Characterization of non-invasive oropharyngeal samples and nucleic acid isolation for molecular diagnostics

Molecular diagnostics is an increasingly important clinical tool, especially in routine sampling. We evaluated two non-invasive methods (oral swabs and mouthwashes) for sampling nucleic acids from the oral/pharyngeal area. We created a workflow from sample collection (n = 59) to RT-qPCR based analysis. The samples were further characterized in terms of their cellular composition as well as the purity, degradation and microbial content of the derived DNA/RNA. We determined the optimal housekeeping genes applicable for these types of samples. The cellular composition indicated that mouthwashes contained more immune cells and bacteria. Even though the protocol was not specifically optimized to extract bacterial RNA it was possible to derive microbial RNA, from both sampling methods. Optimizing the protocol allowed us to generate stable quantities of DNA/RNA. DNA/RNA purity parameters were not significantly different between the two sampling methods. Even though integrity analysis demonstrated a high level of degradation of RNA, corresponding parameters confirmed their sequencing potential. RT-qPCR analysis determined TATA-Box Binding Protein as the most favorable housekeeping gene. In summary, we have developed a robust method suitable for multiple downstream diagnostic techniques. This protocol can be used as a foundation for further research endeavors focusing on developing molecular diagnostics for the oropharyngeal cavity.

Endolymphatic Hydrops Magnet Resonance Imaging in Ménière's Disease Patients after Cochlea Implantation

INTRODUCTION

Cochlear implantation in patients with Ménière's disease (MD) is the treatment of choice in cases of functional deafness. Additional vertigo control is of central importance in this group of patients. Endolymphatic hydrops (ELH) is the pathophysiological correlate of MD and can be evaluated by magnet resonance imaging (MRI). Bilateral MD occurs in 10-33% and can be the reason for a postoperative persisting or newly occurring vertigo in this group. Recent developments in the field of implant magnets and experience in MRI sequences allow the diagnostic performance of MRI in cochlear implantees to be evaluated. The aim of the present study was to evaluate the possibility of MRI as a visual diagnostic tool for endolymphatic hydrops in cochlear implantees.

MATERIAL AND METHODS

This was a retrospective study including three cochlear implantees (age: 61-76 years, one female, two male) suffering from MD who, postoperatively, had a recurrence of vertigo with Ménière's-like symptoms. An MRI was performed for the evaluation of ELH (ELH-MRI). MRI observation was performed by a 4 h iv. delayed Gad 3 D Flair sequence.

RESULTS

In all cases, the ipsilateral implant magnet artifact covered the vestibulum, the semicircular canals and the cochlea. The contralateral vestibulum, the semicircular canal and the cochlea were fully observable, and a classification of the ELH-MRI could be performed.

CONCLUSION

ELH-MRI scanning allows for the detection of contralateral labyrinthine endolymphatic hydrops and is a tool for the postoperative evaluation of vertigo in cochlear implantees.

Recurrent Respiratory Papillomatosis (RRP)-Meta-analyses on the use of the HPV vaccine as adjuvant therapy

Recurrent Respiratory Papillomatosis(RRP) is a rare disease with severe morbidity. Treatment is surgical. Prevailing viewpoint is that prophylactic HPV vaccines do not have therapeutic benefit due to their modus operandi. Studies on HPV vaccination alongside surgery were meta-analysed to test effect on burden of disease. Databases were accessed Nov and Dec 2021 [PubMed, Cochrane, Embase and Web of Science]. Main outcome measured was: Mean paired differences in the number of surgeries or recurrences per month. Analyses was performed using: Random effect maximal likelihood estimation model using the Stata module Mataan(StataCorp. 2019. Stata Statistical Software: Release 16. College Station, TX:StataCorp LLC.) Our results found n = 38 patients, suitable for syntheses with one previous meta-analyses (4 published, 2 unpublished studies) n = 63, total of n = 101 patients. Analyses rendered an overall reduction of 0.123 recurrences or surgeries per month (95% confidence interval [0.064, 0.183]). Our meta-analyses concludes that HPV vaccine is a beneficial adjunct therapy alongside surgery.

Primary head and neck cancer cell cultures are susceptible to proliferation of Epstein-Barr virus infected lymphocytes

BACKGROUND

New concepts for a more effective anti-cancer therapy are urgently needed. Experimental flaws represent a major counter player of this development and lead to inaccurate and unreproducible data as well as unsuccessful translation of research approaches into clinics. In a previous study we have created epithelial cell cultures from head and neck squamous cell carcinoma (HNSCC) tissue.

METHODS

We characterize primary cell populations isolated from human papillomavirus positive HNSCC tissue for their marker expression by RT-qPCR, flow cytometry, and immunofluorescence staining. Their sensitivity to MDM2-inhibition was measured using cell viability assays.

RESULTS

Primary HNSCC cell cultures showed the delayed formation of spheroids at higher passages. These spheroids mimicked the morphology and growth characteristics of other established HNSCC spheroid models. However, expression of epithelial and mesenchymal markers could not be detected in these cells despite the presence of the HNSCC stem cell marker aldehyde dehydrogenase 1 family member A1. Instead, strong expression of B- and T-lymphocytes markers was observed. Flow cytometry analysis revealed a heterogeneous mixture of CD3 + /CD25 + T-lymphocytes and CD19 + B-lymphocytes at a ratio of 4:1 at passage 5 and transformed lymphocytes at late passages (≥ passage 12) with CD45 + CD19 + CD20 + , of which around 10 to 20% were CD3 + CD25 + CD56 + . Interestingly, the whole population was FOXP3-positive indicative of regulatory B-cells (B_regs). Expression of transcripts specific for the Epstein-Barr-virus (EBV) was detected to increase in these spheroid cells along late passages, and this population was vulnerable to MDM2 inhibition. HPV + HNSCC cells but not EBV + lymphocytes were detected to engraft into immunodeficient mice.

CONCLUSIONS

In this study we present a primary cell culture of EBV-infected tumor-infiltrating B-lymphocytes, which could be used to study the role of these cells in tumor biology in future research projects. Moreover, by describing the detailed characteristics of these cells, we aim to caution other researchers in the HNSCC field to test for EBV-infected lymphocyte contaminations in primary cell cultures ahead of further experiments. Especially researchers who are interested in TIL-based adopted immunotherapy should exclude these cells in their primary tumor models, e.g. by MDM2-inhibitor treatment. BI-12-derived xenograft tumors represent a suitable model for in vivo targeting studies.

Corrigendum: A new device for the removal of cochlear schwannoma: A temporal bone study

[This corrects the article DOI: 10.3389/fsurg.2023.1077407.].

Hit and run oncogeneses in head and neck cancers requires greater investigation

Head and neck cancers are unique in so far that two major oncogenic viruses, Epstein Barr virus (EBV) and Human papillomavirus (HPV) infect adjacent anatomy and cause nasopharyngeal and oropharyngeal cancers, respectively. Dominant recognized carcinogens are alcohol and tobacco but some head and neck cancers have been found to have mixed carcinogens (including betel leaf, areca nuts, slaked lime, viruses, etc.) involved in their oncogenesis and conversely, groups of patients with unknown or less dominant carcinogens involved in their development. These cancers may have had viral involvement in the past but then lost most of their viral nucleic acids (be they DNA and/or RNA) below a detection threshold, thus rendering them virus-negative. Some of these virus-negative tumors appear to have mutagenic signatures associated with virus-positive cancers,  for example, from the APOBEC defense mechanism which is known to mutate viral nucleic acids as well as cause collateral damage to host DNA, with subsequent development of strongly viral prejudiced mutational signatures. These mechanisms are likely to be less efficient at oncogenesis than traditional EBV and HPV oncogenes directly driving mutagenesis, thus accounting for the smaller frequencies of these cancers found. More profound investigations of these unusual tumors are warranted to dissect out these mechanistic pathways.

Review of potential medical treatments for middle ear cholesteatoma

Middle ear cholesteatoma (MEC), is a destructive, and locally invasive lesion in the middle ear driven by inflammation with an annual incidence of 10 per 100,000. Surgical extraction/excision remains the only treatment strategy available and recurrence is high (up to 40%), therefore developing the first pharmaceutical treatments for MEC is desperately required. This review was targeted at connecting the dysregulated inflammatory network of MEC to pathogenesis and identification of pharmaceutical targets. We summarized the numerous basic research endeavors undertaken over the last 30+ years to identify the key targets in the dysregulated inflammatory pathways and judged the level of evidence for a given target if it was generated by in vitro, in vivo or clinical experiments. MEC pathogenesis was found to be connected to cytokines characteristic for Th1, Th17 and M1 cells. In addition, we found that the inflammation created damage associated molecular patterns (DAMPs), which further promoted inflammation. Similar positive feedback loops have already been described for other Th1/Th17 driven inflammatory diseases (arthritis, Crohn’s disease or multiple sclerosis). A wide-ranging search for molecular targeted therapies (MTT) led to the discovery of over a hundred clinically approved drugs already applied in precision medicine. Based on exclusion criteria designed to enable fast translation as well as efficacy, we condensed the numerous MTTs down to 13 top drugs. The review should serve as groundwork for the primary goal, which is to provide potential pharmaceutical therapies to MEC patients for the first time in history.

p53 pathway inactivation drives SMARCB1-deficient p53-wildtype epithelioid sarcoma onset indicating therapeutic vulnerability through MDM2 inhibition

Loss of the gene SMARCB1 drives the development of malignant rhabdoid tumors, epithelioid sarcomas, and other malignancies. The SMARCB1 protein is a core component of the SWI/SNF-family of chromatin remodeling complexes, which are important regulators of gene expression and cell differentiation. Here, we use CRISPR-Cas9 to create germline smarcb1 loss-of-function in zebrafish. We demonstrate that the combination of smarcb1-deficiency with mutant p53 results in the development of epithelioid sarcomas, angiosarcomas, and carcinomas of the thyroid and colon. Although human epithelioid sarcomas do not frequently harbor p53 mutations, smarcb1-deficient tumors in zebrafish were only observed following disruption of p53, indicating that p53 signaling in human tumors might be attenuated through alternative mechanisms, such as MDM2-mediated proteasomal degradation of p53. To leverage this possibility for the treatment of human epithelioid sarcoma, we tested small molecule-mediated disruption of the p53-MDM2 interaction, which stabilized p53 protein leading to p53-pathway reactivation, cell cycle arrest and increased apoptosis. Moreover, we found that MDM2 inhibition and the topoisomerase II inhibitor doxorubicin synergize in targeting epithelioid sarcoma cell viability. This could be especially relevant for epithelioid sarcoma patients since doxorubicin represents the current gold standard for their clinical treatment. Our results therefore warrant reactivating p53 protein in SMARCB1-deficient, p53-wildtype epithelioid sarcomas using combined doxorubicin and MDM2 inhibitor therapy.

Abstract 111: Head and neck cancer cells can differentiate and resemble their tissue of origin

Head and neck squamous cell carcinoma (HNSCC) is a highly malignant disease with a mortality rate of about 50%. It represents the sixth most common type of malignant tumor in the world. Risk factors include tobacco and alcohol usage and infection with the human papilloma virus (HPV). HPV-negative HNSCCs frequently display areas of cornification evident by keratin pearls in the tumor tissue. Cornification represents a natural differentiation path of keratinocytes in the normal epidermis and oral mucosa. To investigate the mechanisms of HNSCC cell differentiation we have established spheroid cell cultures from patient-derived HNSCC and parotid gland adenoid cystic carcinoma (ACC) tissue that grow in suspension under serum-free conditions. The use of a specific differentiation medium induced striking adhesion, loss of proliferation, and differentiation in tumor cells. Spheroid cells grew as single cell clones under serum-free conditions with a cloning efficiency of 40-60%, which was fully diminished under differentiating conditions. HNSCC cells cornified as indicated by the formation of lamellar bodies in the cytoplasm of adherent cells and an upregulation of cornification markers SPRR3 and involucrin. ACC cells upregulated parotid gland differentiation markers including α-amylase. RNA-seq analysis in HNSCC cells confirmed an upregulation of signaling pathways associated with cornification and epithelial cell differentiation. Conversely, pathways regulating the three-dimensional organization of the genome were downregulated upon differentiation. This was accompanied by the formation of ATRX-positive heterochromatin foci in the nucleus of differentiated ACC and HNSCC cells resembling those previously described to arise during therapy-induced senescence. Moreover, gas chromatography mass spectrometry analysis revealed a lack of essential amino acids including leucine to be implicated in the differentiation process. Altogether, our spheroid model of HNSCC and ACC cells is suitable to analyze the mechanisms underlying tumor cell differentiation and might lead to new therapeutic approaches that can drive long-term repopulating HNSCC and ACC cells into differentiation.

Citation Format: Felix Oppel, Senyao Shao, Sarah Gendreizig, Philipp Kühnel, Vivien Przybycin, Carsten Hain, Pascal Schmidt, Matthias Schürmann, Peter Goon, Karsten Niehaus, Jörn Kalinowski, Holger Sudhoff. Head and neck cancer cells can differentiate and resemble their tissue of origin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 111.

Sunburn Prevalence is Underestimated in UK-Based People of African Ancestry

Background

Eumelanin, the primary pigment in human epidermis, has a well-established photo-protective role. It can confer a protection factor of up to approximately 13.4 in some individuals. However, the protection eumelanin affords is not absolute and, further, the susceptibility of human skin to the harmful effects of UV radiation is more complex than skin pigmentation alone.

Objective

Our survey explored the lifetime prevalence of sunburn in people of African Ancestry based in the UK (Black African or Black Caribbean).

Results

A significant number of respondents, 52.2% (n=222), reported a history of sunburn. Interestingly, there was a significant increase in frequency of sunburn in those with a lighter skin tone (self-classified from dark, medium and light – 47.3%, 53.5% and 71.4%, respectively). In total 69% reported that the episode of sunburn occurred when they were not using sunscreen, and another 10% could not recall whether sunscreen was used. A large proportion of respondents (59%) indicated that they had been sunburnt while away from the UK in hot/sunny climates, raising the question of whether intermittent sun exposure at high UV indices is a key factor in sunburn risk for those living in temperate climates.

Conclusion

Our findings do not support the hypothesis of a simplistic relationship between skin colour and sun sensitivity and encourage us to re-examine this relationship and its implications for public health promotion. It also adds to a body of evidence revealing the need for more up-to-date and appropriate systems to assess the risk UV radiation poses to diverse populations.

903 React! – An Aide Memoire to Guide Management of Extravasation Injuries

Introduction

Intravenous infusions are common practice but come with the risk of extravasation injury. Although overall incidence is low, in those undergoing chemotherapy and in children the risk is much greater (4.7% and 11-58% respectively). These injuries can have severe consequences ranging from skin necrosis to loss of function, some necessitating complex reconstruction. Prompt recognition and treatment reduces the chance of these outcomes. Whilst classically managed by plastic surgeons, many hospitals do not have such services locally. Time-delays introduced by remote referral or inadequate initial treatment result in poor outcomes. We describe a simple algorithm with accompanying video designed to enable confident immediate management.

Method

We devised a simple acronym describing the basic steps, based on the technique described by Gault. Accompanied by an instructional video demonstrating the technique they form a simple to follow guide.

Results

The initial treatment of an extravasation injury can be split into the following key steps:

These steps, detailed in a simple poster, sit alongside a descriptive video which could be accessed through hospital intranets and video publishing platforms, such as Youtube and Vimeo, can allow potential users access on their portable devices.

Conclusions

The combination of the REACT! acronym and video provides an example of an easy-to-use teaching tool, when combined with local training, could improve the initial management of extravasation injuries in hospitals where plastic surgery input is not immediately available, reducing poor outcomes.

Skin cancers in skin types IV-VI: Does the Fitzpatrick scale give a false sense of security?

The Fitzpatrick scale has been in use for skin colour typing according to the tanning potential of skin since its inception in 1975-1976. Thomas Fitzpatrick developed the scale to classify persons with 'white skin' in order to select the correct amount of UVA in Joules/cm² for PUVA treatment for psoriasis. Since then, it has been widely used in Dermatology to gauge the skin's reaction to UV exposure, tanning potential, assessment of sunburn risk and amount of sun protection required for individual patients. However, the use of this scale has been of limited utility because of different self-perception in different areas of the world, particularly among those with skin of colour. Skin cancer risk is loosely inversely correlated with the initial genetic/inherent amount of melanin (most research has focused on eumelanin) present in the skin, although the pattern of exposure and amount of UV radiation required causing DNA damage varies widely according to different cancers. In this review, we have shown that the Fitzpatrick scale is neither correct nor adequate to reflect sunburn and tanning risk for skin of colour. Therefore, it may give both patients and physicians a false sense of security that there is little risk that people of colour can develop skin cancers. We have reviewed the small but not insignificant risk of skin of colour developing skin cancers and emphasise that there remains much research that needs to be done in this field.

Specific Targeting of Oncogenes Using CRISPR Technology

In recent decades, tools of molecular biology have enabled researchers to genetically modify model organisms, including human cells. RNAi, zinc-finger nucleases, transcription activator-like effector nucleases, CRISPR-Cas9 (clustered regularly-interspaced short palindromic repeats and CRISPR-associated protein 9), retro- or lentiviral gene transfer, and many other methods can be utilized to remove genes, add genes, or change their expression. Within the same timeframe, survival rates for many highly malignant tumor diseases have not improved substantially. If modern medicine could apply even a subset of research methods in clinical management, which are already well established and controllable in basic research laboratories, this could strongly impact patients' prognosis. CRISPR-Cas9 is a method to precisely target and manipulate genomic loci and recent studies have attempted to use this method as a genetic treatment for Duchenne muscular dystrophy, blood disorders, autosomal-dominant hearing loss, and cancer. Some of these approaches target mutant genomic sequences specifically and try to avoid affecting the respective normal loci. Considering obvious genetic risks opposing the objected benefits, data are needed to show whether CRISPR technology is suitable as a future cancer therapy approach or not. Here, we develop strategies for the specific targeting of viral cancer drivers and oncogenes activated by mutation, using the latest CRISPR technology. Cancer Res; 78(19); 5506-12. ©2018 AACR.

Deregulation of SYCP2 predicts early stage human papillomavirus-positive oropharyngeal carcinoma: A prospective whole transcriptome analysis

This study was designed to identify significant differences in gene expression profiles of human papillomavirus (HPV)‐positive and HPV‐negative oropharyngeal squamous cell carcinomas (OPSCC) and to better understand the functional and biological effects of HPV infection in the premalignant pathway. Twenty‐four consecutive patients with locally advanced primary OPSCC were included in a prospective clinical trial. Fresh tissue samples (tumor vs. matched normal epithelium) were subjected to whole transcriptome analysis and the results validated on the same cohort with RT–quantitative real‐time PCR. In a separate retrospective cohort of 27 OPSCC patients, laser capture microdissection of formalin‐fixed, paraffin‐embedded tissue allowed RNA extraction from adjacent regions of normal epithelium, carcinoma in situ (premalignant) and invasive SCC tissue. The majority of patients showed evidence of high‐risk HPV16 positivity (80.4%). Predictable fold changes of RNA expression in HPV‐associated disease included multiple transcripts within the p53 oncogenic pathway (e.g. CDKN2A/CCND1). Other candidate transcripts found to have altered levels of expression in this study have not previously been established (SFRP1, CRCT1, DLG2, SYCP2, and CRNN). Of these, SYCP2 showed the most consistent fold change from baseline in premalignant tissue; aberrant expression of this protein may contribute to genetic instability during HPV‐associated cancer development. If further corroborated, this data may contribute to the development of a non‐invasive screening tool. This study is registered with the UK Clinical Research Network (ref.: 11945).

Testing for 'threads' and leucocyte esterase in first-void urine to exclude the diagnosis of non-specific urethritis in asymptomatic men

Recent evidence suggests that asymptomatic nonspecific urethritis (NSU), which is not routinely tested for, is a clinically significant pathology.The aim of this pilot study was to determine if testing for urinary threads, leucocyte esterase (LE) or both in asymptomatic men is a good screening tool for NSU. Of the126 asymptomatic men, 8% met microscopic criteria for the diagnosis of NSU. The positive predictive value for NSU was 71% (95% confidence interval (CI): 29.3-95.5%) and the negative predictive value was 96% (95% CI: 92.8-99.5%). The absence of threads and negative LE makes urethritis highly unlikely, making urinary chlamydia (Chlamydia trachomatis) and gonorrhoea (Neisseria gonorrhoeae) testing sufficient. Incidental findings of further pathology occurred in 7%.

De-escalation treatment protocols for human papillomavirus-associated oropharyngeal squamous cell carcinoma

BACKGROUND

Human papillomavirus-associated oropharyngeal squamous cell carcinomas are a distinct subgroup of tumours that may have a better prognosis than traditional tobacco/alcohol-related disease. Iatrogenic complications, associated with conventional practice, are estimated to cause mortality of approximately 2% and high morbidity. As a result, clinicians are actively investigating the de-escalation of treatment protocols for disease with a proven viral aetiology.

OBJECTIVES

To summarise the available evidence regarding de-escalation treatment protocols for human papillomavirus-associated, locally advanced oropharyngeal squamous cell carcinoma.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 25 June 2013.

SELECTION CRITERIA

Randomised controlled trials investigating de-escalation treatment protocols for human papillomavirus-associated, locally advanced oropharyngeal carcinoma. Specific de-escalation categories were: 1) bioradiotherapy (experimental) versus chemoradiotherapy (control); 2) radiotherapy (experimental) versus chemoradiotherapy (control); and 3) low-dose (experimental) versus standard-dose radiotherapy (control). The outcomes of interest were overall and disease-specific survival, treatment-related morbidity, quality of life and cost.

DATA COLLECTION AND ANALYSIS

Three authors independently selected studies from the search results and extracted data. We planned to use the Cochrane 'Risk of bias' tool to assess study quality.

MAIN RESULTS

We did not identify any completed randomised controlled trials that could be included in the current version of this systematic review. We did, however, identify seven ongoing trials that will meet our inclusion criteria. These studies will report from 2014 onwards. We excluded 30 studies on methodological grounds (seven randomised trials with post hoc analysis by human papillomavirus status, 11 prospective trials and 12 ongoing studies).

AUTHORS' CONCLUSIONS

There is currently insufficient high-quality evidence for, or against, de-escalation of treatment for human papillomavirus-associated oropharyngeal carcinoma. Future trials should be multicentre to ensure adequate power. Adverse events, morbidity associated with treatment, quality of life outcomes and cost analyses should be reported in a standard format to facilitate comparison with other studies.

High resolution anoscopy may be useful in achieving reductions in anal cancer local disease failure rates

Anal cancer is uncommon, with an incidence rate of 0.5-1.0 per 100,000 of the population but incidence rates have been steadily increasing over the last 3 decades. Biological and epidemiological evidence have been mounting and demonstrate that anal cancer has many similarities to cervical cancer, especially in regard to its aetiology. High-resolution anoscopy (HRA) of the anal region – analogous to colposcopy of the cervix, is a technique that is not well-known in the medical and surgical fraternity. Evidence to support the use of HRA for detection and treatment in the surveillance of AIN exists and strongly suggests that it is beneficial, resulting in reduced rates of cancer progression. Pilot data from our study showed a local disease failure rate of 1.73 per 1000 patient-months compared with a published rate of 9.89 per 1000 patient-months. This demonstrates a 5.72-fold reduction in local disease failure rates of patients with T1-T3 tumours; the data therefore suggests that use of HRA for detection and treatment in surveillance of anal cancer patients will help prevent local regional relapse at the anal site. There is an urgent need for a large, randomised controlled clinical trial to definitively test this hypothesis.

Frequently asked questions about genital warts in the genitourinary medicine clinic: an update and review of recent literature

Genital warts are the commonest viral STI in the UK, and the incidence continues to rise. Diagnosing, treating and advising patients about this infection remain a large part of the work in any department of GU Medicine. This article reviews and provides the levels of evidence currently available on data about genital warts, and is primarily to advise and guide clinicians when faced with commonly asked questions in the clinic.

Melanocyte localization and distribution in human cholesteatoma

INTRODUCTION

Melanocytes in skin are derived from the neural crest and colonize the epidermis in the first trimester of gestation. Melanocytes have been observed in the nasopharyngeal, inner ear and oral mucosa and should therefore be present in the middle ear mucosa.

AIMS

To identify and determine the distribution of melanocytes in human cholesteatoma and normal meatal skin in Caucasian adults.

MATERIAL AND METHODS

Human cholesteatoma (n=18) and normal meatal skin samples (n=10) were investigated immunohistochemically with anti-HMB-45 and MART-1 antibodies. Localization and distribution of melanocytes were assessed in the epidermis and cholesteatoma using an automatic analyzing system.

RESULTS

Regular skin exhibited melanocytes within the epidermis and accounted for 10% of the total cell number. They occurred partly as membrane-bound clusters. Cholesteatoma matrix melanocytes were observed in the basal layer and exhibited an oval or roundmorphology. Decreased numbers of melanocytes in the basal layer correlated with keratinization within cholesteatoma samples. Melanocytes revealed monomorphous nuclei, abundant cytoplasm containing particles of melanin. Found adjacent to glands and blood vessels, melanocytes were also scattered among the mesenchymal cells. Accounting for 2-6% of the total cell number within the squamous epithelium, melanocyte density was significantly lower in cholesteatoma tissue than in skin.

CONCLUSIONS

The melanocyte distribution pattern was different when comparing the epithelia of skin and cholesteatoma. The presence of melanocytes in cholesteatoma may be due to an ingrowth, consequently controlled by keratinocyte-derived signals. In terms of the pathogenesis of cholesteatoma, neither squamous metaplasia nor melanocyte metaplasia can be excluded by our data.

Recurrent respiratory papillomatosis: an overview of current thinking and treatment

Human papillomaviruses (HPV) infection in benign laryngeal papillomas is well established. The vast majority of recurrent respiratory papillomatosis lesions are due to HPV types 6 and 11. Human papillomaviruses are small non-enveloped viruses (>8 kb), that replicate within the nuclei of infected host cells. Infected host basal cell keratinocytes and papillomas arise from the disordered proliferation of these differentiating keratinocytes. Surgical debulking of papillomas is currently the treatment of choice; newer surgical approaches utilizing microdebriders are replacing laser ablation. Surgery aims to secure an adequate airway and improve and maintain an acceptable quality of voice. Adjuvant treatments currently used include cidofovir, indole-3-carbinol, ribavirin, mumps vaccine, and photodynamic therapy. The recent licensing of prophylactic HPV vaccines is a most interesting development. The low incidence of RRP does pose significant problems in recruitment of sufficient numbers to show statistical significance. Large multi-centre collaborative clinical trials are therefore required. Even so, sufficient clinical follow-up data would take several years.

Zidovudine plus lamivudine in Human T-Lymphotropic Virus type-I-associated myelopathy: a randomised trial

BACKGROUND

No therapies have been proven to persistently improve the outcome of HTLV-I-associated myelopathy. Clinical benefit has been reported with zidovudine and with lamivudine in observational studies. We therefore conducted a randomised, double blind, placebo controlled study of six months combination therapy with these nucleoside analogues in sixteen patients.

RESULTS

Primary outcomes were change in HTLV-I proviral load in PBMCs and clinical measures. Secondary endpoints were changes in T-cell subsets and markers of activation and proliferation. Six patients discontinued zidovudine. No significant changes in pain, bladder function, disability score, gait, proviral load or markers of T-cell activation or proliferation were seen between the two arms. Active therapy was associated with an unexplained decrease in CD8 and non-T lymphocyte counts.

CONCLUSION

Failure to detect clinical improvement may have been due irreversible nerve damage in these patients with a long clinical history and future studies should target patients presenting earlier. The lack of virological effect but may reflect a lack of activity of these nucleoside analogues against HTLV-I RT in vivo, inadequate intracellular concentrations of the active moiety or the contribution of new cell infection to maintaining proviral load at this stage of infection may be relatively small masking the effects of RT inhibition.

A functional CD8+ cell assay reveals individual variation in CD8+ cell antiviral efficacy and explains differences in human T-lymphotropic virus type 1 proviral load

The CD8+ lymphocyte response is a main component of host immunity, yet it is difficult to quantify its contribution to the control of persistent viruses. Consequently, it remains controversial as to whether CD8+ cells have a biologically significant impact on viral burden and disease progression in infections such as human immunodeficiency virus-1 and human T-lymphotropic virus type I (HTLV-I). Experiments to ascertain the impact of CD8+ cells on viral burden based on CD8+ cell frequency or specificity alone give inconsistent results. Here, an alternative approach was developed that directly quantifies the impact of CD8+ lymphocytes on HTLV-I proviral burden by measuring the rate at which HTLV-I-infected CD4+ cells were cleared by autologous CD8+ cells ex vivo. It was demonstrated that CD8+ cells reduced the lifespan of infected CD4+ cells to 1 day, considerably shorter than the 30 day lifespan of uninfected cells in vivo. Furthermore, it was shown that HTLV-I-infected individuals vary considerably in the rate at which their CD8+ cells clear infected cells, and that this was a significant predictor of their HTLV-I proviral load. Forty to 50 % of between-individual variation in HTLV-I proviral load was explained by variation in the rate at which CD8+ cells cleared infected cells. This novel approach demonstrates that CD8+ cells are a major determinant of HTLV-I proviral load. This assay is applicable to quantifying the CD8+ cell response to other viruses and malignancies and may be of particular importance in assessing vaccines.

Low frequency of CD94/NKG2A+ T lymphocytes in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis, but not in asymptomatic carriers

Human natural killer (NK)-cell receptors are expressed by NK cells and some T cells, primarily TCR+CD8+ cytotoxic T lymphocytes (CTLs). Inhibitory NK cell receptors (iNKRs) can down-regulate antigen-mediated T-cell effector functions, including cytotoxic activity and cytokine release. In the present study we demonstrate that CD3+ T cells that bind tetramers of HLA-E and express its ligand, the NK-cell inhibitory receptor CD94/NKG2A, were significantly decreased in frequency in patients with human T-cell lymphotropic virus 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) but not in asymptomatic HTLV-1 carriers. These cells were either alphabeta or gammadelta T cells. T-cell receptor (TCR) Vbeta-specific reverse transcription-polymerase chain reaction and spectratyping analysis revealed that the TCR repertoire in directly isolated HLA-E tetramer-positive cells from peripheral blood mononuclear cells was skewed in both HTLV-1-infected and healthy individuals. However, oligoclonally or monoclonally expanded levels of TCR Vbetawere more frequently detected within HTLV-1-infected individuals than healthy controls. Importantly, HLA-E tetramer-positive or NKG2A+ T cells from HTLV-1 patients do not express Tax and display different TCR usage from the immunodominant Tax11-19-specific CD8+ T cells, suggesting that they do not encounter HTLV-1-infected cells. The expression of NK cell-associated receptors by clonally expanded CD8+ T cells during chronic viral infection suggests that these receptors play a role in regulating CD8+ T cell-mediated antiviral immune responses and that a decrease of this cell subset results in an increased risk of inflammatory diseases such as HAM/TSP.

High production of interferon gamma but not interleukin-2 by human T-lymphotropic virus type I-infected peripheral blood mononuclear cells

The transactivator protein of human T-lymphotropic virus I (HTLV-I), Tax, has been associated with the up-regulation of several host cell genes, including interleukin 2 (IL-2), the IL-2 receptor-alpha (IL-2Ralpha) chain (CD25), interferon gamma (IFN-gamma), and tumor necrosis factor (TNF). It has been proposed that an IL-2/CD25 autocrine loop plays a part in maintaining the very high proviral loads often found in HTLV-I infection. Furthermore, abnormal production of inflammatory cytokines might contribute to the pathogenesis of the inflammatory diseases associated with HTLV-I infection. However, there has been no study of the expression of these genes in freshly isolated peripheral blood mononuclear cells (PBMCs) naturally infected with HTLV-I. In the present study, flow cytometry was used to determine which cytokines are produced by freshly isolated PBMCs that spontaneously express the HTLV-I Tax protein. Surprisingly, the results show that intracellular Tax expression is associated with rapid up-regulation of IFN-gamma but not TNF or IL-2. A proportion of HTLV-I-infected cells express both IFN-gamma and the surface markers of effector memory cells. Such cells are capable of migration through peripheral tissues and could therefore contribute to the inflammation seen in diseases such as HTLV-I-associated myelopathy/tropical spastic paraparesis. (Blood. 2001;98:721-726)

MMR vaccine in HIV-infected children -- potential hazards?

Although given routinely as prophylaxis against wild-type measles to HIV-infected children, the live attenuated measles component of the MMR triple vaccine also possesses potential for disease. We document a case of measles proven to be caused by vaccine strain in a HIV-infected child here in the UK and discuss the clinical and immunological aspects. We also consider the new guidelines for MMR vaccination in HIV-infected children adopted last year in the USA.

An airborne intensive care facility (fixed wing)

A fixed-wing aircraft (Beechcraft KingAir B200 C) fitted as an airborne intensive care facility is described. It completed 2000 missions from 1987-1992 for distances up to 1300 km. Features include: 1. Space for carriage of two stretchers, medical cabin crew of up to five persons and equipment and two-pilot operation if necessary. A third stretcher may be carried in emergencies. 2. Two CARDIOCAP (TM) fixed monitors for ECG, invasive and noninvasive pressures pulse oximetry and end-tidal C02 plus SIEMENS 630(TM)/PROPAQ(TM) compact monitors for the ground transport phase of missions, or the total duration. 3. A medical oxygen reservoir of 4650 litres sufficient for two patients on IPPV with FiO2 = 1.0 for a four-hour trip. The medical suction system is powered from the engine or a vacuum pump. 4. Other medical equipment and drugs in portable packs, for ground transport and resuscitation needs and for replenishment by nursing staff at the parent hospitals. 5. Stretchers compatible with helicopter and road ambulance vehicles used. 6. A stretcher loading device energized from the aircraft, operating through a wide (cargo) door. 7. Provision of 24Ov AC (alternating current) and 28v DC (direct current) electrical energy. 8. Pressurization and climate control. 9. Satisfactory aviation performance for conditions encountered, with single-pilot operation.