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G T Gallagher

Publications and source records attributed to G T Gallagher.

At least 19 recordsLinked to original sources
PubMed2001

Oral cancer in vivo gene expression profiling assisted by laser capture microdissection and microarray analysis.

Large scale gene expression profiling was carried out on laser capture microdissected (LCM) tumor and normal oral epithelial cells and analysed on high-density oligonucleotide microarrays. About 600 genes were found to be oral cancer associated. These oral cancer associated genes include oncogenes, tumor suppressors, transcription factors, xenobiotic enzymes, metastatic proteins, differentiation markers, and genes that have not been implicated in oral cancer. The database created provides a verifiable global profile of gene expression during oral carcinogenesis, revealing the potential role of known genes as well as genes that have not been previously implicated in oral cancer.

Aged↗
PubMed2000

Salivary gland changes in chronic fatigue syndrome: a case-controlled preliminary histologic study.

OBJECTIVE: The purpose of this preliminary study is to compare labial salivary gland changes of 11 patients with chronic fatigue syndrome with control subjects. STUDY DESIGN: Changes in labial salivary glands were graded from 0 to 3+ for acinar dilatation, ductal dilatation, periductal fibrosis, plasmacytic infiltrate, lymphocytic infiltrate, mast cell infiltrate, and lymphocytic aggregates or foci. RESULTS: Four of the 11 subjects had 2+ to 3+ changes in at least 4 of the 7 parameters examined. Only the presence of mast cells was statistically significant between the 2 groups. Two of these 4 patients had 1 lymphocytic focus per 4 mm(2) of tissue. CONCLUSIONS: The salivary gland changes in patients with chronic fatigue syndrome show varying degrees of ductal and acinar dilatation, periductal fibrosis, lymphoplasmacytic infiltrates, and occasional lymphocytic foci, all suggestive of primary gland damage. The one parameter that showed statistical significance was the presence of mast cells (Fisher exact test, 0.0125).

Adult↗
PubMed1999

Eosinophil-derived transforming growth factors (TGF-alpha and TGF-beta 1) in human periradicular lesions.

Inflammatory mediators of periradicular lesions are poorly understood. Transforming growth factors-alpha and -beta 1 (TGF-alpha and TGF-beta 1) have been linked with the cellular processes for both soft and hard tissue wound healing. The purpose of this study is to demonstrate the cellular sources of TGF-alpha and TGF-beta 1 mRNA and protein in periapical lesions by in situ hybridization and immunohistochemistry. Nine periapical granulomas and nine periapical cysts were examined. TGF-alpha mRNA and protein were not detectable in the granulomas examined. However, eosinophils surrounding the periapical cysts demonstrated both TGF-alpha mRNA and protein. The vast majority of eosinophils present in the periapical granulomas and cysts also demonstrated TGF-beta 1 mRNA and protein. Other cells producing TGF-beta 1 were lymphocytes, fibroblasts, and monocytes. The presence of wound repair cytokines, such as TGF-alpha and TGF-beta 1, suggests a mechanism by which the host inflammatory response may participate in the repair and remodeling of periapical tissues.

Adult↗
PubMed1999

Eosinophil ablation and tumor development.

Tissue eosinophilia in squamous cell carcinoma has long been recognized; however, the role of eosinophils in tumor development remains unclear. Studies have reported both favorable and unfavorable prognoses for patients with tumors exhibiting tumor-associated tissue eosinophilia (TATE). This study seeks to elucidate the potential role of the eosinophil in squamous cell carcinoma development and provide an experimental model for future studies. The carcinogen-induced hamster oral cancer model was found to fulfill these objectives. Eosinophils progressively infiltrate into this carcinogen-induced oral cancer model. We now demonstrate that TATE is completely abolished by the use of an anti-interleukin-5 monoclonal antibody (mAb) preparation, TRFK-5. Clinical observations revealed that TRFK-5-treated hamsters exhibited smaller tumor burden and delayed onset of tumor development. The results suggest that anti-interleukin-5 antibody treatment may delay and/or inhibit tumor development, and that eosinophils may have a tumor-promoting role.

Animals↗
PubMed1998

Prediction of human oral cancer radiation responsiveness by histone (H3) mRNA in situ hybridization: a preliminary report.

PURPOSE: Cell cycle kinetics are believed to be a key determinant in radiation responsiveness. However, histomorphologic analysis remains an unreliable method of identifying proliferating cells. In this study, the fraction of cells undergoing division within oral cancer biopsy samples was used to predict the responsiveness of the tumor to radiation therapy. PATIENTS AND METHODS: Eighteen cases of T1 or T2 squamous cell carcinoma of the floor of the mouth with known clinical outcomes were identified. All were treated at the Massachusetts General Hospital with external beam radiation therapy alone. The fraction of proliferating cells was determined using in situ hybridization of histone (H3) mRNA expression. Tissue viability and mRNA status was verified using in situ hybridization for beta-actin mRNA expression. RESULTS: Matching the fraction of oral tumor cells positively labeled for histone (H3) mRNA (histone labeling index or HLI) with the actual clinical outcome showed that the HLI of radioresponsive oral tumors (12 cases) was 0.336+/-0.185 (approximately 34%+/-19%), whereas that for radioresistant oral tumors (six cases) was 0.088+/-0.078 (approximately 9%+/-7.8%). Using t-test statistical analysis for unpaired samples showed that the difference in HLI between the two groups was significantly different (P=.0068). CONCLUSIONS: It is concluded that the use of in situ detection of histone (H3) mRNA may be a useful adjunctive criterion in the choice of treatment for human oral cancer.

Adult↗
PubMed1997

Depletion of eosinophil infiltration by anti-IL-5 monoclonal antibody (TRFK-5) accelerates open skin wound epithelial closure.

Wound healing is critical to the survival of the species after injury. Using hamsters as an experimental model, we have shown that eosinophils infiltrate prominently into skin wounds and that they express transforming growth factor-alpha and -beta 1 mRNAs and proteins. We hypothesized that eosinophils are important in wound healing. As no animal model is genetically deficient in eosinophils, a suitable way to test the hypothesis is to selectively reduce and/or deplete the influx of eosinophils into the wound sites. In this study, we report that anti-interleukin-5 monoclonal antibody (TRFK-5) treatment can deplete eosinophils in cutaneous healing wounds. We found that wound closure by re-epithelialization in the experimental group was 4 days faster than in the control group (P < 0.01). The density of eosinophils in day-9 wounds was significantly lower in the experimental group (P < 0.01). Wound-associated eosinophils in each of the TRFK-5-treated hamsters were depleted to the level comparable to unwounded hamster skin. These results demonstrate that anti-interleukin-5 monoclonal antibody treatment can effectively decrease eosinophil infiltration into hamster cutaneous healing wounds and indicate a role for eosinophils in negatively affecting wound re-epithelialization.

Animals↗
PubMed1996

Lack of TGF-alpha and TGF-beta 1 synthesis by human eosinophils in chronic oral ulcers.

We recently demonstrated that eosinophils infiltrate prominently into cutaneous wounds in the Syrian hamster and represent a source of transforming growth factor-alpha and transforming growth factor-beta. In this study, we assessed the role of the eosinophil and eosinophil-derived transforming growth factors in human oral ulcers that exhibit delayed healing, descriptively termed traumatic ulcerative granuloma with stromal eosinophilia. Our aim was to determine whether eosinophils, which characteristically infiltrate traumatic ulcerative granuloma with stromal eosinophilia lesions, produced transforming growth factor-alpha or transforming growth factor-beta. Twelve cases of traumatic ulcerative granuloma with stromal eosinophilia were examined for transforming growth factor-alpha and transforming growth factor-beta mRNA and cellular protein by in situ hybridization and immunohistochemistry. Eosinophils in 92% of the cases did not express detectable cellular levels of mRNA for either of the transforming growth factors. In addition, only a small percentage of the many eosinophils infiltrating these lesions produced transforming growth factor-alpha or transforming growth factor-beta. The lack of significant synthesis of transforming growth factors by eosinophils in most of the cases of traumatic ulcerative granuloma with stromal eosinophilia is in striking contrast to the expression of transforming growth factors by the eosinophils that infiltrate the animal wound-healing model. Our findings may help to explain the delayed healing that is typical of TUGSE lesions.

Adult↗
PubMed1996

Salivary EGF regulates eosinophil-derived TGF-alpha expression in hamster oral wounds.

Using hamster as an oral wound healing model, we examined eosinophils and their expression of transforming growth factor-alpha (TGF-alpha) and transforming growth factor-beta 1 (TGF-beta 1). Oral wounds healed approximately two times faster than their cutaneous counterparts. Eosinophils infiltrated prominently into oral wounds; however, unlike the dual expression of TGF-alpha and TGF-beta 1 in skin wounds, oral wound-associated eosinophils expressed TGF-beta 1, but not TGF-alpha. Because saliva is present in oral environments and contains epidermal growth factor (EGF) and TGF-alpha, sialoadenectomy was performed in this model to determine whether the lack of TGF-alpha expression by eosinophils in oral wounds is due to the presence of salivary EGF and/or TGF-alpha. We found that eosinophils in sialoadenectomized hamsters did express TGF-alpha during oral wound healing but that such expression was suppressed when EGF was added to their drinking water. Taken together, our findings suggest that eosinophil-derived TGF-alpha and salivary TGF-alpha/ EGF may have complementary roles in contributing to TGF-alpha in oral wound healing.

Animals↗
PubMed1995

Maxillary odontogenic carcinoma with distant metastasis to axillary skin, brain, and lung: case report.

We present a case of odontogenic carcinoma with ghost-cell keratinization of the right maxilla, with a history of 23 years after initial treatment. Within this period, multiple local recurrence, as well as metastasis to axilla, brain, and lung, was noted. Several attempts at resection of the primary lesion were unsuccessful at achieving local control, even when supplemented with chemotherapy and radiotherapy. Metastatic tumors were studied histologically, and their morphology coincided with that of the primary tumor. The medical history of the patient and pathologic findings of the tumor are reviewed.

Axilla↗
PubMed1993

Identification of rabbit eosinophils and heterophils in cutaneous healing wounds.

The study of wound healing has traditionally used the rabbit as an experimental model. We have recently localized the production of the multifunctional cytokine, TGF-alpha, to eosinophils in rabbit skin wounds. It was evident that during the process of TGF-alpha localization, the distinction between the two granulocytic cell types, eosinophils and heterophils, was impossible by conventional histochemical techniques. This paper describes a rapid method to distinguish these two granulocytes by virtue of their endogenous peroxidases and differential resistance to blockade by inhibitors. In sections that have been blocked by hydrogen peroxide, the peroxidase substrate 3,3'-diaminobenzidine, together with nickel chloride (DAB-Ni), preferentially stained the cytoplasm of rabbit eosinophils while sparing those of heterophils. This selective DAB staining of rabbit eosinophil peroxidase in H2O2-blocked rabbit wounds was verified at the ultrastructural level by electron microscopy. We applied this technique to quantify eosinophil and heterophil infiltration into the 21-day rabbit cutaneous healing wound model. Heterophils were found infiltrated into all three layers of the wound (clot > granulation > base), but eventually all disappeared by day 21. As with the heterophils, eosinophils which had infiltrated into the clot and base of the wound had disappeared by day 21. Unlike the heterophils, eosinophils in the granulation layer of the wound continued to increase up to day 21. The continually increased and sustained presence of the eosinophils together with their demonstrated production of TGF-alpha, in the granulation layer of the healing would suggests that these cells play an important role in the organizational aspects of healing wounds.

3,3'-Diaminobenzidine↗
PubMed1992

Eosinophils, tissue eosinophilia, and eosinophil-derived transforming growth factor alpha in hamster oral carcinogenesis.

Eosinophilia in tissues and/or circulating blood is known to be associated with a wide variety of malignancies but the role of the eosinophil in neoplastic conditions is not known. Using the cheek pouch of the Syrian hamster as an experimental model for oral carcinogenesis, it has recently been shown that eosinophils at sites of developing oral cancer express the multifunctional cytokine, transforming growth factor alpha (TGF-alpha). This study investigated the time course of eosinophil infiltration, tissue eosinophilia associated with malignant epithelium, and eosinophil-derived TGF-alpha mRNA during the 16-week 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral cancer development process. The results reveal that the occasional eosinophil is normally present in the lamina propria of hamster oral mucosa. With progressive DMBA treatments, there is an increase of eosinophils infiltrating into the lamina propria. By weeks 12-16, the number of eosinophils is significantly higher in DMBA-treated pouches than in control pouches treated with the vehicle mineral oil alone. Analysis of the infiltrating eosinophils into fully developed hamster oral carcinomas reveals that tissue eosinophilia is associated with 78% of the stromal areas associated with malignant epithelium, while only 7% of sites associated with non-tumor oral epithelium (normal, hyperplastic-dysplastic) exhibited eosinophilia. Furthermore, the majority of the eosinophils associated with malignant epithelium were found to contain TGF-alpha mRNA. The number of TGF-alpha mRNAs containing eosinophils associated with malignant oral epithelium is significantly higher than that associated with nonmalignant oral epithelium. Together, these results suggest that eosinophils are recruited to tumor-developing sites, that they predominantly associate with malignant epithelium, and that most tumor-associated eosinophils express the cytokine TGF-alpha.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Cellular sources of transforming growth factor-alpha in human oral cancer.

Aberrant expression of TGF-alpha is associated with human malignant oral epithelium. Experiments were initiated to determine the cellular sources of transforming growth factor-alpha (TGF-alpha) in human oral cancer. Ten freshly resected human oral cancers and four specimens of normal human oral epithelium were studied by in situ hybridization and immunohistochemistry. Tissues were probed with 35S-labeled sense and antisense riboprobes to (i) human TGF-alpha (hTGF-alpha), (ii) human epidermal growth factor receptor (EGFR) to determine the distribution of TGF-alpha responsive cells, and (iii) histone H3 to examine TGF-alpha and/or EGFR's possible contribution to altered proliferation in transformed epithelium. Results of our experiments showed that TGF-alpha mRNA could be detected in normal and transformed human oral epithelium. More surprising, we have identified the major source of TGF-alpha mRNA to be the infiltrating eosinophils. A monoclonal antibody to the mature human TGF-alpha peptide stained similar areas in normal and malignant specimens. Eosinophils associated with tumors exhibited positive cytoplasmic immunostaining for TGF-alpha protein. Labeling of EGFR mRNA in human oral epithelium demonstrated uniform labeling of basal layers in normal, hyperplastic, and mildly dysplastic epithelium. In severely dysplastic epithelium and carcinomas (particularly moderate to poorly differentiated types), cellular levels of EGFR mRNA were significantly higher. The profile of altered cellular levels of EGFR mRNA correlated well with the profile of altered proliferation as indicated by H3 mRNA labeling. We hypothesize that the overproduction of EGFR mRNA in tumor epithelium--together with the localized delivery of high amounts of TGF-alpha by eosinophils at tumor-developing sites--is responsible for the increased proliferation of the tumor epithelium.

Antibodies, Monoclonal↗
PubMed1991

Localization of transforming growth factor-alpha in adult Syrian hamster tissues.

Using the cheek pouch of the Syrian hamster as an experimental model for oral carcinogenesis, it has been shown that the expression of transforming growth factor-alpha (TGF-alpha) is consistently associated with the malignant transformation process. We have recently shown that production of TGF-alpha has been localized to normal hamster oral epithelium and bone marrow eosinophils. In this study we investigated the production of this cytokine in other normal hamster adult tissues. By using an EGF-radioreceptor assay, immunohistochemistry, Northern blot analysis, and in situ hybridization we have now further detected the presence of TGF-alpha mRNA and/or protein in the kidney, stomach, and pancreas of normal adult hamster. Together with the previously reported detection of TGF-alpha in oral mucosa and bone marrow eosinophils, these adult normal tissue/cellular sources can serve as sites of TGF-alpha production. The availability of hamster specific reagents (cDNA and monoclonal antibodies) and the delineation of the various adult tissues that could produce TGF-alpha make the Syrian hamster a suitable model for the study of how this multifunctional cytokine can influence normal and pathological processes.

Animals↗
PubMed1991

Oral mucous membrane reactions to drugs and chemicals.

This article reviews recent reports of interest to practitioners concerned with the damaging effects of drugs and exogenous substances on the oral mucosa. Major topics include the incidence of the use of dentally important drugs in selected populations, lichenoid reactions in oral mucosa, diagnosis and management of mucositis related to cancer therapy, and issues relating to the diagnosis of oral foreign body reactions.

Anticonvulsants↗
PubMed1991

The eosinophil as a cellular source of transforming growth factor alpha in healing cutaneous wounds.

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are known to promote the healing of epithelial wounds. Eosinophils are present in healing wounds and have recently been shown to be capable of producing TGF-alpha. This investigation was done to determine if eosinophils infiltrated into healing wounds are capable of expressing this cytokine. Using the rabbit cutaneous open wound model, the study found that the eosinophil is one of the predominant cell types in the healing wound, beginning from the seventh day and thereafter. Most surprisingly, the majority of the eosinophils present in the healing wound were found to contain TGF-alpha mRNA and protein by in situ hybridization and immunohistochemistry. Thus it is proposed that the delivery of TGF-alpha by eosinophils to epithelial wound healing sites represents a normal body mechanism whereby this multifunctional cytokine can accelerate the wound healing process.

Animals↗
PubMed1990

Human eosinophils express transforming growth factor alpha.

Transforming growth factor alpha (TGF-alpha) is a pleuripotential cytokine with diverse biological effects, including the ability to influence the proliferation of normal cells or neoplastic epithelial cells. Eosinophils are a subset of granulocytes that normally enter the peripheral tissues, particularly those beneath gastrointestinal, respiratory, and urogenital epithelium, where they reside in close proximity to the epithelial elements. In this study, we demonstrate that the great majority of eosinophils infiltrating the interstitial tissues adjacent to two colonic adenocarcinomas and two oral squamous cell carcinomas labeled specifically by in situ hybridization with a 35S-riboprobe for human TGF-alpha (hTGF-alpha). No other identifiable leukocytes in these lesions contained detectable hTGF-alpha mRNA. We also examined leukocytes purified from a patient with the idiopathic hypereosinophilic syndrome. 80% of these eosinophils, but none of the patient's neutrophils or mononuclear cells, were positive for hTGF-alpha mRNA by in situ hybridization, and 55% of these eosinophils were positive by immunohistochemistry with a monoclonal antibody directed against the COOH terminus of the mature hTGF-alpha peptide. Finally, the identification of the purified eosinophil-associated transcript as hTGF-alpha was confirmed by polymerase chain reaction product restriction enzyme analysis followed by Southern blot hybridization. In contrast to eosinophils from the patient with hypereosinophilic syndrome, the peripheral blood eosinophils from only two of seven normal donors had detectable TGF-alpha mRNA and none of these eosinophils contained immunohistochemically detectable TGF-alpha product. Taken together, these findings establish that human eosinophils can express TGF-alpha, but suggest that the expression of TGF-alpha by eosinophils may be under microenvironmental regulation. Demonstration of TGF-alpha production by tissue-infiltrating eosinophils and the eosinophils in the hypereosinophilic syndrome identifies a novel mechanism by which eosinophils might contribute to physiological, immunological, and pathological responses.

Adenocarcinoma↗