Changes in myofilament proteins, but not Ca²⁺ regulation, are associated with a high-fat diet-induced improvement in contractile function in heart failure

Pathological conditions such as diabetes, insulin resistance, and obesity are characterized by elevated plasma and myocardial lipid levels and have been reported to exacerbate the progression of heart failure (HF). Alterations in cardiomyocyte Ca(2+) regulatory properties and myofilament proteins have also been implicated in contractile dysfunction in HF. However, our prior studies reported that high saturated fat (SAT) feeding improves in vivo myocardial contractile function, thereby exerting a cardioprotective effect in HF. Therefore, we hypothesized that SAT feeding improves contractile function by altering Ca(2+) regulatory properties and myofilament protein expression in HF. Male Wistar rats underwent coronary artery ligation (HF) or sham surgery (SH) and were fed normal chow (SHNC and HFNC groups) or a SAT diet (SHSAT and HFSAT groups) for 8 wk. Contractile properties were measured in vivo [echocardiography and left ventricular (LV) cannulation] and in isolated LV cardiomyocytes. In vivo measures of contractility (peak LV +dP/dt and -dP/dt) were depressed in the HFNC versus SHNC group but improved in the HFSAT group. Isolated cardiomyocytes from both HF groups were hypertrophied and had decreased percent cell shortening and a prolonged time to half-decay of the Ca(2+) transient versus the SH group; however, SAT feeding reduced in vivo myocyte hypertrophy in the HFSAT group only. The peak velocity of cell shortening was reduced in the HFNC group but not the HFSAT group and was positively correlated with in vivo contractile function (peak LV +dP/dt). The HFNC group demonstrated a myosin heavy chain (MHC) isoform switch from fast MHC-α to slow MHC-β, which was prevented in the HFSAT group. Alterations in Ca(2+) transients, L-type Ca(2+) currents, and protein expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase and phosphorylated phospholamban could not account for the changes in the in vivo contractile properties. In conclusion, the cardioprotective effects associated with SAT feeding in HF may occur at the level of the isolated cardiomyocyte, specifically involving changes in myofilament function but not sarcoplasmic reticulum Ca(2+) regulatory properties.

Suicidal ideation and attempts among rural Chinese aged 16-34 years--socio-demographic correlates in the context of a transforming China

BACKGROUND

The distinctive epidemiologic profile of suicide in China, with notably high rates among rural young adult females, invites examination of possible underlying risk factors. Although there are accumulating data regarding the epidemiology of suicide among youth and young adults in China, there are meager data on suicidal ideation and attempts despite its importance.

METHODS

Our study in 2005-06 sought to identify all potentially suitable rural participants, aged 16-34 years, from 10 representative villages in rural Sichuan Province. We conducted structured interviews regarding a range of socio-demographic characteristics and suicidal morbidity.

RESULTS

1654 of a potential 3008 participants participated; lifetime and one-year prevalence were: suicidal ideation (18.8% and 5.2%), serious ideation (8.6% and 2.3%), planning (5.8% and 1.5%), and attempt (2.7% and 0.5%). Comparisons among strata of socio-demographic characteristics showed more prevalent suicidal ideation associated with: female gender, lower education, poorer financial perception, greater rurality of residence, and marital status of "never married" or "others". Suicidal attempt was associated with: female gender and a marital status of "others".

LIMITATIONS

The study was carried out in one province and caution is required when considering other rural regions of China. There were a substantial number of unapproachable subjects because of their migrant work at distant sites.

CONCLUSIONS

Our results revealed an apparently higher prevalence for suicide ideation and planning compared with residents of other countries, but a lower prevalence for attempts. These data suggests that the relatively high rate of suicide in rural China reflects an elevated case fatality ratio due to chosen methods. The results also revealed unique patterns for correlates with the occurrence of ideation and attempts.

Three-dimensional secondary instability of a spatially developing von Kármán vortex street in a far wake

This paper presents studies of a three-dimensional secondary instability of a spatially developing von Kármán vortex street. It develops owing to the nonlinear interaction between a two-dimensional mean far-wake flow and its most unstable disturbances. This forms a nonlinear primary wake flow. Sections of this flow are selected to perform a temporal secondary stability study under the assumption of parallel flow. The eigenvalue characteristics of the secondary instability are compared with the results from the use of a linear primary flow comprising unmodified mean wake flow coexisting with a linear primary fundamental disturbance with an empirical amplitude as a parameter, resulting in a simpler Floquet analysis. The maximum amplification rates occur at about the same spanwise wavenumber for both the nonlinear and linear primary flows, in qualitative agreement. But the amplification rate versus the spanwise wavenumber spectrum are both qualitatively and quantitatively different, the nonlinear primary flow results in a lower magnitude of the amplification rates. Some interpretations of controlled experiments are made, and it is concluded that the two- and three-dimensional disturbances so obtained appeared to be from the primary instability, where the amplification mechanisms come from the unmodified mean flow. A general discussion of the nonlinear interaction between the primary two-dimensional flow and the three-dimensional secondary instability is given, which may well form the basis for further nonlinear studies.

Prevalence and characteristics of psoriatic arthritis in Chinese patients with psoriasis

BACKGROUND

The prevalence and clinical characteristics of psoriatic arthritis (PsA) in patients with psoriasis vary widely in different countries and studies on Chinese population are rarely reported.

OBJECTIVE

The aim of this study was to evaluate the prevalence and clinical characteristics of PsA in a Chinese population of patients with psoriasis.

METHODS

A large cross-sectional observational study was conducted in our outpatient dermatology department and consecutive psoriatic patients were evaluated for PsA according to Classification of Psoriatic arthritis (CASPAR) criteria. Demographic and medical parameters were recorded.

RESULTS

Among 1928 patients with psoriasis, 112 patients (5.8%) had PsA, of which 92% was newly diagnosed. Oligoarthritis (48.2%) was the most common manifestation pattern, followed by spondylitis (26.8%), polyarthritis (19.6%) and classic distal interphalangeal (DIP) arthritis (5.4%). Enthesitis was present in 26.8% and dactylitis in 13.4% of the patients. Compared with patients without PsA, patients with PsA had more severe skin disease (mean PASI 9.7 vs. 6.0), higher frequency of nail changes (46.4% vs. 21.0%) and scalp involvement (90.2% vs. 76.4%).

CONCLUSION

The findings are consistent with a low prevalence of PsA among patients with psoriasis in Asia and confirm a high percentage of undiagnosed cases with active arthritis among PsA patients in dermatologist's office. Dermatologists should screen for PsA in their patients, especially those with risk characteristics and early signs.

CIP2A is over-expressed in acute myeloid leukaemia and associated with HL60 cells proliferation and differentiation

INTRODUCTION

CIP2A is a newly identified inhibitor of PP2A. It can stabilize c-Myc and promote anchorage-independent cell growth and tumour formation. CIP2A is over-expressed in some solid tumours although its expression in acute myeloid leukaemia (AML) is still unknown.

METHODS

CIP2A mRNA and protein expressions were determined in bone marrow mononuclear cells of both patients with AML and healthy controls using reverse transcription polymerase chain reaction and Western blot, respectively. We used siRNA to knock-down CIP2A expression in HL60 cells and then examined its potential roles during the pathological progression of AML.

RESULTS

CIP2A mRNA was present in 54 of 70 (77.14%) patients with newly diagnosed AML and in 11 of 14 (70.86%) patients with relapsed AML, which was significantly higher than complete remission specimens and healthy controls (P<0.001). Knock-down of CIP2A in HL60 cells slowed down cell proliferation, decreased clonogenic activity and promoted cell differentiation.

CONCLUSION

These results suggest that CIP2A is over-expressed in patients with newly diagnosed/relapsed AML and the expression of CIP2A could have potential use as a clinical marker for AML relapse after treatment. The high expression of CIP2A in HL60 cells may be related to active cell proliferation and arrest of cell differentiation. This study may shed light on the molecular function of CIP2A in myeloid leukemogenesis.

Clinical features of atopic dermatitis in a hospital-based setting in China

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. There have been few detailed reports of the clinical evaluation of Chinese patients with AD.

OBJECTIVES

To give a profile of the clinical features of Chinese AD patients in a university hospital setting.

METHODS

A total of 1008 cases met Hanifin and Rajka diagnostic criteria of AD were recruited at Xinhua Hospital, Shanghai Jiaotong University School of Medicine, China.

RESULTS

In our survey, 22.7% patients were mild, 66.6% were moderate and 10.7% were severe according to the SCORAD index. Both the frequency and severity of the male patients were slightly higher. The frequency of asthma among the AD patients was 16.7% and it was increased with the age (χ2 = 205.20, P = 0.000). The frequencies of objective minor signs were demonstrated with age-related changes. Besides, three localized variants including eyelid eczema (49.8%), scalp dermatitis (49.7%), infra-auricular and retroauricular fissuring (44.8%) were commonly observed, especially in the infantile phase (P < 0.01). It was showed significant differences in serum total immunoglobulin E (IgE) and eosinophil cationic protein (ECP) levels of different age groups. The positive rate of Phadiatop was raised after 3 years old and that of the common food allergens were decreased after 6 years old.

CONCLUSIONS

More males than females had ongoing AD in our survey. Most AD debuted in the first year of the cases. High incidence of the three clinical signs: eyelid eczema, scalp dermatitis and infra-auricular and retroauricular fissuring among the patients suggests it can be a potential valuable diagnostic clue to AD.

Adenosine 2A receptor is protective against renal injury in MRL/lpr mice

OBJECTIVE

Adenosine is considered as a potent endogenous anti-inflammatory and immunosuppressive molecule. We examined the roles of A2A-adenosine receptor (A(2A)R) in the progression of lupus nephritis.

METHODS

MRL/lpr mice were given a selective A(2A)R agonist, CGS21680 (0.4 mg/kg per day, i.p.) while control mice received saline only. After 8 weeks of treatment, mice were sacrificed for assessment of functional and histological parameters as well as inflammatory infiltration in the kidneys. MCP-1, IFN-γ, MHC-II and A(2A)R mRNA expression was evaluated by RT-PCR. Expression of A(2A)R and nuclear NFκB p65 protein was determined by Western blot analysis. Levels of anti-dsDNA antibody and IFN-γ were measured by ELISA.

RESULTS

CGS21680 treatment resulted in significant decrease in proteinuria, blood urea and creatinine as well as improvement in renal histology. Renal macrophage and T-cell infiltration were significantly attenuated in association with suppressed expression of MCP-1, IFN-γ and MHC-II. CGS21680 treatment reduced the level of serum anti-dsDNA and renal immune complex deposition. CGS21680 inhibited the activation of NFκB and suppressed the expression of IFN-γ, MCP-1 and MHC-II in MRL/lpr splenocytes.

CONCLUSIONS

A(2A)R activation suppressed inflammation in the kidneys of MRL/lpr mice and can be considered as a novel therapeutic approach for human lupus nephritis.