Selective replication and vertical transmission of Ebola virus in experimentally infected Angolan free-tailed bats

The natural reservoir of Ebola virus (EBOV), agent of a zoonosis burdening several African countries, remains unidentified, albeit evidence points towards bats. In contrast, the ecology of the related Marburg virus is much better understood; with experimental infections of bats being instrumental for understanding reservoir-pathogen interactions. Experiments have focused on elucidating reservoir competence, infection kinetics and specifically horizontal transmission, although, vertical transmission plays a key role in many viral enzootic cycles. Herein, we investigate the permissiveness of Angolan free-tailed bats (AFBs), known to harbour Bombali virus, to other filoviruses: Ebola, Marburg, Taï Forest and Reston viruses. We demonstrate that only the bats inoculated with EBOV show high and disseminated viral replication and infectious virus shedding, without clinical disease, while the other filoviruses fail to establish productive infections. Notably, we evidence placental-specific tissue tropism and a unique ability of EBOV to traverse the placenta, infect and persist in foetal tissues of AFBs, which results in distinct genetic signatures of adaptive evolution. These findings not only demonstrate plausible routes of horizontal and vertical transmission in these bats, which are expectant of reservoir hosts, but may also reveal an ancillary transmission mechanism, potentially required for the maintenance of EBOV in small reservoir populations.

Generating human artery and vein cells from pluripotent stem cells highlights the arterial tropism of Nipah and Hendra viruses

Stem cell research endeavors to generate specific subtypes of classically defined "cell types." Here, we generate >90% pure human artery or vein endothelial cells from pluripotent stem cells within 3-4 days. We specified artery cells by inhibiting vein-specifying signals and vice versa. These cells modeled viral infection of human vasculature by Nipah and Hendra viruses, which are extraordinarily deadly (∼57%-59% fatality rate) and require biosafety-level-4 containment. Generating pure populations of artery and vein cells highlighted that Nipah and Hendra viruses preferentially infected arteries; arteries expressed higher levels of their viral-entry receptor. Virally infected artery cells fused into syncytia containing up to 23 nuclei, which rapidly died. Despite infecting arteries and occupying ∼6%-17% of their transcriptome, Nipah and Hendra largely eluded innate immune detection, minimally eliciting interferon signaling. We thus efficiently generate artery and vein cells, introduce stem-cell-based toolkits for biosafety-level-4 virology, and explore the arterial tropism and cellular effects of Nipah and Hendra viruses.

Pharmacologically induced endolysosomal cholesterol imbalance through clinically licensed drugs itraconazole and fluoxetine impairs Ebola virus infection in vitro

Ebola virus disease (EVD) is a severe and frequently lethal disease caused by Ebola virus (EBOV). The latest occasional EVD outbreak (2013–2016) in Western African, which was accompanied by a high fatality rate, showed the great potential of epidemic and pandemic spread. Antiviral therapies against EBOV are very limited, strain-dependent (only antibody therapies are available) and mostly restricted to symptomatic treatment, illustrating the urgent need for novel antiviral strategies. Thus, we evaluated the effect of the clinically widely used antifungal itraconazole and the antidepressant fluoxetine for a repurposing against EBOV infection. While itraconazole, similar to U18666A, directly binds to and inhibits the endosomal membrane protein Niemann-Pick C1 (NPC1), fluoxetine, which belongs to the structurally unrelated group of weakly basic, amphiphile so-called “functional inhibitors of acid sphingomyelinase” (FIASMA) indirectly acts on the lysosome-residing acid sphingomyelinase via enzyme detachment leading to subsequent lysosomal degradation. Both, the drug-induced endolysosomal cholesterol accumulation and the altered endolysosomal pH, might interfere with the fusion of viral and endolysosomal membrane, preventing infection with EBOV. We further provide evidence that cholesterol imbalance is a conserved cross-species mechanism to hamper EBOV infection. Thus, exploring the endolysosomal host–pathogen interface as a suitable antiviral treatment may offer a general strategy to combat EBOV infection.

Inoculation route-dependent Lassa virus dissemination and shedding dynamics in the natural reservoir - Mastomys natalensis

Lassa virus (LASV), a Risk Group-4 zoonotic haemorrhagic fever virus, affects sub-Saharan African countries. Lassa fever, caused by LASV, results in thousands of annual deaths. Although decades have elapsed since the identification of the Natal multimammate mouse (Mastomys natalensis) as a natural reservoir of LASV, little effort has been made to characterize LASV infection in its reservoir. The natural route of infection and transmission of LASV within M. natalensis remains unknown, and the clinical impact of LASV in M. natalensis is mostly undescribed. Herein, using an outbred colony of M. natalensis, we investigate the replication and dissemination dynamics of LASV in this reservoir following various inoculation routes. Inoculation with LASV, regardless of route, resulted in a systemic infection and accumulation of abundant LASV-RNA in many tissues. LASV infection in the Natal multimammate mice was subclinical, however, clinical chemistry values were transiently altered and immune infiltrates were observed histologically in lungs, spleens and livers, indicating a minor disease with coordinated immune responses are elicited, controlling infection. Intranasal infection resulted in unique virus tissue dissemination dynamics and heightened LASV shedding, compared to subcutaneous inoculation. Our study provides important insights into LASV infection in its natural reservoir using a contemporary infection system, demonstrating that specific inoculation routes result in disparate dissemination outcomes, suggesting intranasal inoculation is important in the maintenance of LASV in the natural reservoir, and emphasizes that selection of the appropriate inoculation route is necessary to examine aspects of viral replication, transmission and responses to zoonotic viruses in their natural reservoirs.

Children with congenital colorectal malformations during the UK Sars-CoV-2 pandemic lockdown: an assessment of telemedicine and impact on health

PURPOSE

This pilot study was designed to assess bowel function and quality of life (QoL) in children and adolescents with congenital colorectal malformations (CCM) during the first UK COVID lockdown period.

METHODS

Changes in health were assessed through semi-structured interviews, gastrointestinal functional outcomes using Krickenbeck scoring and QoL by the modified disease-specific HAQL (Hirschsprung's disease anorectal malformation quality of life questionnaire). The State-Trait Anxiety Inventory (STAI)™ for adults was used to assess parental anxiety.

RESULTS

Thirty-two families were interviewed; 19 (59%) reported no change in their child's health during the lockdown, 5 (16%) a deterioration and 8 (25%) an improvement. Neither the severity of the CCM, nor the degree of bowel dysfunction, correlated with any deterioration. The HAQL score was not correlated to a change in health. Anxiety scores ranged from no anxiety to clinical concerns. Telemedicine was well accepted by 28/32 parents (88%); however, in-person appointments were preferred if there were clinical concerns.

CONCLUSION

In the follow-up of children and adolescents with CCM during the first UK lockdown using telemedicine we found that over half had stable health conditions. Patients needing additional care could not be predicted by the severity of their disease or their bowel function alone.

Tolerance and Persistence of Ebola Virus in Primary Cells from Mops condylurus, a Potential Ebola Virus Reservoir

Although there have been documented Ebola virus disease outbreaks for more than 40 years, the natural reservoir host has not been identified. Recent studies provide evidence that the Angolan free-tailed bat (Mops condylurus), an insectivorous microbat, is a possible ebolavirus reservoir. To investigate the potential role of this bat species in the ecology of ebolaviruses, replication, tolerance, and persistence of Ebola virus (EBOV) were investigated in 10 different primary bat cell isolates from M. condylurus. Varying EBOV replication kinetics corresponded to the expression levels of the integral membrane protein NPC1. All primary cells were highly tolerant to EBOV infection without cytopathic effects. The observed persistent EBOV infection for 150 days in lung primary cells, without resultant selective pressure leading to virus mutation, indicate the intrinsic ability of EBOV to persist in this bat species. These results provide further evidence for this bat species to be a likely reservoir of ebolaviruses.

440 Abdominal Heterotaxia: A More Nuanced Anatomy

Introduction

The cardiac anomalies associated with left and right atrial appendage isomerism (LAAI and RAAI) are systematically described. However, for the associated abdominal abnormalities, only the laterality of the organs, cardinality of the spleen (asplenia or polysplenia) and the presence or absence of intestinal malrotation are noted. This study aimed to describe in greater detail the abdominal anatomy in abdominal heterotaxia.

Method

A detailed review of the imaging and clinical records of 23 patients (16 LAAI, 7 RAAI) with abdominal heterotaxia in a cardiac database was performed.

Results

In no patient was a complete description of abdominal anatomy possible, with all patients displaying unique anatomical presentations.

There was a significant association between isomerism and splenic cardinality (12/16 LAAI had polysplenia and 6/7 RAAI had asplenia, p = 0.02). Right-sided stomachs were more commonly associated with gastro-oesophageal reflux (p = 0.048). The stomach and pylorus were ipsilateral in 15/20 patients, with marked variation in gastric orientation; these were novel observations. Ladd’s procedures were performed in 15/23 patients but terminology for intestinal malrotation was inconsistently used.

Conclusions

The heterotaxic anatomy demands better descriptions for scholarly reasons, but these may lead to a better understanding of upper intestinal dysfunction and the subsequent management of these patients.

Development of a multiplex microsphere immunoassay for the detection of antibodies against highly pathogenic viruses in human and animal serum samples

Surveillance of highly pathogenic viruses circulating in both human and animal populations is crucial to unveil endemic infections and potential zoonotic reservoirs. Monitoring the burden of disease by serological assay could be used as an early warning system for imminent outbreaks as an increased seroprevalance often precedes larger outbreaks. However, the multitude of highly pathogenic viruses necessitates the need to identify specific antibodies against several targets from both humans as well as from potential reservoir animals such as bats. In order to address this, we have developed a broadly reactive multiplex microsphere immunoassay (MMIA) for the detection of antibodies against several highly pathogenic viruses from both humans and animals. To this aim, nucleoproteins (NP) of Ebola virus (EBOV), Marburg virus (MARV) and nucleocapsid proteins (NP) of Crimean-Congo haemorrhagic fever virus, Rift Valley fever virus and Dobrava-Belgrade hantavirus were employed in a 5-plex assay for IgG detection. After optimisation, specific binding to each respective NP was shown by testing sera from humans and non-human primates with known infection status. The usefulness of our assay for serosurveillance was shown by determining the immune response against the NP antigens in a panel of 129 human serum samples collected in Guinea between 2011 and 2012 in comparison to a panel of 88 sera from the German blood bank. We found good agreement between our MMIA and commercial or in-house reference methods by ELISA or IIFT with statistically significant higher binding to both EBOV NP and MARV NP coupled microspheres in the Guinea panel. Finally, the MMIA was successfully adapted to detect antibodies from bats that had been inoculated with EBOV- and MARV- virus-like particles, highlighting the versatility of this technique and potentially enabling the monitoring of wildlife as well as human populations with this assay. We were thus able to develop and validate a sensitive and broadly reactive high-throughput serological assay which could be used as a screening tool to detect antibodies against several highly pathogenic viruses.

Utility of primary cells to examine NPC1 receptor expression in Mops condylurus, a potential Ebola virus reservoir

The significance of the integral membrane protein Niemann-Pick C1 (NPC1) in the ebolavirus entry process has been determined using various cell lines derived from humans, non-human primates and fruit bats. Fruit bats have long been purported as the potential reservoir host for ebolaviruses, however several studies provide evidence that Mops condylurus, an insectivorous microbat, is also an ebolavirus reservoir. NPC1 receptor expression in the context of ebolavirus replication in microbat cells remains unstudied.

In order to study Ebola virus (EBOV) cellular entry and replication in M. condylurus, we derived primary and immortalized cell cultures from 12 different organs. The NPC1 receptor expression was characterized by confocal microscopy and flow cytometry comparing the expression levels of M. condylurus primary and immortalized cells, HeLa cells, human embryonic kidney cells and cells from a European microbat species. EBOV replication kinetics was studied for four representative cell cultures using qRT-PCR. The aim was to elucidate the suitability of primary and immortalized cells from different tissues for studying NPC1 receptor expression levels and their potential influence on EBOV replication.

The NPC1 receptor expression level in M. condylurus primary cells differed depending on the organ they were derived from and was for most cell types significantly lower than in human cell lines. Immortalized cells showed for most cell types higher expression levels than their corresponding primary cells. Concluding from our infection experiments with EBOV we suggest a potential correlation between NPC1 receptor expression level and virus replication rate in vitro.

Although there have been Ebola virus (EBOV) outbreaks for more than 40 years, the animal natural reservoir that maintains this virus in nature has not been identified. Viruses and their respective reservoirs coevolve over millions of years, often without causing diseases in the reservoir itself. Upon entering a new host, infection can have devastating consequences, as in the case of EBOV. To gain entry into cells prior to replication, all ebolaviruses utilize the cellular receptor Niemann-Pick C1 (NPC1). In this study the authors focus their work on the Angolan free-tailed bat (Mops condylurus) as a potential reservoir for EBOV. Cells from various organs of this bat were isolated in culture and tested for the presence of NPC1. Most bat cell types had a lower amount of NPC1 compared to the tested human cells. These bat cells were also less efficiently infected by EBOV, indicating adaptation to EBOV. These results suggest low levels of virus replication in the respective tissues of M. condylurus and might be indicative of a virus-natural reservoir relationship.

Dendritic Cells Generated From Mops condylurus, a Likely Filovirus Reservoir Host, Are Susceptible to and Activated by Zaire Ebolavirus Infection

Ebola virus infection of human dendritic cells (DCs) induces atypical adaptive immune responses and thereby exacerbates Ebola virus disease (EVD). Human DCs, infected with Ebola virus aberrantly express low levels of the DC activation markers CD80, CD86, and MHC class II. The T cell responses ensuing are commonly anergic rather than protective against EVD. We hypothesize that DCs derived from potential reservoir hosts such as bats, which do not develop disease signs in response to Ebola virus infection, would exhibit features associated with activation. In this study, we have examined Zaire ebolavirus (EBOV) infection of DCs derived from the Angolan free-tailed bat species, Mops condylurus. This species was previously identified as permissive to EBOV infection in vivo, in the absence of disease signs. M. condylurus has also been recently implicated as the reservoir host for Bombali ebolavirus, a virus species that is closely related to EBOV. Due to the absence of pre-existing M. condylurus species-specific reagents, we characterized its de novo assembled transcriptome and defined its phylogenetic similarity to other mammals, which enabled the identification of cross-reactive reagents for M. condylurus bone marrow-derived DC (bat-BMDC) differentiation and immune cell phenotyping. Our results reveal that bat-BMDCs are susceptible to EBOV infection as determined by detection of EBOV specific viral RNA (vRNA). vRNA increased significantly 72 h after EBOV-infection and was detected in both cells and in culture supernatants. Bat-BMDC infection was further confirmed by the observation of GFP expression in DC cultures infected with a recombinant GFP-EBOV. Bat-BMDCs upregulated CD80 and chemokine ligand 3 (CCL3) transcripts in response to EBOV infection, which positively correlated with the expression levels of EBOV vRNA. In contrast to the aberrant responses to EBOV infection that are typical for human-DC, our findings from bat-BMDCs provide evidence for an immunological basis of asymptomatic EBOV infection outcomes.

Low-fidelity Paediatric Surgical Simulation: Description of Models in Low-Resource Settings

BACKGROUND

Surgical simulation is an important aspect of competency-based training. Recent trends in paediatric surgical simulations have migrated towards high-fidelity simulation with advanced technology resulting in models which are expensive and largely inaccessible in low- and middle-income countries.

METHODS

This article describes four wet simulation models of common surgical procedures in paediatric population created with animal tissue from local abattoir. The models are designed to provide a framework for others to make the models and benefit from the training opportunity they provide especially in low-middle-income countries.

RESULTS

The models created in the wet laboratory are neonatal bowel anastomosis, duodenoduodenostomy for discrepancy anastomosis, gastrostomy and pyeloplasty. These models are easily reproducible in resource-challenged healthcare setting as they are low cost, utilise locally available resources and require only a basic set of surgical instruments with which to perform the procedures.

CONCLUSION

These models provide locally accessible material for sustainable training programmes which are fundamental in developing safe and affordable surgical care worldwide.

Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study

BACKGROUND

By January, 2016, all known transmission chains of the Ebola virus disease (EVD) outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fluid, including clearance parameters.

METHODS

In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fluid at follow-up every 3-6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodeficient mice to test for infectivity. We used a linear mixed-effect model to analyse the dynamics of virus persistence in seminal fluid over time.

FINDINGS

We enrolled 26 participants and tested 130 seminal fluid specimens; median follow up was 197 days (IQR 187-209 days) after enrolment, which corresponded to 255 days (228-287) after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73%) participants. Median duration of Ebola virus RNA detection was 158 days after onset (73-181; maximum 407 days at end of follow-up). Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fluid of -0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fluid at 115 days (90% prediction interval 72-160) and 294 days (212-399) after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in affected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious virus was detected in 15 of 26 (58%) specimens tested in mice.

INTERPRETATION

Time to clearance of Ebola virus RNA from seminal fluid varies greatly between individuals and could be more than 13 months. Our predictions will assist in decision-making about surveillance and preventive measures in EVD outbreaks.

FUNDING

This study was funded by European Union's Horizon 2020 research and innovation programme, Directorate-General for International Cooperation and Development of the European Commission, Institut national de la santé et de la recherche médicale (INSERM), German Research Foundation (DFG), and Innovative Medicines Initiative 2 Joint Undertaking.

Coronavirus and paramyxovirus in bats from Northwest Italy

Background

Bat-borne virus surveillance is necessary for determining inter-species transmission risks and is important due to the wide-range of bat species which may harbour potential pathogens. This study aimed to monitor coronaviruses (CoVs) and paramyxoviruses (PMVs) in bats roosting in northwest Italian regions. Our investigation was focused on CoVs and PMVs due to their proven ability to switch host and their zoonotic potential. Here we provide the phylogenetic characterization of the highly conserved polymerase gene fragments.

Results

Family-wide PCR screenings were used to test 302 bats belonging to 19 different bat species. Thirty-eight animals from 12 locations were confirmed as PCR positive, with an overall detection rate of 12.6% [95% CI: 9.3–16.8]. CoV RNA was found in 36 bats belonging to eight species, while PMV RNA in three Pipistrellus spp. Phylogenetic characterization have been obtained for 15 alpha- CoVs, 5 beta-CoVs and three PMVs; moreover one P. pipistrellus resulted co-infected with both CoV and PMV. A divergent alpha-CoV clade from Myotis nattereri SpA is also described. The compact cluster of beta-CoVs from R. ferrumequinum roosts expands the current viral sequence database, specifically for this species in Europe. To our knowledge this is the first report of CoVs in Plecotus auritus and M. oxygnathus, and of PMVs in P. kuhlii.

Conclusions

This study identified alpha and beta-CoVs in new bat species and in previously unsurveyed Italian regions. To our knowledge this represents the first and unique report of PMVs in Italy. The 23 new bat genetic sequences presented will expand the current molecular bat-borne virus databases. Considering the amount of novel bat-borne PMVs associated with the emergence of zoonotic infections in animals and humans in the last years, the definition of viral diversity within European bat species is needed. Performing surveillance studies within a specific geographic area can provide awareness of viral burden where bats roost in close proximity to spillover hosts, and form the basis for the appropriate control measures against potential threats for public health and optimal management of bats and their habitats.

Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis

Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d’Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA) capsule and the B. anthracis polyglutamate (PDGA) capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged.

Anthrax is caused by the bacterium Bacillus anthracis that affects all mammals worldwide. It emerged more than 10,000 years ago from a Bacillus cereus precursor. In the past decade, B. cereus bacteria were isolated in the USA from anthrax-like pneumonia cases. They harbour one virulence plasmid very similar to the toxin–encoding plasmid of B. anthracis. Recently, an anthrax-like disease in great apes in Africa was caused by emerging B. cereus strains, named B. cereus biovar anthracis. These strains are atypical as they possess both plasmids coding for toxin and capsule similar to those so far found only in B. anthracis. These unusual pathogenic B. cereus are currently neglected. We explored the virulence of these pathogens and their colonisation and dissemination capacity within the murine host. We found that these toxinogenic strains harbour two capsules, the classical B. anthracis capsule and an additional polysaccharidic capsule. This latter capsule confers virulence alone or in combination with toxins. Both capsules are concomitantly expressed, under the control of a common global regulator and host signals. Our results show that acquisition of new genetic information by these B. cereus clearly gives them a selective advantage, favouring their dissemination within infected hosts and the environment.

Brefeldin A inhibits expression of DNA packaging proteins and nucleocapsid formation of human cytomegalovirus

In this study we used the fungal antibiotic brefeldin A (BFA) to analyze its effect on viral replication. Analysis by electron microscopy demonstrated that no viral particles were observed in cells treated before the onset of viral replication. In the presence of BFA expression of IE2, MCP, pUL104, pUL56 and pUL89 were reduced, while no or slight effect was observed on expression of pp65, pUL44 and pUL57. Strikingly, real time PCR revealed that de novo viral DNA synthesis is reduced but not completely abolished in the presence of BFA. These results indicated that BFA represents a multi-functional compound leading to inhibition of several steps of viral maturation such as expression of viral DNA packaging proteins and capsid formation.

Nucleocapsid formation and RNA synthesis of Marburg virus is dependent on two coiled coil motifs in the nucleoprotein

The nucleoprotein (NP) of Marburg virus (MARV) is responsible for the encapsidation of viral genomic RNA and the formation of the helical nucleocapsid precursors that accumulate in intracellular inclusions in infected cells. To form the large helical MARV nucleocapsid, NP needs to interact with itself and the viral proteins VP30, VP35 and L, which are also part of the MARV nucleocapsid. In the present study, a conserved coiled coil motif in the central part of MARV NP was shown to be an important element for the interactions of NP with itself and VP35, the viral polymerase cofactor. Additionally, the coiled coil motif was essential for the formation of NP-induced intracellular inclusions and for the function of NP in the process of transcription and replication of viral RNA in a minigenome system. Transfer of the coiled coil motif to a reporter protein was sufficient to mediate interaction of the constructed fusion protein with the N-terminus of NP. The coiled coil motif is bipartite, constituted by two coiled coils which are separated by a flexible linker.

The use of high resolution magnetic resonance imaging in the prenatal diagnosis of fetal nuchal tumors

Fetal magnetic resonance imaging (fetal MRI) is an important adjunct to antenatal imaging especially when neonatal surgery is contemplated. We report two cases of fetal nuchal tumors, which were diagnosed incidentally on an ultrasound scan and had fetal MRI to aid diagnosis, prognosis, counseling and management planning. In the first case, fetal MRI aided diagnosis and prenatal multidisciplinary management of a cervical teratoma. Tracheal involvement could not be excluded and an ex-utero intrapartum treatment procedure was planned. Postnatal MRI and angiography provided further information prior to surgery. In the second case, fetal MRI assisted thorough counseling following the finding of a cervical lesion thought to be a cervical teratodermoid, a multicystic hygroma or congenital lymphectasia. The parents opted for termination of the pregnancy. Postmortem findings confirmed the extent of involvement of surrounding structures diagnosed prenatally. The mass was found to be a hamartomatous hemangiolymphangioma.

Congenital malformations of the diaphragm: findings of the West Midlands Congenital Anomaly Register 1995 to 2000

OBJECTIVES

To describe trends in incidence, associated anomalies, clinical outcomes and sensitivity of prenatal diagnosis for congenital malformations of the diaphragm in the West Midlands Region between 1995 and 2000.

METHODS

Information was retrieved from a population-based register of major congenital malformations in a health region of England, the West Midlands Congenital Anomaly Register (WMCAR), between 1995 and 2000.

RESULTS

One hundred and sixty-one confirmed cases of congenital malformations of the diaphragm were notified from 396 577 births. This gives an incidence of 4.1 per 10,000 births. After natural losses and terminations, the incidence at birth was 2.9 per 10,000 registered births. For live-born cases, the infant mortality rate was 317 per 1000 births. 47% of the cases had additional structural or chromosomal anomalies; the infant mortality rate for these complex cases was 533 per 1000, an increased relative risk of 2.37 compared with isolated lesions. 66% of the cases were diagnosed prenatally, 51% of isolated lesions and 84% of complex cases. Fourteen prenatally diagnosed cases (12%) were false-positives; however, 11 of these cases had other significant pathology. These 14 cases were not included in the 161 confirmed cases.

CONCLUSION

Congenital malformations of the diaphragm remain associated with considerable infant mortality. Most cases are now diagnosed before birth and the prognosis is adversely affected by the presence of other structural or chromosomal anomalies. This presents significant challenges for those involved in counselling the parents of affected fetuses.

Unusual complication of a central venous line in a neonate

The placement of a central venous line in a low birthweight neonate led to a complication that highlights the need for continued vigilance after the position of the line is checked and thought satisfactory.

Single-system ectopic ureter: a 15-year review

Ectopic ureters present in childhood with symptoms related to an abnormal site or structure (refluxing, obstructed) of the ureteric orifice. The majority drain duplex kidneys. The diagnosis is relatively easy if the poles are functioning or hydronephrotic. Associated malformations are rarely seen and the results of surgery are gratifying. If an ectopic ureter drains a single kidney, it is called a single-system ectopic ureter (SSEU). We reviewed a 15-year experience (1980-1995) with 127 ectopic ureters from our hospital:11 SSEUs in ten consecutive children were managed during this period. Our data lead us to believe that SSEUs are a special subset of ectopic ureters. Diagnosis is often delayed because the ectopic ureter may be associated with a single small, dysplastic, poorly-functioning, non-visualised kidney and the child may be thought to have a contralateral normal "solitary kidney". Associated systemic malformations are common. Residual symptoms of wetting may persist in the early postoperative period. A high degree of suspicion must be maintained for this entity when a child presents with urinary symptoms of wetting or recurrent infection and a "solitary kidney". Early endoscopic examination of the genitourinary tract will clinch the diagnosis in the majority of cases. Residual symptoms of wetting in the postoperative period generally resolve with passage of time.

Exomphalos (omphalocele)

Exomphalos affects approximately 3 in 10,000 births and can arise from a number of developmental insults. The clinical outcome is dependent upon the associated structural and chromosomal anomalies and the gestation at delivery. Accurate antenatal ultrasound diagnosis and karyotyping are important and allow informed prenatal and postnatal management decisions to be made. Prenatal care and counselling should be multidisciplinary and information should ideally be given to parents regarding prognosis and outcome based on prospectively collected population-based data.

Left-right development: mammalian phenotypes and conceptual models

Consistent left-right asymmetry in a population requires a special kind of developmental specification. Models of this process must account for the complex phenotypes seen when left-right is abnormal. In some human and mouse mutations, there appears to be a randomisation of global situs to either solitus or inversus, whereas in the inv/inv mouse essentially all are inversus. However, in these and all additional examples there are frequently other anomalies, including symmetry (isomerism) and discordance between organs (heterotaxia). Current models invoke a molecular chiral referent as the source of the primary handed information. We describe a new two-gradient model which accommodates all defects of situs whilst leaving the primary asymmetry unaltered.

Cisapride reduces neonatal postoperative ileus: randomised placebo controlled trial

AIM

To assess the efficacy of cisapride in reducing ileus persisting to the tenth postoperative day after neonatal abdominal surgery.

METHODS

A prospective, randomised, double blind trial comparing rectal cisapride (1.4-2.3 mg/kg/day) with placebo over seven days was undertaken in 33 neonates.

RESULTS

Seven of 12 (58%) patients receiving placebo and eight of 11 (73%) receiving cisapride achieved a first sustained feed during treatment. Of those receiving cisapride, the first sustained feed occurred at 2.3 days (SEM 0.6) compared with 4.7 days (SEM 0.8) with placebo. By the seventh day the mean daily net enteral balance was 69 (SEM 18) ml/kg in the cisapride subgroup and 17 (SEM 8) ml/kg for those receiving placebo. Stool was passed on 6.3 (SEM 0.4) treatment days in the cisapride subgroup compared with 4.1 (SEM 1.0) treatment days in the placebo subgroup.

CONCLUSION

Cisapride is effective in neonates with a prolonged ileus after abdominal surgery.

Efficacy of ajoene, an organosulphur derived from garlic, in the short-term therapy of tinea pedis

The present report shows the efficacy of ajoene, a garlic-derived organic trisulphur, for short-term therapy of tinea pedis. The use of ajoene as a 0.4% (w/w) cream resulted in complete clinical and mycological cure in 27 of 34 patients (79%) after 7 days of treatment. The remaining seven patients (21%) achieved complete cure after seven additional days of treatment. All patients were evaluated for recurrence of mycotic infections 90 days after the end of treatment, yielding negative cultures for fungus. These results show that ajoene is an alternative, efficient and low-cost antimycotic drug for short-term therapy of tinea pedis. The fact that ajoene can be easily prepared from an alcoholic extract of garlic may make it suitable for Third World public health care.

Cell proliferation in mammalian gastrulation: the ventral node and notochord are relatively quiescent

During gastrulation, the node of the mammalian embryo appears to be an organising centre, homologous to Hensen's node in the chick and the dorsal lip of the amphibian blastopore. In addition, the node serves as a precursor population for the head process, notochord and foregut endoderm. We have studied node architecture and cell morphology by electron microscopy, and cell proliferation using bromodeoxyuridine incorporation and mitotic counts. The dorsal (ectodermal) and ventral (endodermal) components of the node are two distinct populations, separated by a basement membrane. The ventral node, contiguous with the head process, is characterised by a relatively low proliferation rate, with only approximately 10% of cells incorporating BrdU over 4 hr, compared to > 95% in surrounding mesodermal and ectodermal tissues. This is the case from the beginning of node formation, at the no-allantoic-bud stage, until the 7 somite stage, and is not compatible with the idea that the ventral node is a stem cell population. The dorsal node is highly proliferative, its rate of division being indistinguishable from the neurectoderm, with which it is contiguous. In the ventral node, two regions can be recognised: cells in the "pit" are columnar and all monociliated; around them lies a "crown" of cells arranged radially in a horseshoe shape and less often ciliated. Node derivatives share common features with the ventral node; the head process and the notochord are relatively quiescent; and some head process cells are also monociliated. Node and head process monocilia are immotile and appear to be associated with non-proliferation. We suggest that the ventral node contains all the properties of the organiser, while the dorsal node is indistinct from the surrounding epiblast. The cranial end of the foregut pouch, the thyroid diverticulum, and the promyocardium of early somite stage embryos are also areas of low cell division. All the described regions of relative quiescence are sites of expression of members of the TGF beta family, which may be involved in maintaining non-proliferation.

Interdomain interactions of radixin in vitro

We have assayed the domains of the ERM protein radixin for binding activities in vitro. Affinity columns bearing the amino-terminal domain of radixin selectively bound a small subset of the proteins of the chicken erythrocyte cytoskeleton. Two of those proteins were identified as radixin itself and band 4.1. In contrast, the carboxyl-terminal domain of the molecule bound neither protein, and full-length radixin did not bind band 4.1 (binding of full-length radixin to itself was not evaluated). Columns bearing a mixture of the amino- and carboxyl-terminal domains of radixin also failed to bind radixin and band 4.1. These results suggested that the amino- and carboxyl-terminal sequences can interact with one another either in cis or in trans, and so interfere with radixin's interactions with other ligands. Using affinity co-electrophoresis, we confirmed a direct interaction in solution between the two radixin domains; the data are consistent with the formation of a 1:1 complex with a dissociation constant of approximately 5 x 10(-8) M. Competition between intramolecular and intermolecular interactions may help to explain the provocative and dynamic localization of ERM proteins within cells.

Experimental pathogenicity of Sporothrix schenckii preserved in water (Castellani)

Five strains of Sporothrix schenckii preserved in sterile distilled water were found morphologically stable, viable and pure after a period ranging from 16 to 13 years, in the mycology section culture collection from the Instituto de Medicina Tropical, Universidad Central de Venezuela. Each strain was inoculated into the testes of 3 hamsters. All the animals developed disseminated sporotrichosis.

Intravascular haemolysis in association with necrotising enterocolitis

Severe haemolysis is an unusual occurrence in association with necrotising enterocolitis (NEC). Activation of the Thomsen-Friedenreich (T) antigen on the neonatal erythrocytes is proposed as the mechanism. This haemolytic process is precipitated by transfusion with serum-containing blood products, which should therefore be avoided. Once haemolysis has become established the outcome is usually fatal. This report describes the management of four neonates who had established haemolysis complicating severe NEC. T activation was confirmed in two infants, but could not be tested for in the other two. Exchange transfusion abolished the haemolysis in two patients, who survived. Despite reduced use of blood products the other two infants died. We believe that exchange transfusion was essential in the successful management of the infants who survived, and recommend early exchange transfusion when haemolysis complicates NEC.

Contacts with a Canadian "street level" drug and crisis centre, 1972-76

The Calgary Distress Centre/Drug Centre is a "street level" agency that deals with both drug and non-drug related crises. Telephone and drop-in service is available 24 hours a day, seven days a week. The Centre has approximately 60 non-professional volunteers and a paid staff of six. Data about crisis information and counselling contacts over the period 1972-76 are presented and discussed. The Distress Centre/Drug Centre is perhaps a useful model on which to base other crisis intervention facilities. Furthermore, the systematic compilation of data regarding contacts with the agency provides significant insight regarding trends in drug use and evolution of the agency.