Dextrin conjugation to colistin inhibits its toxicity, cellular uptake and acute kidney injury in vivo.

The acute kidney injury (AKI) and dose-limiting nephrotoxicity, which occurs in 20-60% of patients following systemic administration of colistin, represents a challenge in the effective treatment of multi-drug resistant Gram-negative infections. To reduce clinical toxicity of colistin and improve targeting to infected/inflamed tissues, we previously developed dextrin-colistin conjugates, whereby colistin is designed to be released by amylase-triggered degradation of dextrin in infected and inflamed tissues, after passive targeting by the enhanced permeability and retention effect. Whilst it was evident in vitro that polymer conjugation can reduce toxicity and prolong plasma half-life, without significant reduction in antimicrobial activity of colistin, it was unclear how dextrin conjugation would alter cellular uptake and localisation of colistin in renal tubular cells in vivo. We discovered that dextrin conjugation effectively reduced colistin's toxicity towards human kidney proximal tubular epithelial cells (HK-2) in vitro, which was mirrored by significantly less cellular uptake of Oregon Green (OG)-labelled dextrin-colistin conjugate, when compared to colistin. Using live-cell confocal imaging, we revealed localisation of both, free and dextrin-bound colistin in endolysosome compartments of HK-2 and NRK-52E cells. Using a murine AKI model, we demonstrated dextrin-colistin conjugation dramatically diminishes both proximal tubular injury and renal accumulation of colistin. These findings reveal new insight into the mechanism by which dextrin conjugation can overcome colistin's renal toxicity and show the potential of polymer conjugation to improve the side effect profile of nephrotoxic drugs.

Strabismus is more than a misalignment; a cross-sectional pilot study of HRQOL in Finnish strabismic adults referred to a university hospital.

PURPOSE: To evaluate associations between the health-related quality of life (HRQOL) and demographic, self-reported strabismus-related and orthoptic status variables in Finnish strabismic adults. METHODS: Participants (n = 137) of this study were adult patients who previously participated in the pilot study to translate and validate Adult Strabismus Questionnaire (AS-20) into Finnish. For this study, the participants' orthoptic status were collected among the previously obtained self-reported demographic and strabismus-related data. The refined AS-20 structure of 18 items and four subscales of self-perception, interaction, reading function and general function was used. Low scores on AS-20 indicate low HRQOL. The associations were evaluated with cross-tabulation and nonparametric methods of Mann-Whitney U and Kruskal-Wallis tests. Statistical significance was set at p < 0.05. RESULTS: Interaction subscale scores were the highest of all subscale scores among the participants. Age had an association with HRQOL in self-perception and the youngest participants had the lowest scores. Importantly, participants who did not experience diplopia suffered from lower self-perception and interaction but reported higher scores on reading function and general function subscales compared to the participants who experienced diplopia. Exotropia with or without vertical strabismus were most common types among the participants. The education background was not associated with HRQOL. CONCLUSION: Impacts of strabismus are similar in Finnish strabismic adults compared to international studies. Healthcare professionals and decision-makers should always consider the psychosocial impact of strabismus on patients without diplopia when making decisions on strabismus treatment and care processes.

"INTEGRO INTEGRated Psychotherapeutic InterventiOn" on the Management of Chronic Pain in Patients with Fibromyalgia: The Role of the Therapeutic Relationship.

Fibromyalgia (FM) is a chronic disease characterized by a heterogeneous set of physical and psychological conditions. The chronic experience of disability felt by patients and the impact on quality of life (QoL) of the disease may worsen the cognitive reappraisal ability and contribute to maintaining an altered pain modulation mechanism. This paper presents the study protocol of an INTEGRated psychotherapeutic interventiOn on the management of chronic pain in patients with fibromyalgia (INTEGRO). The aim of the study is to investigate the efficacy of an integrated psychotherapeutic intervention focused on pain management on QoL and pain perception, in a pilot sample of 45 FM patients with idiopathic chronic pain. The contribution of perceived therapeutic relationship (alliance) and physiological attunement, in both the patient and therapist, will be considered as possible mediators of intervention efficacy. Attachment dimensions, traumatic experiences, difficulties in emotion regulation, mindfulness attitude and psychophysiological profile will also be considered as covariates. The objectives are to evaluate longitudinally if patients will experience an increase in QoL perception (primary endpoint), pain-managing self-efficacy and emotion-regulation abilities as well as a reduction in pain intensity (secondary endpoints), considering the mediating role of perceived therapeutic alliance and physiological attunement in both the patient and therapist.

Health-Related Quality of Life in Adult Patients with Strabismus-Translation and Psychometric Testing of the Adult Strabismus Questionnaire (AS-20) into Finnish.

(1) Strabismus has an impact on individuals' health-related quality of life. The impact should be assessed with valid patient-reported outcome measures such as the Adult Strabismus Questionnaire (AS-20). The AS-20 was further refined using a Rasch analysis for the American population. The aims of the study were to translate and culturally adapt the AS-20 into Finnish and to evaluate the psychometric properties of the Finnish AS-20. (2) The guidelines of the Professional Society for Health Economics and Outcomes Research steered the process and four items were added from the original data as Finnish additions. The construct and convergent validity and internal consistency were evaluated via psychometric testing for three potential Finnish AS-20 structures. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was applied. (3) The participants (n = 137) reported that the translation was clear and understandable. All structures showed high reliability and internal consistency as measured using Cronbach alpha values. The convergent validity assessed using Spearman's correlation coefficients between the structures and one item of Satisfaction with Life Scale indicated very low to moderate positive correlations. The construct validity evaluated using a confirmatory factor analysis revealed the refined AS-20 structure to be satisfactory. (4) The refined AS-20 can be used in clinical practice and research, but further validation is recommended.

Histopathology reporting for personalised medicine: focus on clinical utility.

Histopathology guidelines generally focus on standardised collection of data items to facilitate completeness and reproducibility of histopathology reporting. A data item is categorised as either core (mandatory) or non-core (recommended but not mandatory), irrespective of the clinical scenario. However, a data item that is critical for patient management in one clinical setting may have little clinical significance in another setting. A diagnosis of limited extent Gleason score 3+3=6 prostate cancer is critical in a patient being investigated for raised serum prostate-specific antigen but would be clinically irrelevant in a repeat biopsy from a patient on an active surveillance protocol. We outline an alternative approach that is focused on the clinical utility of the data items and the requirements of personalised medicine. While all core data items are required to be reported, understanding how these parameters are used to guide patient management will enable pathologists to focus time and resources on the critical aspects of an individual case. Detailed immunohistochemical workup and obtaining a second opinion would not be necessary if resolution of the differential diagnosis is of limited clinical significance. We also highlight some challenges encountered when adopting this approach and suggest some solutions that could positively impact histopathology reporting and patient care.

Mutations That Affect the Surface Expression of TRPV6 Are Associated with the Upregulation of Serine Proteases in the Placenta of an Infant.

Recently, we reported a case of an infant with neonatal severe under-mineralizing skeletal dysplasia caused by mutations within both alleles of the TRPV6 gene. One mutation results in an in frame stop codon (R510stop) that leads to a truncated, nonfunctional TRPV6 channel, and the second in a point mutation (G660R) that, surprisingly, does not affect the Ca2+ permeability of TRPV6. We mimicked the subunit composition of the unaffected heterozygous parent and child by coexpressing the TRPV6 G660R and R510stop mutants and combinations with wild type TRPV6. We show that both the G660R and R510stop mutant subunits are expressed and result in decreased calcium uptake, which is the result of the reduced abundancy of functional TRPV6 channels within the plasma membrane. We compared the proteomic profiles of a healthy placenta with that of the diseased infant and detected, exclusively in the latter two proteases, HTRA1 and cathepsin G. Our results implicate that the combination of the two mutant TRPV6 subunits, which are expressed in the placenta of the diseased child, is responsible for the decreased calcium uptake, which could explain the skeletal dysplasia. In addition, placental calcium deficiency also appears to be associated with an increase in the expression of proteases.

A critical re-analysis of cases of post-transplantation recurrence in genetic nephrotic syndrome.

BACKGROUND: Genetic defects in podocyte proteins account for up to 30% of steroid-resistant nephrotic syndrome (SRNS) in the paediatric population. Most children with genetic SRNS are resistant to immunosuppression and at high risk of progression to stage 5 chronic kidney disease. Kidney transplantation is often the treatment of choice. The possibility of post-transplantation disease recurrence in genetic SRNS remains controversial, and poses fundamental questions about disease biology. METHODS: We critically evaluated the published cases of post-transplantation recurrence in genetic patients, particularly testing 'mutations' against the most recent population variant databases, in order to clarify the diagnoses, and compare the clinical courses and responses to therapy. RESULTS: Biallelic pathogenic variants in NPHS1 leading to a complete absence of nephrin were the most commonly reported and best understood instance of nephrotic syndrome occurring post-transplantation. This is an immune-mediated process driven by antibody production against the novel nephrin protein in the allograft. We also identified a number of plausible reported cases of post-transplantation recurrence involving pathogenic variants in NPHS2 (8 patients, biallelic), one in WT1 (monoallelic) and one in NUP93 (biallelic). However, the mechanism for recurrence in these cases remains unclear. Other instances of recurrence in genetic disease were difficult to interpret due to differing clinical criteria, inclusion of patients without true pathogenic variants or the influence of other factors on renal outcome. CONCLUSIONS: Overall, post-transplantation recurrence remains very rare in patients with genetic SRNS. It appears to occur later after transplantation than in other patients and usually responds well to plasmapheresis with a good renal outcome.

Response to First Course of Intensified Immunosuppression in Genetically Stratified Steroid Resistant Nephrotic Syndrome.

BACKGROUND AND OBJECTIVES: Intensified immunosuppression in steroid-resistant nephrotic syndrome is broadly applied, with disparate outcomes. This review of patients from the United Kingdom National Study of Nephrotic Syndrome cohort aimed to improve disease stratification by determining, in comprehensively genetically screened patients with steroid-resistant nephrotic syndrome, if there is an association between response to initial intensified immunosuppression and disease progression and/or post-transplant recurrence. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Pediatric patients with steroid-resistant nephrotic syndrome were recruited via the UK National Registry of Rare Kidney Diseases. All patients were whole-genome sequenced, whole-exome sequenced, or steroid-resistant nephrotic syndrome gene-panel sequenced. Complete response or partial response within 6 months of starting intensified immunosuppression was ascertained using laboratory data. Response to intensified immunosuppression and outcomes were analyzed according to genetic testing results, pattern of steroid resistance, and first biopsy findings. RESULTS: Of 271 patients, 178 (92 males, median onset age 4.7 years) received intensified immunosuppression with response available. A total of 4% of patients with monogenic disease showed complete response, compared with 25% of genetic-testing-negative patients (P=0.02). None of the former recurred post-transplantation. In genetic-testing-negative patients, 97% with complete response to first intensified immunosuppression did not progress, whereas 44% of nonresponders developed kidney failure with 73% recurrence post-transplant. Secondary steroid resistance had a higher complete response rate than primary/presumed resistance (43% versus 23%; P=0.001). The highest complete response rate in secondary steroid resistance was to rituximab (64%). Biopsy results showed no correlation with intensified immunosuppression response or outcome. CONCLUSIONS: Patients with monogenic steroid-resistant nephrotic syndrome had a poor therapeutic response and no post-transplant recurrence. In genetic-testing-negative patients, there was an association between response to first intensified immunosuppression and long-term outcome. Patients with complete response rarely progressed to kidney failure, whereas nonresponders had poor kidney survival and a high post-transplant recurrence rate. Patients with secondary steroid resistance were more likely to respond, particularly to rituximab.

Post-mortem histology in transient receptor potential cation channel subfamily V member 6 (TRPV6) under-mineralising skeletal dysplasia suggests postnatal skeletal recovery: a case report.

BACKGROUND: The calcium-selective channel TRPV6 (transient receptor potential cation channel subfamily V member 6) is crucial for maternal-fetal calcium transport across the placenta. TRPV6 mutations have recently been associated with an antenatally severe under-mineralising skeletal dysplasia accompanied by postnatal biochemical abnormalities. This is the first post-mortem report in a patient with TRPV6 skeletal dysplasia. CASE PRESENTATION: The female infant had severe antenatal and postnatal skeletal abnormalities by 20 weeks gestation and was ventilator-dependent from birth. These skeletal abnormalities were apparent at an earlier gestational age than in previous reported cases and a more severe clinical course ensued. Biochemical and skeletal abnormalities, including bone density, improved postnatally but cardiac arrest at 4 months of age led to withdrawal of intensive care. Compound heterozygous TRPV6 variants (c.1978G > C p.(Gly660Arg) and c.1528C > T p.(Arg510Ter)) were identified on exome sequencing. Post-mortem identified skeletal abnormalities but no specific abnormalities in other organ systems. No placental pathology was found, multi-organ histological features reflected prolonged intensive care only. Post-mortem macroscopic examination indicated reduced thoracic size and short, pale and pliable ribs. Histological examination identified reduced number of trabeculae in the diaphyses (away from the growth plates), whereas metaphyses showed adequate mineralisation and normal number of trabeculae, but with slightly enlarged reactive chondrocytes, indicating post-natal skeletal growth recovery. Post-mortem radiological findings demonstrated improved bone density, improved rib width, healed fractures, although ribs were still shorter than normal. Long bones (especially humerus and femur) had improved from initial poorly defined metaphyses and reduced bone density to sharply defined metaphyses, prominent growth restart lines in distal diaphyses and bone-in-bone appearance along diaphyses. CONCLUSIONS: This case provide bone histological confirmation that human skeletal development is compromised in the presence of TRPV6 pathogenic variants. Post-mortem findings were consistent with abnormal in utero skeletal mineralisation due to severe calcium deficit from compromised placental calcium transfer, followed by subsequent phenotypic improvement with adequate postnatal calcium availability. Significant skeletal recovery occurs in the early weeks of postnatal life in TRPV6 skeletal dysplasia.

Synthesis of montbretin A analogues yields potent competitive inhibitors of human pancreatic α-amylase.

Simplified analogues of the potent human amylase inhibitor montbretin A were synthesised and shown to bind tightly, K I = 60 and 70 nM, with improved specificity over medically relevant glycosidases, making them promising candidates for controlling blood glucose. Crystallographic analysis confirmed similar binding modes and identified new active site interactions.

Qualitative Exploration of Illness Perceptions of Rheumatoid Arthritis in the General Public.

Treating patients with rheumatoid arthritis (RA) within three months of symptom onset leads to significantly improved outcomes. However, many people delay seeking medical attention. In order to understand the reasons for this delay, it is important to have a thorough understanding of public perceptions about RA. The current study investigated these perceptions using the Self-Regulation Model (SRM) as a framework to explain how health behaviour is influenced by illness perceptions (prototypes) through qualitative interviews with 15 members of the public without RA. Interviews were audio-recorded, transcribed and analysed using framework analysis based on SRM illness perceptions. Both accurate and inaccurate perceptions about the identity, causes, consequences, controllability and timeline of RA were identified. This highlights opportunities to enhance public knowledge about RA. These findings further support the utility of exploring prototypical beliefs of illness, suggesting their potential role in influencing help-seeking behaviours and identifying probable drivers/barriers to early presentation. © 2016 The Authors Musculoskeletal Care Published by John Wiley & Sons Ltd.

Family factors and health behaviour of thin adolescent boys and girls.

AIM: The aim of this study was to examine prevalence of extreme thinness and thinness in adolescent boys and girls and to study associations between family factors, health behaviour and thinness in boys and girls. BACKGROUND: Extreme thinness carries high health risks. The family and health behavioural factors related to adolescent thinness have not been studied previously using a nationally representative data. DESIGN: This is a cross-sectional quantitative study. METHODS: The nationally representative data were obtained from the Finnish School Health Promotion study conducted in 2013. The sample of this study included 12-17 year old adolescents (n = 71,973) who were categorised as extremely thin, thin and normal weight using international age and gender body mass index (BMI) cut-off points for children and adolescents. Associations with family factors and health behaviour were examined separately for boys and girls using cross-tabulations, Chi-square test and multinomial logistic regression. RESULTS: Thinness and extreme thinness were more common in girls than in boys. Health behaviour, such as smoking and exercise, were associated with thinness and extreme thinness in both genders. Regarding family factors; low maternal education, family meal and parental knowledge of adolescents' friends and whereabouts were associated with thinness and, or extreme thinness in both boys and girls. However, there were gender differences in the associations. CONCLUSIONS: It is important for healthcare professionals working with adolescents to be aware of prevalence in thinness and aware of health behaviour and family factors that are associated with thinness and extreme thinness in adolescence.

The 'mirror-image' postulate as a guide to the selection and evaluation of pyrrolidines as α-l-fucosidase inhibitors.

The ability of a series of pyrrolidines to inhibit several glycosidases was investigated. Using Fleet's 'mirror-image postulate', it was proposed that enantiomeric derivatives of 1,4-dideoxy-1,4-imino-d-lyxitol (a known α-d-galactosidase inhibitor) would show inhibitory activity against α-l-fucosidases. Some modest α-l-fucosidase inhibitory activity was observed for selected compounds (particularly an aminomethyl pyrrolidine) and it was proposed that better activity could be obtained by modifying the C-2 side chain of the pyrrolidine core. The d-galacto carbamate scaffold also exhibited somewhat selective, albeit modest, α-l-fucosidase inhibitory activity and may prove to be an interesting scaffold for further development.

Low sperm counts in genitourinary medicine clinic attendees: results from a case-control study.

OBJECTIVES: To conduct a case-control study of abnormalities in the semen of genitourinary (GU) medicine clinic attendees compared with general practice (GP) controls and in patients with asymptomatic and symptomatic non-specific urethritis (NSU) before and after the urethritis resolves. METHODS: Rates of semen abnormalities were compared between the different groups (19 with symptomatic and 27 with asymptomatic NSU, seven with symptomatic non-NSU and 64 clinic controls) and between clinic attendees and 417 patients attending GP for the first investigation of possible infertility. Those with symptomatic or asymptomatic NSU gave repeat semen samples on resolution of the NSU. RESULTS: The study included 117 clinic volunteers. They were shown to have statistically significantly worse total sperm counts (p=0.002), volume of semen (p<0.001) and percentage of abnormal forms (p<0.04) compared with 417 GP controls. Compared with the rest of the clinic volunteers, asymptomatic NSU patients had statistically significantly lower total sperm counts (p<0.02). Asymptomatic NSU patients had statistically significantly lower total sperm counts compared with symptomatic NSU patients (p<0.02). Compared with GP controls, clinic controls had statistically significantly inferior total sperm counts (p=0.009) and semen volume (p<0.001). CONCLUSIONS: GU clinic attendees are more likely to have abnormalities of semen than patients attending GP for the first check for possible infertility. A high rate of abnormal semen findings are found in patients with and without NSU but the highest rate occurred in those with asymptomatic NSU. Is asymptomatic NSU therefore pathogenic and does it require treatment like symptomatic NSU?

I(2)-mediated carbamate annulation: scope and application in the synthesis of azasugars.

The I(2)-mediated carbamate annulation provides an efficient and highly stereoselective route for the synthesis of a variety of pyrrolidines and piperidines, both in the presence and absence of protecting groups. Evidence for the formation of an iodoamine intermediate during the annulation is provided and, for the first time, we explore possible mechanisms of the annulation. The high cis-selectivity of the carbamate annulation is also compared to other N-halocyclisations and aminomercurations and some general conclusions about the diastereoselectivity of these types of reactions are made.

Stereoselective total synthesis of aminoiminohexitols via carbamate annulation.

New methodology for the preparation of a variety of aminoiminohextitols is described. Key in the synthesis is the application of a diastereoselective Strecker reaction and the extension of our carbamate annulation methodology to protected and functionalized alkenylamines. Insight into the effects that the substitution patterns of the alkenylamines have on the diastereoselectivity of the iodocyclization and carbamate annulation is discussed. An evaluation of the glycosidase inhibitory activity of the aminoiminohexitols and derivatives is also presented, with the previously undisclosed D-talo isomer showing good selective inhibition of ß-D-glucosidase.

Interaction between the biological effects of high- and low-LET radiation dose components in a mixed field exposure.

PURPOSE: The relative biological effectiveness of two epithermal neutron sources, a reactor based source at Studsvik, Sweden, and a proton accelerator-based source in Birmingham, UK, was studied in relation to the proportional absorbed dose distribution as a function of neutron energy. Evidence for any interactions between the effects of biological damage induced by high- and low-linear energy transfer (LET) dose components, in this 'mixed field' irradiation, was also examined MATERIALS AND METHODS: Clonogenic survival in Chinese Hamster-derived V79 cells was used to assess biological effectiveness in this study. Cells were irradiated in suspension at 4 °C at depths of 20, 35, 50 and 65 mm in a water phantom. This prevented the repair of sublethal damage, predominantly that produced by both incident and induced γ-rays in the field, over the variable periods of exposure required to irradiate cells with the same total absorbed dose. Cell survival, as a function of the absorbed radiation dose and depth in the phantom, was compared with Monte Carlo N-Particle (MCNP) calculations of the proportional absorbed dose distribution as a function of neutron energy for the two sources. RESULTS: In terms of the dose-related reduction in clonogenic cell survival, the epithermal neutron source at Studsvik was more biologically effective than the Birmingham source at all depths considered in the phantom. Although the contribution from the high-LET dose component was greater for the Studsvik source at 20 mm depth in the phantom, at greater depths the dose contribution from the high-LET dose component at Studsvik overlap with those for the Birmingham source. However, the most striking difference is in the fast neutron component to the dose of the two sources, neutron energies>1 MeV were only associated with the Studsvik source. The relative biological effectiveness (RBE) of both sources declined slightly with depth in the phantom, as the total high-LET dose component declined. The maximum source RBE for Studsvik was 2.70±0.50 at 20 mm; reduced to 2.10±0.35 at depths of 50 and 65 mm. The corresponding values for Birmingham were 1.68±0.25 and 1.31±0.19, all values relate only to the surviving fraction of V79 cells at 37%, since RBE values are only applicable to the selected endpoint. Based on a dose reduction factor (DRF) of 1.0 for the total low-LET component to the absorbed dose, the RBE values for the high-LET dose component (fast neutrons and induced protons from the nitrogen capture reaction) was 14.5 and 7.05 for the Studsvik and Birmingham neutron sources, respectively. This is well outside the range of RBE historically reported values for V79 cells for the same level of cell survival for fast neutrons. The calculation of RBE values, based on the proportional absorbed dose distribution as a function of neutron energy, from historical data, and using a RBE of 1.8 for the dose from the nitrogen capture reaction, suggests RBE values for the total high-LET dose component of 3.1-2.8 and 2.5-2.0 for Studsvik and Birmingham, respectively, values again declining with depth in the phantom. CONCLUSIONS: The overall biological effectiveness of the mixed field irradiation from an epithermal neutron sources depends on the composition and quality of the different dose components. The experimentally derived RBE values for the total high-LET dose components in these 'mixed field' irradiations are well in excess of historical data for fast neutrons. The difference between the historically expected and the observed RBE values is attributed to the interactions between the damage produced by high- and low-LET radiation.

Protecting-group-free synthesis of amines: synthesis of primary amines from aldehydes via reductive amination.

New methodology for the protecting-group-free synthesis of primary amines is presented. By optimizing the metal hydride/ammonia mediated reductive amination of aldehydes and hemiacetals, primary amines were selectively prepared with no or minimal formation of the usual secondary and tertiary amine byproduct. The methodology was performed on a range of functionalized aldehyde substrates, including in situ formed aldehydes from a Vasella reaction. These reductive amination conditions provide a valuable synthetic tool for the selective production of primary amines in fewer steps, in good yields, and without the use of protecting groups.