Histoplasmosis in Australia: A report of a case with a review of the literature

Histoplasmosis is a rare but serious fungal infection commonly presenting as mucosal ulceration of the oral cavity. It is increasingly recognized in Australia but the source of infection remains obscure and it is likely to be under-diagnosed. We report a case of chronic mucosal ulceration which failed to fully respond to periodontal therapy. Histology and culture of a gingival biopsy was consistent with histoplasmosis, and the patient responded favourably to treatment with oral itraconazole. Histoplasmosis may present to general dental practitioners as chronic mucosal ulceration and should be considered in the differential diagnosis of such lesions. Diagnosis is best made by culture and histology of biopsy specimens.

Mechanical disruption of seagrass in the digestive tract of the dugong

The cheek teeth in dugongs are considered to be largely non-functional whereas the oral horny pads are important both in mechanical disruption of the diet and in conveying seagrass through the mouth. Particle size distributions of digesta from 41 dead stranded dugongs were examined to investigate the relationship between degree of food breakdown, gut region and functional surface area of the mouthparts. The in vitro ease of fracture of major dietary seagrass species were compared. The rate of food breakdown through the gut appears to be more closely linked to fibre level of the diet than to size or age of the dugong and its mouthparts. Low fibre seagrass, for example Halophila ovalis, breaks down at a faster rate than high fibre seagrass, for example Zostera capricorni both in dugong guts and in vitro. Several structural characteristics of seagrass, including level and arrangement of fibre, and water content, make it particularly amenable to mechanical breakdown. The soft mouthparts of the dugong are highly modified so that the entire oral cavity functions to crush low fibre seagrasses. Thus, the dugong has developed an efficient method of food ingestion and mastication that is suited to processing large quantities of soft seagrass during short dive times. The potential cost to the dugong in having lost its hard dental surfaces is that it has become restricted to a low fibre diet.

Head and neck cancer: past, present and future

Head and neck cancer consists of a diverse group of cancers that ranges from cutaneous, lip, salivary glands, sinuses, oral cavity, pharynx and larynx. Each group dictates different management. In this review, the primary focus is on head and neck squamous cell carcinoma (HNSCC) arising from the mucosal lining of the oral cavity and pharynx, excluding nasopharyngeal cancer. Presently, HNSCC is the sixth most prevalent neoplasm in the world, with approximately 900,000 cases diagnosed worldwide. Prognosis has improved little in the past 30 years. In those who have survived, pain, disfigurement and physical disability from treatment have had an enormous psychosocial impact on their lives. Management of these patients remains a challenge, especially in developing countries where this disease is most common. Of all human cancers, HNSCC is the most distressing since the head and neck is the site of the most complex functional anatomy in the human body. Its areas of responsibility include breathing, the CNS, vision, hearing, balance, olfaction, taste, swallowing, voice, endocrine and cosmesis. Cancers that occur in this area impact on these important human functions. Consequently, in treating cancers of the head and neck, the effects of the treatment on the functional outcome of the patient need the most serious consideration. In assessing the success of HNSCC treatment, consideration of both the survival and functional deficits that the patient may suffer as a consequence of their treatment are of paramount importance. For this reason, the modern-day management of head and neck patients should be carried out in a multidisciplinary head and neck clinic.

Cytokine-specific Gene-knockout Studies in Oropharyngeal Candidiasis

Oropharyngeal candidiasis is a common clinical problem encountered in patients with defects in innate or cell-mediated immunity. We have previously shown that recovery from chronic oropharyngeal candidiasis is dependent on CD4+ T-cell augmentation of neutrophil and macrophage candidacidal activity, and that the immune response is characterised by the production of cytokines such as IL-12 and IFN-gamma by cells in the local draining lymph nodes, and by the expression of TNF-alpha in the oral tissues. Objective: The purpose of this study was to elaborate on the role of these cytokines in recovery from oropharyngeal candidiasis, by using cytokine-specific gene-knockout mice. Methods: These mice are created by targeted gene mutation (tm1) of embryonic stem (ES) cells microinjected into host embryos. IL-4, IL-10, IL-12, IFN-gamma and TNF-alpha knockout mice, and appropriate controls, were infected orally with 108 viable C. albicans yeasts. The infection was quantified by swabbing the oral cavity and plating on Sabouraud's agar. Results: Tnftm1mice developed an acute severe infection characterized by an increased fungal load in the early stages of infection, but cleared the yeast within the same time frame as control mice (21 days). On the other hand, Il12btm1 mice developed a chronic oropharyngeal infection (120 days) similar to that seen in T-cell deficient (Foxn1nu/Foxn1nu) mutant mice. There was no significant difference between Il4tm1, Il10tm1, and Ifngtm1 mice and their respective controls. Conclusions: Tnftm1 mice may be rendered more susceptible through impaired recruitment of phagocytic cells, and/or impaired killing of C. albicans, whereas Il12btm1 mice may not be capable of activating naïve T-cells or inducing an appropriate cellular immune response. Supported by NHMRC and ADRF.

DETERMINAÇÃO DA POSIÇÃO DE REPOUSO DA LÍNGUA EM INDIVÍDUOS COM OCLUSÃO DENTÁRIA NORMAL

O propósito neste estudo foi determinar a posição de repouso da língua em indivíduos com oclusão dentária normal e respiração nasal, por meio de telerradiografias em norma lateral realizadas após a ingestão de bário. A amostra foi composta por 66 radiografias de indivíduos brancos com oclusão dentária normal, sendo 26 do sexo masculino e 40 do sexo feminino, na faixa etária de 12 a 21 anos de idade, procedentes de escolas da região do Grande ABC Paulista. O critério utilizado para diagnóstico da oclusão normal foi As Seis Chaves para a Oclusão Normal preconizadas por Andrews (1972), devendo estar presentes no mínimo quatro das seis chaves, sendo obrigatória a presença da primeira chave de oclusão que é a da relação interarcos. As radiografias foram obtidas com o indivíduo em posição natural da cabeça após a ingestão de contraste de sulfato de bário para evidenciar o controle da língua. Posteriormente foi feito o desenho anatômico das estruturas pesquisadas, marcados os pontos cefalométricos, traçadas as linhas e os planos, e por último obtidas as seguintes medidas lineares: comprimento e altura da língua, distância do dorso da língua na sua porção média até o palato duro e a distância entre a ponta da língua e a incisal do incisivo inferior. Por meio dos resultados encontrados verificou-se que não existe um padrão único de posicionamento de repouso da língua dentro da cavidade oral, em pacientes respiradores nasais, variando muito sua distância até a incisal dos incisivos inferiores, bem como até o palato duro, havendo uniformidade apenas no fato da língua tocar o palato mole em todos os indivíduos da amostra. Não houve relação estatisticamente significante entre a posição de repouso da língua e os biotipos faciais e nem dimorfismo sexual.

Characterisation of propionibacterium acnes

Propionibacterium acnes forms part of the normal flora of the skin, oral cavity, large intestine and the external ear. Historically, P. acnes is considered to be of low virulence; however, in recent years it has been found as the aetiological agent in various pathologies including acne vulgaris, endophthalmitis, endocarditis, osteomyelitis, sarcoidosis, prosthetic hip infections and sciatica. It currently remains unclear why this normally harmless commensal can cause infection and contribute to a number of clinically significant conditions. This thesis has sought to investigate the phenotypic, genetic and antigenic properties of P.acnes strains isolated from sciatica patients undergoing microdiscectomy, normal skin, blood cultures, prosthetic hips and acne lesions. Isolates' phenotype was examined by determining their biotype by analytical profile index, antimicrobial susceptibility, virulence factor expression and serotype. A molecular typing method for P.acnes was developed using random amplification of polymorphic DNA (RAPD). Patient serum was used to screen P.acnes strains for antigens expressed in vivo and the chemical composition determined. The serodiagnostic potential and inflammatory properties of identified antigens were assessed. The optimised and reproducible RAPD protocol classified strains into three major clusters and was found to distinguish between the serotypes I and II for a large number of clinical isolates. Molecular typing by RAPD also enabled the identification of a genotype that did not react with the type I or II monoclonal antibodies and these strains may therefore constitute a previously undiscovered subspecies of P.acnes with a genetic background different from the type I and II serotypes. A major cell associated antigen produced by all strains was identified and characterised. A serological assay based on the antigen was used to measure IgG and IgM levels in serum from patients with acne, sciatica and controls. No difference in levels of antibodies was detected. Inflammatory properties of the antigen were measured by exposing murine macrophage-like cells and measuring the release of nitric oxide and tumour necrosis factor-alpha (TNF-α). Only TNF-α was elicited in response to the antigen. The phenotypic, genotypic and antigenic properties of this organism may provide a basis for future studies on P.acnes virulence and provide an insight into its mechanisms of pathogenesis.

Propionibacterium acnes:infection beyond the skin

Propionibacterium acnes is a Gram-positive bacterium that forms part of the normal flora of the skin, oral cavity, large intestine, the conjunctiva and the external ear canal. Although primarily recognized for its role in acne, P. acnes is an opportunistic pathogen, causing a range of postoperative and device-related infections. These include infections of the bones and joints, mouth, eye and brain. Device-related infections include those of joint prostheses, shunts and prosthetic heart valves. P. acnes may play a role in other conditions, including inflammation of the prostate leading to cancer, SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, sarcoidosis and sciatica. If an active role in these conditions is established there are major implications for diagnosis, treatment and protection. Genome sequencing of the organism has provided an insight into the pathogenic potential and virulence of P. acnes. © 2011 Expert Reviews Ltd.

Análise microbiológica da cavidade interna de implantes dentais osseointegrados utilizando o checkerboard DNA-DNA hybridization

Introduction: Infiltration of organic fluids and microorganisms at the abutment/implant interface may result in bacterial infection of peri-implant tissues. Internal colonization of periodontal pathogens may be caused by bacteria trapped during installation or penetration of abutment/implant leakage. The aim of this study was to detect periodontal pathogens in the internal area of dental implants before loading. Materials and Methods: Seventy-eight implants in 32 partially edentulous subjects were selected for this evaluation. A bacterial biofilm sample of the internal surface of each implant was taken and analyzed for the presence of 40 microorganisms by checkerboard DNA-DNA hybridization, prior to installation of healing or any other prosthetic abutment. Discussion: Bacteria were detected in 20 patients (62.5%), distributed in 41 implants (52.6%). Forty-seven percent of implants showed no bacterial detection. Spontaneous early implant exposure to oral cavity during the healing period was not significant (P >0.05) to increase bacterial prevalence, but implants placed at mandible had higher bacterial prevalence than maxillary ones. Conclusion: The internal surface of dental implants can serve as a reservoir of periodontal pathogens for future implant/abutment interface.

Acute primary actinomycosis involving the hard palate of a diabetic patient

Actinomycosis is a relatively rare infection caused by saprophytic bacteria of the oral cavity and gastrointestinal tract that can become pathogenic. The chronic hyperglycemia of diabetes mellitus induces events that promote structural changes in various tissues and are associated with problems in wound healing. This infection remains largely unknown to most clinicians because of its different presentations, and palatal involvement is extremely rare. This report describes the case of a 46-year-old woman who was diagnosed with actinomycosis involving the hard palate. The main clinical, histopathologic, and therapeutic characteristics and differential diagnosis of actinomycosis are reviewed. To date, 3 cases of actinomycosis involving the hard palate have been reported.

Acute primary actinomycosis involving the hard palate of a diabetic patient

Actinomycosis is a relatively rare infection caused by saprophytic bacteria of the oral cavity and gastrointestinal tract that can become pathogenic. The chronic hyperglycemia of diabetes mellitus induces events that promote structural changes in various tissues and are associated with problems in wound healing. This infection remains largely unknown to most clinicians because of its different presentations, and palatal involvement is extremely rare. This report describes the case of a 46-year-old woman who was diagnosed with actinomycosis involving the hard palate. The main clinical, histopathologic, and therapeutic characteristics and differential diagnosis of actinomycosis are reviewed. To date, 3 cases of actinomycosis involving the hard palate have been reported.

Statistical modelling of the rheological and mucoadhesive properties of aqueous poly(methylvinylether-co-maleic acid) networks: Redefining biomedical applications and the relationship between viscoelasticity and mucoadhesion

Poly(methylvinylether-co-maleic acid) (PMVE/MA) is commonly used as a component of pharmaceutical platforms, principally to enhance interactions with biological substrates (mucoadhesion). However, the limited knowledge on the rheological properties of this polymer and their relationships with mucoadhesion has negated the biomedical use of this polymer as a mono-component platform. This study presents a comprehensive study of the rheological properties of aqueous PMVE/MA platforms and defines their relationships with mucoadhesion using multiple regression analysis. Using dilute solution viscometry the intrinsic viscosities of un-neutralised PMVE/MA and PMVE/MA neutralised using NaOH or TEA were 22.32 ± 0.89 dL g-1, 274.80 ± 1.94 dL g-1 and 416.49 ± 2.21 dL g-1 illustrating greater polymer chain expansion following neutralisation using Triethylamine (TEA). PMVE/MA platforms exhibited shear-thinning properties. Increasing polymer concentration increased the consistencies, zero shear rate (ZSR) viscosities (determined from flow rheometry), storage and loss moduli, dynamic viscosities (defined using oscillatory analysis) and mucoadhesive properties, yet decreased the loss tangents of the neutralised polymer platforms. TEA neutralised systems possessed significantly and substantially greater consistencies, ZSR and dynamic viscosities, storage and loss moduli, mucoadhesion and lower loss tangents than their NaOH counterparts. Multiple regression analysis enabled identification of the dominant role of polymer viscoelasticity on mucoadhesion (r > 0.98). The mucoadhesive properties of PMVE/MA platforms were considerable and were greater than those of other platforms that have successfully been shown to enhance in vivo retention when applied to the oral cavity, indicating a positive role for PMVE/MA mono-component platforms for pharmaceutical and biomedical applications.

Human Papillomavirus (HPV): Making the case for “Immunisation for All”

Human Papillomavirus (HPV) contributes to the most common sexually transmitted infections, with repeated and persistent infection with particular types causing disease in both men and women. Infection with low-risk HPV types can lead to genital warts and benign lesions of the oral cavity, while high-risk types can cause various HPV-related malignancies. The incidence of head and neck cancer has been rising in the past number of decades mostly due to oropharyngeal cancer linked to HPV infection. HPV vaccination has been shown to be effective for cervical and other anogenital HPV-related cancers, and there is significant potential for HPV vaccination to prevent oropharyngeal cancers, given that the HPV types implicated in this disease can be protected against by the HPV vaccine. Few countries have implemented a universal HPV vaccination programme for males and females, with many countries arguing that female only vaccination programmes protect males via herd immunity, and that men-who-have-sex-with-men will be protected via targeted vaccination programmes. We argue these may be limited in their effectiveness. We propose that the most effective, practical, ethical and potentially cost effective solution is universal HPV vaccination that might lead to control of HPV-related diseases in men and women alike.