mTOR inhibition induces endothelial progenitor cell death

Immunosuppressants are necessary to prevent graft rejection after solid organ transplantation. However, they are also known to have significant side effects, including endothelial toxicity. Endothelial progenitor cells originate in the bone marrow and are recognized by their angiogenic and endothelial reparative properties. The effects of the immunosuppressants cyclosporine A (CyA), tacrolimus and rapamycin were analyzed on endothelial progenitor-like cells. Rapamycin induced rapid cell death, even at concentrations much lower than those used clinically, in peripheral blood mononuclear cells (PBMC) cultured to favor outgrowth of endothelial progenitors. Cyclosporine A and tacrolimus had no significant effects at clinical concentrations. The effect of rapamycin was specific to endothelial progenitor cells, in particular to the early stages of differentiation, as a lesser effect was observed in late outgrowth endothelial progenitors, mature aortic endothelial cells, and macrophages derived from the same PBMCs. The mechanism of cell death appeared to be apoptosis; however, its induction was probably multifactorial and did not depend on caspase or cathepsin activation. In conclusion, rapamycin induces endothelial progenitor cell death, possibly because it blocks survival signals given by growth factors critically required by these cells.

Adrenalectomy and castration in the genetically obese (ob/ob) mouse

The present studies have tested the hypothesis that adrenalectomy could modify the phenotypic expression of genetic obesity by examining the effects of adrenalectomy on the function of the gonadal system in lean and ob/ob mice. Corticosterone concentrations were undetectable in the adrenalectomized animals. Adrenalectomy significantly slowed the weight gain of obese mice in comparison to sham-adrenalectomized controls. Gonadectomy had no independent effect on weight gain. The testes, prostate, and seminal vesicles in the ob/ob mice were significantly smaller than in the lean animals. Castration lowered the weights of the prostate and seminal vesicles in the lean mice to weights close to those observed in the castrated ob/ob mice. Castration significantly increased the concentrations of LH and FSH in both ob/ob and lean mice, but the absolute concentrations were higher in the lean mice in both conditions. Adrenalectomy per se had no effect on the concentration of LH, FSH, or testosterone or on the weights of the prostate or seminal vesicles. These data indicate that adrenalectomy has no effect on the physiologic control of the reproductive system in genetically obese mice, and are consistent with the hypothesis that the defect in the ob/ob mouse is a modulator of steroid action which over expresses glucocorticoid effects and under expresses gonadal steroid effects.

Combined research and clinical learning make Rural Summer Studentship Program a successful model

CONTEXT

Many medical schools would like to provide students with opportunities to learn and perform practical research and to have positive rural learning experiences. Rural physicians often have research ideas, but may lack the skills or assistance to perform the research.

PROGRAM DESCRIPTION

The unique Rural Summer Studentship Program (RSSP) at The University of Western Ontario (Western) places students with preceptors in small and mid-sized communities throughout Southwestern Ontario where they have an opportunity to perform rural health research, combined with clinical learning, for 8 weeks in the summer after the first or second year of medical school. Secretarial coordination, research assistant support and senior faculty supervision were provided.

OUTCOMES

From 1999-2003 inclusive, 44 students have participated including eight who participated over two summers. Projects were carried out in more than 20 communities with over 30 preceptors. Already, two students have had their research published in peer-reviewed journals and six have presented at major conferences. Participating students indicated an increase in interest in rural and regional medicine and in their knowledge of rural and regional medicine and patient care. They rated the value of RSSP highly as part of their medical education, even compared with other electives/selectives.

CONCLUSION

The RSSP model developed at Western provides a highly rated, successful combination of supported medical student research and clinical learning with preceptors in small and mid-sized communities.

Relationship of quality of life and physical function measures with disease activity in children with systemic lupus erythematosus

The objective of this study is to assess relationship of systemic lupus erythematosus (SLE) activity with quality of life (QOL) and physical function and determine which is more closely correlated with SLE activity in children; and identify factors critical to children's QOL. In this cross-sectional study, children with SLE and parents completed corresponding versions of physical function (Childhood Health Assessment Questionnaire CHAQ), and QOL (Pediatric Quality of Life Inventory-PedsQL Generic/Rheumatology modules) questionnaires. SLE Disease Activity Index (SLEDAI), Systemic Lupus International Collaborating Clinics/ACR Damage Index (SDI), severity, self-concept and socioeconomic status (SES) were measured. For 24 children, CHAQ scores significantly correlated with SLEDAI (rho = 0.4, p = 0.04), SDI (rho = 0.6, p = 0.004), and associated with severity (p = 0.03). PedsQL scores did not significantly correlate with above parameters. Higher self-concept/SES correlated (p < 0.05) with better physical function and QOL. For 19 parents, the only significant correlation was between SLEDAI and Worry domain-Rheumatology module (rho = 0.5, p = 0.01). Lack of strong correlation of disease activity with QOL and physical function suggests that they are different constructs with partial overlap, and should be considered collectively while evaluating the impact of SLE on children/families. Self-concept and SES should be assessed while measuring QOL in children. Larger sample is required to confirm results.

Factors associated with development of stroke long-term after myocardial infarction: experiences from the LoWASA trial

OBJECTIVE

To describe factors associated with the development of stroke during long-term follow-up after acute myocardial infarction (AMI) in the LoWASA trial.

PATIENTS

Patients who had been hospitalized for AMI were randomized within 42 days to receive either warfarin 1.25 mg plus aspirin 75 mg daily or aspirin 75 mg alone.

DESIGN

The study was performed according to the probe design, that is open treatment and blinded end-point evaluation.

SETTING

The study was performed in 31 hospitals in Sweden. The mean follow-up time was 5.0 years with a range of 1.7-6.7 years.

RESULTS

In all, 3300 patients were randomized in the trial, of which 194 (5.9%) developed stroke (4.2% nonhaemorrhagic, 0.5% haemorrhagic and 1.3% uncertain. The following factors appeared as independent predictors for an increased risk of stroke: age, hazard ratio and 95% confidence interval (1.07; 1.05-1.08), a history of diabetes mellitus (2.4; 1.8-3.4), a history of stroke (2.3; 1.5-3.5), a history of hypertension (2.0; 1.5-2.7) and a history of smoking (1.5;1.1-2.0). Most of these factors were also predictors of a nonhaemorrhagic stroke whereas no predictor of haemorrhagic stroke was found.

CONCLUSION

Risk indicators for stroke long-term after AMI were increasing age, a history of either diabetes mellitus, stroke, hypertension or smoking.

Acupuncture for chronic low back pain in older patients: a randomized, controlled trial

OBJECTIVE

To determine if acupuncture is an effective, safe adjunctive treatment to standard therapy for chronic low back pain (LBP) in older patients.

METHODS

The inclusion criteria for subjects were: (i) LBP > or =12 weeks and (ii) age > or =60 yr; the exclusion criteria were (i) spinal tumour, infection or fracture and (ii) associated neurological symptoms. The subjects were randomized to two groups. The control group of subjects continued their usual care as directed by their physicians, i.e. NSAIDs, muscle relaxants, paracetamol and back exercises. Subjects in the acupuncture group in addition received biweekly acupuncture with electrical stimulation for 5 weeks. Outcome was measured by the modified Roland Disability Questionnaire (RDQ) at weeks 0, 2, 6 and 9. The primary outcome measure was change in RDQ score between weeks 0 and 6.

RESULTS

Fifty-five patients were enrolled, with eight drop-outs. Twenty-four subjects were randomized to the acupuncture group and 23 were randomized to the control group. Acupuncture subjects had a significant decrease in RDQ score of 4.1 +/- 3.9 at week 6, compared with a mean decrease of 0.7 +/- 2.8 in the control group (P = 0.001). This effect was maintained for up to 4 weeks after treatment at week 9, with a decrease in RDQ of 3.5 +/- 4.4 from baseline, compared with 0.43 +/- 2.7 in the control group (P = 0.007). The mean global transition score was higher in the acupuncture group, 3.7 +/- 1.2, indicating greater improvement, compared with the score in the control group, 2.5 +/- 0.9 (P < 0.001). Fewer acupuncture subjects had medication-related side-effects compared with the control group.

CONCLUSIONS

Acupuncture is an effective, safe adjunctive treatment for chronic LBP in older patients.

Mental health issues in the workplace: a case for a new managerial approach

Anger, stress, and depression in the workplace are growing concerns among management. Traditionally, health outcomes have functioned under the realm of workplace health professionals. This study assessed whether a traditional worksite health promotion program had an impact on mental health factors. The results suggested that worksite health promotion programs play a limited role in ameliorating work-related mental health outcomes. Rather, management must play a greater role in addressing workplace stress, anger, and depression.

Estimated blood loss and transfusion requirements of radical cystectomy

PURPOSE

Radical cystectomy has been associated with significant blood loss and/or transfusion requirement. We defined and characterized blood loss and transfusion parameters in this population.

MATERIALS AND METHODS

We reviewed the records of 304 consecutive patients who underwent radical cystectomy and urinary diversion between October 1995 and July 2000. Charts were examined, and univariate and multivariate logistic regression analysis was performed to evaluate estimated blood loss and the transfusion requirement.

RESULTS

Complete blood loss data were available in 297 cases. Overall 45% of patients had anemia preoperatively. Median estimated blood loss was 600 ml. (range 100 to 3,000). On univariate analysis increased estimated blood loss was related to patient age, American Society of Anesthesiologists score, longer operative time and paralytic ileus. Overall transfusion was done in 88 of 297 cases (30%) with a median requirement of 2 units (range 1 to 10). The transfusion rate in male and female patients was 26% and 40%, respectively (p <0.05). On univariate analysis female gender, ileal conduit diversion and lower preoperative hematocrit correlated with transfusion need (p = 0.04, <0.001 and <0.001, respectively). On multivariate logistic regression analysis lower preoperative hematocrit, increased estimated blood loss, major complications and ileal conduit diversion type correlated with a higher transfusion rate (odds ratio 8.34, 5.88 and 4.60, respectively).

CONCLUSIONS

Acute blood loss anemia is common in patients undergoing radical cystectomy, and predicting blood loss and transfusion requirements remains difficult. These data indicate the need for continued refinement in surgical techniques to decrease blood loss as well as for strategies designed to decrease the need for blood transfusion.

Psychosocial and health-related characteristics of religious well-being

This investigation examined the relationship between religions well-being and eight psychosocial and health-related characteristics. This study assessed the hypothesis that religious well-being is related to overall health. Participants were 462 college students at two separate colleges in the Pacific Northwest. Analysis showed those subjects scoring higher on the measure of religious well-being scored lower on indices like loneliness and hopelessness and higher on self-esteem. Alcohol and drug use also differed significantly between the high and the low, religious well-being groups.

Visual function and quality of life among patients with giant cell (temporal) arteritis

OBJECTIVE

To investigate patient perception of visual and systemic disability associated with giant cell arteritis (GCA) and whether the perceived disability can be correlated with visual performance measures.

METHODS

We prospectively evaluated and compared the visual performance and quality of life survey for 20 patients with GCA after 4 to 5 weeks of corticosteroid therapy and after one year of therapy. We measured visual acuity, contrast sensitivity, and threshold perimetry and patients completed the Activities of Daily Vision Scale (ADVS) and the short-form of the Health Survey (SF-36). The results were grouped by GCA affected or unaffected eye or by better or worse eye and reported as a decimal and percent impairment for acuity, log units for contrast, mean deviation and the Advanced Glaucoma Intervention Study (AGIS) score for perimetry. The results for patients with and without visual loss were compared. Correlation analyses between ADVS categories and visual performance measures, SF-36 categories and the presence of visual loss, total corticosteroid dose, systemic symptoms, secondary hypertension or diabetes mellitus, the presence of vertebral fracture, and visual performance were performed.

RESULTS

Day driving was the only ADVS category significantly reduced at baseline in patients with visual loss (62.5) compared with those without visual loss (96.3, P = 0.04). Modest to moderate correlations between ADVS categories were most frequent for percent binocular acuity impairment with day driving (r = -0.62, P = 0.017), with distance vision (r = -0.5, P = 0.02), and with glare (r = -0.59, P = 0.006); and the AGIS score of the worse eye with day driving (r = -0.66, P = 0.01), with near vision (r = -0.49, P = 0.03), and with glare (r = -0.48, P = 0.04). The baseline SF-36 scores did not correlate with the presence of vision loss at baseline or systemic complications. The ADVS and SF-36 scores were similar at one year. The total dose of corticosteroids only had a modest correlation with the one-year mental health score (r = -0.45, P = 0.05), but there was no correlation between SF-36 scores and other systemic side effects of steroid therapy.

CONCLUSION

Except for the day driving score, the ADVS did not differ between patients with and without visual loss. The SF-36 did not distinguish between patients with and without visual loss and did not reveal significant trends. The ADVS and SF-36 did not reveal significant disability in GCA patients and there were no strong correlations with any visual performance or systemic measures.

Intraoperative nerve stimulation predicts postoperative potency

OBJECTIVES

Intraoperative nerve stimulation has been used to map the course of cavernosal nerve bundles to aid in nerve-sparing radical prostatectomy (RP). We sought to determine whether the intraoperative nerve stimulation response after removal of the prostate specimen predicts postoperative potency.

METHODS

We prospectively evaluated 63 consecutive patients undergoing RP. Among these 63 patients, 41 patients had a bilateral nerve-sparing procedure, and 22 underwent bilateral wide resection of the neurovascular bundles. Potency was determined at 1 year by direct patient interview.

RESULTS

Of the 22 patients with wide resection, 16 (73%) had no observed stimulated response, 4 (18%) had a measurable tumescence response, and 2 (9%) had detumescence. All 22 patients were impotent postoperatively. At a minimum follow-up of 1 year, of the 41 patients who underwent nerve-sparing RP, 27 (66%) had postoperative erections sufficient for penetration. Of the 30 men with an intraoperative stimulated tumescence response, 24 (80%) were potent; of the 6 with a detumescence response, 2 (33%) were potent; and of the 5 with no stimulated nerve response, 1 (20%) was potent. A tumescence response was significantly more predictive of postoperative potency than no intraoperative response (P = 0.017).

CONCLUSIONS

An intraoperative tumescence response with stimulation of the neurovascular bundles after prostate specimen removal is more likely to correspond to successful postoperative sexual function after nerve-sparing RP than is no response.

Improvement of in-rumen digestibility of alfalfa forage by genetic manipulation of lignin O-methyltransferases

Lignin inhibits forage digestibility by ruminant animals, and lignin levels and the proportion of dimethylated syringyl (S) lignin monomers increase with progressive maturity in stems of forage crops. We generated transgenic alfalfa (Medicago sativa L.) with reduced lignin content and altered lignin composition. Down-regulation of caffeic acid 3-O-methyltransferase (COMT) reduces lignin content, accompanied by near total loss of S lignin, whereas down-regulation of caffeoyl coenzyme A 3-O-methyltransferase (CCoAOMT) reduces lignin content without reduction in S lignin. These changes are not accompanied by altered ratios of cell wall polysaccharides. Analysis of rumen digestibility of alfalfa forage in fistulated steers revealed improved digestibility of forage from COMT down-regulated plants, but a greater improvement in digestibility following down-regulation of CCoAOMT. The results indicate that both lignin content and composition affect digestibility of alfalfa forage, and reveal a new strategy for forage quality improvement by genetic manipulation of CCoAOMT expression.

A statistical approach to an outbreak of endophthalmitis following cataract surgery at a hospital in the West of Scotland

The number of cases of endophthalmitis following cataract surgery caused considerable concern in a West of Scotland hospital throughout 1998 and early 1999. A multi-disciplinary team including infection control nurses, doctors, public health officials,epidemiologists and statisticians was set up to investigate the situation. This paper examines the statistical issues surrounding the investigation. A method based on the Poisson distribution showed that the number of cases was significantly higher than expected. Fisher's Exact Test and Logistic Regression were then applied to the data from two related case control studies. These analyses showed that a higher risk of endophthalmitis was associated with being female, having a vitrectomy or having a previous history of respiratory disease. Finally, a method was devised to enable staff to recognize more quickly when the number of cases of endophthalmitis was becoming higher than expected. The method should find application in other clinical situations where the probability of rare events is known.

Finding the right decision tree's induction strategy for a hard real world problem

Decision trees have been already successfully used in medicine, but as in traditional statistics, some hard real world problems can not be solved successfully using the traditional way of induction. In our experiments we tested various methods for building univariate decision trees in order to find the best induction strategy. On a hard real world problem of the Orthopaedic fracture data with 2637 cases, described by 23 attributes and a decision with three possible values, we built decision trees with four classical approaches, one hybrid approach where we combined neural networks and decision trees, and with an evolutionary approach. The results show that all approaches had problems with either accuracy, sensitivity, or decision tree size. The comparison shows that the best compromise in hard real world problem decision trees building is the evolutionary approach.

Combined use of power Doppler and gray-scale sonography: a new technique for the assessment of inflammatory myopathy

OBJECTIVE

Ultrasonography (US) is a utilitarian approach to the assessment of inflammatory myopathy (IM). Power Doppler sonography (PDS), a newer technique, enables detection of muscle vascularity and inflammation. We describe the combined use of PDS and gray-scale US in patients with IM.

METHODS

We studied 37 IM subjects and 6 control subjects. Clinical scores of muscle strength and function were obtained. The maximum score, 31, represented normal function and strength. Ultrasonographic gray-scale and vascularity results were scored 0-4. Nine subjects had serial assessments.

RESULTS

Subjects ranged from 16 to 83 years of age and were predominantly female. IM subjects had significantly abnormal lower clinical scores than controls, 23.0 +/- 5.8 vs 29.8 +/- 2.0 (p < 0.001). Mean peak gray-scale score was 2.1 +/- 0.96 compared to 0.5 +/- 0.84 for controls (p = 0.001), indicating atrophy in the IM group. Similar results were found for average gray-scale scores. Peak vascularity scores were higher in IM, 2.7 +/- 0.8 vs 2.2 +/- 0.3 (p = 0.007). Disease of longer duration was significantly associated with more abnormal gray-scale scores and lower creatine phosphokinase (CPK) levels. PDS scores were more abnormal in disease of shorter duration. There was a negative association between functional scores and inflammatory scores on serial assessment.

CONCLUSION

Sonography is a valuable tool in the assessment of IM. Gray-scale and PDS findings were significantly different between IM and control subjects. Abnormal gray-scale US scores were associated with disease of longer duration and lower CPK levels. In contrast, increased vascularity on PDS detected disease of shorter duration and varied with the clinical course more than did gray-scale findings.

Inhibition of natural killer cell activation signals by killer cell immunoglobulin-like receptors (CD158)

The killer cell immunoglobulin-like receptor (KIR) family includes receptors that bind to HLA class I molecules on target cells and inhibit natural killer (NK)-cell cytotoxicity, and receptors such as KIR3DL7 with no known ligand and function. Inhibitory KIR recruit the tyrosine phosphatase SHP-1 to block signals transduced by any one of a number of activation receptors. Inhibition of overall protein tyrosine phosphorylation by SHP-1 during binding of KIR to MHC class I on target cells is selective, suggesting that a limited number of substrates are dephosphorylated by SHP-1. We have chosen to study KIR inhibition as it occurs during binding of KIR to MHC class I on target cells, despite the technical limitations inherent to studies of processes regulated by cell contact. KIR binding to MHC class I on target cells inhibits tyrosine phosphorylation of the activation receptor 2B4 (CD244) and disrupts adhesion of NK cells to target cells. Inhibition of proximal events in NK activation may increase the availability of NK cells by liberating them from non-productive interactions with resistant target cells. As the receptors and the signaling pathways that induce NK cytotoxicity are not fully characterized, elucidation of the inhibitory mechanism employed by KIR may provide insight into NK activation.