Different Food Preferences in Patients with Gastrointestinal Disorders

Objective Gastrointestinal (GI) disorders such as functional dyspepsia (FD), irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), and inflammatory bowel disease (IBD) can exhibit overlapping GI symptoms, including abdominal pain and alterations in bowel habits. The symptoms of GI disorders are commonly considered to be triggered and exacerbated by fatty food intake. Therefore, this study aimed to compare the food preferences of patients with GI disorders. Methods Forty food images (including fatty and light foods) and 20 animal images were selected to evaluate food preferences. The preference score was assessed using a visual analog scale ranging from 1 to 100. GI symptoms were evaluated using the GI Symptom Rating Scale (GSRS), and correlations between the GSRS and preference scores were investigated. Results Overall, 22 healthy controls and 23, 29, 27, and 20 patients with FD, IBS, GERD, and IBD, respectively, were enrolled. The preference score for all foods in patients with FD was significantly lower than that in healthy controls and those with IBS, GERD, and IBD (52.9 vs. 66.5 vs. 68.5 vs. 69.1 vs. 70.7, p<0.01). The score of fatty foods was lower in patients with FD than in healthy controls and those with IBS, GERD, and IBD (43.8 vs. 72.3 vs. 77.5 vs. 77.4 vs. 80.7, p<0.01), whereas that of light foods and animal images was not different among the groups. No significant correlation was found between the preference score and symptom severity. Conclusions Patients with FD had a negative preference for foods, particularly fatty foods, independent of the severity of GI symptoms.

Artificial Intelligence-Based Diagnostic Support System for Functional Dyspepsia Based on Brain Activity and Food Preference

Background and aim Disorders of gut-brain interaction (DGBI) are disorders where no organic clinical abnormalities are detected such as functional dyspepsia (FD) and irritable bowel syndrome (IBS). The brain activity of individuals with FD and IBS differs from that of healthy controls. Artificial intelligence can distinguish healthy controls from individuals with DGBI using several biomarkers. This study aimed to establish an artificial intelligence-based diagnostic support system using food preferences and brain activity in patients with DGBI. Methods ROME IV criteria were used to diagnose patients with FD and IBS. Their food preference was scored using a visual analog scale, and brain activity in the prefrontal cortex was investigated using functional near-infrared spectroscopy (fNIRS). The diagnostic model was developed based on the brain activity and visual analog scale scores for food using an artificial neural network model. Results Forty-one participants, including 25 patients with DGBI were enrolled in the study. The accuracy of the artificial intelligence-based diagnostic model using an artificial neural network in differentiating between healthy controls and patients with DGBI and between healthy controls and those with FD were 72.3% and 77.1%, respectively. Conclusions The artificial intelligence-based diagnostic model using brain activity and preference to food images showed sufficiently high accuracy in distinguishing patients with DGBI from healthy controls, and those with FD from healthy controls. Therefore, the fNIRS system provides objective evidence for diagnosing DGBI.

Brain activity in response to food images in patients with irritable bowel syndrome and functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are caused and exacerbated by consumption of fatty foods. However, no study has evaluated brain activity in response to food images in patients with disorders of gut-brain interaction (DGBI). This study aimed to compare food preference and brain activity when viewing food images between patients with DGBI and healthy controls.

METHODS

FD and IBS were diagnosed using the ROME IV criteria. Food preference was assessed using a visual analog scale (VAS). Brain activity in the prefrontal cortex (PFC) in response to food images was investigated using functional near-infrared spectroscopy (fNIRS).

RESULTS

Forty-one patients were enrolled, including 25 with DGBI. The mean VAS scores for all foods (controls vs. FD vs. IBS: 69.1 ± 3.3 vs. 54.8 ± 3.8 vs. 62.8 ± 3.7, p = 0.02), including fatty foods (78.1 ± 5.4 vs. 43.4 ± 6.3 vs. 64.7 ± 6.1, p < 0.01), were the lowest in patients with FD among all groups. Patients with FD had significantly higher brain activity in the left PFC than those with IBS and healthy controls (mean z-scores in controls vs. FD vs. IBS: - 0.077 ± 0.03 vs. 0.125 ± 0.04 vs. - 0.002 ± 0.03, p < 0.001).

CONCLUSIONS

Patients with DGBI, particularly those with FD, disliked fatty foods. The brain activity in patients with DGBI differed from that in healthy controls. Increased activity in the PFC of patients with FD was confirmed.

Contribution of default mode network to game and delayed-response task performance: Power and connectivity analyses of theta oscillation in the monkey

Neuroimaging studies have demonstrated the presence of a default mode network (DMN) which shows greater activity during rest, and an executive network (EN) which is activated during cognitive tasks. DMN and EN are thought to have competing functions. However, recent studies reported that the two networks show coactivation during some cognitive tasks. To clarify how DMN works and how DMN interacts with EN for cognitive control, we recorded EEG activities in the medial prefrontal (anterior DMN: aDMN), posterior cingulate/precuneus (posterior DMN: pDMN), and lateral prefrontal (EN) areas in the monkey. As cognitive tasks, we employed a monkey-monkey competitive video game (GAME) and a delayed-response (DR) task. We focused on theta oscillation because of its importance in cognitive control. We also examined theta band connectivity among the three network areas using the Granger causality analysis. DMN and EN were found to work cooperatively in both tasks. In all the three network areas, we found GAME-task-related, but no DR-task-related, increase in theta power from the resting level, maybe because of the higher cognitive demand associated with the GAME task performance. The information flow conveyed by the theta oscillation was directed more to aDMN than from aDMN for both tasks. The GAME-task-related increase in theta power in aDMN is supposed to be supported by more information flow conveyed by the theta oscillation from EN and pDMN.

Ultrasound imaging for evaluation of impalement-related injuries to the oral cavity in pediatric patients: a case series study

BACK GROUND

An impalement-related injury to the oral cavity is common in pediatric patients at emergency department. A computed tomography evaluation is not always suitable in these cases. Herein, we aimed to present oral sonography findings from six pediatric patients presenting with impalement-related injury to the oral cavity.

CASE SERIES

All included patients were younger than 4 years and sustained injuries with a toothbrush, chopstick, water gun, and fork to the tonsils, submandibular gland area, uvula, and under the tongue.

CONCLUSION

Ultrasound imaging appeared useful in helping diagnose impalement-related injuries lateral to the midline.

Individual differences in processing ability to transform visual stimuli during the mental rotation task are closely related to individual motor adaptation ability

Mental rotation (MR) is a well-established experimental paradigm for exploring human spatial ability. Although MR tasks are assumed to be involved in several cognitive processes, it remains unclear which cognitive processes are related to the individual ability of motor adaptation. Therefore, we aimed to elucidate the relationship between the response time (RT) of MR using body parts and the adaptive motor learning capability of gait. In the MR task, dorsal hand, palmar plane, dorsal foot, and plantar plane images rotated in 45° increments were utilized to measure the RTs required for judging hand/foot laterality. A split-belt treadmill paradigm was applied, and the number of strides until the value of the asymmetrical ground reaction force reached a steady state was calculated to evaluate the individual motor adaptation ability. No significant relationship was found between the mean RT of the egocentric perspectives (0°, 45°, and 315°) or allocentric perspectives (135°, 180°, and 225°) and adaptive learning ability of gait, irrespective of body parts or image planes. Contrarily, the change rate of RTs obtained by subtracting the RT of the egocentric perspective from that of the allocentric perspective in dorsal hand/foot images that reflect the time to mentally transform a rotated visual stimulus correlated only with adaptive learning ability. Interestingly, the change rate of RTs calculated using the palmar and plantar images, assumed to reflect the three-dimensional transformation process, was not correlated. These findings suggest that individual differences in the processing capability of visual stimuli during the transformation process involved in the pure motor simulation of MR tasks are precisely related to individual motor adaptation ability.

Monkey Prefrontal Single-Unit Activity Reflecting Category-Based Logical Thinking Process and Its Neural Network Model

Category-based thinking is a fundamental form of logical thinking. Here, we aimed to investigate its neural process at the local circuit level in the prefrontal cortex (PFC). We recorded single-unit PFC activity while male monkeys (Macaca fuscata) performed a task in which the category and rule were prerequisites of logical thinking and the outcome contingency was its consequence. Different groups of neurons coded a single type of information discretely or multiple types in a transitional form. Results of time-by-time analysis of neuronal activity suggest an information flow from category-coding and rule-coding neurons to transitional intermediate neurons, and then to contingency-coding neurons. Category-coding, rule-coding, and contingency-coding neurons showed stable coding of information, whereas intermediate neurons showed dynamic coding, as if it integrated category and rule to derive contingency. A similar process was confirmed by using a spiking neural network model that consisted of subnetworks coding category and rule on the input layer and those coding contingency on the output layer, with a subnetwork for integration in the intermediate layer. These results suggest that category-based logical thinking is realized in the PFC by separated neural populations organized for working in a feedforward manner.SIGNIFICANCE STATEMENT To elucidate the neural process for logical thinking, we combined an in-depth analysis of single-unit activity data with a biologically plausible computational model. Results of time-by-time analysis of prefrontal neuronal activity suggest an information flow from category-coding and rule-coding neurons to transitional intermediate neurons, and then to contingency-coding neurons. Category-coding, rule-coding, and contingency-coding neurons showed stable coding, whereas intermediate neurons showed dynamic coding, as if they integrated category and rule to derive contingency. A spiking neural network model reproduced similar temporal changes of information as the recorded neuronal data. Our results suggest that the prefrontal cortex (PFC) is critically involved in category-based thought process, and this process may be produced by separated neural populations organized for working in a feedforward manner.

Effects of different exercise intensities on prefrontal activity during a dual task

The effects of physical exercise on cognitive tasks have been investigated. However, it is unclear how different exercise intensities affect the neural activity. In this study, we investigated the neural activity in the prefrontal cortex (PFC) by varying the exercise intensity while participants performed a dual task (DT). Twenty healthy young adults performed serial subtraction while driving a cycle ergometer. Exercise intensity was set to one of three levels: low, moderate, or high intensity. We did not find any significant change in PFC activity during DT under either the control (no exercise) or low-intensity conditions. In contrast, we observed a significant increase in PFC activity during DT under moderate- and high-intensity conditions. In addition, we observed complex hemodynamics after DT. PFC activity decreased from baseline after DT under the control condition, while it increased under the low-intensity condition. PFC activity remained higher than the baseline level after DT under the moderate-intensity condition but returned to baseline under the high-intensity condition. The results suggest that moderate-intensity exercise with a cognitive load effectively increases PFC activity, and low-intensity exercise may increase PFC activity when combined with a cognitive load.

Utilization of Anion-exchange Guard Column as an Ion Chromatographic Column of Anions Including Application to Simultaneous Separation of Anions and Cations

This study demonstrated that a guard column containing anion-exchange resin has the potential for use as a separation column for acid eluent. Specifically, a 1-cm long anion-exchange guard column with a 4.6-mm internal diameter provided good separation of monovalent inorganic anions, by elution of 8 mM tartaric acid or 4 mM malic acid. Using the guard column with acid eluent could be applied to evaluation of nitrite and nitrate ions in mountain and urban river water samples. When the guard column was connected in front of a cation-exchange separation column (15 cm long × 4.6 mm internal diameter) in a series, the system provided simultaneous separation of anions and cations in eluent of 8 mM tartaric acid and 0.5 mM 18-crown-6 ether by a single injection.

Behavioral evidence for the use of functional categories during group reversal task performance in monkeys

A functional category is a set of stimuli that are regarded as equivalent independently of their physical properties and elicit the same behavioral responses. Major psychological theories suggest the ability to form and utilize functional categories as a basis of higher cognition that markedly increases behavioral flexibility. Vaughan claimed the category use in pigeons on the basis of partition, a mathematical criterion for equivalence, however, there have been some criticisms that the evidence he showed was insufficient. In this study, by using a group reversal task, a procedure originally used by Vaughan, we aimed to gather further evidence to prove the category use in animals. Macaque monkeys, which served as subjects in our study, could efficiently perform the task not only with familiar stimulus sets as Vaughan demonstrated but also with novel sets, and furthermore the task performance was stable even when the number of stimuli in a set was increased, which we consider as further evidence for the category use in animals. In addition, by varying the timing of the reversal, we found that a category formation takes place soon after encountering new stimuli, i.e. in a few blocks of trial after a novel stimulus set was introduced.

Advantage of Dichromats over Trichromats in Discrimination of Color-Camouflaged Stimuli in Humans

This study investigated whether 12 participants with color-vision deficiency had superior visual discrimination of color-camouflaged stimuli shown on a computer screen compared with 12 participants with normal trichromatic vision. Participants were asked to distinguish a circular pattern from other patterns in which textural elements differed from the background in orientation and thickness. In one condition, stimuli were single-colored, green or red; in the other condition, stimuli were color camouflaged with a green and red mosaic overlaid onto the pattern. Color-vision deficient participants selected the correct stimuli in the color-camouflaged condition as quickly as they did in the single-colored condition. However, normal color-vision participants took longer to select the correct choice in the color-camouflaged condition than in the single-colored condition. These results suggest that participants with color-vision deficiency may have a superior visual ability to discriminate the color-camouflaged stimuli.

Capturing the temporal evolution of choice across prefrontal cortex

Activity in prefrontal cortex (PFC) has been richly described using economic models of choice. Yet such descriptions fail to capture the dynamics of decision formation. Describing dynamic neural processes has proven challenging due to the problem of indexing the internal state of PFC and its trial-by-trial variation. Using primate neurophysiology and human magnetoencephalography, we here recover a single-trial index of PFC internal states from multiple simultaneously recorded PFC subregions. This index can explain the origins of neural representations of economic variables in PFC. It describes the relationship between neural dynamics and behaviour in both human and monkey PFC, directly bridging between human neuroimaging data and underlying neuronal activity. Moreover, it reveals a functionally dissociable interaction between orbitofrontal cortex, anterior cingulate cortex and dorsolateral PFC in guiding cost-benefit decisions. We cast our observations in terms of a recurrent neural network model of choice, providing formal links to mechanistic dynamical accounts of decision-making.

DOI:http://dx.doi.org/10.7554/eLife.11945.001

In 1848, a railroad worker named Phineas Gage suffered an accident that was to secure him a place in neuroscience lore. While constructing a new railway line, a mistimed explosion propelled an iron bar into the base of his skull, where it passed behind his left eye before exiting through the top of his head. Gage survived the accident, but those who knew him reported significant changes in his personality and behaviour.

Gage’s ability to make decisions was particularly impaired by his injury. Decision-making involves weighing up the costs and benefits associated with alternative courses of action. It entails looking into the future to decide whether an anticipated reward will justify the effort or expense necessary to obtain it. This process is dependent on a region of the brain called the prefrontal cortex, the area that sustained the most damage in Phineas Gage.

While many studies have shown correlations between activity in particular parts of prefrontal cortex and the outcome of decisions, little is known about how this activity evolves over time as a decision is made. To explore this process, Hunt et al. trained macaque monkeys to choose between pairs of images that were associated with specific rewards (quantities of fruit juice) and costs (either amounts of work or fixed delays).

Electrode recordings revealed changes in prefrontal activity that varied over time as the monkeys deliberated over each pair of images, choosing for example between a large reward after a long delay versus a smaller reward immediately. This activity was consistent with a mathematical model of decision-making, which also explains data from brain imaging experiments in humans. This provides an important link between human data and electrode recordings in animals.

However, some of the patterns of activity observed in both macaques and humans appeared to reflect the speed at which decisions were made, rather than the outcome of the decisions themselves. By extracting information about decision speed on each decision from each region, it was shown that communication between regions of prefrontal cortex changes when choices are between two different amounts of work, as opposed to two different delays. Further experiments are needed to explore this phenomenon and to determine how other brain regions interact with the prefrontal cortex to support the decision-making process.

DOI:http://dx.doi.org/10.7554/eLife.11945.002

Egalitarian reward contingency in competitive games and primate prefrontal neuronal activity

How people work to obtain a reward depends on the context of the reward delivery, such as the presence/absence of competition and the contingency of reward delivery. Since resources are limited, winning a competition is critically important for organisms' obtaining a reward. People usually expect ordinary performance-reward contingency, with better performers obtaining better rewards. Unordinary reward contingency, such as egalitarianism (equal rewards/no-rewards to both good and poor performers), dampens people's motivation. We previously reported that monkeys were more motivated, and neurons in the lateral prefrontal cortex (LPFC) showed higher outcome-related activity in a competitive than in a noncompetitive game (Hosokawa and Watanabe, 2012). However, monkey's behavior and LPFC neuronal activity have not been examined in a competitive situation with an unordinary performance-reward contingency. Also, the fixed performance-reward contingency in the previous study did not allow us to examine effects of win/loss separately from those of reward/no-reward on prefrontal neuronal activity. Here, we employed the egalitarian competitive situation in which both the winner and loser, or neither of them, got a reward as well as the normal competitive situation in which only the winner got a reward. Monkey's behavioral performance greatly deteriorated in trials with the egalitarian outcome conditions. LPFC neurons showed activities that reflected the normal or egalitarian outcome condition while very few neurons coded win/loss independent of reward/no-reward. Importantly, we found neurons that showed reward-related activity in the normal, but not in the egalitarian outcome conditions, even though the same reward was given to the animal. These results indicate that LPFC may play an important role in monitoring the current reward contingency and integrating it with the performance outcome (win-loss) for better performing the competitive game, and thus for better survival.

Noninvasive estimation of fibrosis progression overtime using the FIB-4 index in chronic hepatitis C

The FIB-4 index is a simple formula to predict liver fibrosis based on the standard biochemical values (AST, ALT and platelet count) and age. We here investigated the utility of the index for noninvasive prediction of progression in liver fibrosis. The time-course alteration in the liver fibrosis stage between paired liver biopsies and the FIB-4 index was examined in 314 patients with chronic hepatitis C. The average interval between liver biopsies was 4.9 years. The cases that showed a time-course improvement in the fibrosis stage exhibited a decrease in the FIB-4 index, and those that showed deterioration in the fibrosis stage exhibited an increase in the FIB-4 index with a significant correlation (P < 0.001). Increase in the ΔFIB-4 index per year was an independent predictive factor for the progression in liver fibrosis with an odds ratio of 3.90 (P = 0.03). The area under the receiver operating characteristic curve of the ΔFIB-4 index/year for the prediction of advancement to cirrhosis was 0.910. Using a cut-off value of the ΔFIB-4 index/year <0.4 or ≥ 0.4, the cumulative incidence of fibrosis progression to cirrhosis at 5 and 10 years was 34% and 59%, respectively in patients with the ΔFIB-4 index/year ≥0.4, whereas it was 0% and 3% in those with the ΔFIB-4 index/year <0.4 (P < 0.001). In conclusion, measurement of the time-course changes in the FIB-4 index is useful for the noninvasive and real-time estimation of the progression in liver fibrosis.

Pharmacokinetics and enhanced PKR response in patients with chronic hepatitis C treated with pegylated interferon alpha-2b and ribavirin

This study investigated the molecular and pharmacokinetic mechanisms of the enhanced antiviral efficacy associated with pegylated interferon (PEG-IFN) alpha-2b and ribavirin. The study involved comparing the expression of serial double-stranded RNA-activated protein kinase (PKR) before and during treatment in 26 PEG-IFN alpha-2b and 26 conventional IFN alpha-2b recipients matched for age, body weight and dose of ribavirin. The pharmacokinetics of PEG-IFN alpha-2b and ribavirin was analysed in 15 of the 26 PEG-IFN recipients. There was a rapid increase in PKR expression in both treatment groups, although expression from day 2 onwards was maintained at a significantly higher level in the PEG-IFN recipients (P < 0.05). C(max) of PEG-IFN occurred 12-48 h after the initial administration, with t(1/2) and C(min) being 49 h and 190 pg/mL, respectively. In contrast to ribavirin, accumulation of PEG-IFN was minimal. There was no association between serum PEG-IFN and ribavirin levels and virological response. Although baseline expression of PKR before treatment was marginally higher in nonresponders (NRs), from day 2 onwards, sequential PKR expression in response to PEG-IFN was higher in sustained viral responders compared with the NRs (P < 0.05). Significant correlations were found between kinetics of PKR expression and viral decline rates in each phase of hepatitis C virus dynamics (first phase, r = 0.67, P = 0.0006; second phase, r = 0.67, P = 0.001). In conclusion, improvement in pharmacokinetics following pegylation led to higher intracellular PKR expression, which was associated with enhanced virological efficacy of PEG-IFN-based combination therapy. The concentrations of both ribavirin and PEG-IFN alpha-2b were not associated with viral response and PKR expression.

Neurons in the macaque orbitofrontal cortex code relative preference of both rewarding and aversive outcomes

Many studies have shown that the orbitofrontal cortex (OFC) is involved in the processing of emotional information. However, although some lines of study showed that the OFC is also involved in negative emotions, few electrophysiological studies have focused on the characteristics of OFC neuronal responses to aversive information at the individual neuron level. On the other hand, a previous study has shown that many OFC neurons code relative preference of available rewards. In this study, we aimed to elucidate how reward information and aversive information are coded in the OFC at the individual neuron level. To achieve this aim, we introduced the electrical stimulus (ES) as an aversive stimulus, and compared the neuronal responses to the ES-predicting stimulus with those to reward-predicting stimuli. We found that many OFC neurons showed responses to both the ES-predicting stimulus and the reward-predicting stimulus, and they code relative preference of not only the reward outcome but also the aversive outcome. This result suggests that the same group of OFC neurons code both reward and aversive information in the form of relative preference.

Correspondence of cue activity to reward activity in the macaque orbitofrontal cortex

It has been reported that neurons in the orbitofrontal cortex (OFC) respond to emotionally significant events such as reward-predicting cues and/or the reward itself. The responses to reward-predicting cues are considered to carry the information of the predicted reward. However, few studies have focused on the relationship of the neuronal activity during a cue period with that during a reward period. We can infer that the cue responses of OFC neurons are correlated to the reward responses if they carry the information of the predicted reward. In this study, we focused on neurons that showed responses during both the cue and reward periods, and compared the response characteristics between these periods. We found 94 of 369 OFC neurons showed significant responses during both the cue and reward periods, and 43 of which preserved their selectivity between these periods. Furthermore, population analysis showed that stronger cue responses corresponded to stronger reward responses, and stronger reward responses corresponded to stronger cue responses. These results suggest that individual neurons in the OFC associate visual information with reward information, and contribute to the prediction of future rewards by forming reward representations.

Personality and cancer survival: the Miyagi cohort study

We tested the hypothesis that personality plays a role in cancer outcome in a population-based prospective cohort study in Japan. In July 1990, 41 442 residents of Japan completed a short form of the Eysenck Personality Questionnaire-Revised and a questionnaire on various health habits, and between January 1993 and December 1997, 890 incident cases of cancer were identified among them. These 890 cases were followed up until March 2001, and a total of 356 deaths from all causes was identified among them. Cox proportional-hazards regression was used to estimate the hazard ratio (HR) of death according to four score levels on each of four personality subscales (extraversion, neuroticism, psychoticism, and lie), with adjustment for potential confounding factors. Multivariable HRs of deaths from all causes for individuals in the highest score level on each personality subscale compared with those at the lowest level were 1.0 for extraversion (95% CI=0.8–1.4; Trend P=0.73), 1.1 for neuroticism (0.8–1.6; Trend P=0.24), 1.2 for psychoticism (0.9–1.6; Trend P=0.29), and 1.0 for lie (0.7–1.5; Trend P=0.90). The data obtained in this population-based prospective cohort study in Japan do not support the hypothesis that personality is associated with cancer survival.

Neurons in the orbitofrontal cortex code both visual shapes and reward types

It has been reported that neurons in the orbitofrontal cortex respond to visual cues that predict reward; however, few studies have focused on the neuronal correlates with the predicted reward type and the cue stimulus. In this study, we used a paired association task and introduced a reversal condition, in which cue stimuli that usually predict water were switched to predict juice, and vice versa. Of 111 cue-responsive neurons, 60 neurons (54.1%) depended on both the cue stimulus and the predicted reward type. The results suggest that neurons in the orbitofrontal cortex can code both visual and reward information, and contribute to the association between these two pieces of information according to the current combination of a cue stimulus and a reward type.

The number of CD10-positive glomerular epithelial cells reflects renal prognosis in IgA nephropathy patients

BACKGROUND

The glomerular epithelial cells play an important role in glomerular filtration of the kidney. The disruption of these cells contributes to the development of glomerulosclerosis. The present study was performed to elucidate whether loss of the glomerular epithelial cells is associated with renal injury in patients with IgA nephropathy.

PATIENTS AND METHODS

Thirty renal biopsy specimens from IgA nephropathy, 12 from minor glomerular abnormalities and 5 from normal controls were observed. The specimens from IgA nephropathy were divided into 2 groups: Group IgA-1, including 11 patients who had received a follow-up renal biopsy because of deterioration of renal function, and Group IgA-2, consisting of the remaining 19 patients without follow-up biopsy. Immunohistochemistry was performed using a monoclonal antibody against CD10 antigen that appears on mature epithelial cells of glomeruli.

RESULTS

The average number of CD10-positive glomerular epithelial cells (GECs) was significantly lower in IgA nephropathy than in either minor glomerular abnormalities or the normal controls. In IgA nephropathy, there were significant correlations of the GECs with renal functions. The GECs were reduced along with the progression of histopathological damage. In group IgA-1, the GECs were significantly reduced at the second biopsy compared with the first biopsy, and significantly fewer in group IgA-1 than in group IgA-2 at the first biopsy. The GECs showed a significant correlation with renal prognosis during the follow-up period.

CONCLUSIONS

The reduction of GECs was associated with renal dysfunction, histopathological damage and renal prognosis. The GECs may be a useful predictor of renal prognosis in IgA nephropathy.

Immunohistochemical study of macrophage migration inhibitory factor in rat liver fibrosis induced by thioacetamide

Macrophage migration inhibitory factor (MIF) is a molecule known to regulate macrophage accumulation at sites of inflammation. To elucidate the role of MIF in progression of liver fibrosis, the immunohistochemical localization of MIF and macrophages in the liver were examined. Male Wistar rats received thioacetamide (TA) injections (200 mg/kg, i.p.) for 1 or 6 weeks. In biochemical and histological tests, it was confirmed that liver fibrosis was induced. In immunohistochemical analyses, the expression of MIF protein was seen in hepatocytes in the areas extending out from the central veins to the portal tracts. In particular, at 6 weeks, immunoreactivity was detected in degenerated hepatocytes adjacent to the fibrotic areas but hardly observed in the fibrotic areas. On the other hand, a number of exudate macrophages stained by antibody ED1 were seen in the areas from the central veins to the portal tracts at 1 week and in the fibrotic areas at 6 weeks. Macrophages also showed a significant increase in number as compared with controls. These results revealed that there was a close relationship between the appearance of MIF expression and ED1-positive exudate macrophages in degenerated hepatocytes during the progression of TA-induced liver fibrosis.

Effect of trichloroethylene on spatiotemporal pattern of LTP in mouse hippocampal slices

The effect of trichloroethylene (TCE) on long-term potentiation (LTP) was studied using both electrical and optical recording. The hippocampi from mice injected with 300 mg/kg or 1000 mg/kg TCE were sliced 24 h after administration. The field potential from the CAI was recorded. After the application of tetanus, population spikes (PS) were potentiated in all groups, but the post-per-pre ratio of PS was smaller in TCE groups than in the control. Optical recording was also carried out in 1000 mg/kg TCE-injected mice and a new analytical method using a high speed camera was employed. After the induction of tetanus, the optical signal was potentiated in both TCE and control groups. However, the post-per-pre ratio of the optical signals and response area were smaller in the TCE groups than in the control. It was suggested that the impairment of LTP is one of the mechanisms of the impairment of immediate memory after acute exposure to TCE in humans.