Monitoring Base Specific Dynamics during Melting of DNA-Ligand Complexes using Temperature-Jump Time-Resolved Infrared Spectroscopy

Ultrafast time-resolved infrared spectroscopy employing nanosecond temperature-jump initiation has been used to study the melting of double-stranded (ds)DNA oligomers in the presence and absence of minor groove-binding ligand Hoechst 33258. Ligand binding to ds(5′-GCAAATTTCC-3′), which binds Hoechst 33258 in the central A-tract region with nanomolar affinity, causes a dramatic increase in the timescales for strand melting from 30 to 250 μs. Ligand binding also suppresses premelting disruption of the dsDNA structure, which takes place on 100 ns timescales and includes end-fraying. In contrast, ligand binding to the ds(5′-GCATATATCC-3′) sequence, which exhibits an order of magnitude lower affinity for Hoechst 33258 than the A-tract motif, leads to an increase by only a factor of 5 in melting timescales and reduced suppression of premelting sequence perturbation and end-fraying. These results demonstrate a dynamic impact of the minor groove ligand on the dsDNA structure that correlates with binding strength and thermodynamic stabilization of the duplex. Moreover, the ability of the ligand to influence base pairs distant from the binding site has potential implications for allosteric communication mechanisms in dsDNA

Parents’ experiences of health visiting for children with Down syndrome

© MA Healthcare Limited.Children with Down syndrome have an increased likelihoodof experiencing serious health conditions. Health visitors canhave an important role in monitoring and promoting healthand development for young children with Down syndrome.This study aimed to explore parents’ experiences of healthvisiting services for children with Down syndrome. Twentyfour parents of children with Down syndrome aged 0–5 yearscompleted a brief questionnaire about the number and natureof visits from health visitors in the previous 12 months andtheir support needs. Some parents commented that otherprofessionals met the needs of their child, whereas others saidthat they would like more advice and support from healthvisitors. A further exploration of broader health serviceprovision, including health visiting, for young children withDown syndrome is needed.Peer reviewedFinal Accepted Versio

Quantifying secondary structure changes in Calmodulin using 2D-IR spectroscopy

Revealing the details of biomolecular processes in solution needs tools that can monitor structural dynamics over a range of time and length scales. We assess the ability of 2D-IR spectroscopy in combination with multivariate data analysis to quantify changes in secondary structure of the multifunctional calcium-binding messenger protein Calmodulin (CaM) as a function of temperature and Ca2+ concentration. Our approach produced quantitative agreement with circular dichroism (CD) spectroscopy in detecting the domain melting transitions of Ca2+-free (apo) CaM (reduction in α-helix structure by 13% (CD) and 15% (2D)). 2D-IR also allows accurate differentiation between melting transitions and generic heating effects observed in the more thermally-stable Ca2+-bound (holo-) CaM. The functionally-relevant random-coil-α-helix transition associated with Ca2+ uptake that involves just 7-8 out of a total of 148 amino acid residues was clearly detected. Temperature-dependent Molecular Dynamics (MD) simulations show that apo-CaM exists in dynamic equilibrium with holo-like conformations while Ca2+ uptake reduces conformational flexibility. The ability to combine quantitative structural insight from 2D-IR with MD simulations thus offers a powerful approach for measuring subtle protein conformational changes in solution

Impacts of caring for a child with the CDKL5 disorder on parental wellbeing and family quality of life

Background: Although research in this area remains sparse, raising a child with some genetic disorders has been shown to adversely impact maternal health and family quality of life. The aim of this study was to investigate such impacts in families with a child with the CDKL5 disorder, a newly recognised genetic disorder causing severe neurodevelopmental impairments and refractory epilepsy. Methods: Data were sourced from the International CDKL5 Disorder Database to which 192 families with a child with a pathogenic CDKL5 mutation had provided data by January 2016. The Short Form 12 Health Survey Version 2, yielding a Physical Component Summary and a Mental Component Summary score, was used to measure primary caregiver's wellbeing. The Beach Center Family Quality of Life Scale was used to measure family quality of life. Linear regression analyses were used to investigate relationships between child and family factors and the various subscale scores. Results: The median (range) age of the primary caregivers was 37.0 (24.6-63.7) years and of the children was 5.2 (0.2-34.1) years. The mean (SD) physical and mental component scores were 53.7 (8.6) and 41.9 (11.6), respectively. In mothers aged 25-54 years the mean mental but not the physical component score was lower than population norms. After covariate adjustment, caregivers with a tube-fed child had lower mean physical but higher mean mental component scores than those whose child fed orally (coefficient = -4.80 and 6.79; p = 0.009 and 0.012, respectively). Child sleep disturbances and financial hardship were negatively associated with the mental component score. The mean (SD) Beach Center Family Quality of Life score was 4.06 (0.66) and those who had used respite services had lower scores than those who had not across the subscales. Conclusions: Emotional wellbeing was considerably impaired in this caregiver population, and was particularly associated with increased severity of child sleep problems and family financial difficulties. Family quality of life was generally rated lowest in those using respite care extensively, suggesting that these families may be more burdened by daily caregiving

'Yeah that made a big difference!': The importance of the relationship between health professionals and fathers who have a child with Down Syndrome

Evidence suggests that medical services do not reflect the increased involvement of fathers in childcare, a discrepancy that can often lead to feelings of exclusion and inequality. Fathers who have a child with Down syndrome may encounter many different health professionals during their child’s life, therefore it is important to consider this relationship, and investigate the factors that influence their experiences. This is particularly important because the limited research focusing on fathers suggest that those who have a child with Down syndrome can experience increased stress levels and lasting feelings of loss and grief. It is therefore important to address their relationships with health professionals, as these may be a significant resource to prevent these feelings. This study used interpretative phenomenological analysis (IPA) to explore the experiences of seven fathers who have a child with Down syndrome, focusing on their interactions with health professionals. The analysis showed that the major factors associated with negative experiences were feelings of exclusion, receiving overly negative information about the condition and a perceived lack of on-going support. Positive experiences were associated with being made to feel like an equal parent, being given direct/clear information and being congratulated on the birth of their child. These results provide an insight into what fathers expect in terms of their own and their child’s care and highlight that health professionals have an important and extensive role in influencing fathers’ experiences of Down syndrome

The role of mother's prenatal substance use disorder and early parenting on child social cognition at school age

This prospective longitudinal study examined how maternal prenatal substance use disorder (SUD) and early mother-infant interaction quality are associated with child social cognition (emotion recognition and mentalization) at school age. A sample of 52 poly-substance-using mothers receiving early interventions and 50 non-users, along with their children, was followed from pregnancy to school age. First-year mother-infant interaction quality was measured with EA scales. At school age, child facial emotion recognition was measured with DANVA and mentalization with LEAS-C. SUD group children did not differ from comparison children in social cognition, but higher severity of maternal prenatal addiction predicted emotion recognition problems. High early mother-infant interaction quality predicted better emotion recognition and mentalization, and mother-infant interaction quality mediated the effect of prenatal SUD on emotion recognition. The results highlight the need for early treatments targeting both parenting and addiction, as well as long-term developmental support for these children. Highlights We examined how mother's prenatal substance use disorder (SUD) and early mother-infant interaction predict child social cognition at school age. Questionnaires, observational and computer tasks were used. Maternal prenatal addiction severity and early parenting problems predicted problematic child social cognition. Early interventions should simultaneously target addiction and parenting. Attention should also be paid to the long-term developmental support of children.Peer reviewe

Attitudes of social service providers towards the sexuality of individuals with intellectual disability

Background The sexual lives of people with intellectual disability is made complex by the involvement and influence of social service providers, whose beliefs and values have a great impact on the support they provide. We hypothesized that social service providers\u2019 role, educational level and service in which they worked could affect attitudes towards the sexual behaviour of individuals with intellectual disability. Materials and methods The current study describes attitudes of social service providers towards the sexuality of individuals with disability measured by 20 items of Sexuality and Mental Retardation Attitudes Inventory (SMRAI). This instrument was devised by Brantlinger [Mental Retardation (1983) Vol. 21, pp. 17\u201322] to assess the attitudes of the staff employed by organizations that supplied services to individuals with intellectual disability. Specifically, analysis of variance (type of service \ub7 professional role \ub7 education) was performed on participants\u2019 scores. Results Results suggested that the social service providers participating in this research study tended to have moderately liberal attitudes. Educational level and role carried out did not produce differences in their attitudes. A significant difference emerged between those who operated in different services. It was especially the staff of the outpatient treatment services who revealed the most liberal and positive attitudes towards the sexuality of individuals with intellectual disability. Conclusions The data reported in the present study seem to underline some differences between the data collected from the Italian and the Anglo-Saxon social service providers. Failure to record influences associated with the role carried out and previous training could be related to the different contextual differences. Results suggest that particular attention should be paid to the training of those who hold managerial posts in Italian residential services

Time-Resolved Temperature-Jump Infrared Spectroscopy at a High Repetition Rate

Time-resolved temperature-jump infrared absorption spectroscopy at a 0.5 to 1 kHz repetition rate is presented. A 1 kHz neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pumping an optical parametric oscillator provided >70 µJ, 3.75 µm pump pulses, which delivered a temperature jump via excitation of the O-D stretch of a D2O solution. A 10 kHz train of mid-infrared probe pulses was used to monitor spectral changes following the temperature jump. Calibration with trifluoroacetic acid solution showed that a temperature jump of 10 K lasting for tens of microseconds was achieved, sufficient to observe fast processes in functionally relevant biomolecular mechanisms. Modeling of heating profiles across ≤10 µm path length cells and subsequent cooling dynamics are used to describe the initial 10 µs cooling dynamics of the bulk solution