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Biomedical subjects

L Gleich

Publications and source records attributed to L Gleich.

8 recordsLinked to original sources
PubMed1999

Cervical metastases of head and neck squamous cell carcinoma correlate with loss of heterozygosity on chromosome 16q.

To assess the potential involvement of putative tumor suppressors or metastasis suppressors on chromosome 16q in head and neck squamous cell carcinoma (HNSCC), we have examined 42 primary HNSCCs for loss of heterozygosity (LOH) at 16q and correlated these findings with the occurrence of cervical nodal metastases and other clinical parameters. Seven of the 42 (17%) HNSCCs examined displayed LOH at chromosome 16q24. Three of the seven HNSCCs showed LOH at all of the informative loci analyzed along the chromosome arm, whereas the other four showed only loss of a subset of markers. When LOH at 16q was correlated with clinical parameters, there was no significant correlation with age, sex, clinical stage, T stage, N stage or survival. However, there was a correlation between LOH at chromosome 16q24 and involvement of cervical lymph nodes. Of the seven HNSCCs that had lost heterozygosity at 16q24, six had local metastases to lymph nodes indicating that LOH at 16q24 may have predictive value for the metastatic potential of HNSCCs.

Adult↗
PubMed1997

Overexpression of glutathione S-transferase pi messenger RNA and its relationship to gene amplification in head and neck squamous cell carcinoma.

Human glutathione S-transferase pi has been known to be a good marker for several tumor types because of the high frequency with which it is overexpressed. In order to determine whether GST pi is useful as an indicator for head and neck cancers, expression of GST pi was investigated by Northern analysis. Overexpression of mRNA was detected in 9 of 36 primary head and neck squamous cell carcinomas. To examine the relationship between overexpression and amplification of GST pi gene, Southern analysis was performed on all samples. Only 3 of the 36 tumors showed amplification GST pi genes, indicating that gene amplification may not play a key role in GST pi mRNA overexpression in these cancers.

Biomarkers, Tumor↗
PubMed1997

Prognostic indicators for squamous cell carcinoma of the oral cavity: a clinicopathologic correlation.

Fifty-three patients with T1 squamous cell cancer of the floor of mouth and ventral surface of the tongue with a known clinical outcome were retrospectively analyzed and arbitrarily divided into "aggressive" and "nonaggressive" groups based on their clinical behavior. Various host and tumor factors were then evaluated in an attempt to determine whether the tumor behavior could have been predicted. The paraffin-embedded tumor specimens were evaluated for tumor differentiation, tumor thickness and tumor invasion, microvessel density, and p53 expression. In addition, a composite morphologic grading score was obtained by combining cell differentiation, nuclear polymorphism, mitosis activity, depth of infiltration, type of infiltration, and lymphatic infiltration. No single technique appeared capable of identifying "aggressive" behavior, although possibly an evaluation of composite factors might show promise in the future.

Carcinoma, Squamous Cell↗
PubMed1997

Overexpression and amplification of glutathione S-transferase pi gene in head and neck squamous cell carcinomas.

Human glutathione S-transferase pi (GST-pi) may serve as a useful tumor marker because of the high frequency with which it is found in elevated levels in several tumor types. To determine whether GST-pi is useful as an indicator for cancers of the head and neck, expression of GST-pi mRNA was investigated by Northern analysis in this tumor type. Overexpression of GST-pi mRNA was detected in 9 of 36 (25%) primary head and neck squamous cell carcinomas (HNSCCs). When Southern blot analysis was used to examine the relationship between overexpression and amplification of the GST-pi gene, only 3 of 36 tumors (8%) showed GST-pi gene amplification. Thus, gene amplification is not critical to GST-pi mRNA overexpression in HNSCCs. Moderately and poorly differentiated HNSCCs tended to manifest elevated GST-pi mRNA compared with well differentiated tumors (30% for moderately and poorly differentiated tumors versus none of the well differentiated tumors examined). However, there was no significant correlation between GST-% mRNA overexpression and clinical stage, T stage (tumor size), N stage (neck nodal status), pathological nodes, or patient survival.

Adult↗
PubMed1995

Amplification and overexpression of the cyclin D1 gene in head and neck squamous cell carcinoma.

Aims-To determine cyclin D1 gene amplification and expression levels in head and neck squamous cell carcinoma (HNSCC) patients.Methods-Total RNA and genomic DNA were isolated from 40 samples of HNSCC tissue and matched normal tissue and were hybridised with a cyclin D1 cDNA probe. Northern and Southern analyses were used to detect mRNA overexpression and cyclin D1 gene amplification, respectively.Results-15 of the 40 HNSCC samples examined (38%) showed cyclin D1 gene amplification. Of these 15 samples, all 13 from which RNA was available showed increased cyclin D1 expression.Conclusions-HNSCC patients with both amplification and overexpression of the cyclin D1 gene are at greater risk than patients who showed no cyclin D1 gene amplification; amplification and over-expression of the cyclin D1 gene may play an important role in the progression of HNSCC and in clinical outcome.

Journal Article↗
PubMed1995

Altered p53 in microdissected, metachronous, premalignant and malignant oral lesions from the same patients.

Aims-To determine whether mutant p53 alleles harboured by malignant tumours of the oral cavity were also present in previous premalignant lesions at the same site.Methods-Paraffin embedded tumour specimens along with their premalignant counterparts were analysed for p53 alterations using immunohistochemistry, microdissection, polymerase chain reaction amplification, and DNA sequencing.Results-Malignant lesions from five of eight patients showed overexpression of p53 protein by immunohistochemistry. Upon DNA sequencing, two of these five specimens had p53 mutations. Of the five patients whose cancers showed p53 overexpression by immunohistochemistry, three had previous premalignant lesions that also had immunohistochemically detectable p53 protein. However, DNA sequencing showed that none of these three had mutations in the p53 gene. The remaining five premalignant lesions had no immunohistochemically detectable p53 protein.Conclusions-Some premalignant lesions have increased p53 protein which can be detected by staining with antibody to p53. This staining is not caused by mutations in p53 that are found in subsequent tumours at the same site.

Journal Article↗
PubMed1990

Accuracy and pitfalls of frozen section during thyroid surgery.

The purpose of this study was to assess the accuracy of frozen sections performed during thyroid surgery and to define any pitfalls they may have. The material includes a series of 190 frozen section examinations of thyroid pathology. The overall accuracy of frozen section in this series was 95%. There were no false positives in our series and false negatives related to only follicular adenomas. In two patients, the report was deferred for permanent slide examination. Nine patients had lesions reported as malignant; however, the distinct cell type was not designated on frozen section. Eight specimens initially reported to have follicular adenoma on frozen section turned out to have angioinvasion or capsular invasion indicative of follicular carcinoma. Minor discrepancies between frozen and permanent sections in the types of benign disease were noted occasionally, but were not clinically significant. There was a discrepancy in the diagnosis of Hashimoto's thyroiditis on three occasions. The major discrepancy in patients with malignant pathology was related to the cell type. The diagnosis of anaplastic thyroid cancer, though suspected, was deferred for permanent sections in all cases. The diagnosis of medullary cancer of thyroid was difficult to make on frozen section. The major problem with frozen section was the diagnosis of follicular adenoma versus carcinoma. The benign diagnosis was changed in eight instances (out of 24 frozen sections) from follicular ademona to follicular carcinoma. Because of this experience, we do not provide the frozen section diagnosis to the patient and we wait until the final diagnosis is available.

Adenocarcinoma↗