PubMed Health⌕ Search

Biomedical subjects

P A Reichart

Publications and source records attributed to P A Reichart.

At least 19 recordsLinked to original sources
PubMed1992

Oral ulceration and iatrogenic disease in HIV infection.

Ulcerative lesions of oropharyngeal mucous membranes are less commonly seen than other lesions in HIV infection and may be associated with mycotic, bacterial, and viral infection, as well as neoplasia. Differential diagnosis may be difficult because of the clinical similarity of ulcerations that can represent various causes. The term "atypical ulceration" has been suggested because it may be impossible to differentiate some of the oral ulcerations from each other. Iatrogenic ulceration is seen occasionally, as the consequence of chemotherapy or irradiation.

Antifungal Agents↗
PubMed1992

Clear cell calcifying epithelial odontogenic tumor. A case report.

Clear cell variants of odontogenic tumors are rare. A case of clear cell calcifying epithelial odontogenic tumor of the mandible in a 38-year-old Caucasian male is described. This case is compared to 8 previously reported cases. The origin of clear cells in odontogenic tumors is still unknown. En bloc resection of the tumor is recommended.

Adult↗
PubMed1992

The desmo- and osteoplastic ameloblastoma. Histologic variant or clinicopathologic entity? Case reports.

Two cases of desmoplastic ameloblastoma (DA) are presented, bringing the total number of reported cases to 29. One case of the so-called "hybrid lesion" is added to the presentation. Immunohistochemical studies indicate that the desmoplasia is caused by active de novo synthesis of extracellular matrix proteins. Moreover, the DA may also show osteoplasia, and this probably explains the characteristic radiographic appearance of many DAs, i.e. the occurrence of both radiolucent and radiopaque changes, suggestive of a fibro-osseous lesion. Many more cases of DA are needed to clarify the true nature of this most interesting tumor.

Adult↗
PubMed1992

Migratory facial swelling due to gnathostomiasis.

Two cases of facial gnathostomiasis in female Thai patients are described. Gnathostomiasis is caused by a roundworm, Gnathostoma spinigerum. In both patients the disease was characterised by intermittent and migratory swelling of the face. At present no effective therapy is available. Surgical removal of the parasite would be a curative treatment; it is however, rarely successful due to the parasite moving relatively rapidly within the soft tissues. The disease can be prevented by avoiding undercooked meat including fish. In endemic areas such as Southeast Asia, gnathostomiasis must be considered in cases of oro-facial swelling of otherwise unknown cause.

Adult↗
PubMed1992

Ectomesenchyme of ameloblastic fibroma reveals a characteristic distribution of extracellular matrix proteins.

The distribution of collagens type I, IV and VI, procollagen type III and of undulin was studied in four cases of ameloblastic fibroma (AF). The ectomesenchyme of AF revealed an as yet unobserved organization of these extracellular matrix proteins with collagen type VI clearly predominating over collagen type I, procollagen type III and undulin, that showed a weak and amorphous distribution throughout the tumor stroma. Undulin, a glycoprotein that is associated with mature collagen fibrils and with differentiated tissues, was not detectable in the tumor stroma of AF except for a slow expression around capillaries and in areas with a high cellularity. We could demonstrate that the characteristics of extracellular matrix composition allowed a clear distinction between the ectomesenchyme of AF and the adjacent normal mesenchymal stroma. Due to the specific staining patterns it was possible to detect epithelial tumor islands outside the typical ectomesenchymal stroma. Our findings furthermore indicate that epithelial cells of AF invade the adjacent normal mesenchyme possibly inducing de novo formation of ectomesenchymal tumor stroma.

Child↗
PubMed1992

Variants of the adenomatoid odontogenic tumor with a note on tumor origin.

Three rare variants of the adenomatoid odontogenic tumor (AOT) are described. A follicular AOT associated with an impacted and displaced 28, an extra-follicular variant mimicking a radicular cyst around the apex of 23 and a peripheral (epulis-like) variant exhibiting a periodontal bone defect palatal to 21. On reappraisal of the origin and pathogenesis of the AOT, it would seem that this tumor or hamartomatous lesion is derived from odontogenic epithelium of the dental lamina complex or its remnants.

Adolescent↗
PubMed1992

Scanning electron microscopy of odontogenic cyst epithelium.

The epithelial lining of 8 odontogenic keratocysts (OKC), 9 radicular (RC) and 3 dentigerous cysts (DC) were examined in SEM in order to study the ultrastructural surface topography of the lumenal surface cells. The orthokeratinized OKC showed a reticular network of intercommunicating microridges surrounding micropits giving a honeycombed appearance to the entire surface. The deep surface of these cells was covered by a complementary array of short stubby microvilli. This pattern was identical to that described for oral epithelium in areas of masticatory mucosa. The parakeratinized OKC showed a complex pattern of microplications (MP) on both upper and deep cell surfaces. The non-keratinized linings of RC and DC revealed a similar MP pattern but of a less complex nature. The MP pattern of cells from para- and non-keratinized cysts was identical to that described for oral epithelial cells from lining mucosa. The surface ultrastructure of ciliated, mucus and brush cells occurring in RC was found to be indistinguishable from that described in the mammalian respiratory tract. The MP pattern forms part of the cellular interdigitation mechanisms in stratified squamous epithelium. Differences in the ultrastructural configuration are related to the type of epithelium in terms of keratinization rather than to protective functions.

Adolescent↗
PubMed1991

Oral Candida and Enterobacteriaceae in HIV-1 infection: correlation with clinical candidiasis and antimycotic therapy.

Oral swabs of 73 HIV-1 infected men (32 under conditions of antimycotic treatment (43.8%)) and 58 controls were cultured for Candida species and Enterobacteriaceae. In Group A without antimycotics, yeasts were isolated from 35/41 swabs (85.4%) (range 2 x 10(1) - 4 x 10(6) cfu/ml). In Group B with antimycotics, yeasts were cultured from 27/32 swabs (84.4%) (4 x 10(1) - 1 x 10(6) cfu/ml). Oral Enterobacteriaceae (o.e.) were grown from 22% of the swabs of both Group A (2 x 10(1) - 2 x 10(6) cfu/ml) and Group B (4 x 10(1) - 1.6 x 10(6) cfu/ml). Growth of o.e. and yeasts (2 x 10(3) - 4 x 10(6) cfu/ml). Correlation between yeasts and o.e. were isolated in 14% (2 x 10(1) - 6.4 x 10(6) cfu/ml). Correlation between yeasts species to local and systemic treatment deserves further investigations.

Administration, Topical↗
PubMed1991

Demonstration of Epstein-Barr virus in scrape material of lateral border of tongue in heart transplant patients by negative staining electron microscopy.

Scrape material from the lateral border of the tongue of 50 heart transplant patients and 20 controls was studied for the presence of EBV by negative staining electron microscopy. Mild oral hairy leukoplakia was observed in two cases. Particles of the herpes virus were found in 20% of the specimens. Controls were negative for EBV. The study has shown that EBV may be expressed at the lateral border of the tongue during immunosuppression, occasionally resulting in the clinical appearance of hairy leukoplakia.

Adult↗
PubMed1991

Oral manifestations of recently described viral infections, including AIDS.

Oral viral diseases secondary to human immunodeficiency virus-1 infection are not commonly observed, except for Epstein-Barr virus infection. For the most part, members of the herpes virus group and the human papilloma viruses are involved. With the introduction of techniques like the polymerase chain reaction, the level of detection has been changed considerably. However, the application of these techniques may also result in difficulties of interpretation, such as is the case with the detection of human papilloma virus in human immunodeficiency virus-associated Kaposi's sarcoma, as recently described. The possible association of "new" viruses with well-known diseases such as Sjögren's syndrome or Paget's disease are of great interest; but the etiologic role of these particles in the disease process has yet to be determined (Scully, in Millard and Mason, eds. Perspectives on 1988 World Workshop on Oral Medicine. YearBook Publishing, 1989, pp 179-182). Oral manifestations in the course of human immunodeficiency virus disease and acquired immunodeficiency syndrome are numerous and have long been considered important for clinical diagnostic reasons. The present review is focused on viral diseases with oral manifestations associated with human immunodeficiency virus infection as well as with some "new" viral diseases that may also produce orofacial symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[The ameloblastic fibroma. An odontogenic tumor in the growth period].

Nine cases of ameloblastic fibroma are described and compared with published data on this odontogenic tumour. The median age of the 7 male and 2 female patients was 11 years (range 2-17 yrs.). The tumour was localized in the posterior segment of the mandible and less often in the maxilla. The neoplasia was frequently associated with impaction and agenesis of teeth. Although recurrences of ameloblastic fibromas are rare, long-term follow-up is recommended.

Adolescent↗
PubMed1990

Negative staining EM for the detection of Epstein-Barr virus in oral hairy leukoplakia.

The performance of two different EM techniques applied for the detection of Epstein-Barr Virus (EBV) in oral hairy leukoplakia (HL) was assessed, i.e. the conventional two-step method of negative staining (CNS) and negative staining after Airfuge enrichment (ANS). Scrape specimens from the lateral borders of tongue of 66 HIV-positive patients with or without HL, of 3 patients with infectious mononucleosis and of 10 HIV-negative patients were evaluated. While CNS resulted in virus detection only in 25% of clinically diagnosed HL cases, EBV was detected by ANS in 85% of clinically suspected cases of HL. Scrape specimens of individuals negative for HIV were negative in EM while 2 of 3 mononucleosis patients were positive without clinical evidence for HL. Due to this high sensitivity the method of negative staining after Airfuge enrichment appears to be useful in the diagnosis of HL. The finding of EBV in clinically normal oral mucosa in HIV-seropositive individuals is interesting and indicates that EBV expression may precede the clinical appearance of HL.

Adult↗
PubMed1979

Radiographic findings in 224Ra-caused dental resorptions.

Dental resorptions as a delayed effect of Thorium X (224Ra) were observed in four patients. The radiographic findings showed distinct and representative patterns. Apparently, the observed changes are typical for delayed alterations related to 224Ra-specific disturbances in the alveolar process. Degenerative and inflammatory reactions may also be involved in the pathogenesis.

Adult↗
PubMed1979

Study of Biopsies from lesions of the oral mucosa by scanning electron microscopy (S.E.M.).

Surface epithelial cells from 55 biopsies including lichen planus, leukoplakia and squamous cell carcinoma were studied by scanning electron microscopy. The surface structures of the various oral lesions demonstrated morphological differences. After more information has been collected, the method of SEM may be of value for the recognition of pre- and early neoplastic lesions in the oral cavity.

Biopsy↗
PubMed1979

224 Ra and 226Ra experimentally induced dental changes in rats.

Sprague-Dawley rats received intragastrically a single dose of 226Ra or 224Ra once weekly for 21 weeks. During this period the animals of both groups were thus exposed to comparable doses. After 12 weeks, a shortening of the maxillary incisors was observed, and this progressed during the course of the 55-week experiment. Radiologically, a loss of pulpal transparency and an apical irregular opacity in the maxillary incisors were demonstrable. Histologically, dysplastic changes of the maxillary incisors and multiple resorptions at the cemento-enamel junction of the molars were seen. The observed alterations were more pronounced in the 226Ra group than in the 224Ra treated group. The experimentally induced resorptions were comparable to those observed in patients who had incorporated 224Ra or 226Ra. Clinical, radiological, histological, gamma-spectrometrical, and autoradiographical findings, as well as dose-estimations, are described.

Animals↗
PubMed1978

Transformation of ameloblastic fibroma to fibrosarcoma.

The direct transformation of an ameloblastic fibroma into a fibrosarcoma in a 16-year-old Caucasian male is reported. Although no ameloblastic epithelium was found in the recurrent tumor, the odontogenic origin of the fibrosarcoma was evident. The ameloblastic fibrosarcoma and the fibrosarcoma of identical odontogenic origin represent an entity which should be distinguished from conventional fibrosarcoma as these tumors demonstrate different clinical behaviors.

Adolescent↗
PubMed1978

Experimental bacteremia to demonstrate the barrier function of epithelium and connective tissue surrounding oral endosseous implants.

The barrier function of the peri-pillary epithelial-connective tissue cuff was experimentally tested with 12 endosseous metal blade vents in four beagles. An identified Staphylococcus aureus test strain was suspended in 0.5 ml saline. This bacterial suspension was then instilled into the sulcus of each implant. For stimulation of bacteremia the animals were fed with pelleted dry food. After 5 minutes, venous blood was drawn and incubated. After 72 hours of incubation none of the cultures showed bacterial growth of the test bacteria. In a second experiment 0.5 ml of the bacterial suspension was inoculated intravenously. After 1 h a bacteriological smear and peri-pillary tissue were taken. The specified Staphylococcus aureus was identified with phage typing in only on tissue specimen. This study demonstrates that the pseudo-attachment of the epithelial-connective tissue complex to the post of metal endosteal implants is functionable. Functionability, however, is endangered if biomechanical imbalance or infection occurs.

Animals↗