Comparative proteomics reveals evidence for evolutionary diversification of rodent seminal fluid and its functional significance in sperm competition

During insemination, males of internally fertilizing species transfer a complex array of seminal fluid proteins to the female reproductive tract. These proteins can have profound effects on female reproductive physiology and behavior and are thought to mediate postcopulatory sexual selection and intersexual conflict. Such selection may cause seminal fluid to evolve rapidly, with potentially important consequences for speciation. Here we investigate the evolution of seminal fluid proteins in a major mammalian radiation, the muroid rodents, by quantifying diversity in seminal fluid proteome composition for the first time across a broad range of closely related species. Using comparative proteomics techniques to identify and cross-match proteins, we demonstrate that rodent seminal fluid is highly diverse at the level of both proteomes and individual proteins. The striking interspecific heterogeneity in seminal fluid composition revealed by our survey far exceeds that seen in a second proteome of comparable complexity, skeletal muscle, indicating that the complement of proteins expressed in seminal fluid may be subject to rapid diversification. We further show that orthologous seminal fluid proteins exhibit substantial interspecific variation in molecular mass. Because this variation cannot be attributed to differential glycosylation or radical differences in termination sites, it is strongly suggestive of rapid amino acid divergence. Sperm competition is implicated in generating such divergence for at least one major seminal fluid protein in our study, SVS II, which is responsible for copulatory plug formation via transglutaminase-catalyzed cross-linking after insemination. We show that the molecular mass of SVS II is positively correlated with relative testis size across species, which could be explained by selection for an increased number of cross-linking sites involved in the formation of the copulatory plug under sperm competition.

Positional proteomics: preparation of amino-terminal peptides as a strategy for proteome simplification and characterization

We describe a protocol for selective extraction of the amino (N)-terminal-most peptide of a protein or a mixture of proteins after proteolysis. The first stage of the protocol blocks the free amino groups alpha and epsilon (the latter being lysyl residues) on the intact proteins by acetylation. In the second stage, proteolysis of the acetylated proteins yields a mixture of N-terminally acetylated (true N-terminal) and non-acetylated (internal and carboxy-terminal) peptides. Affinity capture of peptides bearing free amino groups using an immobilized amine-reactive reagent removes internal peptides from the mixture. The unbound fraction is highly enriched in N-terminal peptides, which can be analyzed without further treatment. This method is compatible with a range of proteolytic enzymes and fragmentation methods, and should take 2 d to complete. The N-terminal peptides can then be analyzed by mass spectrometry. This low cost, rapid method is readily adopted using off the shelf reagents.

Predictors of depressive symptoms in primary caregivers of young children with or at risk for developmental delay

BACKGROUND

Despite extensive research with families raising children with or at risk for developmental delay (DD), it is not clear whether primary caregivers of these children are at increased risk for depressive symptoms. Discrepant findings in the literature may be owing to heterogeneity of child problems. More research is needed on child, parent and family variables that may increase risk for, or resilience to, caregiver depressive symptoms. Some studies have found that parental resources (e.g. social support and coping strategies) may buffer the effects of parental distress, while other studies have highlighted the role of parental self-efficacy.

METHODS

We examined Beck Depression Inventory (BDI) scores in 178 primary caregivers (mainly biological mothers) who had 2-year-old children with or at risk for DD owing to: (a) low birthweight, prematurity or multiple birth (n = 58), (b) other known reasons (e.g. Down syndrome, spina bifida) (n = 67), or (c) unknown reasons (n = 69).

RESULTS

We found that 20% (n = 35) of the caregivers scored above the BDI clinical cut-off for depression. Analysis of variance revealed that caregivers with elevated BDI scores had higher child behaviour problem and escape-avoidance coping scores, and lower social support and parent self-efficacy, compared with caregivers without depressive symptoms. Caregivers with children who had DD for unknown reasons had higher BDI scores than caregivers of the other two groups of children. Regression analyses showed that child behaviour problems, escape-avoidance coping strategies and social support predicted caregiver BDI scores, but caregiver self-efficacy only did so when entered independently of social support. Only social support mediated and (marginally) moderated the relationship between child behaviour problems and caregiver depressive symptoms.

CONCLUSIONS

These findings suggest that early intervention programmes should carefully consider the interaction of child characteristics (e.g. Diagnosis and behaviour problems), caregiver resources (e.g. coping strategies and social support), and parental mental health and mood when planning and tailoring services for families of children with or at risk for DD.

Chemical ripeners increase early season sugar content in a range of sugarcane varieties

Ripening in sugarcane refers to an increase in sugar content on a fresh weight basis before commercial harvest. Certain chemicals are applied to cane in commercial fields in some countries to accelerate ripening and improve profitability of sugar production. However, responses have usually been reported to be variety and environment specific. We examined changes in the sucrose content in the juice extracted from 43 Australian sugarcane (Saccharum spp. hybrid) varieties in response to 4 ripener treatments in the Burdekin region in northern Queensland over 2 years. The 4 treatments applied were ethephon (as Ethrel®) + fluazifop-P butyl (as Fusilade®), Fusilade® alone, glyphosate (as Weedmaster® Duo), and haloxyfop-R methyl (as Verdict®). These treatments were applied in March–April each year and compared with an untreated control. Of particular interest was whether economic responses are possible for Australian varieties harvested in the May and June period when sugar content in cane is usually low. Increases in sucrose (measured by pol) levels in cane juice were observed after combined application of Ethrel + Fusilade (E+F) and after application of glyphosate, although the result for the latter varied between years. These results suggest that opportunities exist in the Australian industry to improve the profitability of early-harvested sugarcane crops, but further research is required to quantify effects on cane yield and responses in diverse environments.

Patient satisfaction in radiation oncology

As part of a quality improvement exercise at the Perth Radiation Oncology Centre, a survey was undertaken to ascertain the current level of patient satisfaction with the information they were receiving from their treating radiation oncologist. In addition, the effect of radiation on patients' anxiety levels was investigated. Two questionnaires were given to patients having radical radiotherapy for malignancy. The first questionnaire consisted of the Information Satisfaction Questionnaire and the State Trait Anxiety Index. It was given to patients before the commencement of their course of radiotherapy. The second questionnaire consisted of the State Trait Anxiety Index and was given at the completion of their radiotherapy. A total of 120 patients completed both the questionnaires. The majority of patients were satisfied/very satisfied with the explanation of their illness and radiation toxicities. Fewer patients were satisfied with the explanation of lifestyle (e.g. diet, exercise, smoking) and practical issues such as parking and treatment costs. The patients showed a statistically significant reduction in both their State and Trait Anxiety scores following radiotherapy. Following this study, we have developed new information booklets addressing lifestyle and practical issues, which were not being adequately addressed as shown in this study. Our next study will assess the effect of these new information booklets.

Investigation of global developmental delay

The investigation of global developmental delay in preschool children varies between centres and between paediatricians. Following a literature search and review of the evidence base, guidelines were developed to assist in the assessment and management of such children presenting to secondary level services. Evidence supporting the use of genetic and biochemical investigations on a screening basis was found, but there was no evidence to support the use of metabolic investigations or neuroimaging in the absence of other positive findings on history or examination. Detailed history and examination are paramount in the assessment of children with global developmental delay. Investigations can be a useful adjunct in determining aetiology. Evidence based guidelines have been developed to assist doctors in the selection of appropriate investigations for this group of children.

The DNA sequence and biological annotation of human chromosome 1

The reference sequence for each human chromosome provides the framework for understanding genome function, variation and evolution. Here we report the finished sequence and biological annotation of human chromosome 1. Chromosome 1 is gene-dense, with 3,141 genes and 991 pseudogenes, and many coding sequences overlap. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Fine-scale recombination occurs in hotspots of varying intensity along the sequence, and is enriched near genes. These and other studies of human biology and disease encoded within chromosome 1 are made possible with the highly accurate annotated sequence, as part of the completed set of chromosome sequences that comprise the reference human genome.

Positional proteomics: selective recovery and analysis of N-terminal proteolytic peptides

Bottom-up proteomics is the analysis of peptides derived from single proteins or protein mixtures, and because each protein generates tens of peptides, there is scope for controlled reduction in complexity. We report here a new strategy for selective isolation of the N-terminal peptides of a protein mixture, yielding positionally defined peptides. The method is tolerant of several fragmentation methods, and the databases that must be searched are substantially less complex.

Ethical and legal issues in caring for asylum seekers and refugees in the UK

Inward migration to the UK remains topical and controversial as numbers continue to increase. Many immigrants have specific health care needs and may shoulder a large burden of infectious disease. Imposition of legal constraints can have a huge impact on the medical care afforded to immigrants. Currently UK policy is to treat, free of charge and with NHS resources, those who fulfil specific criteria. However an increasing number are being asked to pay for their treatment. Many health care professionals are confused as to current legal restrictions and require guidance on the associated ethical issues. We concentrate on provision of care to HIV positive individuals and use cases to illustrate some of the issues. However these issues are equally pertinent to practitioners in all branches of medicine.

How much explanation is enough? A study of parent requests for information and physician responses

OBJECTIVE

To examine the relationship between doctor-parent communication patterns and parents' perceptions that they were listened to by the doctor.

DESIGN

Cross-sectional, clinic-based survey. Before the visit, parents were asked about the strength of their desires/preferences for being listened to; after the visit, they were asked if their desires were fulfilled and to rate their satisfaction with care. Encounters were audiotaped, transcribed, and coded for parent requests for information and action and physician responses to those requests. Coding was performed using an adapted version of the Taxonomy of Requests by Patients (TORP). Physician responses to parental requests for information were coded as brief, moderate, or prolonged fulfillment or as partially fulfilled, ignored, or denied.

SETTING

Two private pediatric practices, 1 community based and 1 university based.

PARTICIPANTS

Ten of 13 eligible physicians (participation rate, 77%) and 306 of 356 eligible parents (participation rate, 86%) who sought care for their children's respiratory illnesses. Parents were invited to participate if they spoke and read English and if their child was 2-10 years old, had a chief complaint of cold symptoms, and was seeing one of the participating physicians. Complete data were obtained for 287 doctor-parent encounters (94%).

RESULTS

Before the visit, 74% of parents reported that they considered it necessary for the physician to listen to their ideas about their child's illness. Among these parents, 62% (n = 130) reported after the visit that the physician had listened to their ideas. As the proportion of moderate-length responses to parent requests for information increased, parents were significantly more likely to report being listened to (P <.05). Multivariate results indicated a 59% probability of parents reporting that they were listened to when given moderate-length responses, 45% when given brief responses, 39% when given prolonged responses, and 12% when requests for information were only partially fulfilled, ignored, or denied. The length of response to parent requests for information was not related to overall parent satisfaction.

CONCLUSIONS

Parents who received moderate-length answers to their questions were most likely to report that they were listened to. Although it is assumed that lengthier, in-depth explanations result in higher satisfaction, this study suggests that more doctor talk does not necessarily constitute better communication.

Parent expectations for antibiotics, physician-parent communication, and satisfaction

OBJECTIVES

To explore how parents communicate their preferences for antibiotics to their child's physician and to examine whether physicians can communicate why antibiotics are not being prescribed in a way that maintains satisfaction with the visit.

DESIGN

Previsit survey of parents, audiotaping of the study encounters, and a postvisit survey of parents and physicians.

SETTING

Two private pediatric practices.

PARTICIPANTS

Ten physicians (response rate = 77%) and a consecutive sample of 295 eligible parents (response rate = 86%) who attended acute care visits for their children between October 1996 and March 1997.

MAIN OUTCOME MEASURES

Physician-perceived pressure to prescribe antibiotics and parental visit-specific satisfaction.

RESULTS

Fifty percent of parents expressed a previsit expectation for antibiotics. Among these parents, only 1% made a direct verbal request for them. Even when no direct requests for antibiotics were made, physicians still perceived an expectation for antibiotics 34% of the time. Among parents who did not receive expected antibiotics, those offered a contingency plan from the physician (i.e., the possibility of receiving antibiotics in the future if their child did not get better) had a higher mean satisfaction score than parents not receiving a contingency plan (76 vs. 58.9; P<.05).

CONCLUSION

Physicians should consider providing a contingency plan to parents who expect antibiotics for their children when there is no clinical indication. Further study is needed to determine how parents indirectly communicate their desire for antibiotics and what additional communication techniques physicians can use to resist the overprescribing of antibiotics.

The meaning of life: animism in the classificatory skills of older adults

Seventy-five participants aged from their teens to their seventies were measured on a battery of measures of personality, lifestyle, intelligence, and educational background. These measures were gauged against performance on a measure of animism, in which participants judged twenty-three items (4 alive, 19 non-living) as living or non-living. Although animism errors increased with age, all groups displayed animism errors, thereby contradicting Piaget (1965). Performance is partially explained by fluid intelligence level, but is more plausibly ascribed to progressive loss of what is essentially peripheral information to non-academic people.

Low-density lipoprotein (LDL)-induced monocyte-endothelial cell adhesion, soluble cell adhesion molecules, and autoantibodies to oxidized-LDL in chronic renal failure patients on dialysis therapy

Premature atherosclerosis is a major cause of morbidity and mortality in chronic renal failure patients undergoing dialysis. In this study, we compared autoantibodies to oxidized low-density lipoprotein (OX-LDL), soluble cell adhesion molecules (CAMs), and the effect of both LDL and OX-LDL on monocyte endothelial cell adhesion in chronic renal failure patients on hemodialysis (HD, n = 16) and peritoneal dialysis (PD, n = 17) compared with matched healthy control subjects (C, n = 17). In addition, we studied the effect of supplementation with RRR-alpha-tocopherol (AT) 800 IU/d for 12 weeks on the above measures. LDL and OX-LDL induced adhesion of U937 cells to cultured endothelium, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intracellular adhesion molecule-1 (sICAM-1), and soluble E-selectin (sE-selectin); autoantibodies to OX-LDL and markers of lipid peroxidation were determined before and after AT supplementation. Native LDL from PD patients induced greater monocyte-endothelial cell adhesion than LDL from C subjects (43.8% +/- 17.0% v25.3% +/- 17.7%, respectively, P = .0028). OX-LDL from chronic renal failure patients on both PD and HD stimulated greater adhesion than OX-LDL from the C subjects (68.0% +/- 18.5% and 57.6% +/- 15.1% v 40.9% +/- 17.3%, respectively, P < .01); OX-LDL from PD patients induced greater adhesion than that from HD patients (P < .01). Plasma methylglyoxal levels were significantly increased in both HD and PD groups, with higher levels in the HD group. Chronic renal failure patients on HD and PD also had higher levels of plasma sVCAM-1 and sE-selectin than C subjects (P < .01), indicating endothelial activation. Titers of autoantibodies to OX-LDL were not elevated in renal failure patients. Supplementation with AT 800 IU/d for 12 weeks, while resulting in significant enrichment with AT in LDL, did not have a significant effect on any of the parameters studied. This study makes the novel observation that the LDL of chronic renal failure patients on HD and PD appears to be potentially more atherogenic, since it induces greater monocyte-endothelial cell adhesion.