Longitudinal assessment of cognition and T2-hyperintensities in NF1: an 18-year study

The developmental course of cognitive deficits in individuals with neurofibromatosis type 1 (NF1) is unclear. The objectives of this study were to determine the natural history of cognitive function and MRI T2-hyperintesities (T2H) from childhood to adulthood and to examine whether the presence of discrete T2H in childhood can predict cognitive performance in adulthood. We present cognitive and structural neuroimaging data from 18 patients with NF1 and five sibling controls assessed prospectively across an 18-year period. Longitudinal analyses revealed a significant increase in general cognitive function in patients with NF1 over the study period. Improvements were limited to individuals with discrete T2H in childhood. Patients without lesions in childhood exhibited a stable profile. The number of T2H decreased over time, particularly discrete lesions. Lesions located within the cerebral hemispheres and deep white matter were primarily stable, whereas those located in the basal ganglia, thalamus and brainstem tended to resolve. Our results support the hypothesis that resolution of T2H is accompanied by an improvement in general cognitive performance, possibly as a result of increased efficiency within white matter tracts.

Comprehension of sarcasm, metaphor and simile in Williams syndrome

BACKGROUND

Although people with Williams syndrome (WS) are often characterized as friendly and sociable with relatively good general language abilities, there is emerging evidence of pragmatic difficulties and trouble comprehending aspects of non-literal language.

AIMS

The main aim was to investigate the comprehension of sarcasm, metaphor and simile in WS relative to typically developing controls. A secondary aim was to examine the association between non-literal language comprehension and a range of other cognitive abilities, both in WS and in the typically developing population.

METHODS & PROCEDURES

Twenty-six participants with WS were compared with 26 typically developing chronological age-matched controls (TDCA) and 26 typically developing mental age-matched controls (TDMA). Participants listened to stories in which characters made non-literal comments. They were then asked what each character meant by their comment. In order to investigate the second aim of the study, cognitive abilities were also assessed using the Woodcock-Johnson (Revised) Tests of Cognitive Ability, including expressive vocabulary, verbal working memory, perceptual integration, inferential reasoning and overall cognitive ability.

OUTCOMES & RESULTS

Comprehension of non-literal language in WS was significantly below TDCA levels, but was not significantly different to TDMA levels. For typically developing controls, each of the cognitive measures was strongly correlated with each of the measures of non-literal language comprehension. The same relationships were not always found for participants with WS. In particular, sarcasm comprehension in WS was not significantly correlated with any of the assessed cognitive abilities, and expressive vocabulary was not significantly correlated with any measure of non-literal comprehension.

CONCLUSIONS & IMPLICATIONS

Comprehension of simile in WS is below TDCA levels but seems on par with their mental age level. It appears that comprehension of sarcasm and metaphors is above the cognitive capabilities and mental age level of most individuals with WS. Further, the pattern of correlations between non-literal comprehension and cognitive abilities in WS relative to controls suggests that perhaps the linguistic and cognitive systems that underpin non-literal language comprehension in typically developing individuals interact and integrate in different ways in WS.

Physiology during smoltification in Atlantic salmon: effect of melatonin implants

Melatonin implants were used to override natural melatonin rhythm in groups of juvenile Atlantic salmon, Salmo salar, raised at simulated natural photoperiod (SNP) and constant light (LL) from mid-March until end of August. The experiment contained also both sham control (with non-melatonin implants) and control (no implants). No differences were found in the experimental variables between these two control groups. Growth and food intake were negatively affected by melatonin implantation. Overall, higher GH levels were observed in the SNP melatonin-implanted group, whereas no differences in GH levels were seen between the SNP control, LL control, or the LL melatonin-implanted groups. Highest food intake was seen in the LL control group. No differences in food intake were recorded between the LL melatonin-implanted and SNP control groups. Gill Na(+), K(+), ATPase (NKA) activity was influenced by time as well as the interaction between photoperiod and time. No differences in gill NKA activity or plasma chloride levels following transfer to seawater were seen between the groups with melatonin implants and their controls. Based on the present results, it seems apparent that melatonin does play a role in regulating food intake and growth in Atlantic salmon smolts.

Which factors determine the wear rate of large-diameter metal-on-metal hip replacements? Multivariate analysis of two hundred and seventy-six components

BACKGROUND

Determining the relationship between clinical factors and engineering analysis of retrieved hip implants can help our understanding of the mechanism of device failure. This is particularly important for metal-on-metal hip arthroplasties because the most common cause of failure is unexplained. We sought to understand the variation in wear rates in a large series of retrieved metal-on-metal hip arthroplasty components.

METHODS

We prospectively recorded preoperative, intraoperative, and postoperative data to study the effect on both head and cup wear rates of the following variables: patient sex, cause of failure, manufacturer type, resurfacing or modular design, blood cobalt and chromium levels, edge-loading, femoral head size, and cup inclination angle. We analyzed 276 components (138 femoral head and acetabular cup couples) retrieved from failed metal-on-metal hip replacements.

RESULTS

We found a high rate of edge-loading (64%), but only forty-three (31%) of 138 hips had a cup inclination angle of >55°. Multivariate analysis showed that the most important factor responsible for the variation in wear rate was the presence or absence of edge-loading, even when adjusted for cup inclination angle. Strong positive correlations were found between acetabular cup and femoral head wear rates and between wear rates and both blood cobalt and chromium ion levels.

CONCLUSIONS

Multivariate analysis of nine factors found that edge-loading was the most important predictor of wear rate and occurred in two-thirds of failed metal-on-metal hip replacements. The majority did not have excessive cup inclination angles: 68% had an inclination angle of ≤55°. This finding, together with the relatively low median wear rate of the components in our study, suggests that cup position and/or wear rate may not be the only outcome related to failure of metal-on-metal hip replacements.

Mid-term equivalent survival of medial and lateral unicondylar knee replacement: an analysis of data from a National Joint Registry

Current analysis of unicondylar knee replacements (UKRs) by national registries is based on the pooled results of medial and lateral implants. Consequently, little is known about the differential performance of medial and lateral replacements and the influence of each implant type within these pooled analyses. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of UKRs implanted on the lateral side of the knee, and their survival and reason for failure compared with medial UKRs. By combining information on the side of operation with component details held on the NJR, we were able to determine implant laterality (medial versus lateral) for 32 847 of the 35 624 unicondylar replacements (92%) registered before December 2010. Of these, 2052 (6%) were inserted on the lateral side of the knee. The rates of survival at five years were 93.1% (95% confidence interval (CI) 92.7 to 93.5) for medial and 93.0% (95% CI 91.1 to 94.9) for lateral UKRs (p = 0.49). The rates of failure remained equivalent after adjusting for patient age, gender, American Society of Anesthesiologists (ASA) grade, indication for surgery and implant design using Cox's proportional hazards method (hazard ratio for lateral relative to medial replacement = 0.88 (95% CI 0.69 to 1.13); p = 0.32). Aseptic loosening/lysis and unexplained pain were the main reasons for revision in both groups, although the reasons did vary depending on whether a mobile- or a fixed-bearing design was used. At a maximum of eight years the mid-term survival rates of medial and lateral UKRs are similar.

Qualitative research and its place in health research in Nepal

There has been a steady growth in recent decades in Nepal in health and health services research, much of it based on quantitative research methods. Over the same period international medical journals such as The Lancet, the British Medical Journal (BMJ), The Journal of the American Medical Association (JAMA) and the Journal of Family Planning and Reproductive Health Care and many more have published methods papers outlining and promoting qualitative methods. This paper argues in favour of more high-quality qualitative research in Nepal, either on its own or as part of a mixed-methods approach, to help strengthen the country's research capacity. After outlining the reasons for using qualitative methods, we discuss the strengths and weaknesses of the three main approaches: (a) observation; (b) in-depth interviews; and (c) focus groups. We also discuss issues around sampling, analysis, presentation of findings, reflexivity of the qualitative researcher and theory building, and highlight some misconceptions about qualitative research and mistakes commonly made.

A longitudinal study of cognitive abilities in Williams syndrome

This longitudinal study assessed cognition in Williams syndrome (WS) over a 5 year period using the same test battery over the two occasions of testing. The aim was to explore whether absolute levels of ability and relative cognitive strengths and weaknesses remain consistent over time. 27 participants with WS were assessed using the Woodcock Johnson Test of Cognitive Ability--Revised (WJ-R COG, Woodcock & Johnson, 1989, 1990). Results suggested some developmental progress over time, but at a slower rate than typically developing peers. Cognitive strengths and weaknesses were consistent, at least on those abilities assessed using the WJ-R COG.

Clinical outcome using a ligament referencing technique in CAS versus conventional technique

PURPOSE

Computer-assisted surgery (CAS) for total knee arthroplasty (TKA) has become increasingly common over the last decade. There are several reports including meta-analyses that show improved alignment, but the clinical results do not differ. Most of these studies have used a bone referencing technique to size and position the prosthesis. The question arises whether CAS has a more pronounced effect on strict ligamentous referencing TKAs.

METHODS

We performed a prospective cohort study comparing clinical outcome of navigated TKA (43 patients) with that of conventional TKA (122 patients). Patients were assessed preoperatively, and 2 and 12 months postoperatively by an independent study nurse using validated patient-reported outcome tools as well as clinical examination.

RESULTS

At 2 months, there was no difference between the two groups. However, after 12 months, CAS was associated with significantly less pain and stiffness, both at rest and during activities of daily living, as well as greater overall patient satisfaction.

CONCLUSION

The present study demonstrated that computer-navigated TKA significantly improves patient outcome scores such as WOMAC score (P=0.002) and Knee Society score (P=0.040) 1 year after surgery in using a ligament referencing technique. Furthermore, 91% were extremely or very satisfied in the CAS TKA group versus 70% after conventional TKA (P=0.007).

Disinfection by-products in filter backwash water: implications to water quality in recycle designs

The overall purpose of this research was to investigate disinfection by-product (DBP) concentrations and formation potential in filter backwash water (FBWW) and evaluate at bench-scale the potential impact of untreated FBWW recycle on water quality in conventional drinking water treatment. Two chlorinated organic compound groups of DBPs currently regulated in North America were evaluated, specifically trihalomethanes (THMs) and haloacetic acids (HAAs). FBWW samples were collected from four conventional filtration water treatment plants (WTP) in Nova Scotia, Canada, in three separate sampling and plant audit campaigns. THM and HAA formation potential tests demonstrated that the particulate organic material contained within FBWW is available for reaction with chlorine to form DBPs. The results of the study found higher concentrations of TTHMs and HAA9s in FBWW samples from two of the plants that target a higher free chlorine residual in the wash water used to clean the filters (e.g., clearwell) compared to the other two plants that target a lower clear well free chlorine residual concentration. Bench-scale experiments showed that FBWW storage time and conditions can impact TTHM concentrations in these waste streams, suggesting that optimization opportunities exist to reduce TTHM concentrations in FBWW recycle streams prior to blending with raw water. However, mass balance calculations demonstrated that FBWW recycle practice by blending 10% untreated FBWW with raw water prior to coagulation did not impact DBP concentrations introduced to the rapid mix stage of a plant's treatment train.

The epidemiology of infertility in the North East of Scotland

BACKGROUND

There is a perception that the prevalence of infertility is on the rise. This study aimed to determine the current prevalence of infertility in a defined geographical population, ascertain changes in self-reported infertility over time and identify risk factors associated with infertility.

METHODS

A postal questionnaire survey of a random population-based sample of women aged 31-50 years was performed in the Grampian region of Scotland. Questions addressed the following areas: pregnancy history, length of time taken to become pregnant each time, whether medical advice had been sought and self-reported exposure to factors associated with infertility.

RESULTS

Among 4466 women who responded, 400 (9.0%) [95% CI 8.1, 9.8] had chosen not to have children. Of the remaining 4066 women, 3283 (80.7%) [95% CI 79.5, 82.0] reported no difficulties in having children and the remaining 783 (19.3%) [95% CI 18.1, 20.5] had experienced infertility, defined as having difficulty in becoming pregnant for more than 12 months and/or seeking medical advice. In total 398 (9.8%) [95% CI 8.9, 10.7] women had primary infertility, 285 (7.0%) [95% CI 6.2, 7.8] had secondary infertility, 100 (2.5%) [95% CI 2.0, 2.9] had primary as well as secondary infertility. A total of 342 (68.7%) and 208 (73.0%) women with primary and secondary infertility, respectively, sought medical advice and 202 (59.1%) and 118 (56.7%) women in each group subsequently conceived. History of pelvic surgery, Chlamydial infection, endometriosis, chemotherapy, long-term health problems and obesity were associated with infertility. In comparison with a similar survey of women aged 46-50 from the same geographical area, the prevalence of both primary infertility (>24 months) [70/1081, (6.5%) versus 68/710 (9.6%) P = 0.02] and secondary infertility [29/1081 (2.7%) versus 40/710 (5.6%) P = 0.002] were significantly lower.

CONCLUSIONS

Nearly one in five women attempting conception sampled in this study experienced infertility, although over half of them eventually conceived. Fertility problems were associated with endometriosis, Chlamydia trachomatis infection and pelvic surgery, as well as obesity, chemotherapy and some long-term chronic medical conditions. There is no evidence of an increase in the prevalence of infertility in this population over the past 20 years.

'Not taken in by media hype': how potential donors, recipients and members of the general public perceive stem cell research

BACKGROUND

Views of embryo donors, scientists and members of the general public on embryonic stem cell research (eSCR) have been widely reported. Less is known about views of potential beneficiaries of stem cell therapy and the influence of media 'hype' on perceptions of eSCR among different groups of stakeholders. This study aimed to examine the perceptions of members of the general public as well as two patient groups likely to benefit from eSCR and to explore the role of the media in shaping these views.

METHODS

A qualitative study carried out in Aberdeen, Scotland included 15 people living with Parkinson's disease (PD), 15 people living with diabetes mellitus (DM), 15 couples with infertility and 21 members of the general public who volunteered for the study. Interview transcripts were analysed thematically using grounded theory.

RESULTS

The two patient groups likely to benefit from eSCR in the future differed in their knowledge (mainly gained from the media) and understanding of eSCR. Those living with PD were older, more debilitated and better informed than those with DM who showed limited interest in potential future benefits of eSCR. Infertile couples learnt about eSCR from health professionals who explained the process of embryo donation to them, and had sought no further information. Most of the general public had accessed information on eSCR and believed themselves to be more discerning than others because of their objectivity, intelligence and 'scientific awareness'. Although, the media and internet were primary sources of information for all except couples with infertility, members of all four groups claimed not to be taken in by the media 'hype' surrounding eSCR.

CONCLUSIONS

Those who expected to benefit from eSCR in the future as well as members of the general public differ in their susceptibility to media 'hype', while believing that they are not taken in by exaggerated claims of benefits. As respondents were a selected group who were not drawn from a representative sample, the findings cannot be generalized to a wider population.

Effect of hormonal growth promotants on palatability and carcass traits of various muscles from steer and heifer carcasses from a Bos indicus - Bos taurus composite cross

The effect of several different hormonal growth promotant (HGP) implant strategies on the palatability and carcass traits of different muscles in beef carcasses was investigated using samples from heifer and steer carcasses from a Bos indicus composite breed. In experiment 1, there were seven different implant strategies evaluated in heifers that were given different combinations of up to three implants (implanted at weaning, during backgrounding and at feedlot entry). A total of 112 heifers were slaughtered and 11 muscles or portions were collected from both sides [Mm. adductor femoris, gracilus, semimembranosus, longissimus dorsi lumborum, triceps brachii caput longum, semispinalis capitis, serratus ventralis cervicis, spinalis dorsi, biceps femoris (syn. gluteobiceps), tensor fasciae latae, gluteus medius (both the ‘D’ and the ‘eye’ portions) rectus femoris, vastus intermedius, vastus lateralis and vastus medialis]. These muscles were used to prepare a total of 1030 sensory samples which were aged for either 7 or 21 days and frozen. Thawed samples were cooked using different cooking methods (grill, roast and stir frying) before being evaluated by a consumer taste panel that scored samples for tenderness, juiciness, like flavour and overall liking. Experiment 2 used the steer portion from the same calving, which were treated to a similar array of HGP strategies, except that they were given up to four implants between weaning and slaughter at ~3 years of age. In experiment 2, there was a total of 12 different HGP implant strategies tested. At boning, three muscles (Mm. psoas major, longisimuss dorsi thoracis and lumborum portions) were collected from each of 79 carcasses with a total of 237 steak samples that consumers tested as grilled steaks. For both experiments, the mean of the HGP implant strategies resulted in increased ossification scores (P < 0.05) and decreased marbling scores (P < 0.05) compared with the controls, with the effect on ossification being much larger in the older steer groups. In both experiments, the different HGP strategies decreased (P < 0.05) all sensory scores compared with the controls, for all cooking method and muscle combinations. In experiment 1, there was no interaction between the mean HGP effect and muscle (P > 0.05), and aging rates differed among the muscles (P < 0.05). In experiment 2, there was a significant (P < 0.05) muscle × HGP treatment interaction, with a decrease in tenderness score due to HGP implant strategies in the M. longisimuss thoracis and lumborum portions, compared with no significant effect in the M. psoas major. For both experiments, there were no significant differences among the different implantation strategies on sensory scores (P > 0.05).

Evolution of the Meat Standards Australia (MSA) beef grading system

The Australian Beef Industry identified variable eating quality as a major contributor to declining beef consumption in the early 1990s and committed research funding to address the problem. The major issue was the ability to predict the eating quality of cooked beef before consumption. The Meat Standards Australia (MSA) program developed a consumer testing protocol, which led to MSA grading standards being defined by consumer score outcomes. Traditional carcass grading parameters proved to be of little value in predicting consumer outcomes. Instead a broader combination of factors forms the basis of an interactive prediction model that performs well. The grading model has evolved from a fixed parameter ‘Pathway’ approach, to a computer model that predicts consumer scores for 135 ‘cut by cooking method’ combinations for each graded carcass. The body of research work conducted in evaluating critical control points and in developing the model predictions and interactions has involved several Australian research groups with strong support and involvement from the industry.

Consumer assessment of eating quality - development of protocols for Meat Standards Australia (MSA) testing

Meat Standards Australia sought a consistent measure of the beef eating experience to the consumer. Rather than objective measurements or trained panel sensory assessment, it was decided to proceed with direct consumer assessment. Consumer-based assessment has much greater variation, but it has the decided advantage of validity. This paper summarises the path taken to obtain consistent consumer assessment. What meat samples to present to consumers? What responses to ask for? What to do with these responses when they were obtained? The answers to these questions have led to the MQ4 measure of consumer assessment of meat eating quality, which now forms the basis of the MSA predictive model.

Effect of repeated implants of oestradiol-17β on beef palatability in Brahman and Braham cross steers finished to different market end points

The effect of repeated implantation with 20 mg oestradiol-17β (Compudose 100) on carcass and meat quality traits was investigated using 478 Bos indicus and B. indicus × Bos taurus cross steers finished on either pasture or grain to achieve carcass weight for one of three market end points (domestic, 220 kg; Korean, 280 kg; or Japanese, 340 kg). In the oestradiol-17β treatment group, animals were administered implants at ~100-day intervals, with the number of implants administered to any steer ranging from one to eight. Cattle were slaughtered and at boning the anterior portion of the M. longissimus lumborum was removed and frozen after aging for 1 day for later objective meat quality measurements (shear force, compression and cook loss %). The adjoining portion was aged for 14 days before consumer sensory testing using the Meat Standards Australia protocols. Each sample was scored for tenderness, juiciness, like flavour and overall liking by 10 untrained consumers. Implanting increased carcass weights and ossification scores (P < 0.05) and reduced marbling scores in comparison to non-implanted carcasses. For tenderness, like flavour, overall liking and MQ4 scores there was a significant (P < 0.05) interaction between B. indicus content and oestradiol-17β treatment, whereby high B. indicus content cattle that were implanted with oestradiol-17β had the lowest sensory scores. The number of implants administered did not affect carcass weights or marbling scores, whereas ossification scores increased in carcasses as the number of implants increased. The number of implants administered had no effect (P > 0.05) on sensory scores, or objective meat tenderness.

The use of telemedicine to care for cancer patients at remote sites

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Background: At the BC Cancer Agency -CSI we are challenged to provide systemic cancer care to a population of 720,000 widely dispersed over 250,000 square kilometers. Video-link technology (VT) has been used at our centre since April 2004 to help provide distant care and prevent patient and physician travel. Methods: Patients gave consent for the use of VT. We prospectively collected data on patient and physician experiences as part of on-going quality assurance. We retrospectively collected the clinical data on these patients. Results: We performed 104 encounters on 100 patients between April 2, 2004 and October 4, 2006. Patient characteristics: female 62%, male 38%, average age was 66 years with a range of 28 –83. Extent of cancer was 67% curable, 31% advanced and 7% unknown. Visit type and cancer sites are shown below. Patients rated this experience very highly and the vast majority would repeat the experience rather than travel or wait several weeks to see the doctor in person. Physicians were not as satisfied as the patients; and both groups expressed a concern about the need for physical exam. In those having a consult, 54% had an exam within 60 days, and in none of these patients were the treatment recommendations changed. The majority (57%) of those consult patients that didn’t have an exam had either Stage 0 or I breast cancer or Stage II or III colorectal cancer; and it seems unlikely that physical exam would have changed management in these patients. Conclusions: We were able to deliver cancer care at distant sites with VT and patients found the experience very acceptable. There may not be a need for repeat physical exam in these patients, who had previously been examined by other physicians, prior to referral.

No significant financial relationships to disclose.

[Table: see text]

The association of scapho-trapezio-trapezoid osteoarthrosis and scapholunate dissociation

There are two parts to this paper. In the first part we report 18 cases of bilateral scapho-trapezio-trapezoid osteoarthrosis associated with uni- or bilateral scapholunate dissociation. This case series was followed prospectively using repeat clinical assessments and radiographs. We were able to document the progression of both the clinical manifestations and radiographic features of the scapholunate dissociation in these patients. In the second part of the paper we compared the radiographic indices of scapholunate dissociation seen in our series, that is, the scapholunate angle and interval, with those of a control group over time, to determine if there was a significant difference. The control group differed from our series principally by being devoid of any clinical or radiographic evidence of scapho-trapezio-trapezoid osteoarthrosis. We found that our case series already had some radiographic evidence of scapholunate attrition at presentation and that at follow-up the scapholunate dissociation became more pronounced both clinically and radiographically relative to the controls. The authors propose a theory to explain the association and temporal relationship between the two conditions.

Anaesthesia for caesarean section in a patient with diastrophic dwarfism

Diastrophic dwarfism is a rare disease in which pregnancy is uncommon. In this report we present a woman with diastrophic dwarfism who underwent caesarean section under epidural anaesthesia. Her care was successfully managed with multidisciplinary team planning. The total dose of local anaesthetic needed for epidural block was greater than the doses reported for achondroplastic dwarfism.

Major problems and key issues in Maternal Health in Nepal

This paper highlights some of the challenges facing maternal health in Nepal and to suggest possible solutions for improvements. Key literature from across the globe is reviewed and discussed in a Nepalese context. Maternal mortality remains one of the biggest public health problems in Nepal. Lack of access to basic maternal healthcare, difficult geographical terrain, poorly developed transportation and communication systems, poverty, illiteracy, women's low status in the society, political conflict, shortage of health care professional and under utilization of currently available services are major challenges to improving maternal health in Nepal. In order to effect real improvements in maternal health, attention needs to be focused both on biomedical and social interventions. Improving health facilities, mother's nutrition, women's position in the society such as freedom of movement, providing education to female children, integrating Traditional Birth Attendants into local health services can play a vital role in the improvement of mothers' health.

Absence of conception after caesarean section: voluntary or involuntary?

BACKGROUND

Women who deliver by caesarean section have been shown to be less likely to have a subsequent pregnancy. It is not clear whether this is due to a direct effect of the procedure on future fertility or due to deliberate avoidance of a future pregnancy.

OBJECTIVE

To investigate whether absence of conception following caesarean section is voluntary or involuntary.

DESIGN

Follow up of a population-based retrospective cohort.

SETTING

Grampian region, Scotland.

POPULATION

Women who had no further viable pregnancies within 5 years of an initial delivery.

METHODS

Cases included women who delivered their first child by caesarean section between 1980 and 1995 but had no further viable pregnancies by December 2000. Controls included women who delivered their first child during the same period, by means of either spontaneous vaginal delivery (SVD) or instrumental vaginal delivery (IVD), and who had no further viable pregnancies by December 2000. Eligible women were identified from the Aberdeen Maternity and Neonatal Databank (AMND) and sent postal questionnaires to determine the extent to which not conceiving after first delivery was voluntary and the reasons for avoiding further pregnancies. Characteristics of the different mode of delivery groups were compared using univariate techniques.

MAIN OUTCOME MEASURES

Extent to which absence of conception following an initial delivery by caesarean section is voluntary.

RESULTS

Questionnaires were returned by 3204 (60%) of 5300 women identified from the AMND. Of these, 1675 women had not conceived at all during the follow-up period (median duration = 13 years). Absence of conception was voluntary in 488 (69%; 95% CI 66-73%) women following caesarean section, 340 (71%; 95% CI 67-76%) following SVD and 354 (72%; 95% CI 68-76%) following IVD. Few women considered seeking fertility treatment (caesarean section = 72 [10%], SVD = 50 [11%], IVD = 39 [8%]). Of the women who decided to delay or avoid a further pregnancy, fewer women who delivered by SVD reported that the birth experience influenced their decision (caesarean section = 163 [32%], SVD = 67 [18%], IVD = 136 [35%]; P < 0.001).

CONCLUSIONS

Irrespective of mode of delivery, not conceiving following the birth of the first child is mainly voluntary. The experience of the previous birth is one of several factors affecting women's decisions to avoid a subsequent pregnancy.

Primary mode of delivery and subsequent pregnancy

OBJECTIVE

To investigate the relationship between primary mode of delivery and subsequent pregnancy and to compare the findings with a previous study conducted on an earlier cohort from the same population.

DESIGN

Population cohort.

SETTING

Aberdeen City, Scotland.

POPULATION

Women who delivered their first singleton child in Aberdeen Maternity Hospital between 1980 and 1997.

METHODS

Population-based data relating to the index and next pregnancy event, if any, were obtained from the Aberdeen Maternity Neonatal Databank. Subsequent pregnancy was compared across the three modes of delivery groups using log rank tests and Cox proportional hazards regression models.

MAIN OUTCOME MEASURE

First subsequent pregnancy following index delivery.

RESULTS

Women who delivered by caesarean section (CS) were less likely to have a subsequent pregnancy compared with those who had a spontaneous vaginal delivery (SVD), hazard ratio = 0.91 (95% CI 0.87, 0.95). This confirmed the findings of a previous study conducted on an earlier cohort of the same population. The median time to next pregnancy following CS was 36.3 months, 31.8 months following instrumental vaginal delivery (IVD) and 30.4 months following SVD. In contrast to the earlier study where women who had an instrumental delivery were found to be an intermediate group, we found no difference in subsequent pregnancy following IVD compared with SVD, HR = 1.0 (95% CI 0.96, 1.03).

CONCLUSIONS

Following an initial delivery by CS, fewer women went on to have another pregnancy compared with SVD. The incidence of subsequent pregnancy is similar following instrumental and SVD.

Visual search: efficiency continuum or distinct processes?

Whether visual search involves two distinct processes--traditionally referred to as serial and parallel--or a single process operating on a continuum of efficiency or speed, is an issue with a long history in the study of attention. On the basis of the unimodality of search slope distributions in a very large data set, Wolfe (1998) argued for a continuum model. Reanalysis of this data set using statistical procedures more appropriate for adjudicating between continuous and discontinuous models supports the existence of two distinct processes.

Forced displacement in Yugoslavia: a meta-analysis of psychological consequences and their moderators

A meta-analysis was conducted to synthesize what is known about differences in mental health between refugees and nonrefugees from the former Yugoslavia. The analysis focused on moderating effects of a variety of enduring, contextual stressors. Results indicated that refugees suffer significantly more mental health impairment than nonrefugees. The psychological consequences of forced displacement were found to vary significantly as a function of chronic stressors (e.g., locus of displacement and type of accommodation in exile) and were also associated with otherfactors (e.g., degree of war exposure in the nondisplaced groups, participant age, and time of data collection as reflected in year of publication). Implications for the study of refugee mental health are discussed.

Genomic structure of three CLN3-like genes in Caenorhabditis elegans

The genome of Caenorhabditis elegans is predicted to carry three genes similar to CLN3, the gene underlying juvenile neuronal ceroid lipofuscinosis. All three genes are transcribed and the genomic structure has been determined. The number and position of exons for two of the genes differ from that predicted from the genomic sequence, but no discrepancies with the genomic nucleotide sequence were found. Gene F07B10.1 (cln-3.1) is predicted to have 7 exons and to encode a protein of 424 amino acids. Gene C01G8.2 (cln-3.2) has 9 exons and encodes a protein of 435 amino acids. Gene ZC190.1 (cln-3.3) is predicted to have 9 exons and to encode a protein of 416 amino acids.

Improving SH3 domain ligand selectivity using a non-natural scaffold

BACKGROUND

Src homology 3 (SH3) domains bind sequences bearing the consensus motif PxxP (where P is proline and x is any amino acid), wherein domain specificity is mediated largely by sequences flanking the PxxP core. This specificity is limited, however, as most SH3 domains show high ligand cross-reactivity. We have recently shown that diverse N-substituted residues (peptoids) can replace the prolines in the PxxP motif, yielding a new source of ligand specificity.

RESULTS

We have tested the effects of combining multiple peptoid substitutions with specific flanking sequences on ligand affinity and specificity. We show that by varying these different elements, a ligand can be selectively tuned to target a single SH3 domain in a test set. In addition, we show that by making multiple peptoid substitutions, high-affinity ligands can be generated that completely lack the canonical PxxP motif. The resulting ligands can potently disrupt natural SH3-mediated interactions.

CONCLUSIONS

Peptide-peptoid hybrid scaffolds yield SH3 ligands with markedly improved domain selectivity, overcoming one of the principal challenges in designing inhibitors against these domains. These compounds represent important leads in the search for orthogonal inhibitors of SH3 domains, and can serve as tools for the dissection of complex signaling pathways.

Individualized care: perceptions of certified nurse's aides

Despite substantial attention devoted to the development of individualized care in nursing homes during recent years, empirical research assessing progress is limited. Further, few studies have explored the experiences of certified nurse's aides (CNAs) in this regard. This survey examines the perceptions and experiences of CNAs in providing individualized care. CNAs (n = 254) were asked to describe a number of current practices and obstacles to implementing individualized care in nursing homes. The majority of respondents reported experiencing: flexibility to change daily schedules; supervisor assistance with challenging residents; active participation in care planning; freedom to test new approaches to care; and supervisors who are open to CNA suggestions. Several barriers to individualized care were also described, including: inadequate staffing; poor team communication; staff attitudes; and a lack of knowledge and training in alternative approaches. These findings provide important insights into the supports and obstacles to implementing individualized care in nursing homes from the perspective of CNAs.

Effects of melatonin on liver estrogen receptor and vitellogenin expression in rainbow trout: an in vitro and in vivo study

Although melatonin is believed to mediate many seasonal and circadian effects of photoperiod on reproduction in salmonids, the precise mechanisms underlying such effects are still largely unknown. Recent data of the literature indicate a relationship between melatonin and expression of estrogen receptors (ER) in various tissues. In this study, the effects of melatonin on estrogen receptor and/or vitellogenin expression were studied by a combination of in vivo and in vitro experiments. In yeast stably expressing ER and transfected with an estrogen-responsive element-beta-galactosidase reporter gene, melatonin had no effect on basal or E2-stimulated ER expression. Incubation of hepatocyte aggregates with melatonin (10(-8) to 10(-4)) for 16 or 48 h did not modify the E2-stimulated ER and vitellogenin mRNA, as measured by dot blots. Finally, neither pinealectomy nor melatonin implants caused any effect on basal or E2-stimulated ER and vitellogenin mRNA contents in the liver. Altogether, these results suggest that, although we cannot exclude potential effects at the brain or pituitary levels, melatonin has no or little effects on estrogen receptor in the liver.

Reciprocal regulation of Hck activity by phosphorylation of Tyr(527) and Tyr(416). Effect of introducing a high affinity intramolecular SH2 ligand

The Src family tyrosine kinase Hck possesses two phosphorylation sites, Tyr(527) and Tyr(416), that affect the catalytic activity in opposite ways. When phosphorylated, Tyr(527) and residues C-terminal to it are involved in an inhibitory intramolecular interaction with the SH2 domain. However, this sequence does not conform to the sequence of the high affinity SH2 ligand, pYEEI. We mutated this sequence to YEEI and show that this mutant form of Hck cannot be activated by exogenous SH2 ligands. The SH3 domain of Hck is also involved in an inhibitory interaction with the catalytic domain. The SH3 ligand Nef binds to and activates YEEI-Hck mutant in a similar manner to wild-type Hck, indicating that disrupting the SH3 interaction overrides the strengthened SH2 interaction. The other phosphorylation site, Tyr(416), is the autophosphorylation site in the activation loop. Phosphorylation of Tyr(416) is required for Hck activation. We mutated this residue to alanine and characterized its catalytic activity. The Y416A mutant shows a higher K(m) value for peptide and a lower V(max) than autophosphorylated wild-type Hck. We also present evidence for cross-talk between the activation loop and the intramolecular binding of the SH2 and SH3 domains.

Mapping genes that control hormone-induced ovulation rate in mice

The present study mapped quantitative trait loci (QTL) that control 6-fold genetic differences in hormone-induced ovulation rate (HIOR) between C57BL/6J (B6) (HIOR = 54) and A/J strain mice (HIOR = 9). (The gene name is Ovulation Rate Induced [ORI] QTL and the gene symbol is Oriq.) QTL linkage analysis was conducted on 167 (B6xA)xA backcross mice at 165 loci. Suggestive B6 ORI QTL that control the number of eggs in cumulus mapped, as follows, near: Cyp19 and D9Mit4 on chromosome (Chr) 9 (Oriq1); D2Mit433 on Chr2 (Oriq2); D6Mit316 on Chr6 (Oriq3); DXMit22 on ChrX (Oriq4) and were associated with a 2.7, 2.7, 2.6, and 4.2 egg increases in HIOR, respectively. Oriq3 was significant (LOD = 3.45) based on composite interval mapping. QTL linkage analysis of the number of eggs matured by endogenous gonadotropins and ovulated by eCG mapped a significant Oriq5 to Chr 10 and suggestive Oriq to Chr 6, 7, and X. These data provide the first molecular genetic markers for reproductive QTL that control major differences in ovarian responsiveness to gonadotropins. These and closely linked syntenic molecular markers will enable a more accurate prediction of ovarian responsiveness to gonadotropins and provide selection criteria for improving reproductive performance in diverse mammalian species.

Plasmin cleavage of the amyloid beta-protein: alteration of secondary structure and stimulation of tissue plasminogen activator activity

Cerebrovascular amyloid beta-protein (A beta) deposition, a key pathological feature of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis Dutch-type, can lead to intracerebral hemorrhage; however, the mechanism for this remains unclear. Assembled A beta is a potent stimulator of tissue-type plasminogen activator (tPA) in vitro. Herein, we investigated the stimulation of tPA by freshly solubilized A beta 1-40. The rate of tPA stimulation by A beta 1-40 increased dramatically over time, suggesting that A beta may be altered during the course of the reaction. SDS-PAGE analysis showed that A beta 1-40 was cleaved during the course of the reaction. Subsequent studies showed that it was plasmin, the product of tPA activation of plasminogen, that specifically cleaved A beta 1-40 in the amino terminal region between Arg5 and His6. Plasmin effectively cleaved a chromogenic substrate corresponding to this cleavage site in A beta. Circular dichroism spectral analysis showed that A beta 6-40 adopted a strong beta-sheet secondary structure. This truncated A beta 6-40 peptide was a potent stimulator of tPA in vitro. Our results indicate that beta-sheet secondary structure of A beta, which can be promoted by plasmin cleavage, stimulates tPA activity. These findings suggest that pathologic interactions between A beta, tPA, and plasmin in the cerebral vessel wall could result in excessive proteolysis contributing to intracerebral hemorrhages.

Developing individualized care in nursing homes: integrating the views of nurses and certified nurse aides

Despite recent attention devoted to the development of individualized care in nursing homes, empirical research assessing changes in practice is quite limited, and very few studies have explored specifically the experiences and perceptions of certified nurse aides (CNAs). This study reports findings from a comparative analysis conducted on a data set including quantitative and qualitative data from CNAs (N = 289) and nurses in Connecticut (N = 245). Measures of obstacles to individualized care and needs for future supports were explored. A number of significant differences in perceptions of obstacles to providing individualized care were found. The nurses were significantly more likely to identify the following impediments to change: cost (p < .0001), concepts not integrated into work (p < .0001), lack of administrative support (p < .10), and staff attitudes (p < .10). The CNAs were significantly more likely to report inadequate staffing (p < .001), lack of interdisciplinary teams (p < .001), and resident and family attitudes (p < .01) as problematic. These findings suggest substantial discordance among nurses and CNAs on a number of important issues surrounding individualized care. Such disparate perceptions pose challenges to nursing homes committed to the implementation of individualized care alternatives. Successful approaches must consider the various vantage points of caregivers and administrators.

Variable dose naltrexone-induced hypothalamic-pituitary-adrenal stimulation in abstinent alcoholics: a preliminary study

Opiate antagonists have been found to stimulate the hypothalamic-pituitary-adrenal axis. However, despite established usefulness in the management of alcoholism, systematic, oral dose-titrated natrexone-induced hypothalamic-pituitary-adrenal stimulation has never been studied in alcoholics. Six patients (5 males, 1 female) with DSM-IV alcohol dependence, who were at least 4 weeks abstinent from any alcohol [mean 55 days (+/-SE 7.5)], were given four challenges of oral naltrexone (0, 25, 50, and 100 mg) in a randomized order at least 3 days apart, after an overnight fast. Naltrexone was administered at 9 AM; serum ACTH, cortisol, and prolactin were measured at time 0 and at 9 time points over the next 4 hr. Subjects also filled out a side effect questionnaire and an alcohol urge questionnaire. Physiological measurements of blood pressure and pulse rate were taken at the same time points. Repeated-measures ANOVA of the changes in serum ACTHs over time revealed a significant effect of drug (placebo vs. any dose of naltrexone) (p < 0.05). Post-hoc analysis revealed a significant difference between placebo and the 25 mg dose (p < 0.01), the 50 mg dose (p < 0.01), but no significance between the placebo and the 100 mg dose (p = 0.1). A repeated-measures ANOVA of the changes in serum cortisols over time revealed a significant effect of drug (p < 0.01). Post-hoc analysis revealed a significant difference between placebo and the 25 mg dose (p < 0.01), between placebo and the 50 mg dose (p < 0.05), and placebo and the 100 mg dose (p < 0.01). There was a significant between dose difference in pulse rate changes over baseline (p < 0.01), and post-hoc analysis revealed a significant diminution in pulse rate at the 100 mg dose relative to placebo (p < 0.001), and to the other doses. There were no significant differences in reported side effects, alcohol urge questionnaire scores, or in other physiological measurements between doses. These data suggest a significant rise in ACTH and cortisol in response to naltrexone in alcoholics compared with placebo, with no differences between 25 mg, 50 mg, and 100 mg doses, and a significant diminution in pulse rate responses at the 100 mg dose.

Intramolecular regulatory interactions in the Src family kinase Hck probed by mutagenesis of a conserved tryptophan residue

Intramolecular interactions between the Src homology domains (SH2 and SH3) and the catalytic domains of Src family kinases result in repression of catalytic activity. The crystal structure of the Src family kinase Hck, with its regulatory domains intact, has been solved. It predicts that a conserved residue, Trp260, at the end of the linker between the SH2 and the catalytic domains plays an important role in regulation by the SH3 and SH2 domains. We have mutated this residue and compared the activities of C-terminally phosphorylated wild type Hck and W260A Hck. The W260A mutant has a higher specific activity than wild type Hck. The W260A mutant requires autophosphorylation at Tyr416 for full activity, but it is not activated by ligand binding to the SH3 or SH2 domains. This mutation also changes the accessibility of the SH2 and SH3 domains to their cognate peptide ligands. Our results indicate that Trp260 plays a critical role in the coupling of the regulatory domains to the catalytic domain, as well as in positioning the ligand binding surfaces.