Region-specific constitutive gene expression in the adult porcine meniscus.

The knee meniscus exhibits extensive spatial variations in native healing capacity, biochemical composition, and cell morphology that suggest the existence of distinct phenotypes for meniscus cells. Constitutive gene expression levels of appropriate extracellular matrix proteins may serve as useful molecular markers of cellular phenotypes; however, relatively little is known of variations in the gene expression for meniscus cells of different regions of the tissue. The objective of the present study was to evaluate constitutive differences between radial inner and outer regions in gene expression for extracellular matrix proteins relevant to the meniscus. A secondary objective was to determine if these region-specific differences in gene expression are maintained after periods of monolayer culture. The innermost regions of the meniscus were found to constitutively express higher mRNA levels for proteins highly expressed in articular cartilage, including aggrecan, type II collagen, and NOS2. In contrast, the outer meniscus was found to contain higher gene expression for proteins associated with fibrous tissues including type I collagen, and the proteases MMP2 and MMP3. Isolated inner and outer meniscus cells maintained these region-specific gene expression patterns for collagens and proteoglycans during short-term monolayer culture. The results provide new information that suggests the utility of constitutive gene expression levels as molecular markers to distinguish tissue and cells of the inner and outer meniscus.     

Acute marijuana effects on human risk taking.

Previous studies have established a relationship between marijuana use and risky behavior in natural settings. A limited number of laboratory investigations of marijuana effects on human risk taking have been conducted. The present study was designed to examine the acute effects of smoked marijuana on human risk taking, and to identify behavioral mechanisms that may be involved in drug-induced changes in the probability of risky behavior. Using a laboratory measure of risk taking designed to address acute drug effects, 10 adults were administered placebo cigarettes and three doses of active marijuana cigarettes (half placebo and half 1.77%; 1.77%; and 3.58% Delta9-THC) in a within-subject repeated-measures experimental design. The risk-taking task presented subjects with a choice between two response options operationally defined as risky and nonrisky. Data analyses examined cardiovascular and subjective effects, response rates, distribution of choices between the risky and nonrisky option, and first-order transition probabilities of trial-by-trial data. The 3.58% THC dose increased selection of the risky response option, and uniquely shifted response probabilities following both winning and losing outcomes following selection of the risky option. Acute marijuana administration thereby produced measurable changes in risky decision making under laboratory conditions. Consistent with previous risk-taking studies, shifts in trial-by-trial response probabilities at the highest dose suggested a change in sensitivity to both reinforced and losing risky outcomes. Altered sensitivity to consequences may be a mechanism in drug-induced changes in risk taking. Possible neurobiological sites of action related to THC are discussed.     

Inappropriate Vancomycin Prescribing Based on Criteria from the Centers for Disease Control and Prevention

Increasing reports of vancomycin resistance have raised concerns about the future effectiveness of this drug in treatment of critically ill patients with gram-positive infections. Due to these concerns the Centers for Disease Control and Prevention (CDC) recently published criteria that delineate the prudent use of vancomycin. Using these criteria, we attempted to determine the appropriateness of vancomycin prescribing patterns at our institution. A retrospective chart review was performed for 135 hospitalized patients treated between May 1993 and April 1994. Inappropriate empiric vancomycin use was documented in 81 (60%) of these patients. When culture results were available, 28 (21%) patients inappropriately received the drug. Results of this study are similar to those of other studies of vancomycin use in hospitals based on non-CDC criteria. If CDC criteria are to have a positive impact on physicians' vancomycin prescribing patterns, significant educational efforts will be required.     

An Integrated Psychotherapy Approach to the Management of Self-Destructive Behavior in Eating Disorder Patients with Borderline Personality Disorder

The management of self-destructive behavior in eating disorder patients with borderline personality is a genuine therapeutic challenge. We present an integrated psychotherapy appproach that we utilize in the context of an extended therapeutic milieu. This treatment model enables coordinated intervention to occur in three different arenas: individual psychotherapy, group psychotherapy, and consultation intervention. The paper closes with a discussion of the limitations of this approach.     

Allergen activates peripheral blood eosinophil nuclear factor-κB to generate granulocyte macrophage-colony stimulating factor, tumour necrosis factor-α and interleukin-8

BACKGROUND: Allergic inflammation is characterized by the influx and activation of eosinophils. Cytokines generated by both resident and infiltrating cells are responsible for the initiation and maintenance of this pathogenesis. This study focuses on allergen-induced activation of eosinophil NF-kappaB and generation of granulocyte macrophage-colony stimulating factor (GM-CSF), TNF-alpha, and IL-8. METHODS: Peripheral blood eosinophils were enriched to >99.9% by Percoll gradient sedimentation and negative magnetic affinity chromatography. NF-kappaB activation by 10 microg/mL house dust mite (HDM) extract was demonstrated immunocytochemically using a monoclonal antibody against the active form of NF-kappaB (NF-kappaBa). The authenticity of NF-kappaB was confirmed by Western blot. Cytokine production was assessed both by immuno-staining of eosinophils and by assay of cytokines in the cell supernatant. RESULTS: Activation of peripheral blood eosinophils from atopic, but not non-atopic, donors induced activation of NF-kappaB, which peaked at 4 h and was accompanied by a decline in IkappaB-alpha. The activation of authentic NF-kappaB was confirmed in gel shift assays. Supershift assays showed p65 to be the major subunit of eosinophil NF-kappaB. Immunofluorescent confocal microscopy demonstrated localization of NF-kappaBa to the nucleus. Following activation, cytokine immunoreactivity was seen in a fraction of the eosinophils and cytokines were released into the supernatant. The NF-kappaB inhibitors, calpain inhibitor 1 (10 microm), pentoxifylline (0.5 mm), pyrrolidine dithiocarbamate (PDTC, 10 microm) or gliotoxin (1 pg/mL) reduced the generation of GM-CSF, TNF-alpha and IL-8 in parallel with their inhibition of NF-kappaB. CONCLUSIONS: HDM allergen activates human eosinophil NF-kappaB leading to the production of the cytokines GM-CSF, TNF-alpha and IL-8. We speculate that a role for eosinophil NF-kappaB-dependent cytokines is to act as an autocrine loop augmenting the survival of eosinophils in vivo.     

Randomized clinical trial of tacrolimus- vs cyclosporine-based immunosuppression in pediatric heart transplantation: preliminary results at 15-month follow-up.

BACKGROUND: While Tacrolimus (Tac) and Cyclosporine (Cya) immunosuppression are used after cardiac transplantation (tx), few studies have evaluated their use in pediatric patients. METHODS: We randomized 26 heart transplant recipients (pts) in a prospective, open-label trial to Tac (n = 14) or Cya (n = 12) to compare their efficacy and side-effects. Mean age at tx was 4.2 years for Tac and 5.8 years for Cya. Mean follow-up was 26 months (range: 11-39 months) for Tac and 24 months for Cya (range: 33-13 months). RESULTS: Our data suggest that both regimens are efficacious in the pediatric population. Conversion from Cya to Tac was useful for dealing with persistent rejection, although this sample did not suggest lower incidence of acute cellular rejection in the Tac group. CONCLUSIONS: Further studies are required to establish pharmacokinetic parameters to enhance therapeutic monitoring of these patients to minimize side effects and enhance outcomes.     

Alterations in the mechanical behavior of the human lumbar nucleus pulposus with degeneration and aging

This study tested the hypothesis that changes in the morphology and composition of the nucleus pulposus with age and degeneration have associated changes in its mechanical properties. A torsional shear experiment was used to determine viscoelastic shear properties of cylindrical samples of human nucleus pulposus with large ranges of grades of morphological degeneration (normal to severely degenerated) and ages (range: 16–88 years; average: 57 ± 21.5 years). Viscoclastic shear properties were determined from stress-relaxation and dynamic sinusoidal tests. A linear viscoelastic law with a variable-amplitude relaxation spectrum was used to model experimental behaviors of nucleus pulposus specimens. A statistically significant increase in the instantaneous and dynamic shear moduli was found with increasing age and grade of degeneration; the values for moduli ranged from 5.0 to 60 kPa. A significant decrease in tanδ was also detected; the values ranged from 0.43 to 0.33, indicating a decreased capacity for the nucleus pulposus to dissipate energy. The dynamic modulus and tanδ were also significantly affected by frequency. It was generally concluded that the nucleus pulposus undergoes a transition from “fluid-like” behavior to more “solid-like” behavior with aging and degeneration.     

Azithromycin protects against hyperoxic lung injury in neonatal rats.

Bronchopulmonary dysplasia (BPD) is a pulmonary disorder that causes significant morbidity and mortality in premature infants. BPD is pathologically characterized by inflammation, fibrosis, and mucosal necrosis, which leads to emphysematous coalescence of alveoli. We tested the hypothesis that azithromycin, a macrolide antibiotic, would decrease the severity of lung injury in an animal model of BPD. Sixty-three rat pups were randomly divided equally into control, hyperoxia, and hyperoxia plus azithromycin groups. The hyperoxia groups were exposed to > 95% oxygen from days of life 4 to 14. On day 14, the animals were processed for lung histology and tissue analysis. Lung morphology was assessed by mean linear intercept, a measure of alveolar size, with larger values corresponding to lungs that are more emphysematous. The degree of lung inflammation was assessed by quantifying interleukin-6 (IL-6) from lung homogenate. Fifty pups survived to day 14 (control = 21, hyperoxia = 11, hyperoxia + azithromycin = 18). Mortality was increased in the hyperoxia group versus the control group (p < .0001). Treatment with azithromycin improved survival in animals subjected to hyperoxia (p < .05). Azithromycin significantly decreased lung damage as determined by the mean linear intercept in the hyperoxia groups (p < .001). Finally, azithromycin-treated pups had lower levels of IL-6 in lung homogenate from the hyperoxia groups (p < .05). Azithromycin treatment resulted in improved survival, less emphysematous change, and decreased IL-6 levels in an animal model of BPD.     

Altered swelling behavior of femoral cartilage following joint immobilization in a canine model.

Periods of reduced joint loading have been shown to induce changes in the biochemical composition. metabolism and mechanics of articular cartilage. In this study, changes in cartilage swelling behavior were studied following a 4-week period of joint immobilization, using a recently developed osmotic loading technique [J. Biomech, 32 (1999) 401-408]. The magnitude and distribution of swelling strains were measured in cartilage-bone samples equilibrated in physiological and hypotonic saline, relative to a hypertonic reference NaCl solution. Physicochemical parameters (glycosaminoglycan fixed charge density and water volume fraction) were determined in site-matched cartilage samples. The experimental data for swelling strains, fixed charge density and water volume fraction were used with a triphasic mechano-chemical theory [J. Biomech. Eng. 113 (1991) 245-258] to determine the effect of joint immobilization on the tensile modulus of the cartilage solid matrix. Four weeks of immobilization resulted in a significant increase in the magnitude of swelling-induced strains, and a significant decrease in fixed charge density in cartilage, as compared with the contralateral controls. Joint immobilization also resulted in decreases in values for the modulus of cartilage, as compared with the contralateral controls. Our results suggest that 4 weeks of joint immobilization had a significant effect on cartilage mechanical function that may be linked to collagen changes in the cartilage extracellular matrix.     

Brief report: Does fenfluramine treatment enhance the cognitive and communicative functioning of autistic children?

This project was supported by two separate research grants from the Trust Fund Board, Washington Association for Retarded Citizens to Richard Neel and Truman E. Coggins. The research was also supported by a training grant to the University of Washington entitled Comprehensive Training in Mental Retardation and Other Handicapping Conditions (MCH-000913, Clifford J. Sells, M.D., Principal investigator); and, a training grant to the University of Arizona entitled Doctoral and Post-Doctoral Leadership Training and Clinical Research, Teaching and Administration: Clinical Language Research Center (G008630088, Linda Swisher, Ph.D., principal investigator). We are indeed grateful to the parents of our five subjects for their patience, understanding, and commitment. Finally, we express our appreciation to Arelene Chaussee for her technical expertise and untiring spirit.