Cardiovascular and abdominal motor responses evoked by intravenous neurotensin in guinea pigs

Developing T cells in the thymus are subject to a screening process, through interactions with thymic stromal cells, from which T cells with appropriate T-cell receptors are selected. The recent generation of T-cell receptor transgenic mice and mice homozygous for disrupted T-cell receptor genes have now supplied tools that improve the prospect for a better understanding of the molecular mechanisms of this thymic selection process. In addition these model systems appear to indicate a role for a, not yet fully characterized, pre-T cell receptor complex in survival and further differentiation of pre-T cells.     

Hypomagnesemia following correction of metabolic acidosis: a case of hungry bones

Severe symptomatic hypomagnesemia (0.15 mmol/L [0.3 mEq/L]) and hypocalcemia (1.47 mmol/L [5.9 mg/dL]) occurred in a 4-week-old infant coincidental with correction of a severe renal tubular acidosis with alkali therapy. The patient had no evidence of gastrointestinal abnormality and magnesium (Mg) intake was adequate for age and weight. Extreme renal conservation of Mg was observed, supporting the presence of Mg depletion. We suggest that Mg depletion in this infant occurred due to acidosis-induced bone demineralization and that symptomatic hypomagnesemia was precipitated by rapid remineralization accompanying correction of systemic acidosis. This patient represents a novel case of hungry bone syndrome (HBS). Since HBS has not been described previously in patients with acidosis undergoing therapy, several other factors may have contributed to this patient's severe hypomagnesemia, namely, prematurity, twin status, severity of acidosis, rapidity of correction of acidosis, catch-up growth and calcium supplementation. Clinicians should be vigilant for HBS in infants with severe acidosis undergoing alkali therapy.     

Design of nonaxisymmetrical image intensifiers

The concept of a nonaxisymmetrical X-ray image intensifier is presented in this paper. Instead of cylindrical electrodes, as in the conventional device, this intensifier is equipped with planar electrodes. Each one consists of some number of elementary quadrilateral patches, which are mutually insulated from each other and supplied with the proper voltages. The algorithm for determining potentials which must be supplied to the elementary electrodes is described in the paper. The algorithm has been validated by comparing the electric field distributions in both configurations. Details of the electric field distribution are also helpful in evaluating the optical characteristics of the intensifier     

Interleukin 8 (IL-8) induces the expression of kinin B1 receptor in human lung fibroblasts

Near-haploidy is a rare cytogenetic finding in childhood acute lymphoblastic leukaemia (ALL) and is associated with a poor prognosis. A second hyperdiploid line, occurring presumably by endoreduplication of the near-haploid stemline, is often observed. We present a case of common ALL in relapse characterized morphologically by a dual population of small and large lymphoblasts. Cytogenetic analysis supplemented with fluorescence in-situ hybridization (FISH) studies localized near-haploidy and hyperdiploidy to the small and large blast population respectively. DNA ploidy determination confirmed two abnormal clones with near-haploidy as the predominant one. A novel t(9;12)(q11;q13) was present in the near-haploid clone and was duplicated in the hyperdiploid clone. This finding identified cells bearing near-haploidy to be the clonogenic population following malignant transformation and confirmed endoreduplication as the mechanism for the presence of associated hyperdiploidy.     

Molecular structure and stereoelectronic properties of sarmazenil--a weak inverse agonist at the omega modulatory sites (benzodiazepine receptors): comparison with bretazenil and flumazenil

X-ray diffraction and ab initio MO theoretical calculations were used in order to investigate the structural and electronic properties of sarmazenil, a weak inverse agonist at the omega modulatory sites (benzodiazepine receptors). This compound was compared to bretazenil, a partial agonist, and to the antagonist flumazenil on the basis of structural and electronic data. The conformational and theoretical properties (interatomic pi overlap populations, molecular electrostatic potential (MEP), the topology of frontier orbitals, and proton affinity) of these three imidazobenzodiazepinones were determined in order to analyse the stereoelectronic properties in relation with their distinct intrinsic efficacies at the omega modulatory sites.     

High levels of interleukin-12 in the aqueous humor and vitreous of patients with uveitis

OBJECTIVE: This study aimed to investigate the role of interleukin-12 (IL-12) and interleukin-10 (IL-10) in initiation and maintenance of intraocular inflammation. DESIGN: Case series. PARTICIPANTS: Aqueous humor and vitreous levels of IL-12 and IL-10 were measured in 22 patients with uveitis undergoing cataract surgery, paracentesis of the anterior chamber, and/or vitrectomy for diagnostic reasons, and in 4 patients with cataract only. INTERVENTION: Aqueous humor and vitreous levels of IL-12 and IL-10 were measured with specific enzyme-linked immunosorbent assays. MAIN OUTCOME MEASURES: Disease activity was correlated to IL-12 levels in the aqueous humor and the vitreous of patients with uveitis. RESULTS: Cytokine levels found in the anterior chamber and the vitreous are presented in picogram/milliliter (medium; range). The highest IL-12 levels were found in patients with active uveitis (108.5 pg/ml; 72-293 pg/ml). Interleukin-12 in patients with moderate uveitis or with their disease in remission was lower (32 pg/ml; 15-94 pg/ml) than in patients with active disease (P > 0.001) but higher than in the control group (10.5 pg/ml; 9-14 pg/ml). Interleukin-10 was detectable in only 3 of 22 patients with uveitis (12 pg/ml; 9-23 pg/ml). CONCLUSION: The authors found statistically significant differences of IL-12 levels in the various patient groups (active vs. inactive vs. control). These results support the idea that these uveitis cases represent type 1 (Th1)-T lymphocyte-mediated diseases in which IL-12 plays a pivotal role in the initiation and maintenance of the intraocular inflammation. The high levels of IL-12 in the vitreous and/or aqueous humor of the patients with uveitis suggest that susceptibility or resistance to ocular autoimmunity may be connected to a genetic predisposition to an elevated Th1 response.     

Limits of the output power in Er3+:ZBLAN singlemodefibre lasers

The saturation of the 2.71 μm laser output has been measured in erbium-doped ZBLAN singlemode fibres with Er³⁺ concentrations of 1000, 5000 and 10000 ppm mol. Limits of the single-mode-laser output are discussed     

Acamprosate and alcohol: I. Effects on alcohol intake following alcohol deprivation in the rat

Acamprosate (calcium-acetyl homotaurinate) is a new compound in the treatment of alcoholism. Its efficacy has been proven in several clinical trials and registration is now pending in most European countries. The basic mechanisms by which acamprosate elicits its anti-craving action, thereby leading to reduced relapse rates, is not known at the moment. In the present study we describe a rat model of long-term alcohol-drinking which mimics relapse behavior in human alcoholics. The effect of acamprosate was studied in this model. Wistar rats had a free choice between water and alcohol solutions of different concentrations (5, 10, 20% v/v). After two months of continuous alcohol access, rats were deprived of alcohol for three days. Following this deprivation phase, all alcohol solutions were presented again. This procedure was repeated monthly for the following six months. The rats consumed 3.5 +/- 0.3 g/kg alcohol a day. After alcohol deprivation, alcohol intake rose to 5.2 +/- 0.3 g/kg per day resulting in blood alcohol levels of 30 +/- 6 mg/dl. Interestingly, the addition of quinine to the alcohol solutions or the additional presentation of a 5% sucrose solution did not affect the alcohol-deprivation effect after eight months of this intermittent alcohol exposure. However, when acamprosate (50-200 mg/kg i.p.) was administered twice daily, alcohol-drinking following an alcohol-deprivation phase was decreased dose dependently. Given at the highest dose alcohol intake even dropped significantly below baseline drinking. Together, these results show that acamprosate effectively diminishes the alcohol-deprivation effect. Furthermore, the described model seems to be a suitable animal model to screen compounds for their anti-relapse properties and subsequently for their anti-craving action.