Functional interaction between APOE4 and LDL receptor isoforms in Alzheimer's disease

BACKGROUND

Multiple genes have been provisionally associated with Alzheimer's disease, including the coding polymorphisms in exons 8 and 13 in the low density lipoprotein receptor gene (LDLR), situated on chromosome 19p13.2.

METHODS

The sample groups consisted of 180 AD patients and 141 control spouses. We carried out genotyping of LDLR8 and LDLR13.

RESULTS

The LDLR8 GG genotype was common, found in 84% of the unaffected control subjects and 91% of the AD patients in our study. There was a ninefold elevation in risk associated with GG:CC versus A- and T- among APOE4+ subjects when compared with APOE4- subjects (odds ratio 9.3; 95% confidence interval 1.8 to 48.2). With the additional information on LDLR polymorphism, we defined an overall 12 fold elevation in risk for APOE4 in combination with LDLR GG:CC (11.9; 2.8 to 50.0; Fisher's exact test, p = 0.0002; standard power 0.999), compared with other subjects lacking all three of these polymorphisms.

CONCLUSION

These results imply a functional interaction between ApoE and LDL receptor proteins that determines risk for Alzheimer's disease.

Clinical use of a commercial Monte Carlo treatment planning system for electron beams

In 2002 we fully implemented clinically a commercial Monte Carlo based treatment planning system for electron beams. The software, developed by MDS Nordion (presently Nucletron), is based on Kawrakow's VMC++ algorithm. The Monte Carlo module is integrated with our Theraplan Plustrade mark treatment planning system. An extensive commissioning process preceded clinical implementation of this software. Using a single virtual 'machine' for each electron beam energy, we can now calculate very accurately the dose distributions and the number of MU for any arbitrary field shape and SSD. This new treatment planning capability has significantly impacted our clinical practice. Since we are more confident of the actual dose delivered to a patient, we now calculate accurate three-dimensional (3D) dose distributions for a greater variety of techniques and anatomical sites than we have in the past. We use the Monte Carlo module to calculate dose for head and neck, breast, chest wall and abdominal treatments with electron beams applied either solo or in conjunction with photons. In some cases patient treatment decisions have been changed, as compared to how such patients would have been treated in the past. In this paper, we present the planning procedure and some clinical examples.

Correlation between culture testing of swabs and ligase chain reaction of first void urine from patients recently treated for Chlamydia trachomatis

We assessed the correlation between ligase chain reaction (LCR) on first void urine (FVU) and cultures of urethral and cervical swabs to detect chlamydia during three post-treatment follow up visits for 10 men and 19 women with genital chlamydial infections who had been treated with azithromycin or doxcycline.

Preload-adjusted maximal power: a novel index of left ventricular contractility in atrial fibrillation

BACKGROUND

Left ventricular contractility in atrial fibrillation is known to change in a beat to beat fashion, but there is no gold standard for contractility indices in atrial fibrillation, especially those measured non-invasively.

OBJECTIVE

To determine whether the non-invasive index of contractility "preload-adjusted PWR(max)" (maximal ventricular power divided by the square of end diastolic volume) can accurately measure left ventricular contractility in a beat to beat fashion in atrial fibrillation.

METHODS

Atrial fibrillation was induced experimentally using 60 Hz stimulation of the atrium and maintained in 12 sheep; four received diltiazem, four digoxin, and four no drugs (control). Aortic flow, left ventricular volume, and left ventricular pressure were monitored simultaneously. Preload-adjusted PWR(max), the slope of the end systolic pressure-volume relation (E(max)), and the maximum rate of change of left ventricular pressure (dP/dt(max)) were calculated in a beat to beat fashion.

RESULTS

Preload-adjusted PWR(max) correlated linearly with load independent E(max) (p < 0.0001) and curvilinearly with load dependent dP/dt(max) (p < 0.0001), which suggested the load independence of preload-adjusted PWR(max). After five minutes of diltiazem administration, preload-adjusted PWR(max), dP/dt(max), and E(max) fell significantly (p < 0.0001) to 62%, 64%, and 61% of baseline, respectively. Changes were not significant after five minutes of digoxin (103%, 98%, and 102%) or in controls (97%, 96%, and 95%).

CONCLUSIONS

Preload-adjusted PWR(max) correlates linearly with E(max) and is a useful measure of contractility even in atrial fibrillation. Non-invasive application of this method, in combination with echocardiography and tonometry, may yield important information for optimising the treatment of patients with atrial fibrillation.

Assessment of the cervix after acetic acid wash: inter-rater agreement using photographs

OBJECTIVE

To estimate the inter-rater agreement on the assessment of cervical photographs after acetic acid wash, using visual inspection with acetic acid categories.

METHODS

Three raters individually assessed 144 photographs as negative, positive, or suspicious for cancer. The inter-rater agreement was analyzed using the unweighted and weighted kappa coefficient. To explore the reasons for concordancy and discordancy, photographs were compared on histologic evidence of cervical intraepithelial neoplasia and on testing for oncogenic types of human papillomavirus.

RESULTS

Overall raw agreement among the three raters was 66.7% (96 of 144) with a kappa of 0.57 (95% confidence interval 0.48, 0.66). Pair-wise agreement using unweighted and weighted kappa was moderate to substantial: 0.54-0.60 and 0.56-0.63, respectively. There was concordance on negative in 25.7% (37 of 144) and on positive or suspicious for cancer in 41.0% (59 of 144). Cervical intraepithelial neoplasia II or III was not present on biopsy if photographs were concordant-negative, and the human papillomavirus test was less likely to be positive (relative risk 0.3; 95% confidence interval 0.2, 0.6) in concordant-negatives compared with concordant-positives, including suspicious for cancer. Cervical intraepithelial neoplasia II or III was more common in photographs that were concordant-positive, including suspicious for cancer, compared with discordants (relative risk 3.4, 95% confidence interval 1.5, 7.6).

CONCLUSION

Based on photographs of the cervix taken after acetic acid wash, the level of agreement among raters using visual inspection with acetic acid categories was moderate to substantial, consistent with other commonly used tests.

Dynamic compartmentalization of bacteria: accurate division in E. coli

Positioning of the midcell division plane within the bacterium E. coli is controlled by the min system of proteins: MinC, MinD, and MinE. These proteins coherently oscillate from end to end of the bacterium. We present a reaction-diffusion model describing the diffusion of min proteins along the bacterium and their transfer between the cytoplasmic membrane and cytoplasm. Our model spontaneously generates protein oscillations in good agreement with experiments. We explore the oscillation stability, frequency, and wavelength as a function of protein concentration and bacterial length.

Mothers' Decision‐Making Processes Regarding Health Care for Their Children

This research study explored mothers' decision-making processes regarding health care for their children. Identifying how decisions are made by mothers about health care for their children will assist health care professionals to be appropriate advocates for mothers, to improve quality of life, and to contain costs of health care for children. A sample of 114 rural mothers (51 with one child, 63 with more than one child) completed questionnaires identifying demographics, social support, client and professional interaction elements, self-determinism, competence in problem-solving skills, and relationships to responses to health care scenarios. Qualitative data were also gathered by structured in-depth interviews of 7 subjects. ANOVA, correlations, and factor analysis were completed to analyze data. Most of the mothers' decisions were based on the perceived degree of seriousness, mother's degree of fear of the child's condition, attitude of the health care provider, previous experience with the situation, and social support for the mother. There were no significant differences in decision-making processes by first time mothers and by mothers with more than one child. Implications include teaching mothers assessment skills to identify serious versus nonserious situations and to utilize other social supports.

Is thrombophilia a factor in the development of hemiplegic cerebral palsy?

A population-based study of children with hemiplegic cerebral palsy (CP) was performed to investigate whether thrombophilic tendencies are implicated in the aetiology of the condition. Thirty-eight children (23 males, 15 females; mean age 8.7 years, SD 4.1 years) with hemiplegic CP were ascertained. Twenty-seven children(18 males, nine females; mean age 8.4 years, SD 4.3) gave consent for inclusion. The non-study group comprised five males and six females; mean age 9.4 years, SD 4.1. In six children, seven thrombophilic 'abnormalities' were identified. Five of these abnormalities were of an equivocal nature and probably did not represent true clinical thrombophilia; reasons for this interpretation are discussed. Contrary to other published non-population-based studies, we have not shown an association between thrombophilia and hemiplegic CP. More studies, including maternal studies, are required to explore this complex subject further.

Cyclic ADP-ribose production by CD38 regulates intracellular calcium release, extracellular calcium influx and chemotaxis in neutrophils and is required for bacterial clearance in vivo

Cyclic ADP-ribose is believed to be an important calcium-mobilizing second messenger in invertebrate, mammalian and plant cells. CD38, the best-characterized mammalian ADP-ribosyl cyclase, is postulated to be an important source of cyclic ADP-ribose in vivo. Using CD38-deficient mice, we demonstrate that the loss of CD38 renders mice susceptible to bacterial infections due to an inability of CD38-deficient neutrophils to directionally migrate to the site of infection. Furthermore, we show that cyclic ADP-ribose can directly induce intracellular Ca++ release in neutrophils and is required for sustained extracellular Ca++ influx in neutrophils that have been stimulated by the bacterial chemoattractant, formyl-methionyl-leucyl-phenylalanine (fMLP). Finally, we demonstrate that neutrophil chemotaxis to fMLP is dependent on Ca++ mobilization mediated by cyclic ADP-ribose. Thus, CD38 controls neutrophil chemotaxis to bacterial chemoattractants through its production of cyclic ADP-ribose, and acts as a critical regulator of inflammation and innate immune responses.

A study of the social and physical environment in catering kitchens and the role of the chef in promoting positive health and safety behaviour

This is the account of a mixed method study of chefs and their kitchens in order to identify the nature of their workplace and how this affects their ability to manage health and safety in the kitchen. It included extended periods of observation, monitoring of physical parameters, analysis of records of reported accidents, and a series of reflexive interviews. The findings were integrated and then fed back in a smaller number of second interviews in order to test whether the findings fitted in with the chefs' understanding of their world. Major factors identified included survival in a market environment, the status of the chef (and the kitchen) within organisations, marked autocracy of chefs, and an increasing tempo building up to service time with commensurate heat, noise, and activity. In particular during the crescendo, a threshold shift in risk tolerance was identified. The factors, their interplay, and their implications for health and safety in the catering kitchen are discussed.

Durability of combined aortic and mitral valve repair

BACKGROUND

This study was undertaken to determine the durability of combined aortic and mitral valve repair.

METHODS

From 1979 through 1999, 158 patients underwent simultaneous aortic and mitral valve repair. Multivariable, multi-phase hazard function analysis was used to determine risk factors for the outcomes of death and reoperation.

RESULTS

Hospital mortality was 3%. Survival after operation was 97%, 93%, 82%, and 62% after 30 days and 1, 5, and 10 years, respectively. Risk factors for late death included aortic stenosis (p = 0.0001), older age (p = 0.002), and abnormal left ventricular function (p = 0.007). Thirty-six patients required reoperation for valvular dysfunction, and freedom from reoperation was 94%, 82%, and 65% after 1, 5, and 10 years, respectively. Risk factors for reoperation included severe aortic regurgitation (p = 0.004), aortic cusp shaving (p = 0.05), mitral valve chordal transfer (p = 0.004), and bovine pericardial annuloplasty (p = 0.002). Five-year freedoms from endocarditis, thromboembolism, and hemorrhage were 97%, 98%, and 99%, respectively, with freedom from any of these valve-related morbidities of 99%, 95%, and 94% after 1, 5, and 10 years, respectively.

CONCLUSIONS

Double valve repair is associated with acceptable late survival and excellent freedom from valve-related morbidity, but limited durability. Therefore, double valve repair should be reserved for patients who cannot be anticoagulated, and should be used with caution in patients with aortic stenosis, rheumatic valve disease, or anterior mitral leaflet pathology.

Branching and annihilating Lévy flights

We consider a system of particles undergoing the branching and annihilating reactions A-->(m+1)A and A+A-->Ø, with m even. The particles move via long-range Lévy flights, where the probability of moving a distance r decays as r(-d-sigma). We analyze this system of branching and annihilating Lévy flights using field theoretic renormalization group techniques close to the upper critical dimension d(c)=sigma with sigma<2. These results are then compared with Monte Carlo simulations in d=1. For sigma close to unity in d=1, the critical point for the transition from an absorbing to an active phase occurs at zero branching. However, for sigma bigger than about 3/2 in d=1, the critical branching rate moves away from zero with increasing sigma, and the transition lies in a different universality class, inaccessible to controlled perturbative expansions. We measure the exponents in both universality classes and examine their behavior as a function of sigma.

Postpartum depression in women receiving public assistance: pilot study of an interpersonal-therapy-oriented group intervention

OBJECTIVE

This study investigated whether a preventive intervention based on the principles of interpersonal psychotherapy administered to pregnant women would reduce the risk of postpartum major depression.

METHOD

Thirty-seven pregnant women receiving public assistance who had at least one risk factor for postpartum depression were randomly assigned to a four-session group intervention or to a treatment-as-usual condition. Thirty-five of the women completed the study. Structured diagnostic interviews were administered to assess for postpartum major depression.

RESULTS

Within 3 months after they gave birth, six (33%) of the 18 women in the treatment-as-usual condition had developed postpartum major depression, compared with none of the 17 women in the intervention condition.

CONCLUSIONS

A four-session interpersonal-therapy-oriented group intervention was successful in preventing the occurrence of major depression during a postpartum period of 3 months in a group of financially disadvantaged women.

Multiple endocytic signals in the C-terminal tail of the cystic fibrosis transmembrane conductance regulator

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-dependent protein kinase (PKA)-activated chloride channel that is localized to the plasma membrane and endosomal compartment. Endosomal targeting of CFTR is attributed to the Tyr(1424)-based internalization signal, identified in the C-terminal tail of the channel. Mutation of the Tyr(1424) residue could partly inhibit the endocytosis of CFTR and its association with the adapter protein AP-2. To reveal additional endosomal targeting signals, site-directed mutagenesis of both a chimaera, composed of a truncated form of interleukin 2 receptor alpha chain (TacT) and the C-terminal tail of CFTR (Ct), and the full-length CFTR was performed. Morphological and functional assays revealed the presence of multiple internalization motifs at the C-terminus, consisting of a phenylalanine-based motif (Phe(1413)) and a bipartite endocytic signal, comprising a tyrosine (Tyr(1424)) and a di-Leu-based (Leu(1430)-Leu) motif. Whereas the replacement of any one of the three internalization motifs with alanine prevented the endocytosis of the TacT-Ct chimaera, mutagenesis of Phe(1413)-Leu impaired the biosynthetic processing of CFTR, indicating that Phe(1413) is indispensable for the native structure of CFTR. In contrast, replacement of Leu(1430)-Leu- and Tyr(1424)-based signals with alanine increased the cell-surface density of both the chimaeras and CFTR in an additive manner. These results suggest that the internalization of CFTR is regulated by multiple endocytic sorting signals.

Ordered and self-disordered dynamics of holes and defects in the one-dimensional complex Ginzburg-Landau equation

We study the dynamics of holes and defects in the 1D complex Ginzburg-Landau equation in ordered and chaotic cases. Ordered hole-defect dynamics occurs when an unstable hole invades a plane wave state and periodically nucleates defects from which new holes are born. The results of a detailed numerical study of these periodic states are incorporated into a simple analytic description of isolated "edge" holes. Extending this description, we obtain a minimal model for general hole-defect dynamics. We show that interactions between the holes and a self-disordered background are essential for the occurrence of spatiotemporal chaos in hole-defect states.

A transient deficit of motion perception in human

We studied the motion perception abilities in a young adult, SF, who had her right occipito-temporal cortices resected to treat epilepsy. Following resection, SF showed transient deficits of both first- and second-order motion perception that recovered to normal within weeks. Previous human studies have shown either first- or second n order motion deficits that have lasted months or years after cerebral damage. SF also showed a transient defect in processing of shape-from-motion with normal perception of shape from non-motion cues. Furthermore, she showed greatly increased reaction times for a mental rotation task, but not for a lexical decision task. The nature and quick recovery of the deficits in SF resembles the transient motion perception deficit observed in monkey following ibotenic acid lesions, and provides additional evidence that humans possess specialized cortical areas subserving similar motion perception functions.

The work-related fatal injury study: numbers, rates and trends of work-related fatal injuries in New Zealand 1985-1994

AIMS

To determine the number and rates of work-related fatal injuries by employment status, occupation, industry, age and gender in New Zealand 1985-1994.

METHODS

Potential cases of work-related injury deaths of persons aged 15-84 years were identified from the national electronic mortality data files. Main exclusions were deaths due to suicide and deaths due to motor vehicle crashes. The circumstances of the deaths of each fatal incident meeting inclusion criteria were then reviewed directly from coronial files to determine work-relatedness.

RESULTS

The rate of work-related fatal injury in New Zealand was 5.03/100000 workers per year for the study period. There was a significant decline in crude rate over the study period. However, this was in substantial part accounted for by changes in occupation and industry mix. Older workers, male workers, self-employed workers, and particular occupational groups, all had substantially elevated rates. Agricultural and helicopter pilots, forestry workers and fishery workers had the highest rates. Farmers, forestry workers, and fishery workers also had high numbers of deaths, together accounting for nearly 40% of all deaths.

CONCLUSIONS

This study has demonstrated that work-related fatal injury remains a pressing problem for New Zealand. Several areas in urgent need of prevention efforts were highlighted.

The role of autoantigens in autoimmune disease

Many autoantigens have been identified in human patients and in rodent models. In numerous experimental settings, these autoantigens or related autoreactive lymphocytes can transfer autoimmunity. Although autoreactivity spreads to new epitopes during the course of disease, single-epitope-specific therapies show considerable efficacy in multi-epitope-induced models of autoimmunity. These observations may indicate that epitope-specific therapies operate at the level of regulating mechanisms of immune tolerance rather than exerting a direct effect on autoreactive T lymphocytes.

Chemokines in autoimmune diseases

Autoimmune diseases like multiple sclerosis (MS) and insulin-dependent diabetes (IDD) are believed to be mediated by pathogenic CD4+ autoreactive T cells which mediate selective destruction of specific host cells. Interrupting the trafficking of such T cells from host circulation to the sites of pathology, such as the central nervous system in the case of MS and the pancreas in the case of IDD, potentially offers a novel opportunity for therapeutic intervention in these diseases. The following summarizes our evolving thoughts on the role of the chemokine network in MS and IDD, and focuses on the chemokine receptor CXCR3 as a potential target for impeding T-cell-mediated destruction in these disease settings.

Comparison of self-collected vaginal, vulvar and urine samples with physician-collected cervical samples for human papillomavirus testing to detect high-grade squamous intraepithelial lesions

BACKGROUND

Certain types of human papillomavirus (HPV) in cervical samples are strongly associated with squamous intraepithelial lesions (SIL) and invasive cervical carcinoma. We determined and compared the test characteristics of testing for HPV with samples obtained by patients and with samples obtained by their physicians.

METHODS

In a consecutive series of women referred to a colposcopy clinic at a teaching hospital because of abnormalities on cervical cytologic screening, 200 agreed to collect vulvar, vaginal and urine samples for HPV testing. The physician then collected cervical samples for HPV testing, and colposcopy, with biopsy as indicated, was performed. Presence of HPV was evaluated using the hybrid capture II assay (Digene Corp., Silver Spring, Md.) with a probe cocktail for 13 carcinogenic types. Cervical specimens were also tested for HPV by polymerase chain reaction and hybridization with type-specific probes. Cervical smears for cytologic examination were obtained from all women.

RESULTS

High-grade lesions (high-grade squamous intraepithelial lesions [HSIL], equivalent to cervical intraepithelial neoplasia [CIN] grade 2 or 3, and adenocarcinoma) were found in 58 (29.0%) of the 200 women. Carcinogenic types of HPV were detected in the self-collected vaginal samples of 50 (86.2%) of these 58 women, in the self-collected vulvar samples of 36 (62.1%) and in the self-collected urine samples of 26 (44.8%). Carcinogenic types of HPV were detected in the cervical samples collected by physicians for 57 (98.3%) of these 58 women. The remaining 142 women (71.0%) had normal findings or low-grade squamous intraepithelial lesions (LSIL, CIN grade 1). Test results were negative or noncarcinogenic types of HPV were detected in the self-collected vaginal samples of 76 (53.5%) of these 142 women, in the self-collected vulvar samples of 89 (62.7%) and in the self-collected urine samples of 99 (69.7%). The sensitivity for self-collected samples ranged from 44.8% to 86.2%, and the specificity from 53.5% to 69.7%. For the samples collected by physicians, the sensitivity was 98.3% and the specificity 52.1%. The self-sampling methods were generally acceptable to the women: 98.4% of respondents (126/128) deemed urine sampling acceptable, 92.9% (118/127) found vulvar sampling acceptable, and 88.2% (112/127) found vaginal sampling acceptable.

INTERPRETATION

Self-collection of samples for HPV testing was acceptable to women attending a colposcopy clinic for investigation of suspected cervical lesions and shows sufficient sensitivity to warrant further evaluation as a screening test for cervical cancer prevention programs.