Group B Streptococcus Infections Caused by Improper Sourcing and Handling of Fish for Raw Consumption, Singapore, 2015-2016.

We assessed microbial safety and quality of raw fish sold in Singapore during 2015-2016 to complement epidemiologic findings for an outbreak of infection with group B Streptococcus serotype III sequence type (ST) 283 associated with raw fish consumption. Fish-associated group B Streptococcus ST283 strains included strains nearly identical (0-2 single-nucleotide polymorphisms) with the human outbreak strain, as well as strains in another distinct ST283 clade (57-71 single-nucleotide polymorphisms). Our investigations highlight the risk for contamination of freshwater fish (which are handled and distributed separately from saltwater fish sold as sashimi) and the need for improved hygienic handling of all fish for raw consumption. These results have led to updated policy and guidelines regarding the sale of ready-to-eat raw fish dishes in Singapore.

Malignant transformation of keratocystic odontogenic tumor: two case reports.

INTRODUCTION: Keratocystic odontogenic tumors (KCOTs) are cystic tumours originating from the dental lamina of the maxilla and mandible that are lined with keratinized epithelium. While benign, they can be locally destructive and have a high recurrence rate despite treatment. Rarely, KCOTs may undergo malignant transformation into Primary Intraosseous Squamous Cell Carcinoma (PIOSCC). CASE REPORT: This study reports the clinical findings, radiological scans and histopathology of 2 patients with KCOTs that underwent malignant transformation into PIOSCC. DISCUSSION: A comprehensive literature review was performed to similar reports documenting the malignant transformation of KCOTs. The potential for KCOTs to undergo malignant change should prompt oral maxillofacial surgeons and otolaryngologists to exercise a high index of suspicion when treating these lesions. Patients persisting with unresolved disease after treatment should be investigated for malignant transformation. Detailed histopathological examination of KCOT specimens is recommended to detect small foci of SCC which may be present in the epithelium.

(2S*,5R*)-2,5-Dimethyl-1,4-bis-(pyridin-2-ylmeth-yl)piperazine.

The title compound, C18H24N4, resides on a crystallographic inversion centre, so that the asymmetric unit comprises one half-mol-ecule. The piperazine ring adopts a chair conformation, with the mean planes of the two equatorial pyridine rings parallel to each other and separated by 2.54 (3) Å. No classical hydrogen bonds are observed.

Syntheses and structures of closely related copper(I) complexes of tridentate (2-pyridylmethyl)imine and (2-pyridylmethyl)amine ligands and their use in mediating atom transfer radical polymerizations.

A series of five copper(I) bromide complexes of tridentate (N,N,L) pyridine-imine and pyridine-amine ligands with a third amine, ether, or thioether neutral donor was synthesized and utilized in the atom transfer radical polymerization of styrene. The ligand design illustrated a systematic approach to the development of copper complexes for use in ATRP. Variations in the nature of the ligand impacted the solid state structures of the complexes. A mononuclear [CuBr(L)] complex was observed for L = pyridine-amine-amine, whereas complexes of L = pyridine-imine-amine and -thioether formed dinuclear [CuBr(L)](2) structures with a central 10-membered ring. A doubly-bromide-bridged dimer was revealed for the [CuBr(L)] complex of L = pyridine-imine-ether and a polymeric species for [CuBr(L)], where L = pyridine-imine-amine and the imine-amine spacer was extended from two to three carbon atoms. In the application of these complexes to the ATRP of styrene, the redox potentials of the complexes were found to be one indicator of ATRP efficiency. Of the series presented, two complexes in particular provided fast polymerization rates and good to excellent molecular weight control. In both of these complexes, the ligand contained all nitrogen-based donor moieties.

Di-µ-bromido-bis-{[N,N-dimethyl-N'-(thio-phen-2-yl-methyl-idene)ethane-1,2-diamine]-copper(I)]}.

In the crystal structure of the title compound, [Cu(2)Br(2)(C(9)H(14)N(2)S)(2)], the mol-ecule resides about a crystallographic inversion center. The coordination sphere around each copper ion has a distorted tetra-hedral geometry, with ligation by two bridging bromide ions, an amine N atom and an imine N atom. The thio-phene ring is disordered over two sites, with occupancies of 0.719 (3) and 0.281 (3). Weak C-H⋯π inter-actions feature in the crystal packing.

Sample-to-answer, extraction-free, real-time RT-LAMP test for SARS-CoV-2 in nasopharyngeal, nasal, and saliva samples: Implications and use for surveillance testing.

The global COVID-19 pandemic has highlighted the need for rapid, accurate and accessible nucleic acid tests to enable timely identification of infected individuals. We optimized a sample-to-answer nucleic acid test for SARS-CoV-2 that provides results in <1 hour using inexpensive and readily available reagents. The test workflow includes a simple lysis and viral inactivation protocol followed by direct isothermal amplification of viral RNA using RT-LAMP. The assay was validated using two different instruments, a portable isothermal fluorimeter and a standard thermocycler. Results of the RT-LAMP assay were compared to traditional RT-qPCR for nasopharyngeal swabs, nasal swabs, and saliva collected from a cohort of patients hospitalized due to COVID-19. For all three sample types, positive agreement with RT-LAMP performed using the isothermal fluorimeter was 100% for samples with Ct <30 and 69-91% for samples with Ct <40. Following validation, the test was successfully scaled to test the saliva of up to 400 asymptomatic individuals per day as part of the campus surveillance program at Rice University. Successful development, validation, and scaling of this sample-to-answer, extraction-free real-time RT-LAMP test for SARS-CoV-2 adds a highly adaptable tool to efforts to control the COVID-19 pandemic, and can inform test development strategies for future infectious disease threats.

Nasal metastases from renal cell carcinoma are associated with Memorial Sloan-Kettering Cancer Center poor-prognosis classification.

Unusual sites of metastases are recognized in patients with renal cell carcinoma (RCC). However, the prognostic implications of these sites are not well understood. We used the Memorial Sloan-Kettering Cancer Center (MSKCC) risk classification for metastatic RCC to evaluate 912 consecutive patients with RCC managed at the Singapore General Hospital between 1990 and 2009. Among these patients, 301 had metastases either at diagnosis or during the course of illness. Nasal metastases, all arising from clear cell RCC, were identified histologically in 4 patients (1.3% of those with metastasis). All 4 patients were classified as MSKCC poor prognosis by current risk criteria. Nasal metastases were significantly associated with lung and bone metastases. The frequency of nasal metastases in patients with metastatic RCC is about 1%, occurring predominantly in patients with clear cell RCC. Nasal metastases are associated with poor prognosis as estimated by the MSKCC risk classification, with attendant implications for selection of targeted therapy, and are usually associated with multi-organ dissemination, including concurrent lung and bone involvement.

Long-term outcome analysis after surgical salvage for recurrent tonsil carcinoma following radical radiotherapy.

The objective of this study is to report the longterm outcomes of salvage surgery following local and/or regional failure of tonsillar carcinoma treated with standard fractionation radiotherapy. All cases of carcinoma of the tonsil treated by radical radiotherapy at the Princess Margaret Hospital between January 1970 and December 1990 were reviewed retrospectively. Patients who underwent salvage surgery for local and/or regional recurrent squamous cell carcinoma of the tonsil following radiation therapy were included for analysis. 239 out of 640 patients with tonsillar carcinoma recurred post radiotherapy. 175 patients were deemed candidates for surgical salvage. At the time of the last follow-up, only 13 patients were alive and 162 patients had died. The majority of patients (n = 96, 59%)died with disease. The median time to death was approximately 1.3 years following salvage surgery. The 5-year overall survival rate was 23%. The 5-year cause-specific survival was 40%. The probability of death due to disease was higher than the probability of death due to other causes. Both N-classification and T-classification were found to be significant predictors of time to death. In conclusion,in spite of the fact that the patients in this study had been treated prior to the widespread introduction of altered fractionation and concurrent chemoradiation for advanced tonsil carcinoma, it demonstrates the poor prognosis of recurrent disease. Despite the poor prognosis, 20% of patients will be alive at 5 years and therefore salvage surgery should be considered when possible.

Management of the neck after chemoradiotherapy for head and neck cancers in Asia: consensus statement from the Asian Oncology Summit 2009.

The addition of a planned neck dissection after radiotherapy has traditionally been considered standard of care for patients with positive neck-nodal disease. With the acceptance of chemoradiotherapy as the new primary treatment for patients with locally advanced squamous-cell head and neck cancers, and the increasing numbers of patients who achieve a complete response, the role of planned neck dissection is now being questioned. The accuracy and availability of a physical examination or of different imaging modalities to identify true complete responses adds controversy to this issue. This consensus statement will address some of the controversies surrounding the role of neck dissection following chemoradiotherapy for squamous-cell carcinomas of the head and neck, with particular reference to patients in Asia.

Phenotypic and functional alterations of Vgamma2Vdelta2 T cell subsets in patients with active nasopharyngeal carcinoma.

INTRODUCTION: Human Vgamma2Vdelta2 T cells play important role in immunity to infection and cancer by monitoring self and foreign isoprenoid metabolites with their gammadelta T cell antigen receptors. Like CD4 and CD8 alphabeta T cells, adult peripheral Vgamma2Vdelta2 T cells represent a pool of heterogeneous cells with distinct functional capabilities. PURPOSE: The aim of this study was to characterize the phenotypes and functions of various Vgamma2Vdelta2 T cell subsets in patients with nasopharyngeal carcinoma (NPC). We sought to develop a better understanding of the role of these cells during the course of disease and to facilitate the development of immunotherapeutic strategies against NPC. RESULTS: Although similar total percentages of peripheral blood Vgamma2Vdelta2 T cells were found in both NPC patients and normal donors, Vgamma2Vdelta2 T cells from NPC patients showed decreased cytotoxicity against tumor cells whereas Vgamma2Vdelta2 T cells from normal donors showed potent cytotoxicity. To investigate further, we compared the phenotypic characteristics of Vgamma2Vdelta2 T cells from 96 patients with NPC and 54 healthy controls. The fraction of late effector memory Vgamma2Vdelta2 T cells (T(EM RA)) was significantly increased in NPC patients with corresponding decreases in the fraction of early memory Vgamma2Vdelta2 T cells (T(CM)) compared with those in healthy controls. Moreover, T(EM RA) and T(CM) Vgamma2Vdelta2 cells from NPC patients produced significantly less IFN-gamma and TNF-alpha, potentially contributing to their impaired cytotoxicity. Radiotherapy or concurrent chemo-radiotherapy further increased the T(EM RA) Vgamma2Vdelta2 T cell population but did not correct the impaired production of IFN-gamma and TNF-alpha observed for T(EM RA) Vgamma2Vdelta2 T cells. CONCLUSION: We have identified distinct alterations in the Vgamma2Vdelta2 T cell subsets of patients with NPC. Moreover, the overall cellular effector function of gammadelta T cells is compromised in these patients. Our data suggest that the contribution of Vgamma2Vdelta2 T cells to control NPC may depend on the activation state and differentiation of these cells.

Parapharyngeal space tumours: an 18 year review.

Parapharyngeal space tumours account for only 0.5 per cent of all head and neck tumours. Due to their inherent location, they present with varied non-specific signs and symptoms, resulting in a delay in diagnosis and unnecessary procedures, such as a 'tonsillectomy' or 'incision and drainage' of a 'quinsy'. Thirty-one patients, operated on over an 18-year period (1981 to 1998), in the Department of Otolaryngology, Singapore General Hospital, are presented. Their ages ranged from 21 to 86 years, with a mean of 52 years, with equal sex distribution. The commonest aetiology was a deep lobe of parotid tumour (44 per cent), followed by neurilemmomas (18 per cent), there was only one paraganglioma. The transcervical and transparotid approaches were the commonest used. The mean surgical time was three hours, mean hospital stay was 5.3 days and post-operative complications were minimal. The average follow-up time was 5.6 years. Although parapharyngeal space tumours are uncommon, recognizing them would enable the correct sequence of investigations, instead of unnecessary procedures resulting in an increased morbidity for the patient.

Esthesioneuroblastomas in an Asian population: similarities and differences.

OBJECTIVE: Esthesioneuroblastoma is an uncommon tumor that is described widely among the Caucasians. In Singapore, we see predominantly Asian patients with esthesioneuroblastomas. From our experience, we note significant and interesting differences between our data on Asian patients and the published ones on the Caucasian patients. METHODS: A retrospective review of all patients who underwent craniofacial resection for esthesioneuroblastomas was conducted from January 1997 to January 2010. Relevant data were collected and statistical analyses were carried out to determine factors that predicted mortality or complications. RESULTS: Out of a total of 48 patients who underwent craniofacial resections, half had esthesioneuroblastomas (50%). There was a peak age distribution at the sixth decade of life and 62% of our patients were male. Both local and regional recurrence rate was 50%. CONCLUSION: Majority of our Asian patients who underwent craniofacial resections had esthesioneuroblastomas. There is a male predilection, and we do not see a bimodal age distribution that is commonly reported.

Janus kinase 3-activating mutations identified in natural killer/T-cell lymphoma.

UNLABELLED: The molecular pathogenesis of natural killer/T-cell lymphoma (NKTCL) is not well understood. We conducted whole-exome sequencing and identified Janus kinase 3 (JAK3) somatic-activating mutations (A572V and A573V) in 2 of 4 patients with NKTCLs. Further validation of the prevalence of JAK3 mutations was determined by Sanger sequencing and high-resolution melt (HRM) analysis in an additional 61 cases. In total, 23 of 65 (35.4%) cases harbored JAK3 mutations. Functional characterization of the JAK3 mutations support its involvement in cytokine-independent JAK/STAT constitutive activation leading to increased cell growth. Moreover, treatment of both JAK3-mutant and wild-type NKTCL cell lines with a novel pan-JAK inhibitor, CP-690550, resulted in dose-dependent reduction of phosphorylated STAT5, reduced cell viability, and increased apoptosis. Hence, targeting the deregulated JAK/STAT pathway could be a promising therapy for patients with NKTCLs. SIGNIFICANCE: Gene mutations causing NKTCL have not been fully identified. Through exome sequencing, we identified activating mutations of JAK3 that may play a significant role in the pathogenesis of NKTCLs. Our findings have important implications for the management of patients with NKTCLs.

Outcomes of oral tongue cancer: does age matter?

INTRODUCTION: This is a retrospective study aimed to analyse the outcomes of oral tongue cancer with emphasis on young people. MATERIALS AND METHODS: Patients treated radically between 1998 and 2006 were included and categorised according to treatment modalities (Group A: Surgery, Group B: Surgery and adjuvant therapy, Group C: Definitive radiotherapy) and age groups (≤ 40 and > 40 years). Overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRS) and metastasis-free survival (MFS) were estimated using Kaplan-Meier method. RESULTS: There were 123 patients with 32%, 53% and 15% in Group A, B and C, respectively. Of these, 17 patients (14%) were ≤40 years with 6 (15%), 8 (12%) and 3 (16%) young oral tongues in Group A, B and C, respectively. Five-year OS and DFS were 69%/72%, 41%/47% and 16%/9.5% for Group A, B and C, respectively. Young patients had similar survival as the older population with 5-year OS of 83%, 75% and 33% in Group A, B and C, as compared to the older patients (66%, 36% and 13%, respectively). CONCLUSION: Young oral tongue patients did not have worse outcomes.

Evaluation of recurrent nodal disease after definitive radiation therapy for nasopharyngeal carcinoma: diagnostic value of fine-needle aspiration cytology and CT scan.

BACKGROUND: Recurrent nodal disease in patients with nasopharyngeal carcinoma (NPC) after definitive radiotherapy presents a difficult clinical problem. This cohort of patients poses a diagnostic challenge to the head and neck surgeon because evaluation of the post-irradiated neck, both clinically and radiologically, is known to be difficult, and it is not uncommon for neck dissection specimen in suspected recurrent nodal disease to contain no viable tumor cells. Currently, there is no well-accepted method for the preoperative determination of the presence of malignancy in these nodal diseases. METHODS: Over a 7-year period in a tertiary hospital, we systematically reviewed the clinical charts of 42 patients with NPC who were diagnosed with suspected recurrent nodal disease, after radical definitive radiotherapy. Fine-needle aspiration cytology (FNAC) was performed on clinically palpable nodes and results were correlated with final histopathologic results. Findings on CT scan were also correlated with final histopathologic specimens. RESULTS: The specificity and sensitivity of FNAC was 75.0% and 75.0%, respectively. The positive and negative predictive value of FNAC was 93.8% and 37.5%, respectively. CT scan had a positive predictive value of 78.6%. The negative predictive value for multilevel involvement on CT scan was 20%. CONCLUSION: Radiological imaging and FNAC are useful diagnostic modalities in assessing recurrent nodal disease in the post-irradiated neck in patients with NPC. Although routine CT scan criteria for pathologic lymphadenopathy cannot be accurately applied in the post-irradiated neck, it is a useful surveillance tool in the routine follow-up of patients with post-irradiated neck with NPC. Clinicians, however, must understand their limitations when assessing these patients. The possibility of negative neck dissection must be conveyed to the patients.