Antibody degradation in tobacco plants: a predominantly apoplastic process.

BACKGROUND: Interest in using plants for production of recombinant proteins such as monoclonal antibodies is growing, but proteolytic degradation, leading to a loss of functionality and complications in downstream purification, is still a serious problem. RESULTS: In this study, we investigated the dynamics of the assembly and breakdown of a human IgG(1)κ antibody expressed in plants. Initial studies in a human IgG transgenic plant line suggested that IgG fragments were present prior to extraction. Indeed, when the proteolytic activity of non-transgenic Nicotiana tabacum leaf extracts was tested against a human IgG1 substrate, little activity was detectable in extraction buffers with pH > 5. Significant degradation was only observed when the plant extract was buffered below pH 5, but this proteolysis could be abrogated by addition of protease inhibitors. Pulse-chase analysis of IgG MAb transgenic plants also demonstrated that IgG assembly intermediates are present intracellularly and are not secreted, and indicates that the majority of proteolytic degradation occurs following secretion into the apoplastic space. CONCLUSIONS: The results provide evidence that proteolytic fragments derived from antibodies of the IgG subtype expressed in tobacco plants do not accumulate within the cell, and are instead likely to occur in the apoplastic space. Furthermore, any proteolytic activity due to the release of proteases from subcellular compartments during tissue disruption and extraction is not a major consideration under most commonly used extraction conditions

Primary aldosteronism: molecular medicine meets public health.

Primary aldosteronism is the most common single cause of hypertension and is potentially curable when only one adrenal gland is the culprit. The importance of primary aldosteronism to public health derives from its high prevalence but huge under-diagnosis (estimated to be <1% of all affected individuals), despite the consequences of poor blood pressure control by conventional therapy and enhanced cardiovascular risk. This state of affairs is attributable to the fact that the tools used for diagnosis or treatment are still those that originated in the 1970-1990s. Conversely, molecular discoveries have transformed our understanding of adrenal physiology and pathology. Many molecules and processes associated with constant adrenocortical renewal and interzonal metamorphosis also feature in aldosterone-producing adenomas and aldosterone-producing micronodules. The adrenal gland has one of the most significant rates of non-silent somatic mutations, with frequent selection of those driving autonomous aldosterone production, and distinct clinical presentations and outcomes for most genotypes. The disappearance of aldosterone synthesis and cells from most of the adult human zona glomerulosa is the likely driver of the mutational success that causes aldosterone-producing adenomas, but insights into the pathways that lead to constitutive aldosterone production and cell survival may open up opportunities for novel therapies

What are the participants’ perspectives of taking melatonin for the treatment of nocturia in Multiple Sclerosis? -a qualitative study embedded within a double blind RCT

Background: Multiple Sclerosis (MS) is a chronic neurological disorder caused by neurodegeneration within the central nervous system. It results in impaired physical, cognitive and psychological functioning and can also lead to lower urinary tract symptoms including nocturia. While clinical trials have suggested an association between nocturia and melatonin secretion, to our knowledge, no qualitative research has been conducted on the experience of taking melatonin to treat nocturia in progressive MS within a clinical trial. Methods: 17 semi-structured qualitative interviews were conducted as part of a double-blind, randomised, placebo controlled, crossover, clinical trial with consenting adults with MS. Interviews explored participants’ experiences of nocturia associated with MS and their experience of taking melatonin as a trial treatment for nocturia versus a placebo. Data was analysed using a thematic analysis. Results: Themes on the experience of nocturia revealed participants’ understandings of nocturia, the impact it had on their night and increased daily fatigue. Themes on the intervention showed perceived improvements to nocturia, sleep and energy and negative effects including lethargy, a lack of significant change and physical side effects including vivid dreams.Conclusion: This qualitative exploration revealed an association between nocturia and increased levels of fatigue during the day by those with MS. However, perspectives towards the effectiveness of melatonin as a potential treatment varied as both placebo and melatonin were perceived as having very similar effects

Annual direct and indirect costs attributable to nocturia in Germany, Sweden, and the UK

OBJECTIVE: Our aim was to estimate the prevalence-based cost of illness imposed by nocturia (≥2 nocturnal voids per night) in Germany, Sweden, and the UK in an average year. METHODS: Information obtained from a systematic review of published literature and clinicians was used to construct an algorithm depicting the management of nocturia in these three countries. This enabled an estimation of (1) annual levels of healthcare resource use, (2) annual cost of healthcare resource use, and (3) annual societal cost arising from presenteeism and absenteeism attributable to nocturia in each country. RESULTS: In an average year, there are an estimated 12.5, 1.2, and 8.6 million patients ≥20 years of age with nocturia in Germany, Sweden, and the UK, respectively. In an average year in each country, respectively, these patients were estimated to have 13.8, 1.4, and 10.0 million visits to a family practitioner or specialist, ~91,000, 9000, and 63,000 hospital admissions attributable to nocturia and 216,000, 19,000, and 130,000 subjects were estimated to incur a fracture resulting from nocturia. The annual direct cost of healthcare resource use attributable to managing nocturia was estimated to be approximately €2.32 billion in Germany, 5.11 billion kr (€0.54 billion) in Sweden, and £1.35 billion (€1.77 billion) in the UK. The annual indirect societal cost arising from both presenteeism and absenteeism was estimated to be approximately €20.76 billion in Germany and 19.65 billion kr (€2.10 billion) in Sweden. In addition, in the UK, the annual indirect cost due to absenteeism was an estimated £4.32 billion (€5.64 billion). CONCLUSIONS: Nocturia appears to impose a substantial socioeconomic burden in all three countries. Clinical and economic benefits could accrue from an increased awareness of the impact that nocturia imposes on patients, health services, and society as a whole

Field evidence for the influence of weathering on rock erodibility and channel form in bedrock rivers

Erosion processes in bedrock-floored rivers shape channel cross-sectional geometry and the broader landscape. However, the influence of weathering on channel slope and geometry is not well understood. Weathering can produce variation in rock erodibility within channel cross-sections. Recent numerical modeling results suggest that weathering may preferentially weaken rock on channel banks relative to the thalweg, strongly influencing channel form. Here, we present the first quantitative field study of differential weathering across channel cross-sections. We hypothesize that average cross-section erosion rate controls the magnitude of this contrast in weathering between the banks and the thalweg. Erosion rate, in turn, is moderated by the extent to which weathering processes increase bedrock erodibility. We test these hypotheses on tributaries to the Potomac River, Virginia, with inferred erosion rates from similar to 0.1m/kyr to \u3e0.8m/kyr, with higher rates in knickpoints spawned by the migratory Great Falls knickzone. We selected nine channel cross-sections on three tributaries spanning the full range of erosion rates, and at multiple flow heights we measured (1) rock compressive strength using a Schmidt hammer, (2) rock surface roughness using a contour gage combined with automated photograph analysis, and (3) crack density (crack length/area) at three cross-sections on one channel. All cross-sections showed significant (

Characterization of mouse neuro-urological dynamics in a novel decerebrate arterially perfused mouse (DAPM) preparation

Aim: To develop the decerebrate arterially perfused mouse (DAPM) preparation, a novel voiding model of the lower urinary tract (LUT) that enables in vitro-like access with in vivo-like neural connectivity. Methods: Adult male mice were decerebrated and arterially perfused with a carbogenated, Ringer’s solution to establish the DAPM. To allow distinction between central and peripheral actions of interventions, experiments were conducted in both the DAPM and in a “pithed” DAPM which has no brainstem or spinal cord control. Results: Functional micturition cycles were observed in response to bladder filling. During each void, the bladder showed strong contractions and the external urethral sphincter (EUS) showed bursting activity. Both the frequency and amplitude of non-voiding contractions (NVCs) in DAPM and putative micromotions (pMM) in pithed DAPM increased with bladder filling. Vasopressin (>400 pM) caused dyssynergy of the LUT resulting in retention in DAPM as it increased tonic EUS activity and basal bladder pressure in a dose-dependent manner (basal pressure increase also noted in pithed DAPM). Both neuromuscular blockade (vecuronium) and autonomic ganglion blockade (hexamethonium), initially caused incomplete voiding, and both drugs eventually stopped voiding in DAPM. Intravesical acetic acid (0.2%) decreased the micturition interval. Recordings from the pelvic nerve in the pithed DAPM showed bladder distention-induced activity in the non-noxious range which was associated with pMM. Conclusions: This study demonstrates the utility of the DAPM which allows a detailed characterization of LUT function in mice

Developing new ways to assess neural control of pelvic organ function in spinal conditions: ICI-RS 2023

Objectives: Several central nervous system (CNS) centers affect muscle groups of the lower urinary tract (LUT) and anorectal tract (ART) via autonomic and somatic pathways, working in different modes (storage or expulsion). Hence spinal cord dysfunction can affect the LUT and ART by several possible mechanisms. Methods: This review reports the discussions of a workshop at the 2023 meeting of the International Consultation on Incontinence Research Society, which reviewed uncertainties and research priorities of spinal dysfunction. Results: Discussion focussed on the levator ani nerve, mechanisms underpinning sensory function and sensation, functional imaging, dyssynergia, and experimental models. The following key research questions were identified. (1) Clinically, how can we evaluate the levator ani muscle to support assessment and identify prognosis for effective treatment selection? (2) How can we reliably measure levator ani tone? (3) How can we evaluate sensory information and sensation for the LUT and the ART? (4) What is the role of functional CNS imaging in development of scientific insights and clinical evaluation? (5) What is the relationship of detrusor sphincter dyssynergia to renal failure? Conclusions: Spinal cord dysfunction can fundamentally disrupt LUT and ART function, with considerable clinical impact. The evaluation needs to reflect the full scope of potential problems, and new clinical and diagnostic approaches are needed, for prognosis and treatment. The preclinical science evaluating spinal cord function in both LUT and ART storage and elimination remains a major priority, even though it is a challenging experimental context. Without this underpinning evidence, development of new clinical evidence may be held back

Stimulation of the Tibial nerve Repetitively to Improve Incontinence in Parkinson's Electronically (STRIPE trial): a randomised control trial of tibial nerve stimulation for bladder symptoms in Parkinson's disease using a self-contained wearable device

Background Bladder symptoms are common in Parkinson’s disease (PD), affecting half of all individuals. These have significant impact on quality of life as well as implications for morbidity, contributing to falls and hospital admission. The treatment of bladder symptoms can be complicated by the tendency to side-effects in people with PD including cognitive impairment and gait instability with anti-muscarinics. The development of new, better treatments is therefore warranted. Tibial nerve stimulation is a form of neuromodulation demonstrated to improve overactive bladder symptoms in non-neurogenic cohorts. Previously requiring hospital attendance, we aim to explore the use of this intervention using a simple device that can be used by patients at home. Methods STRIPE is a phase II randomised control trial of tibial nerve stimulation delivered by the Geko™ device, a small, self-adhesive neuromuscular stimulation device currently used for thromboembolism prophylaxis post-surgery. Active tibial nerve stimulation will be compared to sham stimulation, with participants blinded to treatment allocation and undertaking outcome assessment whilst still blinded. Participants will be asked to self-administer stimulation at home twice per week, for 30 min per session, over the course of 3 months. Primary outcome measure will be the International Consultation on Incontinence Overactive Bladder Questionnaire (OAB) at week 12. Secondary outcomes will include pre- and post-intervention bladder diary (frequency, urgency episodes, nocturia), patient perception of global change, bowel function and bladder-related quality of life. Participants will be recruited from the Proactive Integrated Management and Empowerment (PRIME) cross-sectional trial in which participants have been screened for bladder symptoms and invited to take part, as well as clinician referral from around the region. Discussion This trial will involve a randomised control trial of a novel and easy to use method of delivering tibial nerve stimulation for PD in the patient’s own home. This may potentially have huge benefit, avoiding the problems with side effects that can be seen with anti-muscarinics and providing a new potential modality of treatment. Trial registration ISRCTN11484954. Registered on 22 June 2021