Comparison of green pit viper and Agkistrodon halys antivenom in inhibition of coagulopathy due to Trimeresurus albolabris venom: an in-vitro study using human plasma.

INTRODUCTION: There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. METHODS: This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. RESULTS: The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. CONCLUSIONS: Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.

Hepatosplenic T-cell lymphoma, immunosuppressive agents and biologicals: what are the risks?

We present three cases of the rare hepatosplenic T-cell lymphoma (HSTCL); two patients suffering from Crohn disease who developed HSTCL on azathioprine without exposure to biologicals, and a third patient who had psoriasis treated using etanercept, cyclosporine and methotrexate. The evidence for an association between HSTCL and immunosuppressive drugs and biologicals is reviewed. We argue for improved pharmacovigilance processes to help determine the benefit to risk ratios for the use of these and other new agents.

BCR-ABL1 kinase domain mutations may persist at very low levels for many years and lead to subsequent TKI resistance.

BACKGROUND: BCR-ABL1 mutation analysis is recommended for chronic myeloid leukaemia patients. However, mutations may become undetectable after changing therapy, and it is unknown whether they have been eradicated. METHODS: We examined longitudinal data of patients with imatinib-resistant mutations, which became undetectable by Sanger sequencing to determine whether mutations could reappear, and the related circumstances. RESULTS: Identical imatinib- and nilotinib-resistant mutations reappeared following further therapy changes in five patients, and was associated with subsequent nilotinib resistance in four. CONCLUSION: The data suggest that some BCR-ABL1 mutations may persist at undetectable levels for many years after changing therapy, and can be reselected and confer resistance to subsequent inhibitors.

The volumetric relationship of white matter lesion and contrast-enhanced lesion in delayed radiation brain injury: an MRI-based study.

PURPOSE: This study investigated the volumetric relationship of white matter lesion (WML) and contrast-enhanced lesion (CEL) in delayed radiation brain injury (RBI) during the course of evolution. MATERIALS AND METHODS: MRI results in 45 patients with RBI after receiving radiation for nasopharyngeal carcinoma were analyzed. In total there were 75 lobes with RBI and 114 MRI examinations in this study. WML and CEL lesion volumes were measured. The lesion volume change of less than 5% or 0.25 cm(3) was regarded as being static. RESULTS: The average WML volume was 16.33 cm(3) (ranging 0.11 cm(3) to 102.83 cm(3)), and the average CEL volume was 3.15 cm(3) (ranging 0.03 cm(3) to 27.85 cm(3)). WML was larger than CEL in 164 measurements, and CEL was larger than WML in 10 measurements. In 64.3% follow-ups WML and CEL evolved in the same pattern; and in most follow-ups (93.8%) WML and CEL did not evolve in the opposite directions. A larger WML volume tended to have a larger CEL volume though this relationship was not linear. CONCLUSION: Evolution of WML and CEL tended to follow the same pattern. WML tended to be larger than CEL, and larger WML tended to be associated with larger CEL.

Multiscale design of cell-free biologically active architectural structures.

Cell-free protein expression systems are here combined with 3D-printed structures to study the challenges and opportunities as biofabrication enters the spaces of architecture and design. Harnessing large-scale additive manufacturing of biological materials, we examined the addition of cell-free protein expression systems ("TXTL" i.e., biological transcription-translation machinery without the use of living cells) to printed structures. This allowed us to consider programmable, living-like, responsive systems for product design and indoor architectural applications. This emergent, pluripotent technology offers exciting potential in support of health, resource optimization, and reduction of energy use in the built environment, setting a new path to interactivity with mechanical, optical, and (bio) chemical properties throughout structures. We propose a roadmap towards creating healthier, functional and more durable systems by deploying a multiscale platform containing biologically-active components encapsulated within biopolymer lattices operating at three design scales: (i) supporting cell-free protein expression in a biopolymer matrix (microscale), (ii) varying material properties of porosity and strength within two-dimensional lattices to support biological and structural functions (mesoscale), and (iii) obtaining folded indoor surfaces that are structurally sound at the meter scale and biologically active (we label that regime macroscale). We embedded commercially available cell-free protein expression systems within silk fibroin and sodium alginate biopolymer matrices and used green fluorescent protein as the reporter to confirm their compatibility. We demonstrate mechanical attachment of freeze-dried bioactive pellets into printed foldable fibrous biopolymer lattices showing the first steps towards modular multiscale fabrication of large structures with biologically active zones. Our results discuss challenges to experimental setup affecting expression levels and show the potential of robust cell-free protein-expressing biosites within custom-printed structures at scales relevant to everyday consumer products and human habitats.

A five-colour colour-coded mapping method for DCE-MRI analysis of head and neck tumours.

AIM: To devise a method to convert the time-intensity curves (TICs) of head and neck dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data into a pixel-by-pixel colour-coded map for identifying normal tissues and tumours. MATERIALS AND METHODS: Twenty-three patients with head and neck squamous cell carcinoma (HNSCC) underwent DCE-MRI. TIC patterns of primary tumours, metastatic nodes, and normal tissues were assessed and a program was devised to convert the patterns into a classified colour-coded map. The enhancement patterns of tumours and normal tissue structures were evaluated and categorized into nine grades (0-8) based on the predominance of coloured pixels on maps. RESULTS: Five identified TIC patterns were converted into a colour-coded map consisting of red (maximum enhancement), brown (continuous slow rise-up), yellow (rapid wash-in and wash-out), green (rapid wash-in and plateau), and blue (rapid wash-in and rise-up). The colour-coded map distinguished all 21 primary tumours and 15 metastatic nodes from normal structures. Primary tumours and metastatic nodes were colour coded as predominantly yellow (grades 1-2) in 17/21 and 6/15, green (grades 3-5) in 3/21 and 5/15, and blue (grades 6-7) in 1/21 and 4/15, respectively. Vessels were coded red in 46/46 (grade 0) and muscles were coded brown in 23/23 (grade 8). Salivary glands, thyroid glands, and palatine tonsils were coded into predominantly yellow (grade 1) in 46/46 and 10/10 and 18/22, respectively. CONCLUSION: DCE-MRI derived five-colour-coded mapping provides an objective easy-to-interpret method to assess the dynamic enhancement pattern of head and neck cancers.

Essential, but at what risk? A prospective study on central venous access in patients with haematological malignancies.

AIMS: Central venous catheters (CVC) are integral to modern haematology practice; however, they are associated with a range of complications. This prospective study aimed to determine the rate of CVC-related complications and risk factors in haematology patients, who are vulnerable because of their underlying pathology and treatments. METHODS: All inpatients that had a non-tunnelled CVC inserted in a 14-month period in the haematology ward at St Vincent's Hospital were enrolled. Complications (immediate and late), demographics, type of device, insertion technique and duration of dwell, were examined using multivariate analysis. RESULTS: One hundred and seventy-four CVC in 84 patients were recorded, representing 3016 catheter-days. At least one complication was found in 43 (24.7%) patients. Immediate complications occurred in 13 (7.5%) insertions, with a higher rate in those inserted after ≥2 attempts compared with one (P = 0.02). Catheter-related bloodstream infection occurred at a rate of 7.6 per 1000 catheter-days, with acute lymphoblastic leukaemia associated with a higher rate (P = 0.02), and subclavian vein CVC had a lower rate compared with other locations (P < 0.01). Thrombosis was found in seven (4.0%) patients, with subclavian CVC carrying an increased risk (P = 0.02). CONCLUSIONS: This prospective observational study found almost a quarter of haematology patients experience a CVC-related complication. An association was found with a number of attempts at insertion and immediate complications; other risk factors included anatomical location, underlying disease and duration of catheterisation. The relatively high complication rate, compared with reports of non-haematology patients, highlights the need to improve CVC management, a vital part of care for this population.

Relationship between gender, bone mineral density, and disc degeneration in the lumbar spine: a study in elderly subjects using an eight-level MRI-based disc degeneration grading system.

UNLABELLED: The study cohort comprised 196 females and 163 males. Lumbar spine bone mineral density (BMD) and magnetic resonance imaging (MRI) were acquired. Females had more severe disc degeneration than males. Lumbar spine lower BMD was associated with less severe disc degeneration. Lumbar disc spaces were more likely to be narrower when vertebral BMD was higher. INTRODUCTION: The purpose of this paper is to study the relationship between gender, BMD, and disc degeneration in the lumbar spine. METHODS: The study cohort comprised 196 females and 163 males (age range 67-89 years) with no age difference between the two groups. Lumbar spine BMD was measured with dual X-ray densitometry, and MRI was acquired at 1.5 T. A subgroup of 48 males had additional lumbar vertebral quantitative computerized tomography densitometry. Lumbar disc degeneration was assessed using a MRI-based eight-level grading system. RESULTS: Female subjects had more severe disc degeneration than male subjects. After removing age effect, a positive trend was observed between T-score and severity of lumbar disc degeneration. This was significant in female subjects while not significant in male subjects. Lumbar disc spaces were more likely to be narrowed when vertebral BMD was higher. These observations were more significant in the midlumbar region (L3/4 and L4/5) and less so at the thoracolumbar junction. CONCLUSION: Female subjects tended to have slightly more severe lumbar disc degeneration than male subjects. Lower lumbar spine BMD was associated with less severe disc degeneration.

Tissue characterization using terahertz pulsed imaging in reflection geometry.

Terahertz pulsed imaging (TPI) is a non-ionizing and non-destructive imaging technique that has been recently used to study a wide range of biological materials. The severe attenuation of terahertz radiation in samples with high water content means that biological samples need to be very thin if they are to be measured in transmission geometry. To overcome this limitation, samples could be measured in reflection geometry and this is the most feasible way in which TPI could be performed in a clinical setting. In this study, we therefore used TPI in reflection geometry to characterize the terahertz properties of several organ samples freshly harvested from laboratory rats. We observed differences in the measured time domain responses and determined the frequency-dependent optical properties to characterize the samples further. We found statistically significant differences between the tissue types. These results show that TPI has the potential to accurately differentiate between tissue types non-invasively.

Can CT imaging improve targeting accuracy in clip-based proton therapy of ocular melanoma?

To evaluate the benefit of adding CT imaging to the simulation process of clip-based proton therapy of ocular melanomas. For thirty ocular melanoma cases, the clip position in the eye model was determined based on orthogonal radiographs as well as on a CT image set. The geometrical shift of the clips between the standard simulation process and standard simulation process with addition of CT imaging (CT-guided) was determined. The dosimetric impact was evaluated by developing treatment plans based on both the standard-process model and the CT-guided model. In 40% of the studied cases, the difference in clip position between eye models created with and without CT was less than 0.5 mm. This difference was more than 1 mm in 17% of cases. The dosimetric impact of shifts below 1 mm was low because these shifts did not exceed the planning margins. For the four cases with a shift of more than 1 mm a reduction in target coverage (ΔV99%) of -3% to -6% was observed. Changes in macula and optic-disc mean dose of up to 16% and 35% of the prescribed dose were seen when these structures abutted the target. Adding CT imaging to the simulation process is beneficial in select cases where discrepancies between the eye model and ophthalmology measurements occur or where a critical structure is located close to the target and improved localization accuracy is wanted. For the majority of patients, addition of CT imaging does not result in quantifiable changes in dosimetry. Nevertheless, CT imaging is a valuable tool in the quality control of the modeling and treatment-planning process of clip-based eye treatments.

Serum adipocyte fatty acid-binding protein levels were independently associated with carotid atherosclerosis.

OBJECTIVE: Adipocyte fatty acid-binding protein (A-FABP) has been shown to be an important player in atherosclerosis in animal models. However, the clinical relevance of these findings is still unknown. This study aims to examine the relationship between serum A-FABP level and carotid intima-media thickness (IMT), an indicator of atherosclerosis in humans. METHODS AND RESULTS: The study cohort included 479 Chinese subjects who underwent carotid IMT measurement. Serum A-FABP levels were determined by enzyme-linked immunosorbent assays. Serum A-FABP levels positively correlated with carotid IMT in both men (r=0.211, P=0.001) and women (r=0.435, P<0.001). In women, but not in men, the presence of plaques was associated with significantly higher serum A-FABP levels (P<0.001 versus women without plaques). Stepwise multiple regression analysis showed that serum A-FABP level was independently associated with carotid IMT in women (P=0.034), together with age and hypertension (both P<0.001). CONCLUSIONS: A-FABP is an independent determinant of carotid atherosclerosis in Chinese women, but not in men. This gender difference may be attributed to the lower serum A-FABP levels in men, and the effect of other risk factors, such as smoking, among our male participants. Our results have provided clinical evidence supporting the role of A-FABP in the development of atherosclerosis.

Differential effects on gene transcription and hematopoietic differentiation correlate with GATA2 mutant disease phenotypes.

Heterozygous GATA2 mutations underlie an array of complex hematopoietic and lymphatic diseases. Analysis of the literature reporting three recurrent GATA2 germline (g) mutations (gT354M, gR396Q and gR398W) revealed different phenotype tendencies. Although all three mutants differentially predispose to myeloid malignancies, there was no difference in leukemia-free survival for GATA2 patients. Despite intense interest, the molecular pathogenesis of GATA2 mutation is poorly understood. We functionally characterized a GATA2 mutant allelic series representing major disease phenotypes caused by germline and somatic (s) mutations in zinc finger 2 (ZF2). All GATA2 mutants, except for sL359V, displayed reduced DNA-binding affinity and transactivation compared with wild type (WT), which could be attributed to mutations of arginines critical for DNA binding or amino acids required for ZF2 domain structural integrity. Two GATA2 mutants (gT354M and gC373R) bound the key hematopoietic differentiation factor PU.1 more strongly than WT potentially perturbing differentiation via sequestration of PU.1. Unlike WT, all mutants failed to suppress colony formation and some mutants skewed cell fate to granulocytes, consistent with the monocytopenia phenotype seen in GATA2-related immunodeficiency disorders. These findings implicate perturbations of GATA2 function shaping the course of development of myeloid malignancy subtypes and strengthen complete or nearly complete haploinsufficiency for predisposition to lymphedema.

The telomerase reverse transcriptase is limiting and necessary for telomerase function in vivo.

Mammalian telomerase is essential for the maintenance of telomere length [1-5]. Its catalytic core comprises a reverse transcriptase component (TERT) and an RNA component. While the biochemical role of mammalian TERT is well established [6-11], it is unknown whether it is sufficient for telomere-length maintenance, chromosome stability or other cellular processes. Cells from mice in which the mTert gene had been disrupted showed progressive loss of telomere DNA, a phenotype similar to cells in which the gene encoding the telomerase RNA component (mTR) has been disrupted [1,12]. On prolonged growth, mTert-deficient embryonic stem (ES) cells exhibited genomic instability, aneuploidy and telomeric fusions. ES cells heterozygous for the mTert disruption also showed telomere attrition, a phenotype that differs from heterozygous mTR cells [12]. Thus, telomere maintenance in mammals is carried out by a single, limiting TERT.

Structure-activity relationships of flavonoids for vascular relaxation in porcine coronary artery.

Flavonoids are polyphenolic compounds that are widespread in the plant kingdom, and structure-activity relationships (SAR) for vascular relaxation effects were examined for 17 of them using porcine coronary arteries. Density functional theory was employed to calculate the chemical parameters of these compounds. The order of potency for vascular relaxation was as follows: flavones (apigenin and luteolin) >or= flavonols (kaempferol and quercetin)>isoflavones (genistein and daidzein)>flavanon(ol)es (naringenin)>chalcones (phloretin)>anthocyanidins (pelargonidin)>flavan(ol)es ((+)-catechin and (-)-epicatechin). SAR analysis revealed that for good relaxation activity, the 5-OH, 7-OH, 4'-OH, C2=C3 and C4=O functionalities were essential. Comparison of rutin with quercetin, genistin with genistein, and puerarin with daidzein demonstrated that the presence of a glycosylation group greatly reduced relaxation effect. Total energy and molecular volume were also predictive of their relaxation activities. Our findings indicated that the most effective relaxing agents are apigenin, luteolin, kaempferol and genistein. These flavonoids possess the key chemical structures demonstrated in our SAR analysis.

Telomerase-associated protein TEP1 is not essential for telomerase activity or telomere length maintenance in vivo.

TEP1 is a mammalian telomerase-associated protein with similarity to the Tetrahymena telomerase protein p80. Like p80, TEP1 is associated with telomerase activity and the telomerase reverse transcriptase, and it specifically interacts with the telomerase RNA. To determine the role of mTep1 in telomerase function in vivo, we generated mouse embryonic stem (ES) cells and mice lacking mTep1. The mTep1-deficient (mTep1(-/-)) mice were viable and were bred for seven successive generations with no obvious phenotypic abnormalities. All murine tissues from mTep1(-/-) mice possessed a level of telomerase activity comparable to that in wild-type mice. In addition, analysis of several tissues that normally lack telomerase activity revealed no reactivation of telomerase activity in mTep1(-/-) mice. Telomere length, even in later generations of mTep1(-/-) mice, was equivalent to that in wild-type animals. ES cells deficient in mTep1 also showed no detectable alteration in telomerase activity or telomere length with increased passage in culture. Thus, mTep1 appears to be completely dispensable for telomerase function in vivo. Recently, TEP1 has been identified within a second ribonucleoprotein (RNP) complex, the vault particle. TEP1 can also specifically bind to a small RNA, vRNA, which is associated with the vault particle and is unrelated in sequence to mammalian telomerase RNA. These results reveal that TEP1 is an RNA binding protein that is not restricted to the telomerase complex and that TEP1 plays a redundant role in the assembly or localization of the telomerase RNP in vivo.

The clinical significance of ABCB1 overexpression in predicting outcome of CML patients undergoing first-line imatinib treatment.

Tyrosine kinase inhibitor (TKI) therapy results in excellent responses in the majority of patients with chronic myeloid leukaemia. First-line imatinib treatment, with selective switching to nilotinib when patients fail to meet specific molecular targets or for imatinib intolerance, results in excellent overall molecular responses and survival. However, this strategy is less effective in cases of primary imatinib resistance; moreover, 25% of patients develop secondary resistance such that 20-35% of patients initially treated with imatinib will eventually experience treatment failure. Early identification of these patients is of high clinical relevance. Since the drug efflux transporter ABCB1 has previously been implicated in TKI resistance, we determined if early increases in ABCB1 mRNA expression (fold change from diagnosis to day 22 of imatinib therapy) predict for patient response. Indeed, patients exhibiting a high fold rise (⩾2.2, n=79) were significantly less likely to achieve early molecular response (BCR-ABL1IS ⩽10% at 3 months; P=0.001), major molecular response (P<0.0001) and MR4.5 (P<0.0001). Additionally, patients demonstrated increased levels of ABCB1 mRNA before the development of mutations and/or progression to blast crisis. Patients with high fold rise in ABCB1 mRNA were also less likely to achieve major molecular response when switched to nilotinib therapy (49% vs 82% of patients with low fold rise). We conclude that early evaluation of the fold change in ABCB1 mRNA expression may identify patients likely to be resistant to first- and second-generation TKIs and who may be candidates for alternative therapy.

Diffusion-Weighted Imaging of Nasopharyngeal Carcinoma: Can Pretreatment DWI Predict Local Failure Based on Long-Term Outcome?

BACKGROUND AND PURPOSE: Pretreatment prediction of patients with nasopharyngeal carcinoma who will fail conventional treatment would potentially allow these patients to undergo more intensive treatment or closer posttreatment monitoring. The aim of the study was to determine the ability of pretreatment DWI to predict local failure in patients with nasopharyngeal carcinoma based on long-term clinical outcome. MATERIALS AND METHODS: One hundred fifty-eight patients with pretreatment DWI underwent analysis of the primary tumor to obtain the ADC mean, ADC skewness, ADC kurtosis, volume, and T-stage. Univariate and multivariate analyses using logistic regression were performed to compare the ADC parameters, volume, T-stage, and patient age in primary tumors with local failure and those with local control, by using a minimum of 5-year follow-up to confirm local control. RESULTS: Local control was achieved in 131/158 (83%) patients (range, 60.3-117.7 months) and local failure occurred in 27/158 (17%) patients (range, 5.2-79.8 months). Compared with tumors with local control, those with local failure showed a significantly lower ADC skewness (ADC values with the greatest frequencies were shifted away from the lower ADC range) (P = .006) and lower ADC kurtosis (curve peak broader) (P = .024). The ADC skewness remained significant on multivariate analysis (P = .044). There was a trend toward higher tumor volumes in local failure, but the volume, together with T-stage and ADC mean, were not significantly different between the 2 groups. CONCLUSIONS: Pretreatment DWI of primary tumors found that the skewness of the ADC distribution curve was a predictor of local failure in patients with nasopharyngeal carcinoma, based on long-term clinical outcome.

Liver fibrosis and fatty liver in Asian HIV-infected patients.

BACKGROUND: Little is known about the importance of liver fibrosis and fatty liver in HIV-monoinfected individuals without hepatitis virus co-infection, particularly among the Asian population. AIM: To evaluate prevalence and risk factors for liver fibrosis and fatty liver in Asian HIV-monoinfected individuals. METHODS: Eighty asymptomatic HIV-monoinfected individuals (tested negative for HBV/HCV) were compared with 160 matched HIV-uninfected healthy controls. Transient elastography and proton-magnetic resonance spectroscopy ((1) H-MRS) were performed to measure liver stiffness and hepatic steatosis respectively. Blood samples were analysed for metabolic profiles and markers of steatohepatitis (e.g. cytokeratin-18). RESULTS: All HIV-infected individuals (mean ± s.d. age 54 ± 11 years, male 93%, Chinese 94%; diagnosis median duration 8 (IQR 4-13 years) were stable on anti-retrovirals (PI-based 58.7%, NNRTI-based 25.0% integrase-inhibitors 16.3%); diabetes, dyslipidaemia, and metabolic syndrome were common. Fatty liver disease was detected in 28.7%. There was significantly higher degree of liver stiffness [4.9 (IQR 4.1-6.2) kPa vs. 4.2 (IQR 3.6-5.0) kPa, P < 0.001], and greater proportions developed significant fibrosis (7.0 kPa, 14.3% vs. 3.1%, P = 0.001) and cirrhosis (10.3 kPa, 5.2% vs. 0.6%, P = 0.040) compared with controls. HIV infection was an independent risk factor for significant fibrosis (adjusted OR 4.00, 95% CI 1.29-12.41, P = 0.016). HIV-infected individuals with fatty liver had excessive liver stiffness and fibrosis. Two cases of asymptomatic hepatocellular carcinoma were detected. CONCLUSIONS: HIV-monoinfected patients are at risk for liver fibrosis and cirrhosis. HIV-related mechanisms and fatty liver disease may play important roles. Screening and intervention to prevent severe outcomes should be considered.