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Biomedical subjects

A Richters

Publications and source records attributed to A Richters.

At least 37 records · Page 2Linked to original sources

Air pollutants and the facilitation of cancer metastasis.

Studies have been carried out to determine whether the inhalation of ambient levels of nitrogen dioxide (NO2), a common air pollutant, could influence the frequency of blood-borne cancer cell metastasis to the lungs. B16 mouse melanoma cells were used as an in vivo test model. the results have indicated that animals inhaling ambient levels of NO2 developed a significantly higher number of melanoma nodules in their lungs than the animals inhaling filtered air. Thus, a new concept for the action of air pollutants is proposed. The question is raised whether similar events are taking place in urban human populations.

Air Pollutants↗

Facilitation of cancer metastases by an air pollutant.

An experimental model was designed to test the possibility that inhalation of a noxious air pollutant may facilitate the blood-borne cancer cell metastasis to the lungs. Animals were exposed to inhalation of air containing 0.8 ppm of nitrogen dioxide for 12 weeks. After this period, animals were infused intravenously with melanoma cells, and 3 weeks later lungs were examined for metastases. The results indicate that NO2exposed animals develop significantly higher number of lung metastases (P less than 0.0025) than the controls. Such results raise the possibility that the inhalation of NO2 from ambient air may facilitate the seeding and proliferation of blood-borne cancer cells in the human lung.

Air Pollutants↗

Spleen changes in animals inhaling ambient levels of nitrogen dioxide.

The effects of ambient levels of NO2 on the spleens of adult and newborn Swiss Webster (S/W) mice were determined. Spleens were evaluated by the following criteria: (1) spleen weight, expressed as a percent of the body weight (% spleen weight), (2) size of the spleen lymphoid nodules as determined by computed image analysis, (3) spleen cell counts, and (4) histopathologic evaluation. Data for NO2-exposed animals were compared with data for control animals that inhaled filtered air. Totals of 217 control and 217 NO2-exposed animals were studied. After 6 wk of exposure to NO2 at ambient levels (0.35 +/- 0.05 ppm), the following significant changes were observed in the spleens of exposed mice: (1) increase in % spleen weight (p less than 0.0025), (2) increase in size of spleen lymphoid nodules (p less than 0.01), (3) smaller increase in spleen cell number per given weight increment of spleen as determined by correlation coefficients (p less than 0.0125) and linear regression analysis of spleen cell counts, and (4) an apparently greater predominance of red cells in the red pulp. It is concluded that inhalation of NO2 is associated with quantifiable spleen changes, which may prove to be useful indicators for assessing effects of inhaled NO2.

Air↗

Histoculture of human breast cancers.

Breast cancers from 53 patients were explanted in culture, and 39 with two-year or more follow-up and documentable tissue forms of cancer in culture (histoculture) are the subject of this report. Clinicopathologic findings have been correlated with dynamic aspects of the cancers in short-term histocultures, including cell cohesiveness, yield and survival time of the cancer cells in culture, emigration of macrophages from the explants, and the occurrence of special interactions of lymphocytes with cancer cells. The outstanding finding was the association of special lymphocyte-cancer cell interactions with a more favorable prognosis; six of seven patients (86%) with infiltrating ductal cancer showing lymphocyte congregation, emperiopolesis, or other special activity were tumor-free survivors. Additional findings were: 1) patients having four or fewer lymph nodes positive for cancer had a survival rate of 50%, but this fell to 20% when emigrating macrophages were not present in the cancer cultures; 2) eight of the 12 patients (67%) having discoid histoculture survival time of less than one week were tumor-free, as opposed to three of eight patients (27%) where tumor survival in vitro was greater than one week. The reverse was true for nondiscoid, poorly cohesive colonies of cancer; 3) the combination of tumor-negative lymph nodes and low in vitro cancer yield was associated with the best patient survival rate, 64%. However, the combination of negative nodes and high in vitro yield was linked to the worst patient survival (20%). Although the overall study does not permit definitive conclusions, there is an undeniable potential for the use of histocultures in the evaluation of human cancers. Expanded studies are warranted, including larger numbers of tumors and cultures, and longer patient follow-up periods.

Breast Neoplasms↗

Breast cancer metastasis and lymph node lymphocyte-macrophage interaction.

A lymphocyte-macrophage interaction, known as the lymphocyte clustering phenomenon, was studied in axillary lymph node preparations from 27 breast cancer patients. The study was carried out in primary tissue cultures of lymph nodes and the lymphocyte-macrophage interactions were quantitated with respect to cancer positive and cancer negative axilla. The results indicate that there is a significantly higher (p less than 0.025) lymphocyte-macrophage interaction in negative node preparations from negative axilla of infiltrating ductal carcinoma patients. This new approach to lymph node lymphocyte evaluation may provide assistance in determining the extent of the disease process.

Axilla↗

The relationship between sIgM positive lymph-node lymphocytes and breast cancer metastasis.

The relative frequency of lymphocytes with surface immunoglobulins (sIgM, sIgG, sIgA) was studied in breast-cancer patients' axillary lymph nodes by the immunofluorescence technique. The study encompassed a total of 105 patients, most of whom had infiltrating ductal carcinoma (IDC). The results have indicated a significantly higher (p less than 0.005) average percentage of sIgM positive lymphocytes in lymph nodes in the group of IDC patients with lymph-node metastasis. Short-term followup was available for a limited number of patients, but no conclusions were reached with respect to sIgM positive lymphocytes. It is suggested that evaluation of axillary lymph-node and peripheral blood lymphocyte subpopulations for each cancer patient would provide new information which could aid in determining the extent of the disease process. Moreover, such information may be of assistance in decisions of therapeutic modalities, detection of occult metastasis, and prediction of prognosis.

Axilla↗

Surface immunoglobulin positive lymphocytes in human breast cancer tissue and homolateral axillary lymph nodes.

Surface immunoglobulins were determined on human lymph node lymphocytes by the use of immunofluorescence technique in 59 breast cancer patients undergoing radical mastectomy. In 10 of these cases, lymphocyte surface immunoglobulins were also studied on lymphocytes infiltrating the primary cancer mass. The most outstanding finding was a difference between the IgM lymphocyte populations in the lymph nodes of patients with and without lymph node metastases. When cancer tissue was present in one or more lymph nodes, the tumor-free as well as the tumor-positive nodes showed a higher percentage of IgM positive lymphocytes than did lymph nodes from patients without nodal metastases. The greatest difference was found when IgM lymphocytes from tumor-bearing lymph nodes were compared with those from the lymph nodes of patients without nodal metastases (p is less than .005). The lymphocyte populations infiltrating 5 of the 10 primary cancer masses studied showed no surface immunoglobulins; in the remainder, both IgG and IgM positive lymphocytes were found but in variable proportions. While the findings are not definitive, this is the first study dealing with the quantitation of immunoglobulin specific lymphocytes in the lymph nodes and tumor tissue of patients with breast cancer.

Breast Neoplasms↗