Search PubMed⌕ Search

Biomedical subjects

G B Snow

Publications and source records attributed to G B Snow.

At least 235 records · Page 13Linked to original sources
PubMed1988

The expression of intermediate filaments and mam-6 antigen in relation to the degree of morphologic differentiation of carcinoma of the head and neck: diagnostic implications.

In this study, the immunoreactivity of several cytokeratin antibodies; 115 D8, a monoclonal antibody against MAM-6, an epithelial membrane antigen; and two vimentin antibodies, is examined in relation to the degree of morphologic differentiation in carcinomas of the head and neck. The results indicate that a relationship exists between the degree of morphologic differentiation and the expression of cytokeratin, MAM-6, and vimentin, as detected by polyclonal antikeratin, 115 D8 and anti-vimentin. Expression of cytokeratin and MAM-6 is reversely related to vimentin. Polyclonal anti-keratin; CAM 5.2, a monoclonal antibody against cytokeratin 8, 18 and 19; and 115 D8, used in combination, were still able to identify the epithelial nature of undifferentiated/spindle cells. Since these immunohistochemical markers precede light microscopic detectable signs of epithelial differentiation, they can be used for the identification of the epithelial nature of undifferentiated/spindle tumors of the head and neck.

Antigens, Differentiation↗
PubMed1988

Laryngeal cancer and lung cancer in the same patient: a retrospective study.

Fifty-four patients with laryngeal cancer and lung cancer were analyzed with regard to histology and localization of the lung cancer, the time interval between the detection of the two tumours and survival. It appeared that most lung tumours were squamous cell carcinomas, half of which were centrally localized and most occurred metachronously in the first 4 years after the laryngeal carcinoma. The survival rate was poor, due to the fact that the bronchial carcinoma usually was found beyond a curative stage. It appears that the present follow-up in laryngeal cancer patients--frequent ENT-examination, yearly chest X-ray examination--is often inadequate for early detection of lung cancer and curative treatment. It might be that by intensifying follow-up in laryngeal cancer patients by bronchoscopy, sputum cytology and more frequent chest X-ray examination, more bronchial carcinomas would be detected in a curative stage.

Aged↗
PubMed1987

Radiotherapy versus radiotherapy plus chemotherapy in stages I and II non-Hodgkin's lymphoma of the upper digestive and respiratory tract.

From 1975 through 1985 88 patients with a primary manifestation of non-Hodgkin's lymphoma in the upper digestive and respiratory tract were referred to our hospital. Fifty-seven of them were in Stage I or II. The results of therapy in 48 evaluable patients are the subject of this retrospective study. Low, intermediate, and high grade malignant histologic features were encountered in 6, 27, and 15, respectively. The authors compared retrospectively the patients treated with radiotherapy (RT) with those who received additionally chemotherapy (RT + CT). Patients have been followed for a minimum of 1 year. Four of 29 patients with intermediate-grade or high-grade malignant lymphoma treated with CT and RT relapsed whereas eight of 13 patients treated with RT alone relapsed. Actuarial survival curves differed significantly in favour of the CT and RT group. These figures were also significant when the high-grade lymphomas plus centroblastic lymphomas were considered. It is recommended to add CT to RT in both Stage I and II NHL of high-grade and intermediate-grade malignancy.

Adult↗
PubMed1987

Human leukocyte antigens and immunoglobulin allotypes in head and neck cancer patients with and without multiple primary tumors.

Human leukocyte antigens (HLA) and immunoglobulin (Ig) allotypes were examined in 98 patients with single head and neck cancers, and in 51 patients with multiple primary tumors. Immunoglobulin allotype Km (1) was present in 4% of patients with multiple primary tumors versus 21% in patients with a single head and neck cancer. The frequency of HLA-B8, HLA-DR3, and HLA-DQW2 in patients with multiple primary tumors and of HLA-B8, and HLA-B45 in patients with a single head and neck cancer increased significantly as compared with the control population. Those data suggest genetic influences--next to environmental factors--on the pathogenesis of multiple primary tumors in head and neck squamous cancer. It might be worthwhile to use HLA typing and Ig allotyping in the selection of patients in whom aggressive screening for second tumors is mandatory.

HLA Antigens↗
PubMed1987

Heterogeneity of stage II glottic carcinoma and its therapeutic implications.

The heterogeneity of glottic carcinoma results in variable loco-regional control probabilities from 40 to 80%. These widely different results may be due to two prognostic parameters of the tumor: the mobility of the vocal cord and the volume of the tumor. On the other hand radiation dose and technique may influence the treatment results. Stringent work-up has been prospectively undertaken in 156 patients with Stage II glottic carcinoma since 1974 through 1983 in the Academic Hospital of the Free University in Amsterdam. Several subgroups were defined from the beginning to indicate one or both of these prognostic factors. All were treated with a high quality accurate radiation therapy program delivering high dose to all patients with worse prognostic factors and even higher dosages to voluminous tumors with impaired mobility of a cord or slowly regressing tumors. The latter was individually judged for each patient towards the end of the treatment period. The loco-regional control probability of around 80% for all the subgroups irrespective of the prognostic factors indicate that the heterogeneity of Stage II glottic cancer may be influenced by high dosages of quality controlled radiotherapy. Thus results hitherto reported in literature may be further improved by the dose-schedules outlined here.

Adult↗
PubMed1987

Cartilagenous tumours of the larynx.

A brief review of the literature on cartilagenous tumours of the larynx is presented and their pathology, clinical features and treatment is discussed: Chondromas are rare; Chondrosarcomas can be potentially fatal. Conservative surgical therapy and close follow up is the essential line of treatment for tumours of the cricoid cartilage. Three new cases are presented.

Adult↗
PubMed1987

Squamous cell hyperplasia of the larynx (a clinical follow-up study).

According to Kleinsasser's classification 200 patients with squamous cell hyperplasia, seen between 1963-1981, were reviewed histologically. The untreated patients (47 per cent) have been analysed for the incidence of malignant change and the patients with Class III lesions (carcinoma in situ) who were treated, were analysed for response to treatment. The mean follow-up period was 8.4 years. Only two of the 38 initially untreated patients of Class I (simple squamous cell hyperplasia) developed an invasive carcinoma. In Class II (hyperplasia with atypia), of 62 patients who were not treated initially, 17 developed a laryngeal squamous cell carcinoma later. Only six patients of Class III did not receive any treatment initially, and one of these progressed to invasive carcinoma. Almost all other patients with carcinoma in situ (Class III) were irradiated. In these patients no evidence of local recurrence was found.

Adult↗
PubMed1987

Immunohistochemical detection of retroviral-P15E-related material in carcinomas of the head and neck.

As has been reported previously, head and neck carcinomas produce low molecular weight factors (H/N ca LMWFs); a molecular weight less than 25000 daltons is capable of inhibiting the chemotaxis of mononuclear phagocytes. The effect of the factors could be neutralized by antibodies to P15E, one of the structural envelope proteins of Murine Leukemia Viruses (MuLV). This indicates that these low molecular weight factors derived from the tumors are related to P15E. In this study, 35 biopsy specimens of head and neck carcinomas were subjected to an indirect immunoperoxidase assay, in order for P15E-like material to be detected morphologically. All head and neck carcinomas gave positive results. Sixty-three percent of other carcinomas (used as controls) were positive as well. P15E-like material was also expressed in epithelia-overlaying inflammatory responses. Healthy epithelia were not positive. This report thus supports the view that P15E-like molecules can be easily detected in cancerous disease--not only by way of biologic isolation, but also by use of immunohistochemical techniques. Since the factor is not specific for the malignant state, it cannot be used as a tumor marker. Possibly involved in the pathogenesis of cancerous disease, its relationship to growth factors, oncogenes, and the immune system needs further clarification.

Adult↗
PubMed1987

Effect of P15E related retroviral material isolated from head and neck carcinomas on delayed type hypersensitivity skin reactions in mice.

Low molecular weight factors, derived from head and neck carcinomas (H/N ca LMWFs), exert a serious inhibitory effect on monocyte chemotaxis both in vivo and in vitro. This effect can be neutralized by the treatment of the factors with three different monoclonal antibodies to P15E, one of the structural envelope proteins of murine leukemia virus (MuLV). In this study, we report the effect of the H/N ca LMWFs on the delayed type hypersensitivity responsiveness in mice: the factors significantly inhibited the 24 hour DNFB skin reaction. These effects of the H/N ca LMWFs were again neutralizable by antibodies to P15E. Additional experiments showed that the H/N ca LMWFs had equal suppressive effects on toxic skin reactions to croton oil, and this indicates that the P15E-like H/N ca LMWFs exert their effect by aspecific mechanisms.

Aged↗
PubMed1987

MRI of normal or cancerous laryngeal cartilages: histopathologic correlation.

MRI appearances of laryngeal cartilages, normal or invaded by cancer, are still relatively unfamiliar to most clinicians. Twelve primary laryngeal tumors out of a series of 65 patients which have been investigated by MRI were examined postoperatively by macroscopic and microscopic sectioning of the surgical specimens. Images were obtained with a 0.6 Tesla superconductive system using a solenoid surface coil. The authors emphasize the value of a combined use of T1-weighted and balanced (relatively T2-weighted images with still T1-characteristics) Spin Echo images. T1-weighted images permit differentiation between pathological and normal bone marrow. Balanced images allow separation between nonossified cartilage and tumor tissue. MRI is an additional tool in the diagnostic workup of cartilage invasion by tumor.

Aged↗
PubMed1986

Defective monocyte chemotaxis in patients with head and neck cancer. Restoration after treatment.

Monocyte chemotactic responsiveness (MCR), as measured by the monocytes' capacity to migrate through polymer (Millipore) membranes toward the chemoattractant casein, is impaired in all patients with head and neck cancer thus far examined. Using a more rapid and sensitive test system, the polarization assay, we tested the MCR in 24 patients with head and neck cancer and 31 controls and compared it with the outcomes of the well-established Boyden chamber method. The results of both methods correlated well. All patients showed a seriously depressed monocyte chemotaxis before treatment when tested in the polarization assay. Nine patients were reexamined after surgery, and in seven patients the defective MCR was restored. This illustrates that tumor-derived factors are probably responsible for the inhibitory effect on monocyte chemotaxis. The polarization assay has the potential for predicting early relapse.

Adult↗
PubMed1986

Immunosuppressive retroviral P15E-related factors in head and neck carcinomas.

We report on the effect of low molecular weight factors (LMWFs) derived from 14 different head and neck carcinomas on the chemotactic responsiveness of healthy donor monocytes, as measured by their polarization activity. The factors inhibited the polarization of the monocytes significantly (61.5% to 94.5% vs 12.5% to 29% in cases where the LMWF was derived from healthy oral mucosa). The inhibitory effect exerted by these LMWFs could be neutralized only by absorption with one of three different murine monoclonal antibodies or a rabbit polyclonal antibody to the murine retroviral envelope protein P15E. This shows that retroviral-related material is present in head and neck carcinomas and that this material is responsible for the observed defective polarization that probably underlies the earlier described defects on monocyte chemotactic responsiveness.

Antibodies, Monoclonal↗