The isolated symptom of unilateral tonsillar enlargement has limited value in adults with a suspected head and neck cancer pathway.

OBJECTIVE: Given the uncertainty regarding the predictive value of unilateral tonsillar enlargement and/or lesion in malignancies, this study aimed to evaluate the efficacy of unilateral tonsillar enlargement and/or lesion referral criterion in the adult suspected head and neck cancer pathway. METHODS: All two-week wait referrals received in 2018-2019 were reviewed. All patients referred with unilateral tonsillar enlargement and/or lesion were included and analysed for patient demographic data, presenting symptoms, initial clinic outcomes and final diagnoses. RESULTS: A total of 4934 urgent head and neck cancer referrals were analysed, and 1.9 per cent of these had unilateral tonsillar enlargement and/or lesion. Only 10 patients were diagnosed with tonsil cancer. All the positive tonsil cancer cases had at least one additional head and neck red flag symptom. CONCLUSION: The referral criterion for unilateral tonsillar enlargement and/or lesion may be of limited benefit in an already economically challenged National Health Service. Further multicentre studies should be undertaken to refine conclusions on the value of unilateral tonsillar enlargement and/or lesion alone as a criterion for the head and neck cancer two-week wait pathway.

Instrument for the evaluation of higher surgical training experience in the operating theatre.

OBJECTIVE: The operating theatre, as the primary learning environment for surgeons, needs to be conducive to achieve successful training. A validated 27-item questionnaire aimed at evaluating the training experience of higher surgical trainees in the operating theatre was developed. METHODS: The initial questionnaire was developed using a literature review and a focus group. Items were validated with content validity index (CVI) and Cronbach's alpha. RESULTS: The initial version of 33 questions was modified in the focus group into a 29-item 4-point Likert scale questionnaire covering 3 areas. Of these 29 items, 27 reached the threshold CVI of 0.87, and they achieved a Cronbach's alpha of 0.89 from 17 responses. CONCLUSION: The quantitative validations in the instrument are comparable to other existing medical education evaluation tools. Aspects of non-technical skills and human factors were featured heavily and perceived to be important for learning in the operating theatre.

Sacrifice of the chorda tympani nerve during middle-ear surgery can lead to resolution of dysgeusia.

BACKGROUND: Cholesteatoma often presents with persistent otorrhoea, conductive hearing loss or vestibular dysfunction. Rarely, cholesteatoma can cause dysgeusia if the lesion invades into the chorda tympani nerve. This paper presents an individual with cholesteatoma whose dysgeusia resolved following a mastoidectomy in which the chorda tympani was sacrificed. The current literature was reviewed for explanations behind this phenomenon. CASE REPORT: A previously fit 57-year-old man presented with a 3-month history of persistent otorrhoea and the complaint of a metallic taste in the mouth, and was diagnosed with cholesteatoma. The patient underwent radical mastoidectomy and the chorda tympani nerve was sacrificed. On post-operative review, he reported complete resolution of dysgeusia. CONCLUSION: The sense of taste is mediated by a complex neural network. It is possible that once the diseased chorda tympani is transected, compensation arises from other parts of the network. Sectioning of the chorda tympani could lead to a beneficial outcome in selected patients.

Spontaneous regression of advanced-stage oropharyngeal squamous cell carcinoma.

BACKGROUND: Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour proven by microscopic examination in the absence of any substantial treatment. This paper presents the case of an older woman whose advanced-stage tonsillar squamous cell carcinoma was noted to have spontaneously regressed at seven months. CASE REPORT: A 66-year-old woman presented with a 4-month history of dysphagia and odynophagia in September 2020. An exophytic tumour was seen on the right tonsil; this was diagnosed radiologically and histologically as a squamous cell carcinoma of the tonsils, with tumour-node-metastasis staging of T4aN0M0. The patient received best supportive care. Seven months later, the oropharyngeal lesion had disappeared, with no treatment. Subsequent computed tomography imaging showed radiological resolution of the previously noted right-sided oropharyngeal lesion. CONCLUSION: Several mechanisms of spontaneous regression are discussed. Further studies should review this case in conjunction with other reports of spontaneous tumour regressions, to elucidate underlying mechanisms.

'Primum non nocere': how harmless is routine wide local excision for AJCC stage IA melanoma?

BACKGROUND: Management of primary cutaneous malignant melanoma is with initial excision biopsy followed by a wide local excision to achieve locoregional control. For low-risk thin melanomas, the added survival benefit from the wide local excision is minimal. In this study, we investigated the morbidities of wide local excision and evaluated the current clinical practice in managing stage IA malignant melanoma. METHODS: Patients with confirmed stage IA malignant melanoma who had undergone a wide local excision in the 2013/14 period were identified using a specialist cancer multidisciplinary team-held database. Primary pathology, surgical data and follow-up documentation were analysed. RESULTS: A total of 231 cases were identified; 95% of patients (n = 220) had malignant melanoma excised completely at first excision biopsy, mean margin 2.8mm (range 0.5-8.0mm). Postoperative morbidities occurred in 25% of patients (n = 57), including 6.6% wound problems, 10.9% scarring problems, 10.0% psychological stress and 0.4% cosmetic concern. Wide local excision reconstructions were performed with primary closure in 82% of patients, split skin grafts in 4%, full-thickness skin grafts in 3% and flaps in 10%. Of the total, 44% of patients (n = 101) had further excisions and 17 received new low-risk melanoma diagnoses. CONCLUSIONS: We demonstrated that 1cm wide local excision is associated with significant morbidity, which can affect patients' physical, psychological and social wellbeing. Since wide local excision does not give a survival advantage, and its margin is already frequently reduced in cosmetically sensitive areas, the need for a second full 1cm wide local excision procedure for thin melanoma should be re-evaluated, especially when 95% of our study cohort had their malignant melanoma completely excised by the initial biopsy alone.

Fourier optics of image formation in aberration-corrected LEEM.

We present the extended Fourier Optics (FO) approach for modeling image formation in aberration-corrected low energy electron microscopy (ac-LEEM). The FO formalism is also generalized for image simulations of one or two-dimensional objects in ac and uncorrected (nac) LEEM. A comparison is made of the extended FO approach presented here and the extended contrast transfer function (CTF) approach for ac-LEEM that was developed earlier. The mathematically rigorous extended FO approach gains an advantage under conditions, particularly defocus, that partial coherence of the illumination may compromise the validity of the approximate CTF intensity calculation. The drawback of the FO approach compared to the CTF approach, which is its slow computational speed, is mitigated partly here by the implementation of a multi-core, multi-threading programming architecture. This work broadens our capabilities to understand the origins of LEEM image contrast and to perform quantitative evaluation of contrast observed in an image focal series.

High throughput scanning µLEED imaging of surface structural heterogeneity: Defective graphene on Cu(111).

Micro-low energy electron diffraction (µLEED) is frequently used in conjunction with low energy electron microscopy (LEEM) to learn about local surface structural features in small selected areas. Scanning µLEED measurements performed with a very small electron beam (250 nm) can provide precise quantitative information about structural variations with high spatial resolution. We have developed the Source Extraction and Photometry (SEP) - Spot Profile Analysis (SPA) tool for evaluating scanning µLEED data with high throughput. The capability to automate diffraction peak identification with SEP-SPA opens up the possibility to investigate systems with complex diffraction patterns in which diffraction peak positions vary rapidly for small lateral displacements on the surface. The application of this tool to evaluate scanning µLEED data obtained for defective graphene on Cu(111) demonstrates its capabilities. A rich rotational domain structure is observed in which a majority of the graphene is co-aligned with the Cu(111) substrate and the significant remainder comprises domains with large rotations and small sizes that are comparable to the small beam size.

Neutropenia and Agranulocytosis in Chinese Patients Prescribed Clozapine.

OBJECTIVES: To examine the rate of neutropenia and agranulocytosis, and the pattern of development of these 2 disorders among Chinese patients prescribed clozapine treatment in a local psychiatric unit. METHODS: Patients who were receiving clozapine when they were under the care of Pamela Youde Nethersole Eastern Hospital Psychiatric Unit, Hong Kong, from 1 January 1997 to 31 December 2012 and who developed neutropenia and agranulocytosis from 1 January 1997 to 30 June 2013 were retrospectively reviewed. RESULTS: A total of 13 patients out of 980 clozapine recipients developed neutropenia and 3 developed agranulocytosis during treatment. Half of them were aged > 50 years and three quarters were female. The majority of patients who developed neutropenia and agranulocytosis were prescribed > 1 psychotropic medication in addition to clozapine. Half of the incidents occurred in the first 18 weeks of clozapine treatment. CONCLUSION: Long-term monitoring of white cell count is necessary during clozapine treatment. The concurrent use of clozapine with other potentially leukopenic psychotropic drugs should be limited.

Psychiatric morbidity in Chinese women after cervical cancer treatment in a regional gynaecology clinic.

OBJECTIVES: To identify the prevalence and factors associated with psychiatric disorders in Chinese cervical cancer survivors. METHODS: A cross-sectional study was conducted from May 2011 to April 2012 at the specialist gynaecology outpatient clinic at Pamela Youde Nethersole Eastern Hospital, Hong Kong. All cervical cancer patients who had completed treatment were consecutively recruited. They were interviewed using the Chinese-Bilingual Structured Clinical Interview for DSM-IV Axis I Disorders, Patient Research version. Socio-demographic data and clinical information were collected from the patients and their hospital records were reviewed. RESULTS: A total of 113 patients were recruited into the study. The point prevalence of psychiatric disorders as a group in cervical cancer survivors was 37%. The point prevalence of depressive disorders, anxiety disorders, and schizophrenia were 31%, 16%, and 2%, respectively. Major depressive disorder was the most common mood disorder and generalised anxiety disorder the most common anxiety disorder. Younger age, a history of psychiatric illness, fatigue, menopausal symptoms, and pain were independent predictors of current psychiatric disorders. CONCLUSION: Psychiatric disorders, predominantly depressive and anxiety disorders, are common in Chinese cervical cancer survivors. Identification of independent predictors can help gynaecologists detect these disorders earlier and arrange appropriate interventions.

Use of spent mushroom compost to bioremediate PAH-contaminated samples.

Spent mushroom compost (SMC) is a bulky waste byproduct of mushroom industry and produced abundantly. The SMC of Pleurotus pulmonarius immobilized laccase (0.88 mmoles min(-1) g(-1)) and manganese peroxidase (0.58 mmoles min(-1) g(-1)) of which the optimal temperatures were 45 and 75 degrees C, respectively. In laboratory test, complete degradative removal of individual naphthalene, phenanthrene, benzo[a]pyrene and benzo[g,h,i]perylene (200 mg PAH kg(-1) sandy-loam soil) by 5% SMC was obtained in two days under continuous shaking at 80 degrees C. The SMC-treated PAH samples had significantly reduced or removed their toxicities as revealed by the Microtox bioassay. These results were confirmed by gas chromatography-mass spectrometry analysis on the breakdown products. A phthalic derivative which is reported as a degradative product of PAHs by ozonation or ligninolysis was also detected in the SMC-treated samples. The results demonstrate the potential in employing SMC in ex situ bioremediation.

Projections of purkinje cells in the translation and rotation zones of the vestibulocerebellum in pigeon (Columba livia).

Previous electrophysiological studies have shown that the pigeon vestibulocerebellum (ventral uvula, nodulus, and flocculus) can be divided into two parasagittal zones based on responses to optic flow stimuli. The medial zone (ventral uvula and nodulus) responds best to optic flow resulting from self-translation, whereas the lateral zone (flocculus) responds best to optic flow resulting from self-rotation. In this study we investigated the projections of the Purkinje cells in the translation and rotation zones of the vestibulocerebellum by using the anterograde tracer biotinylated dextran amine. Extracellular recording of Purkinje cell activity (complex spikes) in response to large-field visual stimuli were used to identify the injection sites. Injections into the translation zone resulted in extremely heavy terminal labeling in the cerebellovestibular process adjacent to the medial cerebellar nucleus. A moderate amount of terminal labeling was found in the medial cerebellar nucleus, the superior vestibular nucleus (laterally, dorsally, and medially), and the descending vestibular nucleus, particularly in the lateral half. Light terminal labeling was observed in the dorsolateral vestibular nucleus, the medial vestibular nucleus, the tangential nucleus, and the lateral vestibular nucleus pars ventralis. Injections into the rotation zone resulted in heavy terminal labeling in the superior vestibular nucleus (particularly dorsally and medially), the descending vestibular nucleus (particularly medially), and the medial vestibular nucleus. A moderate amount of terminal labeling was seen in the cerebellovestibular process adjacent to the lateral cerebellar nucleus, and the dorsolateral vestibular nucleus. A small amount of terminal labeling was found in the lateral cerebellar nucleus, the tangential nucleus, the prepositus hypoglossi, and the lateral vestibular nucleus pars ventralis.

Topographical organization of inferior olive cells projecting to translation and rotation zones in the vestibulocerebellum of pigeons.

Previous electrophysiological studies in pigeons have shown that the vestibulocerebellum can be divided into two parasagittal zones based on responses to optic flow stimuli. The medial zone responds best to optic flow resulting from self-translation, whereas the lateral zone responds best to optic flow resulting from self-rotation. This information arrives from the retina via a projection from the accessory optic system to the medial column of the inferior olive. In this study we investigated inferior olive projections to translational and rotational zones of the vestibulocerebellum using the retrograde tracer cholera toxin subunit B. Extracellular recordings of Purkinje cell activity (complex spikes) in response to large-field visual stimuli were used to identify the injection sites. We found a distinct segregation of inferior olive cells projecting to translational and rotational zones of the vestibulocerebellum. Translation zone injections resulted in retrogradely labeled cells in the ventrolateral area of the medial column, whereas rotation zone injections resulted in retrogradely labeled cells in the dorsomedial region of the medial column. Motion of any object through space, including self-motion of organisms, can be described with reference to translation and rotation in three-dimensional space. Our results show that, in pigeons, the brainstem visual systems responsible for detecting optic flow are segregated into channels responsible for the analysis of translational and rotational optic flow in the inferior olive, which is only two synapses from the retina.

Projections from the accessory optic system and pretectum to the dorsolateral thalamus in the pigeon (Columbia livia): a study using both anteretrograde and retrograde tracers.

In birds, optic flow is analyzed by two retinal-recipient nuclei: the nucleus of the basal optic root (nBOR) of the accessory optic system (AOS), and the pretectal nucleus, lentiformis mesencephali (LM). Previous anatomical studies have shown that both of these nuclei have descending projections to structures involved in oculomotor, head movement, and postural control. In this report, using biotinylated dextran amine (BDA) and cholera toxin subunit B (CTB) for anterograde and retrograde labelling, respectively, we investigated projections from the nBOR and LM to the dorsal thalamus. After injections of BDA into the nBOR and LM, terminals were consistently found in the nucleus dorsolateralis anterior pars lateralis and pars medialis, and the nucleus dorsalis intermedius ventralis anterior of the thalamus. Some terminals were also found in the nucleus dorsolateralis anterior, nucleus dorsomedialis anterior pars magnocellularis, nucleus dorsolateralis posterior, nucleus superficialis parvocellularis, and the ventrointermediate area. Injections of CTB into the dorsal thalamus resulted in retrogradely labelled cells in the pretectal region, including LM. Numerous cells were also seen in the nBOR pars lateralis and pars dorsalis, but fewer were seen in the nBOR proper. We suggest that the AOS is providing input to a thalamotelencephalic system that may be involved in several functions including: (1) multi-sensory analysis of self-motion, (2) perception of self-motion, (3) perception of the three-dimensional layout of the environment, (4) distinguishing object-motion from self-motion, and (5) spatial cognition.

Projections of the nucleus of the basal optic root in pigeons (Columba livia) revealed with biotinylated dextran amine.

The nucleus of the basal optic root (nBOR) of the accessory optic system is known to be involved in the analysis of the visual consequences of self-motion. Previous studies have shown that the nBOR in pigeons projects bilaterally to the vestibulocerebellum, the inferior olive, the interstitial nucleus of Cajal, and the oculomotor complex and projects unilaterally to the ipsilateral pretectal nucleus lentiformis mesencephali and the contralateral nBOR. By using the anterograde tracer biotinylated dextran amine, we confirmed these projections and found (previously unreported) projections to the nucleus Darkshewitsch, the nucleus ruber, the mesencephalic reticular formation, and the area ventralis of Tsai as well as ipsilateral projections to the central gray, the pontine nuclei, the cerebellar nuclei, the vestibular nuclei, the processus cerebellovestibularis, and the dorsolateral thalamus. In addition to previous studies, which showed a projection to the dorsomedial subdivision of the contralateral oculomotor complex, we found terminal labelling in the ventral and dorsolateral subdivisions. Individual fibers were reconstructed from serial sections, and collaterals to various nuclei were demonstrated. For example, collaterals of fibers projecting to the vestibulocerebellum terminated in the vestibular or cerebellar nuclei; collaterals of fibers to the inferior olive terminated in the pontine nuclei; many individual neurons projected to the interstitial nucleus of Cajal, the nucleus Darkshewitsch, and the central gray and also projected to the nucleus ruber and the mesencephalic reticular formation; collaterals of fibers to the contralateral nucleus of the basal optic root terminated in the mesencephalic reticular formation and/or the area ventralis of Tsai; neurons projecting to the nucleus lentiformis mesencephali also terminated in the dorsolateral thalamus. The consequences of these data for understanding the visual control of eye movements, neck movements, posture, locomotion, and visual perception are discussed.