Effectiveness of HealthTracker for post-caesarean section surgical site infection surveillance: An intervention study.

This intervention study aimed to implement and evaluate the effectiveness of HealthTracker, a post-discharge surgical site infection surveillance system. Participants were 730 women birthing by caesarean section at a large hospital over a 6-month period. Data were downloaded from clinical data systems and HealthTracker. Receiver operating characteristics were used to assess HealthTracker. Over a 6-month period, 382 women completed HealthTracker, with 83 scoring ≥6, indicating signs and symptoms of surgical site infection. Of this 83, 58 sought advice from health professionals, 29 returned to hospital, and 45 received antibiotics. A total of 20 infections from a total population of 730 were confirmed, with 14 out of 382 respondents confirmed via HealthTracker. Receiver operating characteristics identified HealthTracker as an excellent indicator of surgical site infection. HealthTracker is a feasible mHealth option for monitoring post-discharge surgical site infection post-caesarean section. In addition, by providing alerts, advising women to monitor their symptoms and seek treatment if necessary, HealthTracker has the potential to enhance self-efficacy for surgical wound monitoring at home.

Synthetic lethality of cytolytic HSV-1 in cancer cells with ATRX and PML deficiency.

Cancers that utilize the alternative lengthening of telomeres (ALT) mechanism for telomere maintenance are often difficult to treat and have a poor prognosis. They are also commonly deficient for expression of ATRX protein, a repressor of ALT activity, and a component of promyelocytic leukemia nuclear bodies (PML NBs) that are required for intrinsic immunity to various viruses. Here, we asked whether ATRX deficiency creates a vulnerability in ALT cancer cells that could be exploited for therapeutic purposes. We showed in a range of cell types that a mutant herpes simplex virus type 1 (HSV-1) lacking ICP0, a protein that degrades PML NB components including ATRX, was ten- to one thousand-fold more effective in infecting ATRX-deficient cells than wild-type ATRX-expressing cells. Infection of co-cultured primary and ATRX-deficient cancer cells revealed that mutant HSV-1 selectively killed ATRX-deficient cells. Sensitivity to mutant HSV-1 infection also correlated inversely with PML protein levels, and we showed that ATRX upregulates PML expression at both the transcriptional and post-transcriptional levels. These data provide a basis for predicting, based on ATRX or PML levels, which tumors will respond to a selective oncolytic herpesvirus.

Telomere sequence content can be used to determine ALT activity in tumours.

The replicative immortality of human cancer cells is achieved by activation of a telomere maintenance mechanism (TMM). To achieve this, cancer cells utilise either the enzyme telomerase, or the Alternative Lengthening of Telomeres (ALT) pathway. These distinct molecular pathways are incompletely understood with respect to activation and propagation, as well as their associations with clinical outcomes. We have identified significant differences in the telomere repeat composition of tumours that use ALT compared to tumours that do not. We then employed a machine learning approach to stratify tumours according to telomere repeat content with an accuracy of 91.6%. Importantly, this classification approach is applicable across all tumour types. Analysis of pathway mutations that were under-represented in ALT tumours, across 1,075 tumour samples, revealed that the autophagy, cell cycle control of chromosomal replication, and transcriptional regulatory network in embryonic stem cells pathways are involved in the survival of ALT tumours. Overall, our approach demonstrates that telomere sequence content can be used to stratify ALT activity in cancers, and begin to define the molecular pathways involved in ALT activation.

Automated classification and characterization of the mitotic spindle following knockdown of a mitosis-related protein.

BACKGROUND: Cell division (mitosis) results in the equal segregation of chromosomes between two daughter cells. The mitotic spindle plays a pivotal role in chromosome alignment and segregation during metaphase and anaphase. Structural or functional errors of this spindle can cause aneuploidy, a hallmark of many cancers. To investigate if a given protein associates with the mitotic spindle and regulates its assembly, stability, or function, fluorescence microscopy can be performed to determine if disruption of that protein induces phenotypes indicative of spindle dysfunction. Importantly, functional disruption of proteins with specific roles during mitosis can lead to cancer cell death by inducing mitotic insult. However, there is a lack of automated computational tools to detect and quantify the effects of such disruption on spindle integrity. RESULTS: We developed the image analysis software tool MatQuantify, which detects both large-scale and subtle structural changes in the spindle or DNA and can be used to statistically compare the effects of different treatments. MatQuantify can quantify various physical properties extracted from fluorescence microscopy images, such as area, lengths of various components, perimeter, eccentricity, fractal dimension, satellite objects and orientation. It can also measure textual properties including entropy, intensities and the standard deviation of intensities. Using MatQuantify, we studied the effect of knocking down the protein clathrin heavy chain (CHC) on the mitotic spindle. We analysed 217 microscopy images of untreated metaphase cells, 172 images of metaphase cells transfected with small interfering RNAs targeting the luciferase gene (as a negative control), and 230 images of metaphase cells depleted of CHC. Using the quantified data, we trained 23 supervised machine learning classification algorithms. The Support Vector Machine learning algorithm was the most accurate method (accuracy: 85.1%; area under the curve: 0.92) for classifying a spindle image. The Kruskal-Wallis and Tukey-Kramer tests demonstrated that solidity, compactness, eccentricity, extent, mean intensity and number of satellite objects (multipolar spindles) significantly differed between CHC-depleted cells and untreated/luciferase-knockdown cells. CONCLUSION: MatQuantify enables automated quantitative analysis of images of mitotic spindles. Using this tool, researchers can unambiguously test if disruption of a protein-of-interest changes metaphase spindle maintenance and thereby affects mitosis.

Correction of visual impairment by cataract surgery and improved survival in older persons: the Blue Mountains Eye Study cohort.

OBJECTIVE: We assessed whether correction of visual impairment (VI) by cataract surgery was associated with improved long-term survival in an older Australian population. DESIGN: Population-based cohort study. PARTICIPANTS: In the Blue Mountains Eye Study, 354 participants, aged ≥ 49 years, had both cataract and VI or had undergone cataract surgery before baseline examinations. They were subsequently examined after 5- and 10-year follow-ups. METHODS: Associations between the mortality risk and the surgical correction of VI (visual acuity [VA] <20/40, attributable to cataract) were assessed in Cox proportional hazard regression models, after multivariate adjustment, using time-dependent variables for the study factor. MAIN OUTCOME MEASURES: All-cause mortality. RESULTS: The 15-year crude mortality of participants who had undergone cataract surgery at baseline with no subsequent VI (71.8%) was relatively similar to that in participants with cataract-related VI who had not yet undergone surgery (79.4%). However, after adjusting for age and sex, participants who underwent cataract surgery before baseline or during follow-up and no longer had VI had significantly lower long-term mortality risk (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46-0.77) than participants with VI due to cataract who had not undergone cataract surgery. This lower mortality risk in the group with surgically corrected VI (HR, 0.54; 95% CI, 0.41-0.73) persisted after further adjustment for smoking, body mass index, home ownership, qualifications, poor self-rated health, the presence of poor mobility, hypertension, diabetes, self-reported history of angina, myocardial infarction, stroke, cancer, asthma, and arthritis. This finding remained significant (HR, 0.55; 95% CI, 0.41-0.73) after additional adjustment for the number of medications taken (continuous variable) and the number (≥ 5 vs. <5) of comorbid conditions (poor mobility, hypertension, diabetes, angina, myocardial infarction, stroke, cancer, asthma, or arthritis) as indicators of frailty. CONCLUSIONS: Surgical correction of VI due to cataract was associated with significantly better long-term survival of older persons after accounting for known cataract and mortality risk factors, and indicators of general health. Whether some uncontrolled factors (frailty or general health) could have influenced decisions not to perform cataract surgery in some participants is unknown. However, this finding strongly supports many previous reports linking VI with poor survival. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Does an electronic pathology ordering system change the volume and pattern of routine testing in hospital? An interrupted time series analysis.

AIMS: Identifying and reducing low-value care is a vital issue in Australia, with pathology test ordering a common focus in this field. This study builds on previous research and aimed to quantify the impact of the implementation of an electronic ordering (e-ordering) system on the volume of pathology testing, compared with manual (paper based) ordering. METHODS: An audit and analysis of pathology test data were conducted, using an interrupted time series design to investigate the impact of the e-ordering system on pathology ordering patterns. All medical and surgical adult inpatients at a tertiary referral hospital in Newcastle, Australia, were included over a 3-year period. RESULTS: Overall, there were no statistically significant differences in the volume of orders due to the implementation of the e-ordering system. There was a slight increase in the aggregated volume (tests per admission and tests per bed day) of tests ordered across the entire study period, reflecting a secular trend. CONCLUSIONS: Despite providing greater visibility and tracking of orders, we conclude that the implementation of an e-ordering system does not, in and of itself, reduce ordering volume. Efforts to identify and reduce low-value care will require intentional effort and specifically designed educational programmes or hard-wired algorithms.

Influence of physical activity and screen time on the retinal microvasculature in young children.

OBJECTIVE: It is not clear whether physical activity and sedentary behavior affect retinal microvascular caliber. We investigated associations among physical activity (outdoor and indoor sporting activities), sedentary behaviors (including screen time, television [TV] viewing, and computer and videogame usage), and retinal microvascular caliber in schoolchildren. METHODS AND RESULTS: Six-year-old students (1765/2238) from a random cluster sample of 34 Sydney schools were examined. Parents completed questionnaires about physical and sedentary activities. Retinal images were taken, and retinal vessel caliber was quantified. After adjusting for age, sex, ethnicity, eye color, axial length, body mass index, birth weight, and mean arterial blood pressure, children who spent more time in outdoor sporting activities (in the highest tertile of activity) had 2.2 µm (95% CI 0.65 to 3.71) wider mean retinal arteriolar caliber than those in the lowest tertile (Ptrend=0.004). Increasing quartiles of time spent watching TV were associated with narrower mean retinal arteriolar caliber≈2.3 µm (95% CI 0.73 to 3.92), Ptrend=0.003. CONCLUSIONS: These data suggest that physical activity could have a beneficial influence, whereas screen time has a potential adverse influence on retinal microvascular structure. The magnitude of arteriolar narrowing associated with each hour daily of TV viewing is similar to that associated with a 10-mm Hg increase in systolic blood pressure in children.

Severity of age-related hearing loss is associated with impaired activities of daily living.

BACKGROUND: age-related hearing loss is a common chronic condition; hence, it is important to understand its influence on the functional status of older adults. We assessed the association between hearing impairment with activity limitations as assessed by the activities of daily living (ADL) scale. METHODS: a total of 1,952 Blue Mountains Hearing Study participants aged ≥60 years had their hearing levels measured using pure-tone audiometry. A survey instrument with questions on functional status as determined by the Older Americans Resources and Services ADL scale was administered. RESULTS: one hundred and sixty-four (10.4%) participants reported ADL difficulty. A higher proportion of hearing impaired than non-impaired adults reported difficulties in performing three out of the seven basic ADL and six out of the seven instrumental ADL tasks. After multivariable adjustment, increased severity of hearing loss was associated with impaired ADL (P(trend )= 0.001). Subjects with moderate to severe hearing loss compared with those without, had a 2.9-fold increased likelihood of reporting difficulty in ADL, multivariate-adjusted odds ratio (OR): 2.87 [95% confidence interval (CI): 1.59-5.19]. Participants aged <75 years with hearing loss compared with those without, had 2-fold higher odds of impaired ADL. Having worn or wearing a hearing aid was also associated with a 2-fold increased likelihood of impaired ADL. CONCLUSION: functional status as measured by a common ADL scale is diminished in older hearing impaired adults. Our findings suggest that severely diminished hearing could make the difference between independence and the need for formal support services or placement.

Differentiation of brain and retinal organoids from confluent cultures of pluripotent stem cells connected by nerve-like axonal projections of optic origin.

Advances in the study of neurological conditions have been possible because of pluripotent stem cell technologies and organoids. Studies have described the generation of neural ectoderm-derived retinal and brain structures from pluripotent stem cells. However, the field is still troubled by technical challenges, including high culture costs and variability. Here, we describe a simple and economical protocol that reproducibly gives rise to the neural retina and cortical brain regions from confluent cultures of stem cells. The spontaneously generated cortical organoids are transcriptionally comparable with organoids generated by other methods. Furthermore, these organoids showed spontaneous functional network activity and proteomic analysis confirmed organoids maturity. The generation of retinal and brain organoids in close proximity enabled their mutual isolation. Suspension culture of this complex organoid system demonstrated the formation of nerve-like structures connecting retinal and brain organoids, which might facilitate the investigation of neurological diseases of the eye and brain.

Dietary intake of cholesterol is positively associated and use of cholesterol-lowering medication is negatively associated with prevalent age-related hearing loss.

We aimed to assess associations between dietary intake of fats (saturated and monounsaturated fats and cholesterol) and certain food groups (butter, margarine, and nuts) with the prevalence, incidence, and progression of age-related hearing loss. We also aimed to investigate the link between serum lipids and cholesterol-lowering medication (statins) and hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss. Hearing loss was measured in 2956 participants (aged ≥50 y) and was defined as the pure-tone average (PTA) of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level (PTA(0.5-4 kHz)). Dietary data were collected using a semiquantitative FFQ. After multivariable adjustment, the likelihood of prevalent hearing loss increased from the lowest (reference) to the highest quartile of dietary cholesterol intake (P-trend = 0.04). Among persons self-reporting statin use (n = 274), a 48% reduced odds of prevalent hearing loss was observed after multivariable adjustment [OR = 0.52 (95% CI = 0.29-0.93)]. Participants in the second and 3rd quartiles of dietary monounsaturated fat intake compared with those in the first quartile (reference) had a significantly reduced risk of hearing loss progression 5 y later [multivariable-adjusted OR = 0.39 (95% CI = 0.21-0.71)] and [OR = 0.51 (95% CI = 0.29-0.91)], respectively. Our results suggest that a diet high in cholesterol could have adverse influences on hearing, whereas treatment with statins and consumption of monounsaturated fats may have a beneficial influence.

Exposure to workplace noise and the risk of cardiovascular disease events and mortality among older adults.

BACKGROUND: We aimed to examine whether cross-sectional (prevalence) and longitudinal relationships (5-year incidence and 10-year mortality) exist between workplace noise exposure and cardiovascular diseases (CVD). METHODS: 2942 participants aged 55+years of the Blue Mountains Eye Study, Australia (1997-9 and 2002-4). Participants self-reported workplace noise exposure, hearing protector use and physician diagnosed CVD. CVD deaths were confirmed using the Australian National Death Index. RESULTS: 133 and 937 participants self-reported workplace noise exposure, and use or non-use of hearing protection devices, respectively. After multivariate adjustment, those who did not use hearing protection devices were 53% and 75% more likely to have prevalent CVD and angina, respectively, compared to those never exposed to workplace noise. Exposure to severe workplace noise for less than 1 to 5 years versus no exposure was associated with incident stroke OR 3.44 (95% CI 1.11-10.63). The mortality rate of CVD was 0.94% per year in people unexposed to workplace noise. Participants reporting less than 1 to 5 years versus those with no workplace noise exposure had a higher risk of CVD mortality, hazard ratio, HR, 1.60 (95% CI 1.10-2.33). DISCUSSION: These data highlight the public health impact of workplace noise exposure on the vascular health of older adults.

Smaller birth size is associated with narrower retinal arterioles in early adolescence.

OBJECTIVE: In the current study, we aimed to examine the associations of low birth weight with retinal vascular caliber and vascular fractal dimension during early adolescence. METHODS: A population-based study of 12-year-old schoolchildren (2353/3144 [75.3%]) recruited from a random cluster sample of 21 schools. Birth weight, birth length and head circumference were obtained via parent report of the child's birth record. Retinal images were taken and vessel diameter and fractal dimension were quantified using validated computer-based methods. RESULTS: After adjusting for age, sex, ethnicity, body mass index, iris color, axial length, mean arterial blood pressure, prematurity and fellow retinal vascular caliber, children in the lowest quartiles of birth weight had ∼2.5 µm narrower mean retinal arteriolar caliber than those in the highest quartiles (p for trend = 0.001). Associations were observed between shorter birth length and smaller head circumference with narrower retinal arterioles. Smaller head circumference was associated with decreased fractal dimension (p for trend = 0.03). CONCLUSIONS: Children with lower birth weight were more likely to have narrower retinal arterioles, while those with smaller head circumference were more likely to have reduced complexity of their retinal microvasculature. These variations in microvascular structure in adolescence could reflect a susceptibility to cardiovascular disease during adulthood, resulting from a disadvantaged growth environment in utero.

Comparison of automated candidate gene prediction systems using genes implicated in type 2 diabetes by genome-wide association studies.

BACKGROUND: Automated candidate gene prediction systems allow geneticists to hone in on disease genes more rapidly by identifying the most probable candidate genes linked to the disease phenotypes under investigation. Here we assessed the ability of eight different candidate gene prediction systems to predict disease genes in intervals previously associated with type 2 diabetes by benchmarking their performance against genes implicated by recent genome-wide association studies. RESULTS: Using a search space of 9556 genes, all but one of the systems pruned the genome in favour of genes associated with moderate to highly significant SNPs. Of the 11 genes associated with highly significant SNPs identified by the genome-wide association studies, eight were flagged as likely candidates by at least one of the prediction systems. A list of candidates produced by a previous consensus approach did not match any of the genes implicated by 706 moderate to highly significant SNPs flagged by the genome-wide association studies. We prioritized genes associated with medium significance SNPs. CONCLUSION: The study appraises the relative success of several candidate gene prediction systems against independent genetic data. Even when confronted with challengingly large intervals, the candidate gene prediction systems can successfully select likely disease genes. Furthermore, they can be used to filter statistically less-well-supported genetic data to select more likely candidates. We suggest consensus approaches fail because they penalize novel predictions made from independent underlying databases. To realize their full potential further work needs to be done on prioritization and annotation of genes.

A Signature of Attention-Elicited Electrocortical Activity Distinguishes Response From Non-Response to the Non-Stimulant Atomoxetine in Children and Adolescents With ADHD.

OBJECTIVE: Atomoxetine has several characteristics that make it an attractive alternative to stimulants for treating ADHD, but there are currently no tests identifying individuals for whom the medication should be a first-line option. METHOD: Within the ADHD Controlled Trial Investigation Of a Non-stimulant (ACTION) study, we examined neuro-cortical activity in 52 youth with ADHD. Baseline event-related potentials (ERP) were compared between those who subsequently responded to 6 weeks of atomoxetine versus those who did not. RESULTS: Responders were distinguished by significantly lower auditory oddball N2 amplitudes than both non-responders and typically developing controls, particularly in the right frontocentral region ( p = .002, Cohen's d = 1.1). Leave-one-out cross validation determined that N2 amplitude in this region was able to accurately predict non-responders with a specificity of 80.8%. There were no P3 differences between responders and non-responders. CONCLUSION: The N2 amplitude is a biomarker that may have utility in predicting response to atomoxetine for youth with ADHD.

Telomerase promotes formation of a telomere protective complex in cancer cells.

Telomerase is a ribonucleoprotein complex that catalyzes addition of telomeric DNA repeats to maintain telomeres in replicating cells. Here, we demonstrate that the telomerase protein hTERT performs an additional role at telomeres that is independent of telomerase catalytic activity yet essential for telomere integrity and cell proliferation. Short-term depletion of endogenous hTERT reduced the levels of heat shock protein 70 (Hsp70-1) and the telomere protective protein Apollo at telomeres, and induced telomere deprotection and cell cycle arrest, in the absence of telomere shortening. Short-term expression of hTERT promoted colocalization of Hsp70-1 with telomeres and Apollo and reduced numbers of deprotected telomeres, in a manner independent of telomerase catalytic activity. These data reveal a previously unidentified noncanonical function of hTERT that promotes formation of a telomere protective complex containing Hsp70-1 and Apollo and is essential for sustained proliferation of telomerase-positive cancer cells, likely contributing to the known cancer-promoting effects of both hTERT and Hsp70-1.

Limiting Thymic Precursor Supply Increases the Risk of Lymphoid Malignancy in Murine X-Linked Severe Combined Immunodeficiency.

In early gene therapy trials for SCID-X1, using γ-retroviral vectors, T cell leukemias developed in a subset of patients secondary to insertional proto-oncogene activation. In contrast, we have reported development of T cell leukemias in SCID-X1 mice following lentivirus-mediated gene therapy independent of insertional mutagenesis. A distinguishing feature in our study was that only a proportion of transplanted γc-deficient progenitors were transduced and therefore competent for reconstitution. We hypothesized that reconstitution of SCID-X1 mice with limiting numbers of hematopoietic progenitors might be a risk factor for lymphoid malignancy. To test this hypothesis, in the absence of transduction, SCID-X1 mice were reconstituted with serially fewer wild-type hematopoietic progenitors. A robust inverse correlation between hematopoietic progenitor cell dose and T-lymphoid malignancy was observed, with earlier disease onset at lower cell doses. Malignancies were of donor origin and carried activating Notch1 mutations. These findings align with emerging evidence that thymocyte self-renewal induced by progenitor deprivation carries an oncogenic risk that is modulated by intra-thymic competition from differentiation-committed cells. Although insertional proto-oncogene activation is required for the development of malignancy in humans, failure of γc-deficient thymocytes to effectively compete with this at-risk cell population may have also contributed to oncogenesis observed in early SCID-X1 trials.

Extensive Proliferation of Human Cancer Cells with Ever-Shorter Telomeres.

Acquisition of replicative immortality is currently regarded as essential for malignant transformation. This is achieved by activating a telomere lengthening mechanism (TLM), either telomerase or alternative lengthening of telomeres, to counter normal telomere attrition. However, a substantial proportion of some cancer types, including glioblastomas, liposarcomas, retinoblastomas, and osteosarcomas, are reportedly TLM-negative. As serial samples of human tumors cannot usually be obtained to monitor telomere length changes, it has previously been impossible to determine whether tumors are truly TLM-deficient, there is a previously unrecognized TLM, or the assay results are false-negative. Here, we show that a subset of high-risk neuroblastomas (with ∼50% 5-year mortality) lacked significant TLM activity. Cancer cells derived from these highly aggressive tumors initially had long telomeres and proliferated for >200 population doublings with ever-shorter telomeres. This indicates that prevention of telomere shortening is not always required for oncogenesis, which has implications for inhibiting TLMs for cancer therapy.

Djinn Lite: a tool for customised gene transcript modelling, annotation-data enrichment and exploration.

BACKGROUND: There is an ever increasing rate of data made available on genetic variation, transcriptomes and proteomes. Similarly, a growing variety of bioinformatic programs are becoming available from many diverse sources, designed to identify a myriad of sequence patterns considered to have potential biological importance within inter-genic regions, genes, transcripts, and proteins. However, biologists require easy to use, uncomplicated tools to integrate this information, visualise and print gene annotations. Integrating this information usually requires considerable informatics skills, and comprehensive knowledge of the data format to make full use of this information. Tools are needed to explore gene model variants by allowing users the ability to create alternative transcript models using novel combinations of exons not necessarily represented in current database deposits of mRNA/cDNA sequences. RESULTS: Djinn Lite is designed to be an intuitive program for storing and visually exploring of custom annotations relating to a eukaryotic gene sequence and its modelled gene products. In particular, it is helpful in developing hypothesis regarding alternate splicing of transcripts by allowing the construction of model transcripts and inspection of their resulting translations. It facilitates the ability to view a gene and its gene products in one synchronised graphical view, allowing one to drill down into sequence related data. Colour highlighting of selected sequences and added annotations further supports exploration, visualisation of sequence regions and motifs known or predicted to be biologically significant. CONCLUSION: Gene annotating remains an ongoing and challenging task that will continue as gene structures, gene transcription repertoires, disease loci, protein products and their interactions become more precisely defined. Djinn Lite offers an accessible interface to help accumulate, enrich, and individualize sequence annotations relating to a gene, its transcripts and translations. The mechanism of transcript definition and creation, and subsequent navigation and exploration of features, are very intuitive and demand only a short learning curve. Ultimately, Djinn Lite can form the basis for providing valuable clues to plan new experiments, providing storage of sequences and annotations for dedication to customised projects. The application is appropriate for Windows 98-ME-2000-XP-2003 operating systems.

Frequency of tau mutations in familial and sporadic frontotemporal dementia and other tauopathies.

Tau gene mutations with insoluble Tau neuropathology have been identified in pedigrees with frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). Other neurodegenerative diseases, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), are also characterised by insoluble Tau neuropathology. This study sought to determine the nature and frequency of tau gene mutations in an affected proband cohort of patients within this spectrum of neurodegenerative diseases. Sixty-four individuals with clinical features consistent with FTD and other tauopathies were referred over a three year period. There was neuropathological confirmation of disease in 30%. Individuals were screened for mutations in the coding region and flanking intronic regions of the tau gene by direct sequencing of PCR products. Four confirmed tau gene mutations were identified representing 6.3 % for the total affected proband cohort. Tau gene mutations were found in three of twelve (25%) of the cases with a family history of dominantly inherited frontotemporal dementia, but in only one of 25 cases without a family history (4 %). Although tauopathies have been considered to result from genetic defects, screening for tau gene mutations in sporadic cases is not likely to identify pathogenic mutations.

The use of soluble protein structures in modeling helical proteins in a layered membrane.

Major advances have been made in the prediction of soluble protein structures, led by the knowledge-based modeling methods that extract useful structural trends from known protein structures and incorporate them into scoring functions. The same cannot be reported for the class of transmembrane proteins, primarily due to the lack of high-resolution structural data for transmembrane proteins, which render many of the knowledge-based method unreliable or invalid. We have developed a method that harnesses the vast structural knowledge available in soluble protein data for use in the modeling of transmembrane proteins. At the core of the method, a set of transmembrane protein decoy sets that allow us to filter and train features recognized from soluble proteins for transmembrane protein modeling into a set of scoring functions. We have demonstrated that structures of soluble proteins can provide significant insight into transmembrane protein structures. A complementary novel two-stage modeling/selection process that mimics the two-stage helical membrane protein folding was developed. Combined with the scoring function, the method was successfully applied to model 5 transmembrane proteins. The root mean square deviations of the predicted models ranged from 5.0 to 8.8 Å to the native structures.