Biomedical subjects

A Buchner

Publications and source records attributed to A Buchner.

At least 19 recordsLinked to original sources

PubMed2006

Immunohistochemical expression of glucocorticoid and calcitonin receptors as a tool for selecting therapeutic approach in central giant cell granuloma of the jawbones.

Aggressive cases of central giant cell granuloma (CGCG) have been arbitrarily treated with steroids and calcitonin. The aim of this study was to develop a practical tool, based on the relative percentage of positively stained cells for glucocorticoid and/or calcitonin receptors, for selecting the appropriate therapeutic agents to treat CGCG. Forty-one formalin-fixed, paraffin-embedded blocks of CGCG were immunohistochemically stained for glucocorticoid and calcitonin receptors. Percentage of positive lesional mononuclear and giant cells was estimated for each case. Intense staining was considered as staining 50% or more of the cells. Correlations among staining scores were analysed by Spearman's test. All cases stained for glucocorticoid receptor. Heterogeneity among cases showed as intense staining in both cell types (21 lesions), in only one cell type (13 lesions) and weakly in both cell types (7 lesions). Only 23 cases demonstrated staining for calcitonin receptor, of which 15 stained intensely in both cell types and 7 in only one cell type. Among staining scores of both receptors, no significant statistical correlation was found (P>0.05). It can therefore be suggested that the relative percentage of immunohistochemically stained mononuclear and giant cells for glucocorticoid and/or calcitonin receptors can serve as a reliable and practical tool for selecting the appropriate therapeutic agent to treat CGCG. The clinical application of this method should be assessed in well controlled clinical studies, especially in cases of aggressive lesions, before initiating and during therapeutic treatment.

Adolescent↗

PubMed2006

Giant cell granuloma of the jawbones--a proliferative vascular lesion? Immunohistochemical study with vascular endothelial growth factor and basic fibroblast growth factor.

AIM: To estimate the angiogenic activity in central giant cell granuloma (CGCG) by immunohistochemical stains for vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). VEGF and bFGF immunoreactivity of the lesional mononuclear (MC) and giant (GC) cells was also investigated. METHOD: The study consisted of 41 cases of CGCG. Vascularity was quantified by microvascular volume (MVV) as determined by point counting. In five cases of CGCG, regions at the surrounding border, which demonstrated reactive vascular-rich inflammatory areas, served as control. Immunoreactivity of the MC and GC was assessed as the percentage of VEGF- and bFGF-positive cells from the total number of the respective cell type. RESULTS: Within CGCG lesions the extent of angiogenesis was low; MVV did not exceed 5% for either VEGF (88% of lesions) or bFGF (78% of lesions). The mean MVV of VEGF- and bFGF-positive blood vessels was 2.9% +/- 2.4% and 3.46% +/- 2.35%, respectively, significantly lower than in the control areas (27.5% +/- 7.3% and 28.08% +/- 5.5%, respectively) (P = 0.043). VEGF-positive and bFGF-positive MC and GC were found in nearly all lesions and in less than half of the lesions, respectively. CONCLUSION: The low mean MVV of VEGF- and bFGF-positive blood vessels implies low angiogenic activity, which does not support the designation of CGCG as a true proliferative vascular lesion. MC and GC immunoreactivity for the angiogenic factors is assumed to play an important role in the osteoclastogenesis process, thus contributing to additional growth of the CGCG lesions.

Adolescent↗

PubMed2006

Herpes simplex infection--Part II: Management of HSV infections.

Oral and perioral herpes simplex virus infections are commonly seen and managed by the dental practitioner. Many topical and oral antiviral agents are available in Israel. However, only a few regimens are based on solid evidence. The purpose of this study was to review the mode of action of antiviral agents and to present therapeutic regimens supported by randomized control trials.

Antiviral Agents↗

PubMed2005

Radiological features of central haemangioma of the jaws.

OBJECTIVES: The aim of this study was to evaluate the radiological and clinical features of central haemangioma of the jaws. METHODS: A total of 86 cases (84 from the English-language literature and two new cases) were studied and critically evaluated with emphasis on the radiological features. RESULTS: Age at time of initial diagnosis ranged from 0 to 74 years (mean 23 years, median 17 years). There was approximately equal distribution between females and males. The ratio between the mandible and maxilla was 3.3:1. Of the lesions, 69% were located in the posterior region of the jaws. Lesions were radiolucent in 96% of cases. Of the lesions, 66% were multilocular, 33% unilocular, and 1% not loculated. Borders were described in 41 cases, as well defined in 32% and diffuse in 68%. Tooth resorption was described in 23% of the lesions and tooth displacement in 16%, both more common in the mandible. The inferior alveolar nerve canal was involved in 15% of the mandibular lesions and the sinus in 35% of the maxillary lesions. CONCLUSIONS: Central haemangioma has a marked variability in its radiological appearance and should be considered in the differential diagnosis of many unilocular or multilocular radiolucent lesions of the jaws, especially in the mandible. Some radiographic patterns, such as the spoke-like and sunray appearance frequently described in the literature, are actually extremely rare.

Adolescent↗

PubMed2005

Herpes simplex virus infection: part I--Biology, clinical presentation and latency.

Oro-facial manifestations of herpes simplex virus (HSV) infections are very common, and include primary herpetic gingivo-stomatitis, recurrent herpes labialis and recurrent intra-oral herpes. Recent research in molecular biology has advanced our knowledge of the HSV pathogenesis and behavior. Understanding the exact mechanism of HSV latency and reactivation enables improvement of drug therapy and prevention strategies of HSV infections. The aim of this review is to update the recent development in the biological and clinical research related to HSV infection, focusing on oral and perioral lesions.

Adolescent↗

PubMed2004

Relative frequency of solitary melanocytic lesions of the oral mucosa.

BACKGROUND: Solitary pigmented lesions of melanocytic origin are uncommon in the oral mucosa. These lesions include the oral and labial melanotic macule, oral melanocytic nevus, oral melanoacanthoma, oral melanoma and atypical melanocytic proliferation. The purpose of the study was twofold: to report a large series of solitary melanocytic lesions from one source, and to determine the relative frequency of these lesions. METHODS: The study was based on a systematic search of the files of the Pacific Oral and Maxillofacial Pathology Laboratory, University of the Pacific, San Francisco for solitary pigmented melanocytic lesions (benign and malignant) accessed during the years 1984-2002. RESULTS: Of the 89 430 biopsies accessed during the 19-year period, 773 (0.83%) cases of solitary pigmented melanocytic lesions in the oral mucosa were identified. Oral and labial melanotic macules were the most common melanocytic lesions comprising 86.1% of the entire group and 0.7% of the total number of accessed biopsies. The vermilion border and gingiva were the most common sites (31.1% and 31.0% respectively). Oral melanocytic nevi comprised 11.8% of the entire melanocytic group and 0.1% of the total number of biopsies. The most common site was the palate (44%). Intramucosal nevi were the most common (64%), followed by compound nevi (16.5%) and common blue nevi (16.5%). Junctional nevi were uncommon (3.0%). Oral melanoacanthoma comprised only 0.9% of the entire melanocytic group and 0.008% of the total number of biopsies. Oral melanoma and atypical melanocytic proliferation were the least common lesions each comprising 0.6% of the entire melanocytic group and 0.006% of the total number of biopsies. The most common site for oral melanoma was the palate (60%). CONCLUSION: The palate was the most common location for both melanocytic nevi and oral melanoma. Thus, all melanocytic lesions in the palate should be viewed with caution and biopsy is recommended to rule out melanoma. Further studies are required to elucidate the entity of oral atypical melanocytic proliferation.

Adolescent↗

PubMed2004

Treatment modalities for chemo--and radiotherapy-induced oral mucositis--critical analysis and practical guidelines.

Oral mucositis (OM), an inevitable side effect of almost all anti-cancer treatments, affects the patient's physiological functions and their psychological well being. In spite of numerous treatment modalities for this condition, there is still a lack of evidence-based clinical trials that can provide a single efficient pharmacologic agent or intervention for either prevention or treatment of OM. This study analyses and summarizes some of the more "accepted" modalities for treatment of OM. It is recommended that these modalities rely on simple, convenient and innocuous interventions, which should be adjusted for each individual complaint. Well-designed, controlled and standardized studies are necessary to validate effectiveness of available, as well as newly developed interventions for OM.

Anti-Infective Agents, Local↗

PubMed2004

Amalgam tattoo (amalgam pigmentation) of the oral mucosa: clinical manifestations, diagnosis and treatment.

Amalgam tattoo is an iatrogenic lesion caused by traumatic implantation of dental amalgam into soft tissue. Amalgam tattoo is the most common localized pigmented lesion in the mouth. In a study of a mass screening oral examination in the United States, it was found in about 0.4-0.9% of the adult population and in Sweden in about 8%. Clinically, amalgam tattoo presents as a dark gray or blue, flat macule located adjacent to a restored tooth. Most are located on the gingiva and alveolar mucosa followed by the buccal mucosa and the floor of the mouth. Microscopic examination reveals that amalgam is present in the tissues in two forms: as irregular dark, solid fragments of metal or as numerous, discrete fine, brown or black granules dispersed along collagen bundles and around small blood vessels and nerves. In most lesions, it is presented in both forms. The biologic response to the amalgam is related to particle size, quantity and elemental composition of the amalgam. Large fragments often become surrounded by dense fibrous connective tissue. Smaller particles are associated with mild to moderate chronic inflammatory response with individual macrophages engulfing small amalgam particles. Occasionally, the reaction takes the form of foreign body granuloma in which macrophages and multinucleated giant cells are present. Some of the multinucleated giant cells also contain amalgam particles. Diagnosis of amalgam tattoo is usually obvious from the location and clinical appearance. A radiograph is recommended to confirm the presence of metallic particles, but absence of radiographic evidence does not rule out the possibility, since particles are often too fine or widely dispersed to be visible on radiographs. When there is no radiographic evidence or an adjacent restored tooth, biopsy is recommended to rule out an early melanoma. Once the diagnosis of amalgam tattoo has been established, no additional treatment is necessary except for cosmetic reasons. If the pigmentation is cosmetically unacceptable, surgical excision and transplantation of oral mucosal tissue has been suggested. Q-switched ruby laser and Q-switched alexandrite laser have also been used with favorable results.

Adult↗

PubMed2004

Amalgam tattoo (amalgam pigmentation) of the oral mucosa: clinical manifestations, diagnosis and treatment.

Adult↗

PubMed2004

Oral cancer: diagnostic options as an aid to histology in order to predict patients at high risk for malignant transformation.

Oral cancer continues to afflict the general population in growing numbers with a relatively low survival rate. Today, through histology, the potential danger of a pre-cancerous lesion can be detected, yet it does not reflect with certainty its biologic behavior. Recent studies have shown that some pre-cancerous lesions with mild dysplasia may undergo malignant transformation and lesions with severe dysplasia may remain quiet. Our goal is to locate the relatively small population of patients that are at high risk for malignant transformation at an early stage of carcinogenesis so they can be treated effectively. Methods that can identify the molecular and DNA changes may provide the data needed to predict the true malignant potential of a pre-cancerous lesion and its potential for transformation with a higher degree of certainty. The purpose of this article was to review some of the diagnostic options that are being studied and their link to carcinogenesis.

Aneuploidy↗

PubMed2003

An unrandomized prospective comparison of urinary continence, bowel symptoms and the need for further procedures in patients with and with no adjuvant radiation after radical prostatectomy.

OBJECTIVE: To prospectively assess, using a questionnaire-based study, the relative differences and changes in urinary continence and bowel symptoms, and the need for further surgery, within the first year after radical retropubic prostatectomy (RRP) in patients with and with no adjuvant radiotherapy (aRT). PATIENTS AND METHODS: The study included 96 men with clinically organ-confined adenocarcinoma of the prostate who underwent RRP between March 1998 and June 1999. A subset of 36 patients was recommended aRT of the prostatic fossa (median dose 54 Gy) because of positive surgical margins and/or seminal vesicle involvement. Using a mailed questionnaire all patients were prospectively assessed at 4-month intervals for the first year after RRP. RESULTS: Valid data were analysed from 83 patients (overall response rate 86%), of whom 30 (36%) had received aRT. At 4 months a significantly lower proportion used no pads and significantly more used 1 pad/day in the aRT than in the RRP group (both P < 0.05). Eight and 12 months after RRP there was no statistically significant difference between the groups in urinary incontinence. However, 53% of men in the aRT group had stool urgency and 13% reported fecal incontinence at 4 months, compared with 1.9% and none (both P < 0.01) of the RRP group. At 1 year after RRP bowel symptoms and fecal continence improved in the aRT group and there was no significant difference for these symptoms between the groups. Starting aRT early (< or = 12 weeks after RP) or late (> 12 weeks) had no significant effect on urinary continence, bowel symptoms and fecal incontinence. Apart from dilatation of urethral strictures in one patient in each group, no further procedures were reported during the follow-up. CONCLUSION: A moderate dose of aRT after RRP had a temporary effect on subjective urinary continence at 4 months but not at 8 and 12 months. More patients receiving aRT reported significant bowel symptoms at 4 and 8 months than those with RRP only, but at 1 year most of these symptoms had resolved and there were no significant differences between the groups.

Adenocarcinoma↗

PubMed2003

Mandibular buccal bifurcation cyst: enucleation without extraction.

The mandibular buccal bifurcation cyst (MBBC) is a cystic lesion, which occurs on the buccal surface of the permanent mandibular first molar in children around 6-8 years old. Treatment of the cyst has been controversial: extraction of the involved tooth and enucleation of the cyst, or only enucleation, without extraction. The aim of this article is to familiarize oral and maxillofacial surgeons with this entity and the appropriate treatment approach. The diagnostic features of MBBC are described and the treatment approach in five patients with a total of seven cysts is presented. Two cases were identified in identical twins. Enucleation of the cyst without extraction of the involved tooth is the treatment of choice when the available data and experience in treating MBBC are considered.

Adolescent↗

PubMed2002

Increase in immune cell infiltration with progression of oral epithelium from hyperkeratosis to dysplasia and carcinoma.

In the present study, epithelium derived lesions of various pathological manifestations were examined histologically and immunohistochemically for mononuclear cell infiltration. The infiltrate under the transformed epithelium of oral lesions, was examined for differences in the composition of immune mononuclear cells as the epithelium moves from hyperkeratosis through various degrees of dysplasia to squamous cell carcinoma. The study was performed on 53 human tongue tissues diagnosed as hyperkeratosis (11 cases), mild dysplasia (nine cases), moderate and severe dysplasia (14 cases) and squamous cell carcinoma (19 cases). A similar analysis was performed on 30 parotid gland tissues diagnosed as pleomorphic adenoma (14 cases) and carcinoma ex-pleomorphic adenoma (16 cases). Immunohistochemical analysis of various surface markers of the tumour infiltrating immune cells was performed and correlated with the transformation level as defined by morphology and the expression of p53 in the epithelium. The results revealed that, in the tongue lesions, the changes in the epithelium from normal appearance to transformed were accompanied by a corresponding increase in the infiltration of CD4, CD8, CD14, CD19+20, and HLA/DR positive cells. The most significant change was an increase in B lymphocytes in tongue lesions, that was in accordance with the transformation level (P<0.001). In the salivary gland, a significant number of cases did not show an infiltrate. In cases where an infiltrate was present, a similar pattern was observed and the more malignant tissues exhibited a higher degree of immune cell infiltration.

Carcinoma↗

PubMed2002

[Ambulatory radiosurgery in cerebral metastatic renal cell carcinoma. 5-year outcome in 58 patients].

Brain metastases (BM) indicate an advanced stage of renal cell cancer (RCC). They pose an increasing challenge to urologists as a result of improved survival due to modern therapy. Median survival of untreated patients with BM who often suffer from neurological deficits is 3 months. Radiosurgery with the Gamma Knife (GK) has increased in use as an alternative to whole brain radiation therapy (WBRT) and/or surgery. This study reports the results of a consecutive series of RCC patients treated for BM by GK radiosurgery during a 5-year period. Between 1994 and 1999, 58 patients with a total of 277 BM and 3.0 (1-19) BM/patient were treated. Because of recurrent BM, 23 (40%) patients received repeated (multiple) GK sessions. The median tumor volume was 3.4 cm3 (0.1-19.1). The median interval between diagnosis of RCC and GK treatment was 2.2 years (0.1-17.2). Symptomatic side effects were detected in 9 (16%) of 58 patients. The median actuarial survival time was 9.9 months. Local tumor control could be achieved in 95% of patients. The GK therapy induced a significant tumor remission accompanied by rapid neurological improvement in 70% of patients. Compared to standard radiotherapy, GK radiosurgery is more effective, less time consuming, and can be repeated. Compared to surgery, radiosurgery is less invasive and better suited to treat multiple metastases in one single session. Surgery and radiosurgery, however, are supplementary methods that are highly effective to control intracerebral metastasizing RCC.

Actuarial Analysis↗

PubMed2002

Laser activated fluorescence measurements and morphological features: an in vivo study of clearance time of fluorescein isothiocyanate tagged cell markers.

Fourteen BALB/c mice were divided into two groups. One group served as the control and the second group was injected with a squamous cell carcinoma cell line to the tongue. After tumor development (1-4 weeks), mice were injected with a FITC conjugated CD3 marker to their tongues. Immediately after the marker injection, the clearance of the marker was measured using a laser spectroscopy system. The markers were excited by an argon laser at 488 nm and the fluorescence signal was measured as a function of time. A biopsy was taken from every mouse after the procedure and the excised tissue was histologically evaluated. Analysis of clearance times revealed a second order exponential decay for both groups with a slower pace of signal clearance for the sick mice.

Animals↗

PubMed2001

Simultaneous learning of different regularities in sequence learning tasks: limits and characteristics.

Two experiments are reported which were designed to investigate the generality and the power of the mechanisms underlying sequence learning. In both experiments, participants reacted to systematic sequences of tones. They were informed that there was a tone systematicity. Participants were not told that the interval between a response to a tone and the onset of the subsequent tone (response-signal interval, RSI) also varied according to a fixed regularity. Experiment 1 showed that the unattended RSIs were learned when they were uniquely related to the tone sequence, but not when the relation was ambiguous. Experiment 2 showed that, on the basis of the traditional reaction time performance measure, participants who learned the RSIs by attending to their systematicity could not be distinguished from those in an incidental learning condition in which the RSI systematicity was unattended. However, a model-based analysis of the processes contributing to judgements about the event sequences suggested that the two groups had acquired qualitatively different knowledge.

Adult↗

PubMed2001

Focal lymphocytic infiltration in aging human palatal salivary glands: a comparative study with labial salivary glands.

Investigation of age-related prevalence of various types of focal lymphocytic infiltration (FLI) and degrees of histomorphologic changes was conducted on 120 biopsies of palatal and labial salivary glands (PSG and LSG, respectively) obtained from autopsy subjects free of salivary gland tumors/diseases. Biopsies were divided into young (<30 years, n=30), adult (30-60 years, n=45) and old (>60 years, n=45) age groups. A modified Chisholm & Mason grading system was used to record grades of FLI and a modified Greenspan et al. system was used to evaluate the severity of histomorphologic changes. The prevalence of FLI in PSG increased significantly from 10% in the young group to 46.6% in the old group (P=0.0012). No significant changes were found with aging in LSG. FLI was significantly more prevalent in the adult and old age groups in PSG as compared with LSG (P=0.015 and P=0.003, respectively). Both glands demonstrated significant histomorphologic changes among age groups (p<0.0001); however, these changes were significantly less common in the old age group in PSG as compared to LSG (P=0.003). In cases showing severe histomorphologic changes, FLI was not present. Therefore, FLI should not be considered as part of the deteriorating histomorphologic changes that are usually encountered in salivary glands with aging. The immunologic profile of these infiltrates should be further clarified to understand their role, both in physiologic and pathologic conditions.

Adult↗

PubMed2001

Radiological and clinical features of calcifying epithelial odontogenic tumour.

OBJECTIVES: To analyse systematically the radiographic features of the calcifying epithelial odontogenic tumour (CEOT). METHOD: Clinical and radiological features of 67 cases of CEOT (four new and 63 from the literature) were analysed. RESULTS: There were 27 (41%) males and 39 (59%) females with a male-to-female ratio of 1 : 1.5. Age ranged from 13 - 77 years (mean 43.5 years), with a peak in the fourth and fifth decades. The mandible was involved in 74% of the cases and 69% of all lesions were in the posterior area. The mixed radiolucent-radiopaque pattern was the most frequent (65%), with 32% radiolucent and 3% radiopaque. Coronal clustering of the radiopaque material was found in 12% and in one case, a 'driven snow' pattern of the radiopaque material was clearly recognizable. Lesions were unilocular in 58%, multilocular in 27% and not loculated in 15%. The unilocular type was more frequent in the maxilla than in the mandible. Borders were well defined and corticated in 20%, defined but not corticated in 59% and diffuse in 21%. Sixty per cent were associated with impacted teeth. Lesions larger than 3 cm tended to be more frequent in the mandible, mixed radiolucent-radiopaque and to have a higher proportion of diffuse borders than the smaller lesions. CONCLUSION: Radiographic features which have been considered characteristic of CEOT, coronal clustering and 'driven snow' patterns, are seen in only a small percentage of cases.

Adult↗