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Biomedical subjects

E J Raubenheimer

Publications and source records attributed to E J Raubenheimer.

At least 19 recordsLinked to original sources

Amino acid composition of dentine in permanent human teeth.

Dentine of permanent mandibular incisors from nine individuals was hydrolysed and the amino acid composition determined by ion-exchange chromatography against a standard calibrant of 41 amino acids. Nineteen amino acids were detected, including small quantities of 1-methylhistidine and asparagine, two amino acids whose existence had apparently not been recorded before in human dentine. The total content of hydroxylysine plus lysine varied between 2.6 and 3.3 residues per 100 (SD, 0.74) in different teeth, which therefore did not support previous studies that had proposed a constant total value. This and other quantifiable differences between present and previous findings may be the result of the different methods and the influence of dietary and other regional factors on dentinogenesis.

Amino Acids

Diffuse peripheral odontogenic fibroma: report of 3 cases.

Since peripheral odontogenic fibroma (POF) is characteristically described as a solitary lesion and no diffuse POF had been reported in the literature, our cases should be considered as extremely unusual. Three diffuse cases of POF are described of which one case was seen in association with ocular and skin lesions. The question arises whether POF should be considered as a true odontogenic tumor rather than a diffuse hamartomatous lesion caused by uncontrolled induction of the gingiva. It is also possible that such lesions could be part of a yet undescribed syndrome.

Child

Peripheral dentinogenic ghost cell tumor.

A case of dentinogenic ghost cell tumor, that has originated peripherally in the jaw, is presented and the literature reviewed with particular reference to the origin of the tumor. The total number of central and peripheral cases reported in the English literature is 10 and although mucosal infiltration is common, peripheral origin of the neoplasm could be verified in only 3 cases.

Aged

Intraoral salivary gland neoplasms: a retrospective study of seventy cases in an African population.

Intraoral salivary gland neoplasms diagnosed in the Department of Oral Pathology, Medical University of Southern Africa, Medunsa, were reassessed and revised with regard to histologic diagnosis. New entities and subclassifications that have been described in recent years were taken into account. Seventy cases were diagnosed during an 8-year period, and the sample consisted of black patients only. Benign mixed tumor was the most common entity and accounted for 48% of all tumors. Polymorphous low-grade adenocarcinoma comprised 15.7% of the sample and was the most frequent malignant tumor. The mean age of patients with benign and malignant tumors were 36.5 and 49.8 years, respectively (p less than 0.05), and the palate was the most common site involved. Geographic differences do exist in the pattern and pathology of intraoral salivary gland neoplasms when compared with findings in other studies.

Adenocarcinoma

Non-secretory IgA kappa myeloma with distended endoplasmic reticulum: a case report.

A case of non-secretory multiple myeloma is presented. Plasma cells showed abundant cytoplasmic colloid contained in distended rough endoplasmic reticulum. Uniform cytoplasmic positivity for IgA heavy- and kappa light-chains was demonstrated with the immunoperoxidase staining technique. It is proposed that distension of the endoplasmic reticulum by immunoglobulin-related proteins is indicative of a block in their excretion or of the presence of active synthesis of the immunoglobulins or their subunits.

Endoplasmic Reticulum

Evaluation of the nucleolar organizer region associated proteins in minor salivary gland tumors.

Forty-three intraoral salivary gland tumors were studied to determine the value of the AgNOR technique in the assessment of these neoplasms. Well defined black dots were visible in the nucleii of all the specimens studied. The mean AgNOR count per nucleus for each tumor was calculated as follows: pleomorphic adenoma (n = 15) 1.52; Polymorphous low-grade adenocarcinoma (n = 12) 1.90; adenoid cystic carcinoma (n = 6) 2.92; mucoepidermoid carcinoma (n = 4) 1.93; carcinoma ex mixed tumor (n = 4) 2.05; undifferentiated carcinoma (n = 1) 3.13 and epithelial-myoepithelial carcinoma (n = 1) 2.23. The difference between the means of benign and malignant tumors (P less than 0.01) and polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (P less than 0.01) were highly significant. The overlapping of the AgNOR count between various tumors prohibited the use of this technique as an absolute criterion in establishing a final diagnosis. It could however be used as a diagnostic aid in differentiating between salivary gland neoplasms.

Adenocarcinoma

Adenomatoid odontogenic tumour: a report of two large lesions.

Adenomatoid odontogenic tumours with a diameter of more than 4 cm are uncommon. Two cases, both measuring in excess of 7 cm, are described and the differential diagnosis discussed. The progressive growth and cortical perforation in these two cases support the view that it is a benign neoplasm rather than a hamartoma.

Child

Liposarcoma of bone marrow origin in a kudu (Tragelaphus strepsiceros).

A primary intraosseous liposarcoma in a kudu (Tragelaphus strepsiceros), is reported. The lesion had a multilocular radiographic appearance and caused fracture of a metacarpus of the right front leg. Microscopically the lesion consisted of a lobular proliferation of lipoblasts of varying maturity. This is the first description of an intraosseous liposarcoma in a nondomesticated animal.

Animals

Amelogenesis imperfecta: multiple impactions associated with odontogenic fibromas (WHO) type.

Three types of amelogenesis imperfecta (AI) are recognised, namely hypoplastic, hypomature and hypocalcified varieties. We report on two cases of hypoplastic AI, the type which occurs most frequently. Both patients presented with multiple impacted permanent teeth. Odontogenic fibromas of the WHO type were found to be associated with the crowns of all the impacted teeth and are considered to have prevented normal eruption. Dentinal dysplasia found only in the furcation area of the multirooted impacted teeth was evident. The macroscopic, microscopic and radiological appearance of the affected teeth, pericoronal lesions and interradicular dentinal dysplasia are described, and the most likely origins of the odontogenic fibromas and calcifications observed, are discussed.

Adolescent

Clinical manifestations of oral precancer and cancer.

Oral squamous cell carcinomas generally metastasise early and are associated with a poor survival rate. Their prevention depends largely on timeous identification of precancerous oral mucosal lesions, which may present clinically as a homogeneous or nodular white plaque (leucoplakia), a mixed white and red lesion (erythroleucoplakia) or a homogeneous or nodular red lesion (erythroplakia). Red premalignant lesions generally have a higher malignant potential than white lesions.

Carcinoma, Squamous Cell

Orofacial mucormycosis.

Two cases of orofacial mucormycosis are reported. The first patient represents the typical progression of rhinocerebral mucormycosis with infiltration of the sinuses, the orbit, and the brain. The second patient had a tumorous maxillary lesion resembling fibrous dysplasia clinically and radiographically. Microscopically, the fungal infection in case 2 was associated with new bone formation. The significance of this phenomenon is discussed, and the importance of early diagnosis and possible treatment regimens are highlighted.

Adolescent

Giant ossifying fibroma: a clinicopathologic study of 8 tumors.

Clinical, radiographic and microscopic features of 8 ossifying fibromas diagnosed in 7 patients and measuring more than 8 cm in greatest diameter, were reviewed. The tumors occurred in both juvenile and middle aged patients and all lesions in women involved the maxilla. The abundance of fibrous connective tissue and resorption of mineralized deposits are indicative of altered cellular differentiation and proliferative activities in large ossifying fibromas. Focal areas of aneurysmal bone cyst formation were identified in the majority of lesions.

Adolescent

Clinical manifestations of oral precancer and cancer.

Oral squamous cell carcinomas generally metastasize early and are associated with a poor survival rate. Their prevention depends largely on timeous identification of precancerous oral mucosal lesions, which may present clinically as a homogeneous or nodular white plaque (leucoplakia), a mixed white and red lesion (erythroleucoplakia) or a homogeneous or nodular red lesion (erythroplakia). Red premalignant lesions generally have a higher malignant potential than white lesions.

Carcinoma, Squamous Cell

Odontoma in an African elephant (Loxodonta africana).

The first known case of an odontoma in an African elephant (Loxodonta africana) is described. The tumour was fused with the coronal cementum of the sixth right mandibular molar tooth, thus preventing its eruption.

Animals

Multiple myeloma presenting as localized expansile jaw tumour.

Myelomatous involvement of the maxilla is an exceptionally rare occurrence, and the presentation of the lesion as an expansile jaw bone tumour has not been reported. 2 cases, one with a maxillary lesion, the other with a mandibular lesion are presented, both of which illustrate gross bone expansions. Additionally, 1 case presented with a rare biclonal IgG kappa and IgG lambda light chain secreting myeloma. Relevant clinical, immunological, histological, biochemical and histochemical features are presented and discussed, and suggestions pertaining to surgical management made.

Adult

Multiple myeloma and amyloidosis of the tongue.

Tongue biopsies of 30 diagnosed cases of multiple myeloma were examined light and electron microscopically and amyloid deposits were identified in 8 patients. Immunochemical typing of amyloid in kappa and lambda subtypes was performed successfully although positive staining of tissue-associated immunoglobulin light chains made reliable identification of amyloid with this technique difficult. Cells of macrophage lineage appear to play a central role in light chain-associated amyloidogenesis. Our findings do not agree with the reported higher amyloidogenic potential of lambda light chains and we were unable to show a positive correlation between the percentage plasma cells in bone marrow aspirates or the presence of urinary light chains and myeloma-associated amyloidosis.

Adult