A secretin i.v. infusion activates gene expression in the central amygdala of rats

For the last 100 years secretin has been extensively studied for its hormonal effects on digestion. Recent observations that the deficits in social reciprocity skills seen in young (3-4-year-old) autistic children are improved after secretin infusions suggest an additional influence on neuronal activity. We show here that i.v. administration of secretin in rats induces Fos protein expression in the neurons of the central amygdala as well as the area postrema, bed nucleus of the stria terminalis, external lateral parabrachial nucleus and supraoptic nucleus. However, secretin infusion did not induce Fos expression in the solitary tract nucleus or paraventricular nucleus, regions normally activated by related peptides such as cholecystokinin. The peak blood levels of secretin that induce Fos protein expression in rat brain are similar to the peak blood levels observed during i.v. treatment with secretin in humans. The amygdala is known to be critical for developing reciprocal social interaction skills and abnormalities in this brain region have been demonstrated in autistic children.     

The i.v. infusion of mannitol decreases airway responsiveness to methacholine in asthma

Bronchial asthma and chronic obstructive pulmonary disease (COPD) are characterized by airway inflammation and oedema. The oedema of the airway wall may contribute to airway narrowing and hyperresponsiveness by increasing airway wall thickness, by altering airway compliance, or by impairing the transmission of the lung elastic recoil to the airway smooth muscle (ASM). We hypothesized that the i.v. infusion of mannitol, an osmotic diuretic, would reduce the water content of the airway wall in asthma and COPD, thus decreasing airway responsiveness to methacholine (MCh). In eight asthmatic and in six COPD patients, airway responsiveness to MCh, lung volumes and lung mechanics were measured before and after infusion of mannitol. In the asthmatics, mannitol decreased airway responsiveness to MCh and lung elastic recoil. In the COPD patients, no differences were recorded after mannitol infusion. These data suggest that the airway wall oedema, in asthma, has an impact on airway responsiveness to MCh. The differential effect of mannitol in asthma versus COPD, may relate to the specific pathologic features of the diseases.     

A mathematical model describing the glycemic response of diabetic patients to meal and i.v. infusion of insulin

Nine type 1 diabetic patients were studied for 24 hours. During this period they were given three calibrated meals. The glycemia was feedback-controlled by means of an artificial pancreas. The blood concentration of glucose and the infusion speed of the insulin were measured every minute. The experimental data referring to each of the three meals were used to estimate the parameters of a mathematical model suitable for describing the glycemic response of diabetic patients at meals and at the i.v. infusion of exogenous insulin. From the estimate a marked dispersion of the parameters was found, both interindividual and intraindividual. Nevertheless the models thus obtained seem to be usable for the synthesis of a feedback controller, especially in view of creating a portable artificial pancreas that now seems possible owing to the realization (so far experimental) of sufficiently reliable glucose concentration sensors.     

Once Daily i.v. Busulfan and Fludarabine (i.v. Bu-Flu) Compares Favorably with i.v. Busulfan and Cyclophosphamide (i.v. BuCy2) as Pretransplant Conditioning Therapy in AML/MDS

We postulated that fludarabine (Flu) instead of cyclophosphamide (Cy) combined with i.v. busulfan (Bu) as preconditioning for allogeneic hematopoietic stem cell transplantation (HSCT) would improve safety and retain antileukemic efficacy. Sixty-seven patients received BuCy2, and subsequently, 148 patients received Bu-Flu. We used a Bayesian method to compare outcomes between these nonrandomized patients. The groups had comparable pretreatment characteristics, except that Bu-Flu patients were older (46 versus 39 years, P < .01), more often had unrelated donors (47.3% versus 20.9%, P < .0003), and had shorter median follow-up (39.7 versus 74.6 months). To account for improved supportive care and other unidentified factors that may affect outcome (“period” effects), 78 acute myelogenous leukemia (AML) patients receiving Melphalan-Flu (MF), treated in parallel during this time (1997-2004) were used to estimate the period effect. The MF patients' outcomes worsened during this period. Therefore, the period effect is unlikely to explain the greatly improved outcome with Bu-Flu. Patients transplanted with Bu-Flu in the first complete remission (CR1) had a 3-year overall survival and event-free-survival (EFS) of 78% and 74%, respectively, whereas CR1 patients younger than age 41 had a 3-year EFS of 83%. These results support replacing BuCy ± ATG with Bu-Flu ± rabbit-antithymocyte globulin (ATG), and warrant a prospective comparison between allogeneic HSCT and conventional induction/consolidation chemotherapy for AML in CR1.     

Response to novelty after i.c.v. injection of melanin-concentrating hormone (MCH) in rats

Some behavioral response of rats to spatial novelty after i.c.v. administration of melanin-concentrating hormone (MCH) were evaluated. To this purpose, an open-field test was used, as well as an elevated plus-maze to study the possible anxiolytic effect of this peptide. In the open field, the frequency of exploratory components (locomotion and rearing) increased after MCH administration in comparison to controls. Moreover, in the plus-maze, MCH increased the number of entries into the open arms as well as the time spent on them, whereas no changes in the number of entries onto the closed arms were found. The data indicate that MCH exerts an anxiolytic effect, and suggests a physiological role for this.     

The role of prostanoids in the feline intestinal vascular and central haemodynamic responses to i.v. infusion of live E. coli

Bacterial infusion in the cat, causing experimental septic shock, induces an early vascular response mainly characterized by pulmonary hypertension and intestinal vasoconstriction. Prostanoids are held to be important mediators of the pulmonary vascular reaction. This study was performed to explore the involvement of prostanoids in the central haemodynamics and the small intestinal vascular reactions in experimental septic shock. Aortic blood pressure was continuously monitored, as were aortic blood flow, the pressure in a. pulmonalis and the small intestinal venous outflow. All cats (n = 24) were given live E. coli (10(10) ml-1) as a continuous intravenous infusion. One series was pretreated with indomethacin, another with UK-38,485, a specific thromboxane A2 synthetase inhibitor, and a third series served as untreated control. The pulmonary hypertensive response was clearly attenuated in the two pretreated series, in fact abolished in the one given UK-38,485. The early intestinal vasoconstriction was eliminated in the two pretreated series. Later during bacteraemia, when untreated and indomethacin-pretreated cats showed intestinal vasoconstriction, UK-38-485-pretreated animals kept intestinal blood flow within the preseptic range. These data suggest that in the cat, thromboxane A2 is the prostanoid mediating the vascular reactions, not only in the lung but also in the small intestine.     

Continuous i.c.v. infusion of brain-derived neurotrophic factor modifies hypothalamic-pituitary-adrenal axis activity, locomotor activity and body temperature rhythms in adult male rats

Brain-derived neurotrophic factor is a neurotrophin belonging to the nerve growth factor family, which is involved in the differentiation and survival of many types of neurons. It also participates in neuroprotection and neuronal plasticity in adult rats. Our previous studies showed that a single brain-derived neurotrophic factor injection modifies hypothalamic-pituitary-adrenal axis activity in adult male rats. To investigate the effect of chronic brain-derived neurotrophic factor administration on some physiological parameters, adult rats were implanted with osmotic micro-pumps to deliver brain-derived neurotrophic factor continuously for 14 days in the lateral ventricle (12 microg/day/rat). mRNA levels were evaluated by in situ hybridization analysis, peptide contents and plasma hormone concentrations by radioimmunoassay. Animals were also equipped with telemetric transmitters to study locomotor activity and temperature rhythms modifications, since hypothalamic-pituitary-adrenal axis is known to modulate these two parameters. Decreased body weight was used as a control of brain-derived neurotrophic factor access to hypothalamic areas as already documented. In the hypothalamus the continuous brain-derived neurotrophic factor treatment increases: (i) the mRNA steady state levels of corticotropin releasing hormone and arginin-vasopressin in the paraventricular nucleus, the supraoptic nucleus, and the suprachiasmatic nucleus; (ii) the surface of corticotropin releasing hormone and arginin-vasopressin mRNA signals in these nuclei as detected by in situ hybridization, and (iii) the corticotropin releasing hormone and arginin-vasopressin contents. The plasma concentrations of adrenocorticotropic hormone and corticosterone were decreased and increased, respectively. Finally, this treatment increased daily locomotor activity and temperature, and provoked some circadian perturbations. These results obtained after chronic brain-derived neurotrophic factor administration extend data on the brain-derived neurotrophic factor involvement in the hypothalamic-pituitary-adrenal axis regulation and illustrate its effects on the locomotor and temperature rhythms. They also allow demonstrating that the regulation of the hypothalamic-pituitary-adrenal axis by brain-derived neurotrophic factor differs according to the brain-derived neurotrophic factor administration mode, i.e. acute injection or chronic administration.     

Myocardial cell damage during experimental infective endocarditis.

Infective endocarditis was induced in 15 catheterized rabbits by a single intravenous injection of Streptococcus viridans and the papillary muscles from the left ventricle were examined for histologic and ultrastructural changes at 3 and 6 days of infection. Papillary muscles from 10 normal and 12 catheterized uninfected animals were used for comparison. Catheterized animals, infected and uninfected, had cardiac hypertrophy and papillary muscles which showed an increase in myofiber size and some interstitial edema. The muscle from infected hearts had areas of focal necrosis, diffuse monocytic infiltration, and loss of normal myocardial architecture. The papillary muscles from catheterized uninfected animals showed some degree of mitochondrial and sarcotubular swelling as well as contracture of myofibrils; the infected myocardium exhibited dramatic changes in ultrastructure such as mitochondrial swelling and destruction, sarcotubular swelling, separation of the intercalated disc, and myofibrillar contracture and disruption. These histopathologic and ultrastructural changes in papillary muscles from rabbits with bacterial endocarditis are indicative of the presence of myocardial cell damage.     

Cardiovascular and behavioural changes after i.c.v. infusions of histamine and agonists in conscious goat

Histamine (3 and 10 moles) raised the blood pressure in the conscious goat when given i.c.v. but lowered it when given intravenously. The results with 2-PEA support the view that central H₁-stimulation raises the blood pressure. However, the results with dimaprit do not exclude the participation of central H₂-receptors in the effect of histamine on the blood pressure.It appears that in the goat the stimulation of central H₁- and H₂-receptors mediates opposite actions on behaviour. H₁-agonist increased and H₂-agonist decreased the general activity of the animal.     

Blood count changes due to mononuclear cell apheresis.

Complete blood count and CFU-GM count of 41 healthy donors was determined immediately before and immediately after mononuclear cell (MNC) apheresis. Red blood cell count dropped from a mean of 5.2 to 4.9 x 10(12)/l, the difference being significant (p less than 0.001). Platelet count was reduced from a mean of 219 to 187 x 10(9)/l, the difference was once again significant (p less than 0.005). Polymorphonuclear cell count did not change significantly, while MNC count was reduced substantially (from mean 3.1 to 2.4 x 10(9)/l, p less than 0.001). The difference between pre- and postapheresis CFU-GM count (median 11.3 versus 8.8 x 10(3)/l respectively) was on the borderline of statistical significance (p = 0.05).     

Metyrapone-induced cardiovascular degenerative changes in non-arteriosclerotic and arteriosclerotic rats.

Virgin and breeder, male and female, Sprague-Dawley rats were unilaterally nephrectomized and given 1% saline drinking water. Animals were injected i.p., twice daily, with a 10 mg/100 g body wt dose of the 11-beta hydroxylation inhibitor, Metyrapone. After 7 weeks of treatment, both the previously nonarteriosclerotic virgin rats and the breeder rats with pre-existing arteriosclerosis developed de nove, widely distributed, intimal hyalinization of their peripheral arteries along with myocardial fibrosis and hyalinization of their intramyocardial coronary arteries. The Metyrapone-treated animals developed severe hypertension with greatly elevated serum creatin phosphokinase, glucose, BUN and cholesterol levels. The adrenal glands, hearts, and kidneys were greatly hypertrophied, in keeping with Metyrapone-induced extra ACTH release and the hypertension-induced myocardial and renal histopathology. Uniparous, Metyrapone-treated, female rats manifested an unusually high incidence of saccular aneurysms of the aorta. It is suggested that the hypertension and the intimal hyalinization and other specific morphologic characteristics of the cardiovascular degenerative changes observed were directly related to excess production of mineralocorticoids, e.g., deoxycorticosterone.     

Development of arteriosclerosis after i.v. administered fat in rabbits

In our previous studies performed in rats sclerotic alterations were induced in the vessel wall by Lipofundin-S 20% (Braun, Melsungen) administration for 8 or 16 days, respectively. In order to elucidate eventual species dependency, studies on rabbits were also performed. Alterations were examined in rabbits after Lipofundin treatment for 8 days. Electron microscopic studies revealed the accumulation of granular basement membrane-like material in the subendothelial space due to the activity of immigrated smooth muscle cells. The formation of elastic granules and elastic laminae was also observed among others due to the coalescence of microfibrillary structures formed from glycoseaminoglycans. The lesion developed was similar to that observed in the rat, the only difference was that in the rabbit the accumulation of the collagen fibres was more prominent. Results of our studies obtained in rabbits appear to support our previous findings: Lipofundin-S treatment induces aortic smooth muscle cell mobilization, fibrillogenesis and enlargement of the subendothelial space, namely sclerotic manifestations are induced.     

Liver damage due to perhexiline maleate.

Two middle-aged men, who had received perhexiline in recommended dosage, showed clinical and histological evidence of severe hepatic damage, and one of them died. Histological study of the livers showed a striking resemblance to alcoholic hepatitis.     

Metyrapone-induced cardiovascular degenerative changes in non-arteriosclerotic and arteriosclerotic rats

Virgin and breeder, male and female, Sprague-Dawley rats were unilaterally nephrectomized and given 1% saline drinking water. Animals were injected i.p., twice daily, with a 10 mg/100 g body wt dose of the 11-beta hydroxylation inhibitor, Metyrapone. After 7 weeks of treatment, both the previously nonarteriosclerotic virgin rats and the breeder rats with pre-existing arteriosclerosis developed de nove, widely distributed, intimal hyalinization of their peripheral arteries along with myocardial fibrosis and hyalinization of their intramyocardial coronary arteries. The Metyrapone-treated animals developed severe hypertension with greatly elevated serum creatin phosphokinase, glucose, BUN and cholesterol levels. The adrenal glands, hearts, and kidneys were greatly hypertrophied, in keeping with Metyrapone-induced extra ACTH release and the hypertension-induced myocardial and renal histopathology. Uniparous, Metyrapone-treated, female rats manifested an unusually high incidence of saccular aneurysms of the aorta. It is suggested that the hypertension and the intimal hyalinization and other specific morphologic characteristics of the cardiovascular degenerative changes observed were directly related to excess production of mineralocorticoids, e.g., deoxycorticosterone.     

Myocardial microcirculation stereological changes in rats subjected to nitric oxide synthesis inhibition

This work aims to study stereological changes in intramyocardial blood vessels in rats submitted to nitric oxide (NO) synthesis inhibition within different periods. NO synthesis inhibition was achieved by administration of L-NAME (50 mg/kg/day); control and L-NAME rats were sacrificed 25 and 40 days after experimentation. Light microscopy and stereology [according to references 7, 13 and 14] were used for analyzing the myocardium. Arterial blood pressure and cardiac weight increased by 74.5% and 57.8% after 25 days and by 90.2% and 34.6% after 40 days, respectively. Comparing the L-NAME rats with corresponding controls revealed that the volume density of the vessels decreased by 31.3% after 40 days, and the length density by 53.5% after 25 days and by 25.7% after 40 days. The mean cross-sectional area of the vessels increased by 154.6% after 25 days. In this study on intramyocardial vessels, we observed an important decrease of the length density in L-NAME animals. Likewise, the volume density also decreased significantly in L-NAME animals. The mean cross sectional area of the vessels, which normally increases during cardiac growth between 25 and 40 days, was precociously increased in L-NAME animals at 25 days, suggesting that these animals suffer from a precocious increase of the heart (including blood vessels) due to pressure overload. Stereology of cardiac microvessels revealed remodeling of these vessels in rats under NO synthesis inhibition. Although these changes may be caused by NO inhibition and not by arterial hypertension, further comparative studies on different models of arterial hypertension are needed to confirm this hypothesis.     

Acquisition of i.v. cocaine self-administration in adolescent and adult male rats selectively bred for high and low saccharin intake

Adolescence and excessive intake of saccharin have each been previously associated with enhanced vulnerability to drug abuse. In the present study, we focused on the relationship between these two factors using male adolescent and adult rats selectively bred for high (HiS) and low (LoS) levels of saccharin intake. On postnatal day 25 (adolescents) or 150 (adults), rats were implanted with an intravenous catheter and trained to self-administer cocaine (0.4 mg/kg) using an autoshaping procedure that consisted of two 6-h sessions. In the first 6 h, rats were given non-contingent cocaine infusions at random intervals 10 times per hour, and during the second 6-h session, rats were allowed to self-administer cocaine under a fixed ratio 1 (FR 1) lever-response contingency. Acquisition was defined as a total of at least 250 infusions over 5 consecutive days, and rats were given 30 days to meet the acquisition criterion. Subsequently, saccharin phenotype scores were determined by comparing 24-h saccharin and water consumption in two-bottle tests to verify HiS/LoS status. Adolescent LoS rats had a faster rate of acquisition of cocaine self-administration than adult LoS rats; however, adolescent and adult HiS rats acquired at the same rate. Both HiS and LoS adolescents had significantly higher saccharin phenotype scores than HiS and LoS adults, respectively. Additionally, saccharin score was negatively correlated with the number of days to meet the acquisition criterion for cocaine self-administration, but this was mostly accounted for by the HiS adolescents. These results suggest that during adolescence, compared with adulthood, rats have both an increased avidity for sweets and vulnerability to initiate drug abuse.     

Immunologic effects of intermediate-dose IL-2 i.v. after autologous hematopoietic cell transplantation in pediatric solid tumors.

Adoptive immunotherapy with interleukin-2 (IL-2) may control minimal residual disease (MRD) and prevent relapse after autologous hematopoietic cell transplantation (AHCT). The objective of this study was to determine the immunologic effects of intermediate doses of intravenous (i.v.) IL-2 after AHCT in children with poor-prognosis solid tumors. Eleven patients received a median five cycles consisting of escalating doses of IL-2 i.v. for 5 days after a median time interval of 94 days post-AHCT. The phenotype of lymphocyte subsets was investigated before and after each cycle, and parallel determination of natural killer (NK) cell activity was performed. Immunotherapy induced a significant increase in total lymphocyte count (TLC), T, NK, and, to some extent, B cells. Among NK cells, CD56+ bright cells expanded more than CD56+ dim cells. High expansion of CD56+ cells with CD94 inhibitory receptor was observed, whereas no difference was recorded in the number of CD3+ CD56+ and CD8+ CD57+ cells. NK activity stabilized after the first cycle of IL-2 and remained elevated during the study period. Cycles of IL-2 immunotherapy induced repeated significant expansion of T cells and NK cells, mostly of the immature CD56+ bright phenotype. Despite enhanced NK activity, relapses occurred frequently, which might have been due to increased CD94 activation and a poor response from the cytotoxic NK T cells and CD8+ CD57+ T cells.