Single-cycle immunodeficiency viruses provide strategies for uncoupling in vivo expression levels from viral replicative capacity and for mimicking live-attenuated SIV vaccines

To reduce the risks associated with live-attenuated immunodeficiency virus vaccines, single-cycle immunodeficiency viruses (SCIVs) were developed by primer complementation and production of the vaccine in the absence of vif in a vif-independent cell line. After a single intravenous injection of SCIVs into rhesus monkeys, peak viral RNA levels of 10(3) to 10(4) copies/ml plasma were observed, indicating efficient expression of SCIV in the vaccinee. After booster immunizations with SCIVs, SIV-specific humoral and cellular immune responses were observed. Although the vaccine doses used in this pilot study could not protect vaccinees from subsequent intravenous challenge with pathogenic SIVmac239, our results demonstrate that the novel SCIV approach allows us to uncouple in vivo expression levels from the viral replicative capacity facilitating the analysis of the relationship between viral expression levels or viral genes and immune responses induced by SIV.     

MECP2 duplication syndrome in a patient from Cameroon

MECP2 duplication syndrome (MDS; OMIM 300260) is an X‐linked neurodevelopmental disorder caused by nonrecurrent duplications of the Xq28 region involving the gene methyl‐CpG‐binding protein 2 (MECP2; OMIM 300005). The core phenotype of affected individuals includes infantile hypotonia, severe intellectual disability, very poor‐to‐absent speech, progressive spasticity, seizures, and recurrent infections. The condition is 100% penetrant in males, with observed variability in phenotypic expression within and between families. Features of MDS in individuals of African descent are not well known. Here, we describe a male patient from Cameroon, with MDS caused by an inherited 610 kb microduplication of Xq28 encompassing the genes MECP2, IRAK1, L1CAM, and SLC6A8. This report supplements the public data on MDS and contributes by highlighting the phenotype of this condition in affected individuals of African descent.     

The Schizosaccharomyces pombe protein Yab8p and a novel factor, Yip1p, share structural and functional similarity with the spinal muscular atrophy-associated proteins SMN and SIP1

The motor neuron disease spinal muscular atrophy (SMA) is caused by reduced levels of functional survival of motor neurons (SMN) protein. Previous studies have shown that SMN binds to the SMN-interacting protein SIP1 and mediates the assembly of spliceosomal U snRNPs in the cytoplasm. In addition, a nuclear function for SMN in pre-mRNA splicing has recently been proposed. Here, we describe the analysis of the Schizo-saccharomyces pombe protein Yab8p and provide evidence that it is structurally and functionally related to SMN found in higher eukaryotes. We show that Yab8p interacts via its N-terminus with a novel protein termed Yip1p. Importantly, Yip1p exhibits homology to SIP1, and the mode of binding to Yab8p is remarkably similar to the SMN-SIP1 interaction. Hence, Yip1p is likely to be the homologue of SIP1 in S.pombe. Yab8p and Yip1p localize predominantly in the nucleus. Genetic studies demonstrate that Yab8p is essential for viability. Strikingly, suppression of YAB8 expression in a conditional knock-out strain causes nuclear accumulation of poly(A) mRNA and inhibition of splicing. These data identify Yab8p as a novel factor involved in splicing and suggest that Yab8p exerts a function similar or identical to the nuclear pool of SMN. Our studies provide a model system to study the cellular function of SMN in yeast, and should help in understanding the molecular events leading to SMA.     

Universally conserved and yeast-specific U1 snRNA sequences are important but not essential for U1 snRNP function

To study the contribution of the large, 568-nucleotide yeast (Saccharomyces cerevisiae) U1 snRNA to pre-mRNA splicing, we generated mutations in two regions of the molecule and introduced each mutant gene back into yeast as the sole copy of the U1 snRNA gene. We mutagenized the "A loop," a subregion highly conserved in primary sequence in all U1 snRNA molecules analyzed to date. We also mutagenized a portion of the yeast core subdomain, a region conserved in primary and secondary structure among several yeast species but absent from the much smaller metazoan U1 molecule. Surprisingly, mutations in these two regions had little or no effect on growth rate, yet several of them affected an inefficiently spliced reporter gene construct. In addition, combinations of mutants in both regions gave rise to reduced growth rates. Using the latter assay, we confirmed some of the proposed secondary structure of the yeast core domain. The experiments indicate that both regions contribute to U1 snRNP activity but that mutations in a single region do not have a substantial effect on growth rate because U1 snRNP activity is not rate-limiting for growth.     

Intracranial suppurations in the African child: a severe but preventable complication

Introduction

Intracranial suppurations (ICS) are collections of pus of infectious origin in the skull. The authors present their experience.

Patients and method

All children operated for ICS at the Central Hospital of Yaoundé from January 2000 to December 2008 were retrospectively included.

Results

Thirty-five patients were recruited: 26 (74.29 %) males and 9 (25.71 %) females. These represent 82.9 % of all ICS operated in our institution. ICS represented 14.3 % of intracranial space-occupying lesions. The mean age was 8.34 years. They presented with headaches (80.77 %), altered consciousness (20 %), convulsions (76 %), vomiting (20 %), unilateral motor deficit (69.23 %), speech disorders (12 %), and fever (89.29 %). Bergman’s triad (51.86 %) was frequent. The primary infection was: meningitis, eight cases (22.85 %); sinusitis, six cases (17.14 %); head trauma, five cases (14.28 %); otitis media, one case (2.85 %); suppurations of the face, three cases (8.56 %); cardiopathy, one case (2.85 %); and craniotomy, one case (2.85 %). In seven cases (20 %), the origin was unknown. The lesions were empyema in 23 cases (65.71 %), cerebral abscess in 8 cases (22.85 %) and pyoventriculitis in 2 cases (5.72 %). The surgical procedures were burr holes (88.89 % of empyemas) and trepano-puncture–aspiration (75 % of abscesses). The mortality (21.42 %) and morbidity (42.85 %) were recorded.

Conclusion

ICS are frequent but preventable (early treatment of the primary infection) pathologies of childhood in developing countries. Burr hole drainage (empyemas) and puncture–aspiration (abscesses) are simple, safe, and effective techniques.     

Exosomal vaccines containing the S protein of the SARS coronavirus induce high levels of neutralizing antibodies

Infection with the SARS-associated coronavirus (SARS-CoV) induces an atypical pulmonary disease with a high lethality rate. Although the initial SARS epidemic was contained, sporadic outbreaks of the disease still occur, suggesting a continuous need for a vaccine against this virus. We therefore explored exosome-based vaccines containing the spike S proteins of SARS-CoV. S-containing exosomes were obtained by replacing the transmembrane and cytoplasmic domains of the S protein by those of VSV-G. The immunogenicity and efficacy of the S-containing exosomes were tested in mice and compared to an adenoviral vector vaccine expressing the S protein. Both, S-containing exosomes and the adenoviral vector vaccine induced neutralizing antibody titers. After priming with the SARS-S exosomal vaccine and boosting with the adenoviral vector the neutralizing antibody titers exceeded those observed in the convalescent serum of a SARS patient. Both approaches were effective in a SARS-S-expressing tumor challenge model and thus warrant further investigation.     

Induction of neutralising antibodies restricts the use of human granulocyte/macrophage colony stimulating factor for vaccine studies in rhesus macaques

Granulocyte/macrophage-colony stimulating factor (GM-CSF) is a valuable adjuvant to enhance induction of cellular immune responses in rodents. Less information is available regarding its use as an adjuvant in primates or humans. We explored recombinant human GM-CSF for potential vaccine studies in rhesus macaques and focused on its effect on peripheral monocytes as progenitors of dendritic cells and its potential immunogenicity. Application of human GM-CSF to nine animals led to an average 32-fold increase in monocyte numbers. This was not observed upon re-treatment, which coincided with GM-CSF-specific neutralising antibodies. These also neutralised the activity of rhesus macaque GM-CSF. The data underscore the need to use species-specific GM-CSF for immunomodulation in primates.     

Best supportive care (BSC) versus oxaliplatin, folinic acid and 5-fluorouracil (OFF) plus BSC in patients for second-line advanced pancreatic cancer: a phase III-study from the German CONKO-study group

Background

Gemcitabine usually given until progressive disease (PD) is the main first-line treatment option for patients with inoperable advanced pancreatic cancer (APC). Currently there is no accepted active regimen for second-line chemotherapy. Previous phase II studies suggest clinical relevant activity of oxaliplatin, folinic acid and 5-FU (OFF). We initiated a phase III multicentre study comparing OFF versus best supportive care (BSC) in patients with APC progressing while on gemcitabine therapy.

Methods

In this open randomized study, patients with CT and/or MRI confirmed progressive disease while on gemcitabine therapy were randomized 1:1 to OFF or BSC. Stratification included duration of first-line therapy (<3, 3 to 6 and >6 months), performance status (KPS 70-80%; 90-100%) and tumour stage (M1/M0). OFF consisted of folinic acid 200 mg/m² followed by 5-fluorouracil 2 g/m² (24 h) on d1, d8, d15, d22 and oxaliplatin 85 mg/m² on days 8 and 22. After a rest of 3 weeks the next cycle was started on d43. A total of 165 patients were calculated to demonstrate a doubling of survival time after progression on first-line therapy.

Results

After inclusion of forty six patients the trial was terminated according to predefined protocol regulations due to insufficient accrual (lack of acceptance of BSC by patients and physicians. Patient characteristics were well balanced between both study arms. The OFF regimen was well tolerated with more patients with grade I/II paraesthesia and grade II/III nausea/emesis and diarrhoea. Median second-line survival was 4.82 [95% Confidence Interval; 4.29-5.35] months for OFF treatment and 2.30 [95% CI; 1.76-2.83] months with BSC alone (0.45 [95% CI: 0.24-0.83], p = 0.008). Median overall survival for the sequence GEM-OFF was 9.09 [95% CI: 6.97-11.21] and 7.90 [95% CI: 4.95-10.84] months for GEM-BSC (0.50 [95% CI: 0.27-0.95], p = 0.031) respectively.

Interpretation

Although stopped prematurely, this randomized trial provides at first time evidence for the benefit of second-line chemotherapy as compared to BSC alone for patients with APC. OFF significantly prolonged survival time compared to BSC alone after failure of first-line therapy with gemcitabine.     

Assessment of factors associated with complete immunization coverage in children aged 12-23 months: a cross-sectional study in Nouna district,Burkina Faso

Background

The Expanded Program on Immunization (EPI) is still in need of improvement. In Burkina Faso in 2003, for example, the Nouna health district had an immunization coverage rate of 31.5%, compared to the national rate of 52%. This study identifies specific factors associated with immunization status in Nouna health district in order to advance improved intervention strategies in this district and in those with similar environmental and social contexts.

Methods

A cross-sectional study was undertaken in 41 rural communities and one semi-urban area (urban in the text). Data on 476 children aged 12 to 23 months were analyzed from a representative sample of 489, drawn from the Nouna Health Research Centre's Demographic Surveillance System (DSS) database. The vaccination history of these children was examined. The relationships between their immunization status and social, economic and various contextual variables associated with their parents and households were assessed using Chi square test, Pearson correlation and logistic regression.

Results

The total immunization coverage was 50.2% (CI, 45.71; 54.69). Parental knowledge of the preventive value of immunization was positively related to complete immunization status (p = 0.03) in rural areas. Children of parents who reported a perception of communication problems surrounding immunization had a lower immunization coverage rate (p < 0.001). No distance related difference exists in terms of complete immunization coverage within villages and between villages outside the site of the health centres. Children of non-educated fathers in rural areas have higher rates of complete immunization coverage than those in the urban area (p = 0.028). Good communication about immunization and the importance of availability of immunization booklets, as well as economic and religious factors appear to positively affect children's immunization status.

Conclusion

Vaccination sites in remote areas are intended to provide a greater opportunity for children to access vaccination services. These efforts, however, are often hampered by the poor economic conditions of households and insufficient communication and knowledge regarding immunization issues. While comprehensive communication may improve understanding about immunization, it is necessary that local interventions also take into account religious specificities and critical economic periods. Particular approaches that take into consideration these distinctions need to be applied in both rural and urban settings.

Abstract in French

See the full article online for a translation of this abstract in French.

     

Ligament fibre recruitment of the elbow joint during gravity-loaded passive motion: an experimental study

BACKGROUND: Knowledge of elbow collateral ligament length during passive motion is essential in understanding ligament physiology and pathology, such as tightness and instability. METHODS: Five anatomical unembalmed specimens were passively placed in six flexion positions together with three forearm rotations, using equipment with gravity as motion force. These 18 positions were recorded using CT-scan. Three-dimensional data of ligament insertions were obtained through anatomical millimetre sections. Ligament length was measured in each position. FINDINGS: In neutral rotation, the lateral collateral ligament was long between 0 degrees and 30 degrees as well as at 90 degrees, and short between about 60 degrees and 120 degrees of flexion. In pronation, it was long at about 0 degrees and between 60 degrees and 120 degrees, short at about 30 degrees of flexion. In supination, it was long at about 30 degrees and 90 degrees and short between 120 degrees and 150 degrees of flexion. In any forearm rotation, the highest length of the anterior bundle of the ulnar collateral ligament was measured at about 90 degrees, its smallest length between 120 degrees and 150 degrees of flexion, position at which the posterior bundle length was greatest. INTERPRETATION: At 60 degrees of flexion, the collateral ligaments were slackened in any forearm rotations. Forearm rotation plays an indirect role in the posterolateral stability of elbow as it changes length of the lateral collateral ligament. This ligament can be tested passively at 90 degrees of flexion in supination, the anterior bundle of the ulnar collateral ligament between 0 degrees and 30 degrees in neutral rotation and the posterior bundle between 120 degrees and 150 degrees in neutral rotation.