Detection of ligands in regions anatomically connected to neurons expressing the Eph receptor Bsk: potential roles in neuron-target interaction

Neuron-target interaction is a key feature in the establishment of neuronal networks. However, the underlying mechanism remains unclear. We have shown that at the time of target innervation, Bsk, an eph family receptor, is expressed at high levels in several brain regions including the hippocampus, olfactory bulb, and retina. To study whether the ligands are expressed in the target tissues, we investigated the expression of Bsk ligands using a ligand-affinity probe, Bsk-AP, which consisted of the extracellular domain of Bsk fused in frame with a human placental alkaline phosphatase. These analyses showed that the ligands were expressed at high levels in the developing septum, hypothalamus, olfactory neural epithelium, and tectum. In situ hybridization studies revealed that at least three different factors were responsible for the Bsk-AP binding. In the septum, Elf-1, Lerk3 (Eff-2), and AL-1/Lerk7 were transcribed. In the hypothalamus, AL-1/Lerk7 was the ligand detected by Bsk-AP. In the olfactory system, high levels of Lerk3 were detected in the sensory neurons. Both Elf-1 and AL-1/Lerk7 were present in the tectum. These ligand-positive areas are known to be anatomically connected to Bsk-expressing regions. These observations strongly suggest that Bsk and the ligands participate in neuron-target interactions in multiple systems and provide support for their involvement in topographic projection.     

Nontumorous arterioportal shunt mimicking hypervascular tumor in cirrhotic liver: two-phase spiral CT findings

PURPOSE: To determine the two-phase (hepatic arterial phase [HAP] and portal venous phase [PVP]) spiral computed tomographic (CT) findings of a nontumorous arterioportal shunt in the cirrhotic liver that can mimic a hypervascular tumor. MATERIALS AND METHODS: For 14 months, 803 patients with known or suspected hepatocellular carcinoma were referred for initial or repeated transcatheter arterial chemoembolization (TACE). Twenty-nine hyperattenuating lesions on HAP CT images obtained in 25 patients (23 men, two women; age range, 39-70 years) were regarded as nontumorous arterioportal shunts and were included in this study. The diagnosis of nontumorous arterioportal shunt was established by four radiologists who reviewed the two-phase spiral CT images and hepatic angiograms. RESULTS: The longest dimension of the lesion was 1.0-7.9 cm (mean dimension, 2.9 cm). The morphology at HAP CT was wedge-shaped in 25 (86%), geographic (ie, focal area with irregular outline) in two (7%), and nodular in two (7%) lesions. All lesions were homogeneous in attenuation. Hyperattenuating linear branching structures that represented early opacification of portal veins were demonstrated during the HAP in nine (31%) lesions. PVP CT images showed these lesions as isoattenuating (n = 20 [69%]) or slightly hyperattenuating (n = 9 [31%]). Iodized oil CT images showed faint or no accumulation of iodized oil in all lesions. CONCLUSION: In cirrhotic liver, nontumorous arterioportal shunts can be a cause of pseudolesions that mimic hypervascular tumors at two-phase spiral CT. Lesions that have the typical wedge-shaped and homogeneous appearance with or without internal linear branching structures during the HAP and that are isoattenuating or slightly hyperattenuating during the PVP can suggest this unusual condition.     

FIV infection of IL-2-dependent and -independent feline lymphocyte lines: host cells range distinctions and specific cytokine upregulation

We have analyzed the ability of three molecular clones of feline immunodeficiency virus (FIV) and an ex vivo variant to infect nine distinct specific-pathogen-free feline cell lines in tissue culture. The purpose of these studies was to elucidate mechanisms by which host cells regulate the level of virus infection and expression and to assess host cell cytokine responses to virus infection. Cells used for the analyzes included four IL-2-dependent continuous T-cell lines (104-C1, 104-C7, MCH5-4 and DB FeTs) which arose from long-term passage, followed by limiting dilution cloning of peripheral blood mononuclear cells (PBMCs); two IL-2-independent T-cell lines (104-C1DL and MCH5-4DL) which originated from two of the IL-2-dependent lines, 104-C1 and MCH5-4; respectively; Crandell feline kidney cells (CrFK); G355-5 brain-derived glial cells; and the T-cell lymphoma line, 3201. Cells were infected with FIV-PPR, FIV-34TF10, FIV 34TF10orf2rep, and a variant arising from FIV-PPR during ex vivo passage on 104-C1DL cells, termed FIV-PPRglial. Infection of the IL-2-dependent T-cell line, 104-C1, by FIV-PPR resulted in the specific and distinct upregulation of cytokine expression. In particular, these cells doubled their expression of the pleiotropic cytokines, interleukin-4 and interleukin-12 after FIV infection. Interferon-gamma production also increased after infection with FIV whereas, TNFalpha expression remained constant. Also, a marked upregulation of MHC class II expression was noted post infection of MCH5-4 and 104-C1 cells with FIV-PPR. Similar results were obtained after infection with FIV-34TF10orf2rep, indicating that the upregulation of cytokine expression is not an isolate-specific phenomenon. Changes in cytokine and class II expression are similar to various reports for the in vivo cytokine alterations in FIV, SIV and HIV infections. The ex vivo infection of these cell lines offers amanipulable system to examine the mechanism(s) by which lentiviruses alter cytokine expression.     

Establishing orally self-administered cocaine as a reinforcer in rats using home-cage pre-exposure

1. Rats were force-exposed to a cocaine + saccharin solution in their home cage water bottles for five days. They were then given 5 h home-cage access to both cocaine and cocaine-free solutions for 40 days. 2. The subjects consumed large doses of the cocaine solution despite the ad libitum availability of water. 3. The animals were then trained on a task consisting of operant bar pressing rewarded on an intermittent schedule with a liquid cocaine reinforcer. 4. All subjects performed the operant task and consumed doses of cocaine solution which are preferred over water in other paradigms. 5. Levels of responding were significantly reduced in three of four subjects when vehicle was substituted for liquid cocaine as the reward. 6. This demonstrates that orally self-administered cocaine can be used as a reinforcer in rats.     

Development of quinolone-resistant Campylobacter fetus bacteremia in human immunodeficiency virus-infected patients

Campylobacter fetus subspecies fetus has been recognized as a cause of systemic illness in immunocompromised hosts, including relapsing bacteremia in human immunodeficiency virus (HIV)-infected patients. Acquired resistance to quinolone therapy, while reported for a variety of bacteria, including Campylobacter jejuni, has not been previously documented for C. fetus. Two cases of quinolone-resistant C. fetus bacteremia were detected in HIV-infected patients. Cloning and nucleotide sequencing of the C. fetus gyrA gene in the 2 resistant isolates demonstrated a G-to-T change that led to an Asp-to-Tyr amino acid substitution at a critical residue frequently associated with quinolone resistance. In addition, comparison of the pre- and posttreatment isolates from 1 patient documented outer membrane protein changes temporally linked with the development of resistance. Relapsing C. fetus infections in quinolone-treated HIV-infected patients may be associated with the acquisition of resistance to these agents, and this resistance may be multifactorial.     

Staggered magnetization in La2-xSrxCuO4 from 139La NQR and microSR: Effects of Sr doping in the range 0

F Borsa  P Carreta  JH Cho  FC Chou  Q Hu  DC Johnston  A Lascialfari  DR Torgeson  RJ Gooding  NM Salem  KJ Vos 《Canadian Metallurgical Quarterly》1995,52(10):7334-7345

Factors influencing the protein binding of YH-439 using an equilibrium dialysis technique. A new hepatoprotective agent

Various factors influencing the plasma protein binding of YH-439 to 4% human serum albumin (HSA) were evaluated using the equilibrium dialysis method at the initial YH-439 concentration of 2 micrograms mL-1. It took approximately 12 h of incubation to reach an equilibrium between 4% HSA and isotonic phosphate buffer of pH 7.4 containing 3% of dextran ('the buffer') using a Spectra/Por 2 membrane (molecular weight cut-off, 12,000-14,000) in a water bath shaker kept at 37 degrees C and at a rate of 50 oscillations min-1. YH-439 was fairly stable both in 4% HSA and in the 'buffer' for up to 24 h incubation. The binding of YH-439 to 4% HSA was constant (97.4 +/- 0.55%) at YH-439 concentrations ranging from 0.5 to 10 micrograms mL-1. However, the extent of binding was dependent on HSA concentrations: the values were 90.7, 94.7, 96.7, 97.0, 97.0, 97.1, and 97.5% at HSA concentrations of 0.5, 1, 2, 3, 4, 5, and 6%, respectively. The plasma protein binding decreased with increasing incubation temperature: the binding values were 98.2, 97.6, 97.2, and 96.8% when incubated at 10, 21, 26, and 37 degrees C, respectively. The binding of YH-439 was also influenced by the chloride concentration in the buffer: the binding values were 94.5, 97.0, and 96.8% for the chloride concentrations of 0, 0.249, and 0.546%, respectively. The binding of YH-439 was also dependent on the buffer pH: the percentages of free fraction were 6.0, 4.1, 3.8, 2.8, 2.7 and 2.8% for the buffer pHs of 5.0, 6.0, 6.5, 7.0, 7.4, and 8.0, respectively. The free fraction of YH-439 was slightly increased by the addition of heparin (up to 40 U mL-1), sodium azide (NaN3, up to 0.5%), and its metabolites. The protein binding of YH-439 was influenced neither by AAG, acetylsalicylic acid, or sulphisoxazole, nor by the addition of citrate or EDTA. The free fractions of YH-439 in rabbit (4.2%) and dog (4.7%) plasma seemed to be higher than in rats (2.9%) and humans (3.1%).