PrEP Use, Sexual Behaviour, and PrEP Adherence Among Men who have Sex with Men Living in Wales Prior to and During the COVID-19 Pandemic.

We examined PrEP use, condomless anal sex (CAS), and PrEP adherence among men who have sex with men (MSM) attending sexual health clinics in Wales, UK. In addition, we explored the association between the introduction of measures to control transmission of SARS-CoV-2 on these outcomes. We conducted an ecological momentary assessment study of individuals in receipt of PrEP in Wales. Participants used an electronic medication cap to record PrEP use and completed weekly sexual behaviour surveys. We defined adherence to daily PrEP as the percentage of CAS episodes covered by daily PrEP (preceded by ≥ 3 days of PrEP and followed by ≥ 2 days). Sixty participants were recruited between September 2019 and January 2020. PrEP use data prior to the introduction of control measures were available over 5785 person-days (88%) and following their introduction 7537 person-days (80%). Data on CAS episodes were available for 5559 (85%) and 7354 (78%) person-days prior to and following control measures respectively. Prior to the introduction of control measures, PrEP was taken on 3791/5785 (66%) days, there were CAS episodes on 506/5559 (9%) days, and 207/406 (51%) of CAS episodes were covered by an adequate amount of daily PrEP. The introduction of pandemic-related control measures was associated with a reduction in PrEP use (OR 0.44, 95%CI 0.20-0.95), CAS (OR 0.35, 95%CI 0.17-0.69), and PrEP adherence (RR = 0.55, 95%CI 0.34-0.89) and this may have implications for the health and wellbeing of PrEP users and, in addition to disruption across sexual health services, may contribute to wider threats across the HIV prevention cascade.

2015 UK National Guideline on the management of non-gonococcal urethritis.

We present the updated British Association for Sexual Health and HIV guideline for the management of non-gonococcal urethritis in men. This document includes a review of the current literature on its aetiology, diagnosis and management. In particular it highlights the emerging evidence that azithromycin 1 g may result in the development of antimicrobial resistance in Mycoplasma genitalium and that neither azithromycin 1 g nor doxycycline 100 mg twice daily for seven days achieves a cure rate of >90% for this micro-organism. Evidence-based diagnostic and management strategies for men presenting with symptoms suggestive of urethritis, those confirmed to have non-gonococcal urethritis and those with persistent symptoms following first-line treatment are detailed.

Defense-Related Transcript Accumulation in Phaseolus vulgaris L. Colonized by the Arbuscular Mycorrhizal Fungus Glomus intraradices Schenck Smith.

Accumulation of mRNAs for the defense-related genes phenylalanine ammonia-lyase (PAL), chalcone synthase, chitinase (CHT), glucanase, and hydroxyproline-rich glycoprotein were examined in roots of dark red kidney bean (Phaseolus vulgaris L. cv Moncalm) colonized by the arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith. In three separate experiments the root length colonized ranged from 28 to 55% by 28 d after planting and inoculation. RNA blot analysis revealed little change in the accumulations of PAL, chalcone synthase, CHT, glucanase, and hydroxyproline-rich glycoprotein transcripts from the 28-d mycorrhizal roots compared to the uninoculated controls. Normalizing the ratios of defense-related transcript accumulation against RNA pools regarded as being constitutively expressed, actin mRNA, 25S rRNA, and 18S rRNA, indicated that changes in the ratios of up to 20% occur according to the RNA pool used for normalization. In situ hybridizations of colonized roots using probes for PAL and CHT showed that accumulations of both transcripts occurred only in arbusculated cells. Both young, finely branched arbuscules and older, clumped arbuscules displayed PAL and CHT message accumulations. The PAL and CHT mRNA accumulations were greater in cortical cells containing young arbuscules than in cells containing clumped arbuscules. Intercellular hyphae and vesicles elicited no response.

Recent advances in understanding the origin of the apoplastic oxidative burst in plant cells.

The origin of the oxidative burst during plant-pathogen interactions remains controversial. A number of possibilities have been identified, which involve the protoplast, plasmalemma or apoplast. The apoplastic production of H2O2 requires three components, an extracellular peroxidase, ion fluxes leading to extracellular alkalinisation and release of a substrate. Fatty acids are the major compounds that appear in the apoplast following elicitation, which can activate H2O2 production by peroxidases in vitro. However, the reaction with peroxidases appears to be novel and is uncharacterised at present. The apoplastic mechanism also cannot be readily distinguished from the operation of a plasma membrane NADPH oxidase system by the use of the inhibitors diphenylene iodonium and N,N diethyl-dithiocarbamate since it is also inhibited by these. These inhibitors have often in the past been used to define the involvement of the latter in the oxidative burst. In common with the NADPH oxidase system, the peroxidase responsible has been cloned but unlike the NADPH oxidase it has been shown to function in vitro to generate H2O2. In vivo studies of the oxidative burst have shown that the alkalinisation is essential and the underlying ion fluxes may be regulated by cAMP. Calcium fluxes are also essential. Although the oxidative activity of peroxidase requires calcium the fluxes have obvious other function. These may include activation of release of substrate and through the activation of a CDPK, regulation of enzymes involved in phytoalexin and cell wall phenolic production such as PAL.

Antisense and sense expression of cDNA coding for CYP73A15, a class II cinnamate 4-hydroxylase, leads to a delayed and reduced production of lignin in tobacco.

A number of plant species contain the class II of genes encoding the cytochrome P450, CYP73, the cognate protein of which cinnamic acid 4-hydroxylase, is the second enzyme of the phenylpropanoid pathway. In order to begin to determine possible functionality, tobacco has been transformed with a truncated French bean class II cinnamate hydroxylase (CYP73A15) in the sense and antisense orientations. Signals for C4H protein could be detected in vascular tissue from wild-type plants using heterologous probes. The transformed plants showed a normal phenotype, even though detectable C4H protein was much reduced in tissue prints. Young propagated transformants displayed a range of reduced C4H activities, as well as either reduced or no phloroglucinol-stainable lignin. However, all mature tobacco plants showed the accumulation of lignin, even though its deposition was apparently delayed. This was not due to induction of tyrosine ammonia-lyase activity, which was not detected, but instead it is presumed due to sufficient C4H residual activity. Analysis of the lignin content of the plants showed reductions of up to 30% with a slightly reduced syringyl to guaiacyl ratio as compared to wild type. This reduction level was favourable in comparison with some other targets in the lignification pathway that have been manipulated including that of class I cinnamate 4-hydroxylase. It is proposed that the class II cinnamate 4-hydroxylase might also function in lignification in a number of species including French bean and tobacco, based on these data.

Novel characteristics and regulation of a divergent cinnamate 4-hydroxylase (CYP73A15) from French bean: engineering expression in yeast.

cDNAs showing high sequence similarity (>70%) over large stretches to plant CYP73A orthologues from other species were isolated from a cDNA library derived from mRNAs expressed in elicitor-treated suspension-cultured cells. These clones appear to code for a full-length 1554 bp open reading frame with a 78 bp 5'-untranslated region and a 140 bp 3'-untranslated region. The open reading frame, determined by sequence similarity, codes for a protein with a predicted Mr of 59229 and a pI of 8.8. It contains the conserved cysteine haem-binding site found in all cytochrome P450s. The protein encoded by this cDNA diverges however from other CYP73As in its N- and C-terminus and in four domains internally, so that overall sequence similarity is in the range 58-66%. Many clones contained an identical intron, which may be associated with a novel regulatory mechanism. Sequence similarity is sufficient for it to be classified as CYP73A15, although it is the least similar member of this family classified so far. The cDNA was expressed in yeast. Successful expression of cinnamate 4-hydroxylase activity required removal of the intron. High-level expression also required modification of the N-terminus to that of CYP73A1. Yeast did not process the intron at all and the leader sequence for A15 was not as compatible as that of A1. The mRNA for CYP73A15 was shown to be rapidly induced by elicitor treatment of suspension-cultured cells of French bean but induction was more transient than that of phenylalanine ammonia-lyase (PAL). In contrast, induction in cells undergoing xylogenesis was much more coordinate with PAL. The cloned cDNA may represent a cinnamate 4-hydroxylase isoform, whose expression is more related to differentiation than the responses to stress in which the majority of CYP73As cloned so far are involved.

Molecular identification and expression of the peroxidase responsible for the oxidative burst in French bean (Phaseolus vulgaris L.) and related members of the gene family.

Molecular characterization has been accomplished for five members of the peroxidase gene family in French bean. The most important of these, designated FBPI, corresponds to the isoform believed to be responsible for the apoplastic oxidative burst demonstrated by suspension-cultured cells in response to fungal elicitor. Identification was made by a complete match of six peptide sequences derived from the native protein to the translated sequence of the cDNA. Modelling of the surface structure in comparison with two other members of the peroxidase family did not reveal any unusual features which might account for its role in the oxidative burst. However, FBP1 when expressed in Pichia pastoris generated H2O2 using cysteine at pH 7.2, a specific property of the native protein when isolated from suspension-cultured cells. FBP1, together with other members of the family, were all induced in cell cultures by elicitor action although they all showed some expression in non-induced cultured cells. They were also expressed in all tissues examined with varying levels of intensity of detection in northern blots. This was confirmed by in situ hybridization and FBP1 expression was confirmed in tissues where it has been previously detected by immunolocalization methods. Assigning roles to individual peroxidases is an important goal and molecular identification of the oxidative burst peroxidase allows further exploration of the relative roles of the different systems involved in generating reactive oxygen species.

Proteomic analysis reveals a novel set of cell wall proteins in a transformed tobacco cell culture that synthesises secondary walls as determined by biochemical and morphological parameters.

A cell suspension culture of a tobacco (Nicotiana tabacum L. cv. Petit Havana) cell line derived from a cultivar transformed with the Tcyt gene from Agrobacterium, which leads to high endogenous levels of cytokinin, has been established. This cell line shows increased cell aggregation, elongated cells and a 5-fold increase in wall thickness. If allowed to carry on growing it can form a single mass without shedding cells into the medium. When analysed at an earlier growth stage, these cultures were found to produce improved levels of vascular nodule formation than in other systems that employ exogenous cytokinin. This differentiation was optimised with respect to sucrose and auxin signals in order to induce maximum production of cells with thickened walls and a morphology characteristic of fibre cells and tracheids, in addition to cells that remain meristematic. In order to establish the validity of this system for studying secondary wall formation, the walls and associated biosynthetic changes were analysed in these cells by chemical analysis of the walls, changes in activities of enzymes of xylan and monolignol synthesis, and expression of mRNAs coding for enzymes of lignin biosynthesis. The wall composition of the transformed cells was compared with that determined for primary walls from a typical untransformed tobacco cell line. Recovery of wall material was 50% greater in the transformed culture. In this material a major difference was found in the pectin fraction where there was a distinct difference in size distribution together with a lower level of methylation for the transformed line, which may be related to increased adhesiveness. There were increased amounts of xylan, although the ratio of xyloglucan to xylan content was not substantially different due to the mixture of cell types. There was also an increase in cellulose and phenolic components. Increased activity of enzymes involved in the synthesis of xylan as a marker for the secondary wall occurred around the time of tracheid differentiation and coincided with a broad peak of cinnamyl alcohol dehydrogenase activity. The expression of mRNAs coding for enzymes of the general phenylpropanoid pathway, phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, catechol O-methyl transferase was relatively constitutive in the cultures while transcripts of ferulate 5-hydroxylase, cinnamoyl CoA-reductase, cinnamyl alcohol dehydrogenase and lignin peroxidase were induced. The walls of the transformed cells also showed considerable differences in the subset of extractable proteins from that found in primary walls of tobacco when these were subjected to proteomic analysis. Many of these proteins appear to be novel and not present in primary walls. However an Mr-32,000 chitinase, an Mr-34,000 peroxidase, an Mr-65,000 polyphenoloxidase/laccase and possibly an Mr-68,000 xylanase could be identified as well as structural proteins.