Circulating leucocyte subpopulations in sedentary subjects following graded maximal exercise with hypoxia

Summary Ten healthy sedentary subjects [age, 27.5 (SD 3.5) years; height, 180 (SD 5) cm; mass, 69.3 (SD 6.3) kg] performed two periods of maximal incremental graded cycle ergometer exercise in a supine position. Randomly ordered and using an open spirometric system, one exercise was carried out during normoxia [maximal oxygen consumption ( O_2max)=38.6 (SD 3.5) ml·min^–1·kg^–1; maximal blood lactate concentration, 9.86 (SD 1.85) mmol·l^–1; test duration, 22.6 (SD 2.7) min], the other during hypoxia [ O_2max=33.2 (SD 3.2) ml·min^–1· kg^–1; maximal blood lactate concentration, 10.38 (SD 2.02) mmol·l^–1; test duration, 19.7 (SD 2.8) min]. At rest, immediately (0 p) and 60 min (60 p) after exercise, counts of leucocyte subpopulations (flow cytometry), cortisol and catecholamine concentrations were determined. At 0 p in contrast to normoxia, during hypoxia there was no significant increase of granulocytes. There were no significant differences between normoxia and hypoxia in the increases from rest to 0 p in counts of monocytes, total lymphocytes and lymphocyte subpopulations [clusters of differentiation (CD), CD3⁺, CD4⁺CD45RO^–, CD4⁺CD45RO⁺, CD8⁺CD45RO^–, CD8⁺CD45RO⁺, CD3⁺HLA-DR⁺, CD3^–CD16/CD56⁺, CD3⁺CD16/CD56⁺, CD 19⁺] as well as adrenaline, noradrenaline and cortisol concentrations. The counts of CD3 ^–CD16/CD56⁺-and CD8 ⁺CD45RO⁺-cells increased most. At 60 p, CD3^–CD16/CD56⁺ and CD3⁺CD16/CD56⁺-cell counts were below pre-exercise levels and under hypoxia slightly but significantly lower than under normoxia. We concluded that the exercise-induced mobilization and redistribution of most leucocyte and lymphocyte subpopulations were unimpaired under acute hypoxia at sea level. Reduced increases of granulocyte counts during the study and reduced cell numbers of natural killer cells and cytotoxic, not major histocompatibility complex-restricted T-cells, only indicated marginal effects on the immune system.     

Duke Surgery Research Central: an open-source Web application for the improvement of compliance with research regulation

Background  

Although regulatory compliance in academic research is enforced by law to ensure high quality and safety to participants, its implementation is frequently hindered by cost and logistical barriers. In order to decrease these barriers, we have developed a Web-based application, Duke Surgery Research Central (DSRC), to monitor and streamline the regulatory research process.     

Mineralization behaviour of collagen type I immobilized on different substrates

Collagen type I as a robust fibre protein and main component of the extracellular matrix of most tissues is increasingly utilized for surface engineering of biomaterials using different immobilization methods. In the present work we studied the mineralization behaviour of fibrillar collagen type I in simulated body fluid as a measure for conformational changes caused by adsorptive immobilization or immobilization by partial incorporation into the anodic oxide layer on c.p.-titanium using microscopic and vibration spectroscopic methods. Adsorptive immobilization on highly oriented pyrolytic graphite (HOPG) and c.p.-titanium without collagen were used as references. In the initial phase (1-24 h) the kinetics of formation and the morphology of calcium phosphate phases (CPP) are strongly influenced both by the substrate and the immobilization method. Compared to HOPG both types of immobilization on titanium increasingly inhibit the formation of CPP. For longer times (30 d) these initial differences disappear-mineralization product on titanium, irrespective of the presence of collagen, is a mixture of amorphous calcium phosphate and octacalcium phosphate. Contrary to this the mineralization of HOPG substrates results in hydroxy apatite. This is discussed with respect to the conditions during the immobilization as well as the resulting interactions between substrate and immobilized collagen. It is shown that the mineralization process exhibits a high sensitivity with respect to conformational changes caused by these interactions. Possible cell biological relevance of these conformational changes is discussed.     

Phenotypic and functional properties of murine {gamma}{delta} T cell clones derived from malaria immunized, {alpha}{beta} T cell-deficient mice

Six murine T cell clones expressing TCR were generated frommalaria immunized, ß T celldeficient mice. Phenotypiccharacterization of these clones has revealed that, in contrastto conventional ß T cells, there is a considerabledegree of heterogeneity among these clones with regard to theirsurface markers and their lymphokine profile. One clone wasfound to display significant anti-parasite activity in vivoupon adoptive transfer. We attempted to determine whether theprotective clone differs in one or more key characteristicsfrom the non-protective clones. Although no obvious patternpeculiar to the protective clone was observed, it appears thatmore than one parameter may, in combination, define a distinctprotective phenotype, and thus explain the functional differencebetween the protective and non-protective clones.     

Antigenic profile of mammary fibroadenoma and cystosarcoma phyllodes. A study using antibodies to estrogen- and progesterone receptors and to a panel of cell surface molecules

Using serial frozen sections, monoclonal antibodies and an indirect immunoperoxidase method, 13 fibroadenomas (FA) and 3 cystosarcomas phyllodes (CSP) were analyzed for the expression of Egp34, HEA319-antigen, leucocyte differentiation antigens CD10, CD30, CD57, CD72, CDw75, and CD77, epidermal growth factor receptor (EGFR), estrogen (ER) and progesterone receptor (PR), and transferrin receptor (CD71). Egp34, CDw75, HEA319 antigen, CD10, and CD30 turned out to be consistently expressed in different cell types constituting FA and CSP and revealed that in malignant CSP the myoepithelial compartment acquires the ability to invade the stroma. Phenomenologically, the variable mode of expression of CD57 in myoepithelial cells, of CD77 in ductal epithelium, and of CD72 in both epithelial and stromal cells is suggestive for reflecting differences in their functional state but cannot be further interpreted at present. Expression of PR and ER was restricted to duct cells and was relatively independent, non-systematical. However, expression of ER and EGFR was inverse. This was also true for EGFR and CD71 in both duct cells and myoepithelial cells of FA. In contrast, stromal cells of FA were able to co-express EGFR and CD71 in the absence of PR and ER. This suggests a hormone-independent stimulation of the stromal cell compartment, possibly leading to local proliferation as the primary event in tumorigenesis of FA. In malignant CSP, however, the main proliferating cell is an abnormally mobile, HEA319 antigen-, CD10- and CD30-positive myoepithelial cell found to co-express ERFR and CD71 which is abnormal for this cell type but encountered in (myo-)fibroblasts of FA.     

Lympho-stromal interactions in the thymus: medullary thymocytes react with I-A determinants on autochthonous thymic stimulator cells

Primary (1^o) and secondary (2^o) syngeneic mixed lymphocyte culture (SMLC) reactions in autochthonous murine thymus cell cultures (peanut agglutinin-unreactive) or syngeneic mixed thymus-spleen cell cultures were studied. The 1^o thymic SMLC responder cells were Thy-1⁺, Lyt-1⁺, Lyt-2^?. The 1^o thymic syngeneic mixed lymphocyte reaction (SMLR) could be inhibited with monoclonal antibodies directed against determinants Ia.m1 and Ia.m6, in the absence of complement. Positive selection of thymic SMLC cells from 1^o cultures was achieved by enriching reactive lymphoblasts on discontinuous Percoll density gradients. The 2^o memory populations were obtained by allowing the selected lymphoblasts to revert back to small resting 2^o cells in the absence of SMLC stimulation. The thymic 2^o SMLC populations were highly enriched in their activity and were almost exclusively specific for self stimulator cells. The 2^o thymic SMLC cells were found to be Thy-1⁺, membrane immunoglobulin-negative, H-2K/D⁺, I-A^?, I-E^? and I-J^?. They were hardly lysed by anti-Lyt-1 antibodies and not at all lysed by monoclonal antibodies detecting Qat-4 and 5, and Lyt-2 antigens, in the presence of complement. Stimulator cells were found in fast-sedimenting or low-density fractions of thymus. They expressed H-2K/D, I-A-, and I-E antigens but lacked membrane immunoglobulin and Thy-1. Not all I region determinants seemed to be of equal importance in the 2^o thymic SMLC: I-A subregion compatibility between responding and stimulating cells was a minimal requirement for the induction of 2^o thymic SMLC responses. Although several relevant anti I-region antibodies reacted with the stimulator cells in the presence of C, these and other anti-Ia antibodies varied considerably in their capacity to block 1^o and 2^o autochthonous thymic SMLR in the absence of complement. Our finding that the thymus contains the responder as well as the stimulator cells capable of interacting in an autochthonous proliferative reaction will be discussed with regard to its implications for the intrathymic differentiation of T lymphocytes.     

Center-surround interactions in the middle temporal visual area of the owl monkey

Microelectrode recording and 2-deoxyglucose (2dg) labeling were used to investigate center-surround interactions in the middle temporal visual area (MT) of the owl monkey. These techniques revealed columnar groups of neurons whose receptive fields had opposite types of center-surround interaction with respect to moving visual stimuli. In one type of column, neurons responded well to objects such as a single bar or spot but poorly to large textured stimuli such as random dots. This was often due to the fact that the receptive fields had antagonistic surrounds: surround motion in the same direction as that preferred by the center suppressed responses, thus rendering these neurons unresponsive to wide-field motion. In the second set of complementary, interdigitated columns, neuronal receptive fields had reinforcing surrounds and responded optimally to wide-field motion. This functional organization could not be accounted for by systematic differences in binocular disparity. Within both column types, neurons whose receptive fields exhibited center-surround interactions were found less frequently in the input layers compared with the other layers. Additional tests were done on single units to examine the nature of the center-surround interactions. The direction tuning of the surround was broader than that of the center, and the preferred direction, with respect to that of the center, tended to be either in the same or opposite direction and only rarely in orthogonal directions. Surround motion at various velocities modulated the overall responsiveness to centrally placed moving stimuli, but it did not produce shifts in the peaks of the center's tuning curves for either direction or speed. In layers 3B and 5 of the local motion processing columns, a number of neurons responded only to local motion contrast but did so over a region of the visual field that was much larger than the optimal stimulus size. The central feature of this receptive field type was the generalization of surround antagonism over retinotopic space-a property similar to other "complex" receptive fields described previously. The columnar organization of different types of center-surround interactions may reflect the initial segregation of visual motion information into wide-field and local motion contrast systems that serve complementary functions in visual motion processing. Such segregation appears to occur at later stages of the macaque motion processing stream, in the medial superior temporal area (MST), and has also been described in invertebrate visual systems where it appears to be involved in the important function of distinguishing background motion from object motion.     

Agrin is a major heparan sulfate proteoglycan accumulating in Alzheimer's disease brain

Heparan sulfate proteoglycans (HSPGs) have been suggested to play an important role in the formation and persistence of senile plaques and neurofibrillary tangles in dementia of the Alzheimer's type (DAT). We performed a comparative immunohistochemical analysis of the expression of the HSPGs agrin, perlecan, glypican-1, and syndecans 1-3 in the lesions of DAT brain neocortex and hippocampus. Using a panel of specific antibodies directed against the protein backbone of the various HSPG species and against the glycosaminoglycan (GAG) side-chains, we demonstrated the following. The basement membrane-associated HSPG, agrin, is widely expressed in senile plaques, neurofibrillary tangles and cerebral blood vessels, whereas the expression of the other basement membrane-associated HSPG, perlecan, is lacking in senile plaques and neurofibrillary tangles and is restricted to the cerebral vasculature. Glypican and three different syndecans, all cell membrane-associated HSPG species, are also expressed in senile plaques and neurofibrillary tangles, albeit at a lower frequency than agrin. Heparan sulfate GAG side chains are also associated with both senile plaques and neurofibrillary tangles. Our results suggest that glycosaminoglycan side chains of the HSPGs agrin, syndecan, and glypican, but not perlecan, may play an important role in the formation of both senile plaques and neurofibrillary tangles. In addition, we speculate that agrin, because it contains nine protease-inhibiting domains, may protect the protein aggregates in senile plaques and neurofibrillary tangles against extracellular proteolytic degradation, leading to the persistence of these deposits.     

Diagnosis of metastatic lesions to the stomach by salvage cytology

Summary Secondary neoplasms of the stomach are rare and are often clinical and diagnostic problems. Three patients with bleeding volcano-like ulcers were diagnosed by combined endoscopic salvage cytology and surgical biopsy as having metastatic submucosal lesions from hematologic spread. The combination of endoscopic appearance, clinical findings, and tissue and cytologic examination can lead to the correct diagnosis. The results from these cases support the utility of this cytologic technique in combination with biopsy in this clinical setting.