An Atypical Tropomyosin in Drosophila with Intermediate Filament-like Properties

A longstanding mystery has been the absence of cytoplasmic intermediate filaments (IFs) from Drosophila despite their importance in other organisms. In the course of characterizing the in vivo expression and functions of Drosophila Tropomyosin (Tm) isoforms, we discovered an essential but unusual product of the Tm1 locus, Tm1-I/C, which resembles an IF protein in some respects. Like IFs, Tm1-I/C spontaneously forms filaments in vitro that are intermediate in diameter between F-actin and microtubules. Like IFs but unlike canonical Tms, Tm1-I/C contains N- and C-terminal low-complexity domains flanking a central coiled coil. In vivo, Tm1-I/C forms cytoplasmic filaments that do not associate with F-actin or canonical Tms. Tm1-I/C is essential for collective border cell migration, in epithelial cells for proper cytoarchitecture, and in the germline for the formation of germ plasm. These results suggest that flies have evolved a distinctive type of cytoskeletal filament from Tm.

Gender-related impact on outcomes of high density lipoprotein in acute ST-elevation myocardial infarction

BACKGROUND AND AIMS

There is rising evidence that cardioprotective functions of high-density lipoprotein (HDL) have significant impact on clinical outcomes. ST-elevation myocardial infarction (STEMI) represents a high-risk vascular condition. Whether higher HDL-cholesterol concentrations in women correspond to protective anti-oxidant properties in the setting of STEMI is unknown.

METHODS

We prospectively assessed gender related differences in the anti-oxidant function of HDL, and the impact of HDL properties on mortality in 242 women and men with STEMI. Blood samples to determine HDL function and sex hormone levels were collected during primary percutaneous coronary intervention.

RESULTS

Patients were stratified according to preserved anti-oxidant HDL function (HDL oxidant index (HOI) < 1) and pro-oxidant HDL (HOI≥1). Despite higher serum levels of HDL-cholesterol in postmenopausal women (48 mg/dl, IQR 42-54, versus 39 mg/dl, IQR33-47, p < 0.001 in men), the proportion of patients with pro-oxidant HDL was not different between women (35%) and men (46%, p = 0.132). Kaplan-Meier analysis revealed higher cardiovascular mortality in both women (p = 0.021) and men (p = 0.045) with pro-oxidant HDL. We identified pro-oxidant HDL as strong and independent predictor of cardiovascular mortality with an adjusted HR of 8.33 (95% CI, 1.55-44.63; p = 0.013) in women and with an adjusted HR of 5.14 (95% CI, 1.61-16.42; p = 0.006) in men. Higher levels of free sex hormones (estradiol and testosterone) were associated with pro-oxidant HDL. HDL-cholesterol levels showed no association with mortality (HR in women 1.03, 95% CI 0.96-1.11, p = 0.45 and HR in men 0.99, 95% CI 0.94-1.05, p = 0.72).

CONCLUSIONS

Total HDL-cholesterol serum levels were not associated with mortality in STEMI patients. Pro-oxidant HDL was a strong and independent predictor of mortality in women and men with STEMI. The present study provides a link between sex hormones, HDL function and clinical events in STEMI patients. In clinical practice and future clinical trials, anti-oxidant properties of HDL rather than total HDL serum levels should be used for risk stratification.

Prevalence and molecular characterisation of Giardia duodenalis in calves with diarrhoea

The aim of this study was to investigate the prevalence of Giardia duodenalis in diarrhoeal faeces from calves that were reared in Korea using PCR and ELISA. Diarrhoeal faecal samples were collected from 590 calves (<3 months old) throughout the country from November 2013 through March 2015. Data were analysed according to the region of collection, season, and type of diarrhoea. Of the 590 collected faecal samples, 77 (13.1 per cent) and 78 (13.2 per cent; true prevalence 9.1 per cent) tested positive by PCR and ELISA, respectively. The results from both testing methods were in agreement in 501 (84.9 per cent) samples, with a κ value of 0.34, which suggests fair agreement. The PCR results showed a higher prevalence in summer and in cases of haemorrhagic diarrhoea (P<0.05), while the ELISA results showed a lower prevalence in cases of pasty diarrhoea (P<0.05). Phylogenetic analysis of the β-giardin gene sequences of G duodenalis showed that the sequences detected in this study belonged to assemblage E, which is specific to cattle and livestock. The higher prevalence of giardiasis in calves with haemorrhagic diarrhoea found in this study differed from previous studies. Therefore, researchers and veterinarians should be aware of the possible involvement of giardiasis in haemorrhagic diarrhoea.

Conditional TNF-α Overexpression in the Tooth and Alveolar Bone Results in Painful Pulpitis and Osteitis

Tumor necrosis factor-α (TNF-α) is a proalgesic cytokine that is commonly expressed following tissue injury. TNF-α expression not only promotes inflammation but can also lead to pain hypersensitivity in nociceptors. With the established link between TNF-α and inflammatory pain, we identified its increased expression in the teeth of patients affected with caries and pulpitis. We generated a transgenic mouse model (TNF-α(glo)) that could be used to conditionally overexpress TNF-α. These mice were bred with a dentin matrix protein 1 (DMP1)-Cre line for overexpression of TNF-α in both the tooth pulp and bone to study oral pain that would result from subsequent development of pulpitis and bone loss. The resulting DMP1/TNF-α(glo) mice show inflammation in the tooth pulp that resembles pulpitis while also displaying periodontal bone loss. Inflammatory infiltrates and enlarged blood vessels were observed in the tooth pulp. Pulpitis and osteitis affected the nociceptive neurons innervating the orofacial region by causing increased expression of inflammatory cytokines within the trigeminal ganglia. With this new mouse model morphologically mimicking pulpitis and osteitis, we tested it for signs of oral pain with an oral function assay (dolognawmeter). This assay/device records the time required by a mouse to complete a discrete gnawing task. The duration of gnawing required by the DMP1/TNF-α(glo) mice to complete the task was greater than that for the controls; extended gnaw time in a dolognawmeter indicates reduced orofacial function. With the DMP1/TNF-α(glo) mice, we have shown that TNF-α expression alone can produce inflammation similar to pulpitis and osteitis and that this mouse model can be used to study dental inflammatory pain.

MR Angiographic-Guided Percutaneous Sclerotherapy for Venous Vascular Malformations: A Radiation Dose-Reduction Strategy

We present a new technique using MRA instead of the usual DSA to provide guidance in the treatment of venous vascular malformations. When one performs this embolization procedure, appropriate needle positioning within the malformation must be confirmed before injection of the sclerosing agent to prevent untoward complications. Time-resolved imaging of contrast kinetics-MRA can accurately depict the angioarchitecture of the lesion, which substantially reduces the total radiation dose in these patients who are commonly in the pediatric age group and usually require numerous treatment episodes.

Clinical applications of next-generation sequencing-based gene panel in patients with muscular dystrophy: Korean experience

Muscular dystrophy (MD) is a genetically and clinically heterogeneous group of disorders. Here, we performed targeted sequencing of 18 limb-girdle MD (LGMD)-related genes in 35 patients who were highly suspected of having MD. We identified one or more pathogenic variants in 23 of 35 patients (65.7%), and a genetic diagnosis was performed in 20 patients (57.1%). LGMD2B was the most common LGMD type, followed by LGMD1B, LGMD2A, and LGMD2G. Among the three major LGMD types in this group, LGMD1B was correlated with the lowest creatine kinase (CK) levels and the earliest onset, whereas LGMD2B was correlated with the highest CK levels and the latest onset. Thus, next-generation sequencing-based gene panels can be a helpful tool for the diagnosis of MDs, particularly in young children and those displaying atypical symptoms.