Bivalent engagement of endothelial surface antigens is critical to prolonged surface targeting and protein delivery in vivo.

Targeted drug delivery to the endothelium has the potential to generate localized therapeutic effects at the blood-tissue interface. For some therapeutic cargoes, it is essential to maintain contact with the bloodstream to exert protective effects. The pharmacokinetics (PK) of endothelial surface-targeted affinity ligands and biotherapeutic cargo remain a largely unexplored area, despite obvious translational implications for this strategy. To bridge this gap, we site-specifically radiolabeled mono- (scFv) and bivalent (mAb) affinity ligands specific for the endothelial cell adhesion molecules, PECAM-1 (CD31) and ICAM-1 (CD54). Radiotracing revealed similar lung biodistribution at 30 minutes post-injection (79.3% ± 4.2% vs 80.4% ± 10.6% ID/g for αICAM and 58.9% ± 3.6% ID/g vs. 47.7% ± 5.8% ID/g for αPECAM mAb vs. scFv), but marked differences in organ residence time, with antibodies demonstrating an order of magnitude greater area under the lung concentration vs. time curve (AUCinf 1698 ± 352 vs. 53.3 ± 7.9 ID/g*hrs for αICAM and 1023 ± 507 vs. 114 ± 37 ID/g*hrs for αPECAM mAb vs scFv). A physiologically based pharmacokinetic model, fit to and validated using these data, indicated contributions from both superior binding characteristics and prolonged circulation time supporting multiple binding-detachment cycles. We tested the ability of each affinity ligand to deliver a prototypical surface cargo, thrombomodulin (TM), using one-to-one protein conjugates. Bivalent mAb-TM was superior to monovalent scFv-TM in both pulmonary targeting and lung residence time (AUCinf 141 ± 3.2 vs 12.4 ± 4.2 ID/g*hrs for ICAM and 188 ± 90 vs 34.7 ± 19.9 ID/g*hrs for PECAM), despite having similar blood PK, indicating that binding strength is more important parameter than the kinetics of binding. To maximize bivalent target engagement, we synthesized an oriented, end-to-end anti-ICAM mAb-TM conjugate and found that this therapeutic had the best lung residence time (AUCinf 253 ± 18 ID/g*hrs) of all TM modalities. These observations have implications not only for the delivery of TM, but also potentially all therapeutics targeted to the endothelial surface.

The transcription factor ERG regulates a low shear stress-induced anti-thrombotic pathway in the microvasculature.

Endothelial cells actively maintain an anti-thrombotic environment; loss of this protective function may lead to thrombosis and systemic coagulopathy. The transcription factor ERG is essential to maintain endothelial homeostasis. Here, we show that inducible endothelial ERG deletion (ErgiEC-KO) in mice is associated with spontaneous thrombosis, hemorrhages and systemic coagulopathy. We find that ERG drives transcription of the anticoagulant thrombomodulin (TM), as shown by reporter assays and chromatin immunoprecipitation. TM expression is regulated by shear stress (SS) via Krüppel-like factor 2 (KLF2). In vitro, ERG regulates TM expression under low SS conditions, by facilitating KLF2 binding to the TM promoter. However, ERG is dispensable for TM expression in high SS conditions. In ErgiEC-KO mice, TM expression is decreased in liver and lung microvasculature exposed to low SS but not in blood vessels exposed to high SS. Our study identifies an endogenous, vascular bed-specific anticoagulant pathway in microvasculature exposed to low SS.

[Comparative analysis of amphetamine identification by immunoenzyme assay and gas chromatography with mass spectrometric detection].

The objective of this study was to simultaneously identify amphetamine in biological materials by enzyme-linked immunosorbent assay (ELISA) and gas chromatography with mass spectrometric detection (GH/MS) for the verification of diagnostic value of the proposed ELISA technique. Urine samples from suspected amphetamine and related drug users were available for analysis. It is concluded that the new modification of ELISA can be recommended for application in narcological practice and for the purpose of forensic medical examination.

[The content of biogenic amines in the lymphocytes in bronchial asthma]. / Soderzhanie biogennykh aminov v limfotsitakh pri bronkhial'noi astme.

Serum serotonin and histamine were examined for their effects on lymphocytic dystrophic processes. During an exacerbation, there was an increase in the plasma concentration of biogenic amines (BGA) in patients with atopic and infective-and-allergic bronchial asthma. The elevated levels of BGA affected the activity of lymphocytes that were, on an exacerbation, in the functional stress accompanied by a derangement of adaptive processes that ended in cell dystrophy.

[The catalase activity and lipid peroxidation of donor blood under ultraviolet irradiation]. / Katalaznaia aktivnost' i perekisnoe okislenie lipidov donorskoi krovi pri ul'trafioletovom obluchenii.

Under study were catalase activity and indicators of lipid peroxidation (LP) of donor blood exposed to different doses of UV irradiation. Doses lower than 630 J/m2 were found to activate catalase and to inhibit LP while doses higher than 630 J/m2 inhibited catalase activity and activated LP. The indicators of LP have confirmed that therapeutic doses of UV-irradiated blood were nontoxic. The most optimal therapeutic dose of irradiation (630 J/m2) was determined.

[Red blood function in systematic exposure to +Gz g-forces]. / Funktsional'noe sostoianie krasnoi krovi pri sistematicheskom vozdeistvii peregruzok +Gz.

In 8 healthy men exposed within a year to systematic +Gz accelerations with cycles of 2-month work on centrifuge followed by a month rest the functional state of the red blood cells was studied repeatedly and once in 26 fighter pilots. The blood was tested for such indices as hemoglobin, reticulocyte and erythrocyte counts; the functional state of erythrocyte pool was tested using a modified method of acidic erythrograms enabling one to record kinetic parameters of hemolysis: maximum rate of hemolysis and time of its development. Intensity of loads in the cycles of centrifuging was estimated from the Barton index. It is indicated that one of the effects of systematic exposure to +Gz accelerations is an accelerated destruction of the cells with reduced resistivity a function of exposure intensity. The destructive processes induced by accelerations trigger for a short time the mechanism of compensatory activation of the red blood system. Analysis of diagrams of percentage distribution of the parameters of the erythrocyte function after centrifuge runs of various intensity, and in the pilots revealed a significant compensatory activation of the red blood system only in 25% of pilots. The criterion validity of the indices tested for the system of individual control of the adaptive processes strain in the body is discussed.

[Ultraviolet irradiation of blood in surgery]. / Ultrafioletovoe obluchenie krovi v khirurgii.

The results of complex treatment of 81 patients with pyoinflammatory diseases with the use of blood ultraviolet irradiation are discussed. A marked clinical effect was noted, the terms of treatment reduced by 5-10 days, the outcomes improved, and the number of complications decreased. Irradiation of autologous blood by ultraviolet rays led to modulation of the indices of antimicrobial protection, increase of the intensity of the histochemical reaction to peroxidase up to 40-50%, and diminution of pH in the neutrophil phagosomes to 5.0. The ultrastructure and ability of thrombocytes to store serotonin were restored, and intensity of their metabolic processes increased, the membrane phospholipid composition changed, and juvenile platelet forms appeared.

[Blood lipase activity in cancer patients]. / Lipaznaia aktivnost' plazmy krovi u onkologicheskikh bol'nykh.

Blood plasma lipoprotein lipase level was measured in lung and stomach cancer patients before surgery and during postoperative period. A drop in the enzyme level was observed, particularly, in patients at stage IV. Postoperative infusion and drug therapy was followed by increase in the enzyme activity in stage III disease whereas at stage IV, only a tendency of lipoprotein lipase to rise was observed. Deterioration in patient condition led to a sharp decrease in the enzyme activity.

The "pacemaker" function of the transient outward current in the rabbit myocardium.

The single sucrose gap technique was employed to study the electrically induced automaticity in rabbit papillary muscles. When the potential was clamped at the level of the "maximum diastolic potential" following the first spike of automaticity an initial decline of the outward ionic current with subsequent activation of the delayed potassium current was observed. The initial decline was potential-sensitive with a maximum at approximately -2 mV; it diminished when the rate of stimulation increased and was abolished with 4-aminopyridine plus Sr2+. It is suggested that the transient outward current determines the development of the "pacemaker potential" after the first spike of electrically induced automaticity in rabbit papillary muscles.

[Electroacupuncture and arrhythmia caused by reperfusion of the coronary arteries in rabbits and rats in hypothermia]. / Elektroakupunktura i aritmii, vyzvannye reperfuziei koronarnoi arterii krolikov i krys v usloviiakh gipotermii.

Reperfusion-induced arrhythmias in rats and rabbits are highly temperature-dependent. When the rectal temperature of experimental animals was low, the effects of electroacupuncture at Jian Xi on reperfusion-induced arrhythmias could be observed. The arrhythmias shortened in rabbits, and more ventricular extrasystoles following reperfusion were seen in rats. It is suggested that electroacupuncture at Jian Xi can exert significant influence on reperfusion-induced arrhythmias.

[Reflexotherapeutic effects on biologically active points of the concha auriculae]. / Issledovanie refleksoterapevticheskikh vozdeistviiakh na biologicheski aktivnye tochki rakoviny.

By means of histochemical method, for revealing cholinergic nervous structures, and electron microscopy, innervation of biologically active points (BAP) and that of neutral areas of the rabbit ear skin has been studied, normal and after acu-, electro- and electroacupuncture. The BAP have more intensive vascularization and innervation, their specific feature is presence of well pronounced nervous fasciculi. The latter are formed by 6-10 fibers 1-6 mcm in diameter. The diameter of the fasciculi is within the limits 25-30 mcm up to 40-45 mcm. Under the electron microscopic investigation myelin and amyelin fibers are revealed in the nervous fasciculi. In the area of the epidermal basal layer and in the epidermis itself, single nerve terminals are found; they are considered as the point pain receptors. After acu-, electro- and electroacupuncture, intensity of the nervous fibers staining increases, thus demonstrating an increment of acetylcholine esterase activity. After insertion of acupuncture needles and after electrical irritation, the changes in the nervous and cellular elements in the BAP areas are studied electron microscopically. After the effects mentioned, mast cells situating in the BAP area become, as a rule, degranulated. After repeated electroacupuncture irritation of the BAP, an inflammatory focus appears with peculiarities specific for the given process. The reflexotherapeutic effect is supposed to be transferred via the nervous system. The mechanical irritation of the nerve fasciculi and the accompanying traumatization of the surrounding cellular elements initiate the mechanism of reflexotherapy.

[Ultrastructure of the skin after electroacupuncture]. / Ul'trastruktura kozhi pri élektroakupunkture.

Electron-microscopic examination of the nervous apparatus of the acupuncture points of the rabbit ear has shown that the motor receptor structure of reflexotherapeutic impacts seems to be bundles of nerve fibers with their microenvironment--blood vessels, mast cells, histiocytes. Acupuncture with electrical stimulation and acupuncture based on direct mechanical impact (trauma, compression) and the resultant local inflammation irritate the nerve conductors and initiate the effects of reflexotherapy.

[Ultrastructure of various ganglia of autonomic nervous system of the human embryo at the beginning of the mediator stage of ontogeny]. / Ul'trastruktura nekotorykh gangliev vegetativnoi nervnoi sistemy zarodysha cheloveka v nachale mediatornogo étapa ontogeneza.

Neural ganglia of the heart and stomach, paravertebral and spinal ganglia have been studied electron microscopically in 8-10-week-old human embryos. Amateur neurons in the ganglia are at various stages of differentiation and sometimes they are not divided with glia. In the cardiac ganglia the most mature neural elements are defined, comparing to other ganglia studied. It is demonstrated both in the developmental degree of cellular organelles, including those of the granular endoplasmic reticulum, and in manifestation of the glial tunic. Synaptic contacts at the stage of their formation are revealed in the intracardiac and sympathetic (paraventral) neural ganglia.