Amplification of immune T lymphocyte function in situ: the identification of active components of the immunologic network during tumor rejection

Previous data had indicated that sarcoma-bearing mice receiving combination therapy consisting of a single i.p. injection of cytoxan (CY) and an i.v. injection of tumor-sensitized T cells (immune cells) rejected the neoplasm. The reaction was immunologically specific and dependent on donor T cells. This report is concerned with the hypothesis that the transfer of immune cells results in the amplification of T cell responses at the tumor site. Using C57BL/6J mice bearing the syngeneic rhabdomyosarcoma MCA/76-9, we show that 6 to 9 days after combination therapy those components usually associated with the immunologic network were present at the tumor site. Tumor-associated macrophages (TAM) and lymphocytes (TAL) were shown to produce IL 1 and IL 2, respectively. The TAM expressed Ir gene products (Ia) and were able to present the synthetic polymer GAT to specifically sensitized lymphocytes. In addition, it was demonstrated by in situ labeling with 3H-TdR that lymphocytes associated with the regressing tumors were proliferating. The peak incorporation occurred 7 days after therapy, 24 hr before a significant increase in the T cell content of the tumors. The data indicate that those facets of the immunologic network necessary for amplification were present at the site of rejection.     

Regional Acetylcholine Metabolism in Brain During Acute Hypoglycemia and Recovery

Insulin-induced hypoglycemia in normothermic rats caused progressive neurological depression and differentially altered regional cerebral acetylcholine metabolism. Reductions of plasma glucose from 7.7 mM (control) to 2.5-1.7 mM (moderate hypoglycemia associated with decreased motor activity) or 1.5 mM (severe hypoglycemia with lethargy progressing to stupor) decreased glucose concentrations in the cerebral cortex, striatum, and hippocampus to less than 10% of control. Moderate hypoglycemia diminished acetylcholine concentrations in cortex and striatum (21% and 45%, respectively) and reduced [1-2H2, 2-2H2]choline incorporation into acetylcholine (62% and 41%, respectively). Severe hypoglycemia did not reduce the acetylcholine concentration or synthesis in cortex and striatum further. The concentrations of choline rose in the cortex (+53%) and striatum (+130%) of animals that became stuporous but a similar rise in [1-2H2, 2-2H2]choline left the specific activities of choline in these structures unchanged. Even severe hypoglycemia did not alter the hippocampal cholinergic system. In rats that developed hypoglycemic stupor and were then treated with glucose, the animals recovered apparently normal behavior, and the concentrations of acetylcholine and the incorporation of [1-2H2, 2-2H2]-choline into acetylcholine returned to control values in the striatum but not in the cerebral cortex. Thus, impaired acetylcholine metabolism in selected regions of the brain may contribute to the early symptoms of neurological dysfunction in hypoglycemia.     

Effects of Daily Cocaine and Morphine Treatment on Somatodendritic and Terminal Field Dopamine Release

Daily injections of cocaine or morphine into rodents produces behavioral sensitization such that the last daily injection results in a greater motor stimulant effect than the first injection. To evaluate a role for brain dopamine in behavioral sensitization to cocaine and morphine, tissue slices from the ventromedial mesencephalon (containing dopamine cell bodies), the nucleus accumbens, and striatum (dopamine terminal fields) were obtained from rats pretreated with daily cocaine, morphine, or saline 2-3 weeks earlier. When the tissue slices were depolarized by increasing potassium concentration in the superfusate, the release of endogenous dopamine from the ventromedial mesencephalon of cocaine- and morphine-pretreated rats was significantly decreased. In contrast, the release of dopamine from the nucleus accumbens and striatum was either unaltered or slightly enhanced in rats pretreated with cocaine and morphine. When dopamine was released by amphetamine, a significant decrease in dopamine release from the ventromedial mesencephalon of cocaine-pretreated rats was measured. No other significant changes were measured after amphetamine-induced release. It is postulated that the decrease in dopamine release from the ventromedial mesencephalon of cocaine- and morphine-sensitized rats results in less somatodendritic autoreceptor stimulation, and thereby produces an increase in dopamine neuronal activity.     

The immunological mouse mutants nude (nu) and rhino (hr rh ) generate cytotoxic effector cells following adoptive immunotherapy but fail to reject a transplanted tumor

Summary Adoptive immunotherapy, consisting of cyclophosphamide injection and the i. v. transfer of tumor-sensitized T cells, resulted in rejection of the immunogenic fibrosarcoma, MCA/76-9, by syngeneic C57BL/6J (B6) mice. The same treatment of tumor-bearing congenic immunodeficient mice, homozygous for the deleterious mutations nude (nu) and rhino (hr ^rh ), did not result in tumor rejection. Paradoxically, the intratumor and intrasplenic changes taking place in each of the three strains after therapy were indistinguishable. There was an increase in Thy-1⁺, Lyt-2⁺, or L3T4⁺ cells at the tumor site 8 days after adoptive immunotherapy and a similar increase in Thy-1⁺ cells in the spleen. Moreover, the T cells isolated from the tumors or spleens from each genotype were shown to be specifically cytotoxic in vitro as well as in an in vivo Winn assay. Further evidence that immune amplification had occurred in the immunological mutant mice was provided by experiments showing (a) the ability of spleen cells from tumor-bearers and those tested after therapy to produce IL-2 in response to Con A stimulation and (b) an increase in class II-MHC antigen expression by tumor-associated macrophages. The data suggest that, although amplification of antitumor immune responses occurred in the immunological mutants, the absence of a critical host factor limited the potency of the antitumor response. Abbreviations used: CY, cyclophosphamide; TAM, tumor-associated macrophages; TAL, tumor-associated lymphocytes; TAC, tumor-associated cells; B6, C57BL/6J; class II MHC antigens: Ia; con A, concanavalin A; IL-1, IL-2, interleukin 1 and 2     

Cytokinesis is defective in Dictyostelium mutants with altered phagocytic recognition, adhesion, and vegetative cell cohesion properties

Mutants that have been selected for defects in phagocytic recognition, adhesion, and vegetative cell-cell cohesion were found to be larger and more highly multinucleate than their parent strain. This defect is associated with the complex mutant phenotype of these mutants since revertants of the mutants coordinately acquire the wild-type phenotype for all of the defects. The larger size and multinuclearity were due to a high frequency of failure of cytokinesis in cells of wild-type size. This was shown by purifying the small cells in mutant populations and observing their growth and cell division. The mutant phenotype is more penetrant during axenic growth. Most of the mutants are not multinucleate when grown on bacteria. Recently, new mutants have been isolated that are also multinucleate when grown on bacteria by a strong selection procedure for non-adhesion to tissue culture dishes. The pleiotropic mutant phenotype and the greater penetrance of the mutant phenotype in axenic culture can be explained by hypothesizing a deficiency in a membrane component of the actomyosin motor that is involved in all of the processes defective in the mutants.     

The relationship of glial fibrillary acidic protein to the shape,motility, and differentiation of human astrocytoma cells

Glial fibrillary acidic protein (GFAP), a protein largely limited to astrocytes, was studied in relation to the shape, motility, and differentiation and malignancy of astrocytoma cells in tissue culture by use of time-lapse photography and the immunoperoxidase method.A relationship was observed between the shape of astrocytes and the distribution of GFAP. Spindle-shaped cells showed abundant GFAP in the cell body and processes. In round or polyhedral cells without well developed processes the GFAP was largely perinuclear. As processes developed, GFAP extended out from the nucleus iri dense parallel arrays that radiated into the developing processes. Fully differentiated cells with stellate shape had abundant GFAP throughout.A relationship was also observed between the motility of astrocytes and GFAP. Stellate-shaped cells, showing paucity of locomotion and relatively rigid postures of processes, contained an abundance of GFAP which tended to form dense parallel arrays extending into the processes during their development. Spindle-shaped cells with extending and retracting processes and active migration also contained an abundance of GFAP but not organized into parallel arrays. Bulbous dilatations at the tips of processes (growth cones) contained abundant GFAP. There was also abundant GFAP in the intermittent dilatations along the processes of stellate cells. In contrast to these observations, a retraction of processes, a high degree of plasticity (undulating motion) and multidirectional locomotion were often associated with a paucity of GFAP in less differentiated cells. We hypothesize that GFAP filaments may be inhibitory to great plasticity of motion but not to extension-retraction movements.During mitosis GFAP was sparse at the spindle and in intercellular bridges. Colcemid caused GFAP to disappear from processes and peripheral parts of the cell and to become concentrated near the nucleus.In cultures derived from malignant tumors, undifferentiated and large multinucleated cells usually showed sparsity of GFAP, but occasional well differentiated stellate or spindle-shaped cells containing abundant GFAP were seen. Conversely, although cultures derived from benign tumors may have scattered less well differentiated cells, the differentiated cells with well developed processes were most densely stained and account for the high concentration of GFAP in tissue from these tumors.     

The Biology of Gregarina fernandoi n. sp. in the Cockroach Pysnoscelus surinamensis with Observations on its Development and Cytochemical Nature

SYNOPSIS. Gregarina fernandoi n. sp. is a eugregarine. Its structure, development and life history in the gut of the cockroach Pycnoscelus surinamensis are described. It is named as a new species on the basis of its size, nuclear structure, structure and form of the gametocyst and oocyst. Observations were made on the different stages of the parasite and related to the pH of the gut. In the ceca, pH 4.5–5, the parasite was in its early stages of development, in the midgut, pH 6.5–7, it was in syzygy and in the rectum, pH 7.5–8, gametocysts were found.     

Improved survival after orthotopic liver grafting.

A total of 108 orthotopic liver transplants have been carried out in the Cambridge/King''s College Hospital series. Over 13 years, changes in patient selection, immunosuppression, and surgical and anaesthetic techniques have led to a steady improvement in results. Results obtained in the last 22 patients indicated that over half survive for one year. Although at considerable risk during the operation, patients with non-malignant cirrhotic diseases who survive one year have a good long-term chance of survival     

Sir William Osler revisited.

The basis of Sir William Osler''s fame is elusive to almost all and the appropriateness of such recognition is questioned by many. His many contributions as a practitioner, teacher, writer, and scientist in medicine do not adequately explain his prominence 60 years following his death. It was his participation in the covenant of medicine and the special components of that relationship that may account for his hold on his followers today.