Willie van Heerden
University of Pretoria
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Publication
Featured researches published by Willie van Heerden.
Journal of Oral Pathology & Medicine | 2008
Karin Louise Richter; Estrelita Janse van Rensburg; Willie van Heerden; Sonja C. Boy
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.
Clinical Oral Implants Research | 2009
Andre W. van Zyl; Willie van Heerden
OBJECTIVES This study analysed 200 consecutive computerised tomography (CT) scans, reformatted with specialised software for the identification of maxillary sinus septa. All patients were routine implant patients who had undergone CT scans for dental implant planning. MATERIALS AND METHODS The data of two hundred consecutive patients (400 maxillary sinuses) who had been sent for CT scan, were reformatted with CT software. The group consisted of 115 edentulous and 85 dentate (below sinuses) patients. Septa were identified using three-dimensional (3D) reconstruction and panoramic views. No septa were included unless they were clearly visible on the 3D reconstruction. The prevalence, height and number of septa were analysed for both groups of patients. RESULTS The prevalence of sinus septa was found to be 69% (138 patients), with a significant number of these patients showing multiple septa (89/138). The mean age of the patients was 54 (+/-14). The prevalence of edentulous patients with septa (71%) was not statistically different from the dentate patients (66%) (P=0.7). DISCUSSION This study found a higher prevalence of patients with maxillary sinus septa than what has been reported previously. This may be due to the exact nature of the CT software and the ease of use of the 3D reconstruction for identification of septa. Another explanation could be that all septa that were visible on the 3D reconstruction were included and there was no minimum cut-off height. No significant differences were found between edentulous and dentate patients.
Journal of Forensic Sciences | 2008
Herman Bernitz; Johanna H. Owen; Willie van Heerden; Tore Solheim
Abstract: The high number of murder, rape, and child abuse cases in South Africa has led to increased numbers of bite mark cases being heard in high courts. Objective analysis to match perpetrators to bite marks at crime scenes must be able to withstand vigorous cross‐examination to be of value in conviction of perpetrators. An analysis technique is described in four stages, namely determination of the mark to be a human bite mark, pattern association analysis, metric analysis and comparison with the population data, and illustrated by a real case study. New and accepted techniques are combined to determine the likelihood ratio of guilt expressed as one of a range of conclusions described in the paper. Each stage of the analysis adds to the confirmation (or rejection) of concordance between the dental features present on the victim and the dentition of the suspect. The results illustrate identification to a high degree of certainty.
Journal of Forensic Sciences | 2006
Herman Bernitz; Willie van Heerden; Tore Solheim; Johanna H. Owen
ABSTRACT: Anterior teeth within the human dentition have a specific numerical rotation value. Bite marks show an array of angled indentations, abrasions, microlacerations, and contusions. These marks generally represent the incisal surfaces of the suspects dentition reflecting the rotation values of the teeth in the dental arch. This study described a method for capturing and analyzing anterior dental rotations. The rotations of individual anterior teeth within the study population were categorized as common, uncommon, and very uncommon according to Allens classification. In the absence of a large number of incisal patterns present in a bite mark, a single but heavily weighted tooth rotation could be of equal discriminatory potential to several common rotation values. No prevalence studies quantifying individual tooth rotations are available. The measurement of each individual tooth rotation together with its individual discrimination potential will enhance the evaluation of the concordant features observed in bite marks.
Oral Oncology | 2011
Sonja C. Boy; Marlene van Heerden; Chantal Babb; Willie van Heerden; Pascale Willem
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.
American Journal of Forensic Medicine and Pathology | 2003
Sonja C. Boy; Herman Bernitz; Willie van Heerden
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.
Journal of Oral Pathology & Medicine | 2008
Sonja C. Boy; Marlene van Heerden; Marianne Wolfaardt; Riana Cockeran; Elize Gema; Willie van Heerden
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.
Oral Surgery, Oral Medicine, Oral Pathology, and Oral Radiology | 2015
Belinda K. Bunn; Willie van Heerden
OBJECTIVE To present 2 cases of Epstein-Barr virus (EBV)-positive mucocutaneous ulcer of the oral mucosa in association with human immunodeficiency virus infection. STUDY DESIGN Two recently diagnosed cases of EBV-positive mucocutaneous ulcer of the oral mucosa in patients with human immunodeficiency virus (HIV) were reviewed with regard to their clinical, histomorphologic, and immunophenotypic features. RESULTS Both cases presented clinically as well-circumscribed ulcers that were histomorphologically characterized by dense superficial polymorphous inflammatory infiltrates. The infiltrates comprised cells with a predominant B-cell phenotype that ranged in size from small to intermediate with occasional large immunoblastic forms. Some of the larger B cells had a Reed-Sternberg-like morphology. The B cells were positive for CD20 and coexpressed CD30 and to a lesser extent CD15. Epstein-Barr virus-encoded small RNA (EBER) positivity was detected in most of the B cells. CONCLUSIONS EBV-positive mucocutaneous ulcer represents an unusual form of lymphoproliferative disorder associated with immune suppression. It should be distinguished from other forms of HIV-associated oral ulceration.
Archives of Oral Biology | 2015
Sulette Nel; Marlene van Heerden; Willie van Heerden
AIM To investigate the expression of CD56 in dog odontogenesis in order to elucidate the expression found in ameloblastomas. MATERIALS AND METHODS Immunohistochemical analysis of CD56 expression of developing dog teeth in the bud, cap and bell stages including the remnants of the dental lamina. RESULTS Weak CD56 expression was observed in the dental epithelium during the bud stage with intense staining of certain peripheral epithelial cells. Positive staining of epithelial cells was also observed in the cap stage with intense staining of the inner enamel epithelium at this stage. During the bell stage the staining was concentrated on the cervical loop areas. The dental papilla revealed positive staining throughout the cap and bell stages while the dental follicle stained intensely positive throughout all the phases examined. The dental lamina and Serres rests also stained positive for CD56. CONCLUSIONS The expression of CD56 in dog odontogenic tissue varies according to the stage of tooth development. There is a positive correlation between the positive staining observed in ameloblastomas and their odontogenic cells of origin.
Oral Surgery, Oral Medicine, Oral Pathology, and Oral Radiology | 2013
Belinda K. Bunn; Marianne de Vasconcelos Carvalho; Melanie Louw; Pablo Agustin Vargas; Willie van Heerden
Kaposi sarcoma is the most common HIV-associated neoplasm, frequently presenting with oral mucosal involvement. This retrospective study aimed to assess and highlight the histomorphological spectrum of oral Kaposi sarcoma. A total of 135 cases diagnosed between 1990 and 2011 were retrieved from the archives of the Oral and Dental Hospital of the University of Pretoria, South Africa. Following histologic review, each case was placed into 1 of 7 categories based on the predominant pattern of growth. These histologic divisions included lesions designated as solid, lymphangioma-like, telangiectatic, desmoplastic, lymphangiectatic, ecchymotic, and anaplastic. The presence of coexistent pathology was identified in 25 cases, largely represented by superimposed candidiasis. Concomitant cytomegalovirus and non-necrotizing granulomatous inflammation were also observed. Although the prognostic significance of these variants is yet to be determined, the appreciation and recognition of such morphologic diversity remains essential in distinguishing these lesions from possible mimickers.