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Biomedical subjects

P Alexander

Publications and source records attributed to P Alexander.

At least 145 records · Page 8Linked to original sources
PubMed1976

Metastatic spread and "escape" from the immune defenses of the host.

The effectiveness of the host's immune reaction against primary and disseminated tumors depends not only on the magnitude of the host's immune response, such as the number of cytotoxic cells and antibody molecules produced, but also on the capacity of tumor cells to evade destruction. The latter process which has been termed "escape" depends on several factors including intrinsic properties of the tumor cell. In some experimental systems, it was shown that the capacity of disseminated tumor cells to give rise to distant metastases is in part determined by the efficiency of escape. Tumors which in vivo appear to be nonimmunogenic may still carry tumor-specific antigens to which the host responds by making cytotoxic mononuclear cells, but these fail to kill because escape is effective.

Animals↗
PubMed1976

Some immunologically based reactions that can cause the regression of large tumor masses.

A widely held view is that the immune reactions of the host directed against tumor-specific membrane antigens can only eliminate a relatively small number of tumor cells. There are, however, some therapeutic maneuvers, that under some conditions can cause the regression of large tumor masses to which immune factors make a critical contribution. Among these are the injection of complement, administration of double stranded RNA and endotoxin, and the induction of inflammation.

Animals↗
PubMed1975

The macrophage content of some human tumours.

The number of macrophages present in 44 surgically removed breast tumours and melanomas was determined by making a cell suspension and measuring the proportion of cells which bound a heterologous anti-macrophage serum and spread rapidly in culture. The macrophage content of the different tumours ranged from 0% to 30%. The malignant tumours which were known to have metastasized, as well as metastatic lesions, all contained less than 10% of macrophages whereas cancers for which there was no evidence of spread at operation had widely varying numbers of macrophages.

Breast Neoplasms↗
PubMed1975

The origin and role of blood-borne monocytes in rats with a transplanted myelogenous leukaemia.

The growth of a transplantable myeloid leukaemia into its syngeneic host is accompanied by a progressive increase in the number of blood monocytes. These were shown to be of host origin and were not derived from the inoculated leukaemia cells. The host response which is responsible for the monocytosis differs from that associated with the entry of monocytes into immunogenic sarcomas.

Animals↗
PubMed1975

Rejection of sarcoma cells at the site of an inflammatory reaction: macrophages are not the only effector cells.

Purified protein derivative (PPD) (a soluble protein from tubercle bacilli), when injected together with sarcoma cells into syngeneic mice that had been immunized previously with Bacillus Calmitte-Guérin (BCG), prevents tumour toxic to sarcoma cells [4]. However, non-adherent mononuclear peritoneal exudate cells from BCG-treated mice were also found on addition of PPD to become cytotoxic to sarcoma cells. In vivo assays indicate that such cells may play a major role in the in vivo destruction of tumours at the site of a delayed hypersensitivity reaction.

Animals↗
PubMed1975

Evidence of cytotoxic T and B immunoblasts in the thoracic duct of rats bearing tumour grafts.

Wistar rats were immunised with allogeneic or xenogeneic tumour before collection of their thoracic duct lymph. Specifically cytotoxic effector cells were found in the lymph between 3 and 8 days after immunisation, and their occurrence coincided with an increased number of immunoblasts in the lymphocyte population. The immune response in lymph to allogeneic cells appeared to be affected solely by radiosensitive thymus-dependent lymphocytes; no complement-dependent killing was evident and cytotoxic cells failed to appear when immunised animals were deprived of thymus-dependent lymphocytes. In contrast, the response to immunisation with xenogeneic cells elicited both complement-dependent and complement-independent cytotoxicity, but only the former could be detected in animals deprived of thymus-dependent lymphocytes. In normal animals and in animals deprived of thymus-dependent cells, the cytotoxic cells in the thoracic duct lymph appeared to be large lymphocytes or immunoblasts.

Absorption↗
PubMed1975

Mast cell and anaphylactic antibody responses in inbred rats to syngeneic fibrosarcomas.

The mast cell content of sarcomata induced chemically in inbred rats showed wide variation. After first passage into a normal syngeneic recipient, primary tumours which were heavily infiltrated showed a complete absence of mast cells. Moreover, detectable anaphylactic antibody to passaged tumours was only occasionally detected. An important immunological role for the IgE/mast cell system in host-tumour defence is not supported.

Anaphylaxis↗
PubMed1975

Immunotherapy for acute myelogenous leukemia.

One hundred and seven untreated patients with acute myelogenous leukemia (AML) were admitted to St. Bartholomew's Hospital between the 10th October 1970 and the 31st January 1973. Before receiving drugs to induce remission they were allocated alternatively into 2 groups to decide their remission treatment, a group to receive chemotherapy alone and a group to receive the same chemotherapy with immunotherapy. The patients were then given induction chemotherapy and 45 of them attained complete remission. All patients in remission then received chemotherapy consisting of 5 days treatment every 28 days. Patients receiving immunotherapy were also given multiple weekly intradermal injections of irradiated stored AML cells and Glaxo BCG using a Heaf gun. There were 19 patients in the group which received only chemotherapy during remission; 7 of these patients remain alive (median survival after attaining remission--303 days) and only 5 are still in their first remission (median remission length 188 days). Twenty three patients were allocated to receive immunotherapy during remission in addition to chemotherapy and 16 remain alive (median 545 days) and 8 are in their first remission (median 312 days). The difference in survival of the 2 groups is significant with a sigma value of 0.003.

Age Factors↗
PubMed1975

Rat tumour allografts evoke anaphylactic antibody responses.

In vitro assays of release of histamine from peritoneal mast cells showed that Wistar rats produced anaphylactic antibody in response to a single immunization with an allogeneic sarcoma. The response occurs early after immunization, and no adjuvant is needed. The thermolability of the anaphylactic antibody suggests that it is IgE.

Adjuvants, Immunologic↗