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Ameloblastomas in children. Report of a case and review of the literature

Ramanathan K, Guan LS

Dent J Malaysia Singapore, 1968 Feb;8(1):36-42.
PMID: 4235968
Fulltext Organotypic slice culture based on in ovo electroporation for chicken embryonic central nervous system

Yang C, Li X, Li S, Chai X, Guan L, Qiao L, et al.

J Cell Mol Med, 2019 03;23(3):1813-1826.
PMID: 30565384 DOI: 10.1111/jcmm.14080

Organotypic slice culture is a living cell research technique which blends features of both in vivo and in vitro techniques. While organotypic brain slice culture techniques have been well established in rodents, there are few reports on the study of organotypic slice culture, especially of the central nervous system (CNS), in chicken embryos. We established a combined in ovo electroporation and organotypic slice culture method to study exogenous genes functions in the CNS during chicken embryo development. We performed in ovo electroporation in the spinal cord or optic tectum prior to slice culture. When embryonic development reached a specific stage, green fluorescent protein (GFP)-positive embryos were selected and fluorescent expression sites were cut under stereo fluorescence microscopy. Selected tissues were embedded in 4% agar. Tissues were sectioned on a vibratory microtome and 300 μm thick sections were mounted on a membrane of millicell cell culture insert. The insert was placed in a 30-mm culture dish and 1 ml of slice culture media was added. We show that during serum-free medium culture, the slice loses its original structure and propensity to be strictly regulated, which are the characteristics of the CNS. However, after adding serum, the histological structure of cultured-tissue slices was able to be well maintained and neuronal axons were significantly longer than that those of serum-free medium cultured-tissue slices. As the structure of a complete single neuron can be observed from a slice culture, this is a suitable way of studying single neuronal dynamics. As such, we present an effective method to study axon formation and migration of single neurons in vitro.
Fulltext Cultural Adaptation of Sniffin' Sticks Smell Identification Test: The Malaysian Version

Sai-Guan L, Husain S, Zahedi FD, Ahmad N, Gendeh BS

Iran J Otorhinolaryngol, 2020 Jul;32(111):213-222.
PMID: 32850509 DOI: 10.22038/ijorl.2019.34346.2138

Introduction: Sniffin' Sticks smell identification test is a tool used for evaluation of olfactory function but the results are culture-dependent. It relies on the subject's familiarity to the odorant and descriptors. This study aims to develop the Malaysian version of Sniffin' Sticks smell identification test suitable for local population usage.
Materials and Methods: The odorant descriptors and distractors of the original version of Sniffin' Sticks were translated into Malay language. It was then tested for familiarity and identifiability in 30 normosmic subjects. The descriptors were replaced until the familiarity of all descriptors and identification rates of odorants achieved ≥ 70%. The validity of the new cultural-adapted version was tested in 60 hypo-anosmic subjects and 60 normosmic subjects with Student t-test. The test-retest reliability was evaluated after two weeks with interclass correlation.
Results: Two odorant descriptors and nine distractors achieved familiarity <70% (13.3% - 66.7%) and were replaced. Another three culturally inappropriate distractors were also replaced. The mean score among the healthy subjects was significantly higher than the subject with smell dysfunction [13.7 (1.12) and 7.3 (3.42); t = 7.24 (df = 34.23), P<0.001]. The coefficient of correlation (r) between test and retest scores was 0.93 (P<0.001).
Conclusion: The cultural adapted Malaysian version of Sniffin' Sticks smell identification test is valid and has high test-retest reliability. This is the first smell identification test validated in Malaysia. It is effective for evaluation of olfactory function in local population.
Nasopharyngeal Carcinoma with Cystic Cervical Metastasis Masquerading as Branchial Cleft Cyst: A Potential Pitfall in Diagnosis and Management

Sai-Guan L, Min-Han K, Kah-Wai N, Mohamad-Yunus MR

Iran J Otorhinolaryngol, 2017 Mar;29(91):117-120.
PMID: 28393061

INTRODUCTION: Most metastatic lymph nodes from head and neck malignancy are solid. Cystic nodes are found in 33% - 61% of carcinomas arise from Waldeyer's ring, of which only 1.8% - 8% originate are from the nasopharynx. Some cystic cervical metastases were initially presumed to be branchial cleft cyst. This case report aims to highlight the unusual presentation of cystic cervical metastasis secondary to nasopharyngeal carcinoma in a young adult. The histopathology, radiological features and management strategy were discussed.
CASE REPORT: A 36-year-old man presented with a solitary cystic cervical swelling, initially diagnosed as branchial cleft cyst. Fine needle aspiration yielded 18 ml of straw-coloured fluid. During cytological examination no atypical cells were observed. Computed tomography of the neck showed a heterogeneous mass with multiseptation medial to the sternocleidomastoid muscle. Histopathological examination of the mass, post excision, revealed a metastatic lymph node. A suspicious mucosal lesion at the nasopharynx was detected after repeated thorough head and neck examinations and the biopsy result confirmed undifferentiated nasopharyngeal carcinoma.
CONCLUSION: Cystic cervical metastasis may occur in young patients under 40 years. The primary tumour may not be obvious during initial presentation because it mimicks benign branchial cleft cyst clinically. Retrospective review of the computed tomography images revealed features that were not characteristic of simple branchial cleft cyst. The inadequacy of assessment and interpretation had lead to the error in diagnosis and subsequent management. Metastatic head and neck lesion must be considered in a young adult with a cystic neck mass.
Knockout of CTNNB1 by CRISPR-Cas9 technology inhibits cell proliferation through the Wnt/β-catenin signaling pathway

Guan L, Zhu S, Han Y, Yang C, Liu Y, Qiao L, et al.

Biotechnol Lett, 2018 Mar;40(3):501-508.
PMID: 29249062 DOI: 10.1007/s10529-017-2491-2

OBJECTIVE: To study the effects of CTNNB1 gene knockout by CRISPR-Cas9 technology on cell adhesion, proliferation, apoptosis, and Wnt/β-catenin signaling pathway.
RESULTS: CTNNB1 gene of HEK 293T cells was knocked out by CRISPR-Cas9. This was confirmed by sequencing and western blotting. Methylthiazolyl-tetrazolium bromide assays indicated that deletion of β-catenin significantly weakened adhesion ability and inhibited proliferation rate (P
Fulltext An Atypical Squamous Papilloma of the Uvula

Apandi A, Sai Guan L, Mohamad A, Muhamad Tamyez F, Ishak MN

Cureus, 2024 Apr;16(4):e58008.
PMID: 38738073 DOI: 10.7759/cureus.58008

Squamous papilloma of the oral cavity is frequently seen in adult patients and is typically presented as painless exophytic granular or cauliflower-like lesions over the tongue, floor of the mouth, palate, uvula, lips, and faucial pillars. Most of the lesions are solitary and grow rapidly to about 0.5 cm. Oral squamous papilloma has no known malignant potential, with conservative surgical excision being the treatment of choice. Recurrence is rare. It occasionally causes symptoms, unless the presentation is atypical, as in our case. An elongated uvula can cause discomfort and reduce a patient's quality of life. This study aims to report an atypical presentation of a squamous papilloma over the soft palate.
Distribution of neuronal nitric oxide synthase immunoreactivity in adult male Sprague-Dawley rat brain

Chong PS, Poon CH, Fung ML, Guan L, Steinbusch HWM, Chan YS, et al.

Acta Histochem, 2019 Nov;121(8):151437.
PMID: 31492421 DOI: 10.1016/j.acthis.2019.08.004

Neuronal NOS (nNOS) accounts for most of the NO production in the nervous system that modulates synaptic transmission and neuroplasticity. Although previous studies have selectively described the localisation of nNOS in specific brain regions, a comprehensive distribution profile of nNOS in the brain is lacking. Here we provided a detailed morphological characterization on the rostro-caudal distribution of neurons and fibres exhibiting positive nNOS-immunoreactivity in adult Sprague-Dawley rat brain. Our results demonstrated that neurons and fibres in the brain regions that exhibited high nNOS immunoreactivity include the olfactory-related areas, intermediate endopiriform nucleus, Islands of Calleja, subfornical organ, ventral lateral geniculate nucleus, parafascicular thalamic nucleus, superior colliculus, lateral terminal nucleus, pedunculopontine tegmental nucleus, periaqueductal gray, dorsal raphe nucleus, supragenual nucleus, nucleus of the trapezoid body, and the cerebellum. Moderate nNOS immunoreactivity was detected in the cerebral cortex, caudate putamen, hippocampus, thalamus, hypothalamus, amygdala, and the spinal cord. Finally, low NOS immunoreactivity were found in the corpus callosum, fornix, globus pallidus, anterior commissure, and the dorsal hippocampal commissure. In conclusion, this study provides a comprehensive view of the morphology and localisation of nNOS immunoreactivity in the brain that would contribute to a better understanding of the role played by nNOS in the brain.
Evidence for the Higgs Boson Decay to a Z Boson and a Photon at the LHC

Aad G, Abbott B, Abeling K, Abicht NJ, Abidi SH, Aboulhorma A, et al.

Phys Rev Lett, 2024 Jan 12;132(2):021803.
PMID: 38277607 DOI: 10.1103/PhysRevLett.132.021803

The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb^{-1} for each experiment, at a center-of-mass energy of 13 TeV. The measured signal yield is 2.2±0.7 times the standard model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.
Combination of Measurements of the Top Quark Mass from Data Collected by the ATLAS and CMS Experiments at sqrt[s]=7 and 8 TeV

Hayrapetyan A, Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, et al.

Phys Rev Lett, 2024 Jun 28;132(26):261902.
PMID: 38996325 DOI: 10.1103/PhysRevLett.132.261902

A combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The datasets used correspond to an integrated luminosity of up to 5 and 20 fb^{-1} of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively. The combination includes measurements in top quark pair events that exploit both the semileptonic and hadronic decays of the top quark, and a measurement using events enriched in single top quark production via the electroweak t channel. The combination accounts for the correlations between measurements and achieves an improvement in the total uncertainty of 31% relative to the most precise input measurement. The result is m_{t}=172.52±0.14(stat)±0.30(syst) GeV, with a total uncertainty of 0.33 GeV.