Prognostic models for chronic low back pain outcomes in primary care are at high risk of bias and lack validation-high quality studies are needed: a systematic review

OBJECTIVE: To provide an updated overview of available prognostic models for people with chronic low back pain (LBP) in primary care. DESIGN: Prognosis systematic review. LITERATURE SEARCH: We searched for relevant studies on Medline, Embase, Web of Science and CINAHL databases (up to 13th, July 2022), and performed citation tracking in Web of Science. STUDY SELECTION CRITERIA: We included observational (cohort or nested case-control) studies and randomized controlled trials that developed or validated prognostic models for adults with chronic LBP in primary care. The outcomes of interest were physical functioning, pain intensity, and health-related quality of life at any follow-up time-point. DATA SYNTHESIS: Data were extracted using the CHARMS checklist, and the PROBAST tool was used to evaluate the risk of bias of the models. Due to the number of studies retrieved and the heterogeneity, we reported the results descriptively. RESULTS: Ten studies (out of 5593 hits screened) with 34 models met our inclusion criteria, of which six are development studies and four are external validation studies. Five studies reported the area under the curve of the models (ranging from 0.48 to 0.84), whereas no study reported calibration indices. The most promising model is the Örebro Musculoskeletal Pain Screening Questionnaire Short-Form. CONCLUSIONS: Given the high risk of bias and lack of external validation, we cannot recommend that clinicians use prognostic models for patients with chronic LBP in primary care settings.

Bias in the measurement of the outcome is associated with effect sizes in randomized clinical trials on exercise therapy for chronic low back pain: a meta-epidemiological study

OBJECTIVES

To explore the relationships between the risk of bias and treatment effect estimates for exercise therapy interventions on pain intensity and physical functioning outcomes in randomized controlled trials (RCTs) involving patients with chronic low back pain.

STUDY DESIGN AND SETTING

A cross-sectional meta-epidemiological study of the 230 RCTs (31,674 participants) in the 2021 'Exercise therapy for chronic low back pain' Cochrane Review were included. Study design characteristics, sample size, prospective trial registration, flowchart information, interventions, and comparisons were extracted. Independent pairs of reviewers assessed the risk of bias using the Cochrane Risk of Bias 2 tool.

RESULTS

The metaregression included 220 (pain intensity) and 203 (physical functioning) effect sizes. Unadjusted and adjusted metaregression models showed no significant associations between the bias domains and pain intensity effect sizes. Only domain 'bias in the measurement of the outcome' was significantly associated with physical functioning (standardized mean difference: -0.40, 95% confidence interval: -0.77 to -0.02) when adjusted for flowchart reported (yes/no), prospective trial registration, sample size, and comparator type.

CONCLUSION

The risk of bias in the measurement of the outcome could lead to slight overestimates of the effect size for physical functioning. Clinicians should consider this when they read and assess RCT results in this field. We encourage metaresearchers to replicate our findings using a consistent approach for evaluating the risk of bias (i.e., the RoB 2 tool) in other musculoskeletal conditions and interventions to investigate their generalizability.

Benefits and Harms of Spinal Manipulative Therapy for Treating Recent and Persistent Nonspecific Neck Pain: A Systematic Review With Meta-analysis

OBJECTIVE: We aimed to estimate the benefits and harms of cervical spinal manipulative therapy (SMT) for treating neck pain. DESIGN: Intervention systematic review with meta-analysis of randomized controlled trials (RCTs). LITERATURE SEARCH: We searched the MEDLINE, Cochrane CENTRAL, Embase, CINAHL, PEDro, Chiropractic Literature Index bibliographic databases, and grey literature sources, up to June 6, 2022. STUDY SELECTION CRITERIA: RCTs evaluating SMT compared to guideline-recommended and nonrecommended interventions, sham SMT, and no intervention for adults with neck pain were eligible for our systematic review. Prespecified outcomes included pain, range of motion, disability, health-related quality of life. DATA SYNTHESIS: Random-effects meta-analysis for clinically homogenous RCTs at short-term and long-term outcomes. Risk of bias was assessed using the Cochrane Risk of Bias 2.0 Tool. We used the Grading of Recommendations, Assessment, Development, and Evaluations approach to judge the certainty of evidence. RESULTS: We included 28 RCTs. There was very low to low certainty evidence that SMT was more effective than recommended interventions for improving pain at short term (standardized mean difference [SMD], 0.66; 95% confidence interval [CI]: 0.35, 0.97) and long term (SMD, 0.73; 95% CI: 0.31, 1.16), and for reducing disability at short-term (SMD, 0.95; 95% CI: 0.48, 1.42) and long term (SMD, 0.65; 95% CI: 0.23, 1.06). Transient side effects only were found (eg, muscle soreness). CONCLUSION: There was very low certainty evidence supporting cervical SMT as an intervention to reduce pain and improve disability in people with neck pain. J Orthop Sports Phys Ther 2023;53(9):510-528. Epub: 10 August 2023. doi:10.2519/jospt.2023.11708.

The Reporting of Somatic Sensory Training Interventions in Individuals After a Stroke Is Suboptimal: A Systematic Review and Meta-research Study

OBJECTIVE

The purpose of this systematic review is to assess adherence to the "template for intervention description and replication" checklist among all published randomized controlled trials of sensory retraining strategies for patients with a history of stroke.

METHODS

Medline, the Cochrane Register of Controlled Trials, and the Physiotherapy Evidence Database were investigated, without time restrictions, until September 1, 2021. In addition, a search for additional studies was carried out using the included studies' reference list. Only randomized controlled trials of adults with a history of stroke who aimed to improve sensation, via any type of intervention, were included. The template for intervention description and replication checklist was used to assess the completeness of reporting on each intervention.

RESULTS

A total of 61 trials were included. None of the included studies declared to have used the template for intervention description and replication checklist to report interventions. Overall, the median percentage of adherence to the 12 items of the template for intervention description and replication was 33% (interquartile range, 25%-50%). Only five of the single items were adequately described in more than 50% of the studies. None of the randomized controlled trials reported the entirety of the core intervention components, as described in items 3 to 9.

CONCLUSIONS

This systematic review demonstrates that interventions in sensory retraining strategy trials are described below desirable standards. Without this information, clinicians and researchers cannot reliably replicate interventions.

Physiotherapy Screening for Referral of a Patient with Peripheral Arterial Disease Masquerading as Sciatica: A Case Report

Many causes potentially underline pain in the lower extremities, presenting a real challenge for primary care clinicians in the recognition of the source of the patient's complaints. Peripheral arterial disease (PAD) is defined as a total or partial blockage of the vessels that supply blood from the heart to the periphery. PAD of the lower extremities may masquerade as lumbosacral radiculopathy (LSR)-a common source of leg pain. Physiotherapists should be able to screen for PAD in people presenting with pain in the lower extremities. Failure to correctly screen for PAD could put the patient at risk of severe disability and possible permanent sequelae. This case report outlines the relevant concepts relating to the pathophysiology, screening, and differential diagnosis of PAD, and then further describes the relevant findings from the history and physical examination from the physiotherapist's perspective in a patient with an unusual symptom presentation. Although the patient was referred by a physician with a diagnosis of LSR, our case highlights the pivotal role of skilled physiotherapists in triaging a severe lower-limb PAD in need of referral. Therefore, this case report aims to increase clinicians' awareness of the clinical features of a complex case of PAD.

Exercise for Depressive Symptoms in Parkinson Disease: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy of physical exercise in improving depressive symptoms in Parkinson disease (PD).

DATA SOURCE AND STUDY SELECTION

We conducted a systematic review of randomized controlled trials (RCTs) following a prespecified protocol guidance (PROSPERO CRD42021243142). Two independent authors searched for studies in MEDLINE, Cochrane Register of Controlled Trials, Physiotherapy Evidence Database, Embase, PsycINFO, and Sports Discus from database inception to June 2022.

DATA EXTRACTION

Two independent authors extracted the data and evaluated the risk of bias using the revised Cochrane risk of bias tool. We performed random-effects meta-analyses and rated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DATA SYNTHESIS

A total of 36 RCTs met the inclusion criteria, 14 of which were pooled in the quantitative synthesis. Depression symptomatology significantly decreased in the exercise group compared with usual care (standardized mean difference [SMD], -0.49; 95% confidence interval [CI], -0.74 to -0.24; very low quality of evidence; 14 RCTs; 961 participants). Physical exercise also improved patients' quality of life (SMD, -0.51; 95% CI, -0.81 to -0.21; 7 RCTs; 485 participants). As for acceptability, we did not find any difference between exercise and usual care (relative risk, 1.01; 95% CI, 0.97 to 1.05; 12 RCTs; 1048 participants). We judged all the studies except 2 to be at high risk of bias.

CONCLUSIONS

Results from our systematic review identify physical activity as a viable option to reduce depressive symptoms in PD. Future clinical practice guidelines should consider physical exercise in their recommendations for depression symptomatology reduction in people with PD.

Identifying peripheral arterial diseases or flow limitations of the lower limb: Important aspects for cardiovascular screening for referral in physiotherapy

Many conditions could potentially cause pain in the lower limbs. One of these is peripheral arterial disease (PAD). PAD is often a real challenge to be recognized for clinicians due to symptoms that commonly mimic musculoskeletal conditions. PAD is defined as a total or partial blockage of the vessels that supply blood from the heart to the periphery. Its prevalence is around 7 percent in subjects between 55 and 59, reaching almost 25% in individuals between 95 and 99 years old. The most dominant symptom of PAD is lower limb pain. Also, PAD can produce other symptoms such as discoloration, altered skin temperature, and, when arterial blood flow is insufficient to meet the metabolic demands of resting muscle or tissue, focal areas of ischemia. In our view, physical therapists should be capable of triaging for PAD in a direct access setting. Therefore, in this Professional Issue, we present the main characteristics of PAD and the physiotherapy role in its management. A supplementary step-by-step guide will provide further resources for testing PAD.

Adherence to the PRISMA statement and its association with risk of bias in systematic reviews published in rehabilitation journals: A meta-research study

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The mean overall adherence to the PRISMA checklist across the sample of systematic reviews published in rehabilitation journals was 61.4%.

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A high overall risk of bias was a significant predictor of lower adherence (B=−7.1%; 95%CI −12.1, −2.0).

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Studies published in fourth quartile journals displayed a lower overall adherence than those published in the first quartile.

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No association between adherence and publication options and publication year was found.

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The overall adherence increased (B= 11.9%; 95%CI 5.9, 18.0) when the SR protocol was registered

Background

Systematic reviews (SRs) and meta-analyses are essential resources for the clinicians. They allow to evaluate the strengths and the weaknesses of the evidence to support clinical decision-making if they are adequately reported. Little is known in the rehabilitation field about the completeness of reporting of SRs and its relationship with the risk of bias (ROB).

Objectives

Primary: 1) To evaluate the completeness of reporting of systematic reviews (SRs) published in rehabilitation journals by evaluating their adherence to the PRISMA 2009 checklist, 2) To investigate the relationship between ROB and completeness of reporting. Secondary: To study the association between completeness of reporting and journals and study characteristics.

Methods

A random sample of 200 SRs published between 2011 and 2020 in 68 rehabilitation journals was indexed under the “rehabilitation” category in the InCites database. Two independent reviewers evaluated adherence to the PRISMA checklist and assessed ROB using the ROBIS tool. Overall adherence and adherence to each PRISMA item and section were calculated. Regression analyses investigated the association between completeness of reporting, ROB, and other characteristics (impact factor, publication options, publication year, and study protocol registration).

Results

The mean overall PRISMA adherence across the 200 studies considered was 61.4%. Regression analyses show that having a high overall ROB is a significant predictor of lower adherence (B=-7.1%; 95%CI -12.1, -2.0). Studies published in fourth quartile journals displayed a lower overall adherence (B= -7.2%; 95%CI -13.2, -1.3) than those published in first quartile journals; the overall adherence increased (B= 11.9%; 95%CI 5.9, 18.0) if the SR protocol was registered. No association between adherence, publication options, and publication year was found.

Conclusion

Reporting completeness in rehabilitation SRs is suboptimal and is associated with ROB, impact factor, and study registration. Authors of SRs should improve adherence to the PRISMA guideline, and journal editors should implement strategies to optimize the completeness of reporting.

Using expert knowledge to support Endangered Species Act decision-making for data-deficient species

Many questions relevant to conservation decision-making are characterized by extreme uncertainty due to lack of empirical data and complexity of the underlying ecologic processes, leading to a rapid increase in the use of structured protocols to elicit expert knowledge. Published ecologic applications often employ a modified Delphi method, where experts provide judgments anonymously and mathematical aggregation techniques are used to combine judgments. The Sheffield elicitation framework (SHELF) differs in its behavioral approach to synthesizing individual judgments into a fully specified probability distribution for an unknown quantity. We used the SHELF protocol remotely to assess extinction risk of three subterranean aquatic species that are being considered for listing under the U.S. Endangered Species Act. We provided experts an empirical threat assessment for each known locality over a video conference and recorded judgments on the probability of population persistence over four generations with online submission forms and R-shiny apps available through the SHELF package. Despite large uncertainty for all populations, there were key differences between species' risk of extirpation based on spatial variation in dominant threats, local land use and management practices, and species' microhabitat. The resulting probability distributions provided decision makers with a full picture of uncertainty that was consistent with the probabilistic nature of risk assessments. Discussion among experts during SHELF's behavioral aggregation stage clearly documented dominant threats (e.g., development, timber harvest, animal agriculture, and cave visitation) and their interactions with local cave geology and species' habitat. Our virtual implementation of the SHELF protocol demonstrated the flexibility of the approach for conservation applications operating on budgets and time lines that can limit in-person meetings of geographically dispersed experts.

The effectiveness of median nerve electrical stimulation in patients with disorders of consciousness: a systematic review

OBJECTIVE

To examine the effectiveness of median nerve electrical stimulation on consciousness level in subjects with disorders of consciousness.

METHODS

Electronic databases PubMed, EMBASE, CENTRAL, and PEDro, as well as manual search and gray literature were searched from inception until May 2019. We included only randomized controlled trials. Two reviewers independently conducted the search strategy, study selection, data extraction, risk of bias assessment, and evidence judgment quality.

RESULTS

Five studies met the inclusion criteria. Overall, no clear conclusion can be drawn about the intervention's effectiveness on the level of consciousness. One study reported a benefit of the intervention on the number of hospitalization days in the intensive care unit. Furthermore, another study reported a higher percentage of patients who regained consciousness six months from the event in the experimental group.

CONCLUSION

Due to the limited number of studies that met the inclusion criteria and overall high risk of bias, it is impossible to draw a definitive conclusion. The results of this systematic review should be used to improve future research in this field.

Declaration of use and appropriate use of reporting guidelines in high-impact rehabilitation journals is limited: a meta-research study

OBJECTIVES

The main aims of this metaresearch study conducted among high-impact rehabilitation journals were: 1) to evaluate if the use of reporting guidelines (RGs) was declared and 2) to categorize the declared use as appropriate or inappropriate.

STUDY DESIGN AND SETTING

Cross-sectional analysis of a random sample of 200 studies published in the period 2010-2019 in five generic rehabilitation journals with the highest 5-year impact factor. Randomized controlled trials, systematic reviews, observational studies, and diagnostic studies were included. Prevalence with 95% confidence intervals (CIs) was estimated for the main outcomes.

RESULTS

Among the 200 selected studies, 17.5% (95% CI: 12.2-22.8%) declared using RGs. Among these studies, 48.6% (95% CI: 32-65.1%) declared an appropriate use. There was an increasing trend over time for authors to report the use of RGs (OR: 1.31; 95% CI: 1.13-1.53). Systematic reviews (n = 54) reported more frequently the use of RGs than other study designs (35.2%).

CONCLUSION

In high-impact rehabilitation journals, a small minority of article authors declared the use of RGs. In approximately half of these studies, RGs were used inappropriately. There is an urgent need to improve the use of RGs in this field of research.

Understanding the Acceptability of Subdermal Implants as a Possible New HIV Prevention Method: Multi-Stage Mixed Methods Study

Background

A long-acting implant for HIV pre-exposure prophylaxis (PrEP) is in development in the Sustained Long-Action Prevention Against HIV (SLAP-HIV) trial. This could provide an alternative to oral PrEP.

Objective

Our mixed methods study aimed to understand (1) users’ experiences with a similar subdermal implant for contraception and (2) factors influencing the likelihood that gay and bisexual men (GBM) would use a proposed PrEP implant.

Methods

Work was completed in 4 stages. In stage 1, we conducted a scientific literature review on existing subdermal implants, focusing on users’ experiences with implant devices. In stage 2, we reviewed videos on YouTube, focusing on the experiences of current or former contraceptive implant users (as these implants are similar to those in development in SLAP-HIV). In stage 3, individuals who indicated use of a subdermal implant for contraception in the last 5 years were recruited via a web-based questionnaire. Eligible participants (n=12 individuals who liked implants a lot and n=12 individuals who disliked implants a lot) completed in-depth phone interviews (IDIs) about their experiences. In stage 4, results from IDIs were used to develop a web-based survey for HIV-negative GBM to rate their likelihood of using a PrEP implant on a scale (1=very unlikely and 5=very likely) based on likely device characteristics and implant concerns identified in the IDIs.

Results

In the scientific literature review (stage 1), concerns about contraceptive implants that could apply to the PrEP implants in development included potential side effects (eg, headache), anticipated high cost of the device, misconceptions about PrEP implants (eg, specific contraindications), and difficulty accessing PrEP implants. In the stage 2 YouTube review, individuals who had used contraceptive implants reported mild side effects related to their device. In stage 3, implant users reported that devices were comfortable, unintrusive, and presented only minor discomfort (eg, bruising) before or after insertion and removal. They mainly reported removing or disliking the device due to contraceptive-related side effects (eg, prolonged menstruation). Participants in the stage 4 quantitative survey (N=304) were mainly gay (204/238, 85.7%), white (125/238, 52.5%), cisgender men (231/238, 97.1%), and 42.0% (73/174) of them were on oral PrEP. Not having to take a daily pill increased the likelihood of using PrEP implants (mean 4.13). Requiring >1 device to achieve 1 year of protection (mean range 1.79-2.94) mildly discouraged PrEP implant use. Participants did not mind moderate bruising, a small scar, tenderness, or bleeding after insertion or removal, and an implant with a size slightly larger than a matchstick (mean ratings 3.18-3.69).

Conclusions

PrEP implants are promising among GBM. Implant features and insertion or removal-related concerns do not seem to discourage potential users. To ensure acceptability, PrEP implants should require the fewest possible implants for the greatest protection duration.

HIV Risk Assessment using Longitudinal Electronic Health Records

Background

Universal HIV screening programs are costly, labor-intensive, and in practice unable to identify all individuals at risk of HIV infection. Automated risk assessment methods that leverage longitudinal electronic health records (EHRs) could catalyze targeted screening programs in Emergency Departments and across public health jurisdictions. While information on social and behavioral determinants of health are typically collected in unstructured fields, previous analyses have only considered structured EHR data. We sought to characterize whether clinical notes can improve predictive models of HIV diagnosis.

Methods

181 individuals who received care at an academic medical center in New York City prior to a confirmatory HIV diagnosis were included in the study cohort. 543 HIV- controls with similar utilization patterns were selected using propensity score matching. Demographics, laboratory tests, and diagnosis codes were extracted from longitudinal records. Clinical notes were preprocessed using both topic modeling and an n-grams approach. We fit 3 predictive models using Random Forests including a baseline model which included only structured EHR data, the baseline model plus topic modeling, and baseline model plus clinical keywords.

Results

Predictive models demonstrated a range of performance with F-measures of 0.59 for the baseline model, 0.63 for the baseline plus topic modeling and 0.74 for the baseline plus clinical keyword model. The baseline plus topic model displayed low precision but high recall while the baseline plus clinical keyword model displayed high precision but low recall. Clinical keywords including ‘msm’, ‘unprotected’, ‘hiv’, and ‘methamphetamine’ were indicative of elevated risk.

Conclusion

Clinical notes improved the performance of predictive models for automated HIV risk assessment. Future studies should explore novel techniques for extracting social and behavioral determinants from unstructured text in longitudinal EHRs.

Disclosures

All authors: No reported disclosures.

ABCB1 and ABCG2 drug transporters are differentially expressed in non-small cell lung cancers (NSCLC) and expression is modified by cisplatin treatment via altered Wnt signaling

BACKGROUND

Lung cancer (LC) is still the most common cause of cancer related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of all LC cases but is not a single entity. It is now accepted that, apart from the characteristic driver mutations, the unique molecular signatures of adeno- (AC) and squamous cell carcinomas (SCC), the two most common NSCLC subtypes should be taken into consideration for their management. Therapeutic interventions, however, frequently lead to chemotherapy resistance highlighting the need for in-depth analysis of regulatory mechanisms of multidrug resistance to increase therapeutic efficiency.

METHODS

Non-canonical Wnt5a and canonical Wnt7b and ABC transporter expressions were tested in primary human LC (n = 90) resections of AC and SCC. To investigate drug transporter activity, a three dimensional (3D) human lung aggregate tissue model was set up using differentiated primary human lung cell types. Following modification of the canonical, beta-catenin dependent Wnt pathway or treatment with cisplatin, drug transporter analysis was performed at mRNA, protein and functional level using qRT-PCR, immunohistochemistry, immune-fluorescent staining and transport function analysis.

RESULTS

Non-canonical Wnt5a is significantly up-regulated in SCC samples making the microenvironment different from AC, where the beta-catenin dependent Wnt7b is more prominent. In primary cancer tissues ABCB1 and ABCG2 expression levels were different in the two NSCLC subtypes. Non-canonical rhWnt5a induced down-regulation of both ABCB1 and ABCG2 transporters in the primary human lung aggregate tissue model recreating the SCC-like transporter pattern. Inhibition of the beta-catenin or canonical Wnt pathway resulted in similar down-regulation of both ABC transporter expression and function. In contrast, cisplatin, the frequently used adjuvant chemotherapeutic agent, activated beta-catenin dependent signaling that lead to up-regulation of both ABCB1 and ABCG2 transporter expression and activity.

CONCLUSIONS

The difference in the Wnt microenvironment in AC and SCC leads to variations in ABC transporter expression. Cisplatin via induction of canonical Wnt signaling up-regulates ABCB1 and ABCG2 drug transporters that are not transporters for cisplatin itself but are transporters for drugs that are frequently used in combination therapy with cisplatin modulating drug response.

Increased Wnt5a in squamous cell lung carcinoma inhibits endothelial cell motility

BACKGROUND

Angiogenesis is important both in normal tissue function and disease and represents a key target in lung cancer (LC) therapy. Unfortunately, the two main subtypes of non-small-cell lung cancers (NSCLC) namely, adenocarcinoma (AC) and squamous cell carcinoma (SCC) respond differently to anti-angiogenic e.g. anti-vascular endothelial growth factor (VEGF)-A treatment with life-threatening side effects, often pulmonary hemorrhage in SCC. The mechanisms behind such adverse reactions are still largely unknown, although peroxisome proliferator activator receptor (PPAR) gamma as well as Wnt-s have been named as molecular regulators of the process. As the Wnt microenvironments in NSCLC subtypes are drastically different, we hypothesized that the particularly high levels of non-canonical Wnt5a in SCC might be responsible for alterations in blood vessel growth and result in serious adverse reactions.

METHODS

PPARgamma, VEGF-A, Wnt5a, miR-27b and miR-200b levels were determined in resected adenocarcinoma and squamous cell carcinoma samples by qRT-PCR and TaqMan microRNA assay. The role of PPARgamma in VEGF-A expression, and the role of Wnts in overall regulation was investigated using PPARgamma knock-out mice, cancer cell lines and fully human, in vitro 3 dimensional (3D), distal lung tissue aggregates. PPARgamma mRNA and protein levels were tested by qRT-PCR and immunohistochemistry, respectively. PPARgamma activity was measured by a PPRE reporter system. The tissue engineered lung tissues expressing basal level and lentivirally delivered VEGF-A were treated with recombinant Wnts, chemical Wnt pathway modifiers, and were subjected to PPARgamma agonist and antagonist treatment.

RESULTS

PPARgamma down-regulation and VEGF-A up-regulation are characteristic to both AC and SCC. Increased VEGF-A levels are under direct control of PPARgamma. PPARgamma levels and activity, however, are under Wnt control. Imbalance of both canonical (in AC) and non-canonical (in SCC) Wnts leads to PPARgamma down-regulation. While canonical Wnts down-regulate PPARgamma directly, non-canonical Wnt5a increases miR27b that is known regulator of PPARgamma.

CONCLUSION

During carcinogenesis the Wnt microenvironment alters, which can downregulate PPARgamma leading to increased VEGF-A expression. Differences in the Wnt microenvironment in AC and SCC of NSCLC lead to PPARgamma decrease via mechanisms that differentially alter endothelial cell motility and branching which in turn can influence therapeutic response.

Age-related changes in acute central leptin effects on energy balance are promoted by obesity

Leptin is a key catabolic regulator of food intake (FI) and energy expenditure. Both aging and obesity have been shown to induce leptin-resistance. The present study aimed to analyze age-related changes in the anorexigenic and hypermetabolic responsiveness to acute intracerebroventricular leptin administration in different age-groups of normally fed male Wistar rats (adult and old rats from 3 to 24months of age, NF3 to NF24, respectively). The expressions of the long form of the leptin receptor (Ob-Rb) and inhibitory SOCS3 genes were also assessed by quantitative RT-PCR in the arcuate nucleus (ARC). The influence of high-fat diet-induced obesity (HF) on the anorexigenic leptin effects were also tested in younger and older middle-aged groups (HF6 and HF12). Leptin-induced anorexia varied with age: leptin suppressed re-feeding FI (following 48-h fasting) strongly in young adult (NF3), but not in younger or older middle-aged (NF6 or NF12) or in aging (NF18) rats. However, anorexigenic leptin effects reached statistical significance again in old NF24 rats. Leptin-induced hypermetabolism, on the other hand, showed monotonous age-related decline and disappeared by old age. Ob-Rb expression declined until 12months of age followed by a partial recovery in NF18 and NF24 groups. On the other hand, SOCS3 expression was high in NF6 and NF18 and to some extent in NF24 rats. Age-related alterations of Ob-Rb and SOCS3 expression in the ARC may partly contribute to the explanation of age-related variations in anorexigenic but not hypermetabolic leptin effects. High-fat diet-induced obesity was associated with resistance to leptin-induced anorexia in HF6, similar to that seen in NF6. However, instead of the expected leptin-resistance in HF12, a strong leptin-induced suppression of re-feeding was detected in these obese middle-aged rats. Our results suggest that acute central effects of leptin on anorexia and hypermetabolism change in disparate ways during aging, implying separate mechanisms (e.g. signal transduction pathways) of different leptin actions. The age-related pattern shown by leptin-induced anorexia may contribute to the explanation of middle-aged obesity, and partly to that of aging anorexia. Our findings concerning obese rats are in accord with previous observations on anorexigenic effects of peripherally administered cholecystokinin: diet-induced obesity appeared to accelerate the development of age-related regulatory alterations. Similarly, our present data also raise the possibility that chronic diet-induced obesity promotes responsiveness to centrally applied leptin at least concerning anorexigenic effects.

Dietary calcium modulates blood pressure through alpha 1-adrenergic receptors

To investigate the role of adrenergic receptor activity in dietary calcium-induced alterations in blood pressure, weanling spontaneously hypertensive rats (SHR) were placed on either high-calcium (2.0%) or low-calcium (0.1%) diets for 1-2 wk. Baseline blood pressure was higher and pressor responses to exogenous norepinephrine (NE) were greater in the SHR on low-calcium diets than high-calcium diets. There was no difference between diet groups in circulating NE or in the pressor response to angiotensin II. The difference in basal blood pressure was eliminated by the alpha 1-adrenergic receptor blockers phentolamine and prazosin but was not altered by alpha 2-, beta 1-, or beta 2-adrenergic receptor blockade (idazoxan, metoprolol, and butoxamine, respectively). Furthermore, hypotension produced by either calcitonin gene-related peptide, captopril, or nitroprusside failed to eliminate the diet-induced difference in blood pressure. The results suggest the possibility that diet-induced differences in alpha 1-adrenergic activity may be responsible, in part, for variations in blood pressure on different calcium diets.

Comparing two sampling techniques for endocervical cell recovery on Papanicolaou smears

The importance of endocervical cells in a Pap smear is well-recognized. A Pap smear lacking endocervical cells is considered inadequate and necessitates a repeat test. Clinicians continue to search for techniques that will ensure consistently adequate samples. In this study, Pap smears were obtained for 200 subjects, alternating use of a saline-moistened cotton-tipped applicator with the Zelsmyr Cytobrush for endocervical cell collection. Endocervical cells were present in all 100 Cytobrush smears, compared with 91 of the cotton-tipped applicator smears. The difference is significant (p less than 0.005). The nine smears that lacked endocervical cells were repeated, using the Cytobrush; all nine repeat smears contained endocervical cells. Although the sample used in this study was small, results indicate that the Cytobrush is more effective in obtaining endocervical cells than the cotton-tipped applicator. Use of the Cytobrush is recommended in the interest of reducing the number of false negative reports.

Mechanism of action of a polypeptide neurotoxin from the coral Goniopora on sodium channels in mouse neuroblastoma cells

Goniopora toxin (GPT), a polypeptide toxin of 9700 Da isolated from coral, markedly slows inactivation of sodium currents recorded under voltage clamp in mouse neuroblastoma cells. The voltage dependence of sodium channel activation is shifted to more negative membrane potentials by 9.8 +/- 2.1 mV, and the voltage dependence of channel inactivation is shifted to more positive membrane potential by 6.0 +/- 2.5 mV. These actions of GPT are voltage dependent with an e-fold increase in K0.5 for toxin action for each 48.3-mV depolarization between -80 and +40 mV. GPT requires Na+ or another alkali metal cation in the extracellular medium for its effect on sodium channels. The relative effectiveness of the different cations tested is Na+ greater than K+ greater than Rb+ greater than Li+ greater than Cs+ much greater than choline+. Like other polypeptide neurotoxins that slow inactivation of sodium channels, GPT enhances persistent activation of sodium channels by veratridine. However, GPT does not block the binding of 125I-labeled Leiurus scorpion toxin to neurotoxin receptor site 3 on sodium channels at concentrations which effectively slow channel inactivation. Therefore, our results define a new site on the sodium channel at which specific effects on inactivation can occur.

[Enteral-parenteral feeding with high protein content in++ severe cranio-cerebral injuries]

Brain injured patients (BIP) usually have hugh losses of nitrogen in the early posttraumatic period. Investigations on protein catabolism in 10 young male BIP, not being moribund, were performed to answer the question whether N-loss can be minimized by an enteral-parenteral nutrition with high protein content (greater than 2 g protein/kg body weight). N-balance, 24-h urinary excretion of creatinin and 3-methylhistidine were measured for 8 days after the accident. The alimentary regime, being adapted to body weight, included for an adult 70-kg patient the intake of 470 g carbohydrates, 170 g aminoacids/proteins and 45 g fats per day (3040 kcal/day = 12700 kJ/day with 112 kcal/g N = 468 kJ/g N). Laboratory data indicated a stimulated muscle turnover rate and a considerable protein catabolism. The waste of endogenous sources could therefore not be prevented by the presented combined nutritional regime.

Neurochemical effects of long-term ingestion of ethanol by Sinclair (S-1) swine

Sinclair (S-1) miniature swine were given access to a mixture of ethanol and beer for three years. Control swine were fed an isocaloric diet with corn starch substituted for ethanol. Both groups had free access to tap water. The alcohol group consumed about 4 g ethanol/kg/day (about 50% of their caloric intake) resulting in plasma ethanol concentrations of about 100 mg/dl. Brain membranes were prepared for analysis of neurotransmitter receptor binding, membrane lipid composition and physical properties. Receptor studies demonstrated an increase in the binding of 3H-GABA to cortical and cerebellar membranes from the alcoholic pigs as compared to control. Binding of 3H-ligands to muscarine cholinergic, beta-adrenergic, alpha-adrenergic, dopamine and benzodiazepine receptors was not changed by chronic ethanol ingestion. These results are similar to those obtained in studies of human alcoholics by other investigators. The cholesterol content of myelin and synaptic plasma membranes was not altered by ethanol consumption. The fluorescence polarization of diphenylhexatriene, a measure of membrane order, did not detect any differences in the membranes from control or alcohol-treated swine either before or after in vitro exposure to ethanol. These results are different from those reported for rodents after short-term ethanol treatments and emphasize the importance of evaluating different models of experimental alcoholism.

Sensitization produced by repeated administration of naloxone is blocked by food deprivation

The current study was conducted in order to explore the effects of repeated naloxone administration as a function of food intake. Rats were trained to press a bar to avoid foot-shock. They were allowed either free or restricted access to food. Free-feeding rats developed a strong sensitivity to naloxone, as manifested by an increased shock rate after naloxone injection. When animals were food-deprived, the sensitivity was greatly reduced. A different species (mouse) and two different tests were used to examine further the effects of food intake and pretreatment with naloxone. The mice were given either free access to food or a restricted diet and were pretreated with either naloxone or saline. The effects of food intake and pretreatment with naloxone were examined in terms of motor activity, morphine analgesia and naloxone hyperalgesia. The results showed that prior exposure to naloxone in free-feeding animals enhanced the suppressant effect of naloxone on motor activity and the analgesic effects of morphine (as measured by paw-lick, but not as measured by jump in the hot-plate test), but had no effect on the hyperalgesic effect of naloxone. When mice were food-deprived during naloxone administration, sensitization did not occur. The hypothesis that naloxone sensitivity is due to changes in the number of brain opiate receptors was tested by measuring the number and affinity of [3H]naloxone binding sites on brain membranes from mice chronically treated with naloxone. Neither naloxone pretreatment nor food deprivation affected the number or affinity of binding sites. The gamma-aminobutyric acid antagonist effect of naloxone (as measured by gamma-[3H]aminobutyric acid binding) was also unchanged by naloxone pretreatment. Thus, the basis of the interactions between naloxone and the feeding state remains unclear.

The influence of mouse genotype on the changes in brain cyclic nucleotide levels induced by acute alcohol administration

Two mouse strains (C57BL/6By and BALB/cByJ) were found to differ widely in their sleep-time response to ethanol (3 g/kg), but showed no difference in their hypothermic response to the same ethanol dose. Comparison of brain cyclic nucleotide levels in the two strains revealed a strain difference in the brain cyclic AMP response to ethanol but no strain difference in the magnitude of the brain cyclic GMP change. Alcohol produced a significant drop in cerebellar cyclic GMP in both strains, and a decrease in cerebellar cyclic AMP in C57BL/6By mice. The cyclic AMP/cyclic GMP ratio increased following alcohol in the cerebellum of BALB/cByJ mice but not C57BL/6By mice. The results are discussed in terms of possible relationships between alcohol-induced changes in neurochemistry and behavior.