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Featured researches published by Wood Nh.


Head & Face Medicine | 2010

Human papillomavirus-mediated carcinogenesis and HPV-associated oral and oropharyngeal squamous cell carcinoma. Part 1: Human papillomavirus-mediated carcinogenesis

Feller L; Wood Nh; Razia Ag Khammissa; Lemmer J

High-risk human papillomavirus (HPV) E6 and E7 oncoproteins are essential factors for HPV-induced carcinogenesis, and for the maintenance of the consequent neoplastic growth. Cellular transformation is achieved by complex interaction of these oncogenes with several cellular factors of cell cycle regulation including p53, Rb, cyclin-CDK complexes, p21 and p27. Both persistent infection with high-risk HPV genotypes and immune dysregulation are associated with increased risk of HPV-induced squamous cell carcinoma.


Head & Face Medicine | 2010

Human papillomavirus-mediated carcinogenesis and HPV-associated oral and oropharyngeal squamous cell carcinoma. Part 2: Human papillomavirus associated oral and oropharyngeal squamous cell carcinoma

Feller L; Wood Nh; Razia Ag Khammissa; Lemmer J

Human papillomavirus (HPV) infection of the mouth and oropharynx can be acquired by a variety of sexual and social forms of transmission. HPV-16 genotype is present in many oral and oropharyngeal squamous cell carcinomata. It has an essential aetiologic role in the development of oropharyngeal squamous cell carcinoma in a subset of subjects who are typically younger, are more engaged with high-risk sexual behaviour, have higher HPV-16 serum antibody titer, use less tobacco and have better survival rates than in subjects with HPV-cytonegative oropharyngeal squamous cell carcinoma. In this subset of subjects the HPV-cytopositive carcinomatous cells have a distinct molecular profile.In contrast to HPV-cytopositive oropharyngeal squamous cell carcinoma, the causal association between HPV-16 and other high-risk HPV genotypes and squamous cell carcinoma of the oral mucosa is weak, and the nature of the association is unclear.It is likely that routine administration of HPV vaccination against high-risk HPV genotypes before the start of sexual activity will bring about a reduction in the incidence of HPV-mediated oral and oropharyngeal squamous cell carcinoma.This article focuses on aspects of HPV infection of the mouth and the oropharynx with emphasis on the link between HPV and squamous cell carcinoma, and on the limitations of the available diagnostic tests in identifying a cause-and-effect relationship of HPV with squamous cell carcinoma of the mouth and oropharynx.


Head & Face Medicine | 2009

The nature of fibrous dysplasia

Feller L; Wood Nh; Razia Ag Khammissa; Lemmer J; Erich J. Raubenheimer

Fibrous dysplasia has been regarded as a developmental skeletal disorder characterized by replacement of normal bone with benign cellular fibrous connective tissue. It has now become evident that fibrous dysplasia is a genetic disease caused by somatic activating mutation of the Gsα subunit of G protein-coupled receptor resulting in upregulation of cAMP. This leads to defects in differentiation of osteoblasts with subsequent production of abnormal bone in an abundant fibrous stroma. In addition there is an increased production of IL-6 by mutated stromal fibrous dysplastic cells that induce osteoclastic bone resorption.


Infectious Agents and Cancer | 2009

Epithelial maturation and molecular biology of oral HPV

Feller L; Razia Ag Khammissa; Wood Nh; Johan Lemmer

Human papillomavirus (HPV) is widespread and can cause latent infection in basal cells, with low HPV DNA copy-number insufficient for transmission of infection; can cause subclinical infection that is active but without clinical signs; or can cause clinical infection leading to benign, potentially malignant or malignant lesions. The HPV cycle is influenced by the stage of maturation of the infected keratinocytes, and the production of virions is restricted to the post-mitotic suprabasal epithelial cells where all the virus genes are expressed.Low-risk HPV genotypes are associated with the development of benign oral lesions, whereas high-risk HPV genotypes are implicated in the development of malignant epithelial neoplasms. The rôle of high-risk HPV as a causative agent in epithelial malignancy is different at different anatomical sites: it is almost invariably implicated in squamous cell carcinoma of the uterine cervix, fairly frequently implicated in squamous cell carcinoma of the oropharynx, and it is seldom implicated in squamous cell carcinoma of the mouth.


Cancer Cell International | 2008

The malignant potential of HIV-associated Kaposi sarcoma

Wood Nh; Feller L

Human herpesvirus (HHV)-8 associated oncogenesis, a state of immune impairment, a local inflammatory environment, angiogenesis and HIV infection occurring concurrently are important factors for the development of HIV-associated Kaposi sarcoma (KS).Activation of the interleukin (IL)-6 receptor signalling pathway and constitutive signalling of viral G protein-coupled receptor (vGPCR) play an important role in the activation, proliferation and transformation of HHV-8 infected endothelial cells thus contributing to the initiation and progression of KS. HIV-tat protein, HIV-induced immune suppression and a hyperinflammatory state facilitate the oncogenic activity of HHV-8.In this article we reviewed some aspects of HIV-KS pathogenesis and tried to establish, according to the available information in the literature, whether HIV-KS is a monoclonal neoplasm or a benign angioproliferative disorder.From the data of this review it is evident that most of the HIV-KS lesions are oligoclonal in origin. It remains to be demonstrated whether these multiple monoclonal populations of cells are neoplastic, harbouring specific cytogenetic alterations such as mutations, rearrangements and amplifications, or are, as the current evidence shows, the result of HHV-8 induced intracellular signalling pathways that modulate the expression of cellular genes associated with cell cycle regulation, apoptosis, inflammatory response and angiogenesis, and represent a reactive angioproliferative disorder.


Aids Research and Therapy | 2008

The prognostic significance of facial lymphoedema in HIV-seropositive subjects with Kaposi sarcoma

Feller L; Masipa Jn; Wood Nh; Erich J. Raubenheimer; Lemmer J

BackgroundKaposi Sarcoma (KS) is a multifocal angioproliferative neoplasm characterized by inflammation, oedema, neoangiogenesis and spindle cell proliferation. The pathogenesis of human immunodeficiency virus (HIV)-associated KS (HIV-KS) is multifactorial. HHV-8 is an essential factor but not in itself sufficient to cause HIV-KS, the development of which is influenced by HIV, by increased production of cytokines and by growth factors. Whether HIV-KS is a true malignancy or a reactive hyperplastic inflammatory condition is debatable.Results and ConclusionOedema of the face, legs and hands is a prominent feature of HIV-KS and is probably caused by lymphoedema related to the HIV-KS lesions. The cases of two HIV-seropositive subjects with KS-associated facial lymphoedema are reported. Extensive oral HIV-KS in association with facial oedema in the absence of anti-retroviral treatment appears to be an indication of a poor prognosis.


American Journal of Medical Genetics Part A | 2008

Report of a Black South African Child With Oculodentodigital Dysplasia and a Novel GJA1 Gene Mutation

Feller L; Wood Nh; Michelle D. Sluiter; Claudia E. Noffke; Erich J. Raubenheimer; Lemmer J; Elizabeth J. van Rensburg

Liviu Feller,* Neil H. Wood, Michelle D. Sluiter, Claudia Noffke, Erich J. Raubenheimer, Johan Lemmer, and Elizabeth J. van Rensburg Department of Periodontology and Oral Medicine, School of Dentistry, University of Limpopo (Medunsa Campus), Pretoria, South Africa Department of Genetics, University of Pretoria, Pretoria, South Africa Section of Maxillo-Facial Radiology, School of Dentistry, University of Limpopo (Medunsa Campus), Pretoria, South Africa Department of Oral Pathology, School of Dentistry, University of Limpopo (Medunsa Campus), Pretoria, South Africa


Aids Research and Treatment | 2011

Necrotizing Periodontal Diseases in a Semirural District of South Africa

Wood Nh; Elaine Blignaut; Lemmer J; Meyerov R; Feller L

Objectives. The aim of this study was to characterize the lesions of necrotizing gingivitis (NG) and necrotizing periodontitis (NP) with regard to extent and severity, and to correlate these parameters with the host HIV serostatus, CD4+ T-cell count, neutrophil count, age, and gender. Methods. Eighty-four consecutive patients, 39 black females and 45 black males aged 20–46 years, diagnosed with NG/NP were recruited to the study over a period of two years. Results. For both HIV-seropositive and -seronegative patients, the mandibular anterior gingiva was most frequently affected; 74% had NG/NP affecting ≥5 gingival tooth sites. Ninety percent of all patients had a mean severity of ≤4 mm. There was no statistically significant association between either extent or severity of NG/NP and HIV serostatus, CD4+ T-cell count, neutrophil count, age, or gender. The difference between the number of HIV-seropositive patients with NG/NP who had CD4+ T-cell counts ≤200 cells/mm3 and those who had CD4+ T cell counts of 201–499 cells/mm3 was not statistically significant. Conclusion. The clinical signs of NG/NP are similar in HIV-seropositive and -seronegative patients, and are not related to CD4+ T-cell count, to neutrophil count, to gender, or to age.


Cases Journal | 2008

Multiple congenital oral granular cell tumours in a newborn black female: a case report

Feller L; Wood Nh; Avin S Singh; Erich J. Raubenheimer; Meyerov R; Johan Lemmer

IntroductionCongenital oral granular cell tumour of the newborn is an uncommon benign tumour of uncertain origin. The typical clinical appearance is of a single nodule occurring on the anterior maxillary ridge. In 10% of cases there are multiple lesions. The occurrence of congenital epulis in non-Caucasians is rare.Case presentationTwo firm pedunculated nodular lesions were noticed in the mouth of a 3-day-old black female: one on the anterior maxillary ridge and the other further posteriorly in the midline of the palate. Both lesions were excised when the baby was nine days old. Microscopic examination of the lesions showed densely packed round to oval cells with abundant granular eosinophilic cytoplasm and uniform nuclei. The diagnosis was congenital granular cell tumour.ConclusionCongenital oral granular cell tumour occurs almost exclusively in Caucasian newborns but also rarely in black infants. The parents should be assured of the benign nature and the simple treatment of the condition.


Head & Face Medicine | 2009

Extramedullary myeloma in an HIV-seropositive subject. Literature review and report of an unusual case

Feller L; Jason White; Wood Nh; Bouckaert M; Lemmer J; Erich J. Raubenheimer

Myeloma is characterized by monoclonal bone marrow plasmacytosis, the presence of M-protein in serum and/or in urine and osteolytic bone lesions. HIV-seropositive subjects with myeloma are younger at the time of diagnosis of the tumour and usually the myeloma has a more aggressive clinical course than it does in HIV-seronegative subjects.A case of an HIV-seropositive woman in whom myeloma was diagnosed following progressive swelling of the face, is reported. In addition to bone marrow plasmacytosis and the presence of M-protein in the serum, the patient had an extramedullary lesion affecting the oral cavity, maxilla, parotid gland and paranasal sinuses, and extending intracranially and intraorbitally.

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Feller L

University of Limpopo

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Lemmer J

University of Limpopo

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Meyerov R

University of Limpopo

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Jadwat Y

University of Limpopo

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