Long-term passive wastewater surveillance of SARS-CoV-2 for seven university dormitories in comparison to municipal surveillance

Wastewater-based surveillance (WBS) has been an effective tool for monitoring and understanding potential SARS-CoV-2 transmission across small and large-scale communities. In this study at the University of Saskatchewan, the assessment of SARS-CoV-2 was done over eight months during the 2021-2022 academic year. Wastewater samples were collected using passive samplers that were deployed in domestic sewer lines near adjacent campus residences and extracted for viral RNA, followed by Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR). The results showed similar trends for SARS-CoV-2 detection frequencies and viral loads across university residences, the whole campus, and from related WBS at Saskatoon Wastewater Treatment Plant. The maximum daily detection frequency for seven dormitories considered was about 75 %, while maximum daily case numbers for the residences and campus-wide were about 11 and 75 people, respectively. In addition, self-reported rates of infection on campus peaked during similar time frames as increases in viral load were detected at the Saskatoon wastewater treatment plant. These similarities indicate the usefulness and cost-effectiveness of monitoring the spread of COVID-19 in small-scale communities using WBS.

First record of the nesting whitefly, Paraleyrodes minei, in Greece

On late June 2015, the nesting whitefly Paraleyrodes minei Ιaccarino (Hemiptera: Aleyrodidae) was recorded for first time in Greece. Its occurrence was observed on leaves of sweet orange [Citrus sinensis (L.) Osbeck] trees at Platanias, Chania, on the underside of which tiny white “nests” were observed, due to the woolly waxy material secreted by females, around themselves, as well as by the filamentous translucent wax rods extending from the dorsum of late nymphal instars. In our surveys P. minei was observed at low or moderate population densities. Information on its morphology, biology and present geographical distribution is provided.

Hepatocellular carcinoma risk in HBeAg-negative chronic hepatitis B patients with or without cirrhosis treated with entecavir: HepNet.Greece cohort

Hepatocellular carcinoma (HCC) may still develop in chronic hepatitis B (CHB) patients treated with lamivudine. Whether HCC rates are comparable in patients treated with the current first-line antivirals remains uncertain. We estimated the incidence and evaluated predictors of HCC in a large nationwide prospective cohort (HepNet.Greece) of HBeAg-negative CHB patients treated with entecavir. HBeAg-negative CHB patients from the same cohort who were initially treated with lamivudine were used as controls. We included 321 patients treated with entecavir for a median of 40 months and 818 patients treated initially with lamivudine for a median of 60 months. In the entecavir group, HCC developed in 4 of 321 (1.2%) patients at a median of 1.5 (range: 1.0-4.5) years, while the cumulative HCC incidence was significantly higher in cirrhotics than noncirrhotics (1, 3, 5 years: 0%, 3%, 9% vs 1%, 1%, 1%; P = 0.024) and in older patients (P = 0.026). Entecavir compared with lamivudine group patients had lower HCC incidence (1, 3, 5 years: 0.3%, 1.2%, 2.8% vs 0.7%, 3.8%, 5.6%; P = 0.024). However, in multivariable Cox regression analysis, the HCC risk was independently associated with older age (P < 0.001), male gender (P = 0.011) and cirrhosis (P = 0.025), but not with the initial agent. In conclusion, our large nationwide study indicates that the HCC risk remains increased in entecavir-treated HBeAg-negative CHB patients with cirrhosis, particularly of older age, at least for the first 5 years. The HCC risk does not seem to be significantly reduced with entecavir compared with antiviral therapy starting with lamivudine.

Global distribution and origin of target site insecticide resistance mutations in Tetranychus urticae

The control of Tetranychus urticae, a worldwide agricultural pest, is largely dependent on pesticides. However, their efficacy is often compromised by the development of resistance. Recent molecular studies identified a number of target site resistance mutations, such as G119S, A201S, T280A, G328A, F331W in the acetylcholinesterase gene, L1024V, A1215D, F1538I in the voltage-gated sodium channel gene, G314D and G326E in glutamate-gated chloride channel genes, G126S, I136T, S141F, D161G, P262T in the cytochrome b and the I1017F in the chitin synthase 1 gene. We examined their distribution, by sequencing the relevant gene fragments in a large number of T. urticae collections from a wide geographic range. Our study revealed that most of the resistance mutations are spread worldwide, with remarkably variable frequencies. Furthermore, we analyzed the variability of the ace locus, which has been subjected to longer periods of selection pressure historically, to investigate the evolutionary origin of ace resistant alleles and determine whether they resulted from single or multiple mutation events. By sequencing a 1540 bp ace fragment, encompassing the resistance mutations and downstream introns in 139 T. urticae individuals from 27 countries, we identified 6 susceptible and 31 resistant alleles which have arisen from at least three independent mutation events. The frequency and distribution of these ace haplotypes varied geographically, suggesting an interplay between different mutational events, gene flow and local selection.

Abamectin is metabolized by CYP392A16, a cytochrome P450 associated with high levels of acaricide resistance in Tetranychus urticae

Abamectin is one of the most important insecticides worldwide. It is used against major agricultural pests and insects of public health importance, as well as against endoparasites in animal health. Abamectin has been used successfully for the control of the spider mite Tetranychus urticae, a major agricultural pest with global distribution, an extremely diverse host range, and a remarkable ability to develop resistance against insecticides including abamectin. Target site resistance mutations may explain a large part of resistance, although genetic evidence and transcriptomic data indicated that additional mechanisms may also be implicated in the abamectin resistant phenotype. To investigate a functional link between cytochrome P450-mediated metabolism and abamectin resistance, we recombinantly expressed three cytochrome P450s (CYP392A16, CYP392D8 and CYP392D10) that have been associated with high levels of abamectin resistance in a resistant T. urticae strain isolated from Greece. CYP392A16 was expressed predominately in its P450 form however, both CYP392D8 and CYP392D10 were expressed predominately as P420, despite optimization efforts on expression conditions. CYP392A16 catalyses the hydroxylation of abamectin (Kcat=0.54 pmol/min/pmol P450; Km=45.9 μM), resulting in a substantially less toxic compound as confirmed by bioassays with the partially purified metabolite. However, CYP392A16 did not metabolize hexythiazox, clofentezine and bifenthrin, active ingredients that also showed reduced toxicity in the abamectin resistant strain. Among a number of fluorescent and luminescent substrates screened, Luciferin-ME EGE was preferentially metabolized by CYP392A16, and it may be a potential diagnostic probe for metabolic resistance detection and monitoring.

FcRn overexpression in transgenic animals results in robust immune response (P1069)

Our previous studies have shown that overexpression of the neonatal Fc receptor (FcRn) in transgenic animals (mice and rabbits) leads to (1) improved IgG protection; (2) larger numbers of antigen specific B cells; (3) generation of antibodies against weakly immunogenic antigens; (4) generation of antibodies against highly conserved antigens (breaking immune tolerance); (5) increased humoral diversity and (6) higher levels of circulating antibodies. FcRn transgenesis thus confers a number of practical benefits, including faster antibody production, higher antibody yields and improved generation of hybridomas for monoclonal antibody production. To gain additional insights into the mechanisms underlying this increase in humoral immune response, we further characterized our FcRn transgenic animals. Our analyses showed strong expression of the FcRn transgene in professional antigen presenting cells and we also found that overexpression of the FcRn significantly improves antigen presentation in case of antigen-IgG immune complexes. We have recently analyzed several key factors in the maturation of the immune response, including the structure of the spleen, number and structure of germinal centers, the level of T cell activation and the affinity of the generated antibodies. These results provide further insights of those mechanisms that are involved in the augmented humoral immune response in transgenic animals that overexpress FcRn.

The cys-loop ligand-gated ion channel gene family of Tetranychus urticae: implications for acaricide toxicology and a novel mutation associated with abamectin resistance

The cys-loop ligand-gated ion channel (cysLGIC) super family of Tetranychus urticae, the two-spotted spider mite, represents the largest arthropod cysLGIC super family described to date and the first characterised one within the group of chelicerates. Genome annotation, phylogenetic analysis and comparison of the cysLGIC subunits with their counterparts in insects reveals that the T. urticae genome encodes for a high number of glutamate- and histamine-gated chloride channel genes (GluCl and HisCl) compared to insects. Three orthologues of the insect γ-aminobutyric acid (GABA)-gated chloride channel gene Rdl were detected. Other cysLGIC groups, such as the nAChR subunits, are more conserved and have clear insect orthologues. Members of cysLGIC family mediate endogenous chemical neurotransmission and they are prime targets of insecticides. Implications for toxicology associated with the identity and specific features of T. urticae family members are discussed. We further reveal the accumulation of known and novel mutations in different GluCl channel subunits (Tu_GluCl1 and Tu_GluCl3) associated with abamectin resistance in T. urticae, and provide genetic evidence for their causality. Our study provides useful toxicological insights for the exploration of the T. urticae cysLGIC subunits as putative molecular targets for current and future chemical control strategies.

Identification of pyrethroid resistance associated mutations in the para sodium channel of the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae)

We investigated pyrethroid resistance mechanisms in Tetranychus urticae strains from Greece. Combined bioassay, biochemical and synergistic data indicated that although P450 mono-oxygenase activities were associated with the trait, target site insensitivity was the major resistance component. A 3.3 kb cDNA fragment of the T. urticae para sodium channel gene encompassing segment 4 of domain II to segment 6 of domain IV was obtained by a degenerate PCR strategy. The T. urticae sequence showed highest identity (56%) to the scabies mite, Sarcoptes scabiei, and was phylogenetically classified within the divergent group of Arachnida. Comparison of resistant and susceptible strains identified the point mutation F1538I in segment 6 of domain III, which is known to confer strong resistance to pyrethroids, along with a second mutation (A1215D) in the intracellular linker connecting domains II and III with an unknown role. Three transcripts were identified corresponding to the k and l alternative exons. The mode of inheritance of resistance was confirmed as incompletely recessive, which is consistent with a target site mechanism for pyrethroids.

Buspirone vs amitriptyline in the treatment of chronic tension-type headache

OBJECTIVES

The aim of this study was to explore the efficacy of buspirone (BSR), in comparison with amitriptyline (AML) in the prophylactic treatment of chronic tension-type headache (CTH), in an open and randomized clinical trial.

MATERIAL AND METHODS

Twenty-six CTH patients (10 men and 16 women) were treated with BSR (30 mg daily) for 12 weeks. A parallel group of 32 CTH patients (12 men and 20 women) was treated with AML (50 mg daily). The major clinical parameters evaluated were the headache index (days with headache per month), the frequency of drug use for the acute management of headaches, the patients' opinion for the treatment and the Hamilton anxiety and depression rating scales.

RESULTS

During the study 9 patients dropped out (4 from the BSR group and 5 from the AML group). Twelve (54.4%) patients from the BSR group responded to treatment (> 50% reduction in the headache index), compared to 17 (60.7%) from the AML group. In the BSR group, 14 (53.8%) patients reported various mild side effects (nausea most frequently), vs 21 (65.5%) of the AML group (mouth dryness more frequently). Patients treated with AML had better opinion and used less drugs for the acute treatment of headaches than the BSR treated patients.

CONCLUSION

These results suggest that BSR may be effective in the prophylactic treatment of CTH, and that further investigation in a placebo controlled study is needed.

Two more secondary headaches mimicking chronic paroxysmal hemicrania. Is this the exception or the rule?

Two patients with headaches meeting the criteria of chronic paroxysmal hemicrania, as defined by the International Headache Society classification, are presented. Further investigations revealed a parasellar pituitary microadenoma in the first patient and a maxillary cyst in the second. Surgical removal of the lesions resulted in complete relief from headaches. The clinical features of this rare syndrome are discussed and suggest that a more detailed laboratory study and clinical follow-up is necessary in patients with chronic paroxysmal hemicrania.

External ophthalmoplegia with ragged-red fibres and acetylcholine receptor antibodies

The cases of two elderly women with external ophthalmoplegia, generalized muscle weakness and serum anti-acetylcholine receptor antibodies, are presented. The electophysiological studies showed a myopathic pattern but no indications of myasthenia after repetitive stimulation. The edrophonium test was negative and there was no response to anticholinesterase medication. In addition, elevated serum lactic acid levels and ragged-red muscle fibres in the muscle biopsy, were observed in both patients. These findings are discussed in relation to the fact that anti-acetylcholine receptor antibodies are diagnostic of myasthenia gravis, whereas ragged-red fibres and elevated lactic acid are correlated with mitochondrial myopathies.

An epidemiological study of headache among the Monks of Athos (Greece)

The Monks of Athos in Greece constitute a particular group with unusual sleep schedule and specific diet. In order to study the frequency of headache among them, a special questionnaire was designed. Four hundred forty-nine monks below the age of 50 were approached, 39 of whom suffered from frequent (more than one episode per month, in the last 6 months) headaches (8.68%). The prevalence of migraine was 1.78% (0.66% with aura and 1.11% without) and of tension-type headache 3.34% (1.33% chronic and 2% episodic). Furthermore, 1.87% of monks suffered from mixed headaches (tension-type and migraine attacks as well). Cluster headache was not traced.

Plasma 5-S-cysteinyldopa differentiates patients with primary and metastatic melanoma from patients with dysplastic nevus syndrome and normal subjects

To determine whether plasma 5-S-cysteinyldopa levels are useful in following up patients at risk for melanoma, we measured plasma 5-S-cysteinyldopa in patients with dysplastic nevus syndrome and/or malignant melanoma and in control subjects. In patients with dysplastic nevus syndrome, plasma 5-S-cysteinyldopa levels did not differ from those in control subjects. Conversely, patients with malignant melanomas had significantly higher plasma 5-S-cysteinyldopa levels than did controls. Those with localized cutaneous malignant melanoma and no distant metastases (Stage I and II disease) had 5-S-cysteinyldopa levels twofold greater than those of control subjects, whereas the levels of those with regional lymph node involvement (Stage III disease) were fourfold greater than those of control subjects. Levels of those with extraregional metastases (Stage IV disease) were 7- to 450-fold higher than those of control subjects. Moreover, plasma 5-S-cysteinyldopa levels correlated with the spread of disease and were useful in distinguishing primary melanoma and Stages III and IV melanoma. We conclude that plasma 5-S-cysteinyldopa may be an important tool for identifying melanoma at an earlier, more curable stage and for following up patients at risk for the development of melanoma, for example, those with dysplastic nervus syndrome.

Melkersson-Rosenthal's syndrome in four generations

Melkersson-Rosenthal's syndrome is a rare condition, the hereditary nature of which is still in dispute. A family with seven affected members in four generations is described, which provides further evidence for the genetic basis of the syndrome.