Information transmission by stimulus-dependent modulation of noise correlation.

Cortical neurons that are near one another show correlated response variability (noise correlation), which can contribute to synergistic information transmission. In this study, we investigated the relationship between the level of external stimulation and noise correlation and its effect on population coding. Six levels of electrical stimulation were delivered to a rat's hind paw and responses of several neighboring neurons were simultaneously recorded in the primary somatosensory cortex.

Prefrontal cortex and hippocampus subserve different components of working memory in rats.

Both the medial prefrontal cortex (mPFC) and hippocampus are implicated in working memory tasks in rodents. Specifically, it has been hypothesized that the mPFC is primarily engaged in the temporary storage and processing of information lasting from a subsecond to several seconds, while the hippocampal function becomes more critical as the working memory demand extends into longer temporal scales. Although these structures may be engaged in a temporally separable manner, the extent of their contributions in the "informational content" of working memory remains unclear.

[A case of primary hepatic epithelioid hemangioendothelioma mimicking metastatic carcinoma].

Epithelioid hemangioendothelioma is a rare vascular origin tumor which usually occurs in soft tissues, liver, and lung. It usually affects adult women and presents as multiple hepatic nodules with mainly peripheral distribution. It is difficult to diagnose and treat because of non-specific clinical manifestations and findings on the imaging study.

Covered expandable nitinol stents for malignant gastroduodenal obstructions.

Background And Aim: The aim of the present study was to investigate the clinical effectiveness, safety, and outcome associated with the use of covered expandable Nitinol stents (Taewoong Medical, Seoul, Korea) for the treatment of malignant gastroduodenal obstructions.

Methods: Between March 2001 and October 2004, covered expandable Nitinol stents were placed in 68 consecutive patients under endoscopic and fluoroscopic guidance for the following reasons: gastric carcinoma (n = 49), recurrent carcinoma after partial gastrectomy (n = 7), or another malignant neoplasm involving the duodenum (n = 12).

Results: Technical success was achieved in 60 of the 68 patients (88.

Acute myeloid leukemia presenting as obstructive jaundice caused by granulocytic sarcoma.

We report a rare case of granulocytic sarcoma infiltrating the bile duct in a patient with acute myeloid leukemia. A 23-year-old man presented with jaundice and weight loss. A peripheral blood smear revealed blast cells, and the results of an examination of bone marrow aspirate were consistent with acute myeloid leukemia.

Factors affecting the persistence of tympanic membrane perforation developed with the extubation of ventilation tube.

Objective: To determine which factors are associated with persistence of the tympanic membrane (TM) perforation detected after a spontaneous extrusion or surgical removal of a ventilation tube (VT).

Methods: We conducted a retrospective chart review of all patients who underwent ventilation tube insertion from 1995 to 2003 at our institution. We identified 909 ears in which we could see the final state of TM and found 89 ears that fitted the inclusion/exclusion criteria.

Implementation of the relay server for the ubiquitous integrated biotelemetry system for emergency care (UIBSEC) based on 3.5G HSDPA technology.

When an emergent case occurs, to give proper and immediate emergency treatment to a patient is as important as to transfer him or her to the hospital as early as possible. For this circumstance where first aid usually happens in an ambulance, we developed the Ubiquitous Integrated Biotelemetry System for Emergency Care (UIBSEC) based on wireless 3.5G HSDPA module in order to provide more proper and active medical care to a patient.

HSDPA (3.5G)-based ubiquitous integrated biotelemetry system for emergency care.

We have developed the second prototype system of Ubiquitous Integrated Biotelemetry System for Emergency Care(UIBSEC) using a HSDPA(High Speed Downlink Packet Access) modem to be used by emergency rescuers to get directions from medical doctors in providing emergency medical services for patients in ambulance. Five vital bio-signal instrumentation modules have been implemented, which include noninvasive arterial blood pressure (NIBP), arterial oxygen saturation (SaO2), 6-channel electro-cardiogram(ECG), blood glucose level, and body temperature and real-time motion picture of the patient and GPS information are also taken. Measured patient data, captured motion picture and GPS information are then transferred to a doctor's PC through the HSDPA and TCP/IP networks using stand-alone HSDPA modem.

Preliminary study of motion artifact rejection for NIBP measurement in an ambulance.

Motion artifact resulting from patient's movement is a significant source for disturbing accurate noninvasive blood pressure (NIBP) measurement. In an ambulance, patients are exposed to unstable circumstances due to vehicle's movement and vibration during emergency transportation. Since NIBP is indirectly measured using oscillometry based on the change of cuff pressure, it can be affected by motion artifact much more than other biosignals.

Concomitant inflammatory pseudotumor of the temporal bone and lung: a case report.

Inflammatory pseudotumors are histologically benign but locally destructive lesions that are usually found in the lung, although some cases of temporal bone involvement have been reported. To the best of our knowledge, no case of simultaneous involvement of the temporal bone and the lung has been previously reported in the literature. We describe such a case in a 39-year-old man.

Stress-induced alterations in hippocampal plasticity, place cells, and spatial memory.

Acute, inescapable, and unpredictable stress can profoundly modify brain and cognition in humans and animals. The present study investigated the ensuing effects of 2-h variable "audiogenic" stress on three related levels of hippocampal functions in rats: long-term potentiation, place cell activity, and spatial memory. In agreement with prior findings, we observed that stress reduced the magnitude of Schaffer collateral/commissural-Cornu Ammonis field 1 long-term potentiation in vitro, and selectively impaired spatial memory on a hidden platform version of the Morris water maze task.

Encoding of action history in the rat ventral striatum.

In a dynamic environment, animals need to update information about the rewards expected from their alternative actions continually to make optimal choices for its survival. Because the reward resulting from a given action can be substantially delayed, the process of linking a reward to its causative action would be facilitated by memory signals related to the animal's previous actions. Although the ventral striatum has been proposed to play a key role in updating the information about the rewards expected from specific actions, it is not known whether the signals related to previous actions exist in the ventral striatum.

Thermally cross-linked superparamagnetic iron oxide nanoparticles: synthesis and application as a dual imaging probe for cancer in vivo.

We report the fabrication and characterization of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) and their application to the dual imaging of cancer in vivo. Unlike dextran-coated cross-linked iron oxide nanoparticles, which are prepared by a chemical cross-linking method, TCL-SPION are prepared by a simple, thermal cross-linking method using a Si-OH-containing copolymer. The copolymer, poly(3-(trimethoxysilyl)propyl methacrylate-r-PEG methyl ether methacrylate-r-N-acryloxysuccinimide), was synthesized by radical polymerization and used as a coating material for as-synthesized magnetite (Fe3O4) SPION.

Effectiveness of (99m)Tc-tetrofosmin for assessment of heart functions in micropigs.

This study examined the suitability of a nuclear imaging technique using (99m)Tc-tetrofosmin as an agent to assess the heart functions of healthy micropigs. The mean age of the pigs was 360 days (male), and the mean body weight was 35.3 kg ranging from 34.

Gene expression profiling of rewarding effect in methamphetamine treated Bax-deficient mouse.

Methamphetamine is an illicit drug that is often abused and can cause neuropsychiatric and neurotoxic damage. Repeated administration of psychostimulants such as methamphetamine induces a behavioral sensitization. According to a previous study, Bax was involved in neurotoxicity by methamphetamine, but the function of Bax in rewarding effect has not yet been elucidated.

Gastric schwannomas: endosonographic characteristics.

Gastric schwannomas are rare benign neurogenic mesenchymal tumors that are usually asymptomatic but can present with variable symptoms. We retrospectively reviewed the endosonographic features of four patients with gastric schwannomas. A marginal hypoechoic halo was found in three patients with the schwannomas.

Preoperative staging of colorectal cancer: CT vs. integrated FDG PET/CT.

Accurate preoperative staging is essential in determining the optimal therapeutic planning for individual patients. The computed tomography (CT) in the preoperative staging of colorectal cancer, even if controversial, may be useful for planning surgery and/or neoadjuvant therapy, particularly when local tumor extension into adjacent organs or distant metastases are detected. There have been significant changes in the CT technology with the advent of multi-detector row CT (MDCT) scanner.

[A case with Rotor syndrome in hyperbilirubinemic family].

Rotor syndrome is a rare, benign familial disorder characterized by chronic fluctuating, nonhemolytic and predominantly conjugated hyperbilirubinemia with normal hepatic histology. In contrast to Dubin-Johnson syndrome, there is no liver pigmentation in Rotor syndrome. A 36-year-old man was admitted due to asymptomatic persistent jaundice.

LTP induction modifies functional relationship among hippocampal neurons.

To obtain evidence linking long-term potentiation (LTP) and memory, we examined whether LTP induction modifies functional relationship among neurons in the rat hippocampus. In contrast to neurons in low-frequency stimulated or AP5-treated slices, LTP induction altered 'functional connectivity,' as defined by the degree of synchronous firing, among simultaneously recorded neurons in the CA3 region. Interestingly, functional connectivity changed bidirectionally so that the total sum of functional connectivity remained constant.

Learning-induced enduring changes in functional connectivity among prefrontal cortical neurons.

Current thinking about how memories are stored in the brain has been profoundly influenced by Donald O. Hebb's cell assembly hypothesis, which posits that (1) learning produces a stable alteration in patterns of connectivity among repeatedly coactivated neurons, and (2) memory retrieval involves reactivation of those altered patterns of connectivity. However, learning-induced changes in connectivity that persist over long periods of time have not been clearly demonstrated.

Probiotic properties of Lactobacillus and Bifidobacterium strains isolated from porcine gastrointestinal tract.

One strain of Lactobacillus salivarius, two strains of Lactobacillus reuteri and Lactobacillus amylovorus, and two strains of Bifidobacterium thermacidophilum with antagonistic effect against Clostridium perfringens were isolated from porcine gastrointestinal tract. Isolates were assayed for their ability to survive in synthetic gastric juice at pH 2.5 and were examined for their ability to grow on agar plate containing porcine bile extract.

Polymorphisms in the IL-13 and IL-4 receptor alpha genes and allergic rhinitis.

The IL-4 receptor (IL-4R) and IL-13 genes are candidate genes in atopic diseases. The IL-4Ralpha chain and IL-13 promoter polymorphisms are gain-of-function mutations associated with atopy. We tested whether polymorphisms in the IL-4Ralpha chain and the coding region of the IL-13 gene are associated with allergic rhinitis in a Korean population.

IL-18 enhances the migration ability of murine melanoma cells through the generation of ROI and the MAPK pathway.

Interleukin-18 (IL-18) has multiple effects on various cells that are involved in immune escape of murine melanoma cells and in the inflammatory responses. This study investigated the effect of IL-18 on the ability of murine melanoma cells to migrate by using B16F10 cells and the IL-18 antisense transfectants of B16F10 cells (the B16F10/IL-18 antisense transfectant). The B16F10 cells were more able to migrate than were the B16F10/IL-18 antisense transfectants.

Involvement of calcium-mediated apoptotic signals in H2O2-induced MIN6N8a cell death.

Reactive oxygen species are believed to be the central mediators of beta-cell destruction that leads to type 1 and 2 diabetes, and calcium has been reported to be an important mediator of beta cell death. In the present study, the authors investigated whether Ca(2+) plays a role in hydrogen peroxide (H(2)O(2))-induced MIN6N8a mouse beta cell death. Treatment with low concentration H(2)O(2) (50 microM) was found to be sufficient to reduce MIN6N8a cell viability by 55%, largely via apoptosis.

Enhanced proliferation of progenitor cells following long-term potentiation induction in the rat dentate gyrus.

The dentate gyrus (DG) is among the few areas in the mammalian brain where production of new neurons continues in the adulthood. Although its functional significance is not completely understood, several lines of evidence suggest the role of DG neurogenesis in learning and memory. Considering that long-term potentiation (LTP) is a prime candidate for the process underlying hippocampal learning and memory, these results raise the possibility that LTP and neurogenesis are closely related.