onset Alzheimer disease families linked to 9p21.3

A chromosomal locus for late-onset Alzheimer disease (LOAD) has previously been mapped to 9p21.3. The most significant results were reported in a sample of autopsy-confirmed families. Linkage to this locus has been independently confirmed in AD families from a consanguineous Israeli-Arab community. In the present study we analyzed an expanded clinical sample of 674 late-onset AD families, independently ascertained by three different consortia. Sample subsets were stratified by site and autopsy-confirmation. Linkage analysis of a dense array of SNPs across the chromosomal locus revealed the most significant results in the 166 autopsy-confirmed families of the NIMH sample. Peak HLOD scores of 4.95 at D9S741 and 2.81 at the nearby SNP rs2772677 were obtained in a dominant model. The linked region included the cyclin-dependent kinase inhibitor 2A gene (CDKN2A), which has been suggested as an AD candidate gene. By re-sequencing all exons in the vicinity of CDKN2A in 48 AD cases, we identified and genotyped four novel SNPs, including a non-synonymous, a synonymous, and two variations located in untranslated RNA sequences. Family-based allelic and genotypic association analysis yielded significant results in CDKN2A (rs11515: PDT p = 0.003, genotype-PDT p = 0.014). We conclude that CDKN2A is a promising new candidate gene potentially contributing to AD susceptibility on chromosome 9p.

Falls: a comparison of trends in community, hospital and mortality data in older Australians

BACKGROUND AND AIMS

Falls are major contributors to disability, morbidity and death for older people. Frequently, falls-related data for each of these areas is viewed in isolation. The aim of this study was to establish trends in incidence of falls-related events including: community reporting of falls and falls-related injuries, hospitalizations as a result of accidental falls, and mortality related to accidental falls for older people in two states of Australia (Victoria and South Australia).

METHODS

We analysed data sets for falls hospitalizations and mortality rates for the period 1988 to 1997, and from two longitudinal population-based proportional samples during the same time period.

RESULTS

Age-standardised falls mortality rates have steadily declined in Victoria, and remained unchanged between 1988 and 1997 in South Australia. In both states, age-standardised falls hospitalization rates have increased significantly (in Victoria, RR=1.32, 95% CI: 1.30-1.34; and South Australia, RR=1.05, 95% CI: 1.03-1.06). In both states, there was a clear age-related effect, with those in the 85-year and older age group having a falls-related mortality rate approximately 40 times that of those aged 65-69 years, and a hospitalization rate 9 times that of those in the 65-69 age group. The community studies indicated that falls rates remain high among older Australians, and that injurious falls occurred in 10% in the first wave of data collection in each of these studies.

CONCLUSIONS

The results highlight that various indicators related to falls trends taken in isolation may yield differing conclusions. For a true reflection of the effectiveness of falls prevention programs, falls-related mortality, hospitalization and community data need to be integrated. Increased focus on falls prevention activity in Australia during the 1990's has not reduced the magnitude of this major public health problem.

Pharmacological characterization of human recombinant melatonin mt(1) and MT(2) receptors

We have pharmacologically characterized recombinant human mt(1) and MT(2) receptors, stably expressed in Chinese hamster ovary cells (CHO-mt(1) and CHO-MT(2)), by measurement of [(3)H]-melatonin binding and forskolin-stimulated cyclic AMP (cAMP) production. [3H]-melatonin bound to mt(1) and MT(2) receptors with pK(D) values of 9.89 and 9.56 and B(max) values of 1.20 and 0.82 pmol mg(-1) protein, respectively. Whilst most melatonin receptor agonists had similar affinities for mt(1) and MT(2) receptors, a number of putative antagonists had substantially higher affinities for MT(2) receptors, including luzindole (11 fold), GR128107 (23 fold) and 4-P-PDOT (61 fold). In both CHO-mt(1) and CHO-MT(2) cells, melatonin inhibited forskolin-stimulated accumulation of cyclic AMP in a concentration-dependent manner (pIC(50) 9.53 and 9.74, respectively) causing 83 and 64% inhibition of cyclic AMP production at 100 nM, respectively. The potencies of a range of melatonin receptor agonists were determined. At MT(2) receptors, melatonin, 2-iodomelatonin and 6-chloromelatonin were essentially equipotent, whilst at the mt(1) receptor these agonists gave the rank order of potency of 2-iodomelatonin>melatonin>6-chloromelatonin. In both CHO-mt(1) and CHO-MT(2) cells, melatonin-induced inhibition of forskolin-stimulated cyclic AMP production was antagonized in a concentration-dependent manner by the melatonin receptor antagonist luzindole, with pA(2) values of 5.75 and 7.64, respectively. Melatonin-mediated responses were abolished by pre-treatment of cells with pertussis toxin, consistent with activation of G(i)/G(o) G-proteins. This is the first report of the use of [(3)H]-melatonin for the characterization of recombinant mt(1) and MT(2) receptors. Our results demonstrate that these receptor subtypes have distinct pharmacological profiles.

The provision of preventive care by general practitioners measured by patient completed questionnaires

The objective of this study was, by means of patient self-report, to measure the provision of preventive care to patients of a sample of Australian general practitioners. Patient-completed questionnaires from a consecutive sample of Australian general practitioners enrolled in the Quality Assurance and Continuing Medical Education Program of the Royal Australian College of General Practitioners were used. Patients were attendees at Australian general practices. The main outcome measures included the following: the provision of tetanus immunization within the last 10 years; blood pressure measurement within the last 12 months; cholesterol screening within the past 5 years; provision of adequate information to enable patients to stop smoking if they desired; discussion about the benefits of diet and exercise to enhance life, and about alcohol intake; provision of cervical smears in the past 2 years; provision of adequate instruction in breast self-examination and overall satisfaction with service provision. A total of 12,605 questionnaires from 133 general practices were completed. There was wide variability between practices in the reported provision of preventive care items including an average of 86% (range 36-100) of patients reporting the provision of blood pressure checking in the past 12 months, 62% (range 25-97%) reporting the provision of tetanus immunization in the past 10 years, and 63% (range 10-91%) reporting having had a cervical smear in the past 2 years. Patients who were very satisfied were more likely to have reported that they had received blood pressure measurement in the past 12 months, participated in discussions about the benefits of diet and exercise in enhancing life, and participated in discussions about alcohol intake and provision of adequate instruction in the technique of breast self-examination. Patient self-reporting identified variability between practitioners in the provision of preventive care conforming to accepted guidelines. Patients who reported that they were very satisfied or who regularly attend only one general practice reported the provision of more preventive care than those who were not very satisfied or who regularly visited two or more general practitioners.

A patient determined general practice satisfaction questionnaire

OBJECTIVES

To develop and explore the use of a patient satisfaction questionnaire based on patient perceptions of items which influence satisfaction and to explore patient and practitioner characteristics which influence the results.

METHOD

Twenty focus groups identified 39 items which were then assembled into a questionnaire which was evaluated by attendees at 133 Australian general practices.

MAIN OUTCOME MEASURES

Overall satisfaction with general practitioner services and the appropriateness of the 39 items identified by focus group participants; socio-demographic characteristics of patients and practitioners and the impact of these characteristics on the results; factor analysis of the relationship of the items to each other and to overall satisfaction.

RESULTS

Questionnaires were completed by 12,605 patients of 133 general practices. Seventy-three percent of these patients reported they were overall very satisfied with the care they received and 26% were satisfied. There were five individual items for which an average of more than 10% of patients reported they were not satisfied: waiting time at the surgery (18%); ease of obtaining home visits (17%); ease of seeing the doctor out of normal hours (15%); cost of drugs (12%) and facilities for children in the waiting room (10%). Factors which were more likely to result in a report of patients being very satisfied included: patients being older; if patients had visited recently; if they had attended the practice for a long time; if they visited only one general practice and had more consultations in the past 12 months. Patients of solo practitioners were more likely to report they were satisfied with individual items and patients of practices of three or more practitioners were least likely. No significant differences between practices of different sizes in the level of overall satisfaction were detected. Factor analysis identified three major factors which we have described as containing interaction, technical and accessibility items. These three factors explained 44.4% of the variance in results.

CONCLUSION

This project found the items patients identified were similar to those identified by practitioners, and reiterated previous findings that there is substantial variability in the levels of satisfaction reported by patients of Australian general practices.

Signalling by CXC-chemokine receptors 1 and 2 expressed in CHO cells: a comparison of calcium mobilization, inhibition of adenylyl cyclase and stimulation of GTPgammaS binding induced by IL-8 and GROalpha

The effect of interleukin-8 (IL-8) and growth-related oncogene alpha (GROalpha) on [35S]-guanosine 5'-O-(3-thiotriphosphate) ([35S]GTPgammaS) binding, forskolin-stimulated cyclic AMP accumulation and cytosolic calcium concentration were determined in recombinant CHO cells expressing HA-tagged CXC-chemokine receptors 1 and 2 (CXCR1 and CXCR2). Radioligand binding assays confirmed that the binding profiles of the recombinant receptors were similar to those of the native proteins. IL-8 displaced [125I]-IL-8 binding to CXCR1 and CXCR2 with pKi values of 8.89+/-0.05 and 9.27+/-0.03, respectively. GROalpha, a selective CXCR2 ligand, had a pKi value of 9.66+/-0.39 at CXCR2 but a pKi>8 at CXCR1. Calcium mobilization experiments were also consistent with previous reports on native receptors. Activation of both receptors resulted in stimulation of [35S]GTPgammaS binding and inhibition of adenylyl cyclase. A comparison of the functional data at CXCRI showed that a similar potency order (IL-8> >GROalpha) was obtained in all three assays. However, at CXCR2 whilst the potency orders for calcium mobilization and inhibition of adenylyl cyclase were similar (IL-8 > or = GROalpha), the order was reversed for stimulation of [35S]GTPgammaS binding (GROalpha > IL-8). All of the functional responses at both receptors were inhibited by pertussis toxin (PTX), suggesting coupling to a Gi/Go protein. However, the calcium mobilization induced by IL-8 at CXCR1 was not fully inhibited by PTX, suggesting an interaction with a G-protein of the Gq family. Our results with pertussis toxin also suggested that, in the [35S]GTPgammaS binding assay, CXCR1 displays some constitutive activity. Thus, we have characterized the binding and several functional responses at HA-tagged CXCRs 1 and 2 and have shown that their pharmacology agrees well with that of the native receptors. We also have preliminary evidence that CXCR1 displays constitutive activity in our cell line and that CXCR2 may traffic between different PTX sensitive G-proteins.

Health actions and social class among older Australians

This paper aims to identify aspects of social class that are related to health actions important for older Australians. Data are from the 1994 Health Status of Older People Project baseline survey of 1,000 participants aged 65 and over in Melbourne. Analyses employed logistic regression controlling for age and gender. Physical activity was related to both former occupation and current income; social activity to former occupation; and not smoking to home ownership. Health promotion strategies require a better understanding of the ways in which aspects of social class affect the life course experiences of different birth cohorts. Promotion of physical and social activity in old age needs to take account of the continuing influence of advantages associated with social class.

GR196429: a nonindolic agonist at high-affinity melatonin receptors

N-[2-[2,3,7,8-tetrahydro-1H-furo(2,3-g)indol-1-yl]ethyl]acetamide (GR196429) is a novel, nonindolic melatonin receptor agonist. GR196429 had high affinity for human mt1 (pKi 9.9) and MT2 (pKi 9.8) receptors expressed in Chinese hamster ovary cells and for 2-[125I]-iodomelatonin binding sites in human cerebellum, guinea pig superior colliculus and hypothalamus and chicken retina and tectum (pKi 8.8-9.5). GR196429 was inactive at a wide range of other hormone and neurotransmitter receptors. In Chinese hamster ovary cells expressing human mt1 or MT2 receptors, both melatonin and GR196429 dose-dependently inhibited forskolin-stimulated cAMP accumulation. In rabbit isolated retina, GR196429 inhibited calcium-dependent [3H]-dopamine release with potency (IC50 30 pM) and maximum effect (76 +/- 5% at 1 nM) similar to those of melatonin. The response was antagonized by the melatonin receptor antagonist luzindole (1 microM). In slices of rat brain suprachiasmatic nucleus, perfusion (1 h) with GR196429 at zeitgeber time 10 phase advanced the circadian peak in neuronal activity measured on the following day, with a maximum phase advance of 2.7 +/- 0.3 h at 10 pM and an EC50 of 0.6 pM, results that indicated a melatonin-like action on the phase of the circadian clock. CNS penetration and duration of receptor occupancy was determined in an ex vivo radioligand binding assay. In membranes of guinea pig superior colliculus prepared 30 min after administration of GR196429 (s.c.), 2-[125I]-iodomelatonin binding was inhibited with an ED50 of 0.04 mg/kg. After a dose of 1 mg/kg, binding was significantly inhibited for at least 3 h. Thus GR196429 is a potent and selective agonist at high-affinity melatonin receptors, which modulates circadian rhythms in an in vitro model of the circadian clock and which readily penetrates the CNS.

Preventive care and continuity of attendance. Is there a risk?

OBJECTIVE

To explore whether there are associations between continuity of care and the provision of items of preventive care in Australian general practice.

METHOD

Patient completed questionnaires from a 'consecutive' sample of Australian general practitioners enrolled in the Patient Participation Program of the Quality Assurance and Continuing Medical Education Program of the Royal Australian College of General Practitioners.

MAIN OUTCOME MEASURES

An association was sought between the length of time patients reported attending their practitioner, whether they regularly attended more than one practice, and whether they were provided with preventive care.

RESULTS

Data from 12,605 questionnaires, completed by patients from 133 practices throughout Australia found that patients who reported only visiting one practice on a regular basis were significantly more likely to report the provision of: blood pressure screening within the past 12 months; cholesterol screening in the past 5 years; adequate smoking cessation information if required; to have discussed the benefits of diet and exercise; to have received a cervical smear in the past 2 years; and to have received adequate instruction in the technique of breast self examination. Patients attending the same practices for longer periods were significantly more likely to have received the above items with the exception of adequate information to enable them to stop smoking if they desired; and cervical smears in the past 2 years. Such patients were less likely to report the provision of tetanus immunisation in the past 10 years and cervical smears in the past 2 years.

CONCLUSIONS

Patients reporting greater continuity of care measured by only consulting at one practice or visiting the practice for a longer time period reported a greater provision of preventive care than patients who did not report these characteristics.

The sequence and structure of the 3' arm of the first stem-loop of the human immunodeficiency virus type 2 trans-activation responsive region mediate Tat-2 transactivation

Human immunodeficiency virus type 2 (HIV-2) causes AIDS, but generally after a much longer asymptomatic period than that which follows infection with HIV-1. At the molecular level, HIV-2 is much more closely related to the simian immunodeficiency viruses than to HIV-1 and our previous studies have demonstrated that HIV-2 and HIV-1 enhancer stimulation is mediated by different sets of cellular proteins following T-cell activation. Similar to HIV-1, HIV-2 encodes a transactivating protein, Tat, which appears to be necessary for viral replication and stimulates viral transcriptional initiation and/or elongation. While Tat-1 binds to the RNA of the trans-activation responsive (TAR) region of HIV-1 and HIV-2, cellular factors that bind to the RNA transcript are also necessary for Tat to function in vivo. Since almost all previous investigations of cellular cofactors for Tat had focused on HIV-1, we undertook studies aimed at understanding the interaction between the TAR RNA region of the HIV-2 promoter (TAR-2) and cellular proteins. By using extension inhibition analysis (toeprinting) and RNA electrophoretic mobility shift assays, we demonstrated binding of a nuclear factor(s) in T cells to the base of the promoter-proximal stem-loop structure. Mutational analysis of this region revealed that both the sequence of the 3' arm and the stem structure itself are important for activation of the promoter by Tat-2. In contrast, the structure is necessary for activation of TAR-2 by Tat-1 but the sequence is less important. These results suggest that a cellular factor interacts with the 3' arm of the proximal stem-loop structure of TAR-2 and mediates Tat-2-induced increases in the level of HIV-2 transcripts.

The relevance of hearing a crack in ankle injuries

OBJECTIVE

To examine the predictive value of a crack noise or sensation in the history of injury in the diagnosis of ankle fracture.

METHODS

A short questionnaire was filled in on 464 patients with isolated ankle injuries attending the accident and emergency department in a three month period from July to September. These patients were seen in the usual way in the department and the need for x ray assessed according to clinical judgement and existing departmental guidelines. Cases which subsequently proved to be other than ankle injuries, for example, fractured calcaneus, were excluded from the study.

RESULTS

A positive history of hearing or feeling a crack did not indicate the need for an x ray or increase the possibility of a fracture; indeed the history of a crack made the presence of a fracture less likely. The clinical diagnosis of absence of fracture without radiological examination may require careful explanation to the patient.

CONCLUSIONS

Hearing a crack in the ankle does not suggest a fracture.

Injury patterns in cyclists attending an accident and emergency department: a comparison of helmet wearers and non-wearers

OBJECTIVES

To study circumstances of bicycle accidents and nature of injuries sustained and to determine effect of safety helmets on pattern of injuries.

DESIGN

Prospective study of patients with cycle related injuries.

SETTING

Accident and emergency department of teaching hospital.

SUBJECTS

1040 patients with complete data presenting to the department in one year with cycle related injuries, of whom 114 had worn cycle helmets when accident occurred.

MAIN OUTCOME MEASURES

Type of accident and nature and distribution of injuries among patients with and without safety helmets.

RESULTS

There were no significant differences between the two groups with respect to type of accident or nature and distribution of injuries other than those to the head. Head injury was sustained by 4/114 (4%) of helmet wearers compared with 100/928 (11%) of non-wearers (P = 0.023). Significantly more children wore helmets (50/309 (16%)) than did adults (64/731 (9%)) (P < 0.001). The incidence of head injuries sustained in accidents involving motor vehicles (52/288 (18%)) was significantly higher than in those not involving motor vehicles (52/754 (7%)) (chi 2 = 28.9, P < 0.0001). Multiple logistic regression analysis of probability of sustaining a head injury showed that only two variables were significant: helmet use and involvement of a motor vehicle. Mutually adjusted odds ratios showed a risk factor of 2.95 (95% confidence interval 1.95 to 4.47, P < 0.0001) for accidents involving a motor vehicle and a protective factor of 3.25 (1.17 to 9.06, P = 0.024) for wearing a helmet.

CONCLUSION

The findings suggest an increased risk of sustaining head injury in a bicycle accident when a motor vehicle is involved and confirm protective effect of helmet wearing for any bicycle accident.

Prolonged anorectal manometry and external anal sphincter electromyography in ambulant human subjects

We have developed a method for prolonged combined anorectal manometry and electromyography (EMG) of the external anal sphincter in ambulant subjects. Fourteen healthy volunteers were studied for a total of 284 hr (mean of 20.3 hr/subject). Anorectal manometry was performed using a probe with twin pressure sensors. EMG was recorded by one indifferent and two differential silver-silver chloride surface electrodes positioned 0.5-0.75 cm from the anus on either side. The sampling reflex occurred frequently and was significantly (P less than 0.001) more common during wakefulness than during sleep and also following meals than during fasting (P less than 0.01). The passage of flatus was associated with transient relaxation of the anal canal in 19% of episodes. In contrast, there was a contractile episode with no preceding relaxation in 75% of episodes. The anal sphincter had significantly (P less than 0.05) more action potentials (APs) during the day (12.8 +/- 3.2 APs/10 min) than at night (1.6 +/- 1.3 APs/10 min). During micturition, anal canal pressure rose (mean 15 mm Hg) in association with powerful external anal sphincter contractions. Our data show that, normally, contractile activity both in the anal canal and external anal sphincter maintains fecal continence during micturition and the passage of flatus. The technique should lead to a better understanding of the normal mechanisms of fecal continence during waking and sleep and of the pathophysiology of disorders of anorectal function.

The use of intraluminal strain gauges for recording ambulant small bowel motility

Perfused-tube manometry has hitherto been the standard technique for recording intraluminal intestinal pressure in humans, but it is unsuitable for ambulant use. The aim of our study was to evaluate the ability of resistive strain gauge transducers attached to a fine catheter to detect pressure change. Simultaneous strain gauge and perfused-tube manometry was performed on six fasting subjects; in four, strain gauge activation was continuous and in two, the transducers were activated in a pulsed mode with data encoded as a pulse train with an approximate frequency of 20 Hz. Eight thousand eight hundred eighty-eight pressure waves were recorded by strain gauge, of which 96% were detected by perfused-tube manometry. There was good agreement in both phases II and III of the migrating motor complex. The amplitude of pressure waves recorded by strain gauge was slightly but significantly greater. A proportion (14-17%) of pressure waves recorded by strain gauge were bifid; this was not seen with the perfused tube. These differences are best explained by the greater sensitivity and more rapid rise time of the strain gauges. There was no loss of fidelity in the pulse-interval recording mode. A seventh subject underwent a continuous 72-h recording with the strain gauge catheter attached to a battery-operated encoder and magnetic tape cassette recorder and was freely ambulant during this period. The procedure was well tolerated and motility patterns could be clearly identified. We conclude that intraluminal strain gauge catheters are suitable for prolonged use in ambulant subjects and produce data that are closely comparable to the data acquired from perfused-tube manometry under laboratory conditions.

Measurement of intracellular pH with microelectrodes in rat kidney in vivo

The construction of two types of double-barreled microelectrodes of sufficiently small tip size to record cytosolic pH (pHc) in renal tubular epithelial cells is described. Mean pHc in control anesthetized rats was 7.10 and mean basolateral membrane potential (Em) was -51.8 mV. These results suggest that hydrogen ions are actively extruded from either or both poles of the proximal tubular cell but that bicarbonate exit across the basolateral membrane is passive. In animals treated with acetazolamide, pHc was significantly elevated (mean 7.35) but Em was unchanged, suggesting that proton extrusion continues but that the rate of reaction of OH- with CO2 is diminished due to carbonic anhydrase inhibition. A pH higher than that of arterial blood was obtained from sites presumed to be in the interstitium. The evidence for the various assignments of microelectrode tip position is discussed.

Fascicular conduction disturbances following aortocoronary bypass surgery: the role of hypothermia versus potassium-arrest cardioplegia

Two hundred and sixty six consecutive patients who underwent aortocoronary bypass surgery at our institution were studied to assess the incidence of developing new fascicular conduction disturbance. The first 66 patients (Group I) were operated on using systemic hypothermia and ventricular fibrillation while the next 200 patients (Group II) were operated on using systemic hypothermia plus 4 degrees C potassium cardioplegia. Twelve patients in Group I (18%) developed new fascicular conduction defects, an incidence similar to previous studies of patients operated on using similar conditions. A significantly higher incidence of new fascicular conduction defects occurred in Group II patients where 87 patients (43.5%) developed new defects (p less than .001). The most likely explanations for the marked increase in fascicular conduction defects in Group II patients were either local effects of high concentrations of potassium on the conduction system or excessive cooling of the posterior wall of the heart.

Receiving, decoding and noise limiting systems for a new pressure-sensitive ingestible radio telemetric capsule

A new pressure-sensitive radiotelemetric capsule for recording intraluminal pressures within the human gastrointestinal tract has been developed; this capsule employs a pulsed mode of operation. Data recording as a pulse train greatly simplifies problems encountered hitherto in this field, but has produced the requirement for a decoding system which, on tape replay, will reproduce the original pressure change. A system is described here which, in addition to producing an analogue signal from the recorded pulse train, will also eliminate artefacts due to either spurious radio signals or variations in magnetic tape transport speed; it also provides a sensitive and accurate indication of transient signal loss.

Rickets in premature infants receiving parenteral nutrition: a case report and review of the literature

There is a multifactorial etiology for rickets in premature infants receiving total parenteral nutrition. As an example of this, we describe a premature infant fed almost exclusively parenterally for the first 8 months of life who developed biochemical and radiologic evidence of rickets despite receiving vitamin D, calcium, and phosphorus at presently recommended levels. From our experience and a review of previous literature, there appears to be considerable uncertainty regarding the intravenous requirements of calcium, phosphorus, and vitamin D, particularly in low-birth weight infants. Therefore, measurements of serum 25-hydroxyvitamin D levels, vitamin D, and mineral intakes, and calcium and phosphorus excretion might be clinically useful for monitoring premature infants receiving total parenteral nutrition. Further research delineating more precisely the vitamin D, calcium, and phosphorus requirements of such infants is also suggested.