新しいナノ粒子で調整したマラリアMSP-1 のC 末端DNA ワクチンの免疫原性に対する3種の異なる接種ルートの比較検討

長崎大学学位論文 [学位記番号]博（医歯薬）甲第580号 [学位授与年月日]平成25年3月19

Cryptococcal meningitis associated HIV infection in the Donka national hospital in Conakry (Guinea)

Background Cryptococcal meningitis (CM) is an infection of the brain parenchyma and subarachnoid space by the encapsulated saprophyte yeast organisms such as Cryptococcus neoformans. Over the last twenty years, HIV has created a large and severely immune compromisized population in whom C. neoformans is a dangerous opportunistic infection. In Guinea, the prevalence of CM is unknown. We hypothesized that the occurrence of CM correlates with AIDS/ HIV prevalence.Method This retrospective observational study was carried out at the national Hospital of Conakry (Guinea) between 2001 and 2002. We describe here the epidemiological and clinical and biological characteristics of CM disease in our national hospital.Results Our data show that, 28.6 % of HIV patients with neurological symptoms had Cryptococcus neoformans in their CSF by using Indian ink staining. The median age was 36±3 years and sex ratio (M/F) was 1.8. The major complaints were fever and cephalgia, giddiness while the major complications were altered consciousness and hemiplegia. CSF was clear with low level of glucose and higher level of albumin. The means of lymphocytes in CSF was 8±2/mm3.Conclusion This data therefore becomes relevant in not only focusing of neurological symptoms associated with HIV to be toxoplasmosis but the possibility of C neoformans in these patients; particularly when they present symptoms such as headaches, giddiness and sniff neck etc. This can easily be carried out with Indian ink staining technique

Case Report: COVID-19 and Lassa Fever Coinfection in an Ebola Suspected Patient in Guinea

ABSTRACT. In this case report, we describe a clinical presentation and therapeutic history of a unique case diagnosed with Lassa fever and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a 23-year-old man from Yomou prefecture in southeast Guinea identified with suspected Ebola Virus Disease (EVD) in the midst of an ongoing outbreak of that disease in the same region. On May 3, 2021, he was admitted to the Nzérékoré Epidemic disease treatment center where his clinical condition deteriorated significantly. Laboratory testing performed on the same day reveals a negative EVD polymerase chain reaction (PCR). Three days later, the patient was tested positive for SARS-CoV-2 and Lassa fever by reverse transcriptase PCR (RT-PCR) assays. Laboratory examination also indicated severe hematological and biochemical deteriorations in the patient. This case substantiates the need for systematic differential diagnosis during epidemic-prone disease outbreaks to better manage severely unwell patients.</jats:p

Dengue Virus Serotypes 1 and 2 Responsible for Major Dengue Outbreaks in Nepal: Clinical, Laboratory, and Epidemiological Features

Dengue virus (DENV) is expanding toward previously nonendemic areas. DENV has recently been introduced in Nepal with limited information. We report the clinical features and serotype distribution of DENV in Nepal during the 2010 outbreaks. A total of 1,215 clinical dengue cases at two major hospitals of central and western Nepal were investigated. Demographic, clinical, and laboratory parameters were recorded. Serum specimens were tested for DENV by IgM/IgG enzyme-linked immunosorbent assays (ELISAs) and reverse transcription polymerase chain reaction (RT-PCR). We confirmed DENV infection in 403 (33%) patients from 12 districts with an estimated case fatality rate of 1.5%. DENV infection was more common in adults (87%) and urban settings (74%). We detected all four serotypes but DENV-1 and -2 were mainly responsible for major outbreaks (92%). Overall, 60% of all DENV infections were secondary and 17% were severe dengue; both being more frequent among the DENV-2 infections. Rash, bleeding, abdominal pain, hepatomegaly, elevated liver enzymes, and thrombocytopenia were significantly more common in severe dengue compared with nonsevere infections. We also confirmed the expansion of dengue to hill urban areas (DENV-1 and -2), including the capital Kathmandu (altitude, 1,300 m) though > 90% cases were from southern plains. Differential clinical and laboratory features probably help in clinical decisions. Multiple serotypes circulation and elevated secondary infections pose potential risk of severe outbreaks and deaths in the future. Therefore, a country with recent dengue introduction, like Nepal, urgently requires a systematic surveillance and appropriate control measures in place to respond to any disastrous outbreaks

Characterization of a Gene Family Encoding SEA (Sea-urchin Sperm Protein, Enterokinase and Agrin)-Domain Proteins with Lectin-Like and Heme-Binding Properties from Schistosoma japonicum

BackgroundWe previously identified a novel gene family dispersed in the genome of Schistosoma japonicum by retrotransposon-mediated gene duplication mechanism. Although many transcripts were identified, no homolog was readily identifiable from sequence information.Methodology/Principal FindingsHere, we utilized structural homology modeling and biochemical methods to identify remote homologs, and characterized the gene products as SEA (sea-urchin sperm protein, enterokinase and agrin)-domain containing proteins. A common extracellular domain in this family was structurally similar to SEA-domain. SEA-domain is primarily a structural domain, known to assist or regulate binding to glycans. Recombinant proteins from three members of this gene family specifically interacted with glycosaminoglycans with high affinity, with potential implication in ligand acquisition and immune evasion. Similar approach was used to identify a heme-binding site on the SEA-domain. The heme-binding mode showed heme molecule inserted into a hydrophobic pocket, with heme iron putatively coordinated to two histidine axial ligands. Heme-binding properties were confirmed using biochemical assays and UV-visible absorption spectroscopy, which showed high affinity heme-binding (KD = 1.605×10?6 M) and cognate spectroscopic attributes of hexa-coordinated heme iron. The native proteins were oligomers, antigenic, and are localized on adult worm teguments and gastrodermis; major host-parasite interfaces and site for heme detoxification and acquisition.ConclusionsThe results suggest potential role, at least in the nucleation step of heme crystallization (hemozoin formation), and as receptors for heme uptake. Survival strategies exploited by parasites, including heme homeostasis mechanism in hemoparasites, are paramount for successful parasitism. Thus, assessing prospects for application in disease intervention is warranted

Factors Associated with Reliable Contact Tracing During the 2021 Ebola Virus Disease Outbreak in Guinea

Background: In 2021, an Ebola virus disease (EVD) outbreak was declared in Guinea, linked to persistent virus from the 2014-2016 West Africa Epidemic. This paper analyzes factors associated with contact tracing reliability (defined as completion of a 21-day daily follow-up) during the 2021 outbreak, and transitively, provides recommendations for enhancing contact tracing reliability in future. Methods: We conducted a descriptive and analytical cross-sectional study using multivariate regression analysis of contact tracing data from 1071 EVD contacts of 23 EVD cases (16 confirmed and 7 probable). Results: Findings revealed statistically significant factors affecting contact tracing reliability. Unmarried contacts were 12.76× more likely to miss follow-up than those married (OR = 12.76; 95% CI [3.39-48.05]; p &lt; 0.001). Rural-dwelling contacts had 99% lower odds of being missed during the 21-day follow-up, compared to those living in urban areas (OR = 0.01; 95% CI [0.00-0.02]; p &lt; 0.01). Contacts who did not receive food donations were 3× more likely to be missed (OR = 3.09; 95% CI [1.68-5.65]; p &lt; 0.001) compared to those who received them. Contacts in health areas with a single team were 8× more likely to be missed (OR = 8.16; 95% CI [5.57-11.96]; p &lt; 0.01) than those in health areas with two or more teams (OR = 1.00; 95% CI [1.68-5.65]; p &lt; 0.001). Unvaccinated contacts were 30.1× more likely to be missed compared to vaccinated contacts (OR = 30.1; 95% CI [5.12-176.83]; p &lt; 0.001). Conclusion: Findings suggest that contact tracing reliability can be significantly influenced by various demographic and organizational factors. Considering and understanding these factors-and where possible addressing them-may be crucial when designing and implementing contact tracing strategies during future outbreaks in low-resource settings.</p

Extracellular loop of the candidate proteins contain SEA-domains.

<p>(<b>A</b>) Modeled molecular structures of the extracellular domains with striking similarity with SEA-domain. Also shown for comparison is the SEA-domain of mouse TMPRSS2. Typical of SEA-domains, the secondary structure components showed an antiparallel arrangement of β-sheets. A summary of structural models of the entire transcripts in this gene family is shown in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002644#pntd.0002644.s008" target="_blank">Table S1</a>. (<b>B</b>) Rigid body superposition of SjP3842 (blue) over the highest scoring template, PDB: 2e7v (olive). The graph is the Ramachandran plot (φ/ψ) showing conformational angles distribution of the residues. Over 98% of residues were in the favored regions while less than 2% were in the outlier region. (<b>C</b>) Alignments of SjCP3842 with two well defined SEA-domains (human MUC1 and mouse TMPRSS2). Putative SEA-domain consensus cleavage site (red arrow) was identified between β2 and β3.</p

Protein expression and antigenicity of the candidate proteins.

<p>(<b>A</b>) SDS-PAGE of recombinant <i>E. coli</i> lysates (lane L) and purified protein without inclusion bodies (lane P). Arrows indicate expected molecular weights of oligomers. Other bands are expected SEA-domain cleavage products. (<b>B</b>) Western blots of recombinant protein expression as in (B), probed with anti-HisG antibody. (<b>C</b>) Anti-HisG probed western blots showing oligomerization of proteins with multiple bands of additive ∼30 kDa subunits, and tetramer as the most stable state. (<b>D</b>) Size exclusion gel filtration chromatography of SjCP3842 showed multiple elution peaks, another evidence of oligomerization. (<b>E</b>) Immunoblots showing reactivity of parasite crude antigen preparations (SEA and SWA) with immune sera. (<b>F</b>) The candidate proteins specifically reacted with infected miniature pig sera in IgG ELISA, indicating potential antigenicity during schistosomiasis. Bars represent standard deviation (SD). * = p<0.05, ** = p<0.01. n = 4 for each group.</p