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Biomedical subjects

M B Papageorge

Publications and source records attributed to M B Papageorge.

13 recordsLinked to original sources
PubMed1996

The effect of N-nitrosonornicotine on the buccal mucosa of Syrian hamsters.

PURPOSE: The carcinogens in smokeless tobacco have been identified as the tobacco-specific nitrosamines and the effect of one of these, N-Nitrosonornicotine (NNN), on the buccal mucosa of the Syrian hamster was studied. MATERIALS AND METHODS: Buccal pouches of 36 Syrian hamsters were painted five times per week for 24 weeks with 10 mg/mL 98% pure NNN in suspension with mineral oil. Animals were killed at 6, 8, 12, and 24 weeks. RESULTS: At 6 weeks, the buccal pouch mucosa of the experimental animals appeared clinically more hyperemic than those of the controls. From 12 weeks onward, all experimental animals showed epithelial hyperplasia and inflammation on histologic examination. Three animals killed at 24 weeks showed mild epithelial dysplasia. CONCLUSIONS: Exposure of Syrian hamster buccal mucosa to NNN, five times per week for 24 weeks, did not result in clinical or histologic cancerous changes. NNN may require other factors for cancer production, such as a cocarcinogen, a higher concentration, or a longer period of application.

Animals↗
PubMed1995

The cancer-promoting effect of N-nitrosonornicotine used in combination with a subcarcinogenic dose of 4-nitroquinoline-N-oxide and 7,12-dimethylbenz (A) anthracene.

PURPOSE: This study was conducted to determine the possible carcinogenic role of N-Nitrosonornicotine (NNN) when combined with subcarcinogenic doses of strong carcinogens dimethylbenz (a) anthracene (DMBA) and 4-nitroquinoline-N-oxide (4NQO) in the hamster cheek pouch. MATERIALS AND METHODS: Eighty-five Syrian golden hamsters were randomly divided into three main groups. Group A contained 35 animals, 20 of which were treated with 0.1% DMBA followed by 4% NNN (A-I), 5 with 0.1% DMBA (A-II), 5 with 4% NNN (A-III), and 5 with mineral oil alone (A-IV). Group B contained 23 animals, 13 of which were treated with 0.5% 4NQO followed by 4% NNN (B-I), 5 with 0.5% 4NQO (B-II), and 5 animals with propyleneglycol alone (B-III). Group C contained 27 animals, 14 of which were treated with 0.1% DMBA followed by 4% NNN and 0.5% 4NQC (C-I), and 13 with 0.1% DMBA followed by 0.5% 4NQO (C-II). All animals were treated three times per week for 16 weeks. A total of 7 animals died during this period. RESULTS: Squamous cell carcinoma (SCCA) developed in eight animals (67%) in the group treated with all three chemicals (C-I), in four animals (33%) treated with DMBA and 4NQO (C-II), in two animals (15%) treated with 4NQO and NNN (B-I), and in two animals (11%) treated with DMBA and NNN (A-I). The difference between the number of animals that developed carcinoma in group C-I and those in groups A-I and B-I was statistically significant (P < .05) and this difference reached a significant value when group C-I and C-II were compared (P < or = .1). There was a direct relationship between the number of tumors produced in animals and the number of different chemicals applied. CONCLUSION: The results of this study indicate that NNN, when combined with subcarcinogenic doses of other strong carcinogens, is a promoter in the development of squamous cell carcinoma and that 4NQO in 0.5% concentration is a stronger carcinogen than 0.1% DMBA.

4-Nitroquinoline-1-oxide↗
PubMed1995

The poisoned patient. Toxicologic emergencies.

Local anesthetics with and without vasoconstrictors, analgesics, antibiotics, and antianxiety medications are used routinely in dentistry. Most agents used in the dental office have a safe therapeutic dose range between effective and toxic so that the potential for adverse reactions is easily ignored. This article discusses toxicity, allergy, idiosyncrasy, drug interactions, local anesthesia, and the use of recreational drugs and alcohol.

Analgesics↗
PubMed1993

Diffusion hypoxia: another view.

Arterial oxygen saturation (SaO2) was monitored postoperatively with pulse oximetry in 80 dental patients receiving nitrous oxide and oxygen. These patients were divided into four equal groups, three of which received nitrous oxide (N2O) and oxygen (O2) in ratios of 20:80, 40:60, and 60:40, respectively. The fourth group received 100% O2 and served as the control. The SaO2 was monitored for 15 minutes after termination of the procedure as the patient breathed room air. Continuous pulse oximetry revealed 43 episodes of SaO2 (a decrease greater than 3% from the baseline) in patients who received 20% N2O, 268 episodes in patients who received 40% N2O, 594 episodes in patients who received 60% N2O, and 21 episodes in patients who received 100% O2. The number of patients who experienced desaturation episodes increased with the increase in N2O concentration. The SaO2 values ranged from a decrease of 1.0% to 7.0% with a mean of 2.1%. Smokers experienced a greater number of desaturation episodes in the 40% N2O group and in the control group. One patient in the 40% N2O group experienced an SaO2 of less than 90%, but no patient experienced clinically significant hypoxia. In the 40% and 60% N2O groups, the percent change of SaO2 from the baseline was greater, and the SaO2 returned to baseline slower. The difference in mean SaO2 between smokers and nonsmokers was greater in the 40% N2O group.

Adult↗
PubMed1993

A case of a central odontogenic fibroma presenting a differential diagnostic problem.

Central odontogenic fibromas are rare benign tumors. We are presenting a case of a 67-year-old female with a central odontogenic fibroma which posed considerable difficulty in microscopic interpretation. The differential diagnosis ranged from metastatic carcinoma to a benign odontogenic neoplasm. The final diagnosis was made through persisting on multiple pathologic consultations, which allowed for conservative rather than aggressive surgery. Follow-up evaluation has confirmed the benign diagnosis.

Aged↗
PubMed1992

Solitary neurofibroma of the mandible and infratemporal fossa in a young child. Report of a case.

The first case of a rare and unusual solitary neurofibroma of the mandible that caused bony erosion and extension into the adjacent soft tissues of the infratemporal fossa is presented. The clinical, radiographic, and histopathologic features of the neurofibroma are reviewed. The diagnostic procedures and the surgical treatment of this tumor in a young child are discussed.

Child, Preschool↗
PubMed1992

An exaggerated response of intra-oral pyogenic granuloma during puberty.

Intra-oral pyogenic granulomas have been associated with pregnancy. The exaggerated response of these tumors has been related to the hormonal changes occurring during this period. A change in the hormonal balance also occurs during puberty. In this paper, we present two young patients with large pyogenic granulomas and suggest that the hormonal changes play a primary role in the pathogenesis of this tumor.

Child↗
PubMed1992

Supplemental oxygen after outpatient oral and maxillofacial surgery.

Arterial oxygen saturation (SpO2) was monitored postoperatively with pulse oximetry in 72 dental patients. Intravenous general anesthesia was employed in 57 patients. All of these patients received supplemental oxygen intraoperatively, and of these, 29 received supplemental oxygen postoperatively. Fifteen patients received only local anesthesia without supplemental oxygen and served as the control group. Continuous pulse oximetry revealed 43 episodes of arterial oxygen desaturation (SpO2 decreases greater than 3% from baseline) in patients who did not receive postanesthesia supplemental oxygen and eight episodes of desaturation in patients who did receive postanesthesia oxygen. Patients with a smoking history had more episodes of desaturation than did nonsmokers in the group that received general anesthesia and breathed room air postoperatively. The total amount of methohexital administered had no significant effect on the number of patients with desaturation episodes. These observations emphasize the need for postoperative oxygen for patients who undergo general anesthesia for outpatient oral and maxillofacial surgery.

Adolescent↗
PubMed1988

A comparative study of magnetic resonance imaging versus computed tomography for the evaluation of maxillary and mandibular tumors.

The relative value of magnetic resonance imaging (MRI) versus computed tomography (CT) for imaging benign and malignant lesions of the maxilla and mandible was studied in a group of 16 patients. The imaging methods were evaluated for their ability to detect the lesion and define lesion margins, soft tissue extension, and bone involvement. The abnormality was identifiable with both imaging methods. For benign cystic lesions of either the maxilla or mandible (50%), MRI was overall equal to or better than CT. Magnetic resonance imaging was superior to CT in the evaluation of lesion margins and soft tissue extent of disease, whereas it was equal or slightly inferior to CT in lesion detection and in the evaluation of bone involvement. In the imaging of malignant neoplasms (50%), MRI was overall superior to CT in all four categories reviewed. Magnetic resonance imaging also had the highest rate of correlation with clinical findings, either from physical examination or at the time of surgery.

Adolescent↗
PubMed1987

Cementoblastoma involving multiple deciduous teeth.

The first case of a cementoblastoma involving multiple mandibular deciduous incisors is presented. The clinical, radiographic, and histopathologic features of the cementoblastoma are reviewed. The possible etiology for the pain frequently associated with this lesion is discussed.

Child↗