Whole genome sequencing of Streptococcus suis revealed potential drug resistance and zoonotic transmission in companion cat

Streptococcus suis is a bacterium of clinical importance in diverse animal hosts including companion animals and humans. Companion animals are closely associated in the living environment of humans and are potential reservoirs for zoonotic pathogens. Given the zoonotic potential of S. suis, it is crucial to determine whether this bacterium is present among the companion animal population. This study aimed to detect Streptococcus suis in companion animals namely cats and dogs of the central west coast of Peninsular Malaysia and further characterize the positive isolates via molecular and genomic approach. The detection of S. suis was done via bacterial isolation and polymerase chain reaction assay of gdh and recN gene from oral swabs. Characterization was done by multiplex PCR serotyping, as well as muti-locus sequence typing, AMR gene prediction, MGE identification and phylogenomic analysis on whole genome sequence acquired from Illumina and Oxford Nanopore sequencing. Among the 115 samples, PCR assay detected 2/59 of the cats were positive for S. suis serotype 8 while all screened dog samples were negative. This study further described the first complete whole genome of S. suis strain SS/UPM/MY/F001 isolated from the oral cavity of a companion cat. Genomic analysis revealed a novel strain of S. suis having a unique MLST profile and antimicrobial resistance genes of mefA, msrD, patA, patB and vanY. Mobile genetic elements were described, and pathogenic determinants matched to human and swine strains were identified. Phylogenetic tree analysis on the core genome alignment revealed strain SS/UPM/MY/F001 was distinct from other S. suis strains. This study provided insight into the detection and genomic features of the S. suis isolate of a companion cat and highlighted its potential for antimicrobial resistance and pathogenicity.

Iron-based biomarkers for personalizing pharmacological ascorbate therapy in glioblastoma: insights from a phase 2 clinical trial

BACKGROUND

Pharmacological ascorbate (intravenous delivery reaching plasma concentrations ≈ 20 mM; P-AscH-) has emerged as a promising therapeutic strategy for glioblastoma. Recently, a single-arm phase 2 clinical trial demonstrated a significant increase in overall survival when P-AscH- was combined with temozolomide and radiotherapy. As P-AscH- relies on iron-dependent mechanisms, this study aimed to assess the predictive potential of both molecular and imaging-based iron-related markers to enhance the personalization of P-AscH- therapy in glioblastoma participants.

METHODS

Participants (n = 55) with newly diagnosed glioblastoma were enrolled in a phase 2 clinical trial conducted at the University of Iowa (NCT02344355). Tumor samples obtained during surgical resection were processed and stained for transferrin receptor and ferritin heavy chain expression. A blinded pathologist performed pathological assessment. Quantitative susceptibility mapping (QSM) measures were obtained from pre-radiotherapy MRI scans following maximal safe surgical resection. Circulating blood iron panels were evaluated prior to therapy through the University of Iowa Diagnostic Laboratory.

RESULTS

Through univariate analysis, a significant inverse association was observed between tumor transferrin receptor expression and overall and progression-free survival. QSM measures exhibited a significant, positive association with progression-free survival. Subjects were actively followed until disease progression and then were followed through chart review or clinical visits for overall survival.

CONCLUSIONS

This study analyzes iron-related biomarkers in the context of P-AscH- therapy for glioblastoma. Integrating molecular, systemic, and imaging-based markers offers a multifaceted approach to tailoring treatment strategies, thereby contributing to improved patient outcomes and advancing the field of glioblastoma therapy.

Neoantigen Cancer Vaccine for Immunologically Cold Microsatellite-stable Colorectal Cancer

PURPOSE/OBJECTIVE(S)

Immunotherapies, such as immune checkpoint inhibitors (ICIs), have revolutionized management of some cancers but have little benefit for microsatellite-stable colorectal cancer patients (MSS-CRC). This is, in part, due to the low mutations and neoantigen expression in this immunogenically "cold" MSS-CRC. Therefore, we aim to develop novel shared neoantigen-based therapeutic cancer vaccine to reinvigorate antitumor immunity and enhance the therapeutic benefit of radiotherapy in MSS-CRC.

MATERIALS/METHODS

To identify novel highly expressed and shared neoantigens, we collected 40 match-paired adjacent normal and tumor tissues from MSS-CRC patients for WES-seq, RNA-seq, and liquid chromatography-MS/MS (LC-MS/MS). By incorporating these databases, we established Neoantigen Discovery and Validation (NeoDiva) system to identify a cluster of highly expressed and shared neoantigens derived from non-coding regions and evaluate its immunogenicity by HLA-A*11 transgenic mice. We then develop a neoantigen-based therapeutic cancer vaccine by an engineered adenovirus-associated virus (AAV) to evaluate its therapeutic efficacy in combination with radiotherapy in MSS-CRC animal model.

RESULTS

We identified a cluster of highly expressed and shared neoantigens (HLA-A*11-restricted) derived from non-coding regions. The immunogenicity of these novel neoantigens was demonstrated by HLA-A*11 transgenic mice and ex vivo stimulation. Moreover, the engineered AAV-based neoantigen cancer vaccine significantly eradicates cancer cells, prevents distant metastasis, prolong survival period in combination with radiotherapy. By flow cytometry, ELISPOT and MHC-I-tetramer assay, we demonstrated the recruitment of tumor-infiltrating lymphocytes was remarkably increased and neoantigen-specific T cell response was enhanced. Moreover, these isolated neoantigen-specific T cells can recognize cancer cells and produce IFNg to kill cancer cells.

CONCLUSION

Neoantigens identified by our NeoDiVa platform, via the combination of radiotherapy and a novel AAV vaccine delivery system, boosted antigen-specific T-cell function and improve tumor control of limnologically "cold" MSS colorectal cancer in vivo. We are in the process of obtaining an IND and initiating Phase I/II clinical trial to validate safety and efficacy of these exciting findings.

First molecular detection of porcine circovirus type 4 (PCV4) in Malaysia

Porcine circovirus type 4 (PCV4) is the newest member in the porcine circovirus family, first reported in 2020. To date, the presence of PCV4 has only been reported in China, South Korea and most recently in Thailand. Detection of PCV4 have been reported in various production stages of pigs from piglets, finishers to sows; associated with a myriad of clinical manifestations including porcine dermatitis and nephropathy syndrome (PDNS), postweaning multisystemic wasting syndrome (PMWS), respiratory, enteric and neurological diseases. While successful virus isolation and culture has yet to be reported, pathogenicity of PCV4 has been demonstrated through infectious clone studies. The objective of this study is to investigate the presence of PCV4 in Malaysian porcine population to update the epidemiology of porcine circoviruses in Malaysia. A total of 49 samples from commercial intensive pig farms, abattoir and wild boar population were subjected to conventional polymerase chain reaction assay to detect PCV4 capsid (cap) genome. Resulting cap nucleotide sequences were analyzed for maximum likelihood phylogeny relationship. Results revealed that PCV4 is present in Peninsular Malaysia at a molecular prevalence of 4.08% (2 / 49 samples). Both PCV4 positive samples originated from clinically healthy finishers. Malaysian PCV4 strains were classified as genotype PCV4b, and were found to be phylogenetically distinct from the China, South Korea and Thailand strains. With this latest update of the novel PCV4 in Malaysia, it is clear that more attention needs to be given to the investigation of novel porcine circoviruses (PCV) and management of PCV diseases.

Impact of COVID-19 on TB epidemiology in South Korea

SETTING: Five referral hospitals, South Korea.OBJECTIVE: To assess epidemiological changes in TB before and during the COVID-19 pandemic.DESIGN: This was a multicentre cohort study of 3,969 patients diagnosed with TB.RESULTS: We analysed 3,453 patients diagnosed with TB prior to the COVID-19 pandemic (January 2016-February 2020) and 516 during the pandemic (March-November 2020). During the pandemic, the number of patients visits declined by 15% from the previous 4-year average, and the number of patients diagnosed with TB decreased by 17%. Patients diagnosed during the pandemic were older than those diagnosed before the pandemic (mean age, 60.2 vs. 56.6 years, P < 0.001). The proportion of patients to have primary TB at a younger age (births after 1980) among those diagnosed with TB was significantly lower during the pandemic than before (17.8% in 2020 vs. 23.5% in 2016, 24.0% in 2017, 22.5% in 2018, 23.5% in 2019; P = 0.005).CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of visits to respiratory departments, leading to fewer patients being diagnosed with TB. However, our results suggest that universal personal preventive measures help to suppress TB transmission in regions with intermediate TB burden.

Cervical disc arthroplasty for Klippel-Feil syndrome

OBJECTIVE

Klippel-Feil syndrome (KFS) is a congenital musculoskeletal condition characterized by improper segmentation of the cervical spine. This study aimed to evaluate outcomes of KFS patients who underwent cervical disc arthroplasty (CDA).

METHODS

Consecutive patients who underwent anterior cervical surgery were retrospectively reviewed. Those patients with KFS who received discectomy adjacent to the congenitally fused vertebral segments were extracted and grouped into either the fusion or the CDA group. Clinical and radiological evaluations included visual analog scales, Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) scores, C2-7 range of motion (ROM), C2-7 Cobb angle, C2-7 sagittal vertical axis (SVA), and T1-slope.

RESULTS

Among 2320 patients, there were 41 with KFS (prevalence = 1.77%), who were younger than the entire cohort (53.3 vs 56.4 years). Thirty KFS patients had adjacent discs and were grouped into the CDA and fusion groups (14 vs 16). Type-I KFS with C3-4 involvement was the most common for both groups (92.8% vs 81.2% with 57% vs 50%, respectively). Post-operation, both groups demonstrated improvement of all the patient reported outcomes. The C2-7 ROM significantly decreased in the fusion group than that of pre-operation (12.8 ± 6° vs 28.1 ± 11.5°). In contrast, the CDA group successfully preserved C2-7 and segmental ROM without additional complications.

CONCLUSIONS

KFS is rare (prevalence = 1.77%) among cervical spine surgery patients, and it rarely affects the overall cervical spinal alignment, except that it decreases segmental mobility. CDA is a feasible option for KFS because it not only avoids long-segment fusion but also preserves segmental and global mobility.

Telomere-led meiotic chromosome movements: recent update in structure and function

In S. cerevisiae prophase meiotic chromosomes move by forces generated in the cytoplasm and transduced to the telomere via a protein complex located in the nuclear membrane. We know that chromosome movements require actin cytoskeleton [13,31] and the proteins Ndj1, Mps3, and Csm4. Until recently, the identity of the protein connecting Ndj1-Mps3 with the cytoskeleton components was missing. It was also not known the identity of a cytoplasmic motor responsible for interacting with the actin cytoskeleton and a protein at the outer nuclear envelope. Our recent work [36] identified Mps2 as the protein connecting Ndj1-Mps3 with cytoskeleton components; Myo2 as the cytoplasmic motor that interacts with Mps2; and Cms4 as a regulator of Mps2 and Myo2 interaction and activities (Figure 1). Below we present a model for how Mps2, Csm4, and Myo2 promote chromosome movements by providing the primary connections joining telomeres to the actin cytoskeleton through the LINC complex.

A case of arrhythmogenic right ventricular cardiomyopathy with right ventricle thrombus: A case report

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited cardiomyopathy characterised by right ventricular dysfunction, ventricular arrhythmias and increased risk of sudden cardiac death. Due to the replacement of myocardium with fibro-fatty and fibrous tissue, patients with ARVC are prone to develop ventricular tachycardia. Histologically, it is often reported as the 'triangle of dysplasia' involving the inflow tract, outflow tract and apex of the right ventricle.2 We describe a 20-years-old patient who collapsed during a futsal match and was subsequently diagnosed to have ARVC with a right ventricular thrombus from cardiac magnetic resonance imaging.

A spontaneous missense mutation in the chromodomain helicase DNA-binding protein 8 (CHD8) gene: a novel association with congenital myasthenic syndrome

AIMS

Congenital myasthenic syndromes (CMS) are characterized by muscle weakness, ptosis and episodic apnoea. Mutations affect integral protein components of the neuromuscular junction (NMJ). Here we searched for the genetic basis of CMS in female monozygotic twins.

METHODS

We employed whole-exome sequencing for mutation detection and Sanger sequencing for segregation analysis. Immunohistology was done with antibodies against CHD8, rapsyn, β-catenin (βCAT) and golgin on fi-bro-blasts, human and mouse muscle. We recorded superresolution images of the NMJ using 3D-structured illumination microscopy.

RESULTS

We discovered a spontaneous missense mutation in CHD8 [chr14:g.21,884,051G>A, GRCh37.p11 | c.1732C>T, NM_00117062 | p.(R578C)], the gene encoding chromodomain helicase DNA-binding protein 8. This is the first missense mutation affecting Duplin, the short 110 kDa isoform of CHD8. It is known that CHD8/Duplin negatively regulates βCAT signalling in the WNT pathway and plays a role in chromatin remodelling. Inactivating CHD8 mutations are associated with autism spectrum disorder and intellectual disability in combination with facial dysmorphism, overgrowth and macrocephalus. No muscle-specific phenotype has been reported to date. Co-immunostaining with rapsyn on human and mouse muscle revealed a strong presence of CHD8 at the NMJ being located towards the sarcoplasmic side of the rapsyn cluster, where it co-localizes with βCAT.

CONCLUSION

We hypothesize CHD8 to have a role in the maintenance of the structural integrity and function of the NMJ. Both patients benefited from treatment with 3,4-diaminopyridine, a reversible blocker of voltage-gated potassium channels at the nerve terminal that prolongs the action potential and increases acetylcholine release.

Cervical disc arthroplasty for less-mobile discs

OBJECTIVE

The published clinical trials of cervical disc arthroplasty (CDA) have unanimously demonstrated the success of preservation of motion (average 7°-9°) at the index level for up to 10 years postoperatively. The inclusion criteria in these trials usually required patients to have evident mobility at the level to be treated (≥ 2° on lateral flexion-extension radiographs) prior to the surgery. Although the mean range of motion (ROM) remained similar after CDA, it was unclear in these trials if patients with less preoperative ROM would have different outcomes than patients with more ROM.

METHODS

A series of consecutive patients who underwent CDA at the level of C5-6 were followed up and retrospectively reviewed. The indications for surgery were medically refractory cervical radiculopathy, myelopathy, or both, caused by cervical disc herniation or spondylosis. All patients were assigned to 1 of 2 groups: a less-mobile group, which consisted of those patients who had an ROM of ≤ 5° at C5-6 preoperatively, or a more-mobile group, which consisted of patients whose ROM at C5-6 was > 5° preoperatively. Clinical outcomes, including visual analog scale, Neck Disability Index, and Japanese Orthopaedic Association Scale scores, were evaluated at each time point. Radiological outcomes were also assessed.

RESULTS

A total of 60 patients who had follow-up for more than 2 years were analyzed. There were 27 patients in the less-mobile group (mean preoperative ROM 3.0°) and 33 in the more-mobile group (mean ROM 11.7°). The 2 groups were similar in demographics, including age, sex, diabetes, and cigarette smoking. Both groups had significant improvements in clinical outcomes, with no significant differences between the 2 groups. However, the radiological evaluations demonstrated remarkable differences. The less-mobile group had a greater increase in ΔROM than the more-mobile group (ΔROM 5.5° vs 0.1°, p = 0.001), though the less-mobile group still had less segmental mobility (ROM 8.5° vs 11.7°, p = 0.04). The rates of complications were similar in both groups.

CONCLUSIONS

Preoperative segmental mobility did not alter the clinical outcomes of CDA. The preoperatively less-mobile (ROM ≤ 5°) discs had similar clinical improvements and greater increase of segmental mobility (ΔROM), but remained less mobile, than the preoperatively more-mobile (ROM > 5°) discs at 2 years postoperatively.

Acute myocarditis mimicking ST-elevation myocardial infarction: A diagnostic challenge for frontline clinicians

The clinical presentation of acute myocarditis is highly variable ranging from no symptoms to cardiogenic shock. Despite considerable progress, it remains a challenge for frontline physicians to discriminate between acute myocarditis and myocardial infarction, especially in the early phase. Our case serves as a reminder that acute presentation of myocarditis could resemble ST elevation myocardial infarction potentially misdirecting the therapeutic decision. The clinical presentation, electrocardiographic and laboratory findings of the patient are not specific enough to distinguish acute myocarditis from myocardial infarction. The gold standard tests such coronary angiography and cardiovascular magnetic resonance (CMR) can reliably differentiate the two entities.

3052Non-vitamin K antagonist oral anticoagulants are safe and effective alternatives to warfarin across subgroups by renal function: results from Danish registries

Background

All non-vitamin K antagonist oral anticoagulants (NOACs) have some degree of renal excretion, and patients with severely reduced renal function have been excluded from randomized controlled clinical trials of stroke prevention in atrial fibrillation (AF). Influence of renal function on outcomes has not been assessed in previous real-world studies of NOACs in AF.

Purpose

To assess influence of renal function on efficacy and safety of dabigatran, rivaroxaban or apixaban vs. warfarin.

Methods

Using nationwide registries, we identified all Danish AF patients who initiated warfarin, dabigatran, rivaroxaban or apixaban between 2012 and 2016. We included patients with a plasma creatinine measurement within 14 days from drug initiation and calculated estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Hazard ratio (HR) of stroke/thromboembolism (TE) or major bleeding according to oral anticoagulation was calculated using multivariable-adjusted Cox regression analyses with warfarin as reference.

Results

We included 14,673 AF patients who started first-time oral anticoagulation within 14 days from AF diagnosis, and our study population comprised 2482 (16.9%) initiators of dabigatran (median age 72, 44.5% women), 3806 (25.9%) initiators of rivaroxaban (median age 75, 48.0% women), 5067 (34.5%) initiators of apixaban (median age 76, 48.8% women), and 3318 (22.6%) initiators of warfarin (median age 75, 45.4% women). eGFR was >50, 30–50 and 15 to <30 mL/min/1.73m2 in 10,281 (83.1%), 2079 (14.2%) and 404 (2.8%) patients at baseline. After adjustment for age, sex, year of inclusion, income, cohabitation status, eGFR, hemoglobin, medications and comorbidities, the HRs for stroke/TE compared to warfarin were 0.94 (95% confidence interval (CI) 0.74–1.20) for dabigatran, 1.06 (CI 0.84–1.34) for rivaroxaban, and 1.10 (CI 0.88–1.36) for apixaban. There were no significant heterogeneities in HRs of stroke/TE across subgroups by eGFR. Apixaban (HR 0.74, CI 0.62–0.89) was associated with lower risk of major bleeding compared to warfarin, rivaroxaban (HR 1.06, CI 0.88–1.27) with risk of major bleeding comparable to warfarin, and there were no significant heterogeneities in risk of major bleeding with rivaroxaban or apixaban across subgroups by eGFR. Dabigatran was associated with lower risk of bleeding among patients with eGFR >50 mL/min/1.73m2, but not among patients with eGFR 30–50 mL/min/1.73m2 (interaction P=0.03).

Conclusions

In a large real-world cohort, renal function had no significant influence on efficacy or safety of apixaban or rivaroxaban when compared with warfarin. Dabigatran was associated with lower risk of bleeding among patients with normal or mildly decreased renal function, but not among patients with moderately decreased renal function.

Acknowledgement/Funding

This study was funded by an unrestricted grant from the Capital Region of Denmark, Foundation for Health Research.

P4779High facility preference for rivaroxaban in atrial fibrillation increases risk of major bleeding compared to facility preference for apixaban

Background

No randomized trial has compared efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF). Previous real-world comparisons could be biased by patient characteristics of importance for treatment selection, but instrumental variables could potentially account for measured and unmeasured confounders.

Purpose

To compare efficacy and safety of rivaroxaban and apixaban using facility preference for type of NOAC as instrumental variable.

Methods

AF patients started on apixaban or rivaroxaban were identified using nationwide registries. We categorized patients according to facility preference for type of NOAC, measured as percentage of the prior 20 AF patients started on rivaroxaban in the same facility. Occurrence of stroke/thromboembolism (TE), major bleeding, myocardial infarction and all-cause mortality during two years of follow-up were investigated using adjusted Cox regressions. To further examine general frailty according to facility preferences we also investigated occurrence of cancer, urogenital tract infection, dehydration and fracture.

Results

We analyzed 6264 AF patients initiated on rivaroxaban or apixaban. Compared with patients treated in facilities that used rivaroxaban in 0–20% of cases, the adjusted hazard ratio for bleeding was 1.05 when treated in a facility with 25–40% use; 1.40 with 45–60% use; 1.50 with 65–80% use; and 1.81 for 85–100% use (Ptrend=0.002). Higher facility level use of rivaroxaban was not associated with increased risk of stroke/TE (Ptrend=0.06), myocardial infarction (Ptrend=0.87) or all-cause mortality (Ptrend=0.91), and there was no association between facility preference for rivaroxaban and risk of cancer (Ptrend=0.83), urogenital tract infection (Ptrend=0.49), dehydration (Ptrend=0.91) or fracture (Ptrend=0.47).

Characteristics by facility preference Percent of previous AF patients from facility started on rivaroxaban P for trend 0–20% 25–40% 45–60% 65–80% 85–100% No. of patients 1406 1421 1551 930 956 Received rivaroxaban, (%) 279, (19.8) 499, (35.1) 711, (45.8) 632, (68.0) 774, (81.0) <0.001 Standard dose, (%) 1216, (86.5) 1232, (86.7%) 1366, (88.1%) 793, (85.3%) 824, (86.2%) 0.62 Median age, (interquartile range) 70, (63.3–74) 69, (63–74) 70, (64–74) 70, (64–75) 70, (63–75) 0.11 Below median income, (%) 740, (52.6) 699, (49.2) 764, (49.3) 458, (49.3) 471, (49.3) 0.31 Prior stroke, (%) 99, (7.0) 115, (8.1) 134, (8.6) 69, (7.4) 74, (7.7) 0.56 Prior bleeding, (%) 136, (9.7) 141, (9.9) 163, (10.5) 91, (9.8) 97, (10.1) 0.51 Antiplatelet therapy, (%) 445, (31.7) 465, (32.7) 491, (31.7) 303, (32.6) 317, (33.2) 0.49

Rate of events according to instrument

Conclusion

High facility preference for rivaroxaban increases risk of major bleeding compared to facility preference for apixaban.

Acknowledgement/Funding

This study was funded by an unrestricted grant from the Capital Region of Denmark, Foundation for Health Research.

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BACKGROUND

Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.

PATIENTS AND METHODS

We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.

RESULTS

A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate.

CONCLUSION

HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Molecular detection of Haemophilus parasuis serotypes 4, 5 or 12 and 13 in Peninsular Malaysia

Although the economic importance of Haemophilus parasuis infection causing Glasser's disease is prevalent throughout pig farms in Peninsular Malaysia, there is a dearth of knowledge on its actual nature. In this study, a multiplex PCR was performed to screen for three major predominant virulent strains of H. parasuis, which are serotypes 4, 5 or 12 and 13. A total of 175 tissues or bodily fluid samples of various parts were collected from diseased animals from October, 2016 to February, 2018; with total of 62.9% positive detection of H. parasuis. The highest detection was found to be in the pericardial sac fibrin (90.9%) followed by pleural fibrin, lung, pleural fluid, tonsil, pericardial sac, peritoneal fluid, abdominal fibrin, joint fluid, brain and pericardium. Serotype 13 was the highest (40/110) followed by serotype 4(37/110), serotype 5(31/110) and 12 samples were nontypable (12/110). The presence of untypable serotype also drives to further identification of other serotypes in Malaysia.

Diagnostic value of electrocardiogram in cardiac tamponade

INTRODUCTION

We aim to study the diagnostic value of electrocardiogram (ECG) in cardiac tamponade.

METHODS

This study was a single centre, retrospective casecontrol study. We recruited 42 patients diagnosed with cardiac tamponade of various aetiologies confirmed by transthoracic echocardiography and 100 controls between January 2011 and December 2015. The ECG criteria of cardiac tamponade we adopted was as follows: 1) Low QRS voltage in a) the limb leads alone, b) in the precordial leads alone or, c) in all leads, 2) PR segment depression, 3) Electrical alternans, and 4) Sinus tachycardia.

RESULTS

Malignancy was the most common causes of cardiac tamponade, the two groups were of similar proportion of gender and ethnicity. We calculated the sensitivity (SN), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of each ECG criteria. Among the ECG abnormalities, we noted the SN of 'low voltage in all chest leads' (69%), 'low voltage in all limb leads' (67%) and 'sinus tachycardia' (69%) were higher as compared to 'PR depression' (12%) and 'electrical alternan' (5%). On the other hand, 'low voltage in all chest leads' (98%), 'low voltage in all leads' (99%), 'PR depression' (100%) and 'electrical alternans' (100%) has highest SP.

CONCLUSION

Our study reaffirmed the findings of previous studies that electrocardiography cannot be used as a screening tool for diagnosing cardiac tamponade due to its low sensitivity. However, with clinical correlation, electrocardiography is a valuable adjuvant test to 'rule in' cardiac tamponade because of its high specificity.

Immunohistochemical and molecular analysis of spitzoid neoplasms with pulverocyte subclones

BACKGROUND

Clonal naevi are characterized by a focal proliferation of pigmented melanocytes in an otherwise banal naevus. These subclones are often composed of aggregates of larger, epithelioid melanocytes with nuclear atypia and dusty-grey cytoplasmic pigmentation, which are referred to as 'pulverocytes', and this finding may lead to a misdiagnosis of malignant melanoma (MM).

AIM

To characterize the significance of subclones of dusty-grey pigmented epithelioid melanocytes within spitzoid neoplasms.

METHODS

We studied the histological and molecular features of a series of 20 spitzoid neoplasms with pulverocyte subclones encountered in our practice, including both atypical Spitz tumours (ASTs) and invasive MMs.

RESULTS

Pulverocytes were predominantly dermal, and the percentage of subclones ranged from 2% to 40%, with a median of 10% in ASTs and 25% in lesions we classified as MM. In cases with > 10% subclones, there was an increased odds of fluorescence in situ hybridization positivity (OR = 12; 95% CI 1.2-293.4; P = 0.03) and an increased odds of homozygous 9p21 deletion (OR = 3.6; 95 CI 0.28-89.82; P = 0.33), although the latter did not reach statistical significance.

CONCLUSIONS

We consider spitzoid lesions with a small subclone population to be a variant of a clonal naevus with indolent behaviour, whereas lesions with larger pulverocyte populations are more likely to have chromosomal copy number aberrations and in some cases may represent malignant transformation.

Irradiation-Induced Secondary Tumors following Pediatric Central Nervous System Tumors: Experiences of a Single Institute in Taiwan (1975-2013)

PURPOSE

Complications can occur following a prolonged latency period after radiation therapy for cancer, and this is a growing concern because secondary tumors are potentially fatal. Few studies have examined secondary tumors in patients who received radiation therapy as children.

METHODS AND MATERIALS

This retrospective study examined 1697 pediatric patients with central nervous system tumors who received treatment at Taipei Veterans General Hospital from January 1, 1975, to December 31, 2013. Secondary tumors developed in 27 of 681 patients who received cranial irradiation. Overall survival was estimated using the Kaplan-Meier method, and the significance of differences was determined by the log-rank test.

RESULTS

The overall cumulative incidence of secondary tumors at 25 years was 3.96%, and there were similar numbers of male patients (n = 16) and female patients (n = 11). The mean age at diagnosis was 8.8 years (range, 3-16.5 years), the median dose of cranial irradiation was 52.5 Gy (mean, 53.4 Gy), the mean latency period was 14.6 years (range, 2-33 years), and the mean age at diagnosis of a secondary tumor was 23.1 years. The secondary tumors were mainly meningiomas (n = 13), sarcomas (n = 7), and high-grade gliomas (n = 6), and the mean latency periods were 19.66, 8.00, and 10.83 years, respectively. The overall survival rate from these secondary tumors was significantly different (P < .05). Age at irradiation of <7 years and craniospinal irradiation significantly increased the risk of a secondary tumor (P < .05). Secondary tumors developed in 11 of 128 patients (8.6%) with primary medulloblastomas, which was higher than the overall cumulative incidence.

CONCLUSIONS

Clinicians should consider the increased risk of secondary tumors in long-term cancer survivors who received craniospinal irradiation as children. Using a selective dose de-escalation strategy or deferring radiation therapy for young patients at highest risk of secondary cancers should be studied.

Co-clinical trials demonstrate predictive biomarkers for dovitinib, an FGFR inhibitor, in lung squamous cell carcinoma

Background

We conducted co-clinical trials in patient-derived xenograft (PDX) models to identify predictive biomarkers for the multikinase inhibitor dovitinib in lung squamous cell carcinoma (LSCC).

Methods

The PDX01-02 were established from LSCC patients enrolled in the phase II trial of dovitinib (NCT01861197) and PDX03-05 were established from LSCC patients receiving surgery. These five PDX tumors were subjected to in vivo test of dovitinib efficacy, whole exome sequencing and gene expression profiling.

Results

The PDX tumors recapitulate histopathological properties and maintain genomic characteristics of originating tumors. Concordant with clinical outcomes of the trial enrolled-LSCC patients, dovitinib produced substantial tumor regression in PDX-01 and PDX-05, whereas it resulted in tumor progression in PDX-02. PDX-03 and -04 also displayed poor antitumor efficacy to dovitinib. Mutational and genome-wide copy number profiles revealed no correlation between genomic alterations of FGFR1-3 and sensitivity to dovitinib. Of note, gene expression profiles revealed differentially expressed genes including FGF3 and FGF19 between PDX-01 and 05 and PDX-02-04. Pathway analysis identified two FGFR signaling-related gene sets, FGFR ligand binding/activation and SHC-mediated cascade pathway were substantially up-regulated in PDX-01 and 05, compared with PDX-02-04. The comparison of gene expression profiles between dovitinib-sensitive versus -resistant lung cancer cell lines in the Cancer Cell Line Encyclopedia database also found that transcriptional activation of 18 key signaling components in FGFR pathways can predict the sensitivity to dovitinib both in cell lines and PDX tumors. These results highlight FGFR pathway activation as a key molecular determinant for sensitivity to dovitinib.

Conclusions

FGFR gene expression signatures are predictors for the response to dovitinib in LSCC.

Modelling end-pumped passively Q-switched Nd-doped crystal lasers: manifestation by a Nd:YVO4/Cr4+:YAG system with a concave-convex resonator

A theoretical model for the passively Q-switched (PQS) operation which includes the spatial overlapping between the pump and lasing modes under the thermal lensing effect is developed to give a transcendental equation that can directly determine the critical parameters such as pulse energy, pulse repetition rate, and pulse width for the PQS performance. More importantly, an analytical function which gives the approximate solution for the transcendental equation as well as a specific critical criterion for good PQS operation are derived for practical analyses and design. A Nd:YVO₄/Cr⁴⁺:YAG system with a concave-convex resonator which can achieve fairly stable PQS pulse trains even at a high pump level is further exploited to manifest the proposed spatially dependent model. The good agreement between the experimental results and the theoretical predictions is verified to show the feasibility of the proposed model for designing high-power PQS lasers with high accuracy.

Generation of terahertz optical beating from a simultaneously self-mode-locked Nd:YAG laser at 1064 and 1123 nm

The reflectivity of the output coupler is designed to achieve the synchronously self-mode-locked operation at 1064 and 1123 nm in a diode-end-pumped Nd:YAG laser. Numerical analyses are performed to confirm that the designed output coupler can lead the emission lines to be predominant at 1064 and 1123 nm. Moreover, the crossover of the threshold pump powers for the 1064 and 1123 nm emission lines can be exploited to obtain the single central wavelength of 1064 nm or the single central wavelength of 1123 nm or, simultaneously, dual-central-wavelength self-mode-locked operation by finely adjusting the cavity alignment. For the dual-central-wavelength mode-locked emissions, the pulse repetition rate and the pulse duration are 4.5 GHz and 50.8 ps, respectively. The maximum output power can be up to 2.47 W at a pump power of 7.5 W. The synchronization of the 1064 and 1123 nm mode-locked pulses generates the optical beating pulse trains with repetition rates up to 14.7 THz.

Exploiting concave-convex linear resonators to design end-pumped solid-state lasers with flexible cavity lengths: Application for exploring the self-mode-locked operation

The characteristics of a convex-concave linear resonator under the thermal lensing effect are theoretically analyzed to find an analytical model for designing end-pumped solid-state lasers with flexible cavity lengths. By exploiting the design model, the power scaling for continuous-wave operation under strong thermal lensing can be easily achieved in the proposed resonator with different cavity lengths. Furthermore, the proposed resonator is applied to explore the exclusive influence of cavity length on the self-mode-locked (SML) operation. It is discovered that the lasing longitudinal modes will split into multiple groups in optical spectrum to lead to a multi-pulse mode-locked temporal state when the cavity length increases. Finally, a theoretical model is derived to reconstruct the experimental results of SML operation to deduce a simple relationship between the group number of lasing modes and the cavity length.

Monolithic dual-polarization self-mode-locked Nd:YAG 946-nm lasers: controlling beat frequency and observation of temporal chaos

The self-mode-locked (SML) operation at 946 nm can be achieved with a monolithic Nd:YAG crystal when the pump power is above the threshold of the multiple-longitudinal-mode generation. The SML output is further found to include two orthogonal polarization components with a beat frequency coming from the birefringence effect in the laser crystal. The beat frequency can be widely adjusted in the range of 5-220 MHz by controlling the cooling temperature. The present experiment also confirms the theoretical prediction that the two-mode operation generally exhibits the chaotic dynamics when the frequency difference is sufficiently close to the relaxation frequency.