Dynamics of blood clearance of liposomes prepared from nonhydrolyzed diester analog of phosphatidylcholine after intravenous injection into mice

Changes in the content of liposomes prepared from egg phosphatidylcholine and its nonhydrolyzed diester analog 1,2-dipalmitylphosphatidylcholine in the blood and liver in the course of time after intravenous injection of the liposomes into mice were studied. Cholesteryl-[1-¹⁴C]-oleate was used as marked. The kinetics of blood clearance of the two types of liposomes consists of two phases: an initial rapid phase connected with removal of intact liposomes from the blood, and a subsequent slow phase. Replacement of phosphatidylcholine by its diester analog did not cause any delay in the disappearance of liposomes from the blood during the first phase, but reduced the rate of decrease of radioactivity of the blood somewhat during the slow phase. The results show that lipolytic enzymes capable of hydrolyzing the ester bonds in the 1 and 2 positions of phosphatidylcholine evidently do not participate in the mechanisms of removal of intact liposomes from the blood stream. Since liposomes prepared from the diester analog of phosphatidylcholine are rapidly cleared from the blood stream and since they cause unfavorable side effects, they appear to have no prospects for use as drug carriers capable of circulating in the blood stream for a long time.All-Union Cardiologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 8, pp. 160–161, August, 1979.     

Late to early velocity index as a predictor of iatrogenic femoral artery pseudoaneurysm recurrence in patients treated with ultrasound-guided thrombin injection

IntroductionUltrasound-guided thrombin injection (UGTI) is the preferred treatment of pseudoaneurysms (psA). The potential risk of complications increases with the number of UGTI treatments needed for complete psA obliteration. Identification of risk factors for recurrent psA is needed.Material and methodsIn total, 508 patients with femoral artery psA underwent UGTI, followed by ultrasound examination repeated twice, at 1-week intervals, to assess UGTI effectiveness. In cases of psA recurrence, the procedure was repeated. Clinical and ultrasound data were prospectively collected.ResultsThe psA recurrence occurred in 76 (15%) patients. UGTI was repeated twice in 49 (64%), three times in 15 (20%) and more than three times in 12 (16%) patients. The median thrombin dose was 150 IU (80–250 IU), and was lower in initial procedures than repeated UGTI (p = 0.025). The median psA volume was 2.26 ml (0.86–5.47 ml). The median length of the communicating channel was 4 mm (0–12 mm). A time interval between vessel catheterization and UGTI greater than 7 days (p < 0.001), a late to early velocity index (LEVI) of < 0.2 identified during the outflow phase (p < 0.001), a psA volume > 5 ml (p = 0.032), and a short communicating channel between the psA and the artery (p = 0.037) predicted psA recurrence. Antiplatelet and anticoagulant agents did not increase the risk.ConclusionsThe LEVI and time interval between artery cannulation and UGTI treatment are strong parameters identifying patients at risk of psA recurrence. The psA volume and communicating channel length are less substantial risks, but still significant. Concomitant antiplatelet and anticoagulant therapy do not affect the success rate of UGTI.     

Parameters of estrous cycles in albino rats normally and after injection of xenogenic cerebrospinal fluid

We studied biological effects of xenogenic cerebrospinal fluid. Injection of the liquor to albino female rats during different periods of postnatal ontogeny induced changes in the dynamics of estrous cycles. Changes in the picture of vaginal smears, duration of estrous cycles, and proportion between their phases were found. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 8, pp. 213–215, August, 2007     

Plasticity of cerebellar efferents after neonatal lesions in albino rats

In normal adult albino rats the interposed and dentate nuclei project to the contralateral red nucleus, zona incerta (ZI) lateral geniculate nucleus, pars ventralis (LGv), and the thalamic nuclei ventralis medialis (VM), ventralis anterior (VA), ventralis lateralis (VL) and medialis ventralis (MV). Following unilateral cerebellar hemispherectomy with removal of the major parts of the dentate and interposed nuclei at birth, 2 days, 3 days, 5 days and 10 days after birth, cerebellar efferents from the remaining opposite dentate and interposed nuclei were shown to project bilaterally to the red nucleus, ZI, LGV and the thalamic nuclei, VM, VA, VL, and MV. The density of anomalous projections to the various nuclei was greater in animals receiving their initial lesions within the first 5 days after birth, and very much less in animals first lesioned at 10 days postnatally. No anomalous fibre could be detected in animals lesioned at 15 days postnatally. The anomalous fibre formation was correlated with the apparent functional recovery of the animals lesioned within the first 10 days after birth.     

Simultaneous determination of precursors of kallikrein,plasmin, and thrombin and their inhibitors in human blood plasma

Prekallikrein, plasminogen, and prothrombin of human blood plasma are separately activated by kaolin, streptokinase, or thromboplastin. Measurement of the TAME-esterase (TAME: N-tosyl-L-arginine methyl ester) activity of each of the enzymes thus produced and its changes during incubation of the plasma with the activator can be used to estimate the content of kallikrein, plasmin, and thrombin and their inhibitors. Evidence is given that under the conditions of determination as described activation is specific for each enzyme and does not affect the level of the other precursors. The method is developed in modifications enabling the values of seven indices to be obtained with 0.4–0.7 ml of blood plasma.Insitute of General Pathology and Pathophysiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 5, pp. 632–634, May, 1976.     

Distribution of c-Fos immunoreactive neurons in the brain after intraperitoneal injection of apelin-12 in Wistar rats

The present study surveyed activation of central neurons following peripheral administration of apelin-12 (AP12), an apelin peptide homologue, by examining the distribution of neurons expressing c-Fos protein. AP12 is known to induce gastric acid secretion among other physiological functions such as regulation of circulation. It was recently reported that apelin counteracted the effect of arginine vasopressin (AVP) in the maintenance of body fluid homeostasis. We attempted to clarify which neurons in the central nervous system express c-Fos protein after intraperitoneal injection of AP12. Intraperitoneally administered AP12 induced expression of c-Fos protein in several nuclei throughout the brain. In the paraventricular nucleus of the hypothalamus (PAH), lateral hypothalamic area (LH), paraventricular nucleus of the thalamus (PVT), periaqueductal gray matter (PAG), bed nucleus of the stria terminalis (BNST), locus coeruleus (LC), lateral parabrachial nucleus (Pbl), the complex of the solitary tract nucleus (NTS) and dorsal motor nucleus of the vagus nerve (DMX), numbers of neurons expressing c-Fos protein were much higher in test than in control experiments. These findings suggest that AP12 stimulates central neurons that may play roles in the regulation of gastric acid, and hypothalamic neurons that may play roles in the maintenance of body fluid homeostasis as well as other physiological functions.     

Correction effect of ATP on platelet aggregation and blood coagulation <Emphasis Type="Italic">In Vitro</Emphasis> and in the presence of circulating thrombin in rats

ATP added to plasma samples in concentrations of 5×10⁻³−5×10⁻⁵ M in vitro decreased ADP-induced platelet aggregation. Platelet aggregation stimulated with thrombin under similar experimental in vitro conditions significantly decreased in the presence of 5×10⁻⁶ M ATP and tended to decrease under the influence of ATP in concentrations of 5×10⁻³ and 5×10⁻⁷−5×10⁻⁹ M ATP. When endogenous thrombin in the circulation was stimulated by intravenous infusion of tissue thromboplastin, pretreatment with ATP (4 intramuscular injections, 0.75 mg/kg) produced a correction effect and normalized disturbed anticoagulant activity and platelet aggregation. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 4, pp. 364–366, April, 2007     

State of some indices of nonspecific immunity in rats with nephrotoxic glomerulonephritis

Changes in the interferon response of leukocytes, the bactericidal properties of the blood serum againstEscherichia coli andStreptococcus, and activity of -lysins were studied in experimental nephrotoxic glomerulonephritis produced in noninbred male rats by means of heterologous nephrotoxic serum. With this, experimental model changes in the nonspecific defense mechanisms depending on the pathological process in the kidneys could be studied in isolation. In rats with nephrotoxic glomerulonephritis the most marked changes occurred in the interferon response of the leukocytes. It was reduced by up to 90% of the normal level depending on the duration of the disease. By contrast, a change in the indices of antibacterial immunity was observed during the period of marked activity of the nephritic process.Presented by Academician of the Academy of Medical Sciences of the USSR V. D. Solov'ev.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 7, pp. 831–834, July, 1976.     

Kinetics of [14C]phenazepam excretion in albino rats after single and repeated injections of the drug

During the 5 days after intraperitoneal injection of [¹⁴C] phenazepam into albino rats, both intact animals and animals previously receiving phenazepam injections for 15 days, about 77% of the total radioactivity was excreted with the urine and feces. The excretion processes can be described by a first-order equation. The rate of total excretion of phenazepam was identical after single or repeated injections of the drug. Meanwhile, after a single injection of phenazepam into the animals, it was excreted mainly with the urine, whereas after repeated injections it was excreted mainly with the feces. The process of excretion of phenazepam with the urine after repeated injection is biexponential in character.Laboratory of Psychotropic Drugs, I. I. Mechnikov Odessa University. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 6, pp. 561–563, June, 1979.