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Biomedical subjects

R F Todd

Publications and source records attributed to R F Todd.

160 records · Page 9Linked to original sources
PubMed1981

Antigens on human monocytes identified by monoclonal antibodies.

Two antigens (Mo1 and Mo2) present on human peripheral blood monocytes have been defined by lytic IgM monoclonal antibodies. Both antigens are present on greater than 70% of adherent mononuclear cells (predominantly monocytes). Mo1 is expressed by monocytes, granulocytes, and Null cells, but is absent from T and B lymphocytes. Mo2, on the other hand, appears specific for peripheral blood monocytes. Neither antigen is present on Ia-positive B cell lines or on tumor cells from patients with B cell lymphoproliferative malignancies, further excluding the possibility that Mo1 and Mo2 are Ia antigens. Mo1 and Mo2 are, however, present on a significant number of blast cells from patients with monocytic leukemia (both myelomonocytic and pure monocytic variants), but relatively infrequently expressed by cells from patients with acute granulocytic leukemia. These results indicate that Mo1 and Mo2 are unique antigens that may represent distinct stages of late monocyte-granulocyte differentiation.

Animals↗
PubMed1980

Prostatic adenocarcinoma, sarcoidosis and hypercalcemia: an unusual association.

A case is reported of hypercalcemia, prostatic adenocarcinoma and sarcoidosis. This represents the second reported occurrence of sarcoidosis and prostatic carcinoma, and illustrates the intriguing association between systemic sarcoidosis and malignancy. The reported experience demonstrating the association between sarcoidosis and malignant disease is reviewed.

Adenocarcinoma↗
PubMed1975

Functional characterization of membrane components of cytotoxic peritoneal exudate T lymphocytes. II. Trypsin sensitivity of the killer cell receptor.

Studies were carried out to investigate the nature of the lymphocyte membrane receptor involved in the specific lysis of [51Cr]EL4 target cells by BALB/c cytotoxic peritoneal exudate lymphocytes (PEL) in vitro. In confirmation of earlier related studies, the cytolytic reaction is markedly inhibited by trypsin treatment (1 mg of trypsin/10(6) PEL/ml; 37 C for 30 min) of the PEL. Trypsinized PEL recover their cytolytic activity after 6 hr of incubation in trypsin-free medium at 37 C; recovery is suppressed at 4 C. Significantly, trypsinization of PEL inhibits their ability to adsorb to EL4 target monolayers, indicating that lymphocyte-target cell binding is a trypsinsensitive step of the cytolytic interaction. Specificity of binding for EL4 is restored upon recovery from trypsin treatment. In addition, trypsin treatment, under conditions sufficient to inhibit cytolysis, causes a drastic nonspecific deletion of iodinatable membrane species from the surface of PEL. Thus, a direct correlation between altered cytolytic function and membrane structure cannot be made. Interestingly, trypsinized PEL retain the capacity to kill EL4 to which they are agglutinated by concanavalin-A, suggesting that the lytic mechanism, as distinguished from the binding receptor, is still intact. Papain and pronase also have an inhibitory effect on cytolysis, while neuraminidase causes a significant augmentation of lymphocyte-mediated cytolysis.

Animals↗
PubMedDate not supplied

Imaging the spatial distribution of membrane receptors during neutrophil phagocytosis.

Optical microscopy and image processing have been employed to study the distribution of several cell surface receptors on living human neutrophils during opsonin-dependent and opsonin-independent phagocytosis. Receptors were labeled using fluorescein-, rhodamine-, or AMCA-conjugated F(ab')2 fragments of anti-Fc gamma RIIIB (CD16), anti-CR3 (CD11b/CD18), and anti-uPAR (urokinase-type plasminogen activator receptor) antibodies, intact phycoerythrin-labeled interleukin 8, and fluorescein- or rhodamine-labeled Con A (concanavalin A), Boc-PLPLP (tert-butyl-oxycarbonyl-Phe(D)-Leu-Phe(D)-Leu-Phe-OH), and N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys. Labeled neutrophils were observed during the phagocytosis of IgG-opsonized erythrocytes and nonopsonized latex beads, Escherichia coli, and Staphylococcus aureus. To quantitate receptor distribution, cells were divided into four quadrants with the first being the point of attachment and the fourth being opposite the point of attachment. Ligated formyl peptide receptors, and to a lesser extent CR3, accumulated at the sites of target internalization for all forms of phagocytosis examined. However, Fc gamma RIIIB, uPAR, IL-8, Con A, and the FPR antagonist FBoc-PLPLP were not polarized on cells during phagocytosis. These data suggest that agonist-labeled formyl peptide receptors may play a broader role in leukocyte function than previously suggested, including possible participation in phagocytosis.

Amino Acid Sequence↗
PubMedDate not supplied

Phase I--II trial of methyl-GAG in the treatment of patients with metastatic renal adenocarcinoma.

Methyl-GAG, a polyamine synthesis inhibitor, was prospectively evaluated in the treatment of advanced renal adenocarcinoma. Twenty-five patients with measurable disease received methyl-GAG weekly at a starting dose of 500 mg/m2 iv, with dose escalation by 50 mg/m2/week (maximum dose, 825). All 25 patients are evaluable for response. Four of these patients (16%) achieved responses including three partial responses and one complete response, with a median duration of 9 weeks (range, 4--15). Nine patients (36%) remained stable and 12 (48%) had progressive disease. In the four responders, regression of disease occurred within the first 4 weeks of therapy. Toxic effects were generally mild and included nausea or vomiting (68%), myalgia (44%), mucositis (40%), neuralgia (40%), weight loss (32%), diarrhea (24%), skin rash (8%), leukopenia (8%), and genital ulcers (4%). We conclude that methyl-GAG has clear, albeit limited, activity against renal adenocarcinoma.

Adenocarcinoma↗