The effect of ritodrine on PgE levels in pregnant rabbit vena cava blood

A chronic model was utilized in the rabbit to determine the effect of ritodrine hydrochloride infusions on pregnancy. Infusions were carried out for 6 hours in the unanesthetized, conscious animal between the 25 to 27 day of pregnancy. Pre and post infusion blood samples were drawn from a catheter lying at the lower inferior vena cava and analyzed for prostaglandin E and F, and progesterone. As compared to a control animal, there was a significant fall in prostaglandin E after 6 hour infusion of drug, but no change in prostaglandin F or progesterone was observed.     

The individualization of activities of blood vessels]

Due to its short half life and high tryptophan content, prealbumin has been considered a sensitive indicator of protein and/or energy deficiency. In addition, prealbumin diminishes during the acute phase response elicited by either infection or tissue injury. Serum levels of prealbumin were determined in undernourished children with or without associated clinical infection and in their infected or non-infected controls matched for age, sex, race and socioeconomical conditions. Serum levels of prealbumin were significantly lower in undernourished than in control children without overt infections. On the other hand, the concentrations of serum prealbumin diminished significantly and to similar levels both in undernourished and control children with associated clinical infection as compared with those observed in non infected children belonging to the similar nutritional status. A positive correlation was found between prealbumin level and the Z-scores of weight-for-age, height-for-age and weight-for height in children without associated infections, which disappeared in clinically infected patients. Thus, prealbumin is a marker of undernutrition in the absence of infection and could be an earlier and more sensitive indicator of actual undernutrition caused by the metabolic effects of acute phase cytokines, than the anthropometrical measurements used here.     

Thrombosis of the superior vena cava, hemolytic anemia and hyper-homocysteinemia]

A case of zoonotic Mycobacterium tuberculosis infection in a marmoset (Callithrix jacchus) is reported. Genomic typing of the relevant M. tuberculosis isolates strongly suggests that the marmoset, which was kept as companion animal, acquired the disease from an infected member in the household who had been treated for pulmonary tuberculosis 8 years prior to this case.     

Treatment of acute thrombosis of the system of the inferior vena cava

Burkitt's lymphoma in Africa may be curable by chemotherapy alone; in nonendemic regions results are reportedly less favorable. Fifty-four Americans with Burkitt's lymphoma were treated with two sequential combined treatment regimens that incorporated therapeutic approaches from clinical trials in Africa. Four patients died during induction therapy, and 48 of the remaining 50 achieved complete remissions. Twenty-two relapsed at a median of three months from the start of therapy. The overall two-year actuarial survival was 54 percent: younger patients ( less than 12 years old) and patients with minimal tumor burden (stages A, B and AR) had significantly better survivals than older patients (P less than 0.02) and patients with advanced abdominal tumors (stages C and D) (P less than 0.01). No differences in survival were detected between patients treated at the National Institutes of Health and those treated in regional institutions on either protocol. Complete response rates, relapse frequency and survival in American patients are similar to results in Africa.     

Changes in resistance and capacitance functions of skeletal muscle vessels during the amplitude-frequency modulation of the perfusion blood flow

Changes of venous outflow, pre- and postcapillary resistance of the skeletal muscle vessels were found to depend on values of amplitude and frequency of the perfusion blood flow in cats. Three types of the responses were distinguished: either increase, or decrease, or absence of them. The findings suggest a possibility to affect haemodynamic parameters with the aid of amplitude-frequency deviations in the organ blood flow.     

The effects of treatment with lipopolysaccharide on responsiveness of rat blood vessels

Effects of treatment with lipopolysaccharide (LPS) both in vivo (intraperitoneal administration of 20 mg.kg-1 LPS for 6 hours) and in vitro (incubation with 1 microgram.kg-1 LPS for 6 hours) on the responsiveness of the rat thoracic aorta, carotid, renal, femoral, mesenteric, pulmonary arteries, and the femoral and mesenteric veins were examined. Intraperitoneal administration of LPS did not change the blood pressure of rats, but increased the heart rate significantly. The same amplitude of relaxation was produced by L-arginine in the aortic strips treated by LPS in vivo and in vitro, and the responses were inhibited by NG-nitro-L-arginine (L-NOARG). The contractile responses to phenylephrine in the aortic strips were reduced by LPS-treatment in vivo or in vitro, but the extent of inhibition was greater in vivo than in vitro. Further, the attenuation of contractile responses to phenylephrine was completely reversed by L-NOARG in the strips treated with LPS in vitro, whereas the reversal by L-NOARG was incomplete in the strips treated with LPS in vivo. Different amplitudes of relaxations were also produced by L-arginine or SNP in the blood vessels treated by LPS in vivo or in vitro. However, the tail artery treated with LPS in vivo or in vitro did not relax in response to L-arginine but did produce a relaxation to SNP. These results suggest that the hyporesponsiveness of rat blood vessels after treatment with LPS in vivo or in vitro may be related to an enhanced NO production in the smooth muscle cells and that there is a possible heterogeneity of regional induction or activation of L-arginine/NO pathway by LPS in rat blood vessels.     

Morpho-functional characteristics of the uterine blood vessels and other systemic vessels of the abdominal cavity in pregnancy]

Biostereometrics-the spatial and spatio-temporal analysis of biological form and function based on principles geometry-is a modern approach to the measurement and analysis of biological form which recognizes that organic structures are irregular and three-dimensional (or four-dimensional, as in movement or growth). Stereometric sensors of various types are used to determine the coordinates of points distributed over the surface (internal or external). The resulting data provide a more comprehensive, parsimonious and unambiguous spatial quantification than heretofore possible using traditional lengths, breadths, and circumferences. Recent and prospective biomedical applications are described.     

Dependence of cardiovascular effects of adenosine on the blood circulation type in rats

Administration of adenosine increased the RR interval in greater degree at hyper- than in hypodynamic blood circulation type. The AV-blockade and atrial flutter were maximal in rats with hyperdynamic type of blood circulation. Propranolol weakened the adenosine cardiotropic effect whereas cholinoblockators enhanced it. Neurohumoral regulation exerted no effect on the adenosine hypotensive action.     

Dissection of the inferior vena cava by Fogarty balloon maneuver. A rare complication in venous surgery]

Laceration of the inferior vena cava is an uncommon complication of vascular surgery. This report describes the radiologic features (CT and venography) of a patient with iatrogenic dissection and perforation of the vessel as a sequel of a Fogarty balloon procedure for deep venous thrombosis.     

Relatively immediate relaxant effects of cholera toxin on isolated rabbit blood vessels

A study was made on the relatively immediate relaxant effect of cholera toxin (CTX) on the isolated ear artery, thoracic aorta and saphenous vein of the rabbit. Both preparations of CTX, containing sodium azide (NaN3) and azide-free, showed no effect on the non-precontracted artery, but CTX containing NaN3 relaxed the moderately precontracted blood vessels with methoxamine promptly, i.e., with a time course of min order. However, the immediate relaxation produced by CTX containing NaN3 was attributed mainly to NaN3. Azide-free CTX, on the other hand, at 1-10 micrograms/ml gradually produced concentration-dependent relaxation of the precontracted vessels. The relaxant effects of CTX on the vessels were slow and long-lasting, i.e., with a time course of 10 min order. The relaxation induced by CTX was not influenced by the removal of endothelium nor by pretreatment with 10 microM indomethacin, 3 microM atropine or 3 microM propranolol. Activation of protein kinase C by a phorbol ester inhibited the relaxant effect of CTX. These results indicate that CTX relaxes the blood vessels by directly acting on the smooth muscles, without mediation by known endogenous relaxing factor, such as endothelium-derived relaxing factor (EDRF = NO) or prostaglandin I2 (prostacyclin) and by muscarinic receptor or beta-adrenoceptor.     

The formation of blood system tolerance in rats to the repeated action of a stressor stimulus

Repeated immobilisation induced a biphasic dynamic of the blood system stress sensitivity: first, an increased neutrophilia, lymphocytopenia, bone marrow granulocyte depletion and activation of the erythropoiesis; second, a restitution of mature granulocyte-monocyte cells number in the bone marrow and accumulation of neutrophils in the spleen.     

Protective effect of N-acetyl-L-cysteine on the renal failure induced by inferior vena cava occlusion

BACKGROUND: Renal ischemia is produced during orthotopic liver transplantation when the inferior vena cava is clamped above the renal veins (inferior vena cava occlusion [IVCO]), and it often leads to postoperative renal failure. Although free radicals and nitric oxide (NO) have been implicated in the pathogenesis of ischemic renal failure, the effect of free radical scavengers in this model is unknown. METHODS: The effects of N-acetyl-L-cysteine (NAC), a free radical scavenger, on the acute renal failure that follows IVCO were evaluated in pentobarbital-anesthetized dogs. The effect of NO synthesis inhibition with NG-nitro-L-arginine methyl ester (NAME) was also studied. Renal vascular endothelial function was tested by infusing acetylcholine (Ach) into the renal artery before the ischemia and during reperfusion. RESULTS: Renal failure developed during IVCO and persisted during reperfusion in all groups. However, in NAC-pretreated dogs, the glomerular filtration rate recovered progressively, reaching 31% of basal preischemic values 150 min after reperfusion. During reperfusion, fractional excretion of sodium increased above preischemic values only in the control group, which indicates a beneficial effect of NAC and NAME on the tubular dysfunction observed during reperfusion. The renal response to Ach was abolished in control dogs and in animals given NAME during reperfusion, which indicates endothelial dysfunction. However, in NAC-pretreated dogs, the renal response to Ach was preserved during reperfusion. CONCLUSIONS: These results demonstrate that NAC ameliorates the renal failure and renal endothelial dysfunction induced by IVCO. This protective effect was abolished by NAME, which suggests that NO is involved in the beneficial effects of NAC. These data also suggest that the use of NAC could be beneficial in ameliorating the acute renal failure observed after orthotopic liver transplantation.     

Effect of inferior vena cava occlusion on left ventricular end-systolic pressure-volume relations in intact canine hearts--modulation by the autonomic nervous system

The effect of inferior vena cava occlusion (IVCO) on end-systolic pressure-volume relations (ESPVR) of the left ventricle was studied in intact canine hearts. In 12 anesthetized open-chest dogs, left ventricular (LV) pressure and volume were measured simultaneously using a microtip catheter and a conductance catheter, respectively. ESPVR was constructed from LV pressure-volume loops during IVCO (10 sec) and subsequent IVCO release under 5 conditions: control, after righ or left cardiac sympathetic nerve (CSN) stimulation, bilateral vagotomy (VAT), and both VAT and bilateral CSN resection. Emax in IVCO release was significantly greater than that in IVCO in the control state. Following right or left CSN stimulation, Emax was increased increased in both IVCO and IVCO release, with the same hysteretic change in Emax. With VAT, however, no hysteretic change was observed because Emax was the same in IVCO and IVCO release. After VAT and CSN resection, Emax was decreased in both IVCO and IVCO release, and again no hysteretic change was observed. These data imply that a sudden decrease in venous return into the heart induces a decrease in afferent vagal nerve activity, and thus increases efferent CSN activity, resulting in enhanced myocardial contractility.     

The discriminative stimulus effects of clomethiazole in the rat

Rats were trained in a two-lever drug discrimination procedure using saline or clomethiazole (8 mg/kg, s.c. 15 min) as the training stimuli. A criterion of 9/10 days correct lever choice was adopted to select rats for substitution tests. The clomethiazole (CMZ) cue was not especially strong, and stable performance at this level was not achieved consistently. Nevertheless, in a series of substitution tests carried out in extinction, diazepam (3 mg/kg), chlordiazepoxide (10 mg/kg), phenobarbital (60 mg/kg), dizocilpine (0.1 mg/kg) and mianserin (3.0 mg/kg) were found to substitute for the training dose of CMZ. The first two of these produced a percentage choice of the drug lever equal to that produced by the training dose of CMZ (full generalization) whereas the latter three produced only partial generalization. Ethanol, muscimol, allopregnanolone, chlorpromazine and amitriptyline did not generalize to CMZ. CMZ is known to potentiate gamma-aminobutyric acid (GABAA) receptor function, a finding supported by the generalization to CMZ of the two benzodiazepines and phenobarbital. However, not all drugs acting at GABAA receptors generalized to CMZ. Although CMZ has no affinity for the N-methyl-D-aspartate (NMDA) receptor, it antagonizes a number of pharmacological responses mediated by NMDA receptors. The generalization in the drug discrimination procedure reported here support the suggestion that altering GABA activity can modulate NMDA-mediated responses. The lack of generalization after treatment with ethanol, chlorpromazine and amitriptyline suggests that the interoceptive cues are not mediated by a generalized sedation or drug-induced motor impairment.     

The significance of blood vessels on both sides of the growth plate

A new 3-D presentation of the whole vasculature of the epiphyseal growth plate clearly allows for a distinction between arterial and venous sections of the blood circulation. Histological investigations using these processing methods could neither prove the connection between epiphyseal and metaphyseal vessels through the growth plate in newborns nor the concept of an arterial epiphyseal blood supply of the growth plate presented by Trueta. It is rather a question of an arterial metaphyseal perfusion and an epiphyseal venous drainage system.