Activation of inflammatory systems during cardiopulmonary bypass

"Whole body inflammation" induced by cardiopulmonary bypass may play a role in the pathogenesis of postoperative complications after open-heart surgery. The inflammatory response, in terms of complement activation and release of granular proteins from neutrophil granulocytes, was investigated in six patients undergoing aortocoronary bypass surgery. Complement activation was demonstrated as well as substantially increased plasma levels of lactoferrin and myeloperoxidase--two granulocyte factors. The activation of inflammatory systems probably takes place on the artificial surfaces of the extracorporeal device. The biocompatibility of these components therefore should be further studied.     

Prefabricated neovascularized free muscle flaps: pedicle variations

Current techniques of free muscle transplantation with microvascular anastomosis have the disadvantages of limitation of available donor sites, loss of donor muscle function, and the possibility of donor site defect or deformity. Using modifications of a "secondary tissue flap" created by neovascularization of a given tissue, neovascularized muscle flaps with pedicle vessels were created by wrapping external abdominal oblique muscles around the superficial inferior epigastric blood vessels. Different pedicle types were examined to explore possible differences in neovascularization. In 60 rats, four groups of neovascularized muscle flaps were created and transplanted as free flaps, with a high degree of success. After transplantation, neovascularization of the flaps was evaluated by histology and latex casts of vascular tree of the muscle flaps. Degree of neovascularization differed, depending on the type of vascular pedicle used to create the flap.     

A Biotin–Avidin-Based Enzyme Immunoassay for βh-Endorphin

An avidin–biotin enzyme-linked immunosorbent assay (ELISA) is described for _h-endorphin (_h-EP). Microtiter plates coated with commercially available antibodies were used together with _h-EP tracer derivatives that were biotinylated in positions 24, 28, and 29 via a C₆ spacer arm. Nonspecific binding of biotinylated derivatives to the microtiter plates was blocked with a mixture of 1% casein and 10% ethanolamine in 0.1 M NaHCO₃. A sequential saturation procedure using a high-affinity antiserum in combination with an avidin–alkaline phosphatase complex matched the sensitivity of reported radioimmunoassays (RIAs), with a detection limit of 0.5 fmol/assay. The intra- and interassay coefficients of variation were 5 and 12%, respectively. Results obtained by ELISA and RIA showed good correlations (r = 0.95). The -EP concentration in extracted rat plasma after high-performance liquid chromatographic (HPLC) fractionation was determined by this method to be 1600 fmol/ml.     

Selection for increased pheromone response in the male pink bollworm,Pectinophora gossypiella (lepidoptera: Gelechiidae)

The genetic basis of the duration and incidence of male wing fanning to pheromone in the pink bollworm moth,Pectinophora gossypiella (Saunders), was examined by artificial selection. Using a still-air bioassay, males from a laboratory colony were selected for increased duration of wing fanning when exposed to a 6535 blend of (Z,E)- and (Z,Z)-7,11-hexadecadienyl acetates. The mean (±SE) duration of wing fanning in the selected line increased from 5.4±1.4 to 17.4±2.7 s after six generations. The increase in wing fanning duration was the result of an increase in response duration among responders and not the percentage of males that responded. Realized heritability of wing-fanning duration was 0.16±0.02. The amount and ratio of pheromone produced by females in the male-selected line did not change.This research was supported in part by NSF Grant PCM-8309398 and a University of Massachusetts Biomedical Research Grant.     

The depressing effect of tetracaine and ryanodine on the slow outward current correlated with that of contraction in voltage-clamped frog muscle fibres

The effects of tetracaine (10–50 M) and ryanodine (0.1–10 M) were tested on the slow outward K⁺ current (I _so) and the mechanical tension of isolated frog muscle fibres in a voltage-clamp device (double mannitol-gap) connected to a mechanoelectric transducer. In the concentration range tested, both drugs induced a simultaneous inhibition of tension and current. In all cases the effect on tension was twice that on current. The tetracaine-induced current and tension blocks were fully reversible and dose-dependent. In contrast the ryanodine effects on current and tension were not reversible and did not exhibit a dose dependence except for the delay before the onset of the response, which was shortened when the concentration was raised. Linear regression analysis of the time-dependent and dose-dependent effects of both drugs indicated a strong correlation between the decreases in tension and current. It is concluded that the slow outward current is partly under the control of the Ca²⁺ release from sarcoplasmic reticulum during contraction.     

Comparison of the chelating capacity of EDTA and EGTA, a new demineralized agent, on molars in vitro

Recent morphologic studies have shown qualitative, how demineralizing substances clean teeth roots. In this work we attempt to describe quantitatively the "chelation process" and pH evolution of the quelator solution in-vitro inside the teeth during the reaction. These results indicate that Ca++ coming from hydroxyapatite release protons from EDTAH under neutral conditions. This is the most likely mechanism of the "self-limitation". Furthermore, it allow us to explain why EDTA Im and EGTA Im were more efficient than EDTA Na and EGTA Na upon demineralizing the tooth. EGTA Im turn out to be the fastest demineralizing agent as compared to EDTA Na which is currently employed in endodontic therapy.     

Comparison of mathematically determined blood lactate and heart rate “threshold” points and relationship with performance

Summary The purpose of this study was to investigate the relationship between threshold points for heart rate ( ) and blood lactate (Th_1a) as determined by two objective mathematical models. The models used were the mono-segmental exponential (EXP) model of Hughson et al. and the log-log (LOG) model of Beaver et al. Inter-correlations of these threshold points and correlations with performance were also studied. Seventeen elite runners (mean, SD = 27.5, 6.5 years; 1.73, 0.05 m; 63.8, 7.3 kg; and maximum oxygen consumption of 67.8, 3.7 ml · kg^–1 · min^–1) performed two maximal multistage running field tests on a 183.9-m indoor track with inclined turns. The initial speed of 9 km · h^–1 (2.5 m · s^–1) was increased by 0.5 km · h^–1 (0.14 m · s^–1) every lap for thef _c test and by 1 km · h^–1 (0.28 m · s^–1) every 4 min for the la test. After fitting the la or thef _c data to the two mathematical models, the threshold speed was assessed in the LOG model from the intersection of the two linear segments (LOG-1a; LOG-f _c) and in the EXP model from a tangent point (TI-1a; TI-f _c). Th_1a and speeds computed with the two models were significantly different (P<0.001) and poorly correlated (LOG-1a vs LOG-f _c:r=0.36, TI-1a vs TI-f _c:r=0.13). In general, were less well correlated with performance than Th_1a. With two different objective mathematical models, this study has shown significant differences and poor correlations between Th_1a and . Thus thef _c inflection point with Conconi's protocol is a poor indicator of the la breakpoint with a conventional multistage protocol and a weaker indicator of running performance.     

Postmarketing surveillance-one of the key issues in drug development.

The terms "postmarketing surveillance" or "human phase IV studies" are applied to all those examinations which are performed with a drug following its registration. The principles, methods of these examinations are discussed on the basis of international experiences. The authors also give some examples from Hungarian practice referring to this subject. They consider postmarketing examinations to be as important as the clinical pharmacological examinations preceding the introduction of a drug. The usefulness, role of a drug in the therapy may be definitely determined on the basis of the results of these studies.     

Clonality of cold agglutinins in patients with hemolytic anemia: an analysis by high-resolution two-dimensional gel electrophoresis.

High-resolution two-dimensional gel electrophoresis (2-DGE) was used to analyse plasma samples and partially purified cold agglutinins (CA) obtained from two selected patients. Both presented an acute hemolytic anemia with CA of high thermal amplitude, normal immunoglobulin levels, no detectable paraproteinemia, and no clinical evidence of a malignant B-cell disorder. The electrophoretograms of their plasma showed evident alternations of the "normal" protein profile, which were directly related to hemolysis (absence of the spots of haptoglobin and in one case of those of hemopexin), but no monoclonal gammopathy. The electrophoretograms of their purified CA revealed two clearly different spot patterns respectively corresponding to a monoclonal IgM and to polyclonal IgM. These results show that the clonality of CA associated with hemolytic anemia can be easily determined by 2-DGE. This technique may be very useful to discriminate chronic cold agglutinin disease in the early phase from "parainfectious" CA.