Extracellular Enzyme Activities in Relation to Hydrodynamics in the Pomeranian Bight (Southern Baltic Sea).

Abstract The Pomeranian Bight in the southern Baltic Sea is characterized by a huge input of nutrients from the Oder river. This input shows seasonal variation. In winter, the nutrients are introduced in inorganic form. Particulate organic material is dominant in the growth season (summer/autumn). From 1993 to 1996, extracellular enzyme activities (alkaline phosphatase, peptidase, alpha-, beta-glucosidase, and chitinase) were investigated to describe microbial reaction to the input of organic material and the modification of introduced material. The distribution patterns of extracellular enzyme activities in salinity gradients were studied, in response to the nutrient load. These activities were distinctly lower in winter than in summer and autumn. A close relationship to other biological parameters (Chl a, POC, PON) was observed during the growth season, but not in winter. Changes in peptidase and phosphatase activities between summer and autumn were also observed. The peptidase activity was 9 to 72 times higher in autumn than in summer. In contrast, the alkaline phosphatase activity was 5 to 30 times higher in summer than in autumn. The organic compound turnover rate/hydrolysis rate (To/Hr) ratio is a relative index which describes the coupling of enzymatic hydrolysis and utilization of monomers from investigated substrates (carbohydrates and proteins). In summer, after dilution, the raised To/Hr quotients of glucose indicated limited importance for hydrolysis products in bacterial turnover. The increased demand for glucose resulted in a parallel decrease in monosaccharides. In autumn, the relationship between the turnover of glucose and amino acids and the supply of these substances by enzymatic degradation remained at the same level.

Immunohistochemical characterization of the pancreatic cellular infiltrate in normal pancreas, chronic pancreatitis and pancreatic carcinoma.

BACKGROUND/AIMS: Chronic pancreatitis is histologically characterized by an extended fibrosis and infiltration of leukocytes. We intended to differentiate the infiltration to evaluate the inflammatory process. METHODS: Samples of tissues of normal pancreas (NP, n = 12), of chronic pancreatitis (CP, n = 7), and pancreatic tissues surrounding pancreatic carcinoma (CA, n = 7) were investigated by immunohistochemical staining using the APAAP technique. RESULTS: In normal pancreas, mononuclear cells (47.1 +/- 26.0 cells/mm2) were observed with a predominance of macrophages (56.3%) and T lymphocytes (31.3%) which were differentiated in CD8+ lymphocytes (9.3 +/- 7.2 cells/ mm2) and CD4+ lymphocytes (6.7 +/- 3.2 cells/mm2). Rarely, plasma cells (5.3%) and B lymphocytes (7.1%) could be detected. In pancreatic tissue of patients with CP and in CA there was a significant increase of mononuclear cells to 264.4 +/- 120.3 cells/mm2 and 284.3 +/- 67.8 cells/mm2, respectively. In both diseases percentages of T lymphocytes (CP: 50.5%; CA: 48.1%) were higher than in normal controls. CD4+/CD8+ ratio of 0.77 in CP and 0.82 in CA demonstrated a predominance of CD8+ cells compared to the peripheral blood. In NP and CA, nearly all T lymphocytes expressed CD45R0 identifying memory cells, while only 58% of T lymphocytes were CD45R0 positive in CP. CONCLUSION: Our data suggest that the investigated cases of CP were of a common inflammatory type rather than due to an autoimmunological reaction. CD8+ T lymphocytes were the predominant T cell subset in the inflammatory infiltrates in both CP and CA.

[Interleukin 1 (IL 1)]. / Interleukin 1 (IL 1).

Interleukin 1 is an essential factor of macrophage dependent T cell activation and has a large quantity of other biological activities. This paper gives a review of present knowledge of Interleukin 1. In addition to biochemical properties, the IL 1 production and IL 1 activities, methods for determining of IL 1 and inhibitory factors of IL 1 induced T cell proliferation are described.

Human monocyte activation induced by an anti-CD14 monoclonal antibody.

An anti-CD14 mAb RoMo-1 rapidly induces in human monocytes a transient oxidative burst activity as detected by chemiluminescence assay. Pretreatment of these cells with the mAb markedly suppresses the monocyte chemiluminescence response to opsonized zymosan. In addition, the antibody induces a significant increase of IL-1 production and secretion by mononuclear cells, comparable to a similar effect of rIFN-gamma or LPS. Electron microscopy demonstrates internalization of the CD14 molecules after interaction with the mAb in a characteristic receptor-like manner.

Histamine induced murine suppressor and potentiating factors.

Mouse spleen cells were incubated for 24 hours in the presence of histamine (10(-13)-10(-3) M). Aliquots of the histamine free supernatants were intravenously injected into either syngenic or allogenic mice which were subsequently analysed by the Jerne plaque assay in respect of their specific IgM response against red blood cells from sheep. Depending on the histamine concentration during the preincubation and the mouse strain, the effects of the supernatants were found to be suppressive or potentiating. Both the histamine induced suppressor and potentiating factor are generated by T-cells and can be precipitated by (NH4)2SO4. These precipitates were fractionated by gel filtration which revealed a molecular weight of both factors in the range of 20 to 50 kDa. Both lymphokines were found to be sensitive to trypsin, low pH, and heat treatment but were not affected by neuraminidase. They do only interfere with the early events of the IgM response within 24 hours after the administration of the antigen. The conclusion is that the bidirectional modulation of the humoral immune response by histamine in mice is partially due to the induction of these lymphokines by a different efficacy of the histamine receptor activation at different T-cell subsets.

[Cell distribution and macrophage function in bronchoalveolar lavage of patients with sarcoidosis and lung tumors]. / Untersuchungen zur Zellverteilung und Makrophagenfunktion in der Bronchoalveolären Lavage (BAL) von Patienten mit Sarkoidose und Lungentumoren.

BAL was performed to differentiate cases of sarcoidosis and bronchial carcinoma. Significant differences in the cell differentiation are stated. An increase of spontaneous interleukin production seems to be another sign of activity of sarcoidosis.

[Interleukin 2 inhibitor activity in blood serum]. / IL 2-Inhibitor-Aktivität im Blutserum.

Normal murine, horse and human sera inhibit the proliferation of thymocytes, T blast cells and cloned cytotoxic T lymphocytes in vitro dose dependently. This effect is specific to IL 2-dependent cell proliferations. The inhibitory activity does not decrease the binding of IL 2 to its receptor, but inhibits the IL 2 receptor expression dose dependently. An excess of purified IL 2 can overcome the inhibition of IL 2-dependent cell proliferation. Using gel filtration, we have found the inhibitory activity in the region of 80,000 MW. This inhibitory activity is precipitated by 50% saturated ammonium sulfate. The species-specificity of this inhibitor in serum is very low. The IL 2-inhibitor is discussed as a part of natural immunoregulation and as a hint for activation of the immune system.

[Determination of interleukin 1]. / Zur Bestimmung von Interleukin 1.

Interleukin 1 is an essential factor of macrophage dependent T cell activation. As a method for determining IL 1 the estimation of its comitogenic activity is used with mouse thymocytes. For preparation IL 1 standards the macrophage cell line P388D1 or human leukocytes are stimulated with LPS. The mitogenic activity of the thymocytes is tested in five different mouse strains; LPS does not disturb the IL 1 determination in the concentration range between 10(2) micrograms ml-1 and 10(-3) micrograms ml-1. Contrary to the Con A reactivity the susceptibility of the thymocytes on IL 1 is developing more slowly. The age of the animals for preparation thymocytes should not be under 8 to 10 weeks. IL 1 and IL 2 inhibitors must be considered in determining IL 1.