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Biomedical subjects

A Simmons

Publications and source records attributed to A Simmons.

At least 163 records · Page 9Linked to original sources
PubMed1984

Zosteriform spread of herpes simplex virus as a model of recrudescence and its use to investigate the role of immune cells in prevention of recurrent disease.

During the development of a zosteriform rash, which occurs after flank inoculation of BALB/c mice with herpes simplex virus, clinically normal skin becomes infected via nerve endings. This is analogous to the final step in the development of a recrudescent lesion, which may occur after reactivation of latent virus. Therefore, the zosteriform reaction has potential as a model with which to study the modification of such a recrudescent infection by immune processes. Using an adoptive transfer system, we confirmed that immune lymph node cells are potent in accelerating the clearance of virus from the primary site of replication (the inoculation site). This effect was T cell dependent. However, if injection of the same cell population was delayed until ganglionic infection was established, the appearance of the zosteriform rash was not prevented, and the virus titer recovered from the lower flank was not reduced. Immunoperoxidase studies showed that virus is at first highly localized to the epidermis after it emerges from nerves. As determined by conventional histology, little cellular infiltration was seen until clinical lesions were apparent. These observations indicate that recrudescent lesions appear in the presence of cell populations normally associated with rapid virus clearance; cellular immune mechanisms may be rendered ineffective owing to the lack of recruitment to the site of recrudescence until tissue breakdown instigates an inflammatory response.

Animals↗
PubMed1982

Blood storage.

Explore the source record for details and available documents.

Blood Cells↗
PubMed1981

Heterotransplantation of small-cell carcinoma of the lung into nude mice: comparison of intracranial and subcutaneous routes.

We compared and contrasted intracranial (i.c.) and subcutaneous (s.c.) heterotransplantation of small-cell carcinoma of the lung (SCCL) into athymic nude mice. Fresh human SCCL tumor specimens, tumor colonies grown in soft agarose and continuous cell lines were used. Tumors induced by the three types of specimens were similar, but s.c. and i.c. transplants differed. S.c. tumors had longer latent times, were non-invasive and non-lethal. I.c. tumors has shorter latent periods, invariably grew in the meninges, frequently invaded and destroyed the underlying brain, and were lethal. The tumor-inducing dose for i.c. transplantation was 10 to 1,000 times lower than for s.c. transplantation. Pooled colonies of SCCL tumor specimens grown in soft agarose were inoculated i.c. While they contained relatively small numbers of cells (400-10,000), 83% of these colony specimens induced tumors after 58-243 days, confirming the "stem-cell" origin of the colonies. I.c. and s.c. transplants retained the characteristic morphology of SCCL, and, with one exception, did not metastasize to distant organs. Continuous cell lines could be established readily from both types of transplants, and they retained the characteristic cytology, growth and biochemical properties of the original SCCL tumors. I.c. heterotransplantation of SCCL is a useful tool, especially when small numbers of tumor cells are available, and may provide a model to study the biology and therapy of meningeal carcinomatosis.

Animals↗
PubMed1979

Specific absorption of human serum albumin, immunoglobulin A, and immunoglobulin G with selected strains of group A and G streptococci.

Five gram-positive bacterial strains were selected for absorption studies of human serum samples. Strain AR1 (group A, M-type 1) and G148 (group G), with strong immunoglobulin G (IgG) binding capacities, and strain AW43 (group A, M-type 60), binding both IgA1 and IgA2, were compared with Staphylococcus aureus Cowan I and with Staphylococcus epidermidis L603. Both AR1 and G148 were capable of completely absorbing out serum IgG. In contrast, S. aureus Cowan I left a fraction unabsorbed, as expected from its known lack of IgG3 binding. Strain AW43 absorbed out all serum IgA, using a 10-microliter bacterial pellet for 20 microliter of serum. Serum IgM levels were slightly reduced by S. aureus Cowan I absorption. On the basis of the experiments, a bacterial mixture was designed consisting of S. aureus Cowan I and group A streptococcus strains AR1 and AW43, with absorption characteristics suitable for use in discriminating between early IgM and late IgG and IgA immune responses in routine serological work. A new type of bacteria-mammalian protein binding was discovered. Human serum albumin was completely absorbed out by strain G148 and to a lesser extent by strain AR1 and AW43. S. aureus Cowan I and S. epidermidis were negative. The binding capacity of G148 for albumin equalled that of Cowan I for IgG. The binding pattern of albumin to the strains was different from those of IgG, IgA, IgM, fibrinogen, haptoglobin, or aggregated beta 2-microglobulin and therefore seems to represent another type of bacterial-mammalian interaction with a specific albumin receptor on the surface of streptococci.

Absorption↗
PubMed1978

A pesticide (dieldrin)-induced immunohemolytic anemia.

The unusual presentation of a factory worker with severe hemolytic anemia which remitted following splenectomy prompted a search for an environmental cause for red cell injury. The investigation showed the presence of an immunoglobulin in the patient's serum and on the red cells and small amounts of complement on red cells. The patient's serum caused agglutination of a normal person's red cells only when dieldrin-coated, a reaction blocked by first reacting the serum with dieldrin. The spleen of the patient had a greater than normal concentration of dieldrin, the source of dieldrin being dietary. It is concluded that dieldrin became immunogenic and provoked a chemical immunohemolytic anemia. The spleen played a major role in destruction of red cells injured by the immunopathic process and in accumulation of the antigenic substance dieldrin.

Anemia, Hemolytic↗
PubMed1974

Normal laboratory values for differential white cell counts established by manual and automated cytochemical methods (Hemalog D-TM).

The central 95 percentile estimates of the normal white cell types (as determined by a standard differential count) were calculated from 777 normal individuals. The results were divided into groups by age and sex and expressed both as percentages and as absolute numbers of cells.A similar survey was made using the prototype of a new automated differential counting method (Hemalog-D(TM)). The two sets of laboratory values showed no statistically significant differences regarding age or sex and were strikingly similar in most cell types with the exception of band and juvenile forms of granulocytes. As expected, the normal range using the manual technique was somewhat broader than that found with the automated method. In addition to being the first comparison of machine counts with visual differentials this study provides additional insight into the age distributions of normal cells.

Adolescent↗