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Biomedical subjects

G B Snow

Publications and source records attributed to G B Snow.

At least 217 records · Page 12Linked to original sources
PubMed1990

A 22-kd surface antigen detected by monoclonal antibody E 48 is exclusively expressed in stratified squamous and transitional epithelia.

After immunization of mice with viable cells of a metastasis of a laryngeal squamous cell carcinoma, a monoclonal antibody E 48 was obtained that detects an epitope present exclusively in squamous and transitional epithelium and their neoplastic counterparts. Immunoblotting revealed that E 48 recognizes a 22 kd molecule. Seventy-five of 76 squamous cell carcinomas from the head and neck, lung, cervix, and skin stained positively, whereas various adenocarcinomas from the colon, lung, and breast, and small cell lung carcinomas consistently stained negatively. The E 48 antigen, which is formaldehyde resistant, appears to be a reliable marker for differentiation of squamous cell carcinomas from adenocarcinoma, and small cell carcinomas.

Animals↗
PubMed1989

Localization and imaging of radiolabelled monoclonal antibody against squamous-cell carcinoma of the head and neck in tumor-bearing nude mice.

Nude mice carrying human squamous-cell carcinoma xenografts were given i.v. injections of radiolabelled monoclonal antibodies (MAbs). MAb E 48, which reacts with squamous-cell carcinomas, was labelled with 131I, while a second control MAb of similar immunoglobulin subclass was labelled with 125I. Both antibodies were injected simultaneously, then the mice were scanned with a gamma camera or their tissues were removed and antibody uptake was calculated as a percentage of the injected dose. Uptake of E 48 reached a peak value of 16%/g on day 3, while uptake of the control antibody was less than 1.8%/g. By 24 hr after injection tumor could be visualized without subtraction techniques. At days 3 and 7, only xenografts were visible on imaging. These findings suggest that E 48 is capable of high specificity in targeting isotopes to squamous-cell carcinomas in an experimental setting.

Animals↗
PubMed1989

[Diagnosis of laryngeal carcinoma using proton spin resonance tomography].

Seventy-eight patients were investigated by magnetic resonance (MR) imaging using optimal scan parameters and a surface coil. Forty-two patients were also examined by computer tomography (CT). Sixteen patients underwent laryngectomy. MR imaging of cancerous tissue in the larynx, and particularly of non-invaded and invaded cartilages, was examined by comparing MR images with sliced surgical specimens. Pre-operative CT and MRI findings were evaluated by comparing them with postoperative histopathological findings. MR T1-weighted images demonstrate localisation and extent of cancerous tissue. With combined use of T1-weighted and proton-density images MR imaging is superior to CT for showing cartilage invasion. Unfortunately, gross movement artifacts, which resulted in non-diagnostic images, occurred in 16% of the examinations.

Aged↗
PubMed1989

[Tumors of the accessory salivary glands of the mouth; a follow-up study of 101 patients].

In the period 1970-1987 101 patients were seen with a neoplasm of the intraoral accessory salivary glands. There was no sex preference; mean age of the patients was 51 years. The junction of the hard and soft palates is a site of predilection. Over 50 per cent of these tumours are malignant, the adenoid cystic carcinoma being the most notorious. Treatment consists primarily in surgical removal. In case of malignancy postoperative radiotherapy is often instituted, resulting in local cure in almost all cases. However, the prognosis of the malignant salivary gland tumours, especially of the adenoid cystic carcinoma, is rather unfavourable due to distant metastases.

Adolescent↗
PubMed1989

Anti-tumor and differentiation-inducing activity of N,N-dimethylformamide (DMF) in head-and-neck cancer xenografts.

The anti-tumor activity of the putative differentiation-inducing agent dimethylformamide (DMF) was assessed in 7 head-and-neck xenograft (HNX) lines transplanted into nude mice. The drug was administered intra-peritoneally at the maximum tolerated dose. A significant growth-inhibitory effect was observed in 3 out of 7 tumor lines tested. When compared with 5 conventional drugs active in patients with squamous-cell carcinoma of the head and neck (HNSCC), DMF was as effective as the most active drugs (cisplatin and bleomycin). The most sensitive xenograft line, the poorly differentiated tumor HNX-14C, was used to test the hypothesis that differentiation induction might play a role in the anti-tumor activity of DMF. Light microscopic examination did not show clear-cut alteration of differentiation characteristics such as keratin and keratin pearl formation. Furthermore, we used a monoclonal antibody to study the expression of cytokeratin 10 which is useful as a differentiation marker of human HNSCC tumors. Keratin 10, not present in HNX-14C tumors grown under control conditions, became expressed in some cells upon DMF treatment. Further evidence for a differentiation-inducing activity of DMF was found in electron-microscopic studies. In treated HNX-14C tumors, in addition to cells with normal ultrastructural features, better-differentiated cells were observed, as manifested by an increase in the number of tonofilaments and desmosomes. The results show that DMF has a potential value for the treatment of patients with head-and-neck cancer, and that differentiation induction might play a role in the anti-tumor action of the drug.

Animals↗
PubMed1989

Transplantability of human head and neck squamous cell carcinomas in athymic nude mice.

Tumor material from 91 patients with squamous cell carcinoma of the head and neck was transplanted subcutaneously in athymic nude mice. In the first (man to mouse) passage, the calculated mean probability of tumor take in a single mouse was 11%. The probability of growth in the first passage was significantly better for moderately and poorly differentiated tumors than for well-differentiated tumors. Also, the implantation of lymph node material resulted in a significantly better tumor take rate than material taken from a primary tumor. Transplantability was not dependent on the following characteristics: localization, T or N stage of the tumor, or the sex of the patients. Once growth was established, all variables studied had no influence on the probability of growth in the subsequent mouse passages. A relationship between tumor growth in nude mice and patient prognosis could not be found. When transplanting head and neck squamous cell carcinoma in nude mice, it has to be recognized that some tumor characteristics will influence the success of tumor growth.

Animals↗
PubMed1989

Role of masseter crossover flap in oropharyngeal reconstruction.

Oropharyngeal reconstruction especially after surgery for medially located lesions of moderate dimensions presents a challenge. The risk of using well vascularized, but insensitive tissues close to the airway has led to the development of several measures to overcome the difficulties involved. The transposition of masseter muscle which has been put forward in recent years provides successfully primary closure with preservation of function.

Aged↗
PubMed1989

Adenoid cystic carcinoma of the salivary glands: clinicopathological survey of 51 patients.

A clinicopathological study of 51 cases of adenoid cystic carcinoma in the head and neck region seen over a period of 20 years is presented. The correlation between various histological features and their impact on the results is attempted. Longterm results with respect to loco-regional recurrences, distant metastases and survival with various modalities of therapy are presented. Although this is a small series, radical surgery in keeping with the aim of avoiding undue mutilation, thus preserving the quality of life, followed by a full course of radiotherapy has been the mainstay of treatment and the results here presented justify this approach.

Adult↗
PubMed1989

Total glossectomy: reconstruction and rehabilitation.

Patients with carcinoma of the tongue including the base of the tongue who underwent total glossectomy in a period of just over ten years since January 1979 have been reviewed. Total glossectomy may be indicated as salvage surgery or as a primary procedure. The larynx may be preserved or may have to be sacrificed depending upon the site of the lesion. When the larynx is preserved the use of laryngeal suspension facilitates early rehabilitation and preserves the quality of life to a large extent. Cricopharyngeal myotomy seems unnecessary.

Aged↗
PubMed1989

Induction chemotherapy with cisplatin and continuous infusion 5-fluorouracil in locally far-advanced head and neck cancer.

Induction combination chemotherapy with cisplatin, 100 mg/m2 i.v. day 1, and 5-fluorouracil, 1,000 mg/m2/24-h infusion days 1-4, was applied in 76 patients with locally far advanced squamous-cell cancer of the head and neck. The treatment program consisted of 3 cycles of chemotherapy, followed by local radiotherapy and/or surgery. Hematologic side effects were leukocytopenia (50%) and thrombocytopenia (35%). Other side effects included renal toxicity (23%), nausea and/or vomiting (86%), alopecia (18%), and phlebitis (45%). Thirteen patients (17%) achieved a complete remission and 37 patients (49%) a partial remission. Median progression-free and overall survival were 8 and 11 months, respectively. Only patients achieving a complete remission had a better prognosis. Although induction chemotherapy may facilitate further local treatment in about half of the patients, on the basis of presently available data, this procedure should not be routinely applied with the aim of better survival.

Adult↗
PubMed1989

Parapharyngeal tumours: a review of 23 cases.

The anatomy of the parapharyngeal space is described and experience with 23 patients with parapharyngeal tumours seen over a 10-year period is reported. Despite reaching a large size, these tumours may be relatively asymptomatic, or be discovered incidently. CT scan, MRI, arteriography and fine needle aspiration are useful in establishing a diagnosis. The most common histological type (13/23 patients) was pleomorphic adenoma and these tumours were managed by transoral removal if small, or a combined transoral-external approach if large. No patient required a mandibulotomy for access and no benign tumour recurred. The outcome was poor in the 5 patients with malignant tumours and a more radical approach, midline mandibulotomy, should be considered if malignancy is suspected.

Adenoma, Pleomorphic↗
PubMed1989

Primary radiotherapy with surgery in reserve for advanced laryngeal carcinoma. Results and complications.

A retrospective study of a selected group of 58 patients with T3 and T4 squamous cell carcinomas of the larynx presenting between 1974 and 1984 was undertaken. These patients were treated primarily with radical radiotherapy and salvage surgery in reserve. The aim of this study was to examine survival, recurrence rate and the complications after salvage surgery. In 30 patients the tumor was classified as a T3 and in 28 as a T4. In 14 patients (24%) nodal disease in the neck was present prior to the radiotherapy. Follow-up in all patients continued for at least 3 years or until death. Nineteen patients (33%) developed locally recurrent tumor and five (9%) developed nodal metastases to the neck. The recurrence in almost every patient was detected within 2 years after completion of the irradiation. Thirty patients (52%) are alive of whom 29 have no evidence of disease. Of these 30 patients 22 (73%) have their larynx intact and functioning. The 5-year adjusted acturial survival for the whole group of patients is 73%, for the T3N0 group 87% and for the T4N0 group 75%. Patients with nodal disease responded poorly. After salvage surgery severe postoperative complications developed in 37% of the patients. There were no deaths following salvage surgery.

Adult↗
PubMed1988

Diagnostic application of panels of antibodies in mucosal melanomas of the head and neck.

This article describes the use of panels of antibodies in the histopathologic diagnosis of ten malignant melanomas arising in the mucosa of the head and neck. The immunohistochemistry analysis was performed in a step-by-step manner. In the first step a panel of antibodies discriminating between carcinoma, malignant lymphoma, and melanoma was used. Staining with antivimentin and the melanoma-associated antigen, moAb NKI/C-3, was found to occur in all cases. The NKI/C-3 stained nine of 10 specimens from the first biopsy. Anti-S-100 protein, anti-HMW-MAA, and NKI-beteb was used as a panel in the second step. These stained ten of ten, five of six, and seven of seven cases, respectively. The diagnosis for melanin was confirmed by extensive sampling and a diligent search for melanin and (pre)melanosomes in different biopsy and surgical specimens. These results indicate that a step-wise application of immunohistochemistry is a very useful tool in the diagnosis of mucosal melanoma of the head and neck.

Aged↗
PubMed1988

Preclinical antitumor activity of 5-aza-2'-deoxycytidine against human and neck cancer xenografts [corrected].

The antitumor activity of 5-aza-2'-deoxycytidine (5-aza-dCyd), a nucleoside analog, was established in human head and neck cancer xenografts, transplanted in nude mice. A significant response was noted in 3 of 5 lines, when the drug was injected intraperitoneally at a maximum tolerated dose of 2 mg/kg every four days for three doses. In two most sensitive lines 1 out of 6 tumors regressed completely. The antitumor activity of the drug may depend on the schedule used, as illustrated by the fact that just one of these two lines appeared to be sensitive when treated with low daily doses (0.25 mg/kg). In two lines, 5-aza-dCyd showed equal or better antitumor activity when compared to the conventional drugs known to produce remissions in patients with head and neck cancer (cisplatin, methotrexate, bleomycin, 5-fluorouracil and cyclophosphamide). 5-Aza-dCyd is a drug with potential value in the chemotherapeutic treatment of patients with head and neck cancer [corrected].

Animals↗