Development of the coronary arteries in a murine model of transposition of great arteries

Transposition of great arteries in humans is associated with a wide spectrum of coronary artery patterns. However, no information is available about how this pattern diversity develops. We have studied the development of the coronary arteries in mouse embryos with a targeted mutation of perlecan, a mutation that leads to ventriculo-arterial discordance and complete transposition in about 70% of the embryos. The perlecan-deficient embryos bearing complete transposition showed a coronary artery pattern consisting of right and left coronary arteries arising from the morphologically dorsal and ventral sinuses of Valsalva, respectively. The left coronary artery gives rise to a large septal artery and runs along the ventral margin of the pulmonary root. In the earliest embryos where transposition could be confirmed (12.5 d post coitum), a dense subepicardial vascular plexus is located in this ventral margin. In wild-type mice, however, capillaries are very scarce on the ventral surface of the pulmonary root and the left coronary artery runs dorsally to this root. We suggest that the establishment of the diverse coronary artery patterns is determined by the anatomical arrangement and the capillary density of the peritruncal vascular plexus, a plexus that spreads from the atrio-ventricular groove and grows around the aortic or pulmonary roots depending on the degree of the short-axis aortopulmonary rotation. This simple model, based on very few assumptions, might explain all the observed variation of the coronary artery patterns in humans with transposition, as well as our observations on the perlecan-deficient and the normal mice.     

Major lower limb amputations in the elderly observed over ten years: the role of diabetes and peripheral arterial disease

BACKGROUND: Major amputation is a dreaded event with high mortality and morbidity. However, few studies have investigated the epidemiology of amputation in the elderly over time, in the face of evolving management and prevention efforts. METHODS: We undertook a retrospective study to determine the incidence rate, etiology and prognosis of major lower limb amputations (transtibial or higher) in elderly patients (> 65 years). Cases were identified over a 10-year period in the Geneva (Switzerland) area, where all amputations are performed in a single center and reliable demographic data are available. RESULTS: The rate of amputation varied from 1.8 to 11.4/10000 patients/year, increasing with age and male gender. Diabetes was present in 48% patients, and conferred a 10 times higher risk of amputation. Severe peripheral arterial disease (PAD) was present in > 94% patients. The prognosis remains poor, 47% patients had died after two years and only 53% patients could be equipped with a prosthetic limb. Over 10 years we found a progressive increase in age at amputation; this encouraging increase was mostly accounted for by diabetic patients (> 6 months per year). CONCLUSIONS: The rate of amputation observed among elderly patients was low. Neither the rate nor the prognosis improved over the decade studied. However, the age at amputation increased by > 6 months/year, particularly in diabetic amputees, suggesting that current management successfully delays amputation. Amputations were almost exclusively performed for severe PAD. Further reduction in the rate of amputation will require progress in the prevention and management of PAD.     

Cardiovascular Interactions of Desipramine,Fluoxetine, and Cocaine in Cocaine-Dependent Outpatients

The authors investigated the subacute cardiovascular effects of cocaine use alone and with antidepressants. At study entry, 55 cocaine-dependent (DSM-III-R) patients with cocaine-positive urines had slightly higher resting heart rates and blood pressures than 36 patients with cocaine-negative urines, which achieved significance (P < 0.05) for three of eleven parameters. A repeated-measures analysis of medication-compliant patients found no significant cardiovascular differences between cocaine-positive and cocaine-negative urine conditions for either desipramine (n = 10) or fluoxetine (n = 20). Cocaine use appears to produce minimal subacute cardiovascular effects, which are not accentuated by desipramine or fluoxetine, in physically healthy cocaine-dependent patients. (American Journal on Addictions 1996; 5:321–326)     

High-dose chemoradiotherapy and autologous blood stem cell transplantation in multiple myeloma: results of a phase II trial involving 63 patients

Sixty-three patients with high tumor mass multiple myeloma were treated with high-dose chemotherapy and total body irradiation supported by autologous blood stem cell transplantation. After high-dose therapy, they were monitored for a median of 44 months. Seven patients died early from toxicity. All the other patients, including those whose disease was resistant to previous therapies, showed a tumor mass reduction. At 6 months postengraftment, 40 (71%) of the surviving patients had minimal residual disease and 11 (20%) were in apparent complete remission. During follow-up, 25 out of the 63 (39%) patients relapsed and 16 of these died; 31 (49%) had a sustained remission. The median overall and event-free survival times after transplantation were 59 and 43 months, respectively. The initial serum beta 2-microglobulin value (> or < 2.8 mg/L) and length of previous therapy (> or < 6 courses of chemotherapy) were the only significant prognostic factors. In all surviving patients, blood stem cell autograft provided satisfactory and sustained haematopoietic reconstitution most often within 15 days. High dose chemoradiotherapy followed by autologous blood stem cell transplantation is thus an important therapeutic option for young patients with aggressive multiple myeloma.     

HLA antigens and anti-neutrophil cytoplasmic antibodies (ANCA) in inflammatory bowel disease.

HYPOTHESIS AND OBJECTIVES: the hypothesis of this study is that genes involved in the regulation of the immune system, expressed by HLA antigens and anti-neutrophil cytoplasmic antibodies (ANCA), could be determinants of disease susceptibility and behavior in inflammatory bowel disease (IBD). MATERIAL AND METHOD: seventy patients with a diagnosis of inflammatory bowel disease, 46 with ulcerative colitis and 24 with Crohn"s disease were included. HLA class I (A and B) and II (DR) antigens were studied by serological techniques. Detection of ANCA was carried out in all patients by an indirect immunofluorescence method. The relative frequencies of HLA antigens were compared with a control group made up of 156 blood donors. The control group for the ANCA study was made up of 100 individuals. RESULTS: we found a significant increased frequency of HLA-DR2 in patients with ulcerative colitis. No significant differences were found between patients with Crohn"s disease and controls regarding HLA typing. We detected a significant increase of HLA-DR3 in extensive forms of ulcerative colitis. Detection of ANCA was positive in 46% of the patients with ulcerative colitis and in 12% of the patients with Crohn"s disease (p <0.05). We observed an increased frequency of ANCA in patients with UC and HLA-DR2 (p = 0.15). CONCLUSIONS: the association found between HLA-DR3 and extensive forms of ulcerative colitis provides evidence of genetic heterogeneity. The relationship between ANCA and HLA phenotype (although not significant) supports this concept.     

Rheumatoid arthritis in Spain: occurrence of extra-articular manifestations and estimates of disease severity

Methods: Cross sectional analysis of a cohort of patients with RA randomly selected from the clinical databases of 34 centres. Standard definitions and measurements were used, and radiographs read centrally. Estimates and confidence intervals were adjusted to sampling. Results: Data were available for 788 patients. Extra-articular RA was present in 285 (36.2%) patients. Cumulative prevalence and 95% confidence intervals of extra-articular manifestations were estimated: nodules 24.5% (21.5 to 27.5), Sjögren''s syndrome 17.0% (14.4 to 19.6), atlantoaxial subluxation 12.1% (9.8 to 14.4), carpal tunnel syndrome 10.7% (7.8 to 13.6), interstitial lung disease 3.7% (2.4 to 5.0), serositis 2.5% (1.4 to 3.5), eye disease 2.5% (1.1 to 3.9), vasculitis 1.3% (0.5 to 2.1), amyloidosis 0.6% (0.1 to 1.2), and Felty''s syndrome 0.3% (<0.6). Mean (SD) activity/progression indexes were: DAS28-3 3.4 (1.2), HAQ 1.6 (0.4), Larsen score 54.7 (26.4). Less than 5% of the patients were in remission. 205 (72%) patients were receiving disease modifying antirheumatic drugs (DMARDs). Conclusion: Spanish patients with RA ever seen by a rheumatologist have, on average, a moderate degree of activity, despite widespread use of DMARDs. Measures of the degree of progression do not show a benign disease. The proportion of extra-articular manifestations in Spanish patients with RA is similar to that found in other Mediterranean populations, and lower than that reported in Anglo Saxon countries.     

Activation of Epac stimulates integrin-dependent homing of progenitor cells

Cell therapy is a novel promising option for treatment of ischemic diseases. Administered endothelial progenitor cells (EPCs) are recruited to ischemic regions and improve neovascularization. However, the number of cells that home to ischemic tissues is restricted. The GTPase Rap1 plays an important role in the regulation of adhesion and chemotaxis. We investigated whether pharmacologic activation of Epac1, a nucleotide exchange protein for Rap1, which is directly activated by cAMP, can improve the adhesive and migratory capacity of distinct progenitor cell populations. Stimulation of Epac by a cAMP-analog increased Rap1 activity and stimulated the adhesion of human EPCs, CD34(+) hematopoietic progenitor cells, and mesenchymal stem cells (MSCs). Specifically, short-term stimulation with a specific Epac activator increased the beta2-integrin-dependent adhesion of EPCs to endothelial cell monolayers, and of EPC and CD34(+) cells to ICAM-1. Furthermore, the Epac activator enhanced the beta1-integrin-dependent adhesion of EPCs and MSCs to the matrix protein fibronectin. In addition, Epac1 activation induced the beta1- and beta2-integrin-dependent migration of EPCs on fibronectin and fibrinogen. Interestingly, activation of Epac rapidly increased lateral mobility of beta1- and beta2-integrins, thereby inducing integrin polarization, and stimulated beta1-integrin affinity, whereas the beta2-integrin affinity was not increased. Furthermore, prestimulation of EPCs with the Epac activator increased homing to ischemic muscles and neovascularization-promoting capacity of intravenously injected EPCs in the model of hind limb ischemia. These data demonstrate that activation of Epac1 increases integrin activity and integrin-dependent homing functions of progenitor cells and enhances their in vivo therapeutic potential. These results may provide a platform for the development of novel therapeutic approaches to improve progenitor cell homing.     

Detection of genomic deletions of PKP2 in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis.     

The chronic blockade of angiotensin I-converting enzyme eliminates the sex differences of serum cytokine levels of spontaneously hypertensive rats

Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.