Lipaemic serum in Hb E-Beta thalassaemia major: A rare case of hypertriglyceridaemia thalassaemia syndrome

INTRODUCTION

A 1-year-old Malay girl presented with pallor, failure to thrive and hepatosplenomegaly. Her blood was sent for thalassaemia screening and it was incidentally found that her blood appeared lipaemic.

CASE REPORT

Primary and secondary causes of hyperlipidaemia were investigated. Her blood was sent for fasting lipid profile, thyroid function test (TFT), fasting plasma glucose (FPG), liver function test (LFT), renal profile (RP) and HIV screening. Lipaemic interference was removed by high-speed centrifugation. She is a product of non-consanguineous marriage. She is staying together with her stepfather who is HIV positive. Her mother's infective status was negative with no dyslipidaemic features and a normal lipid profile. Lipid profile of her biological father was not known. No other lipid stigmata such as eruptive xanthoma or lipaemia retinalis was seen in the patient. Haemoglobin analysis showed Hb E-Beta thalassaemia major. Her triglycerides was 9.05 mmol/L with normal total cholesterol, 2.85 mmol/L and high-density lipoprotein cholesterol (HDL-c), 0.26 mmol/L. Calculated low-density lipoprotein cholesterol (LDL-c) was invalid as triglycerides was >4.5 mmol/L. TFT, RP, FPG, LFT were normal and HIV status was negative. She was transfused with 10 ml/kg packed cell and her blood post transfusion appeared non lipaemic.

CONCLUSION

Primary hypertriglyceridaemia was excluded based on insignificant family history of dyslipidaemia. Secondary causes of hypertriglyceridaemia were ruled out based on unremarkable laboratory investigations. Thus, we conclude that this patient is having hypertriglyceridaemia thalassaemia syndrome (HTS) which is a rare disorder with unknown pathogenesis. Further research may be required to explore this unknown association.

Ursodeoxycholic acid upregulates ERK and Akt in the protection of cardiomyocytes against CoCl2

Ursodeoxycholic acid (UDCA) is used to treat liver diseases and demonstrates cardioprotective effects. Accumulation of the plasma membrane sphingolipid sphingomyelin in the heart can lead to atherosclerosis and coronary artery disease. Sphingomyelinases (SMases) break down sphingomyelin, producing ceramide, and inhibition of SMases activity can promote cell survival. We hypothesized that UDCA regulates activation of ERK and Akt survival signaling pathways and SMases in protecting cardiac cells against hypoxia. Neonatal cardiomyocytes were isolated from 0- to 2-day-old Sprague Dawley rats, and given 100 μM CoCl2, 150 μM H2O2, or placed in a hypoxia chamber for 24 h. The ameliorative effects of 100-μM UDCA treatment for 12 h were then assessed using MTS, QuantiGene Plex (for Smpd1 and Smpd2), and SMase assays, beating rate assessment, and western blotting (for ERK and Akt). Data were analyzed by the paired Student t-tests and one-way analyses of variance. Cell viability decreased significantly after H2O2 (85%), CoCl2 (50%), and hypoxia chamber (52%) treatments compared to the untreated control (100%). UDCA significantly counteracted the effects of chamber- and CoCl2- induced hypoxia on viability and beating rate. However, no significant differences were observed in acid SMase gene and protein expression between the untreated, CoCl2, and UDCA-CoCl2 groups. In contrast, neutral SMase gene and protein expression did significantly differ between the latter two groups. ERK and Akt phosphorylation was higher in hypoxic cardiomyocytes treated with UDCA than those given CoCl2 alone. In conclusion, UDCA regulates the activation of survival signaling proteins and SMases in neonatal rat cardiomyocytes during hypoxia.

Scanning ion conductance microscopy: a convergent high-resolution technology for multi-parametric analysis of living cardiovascular cells

Cardiovascular diseases are complex pathologies that include alterations of various cell functions at the levels of intact tissue, single cells and subcellular signalling compartments. Conventional techniques to study these processes are extremely divergent and rely on a combination of individual methods, which usually provide spatially and temporally limited information on single parameters of interest. This review describes scanning ion conductance microscopy (SICM) as a novel versatile technique capable of simultaneously reporting various structural and functional parameters at nanometre resolution in living cardiovascular cells at the level of the whole tissue, single cells and at the subcellular level, to investigate the mechanisms of cardiovascular disease. SICM is a multimodal imaging technology that allows concurrent and dynamic analysis of membrane morphology and various functional parameters (cell volume, membrane potentials, cellular contraction, single ion-channel currents and some parameters of intracellular signalling) in intact living cardiovascular cells and tissues with nanometre resolution at different levels of organization (tissue, cellular and subcellular levels). Using this technique, we showed that at the tissue level, cell orientation in the inner and outer aortic arch distinguishes atheroprone and atheroprotected regions. At the cellular level, heart failure leads to a pronounced loss of T-tubules in cardiac myocytes accompanied by a reduction in Z-groove ratio. We also demonstrated the capability of SICM to measure the entire cell volume as an index of cellular hypertrophy. This method can be further combined with fluorescence to simultaneously measure cardiomyocyte contraction and intracellular calcium transients or to map subcellular localization of membrane receptors coupled to cyclic adenosine monophosphate production. The SICM pipette can be used for patch-clamp recordings of membrane potential and single channel currents. In conclusion, SICM provides a highly informative multimodal imaging platform for functional analysis of the mechanisms of cardiovascular diseases, which should facilitate identification of novel therapeutic strategies.