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Biomedical subjects

R Morency

Publications and source records attributed to R Morency.

17 recordsLinked to original sources
PubMed2000

Nuclear DNA content, an adjunct to p53 and Ki-67 as a marker of resistance to radiation therapy in oral cavity and pharyngeal squamous cell carcinoma.

Factors of prognosis and radioresistance in oral cavity and pharyngeal squamous cell carcinoma (OCPSCC) are limited. In the present study, the usefulness of tumor DNA content in predicting radioresistance in patients with OCPSCC has been investigated. Radioresistance has been defined as local recurrence or tumor persistence after radiation therapy. DNA-ploidy analysis was performed by static cytometry on smears of cell suspensions obtained from formalin-fixed paraffin-embedded material and stained with Feulgen. DNA-ploidy was correlated with the proliferation rate (Ki-67) and p53 protein accumulation obtained by immunohistochemistry. The follow-up of patients ranged from 8 to 62 months. Radioresistance was more common in non-diploid tumors; 14/28 (50%) non-diploid tumors recurred, whereas only 3 (10.7%) out of 28 diploid tumors had local failure (P=0.0019). Proliferation rate and p53 accumulation, evaluated by immunohistochemistry, also added prognostic information. Twelve out of 14 failures were from non-diploid tumors with a low proliferation rate (Ki-67<20%), whereas none of 20 p53-negative diploid tumors developed recurrences. This study showed that non-diploid tumors responded poorly to radiotherapy. DNA content appeared, therefore, as a significant prognostic marker for the evaluation of OCPSCC in patients receiving radiation therapy. This study also showed that DNA content adds information to p53 accumulation and the proliferation rate (Ki-67) for the purposes of determining patient management.

Adult↗
PubMed1997

Markers of radioresistance in squamous cell carcinomas of the head and neck: a clinicopathologic and immunohistochemical study.

PURPOSE: The lack of accurate criteria to predict the response to radiotherapy for individual patients with squamous cell carcinoma of the head and neck (HN-SCC) remains a major problem. The purpose of this study was to investigate the role of several biologic tumor markers to complement clinical prognostic factors in the assessment of response to radiotherapy in SCCs. PATIENTS AND METHODS: p53, ki-67, c-erb B-2, heat-shock protein-27 (HSP-27), and glutathione S transferase (GSTpi) were evaluated by immunohistochemistry on biopsies from 101 patients treated for head and neck cancer by radical radiotherapy. Expression of each marker was correlated with local control and survival using Kaplan-Meier curves. A Cox regression multivariate analysis was also performed that included all clinical and immunohistochemical variables. RESULTS: Expression of p53 and low cell proliferation allowed identification of patients whose tumors did not respond to radiation. Patients with p53-expressing tumors displayed a relative risk (RR) of 3.78 for not being controlled by radiotherapy compared with patients with p53-negative tumors. For tumors with a high growth fraction (ki-67 > 20%) the RR was 0.25 compared with tumors with a low growth fraction (ki-67 < 20%). When p53 expression and cell proliferation were considered simultaneously in a Cox model, the association with resistance to radiation was significant (P = .000004). The RR for resistance with one (p53 staining or ki-67 < 20%) or two (p53 staining and ki-67 < 20%) unfavorable markers was, respectively, 3.8 and 14.87. CONCLUSION: Patients whose tumor expressed p53 with low growth fraction (ki-67 < 20%) had a strong probability not to respond to radiation therapy. Similarly, absence of p53 expression with a high cell proliferation predicted an excellent outcome after radiotherapy even for patients with advanced disease. Prediction of the outcome of radiotherapy would eventually facilitate the early choice of an adequate treatment.

Adult↗
PubMed1996

p53 overexpression in head and neck squamous cell carcinoma: review of the literature.

As a tumour suppressor gene, the inactivation of p53 induces the development of numerous human cancers. Mutations of p53 have been implicated in the pathogenesis of head and neck squamous cell carcinoma (HN-SCC) at a high incidence. In premalignant lesions and in situ carcinomas, p53 overexpression is not exclusively restricted to neoplastic cells, but frequently affects the normal appearing keratinocytes adjacent to p53 positive neoplasms or present in dysplastic areas. These results suggest that as contributors to the early phases of HN-SCC development, p53 alterations may be excellent biomarkers that indicate the predisposition of a particular oral cavity premalignant lesion toward malignancy. In most cases, the p53 overexpression status of a tumour metastasis is identical to that of a primary tumour, indicating that a p53 mutation precedes metastatic spread. In patients with multiple primary tumours, multiple foci of p53 overexpression are observed in epithelia distant from the tumour. So the expression of p53 in normal epithelium would indicate an increased risk for transformation to second or third primary cancers. Distinct p53 mutations in different primary tumours of the same patient indicate that these cancers arise as independent events; these results support the existence of multifocal polyclonal processes. Regardless of the aforementioned results that support p53 as a valid tumour biomarker, most studies have shown no relationship between the expression of p53 and clinical and histopathological parameters. The role played by p53 mutations in the progression and vital prognosis of HN-SCC has not yet been demonstrated.

Biomarkers, Tumor↗
PubMed1993

Effectiveness of soft laser treatment in periodontal surgery.

The aim of this study was to determine the analgesic, anti-inflammatory and healing effects of soft-laser treatment in a double-blind crossover study of periodontal post-surgical patients. For each patient, mucogingival procedures were required on contralateral sides of the mouth for similar problems. Twenty-eight patients had a total of 28 pairs of surgical procedures performed. Prior to surgery, a complete examination was carried out, scaling and root planing were performed, and oral hygiene instructions were given. Following surgery on both sides of the mouth, one site was lased and a placebo procedure was carried out on the other site. The patients evaluated pain three times a day for one week (modified McGill pain scale). An inflammatory index (Loe and Silness Index) was ascertained at days 7 and 14 for both sides of the mouth. A healing score (Landry, Turnbull, Howley Index) was evaluated at days 7 and 14. For both surgical procedures, the assessments were carried out in the same manner. Univariate and multivariate analyses of variance were performed for all parameters. The results showed no significant differences in the gingival index, healing index and pain reduction when the soft laser treatment was compared to the placebo operation. These results suggest that soft laser (As-Ga and He-Ne) treatments may not be a useful adjunct after certain periodontal surgical procedures.

Adult↗
PubMed1991

Oral pigmentation induced by Premarin.

Pigmented lesions of the oral cavity are important entities. The wide range of their clinical differential diagnosis includes such diverse systemic conditions as Addison's disease, Peutz-Jeghers syndrome, malignant melanoma, Kaposi's sarcoma, as well as specific oral lesions, such as amalgam tattoo or gingival melanosis. This paper reports a very rare cause of oral pigmentation, a melanic type, related to the use of Premarin.

Cheek↗
PubMed1988

The glandular odontogenic cyst: an apparent entity.

This article reports 8 examples of a rare cyst of the jaws that appears to be a distinct entity and which we have named glandular odontogenic cyst because of its unusual histopathological features. This lesion occurs over a wide age range in both sexes, tends to recur, and may become very large. However, one example in this series remained small over a period of 9 years; another, somewhat atypical example, was associated with an ameloblastoma.

Adult↗
PubMed1987

Nevus sebaceus of Jadassohn: a rare oral presentation.

Nevus sebaceus of Jadassohn occurring exclusively in the oral cavity as a single lesion has not, to our knowledge, been reported previously. A case of this rare developmental anomaly at the palatine papilla of a 40-year-old woman is described.

Adult↗
PubMed1982

Focal epithelial hyperplasia of the oral mucosa.

Focal epithelial hyperplasia (FEH) of the oral mucosa has been reported mainly among American Indians, Eskimos, and south Africans. Our investigation is the first among Canadian Indians and combines an epidemiological study of FEH in a Cree Indian population living in Fort Georges. P.Q., and a description of its histologic and ultrastructural features. The sample consists of 150 individuals divided into six age groups. The prevalence rate for all groups is 18.6%. Clinically the lesions are nodular, sessile, and tend to merge with the adjoining mucosa upon stretching. Histologically the hyperplasia is limited to the epithelium. E.M. shows papova-virus-like particles. Otolaryngologists' awareness of this lesion could possibly lead to its recognition on a larger scale.

Adolescent↗