Adjustment of metabolism,catecholamines and β-adrenoceptors to 90 min of cycle ergometry

Adrenaline infusion of 0.1 g · kg^–1 · min^–1 in healthy volunteers results in an increase of hepatic glucose production, an increase of the absolute number of occupied -adrenoceptors and specific changes in metabolism. To compare these effects with the changes induced by an endogenous catecholamine release, we investigated healthy volunteers during cycle ergometry. After fasting at least 14 h seven healthy subjects exercised for 90 min at an intensity of 20% below their individual anaerobic threshold. The rate of glucose production as well as the turnover rates of alanine and leucine were calculated using stable isotope tracers. High and low affinity -adrenergic binding sites on lymphocytes were determined by an equilibrium binding assay with (–)¹²⁵ Iodocyanopindolol. After 90 min of cycling the rate of appearance of glucose increased significantly from means of 2.0 (SD 0.2) to 2.65 (SD 0.50) mg · kg^–1 · min^–1 with unchanged blood concentrations of glucose and lactate. The flux of the amino acids alanine and leucine decreased significantly from means of 0.91 (SD 0.21) to 0.62 (SD 0.14) mg · kg^–1 · min^–1 and from 0.40 (SD 0.05) to 0.32(SD 0.04) mg · kg^–1 · min^–1, respectively. The mean free fatty acid concentration increased significantly from 0.65 (SD 0.33) to 1.27 (SD 0.45) mmol · l^–1 during the endurance trial. The increase of glucose turnover and the decrease of amino acid flux point to a metabolic shift towards enhanced utilization of free fatty acids. Adrenaline and noradrenaline concentrations showed a moderate but significant increase from means of 0.61 (SD 0.20) to 0.99 (SD 0.36) nmol · l^–1 and from 2.27 (SD 0.75) to 3.46 (SD 0.38) nmol · 1^–1, respectively. The number of high affinity -adrenergic binding sites per cell (-adrenoceptors) nearly doubled from 770 (SD 130) to 1490 (SD 150) during 90 min of cycling. The observed endogenous plasma catecholamine concentrations were not sufficient to change significantly the relative receptor occupancy. This would seem to indicate that the aerobic exercise induced effects depended more on the absolute number of occupied -adrenoceptors than on their relative receptor occupancy. When compared to the results of the adrenaline infusion experiment the increases of the hepatic glucose production and the increase of -adrenoceptors were very similar in both groups despite ten times higher adrenaline plasma concentrations in the infusion group. This would seem to indicate that -adrenoceptors mediated effects do not correlate with catecholamine plasma concentrations.     

Laboratory diagnosis of inherited protein S deficiency

The authors investigated assays for free protein S (ProS) antigen, total ProS antigen, and ProS crossed immunoelectrophoresis (CIEP) in the diagnosis of type 1 inherited ProS deficiency. Accurate measurement of the hemostatically important free ProS required showing that, on each specimen, precipitation of the C4b-binding protein (C4b-BP)/protein S complex (C4b-BP/ProS) by polyethylene glycol-8,000 (PEG) was complete. The authors showed this by doing a ProS CIEP on the same PEG supernate that was used for quantitative measurement of free ProS. The +/- 2 standard deviation (+/- 2 SD) ranges for free ProS were 81-133% for males and 50-130% for females. This striking male-female difference has been reported only twice before. With the use of a graph of values for free ProS versus prothrombin time (PT), patients with inherited ProS deficiency segregated cleanly from normals and from patients on warfarin therapy without ProS deficiency until the PT was greater than 20 seconds. There is overlap of total ProS antigen values between normals and patients with inherited ProS deficiency.     

Reduction of systemic fungal infections in patients with hematological malignancies,neutropenia, and prolonged fever by early amphotericin B therapy

Summary A rate on autopsy of up to 30% systemic fungal infections and difficulties in diagnosing systemic mycosis antemortem have led to the empiric use of amphotericin B in patients with hematological malignancies, prolonged fever, and neutropenia. Routine empiric antifungal treatment was initiated in our institution in 1982. Amphotericin B was given to granulocytopenic patients with hematological malignancies with (a) unremitting fever after 48–72 h of antibiotic treatment, (b) recurrent fever during antibiotic treatment, or (c) with newly detected pulmonary infiltrates, sinusitis, skin and retinal lesions suggestive of a fungal infection. With this approach the rate of systemic fungal infections decreased significantly from 10% (27 of 270 patients; 1973–1981) to 4% (6 of 153 patients; 1982–1986,P<0.02). The reduction of systemic fungal infections was most prominent in patients with acute myelogenous leukemia, where its proportion decreased from 16% (16 of 98 patients; 1973–1981) to 4% (2 of 50 patients; 1982–1986,P<0.023). Our data support the hypothesis that the incidence of systemic fungal infections in patients with hematological malignancies and especially in acute myelogenous leukemia can be reduced significantly by empirical treatment with amphotericin B.     

Class II defective avian sarcoma viruses: Comparative analysis of genome structure

The genomes of class II avian sarcoma viruses PRCII, PRCII-p, PRCIV, and Fujinami sarcoma virus (FSV), were studied by oligonucleotide fingerprinting, heteroduplex mapping, and nucleic acid hybridization. All of these viruses are genetically defective and have a small RNA genome between 4.5 and 6.1 kilobases (kb) in length. They contain helper-related sequences at both the 5′- and 3′-ends, but most of the retroviral sequences in the middle of the genome are deleted. In place of this deleted information, a contiguous stretch of transformation-specific sequences, termed fps, is found. These putative oncogenic sequences are about 1.2 kb in PRCII, and those in PRCII-p and PRCIV are roughly 2.9 kb. From the analysis of oligonucleotides, it appears that the fps sequences of PRCII represent a subset of those of PRCII-p. Most of the additional sequences present in PRCII-p but absent from PRCII are at the 5′-half of fps. The helper-related sequences in PRCII and PRCII-p are almost indistinguishable, except that PRCII-p contains slightly more retroviral information at the 3′-end of the genome. Therefore, it is possible that PRCII has been derived by deletion from PRCII-p. By contrast, PRCII-p and PRCIV were found to contain identical fps sequences, but their helper-related sequences have diverged substantially. These two sarcoma viruses either represent two independent isolates or, if derived from a single isolate, they have undergone extensive mutation and recombination with diverse avian retroviruses. FSV was found to differ to a greater extent from other class II sarcoma viruses in both helper-related and fps sequences. The difference in fps sequences is localized in the 5′-half of that region. Considering the variation in fps among all members of class II avian sarcoma viruses, it appears that the 3′-half of that genetic region is more conserved than the 5′-half.     

Isolation and characterization of immunoferritin conjugates: I. The molecular ratio

¹²⁵I-labelled γ-globulin was conjugated to ferritin for the determination of the molecular ratio in ferritin—γ-globulin conjugates. Equimolar ratios were found in all conjugates free of uncoupled γ-globulin.     

Multiple effects of a diamidine (propamidine) on complement activation.

Propamidine, one of the diamidines used against infections with babesiae has inhibitory and enhancing effects on complement activation as assessed by immune haemolysis of sensitized sheep red cells. Utilization of C1 is powerfully, that of C3 weakly improved by propamidine while activation and/or fixation of C4, C5 and to a lesser degree of C8 and C9 are inhibited. At low concentrations of propamidine (less than 2 mM) the enhancing effects, at higher concentrations the inhibitory effects predominate. Inhibition is produced, in some cases certainly, in others likely, by interference of propamidine with binding properties of complement components. None of the complement enzymes, C1s, C42 or C3bBb was inhibited in its hydrolytic activity. The possible significance of propamidine actions is discussed.     

Improved contrast by a simplified post-staining procedure for ultrathin sections of resin-embedded bacterial cells: Application of ruthenium red

High contrast can be obtained in ultrathin sections of bacterial cells embedded in the low-temperature resin Lowieryl by post-staining of the sections on an aqueous ruthenium red solution. Post-staining with lead citrate can be omitted. Combination with post-staining with uranyl acetate results in further improvement of contrast. This is shown for Gram-positive, Gram-negative, and methanogenic bacteria. Improved visibility is demonstrated for wall layers including slime and capsule, cytoplasmic membrane, nucleoid, envelope of PHB inclusion bodies, polyphosphate, and intracellular defective bacteriophages. The procedure is suited as post-staining for immunocytochemical analyses.     

Expression of cytokine mRNA in lentivirus-induced arthritis.

Infection of goats with the lentivirus caprine arthritis encephalitis virus (CAEV) leads to persistent infection and development of chronic arthritis. We analyzed the expression of cytokines and viral RNA in the joints of goats at early time points after experimental infection with CAEV and in those of animals suffering from chronic arthritis as a result of natural infection. In situ hybridization experiments showed that the pattern of cytokine expression in caprine arthritis was similar to that found in rheumatoid arthritis (RA), with a few cells expressing the lymphocyte-derived cytokines interferon (IFN)-gamma and interleukin (IL)-2 and rather more cells expressing monocyte chemoattractant protein (MCP)-1, IL-6, and tumor necrosis factor (TNF)-alpha. IFN-gamma mRNA expression in experimentally infected joints peaked at day 12 and was mostly detected in areas containing viral RNA. At later time points, no IFN-gamma- or virus-expressing cells were found in inflamed joints but both were again detected in goats with severe arthritis. Interestingly, at the clinical stage of arthritis reflecting the chronic stage of infection, the inflammatory lesion was found to be immunologically compartmentalized. Humoral immune responses and cell-mediated immune responses appeared to concurrently occur in distinct areas of the synovial membrane.