Sonja C. Boy

Human papilloma virus types in the oral and cervical mucosa of HIV‐positive South African women prior to antiretroviral therapy

BACKGROUND To evaluate the prevalence of human papilloma virus (HPV) infection and types in the oral and cervix mucosa of treatment-naïve HIV-1-positive women with CD4 counts less than 300 cells per ml with no HPV-associated oral lesions. METHODS Oral epithelium was harvested from the buccal mucosa and lateral borders of the tongue and cervical samples were collected from the endocervical area of 30 women, 22-64 years old. Cytobrush Plus cell collectors were used for sampling both anatomical areas. Genital pathology, obstetric and gynaecological history, co-morbid disease, hormone therapy, sexual behavior and smoking history were assessed via physical examination and clinical interviews. Special investigations included cervical Papanicolau smears, CD4 counts and HIV-1 viral loads. The linear array HPV test was used to determine HPV genotypes present in the specimens. RESULTS Oral HPV were identified in 20% (n = 6) of the patients, of which two had infection with two HPV types. Genital HPV was found in 96.7% (n = 29) of the women, of which only 14 had cytological abnormalities on Papanicolau smear. Infection with multiple HPV types were present in 93.1% (n = 27) of the patients, with an average of four HPV types per individual. CONCLUSIONS South African HIV-positive women with CD4 counts less than 300 cells per ml have a significant risk of cervical HPV strains and multiple strain infection of the cervix. The prevalence of HPV in normal oral mucosa was low but high-risk types were present. Limited correlation between oral HPV types and those identified in the cervical mucosa was found.

Dominant genetic aberrations and coexistent EBV infection in HIV-related oral plasmablastic lymphomas

We present common cytogenetic features in the largest cohort of plasmablastic lymphoma (PBL) of the oral cavity published to date. This cohort included 45 patients, 32 of whom had a known HIV status, of which 31 were HIV positive. Ninety eight per cent of all PBL cases were known to be EBV positive. In line with previous studies, we found that rearrangements of the MYC gene was the most common genetic abnormality seen in 60% of cases with the immunoglobulin heavy chain (IGH) locus as a partner in 51% of cases. Additional complex genetic aberrations were frequent, in particular, an increased copy number of the CCND1 gene was seen in 41% of cases with true amplification of CCND1 in 15% of cases. Aneuploidy was also observed for the BCL6 gene in 28% of cases. Interestingly, rearrangements of both IGH genes were detected in 16% of cases with t(14;18) and t(11;14) respectively involved in conjunction with a t(8;14) in two cases. These bi-allelic IGH rearrangements have not been described before in oral PBL. Our results reinforce the notion that EBV infection and MYC rearrangements are important events in the pathogenesis of oral PBL. The genetic diversity and complexity observed in these cases, underlines the importance to genetically characterise PBL patients at presentation as this may inform the choice of more effective treatment modalities.

Flow cytometric evaluation of postmortem pulp DNA degradation.

During postmortem autolysis, cellular organelles and nuclear DNA break down into their constituent parts. DNA flow cytometric analysis was applied to study the denaturation of splenic cell DNA as a possible method for postmortem interval determination. DNA denaturation continued for 72 hours at a constant rate, with no intact DNA peaks thereafter. The value of using dental pulp tissue for flow cytometric determination of postmortem interval was investigated. The pulps of 57 routinely removed impacted third molars from patients 15 to 30 years of age were obtained. Pulp tissue was removed at 24, 48, 72, 96, 120, and 144 hours postextraction. Debris (degraded DNA) was defined as all signals left of the standardized mean 2 n peak and expressed as a percentage of the total number of signals. In contrast to the splenic cell DNA, dental pulp tissue exhibited minimal DNA degradation by 144 hours postextraction, and no constant relation was found between time and DNA degradation during this time. In this study, pulp tissue was found to be unreliable to determine the early postmortem interval but might be of greater value in the later stages.

Diagnosis and management of odontogenic myxoma in a dog.

A three-year-old Jack Russell terrier dog was presented with a large gingival mass of the right mandible extending from the fourth premolar to the first molar teeth. Radiographic examination of the expansile mass revealed moth-eaten, honeycomb-like lyses of the mandible and extended into the mandibular alveolar canal based on computed tomography. The histopathological diagnosis of the biopsy was odontogenic fibromyxoma. Mandibulectomy with resection of the associated soft tissues was performed. Surgical management was curative with no clinical signs of disease 2-years after treatment. These neoplasms are slow growing, locally destructive tumors of odontogenic origin that have been described in the jaw of only one dog. In this paper, the clinico-radiological and pathologic features, diagnostic modalities as well as the factors that might influence treatment outcome of odontogenic myxomas are discussed. These odontogenic tumors are currently excluded from the WHO classification of odontogenic tumors in domestic animals and inclusion in future classifications systems is proposed.

An investigation of the role of oral epithelial cells and Langerhans cells as possible HIV viral reservoirs

BACKGROUND The role of the oral mucosa as a target of human immunodeficiency virus (HIV-1) infection and persistence is unclear. HIV-1 has been reported in oral epithelial cells, but this has not been confirmed. Cellular reservoirs may impede antiretroviral therapies and should be identified. This study was performed to determine the presence of HIV-1 in oral epithelial and Langerhans cells (LCs) of HIV-1-positive antiretroviral naïve patients. Non-invasive brush biopsy technique for future in vivo HIV research was also evaluated. METHODS Oral mucosal cells were harvested from the buccal mucosae, dorsal tongue and the gingiva of the mandibular teeth of 35 HIV-1-positive patients using a Cytobrush Plus cell collector. Epithelial cells were purified from the samples by flow cytometric cell sorting using cytokeratin stains after which the epithelial cell samples were further purified and divided into superficial and deep epithelial cells by laser microdissection on Pap stained cytospin smears. LCs were picked up individually by laser microdissection from CD1a stained cytospin smears. Purified epithelial and LC samples were tested for the presence of HIV-1 DNA by polymerase chain reaction analysis. RESULTS Ten of the patients had HIV-1 DNA in one or more of the sampled anatomical locations. No HIV-1 DNA could be demonstrated in any of the purified superficial or deep epithelial or LC samples. CONCLUSIONS HIV-DNA can be found using non-invasive oral brush biopsies and should be investigated further as an experimental model for in vivo oral HIV research. Better ways to purify the different cell types should be investigated.

In vitro comparison of three materials as apical sealants of equine premolar and molar teeth

REASONS FOR PERFORMING STUDY Surgical endodontic therapy is a conservative dental technique used in horses with some degree of clinical success. Failure of this procedure can partially be explained by inadequate sealing of the root apices with resultant microleakage in the periapical area. OBJECTIVES To assess and compare in vitro sealing ability of 3 different dental restorative materials used as apical sealants during equine surgical endodontics. METHODS Thirty extracted equine cheek teeth were divided randomly into 3 groups and subjected to apicoectomy and apical sealing using 3 materials: reinforced zinc oxide-eugenol cement; intermediate restorative material (IRM); a resin-modified glass ionomer; and amalgam. After apical sealing, the teeth were submerged in a solution of Procion Brilliant Cresyl Blue stain for a period of 7 days. The teeth were then washed, embedded in resin, sectioned and assessed microscopically for dye leakage around the apical restorations. RESULTS Although the materials proved effective as apical sealants, some dye leakage was encountered in all 3 groups with no statistical difference (P = 0.114). CONCLUSIONS AND POTENTIAL RELEVANCE IRM, a resin-modified glass ionomer and amalgam all showed comparative features as apical sealants when used in vitro in equine teeth. IRM is currently regarded as the superior material in clinical situations due to its ease of handling and lesser sensitivity to environmental moisture during placement compared to the other 2 materials.

Scanning Electron Microscopic Study of the Dentinal Tubules in Dog Canine Teeth

Dentin adhesive restorative techniques are regularly used in veterinary dentistry. Knowledge of the microanatomic structure and properties of dentin is essential to ensure success in restorative procedures. The aim of this study was to describe the density and diameter of dentinal tubules in dog canine teeth using recently described standardized scanning electron microscopy techniques. The results showed dentin of dog canine teeth to be more oval-shaped with a higher tubular density and slightly larger tubular diameters compared with human teeth. These features suggest dog canine teeth have less intertubular dentin compared with human teeth, which may theoretically result in lower resin-dentin shear bond strengths.

Diagnosis and treatment of primary intraoral leiomyosarcomas in four dogs

This paper describes the clinical and pathological features, diagnosis and management of primary intraoral leiomyosarcomas in the oral cavity of four dogs; they involved the gingivae of the rostral maxilla and mandible, the mucosa of the upper lip and the soft palate. Their features are compared with the those of leiomyosarcomas commonly encountered in the gastrointestinal tract of dogs. Two of the dogs responded well to surgical treatment; one died after its airways were obstructed by a large palatal tumour; and the fourth was lost to follow-up after its owners declined treatment.

A novel technique for ventral orbital stabilization : the masseter muscle flap

Loss of the caudal maxilla and ventral orbit after tumor resections can have negative functional and esthetic influences on the eye involved. This article reports on a case of a caudal maxillary acanthomatous ameloblastoma involving the ventral orbit that was resected and stabilized with a masseter muscle flap. The masseter muscle flap was generated from the superficial belly of the masseter muscle in order to close a defect in the orbital rim, created by a caudal maxillectomy. None of the published complications such as enophthalmos, excessive lacrimation, globe deviation, or strabismus were noted, 8 months following the procedure. The only clinical sign present at the time of re-evaluation was mild lacrimation. The authors propose the use of a masseter muscle flap as a viable technique in stabilizing the ventral orbit after caudal maxillectomy and ventral orbitectomy, preventing the complications associated with this surgery.