Movement characteristics of the tennis volley

PURPOSE

The purpose of this study was to examine selected movement characteristics of the tennis volley by evaluating temporal and ground reaction force (GRF) parameters.

METHODS

Seven skilled tennis players performed volley strokes under 18 experimental conditions including variations in lateral contact location (forehand (FH) and backhand (BH)), ball contact height (high, middle, low), and ball speed (fast, medium, slow). A ball machine was modified so that the subjects could not predict the ball trajectory before it was released from the machine. The GRF and temporal parameters were determined using two force platforms and two high-speed (120 Hz) video cameras, respectively. Average and maximum values of each measured parameter were computed for different phases of the volley.

RESULTS

The average reaction times (from ball release to initial racquet movement (IRM)) for FH and BH trials were 226 and 205 ms, respectively, and the difference was statistically significant. The average stroke time (from IRM to ball impact) ranged from 381 ms in fast speed trials to 803 ms in slow speed trials. A distinct racquet forward motion immediately before ball impact occurred in 75% of the trials and they were evenly distributed between FH and BH trials. An ipsilateral side step (a side step of the foot on the same side of the oncoming ball before the crossover step of the other foot) occurred more often in FH (45%) than in BH (34%) trials.

CONCLUSIONS

The GRF during the stroke phase suggest that the subjects initiated lateral movement by leaning sideward when ball velocity was low and by a vigorous pushoff of the contralateral foot when ball velocity was high.

Ruptured giant intrathoracic lipoblastoma in a 4-month-old infant: CT and MR findings

BACKGROUND

We describe a 4-month-old infant with a ruptured intrathoracic lipoblastoma arising from the parietal pleura and associated with a pleural effusion.

OBJECTIVE

The clinical presentation was rapidly evolving respiratory distress. The chest radiograph showed a large mass and a pleural effusion in the right thoracic cavity. CT demonstrated an inhomogeneous low-attenuation mass which was 7 cm in diameter and which showed areas of enhancement after intravenous contrast medium. MRI showed a fatty intrathoracic mass with intratumoral streaks and whorls, which were attributed to loose fibrovascular connective tissue on pathological examination.

RESULTS

Thoracotomy and pathological examination revealed a ruptured intrathoracic lipoblastoma arising from the parietal pleura.

CONCLUSION

The pleural effusion might have suggested rupture of the tumour.

Assessment of colorectal cancer knowledge and patient attitudes towards screening: is Ireland ready to embrace colon cancer screening?

INTRODUCTION

The level of awareness among the Irish public regarding colorectal cancer (CRC) remains uncertain. This study aimed to characterise CRC knowledge levels among a cohort of Irish patients.

METHODS

A survey evaluating CRC knowledge levels was distributed among outpatients at a gastroenterology clinic in a Dublin teaching hospital.

RESULTS

In total, 472 surveys were distributed of which 465 (98.5%) were returned. Twenty-nine percent of respondents correctly judged CRC to be the commonest cause of cancer death among the options provided while 26% correctly judged the lifetime risk of CRC; 59% underestimated and 15% overestimated the risk. Most patients (91%) were willing to pay 300 euros for a prompt colonoscopy if recommended by their physician while 7% opted to wait 6 months for a free colonoscopy.

CONCLUSIONS

There is a willingness to embrace CRC screening and to shoulder some of the financial burden that this entails.

System Biology-Guided Chemical Proteomics to Discover Protein Targets of Monoethylhexyl Phthalate in Regulating Cell Cycle

Chemical proteomics methods have been used as effective tools to identify novel protein targets for small molecules. These methods have great potential to be applied as environmental toxicants to figure out their mode of action. However, these assays usually generate dozens of possible targets, making it challenging to validate the most important one. In this study, we have integrated the cellular thermal shift assay (CETSA), quantitative proteomics, metabolomics, computer-assisted docking, and target validation methods to uncover the protein targets of monoethylhexyl phthalate (MEHP). Using the mass spectrometry implementation of CETSA (MS-CETSA), we have identified 74 possible protein targets of MEHP. The Gene Ontology (GO) enrichment integration was further conducted for the target proteins, the cellular dysregulated proteins, and the metabolites, showing that cell cycle dysregulation could be one primary change due to the MEHP-induced toxicity. Flow cytometry analysis confirmed that hepatocytes were arrested at the G1 stage due to the treatment with MEHP. Subsequently, the potential protein targets were ranked by their binding energy calculated from the computer-assisted docking with MEHP. In summary, we have demonstrated the development of interactomics workflow to simplify the redundant information from multiomics data and identified novel cell cycle regulatory protein targets (CPEB4, ANAPC5, and SPOUT1) for MEHP.

Can bone turnover markers correlate bone mass at the hip and spine according to menopausal period?

Changes in bone turnover with years since menopause (YSM) are responsible for bone loss and play a major role in osteoporosis. Although single measurements of the bone turnover marker appear unlikely to be clinically useful in predicting bone mineral density, the usefulness of these measurements in relation to the YSM has not been well established. The establishment of this relationship was the aim of this study. To address this issue, we have measured a battery of sensitive and specific markers of bone turnover in 272 women postmenopausal from -5 to 15 a, and the data was correlated with bone mineral density (BMD) at different skeletal sites measured utilizing dual-energy X-ray absorptiometry (DXA). Bone formation was assessed by serum osteocalcin (OC), and bone resorption by Pyr and D-pyr. The three markers and BMD were compared between the groups (YSM). Among the three markers, only Pyr exhibited a significant difference between pre and postmenopausal groups. In the aspect of correlation between bone turnover marker and BMD according to the groups (YSM), we found negative strong correlations between the BMD of lumbar spine (L2-4) vs. Pyr (P=0.01, r=-0.75) in the premenopausal group (-5 approximately 0 YSM), and we found negative correlation between the BMD of L2-4 vs. osteocalcin (P=0.05, r=-0.2 and P=0.01, r=-4).44) in the postmenopause groups (0 approximately 5 and 5 approximately 10 YSM). We concluded that Pyr in women -5 approximately 0 YSM and osteocalcin in women 0 approximately 10 YSM displayed negative correlation with BMD of L2-4.

A Novel Mechanism of Monoethylhexyl Phthalate in Lipid Accumulation via Inhibiting Fatty Acid Beta-Oxidation on Hepatic Cells

Monoethylhexyl phthalate (MEHP) is one of the main active metabolites of the plasticizer di(2-ethylhexyl) phthalate. It has been known that MEHP has an impact on lipolysis; however, its mechanism on the cellular lipid metabolism remains largely unclear. Here, we first utilized global lipid profiling to fully characterize the lipid synthesis and degradation pathways upon MEHP treatment on hepatic cells. Meanwhile, we further identified the possible MEHP-targeted proteins in living cells using the cellular thermal shift assay (CETSA) method. The lipidomics results showed that there was a significant accumulation of fatty acids and other lipids in the cell. The CETSA identified 18 proteins and fatty acid β-oxidation inhibition pathways that were significantly perturbed. MEHP's binding with selected proteins HADH and HSD17B10 was further evaluated using molecule docking, and results showed that MEHP has higher affinities as compared to endogenous substrates, which was further experimentally confirmed in the surface plasma resonance interaction assay. In summary, we found a novel mechanism for MEHP-induced lipid accumulation, which was probably due to its inhibitive effects on the enzymes in fatty acid β-oxidation. This mechanism substantiates the public concerns on the high exposure level to plasticizers and their possible role as an obesogen.

Domain-specific p53 mutants activate EGFR by distinct mechanisms exposing tissue-independent therapeutic vulnerabilities

Mis-sense mutations affecting TP53 promote carcinogenesis both by inactivating tumor suppression, and by conferring pro-carcinogenic activities. We report here that p53 DNA-binding domain (DBD) and transactivation domain (TAD) mis-sense mutants unexpectedly activate pro-carcinogenic epidermal growth factor receptor (EGFR) signaling via distinct, previously unrecognized molecular mechanisms. DBD- and TAD-specific TP53 mutants exhibited different cellular localization and induced distinct gene expression profiles. In multiple tissues, EGFR is stabilized by TAD and DBD mutants in the cytosolic and nuclear compartments respectively. TAD mutants promote EGFR-mediated signaling by enhancing EGFR interaction with AKT via DDX31 in the cytosol. Conversely, DBD mutants maintain EGFR activity in the nucleus, by blocking EGFR interaction with the phosphatase SHP1, triggering c-Myc and Cyclin D1 upregulation. Our findings suggest that p53 mutants carrying gain-of-function, mis-sense mutations affecting two different domains form new protein complexes that promote carcinogenesis by enhancing EGFR signaling via distinctive mechanisms, exposing clinically relevant therapeutic vulnerabilities.

Value of troponin-T rapid assay, cardiac enzymes, electrocardiogram and history of chest pain in the initial diagnosis of myocardial infarction in the emergency department

We conducted a prospective study of 152 adult patients presenting to an emergency department with chest pain or symptoms suggestive of acute myocardial infarction (AMI) to evaluate the first electrocardiogram (ECG), creatine kinase (CK)-MB and Troponin-T Rapid Assay (TnT) alone or in combination with chest pain in the initial diagnosis of AMI. A provisional diagnosis was made after the history, physical examination and the first ECG reading. Blood specimens were taken for TnT, CK and CK-MB mass. A final discharge diagnosis of AMI was made according to World Health Organization criteria. Seventy-six (50%) of patients had a final diagnosis of AMI. The sensitivities of the first ECG, first CK-MB mass and first TnT were 76.3% (95% confidence interval (CI), 66.8-85.9), 38.2% (95% CI, 27.2-49.1) and 31.6% (95% CI, 21.2-42.0) respectively. The area under the curve for a combination of ECG, CK-MB mass, TnT and chest pain was the highest at 0.937 when compared with chest pain with varying combinations of tests. A combination of the first ECG, CK-MB mass and TnT had a negative predictive value (NPV) of 87.9% (95% CI, 80.0-95.8). The first ECG was the most sensitive test while the combination of chest pain, ECG, cardiac enzymes and TnT gave the best results in the initial diagnosis of AMI. If the first ECG, CK-MB mass and TnT are all negative, the probability of having an AMI is 12%.

Complete Sequences of the Velvet Worm Slime Proteins Reveal that Slime Formation is Enabled by Disulfide Bonds and Intrinsically Disordered Regions

The slime of velvet worms (Onychophora) is a strong and fully biodegradable protein material, which upon ejection undergoes a fast liquid-to-solid transition to ensnare prey. However, the molecular mechanisms of slime self-assembly are still not well understood, notably because the primary structures of slime proteins are yet unknown. Combining transcriptomic and proteomic studies, the authors have obtained the complete primary sequences of slime proteins and identified key features for slime self-assembly. The high molecular weight slime proteins contain cysteine residues at the N- and C-termini that mediate the formation of multi-protein complexes via disulfide bonding. Low complexity domains in the N-termini are also identified and their propensity for liquid-liquid phase separation is established, which may play a central role in slime biofabrication. Using solid-state nuclear magnetic resonance, rigid and flexible domains of the slime proteins are mapped to specific peptide domains. The complete sequencing of major slime proteins is an important step toward sustainable fabrication of polymers inspired by the velvet worm slime.

Phosphosites of the yeast centrosome component Spc110 contribute to cell cycle progression and mitotic exit

Spc110 is an essential component of the spindle pole body (SPB), the yeast equivalent of the centrosome, that recruits the γ-tubulin complex to the nuclear side of the SPB to produce the microtubules that form the mitotic spindle. Here, we identified phosphosites S11 and S36 in maternally originated Spc110 and explored their functions in vivo. Yeast expressing non-phosphorylatable Spc110^S11A had a distinct spindle phenotype characterised by higher levels of α-tubulin, which was frequently asymmetrically distributed between the two SPBs. Furthermore, expression of the double mutant Spc110^S11AS36A had a delayed cell cycle progression. Specifically, the final steps of mitosis were delayed in Spc110^S11AS36A cells, including expression and degradation of the mitotic cyclin Clb2, disassembling the mitotic spindle and re-localizing Cdc14 to the nucleoli, resulting in late mitotic exit and entry in G1. Thus, we propose that Spc110 phosphorylation at S11 and S36 is required to regulate timely cell cycle progression in budding yeast.

This article has an associated First Person interview with the first author of the paper.

WNTinib is a multi-kinase inhibitor with specificity against β-catenin mutant hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. β-Catenin (CTNNB1)-mutated HCC represents 30% of cases of the disease with no precision therapeutics available. Using chemical libraries derived from clinical multi-kinase inhibitor (KI) scaffolds, we screened HCC organoids to identify WNTinib, a KI with exquisite selectivity in CTNNB1-mutated human and murine models, including patient samples. Multiomic and target engagement analyses, combined with rescue experiments and in vitro and in vivo efficacy studies, revealed that WNTinib is superior to clinical KIs and inhibits KIT/mitogen-activated protein kinase (MAPK) signaling at multiple nodes. Moreover, we demonstrate that reduced engagement on BRAF and p38α kinases by WNTinib relative to several multi-KIs is necessary to avoid compensatory feedback signaling-providing a durable and selective transcriptional repression of mutant β-catenin/Wnt targets through nuclear translocation of the EZH2 transcriptional repressor. Our studies uncover a previously unknown mechanism to harness the KIT/MAPK/EZH2 pathway to potently and selectively antagonize CTNNB1-mutant HCC with an unprecedented wide therapeutic index.

Left bundle branch block and increased transverse:frontal plane QRS voltage ratio in severe left ventricular dysfunction

Six patients with complete left bundle branch block and an increase in the transverse:frontal plane QRS voltage ratio are described. All these patients presented with congestive heart failure which was due to severe left ventricular dysfunction.

Abstract 4303: Modulation of protein interaction states through the cell cycle

Global profiling of protein expression through the cell cycle has revealed subsets of periodically expressed proteins. However, expression levels alone only give a partial view of processes determining cellular events. The cell cycle progression events are to a large extent controlled by the dynamic biochemical interactions of proteins with physiological ligands such as other proteins, metabolites, lipids, nucleic acids or low molecular weight effectors. Using a proteome-wide implementation of the Cellular Thermal Shift Assay (CETSA) to study specific cell cycle phases in K562 cell, we uncover modulations of interaction states for more than 750 proteins along the cell cycle. Notably, many protein complexes are modulated in specific cell cycle phases, reflecting their roles in processes such as DNA replication, chromatin remodeling, transcription, translation, and nuclear membrane decomposition. Surprisingly, only small differences in interaction states were seen between G1 and G2 phases, suggesting similar hardwiring of biochemical processes in these two phases. The present work reveals novel molecular details of the cell cycle. CETSA, therefore emerge as a novel approach to discover cellular modulations during cancer development and therapy.

Citation Format: Lingyun Dai, Tianyun Zhao, Xavier Bisteau, Wendi Sun, Nayana Prabhu, Yan Ting Lim, Radoslaw Sobota, Philipp Kaldis, Pär Nordlund. Modulation of protein interaction states through the cell cycle [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4303.

Abstract 4386: CETSA as a new strategy to understand efficacy, adverse effects and resistance development of anticancer drugs

A key step of the action of most drugs is their binding (engagement) of the target protein(s). However, limitations in the available methods for directly accessing this critical step have added uncertainties in many stages of drug development.

We have developed a generic method for evaluating drug binding to target proteins in cells and tissues (Martinez Molina et al. Science, 341:84). The technique is based on the physical phenomenon of ligand-induced thermal stabilization of target proteins; the method is therefore called the cellular thermal shift assay (CETSA). The technique allows for the first time to directly measure the biophysical interactions between a drug and protein target in non- engineered cells and tissues. We show that using CETSA a range of critical factors for drug development can be addressed at the target engagement level, including drug transport and activation, off-target effects, drug resistance as well as drug distribution in cells, patient and animal tissues. Using quantitative mass-spectrometry, proteome-wide CETSA has been established which allows for off-target effects as well as downstream biochemistry to be discovered (Savitsk et al. Science, 346, 6205:1255784). Together the data supports that CETSA is likely to become a valuable tool for developing and understanding the action of cancer drugs in the future.

Citation Format: Pär Nordlund, Sara Lööf, Henritte Laursen, Anette Öberg, Johan Lengqvist, Rozbeh Jafari, Lingyun Dai, Ka DIam Go, Nayana Prabhu, Radoslaw Sobota, Andreas Larsson, Anna Jansson, Chris Heng Tan Soon, Lekshmy Sreekumar, Yan Ting Lim, Daniel Martines Molina. CETSA as a new strategy to understand efficacy, adverse effects and resistance development of anticancer drugs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4386.

Role of contrast-enhanced ultrasound in the evaluation of post-liver transplant vasculature

Liver transplantation is a frequently used treatment for patients with end-stage liver disease and ultrasound is often the first-line imaging technique for detection of vascular complications after liver transplant. Although colour Doppler ultrasound is a good screening method for evaluation of post-liver transplant vasculature, it has limitations in evaluating small-calibre vessels and vessels in close proximity. Contrast-enhanced ultrasound (CEUS) has been proposed to overcome these limitations by improving visualisation of post-liver transplant vasculature and reducing the number of false-positive cases, which necessitate unnecessary additional investigations such as computed tomography or angiography. Liver transplant anatomy and the wide array of post-transplant imaging findings on colour Doppler have already been well described but literature on the use of CEUS and its image interpretation remain scarce. This review aims to discuss the indications for CEUS after liver transplant, to demonstrate CEUS technique and familiarise readers with the imaging appearances of post-transplant vascular complications on CEUS.

High-sensitivity C-reactive protein is predictive of medium-term cardiac outcome in high-risk Asian patients presenting with chest pain syndrome without myocardial infarction

INTRODUCTION

High-sensitivity C-reactive protein (hs-CRP) has been shown to be predictive of cardiac events but data among Asians is comparatively few. We evaluated the role of hs-CRP in the prediction of adverse cardiac outcome in a cohort of high-risk patients presenting with chest pain syndrome without myocardial infarction (MI).

MATERIALS AND METHODS

Three hundred and forty-seven patients were prospectively recruited over an 18-month period and patients with MI as documented by serial electrocardiogram abnormalities, and creatinine kinase or troponin elevation were excluded. Mean follow-up duration was 901 +/- 306 days. Kaplan-Meier and Cox proportional hazards modelling were used to evaluate outcome and determine association with predictor variables.

RESULTS

The composite primary endpoint of cardiac mortality, non-fatal MI, cardiac failure or coronary revascularisation procedure (coronary artery bypass grafting or angioplasty) unrelated to the index admission was reached in 37 patients. History of previous MI (P = 0.002), presence of at least 1 coronary artery with > or =50% stenosis (P = 0.028) and elevated hs-CRP levels were associated with an adverse cardiac outcome (P = 0.001 for CRP in the upper quartile, and 0.002 for CRP > or = 1mg/L, respectively). None of the traditional cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, significant family history, smoking, male gender and increased age) was predictive. Multivariate modelling showed elevated hs-CRP to confer the highest risk for an adverse cardiac outcome (P <0.001).

CONCLUSION

Hs-CRP is useful in further stratifying high-risk multi-ethnic patients presenting with chest pain despite no evidence of MI. Close follow-up and aggressive management of these patients may be warranted.

Simultaneous thromboses of multiple coronary arteries in acute myocardial infarction

Simultaneous thrombotic occlusion of multiple coronary arteries in acute myocardial infarction is a well-recognised phenomenon. Studies have reported diffuse destabilisation of atherosclerotic plaques in patients with acute myocardial infarction, leading to the concept of "pan-coronaritis". The putative mechanism is attributed to a systemic thrombophilic and inflammatory state. We report the occurrence of this phenomenon in two middle-aged male patients.

A review of patients with a 'normal' coronary angiogram over a 3-year period

Over a period of 36 months, we detected 54 patients with normal coronary arteries or non-critical coronary artery stenosis within our study series of coronary angiography. We studied these patients to determine their clinical, electrocardiographic, stress testing and angiocardiographic characteristics. We detected among them a preponderance of female sex and a higher incidence of ethnic Indians. The majority of the patients studied had one or more coronary risk factors. 52% had a normal resting ECG. In those with a positive stress test and reports available for review, there is a near equal distribution of horizontal and J-type ST depression. Those patients with a positive treadmill tend to have a higher left ventricular end diastolic pressure (LVEDP) at cardiac catheterization. We also noted in this group of patients a higher proportion with a small distal left anterior descending artery. These patients also tend to have higher LVEDP even in the presence of normal left ventriculogram. Our current series suggests the possibility of raised left ventricular end-diastolic pressure and the presence of a "small distal left anterior descending artery" syndrome in association with patients with a 'false positive' treadmill test.

Dependency of NELF-E-SLUG-KAT2B epigenetic axis in breast cancer carcinogenesis

Cancer cells undergo transcriptional reprogramming to drive tumor progression and metastasis. Using cancer cell lines and patient-derived tumor organoids, we demonstrate that loss of the negative elongation factor (NELF) complex inhibits breast cancer development through downregulating epithelial-mesenchymal transition (EMT) and stemness-associated genes. Quantitative multiplexed Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins (qPLEX-RIME) further reveals a significant rewiring of NELF-E-associated chromatin partners as a function of EMT and a co-option of NELF-E with the key EMT transcription factor SLUG. Accordingly, loss of NELF-E leads to impaired SLUG binding on chromatin. Through integrative transcriptomic and genomic analyses, we identify the histone acetyltransferase, KAT2B, as a key functional target of NELF-E-SLUG. Genetic and pharmacological inactivation of KAT2B ameliorate the expression of EMT markers, phenocopying NELF ablation. Elevated expression of NELF-E and KAT2B is associated with poorer prognosis in breast cancer patients, highlighting the clinical relevance of our findings. Taken together, we uncover a crucial role of the NELF-E-SLUG-KAT2B epigenetic axis in breast cancer carcinogenesis.