Mutations in LPAR6/P2RY5 and LIPH are associated with woolly hair and/or hypotrichosis

Background Woolly hair (WH) belongs to a family of disorders characterized by hair shaft anomalies that clinically presents with tightly curled hair, which can be divided into syndromic and non‐syndromic forms of WH. We have recently identified mutations in both LPAR6/P2RY5 and LIPH that are associated with autosomal recessive woolly hair (ARWH). Objective To study the underlying genetic causes of autosomal woolly hair in Pakistani population. Methods We studied 10 Pakistani families with ARWH for mutations in LPAR6/P2RY5 and LIPH and then performed haplotype analysis to confirm their segregation in the families. Results We identified five mutations in LPAR6/P2RY5, among which three were recurrent and two were novel in eight Pakistani families. We then showed that two of the mutations in LPAR6/P2RY5 are founder mutations in Pakistani families. Moreover, we identified two recurrent mutations in the LIPH gene in two Pakistani families. Conclusion Our study extends the spectrum of mutations in LPAR6/P2RY5 gene and underscores those mutations in LPAR6/P2RY5 and LIPH result in similar phenotypes.     

Delayed improvement of autonomic nervous abnormality after the Maze procedure: time and frequency domain analysis of heart rate variability using 24 hour Holter monitoring

Objective—To analyse heart rate variability in patients with atrial fibrillation after the Maze procedure, to investigate whether the procedure damages the cardiac autonomic fibres supplying the sinus node.
Design and patients—Time and frequency domain analyses of RR variability were performed using 24 hour Holter monitoring one month after surgery in 12 patients with atrial fibrillation who underwent the Maze procedure (Maze group) and in seven patients who underwent cardiac surgery without the Maze procedure (control group). Mean RR intervals (mRR) and the standard deviation of successive RR intervals (SDRR) were determined by time domain analysis, and high frequency (HF), low frequency (LF), and total power (TP) spectral components of RR variability were calculated by frequency domain analysis. Holter monitoring was also performed at six and 12 months after cardiac surgery in the Maze group.
Results—Circadian variation (mean (SD)) in mRR (daytime to night time difference: 119 (60) v 302 (143) ms), SDRR (daytime: 8.4 (3.3) v 37.0 (12.0) ms), TP (daytime: 46.7 (16.0) v 171.8 (30.4) ms), HF (daytime: 19.6 (9.9) v 36.7 (7.1) ms²), and LF/HF (daytime: 0.31 (0.07) v 1.18 (0.46)) was decreased in the Maze group at one month compared with the control group (p < 0.01), but showed improvement at six and 12 months (p < 0.05).
Conclusions—Surgery combined with the Maze procedure markedly suppressed the circadian variation of heart rate over a 24 hour period within one month after surgery, mainly because of damage to the innervation of the sinus node. However, at six and 12 months there was restoration of circadian variation, probably as the result of reinnervation of the sinus node.

Keywords: autonomic nervous system;  heart rate variability;  Maze procedure     

Cardiac sarcoidosis underlies idiopathic dilated cardiomyopathy: importance of mediastinal lymphadenopathy in differential diagnosis.

BACKGROUND: Cardiac sarcoidosis is frequently overlooked or misdiagnosed as idiopathic dilated cardiomyopathy (DCM), primarily because of difficulties in its diagnosis. This is a crucial issue because appropriate therapy with immunosuppressive agents can be initiated if early diagnosis is achieved. METHODS AND RESULTS: Thoracic computed tomography (CT) was retrospectively analyzed in detail with special reference to lymph node swelling (LNS) in the mediastinum of 8 patients diagnosed with idiopathic DCM who underwent left ventriculoplasty (LVP), and were later proven to have active cardiac sarcoidosis by histological evaluation of the resected myocardium. Twenty age-matched patients with idiopathic DCM who also underwent LVP served as controls. On conventional chest radiographs, none of the cardiac sarcoidosis patients exhibited lymph node involvement, including bilateral hilar lymphadenopathy. However, CT demonstrated significant mediastinal LNS in 7 (88%) of them and in only 1 (5%) of the 20 controls. There was a significant difference in the incidence of LNS in the 2 groups (p=0.00005). CONCLUSION: Evaluation of mediastinal lymphadenopathy by CT is an easy and valuable initial screening method for distinguishing cardiac sarcoidosis from idiopathic DCM.     

Chronic persistent Epstein-Barr virus infection of natural killer cells and B cells associated with granular lymphocytes expansion

B lymphocytes and epithelial cells are the only cell types known to be infected with Epstein-Barr virus (EBV) in normal individuals. Rarely, EBV also infects other cells, including natural killer (NK) cells, almost always in the context of fatal leukaemias or lymphoproliferative disorders. We report on a 6-year-old previously healthy girl who developed fevers and liver function abnormalities for 3 months. The peripheral blood revealed an abnormal expansion of large granular lymphocytes, comprising 24% of the white blood cells. Flow cytometric analysis of the peripheral blood mononuclear cells showed an abnormal increase of CD16-positive NK cells, 62% of which were EBV-infected by in situ EBER-1 hybridization. The circulating B cells were normal in number, but 18% were infected with EBV by in situ EBER-1 hybridization. Approximately 2 years after resolution of all symptoms and continued good health, 35% of the circulating mononuclear cells were EBV-infected, indicative of persistent expansion of EBV-infected cells. We conclude that abnormal expansions of EBV-infected NK and B cells can be associated with a chronic benign course.     

50-kD integrin-associated protein does not detectably influence several functions of glycoprotein IIb-IIIa complex in human platelets

A 50-kD integrin-associated protein (IAP) has been reported to be associated with beta 3 integrins and to modulate their function, especially vitronectin receptor in human erythroleukemia (HEL) cells and leukocyte response integrin in neutrophils. We studied the involvement of IAP in the function of platelet beta 3 integrin, glycoprotein (GP) IIb-IIIa complex. IAP was a widely distributed protein and was also expressed in the cells that do not have beta 3 integrin. Platelets from a patient with thrombasthenia, which lack GPIIb and IIIa, expressed IAP as well as normal platelets. Neither platelet aggregation nor intracellular Ca2+ elevation after stimulation was influenced by the anti-IAP antibody, B6H12, which was reported to be inhibitory for other beta 3 integrins. The expression level of GPIIb- IIIa complex was not influenced by coexpression of human IAP in the transfected Chinese hamster ovary (CHO) cells. IAP did not facilitate the binding of soluble fibrinogen to the CHO cells expressing GPIIb- IIIa complex. Furthermore, cell adhesion onto the immobilized fibrinogen via GPIIb-IIIa complex was not inhibited by B6H12 in HEL cells and was not altered by coexpression of human IAP in CHO cells. We concluded that expression of IAP is regulated independently with that of GPIIb-IIIa complex and that IAP does not influence the function of GPIIb-IIIa complex.     

Adipocyte-derived plasma protein adiponectin acts as a platelet-derived growth factor-BB-binding protein and regulates growth factor-induced common postreceptor signal in vascular smooth muscle cell

BACKGROUND: Vascular smooth muscle cell proliferation plays an important role in the development of atherosclerosis. We previously reported that adiponectin, an adipocyte-specific plasma protein, accumulated in the human injured artery and suppressed endothelial inflammatory response as well as macrophage-to-foam cell transformation. The present study investigated the effects of adiponectin on proliferation and migration of human aortic smooth muscle cells (HASMCs). Methods and Results- HASMC proliferation was estimated by [(3)H] thymidine uptake and cell number. Cell migration assay was performed using a Boyden chamber. Physiological concentrations of adiponectin significantly suppressed both proliferation and migration of HASMCs stimulated with platelet-derived growth factor (PDGF)-BB. Adiponectin specifically bound to (125)I-PDGF-BB and significantly inhibited the association of (125)I-PDGF-BB with HASMCs, but no effects were observed on the binding of (125)I-PDGF-AA or (125)I-heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) to HASMCs. Adiponectin strongly and dose-dependently suppressed PDGF-BB-induced p42/44 extracellular signal-related kinase (ERK) phosphorylation and PDGF beta-receptor autophosphorylation analyzed by immunoblot. Adiponectin also reduced PDGF-AA-stimulated or HB-EGF-stimulated ERK phosphorylation in a dose-dependent manner without affecting autophosphorylation of PDGF alpha-receptor or EGF receptor. CONCLUSIONS: The adipocyte-derived plasma protein adiponectin strongly suppressed HASMC proliferation and migration through direct binding with PDGF-BB and generally inhibited growth factor-stimulated ERK signal in HASMCs, suggesting that adiponectin acts as a modulator for vascular remodeling.