Oxidative sensitivity of alternative functions of the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase

The glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is susceptible to inflammatory oxidants such as hypochlorite (OCl ) and hydrogen peroxide (H2O2). Evidence [1] suggests that the monomeric form of GAPDH exhibits uracil-DNA glycosylase (UDG) activity. As oxidative damage has often been implicated as a possible cause of carcinogenesis, the sensitivity of UDG to inflammatory oxidants was investigated. An assay, modified from Sirover (1979) [2], was developed which successfully quantitated the UDG activity of both bacterial UDG and UDG extracted from a human cell line, HCT 116. UDG activity in these cells was proportional to cell number, with an upper limit of 2.5 x 10^ cells, possessing 3033U UDG/mg protein. Aliquots containing 2.5 x 10^ cells were exposed to the inflammatory oxidants, OCl and H2O2. Exposure of HCT 116 cells to OCl up to a concentration of 5 x lO\u27^M resulted in no change in UDG activity released from these cells. However, exposure to OCl at concentrations higher than 5 x lO\u27^M resulted in complete loss of cellular UDG activity. In contrast, UDG activity was not inhibited at all in HCT 116 cells exposed to H2O2 up to a concentration of lO\u27^M. Bacterial UDG, however, was not inhibited by either OCl\u27 up to a concentration of lO\u27^M, or H2O2 up to a concentration of lO\u27^M. As bacterial UDG displays different properties to human UDG, it may not be used as a model to investigate the mode of inactivation of human UDG by OCl

The neurological characterization of the wildtype-transthyretin-amyloidosis

There are different types of transthyretin amyloidosis (ATTR). Hereditary transthyretin amyloidosis or also referred as variant transthyretin amyloidosis (ATTRv) caused by genetic mutations in the transthyretin (TTR) gene and wildtype transthyretin amyloidosis (ATTRwt) which affects mostly elderly men. Depending on the underlying mutation, ATTRv is associated with pronounced neurological involvement like severe polyneuropathy (PNP). Other associated neurologic characteristics, which can be found in both subtypes, are spinal canal stenosis (SCS) and carpal tunnel syndrome (CTS). Unlike ATTRv, the neurological characteristics of ATTRwt have not yet been fully defined. We prospectively studied 50 patients (46 men, mean age of 80.6 years) with ATTRwt over a period of 11 months to answer these questions. The workup included neurological examinations, cardiological assessments, laboratory tests, electrophysiological testing and the DPD-scintigraphy. A subgroup (n=8) was tested for orthostatic intolerance (OI). Seventy-four percent (n=37) of the patients suffered from a peripheral, symmetric and length-depended, sensory PNP with a mean of 8.4 points (SD ± 10.1) in the Neuropathy Impairment Score (NIS). NIS ranged from zero to 50 points, indicating a mild to moderate neuropathy impairment without severe walking disability. 90% were classified as FAP stage 1 in the FAP scoring system and 92% of patients were rated as stage 1 in the PND classification. More than half of the patients presented with a history for CTS. This was found predominantly as a bilateral manifestation in 66% (n=21) of the patients and to a small extent of 34% (n=11) as an unilateral manifestation. CTS preceded the diagnosis cardial ATTRwt about 11 years. The echocardiography identified a heart failure with preserved ejection fraction (HfpEF) in 48% (n=22) of the patients. The median COMPASS-31 total score was 18.4 points (IQR 32.4 points) also with mild scoring in the part of orthostatic intolerance (OI). However, the Tilt-table test could not reproduce an OI in a subpopulation of 8 patients. Taken together we showed that distal-symmetric, mostly sensory PNP without relevant mobility impairment is a characteristic attribute of ATTRwt. Furthermore, CTS and SCS are also typical neurological complications, which manifest 10-12 years before cardiomyopathy. Autonomic nervous system involvement did not appear to be typical in our study. In summary, ATTRwt should be considered as a differential diagnosis of sensory PNP and additional SCS in advanced aged men.Die Transthyretin-Amyloidose (ATTR) ist eine heterogene und auf fibrillären Amyloidablagerungen basierende Erkrankung. Auf Grundlage des Vorliegens genetischer Mutationen im Transthyretin (TTR)-Gen werden zwei Formen unterschieden. Zum einen die hereditäre Transthyretin-Amyloidose (ATTRv) mit Mutationen im TTR-Gen, zum anderen die Wildtyp-Transthyretin-Amyloidose (ATTRwt). Während für die ATTRv bekannt ist, dass sie mit einer schweren neuropathischen Beteiligung einhergehen kann, ist es umso überraschender, dass über die neurologische Manifestation der ATTRwt bisher nur wenig bekannt ist. Lange galt die ATTRwt als kardiologische Erkrankung, welche vorwiegend älterer Männer (25% der >80-85-Jährigen (2)) betrifft (3). Die exakte Prävalenz ist bisher nicht bekannt (2, 4). Im Rahmen der neurologischen Beteiligung ist bisher überwiegend das Karpaltunnelsyndrom (carpal tunnel syndrome, CTS) (5) beschrieben worden. Die Symptompräsentation ist oft unspezifisch, wodurch die Diagnostik und ein früher Therapiebeginn erschwert werden. Ziel unserer Studie ist daher die neurologische Charakterisierung der ATTRwt. In dieser Studie wurden, zwischen September 2019 und November 2020, 50 ATTRwt-Patient*innen eingeschlossen. Unsere Kohorte setzte sich aus 92% (n=46) Männern und 8% (n=4) Frauen, mit einem Durchschnittsalter von 80.6 Jahren (SD±5.0), zusammen. Alle zeigten echokardiographische Zeichen einer Kardiomyopathie. In der klinisch-neurologischen Diagnostik wiesen 74% (n=37) eine periphere, längenabhängige, symmetrische und vorwiegend sensible Polyneuropathie (PNP) auf. Die Ergebnisse des Neuropathy Impairment Scores (NIS) lagen in unserer Studie zwischen 0 bis 50 Punkten. Der Durchschnittswert des NIS betrug 8.4 Punkte (SD±10.1), als Ausdruck einer mehrheitlich milden Beeinträchtigung. In der FAP (Familial Amyloidotic Polyneuropathy)-Klassifikation fand sich bei 90% ein FAP-Stadium I und ebenfalls bei 92% ein PND-Stadium I, welches einer geringen Gehbeeinträchtigung entspricht. 70% (n=35) zeigten ein uni- oder bilaterales CTS. Eine Spinalkanalstenose (spinal canal stenosis, SCS) lag bei 11% (n=5) vor. Der Median des COMPASS-31 lag bei 18.4 Punkten (IQR 32.4 Punkte) mit etwas erhöhten Werten in der Unterkategorie der autonomen Beteiligung. Der Kipptischversuch (n=8) konnte das Vorliegen einer Orthostatischen Intoleranz (OI) jedoch nicht bestätigen. Unsere Studie konnte zeigen, dass neben dem CTS und der SCS auch die distal-symmetrische, vorwiegend sensible, längenabhängige PNP eine typische neurologische Komplikation der ATTRwt ist, welches den Systemcharakter der ATTRwt weiter erhärtet. Im Vergleich zur ATTRv scheint die Ausprägung der ATTRwt-PNP jedoch milder und ohne relevante Beeinträchtigung Motorik zu verlaufen. Zusammenfassend handelt es sich bei der ATTRwt um eine häufig erst spät diagnostizierte Erkrankung, welche eine wichtige Differentialdiagnose der sensorischen PNP, besonders bei Männern höheren Alters, darstellt

Putative New Lineage of West Nile Virus, Spain

To ascertain the presence of West Nile virus (WNV), we sampled mosquitoes in 2006 in locations in southern Spain where humans had been infected. WNV genomic RNA was detected in 1 pool from unfed female Culex pipiens mosquitoes. Phylogenetic analysis demonstrated that this sequence cannot be assigned to previously described lineages of WNV

The relationships between West Nile and Kunjin viruses.

Until recently, West Nile (WN) and Kunjin (KUN) viruses were classified as distinct types in the Flavivirus genus. However, genetic and antigenic studies on isolates of these two viruses indicate that the relationship between them is more complex. To better define this relationship, we performed sequence analyses on 32 isolates of KUN virus and 28 isolates of WN virus from different geographic areas, including a WN isolate from the recent outbreak in New York. Sequence comparisons showed that the KUN virus isolates from Australia were tightly grouped but that the WN virus isolates exhibited substantial divergence and could be differentiated into four distinct groups. KUN virus isolates from Australia were antigenically homologous and distinct from the WN isolates and a Malaysian KUN virus. Our results suggest that KUN and WN viruses comprise a group of closely related viruses that can be differentiated into subgroups on the basis of genetic and antigenic analyses

Genetic variation of St. Louis encephalitis virus

St. Louis encephalitis virus (SLEV) has been regularly isolated throughout the Americas since 1933. Previous phylogenetic studies involving 62 isolates have defined seven major lineages (I–VII), further divided into 14 clades. In this study, 28 strains isolated in Texas in 1991 and 2001–2003, and three older, previously unsequenced strains from Jamaica and California were sequenced over the envelope protein gene. The inclusion of these new sequences, and others published since 2001, has allowed better delineation of the previously published SLEV lineages, in particular the clades of lineage II. Phylogenetic analysis of 106 isolates identified 13 clades. All 1991 and 2001–2003 isolates from Nueces, Jefferson and Harris Counties (Texas Gulf Coast) group in clade IIB with other isolates from these counties isolated during the 1980s and 1990s. This lack of evidence for introduction of novel strains into the Texas Gulf Coast over a long period of time is consistent with overwintering of SLEV in this region. Two El Paso isolates, both from 2002, group in clade VA with recent Californian isolates from 1998–2001 and some South American strains with a broad temporal range. Overall, these data are consistent with multiple introductions of SLEV from South America into North America, and provide support for the hypothesis that in most situations, SLEV circulates within a locality, with occasional incursions from other areas. Finally, SLEV has much lower nucleotide (10.1 %) and amino acid variation (2.8 %) than other members of the Japanese encephalitis virus complex (maximum variation 24.6 % nucleotide and 11.8 % amino acid)

Kunjin Virus: An Australian Variant of West Nile?

Kunjin (KUN) Is a flavivirus in the Japanese encephalitis antigenic complex that was first isolated from Culex annulirostris mosquitoes captured in northern Australia in 1960. It is the etiological agent of a human disease characterized by febrile illness with rash or mild encephalitis and, occasionally, of a neurological disease In horses. KUN virus shares a similar epidemiology and ecology with the closely related Murray Valley encephalitis (MVE) virus, the major causative agent of arboviral encephalitis in Australia. Based on traditional antigenic methods, KUN was initially found to be similar to, but distinct from, reference strains of West Nile (WN) virus and designated as a new species. However, more recent phylogenic analyses have revealed that some strains of WN virus, including the Isolates from New York, are more similar to KUN virus and form a separate lineage to other WN viruses. An unusual KUN isolate from Malaysia and the African virus Koutango appear to form additional lineages within the WN group of viruses. While these findings are in agreement with the Seventh Report of the International Committee for the Taxonomy of Viruses that designates KUN as a subtype of West Nile, they also suggest that the species should be further subdivided into additional subtypes

The Naturally Attenuated Kunjin Strain of West Nile Virus Shows Enhanced Sensitivity to the Host Type I Interferon Response▿

The host determinants that contribute to attenuation of the naturally occurring nonpathogenic strain of West Nile virus (WNV), the Kunjin strain (WNVKUN), remain unknown. Here, we show that compared to a highly pathogenic North American strain, WNVKUN exhibited an enhanced sensitivity to the antiviral effects of type I interferon. Our studies establish that the virulence of WNVKUN can be restored in cells and mice deficient in specific interferon regulatory factors (IRFs) or the common type I interferon receptor. Thus, WNVKUN is attenuated primarily through its enhanced restriction by type I interferon- and IRF-3-dependent mechanisms