Effects of forest fragmentation on the dietary ecology and activity of a nocturnal lemur community in North West Madagascar

Deforestation and habitat fragmentation is the primary threat to primate populations. The primates that live within degraded and anthropogenically disturbed habitats typical of fragmented landscapes have to cope with lower availability of resources in comparison to primates in continuous, undisturbed forests. While some species are sensitive to forest fragmentation, some evidence exists to suggest that primates can alter their behavior and adapt to such changes, which enables their survival in suboptimal habitat. In this study, we assessed how forest fragmentation and its associated edge-effects impact the feeding ecology and activity levels of a nocturnal primate community in the Sahamalaza-Iles Radama National Park, North West Madagascar. From March 06, 2019 to May 17, 2022, we collected data on tree and invertebrate phenology at our study site, and feeding ecology and activity for 159 lemur individuals from four species. Fruit and flower availability varied significantly between continuous and fragmented forest, and between forest core and edge areas, with continuous forest exhibiting higher continuous fruit and flower availability. Lemur feeding ecology varied significantly too, as the feeding niches of all four species were significantly different between continuous and fragmented forest and between core and edge areas. However, lemur activity levels were mostly consistent among all forest areas. The results of this study suggest that nocturnal lemurs are able to adapt their dietary ecology in response to the available food sources within their habitat. Due to this flexible ecology and dietary plasticity, the lemurs do not need to significantly alter their behavior in different environments to fulfill their dietary needs. While nocturnal lemurs demonstrate adaptability and flexibility to degraded habitat, it is unclear how far this plasticity will stretch considering that Madagascar's forests are still being cleared at an alarming rate. Urgent conservation action is therefore needed to ensure the future of lemur habitat.

Predictors of dominance rank and agonistic interactions in captive Livingstone's fruit bats

Male dominance hierarchies have been studied in many animals but rarely in bats (Chiroptera). The dominance rank of social animals may dictate access to resources and mates; therefore, it has important implications for an individual's fitness and is crucial for successful captive management. Between January and December 2018, at both Bristol Zoo Gardens (Bristol, UK) and Jersey Zoo (Jersey, British Isles), we observed 19 male Livingstone's fruit bats Pteropus livingstonii using focal follows for 345 h overall, noting the outcome of all agonistic interactions. We recorded instigators of interactions, along with winners and losers, and analyzed these data using the R-package "EloRating" to create Elo-rating temporal plots of dominance ranks. We used generalized linear mixed models and multiple linear regression to analyze interaction data and test hypotheses regarding predictors of dominance rank, frequency of agonistic interaction, and choice of interaction partner. Age was positively correlated with dominance rank up to around year 9, when an asymptote was attained. Highly ranked bats instigated the most agonistic interactions, and largely directed these interactions at bats with much lower rankings than themselves. Hierarchies were extremely stable throughout the data collection period at both sites. We conclude that Livingstone's fruit bats have a stable linear dominance hierarchy, with high-ranking, typically older males instigating the most interactions with lowest ranking males to secure dominance rank. This study adds to the limited discourse on Pteropus social behaviors, indicating that some bat species may have social systems similar in complexity to some nonhuman primates.

Seasonal Differences in the Encounter Rate of the Fat-Tailed Dwarf Lemur (Cheirogaleus medius) in the Transitional Forests of Northwest Madagascar: Implications for Reliable Population Density Assessment

Primate encounter rates often vary throughout the year due to seasonal differences in activity, ecology, and behaviour. One notably extreme behaviour is continuous hibernation. Although a rare adaptation in primates, the dwarf lemurs of Madagascar (genus Cheirogaleus) enter obligate hibernation each year during the dry season, after spending the wet season consuming high-energy foods. Whilst seasonal changes in activity in some Cheirogaleus populations are well-known, many species remain little-studied, and there is no specific information on their encounter rates, nor when they enter and emerge from hibernation. This uncertainty critically affects reliable calculation of population density estimates for these highly threatened lemurs. In this study, we assessed how encounter rates of the fat-tailed dwarf lemur (C. medius) vary seasonally in the transitional forests of the Sahamalaza-Iles Radama National Park, northwest Madagascar, during a 4-year period. We established a system of line transects (N = 60) throughout our study area, on which we conducted distance sampling of C. medius. We then used our distance sampling data to calculate encounter rate and population density data. We found encounter rates of C. medius to be significantly higher during the wet season compared with the dry season. Furthermore, encounter rates of C. medius were particularly low from May–August. These results provide some evidence to suggest the time period that C. medius hibernate in Sahamalaza-Iles Radama National Park. These findings underpin the importance of careful study design when surveying threatened species with seasonal differences in activity, such as those that hibernate. This study also demonstrates the importance of species-specific behavioural data for accurate population density assessment, which is required to inform conservation action.

573 What's in A Name? An Audit of Correct Identification of Patients During Ward-Rounds in A Surgical and Urology Receiving Ward

Aim

Clinical governance states that patients should have a named Consultant during their in-patient stay. In our institution, every bed has a whiteboard above it, which mentions the name of the patient and the responsible Consultant. This should correspond with the electronic system, TrakCare. Ouraim was to audit and look into the accuracy of this practice, in order to improve the efficacy of ward-rounds and hence improve patient care and safety.

Method

Data was collected for general surgery and urology receiving wards over 3 consecutive days and was matched to the data available on the electronic system, TrakCare. Intervention was made in the form of verbal and written communication with the nursing staff and junior doctors. Effect of intervention was assessed 2 weeks later.

Results

n = 38 bed-boards were assessed. The first cycle of the audit demonstrated that 7 (18.4%) had either incorrect or no entries. The detailed analysis revealed that of these, 2 had no consultant names whereas 5 were incorrect. The second cycle demonstrated a good improvement with only 1(2.6%) bed-boards having incorrect or no names. The third cycle demonstrated sustainable impact with only 1 (2.6%) missing consultant’s name.

Conclusions

Ward-rounds have been an age-old practice to review patients and are vital to formulate a care plan for patients, particularly in acute settings. It is also important for the patient to know who is providing their care. Wrong or missing entries could compromise patient care and has implications in patient follow up and chasing results. A simple intervention by the nursing and medical staff can improve the quality of care.

576 Audit of Instillation of Intravesical Mitomycin-C Following Transurethral Resection for Bladder Tumour

Aim

The administration of intravesical chemotherapy (IVCT) following transurethral resection of bladder tumour (TURBT) has been shown to decrease the risk of recurrence and is recommended as standard practice following TURBT for new & recurrent tumours.

Our aim was to evaluate the adherence to this guideline in our trust and if needed, to implement changes in order to improve the patient care.

Method

A retrospective analysis of 25 patients was done and details regarding the time interval between administration, demographic details and disease staging was collected. NICE guidelines were later implemented, and the data was recollected for 24 patients who underwent TURBT

Results

The analysis showed that the mean time between the end point of TURBT and instillation of Intravesicular Mitomycin-C was 7.66 hours. Thereafter, we tried to implement the guidelines by improving communication between the Theatre staff, Nursing staff and the pharmacy. The data was collected for re-audit for 24 patients and it was observed that the interval between surgery and Mitomycin administration had dropped down to 4.67 hours. The 3rd cycle of the audit revealed the interval dropping down further to 4.24hours.The 24hr administration rate was >90%, which was much higher than previous year audits

Conclusions

Engagement with theatre team and pharmacy is required, in order to coordinate the delivery of the IVCT to theatre for administration at the time of surgery. If everyone (hospital pharmacy and theatre staff) is supportive, patients’ quality of care can be improved by following the standardised protocol.

Observations of daytime activity in the nocturnal northern giant mouse lemur (Mirza zaza)

We provide an anecdote of daytime activity within the northern giant mouse lemur (Mirza zaza), a small threatened primate that has always been considered strictly nocturnal, in the Anabohazo forest of northwestern Madagascar. During the dry season, we witnessed two individual M. zaza travelling separately in the afternoon period of three different days. Our observations indicate that M. zaza may undertake activity that is essential for their survival within both the light and dark periods of a day-cycle, and our findings suggest that the activity cycle of this species may be highly flexible. These observations have important implications to understand the evolution of activity patterns in M. zaza, and these findings warrant future, long term studies to establish the annual activity patterns of M. zaza and to determine whether this species is potentially cathemeral and why.

Addressing cognitive impairment following stroke: systematic review and meta-analysis of non-randomised controlled studies of psychological interventions

OBJECTIVE

Cognitive impairment is a pervasive outcome of stroke, reported in over half of patients 6 months post-stroke and is associated with increased disability and a poorer quality of life. Despite the prevalence of post-stroke cognitive impairment, the efficacy of existing psychological interventions for the rehabilitation of cognitive impairment following stroke has yet to be established. The aim of this study is to identify psychological interventions from non-randomised studies that intended to improve post-stroke cognitive function and establish their efficacy.

DESIGN

Systematic review and meta-analysis of non-randomised studies of psychological interventions addressing post-stroke cognitive impairment.

DATA SOURCES

Electronic searches were performed in the Pubmed, EMBASE and PsycINFO databases, the search dating from inception to February 2017.

ELIGIBILITY CRITERIA

All non-randomised controlled studies and quasi-randomised controlled trials examining psychological interventions to improve cognitive function following stroke were included, such as feasibility studies, pilot studies, experimental studies, and quasi-experimental studies. The primary outcome was cognitive function. The prespecified secondary outcomes were functional abilities in daily life and quality of life.

METHODS

The current meta-analyses combined the findings of seven controlled studies, examining the efficacy of psychological interventions compared with treatment-as-usual controls or active controls, and 13 one-group pre-post studies.

RESULTS

Results indicated an overall small effect on cognition across the controlled studies (Hedges' g=0.38, 95% CI=0.06 to 0.7) and a moderate effect on cognition across the one-group pre-post studies (Hedges' g=0.51, 95% CI=0.3 to 0.73). Specific cognitive domains, such as memory and attention also demonstrated a benefit of psychological interventions.

CONCLUSIONS

This review provides support for the potential of psychological interventions to improve overall cognitive function post-stroke. Limitations of the study, in terms of risk of bias and quality of included studies, and future research directions are explored.

PROSPERO REGISTRATION NUMBER

CRD42017069714.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Managing cognitive impairment following stroke: protocol for a systematic review of non-randomised controlled studies of psychological interventions

INTRODUCTION

Stroke is one of the primary causes of death and disability worldwide, leaving a considerable proportion of survivors with persistent cognitive and functional deficits. Despite the prevalence of poststroke cognitive impairment, there is no established treatment aimed at improving cognitive function following a stroke. Therefore, the aims of this systematic review are to identify psychological interventions intended to improve poststroke cognitive function and establish their efficacy.

METHODS AND ANALYSIS

A systematic review of non-randomised controlled studies that investigated the efficacy of psychological interventions aimed at improving cognitive function in stroke survivors will be conducted. Electronic searches will be performed in the PubMed, Embase and PsycINFO databases, the search dating from the beginning of the index to February 2017. Reference lists of all identified relevant articles will be reviewed to identify additional studies not previously identified by the electronic search. Potential grey literature will be reviewed using Google Scholar. Titles and abstracts will be assessed for eligibility by one reviewer, with a random sample of 50% independently double-screened by second reviewers. Any discrepancies will be resolved through discussion, with referral to a third reviewer where necessary. Risk of bias will be assessed with the Risk of Bias in Non-randomized Studies of Interventions tool. Meta-analyses will be performed if studies are sufficiently homogeneous. This review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The quality of the evidence regarding cognitive function will be assessed according to the Grading of Recommendations Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

This systematic review will collect secondary data only and as such ethical approval is not required. Findings will be disseminated through presentations and peer-reviewed publication. This review will provide information on the effectiveness of psychological interventions for poststroke cognitive impairment, identifying which psychological interventions are effective for improving poststroke cognitive function.

PROSPERO REGISTRATION NUMBER

CRD42017069714.

Sleeping and Ranging Behavior of the Sambirano Mouse Lemur, Microcebus sambiranensis

Primates require secure sleeping sites for periods of rest, but despite their importance, the characteristics of desired sleeping sites are poorly known. Here we investigated the sleeping ecology of a radio-collared population of the Sambirano mouse lemur, Microcebus sambiranensis, during the nonreproductive season in the Anabohazo forest, northwestern Madagascar. We also investigated their ranging behavior and examined the spatial distribution of sleeping sites within the home ranges of the collared individuals. We took measurements of the sleeping tree's physical characteristics and recorded the number of collared individuals using each sleeping site. We found that M. sambiranensis generally use foliage sleeping sites more frequently than tree holes and individuals slept more frequently in densely foliated trees than in sparsely foliated trees, often alone. We observed no significant differences in home range size or nightly travel distance between males and females; however, home ranges were smaller than those described for other mouse lemur species. Finally, we found that M. sambiranensis sleep peripherally and forage centrally within their home ranges, a behavior not previously described for mouse lemurs. Our results indicate profound differences in the social organization between M. sambiranensis and other mouse lemur species described in the literature, suggesting species-specificity in mouse lemur ecology. Understanding the sleeping ecology and ranging behavior of mouse lemurs is of great importance to their conservation, as these data facilitate the planning of long-term reforestation, habitat management, and population assessment.

Simple aspiration versus intercostal tube drainage for primary spontaneous pneumothorax in adults

BACKGROUND

For management of pneumothorax that occurs without underlying lung disease, also referred to as primary spontaneous pneumothorax, simple aspiration is technically easier to perform than intercostal tube drainage. In this systematic review, we seek to compare the clinical efficacy and safety of simple aspiration versus intercostal tube drainage for management of primary spontaneous pneumothorax. This review was first published in 2007 and was updated in 2017.

OBJECTIVES

To compare the clinical efficacy and safety of simple aspiration versus intercostal tube drainage for management of primary spontaneous pneumothorax.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1) in the Cochrane Library; MEDLINE (1966 to January 2017); and Embase (1980 to January 2017). We searched the World Health Organization (WHO) International Clinical Trials Registry for ongoing trials (January 2017). We checked the reference lists of included trials and contacted trial authors. We imposed no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of adults 18 years of age and older with primary spontaneous pneumothorax that compared simple aspiration versus intercostal tube drainage.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed trial quality, and extracted data. We combined studies using the random-effects model.

MAIN RESULTS

Of 2332 publications obtained through the search strategy, seven studies met the inclusion criteria; one study was ongoing and six studies of 435 participants were eligible for inclusion in the updated review. Data show a significant difference in immediate success rates of procedures favouring tube drainage over simple aspiration for management of primary spontaneous pneumothorax (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.69 to 0.89; 435 participants, 6 studies; moderate-quality evidence). Duration of hospitalization however was significantly less for patients treated by simple aspiration (mean difference (MD) -1.66, 95% CI -2.28 to -1.04; 387 participants, 5 studies; moderate-quality evidence). A narrative synthesis of evidence revealed that simple aspiration led to fewer adverse events (245 participants, 3 studies; low-quality evidence), but data suggest no differences between groups in terms of one-year success rate (RR 1.07, 95% CI 0.96 to 1.18; 318 participants, 4 studies; moderate-quality evidence), hospitalization rate (RR 0.60, 95% CI 0.25 to 1.47; 245 participants, 3 studies; very low-quality evidence), and patient satisfaction (median between-group difference of 0.5 on a scale from 1 to 10; 48 participants, 1 study; low-quality evidence). No studies provided data on cost-effectiveness.

AUTHORS' CONCLUSIONS

Available trials showed low to moderate-quality evidence that intercostal tube drainage produced higher rates of immediate success, while simple aspiration resulted in a shorter duration of hospitalization. Although adverse events were reported more commonly for patients treated with tube drainage, the low quality of the evidence warrants caution in interpreting these findings. Similarly, although this review observed no differences between groups when early failure rate, one-year success rate, or hospital admission rate was evaluated, this too needs to be put into the perspective of the quality of evidence, specifically, for evidence of very low and low quality for hospitalization rate and patient satisfaction, respectively. Future adequately powered research is needed to strengthen the evidence presented in this review.

The use of Vocalizations of the Sambirano Mouse Lemur (Microcebus sambiranensis) in an Acoustic Survey of Habitat Preference

Primate vocalizations convey a variety of information to conspecifics. The acoustic traits of these vocalizations are an effective vocal fingerprint to discriminate between sibling species for taxonomic diagnosis. However, the vocal behavior of nocturnal primates has been poorly studied and there are few studies of their vocal repertoires. We compiled a vocal repertoire for the Endangered Sambirano mouse lemur, Microcebus sambiranensis, an unstudied nocturnal primate of northwestern Madagascar, and compared the acoustic properties of one of their call types to those of M. murinus and M. rufus. We recorded vocalizations from radio-collared individuals using handheld recorders over 3 months. We also conducted an acoustic survey to measure the vocal activity of M. sambiranensis in four forest habitat types at the study site. We identified and classified five vocalization types in M. sambiranensis. The vocal repertoires of the three Microcebus species contain very similar call types but have different acoustic properties, with one loud call type, the whistle, having significantly different acoustic properties between species. Our acoustic survey detected more calls of M. sambiranensis in secondary forest, riparian forest, and forest edge habitats, suggesting that individuals may prefer these habitat types over primary forest. Our results suggest interspecific differences in the vocal repertoire of mouse lemurs, and that these differences can be used to investigate habitat preference via acoustic surveys.

Simple aspiration versus intercostal tube drainage for primary spontaneous pneumothorax in adults

BACKGROUND

In the management of primary spontaneous pneumothorax, simple aspiration is technically easier to perform. A systematic review may better define the clinical effectiveness and safety of simple aspiration compared to intercostal tube drainage in the management of primary spontaneous pneumothorax.

OBJECTIVES

To compare the clinically efficacy and safety of simple aspiration and intercostal tube drainage in the management of primary spontaneous pneumothorax.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2006), MEDLINE (1966 to August 2006), and EMBASE (1980 to August 2006). We searched Current Controlled Trials metaRegister of Clinical Trials (compiled by Current Science) (August 2006). We checked the reference lists of trials and contacted trial authors . We imposed no language restriction.

SELECTION CRITERIA

Randomized controlled trials comparing simple aspiration with intercostal tube drainage in adults aged 18 and over with primary spontaneous pneumothorax.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. No statistical methods were necessary because only one study met the inclusion criteria.

MAIN RESULTS

Of the 1239 publications obtained from the search strategy, we examined six studies. Five studies were excluded, and one study of 60 participants was eligible for inclusion. There was no difference in immediate success rate of simple aspiration when compared with intercostal tube drainage in the management of primary spontaneous pneumothorax (relative risk (RR) = 0.93; 95% confidence interval (CI) 0.62 to 1.40). There was no significant difference in the early failure rate between the two interventions: RR 1.12 (95% CI 0.59 to 2.13). Simple aspiration reduced the proportion of patients hospitalized (RR = 0.52; 95% CI 0.36 to 0.75). There was no significant difference between the two interventions with regard to the following outcome measures: duration of hospitalization (weighted mean difference = 1.09; 95% CI 2.18 to 0.00); number of participants undergoing any procedure for lung pleurodesis within one year (RR = 0.95; 95% CI 0.41 to 2.22);and one year success rate (RR = 1.02; 95% CI 0.75 to 1.38).

AUTHORS' CONCLUSIONS

There is no significant difference between simple aspiration and intercostal tube drainage with regard to: immediate success rate, early failure rate, duration of hospitalisation, one year success rate and number of patients requiring pleurodesis at one year. Simple aspiration is associated with a reduction in the per cent of patients hospitalized when compared with intercostal tube drainage.

Using functional data analysis to summarise and interpret lactate curves

John Tukey used the term exploratory data analysis (EDA) to describe a philosophy for analyzing data where graphical and numerical summaries are used to uncover interesting structures. The applied statistician today has a much more sophisticated set of methods to use when applying the EDA philosophy. One such collection of methods is functional data analysis (FDA), which was used to explore the structure of lactate curves. A principal components analysis and plots of the second derivatives provide new intuitive endurance markers which correlates highly with other numerical summaries of lactate curves that have been suggested in the literature.

Marrow-derived cells populate scaffolds composed of xenogeneic extracellular matrix

INTRODUCTION

The source of cells that participate in wound repair directly affects outcome. The extracellular matrix (ECM) and other acellular biomaterials have been used as therapeutic scaffolds for cell attachment and proliferation and as templates for tissue repair. The ECM consists of structural and functional proteins that influence cell attachment, gene expression patterns, and the differentiation of cells.

OBJECTIVE

The objective of this study was to determine if the composition of acellular matrix scaffolds affects the recruitment of bone marrow-derived cellular elements that populate the scaffolds in vivo.

METHODS

Scaffolds composed of porcine tissue ECM, purified Type I collagen, poly(L)lactic coglycolic acid (PLGA), or a mixture of porcine ECM and PLGA were implanted into subcutaneous pouches on the dorsum of mice. The origin of cells that populated the matrices was determined by first performing bone marrow transplantation to convert the marrow of glucose phosphate isomerase 1b (Gpi-1(b)) mice to cells expressing glucose phosphate isomerase 1a (Gpi-1(a)).

RESULTS

A significant increase in Gpi-1(a) expressing cells was present in sites implanted with the porcine ECM compared to sites implanted with either Type I collagen or PLGA. Use of recipient mice transplanted with marrow cells that expressed beta-galactosidase confirmed that the majority of cells that populated and remodeled the naturally occurring porcine ECM were marrow derived. Addition of porcine ECM to the PLGA scaffold caused a significant increase in the number of marrow-derived cells that became part of the remodeled implant site.

CONCLUSION

The composition of bioscaffolds affects the cellular recruitment pattern during tissue repair. ECM scaffolds facilitate the recruitment of marrow-derived cells into sites of remodeling.

Exercise and oral contraceptive use suppress the normal age-related increase in bone mass and strength of the femoral neck in women 18-31 years of age

Women who exercise during their second and third decades may increase their peak bone mass and lower their eventual risk for postmenopausal fracture. However, the effects of exercise in younger women can be modulated by the use of oral contraceptives, which may prevent the normal accretion of bone mass that would otherwise occur. We hypothesized that exercise intervention in young adult women would significantly increase both bone mass and the bending rigidity of the femoral neck. We further hypothesized that exercise intervention in the presence of oral contraceptive use would have a negative effect on bone mass and bending rigidity. Women 18-31 years of age (n = 123) were classified by oral contraceptive use (OC, NOC) and age (18-23, 24-31 years), and then randomized into exercise or nonexercise groups. The exercise protocol consisted of three sessions/week of aerobic and nonaerobic exercises, and continued for 2 years. Each 6 months, the femoral neck of each subject was scanned using a Lunar dual-energy X-ray absorptiometry (DEXA) scanner, and bone mineral content, density and geometric information were used to calculate estimated stresses and bending rigidity at the hip. Percent changes from baseline were analyzed using two-way analysis of variance (ANOVA) at 6, 12, 18, and 24 months. Women who neither exercised nor took oral contraceptives (NE/NOC) had the greatest percentage increases in cross-sectional area (4.98 +/- 2.29%), cross-sectional moment of inertia (9.45 +/- 2.37%), total bone mineral density (2.07 +/- 2.09%), fracture index (8.03 +/- 2.03%), and safety factor (20.03 +/- 5.79%) over the 24 month exercise program. Women who exercised and did not take oral contraceptives (E/NOC) declined on most variables related to femoral strength and bone mass, whereas those women who took oral contraceptives were usually intermediate between NE/NOC and E/NOC, whether they exercised or not. These data show that either exercise or OC use is associated with a suppression of the normal increase in bone mass and mechanical strength in the femoral neck in women 18-31 years old, but the combination of exercise and OC use appears to have a less suppressive effect.

Making the most of MEDLINE

The MEDLINE database is firmly established as an essential tool in medical research and practice, and all doctors should develop MEDLINE search skills. This article reviews key elements of the database, looking particularly at areas of common error, and the options available when fine-tuning a search. A better understanding of MEDLINE should lead to more effective use of this invaluable resource.

Chondrocyte-derived apoptotic bodies and calcification of articular cartilage

Chondrocytes exposed to nitric oxide (NO) or antibody to Fas undergo cell death by apoptosis. This study examines structural and functional properties of chondrocyte-derived apoptotic bodies. In NO treated cartilage, the dense pericellular matrix that normally surrounds the cells is degraded and apoptotic bodies accumulate within and in the vicinity of the chondrocyte lacunae. Functional analysis shows that apoptotic bodies isolated from NO-treated chondrocytes or cartilage produce pyrophosphate. The levels of pyrophosphate produced by apoptotic bodies are increased by pretreatment of the chondrocytes with transforming growth factor beta and decreased by interleukin 1. Apoptotic bodies contain alkaline phosphatase and NTP pyrophosphohydrolase activities and can precipitate calcium. These results suggest that chondrocyte-derived apoptotic bodies express functional properties that may contribute to the pathologic cartilage calcification observed in aging and osteoarthritis.

Differential effects of aging on human chondrocyte responses to transforming growth factor beta: increased pyrophosphate production and decreased cell proliferation

OBJECTIVE

To address the influence of age on inorganic pyrophosphate (PPi) accumulation in human articular chondrocytes.

METHODS

Articular cartilage was obtained from men and women in 2 different age groups: ages 15-55 and 56-91. The effects of transforming growth factor beta1 (TGFbeta1) on PPi levels in the media and cell lysates of chondrocytes were investigated. In addition, the effects of TGFbeta on PPi accumulation were compared with chondrocyte proliferation.

RESULTS

TGFbeta1 increased PPi levels to a greater extent in chondrocytes from subjects in the older age group compared with those obtained from younger subjects. Treatment of chondrocytes with TGFbeta1 led to a similar increase in total intracellular protein in both age groups. Although TGFbeta increased nucleoside triphosphate pyrophosphohydrolase activity and decreased alkaline phosphatase activity, these effects did not differ between the 2 age groups. Analysis of the same cell preparations showed an age-related decrease in TGFbeta-induced chondrocyte proliferation, whereas these same cells showed an increased response with respect to PPi elaboration.

CONCLUSION

These results show that aging differentially affected TGFbeta-induced PPi accumulation versus proliferation in human articular chondrocytes. These differences in TGFbeta response are likely to contribute to the development of age-associated cartilage diseases such as osteoarthritis.

Earth-Based Observations of the Galileo Probe Entry Site

Earth-based observations of Jupiter indicate that the Galileo probe probably entered Jupiter's atmosphere just inside a region that has less cloud cover and drier conditions than more than 99 percent of the rest of the planet. The visual appearance of the clouds at the site was generally dark at longer wavelengths. The tropospheric and stratospheric temperature fields have a strong longitudinal wave structure that is expected to manifest itself in the vertical temperature profile.

Interleukin 1 beta suppresses transforming growth factor-induced inorganic pyrophosphate (PPi) production and expression of the PPi-generating enzyme PC-1 in human chondrocytes

Articular cartilage chondrocytes have the unique ability to elaborate large amounts of extracellular pyrophosphate (PPi), and transforming growth factor beta (TGF beta) appears singular among cartilage regulatory factors in stimulating PPi production. TGF beta caused a time and dose-dependent increase in intracellular and extracellular PPi in human articular chondrocyte cultures. TGF beta and interleukin 1 beta (IL-1 beta) antagonistically regulate certain chondrocyte functions. IL-1 beta profoundly inhibited basal and TGF beta-induced PPi elaboration. To address mechanisms involved with the regulation of PPi synthesis by IL-1 beta and TGF beta, we analyzed the activity of the PPi-generating enzyme NTP pyrophosphohydrolase (NTPPPH) and the PPi-hydrolyzing enzyme alkaline phosphatase. Human chondrocyte NTPPPH activity was largely attributable to plasma cell membrane glycoprotein 1, PC-1. Furthermore, TGF beta induced comparable increases in the activity of extracellular PPi, intracellular PPi, and cellular NTPPPH and in the levels of PC-1 protein and mRNA in chondrocytes as well as a decrease in alkaline phosphatase. All of these TGF beta-induced responses were completely blocked by IL-1 beta. Thus, IL-1 beta may be an important regulator of mineralization in chondrocytes by inhibiting TGF beta-induced PPi production and PC-1 expression.

Relation of rearing environment to adaptive behavior of Egyptian toddlers

2 questions were explored: (1) Do observed relations found in Western cultures between specific psychosocial environmental factors and toddlers adaptive behavior resemble the pattern of relations found in a non-Western setting? (2) Does the specificity of relations between environment and performance found in Western cultures also operate in a non-Western culture? Subjects were 153 Egyptian toddlers, 18-30 months of age, and their caregivers. Twice a month between 18 and 30 months toddlers were observed in naturalistic interactions with their caregivers, and measures of caregiver behavior and toddler functioning were coded. Replicating previous results from Western cultures, canonical analysis indicated that caregiver vocal stimulation was positively related to indices of toddler behavioral competence, while nonverbal response to vocalization and physical contact stimulation were negatively related. The salience of sib caregivers was also noted. Particularly for the age period between 24 and 29 months, results indicated specificity of environmental action such that measures of caregiver vocal stimulation were uniquely related to measures of toddler vocalization, while caregiver response to distress was uniquely related to toddler emotionality. The present pattern of results suggests at least some degree of cross-cultural generalizability of environment-development relations and of the specificity model of environmental action.

Expression of c-fos and AP-1 activity in senescent human fibroblasts is not sufficient for DNA synthesis

Human fibroblasts have a limited replicative life span when maintained in culture after which they become unresponsive to treatment with mitogens, a phenomenon most commonly called senescence. Experiments indicating that serum does not induce expression of the c-fos proto-oncogene in senescent fibroblasts raised the issue of a potential central role for c-fos in the phenotype of sustained growth arrest. This was directly tested by microinjection of oncogenic c-Ha-ras protein into senescent fibroblasts. While ras injection was found to induce marked nuclear c-fos expression and functional AP-1 transcription activity, this did not lead to DNA synthesis. These results suggest that the senescence phenotype cannot be solely attributed to the absence of c-fos expression and that the proliferative block in these cells is either independent of AP-1 transcriptional activity, downstream of it, or involves multiple molecular mechanisms.

Spatial topological constraints in a bimanual task

Previous research has shown that the concurrent performance of two manual tasks results in a tight temporal coupling of the limbs. The intent of the present experiment was to investigate whether a similar coupling exists in the spatial domain. Subjects produced continuous drawing of circles and lines, one task at a time or bimanually, for a 20 s trial. In bimanual conditions in which subjects produced the circle task with one hand and the line task with the other, there was a clear tendency for the movement path of the circle task to become more line-like and the movement path of the line task to become more circle-like, i.e., a spatial magnet effect. A bimanual circle task and a bimanual line task did not exhibit changes in the movement path when compared to single-hand controls. In all bimanual conditions, the hands were tightly temporally locked. The evidence of temporal coupling and concomitant accommodation in the movement path for the conditions in which the hands were producing different shapes suggests that spatial constraints play a role in the governance of bimanual coordinated actions.

Serum potassium testing in diuretic-treated outpatients. A multivariate approach

We evaluated risk factors for abnormal serum potassium (K+) concentrations in 5817 outpatients on chronic diuretic therapy. Hypokalemia (K+ less than 3.5 meq/L) occurred in 18.8 percent at the last clinic measurement. Hyperkalemia (K+ greater than 5.5) was rare (0.5%) and was even less common in those also taking KCl or a K+ sparing drug (0.2%). Hypokalemic patients were younger, healthier, more often hypertensive, more commonly taking a thiazide diuretic, and more likely to have been hypokalemic in the past. Hyperkalemic patients were older, more often suffering from heart or renal failure, and more commonly taking furosemide. Logistic regression analysis yielded eight variables that contributed significantly to the prediction of hypokalemia: mean and most recent serum K+, thiazide use, the use and duration of use of potassium-sparing diuretics, age, and most recent serum sodium and bicarbonate determinations. The regression equation allowed us to identify a group of patients (63% of the total) at low risk for hypokalemia (K+ less than 3.5 in 9.4%; K+ less than 3.0 in 0.5%) and another group (37% of the total) at high risk for hypokalemia (K+ less than 3.5 in 35%; K+ less than 3.0 in 5%). Information about the risk of hypokalemia can be used to decide when to measure serum potassium concentration in individual diuretic-treated outpatients.