Training on a visual task improves the outcome of optic nerve regeneration

Optic nerve regeneration in a lizard, Ctenophorus ornatus, is dysfunctional despite survival of most retinal ganglion cells and axon regeneration to the optic tectum. The regenerated retino-tectal projection at 6 months has crude topography but by 1 year is disordered; visually-elicited behavior is absent via the experimental eye. Here, we assess the influence of training on the outcome of optic nerve regeneration. Lizards were trained to catch prey presented within the monocular field of either eye. One optic nerve was then severed and visual stimulation resumed throughout regeneration. In the trained group, presentation was restricted to the eye undergoing optic nerve regeneration; for the untrained group, the unoperated eye was stimulated. Pupil responses returned in trained but not in untrained animals. At 1 year, trained animals oriented to and captured prey; untrained animals demonstrated minimal orienting and failed to capture prey. Regenerated retino-tectal projections were topographic in the trained but not in the untrained group as assessed by in vitro electrophysiological recording and by carbocyanine dye tracing. In vitro electrophysiological recording during application of neurotransmitter antagonists to the tectum revealed that the level of GABAergic inhibition was modest in trained animals but elevated in the untrained group; responses were mainly AMPA-mediated in both groups. We conclude that training improves the behavioral outcome of regeneration, presumably by stabilizing and refining the transient retino-tectal map and preventing a build-up of tectal inhibition. The results suggest that for successful central nerve regeneration to occur in mammals, it may be necessary to introduce training to complement procedures stimulating axon regeneration.

Maternal fish oil supplementation in pregnancy reduces interleukin-13 levels in cord blood of infants at high risk of atopy

BACKGROUND AND OBJECTIVES

The epidemiological association between higher dietary n-3 polyunsaturated fatty acids (PUFA) and lower prevalence of asthma, has led to interest in the role of early dietary modification in allergic disease prevention. In this study we examined the effects of maternal n-3 (PUFA)-rich fish oil supplementation on cord blood (CB) IgE and cytokine levels in neonates at risk of developing allergic disease.

METHODS

In a randomized double-blind, placebo-controlled trial, 83 atopic pregnant women received either fish oil capsules (n = 40) containing 3.7 g n-3 PUFA/day or placebo capsules (n = 43) from 20 weeks gestation until delivery. CB cytokine levels (IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, TNF-alpha and IFN-gamma) and total IgE levels were measured and compared between the two groups. Fatty acid composition of red cell membranes was analysed by gas chromatography and the relationships among PUFA, cytokine and IgE levels were examined.

RESULTS

Maternal fish oil supplementation resulted in a significant increase in n-3 PUFA levels (P < 0.001) in neonatal erythrocyte membranes. Neonates whose mothers had fish oil supplementation had significantly lower plasma IL-13 (P < 0.05) compared to the control group. There was also a significant inverse relationship between levels of n-3 PUFA in neonatal cell membranes and plasma IL-13. There was no difference in levels of IgE and the other cytokines measured.

CONCLUSIONS

This study provides preliminary evidence that increasing neonatal n-3 PUFA levels with maternal dietary supplementation can achieve subtle modification of neonatal cytokine levels. Further assessment of immune function and clinical follow-up of these infants will help determine if there are any significant effects on postnatal immune development and expression of allergic disease.

Day-case ureteroscopy: an observational study

OBJECTIVE

To evaluate the outcome after day-case ureteroscopy (used in diagnosing and managing ureteric disease, primarily urolithiasis), as awareness of reduced resources has resulted in increasing pressure to undertake procedures in a day-surgery setting.

PATIENTS AND METHODS

All patients presenting to the unit and requiring ureteroscopy between May 1995 and May 2000 were considered for a day-surgery procedure. The assessment of suitability comprised anaesthetic and social factors; no urological criteria precluded a day-surgery procedure. Outcomes after day-case ureteroscopy, including immediate or delayed admissions and subsequent inpatient management, were reviewed retrospectively.

RESULTS

Sixty-three day-case ureteroscopies were performed on 56 patients (mean age 47 years, range 19-78); eight procedures were diagnostic. Therapeutic ureteroscopies included one balloon dilatation of a ureteric stricture and 54 procedures for urolithiasis, with 98% stone clearance. Most patients were discharged with a JJ stent in situ. Of nine patients requiring immediate admission, seven were for pain control; eight were discharged on the following day. Seven patients required delayed admission 1-13 days after the procedure, three for stent-related symptoms and three for infection. No significant predictors of immediate or delayed admission were identified, although antibiotic prophylaxis was associated with a reduced admission rate.

CONCLUSION

Ureteroscopy can be used successfully as a planned day-case procedure in a dedicated day-surgery unit, with few patients requiring hospitalization. Implementation of analgesia protocols and routine antibiotic prophylaxis may reduce admission after day-case ureteroscopy.

SERMs, ethnicity, and clinical trials: opportunities and challenges

Selective estrogen receptor modulators (SERMs) are an exciting new class of pharmacotherapeutics that may have application in a wide variety of disease states. The science, both basic and clinical, that would guide the usage of these agents is in some respects at a relatively early developmental stage. Thus, the research community has an opportunity, before their use becomes widespread, to structure clinical trials such that the most complete profiles of benefits and risks are described. Tamoxifen is the SERM that has been most extensively studied and for which there are indications for both treatment and prevention of breast cancer based on trials involving more than 50,000 women. Despite this seemingly adequate sample size, an extremely important question remains unanswered--namely, whether there are ethnic differences in benefit and adverse effects of SERMs. It has generally been the case that new pharmacologic agents are tested in relatively small numbers of subjects, often only male, in North America and western Europe. While the populations are multi-ethnic, clinical trial subjects are most often not representative of the ethnic variability of these areas. Guidelines for usage of new drugs based on data from small, ethnically limited population groups are then generalized to other population groups, without consideration that differences in drug metabolism and/or responsiveness might exist.

Race and the decision to refer for coronary revascularization: the effect of physician awareness of patient ethnicity

OBJECTIVES

We sought to assess whether there were differences, relative to racial ethnicity, in coronary revascularization recommendations made by a panel that had no knowledge of the patients' ethnicity.

BACKGROUND

Coronary revascularization is employed less frequently in African American than in white patients. It is unclear whether this utilization pattern is driven by clinical differences between the two populations or by nonclinical factors.

METHODS

Data were reviewed from 938 (26.5% African American, 73.5% white) consecutive cardiac catheterizations done between 1993 and 1995. Revascularization recommendations were made by cardiologists and cardiothoracic surgeons provided with the patients' clinical and angiographic data, but without knowledge of their ethnicity. Revascularization recommendations were compared between African American and white patients and correlated with clinical characteristics.

RESULTS

No difference was noted in the percentage of African American and white patients recommended for revascularization, without reference to whether the recommendation was for percutaneous transluminal coronary angioplasty (PTCA) or for coronary artery bypass graft surgery (CABG) 40 vs. 46%, p = NS). African Americans were recommended more frequently for PTCA (22 vs. 18%, p = NS), whereas CABG was recommended for more white patients (28 vs. 18%, p = 0.002). Significantly fewer African Americans had disease in the left main or left anterior descending coronary artery or in multiple arteries. After adjusting for age, co-morbidity, left ventricular dysfunction and the extent of coronary disease, African Americans were more likely to have a recommendation for PTCA (odds ratio [OR] 1.42, 95% confidence interval [CI] 0.96 to 2.11, p = 0.08) and less likely to have a recommendation for CABG (OR 0.59, 95% CI 0.37 to 0.94, p = 0.02).

CONCLUSIONS

This study suggests that when only clinical factors are considered, the rates of recommendations for revascularization will be similar for white and African American patients; but the type of revascularization procedure may differ by ethnicity and may depend, in part, on clinical factors.

Relationship between 24-H blood pressure and sleep disordered breathing in a normotensive community sample

Sleep disordered breathing (SDB) and hypertension are commonly associated. In this study, we assessed how longitudinal measures of SDB predict a 24-h ambulatory blood pressure monitoring (ABPM) profile. Participants (n = 82) were recruited from a community-based urban (26% African American) sample and included family members of patients with laboratory diagnosed SDB (cases) and family members of neighborhood control subjects evaluated at baseline and at 5 years. Nearly all participants were normotensive and were not receiving therapy for SDB. During both examinations, the respiratory distress index (RDI) was assessed with overnight in-home polysomnography. Seated blood pressure (BP) was assessed at a baseline examination (t,) and after a 5-year follow-up period (t5), when 24-h ABPM also was performed. The change in RDI (t5-t1) over 5 years was significantly associated with 24-h mean systolic blood pressure (SBP) (P = .04), 24-h maximum diastolic blood pressure (DBP) (P = .03), sleep mean SBP (P = .05), sleep mean DBP (P < .05), and sleep maximum SBP (P = .02). Regression analysis revealed that average 24-h mean arterial pressure (MAP) and mean 24-h DBP were each best predicted by change in RDI, explaining 5% of the variance in these 24-h BP readings, and by current smoking status. After accounting for these variables, BP was not predicted by any of the other potential confounders (all P > .10). Mean RDI (averaged between t5 and t1) was associated with mean MAP, mean SBP, and maximal SBP measured during sleep. This study documents for the first time the association between changes in sleep apnea activity and BP and in a community-based normotensive sample. Further long-term evaluation of the effects of these findings and the long-term consequences of hypertension are needed.

Percutaneous endoscopic gastrostomy in patients with ventriculoperitoneal shunts

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) may be required in neurosurgical patients with a persistently depressed neurological status or severe lower cranial nerve palsies. Such patients may have a coexisting hydrocephalus requiring cerebrospinal fluid (CSF) diversion. Despite the risk of infection resulting from exposure to oropharyngeal flora by the pull-through PEG technique and the secondary pneumoperitoneum seen in one-third of patients, simultaneous peritoneal placement of CSF shunt catheters with PEG is the current practice. The aim of the study was to determine the frequency of CSF diversionary procedures in neurosurgical patients undergoing PEG insertion and the occurrence of infective complications in patients with simultaneous placement of a PEG and a ventriculoperitoneal (VP) shunt.

METHODS

This was a retrospective review of all neurosurgical patients undergoing PEG. The presence of hydrocephalus, mode of CSF diversion and the development of subsequent infection in those having coexistent distal peritoneal catheter placement and PEG were determined.

RESULTS

PEGs were placed in 42 neurosurgical patients (9.3 per cent of all PEGs inserted), of whom 21 had a coexisting hydrocephalus. Eight of 16 shunts with distal catheter placement in the peritoneal cavity developed infection requiring revision. Infections occurred with greater frequency in patients with a tracheostomy. There were no shunt infections requiring revision in a second group of 21 patients who had a coexisting shunt and tracheostomy without PEG.

CONCLUSION

Simultaneous placement of a PEG and a VP shunt should be avoided in the acute phase of a patient's hospital admission.

Effect of gender on fast-track recovery after coronary artery bypass graft surgery

OBJECTIVE

To examine the effects of gender on time to extubation after coronary artery bypass graft (CABG) surgery and intensive care unit and hospital length of stay.

DESIGN

Retrospective study comparing outcomes as related to gender.

SETTING

Tertiary care university teaching hospital.

PARTICIPANTS

Consecutive patients (n = 561; 376 men, 185 women) undergoing CABG surgery between January 1995 and December 1997.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Early extubation was possible in 74% of men versus 64% of women (p = 0.03); length of stay was < or =5 days in 60% of men versus 48% of women (p = 0.008); overall postoperative length of stay was 5.7 days for men versus 6.5 days for women (p = 0.003); morbidity and mortality were not significantly different between groups.

CONCLUSION

Women undergoing CABG surgery with a standardized fast-track protocol have longer intubation times, intensive care unit length of stay, and hospital length of stay than their male counterparts.

A role for syndecan-1 in coupling fascin spike formation by thrombospondin-1

An important role of cell matrix adhesion receptors is to mediate transmembrane coupling between extracellular matrix attachment, actin reorganization, and cell spreading. Thrombospondin (TSP)-1 is a modulatory component of matrix expressed during development, immune response, or wound repair. Cell adhesion to TSP-1 involves formation of biochemically distinct matrix contacts based on stable fascin spikes. The cell surface adhesion receptors required have not been identified. We report here that antibody clustering of syndecan-1 proteoglycan specifically transduces organization of cortical actin and fascin bundles in several cell types. Transfection of COS-7 cells with syndecan-1 is sufficient to stimulate cell spreading, fascin spike assembly, and extensive protrusive lateral ruffling on TSP-1 or on syndecan-1 antibody. The underlying molecular mechanism depends on glycosaminoglycan (GAG) modification of the syndecan-1 core protein at residues S45 or S47 for cell membrane spreading and on the VC2 region of the cytoplasmic domain for spreading and fascin spike formation. Expression of the VC2 deletion mutant or GAG-negative syndecan-1 showed that syndecan-1 is necessary in spreading and fascin spike formation by C2C12 cells on TSP-1. These results establish a novel role for syndecan-1 protein in coupling a physiological matrix ligand to formation of a specific matrix contact structure.

Cystic fibrosis transmembrane conductance regulator facilitates ATP release by stimulating a separate ATP release channel for autocrine control of cell volume regulation

These studies provide evidence that cystic fibrosis transmembrane conductance regulator (CFTR) potentiates and accelerates regulatory volume decrease (RVD) following hypotonic challenge by an autocrine mechanism involving ATP release and signaling. In wild-type CFTR-expressing cells, CFTR augments constitutive ATP release and enhances ATP release stimulated by hypotonic challenge. CFTR itself does not appear to conduct ATP. Instead, ATP is released by a separate channel, whose activity is potentiated by CFTR. Blockade of ATP release by ion channel blocking drugs, gadolinium chloride (Gd(3+)) and 4,4'-diisothiocyanatostilbene-2,2'disulfonic acid (DIDS), attenuated the effects of CFTR on acceleration and potentiation of RVD. These results support a key role for extracellular ATP and autocrine and paracrine purinergic signaling in the regulation of membrane ion permeability and suggest that CFTR potentiates ATP release by stimulating a separate ATP channel to strengthen autocrine control of cell volume regulation.

Developing a public policy response to the tobacco industry's targeting of women and girls: the role of the WHO Framework Convention on Tobacco Control

More than 1 billion people smoke worldwide, and 200 million of them are women. The prevalence of tobacco use among women is rising, as is the tobacco-related disease burden. Recently released tobacco industry documents unequivocally establish that the tobacco industry has made a practice of targeting women and girls for decades in an effort to cultivate what it considers an underexploited market. This article discusses the importance of strategies to limit the growth of the tobacco pandemic and describes the World Health Organization's Framework Convention on Tobacco Control, which may have important implications for preventing the further spread of tobacco use among women.

Nucleotides regulate NaCl transport in mIMCD-K2 cells via P2X and P2Y purinergic receptors

Extracellular nucleotides regulate NaCl transport in some epithelia. However, the effects of nucleotide agonists on NaCl transport in the renal inner medullary collecting duct (IMCD) are not known. The objective of this study was to determine whether ATP and related nucleotides regulate NaCl transport across mouse IMCD cell line (mIMCD-K2) epithelial monolayers and, if so, via what purinergic receptor subtypes. ATP and UTP inhibited Na(+) absorption [measured via Na(+) short-circuit current (I(Na)(sc))] and stimulated Cl(-) secretion [measured via Cl(-) short-circuit current (I(Cl)(sc))]. Using selective P2 agonists, we report that P2X and P2Y purinoceptors regulate I(Na)(sc) and I(Cl)(sc). By RT-PCR, two P2X receptor channels (P2X(3), P2X(4)) and two P2Y G protein-coupled receptors (P2Y(1), P2Y(2)) were identified. Functional localization of P2 purinoceptors suggest that I(Cl)(sc) is stimulated by apical membrane-resident P2Y purinoceptors and P2X receptor channels, whereas I(Na)(sc) is inhibited by apical membrane-resident P2Y purinoceptors and P2X receptor channels. Together, we conclude that nucleotide agonists inhibit I(Na)(sc) across mIMCD-K2 monolayers through interactions with P2X and P2Y purinoceptors expressed on the apical plasma membrane, whereas extracellular nucleotides stimulate I(Cl)(sc) through interactions with P2X and P2Y purinoceptors expressed on the apical plasma membrane.

Epithelial P2X purinergic receptor channel expression and function

P2X purinergic receptor (P2XR) channels bind ATP and mediate Ca(2+) influx--2 signals that stimulate secretory Cl(-) transport across epithelia. We tested the hypotheses that P2XR channels are expressed by epithelia and that P2XRs transduce extracellular ATP signals into stimulation of Cl(-) transport across epithelia. Electrophysiological data and mRNA analysis of human and mouse pulmonary epithelia and other epithelial cells indicate that multiple P2XRs are broadly expressed in these tissues and that they are active on both apical and basolateral surfaces. Because P2X-selective agonists bind multiple P2XR subtypes, and because P2X agonists stimulate Cl(-) transport across nasal mucosa of cystic fibrosis (CF) patients as well as across non-CF nasal mucosa, P2XRs may provide novel targets for extracellular nucleotide therapy of CF.

Operative management of Haglund's deformity in the nonathlete: a retrospective study

Haglund's deformity, or "pump bump," is a common cause of posterior heel pain. Management of the condition usually consists of nonoperative therapy. This study presents a retrospective study of 65 cases (53 patients), with symptomatic Haglund's deformity in nonathletes (13 male and 40 female), who presented during a 4-year period (1989-1994). Sixty-five percent (39 heels) of these patients failed to respond to nonoperative therapy for an average of 62 weeks, (range, 4-260 weeks). This group of patients went on to operative treatment. Surgical management consisted of excision of the posterior calcaneal tuberosity through a medial longitudinal incision with debridement, reattachment of the Achilles tendon using bone anchors, and 4 weeks of postoperative immobilization. Thirty-nine patients (74%) were contacted for follow-up. The average follow-up period for these patients was 155 weeks, (range, 92-335 weeks). There were 50% excellent results, 47% good results, 3% fair results (1 patient), and no poor results. The Maryland Foot Score for operated heels was an average of 67/100 preoperative and an average of 92/100 postoperative. On unoperated heels the score was an average of 81/100 at first evaluation and an average of 86/100 at final evaluation. Complications included one recurrence of painful prominence, one wound infection, and one incisional neuroma. The outcome of these cases demonstrated that in those patients who fail nonoperative treatment, surgical treatment of Haglund's deformity produces a predictably good surgical result when performed using the technique described.

Bioluminescence detection of ATP release mechanisms in epithelia

Autocrine and paracrine release of and extracellular signaling by ATP is a ubiquitous cell biological and physiological process. Despite this knowledge, the mechanisms and physiological roles of cellular ATP release are unknown. We tested the hypothesis that epithelia release ATP under basal and stimulated conditions by using a newly designed and highly sensitive assay for bioluminescence detection of ATP released from polarized epithelial monolayers. This bioluminescence assay measures ATP released from cystic fibrosis (CF) and non-CF human epithelial monolayers in a reduced serum medium through catalysis of the luciferase-luciferin reaction, yielding a photon of light collected by a luminometer. This novel assay measures ATP released into the apical or basolateral medium surrounding epithelia. Of relevance to CF, CF epithelia fail to release ATP across the apical membrane under basal conditions. Moreover, hypotonicity is an extracellular signal that stimulates ATP release into both compartments of non-CF epithelia in a reversible manner; the response to hypotonicity is also lost in CF epithelia. The bioluminescence detection assay for ATP released from epithelia and other cells will be useful in the study of extracellular nucleotide signaling in physiological and pathophysiological paradigms. Taken together, these results suggest that extracellular ATP may be a constant regulator of epithelial cell function under basal conditions and an autocrine regulator of cell volume under hypotonic conditions, two functions that may be lost in CF and contribute to CF pathophysiology.

Reference centile charts for measures of disease activity, functional impairment, and metrology in ankylosing spondylitis

OBJECTIVE

To construct reference centile charts for validated measures of disease activity, functional impairment, and metrology (the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI], Bath Ankylosing Spondylitis Functional Index [BASFI], and Bath Ankylosing Spondylitis Metrology Index [BASMI]) in a population of patients with AS, and to explore the potential application of these charts in patient care and clinical research.

METHODS

We collected BASDAI and BASFI data on 2,979 patients with AS from the Royal National Hospital for Rheumatic Diseases (RNHRD) database and BASMI data on 393 patients at RNHRD. Data on age, sex, and duration of AS were also obtained. Centile charts were constructed for the BASDAI, BASFI, and BASMI in both males and females, with duration of AS as the time-dependant variable. Where necessary, BASDAI, BASFI, and BASMI raw scores were transformed to ensure that the indices were normally distributed over the range of disease duration, and allowance was made for change in variability of the indices.

RESULTS

Linear models were fitted to the mean and standard deviations of BASDAI, BASFI, and BASMI scores in males and females as a function of disease duration. A standard deviation score plot confirmed goodness of fit of the models, and fitted centiles were derived. Charts showing the 5th, 10th, 25th, 50th, 75th, 90th, and 95th centiles were constructed. The charts confirmed that AS remains active after 40 years' duration (mean BASDAI score 2.22 and 2.99 in males and females, respectively). The charts also demonstrated that females have greater disease activity and more functional impairment than males, despite better metrology.

CONCLUSION

The use of centile reference charts for disease activity, functional impairment, and metrology in AS will allow physicians and patients to interpret index scores relative to a reference population and will provide the opportunity to assess change over time and response to therapeutic interventions, to improve definition of disease status, and to enhance patients' involvement in their care.

Scleromyxoedema associated with synovitis and myopathy

Scleromyxoedema is a rare skin disease characterized by the deposition of hyaluronic acid in the papillary dermis and often associated with the presence of a monoclonal para protein. Patients with this disorder may also have systemic manifestations. A case of a patient with biopsy proven scleromyxoedema who, in addition to the skin changes had a steroid responsive myopathy and polysynovitis is presented.

Developing guidelines for local use: algorithms for cost-efficient outpatient management of cardiovascular disorders in a VA Medical Center

Local use of practice guidelines requires paying close attention to the concerns of the patient within the framework of society, to the professional and educational needs of the provider, and to the realities of cost. One Veterans Affairs facility took the challenge of balancing these factors and developed their own algorithms for three cardiovascular disorders.