Young athletes' health knowledge system: Qualitative analysis of health learning processes in adolescent sportspersons.

Recognized side effects on health associated with sports participation in youth include overtraining, doping, and exposure to harassment and violence. Many of these effects originate in contexts where young athletes are beginning to make decisions about their sports practices on their own. This study sets out to explore knowledge and reasoning about health among adolescent athletes and to describe how health knowledge management structures are associated with different social systems. Qualitative data were collected from focus groups involving 65 young Swedish athletes aged 16-17 years. The participants' knowledge and reasoning about health were examined using a deductive thematic analysis, categories from Bloom's taxonomy of educational objectives, and Luhmann's social systems theory. The meaning of health was found to have a dynamic character for the young athletes, associated with constantly striving to satisfy immediate needs and fulfill short-time life goals. The athletes' thinking about health was associated with a pragmatic "health-as-a-resource" perspective, characterized by group self-comparisons, rapid cognitive processing, and opportunistic substitutions. They expressed a particular interest in experiential learning and personally relevant procedural knowledge, and they perceived that their factual knowledge about health was saturated. The results of this study add emphasis to the importance of involving adolescent sportspersons in the development of health education programs and contextualizing the programs to the athletes' specific age and social environment.

Semi-automated QRS score as a predictor of survival in CRT treated patients with strict left bundle branch block.

BACKGROUND: Cardiac Resynchronization Therapy (CRT) is widely used for treating selected heart failure patients, but patients with myocardial scar respond worse to treatment. The Selvester QRS scoring system estimates myocardial scar burden using 12-lead ECG. This study's objective was to investigate the scores correlation to mortality in a CRT population. METHODS AND RESULTS: Data on consecutive CRT patients was collected. 401 patients with LBBB and available ECG data were included in the study. QuAReSS software was used to perform Selvester scoring. Mean Selvester score was 6.4, corresponding to 19% scar burden. The endpoint was death or heart transplant; outcome was analyzed using Cox proportional hazards models. A Selvester score >8 was significantly associated with higher risk of the combined endpoint (HR 1.59, p=.014, CI 1.09-2.3). CONCLUSION: Higher Selvester scores correlate to mortality in CRT patients with strict LBBB and might be of value in prognosticating survival.

Injuries in youth track and field are perceived to have multiple-level causes that call for ecological (holistic-developmental) interventions: A national sporting community perceptions and experiences.

Engaging in competitive sports as a youth can have many health benefits, but recent studies also report a high risk for injury. The long-term purpose of this Swedish research program is to develop a framework for safe track and field training for young athletes (aged 12-15 years). The aim of this study was to establish what is perceived to contribute and cause injuries in youth track and field by compiling the best available experiential knowledge about the underlying factors and use this knowledge to identify appropriate areas to handle these in practical ways. Nine focus group interviews with in total 74 participants and confirming interviews with five individuals were performed in seven Swedish regions. Qualitative research methods were used for data analysis. Injuries in youth athletes were not considered to be strictly the result of individual factors but rather the result of the interactions between factors at different levels. Three major factors emerged as follows: Insufficient knowledge for athletic development in daily practice; shortsighted communities of practice and sports policies not adjusted to youth; and societal health behaviors. The experiential knowledge in the national sporting community suggests that if effective and sustainable injury prevention processes are to be implemented for youth track and field, an ecological (holistic-developmental) approach to injury prevention is needed. Such an approach allows a longitudinal development-focused strategy for prevention that spans an athlete's entire career.

Cerebrospinal fluid and blood flow patterns in idiopathic normal pressure hydrocephalus.

OBJECTIVES: Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology. MATERIALS AND METHODS: Sixteen INPH patients (73 years) and 35 healthy subjects (72 years) underwent phase-contrast magnetic resonance imaging (MRI). Measurements included aqueduct and cervical CSF flow, total arterial inflow (tCBF; i.e. carotid + vertebral arteries), and internal jugular vein flow. Flow pulsatility, net flow, and flow delays were compared (multiple linear regression, correcting for sex and age). RESULTS: Aqueduct stroke volume was higher in INPH than healthy (148±95 vs 90±50 mL, P<.05). Net aqueduct CSF flow was similar in magnitude and direction. The cervical CSF stroke volume was lower (P<.05). The internal carotid artery net flow was lower in INPH (P<.05), although tCBF was not. No differences were found in internal jugular vein flow or flow delays. CONCLUSIONS: The typical flow of blood and CSF in INPH was mainly characterized by increased CSF pulsatility in the aqueduct and reduced cervical CSF pulsatility. The direction of mean net aqueduct CSF flow was from the third to the fourth ventricle. Our findings may reflect the altered distribution of intracranial CSF volume in INPH, although the causality of these relationships is unclear.

Overcoming the organization-practice barrier in sports injury prevention: A nonhierarchical organizational model.

The organization of sports at the national level has seldom been included in scientific discussions of sports injury prevention. The aim of this study was to develop a model for organization of sports that supports prevention of overuse injuries. The quality function deployment technique was applied in seminars over a two-season period to develop a national organizational structure for athletics in Sweden that facilitates prevention of overuse injuries. Three central features of the resulting model for organization of sports at the national level are (a) diminishment of the organizational hierarchy: participatory safety policy design is introduced through annual meetings where actors from different sectors of the sporting community discuss training, injury prevention, and sports safety policy; (b) introduction of a safety surveillance system: a ubiquitous system for routine collection of injury and illness data; and (c) an open forum for discussion of safety issues: maintenance of a safety forum for participants from different sectors of the sport. A nonhierarchical model for organization of sports at the national level - facilitated by modern information technology - adapted for the prevention of overuse injuries has been developed. Further research is warranted to evaluate the new organizational model in prospective effectiveness studies.

Mental health nursing staff's attitudes towards mental illness: an analysis of related factors.

ACCESSIBLE SUMMARY: Employer/workplaces have an impact on mental health nursing staff's general attitudes towards persons with mental illness. Staff have more positive attitudes if their knowledge about mental illness is less stigmatized and currently have or have once had a close friend with mental problem. More favourable attitudes among staff towards persons with mental illness could be developed and transmitted in the subculture at work places. There is growing awareness that mental illness is surrounded by negative attitudes and stigmas. The aim of the present study was to investigate factors associated with mental health nursing staff's attitudes towards persons with mental illness. Data were collected from 256 mental health nursing staff employed by one county council and 10 municipalities. The findings show that staff have more positive attitudes towards persons with mental illness if their knowledge about mental illness is less stigmatized, their work places are in the county council, and they currently have or have once had a close friend with mental health problems. The multiple regression model explained 16% of the variance; stigma-related knowledge and employer had significant Beta-coefficients. To account for unknown correlations in data, a linear generalized estimating equation was performed. In this model, stigma-related knowledge and employer remained significant, but a new significant factor also emerged: personal contact, i.e. currently having or having once had a close friend with mental health problems. This indicates correlations at unit level in the county council and in the municipalities. The conclusion is that more favourable attitudes among staff towards persons with mental illness could be developed and transmitted in the subculture at work places.

Determination of the obesity-associated gene variants within the entire FTO gene by ultra-deep targeted sequencing in obese and lean children.

BACKGROUND: The Fat mass and obesity-associated gene (FTO) was the first gene reliably associated with body mass index in genome-wide association studies on a population level. At present, the genetic variations within the FTO gene are still the common variants that have the largest influence on body mass index. METHODS: In the current study, we amplified the entire FTO gene, in total 412 Kbp, in over 200 long-range PCR fragments from each individual, from 524 severely obese and 527 lean Swedish children, and sequenced the products as two DNA pools using massive parallel sequencing (SOLiD). RESULTS: The sequencing achieved very high coverage (median 18 000 reads) and we detected and estimated allele frequencies for 705 single nucleotide polymorphisms (SNPs) (19 novel) and 40 indels (24 novel) using a sophisticated statistical approach to remove false-positive SNPs. We identified 19 obesity-associated SNPs within intron one of the FTO gene, and validated our findings with genotyping. Ten of the validated obesity-associated SNPs have a stronger obesity association (P<0.007) than the commonly studied rs9939609 SNP (P<0.012). CONCLUSIONS: This study provides a comprehensive obesity-associated variation map of FTO, identifies novel lead SNPs and evaluates putative causative variants. We conclude that intron one is the only region within the FTO gene associated with obesity, and finally, we establish next generation sequencing of pooled DNA as a powerful method to investigate genetic association with complex diseases and traits.

The impact of intronic single nucleotide polymorphisms and ethnic diversity for studies on the obesity gene FTO.

In 2007, the first common genetic variants were identified, which undoubtedly affect our susceptibility to obesity. These variants are located in the fat mass and obesity-associated gene FTO. Since then, over 50 loci for common obesity have been identified. As the research on these loci is still at an early stage, there is a great need to review, for clarification purposes, the current research on FTO, as this is likely to influence future studies. Based on the current knowledge, FTO seems to be directly involved in the regulation of energy intake, but there is an urgent need for the identification of regulatory polymorphisms. Thus, herein, we discuss current knowledge and highlight putative functional regions in FTO based on published data and computer-based analysis.

Genetic variants near the MGAT1 gene are associated with body weight, BMI and fatty acid metabolism among adults and children.

OBJECTIVE: Recently a genome-wide association analysis from five European populations identified a polymorphism located downstream of the mannosyl-(α-1,3)-glycoprotein-ß-1,2-N-acetylglucosaminyltransferase (MGAT1) gene that was associated with body-weight. In the present study, associations between MGAT1 variants combined with obesity and insulin measurements were investigated in three cohorts. Levels of fatty acids and estimated measures of Δ desaturases were also investigated among adult men. DESIGN: Six polymorphisms downstream of MGAT1 were genotyped in a cross-sectional cohort of 1152 Swedish men. Three polymorphisms were further analyzed in a case-control study of 1076 Swedish children and in a cross-sectional study of 2249 Greek children. RESULTS: Three polymorphisms, rs12186500 (odds ratio (OR): 1.892, 95% confidence interval (CI): 1.237-2.895, P=0.003), rs1021001 (OR: 2.102, 95% CI: 1.280-3.455, P=0.003) and rs4285184 (OR: 1.587, 95% CI: 1.024-2.459, P=0.038) were associated with a higher prevalence of obesity among the adult men and a trend for obesity was observed for rs4285184 among the Swedish (OR: 1.205, 95% CI: 0.987-1.471, P=0.067) and Greek children (OR: 1.192, 95%CI: 0.978-1.454, P=0.081). Association with body weight was observed for rs12186500 (P=0.017) and rs4285184 (P=0.024) among the men. The rs1021001 and rs4285184 were also associated with body mass index (BMI) in the two Swedish cohorts and similar trends were observed among the Greek children. The combined effect size for rs1021001 and rs4285184 on BMI z-score from a meta-analysis was 0.233 (95% CI:0.093-0.373, P=0.001) and 0.147 (95% CI:0.057-0.236, P=0.001), respectively. We further observed associations between the genetic variants and fatty acids (P<0.039) and estimated measures of Δ desaturases (P<0.040), as well as interactions for rs12186500 (P<0.019) with an effect on BMI. No association was found with homeostatic model assessment-insulin resistance in any cohort but increased insulin levels, insulin response and decreased insulin sensitivity were observed among the children (P<0.038). CONCLUSION: Genetic variants downstream MGAT1 seem to influence susceptibility to obesity. Moreover, these genetic variants affect the levels of serum unsaturated fatty acids and Δ desaturase indices, variables previously shown to correlate with obesity.

Associations between severity of obesity in childhood and adolescence, obesity onset and parental BMI: a longitudinal cohort study.

OBJECTIVE: To explore the relationship between severity of obesity at age 7 and age 15, age at onset of obesity, and parental body mass index (BMI) in obese children and adolescents. DESIGN: Longitudinal cohort study. SUBJECTS: Obese children (n = 231) and their parents (n = 462) from the Swedish National Childhood Obesity Centre. METHODS: Multivariate regression analyses were applied with severity of obesity (BMI standard deviation score (BMI SDS)) and onset of obesity as dependent variables. The effect of parental BMI was evaluated and in the final models adjusted for gender, parental education, age at onset of obesity, severity of obesity at age 7 and obesity treatment. RESULTS: For severity of obesity at age 7, a positive correlation with maternal BMI was indicated (P = 0.05). Severity of obesity at this age also showed a strong negative correlation with the age at onset of obesity. Severity of obesity at age 15 was significantly correlated with both maternal and paternal BMI (P < 0.01). In addition, BMI SDS at age 15 differed by gender (higher for boys) and was positively correlated with severity of obesity at age 7 and negatively correlated with treatment. Also, a negative correlation was indicated at this age for parental education. No correlation with age at onset was found at age 15. For age at onset of obesity there was no relevant correlation with parental BMI. Children within the highest tertile of the BMI SDS range were more likely to have two obese parents. CONCLUSION: The impact of parental BMI on the severity of obesity in children is strengthened as the child grows into adolescence, whereas the age at onset is probably of less importance than previously thought. The influence of parental relative weight primarily affects the severity of childhood obesity and not the timing.

Novel genetic variant in FTO influences insulin levels and insulin resistance in severely obese children and adolescents.

BACKGROUND: The global prevalence of obesity and overweight is increasing rapidly among adults as well as among children and adolescents. Recent genome-wide association studies have provided strong support for association between variants in the FTO gene and obesity. We sequenced regions of the FTO gene to identify novel variants that are associated with obesity and related metabolic traits. RESULTS: We screened exons 3 and 4 including exon-intron boundaries in FTO in 48 obese children and adolescents and identified three novel single nucleotide polymorphism in the fourth intronic region, (c.896+37A>G, c.896+117C>G and c.896+223A>G). We further genotyped c.896+223A>G in 962 subjects, 450 well-characterized obese children and adolescents and 512 adolescents with normal weight. Evidence for differences in genotype frequencies were not detected for the c.896+223A>G variant between extremely obese children and adolescents and normal weight adolescents (P=0.406, OR=1.154 (0.768-1.736)). Obese subjects with the GG genotype, however, had 30% increased fasting serum insulin levels (P=0.017) and increased degree of insulin resistance (P=0.025). There were in addition no differences in body mass index (BMI) or BMI standard deviation score (SDS) levels among the obese subjects according to genotype and the associations with insulin levels and insulin resistance remained significant when adjusting for BMI SDS. CONCLUSION: These findings suggest that this novel variant in FTO is affecting metabolic phenotypes such as insulin resistance, which are not mediated through differences in BMI levels.

Cerebrospinal fluid neurofilament light levels in amyotrophic lateral sclerosis: impact of SOD1 genotype.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative syndrome with familial and sporadic forms. Most ALS-associated mutations are found in the superoxide dismutase 1 (SOD1) gene. We conducted a study including 60 sporadic and 19 familial ALS patients, 206 reference patients with other neurological disorders and 40 age- and sex-matched healthy controls to test the hypothesis that cerebrospinal fluid (CSF) levels of neurofilament light (NF-L) protein, a marker of axonal degeneration, might provide diagnostic and prognostic information on the disease. All ALS patients were screened for SOD1 mutations. Ten of the familial and five of the sporadic cases carried SOD1 mutations. NF-L concentration [median (range)] was strongly elevated in ALS [2110 (255-10 800) ng/l] compared with reference patients and healthy controls [277 (<125-15 506) and 175 (<125-710) ng/l, respectively, P < 0.001] and correlated inversely with disease duration (Spearman R = -0.518, P = 0.001). NF-L levels were lower in SOD1 mutation-associated ALS compared with SOD1 wild-type (wt) ALS (P = 0.03). In conclusion, CSF NF-L levels may provide both diagnostic and prognostic information, particularly in SOD1 wt ALS.

Corticosterone inhibits expression of the microglial glutamate transporter GLT-1 in vitro.

The present study investigates the effect of the glucocorticoid corticosterone on microglial glutamate transporters in vitro. Microglial cultures obtained from rat cerebral cortex were found to express the excitatory amino acid transporter GLT-1, but not GLAST, and this expression was increased by 1 ng/ml lipopolysaccharide after 12 h of stimulation. This increase has previously been shown to be mediated by tumor necrosis factor-alpha, a cytokine released by microglia during pathological conditions. Furthermore, lipopolysaccharide increased the microglial release of tumor necrosis factor-alpha and 1 microM corticosterone inhibited this effect. Corticosterone also inhibited the lipopolysaccharide-induced increase of the GLT-1 expression as well as the expression in non-activated cells. The effect of corticosterone on the GLT-1 expression was dose dependent and accompanied by similar effects on the microglial glutamate uptake capacity. Additionally, exogenous tumor necrosis factor-alpha was found to counteract the effect of corticosterone on microglial GLT-1 expression. The effect of corticosterone appeared to be glucocorticoid receptor specific since 10 microM of the glucocorticoid receptor antagonist mifepristone inhibited the effect. Thus, corticosterone decreased the microglial uptake of glutamate by decreasing the expression of glutamate transporters, probably due to the inhibited microglial tumor necrosis factor-alpha release. These results provide insights into the mechanisms behind microglial glutamate transporter expression during pathological conditions, and contribute to the debate about the beneficial or harmful effects of glucocorticoids.

Superoxide dismutase in CSF from amyotrophic lateral sclerosis patients with and without CuZn-superoxide dismutase mutations.

Mutations in CuZn-superoxide dismutase (CuZn-SOD) have been linked to familial amyotrophic lateral sclerosis (ALS), and motor neurone death is caused by the gain of a toxic property of the mutant protein. Here we determined amounts, activity and molecular forms of CuZn-SOD in CSF from ALS patients carrying the D90A and other CuZn-SOD mutations and patients without such mutations. There were no differences in amount of protein and enzymic activities of CuZn-SOD between 37 neurological controls, 54 sporadic and 12 familial ALS cases, and 10 cases homozygous for the D90A mutation. Three cases heterozygous for the A89V, S105L and G114A CuZn-SOD mutations showed low amounts of CuZn-SOD. There was no evidence for accumulation of inactive protein in any of the groups. Immunoblots showed no evidence for the presence of any precipitates or other molecular forms of CuZn-SOD with higher molecular weight in the groups. About 25% of the CuZn-SOD subunits in CSF from controls shows an N-terminal truncation. This truncated portion does not differ between controls and ALS groups not carrying CuZn-SOD mutations, but is 70% larger in samples from D90A homozygous ALS patients. The findings suggest an essentially normal amount and activity of D90A mutant CuZn-SOD in CNS tissues of ALS cases. The increased occurrence of N-terminally truncated mutant subunits may indicate a difference in degradation routes compared with the wild-type enzyme, resistance against subsequent proteolytic steps and/or a compromised downstream proteolytic machinery. Molecular fragments accumulated to a greater extent from the D90A mutant enzyme might contribute to the motor neurone degeneration. We also determined the other SOD isoenzymes: in the controls, CuZn-SOD contributed 75%, extracellular SOD 25% and Mn-SOD <5% of the total SOD activity. There was no difference in the amount of extracellular SOD between any of the groups.

Protective effects of the lazaroid U74500A and lidoflazine on liver preservation with UW solution.

The effect of adding a 21-aminosteroid, U74500A, and a Ca2+ antagonist, lidoflazine, alone and together to UW solution was assessed in a rat liver preservation model. Following preservation, the livers were reperfused using a closed circuit, and the release of hepatocellular enzymes (ASAT, ALAT, and LDH) into the perfusate was determined with increasing time. Both drugs reduced the amount of enzymes lost from the liver. The combination of the two drugs was better than either drug alone. These data suggest that both agents may be of value in organ preservation for clinical liver transplantation.

Effect of estradiol on accelerated atherosclerosis in rabbit heterotopic aortic allografts.

Migration and proliferation of vascular smooth muscle cells are early and major events in the formation of atherosclerotic lesions. We report on an aorta transplant model in rabbits wherein myointimal proliferation is inhibited by 17-beta-estradiol. The abdominal aortas of outbred white New Zealand rabbits were harvested and allografted to the carotid artery of the recipient. The animals, which were fed either a normal or a high-cholesterol (0.5%) diet, were killed 3 weeks later. The degree of myointimal proliferation was measured with a digitized system attached to a light microscope. The myointimal hyperplasia was expressed as the cross section area of the intima/the area of the intima + the area of the media x 100. Transmission electron micrographs were obtained for all vessels. Intimal thickening was shown mainly to consist of proliferating smooth muscle cells. The cholesterol diet resulted in significantly higher serum total cholesterol levels compared to animals on a normal diet (p < 0.0001) but did not affect serum high-density lipoprotein-cholesterol or serum triglyceride levels. The cholesterol diet was also associated with a greater but not significant amount of intimal thickening. Treatment with 17-beta-estradiol significantly decreased both serum triglyceride concentration (p < 0.05) and myointimal thickening (p < 0.01) in cholesterol-fed animals. Transmission electron microscopy showed that the endothelial cells appeared structurally normal in the estradiol-treated animals. Further, estradiol prevented the appearance of vacuolized macrophages. Thus estradiol may decrease myointimal thickening by preserving the endothelium and preventing macrophage appearance in the intima.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of renal preservation by adding lidoflazine to University of Wisconsin solution. An experimental study in the rat.

The purpose of this study was to investigate the possibility of improving the organ preservation properties of the University of Wisconsin (UW) solution by adding the calcium entry blocker lidoflazine. We also investigated the possibility of decreasing the cold ischemia and reperfusion damage by pretreatment with lidoflazine of the donor and/or recipient. The protective effects of lidoflazine treatment were estimated by measuring the amount of trapped erythrocytes in the rat renal medulla after 48 h of cold storage, subsequent transplantation, and 20 min of reperfusion. Lidoflazine (20 mg/liter) added to the UW solution decreased the amount of erythrocyte trapping from 14.8 +/- 3.1% in controls to 8.6 +/- 1.7% (P less than 0.01). The flow rate of the flush-out solution during the harvesting procedure was also significantly (P less than 0.01) increased when lidoflazine was included in the UW solution (1.10 +/- 0.21 ml/min vs 0.75 +/- 0.22 ml/min). Administration of lidoflazine (0.28 mg/kg body wt) to the donor and/or the recipient did not further reduce the postischemia/reperfusion damage as estimated by the degree of erythrocyte trapping. In conclusion, the results indicate that the preservation properties of the UW solution can be significantly improved by adding lidoflazine to the solution.

Inhibition of myointimal hyperplasia and macrophage infiltration by estradiol in aorta allografts.

A major cause of organ graft loss after heart transplantation is accelerated atherosclerosis. In this study we used aorta allografts and investigated the effect of estradiol-17 beta treatment on both the degree of myointimal hyperplasia and morphological changes evaluated by light and electron microscopy. Outbred New Zealand white male rabbits (2.7-3.5 kg) were fed cholesterol (0.5%) from one week prior to transplantation, and until sacrifice three weeks later. The donor abdominal aorta was transplanted end-to-end to the right carotid artery of the recipient animals. Immediately following surgery, cyclosporine (10 mg/kg/d s.c.) was administered to prevent graft rejection. The allograft recipients were randomly assigned to one of five groups and treated with cottonseed oil (placebo) or estradiol cypionate at 1, 10, 100, or 1000 micrograms/kg/d i.m. for 3 weeks. The aorta grafts were harvested and fixed for transmission electron microscopy and morphometry. The area of myointimal thickening was calculated as a percent of total vessel area (mean +/- SEM); the control group was 6.6 +/- 0.5% (n = 5). Estradiol treatment significantly inhibited (P less than 0.05) myointimal hyperplasia at all doses. The values were 3.9 +/- 0.6% (n = 6) for 1 microgram/kg/day; 4.4 +/- 0.7% (n = 5) for 10 micrograms/kg/day; 3.5 +/- 0.4% (n = 6) for 100 micrograms/kg/day; and 2.9 +/- 0.1% (n = 3) for 1000 micrograms/kg/day. Electron microscopic evaluation revealed that the four doses of estradiol protected the endothelium from the degenerative changes seen in all aorta allografts from the animals in the control group. Furthermore 10, 100, and 1000 micrograms/kg/day of estradiol prevented the appearance of vacuolized macrophages (foam cells) and also the vacuolization of smooth muscle cells that was observed in the aorta allografts from the control group and the group treated with 1 microgram/kg/day of estradiol. We conclude that the inhibitory effect of estradiol on the development of graft atherosclerosis may be due to inhibition of smooth muscle cell proliferation and preservation of ultrastructurally normal endothelial cells. The inhibitory effect on foam cell production and a concomitant vacuolization of smooth muscle cells may play a lesser role. We suggest that estrogen replacement therapy may be beneficial in postmenopausal women with organ allografts.

Coronary artery ultrastructural changes in cardiac transplant atherosclerosis in the rabbit.

Accelerated coronary atherosclerosis is the limiting factor for long-term survival of cardiac transplant recipients, but its pathogenesis is poorly understood. Morphologic and ultrastructural changes in suitable models may help explain the underlying mechanisms. In this study, early (3, 7, 14, and 21 days) and late (42 days) ultrastructural changes of the coronary artery were characterized in rabbit cardiac allografts. Thirty-four New Zealand white male rabbits (3.0-4.0 kg) served as donors and recipients. All recipients received cyclosporine (10 mg/kg/day i.m.) as immunosuppressant. In order to increase the normally very low cholesterol levels in rabbits, both the donor and recipient animals were fed a 0.5% cholesterol diet. Recipient animals were sacrificed between 3 days and 6 weeks after transplantation. The specimens from both donor and recipient were examined by transmission electron microscopy, immunohistochemistry, and morphometry. Our data indicate that intimal thickening was initiated with smooth muscle cell migration within 1 week after transplantation, and occurrence of macrophage-derived foam cells and vacuolized smooth muscle cells 3 weeks after transplantation. These changes occurred in the presence of an ultrastructurally intact endothelium. Platelets were only seldom seen adhering to the endothelium. In contrast, lymphocytes and monocytes were frequently found adhering to the endothelium at 2 and 3 weeks posttransplantation. From 3 weeks posttransplantation, lymphocytes were seen only occasionally in the intima but not in the media. This study suggests that early events elicit a change in the smooth muscle cells in the media to the secretory phenotype that migrates to the intima and proliferate. Lymphocyte and monocyte adhesion to the endothelium may enhance smooth muscle migration and proliferation. The large macrophage involvement may relate to the high serum cholesterol levels induced by the cholesterol diet. All these changes occurred in the presence of a structurally normal endothelium and without apparent platelet involvement.