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Biomedical subjects

G Bronner

Publications and source records attributed to G Bronner.

18 recordsLinked to original sources
PubMed2002

Modeling comparative mapping using objects and associations.

Spatial information on genome organization is essential for both gene prediction and annotation among species and a better understanding of genomes functioning and evolution. We propose in this article an object-association model to formalize comparative genomic mapping. This model is being implemented in the GeMCore knowledge base, for which some original capabilities are described. GeMCore associated to the GeMME graphical interface for molecular evolution was used to spatially characterize the minor shift phenomenon between human and mouse.

Animals↗
PubMed2001

Systematic esophageal endoscopy screening in patients previously treated for head and neck squamous-cell carcinoma.

BACKGROUND: An attempt was made to improve metachronous oesophageal cancer prognosis through bi-annual systematic esophageal endoscopy screening in patients treated for head and neck cancer. PATIENTS AND METHODS: Bi-annual esophageal endoscopy, without a staining procedure, was performed in 1560 patients from 1987 to 1997. The distribution of previous head and neck cancer was oral cavity (20%), oropharynx (30%), hypopharynx (34%), and larynx (16%). All patients had initial panendoscopic inspection before HNSCC treatment. Esophageal tumors were considered to be second synchronous primaries when discovered within the first six months of initial tumor diagnosis. RESULTS: Fifty metachronous esophageal asymptomatic cancers (42 T1 and 7 in situ carcinomas) were diagnosed by endoscopy. The median time between the HNC and the esophageal carcinoma was 43 months (7-137 months). Metachronous esophageal carcinoma was discovered in 2.6% of patients with oral cavity tumor, 5.7% of patients with oropharynx tumor, 2.3% of patients with hypopharynx tumor, and 1.7% of patients with larynx tumor. Causes of death were: 41.1% related to esophageal tumor with tumor progression, metastatic evolution, or treatment toxicity; 28.9% related to non malignant causes; 26.6% related to a cancer that was not of esophageal origin. CONCLUSIONS: Over a 10-year period, systematic bi-annual esophageal endoscopy uncovered metachronous esophageal tumors in 3.2% of 1560 patients originally treated for head and neck carcinoma, developing in a median time of 47 months. Patients with initial oropharyngeal tumors had a significantly higher risk of metachronous esophageal SCC, compared to the other tumor sites (P < 0.02 with Fisher exact test). Given the elevated death rate not related to the esophageal cancer and the median survival of 16 months, any potential benefit from this time-consuming procedure is debatable.

Adult↗
PubMed2001

Karyotype comparison and phylogenetic relationships of Pipistrellus-like bats (Vespertilionidae; Chiroptera; Mammalia).

Detailed karyotype descriptions of 20 Pipistrellus-like bat species belonging to the family Vespertilionidae are presented. For the first time, chromosomal complements of four species, i.e. Pipistrellus stenopterus (2n = 32), P. javanicus (2n = 34), Hypsugo eisentrauti (2n = 42) and H. crassulus (2n = 30) are reported. A Pipistrellus kuhlii-like species from Madagascar represents a separate species distinguished from the European Pipistrellus kuhlii (2n = 44) by a diploid chromosome number of 42. Banded karyotypes are presented for the first time for Scotozous dormeri, Hypsugo capensis, Hesperoptenus blanfordi, Tylonycteris pachypus and robustula. Chromosomal evolution in the family Vespertilionidae is characterized by the conservation of entire chromosomal arms and reductions in diploid chromosome number via Robertsonian fusions. Less frequently, centric fissions, para- and pericentric inversions and centromere shifts were found to have occurred. In several cases a certain type of chromosomal change predominates in a karyotype. Examples of this are the acquisition of interstitial heterochromatic bands in Tylonycteris robustula, and centric shifts in P. javanicus, H. eisentrauti and Hesp. blanfordi. The species examined here belong to three tribes, i.e. Pipistrellini, Vespertilionini and Eptesicini, which are distinguished by chromosomal characteristics. According to our results, the species Pipistrellus (Neoromicia) capensis belongs to the Vespertilionini and not to the Pipistrellini. We therefore propose to elevate the subgenus Neoromicia to generic rank.

Animals↗
PubMed1999

Sexuality among institutionalized elderly patients with dementia.

The subject of sexuality among elderly patients with dementia was examined, focusing on two main aspects: the sexual behaviour of institutionalized elderly people with dementia; and the reactions of other patients, staff and family members to this behaviour. The behaviour was found to be mostly heterosexual and ranged from love and caring to romance and outright eroticism. Reactions varied, being accepting of love and care but often objecting to erotic behaviour. Understanding of the sexual needs of elderly people should become an integral part of the training and continued education of health care staff, thus helping to resolve conflicts and clarify common misconceptions.

Aged↗
PubMed1998

Cerebrovascular adaptation after unilateral carotid artery ligation in the rat: preservation of blood flow and ATP during forebrain ischemia.

To investigate long-term adaptations after unilateral carotid artery ligation, the effect of forebrain ischemia on cerebral blood flow and ATP levels was determined at various times after ligation. Unilateral carotid artery ligation was performed in male Wistar rats 0, 3, or 7 days before forebrain ischemia. Laser-Doppler blood flow was monitored bilaterally over the parietal cortex and ATP was measured in the subadjacent cortex of both hemispheres at the end of a 10-minute episode of ischemia. In the 0-day group, forebrain ischemia reduced cortical blood flow to 12% +/- 8% (mean +/- SD) of preischemic values and lowered cortical ATP to 26% +/- 35% of control levels in the ipsilateral hemisphere. Delaying the onset of forebrain ischemia for 3 days after carotid artery ligation significantly improved cortical blood flow (29% +/- 12%, P < 0.05) and ATP levels (92% +/- 11%, P < 0.05) in the ipsilateral hemisphere. Delaying forebrain ischemia for 7 days also significantly improved ipsilateral blood flow (36% +/- 11%, P < 0.05) and ATP levels (81% +/- 29%, P < 0.05) compared with the 0-day group. In the contralateral hemisphere, the reduction in blood flow and ATP levels was not significantly altered by delaying the onset of forebrain ischemia for 3 or 7 days. These results show that unilateral carotid artery ligation induces long-term vascular adaptations that improve the collateral circulation and preserve ATP levels during a subsequent episode of ischemia.

Adaptation, Physiological↗
PubMed1997

Amplification of 11q13 DNA markers in head and neck squamous cell carcinomas: correlation with clinical outcome.

This study was performed on 282 patients with primary head and neck squamous cell carcinomas to evaluate the prognostic importance of 11q13 amplification. Amplification of the 11q13 DNA markers, HST-1/FGF-4 and BCL-1, evaluated by Southern and slot blot hybridisation, was detected in 52% of tumours. 11q13 amplification was associated with tumour site since this alteration occurred in 76% of tumours arising in the hypopharynx, versus 40% in the other sites (P = 0.0007). 11q13 amplification was also significantly related to the presence of involved neck lymph nodes (P = 0.013). The relationship between 11q13 amplification and risk of progression was studied in two subgroups of head and neck cancer patients with regard to treatment modalities. The presence of 11q13 amplification in the tumour was not significantly associated with a shorter event-free survival (P = 0.82) and crude survival (P = 0.61) of the 201 patients treated by surgery and postoperative radiotherapy. Similarly, absence of a relationship was observed for the group of 79 patients treated by surgery alone. These results confirm that 11q13 amplification is a prominent event in head and neck squamous cell carcinoma, indicating that it may be a common genetic event in the development of these neoplasms, but is not a reliable prognostic marker.

Adult↗
PubMed1997

Ethical dilemmas concerning sexuality of elderly patients suffering from dementia.

This study endeavoured to clarify the ethical dilemmas concerning sexuality encountered by nurses caring for elderly patients suffering from dementia, and to assist the decision-making process of the nurses and staff who handle dilemmas of this nature. Many of the staff in geriatric institutions report difficulties, confusion, embarrassment and helplessness as well as negative responses and rejection when encountering sexual situations between patients of the same or different sex, patients and staff members or between patients and visitors. Embarrassment over sexuality is felt by staff members, visitors and family. This embarrassment may result in elderly patients being treated like children, and being separated from their partners. A response of this nature can provoke anger in the patients, sometimes leading to violence. The central dilemma on the subject of sexuality in a geriatric institution is the fact that staff are in conflict between the desire to protect the elderly patients and maintain their dignity and the patients' desire to fulfil their sexual needs. Since no single, definitive prescription can be provided for conduct acceptable to the staff, the patients and their families, it was decided to work with the staff on the basis of case studies to help them in selecting ways of coping.

Aged↗
PubMed1994

Frequent amplification of 11q13 DNA markers is associated with lymph node involvement in human head and neck squamous cell carcinomas.

Amplification of 11q13 DNA markers, particularly hst-1/FGF4 oncogene and the bcl-1 locus, was evaluated in 178 head and neck squamous cell carcinomas (SCCs) by Southern blot and slot blot hybridisation. Coamplification of hst-1/FGF4 and bcl-1 genes was found in 57% of primary tumours and in 60% of the 89 metastatic lymph nodes tested. The pattern of amplification was significantly similar in matched sets of primary SCCs and metastatic lymph nodes. Levels of amplification, quantified by densitometric analysis of slot blots, ranged from 2 to 18-fold normal gene dosage. Also, c-myc oncogene (8q24) was found amplified less frequently, since 7% of 169 SCCs tested contained amplification of this gene, the level of which ranged from 2 to 8-fold. Hst-1/bcl-1 gene amplification was observed more frequently in the tumours arising from the hypopharynx. Coamplification of hst-1 and bcl-1 genes was significantly positively associated with tumours with nodal involvement (P = 0.001). Incidence of hst-1/bcl-1 gene amplification is higher in the tumours with a clinical stage III or IV. Hst-1/bcl-1 gene amplification was not related to tumour differentiation or local invasiveness. This prospective study shows that amplification of 11q13 DNA markers is a prominent event occurring in head and neck SCC and may contribute to the pathogenesis and evolution of a subset of patients bearing this type of cancer.

Blotting, Southern↗
PubMed1993

Increased stromelysin 3 gene expression is associated with increased local invasiveness in head and neck squamous cell carcinomas.

Matrix metalloproteinases are believed to play an important role in tumor invasion and metastasis. To examine the expression of the stromelysin 3 (ST3) gene, a new member of the matrix metalloproteinase gene family, 111 head and neck squamous cell carcinomas and 21 metastatic lymph nodes were analyzed by Northern blot. ST3 gene expression was observed in 106 carcinomas and 19 metastatic nodes, but in only 2 of 60 samples of corresponding normal tissue tested in parallel. ST3 RNA, by in situ hybridization, and ST3 protein, by immunohistochemical analysis, were specifically detected in fibroblastic cells immediately surrounding invasive cancer cells. This fibroblastic expression of the ST3 gene is characteristic among the matrix metalloproteinase genes known to be overexpressed in head and neck carcinomas, since stromelysin 2 transcripts were specifically detected in neoplastic cells, and type I collagenase transcripts in both neoplastic cells and stromal fibroblasts. Furthermore, there was a highly significant positive correlation (P < 0.0001) between ST3 RNA levels and local invasiveness by the cancer cells, suggesting that enhanced expression of the ST3 gene may contribute to the neoplastic phenotype in head and neck carcinomas.

Carcinoma, Squamous Cell↗
PubMed1991

Expression of collagenase-related metalloproteinase genes in human lung or head and neck tumours.

We address the question as to whether increased metalloproteinase production might be related to the high regional recurrence rate of some carcinomas, and particularly head and neck squamous-cell carcinomas (SCC). Northern blot of total RNA prepared from 26 lung carcinomas, 107 head and neck carcinoma samples and corresponding normal tissue samples demonstrates the frequent and sometimes concomitant over-expression of the 2 stromelysin genes, the type-I collagenase gene and the pump-I gene in the head and neck tumour tissue samples. In these SCC, over-expression of the 2 stromelysin genes and the type-I collagenase gene (but not the pump-I gene) is associated with a high degree of tumour differentiation. Moreover, a tumour with high levels of the stromelysin mRNAs is more likely to show high local invasiveness, suggesting that the stromelysins may be implicated in the clinical course of head and neck tumours. Evaluation of the corresponding mRNA levels may prove a useful indicator for predicting the clinical aggressiveness of these tumours.

Biomarkers, Tumor↗