Two forms of synaptic plasticity with distinct dependence on age, experience, and NMDA receptor subtype in rat visual cortex.

In visual cortex, NMDA receptor (NMDAR) properties depend primarily on NR2A and NR2B subunits, and NR2 subunit composition changes with age and visual experience. We examined the roles of these NR2 subunits in activity-dependent long-term modification of synaptic responses, which were evoked in layer 2/3 cells by stimulation of layer 4 in rat visual cortical slices. We used theta-burst stimulation (TBS) of presynaptic fibers or low-frequency stimulation paired with postsynaptic depolarization, which has been commonly used to induce NMDAR-dependent long-term potentiation (LTP) in visual cortex.

Age and experience dependence of N-methyl-D-aspartate receptor-independent long-term potentiation in rat visual cortex.

Dark rearing prolongs the critical period for experience-dependent modification of visual cortical functions. To test whether long-term potentiation (LTP) could potentially underlie this modification, we studied the age and experience dependence of LTP, induced in layer 2/3 cells by layer 4 stimulation continued for 15 min at 2 Hz, in rat visual cortical slices. This LTP was independent of N-methyl-D-aspartate receptor (NMDAR) activation, but it likely required Ni(2+)-sensitive Ca(2+) channel activation for induction.

Hepatitis C virus genotypes and hepatic fibrosis regulate 24-h decline of serum hepatitis C virus RNA during interferon therapy in patients with chronic hepatitis C.

Background And Aims: Recently, hepatitis C virus (HCV) dynamics during interferon (IFN) therapy have been studied in detail. We examined factors that regulate the viral kinetics and the relationship between the viral kinetics and clinical effect of IFN therapy.

Methods: Eighty-eight patients with chronic hepatitis C entered this study.

Evaluation of hemodynamics in esophageal varices. Value of endoscopic color Doppler ultrasonography with a galactose-based contrast agent.

Endoscopic color Doppler ultrasonography (ECDUS) is a useful modality for obtaining color flow images of esophageal varices. Levovist is a microbubble echo-enhancing agent, which improves Doppler ultrasound examination. In this paper, we compared vessel images detected with pre-contrast with those detected by enhanced ECDUS using Levovist in 62 patients with esophageal varices.

Regio- and enantioselective iridium-catalyzed intermolecular allylic etherification of achiral allylic carbonates with phenoxides.

An enantioselective and regioselective iridium-catalyzed allylic etherification is described. The reaction of sodium and lithium aryloxides with achiral (E)-cinnamyl and terminal aliphatic allylic electrophiles in the presence of 2 mol % of an iridium-phosphoramidite complex provides chiral allylic aryl ethers in high yields and excellent levels of regio- and enantioselectivity. Lithium aryloxides containing a single substituent at an ortho, meta, or para position as well as sterically hindered phenoxides were tolerated.

Relationship between head orientation and torsional eye movements in goldfish during linear acceleration.

We analyzed torsional eye movements of normal goldfish during sinusoidal linear acceleration, altering the orientation of the fish on the linear accelerator in the yaw plane over a range of 90 degrees and in the pitch plane up to 30 degrees. We video-recorded changes of torsional eye movements associated with a body rotation in the yaw and pitch plane and analyzed them frame by frame. In normal fish, we observed clear torsional eye movements for stimuli of 0.

Regio- and enantioselective allylic amination of achiral allylic esters catalyzed by an iridium-phosphoramidite complex.

A new catalytic asymmetric process, the iridium-catalyzed enantioselective allylic amination of (E)-cinnamyl and terminal aliphatic allylic carbonates, was developed by exploring complexes of chiral phosphoramidites. The reaction provided branched secondary and tertiary allylic amines in high yields with excellent regio- and enantioselectivity (13 examples over 94% ee). Although the reactions in polar solvent such as DMF, EtOH, and MeOH were fast, they gave low enantiomeric excesses.

[A case of recurrent hepatocellular carcinoma successfully treated with a combination therapy of interferon-alpha and intravenous continuous infusion of 5-fluorouracil].

We report a case of recurrent hepatocellular carcinoma (HCC) successfully treated with a combination therapy of interferon-alpha (IFN-alpha) and 5-fluorouracil (5-FU), which was administered intravenously. A 49-year-old Japanese man who underwent a right hepatectomy for HCC developed tumor recurrence in the liver 19 months after surgery. Abdominal CT revealed multiple metastatic lesions in the liver.

Free radicals in phacoemulsification and aspiration procedures.

Objectives: To detect free radicals in phacoemulsification and aspiration procedures using electron-spin resonance and to observe the effect of ophthalmic viscosurgical devices (viscoelastic agents) on free radical intensity.

Methods: (1) A test tube containing BSS Plus (Alcon Laboratories, Inc, Fort Worth, Tex) with 1% of the spin-trapping agent, 5,5'-dimethyl-1-pyrroline N-oxide, without irrigation and aspiration, was exposed to ultrasound (100% for 20 seconds). A preparation of hyaluronate sodium (Healon [a cohesive agent that contains 1% hyaluronate sodium] (Pharmacia, Uppsala, Sweden) or Viscoat [a dispersive agent that contains 3% hyaluronate sodium and 4% chondroitin sulfate] (Alcon Laboratories, Inc)) was added to the solution to observe inhibitory effects.

Color Doppler findings of gastric varices compared with findings on computed tomography.

Background: The aim of this study was to evaluate the hemodynamics of gastric varices.

Methods: We evaluated the detection rates of gastric varices, inflowing vessels to gastric varices, and outflowing vessels from gastric varices in 24 patients with gastric varices, using color Doppler sonography, and compared these findings with computed tomography findings. Eighteen patients had F2-type varices and 6 had F3-type, classified according to the Japanese Research Society for Portal Hypertension.

Studies on the effects of microgravity on the ultrastructure and function of cultured mammalian cells.

Four cultures of monkey kidney cell line, JTC-12, were flown on the Spacelab-J (SL-J) mission during 8 days. The results of the present study showed that the space flight gave no essential effect on morphology, cell cycle, glucose consumption and urokinase production of the mammalian culture cell. However, the cell proliferation slightly decreased under microgravity.

Redox-coupled conformational alternations in cytochrome c(3) from D. vulgaris Miyazaki F on the basis of its reduced solution structure.

Heteronuclear NMR spectroscopy was performed to determine the solution structure of (15)N-labeled ferrocytochrome c(3) from Desulfovibrio vulgaris Miyazaki F (DvMF). Although the folding of the reduced cytochrome c(3) in solution was similar to that of the oxidized one in the crystal structure, the region involving hemes 1 and 2 was different. The redox-coupled conformational change is consistent with the reported solution structure of D.

Transanal repair of rectourethral fistula after a radical retropubic prostatectomy: report of a case.

Rectourethral fistula occurred in a 64-year-old man after a radical prostatectomy. Despite conservative treatment the fistula did not close spontaneously. Eleven months after the original prostatectomy, an operation was performed.

Fluctuations in free or substrate-complexed lysozyme and a mutant of it detected on x-ray crystallography and comparison with those detected on NMR.

A mutant lysozyme in which Arg14 and His15 were deleted together exhibited higher activity toward glycol chitin than the wild-type lysozyme. Moreover, the mutant lysozyme, which is less stable than the wild-type lysozyme by 7 degrees C, showed a shift of temperature dependence of activity to the low temperature side compared with the wild-type lysozyme [Protein Eng. 7, 743-748 (1994)].

Bromocriptine reverses P-glycoprotein-mediated multidrug resistance in tumor cells.

One of the most important causes of anticancer treatment failure is the development of multidrug resistance (MDR). The main characteristics of tumor cells displaying the MDR phenomena are cross-resistance to structurally unrelated cytotoxic drugs having different mechanisms of action and the overexpression of the MDR1 gene, which encodes a transmembrane glycoprotein named P-glycoprotein (P-gp). This study evaluated whether bromocriptine, a D2 dopaminergic receptor agonist, influenced anticancer drug cytotoxicity and P-gp activity in a P-gp-expressing cell line compared to a non-expressing subline.

A nucleotide switch in the Escherichia coli DnaA protein initiates chromosomal replication: evidnece from a mutant DnaA protein defective in regulatory ATP hydrolysis in vitro and in vivo.

The ATP-bound DnaA protein opens duplex DNA at the Escherichia coli origin of replication, leading to a series of initiation reactions in vitro. When loaded on DNA, the DNA polymerase III sliding clamp stimulates hydrolysis of DnaA-bound ATP in the presence of the IdaB/Hda protein, thereby yielding ADP-DnaA, which is inactive for initiation in vitro. This negative feedback regulation of DnaA activity is proposed to play a crucial role in the replication cycle.

A new method for preventing pulse pileup in scintillation detectors.

A new method for preventing pulse pileup in scintillation detectors is proposed. In the new method (G-INT), the energy of an event is calculated from the 'gated integral' of the pulse signal and the period of integration. The period of integration is not fixed but is shortened by the arrival of the succeeding pulse so as to avoid post-pulse pileup.

Successful treatment with 5-fluorouracil of conjunctival intraepithelial neoplasia refractive to mitomycin-C.

Purpose: To describe the histopathological findings and successful treatment with 5-fluorouracil (5-FU) of a conjunctival intraepithelial neoplasia with limbal stem cell deficiency that was refractive to topical mitomycin-C (MMC).

Design: Interventional case report.

Intervention: A 64-year-old male patient presented with a diffuse conjunctival intraepithelial neoplasia (CIN) that was excised with concurrent keratoepithelioplasty.

Distal cement mantle thickness with a triangular distal centralizer inserted into the stem tip in cemented total hip arthroplasty.

Fifty-seven hips undergoing a primary cemented total hip arthroplasty with use of a triangular distal centralizer inserted into the stem tip were investigated, with a special focus on distal cement mantle thickness. The subjects were 43 women and 3 men. When evaluated on conventional anteroposterior and lateral radiographs, the relative incidence of thin cement mantles in zones 3 or 5 owing to the distal centralizer was 15.