High Prevalence of Anti-HCV Antibodies in Two Metropolitan Emergency Departments in Germany: A Prospective Screening Analysis of 28,809 Patients

Background and Aims

The prevalence of hepatitis C virus (HCV) antibodies in Germany has been estimated to be in the range of 0.4–0.63%. Screening for HCV is recommended in patients with elevated ALT levels or significant risk factors for HCV transmission only. However, 15–30% of patients report no risk factors and ALT levels can be normal in up to 20–30% of patients with chronic HCV infection. The aim of this study was to assess the HCV seroprevalence in patients visiting two tertiary care emergency departments in Berlin and Frankfurt, respectively.

Methods

Between May 2008 and March 2010, a total of 28,809 consecutive patients were screened for the presence of anti-HCV antibodies. Anti-HCV positive sera were subsequently tested for HCV-RNA.

Results

The overall HCV seroprevalence was 2.6% (95% CI: 2.4–2.8; 2.4% in Berlin and 3.5% in Frankfurt). HCV-RNA was detectable in 68% of anti-HCV positive cases. Thus, the prevalence of chronic HCV infection in the overall study population was 1.6% (95% CI 1.5–1.8). The most commonly reported risk factor was former/current injection drug use (IDU; 31.2%) and those with IDU as the main risk factor were significantly younger than patients without IDU (p<0.001) and the male-to-female ratio was 72% (121 vs. 46 patients; p<0.001). Finally, 18.8% of contacted HCV-RNA positive patients had not been diagnosed previously.

Conclusions

The HCV seroprevalence was more than four times higher compared to current estimates and almost one fifth of contacted HCV-RNA positive patients had not been diagnosed previously.     

Missense mutations in the catalase-peroxidase gene, katG, are associated with isoniazid resistance in Mycobacterium tuberculosis

The toxicity of the powerful anti-tuberculosis drug isoniazid (INH) is believed to be mediated by the haem-containing enzyme catalase-peroxidase, encoded by the katG gene of Mycobacterium tuberculosis. Compelling evidence for this was obtained by studying a panel of INH-resistant clinical isolates using a novel strategy based on the polymerase chain reaction and single-strand-conformation polymorphism analysis (PCR-SSCP) to detect mutations in katG. In most cases INH resistance was associated with missense mutations while in a small number of strains the gene had been completely, or partially, deleted. The missense mutations fell into two groups, the larger of which contained several independent mutations that affected the N-terminal peroxidase domain of the protein, resulting in the production of a catalase peroxidase with strongly reduced enzyme activity and increased heat lability. The effects of these substitutions could be interpreted by means of molecular modelling using the crystal structure of the related enzyme cytochrome c peroxidase from yeast as a template. The second group comprises a frequently occurring amino acid substitution and a single mutation that are both located in the C-terminal domain but do not noticeably alter either enzyme activity or heat stability.     

N-Terminal-Specific Anti-B-50 (GAP-43) Antibodies Inhibit Ca2+-Induced Noradrenaline Release, B-50 Phosphorylation and Dephosphorylation, and Calmodulin Binding

Abstract: B-50 (GAP-43) is a presynaptic protein kinase C (PKC) substrate implicated in the molecular mechanism of noradrenaline release. To evaluate the importance of the PKC phosphorylation site and calmodulin-binding domain of B-50 in the regulation of neurotransmitter release, we introduced two monoclonal antibodies to B-50 into streptolysin O-permeated synaptosomes isolated from rat cerebral cortex. NM2 antibodies directed to the N-terminal residues 39–43 of rat B-50 dose-dependently inhibited Ca²⁺-induced radiolabeled and endogenous noradrenaline release from permeated synaptosomes. NM6 C-terminal-directed (residues 132–213) anti-B-50 antibodies were without effect in the same dose range. NM2 inhibited PKC-mediated B-50 phosphorylation at Ser⁴¹ in synaptosomal plasma membranes and permeated synaptosomes, inhibited ³²P-B-50 dephosphorylation by endogenous synaptosomal phosphatases, and inhibited the binding of calmodulin to synaptosomal B-50 in the absence of Ca²⁺. Similar concentrations of NM6 did not affect B-50 phosphorylation or dephosphorylation or B-50/calmodulin binding. We conclude that the N-terminal residues 39–43 of the rat B-50 protein play an important role in the process of Ca²⁺-induced noradrenaline release, presumably by serving as a local calmodulin store that is regulated in a Ca²⁺- and phosphorylation-dependent fashion.     

Clinical manifestations and health outcomes associated with Zika virus infections in adults: A systematic review

BackgroundZika virus (ZIKV) has generated global interest in the last five years mostly due to its resurgence in the Americas between 2015 and 2016. It was previously thought to be a self-limiting infection causing febrile illness in less than one quarter of those infected. However, a rise in birth defects amongst children born to infected pregnant women, as well as increases in neurological manifestations in adults has been demonstrated. We systemically reviewed the literature to understand clinical manifestations and health outcomes in adults globally.MethodsThis review was registered prospectively with PROPSERO (CRD 42018096558). We systematically searched for studies in six databases from inception to the end of September 2020. There were no language restrictions. Critical appraisal was completed using the Joanna Briggs Institute Critical Appraisal Tools.FindingsWe identified 73 studies globally that reported clinical outcomes in ZIKV-infected adults, of which 55 studies were from the Americas. For further analysis, we considered studies that met 70% of critical appraisal criteria and described subjects with confirmed ZIKV. The most common symptoms included: exanthema (5,456/6,129; 89%), arthralgia (3,809/6,093; 63%), fever (3,787/6,124; 62%), conjunctivitis (2,738/3,283; 45%), myalgia (2,498/5,192; 48%), headache (2,165/4,722; 46%), and diarrhea (337/2,622; 13%). 36/14,335 (0.3%) of infected cases developed neurologic sequelae, of which 75% were Guillain-Barré Syndrome (GBS). Several subjects reported recovery from peak of neurological complications, though some endured chronic disability. Mortality was rare (0.1%) and hospitalization (11%) was often associated with co-morbidities or GBS.ConclusionsThe ZIKV literature in adults was predominantly from the Americas. The most common systemic symptoms were exanthema, fever, arthralgia, and conjunctivitis; GBS was the most prevalent neurological complication. Future ZIKV studies are warranted with standardization of testing and case definitions, consistent co-infection testing, reporting of laboratory abnormalities, separation of adult and pediatric outcomes, and assessing for causation between ZIKV and neurological sequelae.     

The essential human cytomegalovirus gene UL52 is required for cleavage-packaging of the viral genome

Replication of human cytomegalovirus (HCMV) produces large DNA concatemers of head-to-tail-linked viral genomes that upon packaging into capsids are cut into unit-length genomes. The mechanisms underlying cleavage-packaging and the subsequent steps prior to nuclear egress of DNA-filled capsids are incompletely understood. The hitherto uncharacterized product of the essential HCMV UL52 gene was proposed to participate in these processes. To investigate the function of pUL52, we constructed a ΔUL52 mutant as well as a complementing cell line. We found that replication of viral DNA was not impaired in noncomplementing cells infected with the ΔUL52 virus, but viral concatemers remained uncleaved. Since the subnuclear localization of the known cleavage-packaging proteins pUL56, pUL89, and pUL104 was unchanged in ΔUL52-infected fibroblasts, pUL52 does not seem to act via these proteins. Electron microscopy studies revealed only B capsids in the nuclei of ΔUL52-infected cells, indicating that the mutant virus has a defect in encapsidation of viral DNA. Generation of recombinant HCMV genomes encoding epitope-tagged pUL52 versions showed that only the N-terminally tagged pUL52 supported viral growth, suggesting that the C terminus is crucial for its function. pUL52 was expressed as a 75-kDa protein with true late kinetics. It localized preferentially to the nuclei of infected cells and was found to enclose the replication compartments. Taken together, our results demonstrate an essential role for pUL52 in cleavage-packaging of HCMV DNA. Given its unique subnuclear localization, the function of pUL52 might be distinct from that of other cleavage-packaging proteins.     

Solubility of phenothiazines in red blood cell membranes as evidenced by photoaffinity labeling

Radioactively labeled 7-azido-fluphenazine and 7-azido-triflupromazine methiodide have been synthesized and their binding to membranes of intact red blood cells and to ghosts was compared after irradiation. The results indicated that tertiary phenothiazines react with integral membrane components. We conclude from the results that amphiphilic substances solubilize in biological membranes. This is in contradiction to the proposal that these compounds are excluded from the hydrophobic core of biological membranes (Conrad & Singer (1979) Proc.Natl.Acad.Sci.U.S.A. 76, 5202-5206 and (1981) Biochemistry 20, 808-818).     

SV2 and o-rab3 Remain Associated with Recycling Synaptic Vesicles

Abstract: o-rab3 is an electric ray homologue of low molecular weight GTP-binding proteins thought to be involved in targeting of secretory vesicles to sites of exocytosis. The stimulation-dependent association of o-rab3 with synaptic vesicles was compared with that of the membrane-integral synaptic vesicle protein 2 (SV2). On application of immunoelectron microscopy and the colloidal gold technique, antibodies against either protein labeled the synaptic vesicle membrane compartment. Synaptic vesicles recycled under conditions of low frequency stimulation (0.1 Hz) retained their complement of both SV2 and o-rab3. Isolation of synaptic vesicles by density-gradient centrifugation and subsequent column chromatography yielded no indication of a stimulation-dependent release of o-rab3 from synaptic vesicles. In contrast, multivesicular bodies and vacuoles occasionally observed in the nerve terminals contained SV2 but little if any o-rab3. It is concluded that o-rab3 remains associated with the synaptic vesicle membrane compartment during stimulation-induced cycles of repeated exo- and endocytosis. o-rab3 may be lost once the vesicle enters the prelysosomal pathway.     

Photoreceptors with mitochondrial lenses inPogaina suecica (Plathelminthes,Rhabdocoela)

Summary The photoreceptors ofPogaina suecica correspond to the type of pigment cup ocelli. Each eye consists of one cup cell and three sensory cells. The most conspicuous differentiations of these eyes are lens elements formed by giant mitochondria densely filled with homogeneous electron-dense material. From electron microscopical findings available to date it is hypothesized that mitochondrial lensing might be an autapomorphy of a taxon comprising the Provorticidae Kirgisellinae, Dalyelliidae and Graffillidae groups which are ascribed to the paraphyletic Dalyellioida.Abbreviations l _1–3 lenses - npc nucleus of the pigment cell - pc pigment cell - pg pigment granule - rh rhabdomeres - sc _1–3 sensory cells     

Touch- and Methyl Jasmonate-induced Lignification in Tendrils of Bryonia dioica Jacq.

The touch-induced free coiling response of Bryonia dioica tendrils is accompanied by the differentiation of supporting tissue at the ventral side of the organ, becoming the inner (concave) side of the coiled tendril. As part of this process, the Bianconi plate, a continuous sclerenchyma sheath stretching along the ventral face of the five bicollateral vascular bundles, becomes strongly lignified. During this reaction, the extractable activity of phenylalanine ammonia-lyase in the tendrils increases four- to five-fold, while the amount of PAL, as demonstrated by immunoblotting, remains unchanged. This touch-induced process can also be elicited by airborne application of methyl jasmonate. The PAL inhibitor, 2-aminoindan-2-phosphonic acid (AIP) completely inhibits both the touch- and methyl jasmonate-induced deposition of lignin-like material in the Bianconi plate, but has no effect on coiling. From these results, it can be concluded that the cessation of growth at the ventral side of a free-coiling tendril is not due to induced lignification but rather, lignification seems to serve the function of increasing the mechanical strength of the coiled tendril.