The spectrum of neurological manifestations of varicella-zoster virus reactivation

Abstract Varicella–Zoster virus (VZV) is a pathogenic human alpha herpes virus that causes varicella (chicken pox) as a primary infection and, following a variable period of latency in different ganglionic neurons, it reactivates to produce herpes zoster (shingles). The focus of this review is on the wide spectrum of the possible neurological manifestations of VZV reactivation. While the most frequent reactivation syndrome is herpes zoster, this may be followed by the serious and painful post-herpetic neuralgia (PHN) and by many other neurological conditions. Prominent among these conditions is a VZV vasculopathy, but the role of VZV in causing giant cell arteritis (GCA) is currently controversial. VZV reactivation can also cause segmental motor weakness, myelitis, cranial nerve syndromes, Guillain–Barre syndrome, meningoencephalitis, and zoster sine herpete, where a neurological syndrome occurs in the absence of the zoster rash. The field is complicated by the relatively few cases of neurological complications described and by the issue of causation when a neurological condition is not manifest at the same time as the zoster rash

Root presence modifies the long-term decomposition dynamics of fungal necromass and the associated microbial communities in a boreal forest

Recent studies have highlighted that dead fungal mycelium represents an important fraction of soil carbon (C) and nitrogen (N) inputs and stocks. Consequently, identifying the microbial communities and the ecological factors that govern the decomposition of fungal necromass will provide critical insight into how fungal organic matter (OM) affects forest soil C and nutrient cycles. Here, we examined the microbial communities colonising fungal necromass during a multiyear decomposition experiment in a boreal forest, which included incubation bags with different mesh sizes to manipulate both plant root and microbial decomposer group access. Necromass-associated bacterial and fungal communities were taxonomically and functionally rich throughout the 30 months of incubation, with increasing abundances of oligotrophic bacteria and root-associated fungi (i.e., ectomycorrhizal, ericoid mycorrhizal and endophytic fungi) in the late stages of decomposition in the mesh bags to which they had access. Necromass-associated beta-glucosidase activity was highest at 6 months, while leucine aminopeptidase peptidase was highest at 18 months. Based on an asymptotic decomposition model, root presence was associated with an initial faster rate of fungal necromass decomposition, but resulted in higher amounts of fungal necromass retained at later sampling times. Collectively, these results indicate that microbial community composition and enzyme activities on decomposing fungal necromass remain dynamic years after initial input, and that roots and their associated fungal symbionts result in the slowing of microbial necromass turnover with time.Peer reviewe

Analgesic Activity of Conyza Floribunda Extracts in Swiss Albino Mice

Traditional medicine still plays an important role in managing infections especially in Africa. Extracts of Conyza floribunda Kunth are used to treat sore throat, ringworm and other skin related infections, toothache and to stop bleeding from injuries. Extracts from the plant have been reported to exhibit antibacterial and antifungal activities. Previous phytochemical studies on the plant yielded terpenoid, sterols and flavonoids. The aim of the present study was to determine the analgesic activity Conyza floribunda extracts. Methanol, DCM and n-hexane extracts of the plant were subjects to toxicity, hot plate latency and acetic acid induced-writhing tests using Swiss Albino Mice. The plant extract showed analgesic activity in both hot plate latency and acetic acid induced-writhing tests. The extracts significantly increased the response time in the animals compared to the negative control. In the hot plate latency test, the analgesic activity of the extracts and that of morphine rose over time to peak at 90 minutes and then decreased afterwards. In the acetic acid-induces writhing test, administration of the plant extracts significantly reduced the number of abdominal contractions compared to the negative control. The percentage inhibitions of abdominal contractions were 67.2, 46.5 and 39.4 for methanol, DCM and n-hexane extracts respectively. The findings from this study have confirmed the folkloric information that extracts from C. floribunda have analgesic properties. We therefore recommend the extracts from the plant for use in pain management. Further studies should be carried out to isolate and characterize the analgesic principles from the plant. Keywords: Conyza floribunda, Toxicity test, Analgesic activity, Hot plate test, Writhing test DOI: 10.7176/JNSR/12-12-01 Publication date:June 30th 2021

Processing and Transmission of Information

Contains research objectives, summary of research and reports on one research project.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)National Aeronautics and Space Administration (Grant NGL-22-009-013

The relationship of endotoxaemia to peripheral and central nervous system inflammatory responses in Human African Trypanosomiasis

Endotoxaemia has been described in cases of Human African trypanosomiasis (HAT), but it is unclear if this phenomenon influences inflammatory pathology either in the periphery or central nervous system (CNS). We studied endotoxin concentrations in the plasma and cerebrospinal fluid (CSF) of Trypanosoma brucei rhodesiense patients using the chromogenic Limulus Amoebocyte lysate assay. The relationship of endotoxin concentration to the presentation of gross signs of inflammation and the inflammatory/counter-inflammatory cytokine profile of the relevant compartments were analysed. We demonstrate that HAT patients exhibit parasitaemia-independent plasma endotoxaemia, and that this is associated with splenomegaly and lymphadenopathy. Endotoxin concentrations normalize rapidly after treatment. There was no evidence of endotoxin release in the CNS. A rapid normalization of endotoxin levels after treatment and lack of association with parasitaemia suggest that gut leakage is the main source of endotoxin in the circulation. Low CSF endotoxin concentrations and a lack of any association with neuroinflammatory markers or neurological sequelae suggest that endotoxin does not play a role in the pathogenesis of the disease in the CNS

Melarsoprol cyclodextrin inclusion complexes as promising oral candidates for the treatment of human African trypanosomiasis

Human African trypanosomiasis (HAT), or sleeping sickness, results from infection with the protozoan parasites <i>Trypanosoma brucei</i> (<i>T.b.</i>) <i>gambiense</i> or <i>T.b.rhodesiense</i> and is invariably fatal if untreated. There are 60 million people at risk from the disease throughout sub-Saharan Africa. The infection progresses from the haemolymphatic stage where parasites invade the blood, lymphatics and peripheral organs, to the late encephalitic stage where they enter the central nervous system (CNS) to cause serious neurological disease. The trivalent arsenical drug melarsoprol (Arsobal) is the only currently available treatment for CNS-stage <i>T.b.rhodesiense</i> infection. However, it must be administered intravenously due to the presence of propylene glycol solvent and is associated with numerous adverse reactions. A severe post-treatment reactive encephalopathy occurs in about 10% of treated patients, half of whom die. Thus melarsoprol kills 5% of all patients receiving it. Cyclodextrins have been used to improve the solubility and reduce the toxicity of a wide variety of drugs. We therefore investigated two melarsoprol cyclodextrin inclusion complexes; melarsoprol hydroxypropyl-͎-cyclodextrin and melarsoprol randomly-methylated-β-cyclodextrin. We found that these compounds retain trypanocidal properties <i>in vitro</i> and cure CNS-stage murine infections when delivered orally, once per day for 7-days, at a dosage of 0.05 mmol/kg. No overt signs of toxicity were detected. Parasite load within the brain was rapidly reduced following treatment onset and magnetic resonance imaging showed restoration of normal blood-brain barrier integrity on completion of chemotherapy. These findings strongly suggest that complexed melarsoprol could be employed as an oral treatment for CNS-stage HAT, delivering considerable improvements over current parenteral chemotherapy

Central Nervous System Parasitosis and Neuroinflammation Ameliorated by Systemic IL-10 Administration in Trypanosoma brucei-Infected Mice

Peer reviewedPublisher PD

Stem-inhabiting fungal communities differ between intact and snapped trees after hurricane Maria in a Puerto Rican tropical dry forest

Hurricanes impact forests by damaging trees and altering multiple ecosystem functions. As such, predicting which individuals are likely to be most affected has crucial economic importance as well as conservation value. Tree stem-inhabiting fungal communities, notably rot-causing agents, have been mentioned as a potential factor of tree predisposition to hurricane damage, but this assumption remains poorly explored. To examine this relationship, we sampled the stem wood of intact and damaged trees shortly after Hurricane Maria in a Puerto Rican dry tropical forest in 2017. We categorized samples depending on two types: trees with intact stems and trees in which stems were snapped. We extracted fungal environmental DNA of wood from 40 samples consisting of four different tree species. Fungal community taxonomic and functional richness and composition was assessed using high-throughput DNA metabarcoding. We found that snapped trees harbored significantly higher fungal operational taxonomic unit (OTU) richness than the intact trees and that the composition of the stem-inhabiting fungal communities diverged consistently between intact and snapped trees. On average, snapped trees’ fungal communities were relatively enriched in “other saprotrophs” guild category and depleted in endophytes. Conversely, intact trees had high relative abundances of Clonostachys, a mycoparasitic endophyte, suggesting that endophytic fungi might act as biocontrols in tree stems. Overall, our results support the hypothesis that stem-inhabiting fungal communities could represent a predisposition factor of tree damage caused by hurricanes in tropical dry forests