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Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

At least 217 records · Page 12Linked to original sources
PubMed1985

Aerobic capacity estimated by exercise vs cold-exposure: endurance training effects in rats.

Two widely used measures of aerobic capacity, the maximal rate of oxygen consumption elicited by exercise (VO2max(ex)) and that induced by cold-exposure (VO2max(cold)), were compared before and after a six-week endurance training period in rats. A laddermill was used to elicit by running VO2max(ex) in a few attempts without training. Endurance training was incremented to achieve 85% of the weekly measured VO2max(ex) during the 25 min/day, 5 days/week sessions. Additional rats were left untrained either as controls or for weekly VO2max(ex) measurement. Mean VO2max(ex) was significantly greater by 34% and 20% (VO2max(ex)Mb, 29% and 9%) in the trained and weekly run groups, respectively, but no differences were found in either VO2max(cold) or body mass. Both training and the measurement of VO2max by exercise were sufficient to elevate VO2max(ex) but the enhancement of cold-exposure VO2 reported by others after endurance training was not apparent in VO2max(cold). Thus, the thermogenically-based VO2max(cold) did not reflect the adaptation to endurance training shown by exercise-elicited VO2max. We conclude that VO2max(ex) and VO2max(cold) cannot be used interchangeably as measures of aerobic capacity.

Animals↗
PubMed1985

Immunoblastic sarcoma of T- and B-cell types: morphologic description and comparison.

Immunoblastic sarcoma (IBS) is a large cell lymphoma conceptually related to transformed T and B lymphocytes of the extrafollicular compartment of the immune system (immunoblasts). This light microscopic study of a series of 47 immunologically defined cases of IBS was undertaken in an attempt to define more precisely the morphologic features of the T- and B-cell subtypes. A remarkable morphologic spectrum characterized T-IBS (31 cases), which could be divided into two main groups: 1) tumors composed of varying mixtures of small, medium-sized, and large transformed cells; and 2) tumors with more homogeneous populations of medium-sized or large transformed cells. These cells, in all sizes, generally had abundant pale-staining cytoplasm, delicate nuclear membranes, finely dispersed chromatin, and one to several, small or medium-sized, prominent nucleoli. A distinctive background of small, irregular lymphocytes was frequently present. Plasmacytoid differentiation, seen most consistently as amphophilic staining of the cytoplasm, generally characterized B-IBS (16 cases). B-IBS similarly showed a morphologic spectrum that occurred in two main forms: 1) tumors consisting of a spectrum of transformed cells, with the smaller cells often showing the most striking plasmacytoid differentiation; and 2) tumors consisting predominantly of medium-sized to large transformed cells with varying degrees of plasmacytoid differentiation. With this constellation of features, all but two cases of T-IBS and one case of B-IBS were morphologically distinguishable.

Adolescent↗
PubMed1985

In situ localization of T lymphocytes in disseminated coccidioidomycosis.

Immunohistochemical techniques using monoclonal antibodies to T lymphocyte subpopulations were used to characterize further the granulomas of disseminated coccidioidomycosis. Skin biopsy specimens from patients with disseminated coccidioidomycosis were studied and compared with tissues from experimentally infected mice. In human skin biopsy specimens and infected mouse tissues, discrete granulomata were seen in which T lymphocytes formed a peripheral mantle surrounding central aggregates of macrophages. This unusual pattern of granuloma formation may represent an ineffective host response because these individuals are unable to clear their infection. Because of the close similarity of immunopathology in both human and mouse infections, the mouse model should serve as a useful tool in elucidating the factors contributing to ineffective host responses in systemic fungal infections.

Adolescent↗
PubMed1985

Force development during sustained locomotion: a determinant of gait, speed and metabolic power.

This paper develops three simple ideas about force development during sustained locomotion which provide some insights into the mechanisms that determine why animals change gait, how fast they can run, and how much metabolic energy they consume. The first idea is that the alternate stretch-shorten pattern of activity of the muscles involved in locomotion allows muscle-tendon units to function as springs, affecting the amount of force a given cross-sectional area of muscle develops, and the metabolic requirements of the muscles for force development. Animals select speeds and stride frequencies which optimize the performance of these springs. The second idea is that muscle stress (force/cross-sectional area) determines when animals change gait, how fast they run and their peak accelerations and decelerations. It is proposed that terrestrial birds and mammals develop similar muscle stresses under equivalent conditions (i.e. preferred speed within a gait) and that animals change gaits in order to reduce peak stresses as they increase speed. Finally, evidence is presented to support the idea that it is the time course of force development during locomotion, rather than the mechanical work that the muscles perform, that determines the metabolic cost of locomotion.

Animals↗
PubMed1985

Duplex Doppler: identification of cavernous transformation of the portal vein.

Three cases of cavernous transformation of the portal vein are presented, which emphasize the value of duplex Doppler sonography in the recognition of abnormal vascular structures. In all three cases, cavernous transformation was unsuspected; in two, the initial sonographic or CT examinations were interpreted incorrectly. These cases suggest that the combination of characteristic pulsed-Doppler waveforms and the real-time appearance of cavernous transformation is virtually diagnostic.

Adult↗
PubMed1985

Generation and immunohistological characterization of human monoclonal antibodies to mammary carcinoma cells.

The purpose of this study was to identify human antibodies generated against autologous breast tumor cells by the host's immune response. Accordingly, lymphocytes from lymph nodes of seven different patients with metastatic breast carcinomas were immortalized by fusing them with a nonsecreting variant of murine myeloma cells. The screening for binding of antibodies to tumor cells was performed by indirect immunoperoxidase staining of paraffin-embedded tissue sections of the autologous tumor. The selected hybrid cells, after being cloned three times, were stable for the secretion of immunoglobulins for over 2 years. A total of 81 human immunoglobulin-producing clones was obtained from an initial 595 wells with hybrid growth. Nine of these clones produced immunoglobulin M, none of which showed detectable binding to tissue antigens in breast. Seventy-two clones produced immunoglobulin G monoclonal antibodies, and 15 of these showed preferential binding to breast carcinoma cells. Three of these immunoglobulin G monoclonal antibodies were subjected to detailed immunohistological evaluations. Using these antibodies at concentrations ranging from 10 to 100 ng/tissue section, the morphologically normal mammary epithelial cells could be discriminated from their malignant counterparts. The antibodies showed diffuse staining of cytoplasmic components in the malignant counterparts. Under these conditions, lymphocytes, erythrocytes, and stromal cells in breast tissues were unstained. The antibodies showed variable reactivity with malignant epithelial cells of colon and stomach, and with normal epithelial cells lining the renal tubules and sebaceous glands in skin. Antigenic heterogeneity of malignant mammary epithelial cells was revealed. The antibodies may have value in the characterization of tumor-associated antigens responsible for inducing autologous immune responses.

Animals↗
PubMed1985

Distribution of cells bearing the Tac antigen during ontogeny of human lymphoid tissue.

The monoclonal antibody anti-Tac, which binds to the interleukin 2 (IL 2) receptor, was used to identify this antigen in human fetal and adult lymphoid tissue. Liver, spleen, thymus, lymph node, and peripheral blood were examined for Tac-positive cells with the use of frozen sections or cytocentrifuge preparations. The results show that cells in the fetal and neonatal thymus express the Tac antigen; these cells are predominantly located in the medulla. The liver and spleen of both fetus and adult exhibit very few Tac-positive cells. Double staining demonstrates that cells bearing the Tac-antigen stain with Leu-4, an anti-T cell antibody. In adult lymph node tissue, the Tac-bearing cells are predominantly distributed in the interfollicular area, with positive cells also present in the germinal center and mantle zone. The Tac antigen is present on both T and B cells. Few Tac-positive cells are present in the circulating peripheral blood.

Adult↗
PubMed1985

Tissue and blood T-lymphocyte subpopulations in erythema nodosum leprosum.

To study T lymphocytes in erythema nodosum leprosum (ENL), monoclonal antibodies were used to identify T-lymphocyte subpopulations in the blood and skin lesions of patients with ENL and patients with nonreactional lepromatous leprosy. The blood of nonreactional lepromatous patients had a lymphopenia and a proportionate reduction in pan T cells, helper-inducer, and suppressor-cytotoxic subsets, but a normal helper-suppressor ratio, as compared with controls. Patients with ENL did not differ significantly from the controls. In skin lesions, an admixture of helper and suppressor phenotypes among foamy histiocytes was found. The ENL tissue had more numerous cells of the helper-inducer phenotype and fewer of the suppressor-cytotoxic phenotype, as compared with nonreaction lepromatous tissues. In 22 patients with simultaneous examination of tissue and blood T-cell subsets, there was no correlation between tissue and blood helper-suppressor ratios, indicating that some sort of selection process brings lymphocytes into tissues from peripheral blood.

Cell Count↗
PubMed1984

Heterogeneity of macrophage populations in human lymphoid tissue and peripheral blood.

Human lymphoid tissue and peripheral blood leukocytes were stained with six monoclonal antibodies directed against monocyte/macrophage populations. The staining pattern described by each of these monoclonal reagents was compared with the distribution of morphologically distinguishable tissue macrophages. The results show that there exists considerable heterogeneity of tissue macrophages based on the expression of surface and/or cytoplasmic antigens; furthermore, the distribution of cells bearing particular antigenic determinants is associated with distinct regions in normal lymphoid tissue. Double staining methods demonstrated that these antibodies bind to different, as well as to identical, macrophage populations. OKM-1 antibody binds predominantly to sinus histiocytes and tingible body macrophages. The Leu M-1 reagent stains interdigitating reticulum cells, while the KiM-4 antibody labels follicular dendritic cells. Leu M-3 antibody identifies cells predominantly in the germinal center, and histiocytes lining the sinuses. Both CM-1 and BRL-M.1 appear to stain tissue macrophages distributed throughout the lymphoid tissue.

Antibodies, Monoclonal↗
PubMed1984

Scaling mitochondrial volume in heart to body mass.

The heart mass was measured and the volume density of mitochondria, VV(mt,f), morphometrically estimated in 11 mammalian species ranging from shrew (3 g) to cattle (920 kg). The mass or the volume of the heart muscle (Vh) was found to scale as Mb0 .970 whereas VV(mt,f) scaled as Mb-0.044. Hence, the total volume of mitochondria in heart, V(mt), scaled as Mb0 .927 (V(mt) = VV(mt,f) x Vh). The volume of heart mitochondria was found to scale disproportionately to VO2max ( Mb0 .75) but in proportion to resting cardiac work rate ( Mb0 .9).

Animals↗
PubMed1984

Demonstration in situ of subsets of T-lymphocytes in sarcoidosis.

Five biopsy specimens of skin, four of lung, and one of a lymph node were taken from nine patients with sarcoidosis. Monoclonal antibodies were applied to frozen sections of the specimens by an immunoperoxidase technique to test for the presence and distribution of subsets of T-lymphocytes. T-cells expressing the suppressor/cytotoxic phenotype were found predominantly in lymphocytic mantles surrounding sarcoidal granulomas, whereas cells displaying the helper/inducer phenotype were distributed diffusely throughout granulomas. The ratio of helper to suppressor phenotypes in cutaneous sarcoidosis was 5.1 +/- 1.8. The microanatomic location of subpopulations of T-lymphocytes may be important in the pathogenesis of the granulomatous response of sarcoidosis.

Antibodies, Monoclonal↗
PubMed1984

Limitations of computed tomography in the recognition of delayed splenic rupture.

Delayed splenic rupture is a rare but life threatening complication of abdominal trauma. A case is reported in which initial evaluation by CT did not show hemoperitoneum or splenic laceration in a patient who ruptured his spleen 10 days following the initial injury. The limitations of current diagnostic methods are reviewed.

Adult↗
PubMed1984

HLA-DR (Ia)-positive dendritic-like cells in human fetal nonlymphoid tissues.

Nonlymphoid tissues from human fetuses ranging in age from 12 to 21 weeks' gestation were examined for the presence of HLA-DR (Ia)-positive cells. Immunoperoxidase staining of cryostat sections revealed Ia-positive cells with dendritic-like morphology, in kidney, heart, pancreas, and lung--but not in brain tissue. These Ia-bearing cells were present at 12 weeks' gestation, and by 21 weeks had increased to substantial numbers in all the organs tested, except for the brain, which remained negative. To further characterize the nature of these Ia-positive cells serial sections were studied with a panel of monoclonal antibodies (MAb) consisting of four reagents identifying monocyte/macrophages and two reagents staining lymphoid cells. The four anti-monocyte/macrophage MAb stained few if any cells in all the tissues examined. Lymphoid cells, as identified by anti-B-cell and anti-T-cell MAb, were also present in very low numbers. Additional studies using a double-staining technique provided direct evidence that the Ia-positive cells bear the human common leukocyte antigen detected by MAb T29 /33 and, with few exceptions, are negative for the macrophage antigen detected by MAb OKM1. The data suggest that nonlymphoid fetal tissues contain Ia-positive dendritic-like cells that are not monocyte/macrophage or lymphoid in origin. These Ia-bearing cells may be related to the dendritic cells found in lymphoid tissues, which are highly stimulatory in mixed leukocyte reactions and are thought to be responsible for the initiation of allograft rejection.

Antibodies, Monoclonal↗
PubMed1984

Comparison of S-100 and OKT6 antisera in human skin.

The monoclonal antibody OKT6 and antisera against S-100 protein have both been advocated as immunologic markers of Langerhans cells in the skin. S-100 antiserum has an advantage in its ability to stain Langerhans cells in paraffin tissues. In order to evaluate whether these antibodies stain equivalent numbers of Langerhans cells in skin, we compared the staining patterns of S-100 antiserum and OKT6 antibody on biopsy specimens from 40 patients with leprosy using immunoperoxidase techniques. Utilizing OKT6 antibody, greater numbers of positive Langerhans cells were found in the epidermis in tuberculoid leprosy, reversal reaction, and erythema nodosum leprosum than in lepromatous leprosy. However, these differences were not observed with the S-100 antiserum and, overall, fewer cells were found as compared with the OKT6 antibody. In the dermis both antibodies stained "dendritic cells" that were found encircling granulomas in tuberculoid leprosy and reversal reaction. Staining in lepromatous leprosy granulomas, in contrast to the epidermal staining pattern, revealed rare OKT6-positive cells, while S-100 cells were numerous and were more diffusely distributed throughout the granuloma. Our results indicate that antiserum to S-100 protein and OKT6 antibody stain morphologically similar cells (dendritic cells), but do not provide comparable results concerning distribution and frequency of these cells.

Antibodies, Monoclonal↗
PubMed1984

Immunopathologic demonstration of T lymphocyte subpopulations and interleukin 2 in granuloma annulare.

Immunopathologic aspects of granuloma annulare were studied in frozen sections of nine skin biopsy specimens with monoclonal antibodies directed against T lymphocytes, Langerhans' cells, interleukin 2, and interleukin 2 receptors in conjunction with immunoperoxidase techniques. The predominant lymphocyte was an activated T lymphocyte (Leu 1+, HLA-DR+) with an excess of helper/inducer phenotype (Leu 3a+) as compared with suppressor/cytotoxic phenotype (Leu 2a+). Langerhans' cells were increased in the epidermis and numerous OKT6+ cells were observed in the perivascular and granulomatous infiltrate. Both interleukin 2-positive cells and interleukin 2 receptor-positive cells were identified in the dermal lesions according to observed reactivity with the corresponding monoclonal antibodies. These findings suggest that a cell-mediated immune response producing cytokines may be important in the pathogenesis of granuloma annulare. Comparison of these results with skin specimens from patients with sarcoidosis and from a patient with granuloma annulare having some of the histologic features of sarcoidosis, suggests that the cutaneous infiltrate in granuloma annulare represents a response distinct from that of sarcoidosis.

Antibodies, Monoclonal↗
PubMed1984

Immunohistochemical studies of ovarian and testicular teratomas with antiserum to glial fibrillary acidic protein.

Twenty cases of ovarian or testicular teratomas were studied with a sensitive peroxidase-antiperoxidase (PAP) method utilizing an antibody to glial fibrillary acidic protein (GFAP). Positive staining was restricted to the perikaryon, to extensively distributed neuroglial fibrils, or to ependymal lining cells in 13 of 20 teratomas studied. Positively stained cells were also occasionally observed in the choroid plexus, thus indicating the possibility that such cells also retain the capability of producing GFAP. GFAP-positive material was also found in the tumour cells of an undifferentiated ovarian teratocarcinoma; this tumour was believed to represent an ovarian glioma. It is concluded that the PAP method represents a sensitive and valuable histochemical tool which should be further explored to characterize a functional basis of normal and neoplastic cells. Findings are of particular interest in the "germ cell tumours" in which multiple differentiation patterns may be expressed.

Adolescent↗