Vasopressin receptors in the mouse (Mus musculus) brain: sex-related expression in the medial preoptic area and hypothalamus

We have investigated the distribution of vasopressin binding sites in the brain of male and female adult mice using a radio-iodinated ligand and film autoradiography. Vasopressin receptors were uncovered in various regions of the brain including the basal nucleus of Meynert, the substantia innominata, the hypothalamic paraventricular nucleus, the substantia nigra pars compacta and the hypoglossal nucleus. A sex-related difference in the expression of vasopressin receptors was seen in the medial preoptic area/anterior hypothalamus corresponding to the rat sexually dimorphic nucleus in the rat and in the hypothalamic mammillary nuclei. In both structures the autoradiographic labeling is more intense in females than in males. These observations confirm that vasopressin binding sites are present in the hypothalamic preoptic area of most species examined so far and that sex-related expression of neuropeptide receptors could trigger sex-related behavioral differences.     

Topography of the oxytocin receptor system in rat brain: an autoradiographical study with a selective radioiodinated oxytocin antagonist

A new, highly selective radio-iodinated oxytocin receptor antagonist [( 1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic acid, 2-O-methyltyrosine, 4-threonine, 8-ornithine, 9-tyrosylamide]-vasotocin) was used to identify and quantitate specific binding sites for the neurohypophyseal hormone oxytocin with in vitro incubation of rat brain sections and autoradiography. Exclusively oxytocin binding sites were detected in view of the high affinity of the [125I]-labelled oxytocin antagonist for oxytocin binding sites and the negligible affinity for the vasopressin liver (V1) and kidney (V2) receptor types. The putative oxytocin receptors were abundantly present in several brain regions, where previously discrimination between oxytocin and vasopressin binding was difficult, i.e. the olfactory nucleus, the islands of Calleja, the ventromedial nucleus of the hypothalamus, the central amygdaloid nucleus and the ventral subiculum of the hippocampus. In addition oxytocin receptors were demonstrated in other areas, such as the taenia tecta, dorsolateral caudate putamen, ventral pallidum, accumbens, lateral septum, bed nucleus of the stria terminalis, thalamic paraventricular nucleus, lateral, basolateral and medial amygdala, the dorsal subiculum, perirhinal cortex and the amygdaloid-hippocampal area. The high affinity and the low detection threshold of this [125I]-labelled oxytocin antagonist permitted identification of oxytocin receptors in new regions such as the ventral part of the lateral septum, medial septum, dorsal motor nucleus of the vagus nerve and the olive nuclei in the brain stem.     

Fluorescent pseudo-peptide linear vasopressin antagonists: design, synthesis, and applications

Fluoresceinyl and rhodamyl groups have been coupled by an amide link to side-chain amino groups at positions 1, 6, and 8 of pseudo-peptide linear vasopressin antagonists (Manning et al. Int. J. Pept. Protein Res. 1992, 40, 261-267) through different positions on the fluorophore, to give tetraethylrhodamyl-DTyr(Me)-Phe-Gln-Asn-Arg-Pro-Arg-Tyr-NH2 (2), 4-HOPh(CH2)2CO-DTyr(Me)-Phe-Gln-Asn-Lys(5-carboxyfl uoresceinyl)-Pro-A rg-NH2 (4), 4-HOPh(CH2)2CO-DTyr(Me)-Phe-Gln-Asn-Lys(5- or 6-carboxytetramethylrhodamyl)-Pro-Arg-NH2 (5, 6), 4-HOPh(CH2)2CO-DTyr(Me)-Phe-Gln-Asn-Arg-Pro-Lys(5- or 6- carboxyfluoresceinyl)-NH2 (8, 9), and 4-HOPh(CH2)2CO-DTyr(Me)-Phe-Gln-Asn-Arg-Pro-Lys(5- or 6- carboxytetramethylrhodamyl)-NH2 (10, 11). The closer to the C-terminus the fluorophore, the higher the affinities of the fluorescent derivatives for the human vasopressin V1a receptor transfected in CHO cells. The compound 10 has a Ki of 70 pM, as determined by competition experiments with [125I]-4-HOPhCH2CO-DTyr(Me)-Phe-Gln-Asn-Arg-Pro-Arg-NH2. It showed a good selectivity for human V1a receptor versus human OT (Ki = 1.2 nM), human vasopressin V1b (Ki approximately 27 nM), and human vasopressin V2 (Ki > 5000 nM) receptor subtypes. All fluorescent analogues were antagonists as shown by the inhibition of vasopressin induced inositol phosphate accumulation. These fluorescent ligands are efficient for labeling cells expressing the human V1a receptor subtype, as shown by flow cytofluorometric experiments or fluorescence microscopy. They are also appropriate tools for structural analysis of the vasopressin receptors by fluorescence.     

Measuring complexity/level of care and appropriateness of resource use in intensive care units

BACKGROUND: Throughout the world, the cost of critical care medicine is increasing more than the overall health care cost. Thus, a higher attention to improve the efficiency of the use of ICU resources is indispensable. The objective of this study was the development of a simple and reliable tool for the evaluation of the appropriateness of ICU utilization. METHODS: Design: A repeated cross-sectional data collection was performed twice a week, during a 61-day study period. Setting: Twenty-three Italian general ICUs. Patients: All patients present in the 23 ICUs on the 17 index days. Interventions: On each index day, patients were checked for receiving ventilation/CPAP, pulmonary arterial pressure monitoring, intracranial pressure monitoring, vaso-active drug infusion and hemodialysis-ultrafiltration. Simultaneously, each ICU bed was assessed for its technical and personnel facilities in order to estimate the deliverable level of care. RESULTS: A total of 1250 patients were studied, for a total number of 7533 patient-days. The overall occupancy rate per ICU was 83.8% (-range: 54.4% to 96.1%). The high-level occupancy rate (rate of patients requiring high level of care and actually occupying high-facility beds) was 69.4% (range: 25.0% to 149.0%), while the corresponding low-level occupancy rate was 101.1% (range: 31.3% to 329.4%). CONCLUSIONS: Our model clearly showed up a certain degree of inappropriateness in the use of ICU resources. Most of the ICUs (69.6%) used a very large proportion of their high-facility beds for patients who did not need high-level care. Being very simple, our method could represent a useful tool for continuous evaluation of the appropriateness of resource utilization in the ICU.     

Human fluids alter DNA-acquisition in Acinetobacter baumannii

Transformation is one of the mechanisms of acquisition of foreign genetic material leading to the emergence of multidrug resistant (MDR) bacteria. Recently, human serum albumin (HSA) was shown to specifically increase transformation frequency in the nosocomial pathogen Acinetobacter baumannii. To further assess the relevance of HSA as a possible modulator of A. baumannii transformation in host-pathogen interactions, in this work we examined the effect of different human fluids. We observed a significant increase in transformation frequencies in the presence of pleural fluid, whole blood cells and liquid ascites, and to a lesser extent with urine. The observed effects correlate with both HSA and bacterial content found in the assayed patient fluids. Taken together, these results are in agreement with our previous findings that highlight HSA as a possible host signal with the ability to trigger natural transformation in A. baumannii.     

Mathematical and Pharmacokinetic Approaches for the Design of New 3D Printing Inks Using Ricobendazole

Pharmaceutical Research - 3D printing (3DP) makes it possible to obtain systems that are not achievable with current conventional methods, one of them, sustained release floating systems. Floating...     

Biosynthetic studies and gamma-chain composition in the Greek type of hereditary persistence of fetal hemoglobin and in its association with beta-thalassemia.

Hematological data, biosynthetic studies and gamma-chain structure of three heterozygotes for HPFH Greek type and of two heterozygotes for both HPFH and beta-thalassemia are reported. In the HPFH heterozygotes, hematological data were normal and globin chain synthesis balanced, while subjects carrying both HPFH and beta-thalassemia presented a thalassemic picture and the same degree of alpha/non-alpha-chain imbalance as the beta-thalassemia carrier belonging to the same family. The gamma-chain composition studies showed only the presence of Agamma-chains in HPFH; in the association HPFH/beta-thalassemia also some Ggamma and Tgamma were found. The mechanisms determining the high production of Hb F in the association HPFH/beta-thalassemia are discussed.