Progestin primed ovarian stimulation using dydrogesterone from day 7 of the cycle onwards in oocyte donation cycles: a longitudinal study

RESEARCH QUESTION

Does a progestin-primed ovarian stimulation (PPOS) protocol with dydrogesterone from cycle day 7 yield similar outcomes compared with a gonadotrophin-releasing hormone (GnRH) antagonist protocol in the same oocyte donors?

DESIGN

This retrospective longitudinal study included 128 cycles from 64 oocyte donors. All oocyte donors had the same type of gonadotrophin and daily dose in both stimulation cycles. The primary outcome was the number of cumulus-oocyte complexes (COC) retrieved.

RESULTS

The number of COC retrieved (mean ± SD 19.7 ± 10.8 versus 19.2 ± 8.3; P = 0.5) and the number of metaphase II oocytes (15.5 ± 8.4 versus 16.2 ± 7.0; P = 0.19) were similar for the PPOS and GnRH antagonist protocols, respectively. The duration of stimulation (10.5 ± 1.5 days versus 10.8 ± 1.5 days; P = 0.14) and consumption of gonadotrophins (2271.9 ± 429.7 IU versus 2321.5 ± 403.4 IU; P = 0.2) were also comparable, without any cases of premature ovulation. Nevertheless, there was a significant difference in the total cost of medication per cycle: €898.3 ± 169.9 for the PPOS protocol versus €1196.4 ± 207.5 (P < 0.001) for the GnRH antagonist protocol.

CONCLUSION

The number of oocytes retrieved and number of metaphase II oocytes were comparable in both stimulation protocols, with the advantage of significant cost reduction in favour of the PPOS protocol compared with the GnRH antagonist protocol. No cases of premature ovulation were observed, even when progestin was started later in the stimulation.

P-671 Progestin primed ovarian stimulation using dydrogesterone in oocyte donation cycles: a longitudinal study

Study question

Does progestin primed ovarian stimulation (PPOS) with dydrogesterone starting from stimulation day 6 yield similar outcomes compared with a GnRH antagonist protocol in oocyte donors?

Summary answer

The number of retrieved oocytes and metaphase II oocytes was similar in both stimulation protocols.

What is known already

The use of progestins in the follicular phase to suppress a premature LH surge as an alternative to the GnRH analogue is an emerging regimen for ovarian stimulation. There is robust evidence of the safety and efficacy of PPOS compared to conventional ovarian stimulation regimens in oocyte donation cycles. Progestins and gonadotropins are typically administered simultaneously from day 2 or day 3 of the cycle onwards. Reports on initiation of progestins at a later stage, from day 6 of stimulation, are scarce.

Study design, size, duration

This is a retrospective longitudinal cohort study comparing two strategies of ovarian stimulation in the same oocyte donors. Oocyte donors who had a PPOS protocol between January 2021 and December 2021 and who had another ovarian stimulation cycle using a GnRH antagonist protocol within the same year were included in the analysis. Dydrogesterone 10 mg twice daily was started on day 6 of stimulation onwards. In total, 68 cycles from 34 oocyte donors were Included.

Participants/materials, setting, methods

All oocyte donors had the same type of gonadotropin and daily dose in both stimulation cycles. The primary outcome was the number of retrieved cumulus oocyte complexes (COC) and the number of metaphase II oocytes. Secondary outcomes were the duration of stimulation, the total dose of gonadotropins, the occurrence of premature ovulation and the difference in total cost between the two stimulation protocols.

Main results and the role of chance

The average female age was 28.3 years (SD 4.3), BMI 24.0 kg/m2 (SD 2.9) and AMH 2.9 µg/l (SD 1.5). When comparing the PPOS cycle with the GnRH antagonist cycle, the mean number of retrieved COCs was 20.0 ± 9.9 and 20.2 ± 9.3, respectively (p = 0.33) and the number of metaphase II oocytes was also similar (15.6 ± 7.9 and 16.9 ± 8.0, respectively; p = 0.35). The duration of stimulation (10.6 ± 1.7 days versus 10.9 ± 1.7 days; p = 0.26) and cumulative dose of gonadotropins (2284.6 ± 494.9 IU versus 2338.2 ± 462.1 IU; p = 0.25) were comparable in the PPOS and the GnRH antagonist group. No events of premature ovulation were observed in both groups. There was a significant difference in total medication cost per cycle between both protocols, 903.3 ± 195.7 € for PPOS versus 1205.3 ± 243.9 € (p &lt; 0.001) for the GnRH antagonist protocol. This means a cost reduction of 25% for the PPOS group compared to the GnRH antagonist group. GEE multivariate regression analysis allowing adjustment for relevant confounders (age, BMI, AMH) showed that the type of protocol was not significantly associated with the number of MII oocytes retrieved (coefficient 1.23, p = 0.33).

Limitations, reasons for caution

The small sample and the retrospective design are limitations of this study.

Wider implications of the findings

PPOS is a patient friendly and well-tolerated protocol. A simplified protocol of ovarian stimulation with the advantage of cost reduction. The protocol can easily be applied in oocyte donation and cycles with elective freeze all. Adequately powered RCTs should be performed to confirm our results.

Trial registration number

not applicable

Dg-mapping as a tool to determine the spatial distribution of the focal sources and the number of reentries during torsade de pointes in the cavb dog model

Funding Acknowledgements

Type of funding sources: None.

Background

Torsade de Pointes (TdP) is a ventricular tachycardia that is still incompletely understood. While the origin of the arrhythmia is generally accepted to be caused by triggered activity, the perpetuation of such an episode is still under debate.

Purpose

We compare the difference in reentrant activity between self- and non-terminating(ST and NT) TdP episodes. In addition, we analyzed the distribution of the triggered activity for preferred locations.

Methods

A total of 5 dogs with Chronic Atrioventricular Block developed 54 episodes of TdP. These episodes were examined for reentry loops and focal sources. First, to detect loops, we used Directed Graph Mapping, a novel mapping technique based on principles from network theory. Subsequently, the number of simultaneous loops and the presence of (bi-)ventricular reentry was compared between the ST and NT groups. Second, focal sources were accumulated into heatmaps. The distribution of sources was compared to a randomly distributed model for the detection of preferred locations.

Results

Concerning reentry, during the time at which loops are present, a typical ST episode shows an average of 1.33(±0.66) reentry loops present at one time compared to an average of 2.72(±1.48) for a typical NT episode. Looking at the (bi-)ventricular reentry, only 1 of the 4 ST episodes (25%) shows the presence of this type of reentry and only 7.12 % of the total reentry duration, while all 9 NT episodes (100%) develop (bi-)ventricular reentry to a greater degree than in the one ST episode (Between 10.10% and 69.62% of their total reentry duration). Regarding the triggered activity, we see locations in the heatmaps containing up to 23% of all detected focal sources in the entire system. Compared to a random distribution of focal sources, the chances to get as many sources in one location as shown in the data are close to 0%.

Conclusion

Reentry in NT TdP differentiates itself from the reentry in ST cases on the basis of the number of simultaneous loops in the system and the presence of (bi-)ventricular reentry. Triggered activity in CAVB dogs occurs at preferred locations in the ventricles. Therefore, ablating these preferred regions could be a possible strategy to prevent TdP.

Measurement and sampling error in mixed-methods research for the control of Peste des Petits Ruminants in the Karamoja subregion of Northeastern Uganda: A cautionary tale

A team of interdisciplinary researchers undertook a mixed methods, participatory epidemiology (PE) based study as part of a pilot project for localized control of Peste des petits ruminants (PPR), a small ruminant disease of high socio-economic impact. Mixed methods research combines qualitative and quantitative methods, allowing iterative comparison of results to arrive at a more comprehensive and informed outcome. In this study, the use of PE and a household survey (HHS) resulted in contradictory results. However, the mixed methods approach also facilitated the detection and the explanation of bias in the HHS, which may have gone undetected and unexplored had only one method been used. Results show that logistical constraints leading to a failure to apply key aspects of the sampling strategy led to problematic gender/ethnic composition of the HHS sample population. Additionally, while PE findings on local disease and terminology were integrated during HHS development and training, there is apparent measurement error related to enumerator bias in HHS results, possibly due to insufficient respondent understanding or a lack of analytic clarity. The extensive nature of the PE, surveillance methodologies used in the initial site assessment, and formative research for the HHS allowed for a critical analysis and interpretation of HHS results as well as reflection on the research process. The findings of this paper underscore the (1) flexibility and utility of participatory methods, (2) the importance of mixed methods research in designing health interventions, and (3) the necessity of tight integration of study design with team planning for implementation of research in environments such as Karamoja, Uganda. If all three are to be achieved not only researchers but funders must provide these space and structure beginning in the study design phase. These findings are relevant in many places, but have particular importance for international, interdisciplinary teams working from various on-and-off-site locations with traditional or indigenous knowledge systems.

Transmission potential of paromomycin-resistant Leishmania infantum and Leishmania donovani

OBJECTIVES

Former studies demonstrated quick selection of paromomycin resistance for Leishmania infantum and Leishmania donovani accompanied by increased fitness. The present study aimed to interpret these findings in an epidemiological context by comparing infection of WT and experimentally derived paromomycin-resistant strains in the sand fly vector.

METHODS

Depending on the Leishmania species, Lutzomyia longipalpis and Phlebotomus perniciosus or Phlebotomus argentipes sand flies were artificially infected with procyclic promastigotes of WT and paromomycin-resistant L. infantum (MHOM/FR/96/LEM3323-cl4) or L. donovani (MHOM/NP/03/BPK275/0-cl18). The infection rate and gut/stomodeal valve colonization were determined to monitor parasite phenotypic behaviour within the vector. The impact of the previously described gain of fitness in the vertebrate host on infectivity for the vector was assessed by feeding L. longipalpis on Syrian golden hamsters heavily infected with either WT or paromomycin-resistant parasites.

RESULTS

WT and paromomycin-resistant Leishmania of both species behaved similarly in terms of infection and parasite location within the studied sand fly species. Blood feeding on infected hamsters did not reveal differences in acquisition of WT and paromomycin-resistant parasites, despite the higher organ burdens observed for the paromomycin-resistant strain. Strains remained resistant after passage in the vector.

CONCLUSIONS

Although paromomycin-resistant parasites show an increased parasite fitness in vitro and in laboratory rodents, the intrinsic infection potential of paromomycin-resistant parasites remains unaltered in the sand fly. Of importance is the fact that paromomycin-resistant Leishmania are able to complete development in the natural vectors and produce stomodeal infection with metacyclic forms, which clearly suggests their potential to spread and circulate in nature.

The livestock vaccine supply chain: Why it matters and how it can help eradicate peste des petits Ruminants, based on findings in Karamoja, Uganda

Understanding factors that hinder vaccination, including logistical and social constraints, is critical to finding the most effective approach for the global eradication of peste des petits ruminants (PPR). Vaccination projects should analyze the supply chain and take it into consideration when planning and creating a vaccination strategy. Adequate supply chain management of the PPR vaccine could lead to reduced cost, increased availability, and the construction of a data platform for other livestock vaccines. Integrating the supply chain of PPR vaccine with other veterinary or health commodities could reduce cost, as well as increase uptake. The use of a thermostable vaccine could potentially have a positive impact on the eradication of PPR in remote areas, such as the Karamoja subregion in Uganda, as it did with rinderpest across Sub Saharan Africa. In terms of vaccine delivery, the use of community animal health workers (CAHWs) could be beneficial in certain areas, such as the Karamoja subregion of Uganda, by alleviating supply chain constraints in the last-mile delivery, as well as increasing coverage and uptake. A gendered approach to livestock vaccines should also be considered, as decision-making power regarding livestock vaccination is gendered in many various contexts. The PPR eradication strategy-as well as other livestock vaccination programs-would be more effective and efficient if the supply chain management were considered as a key component in the process and efforts tailored, accordingly.

Identification of Peste des Petits Ruminants Transmission Hotspots in the Karamoja Subregion of Uganda for Targeting of Eradication Interventions

This paper describes an assessment of the patterns of peste des petits ruminants virus circulation in the Karamoja subregion of Uganda conducted to identify the communities that maintain the virus and inform the development of a targeted vaccination strategy. Participatory epidemiological methods were used to develop an operational hypothesis for the patterns of PPR in Karamoja that was subsequently validated through outbreak investigation and genomics. The participatory epidemiological assessment included risk mapping with livestock owners, community animal health workers and veterinarians and indicated there were two critical foci of virus transmission on the Uganda-Kenya border. One was located in two adjacent subcounties of Kotido and Kaabong Districts in northern Karamoja and the other in Loroo subcounty of Amudat District in southern Karamoja. Participants reported that these were locations where outbreaks were usually first observed in Karamoja and subsequently spread to other areas. Following the participatory assessment, surveillance activities were implemented across the Karamoja subregion in 2018. Three outbreak were detected, investigated and sampled. Two outbreaks were located in the northern and one on the southern focus of transmission. No Outbreaks were diagnosed in Karamoja outside of these foci during 2018. Genomics indicated different clusters of viruses were associated with the northern and southern foci that were more closely related to other East African isolates than to each other. This indicates these are two separate systems of virus circulation which should be explicitly addressed in eradication as separate cross-border systems that require integrated cross-border interventions.

Immunosuppression of Syrian golden hamsters accelerates relapse but not the emergence of resistance in Leishmania infantum following recurrent miltefosine pressure

Although miltefosine (MIL) has only been approved for the treatment of visceral leishmaniasis (VL) in 2002, its application in monotherapy already led to the development of two confirmed MIL-resistant isolates by 2009. Although liposomal amphotericin B is recommended as first-line treatment in Europe, MIL is still occasionally used in HIV co-infected patients. Since their immune system is incapable of controlling the infection, high parasite burdens and post-treatment relapses are common. Linked to the particular pharmacokinetic profile of MIL, successive treatment of recurrent relapses could in principle facilitate the emergence of drug resistance. This study evaluated the effect of immunosuppression (cyclophosphamide 150 mg/kg once weekly) on the development of MIL-resistance in Syrian golden hamsters infected with Leishmania infantum. The hamsters were treated with MIL (20 mg/kg orally for 5 days) whenever clinical signs of infection or relapse were observed. The immunosuppression resulted in a significant depletion of CD4⁺ lymphocytes and MHCII-expressing cells in peripheral blood, and a concomitant increase in tissue parasite burdens and shorter time to relapse, but the strain's susceptibility upon repeated MIL exposure remained unaltered. This study demonstrates that immunosuppression accelerates the occurrence of relapse without expediting MIL resistance development.

In vitro and in vivo pharmacodynamics of three novel antileishmanial lead series

Objectives

Three new chemical series (bicyclic nitroimidazoles, aminopyrazoles and oxaboroles) were selected by Drugs for Neglected Diseases initiative as potential new drug leads for leishmaniasis. Pharmacodynamics studies included both in vitro and in vivo efficacy, cross-resistance profiling against the current antileishmanial reference drugs and evaluation of their cidal activity potential.

Methods

Efficacy against the reference laboratory strains of Leishmania infantum (MHOM/MA(BE)/67/ITMAP263) and L. donovani (MHOM/ET/67/L82) was evaluated in vitro on intracellular amastigotes and in vivo in the early curative hamster model. Cidal activity was assessed over a period of 15 days in an in vitro ‘time-to-kill’ assay. Cross-resistance was assessed in vitro on a panel of L. infantum strains with different degrees of resistance to either antimony, miltefosine or paromomycin.

Results

All lead compounds showed potent and selective in vitro activity against the Leishmania strains tested and no cross-resistance could be demonstrated against any of the current antileishmanial drugs. Cidal activity was obtained in vitro for all series within 15 days of exposure with some differences noted between L. donovani and L. infantum. When evaluated in vivo, all lead compounds showed high efficacy and no adverse effects were observed.

Conclusions

The new lead series were shown to have cidal pharmacodynamic activity. The absence of cross-resistance with any of the current antileishmanial drugs opens possibilities for combination treatment to reduce the likelihood of treatment failures and drug resistance.

•

Good efficacy was evaluated for all series in vitro and in vivo.

•

No cross-resistance towards current anti-leishmanial drugs was observed.

•

Cidal activity was obtained in vitro for all series within 15 days of exposure.

•

Some differences were observed between L. infantum and L. donovani.

Electrical stimulation in the bed nucleus of the stria terminalis alleviates severe obsessive-compulsive disorder

In 1998, we proposed deep brain stimulation as a last-resort treatment option for patients suffering from severe, treatment-resistant obsessive-compulsive disorder (OCD). Here, 24 OCD patients were included in a long-term follow-up study to evaluate the effects of electrical stimulation in the anterior limbs of the internal capsule (ALIC) and bed nucleus of the stria terminalis (BST). We find that electrical stimulation in the ALIC/BST area is safe and significantly decreases obsessions, compulsions, and associated anxiety and depressive symptoms, and improves global functioning in a blinded crossover trial (n=17), after 4 years (n=18), and at last follow-up (up to 171 months, n=24). Moreover, our data indicate that BST may be a better stimulation target compared with ALIC to alleviate OCD symptoms. We conclude that electrical stimulation in BST is a promising therapeutic option for otherwise treatment-resistant OCD patients.

Evidence of a drug-specific impact of experimentally selected paromomycin and miltefosine resistance on parasite fitness in Leishmania infantum

OBJECTIVES

Although miltefosine and paromomycin were only recently introduced to treat visceral leishmaniasis, increasing numbers of miltefosine treatment failures and occasional primary resistance to both drugs have been reported. Understanding alterations in parasite behaviour linked to drug resistance is essential to assess the propensity for emergence and spread of resistant strains, particularly since a positive effect on fitness has been reported for antimony-resistant parasites. This laboratory study compared the fitness of a drug-susceptible parent WT clinical Leishmania infantum isolate (MHOM/FR/96/LEM3323) and derived miltefosine and paromomycin drug-resistant lines that were experimentally selected at the intracellular amastigote level.

METHODS

Parasite fitness of WT, paromomycin-resistant and miltefosine-resistant strains, in vitro and in vivo parasite growth, metacyclogenesis, infectivity and macrophage stress responses were comparatively evaluated.

RESULTS

No significant differences in promastigote fitness were noted between the WT and paromomycin-resistant strain, while clear benefits could be demonstrated for paromomycin-resistant amastigotes in terms of enhanced in vitro and in vivo growth potential and intracellular stress response. The miltefosine-resistant phenotype showed incomplete promastigote metacyclogenesis, decreased intracellular growth and weakened stress response, revealing a reduced fitness compared with WT parent parasites.

CONCLUSIONS

The rapid selection and fitness advantages of paromomycin-resistant amastigotes endorse the current use of paromomycin in combination therapy. Although a reduced fitness of miltefosine-resistant strains may explain the difficulty of miltefosine resistance selection in vitro, the growing number of miltefosine treatment failures in the field still requires further exploratory research.

Validation of the Flemish version of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire

OBJECTIVES

The Quality of Life in Short Stature Youth (QoLISSY) questionnaire was recently developed in five European countries to assess health-related quality of life in children and adolescents with idiopathic short stature or growth hormone deficiency from child and parent perspectives. In addition to the existing French version, a Flemish version is needed for use of QoLISSY in the Flemish speaking part of Belgium.

METHODS

Children (8-18 years) and their parents recruited from two Belgian paediatric endocrinology clinics completed the QoLISSY in a cross-sectional study. Cronbach's Alpha and test-retest reliability was assessed. Validity was examined by correlation with the generic KIDSCREEN questionnaire as well as by group comparisons according to diagnostic and treatment status.

RESULTS

The QoLISSY scales had an acceptable internal consistency with Cronbach's Alpha ranging from 0·80 to 0·94 (child version) and from 0·77 to 0·92 (parent version). Test-retest reliability correlation coefficients ranged from r = 0·75 to 0·89 in the child version and from r = 0·58 to 0·85 in the parent version. Moderate correlations with the generic KIDSCREEN questionnaire suggested construct validity. Differences between child groups according to child age, underlying diagnosis, and degree of height deficit were found. Correlations with the European QoLISSY were significant for all scales.

DISCUSSION

The Flemish QoLISSY instrument is a psychometrically sound, reliable, and valid short stature specific questionnaire measuring health-related quality of life. It is expected to be of great use in upcoming clinical research on growth disorders and growth hormone treatment in Belgium and Europe.

Experiences in participatory surveillance and community-based reporting systems for H5N1 highly pathogenic avian influenza: a case study approach

Participatory surveillance (PS) is the application of participatory rural appraisal methods to the collection of epidemiological information to inform decision-making and action. It was applied in Africa and Asia as part of emergency programs to address the H5N1 highly pathogenic avian influenza (HPAI) pandemic. The approach resulted in markedly increased case detection in countries experiencing HPAI, and a better understanding of the epidemiological situation. Where HPAI was absent and PS was implemented, the method did not result in false positives and contributed to the overall epidemiological assessment that the country was free of disease. It was noted that clarity of surveillance objectives and resulting data needs at the outset was essential to optimize the balance of surveillance methods, size of the program and costs. The quality of training programs and adherence to international guidelines on good PS training practice were important for assuring the competence of PS practitioners. Orientation of senior decision-makers was an important step in assuring effective program management and appropriate use of results. As a problem-solving methodology, PS is best used to rapidly assess situations and inform strategy. Several countries continued PS after the end of projects and went on to apply PS to other health challenges.

Experimental selection of paromomycin and miltefosine resistance in intracellular amastigotes of Leishmania donovani and L. infantum

Although widespread resistance of Leishmania donovani and L. infantum against miltefosine (MIL) and paromomycin (PMM) has not yet been demonstrated, both run the risk of resistance selection. Unraveling the dynamics and mechanisms of resistance development is key to preserve drug efficacy in the field. In this study, resistance against PMM and MIL was experimentally selected in vitro in intracellular amastigotes of several strains of both species with different antimony susceptibility background. To monitor amastigote susceptibility, microscopic determination of IC50-values and promastigote back-transformation assays were performed. Both techniques were also used to evaluate the susceptibility of field isolates from MIL-relapse patients. PMM-resistance could readily be selected in all species/strains, although promastigotes remained fully PMM-susceptible. Successful MIL-resistance selection was demonstrated only by promastigote back-transformation at increasing MIL-concentrations upon successive selection cycles. Important to note is that amastigotes with the MIL-resistant phenotype could not be visualized after Giemsa staining; hence, MIL-IC50-values showed no shift. The same phenomenon was observed in a set of recent clinical isolates from MIL-relapse patients. This study clearly endorses the need to use intracellular amastigotes for PMM- and MIL-susceptibility testing. When monitoring MIL-resistance, promastigote back-transformation should be used instead of the standard Giemsa staining. In-depth exploration of the mechanistic background of this finding is warranted.

Paracetamol and ketorolac pharmacokinetics and metabolism at delivery and during postpartum

During pregnancy, changes in renal elimination, body composition and metabolic activity occur. Since these important alterations in physiology also affect drug disposition, pregnancy warrants a focused approach. Despite these differences, even commonly administered drugs have not undergone pharmacokinetic evaluation in pregnant women or at delivery. This is also true for analgesics routinely administered by anesthesiologists during pregnancy or at delivery, like intravenous (i.v.) paracetamol or ketorolac. We report on our observations on i.v. paracetamol and ketorolac disposition following cesarean delivery to illustrate the feasibility of such focused studies and the impact of pregnancy on drug disposition. The clinical relevance of these observations are subsequently discussed, and some future research directions are suggested.

Current status of human rabies transmitted by dogs in Latin America

Latin American countries made the political decision to eliminate human rabies transmitted by dogs by the year 2005. The purpose of the current study is to evaluate to what extent this goal has been reached. The epidemiological situation and control measures were analyzed and broken down within the countries by georeferencing. The 27 human cases reported in 2003 occurred in some 0.2% of the second-level geopolitical units (municipalities or counties) in the region, suggesting that the disease is a local problem. Several areas within the countries reported no more transmission of rabies in dogs. Nearly 1 million people potentially exposed to rabies received treatment. On average, 34,383 inhabitants per health post receive anti-rabies treatment (range: 4,300-148,043). Nearly 42 million dogs are vaccinated annually. Surveillance is considered fair according to the epidemiological criteria adopted by the study. Samples sent for rabies testing represent 0.05% of the estimated canine population (range: 0.001 to 0.2%). The countries are quite close to achieving the goal.

The Global Burden of Disease assessments--WHO is responsible?

The Global Burden of Disease (GBD) concept has been used by the World Health Organization (WHO) for its reporting on health information for nearly 10 years. The GBD approach results in a single summary measure of morbidity, disability, and mortality, the so-called disability-adjusted life year (DALY). To ensure transparency and objectivity in the derivation of health information, WHO has been urged to use reference groups of external experts to estimate burden of disease. Under the leadership and coordination of WHO, expert groups have been appraising and abstracting burden of disease information. Examples include the Child Health Epidemiology Reference Group (CHERG), the Malaria Monitoring and Evaluation Reference Group (MERG), and the recently established Foodborne Disease Burden Epidemiology Reference Group (FERG). The structure and functioning of and lessons learnt by these groups are described in this paper. External WHO expert groups have provided independent scientific health information while operating under considerable differences in structure and functioning. Although it is not appropriate to devise a single "best practice" model, the common thread described by all groups is the necessity of WHO's leadership and coordination to ensure the provision and dissemination of health information that is to be globally accepted and valued.

Avian influenza H5N1: risks at the human-animal interface

BACKGROUND

Great concern has arisen over the continued infection of humans with highly pathogenic avian influenza (HPAI) of the H5N1 subtype. Ongoing human exposure potentially increases the risk that a pandemic virus strain will emerge that is easily transmissible among humans. Although the pathogenicity of a pandemic strain cannot be predicted, the high mortality seen in documented H5N1 human infections thus far has raised the level of concern.

OBJECTIVES

To define the three types of influenza that can affect humans, discuss potential exposure risks at the human-animal interface, and suggest ways to reduce exposure and help prevent development of a pandemic virus.

METHODS

This review is based on data and guidelines available from the World Health Organization, the scientific literature, and official governmental reports.

RESULTS

Epidemiological data on human exposure risk are generally incomplete. Transmission of HPAI to humans is thought to occur through contact with respiratory secretions, feces, contaminated feathers, organs, and blood from live or dead infected birds and possibly from contaminated surfaces. Consumption of properly cooked poultry and eggs is not thought to pose a risk. Use of antiviral containment and vaccination may protect against development of a pandemic.

CONCLUSIONS

To most effectively decrease the risk of a pandemic, the public health and animal health sectors--those which are responsible for protecting and improving the health of humans and animals, respectively--must collaborate to decrease human exposure to HPAI virus, both by controlling virus circulation among poultry and by assessing the risks of human exposure to avian influenza virus at the human-animal interface from primary production through consumption of poultry and poultry products, and implementing risk-based mitigation measures.

Struma ovarii: US and CT findings

We describe the ultrasound and CT findings in a case of struma ovarii. Ultrasound showed a multicystic mass with a well-vascularized solid part. CT demonstrated a multilocular cystic mass with calcifications and solid, enhancing components. To prevent radical surgery, struma ovarii should be included in the differential diagnosis when a mixed, multilocular, teratoma-like tumour of the ovary shows a well-vascularized, enhancing, central solid component.

Partial characterization of matrix components interacting with cartilage proteoglycans

The charge content of aqueous suspensions of milled cartilage samples was determined by a colloid titration technique using a particle charge detector, and the data were compared with estimates from chemical analyses. Results indicated a close correlation between charge content determined by titration and that estimated by chemical analyses for samples of nasal septa only (a nonarticular cartilage). Such correlation did not hold for articular cartilages (metacarpalphalangeal joint and patella); extraction of these tissues with 0.1 or 1.2 M NaCl markedly increased the availability of the negative groups. Protein analysis, by SDS--PAGE, of the 1.2 M extracts indicated the presence of basic proteins, some of collagenous origin, such as chondrocalcin and proline-arginine-rich protein, and some of noncollagenous proteins such as pleiotrophin and histone-H2b. These data thus suggest electrostatic interactions between these basic proteins and the negative groups of proteoglycans. Such interactions would have an important effect on the osmotic properties and in the organization of cartilage.