Sparse ensemble neural code for a complete vocal repertoire

The categorization of animal vocalizations into distinct behaviorally relevant groups for communication is an essential operation that must be performed by the auditory system. This auditory object recognition is a difficult task that requires selectivity to the group identifying acoustic features and invariance to renditions within each group. We find that small ensembles of auditory neurons in the forebrain of a social songbird can code the bird's entire vocal repertoire (∼10 call types). Ensemble neural discrimination is not, however, correlated with single unit selectivity, but instead with how well the joint single unit tunings to characteristic spectro-temporal modulations span the acoustic subspace optimized for the discrimination of call types. Thus, akin to face recognition in the visual system, call type recognition in the auditory system is based on a sparse code representing a small number of high-level features and not on highly selective grandmother neurons.

Core outcome set for uncomplicated acute appendicitis in children and young people

Background

Research studies to inform clinical practice and policy in children and young people with appendicitis are hampered by inconsistent selection and reporting of outcomes. The aim of this study was to develop a core outcome set for reporting all studies of uncomplicated acute appendicitis in children and young people.

Methods

Systematic literature reviews, qualitative interviews with parents and patients treated for uncomplicated acute appendicitis, and a Study‐Specific Advisory Group informed a long list of outcomes. Outcomes were then prioritized by stakeholders based in the UK (patients, parents, and paediatric and general surgeons) in an online three‐round Delphi consensus process, followed by face‐to‐face consensus meetings.

Results

A long list of 40 items was scored by 147 key stakeholders in the first Delphi round, of whom 90 completed the two subsequent Delphi rounds. The final core outcome set comprises 14 outcomes: intra‐abdominal abscess, reoperation (including interventional radiology procedure), readmission to hospital, bowel obstruction, wound infection, antibiotic failure, wound complication, negative appendicectomy, recurrent appendicitis, death, patient stress/psychological distress, length of hospital stay, time away from full activity and child's quality of life.

Conclusion

A core outcome set comprising 14 outcomes across five key domains has been developed for reporting studies in children and young people with uncomplicated acute appendicitis. Further work is required to determine how and when to measure these outcomes.

Susceptibility of Flowering Cotton to Damage and Yield Loss from Tarnished Plant Bug (Hemiptera: Miridae)

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is a major pest of cotton in the midsouthern United States, including the states of Arkansas, Mississippi, Louisiana, western Tennessee, and southeastern Missouri. Insecticides provide the primary form of control for this pest, and numerous applications are required annually to control the tarnished plant bug. Little information exists regarding when to terminate insecticide applications targeting tarnished plant bugs in cotton. Numerous sprays are made late in the season to protect a small percentage of the overall yield. Experiments were conducted at the Mississippi State University Delta Research and Extension Center to determine the impact of tarnished plant bug infestation timings on cotton yield. Two separate planting dates were utilized to determine the weeks of flowering that tarnished plant bugs can cause significant yield losses. There was a significant planting date by treatment interaction. Overall, yields were greater in the first planting date than the second planting date. In both planting dates, the first 4 wk of flowering were the most critical for tarnished plant bug control, and this is when the greatest yield losses occurred. Also, when no insecticide applications were made after the fourth week of flowering, no significant yield loss was observed. These data demonstrate the importance of scouting and adhering to treatment thresholds during the early flowering period. These data also suggest that thresholds may be able to be modified or eliminated after the fourth week of flowering, but more research is needed to confirm this.

The association between loss of ankle dorsiflexion range of movement, and hip adduction and internal rotation during a step down test

A pattern of excessive hip adduction and internal rotation with medial deviation of the knee has been associated with numerous musculo-skeletal dysfunctions. Research into the role that ankle dorsiflexion (DF) range of motion (ROM) play in lower limb kinematics is lacking. The objective of this cross-sectional, observational study was to investigate the relationship between ankle DF ROM, and hip adduction and hip internal rotation during a step-down test with and without heel elevation in a healthy female population. Hip and ankle ROM was measured kinematically using a ten-camera Optitrack motion analysis system. Thirty healthy female participants (mean age = 20.4 years; SD = 0.9 years) first performed a step-down test with the heel of the weight bearing foot flat on the step and then with the heel elevated on a platform. Ankle DF, hip adduction and hip internal rotation were measured kinematically for the supporting leg. Participants who had 17° or less of ankle DF ROM displayed significantly more hip adduction ROM (p = 0.001; Cohen's d effect size = 1.2) than the participants with more than 17° of DF during the step-down test. Participants with limited DF ROM showed a significant reduction in hip adduction ROM during the elevated-heel step-down test (p = 0.008). Hip internal rotation increased in both groups during the EHSD compared to the step-down test (p > 0.05) Reduced ankle DF ROM is associated with increased hip adduction utilised during the step-down test. Ankle DF should be taken into account when assessing patients with aberrant frontal plane lower limb alignment.

Do stressed mothers have heavier children? A meta-analysis on the relationship between maternal stress and child body mass index

Child obesity continues to be a prevalent public health issue. This meta-analysis synthesized 17 studies investigating the association between levels of psychological stress experienced by mothers and the body mass index of their children. The overall standardized mean difference effect size was positive and significantly different from zero in cross-sectional d = 0.20 (k = 14, 95% confidence interval [CI]: 0.06, 0.34) and longitudinal studies d = 0.18 (k = 5, 95% CI: 0.00, 0.351) and had significant heterogeneity in both (cross-sectional, Q[13] = 193.00, P < 0.001; longitudinal, Q[4] = 29.46, P < 0.001). In longitudinal studies, effect sizes were larger when children also would have experienced the stressor, Q(6) = 4.68, P < 0.05, for toddlers than infants, Q(4) = 5.04, P < 0.05, and in higher quality studies, Q(4) = 14.58, P < 0.05. Results highlight the potential benefits of including a parent stress management component in childhood obesity prevention programmes.

Effects of different frequencies of loading on healing in partial rupture of the Achilles tendon in a rat model

OBJECTIVE

To determine the histological effects of different frequencies of loading in a healing Achilles tendon following partial rupture.

DESIGN

Experimental laboratory study.

SETTING

University of Zimbabwe, Department of Physiology, Animal house.

SUBJECTS

Sixty female Sprague-Dawley rats.

INTERVENTION

Partial tenotomies of the right Achilles tendon were performed surgically. From day 1 post operatively, the animals were allocated to treadmill running at different frequencies (once (OD), two (BD), three (TDS) and four (QID) times daily) up to 21 days. Histological sides of the tendons were made at days 7,14 and 21 and interpreted by a blinded pathologist.

MAIN OUTCOME MEASURES

Collagen fibre orientation, inflammatory cell populations, fibroblast morphology and neoangiogenesis were observed and scored using the Grande Biomechanical Histological Correlation Score.

RESULTS

Mean weight was 209.67g ±30.14. The best and worst arrangements of collagen were in the QID group (73%) and OD group (46.7%) respectively. These differences were not statistically significant (p=0.487). The BD group had the most mature fibroblast nuclei and the QID tendons had the least mature (p=0.577). Inflammatory cell populations were independent of loading frequency (p=0.132).

CONCLUSION

Changing the frequency of the same type of loading in a healing tendon does not have an effect on the healing process in partially ruptured Achilles tendons during the inflammatory and proliferative phases.

The association between trunk muscle endurance and lumbo-pelvic stability in adolescent low back pain: A cross sectional study

Decreased trunk muscle endurance has been identified as a risk factor for adolescent LBP, and poor lumbo-pelvic stability has been found to be associated with LBP in the adult population. The aim of the study was to investigate the association between adolescent LBP, trunk muscle endurance and poor lumbo-pelvic stability. Design: A cross sectional study. Participants: 80 adolescents in grade 8 to grade 11, aged 12 to 17 years, at three high schools in Gauteng, who agreed to participate in the study. Method: Data was collected by means of a validated questionnaire and physical tests. The active straight leg raise test was used to record the lumbo-pelvic stabilising muscles. The Sorensen, Shirado and side-bridge tests were used to record trunk extensor, flexor and side flexor muscle endurance, respectively. Results: The results revealed a lifetime prevalence of LBP of 82.50%, one year prevalence of 78.80% and point prevalence of 23.80%. Adolescents with LBP demonstrated decreased trunk extensor muscle endurance but increased trunk flexor muscle endurance (p=0.044), compared to non-LBP adolescents. Poor lumbo-pelvic stability was not associated with adolescent LBP, but was associated with decreased extensor trunk muscle endurance (p=0.031). Conclusion: There was an association between trunk flexor muscle endurance and adolescent LBP, and between decreased trunk extensor muscle endurance and poor lumbo-pelvic stability. No association was found between LBP and poor lumbo-pelvic stability.

The effect of trigger point therapy and medicine ball exercises vs trigger point therapy and stretching on hip rotational biomechanics of the golf swings

Background: Elite golfers sustain a large number of lumbar spine injuries. Poor rotational biomechanics, which may occur as a result of a shortened iliopsoas muscle, increase the incidence of lumbar spine injuries in golfers. Stretches and medicine ball exercises are often used as part of golf training programmes in an attempt to restore hip flexor length and improve rotational biomechanics. The aim of this study was to ascertain the effect of a combination of trigger point therapy and medicine ball exercises compared to a combination of trigger point therapy and stretching on rotational bio-mechanics of the golf swing. Method: This is a randomised controlled trial consisting of two experimental groups (trigger point therapy and stretching vs. trigger point therapy and medicine ball exercises) and one control group (no intervention). Hip flexor length and 3D biomechanical analysis of the golf swing was performed at baseline and one week later. Results: One-hundred elite male golfers participated in this study. Rotational biomechanics, specifically downswing hip turn in the group that received trigger point therapy combined with medicine ball exercises, showed statistically significant improvement at reassessment compared to the control group (p=0.0328). Conclusion: Rotational biomechanics (downswing hip turn) improved following a combination of trigger point therapy treatment and a one week programme of medicine ball exercises. This is postulated to have occurred through neural reorganisation and not through improved tensile muscle strength. This improvement in rotational biomechanics has the potential to decrease lumbar spine injury incidence in elite golfers. This study advocates the use of trigger point therapy combined with medicine ball exercises in the treatment of golfers with shortened hip flexors.

Relationship between taxane-induced neuropathy and clinical outcomes after adjuvant chemotherapy

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Background: Neuropathy is a common and potentially enduring and disabling complication of adjuvant taxane therapy. Recent studies have identified candidate host single nucleotide polymorphisms (SNPs) associated with taxane-induced neuropathy (Schneider et al. ASCO 2011, abstr. 1000). We therefore sought to determine whether neuropathy was associated with breast cancer recurrence.

Methods: This study included 4,950 eligible women with axillary lymph node positive or high-risk node-negative breast cancer who received up to 4 cycles of AC (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2) every 3 weeks, followed by either: (1) paclitaxel 175 mg/m2 every 3 weeks x 4 (P3), (2) paclitaxel 80 mg/m2 weekly x 12 (P1), (3) docetaxel 100 mg/m2 every 3 weeks x 4 (D3), or (4) docetaxel 35 mg/m2 weekly x 12 (D1). Chemotherapy doses were based on actual body weight. Cox proportional hazards model were used to determine the relationship between neuropathy and disease free survival (DFS) and overall survival (OS) treating neuropathy status as a time dependent covariate and using a landmark analysis.

Results: Of 4,702 patients who received at least 1 taxane dose, grade 2-4 neuropathy developed in 20%, 27%, 16%, and 16% in the P3, P1, D3, and D1 arms, respectively. In a model including age, tumor size, nodal status, treatment arm, neuropathy, and the neuropathy- treatment interaction, there was no relationship between neuropathy and DFS and OS in the entire population, for any of the individual treatment arms, or for any breast cancer subtypes, whether analyzed as a time-dependent covariate or using a landmark analysis. Baseline covariates associated with an increase rate of neuropathy included black race (25% vs. 19% grade 2-4, p=0.02) and obesity (21% vs. 19%, p=0.04), but not age.

Conclusions: There was no association between taxane-induced neuropathy and DFS or OS in patients treated with contemporary AC-taxane therapy, including weekly paclitaxel. These findings show that taxane-induced neuropathy is not associated with outcome, thus suggesting that validation of SNPs predictive of neuropathy may be useful in identifying patients at higher risk for neuropathy but not taxane benefit and thereby improve therapeutic individualization.

Dynamic synergy of graphitic nanoplatelets and multi-walled carbon nanotubes in polyetherimide nanocomposites

Hybridizing graphitic nanoplatelets (GNP) with commercially functionalized multi-walled carbon nanotubes (MWCNTs) in a polyetherimide (PEI) composite at a total loading of 0.5 wt% resulted in considerable improvements in electrical conductivity, thermal conductivity and dynamic mechanical properties, compared to solely GNP or solely MWCNT composites at the same total loading. The results reveal a synergistic interaction between the GNPs and MWCNTs based on GNP protection against fragmentation of the MWCNTs during high power sonication, while still allowing full dispersion of both fillers, by providing a shielding mechanism against MWCNT damage during dispersion processing. A new process for molecular level dispersion of exfoliated GNPs in PEI is also reported. Field emission scanning electron microscopy revealed strong interactions between PEI and the flat surfaces of GNPs and effectively intercalated GNP morphology within the matrix. GNPs alone can also produce excellent electrical conductivity improvements: at 1.0 wt% of GNP, electrical conductivity of the composite increased by 11 orders of magnitude and the percolation threshold was determined to be between 0.5 and 1.0 wt% of GNP.

Intra- and inter-rater reliability of the Knee Society Knee Score when used by two physiotherapists in patients post total knee arthroplasty

Background and Purpose: It has yet to be shown whether routine physiotherapy plays a role in the rehabilitation of patients post totalknee arthroplasty (Rajan et al 2004). Physiotherapists should be using validoutcome measures to provide evidence of the benefit of their intervention. The aim of this study was to establish the intra and inter-rater reliability of the Knee Society Knee Score, a scoring system developed by Insall et al(1989). The Knee Society Knee Score can be used to assess the integrity of theknee joint of patients undergoing total knee arthroplasty. Since the scoreinvolves clinical testing, the intra-rater reliability of the clinician should be established prior to using the scores as datain clinical research. W here multiple clinicians are involved, inter-rater reliability should also be established.Design: This was a correlation study.Subjects: A  sample of thirty patients post total knee arthroplasty attending the arthroplasty clinic at Johannesburg Hospital between six weeks and twelve months postoperatively.M ethod: Recruited patients were evaluated twice with a time interval of one hour between each assessment. Statistical A nalysis: The intra- and inter-rater reliability were estimated using Intraclass Correlation Coefficient (ICC). R esults: The intra-rater reliability showed excellent reliability (h= 0.95) for Examiner A  and good reliability (h= 0.71)for Examiner B. The inter-rater reliability showed moderate reliability (h= 0.67 during test one and h= 0.66 during test two).Conclusion: The KSKS has good intra-rater reliability when tested within a period of one hour. The KSKS demonstrated moderate agreement for inter rater reliability.

Diagnosis and prevention of breast cancer in women at high risk

Abstract #MS1-3

The definition of women at highest risk is those possessing a genetic mutation establishing a defined high risk. These and women at high risk by family history but lacking geneticly defined risk should undergo surveillance by MRI as well as mammography. This should begin ten years prior to their youngest first degree relative with breast cancer. Because early stage ovarian carcinoma is so difficult to detect, women with BRCA1 or 2 mutations should be encouraged to have salpingo-oophorectomy as soon as childbearing is finished. Premenopausal oophorectomy will cut the annual risk of breast cancer in half. This means that the risk of breast cancer in the next year is not astronomical, affording the opportunity to make very deliberate decisions about possible prophylactic surgery. With the added safety of MRI surveillance, many women will delay prophylactic surgery for a time, some will never elect it. The additional benefit of tamoxifen in this setting is controversial.&#x2028; Women with known mutations who develop breast cancer will generally elect mastectomy and have the considerations of contralateral prophylactic mastectomy previously reviewed. Breast conserving surgery is an option that is valid, however, and several studies have shown good results at 5 and 10 years. For those electing mastectomy for breast cancer, the options and standards are those for any woman with the same stage of disease.&#x2028; Women without a genetically defined high risk can be followed with MRI/mammographic surveillance, participate in chemo-prevention programs, and be spared prophylactic surgery.&#x2028; Prophylactic mastectomy should be preceded by MRI and mammograms to minimize risk of an unexpected finding of breast cancer. Even when these studies are clear, a good case can be made for performing sentinel lymph node biopsy at the time of the mastectomy so that the discovery of an occult breast cancer need not raise the issue of later axillary dissection for staging. With those caveats, prophylactic mastectomy is a total mastectomy and can be either skin sparing or nipple sparing. The former provides the lowest risk of breast cancer arising in residual breast and seems preferable. Nipple sparing prophylactic mastectomy has minimal data on long term effectiveness in this population. Much of the reason for sparing the nipple skin is cosmetic and experts in breast reconstruction are not uniform in believing that there is any improvement in aesthetics with a spared-nipple over a neo-nipple if the breast tissue beneath the spared-nipple was adequately removed [it is basically a full thickness skin graft over the reconstruction tissue]. With skin sparing mastectomy the flaps must be sufficiently thin to virtually [completely is impossible] eliminate all breast tissue. The pectoralis fascia is taken for the same reason. Depending upon breast volume, sub-muscular expanders, latissimus myo-cutaneous flaps, or TRAM flaps may be used to provide the feeling of normal breast tissue and a new blood supply for the spared skin. The cosmetic result should be excellent.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr MS1-3.

National study of colorectal cancer genetics

Approximately, a third of all colorectal cancer (CRC) is due to inherited susceptibility. However, high-risk mutations in APC, the mismatch repair (MMR) genes, MUTYH/MYH, SMAD4, ALK3 and STK11/LKB1 are rare and account for <5% of cases. Much of the remaining variation in genetic risk is likely to be explained by combinations of more common gene variants that modestly increase risk. Reliable identification of such 'low penetrance' alleles would provide insight into the aetiology of CRC and might highlight potential therapeutic and preventative interventions. In 2003, the National Study of Colorectal Cancer Genetics (NSCCG) was established with the aim of collecting DNA and clinicopathological data from 20,000 CRC cases and a series of spouse/partner controls, thereby creating a unique resource for identifying low-penetrance CRC susceptibility alleles. The National Cancer Research Network (NCRN) adopted NSCCG onto its portfolio of trials and 148 centres in the United Kingdom (UK) are now actively participating. Over 8,700 cases and 2,185 controls have so far been entered into NSCCG. Our experience in developing NSCCG serves to illustrate how world-class DNA databases for genetic analyses can be rapidly developed in the United Kingdom.

Interleukin-1 alpha mediates the growth proliferative effects of transforming growth factor-beta in p21 null MCF-10A human mammary epithelial cells

Transforming growth factor-beta type 1 (TGF-beta) has been implicated as both a tumor suppressor and a tumor promoter in many solid epithelial cancers. We have previously demonstrated that the cyclin dependent kinase (CDK) inhibitor p21 acts as a molecular switch in determining a growth inhibitory versus growth proliferative response to TGF-beta in the spontaneously immortalized human mammary epithelial cell line MCF-10A. We now demonstrate that this proliferative effect of TGF-beta is mediated through the proinflammatory cytokine, interleukin-1alpha (IL-1alpha). Using gene expression array analysis, we identified IL-1alpha as a cytokine specifically upregulated only in cells lacking p21 and only upon TGF-beta stimulation. Cell proliferation assays verified that recombinant IL-1alpha was capable of inducing a growth proliferative response in p21 null MCF-10A cells, while neutralizing antibodies against IL-1alpha prevented the growth proliferative effects of TGF-beta. Mechanistically, both the CDK and proliferating cell nuclear antigen (PCNA) inhibitory functions of p21 were responsible for preventing TGF-beta induced cell proliferation, but only PCNA inhibition by p21 regulated IL-1alpha gene expression. These studies demonstrate a novel role for IL-1alpha in mediating a proliferative response to TGF-beta signaling, and suggest that therapies directed against IL-1alpha could abate the growth proliferative effects of TGF-beta without compromising its tumor suppressive function.

Locally invasive tumors arising from hyperplasia of the retinal pigment epithelium

PURPOSE

Focal hyperplasia of the retinal pigment epithelium (RPE) is a common fundus condition that is generally stationary, with little or no tendency to enlarge or spawn neoplasms. The purpose of this report is to describe the unusual clinical features of two similar cases in which a nodular tumor of the RPE was documented to arise from a small focus of hyperplasia of the RPE.

METHODS

Clinical and cytopathologic observations of two patients.

RESULTS

Both patients were observed for approximately 25 years with an unusual progressive fundus tumor that originally arose from a small, flat, irregular focus of hyperplasia of the RPE. The originally observed pigmented lesion was attributed to toxoplasmosis in one patient and laser treatment for central serous chorioretinopathy in the other. In both patients, the tumor enlarged, invaded through the full-thickness sensory retina, and produced a characteristic retinal perforation with apposition of the mass to the vitreous. In both instances, fine-needle aspiration biopsy showed scant pigmented cells, but a definite diagnosis was not made. However, clinical observations in both patients suggested that these tumors were acquired neoplasms that arose from small foci of hyperplasia of the RPE.

CONCLUSION

Focal hyperplasia of the RPE can give rise to unusual invasive tumors that invade and replace the overlying sensory retina. These tumors have unique clinical features that differentiate them from uveal melanoma and other pigmented fundus lesions.

Disruption of the interaction of mammalian protein synthesis eukaryotic initiation factor 4B with the poly(A)-binding protein by caspase- and viral protease-mediated cleavages

Eukaryotic initiation factor (eIF) 4B interacts with several components of the initiation pathway and is targeted for cleavage during apoptosis. In a cell-free system, cleavage of eIF4B by caspase-3 coincides with a general inhibition of protein synthetic activity. Affinity chromatography demonstrates that mammalian eIF4B interacts with the poly(A)-binding protein and that a region consisting of the N-terminal 80 amino acids of eIF4B is both necessary and sufficient for such binding. This interaction is lost when eIF4B is cleaved by caspase-3, which removes the N-terminal 45 amino acids. Similarly, the association of eIF4B with the poly(A)-binding protein in vivo is reduced when cells are induced to undergo apoptosis. Cleavage of the poly(A)-binding protein itself, using human rhinovirus 3C protease, also eliminates the interaction with eIF4B. Thus, disruption of the association between mammalian eIF4B and the poly(A)-binding protein can occur during both apoptosis and picornaviral infection and is likely to contribute to the inhibition of translation observed under these conditions.

Attitude change: persuasion and social influence

This chapter reviews empirical and theoretical developments in research on social influence and message-based persuasion. The review emphasizes research published during the period from 1996-1998. Across these literatures, three central motives have been identified that generate attitude change and resistance. These involve concerns with the self, with others and the rewards/punishments they can provide, and with a valid understanding of reality. The motives have implications for information processing and for attitude change in public and private contexts. Motives in persuasion also have been investigated in research on attitude functions and cognitive dissonance theory. In addition, the chapter reviews the relatively unique aspects of each literature: In persuasion, it considers the cognitive and affective mechanisms underlying attitude change, especially dual-mode processing models, recipients' affective reactions, and biased processing. In social influence, the chapter considers how attitudes are embedded in social relations, including social identity theory and majority/minority group influence.

The effect of system design on bacterial contamination of enteral tube feeds

The effect of recent changes in system design on the levels and incidence of bacterial contamination in enteral tube feeds was examined by comparing two different systems. Adult patients who had been identified as requiring enteral tube feeding were allocated to receive sterile, whole protein enteral feed from either 2 x 1000 mL triple foil laminated pouches (Nutrison Standard, Nutrison Pack, Nutricia Ltd, UK) attached to a Flocare 800 pack giving set or from 2 x 1000 mL rigid plastic bottles (Osmolite, Ross Ready-to-Hang, Abbott Laboratories, UK) connected to a Patrol Pump set. Samples of feed from the nutrient containers were sent for microbiological analysis each time the container was changed (12 and 24 h) and samples from the distal ends of giving sets after 24 h.Bacterial contamination was found in a significantly lower number of Nutrison Packs (14/120; 12%) as compared with Ross Ready-to-Hang containers (25/120; 21%) (Fisher's exact test, 1 tailed test, P > or = 0.05). However, both the level and frequency of contamination of the feed samples collected from the distal ends of the giving sets of both types of system were similar to each other but higher than those from the nutrient containers (57/120 contaminated giving sets as compared with 39/240 nutrient containers; P > or = 0.00001). On 32/120 patient days only the giving set samples were contaminated. The results highlight the important role that improvements in system design, such as the use of recessed spikes on giving sets have in reducing the risk of bacterial contamination of enteral tube feeds introduced due to faulty handling procedures, and further implicate retrograde spread of the patients' own flora as a source of contamination in the giving set.

Mesenchymal cells engulf and clear apoptotic footplate cells in macrophageless PU.1 null mouse embryos

Apoptosis is one of the key tools used by an embryo to regulate cell numbers and sculpt body shape. Although massive numbers of cells die during development, they are so rapidly phagocytosed that very few corpses are ever seen in most embryonic tissues. In this paper, we focus on the catastrophic cell death that occurs as the developing footplate is remodelled to transform webbed regions into free interdigital spaces. In the wild-type embryo, these dead cells are rapidly engulfed and cleared by macrophages. We show that in a macrophageless mouse embryo, null for the haemopoetic-lineage-specific transcription factor, PU.1, the task of phagocytosis is taken over by ‘stand-in’ mesenchymal neighbours in a clear example of cell redundancy. However, it takes three times as many of these mesenchymal phagocytes to complete the task and, at each stage of the clearance process - in the recognition of apoptotic debris, its engulfment and finally its digestion - they appear to be less efficient than macrophages. A molecular explanation for this may be that several of the engulfment genes expressed by macrophages, including the ABC1 transporter (believed to be part of the phagocytic machinery conserved from Caenorhabditis elegans to mouse), are not upregulated by these ‘stand-in’ phagocytes.

Dynamic actin-based epithelial adhesion and cell matching during Drosophila dorsal closure

BACKGROUND

The adhesion of two epithelial sheets is a fundamental process that occurs throughout embryogenesis and during wound repair. Sealing of the dorsal epidermis along the midline of the Drosophila embryo provides a genetically tractable model to analyse the closure of such holes. Several studies indicate that the actin cytoskeleton plays a critical role in dorsal closure. Although many components of the signalling cascade directing this process have been identified, the precise cell-biological events upon which these signals act remain poorly described.

RESULTS

By confocal imaging of living fly embryos expressing green fluorescent protein (GFP)-tagged actin, we found that dorsal closure relies on the activity of dynamic filopodia and lamellipodia that extend from front-row cells to actively zipper the epithelial sheets together. As these epithelial fronts approach one another, we observed long, thin filopodia, apparently 'sampling' cells on the opposing face. When the assembly of these actin-based protrusions was blocked (by interfering with the activities of Cdc42 and Jun N-terminal kinase signalling), the adhesion and fusion of opposing epithelial cells was prevented and their ability to 'sense' correct partners was also blocked, leading to segment misalignment along the midline seam.

CONCLUSIONS

Dynamic, actin-based protrusions (filopodia and lamellae) are critical, both in the mechanics of epithelial adhesion during dorsal closure and in the correct 'matching' of opposing cells along the fusion seam.

A curricular renaissance: graduate education centered on occupation

A 3-year project of curricular renaissance undertaken by the faculty of an entry-level master's degree program is described. This project culminated in a thoroughly redesigned program of study centered around the construct of occupation and built on a foundation of knowledge in occupational science. Described herein are three developmental and highly iterative domains of activity that were crucial to the project's success: (a) environmental scanning and analysis, (b) creation of a compelling future vision of occupational therapy, and (c) curriculum planning. Also detailed are especially salient assumptions and beliefs about graduate education as well as seven themes that encompass the program's academic content and illustrate its defining emphases. These themes are (a) occupation, (b) the human as an occupational being, (c) occupation as a medium of change, (d) clinical reasoning, (e) ethical reasoning, (f) investigative reasoning, and (g) occupational therapists as scholars and change agents in systems. The article concludes with reflections on innovation in graduate education in occupational therapy today.

Changes in integrity and association of eukaryotic protein synthesis initiation factors during apoptosis

Induction of apoptosis results in inhibition of the rate of overall protein synthesis in a variety of cell types. We have shown previously that polypeptide chain initiation factor eIF4GI is rapidly cleaved by caspase-3, whereas other components of the eIF4F complex are much more stable during apoptosis in BJAB and Jurkat cells. We have now extended our analysis to other factors involved in the initiation of protein synthesis and we report here that eIF4B, the p35 subunit of eIF3, and minor proportions of the alpha subunit of eIF2 and the eIF4E-binding protein 4E-BP1 are also cleaved to give rise to discrete fragments. These cleavages occur with delayed kinetics relative to that seen for eIF4GI, and eIF2beta and eIF2gamma levels also decrease at a relatively late stage of apoptosis. In contrast, the second form of eIF4G described recently, eIF4GII, is cleaved as rapidly as eIF4GI under the same conditions. Purified recombinant caspase-3 is able to degrade eIF4B and eIF3(p35) in vitro, producing fragments of the same sizes as those seen in intact cells. Induction of apoptosis also results in a biphasic change in the association of 4E-BP1 with eIF4E. Thus the progress of apoptosis is characterized by a complex programme of changes in several initiation factors, including the specific fragmentation or complete degradation of some and alterations in the association status of others. These events are likely to contribute to the inhibition of protein synthesis seen under these conditions.

The anatomy of the extrathoracic intercostobrachial nerve

BACKGROUND

In the past decade surgeons have become increasingly aware of the morbidity caused by the division of the intercostobrachial nerve (ICBN) during axillary dissection. To prevent this problem and also to explain its variable occurrence, a detailed knowledge of the anatomy of the nerve is required.

METHODS

Twenty-eight axillary dissections were performed demonstrating the anatomy of the ICBN.

RESULTS

In all dissections the nerve originated from the second intercostal space, with contributions from the first and third intercostal nerve each on one occasion. The posterior axillary branch was constant but may branch early, simulating a second nerve. The ICBN had a variable relationship to the lateral thoracic vein: anterior, posterior or wrapping around it. In 36% there was a connection to the medial cord of the brachial plexus in the axilla. In the upper arm the nerve lies in the subcutaneous fat; in the majority it supplied at least the proximal half of the arm, and in one-third it reached the level of the elbow joint. In 18% there was a connection to the medial cutaneous nerve of the arm.

CONCLUSION

The ICBN and its main branch (the posterior axillary nerve) were constant in all dissections. But its origin, size, connection to the brachial plexus and medial cutaneous nerve of the arm were variable, as was its ultimate destination in the arm.

The self-esteem motive in social influence: agreement with valued majorities and disagreement with derogated minorities

This research provides evidence for the role of self-esteem in social influence; it demonstrates that the positions taken by self-relevant social groups can threaten people's self-esteem. Participants who wished to align themselves with a majority group and who learned that the group held a counterattitudinal position suffered a reduction in self-esteem. Similarly, participants who wished to differentiate themselves from a derogated minority group and who learned that the group held attitudes similar to theirs experienced reduced self-esteem. Group attitudes, however, did not affect the self-esteem of participants who were indifferent to the group. In addition, this study demonstrates that self-relevant motivations direct the way people process influence appeals. Participants adopted interpretations of the issues that allowed them to align themselves with valued majorities and differentiate themselves from derogated minorities.

Implementation of the i.v. push method of antibiotic administration using the FOCUS/PDCA approach

Home health agencies constantly seek ways to improve patient care as part of their performance improvement program. This includes revising and updating agency policies and procedures. Changing care processes, such as administering intravenous medications, requires input from pharmacy and nursing staff as well as administration. The authors describe how one agency used this process while adopting the i.v. push method of administering certain antibiotics to home care patients.

Correlation of defense gene induction defects with powdery mildew susceptibility in Arabidopsis enhanced disease susceptibility mutants

We investigated the relative importance of specific Arabidopsis thaliana genes in conferring resistance to bacterial versus fungal pathogens. We first developed a pathosystem involving the infection of Arabidopsis accession Columbia with a virulent isolate of the obligate biotrophic fungal pathogen Erysiphe orontii. E. orontii elicited the accumulation of mRNAs corresponding to the defense-related genes PR1, BGL2 (PR2), PR5 and GST1, but did not elicit production of the phytoalexin camalexin or the accumulation of defensin (PDF1.2) or thionin (THI2.1) mRNAs. We tested a set of 15 previously isolated Arabidopsis phytoalexin deficient (pad), non-expresser of PR (npr) and enhanced disease susceptibility (eds) mutants that are more susceptible to Pseudomonas syringae for their susceptibility to E. orontii. Four of these mutants (pad4-1, npr1-1, eds5-1 and a double npr1-1 eds5-1 mutant) as well as Arabidopsis lines carrying a nahG transgene exhibited enhanced susceptibility to E. orontii and reduced levels of PR gene expression. Comparison of the PR gene induction patterns in response to E. orontii in the various mutants and in the nahG transgenics suggests the existence of NPR1-independent salicylate-dependent and NPR1-independent salicylate-independent defense gene activation pathways. Eleven other eds and pad mutants did not show measurable enhanced susceptibility to E. orontii, suggesting that these mutants are defective in factors that are not important for the limitation of E. orontii growth.

The self-esteem motive in social influence: agreement with valued majorities and disagreement with derogated minorities

This research provides evidence for the role of self-esteem in social influence; it demonstrates that the positions taken by self-relevant social groups can threaten people's self-esteem. Participants who wished to align themselves with a majority group and who learned that the group held a counterattitudinal position suffered a reduction in self-esteem. Similarly, participants who wished to differentiate themselves from a derogated minority group and who learned that the group held attitudes similar to theirs experienced reduced self-esteem. Group attitudes, however, did not affect the self-esteem of participants who were indifferent to the group. In addition, this study demonstrates that self-relevant motivations direct the way people process influence appeals. Participants adopted interpretations of the issues that allowed them to align themselves with valued majorities and differentiate themselves from derogated minorities.

Evaluation of a room for tuberculosis patient isolation using theatrical fog

OBJECTIVE

To develop a method to evaluate directional airflow patterns, air dilution, and air mixing in facilities where tuberculosis patients are seen.

DESIGN

A tuberculosis patient isolation room was evaluated by analyzing pressure differential between the room and the corridor and by using theatrical fog to visualize room air movement and impact of dilution and exchange, as well as air capture and displacement. Tracer gas was compared to fog results and used to calculate air exchange rates.

SETTING

A small research hospital.

RESULTS

By adding theatrical fog to the patient room at several locations, we quickly learned that most of the air entering the room through the transom and around the door to the corridor was exhausted through the three exhaust vents. Little air appeared to move toward the exhaust fan. For comparison and to confirm the room air exchange rate, tracer gas was distributed and sampled. The kinetics of decay were very similar whether the tracer gas and room air were mixed during sampling or not.

CONCLUSIONS

The fog procedure allowed good visual confirmation of air mixing and airflow patterns and provided quantitative data for evaluating the efficacy of air capture and displacement or dilution and exchange.

Accurate and cost-effective evaluation of breast masses in males

BACKGROUND

Because the majority of breast masses in males are benign and need not be excised if asymptomatic, we studied the combination of physical examination (PE) and fine needle aspiration (FNA), with or without mammography, as a diagnostic alternative to routine surgical biopsy of these lesions.

METHODS

A diagnostic test study and cost-effectiveness analysis was performed in three participating multidisciplinary breast clinics, involving a consecutive sample of 51 males with unilateral breast masses. Each lesion was tested with both PE and FNA; 13 were also studied with mammography, and each test was scored as benign or suspicious. Lesions for which all tests were benign were followed up clinically (mean 19 months). Lesions for which any test was suspicious were excised.

RESULTS

All tests were benign in 38 cases. No cancers developed at the index sites during follow-up of these lesions, including 8 excisional biopsies done for symptoms (negative predictive value and specificity 100%). Open biopsy confirmed malignancy in all 6 cases for which all tests were suspicious (positive predictive value and sensitivity 100%). In all 7 cases where the tests were not in agreement, open biopsy was benign. In these cases FNA (2 false positives) proved more accurate than PE (5 false positives). Mammography added no additional diagnostic information to the combination of PE and FNA. Compared with routine open biopsy, the combination of PE and FNA avoided surgical biopsy in 30 of the 51 lesions, and was associated with an average decrease in charges of up to $510 per case.

CONCLUSIONS

The combination of PE and FNA for the evaluation of breast masses in males is diagnostically accurate and results in a reduction in patient charges compared with routine open biopsy.

Comparison of the E test with broth microdilution for antifungal susceptibility testing of yeasts

The susceptibilities of 26 recent invasive clinical isolates to amphotericin B (AMP), 5-flucytosine (5FC), fluconazole (FLU) and itraconazole (ITR) were determined by a broth microdilution modification of the NCCLS M27P method and also by E test. Using breakpoint criteria each result was classified as either sensitive (S), intermediate (I) or resistant (R). Taking the optical density (OD)80 as the standard, the results were further classified into major (M) or minor (m) errors. E test: AMP = 0M 0m, 5FC = 0M 5m, FLU = 1M 12m, ITR = 1M 5m errors. Minimal inhibitory concentrations (MIC): AMP = 0M 2m, 5FC = 0M 0m, FLU = 3M 4m, ITR = 1M 7m errors. The E test was quick and relatively simple to perform. Results using the E test compared favourably with those of the OD80 and it should be suitable for the routine susceptibility testing of yeasts to antifungal agents.

Conformity to sex-typed norms, affect, and the self-concept

The self-concept plays an important role in conformity to sex-typed social norms. Normative beliefs that men are powerful, dominant, and self-assertive and that women are caring, intimate with others, and emotionally expressive represent possible standards for whom people ought to be and whom they ideally would like to be. In the present research, to the extent that sex role norms were personally relevant for participants, norm-congruent experiences (i.e., those involving dominance for men and communion for women) yielded positive feelings and brought their actual self-concepts closer to the standards represented by ought and ideal selves.

Phase II trial of biweekly paclitaxel and cisplatin in advanced breast carcinoma: an Eastern Cooperative Oncology Group study

PURPOSE

To determine the efficacy of a biweekly paclitaxel and cisplatin regimen in patients with advanced breast carcinoma, which has previously been reported to produce an 85% response rate in such patients.

PATIENTS AND METHODS

Sixteen patients with metastatic breast carcinoma who had relapsed after prior doxorubicin-containing adjuvant chemotherapy were treated with paclitaxel (90 mg/m2) by intravenous (i.v.) infusion over 3 hours followed by cisplatin (60 mg/m2) given by i.v. infusion over 1 hour on an outpatient basis. Treatment was repeated every 2 weeks if the absolute neutrophil count was > or = 750/microL and platelet count > or = 75,000/microL. After a maximum of eight cycles of paclitaxel/cisplatin, patients received biweekly paclitaxel alone (90 mg/m2 with dose escalation). Thirteen patients were assessable for response and all for toxicity. Nine of 13 patients assessable for response (69%) had at least three sites of metastases and 10 patients (77%) had visceral-dominant disease.

RESULTS

Partial response occurred in three of 13 assessable patients (23%; 90% confidence interval, 7% to 49%). All responders had two or fewer sites of metastases. The median time to progression was 4.3 months and the median survival duration was 11.4 months. Patients received a median of seven cycles of therapy (range, two to 21). Severe and/or life-threatening toxicity occurred in 50% and 38%, respectively, and consisted primarily of granulocytopenia, anemia, and neuropathy. The trial was terminated after the first interim analysis as per its two-stage design, since it was unlikely that the response rate would exceed 70%.

CONCLUSION

Biweekly paclitaxel/cisplatin is not likely to produce a response rate greater than 70% in patients with metastatic breast cancer who have relapsed after prior doxorubicin-containing adjuvant chemotherapy and who have multiple sites of metastases and/or visceral-dominant disease.

The proteolytic cleavage of eukaryotic initiation factor (eIF) 4G is prevented by eIF4E binding protein (PHAS-I; 4E-BP1) in the reticulocyte lysate

A common feature of viral infection is the subversion of the host cell machinery towards the preferential translation of viral products. In some instances, this is partly mediated by the expression of virally encoded proteases which lead to the cleavage of initiation factor eIF4G. The foot-and-mouth disease virus encodes two forms of a cysteine proteinase (L protease) which bisects the eIF4G polypeptide into an N-terminal fragment containing the eIF4E binding site, and a C-terminal fragment which contains binding sites for eIF4A and eIF3 and which associates with the 40S ribosomal subunit. Previously, we have demonstrated that the cleavage of eIF4G by L protease stimulates the translation of uncapped transcripts encoding cellular proteins and supports internal initiation driven by picornavirus internal ribosome entry segment (IRES) elements. Use of reticulocyte lysates manipulated to deplete them of eIF4E and the N-terminal fragment suggests that the C-terminal fragment of eIF4G is responsible for these effects, and we have now confirmed this by purifying the C-terminal fragment and analysing its effects directly in the absence of L protease. Interestingly, we find that pre-incubation of reticulocyte lysates or ribosomal salt wash fractions with the specific eIF4E binding protein, PHAS-I (eIF4E-BP1), blocks the proteolytic cleavage of eIF4G by L protease. This effect can be reversed by addition of recombinant eIF4E. These data are consistent with a model whereby the L protease cleavage site in eIF4G is inaccessible until a change in conformation is induced by the binding of eIF4E. This may have implications for a role for eIF4E binding in triggering changes that expose other domains in the eIF4G molecule during initiation of translation.

Self-definition, defensive processing, and influence: the normative impact of majority and minority groups

Past research has found that recipients agree with majority group positions and resist minority group positions on direct measures of influence. The authors suggest that these attitude shifts reflect normative pressures to align with valued majorities and to differentiate from derogated minorities. In support of this idea, participants who considered a majority group relevant to their own self-definitions (but not those who judged it irrelevant), on learning that the group held a counterattitudinal position, shifted their attitudes to agree with the source. In a second study, recipients who judged a minority group (negatively) self-relevant, on learning that the group held a similar attitude to their own, shifted their attitudes to diverge from the source. These shifts in attitudes were based on participants' interpretations of the attitude issues.