AT1 receptor blockade reduces cardiac calcineurin activity in hypertensive rats

The possible role of calcineurin in the attenuation of cardiac hypertrophy and fibrosis by blockade of the angiotensin II type 1 (AT1) receptor was investigated in Dahl salt-sensitive (DS) rats. The effect of the calcineurin inhibitor FK506 was also studied. DS rats progressively developed severe hypertension when fed a diet containing 8% NaCl from 7 weeks of age. In addition, marked cardiac hypertrophy and fibrosis were apparent and the activity of calcineurin and its mRNA expression in the myocardium was increased in these animals at 12 weeks in comparison with age-matched Dahl salt-resistant rats. The abundance of angiotensin-converting enzyme (ACE) and transforming growth factor (TGF)-beta1 mRNAs was also increased in the hearts of DS rats at 12 weeks. Treatment of DS rats with a non-antihypertensive dose of the selective AT1 receptor blocker candesartan (1 mg/kg per day) or FK506 (0.1 mg/kg per day) from 7 to 12 weeks attenuated both calcineurin activity and its mRNA expression in the heart, as well as the development of cardiac hypertrophy and fibrosis, without affecting cardiac function. Treatment with candesartan, but not FK506, prevented the upregulation of ACE and TGF-beta1 gene expression. Both candesartan and FK506 prevented the load-induced induction of fetal-type cardiac genes. These results demonstrate that AT1 receptor blockade attenuates the development of cardiac hypertrophy and fibrosis as well as the activation of calcineurin, without an antihypertensive effect, in rats with salt-sensitive hypertension. Calcineurin may be downstream from TGF-beta1 in AT1 receptor-mediated angiotensin II signaling in vivo.     

Ten-year follow-up of familial hypercholesterolemia patients after intensive cholesterol-lowering therapy

To prevent coronary artery disease, it is necessary for patients with familial hyper-cholesterolemia (FH) to maintain a low cholesterol level. Recently a combination therapy of low-density lipoprotein (LDL) apheresis and statins has been used for FH patients, but their long-term prognosis over 10 years is unknown. In this single center prospective report, 18 FH patients with severe coronary stenosis received LDL apheresis every 2 or 4 weeks and statin therapy for 9.8 +/- 3.0 years. Probucol was given to 17 of the 18 patients. We observed their clinical events as well as coronary stenosis findings and ejection fractions for 10.7 +/- 2.6 years. Total and LDL cholesterol levels before therapy were 345 +/- 46 and 277 +/- 48 mg/dL, respectively. Immediately following LDL-apheresis, these levels decreased to 104 +/- 7.5 and 66 +/- 16 mg/dL, respectively. There were no cardiac deaths and 4 patients were free from any coronary events. There was one noncardiac death. Nonfatal myocardial in-farction occurred in 2 patients and coronary bypass surgery was required in one patient. Twelve patients received additional coronary angioplasty. There was little change in coronary stenosis and ejection fraction following 10 years of the combination therapy. Univariate Cox regression analysis revealed that the calculated mean LDL cholesterol level was the predictive value of treatment efficacy (mean LDL cholesterol < 140 mg/dL, hazard ratio 0.23, P = 0.028). The combination therapy of LDL-apheresis and antilipid drugs delayed the progression of coronary atherosclerosis and prevented a major cardiac event, although complete inhibition was limited to a small group. Additional coronary angioplasty is likely to be required for a favorable clinical outcome in FH patients.     

Prediction of genetic risk for hypertension

BACKGROUND: Although genetic epidemiological studies have suggested that several genetic variants increase the risk for hypertension, the genes that underlie genetic susceptibility to this condition remain to be identified definitively. Large-scale association studies that examine many gene polymorphisms simultaneously are required to predict genetic risk for hypertension. METHODS and RESULTS: The population of the present study comprised 1,940 unrelated Japanese individuals, including 1,067 subjects with hypertension (574 men, 493 women) and 873 controls (533 men, 340 women). The genotypes for 33 single nucleotide polymorphisms of 27 candidate genes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay system. Multivariate logistic regression analysis with adjustment for age, body mass index, and the prevalence of smoking, diabetes mellitus, hypercholesterolemia, and hyperuricemia revealed that two polymorphisms (825C -> T in the G protein beta3 subunit gene and 190G -> A in the CC chemokine receptor 2 gene) were significantly associated with hypertension in men and that one polymorphism (-238G -> A in the tumor necrosis factor- alpha gene) was significantly associated with hypertension in women. CONCLUSION: These results suggest that two and one genes may be susceptibility loci for hypertension in Japanese men and women, respectively, and that genotyping of these polymorphisms may prove informative for prediction of the genetic risk for hypertension.     

Toxoplasmosis encephalitis following severe graft-vs.-host disease after allogeneic hematopoietic stem cell transplantation: 17 yr experience in Fukuoka BMT group

Toxoplasmosis is a rare but rapidly fatal complication that can occur following hematopoietic stem cell transplantation (HSCT). Over a 17-yr period at our institutions, a definite diagnosis of toxoplasmosis was made in only two of 925 allogeneic HSCT recipients (0.22%) and none of 641 autologous HSCT recipients. These two patients received a conventional conditioning regimen followed by transplantation from an HLA-matched donor; however, they developed severe graft-vs.-host disease, which required intensive immunosuppressive therapy. Despite prophylactic treatment with trimethoprim/sulfamethoxazole, their immunosuppressive state, as indicated by a low CD4(+) cell count, might have resulted in toxoplasmosis encephalitis. Rapid and non-invasive methods such as a polymerase chain reaction (PCR) test of their cerebrospinal fluid for Toxoplasma gondii and magnetic resonance imaging of the brain were useful for providing a definitive diagnosis and prompt therapy in these patients: one patient stabilized and survived after responding to treatment with pyrimethamine/sulfodiazine whereas the other died of bacterial infection. In addition, retrospective PCR analyses of the frozen stored peripheral blood samples disclosed that detection of T. gondii preceded the onset of disease, indicating routine PCR testing of peripheral blood specimens may be an early diagnostic tool. It should be noted that when patients receiving HSCT have an unexplained fever and/or neurological complications, PCR tests should be considered to avoid cerebral lesions and improve the outcome of the patients.     

Safety and efficacy of autologous progenitor cell transplantation for therapeutic angiogenesis in patients with critical limb ischemia.

BACKGROUND: Therapeutic angiogenesis using cell transplantation (TACT) is a treatment strategy for no-option patients with critical limb ischemia (CLI). However, because one-third of treated patients fail to respond, the present study was an exploration of the characteristics of responders and non-responders to this treatment regimen. METHODS AND RESULTS: Seven CLI patients (3 with Buerger's disease, 4 with arteriosclerosis obliterans undergoing chronic hemodialysis (ASO-HD)) were treated according to the TACT protocol (n=6: bone marrow-mononuclear cells (MNCs); n=1: peripheral blood-MNCs). Subjective symptoms (visual analog scale) and objective findings (extent of ulcer, ankle-brachial pressure index, transcutaneous oxygen pressure, thermography and angiography) were assessed. Numbers of transplanted CD34+, CD133+ and CD34+ CD133+ cells were counted. Changes in circulating CD34+ and CD133+ cell numbers were also examined before and after the treatment. All responders (n=3) had Buerger's disease, and ASO-HD patients did not respond well. Among the responders, the numbers of circulating CD34+ and CD133+ cells persistently increased for 1 month after the treatment, but not in non-responders. CONCLUSIONS: The TACT regimen improved CLI in patients with Buerger's disease but not in those with ASO-HD in this small study. In responders, post procedural circulating CD34+ and CD133+ cells persistently increased for 1 month (ClinicalTrials.gov Identifier: NCT00145262, TACT-NAGOYA).     

Cre/loxP-mediated CTLA4IgG gene transfer induces clinically relevant immunosuppression via on-off gene recombination in vivo

OBJECTIVE: Transfer of the CTLA4IgG gene induces long-term and high levels of CTLA4IgG expression, which can result in generalized immunosuppression. In this study, we utilized Cre/loxP-mediated on-off switch recombination to eliminate transgene expression of CTLA4IgG following acceptance of murine cardiac allografts. METHODS: Fully MHC-mismatched hearts from BALB/c donor mice were transplanted into C3H/He recipient mice. Adenovirus-containing CTLA4IgG flanked between two loxP sites was administered via a recipient tail vein immediately after transplantation. Cre-recombinase gene was subsequently transferred at day 30 posttransplantation. RESULTS: Long-term allograft survival was observed in recipients that received the CTLA4IgG gene. Cre-mediated recombination reduced CTLA4IgG gene expression without any adverse effect on the graft survival. Secondary skin grafts of donor type and of third party were promptly rejected in the recipients that accepted cardiac allografts. In addition, the B cell response against ovalbumin was suppressed during high levels of serum CTLA4IgG, but recovered after Cre-mediated inactivation of CTLA4IgG gene. CONCLUSION: CTLA4IgG gene transfer promoted long-term survival of murine cardiac allografts; however, this was not sufficient to induce tolerance. Cre/loxP-mediated on-off switch recombination was useful to inactivate the CTLA4IgG gene so that recipients' immune responses against neoantigens were restored without an influence on the allograft survival. This system may open novel strategies to orchestrate clinically relevant immunosuppression.     

CD19-targeting liposomes containing imatinib efficiently kill Philadelphia chromosome-positive acute lymphoblastic leukemia cells

Patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) have poor prognosis despite intensive therapeutic intervention. Recently, imatinib, a BCR-ABL tyrosine kinase inhibitor, has been proven to be an effective treatment for Ph(+) ALL, but nearly all patients rapidly acquire resistance. High-dose imatinib administration might overcome this resistance; however, systemic toxicities would likely limit this approach. Therefore, a new delivery system allowing for the specific targeting of imatinib is urgently needed. Because almost all Ph(+) ALL cells express CD19 on their surface, we have developed an immunoliposome carrying anti-CD19 antibody (CD19-liposomes). The internalization efficiency of the CD19-liposomes approached 100% in all Ph(+) ALL cells but was very low in CD19(-) cells. The cytocidal effect of imatinib-encapsulated CD19-liposomes (imatinib-CD19-liposomes) on Ph(+) ALL cell lines and primary leukemia cells from patients with Ph(+) ALL was much greater than that of imatinib with or without control liposomes. Importantly, the imatinib-CD19-liposomes did not affect the colony formation of CD34(+) hematopoietic cells, even at inhibitory concentration of free imatinib. Taken together, these data clearly demonstrate that the imatinib-CD19-liposomes induced specific and efficient death of Ph(+) ALL cells. This new therapeutic approach might be a useful treatment for Ph(+) ALL with fewer side effects than free imatinib.     

Hepatocellular carcinoma in a patient with liver cirrhosis associated with negative serum HCV tests but positive liver tissue HCV RNA

A 70-year-old woman was admitted to our hospital because of a liver tumor. Laboratory data revealed mild liver dysfunction. Neither serum anti-HCV antibody nor HCV-RNA was detected. Computed tomography revealed a tumor lesion measuring 2 cm in diameter within the liver. Histological examination of the tumor revealed moderately differentiated hepatocellular carcinoma while the non-tumorous liver tissue demonstrated liver cirrhosis. By the RT-PCR method, HCV-RNA was detected from the non-tumorous liver tissue. We herein report a very rare case of hepatocellular carcinoma in a patient with liver cirrhosis associated with negative serum HCV findings, but positive finding for liver tissue HCV RNA.