Search PubMed⌕ Search

Biomedical subjects

D Mock

Publications and source records attributed to D Mock.

At least 19 recordsLinked to original sources
PubMed2003

Observer agreement in the grading of oral epithelial dysplasia.

OBJECTIVES: To determine the extent of observer agreement in diagnosis of oral epithelial dysplasia (OED). Published studies of OED examiner agreement report relatively low agreement levels; however, these studies were limited by the methodologies employed. METHODS: For this study, 64 slides were each independently examined twice by three oral pathologists. Consistency was assessed by determining intra- and interexaminer agreement. Conformity was assessed by using the modal diagnosis as a gold standard. RESULTS: The group showed moderate interobserver agreement when grading the presence or absence of OED with a group-simple kappa (Ks) of 0.51 (95% CI = 0.42-0.61), and substantial agreement when using a 5-point ordinal scale with a group-weighted kappa (Kw) of 0.74 (95% CI = 0.64-0.85). The group showed fair to substantial intraexaminer agreement when assessing the presence or absence of OED, with Ks ranging from 0.22 to 0.78, and showing almost a perfect agreement using a 5-point ordinal scale, with Kw ranging from 0.82-0.96. Conformity with the comparison standard modal diagnosis was almost perfect, with pairwise Kw ranging from 0.81 to 0.92. CONCLUSION: Overall, there was substantial intra- and interobserver consistency and almost perfect conformity in the grading of OED. Appropriate statistical methods are necessary to determine the degree of observer agreement.

Adult↗
PubMed2002

Tuberous sclerosis: clinicopathologic features and review of the literature.

INTRODUCTION: Tuberous sclerosis is a hamartoneoplastic syndrome, which may involve multiple organ systems. Oral hard tissue manifestations of the syndrome have been described in the literature only as recently as 1955. Patients who presented with clinical manifestations of tuberous sclerosis did not routinely undergo oral surveys to rule out 'lesions', and consequently data on 'lesions' in the maxillofacial complex is scant. Ten cases have been found in the English language literature, which describe maxillofacial 'lesions', which may be tumours, new growths, neoplasms or overgrowths occurring in patients diagnosed with tuberous sclerosis. PURPOSE: To review the literature for all maxillofacial lesions associated with tuberous sclerosis and to present an eleventh case of a patient with a maxillofacial lesion diagnosed as having tuberous sclerosis. RESULTS: Eleven cases were found with maxillofacial fibroblastic lesions associated with tuberous sclerosis. These lesions were all fibrous benign neoplasms found in the maxillofacial bony complex. CONCLUSIONS: Maxillofacial fibroblastic lesions in tuberous sclerosis have various histopathological presentations, some of which may be difficult to differentiate. Consequently, close microscopic examination of these lesions is necessary so that adequate surgical treatment is provided.

Child, Preschool↗
PubMed2001

Epstein-Barr virus detection in non-Hodgkin's lymphoma of the oral cavity: an immunocytochemical and in situ hybridization study.

OBJECTIVE: The purpose of this study was to histologically characterize a series of oral non-Hodgkin's lymphomas (NHLs) and to investigate latent and lytic Epstein-Barr virus (EBV) infection in these. STUDY DESIGN: The revised European-American Lymphoma classification system (41) was used to categorize 58 cases of oral NHL, which included 9 immunosuppression-related NHLs. EBV infection was determined by in situ hybridization for Epstein-Barr virus-encoded RNA and by immunohistochemistry for the EBV antigens latency membrane protein, Epstein-Barr nuclear antigen-2 (EBNA2) and Z EBV replication activator protein. RESULTS: Most tumors were B-cell lymphomas (78%), but the proportion of T-cell lymphomas was surprisingly high (22%). The most common histologic subtypes were diffuse large B-cell lymphomas (45%), peripheral T-cell lymphomas (19%), and follicle center lymphomas (14%). Two thirds of the known immunosuppression-related NHLs were T-cell lymphomas. All of the immunosuppression-related tumors were EBV-infected, whereas the EBV infection rate in the NHLs of the remaining patients presumed to be immunocompetent was only 9%. Most EBV-positive tumors expressed neither of the latent antigens (ie, latency membrane protein and Epstein-Barr nuclear antigen-2), and coexpression of the 2 was observed only in immunosuppressed patients. Z EBV replication activator protein expression, which is indicative of replicative infection, occurred only in immunosuppressed individuals. CONCLUSIONS: Diffuse large B-cell lymphomas were the most common histologic subtype of oral NHLs, but T-cell lymphomas were relatively common and frequently occurred in states of immunosuppression. EBV may play a limited role in the initiation of lymphoma in the immunocompetent patient, but the virus may be of importance in progression of the disease in those patients with more aggressive tumors, as immunosuppression occurs.

Adult↗
PubMed2001

Sensory and affective components of orofacial pain: is it all in your brain?

In this paper, we shall review several chronic orofacial pain conditions with emphasis on those that are essentially refractory to treatment. We shall present a review of current and past literature that describes the various pain phenomena as well as their underlying central mechanisms. New data concerning refractory pain will be used to underscore the importance of central processing of pain, with particular emphasis on neuropsychological and cognitive function and capacity that may play important roles in pain processing and maintenance of the pain state. Further, neurophysiological data showing that the anterior cingulate cortex (ACC) and other structures in the brain may play key roles in modulation of chronic pain will also be discussed. Although peripheral triggering events surely play an important role in initiating pain, the development of chronic and, in particular, refractory pain may depend on changes or malfunctions in the central nervous system. These changes may be quite subtle and require sophisticated approaches, such as functional MRI, to study them, as is now being done. New findings obtained therefore may lead to more rational and reliable treatment for orofacial pain.

Accidents, Traffic↗
PubMed2000

Foreign body granuloma following placement of hard tissue replacement material: a case report.

The placement of grafting material in extraction sites for ridge preservation is an increasingly common practice among clinicians. This is a case report of a patient presenting with a symptomatic, foreign body granuloma following the placement of hard tissue replacement (HTR) in extraction sockets. The surgical specimen revealed numerous histiocytes and foreign body type giant cells. The grafting material was surgically removed and the patient's symptoms were alleviated. Although biocompatibility of HTR has previously been shown, specific applications may be contraindicated or some patients may exhibit sensitivity to this material.

Alveolar Ridge Augmentation↗
PubMed1999

Immunohistochemical and histochemical characterization of the mucosubstances of odontogenic myxoma: histogenesis and differential diagnosis.

To discuss the dental origin of odontogenic myxoma and to provide further information for the differential diagnosis between this tumor and myxoid malignant fibrous histiocytoma (MFH) which occasionally occurs in jaw bones, the contents of glycosaminoglycans (GAGs) and proteoglycans (PGs) in the mucosubstances of 15 odontogenic myxomas, 5 myxoid MFH and 3 human fetal tooth germs in the bell stage of development were characterized using histochemical and immunohistochemical methods. Histochemical staining of hyaluronic acid (HA) was undertaken using biotinylated HA binding protein (B-HABP), and immunohistochemical detection was done using a panel of antibodies against chondroitin 6-sulfate (CS-6), chondroitin 4-sulfate (CS-4), dermatan sulfate (DS), keratan sulfate (KS), heparan sulfate (HS), aggrecan, PG-M/versican, decorin and biglycan. In odontogenic myxoma, CS-6, HA and PG-M/versican were observed in the myxomatous matrix of all cases, while KS and HS were seen in none. As for CS-4, DS, aggrecan, decorin and biglycan, only irregular and mild stainings were shown. Consistent and strong positive straining for CS-6, HA and PG-M/versican were seen in dental papilla and provided evidence supporting the origin of this tumor from dental papilla. Except for the constant staining for HA, the myxoid matrix was rarely stained for most GAGs and PGs in myxoid MFH. Immunodetection of CS-6 and PG-M/version with the use of monoclonal antibodies 3-B-3 and 2-B-1 is therefore recommended as a useful tool in differentiating odontogenic myoma from myxoid MFH.

Diagnosis, Differential↗
PubMed1999

Multiple canalicular adenomas: a case report and review of the literature.

The canalicular adenoma is an uncommon, benign salivary gland tumor that most frequently occurs in the upper lip. Rarely, it manifests itself clinically and histologically as a multifocal lesion, a feature not generally seen with other intraoral salivary gland tumors. Here we report a case of canalicular adenoma that manifested itself with 13 clinically discrete tumor masses involving the upper lip and anterior buccal mucosa. In addition to the clinical nodules, there were microscopic foci of tumor cells in the adjacent normal-appearing salivary gland tissue surrounding the tumors. This article also reviews previously reported multifocal canalicular adenomas and discusses their features, emphasizing differences in the reported growth patterns of this unusual tumor.

Adenoma↗
PubMed1999

Odontogenic ghost cell carcinoma: report of four new cases and review of the literature.

Only 12 odontogenic ghost cell carcinomas (OGCC) have been reported in the English language literature to date. This article reports four additional cases of this rare odontogenic tumour and examines them in relation to those previously described. Judging from the number of published cases, the OGCC is more prevalent in Asians than other racial groups, occurs more often in the maxilla than the mandible, and is slightly more common in males than females. Histologically, elements of a benign calcifying odontogenic cyst (COC) can be identified in all the malignant variants, either separated or admixed with the malignant epithelial component. The latter can consist of either small basaloid cells or large epithelial cells. Despite the differing histological presentations, the biological behavior of the tumour is unpredictable, with some cases characterized by relatively indolent growth and others by a locally aggressive and potentially fatal course. The tumour apparently arises most often from malignant transformation of a preexisting benign COC, although it may also develop from other odontogenic tumours.

Adult↗
PubMed1999

Physiologic changes in humans subjected to severe, selective calorie restriction for two years in biosphere 2: health, aging, and toxicological perspectives.

Biosphere 2 is a closed ecological space of 7-million cubic feet near Tucson, AZ, containing 7 biomes: rain forest, Savannah, ocean, marsh, desert, agricultural station, and habitat for humans and domestic animals. Sealed inside, 4 men and 4 women maintained themselves and the various systems for 2 years. All organic material, all water, and nearly all air was recycled, and virtually all food was grown inside. On the low calorie but nutrient-dense diet available, the men sustained 18% and the women 10% weight loss, mostly within the first 6 to 9 months. The nature of the diet duplicated rodent diets that had been shown to enhance health, lower disease incidence, and retard aging. Using blood specimens frozen at different points during and after the 2 years, determinations were made of a number of biochemical parameters judged to be pertinent based on past studies of rodents and monkeys on similar diets. These included blood lipids, glucose, insulin, glycosylated hemoglobin, renin, and others. The results clearly suggest that humans react to such a nutritional regime similarly to other vertebrates. In addition to these studies, and because this was a tightly closed, isolated environment, the levels of insecticides or pollutants or their derivatives were determined in the sera of 2 crew members. It was found that levels of the lipophilic toxicant DDE and the "total PCB" load increased with the loss of body fat during the first 12-18 months inside Biosphere 2, then decreased.

Adult↗
PubMed1998

Odontogenic tumors. A demographic study of 759 cases in a Chinese population.

Seven hundred fifty-nine cases of odontogenic tumors retrieved from the files of College of Stomatology, West China University of Medical Sciences were classified according to the World Health Organization's Histological Classification of Odontogenic Tumors and compared with similar reports from other countries. Among these cases, 93.9% of the tumors were benign and 6.1% were malignant. Ameloblastomas predominated (58.6%) with a predilection for the mandible, while odontomas, generally regarded as the most frequent odontogenic tumor in North America, only accounted for 6.7%, the fourth most common tumor in this series. The mandible and the maxilla were divided into eight anatomic regions, and the distribution of each odontogenic tumor type amongst these regions was recorded. The relative incidence of each tumor type, patient age and gender were also compared with data from other selected large series. Geographic differences were noted in the relative incidence of ameloblastoma, odontoma and malignant odontogenic tumors among the Chinese/African, North American and Turkish/German groups. Ameloblastoma and malignant odontogenic tumors are not considered rare in a Chinese population.

Adolescent↗
PubMed1998

Proliferative activity of calcifying odontogenic cysts as evaluated by proliferating cell nuclear antigen labeling index.

The calcifying odontogenic cyst (COC) presents with diverse histological features; thus, several subclassifications have been proposed. To evaluate the significance of the various histological features and subtypes of COC from the perspective of proliferative activity, the proliferating cell nuclear antigen (PCNA) labeling index (LI; the percentage of positive nuclei) was assessed immunohistochemically in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclassified into non-proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nine cases). The PCNA LI of the malignant COC (65.2+/-5.6) was significantly higher than that of the benign COC (11.6+/-9.0; P = 0.002). Non-proliferative subtype (6.8+/-2.8) showed the lowest PCNA LI and PS (17.2+/-11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non-proliferative type as NPS and the other three had lining with proliferative features as PS. The PCNA LI of the latter COCaO group (14.3+/-6.6) was significantly higher than that of the former (6.1+/-4.3; P = 0.05), as seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating malignant COC from benign COC and, whatever the subtypes, the proliferative features in the lining are the main factor influencing the proliferating activity of COC.

Cell Division↗
PubMed1998

Management of gingival vitiligo with the use of a tattoo technique.

The purpose of this report is to describe the management of gingival vitiligo in a black female. This patient was referred by her psychiatrist to the Mount Sinai Hospital Dental Department (Toronto) for assessment of progressive loss in gingival pigmentation. According to her psychiatrist this loss of pigmentation, which the patient indicated may be considered in Africa as a hallmark of HIV infection, was a significant exogenous factor in relation to the patient's ongoing clinical depression. After obtaining informed consent, a modification of a tattooing method used for skin was applied to the patient's attached gingival tissues. Test sites were tattooed prior to performing full gingival tattooing under local anaesthesia. The results demonstrate that it was possible to restore this patient's gingival pigmentation in a highly esthetically acceptable manner. The resulting coloration was reminiscent of the patient's natural pigmentation that had been lost ostensibly because of her systemic disorder. Our findings also showed that the artificial pigmentation established via the tattoo method was stable 4 months postoperatively and continues to be stable, as expected. A profound improvement in the patient's mood was noted.

Adult↗