Biomedical subjects

Abraham Hirshberg

Publications and source records attributed to Abraham Hirshberg.

9 recordsLinked to original sources

PubMed2006

The influence of inflammation on the polarization colors of collagen fibers in the wall of odontogenic keratocyst.

Epithelial-mesenchymal interactions have been found to play a role in the pathogenesis of odontogenic keratocyst (OKC). In the present study we investigated the effect of inflammation in the OKC wall on the polarization colors of Picrosirius red-stained collagen fibers. 50 cases of OKC were selected and separated into two groups according to the inflammatory intensity: those with mild-to-moderate inflammation (Group A), and those with intense inflammation (Group B). The polarization colors of the collagen fibers were recorded separately for thick and thin fibers. Polarization colors of the thin fibers were in the green- to yellow spectrum, without significant differences between the groups. However, polarization colors of the thick fibers significantly differ between the groups. In Group B, the frequency of thick fibers with green birefringence decreased significantly, whereas fibers with red polarization colors increased in frequency (4.6% and 44%, respectively) compared with Group A (12.3% and 23.6%, respectively). It can than be concluded that inflammation has an impact on the packing of collagen fibers in the connective tissue wall of OKC as reflected by their birefringence colors under polarized light. In the presence of dense inflammation, the percentage of thick fibers with green birefringence decreases, with an increase in thick fibers with red birefringence which appeared more packed.

Azo Compounds↗

PubMed2006

Traumatic ulcerative granuloma with stromal eosinophilia: a reactive lesion of the oral mucosa.

Traumatic ulcerative granuloma with stromal eosinophilia (TUGSE) is a benign lesion of the oral mucosa of an unclear pathogenesis. We analyzed the profile of the inflammatory infiltrate in 12 cases of TUGSE by using immunohistochemical analysis and polymerase chain reaction-based repertoire analysis to detect T- and B-cell receptor gene rearrangements. The inflammatory infiltrate consisted in most cases of B and T lymphocytes, macrophages, abundant eosinophils, and large atypical cells. In 5 cases, CD30+ cells were found. Spectratyping analysis displayed a polyclonal rearrangement of the T-cell receptor g gene in 6 cases and oligoclonality in 5 cases. Monoclonality was observed in 1 case that also fulfilled histologic criteria for lymphoma. Healing was uneventful in all cases, including the one suspected of being lymphoma, with no recurrences in more than 2 years'follow-up. TUGSE can be regarded reactive. Some cases, however, may harbor a dominant clonal T-cell population; in these cases, long-term follow-up is mandatory.

Adolescent↗

PubMed2005

Identification of RNA editing sites in the SNP database.

The relationship between human inherited genomic variations and phenotypic differences has been the focus of much research effort in recent years. These studies benefit from millions of single-nucleotide polymorphism (SNP) records available in public databases, such as dbSNP. The importance of identifying false dbSNP records increases with the growing role played by SNPs in linkage analysis for disease traits. In particular, the emerging understanding of the abundance of DNA and RNA editing calls for a careful distinction between inherited SNPs and somatic DNA and RNA modifications. In order to demonstrate that some of the SNP database records are actually somatic modification, we focus on one type of these modifications, namely A-to-I RNA editing, and present evidence for hundreds of dbSNP records that are actually editing sites. We provide a list of 102 RNA editing sites previously annotated in dbSNP database as SNPs, and experimentally validate seven of these. Interestingly, we show how dbSNP can serve as a starting point to look for new editing sites. Our results, for this particular type of RNA editing, demonstrate the need for a careful analysis of SNP databases in light of the increasing recognition of the significance of somatic sequence modifications.

Base Sequence↗

PubMed2005

Effect of air-polishing devices on the gingiva: histologic study in the canine.

OBJECTIVES: The aim of this study was to evaluate histologically the immediate effect of two types of air-polishing devices (APDs) on the gingiva. MATERIAL AND METHODS: The buccal gingiva in four mongrel dogs was exposed to 5, 10 and 20 s of instrumentation, applying a hand-piece type of APD (HP-APD) PROPHYflex and a stand-alone type of APD (SA-APD) Jetpolisher in a split-mouth design. Immediately after treatment, the exposed gingiva was excised by sharp dissection and fixed in 10% buffered formalin. For each specimen, 15 sections, 20 microm apart, corresponding to the central part of the treated and control untreated gingiva were cut and stained with haematoxylin and eosin. Stained sections were examined histomorphometrically for keratin width and epithelial cell layer (ECL) (prickle and basal cell layers) width. Extent of erosion was expressed as loss of keratin and ECL compared with control. RESULTS: Microscopic examination presented changes in keratin and ECL, including keratin detachment and disruption of the normal ECL architecture. The erosive changes in the gingiva caused by both APD, positively correlated with instrumentation time (p<0.001) and type of instrument (p=0.008). Keratin loss was significantly higher for SA APD than for the HP APD in each time interval (p=0.019). Following exposure for 5 s, both APD caused a 25% loss of the ECL. Exposure for 10 and 20 s revealed a significantly greater ECL loss caused by the SA-APD than the HP-APD (p=0.018). Exposure for 20 s was the only time interval that presented the area of total epithelium erosion with SA-APD causing significantly more (p=0.002) areas of total epithelial erosion than the HP-APD. CONCLUSION: Gingiva exposure to air-polishing slurry delivered by APD caused localized trauma because of epithelial erosive changes with severity, positively correlated with instrumentation time and design principles of the applied APD. The clinician should be aware of the potential insult of the gingiva when applying the APD and careful precautions should be taken.

Animals↗

PubMed2004

The correlation between epithelial cell proliferation and inflammation in odontogenic keratocyst.

The objective of this study was to investigate the effect of inflammation on Ki-67 and PCNA labeling indices of odontogenic keratocysts. The study included 45 cases of OKC. From each case, three 5-microm sections were cut and stained with hematoxylin and eosin and with monoclonal antibodies for PCNA and Ki-67. In 10 high power fields (HPF), the type of epithelial lining was recorded separately for each field (metaplastic squamous or classic parakeratinized). Labeling indices for Ki-67 and PCNA and the inflammatory infiltrate density in the depth of 1 HPF adjacent to the basement membrane were recorded for each HPF. Parameters were compared between fields, and for each case the average inflammatory score and average labeling indices were calculated, and cases compared. No inflammation was observed in 24.5% of cases, mild in 30.5% and moderate to severe in 45%. Foci of metaplastic non-keratinizing epithelium were observed in 64% of cases, which were twice as common in inflamed cysts (90%) than in non-inflamed cysts (44%). The average labeling indices for PCNA and Ki-67 yielded no significant differences between inflamed and non-inflamed cysts. When compared between HPF's, there was an increase in the Ki-67 labeling index in metaplastic epithelium in areas with moderate to severe inflammation score (p=0.036). PCNA labeling index did not significantly change between areas with low and high inflammation. No differences in labeling indices were observed between areas of classic and metaplastic epithelium with equal inflammation density. A focal increase in Ki-67 expression adjacent to moderate to severe inflammation was found, with no significant effect on the overall proliferation activity of the cysts.

Cell Division↗

PubMed2003

Temporomandibular joint involvement in malignant external otitis.

OBJECTIVE: The purpose of this study was to present 6 patients with malignant external otitis (MEO) that resulted in temporomandibular joint (TMJ) involvement and to discuss the incidence, clinical presentation, and treatment modalities. STUDY DESIGN: All patients diagnosed with MEO between 1994 and 2002 were reviewed for cases in which the TMJ was invaded by the infectious process. Only patients in whom TMJ involvement was documented radiographically and in whom the clinical course was well documented were included in this study. RESULTS: MEO was diagnosed in 42 patients over an 8-year period; TMJ involvement was recorded in 6 patients (14%). The medical history revealed controlled type 2 diabetes mellitus in 4 of the 6 patients. All patients reported early ear symptoms, mainly otalgia and otorrhea. Local signs included an ear canal filled with granulation material, edematous overlying skin, and sensitivity to palpation. Cultures taken from the external ear were positive for either Pseudomonas aeruginosa, Staphylococcus epidermidis, Aspergillus, or Proteus mirabilis. TMJ symptoms developed between 1 and 5 months after admission and included painful periauricular swelling and trismus. In 3 patients, healing was uneventful; 3 also died of the disease. CONCLUSIONS: TMJ involvement in MEO is associated with a resistant disease process, often with several recurrences. Prolonged administration of antibiotics is the treatment of choice. Surgical debridement of the TMJ is necessary for the positive identification of the pathogenic organism, in cases of abscess formation, or when osteomyelitic bone destruction of the condyle and glenoid fossa develop.

Aged↗

PubMed2003

Histomorphologic and morphometric changes in minor salivary glands of the rat tongue during 4-nitroquinoline-1-oxide-induced carcinogenesis.

4-Nitroqinoline-1-Oxide (4NQO)-induced tongue carcinogenesis in rats is considered to be a preferred model for study of oral squamous cell carcinoma. Aim of study was to investigate histomorphologic and morphometric 4NQO-induced changes in tongue minor salivary glands. Histopathological examinations of serous and mucous acini and ducts of tongue salivary glands of 26 Wistar-derived rats were performed after 14 (T(1)), 22 (T(2)) and 28 (T(3)) weeks of 0.001% 4NQO administration in drinking water and compared with nine controls. Histomorphological findings were recorded as normal/abnormal acini and as normal/dysplastic ducts. Morphometrical results were expressed as volume fraction (Vv%) of each of the components. Morphometric and histomorphologic changes in the salivary glands were evident only at T(3) and they included a significant (P=0.008) decrease in the Vv of the serous acini compared with the control group accompanied by abnormal acini (Vv=18%). In contrast, mucous acini and ducts did not demonstrate significant changes. In one case (3.8%), dysplastic ducts were found adjacent to islands of invasive squamous cell carcinoma of tongue mucosa origin. The change in saliva composition expected after considerable damage of the serous glands could create a microenvironment that makes entrapment of the carcinogen easier and prolongs exposure of tongue epithelium. Furthermore, the dysplastic changes in the ducts can serve as a reservoir of carcinoma cells. These observations should be considered in human patients diagnosed with oral dysplasia or carcinoma, especially involving the tongue and floor of mouth.

4-Nitroquinoline-1-oxide↗

PubMed2003

Periapical actinomycosis: a clinicopathologic study.

OBJECTIVE: We sought to evaluate the incidence and clinical outcome of an accidental finding of actinomycotic colonies in periapical lesions submitted for histologic examination. STUDY DESIGN: The study included all periapical biopsy specimens submitted for histologic examination between 1997 and 2000. Sections of paraffin-embedded tissues, 5 microm, were cut and stained by using hematoxylin and eosin, periodic acid-Schiff, and the Gram stain. The presence of typical branching colonies of filamentous bacteria staining positive for periodic acid-Schiff and Gram stain was indicative of Actinomyces. RESULTS: Typical actinomycotic colonies were identified in 17 of 963 (1.8%) periapical biopsy specimens. The mean patient age was 42, and males were predominant (65%). The maxilla was the most frequently involved site (65%), with equal distribution in the anterior and posterior areas. Radiographically, most cases presented as well-demarcated radiolucent lesions. Malignancy was suspected in 3 cases. Of the periapical lesions, 15 were epithelialized, and in 4 cases, a true epithelial-lined lumen was found, which was diagnosed as a radicular cyst. A residual cyst was diagnosed in 1 case, and in 1 case, an epithelial lining was not identified. Treatment included surgical curettage and a short course of antibiotic therapy. Healing was uneventful in all cases. CONCLUSIONS: Periapical actinomycosis is not common. Its outcome is favorable after surgical curettage supplemented by short-term antibiotic treatment. The relationship of periapical actinomycosis with the more serious cervicofacial actinomycosis should be evaluated.

Actinomyces↗

PubMed2003

Peripheral giant cell granuloma associated with dental implants.

BACKGROUND: Peripheral giant cell granuloma (PGCG) is a well-circumscribed lesion confined to the alveolar and gingival mucosa. PGCG is considered a reactive lesion caused by local irritation or trauma. The objectives of the present study were to evaluate the incidence of PGCG in peri-implant lesions submitted for histologic examination, to establish its correlation with implant failure, and to discuss its pathogenesis. METHODS: The study was conducted on 25 periimplant biopsy specimens submitted for histological examination between 1999 and 2001. Sections (5 microm) of paraffin embedded tissues were cut and stained with hematoxylin and eosin. RESULTS: From the 25 specimens, three (two males and one female, ranging in age from 31 to 69 years) were identified as peripheral giant cell granuloma. The posterior mandible was affected in two cases and the anterior maxilla in one. The clinical appearance was an exophytic mass with a bleeding surface. The time interval between implantation and lesion development was from several months to 6 years. Recurrence following curettage was found in all cases. The implants were stable; however, two were removed either because of bone loss around the implant or because of several recurrences. In all cases healing was uneventful. CONCLUSIONS: Peripheral giant cell granuloma can develop in association with dental implants. Clinically, the lesions are similar to the classical PGCG. In the present study, the precise incidence could not be concluded because of the small number of selected cases. Due to the aggressive nature of the lesion and the high recurrence rate, implants can fail unless the lesion is detected early and proper surgical removal is performed. Tissue removed from the peri-implant area should always be submitted for histologic examination for accurate diagnosis.

Adult↗