Safety and efficacy of direct percutaneous endoscopic jejunostomy tube placement compared with surgical jejunostomy: a tertiary care analysis.

BACKGROUND AND AIMS: Jejunostomy tube placements provides enteral access for feeding in eligible patients who cannot meet their nutritional needs by mouth. They can be surgically placed laparoscopically (lap-J) or with the use of a conventional open laparotomy approach (open-J). Recently, direct percutaneous endoscopic jejunostomy (DPEJ) has emerged as an alternative owing to its low cost and shorter recovery times. We sought to retrospectively compare the procedural success rates and adverse events of these methods. METHODS: Patients were identified by querying our health system patient database and the departmental database of patients who underwent DPEJ. The patients were divided into 3 cohorts based on the procedure: DPEJ, lap-J, or open-J. Patient age and body mass index, procedural success rate, and adverse event rate were compared among the 3 groups. RESULTS: A total of 201 patients met inclusion criteria (65 DPEJ, 111 lap-J, and 25 open-J). Procedural success rates were similar among the 3 groups (DPEJ 96.9%, lap-J 99.1%, open-J 100%; P = .702). Rates of infection and bleeding were also similar among the 3 groups. There were no cases of GI perforation. Tube dysfunction for any reason that required complete removal or replacement within 90 days occurred more often in the surgical groups than in the DPEJ group (DPEJ 0%, lap-J 35.1%, open-J 40.0%; P < .001). This was driven largely by increased rates of tube clogging and tube dislodgement in the surgical groups. CONCLUSIONS: DPEJ is a safe and effective alternative to surgical jejunostomy in eligible patients and may be associated with decreased adverse event rates at 90 days.

Direct percutaneous endoscopic jejunostomy tube placement in patients post Roux-en-Y gastric bypass, a single tertiary care center experience.

Background and study aims Obesity prevalence continues to rise in the United States with Roux-en-Y gastric bypass (RYGB) surgery being one of the most common bariatric procedures. With this trend, more patients with altered upper gastrointestinal (UGI) anatomy have required endoscopic intervention including direct percutaneous endoscopic jejunostomy (DPEJ) placement. We aimed to assess the safety and success rates of DPEJ in RYGB patients. Patients and methods All patients at a tertiary care referral center who underwent DPEJ during an 8-year period were queried from a prospectively maintained registry of all enteroscopy procedures. Duplicate cases and altered upper UGI anatomy subtypes other than RYGB were excluded. The final cohort consisted of two groups: RYGB vs native anatomy (NA). Demographic, procedural, readmission, follow-up, and complication data were recorded. Comparative analysis was performed. Results Seventy-two patients were included where 28 had RYGB and 44 had NA. Both groups had similar baseline and pre-procedure data. Procedure success rate was 89 % in RYGB patients and 98 % in NA patients ( P  = 0.13). There were no intraprocedural complications. Early and late postprocedural complication rates were similar between the groups (both 4 % vs 7 %). Average follow-up times in the RYGB and NA groups were 12.97 ±â€Š9.35 and 13.44 ±â€Š9.21 months, respectively. Although readmission rates at 1 and 6 months were higher in the NA versus the RYGB group (21 % vs 7 % and 25 % vs 15 %), these differences were not significant. Conclusions DPEJ can be successful and safely placed in RYGB patients with no significant difference in procedure success, complication, or readmission rates when compared to control.

Comparing the efficacy of adipose-derived and bone marrow-derived cells in a rat model of posterolateral lumbar fusion.

Although bone marrow-derived mesenchymal stem cells (BMCs) have been widely used in spinal fusion procedures, adipose-derived stem cells (ASCs) offer a number of advantages as an alternative clinical cell source. This study directly compares the efficacy of ASCs and BMCs from the same donor animals to achieve successful fusion when combined with a clinical-grade bone graft substitute in a rat lumbar fusion model. ASCs and BMCs were isolated from the same Lewis donor rats and grown to passage 2 (P2). Single-level bilateral posterolateral intertransverse process lumbar fusion surgery was performed on syngeneic rats divided into three experimental groups: clinical-grade bone graft substitute alone (CBGS); CBGS+ rat ASCs (rASC); and, CBGS+ rat BMCs (rBMC). Eight weeks postoperatively, fusion was evaluated via micro-CT, manual palpation and histology. In vitro analysis of the osteogenic capacity of rBMCs and rASCs was also performed. Results indicated that the average fusion volume in the rASC group was the largest and was significantly larger than the CBGS group. Although the rASC group displayed the highest fusion rates via micro-CT and manual palpation, this difference was not statistically significant. Cell-seeded grafts showed more histological bone formation than cell-free grafts. P2 rASCs and rBMCs displayed similar in vitro osteogenic differentiation capacities. Overall, this study showed that, when combined with a clinical-grade bone graft substitute in a rat model, rASCs cells yielded the largest fusion masses and comparable fusion results to rBMCs. These results add to growing evidence that ASCs provide an attractive alternative to BMCs for spinal fusion procedures.

The Indexical Voice: Communication of Personal States and Traits in Humans and Other Primates.

Many studies of primate vocalization have been undertaken to improve our understanding of the evolution of language. Perhaps, for this reason, investigators have focused on calls that were thought to carry symbolic information about the environment. Here I suggest that even if these calls were in fact symbolic, there were independent reasons to question this approach in the first place. I begin by asking what kind of communication system would satisfy a species' biological needs. For example, where animals benefit from living in large groups, I ask how members would need to communicate to keep their groups from fragmenting. In this context, I discuss the role of social grooming and "close calls," including lip-smacking and grunting. Parallels exist in human societies, where information is exchanged about all kinds of things, often less about the nominal topic than the communicants themselves. This sort of indexical (or personal) information is vital to group living, which presupposes the ability to tolerate, relate to, and interact constructively with other individuals. Making indexical communication the focus of comparative research encourages consideration of somatic and behavioral cues that facilitate relationships and social benefits, including cooperation and collaboration. There is ample room here for a different and potentially more fruitful approach to communication in humans and other primates, one that focuses on personal appraisals, based on cues originating with individuals, rather than signals excited by environmental events.

Comparing the efficacy of syngeneic iliac and femoral allografts with iliac crest autograft in a rat model of lumbar spinal fusion.

BACKGROUND: Despite widespread use of femoral-sourced allografts in clinical spinal fusion procedures and the increasing interest in using femoral reamer-irrigator-aspirator (RIA) autograft in clinical bone grafting, few studies have examined the efficacy of femoral grafts compared to iliac crest grafts in spinal fusion. The objective of this study was to directly compare the use of autologous iliac crest with syngeneic femoral and iliac allograft bone in the rat model of lumbar spinal fusion. METHODS: Single-level bilateral posterolateral intertransverse process lumbar spinal fusion surgery was performed on Lewis rats divided into three experimental groups: iliac crest autograft, syngeneic iliac crest allograft, and syngeneic femoral allograft bone. Eight weeks postoperatively, fusion was evaluated via microCT analysis, manual palpation, and histology. In vitro analysis of the colony-forming and osteogenic capacity of bone marrow cells derived from rat femurs and hips was also performed to determine whether there was a correlation with the fusion efficacy of these graft sources. RESULTS: Although no differences were observed between groups in CT fusion mass volumes, iliac allografts displayed an increased number of radiographically fused fusion masses and a higher rate of bilateral fusion via manual palpation. Histologically, hip-derived grafts showed better integration with host bone than femur derived ones, likely associated with the higher concentration of osteogenic progenitor cells observed in hip-derived bone marrow. CONCLUSIONS: This study demonstrates the feasibility of using syngeneic allograft bone in place of autograft bone within inbred rat fusion models and highlights the need for further study of femoral-derived grafts in fusion.

Effects of Intraoperative Intrawound Antibiotic Administration on Spinal Fusion: A Comparison of Vancomycin and Tobramycin in a Rat Model.

BACKGROUND: Local, intrawound use of antibiotic powder, such as vancomycin and tobramycin, in spinal fusion surgery has become an increasingly common prophylactic measure in an attempt to reduce rates of postsurgical infection. However, the effects of localized antibiotic delivery on fusion remain unclear. The objective of this study was to examine the in vivo effects of intraoperative local delivery of 2 antibiotics commonly used in bone-grafting surgery on spinal fusion outcomes in a rat model. METHODS: Single-level (L4-L5), bilateral posterolateral intertransverse process lumbar fusion surgery was performed on 60 female Lewis rats (6 to 8 weeks of age) using syngeneic iliac crest allograft mixed with clinical bone-graft substitute and varying concentrations of antibiotics (n = 12 each): (1) control without any antibiotics, (2) low-dose vancomycin (14.3 mg/kg), (3) high-dose vancomycin (71.5 mg/kg), (4) low-dose tobramycin (28.6 mg/kg), and (5) high-dose tobramycin (143 mg/kg). Eight weeks postoperatively, fusion was evaluated via micro-computed tomography (µCT), manual palpation, and histological analysis, with blinding to treatment group. In the µCT analysis, fusion-mass volumes were measured for each rat. Each spine specimen (L4-L5) was rated (manual palpation score) on a scale of 2 to 0 (2 = fused, 1 = partially fused, and 0 = non-fused). RESULTS: The mean fusion-mass volume on µCT (mm) was as follows: control, 29.3 ± 6.2; low-dose vancomycin, 26.3 ± 8.9; high-dose vancomycin, 18.8 ± 7.9; low-dose tobramycin, 32.7 ± 9.0; and high-dose tobramycin, 43.8 ± 11.9 (control versus high-dose vancomycin, p < 0.05; and control versus high-dose tobramycin, p < 0.05). The mean manual palpation score for each group was as follows: control, 1.46 ± 0.58; low-dose vancomycin, 0.86 ± 0.87; high-dose vancomycin, 0.68 ± 0.62; low-dose tobramycin, 1.25 ± 0.71; and high-dose tobramycin, 1.32 ± 0.72 (control versus high-dose vancomycin, p < 0.05). The histological analyses demonstrated a similar trend with regard to spinal fusion volume. CONCLUSIONS: Intraoperative local application of vancomycin, particularly at a supraphysiological dosage, may have detrimental effects on fusion-mass formation. No inhibitory effect of tobramycin on fusion-mass formation was observed. CLINICAL RELEVANCE: When spine surgeons decide to use intraoperative intrawound antibiotics in spinal fusion surgery, they should weigh the reduction in surgical site infection against a possible inhibitory effect on fusion.

The Effects of High-Dose Parathyroid Hormone Treatment on Fusion Outcomes in a Rabbit Model of Posterolateral Lumbar Spinal Fusion Alone and in Combination with Bone Morphogenetic Protein 2 Treatment.

BACKGROUND: Parathyroid hormone (PTH) (1-34) treatment reduces fracture risk in osteoporotic patients. Previously, we demonstrated in a rabbit model that low-dose PTH treatment resulted in increased fusion mass volume. As effects of PTH on bone are dose-dependent, we aimed to evaluate whether increasing dosage of PTH increases both volume and biomechanical stiffness of the resulting fusion masses and/or exhibits synergistic effects with low-dose bone morphogenetic protein 2 (BMP-2). METHODS: Posterolateral lumbar spinal fusion surgery was performed on 60 New Zealand White rabbits divided into 6 experimental groups: iliac crest autograft alone, autograft plus 20 µg/kg/day PTH, autograft plus 40 µg/kg/day PTH, BMP-2 alone, BMP-2 plus 20 µg/kg/day PTH, and BMP-2 plus 40 µg/kg PTH. Fusion was assessed at postoperative week 6 via manual palpation, volumetric computed tomography analysis, and 4-point bending biomechanical testing. RESULTS: All groups treated with BMP-2 fused. Increasing doses of PTH resulted in increased fusion mass volume compared with autograft alone. Autograft plus 40 µg/kg/day PTH yielded fusion mass volumes comparable to BMP-2. When the autograft groups were considered alone, increased mechanical stiffness was observed only in the 20 µg/kg/day group. No significant stiffness differences were observed between BMP-2 groups. CONCLUSIONS: Treatment with the highest dose of PTH resulted in fusion mass volumes similar to those obtained with BMP-2. When the autograft groups were considered alone, significant increases in mechanical stiffness were observed at a dosage of 20 µg/kg/day, suggesting there may be an optimal dose of PTH in the rabbit model. Effects of BMP-2 on fusion were dominant.

Morpho-phonemic analysis boosts word reading for adult struggling readers.

A randomized control trial compared the effects of two kinds of vocabulary instruction on component reading skills of adult struggling readers. Participants seeking alternative high school diplomas received 8 h of scripted tutoring to learn forty academic vocabulary words embedded within a civics curriculum. They were matched for language background and reading levels, then randomly assigned to either morpho-phonemic analysis teaching word origins, morpheme and syllable structures, or traditional whole word study teaching multiple sentence contexts, meaningful connections, and spellings. Both groups made comparable gains in learning the target words, but the morpho-phonemic group showed greater gains in reading unfamiliar words on standardized tests of word reading, including word attack and word recognition. Findings support theories of word learning and literacy that promote explicit instruction in word analysis to increase poor readers' linguistic awareness by revealing connections between morphological, phonological, and orthographic structures within words.

Emancipation of the voice: Vocal complexity as a fitness indicator.

Although language is generally spoken, most evolutionary proposals say little about any changes that may have induced vocal control. Here I suggest that the interaction of two changes in our species-one in sociality, the other in life history-liberated the voice from its affective moorings, enabling it to serve as a fitness cue or signal. The modification of life history increased the helplessness of infants, thus their competition for care, pressuring them to emit, and parents (and others) to evaluate, new vocal cues in bids for attention. This change elaborated and formalized the care communication system that was used in infancy and, because of parental adoption of social criteria, extended it into childhood, supporting the extrafamilial relationships that intensify in those stages. The remodeling of life history, in conjunction with intensified sociality, also enhanced vocal signaling in adolescence-a second stage that is unique to humans-and adulthood. Building on the new vocal skills and fitness criteria that emerged earlier, I claim that males with ornamented speech enjoyed advantages in their pursuit of dominance and reproductive opportunities in evolutionary history, as they do today. There are implications of this scenario for the mechanistic level of vocal diversification. Today, intentionality plays a role both in the instrumental crying of infants and the modulated vocalizations of adults. In evolutionary history, I claim that in both cases, spontaneously emitted behavioral cues elicited perceptible responses, giving rise to strategic signals that were sent, and processed, under a new and fundamentally different neural regime.

Effectiveness of percutaneous flexor tenotomies for the management and prevention of recurrence of diabetic toe ulcers: a systematic review.

BACKGROUND: Diabetic toe ulcers are a potentially devastating complication of diabetes. In recent years, the percutaneous flexor tenotomy procedure for the correction of flexible claw and hammer-toe contraction deformities has been proposed as a safe and effective technique for facilitating the healing of toe-deformity related diabetic ulcers. The aim of this review is to critically appraise the evidence for the effectiveness of this surgical procedure in achieving ulcer healing, prevention of re-ulceration, and to summarise the rate of post-operative complications. METHOD: A search of medical databases, was performed to locate relevant literature. Titles were screened prior to abstract and full text review to identify articles relevant to the research question. Search terms included truncations of "tenotomy", "toe", "hallux", "digit", "diabetes" and "ulcer". Peer reviewed primary research study designs specified as suitable for systematic reviews by the Centre for Reviews and Dissemination were included. Studies were excluded if they used a concurrent secondary procedure or included non-diabetic patients without reporting outcomes separately. Included studies were appraised for quality using the Methodological Index for Non-Randomised Studies tool. Levels of evidence were subsequently assigned to each outcome of interest (healing rate and prevention of re-ulceration). RESULTS: From a total search yield of 42 articles, 5 eligible studies (all case series designs) were identified for inclusion. Included studies were of low-to-moderate methodological quality when assessed using the MINORS tool. A total of 250 flexor tenotomy procedures were performed in a total of 163 patients. Included studies generally reported good healing rates (92-100 % within 2 months) post-op follow-up), relatively few recurrences (0-18 % at 22 months median post-op follow-up), and low incidences of infection or new deformity. Transfer ulcers developing on adjacent areas as a result of shifted pressure were reported by several authors. The validity of these results is undermined by methodological limitations inherent to case series designs such as a lack of control groups, non-randomised designs, as well as inconsistent reporting of post-intervention follow-up periods. There was level 4 evidence for the flexor tenotomy procedure in facilitating ulcer healing and preventing re-ulceration. CONCLUSION: More definitive research evidence is needed in this area to determine whether or not the flexor tenotomy is a safe and effective treatment option for people with, or at risk of developing diabetic toe ulcers. Whilst the available literature reports that the procedure may be associated with high healing rates, relatively low recurrence rates and low incidences of post-op complications, methodological limitations restrict the value of these findings.

Mutations in ash1 and trx enhance P-element-dependent silencing in Drosophila melanogaster.

In Drosophila melanogaster, the mini-w(+) transgene in Pci is normally expressed throughout the adult eye; however, when other P or KP elements are present, a variegated-eye phenotype results, indicating random w(+) silencing during development called P-element-dependent silencing (PDS). Mutant Su(var)205 and Su(var)3-7 alleles act as haplo-suppressors/triplo-enhancers of this variegated phenotype, indicating that these heterochromatic modifiers act dose dependently in PDS. Previously, we recovered a spontaneous mutation of P{lacW}ci(Dplac) called P{lacW}ci(DplacE1) (E1) that variegated in the absence of P elements, presumably due to the insertion of an adjacent gypsy element. From a screen for genetic modifiers of E1 variegation, we describe here the isolation of five mutations in ash1 and three in trx that enhance the E1 variegated phenotype in a dose-dependent and cumulative manner. These mutant alleles enhance PDS at E1, and in E1/P{lacW}ci(Dplac), but suppress position effect variegation (PEV) at In(1)w(m)(4). This opposite action is consistent with a model where ASH1 and TRX mark transcriptionally active chromatin domains. If ASH1 or TRX function is lost or reduced, heterochromatin can spread into these domains creating a sink that diverts heterochromatic proteins from other variegating locations, which then may express a suppressed phenotype.

A systematic review of the use of expandable cages in the cervical spine.

Expandable vertebral body replacement cages (VBRs) have been widely used for reconstruction of the thoracolumbar spine following corpectomy. However, their use in the cervical spine is less common, and currently, no expandable cages on the market are cleared or approved by the US Food and Drug Administration for use in the cervical spine. The objective of this study was to perform a systematic review on the use of expandable cages in the treatment of cervical spine pathology with a focus on fusion rates, deformity correction, complications, and indications. A comprehensive Medline search was performed, and 24 applicable articles were identified and included in this review. The advantages of expandable cages include greater ease of implantation with less risk of damage to the end plate, less intraoperative manipulation of the device, and potentially greater control over lordosis. They may be particularly advantageous in cases with poor bone quality, such as patients with osteoporosis or metastatic tumors that have been radiated. However, there is a potential risk of overdistraction, which is increased in the cervical spine, their minimum height limits their use in cases with collapsed vertebra, and the amount of hardware in the expansion mechanism may limit the surface area available for fusion. The use of expandable VBRs are a valuable tool in the armamentarium for reconstruction of the anterior column of the cervical spine with an acceptable safety profile. Although expandable cervical cages are clearly beneficial in certain clinical situations, widespread use following all corpectomies is not justified due to their significantly greater cost compared to structural bone grafts or non-expandable VBRs, which can be utilized to achieve similar clinical outcomes.

A systematic assessment of the use of platelet-rich plasma in spinal fusion.

Spinal fusion is one of the most commonly performed procedures for the treatment of spinal instability caused by a multitude of pathologies. However, despite significant advances in spinal instrumentation, failed fusion, or pseudoarthrosis, remains a significant challenge. Therefore, other additives such as bone graft extenders and growth factors have been explored as a method to augment fusion rates. Platelet-rich plasma (PRP) represents an additional approach, as it has shown some promise in bone regeneration. While the general use of PRP in orthopedic applications has been reviewed previously, its use in spinal fusion has not been systematically analyzed. The objective of this review is to systematically discuss the role of PRP in augmentation of bone regeneration for the purpose of spinal fusion. Background information on PRP, including a discussion of its preparation, activation, and growth factors, is included. Additionally, data from in vitro studies utilizing PRP in bone tissue engineering strategies is analyzed, and the available animal and clinical studies are systematically reviewed in order to provide guidance on future research pathways as well as the potential role of PRP in spinal fusion surgery.

The biomechanics of pedicle screw augmentation with cement.

BACKGROUND CONTEXT: A persistent challenge in spine surgery is improving screw fixation in patients with poor bone quality. Augmenting pedicle screw fixation with cement appears to be a promising approach. PURPOSE: The purpose of this study was to survey the literature and assess the previous biomechanical studies on pedicle screw augmentation with cement to provide in-depth discussions of the biomechanical benefits of multiple parameters in screw augmentation. STUDY DESIGN/SETTING: This is a systematic literature review. METHODS: A search of Medline was performed, combining search terms of pedicle screw, augmentation, vertebroplasty, kyphoplasty, polymethylmethacrylate, calcium phosphate, or calcium sulfate. The retrieved articles and their references were reviewed, and articles dealing with biomechanical testing were included in this article. RESULTS: Polymethylmethacrylate is an effective material for enhancing pedicle screw fixation in both osteoporosis and revision spine surgery models. Several other calcium ceramics also appear promising, although further work is needed in material development. Although fenestrated screw delivery appears to have some benefits, it results in similar screw fixation to prefilling the cement with a solid screw. Some differences in screw biomechanics were noted with varying cement volume and curing time, and some benefits from a kyphoplasty approach over a vertebroplasty approach have been noted. Additionally, in cadaveric models, cemented-augmented screws were able to be removed, albeit at higher extraction torques, without catastrophic damage to the vertebral body. However, there is a risk of cement extravasation leading to potentially neurological or cardiovascular complications with cement use. A major limitation of these reviewed studies is that biomechanical tests were generally performed at screw implantation or after a limited cyclic loading cycle; thus, the results may not be entirely clinically applicable. This is particularly true in the case of the bioactive calcium ceramics, as these biomechanical studies would not have measured the effects of osseointegration. CONCLUSIONS: Polymethylmethacrylate and various calcium ceramics appear promising for the augmentation of pedicle screw fixation biomechanically in both osteoporosis and revision spine surgery models. Further translational studies should be performed, and the results summarized in this review will need to be correlated with the clinical outcomes.

An online spatial database of Australian Indigenous Biocultural Knowledge for contemporary natural and cultural resource management.

With growing international calls for the enhanced involvement of Indigenous peoples and their biocultural knowledge in managing conservation and the sustainable use of physical environment, it is timely to review the available literature and develop cross-cultural approaches to the management of biocultural resources. Online spatial databases are becoming common tools for educating land managers about Indigenous Biocultural Knowledge (IBK), specifically to raise a broad awareness of issues, identify knowledge gaps and opportunities, and to promote collaboration. Here we describe a novel approach to the application of internet and spatial analysis tools that provide an overview of publically available documented Australian IBK (AIBK) and outline the processes used to develop the online resource. By funding an AIBK working group, the Australian Centre for Ecological Analysis and Synthesis (ACEAS) provided a unique opportunity to bring together cross-cultural, cross-disciplinary and trans-organizational contributors who developed these resources. Without such an intentionally collaborative process, this unique tool would not have been developed. The tool developed through this process is derived from a spatial and temporal literature review, case studies and a compilation of methods, as well as other relevant AIBK papers. The online resource illustrates the depth and breadth of documented IBK and identifies opportunities for further work, partnerships and investment for the benefit of not only Indigenous Australians, but all Australians. The database currently includes links to over 1500 publically available IBK documents, of which 568 are geo-referenced and were mapped. It is anticipated that as awareness of the online resource grows, more documents will be provided through the website to build the database. It is envisaged that this will become a well-used tool, integral to future natural and cultural resource management and maintenance.

Mutations in CG8878, a novel putative protein kinase, enhance P element dependent silencing (PDS) and position effect variegation (PEV) in Drosophila melanogaster.

Genes in multicellular organisms are expressed as part of a developmental program that is largely dependent on self-perpetuating higher-order chromatin states. The mechanism of establishing and maintaining these epigenetic events is well studied in Drosophila. The first known example of an epigenetic effect was that of (PEV) in Drosophila, which has been shown to be due to gene silencing via heterochromatin formation. We are investigating a process similar to Position Effect Variegation (PEV) using a mini-w transgene, called Pci, inserted in the upstream regulatory region of ci. The mini-white+ transgene in Pci is expressed throughout the adult eye; however, when other P or KP elements are present, a variegated eye phenotype results indicating random w+ silencing during development. This P element dependent silencing (PDS) can be modified by the haplo-suppressors/triplo-enhancers, Su(var)205 and Su(var)3-7, indicating that these heterochromatic modifiers also act dose dependently in PDS. Here we use a spontaneous derivative mutation of Pci called PciE1 (E1) that variegates like PDS in the absence of P elements, presumably due to an adjacent gypsy element insertion, to screen for second-site modifier mutations that enhance variable silencing of white+ in E1. We isolated 7 mutations in CG8878, an essential gene, that enhance the E1 variegated phenotype. CG8878, a previously uncharacterized gene, potentially encodes a serine/threonine kinase whose closest Drosophila paralogue, ballchen (nhk-1), phosphorylates histones. These mutant alleles enhance both PDS at E1 and Position Effect Variegation (PEV) at w(m4), indicating a previously unknown common silencing mechanism between the two.

Nurses' understandings of suitable footwear for older people.

PURPOSE: The purpose of this paper is to gain insight into nurses' understandings of what constitutes suitable footwear for older people in care homes. DESIGN/METHODOLOGY/APPROACH: An exploratory descriptive qualitative survey was carried out of 20 registered nurses employed in six Scottish care homes for older people. Data were collected using a semi-structured questionnaire that included five open-ended questions. Content analysis was used to theme footwear perceptions. FINDINGS: Participants had several views about what encompasses safe footwear; some were erroneous. The link between inappropriate footwear and falls was recognised by 80 per cent of respondents, but some were unclear about the features that effect or inhibit safety. No UK or international standardised guidelines were identified that advise nurses about appropriate footwear for older people. PRACTICAL IMPLICATIONS: It is unknown whether respondents represent the nurse population because findings are restricted by a small sample size. Nonetheless, the group showed variable understanding of what constitutes safe footwear for older people and links with fall prevention. Improved nurse-education about what comprises safe footwear and the links with falls prevention in older people is required. Structured guidelines to direct nurse educators about what to teach student nurses about appropriate footwear for older people may work towards reducing falls. ORIGINALITY/VALUE: No guidelines to direct nurses about appropriate footwear for older people in care homes have been written. Key points have been developed.

The need for psychological needs: a role for social capital.

Van de Vliert embraces a "supply side" model of human needs, underplaying a "demand" model whereby individuals, motivated by psychological needs, develop coping strategies that help them meet their personal goals and collectively exert an influence on social and economic systems. Undesirable climates may inflate the value of financial capital, but they also boost the value of social capital.

Point mutations in a Drosophila P element abolish both P element-dependent silencing (PDS) of a transgene and repressor functions.

The P elements of Drosophila melanogaster are well-studied transposons with both mobilizing and repressor functions. P elements can also variably silence the expression of certain other transgenes through a phenomenon known as P element-dependent silencing (PDS). To examine the role of the P repressor in PDS, we have induced, isolated, and characterized 22 point mutations in an archetype P element called P[SalI]89D. All mutations showed a loss in the ability to silence one or more assays for the PDS phenotype. These mutants also lost the ability to induce the suppression of variegation in P[hsp26-pt-T]39C-12, another P element-dependent phenotype. A subgroup of 11 mutations was further assayed for their ability to act as a P repressor and silence the P element promoter transcribing a lacZ ( + ) gene, and this function was lost as well. Taken together, this study supports a model of PDS acting through protein interactions, not RNA, with heterochromatic proteins to modify the extent of variegation seen in PDS. Furthermore, the common loss of functions for PDS and P repressor silencing (from another P promoter) argues for a common role of the repressor. This makes the PDS model a good system for examining P repressor functions and how they relate to transposon-mediated gene silencing in general.

The P-element-induced silencing effect of KP transposons is dose dependent in Drosophila melanogaster.

Transposable elements are found in the genomes of all eukaryotes and play a critical role in altering gene expression and genome organization. In Drosophila melanogaster, transposable P elements are responsible for the phenomenon of hybrid dysgenesis. KP elements, a deletion-derivative of the complete P element, can suppress this mutagenic effect. KP elements can also silence the expression of certain other P-element-mediated transgenes in a process called P-element-dependent silencing (PDS), which is thought to involve the recruitment of heterochromatin proteins. To explore the mechanism of this silencing, we have mobilized KP elements to create a series of strains that contain single, well-defined KP insertions that show PDS. To understand the quantitative role of KP elements in PDS, these single inserts were combined in a series of crosses to obtain genotypes with zero, one, or two KP elements, from which we could examine the effect of KP gene dose. The extent of PDS in these genotypes was shown to be dose dependent in a logarithmic rather than linear fashion. A logarithmic dose dependency is consistent with the KP products interacting with heterochromatic proteins in a concentration-dependent manner such that two molecules are needed to induce gene silencing.