Induction of plasminogen activator inhibitor type 1 and type 1 collagen expression in rat cardiac microvascular endothelial cells by interleukin-1 and its dependence on oxygen-centered free radicals

BACKGROUND

Ischemia with or without reperfusion induces the release of diverse products from monocytes, including cytokines such as interleukin-1 (IL-1). To determine whether these phenomena modulate fibrinolysis and potentially exacerbate impairment of the macrocirculation, microcirculation, or both, we characterized the effects of IL-1 on the expression of fibrinolytic system and matrix proteins in rat cardiac microvascular endothelial cells (CMECs).

METHODS AND RESULTS

Confluent CMECs were exposed to IL-1 in serum-free medium for 24 hours, and cell-conditioned medium was assayed for plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of plasminogen activators, and for type 1 collagen with Western blotting. IL-1 (2 ng/mL) specifically increased the accumulation of PAI-1 (4.4 +/- 0.6-fold; mean +/- SD; n = 9) without affecting tissue plasminogen activator (t-PA) or urokinase plasminogen activator (u-PA) levels, which remained unchanged. IL-1 increased the accumulation of collagen in conditioned media by 3.5 +/- 0.7-fold (n = 6). Conversely, the accumulation of both PAI-1 and collagen induced by IL-1 was inhibited with an IL-1 receptor antagonist (200 ng/mL; n = 6) and with cycloheximide (10 micrograms/mL; n = 6), implying that protein synthesis was a requirement for the effect. To determine whether the IL-1 effect was mediated by induction of oxygen-centered free radical production, known to be induced by IL-1, we exposed the cells to the hydroxyl radical scavenger tetramethylthiourea (10 mmol/L) and observed abolition of the IL-1-induced increase in the expression of PAI-1 and collagen (n = 6). Conversely, superoxides (generated with 10 mU/mL xanthine oxidase plus 0.6 mmol/L hypoxanthine, and 100 mumol/L hydrogen peroxide) induced the accumulation of PAI-1 and collagen (n = 6). IL-1 (1 microgram/kg body wt) and lipopolysaccharide (50 micrograms/kg body wt) administered in vivo increased PAI-1 protein in rat hearts as detected with Western blotting and PAI-1 immunostaining of rat heart microvessels, indicating the effects delineated in vitro were paralleled by effects in vivo.

CONCLUSIONS

These results indicate that IL-1-induced oxygen-centered free radicals stimulate elaboration of PAI-1 and collagen by CMECs. Accordingly, microvascularly mediated inhibition of fibrinolysis may predispose to the persistence of microvascular thrombi, thereby contributing to impaired microcirculatory function, the no-reflow phenomenon, and cardiac dysfunction after ischemia and reperfusion.

HMI education for HIMs

This paper analyses the curricula of the four Australian university programs for health information managers (HIMs) in relation to their coverage of health and medical informatics (HMI). The overlap between HIMs and HMIs should be increased through exchange of information at conferences such as this as well as communication and co-operation between the Schools of HIM and those offering health informatics related training at other Australian universities.

University entry scores as a predictor of academic performance in a health information management program

The university entry scores for school leavers admitted to the first year of the Bachelor of Applied Science (Health Information Management) degree at the University of Sydney in 1996 were examined to determine whether the Tertiary Entrance Rank (TER) was a good predictor of academic performance, as measured by grade point average (GPA). The study also examined Higher School Certificate (HSC) results in English and mathematics, and preference selection for the health information management (HIM) course to determine whether any of these had predictive validity. The results showed that TER, HSC English and mathematics scores and preference for the course were all poor predictors of academic performance in the student's first year. Low TER was not associated with low GPA and low scores in English and mathematics were not associated with low GPA. There was no significant difference between the performance of those students who listed the HIM course as their first preference and those who did not. These results suggest that there may be no need to establish a minimum entry level for admission to the HIM course, or for prerequisites in English and mathematics. It may be that multiple criteria are required to predict academic success in this course.

Haplotype mapping of a major quantitative-trait locus for fetal hemoglobin production, on chromosome 6q23

Fetal hemoglobin (Hb F) and fetal cell (FC) levels in adults show considerable variation and are influenced by several genetic variants; the major determinants appear to be unlinked to the beta-globin gene cluster. Recently, a trans-acting locus controlling Hb F and FC production has been mapped to chromosome 6q23 in an Asian Indian kindred that includes individuals with heterocellular hereditary persistence of Hb F (HPFH) associated with beta thalassemia. We have extended the kindred by 57 members, bringing the total studied to 210, and have saturated the region with 26 additional markers. Linkage analysis showed tight linkage of the quantitative-trait locus (QTL) to the anonymous markers D6S976 (LOD score 11.3; recombination fraction .00) and D6S270 (LOD score 7.4; recombination fraction .00). Key recombination events now place this QTL within a 1-2-cM interval spanning approximately 1.5 Mb between D6S270 and D6S1626. Furthermore, haplotype analysis has led to a reevaluation of the genealogy and to the identification of additional relationships in the kindred.

Managed care in rural Minnesota. Family physicians' attitudes and perceptions

Prepaid managed care medicine has become dominant in urban Minnesota and is making its way into the rural setting. This study assesses the attitudes of rural family practice physicians in Minnesota toward managed care. A survey, consisting primarily of five-point Likert scale statements, was mailed to 798 rural Minnesota family practice physicians, with a response rate of 35% (281 respondents). We tabulated overall responses and made comparisons based on practice characteristics and years in practice. Twenty physicians participated in a follow-up telephone interview. We also conducted telephone interviews with 10 representatives from managed care organizations. Both positive and negative attitudes toward managed care emerged. Two-thirds of respondents did not feel that their time with patients was diminished under managed care. However, 67% of respondents felt that managed care organizations had failed to incorporate rural patients' specific needs into their policies. Only 7% of respondents felt that managed care organizations adequately explained their benefits packages to enrollees. Rural family practitioners' apparent disillusionment with current managed care models merits the attention of those concerned with medical care in rural areas.

Smooth muscle actin and myosin expression in cultured airway smooth muscle cells

In this study, the expression of smooth muscle actin and myosin was examined in cultures of rat tracheal smooth muscle cells. Protein and mRNA analyses demonstrated that these cells express alpha- and gamma-smooth muscle actin and smooth muscle myosin and nonmuscle myosin-B heavy chains. The expression of the smooth muscle specific actin and myosin isoforms was regulated in the same direction when growth conditions were changed. Thus, at confluency in 1 or 10% serum-containing medium as well as for low-density cells (50-60% confluent) deprived of serum, the expression of the smooth muscle forms of actin and myosin was relatively high. Conversely, in rapidly proliferating cultures at low density in 10% serum, smooth muscle contractile protein expression was low. The expression of nonmuscle myosin-B mRNA and protein was more stable and was upregulated only to a small degree in growing cells. Our results provide new insight into the molecular basis of differentiation and contractile function in airway smooth muscle cells.

Peripheral blood manifestations of T(H)2 lymphocyte activation in stable atopic asthma and during exercise-induced bronchospasm

BACKGROUND

Recently, TH2 lymphocyte activation has been shown to play a key role in initiating and propagating the inflammatory response in asthmatic airways. This is manifest through increased numbers of "activated" CD25-(IL-2R)-bearing T-helper cells and can be seen through the IL-5 driven recruitment of eosinophils and IL-4-mediated B-cell expression of CD23 (low affinity IgE receptor) and ultimately IgE production.

OBJECTIVE

To gain a better understanding of the role of immune cells in asthma by describing the peripheral blood immune cell phenotypes in mild atopic asthma.

METHODS

We enrolled 13 patients with mild atopic asthma and a group of seven nonatopic, nonasthmatic controls. Objective measures of lung function were obtained. The peripheral blood was analyzed by flow cytometry for specific cellular markers at rest and during the development of exercise induced bronchospasm.

RESULTS

At rest the number of CD23-bearing B cells (169/mL versus 117/mL; P = .05) and the number of CD25-bearing T cells (355/mL versus 237/mL; P = .03) were increased in the asthma group. There was a linear relationship between these two lymphocyte subsets and the maximum voluntary ventilation at rest (r = 0.56, P = .01 and r = 0.57, P = .01). With the development of exercise-induced bronchospasm there was a significantly greater increase in CD23-positive B cells (96.7/mL versus 59.7/mL; P = .05) and CD25-positive T cells (111.8/mL versus 45.1; P = .01) in the asthma group.

CONCLUSIONS

These data indicate that TH2 lymphocyte activation is manifested by increased numbers of CD23-bearing B cells and CD25-bearing T cells in the peripheral blood of patients with stable mild atopic asthma. Further, these immune cell subsets correlate with markers of resting lung function and increase in the peripheral blood early after the development of exercise-induced bronchospasm.

Discretion and service use among older adults: the behavioral model revisited

Research applying the behavioral model to the use of services among older adults could be enriched by the classification of services along a discretionary dimension. Survey responses from 2,178 community-dwelling older adults were used to test the hypothesis that predisposing, enabling, and need characteristics are better predictors of discretionary than nondiscretionary service use. Logistic regression results predicting the use of a variety of community-based and medical services categorized as most discretionary, partially discretionary, and least discretionary generally support our hypothesis, underscoring the importance of need characteristics for least discretionary service use.

Tetanus toxin-enhanced GABA immunoreactivity in living neurons

Analysis of the connectivity between different neuronal cell types is dependent on an appreciation of their dendritic and axonal arborizations. A detailed study of the dendrites and axons of GABAergic neurons has been thwarted by the lack of a suitable technique for enhancing GABA immunoreactivity. This article describes a procedure using tetanus toxin which, when applied to organotypic hippocampal cultures, considerably enhances the immunoreactivity in the dendrites and axons of the GABA- and somatostatin-containing neurons and clearly demonstrates the co-localization of GABA and somatostatin immunoreactivities in the same neuron. Tetanus toxin was applied to the culture medium on Day 14 for a 24-hr period and the cultures were fixed at the end of Day 18. Tetanus toxin-treated cultures (n = 30) or untreated cultures (n = 40) were incubated for either GABA or somatostatin immunoreactivity. Tetanus toxin-treated cultures used for co-localization studies (n = 20) were incubated for both GABA and somatostatin immunoreactivity.

Altered G protein activity in a desensitization-resistant mutant of the Y1 adrenocortical tumor cell line

Mutant isolates [designated desensitization resistant (DR)] from the Y1 mouse adrenocortical tumor cell line resist agonist-induced desensitization of adenylyl cyclase by preventing the uncoupling of receptors from their guanyl nucleotide-binding regulatory G proteins. In this study, we tested the hypothesis that an underlying G protein defect is associated with the DR phenotype. We found that the G protein reagent guanyl-5'-yl imidodiphosphate [Gpp(NH)p] shifted beta2-adrenergic receptors from a high affinity state to a low affinity state 4-fold more effectively in mutant DR cells than in parent Y1 cells. In the DR mutant, Gpp(NH)p was able to shift receptors to a low affinity state in the absence of NaCl, whereas the effect of Gpp(NH)p in parent Y1 cells was dependent upon the presence of NaCl. Moreover, these differences in sensitivity to Gpp(NH)p and NaCl were transferred to Gs alpha-deficient S49(CYC-) lymphoma cell membranes in G protein reconstitution assays. These observations suggested that the DR mutation was associated with altered activity of the stimulatory G protein, Gs. Cloning and sequence analysis demonstrated that Gs alpha transcripts in the DR mutant were normal, suggesting that another factor involved in guanyl nucleotide exchange is responsible for the altered G protein activity in DR mutant cells.

Accuracy in identifying affect in child and adult faces and voices and social competence in preschool children

The association between social competence and preschool children's ability to identify affect in child and adult facial expressions and tones of voice was investigated in 2 studies. A Sullivan theoretical framework was used. Results indicate that gender plays an important role in the association. For boys, accuracy in identifying low-intensity adult faces and, to a lesser extent, low-intensity adult voices was related to social competence regardless of whether social competence was being measured in interactions with other children or with adults. In contrast, for girls, the ability to read high-intensity expressions across child and adult faces and voices was more specifically related to social competence, depending on whether it was defined by interactions with children or adults. Social competence at this age seems to involve different types of nonverbal skills for boys and girls.

Production of nitric oxide during surgery involving cardiopulmonary bypass

OBJECTIVES

Surgery involving cardiopulmonary bypass induces an inflammatory response due to the contact of blood with the extracorporeal circuit. In some patients, this inflammatory response leads to multiple organ failure and death. Inflammatory states may increase the production of nitric oxide, either by increasing the activity of constitutive enzyme systems or by inducing of inflammation-specific systems. We hypothesized that surgery involving cardiopulmonary bypass would increase the production of nitric oxide in association with the inflammatory response.

DESIGN

Prospective, single center, observational study.

SETTING

University-affiliated, tertiary referral cardiothoracic center.

PATIENTS

Eleven adult patients undergoing routine myocardial revascularization.

INTERVENTIONS

Surgery for myocardial revascularization.

MEASUREMENTS AND MAIN RESULTS

Observations were made after induction of anesthesia, before bypass, after completion of the bypass, and on return to the recovery area. Parameters measured included hemodynamics, exhaled nitric oxide concentrations, plasma nitrate/nitrite concentration, plasma and bronchoalveolar lavage myeloperoxidase concentrations, and protein carbonyl conversion. All patients survived surgery. Oxygenation index fell significantly after bypass. Plasma myeloperoxidase increased significantly during the study period. Plasma carbonyl conversion also increased, although not significantly. Plasma nitrate/nitrite and airway nitric oxide concentrations did not change through the course of the study.

CONCLUSION

Surgery involving cardiopulmonary bypass induced a demonstrable inflammatory response, but this response was not associated with increased nitric oxide production.

The effectiveness of aerial baiting for control of feral pigs (Sus scrofa) in North Queensland

This study assessed the proportion of a feral pig population that consumed aerially distributed baits incorporating a non-toxic biomarker (iophenoxic acid). Baits were distributed at a rate of 18 baits km-2 over 70 km2 of a seasonally inaccessible habitat. A total of 102 feral pigs were then captured by trapping and ground-shooting. Blood samples from 63 adult feral pigs were analysed for the presence of the biomarker; 40 (63%) were considered to have consumed at least one bait. Ground-shooting and trapping over 6 days resulted in 18% and 16% population reduction respectively.

Managing the excited skin syndrome: patch testing hyperirritable skin

Inflammation-modulating phenomena (IMPs), humoral and cellular, fluctuate during the course of irritant and allergic contact dermatitis influencing irritability of the skin. The patch test procedure is a biological assay, a titration of responses of IMPs which can produce hyporeactivity or hyperirritability of the skin of patients who have dermatitis (PDs) and a single patch test is a 'snapshot' of the tempo of an evolving process. The excited skin syndrome (ESS) refers to hyperirritability from clinical and patch test dermatitis creating false-positive patch test reactions which are not reproducible when dermatitis and IMPs have subsided. During ESS, the threshold for irritancy decreases and irritant reactions increase. Patch test concentrations should be determined and ESS investigated in PDs having enhanced IMPs, not in 'normal' individuals, and if a patch test result is important to a patient the test should be performed more than once. Variable reproducibility is inherent in the patch test method, but ESS can be managed by appropriate testing and retesting, and search for relevance.

Platelet serotonin measures in adolescents with conduct disorder

Dysregulation of serotonergic function has been associated with aggression in several studies involving children, adolescents, and adults. This study investigated the relationship of platelet serotonergic measures to conduct disorder type, severity of aggression, and social skills impairment. Standardized assessments of diagnosis, aggression, impulsivity, and social skills were obtained from 43 male adolescents (ages 13-17) incarcerated at an involuntary residential treatment facility for juvenile offenders. Blood samples were collected and assayed for whole blood serotonin (5-HT) and platelet [3H]-paroxetine-labeled 5-HT-transporter binding. Whole blood 5-HT was higher in adolescents with conduct disorder, childhood type than in subjects with conduct disorder, adolescent type. Whole blood 5-HT was positively correlated with violence rating of the current offense and total offense points, and staff ratings of social skills impairment. Our findings are consistent with a relationship between 5-HT dysregulation and aggressive behavior in incarcerated adolescent boys with conduct disorder, particularly of childhood onset.

Dexamethasone increases G alpha q-11 expression and hormone-stimulated phospholipase C activity in UMR-106-01 cells

Glucocorticoids regulate responsiveness of many cells to hormones that bind to G protein-coupled receptors. We examined the effect of glucocorticoids on parathyroid hormone (PTH) activation of two G protein-activated signal transduction pathways, phospholipase C (PLC) and adenylyl cyclase, in osteosarcoma UMR-106-01 cells. Dexamethasone (100 nM) increased PTH-stimulated and NaF-stimulated PLC activity by > 100% over 4 days (223 +/- 8 and 293 +/- 8.2% of control after 4 days for PTH and NaF-stimulated activity, respectively). The increase in PTH-stimulated adenylyl cyclase response in the same cells was more modest (162 +/- 5.4 and 171 +/- 6.8% of control after 4 days for PTH and NaF-stimulated activity, respectively). PTH activation of PLC was blocked by antiserums to G alpha q-11 and activation of adenylyl cyclase by G alpha s antiserums. Quantification of these G protein subunits in control and dexamethasone-treated cells showed a 78% increase in G alpha q-11 (from 18.1 +/- 1.2 to 32.2 +/- 1.5 pmol/mg), whereas G alpha s was increased only 34% (from 6.2 +/- 0.5 to 8.2 +/- 0.3 pmol/mg) and G beta-subunits were increased 40% (from 54 +/- 2.3 to 75.2 +/- 3.8 pmol/mg). These results suggest that glucocorticoids are more potent regulators of PLC activity than adenylyl cyclase activity in UMR cells, and this is mediated, at least in part, by differential increases in G alpha q-11 proteins.

Effect of seizures on hippocampal peptidergic neurons

Results from animal studies and from human tissue removed from epileptics show that certain subgroups of hippocampal neurons are more vulnerable to seizure activity than others. It is possible that neurons which contain calcium-binding proteins, such as parvalbumin, may be protected from the high calcium overload that results from seizure activity. In the present study, seizures were induced by an injection of tetanus toxin into the rat hippocampus. A morphological and quantitative analysis was made of the parvalbumin-containing neurons and of those which co-localized somatostatin and neuropeptide Y. At 2 weeks there was a generalized increase in immunoreactivity in both groups of neurons. From 1 month through to 3 months after injection, the up-regulation in immunoreactivity was sustained in the surviving hilar neurons which co-localized somatostatin and neuropeptide Y but there was a marked reduction in immunoreactivity of the parvalbumin neurons. Although there was no evidence for a loss of parvalbumin neurons there was a small and significant reduction in the number of somatostatin + neuropeptide Y double-labelled neurons in the contralateral hilus at 3 and 4 months after a tetanus injection. The vulnerability of the somatostatin + neuropeptide Y double-labelled hilar neurons but not of the parvalbumin-containing, presumed, basket cells are considered in terms of their connectivity.

Effect of body weight and caloric restriction on serum complement proteins, including Factor D/adipsin: studies in anorexia nervosa and obesity

Complement plays important roles in host immune defences, and recent studies suggest that adipose tissue is an important site of production for some complement proteins. Starvation has been associated with low complement levels, but studied populations have usually had concomitant opportunistic infections or other conditions which might affect complement levels. To determine the impact of body weight and changes in body weight on serum complement, we investigated levels of complement proteins in otherwise healthy patients with a wide range of body weights, including patients with anorexia nervosa before and after treatment, obese dieters before and after weight loss, and normal weight controls. We found that complement proteins of the alternative pathway (C3, B, and D), alternative pathway haemolytic activity (AP50) and the inhibitors H and I were low in starving anorectics and normalized with weight gain. C3a levels were comparable in anorectics at low weight and after weight gain, indicating that low serum complement levels were attributable to hypoproduction and not complement cascade activation with consumption. Further, levels of C3, B, AP50, H and I, but not D, were higher than controls in obese patients and decreased toward normal after weight loss. Overall, percentage of ideal body weight, changes in body weight, and serum transferrin were each highly correlated with serum levels of complement proteins. We conclude that levels of alternative pathway complement components are determined in part by factors that influence body weight and by weight changes, possibly due to changes in production in adipose tissue or at other sites.