Mapping of bionic array electric field focusing in plasmid DNA-based gene electrotransfer.

Molecular medicine through gene therapy is challenged to achieve targeted action. This is now possible utilizing bionic electrode arrays for focal delivery of naked (plasmid) DNA via gene electrotransfer. Here, we establish the properties of array-based electroporation affecting targeted gene delivery. An array with eight 300 µm platinum ring electrodes configured as a cochlear implant bionic interface was used to transduce HEK293 cell monolayers with a plasmid-DNA green fluorescent protein (GFP) reporter gene construct. Electroporation parameters were pulse intensity, number, duration, separation and electrode configuration. The latter determined the shape of the electric fields, which were mapped using a voltage probe. Electrode array-based electroporation was found to require ~100 × lower applied voltages for cell transduction than conventional electroporation. This was found to be due to compression of the field lines orthogonal to the array. A circular area of GFP-positive cells was created when the electrodes were ganged together as four adjacent anodes and four cathodes, whereas alternating electrode polarity created a linear area of GFP-positive cells. The refinement of gene delivery parameters was validated in vivo in the guinea pig cochlea. These findings have significant clinical ramifications, where spatiotemporal control of gene expression can be predicted by manipulation of the electric field via current steering at a cellular level.

Mal de Debarquement Syndrome: a survey on subtypes, misdiagnoses, onset and associated psychological features.

INTRODUCTION: Mal de Debarquement Syndrome (MdDS) is a neurological condition typically characterized by a sensation of motion, that persists longer than a month following exposure to passive motion (e.g., cruise, flight, etc.). The most common form of MdDS is motion triggered (MT). However, recently it has been acknowledged that some patients develop typical MdDS symptoms without an apparent motion trigger. These cases are identified here as spontaneous or other onset (SO) MdDS. This study aimed to address similarities and differences between the MdDS subtypes. Diagnostic procedures were compared and extensive diagnostic guidelines were proposed. Second, potential triggers and associated psychological components of MdDS were revealed. METHODS: This was a retrospective online survey study for MT and SO MdDS patients. Participants were required to respond to a set of comprehensive questions regarding epidemiological details, as well as the diagnostic procedures and onset triggers. RESULTS: There were 370 patients who participated in the surveys. It is indicated that MdDS is often misdiagnosed; more so for the SO group. In addition to the apparent self-motion, both groups reported associated levels of stress, anxiety and depression. DISCUSSION: It appears at present that both MdDS subtypes are still poorly recognised. This was the first attempt to evaluate the diagnostic differences between MdDS subtypes and to propose a set of comprehensive diagnostic guidelines for both MdDS subtypes. In addition, the current research addressed that associated symptoms such as stress, anxiety and depression should also be considered when treating patients. We hope this study will help the medical community to broaden their awareness and diagnostic knowledge of this condition.

A model of the Ebola epidemics in West Africa incorporating age of infection.

A model of an Ebola epidemic is developed with infected individuals structured according to disease age. The transmission of the infection is tracked by disease age through an initial incubation (exposed) phase, followed by an infectious phase with variable transmission infectiousness. The removal of infected individuals is dependent on disease age, with three types of removal rates: (1) removal due to hospitalization (isolation), (2) removal due to mortality separate from hospitalization, and (3) removal due to recovery separate from hospitalization. The model is applied to the Ebola epidemics in Sierra Leone and Guinea. Model simulations indicate that successive stages of increased and earlier hospitalization of cases have resulted in mitigation of the epidemics.

Attachment theory, ageing and dementia: a review of the literature.

The following review draws together recent theoretical contributions and research findings highlighting the pertinence of attachment issues for older adults. Beginning with a brief overview of the principles of attachment theory, the paper proceeds to illustrate that attachment remains a key feature of relationships throughout the life cycle. Research findings suggest that past and present secure attachment relationships function as a protective resource in later life and preliminary studies highlight the continuing salience of parents as attachment figures for older adults. Particular attention is given to the significance of attachment theory in thinking about the subjective experiences of people with dementia, for whom unwilling separation and disruption of attachment bonds can be common themes. Research indicates the frequent occurrence of attachment behaviours and parent fixation amongst people with dementia living in residential care. Pre-morbid attachment style has been shown to interact with emotional and behavioural expression during the course of dementia. Clinical applications of attachment theory in dementia care are discussed and initial evidence for the effectiveness of Simulated Presence Therapy is provided. Methodological issues raised by the review are considered, together with suggestions for future research.

Attachment behaviours and parent fixation in people with dementia: the role of cognitive functioning and pre-morbid attachment style.

This study replicates and extends exploratory research into the occurrence of attachment behaviours and parent fixation amongst people with dementia. Relationships between cognitive functioning, pre-morbid attachment style, attachment behaviours and parent fixation were examined. Fifty-three people with dementia, living in residential or nursing homes, completed the Standardised Mini-Mental State Examination and were interviewed about their parents. A family member or friend rated pre-morbid attachment style and care staff made observations of attachment behaviour. Results indicated that parent fixation occurred more often in participants with lower levels of cognitive functioning. Parent fixation was not related to pre-morbid attachment style. The occurrence of overt attachment behaviour was inconsistently associated with both high and low levels of cognitive functioning, at different times of the day. Participants with an avoidant attachment style exhibited more overt attachment behaviour than participants with a secure attachment style. Findings are interpreted in terms of attachment theory and the clinical and research implications of the study are discussed.