The effect of paliperidone extended release on subjective well-being and responses in patients with schizophrenia

OBJECTIVE

This study aimed to evaluate the subjective well-being and attitudes toward antipsychotic medication of patients with schizophrenia who had switched to paliperidone extended release (ER).

METHODS

A total of 291 patients with schizophrenia treated with antipsychotics participated in this open-label, 24-week switching study. The primary outcome measures were the Subjective Well-Being under Neuroleptic Treatment Scale-short version (SWN-K) and the Drug Attitude Inventory (DAI). The Krawiecka scale, Clinical Global Impression-Schizophrenia (CGI-SCH), Personal and Social Performance scale (PSP) were used to evaluate psychopathology and psychosocial functioning, respectively.

RESULTS

Data from a total of 243 subjects who received the study medication and had at least one follow-up assessment without a major protocol violation were analyzed. Scores on the DAI and SWN-K showed significant improvement between baseline and end-point measurements beginning during the second week. Scores on the Krawiecka scale, all five subscales of the CGI-SCH scale, and the PSP scale were also significantly improved at the end point compared with the baseline. Significant predictors of improvements in the SWN-K and DAI after a switch to paliperidone ER were baseline scores, reductions in scores on the Krawiecka scale, and previous risperidone use. A clinically relevant increase in body weight (≥7% weight gain) occurred in one-fourth of the participants who completed the 24-week study.

CONCLUSION

Switching to paliperidone ER improved the subjective well-being and attitudes towards antipsychotic medication in patients with schizophrenia. Exploratory analyses revealed that these improvements were particularly pronounced in patients who had been treated with risperidone before treatment with paliperidone ER.

Long-reach 10-Gb/s RSOA-based WDM PON employing QPSK signal and coherent receiver

We demonstrate a long-reach wavelength-division-multiplexed passive optical network (WDM PON) operating at the symmetric rate of 10.3 Gb/s. For the cost-effectiveness, we realize the upstream transmission by utilizing directly-modulated TO-can packaged reflective semiconductor optical amplifiers (RSOAs) and digital coherent receivers. In addition, to overcome the limited modulation bandwidth of this TO-can packaged RSOA (~2.2 GHz) and operate it at 10.3 Gb/s, we utilize the quadrature phase shift keying (QPSK) format and the electronic phase equalization technique. The result shows that we can extend the maximum reach of the 10.3-Gb/s RSOA-based WDM PON to ~80 km without using any remote amplifiers.

Different safety profiles of risperidone and paliperidone extended-release: a double-blind, placebo-controlled trial with healthy volunteers

OBJECTIVE

The present study investigated subjective experiences related to secondary negative symptoms and cognitive performance in healthy volunteers in response to the repeated administration of paliperidone extended-release (ER) and risperidone in a double-blind, placebo-controlled trial.

METHODS

Participants (n = 32) received a fixed dose of one of three study medications for three consecutive days: 6 mg of paliperidone ER, 3 mg of risperidone, or placebo. Subjects were evaluated at baseline and after the first and third administrations of the medications by using the Neuroleptic-Induced Deficit Syndrome Scale and the Scale for the Assessment of Negative Symptoms. Cognitive function was measured at baseline and after the third administration of the medications by using the computerized neuropsychological test.

RESULTS

Risperidone was associated with more detrimental subjective experiences compared with paliperidone ER and placebo (p < .05), and these differences persisted after controlling for mental and physical sedation. Analysis of computerized neuropsychological test variables revealed significant differences in the changes in Stroop word-color test results from baseline between the paliperidone ER and risperidone groups (p < .005) and between the placebo and risperidone groups (p < .005).

CONCLUSIONS

These results suggest that paliperidone ER may have a better safety profile than risperidone in terms of negative subjective experiences and cognitive function among normal volunteers.

Correlation-based OTDR for in-service monitoring of 64-split TDM PON

We demonstrate that the correlation-based optical time domain reflectometer (OTDR) can be used for the in-service monitoring of the 64-split time-division-multiplexed passive optical network (TDM PON). To achieve this objective, we superimpose a pseudo noise (PN) sequence having a modulation depth of ~40% to the downstream signal and utilize it for the correlation detection. However, the use of such a large PN sequence can seriously deteriorate the performance of the downstream receiver. Thus, we apply 8B/10B encoding to the downstream signal, and then filter out the PN sequence at the downstream receiver by using a high-pass filter. As a result, the power penalty caused by the use of a large PN sequence is reduced to an acceptable level (<3 dB), while the dynamic range of this correlation-based OTDR is increased to ~30 dB. We then evaluate the performance of the proposed OTDR in the fiber link similar to the optical distribution network of the 64-split TDM PON. The results show that this OTDR can detect both the reflective and non-reflective events occurred in the feeder fiber as well as the reflective events in the drop fibers even in the 64-split TDM PON.

Effects of Aripiprazole and Haloperidol on Fos-like Immunoreactivity in the Prefrontal Cortex and Amygdala

Objective

Aripiprazole, a dopamine system stabilizer, shows efficacy against both negative symptoms and positive symptoms in patients with schizophrenia. The aim of this study was to investigate the effects of aripiprazole and haloperidol on c-FOS expression in rat brain.

Methods

Aripiprazole (1, 10 and 30 mg/kg, i.p.) and haloperidol (0.1 and 1 mg/kg, i.p.) were administered to adult Male Sprague-Dawley rats. After 2 h of drug or vehicle administration, the rats were killed and their brains were removed and perfused with fixative, then cut into 40 µm slices on a freezing microtome. Brain regions of interest were the medial prefrontal cortex (mPFC), the nucleus accumbens core and shell (NAC-C and NAC-S), the hippocampus (CA1, CA3 and DG), the central amygdala (Ce), the basolateral amygdala (BL) and the temporal cortex (Tc). Immunohistochemistry was performed to label cell bodies containing c-FOS.

Results

The administration of aripiprazole at all doses (1, 10 or 30 mg/kg) resulted in greater Fos-like immunoreactivity (FLI) in the investigated brain areas, as compared to the vehicle. Comparable increases in FLI were demonstrated in the NAC-C and NAC-S in response to both aripiprazole and haloperidol treatment. The administration of haloperidol (0.1 or 1 mg/kg) also resulted in greater FLI in the investigated brain areas, except the mPFC, where no changes were observed. In the Ce and BL, a significant increase in Fos-positive neurons was observed only with 0.1 mg/kg of haloperidol.

Conclusion

Both aripiprazole and haloperidol increased FLI in limbic areas, which are considered important targets of antipsychotic drugs. The differential action of aripiprazole on FLI in the amygdala and mPFC as compared to haloperidol may be a good way to differentiate atypical from typical antipsychotics.

Large-scale mitochondrial DNA deletions in weak goslings

1. Evidence has accumulated in mammals to support the idea that mitochondrial DNA (mtDNA) deletions and mutations might contribute to ageing and reproductive failure. White Roman geese were monitored to evaluate the effect of large-scale deletions of mtDNA in an avian species. 2. A total of 340 samples from 114 dead embryos, 111 weak goslings, and 115 normal goslings were used in this experiment. The regions of these two large-scale mtDNA deletions, ΔmtDNA6829 and ΔmtDNA6992, were between the COI and ND5 genes. A 3·6% (4 out of 111) positive sample was detected in the weak goslings. In contrast, no large-scale mitochondrial DNA deletions were detected in either the dead embryos (0 out of 114) or the normal goslings (0 out of 115). 3. Large-scale mtDNA deletions may be a factor causing weak goslings.

Clinical significance of tumor suppressor PTEN in colorectal carcinoma

BACKGROUND

It has been demonstrated that the deletion, mutation, hypermethylation and subcellular location of the tumor suppressor phosphatase and tensin homologue (PTEN) are closely correlated with carcinogenesis, progression and prognosis of malignancy. Both mutation and the microsatellite instability of the PTEN gene influence regulation of the PI3K/Akt signaling pathway. This study investigated whether loss of nuclear PTEN is correlated with chemosensitivity, clinicopathological parameters and survival.

METHODS

Intracellular levels of PTEN of multiple cell lines of colorectal carcinoma (CRC) were evaluated by Western blotting and immunocytochemistry. The chemosensitivity of cell lines with various expression levels of PTEN was evaluated using 5-flurouracil (5-FU), oxaliplatin and irinotecan (CPT), and clinical significance was evaluated by immunohistochemical analysis of 133 CRC specimens.

RESULTS

Colon cancer cell lines HT-29, LoVo and SW480 differed in expression of PTEN, with high, moderate and low levels, respectively. HT-29 and LoVo PTEN expression was suppressed by a low concentration of 5-FU and oxaliplatin; however, SW480 was insensitive to these chemotherapeutic agents. Nuclear PTEN was overexpressed in most (>80%) normal colon mucosa samples, but the incidence significantly decreased (89.2% → 53.4%) in the CRC group. PTEN in the nucleus was negatively correlated with tumor size and vascular invasion in CRC, and CRC patients with negative PTEN expression in the nucleus exhibited poor survival.

CONCLUSION

Cell lines with a high expression of PTEN are sensitive to chemotherapy with 5-FU and oxaliplatin. Nuclear PTEN expression gradually decreases after malignant transformation, and loss of PTEN expression in the nucleus is associated with tumor progression and poor clinical outcome in CRC.

Phasor monitoring of DxPSK signals using software-based synchronization technique

We develop a novel phasor monitor to obtain the constellation diagram from asynchronously sampled data measured by using the delay-detection technique. This phasor monitor consists of three parts; a phase-adjustment-free delay-interferometer, an optical front-end made of three photodetectors, and analog-to-digital (A/D) convertors, and a digital signal processor. We operate the A/D convertor at the sampling rate much slower than the symbol rate and acquire the data asynchronously. However, despite the use of such a slow and asynchronous sampling rate, we obtain the clear eye and constellation diagrams by utilizing the software-based synchronization technique based on a novel phased-reference detection algorithm. Thus, the proposed phasor monitor can be implemented without using high-speed A/D convertors and buffer memories, which have been the major obstacles for the cost-effective realization of the phasor monitor. For a demonstration, we realize the proposed phasor monitor by using an A/D converter operating at 9.77 MS/s and used it for the constellation monitoring and bit-error-rate (BER) estimation of 10.7-Gsymbol/s differential quadrature phase-shift keying (DQPSK) and differential 8-ary phase-shift keying (D8PSK) signals.

Age-specific effects of 6-hydroxydopamine lesions of the rat medial prefrontal cortex on stress-induced c-fos expression in subcortical areas

As adolescence is a critical period when dopaminergic neuronal maturation peaks, we hypothesized that 6-hydroxydopamine (OHDA) lesions of the medial prefrontal cortex (mPFC) in adolescent rats would have more negative effects than lesions in adult rats. Therefore, we investigated the effects of 6-OHDA lesions of the mPFC in adolescent and adult rats on stress-induced c-fos expression in the brain. Adolescent and adult Sprague-Dawley rats, aged 4 and 7 weeks on arrival, respectively, were studied. 6-OHDA (8.0 microg) for the lesion groups and ascorbic acid for the sham groups were injected bilaterally into the mPFC. All animals were pretreated with desipramine 30 min before being anesthetized. The control group did not undergo any surgery-related procedure except the desipramine injection. After recovery for 1 week, the rats were subjected to restraint stress for 1 h. Immediately after the stress, the rats were killed and c-fos immunohistochemistry was examined. The c-fos expression in the nucleus accumbens core (AcbC), nucleus accumbens shell (AcbSh), CA1, CA3, dentate gyrus (DG), central amygdaloid (Ce), basolateral amygdaloid (BL), and temporal cortex (Tc) was compared. Adolescent rats with 6-OHDA lesions subjected to restraint stress had greater c-fos expression in the AcbC, AcbSh, DG, Ce, BL, and Tc, compared to the sham and control groups, whereas these differences were not observed among the adult groups. These results suggest that a hypodopaminergic state in the mPFC of adolescent rats, but not adult rats, is related to increased sensitivity to stress, suggesting that damage to or maldevelopment of dopaminergic neurons during adolescence has an age-specific effect. Further research is warranted to investigate the mechanism of the age-specific effect of 6-OHDA lesions of the mPFC.

Transmission of 1.25-Gb/s PSK signal generated by using RSOA in 110-km coherent WDM PON

We generate the phase-modulated signal by utilizing the chirp characteristics of the directly-modulated reflective semiconductor optical amplifier (RSOA) for the cost-effective realization of a long-reach wavelength-division-multiplexed passive optical network (WDM PON). We first investigate the relation between the amplitude and phase modulation indices in a directly-modulated RSOA and optimize these modulation indices to maximize the symbol distance on the constellation diagram. The results show that, by operating the RSOA under this optimum condition, we can achieve the excellent receiver sensitivity of -49.8 dBm at 1.25 Gb/s. We implement a long-reach WDM PON by using the phase-modulated RSOAs and self-homodyne receivers, and demonstrate the error-free transmission of 1.25-Gb/s signal over a 110-km long link without using any optical amplifiers.

Effects of 6-hydroxydopamine lesioning of the medial prefrontal cortex on social interactions in adolescent and adult rats

Bilateral depletion of dopamine (DA) in the medial prefrontal cortex (mPFC) following local infusions of 6-hydroxydopamine (6-OHDA) was reported to affect mesolimbic DA neurotransmission and augment spontaneous and amphetamine-induced locomotion. However, the effects of 6-OHDA lesioning of the mPFC of adolescent rats have never been investigated. Given that dopaminergic neurons reach the peak of maturation during adolescence, we hypothesized that 6-OHDA lesioning of the mPFC during adolescence would have greater impact on subsequent behavioral parameters than would such lesioning during adulthood. The aim of this study was to investigate the effects of 6-OHDA lesioning of the mPFC on the open-field activities and novel investigative and socially interactive behaviors of adolescent and adult rats. Using a stereotaxic apparatus, 6-OHDA (8.0 microg) was injected bilaterally into the mPFC of adolescent and adult rats. After a 1-week recovery period, rats were placed in an open-field chamber, and spontaneous locomotion and other behaviors were monitored. Next, a novel toy was place in the center and behavioral responses were observed. One day later, socially interactive behaviors were measured by placing the lesioned rats into a cage with four unfamiliar rats matched for age. The tests of locomotor activity and novel investigative behaviors revealed no significant differences between the lesioned and sham groups of adolescent or adult rats. Grooming and socially interactive behaviors were significantly lower in the adolescent and adult lesioned groups than in each sham group. Interestingly, we observed more extensive impairment in socially interactive behaviors among the adolescent lesioned rats compared to the adult lesioned rats. The present study indicates that DA depletion in the mPFC causes significantly reduced grooming and socially interactive behaviors; this phenomenon may be comparable to the negative symptoms observed in schizophrenia. Further research is warranted to investigate the mechanisms underpinning the detrimental effects of 6-OHDA lesioning of the mPFC on social behaviors.

Quantitation of fatty acid ethyl esters in human meconium by an improved liquid chromatography/tandem mass spectrometry

This paper reports the development and validation of an improved assay for quantitation of fatty acid ethyl esters (FAEEs) in human meconium using liquid chromatography/tandem mass spectrometry (LC-MS/MS). FAAEs (ethyl laurate, ethyl myristate, ethyl palmitate, ethyl palmitoleate, ethyl stearate, ethyl oleate, ethyl linoleate, ethyl linolenate, and ethyl arachidonate) and the internal standard (I.S.), ethyl heptadecanoate, were separated by reverse phase HPLC and quantified by MS/MS using electrospray ionization (ESI) and multiple reaction monitoring (MRM) in the positive ionization mode. The absolute recovery of FAEEs varied from 55+/-10% for 0.33 nmol/g (100 ng/g) of ethyl linoleate up to 86+/-8% for 1.55 nmol/g (500 ng/g) of ethyl miristate. The LODs and LOQs varied from 0.01 to 0.08 nmol/g and from 0.02 to 0.27 nmol/g, respectively. The assay has been successfully applied to examine the FAEE levels in 81 meconium samples from babies born to mothers reporting alcohol consumption, to varying degrees, during pregnancy.

What factors are related to delayed treatment in individuals at high risk for psychosis?

BACKGROUND

Previous studies have shown that the individuals at high risk for psychosis suffer from depression, anxiety, and deficits in social functioning. The present report describes help-seeking behaviours, baseline psychopathology, and duration of attenuated psychotic symptoms (DUAPS) and their associations with other variables.

METHODS

Using the Comprehensive Assessment of At-Risk Mental States (CAARMS), we conducted systematic evaluations of individuals at high risk for psychosis. Help-seeking behaviours, current Axis I diagnoses, DUAPS, and baseline psychopathology were investigated. Demographic and clinical characteristics of short and long DUAPS groups were compared.

RESULTS

Thirty-eight subjects were recruited from nine centres. Participants seldom sought psychiatric services at their first help-seeking contact, and the mean DUAPS was 22.00 +/- 28.59 months. Most participants had current Axis I diagnoses, and depressive disorder NOS was the most common of these. Higher levels of depression, anxiety, obsessive-compulsive symptoms, and functional impairment were also identified. We found no significant differences between short and long DUAPS groups in baseline psychopathology. However, we observed significantly lesser distressing intensity of thought contents and significantly greater social impairment in the long-DUAPS group.

CONCLUSION

These findings suggest that high-risk subjects frequently received delayed treatment despite symptomatic distress and functional impairment. No direct evidence supporting the delayed effect of the DUAPS on baseline psychopathology was found.

A descriptive study of pathways to care of high risk for psychosis adolescents in Korea

AIM

To cut down on the time of untreated psychosis it is necessary to know the pathways to care of patients. We designed this study to examine patients' help seeking contacts. There have only been a few studies in developing countries examining the pathways to care, and this research is the first of its kind in Korea focusing on adolescents.

METHODS

The sample consisted of 18 adolescents aged 15 to 18 years. We evaluated the Comprehensive Assessment of At-Risk Mental States and 'pathway to care' at the initial evaluation of the patient. 'Pathways to care' data was collected via an interview with the patient. In each interview, the prospective description of each participants' help contacts, from the initial suspected psychiatric illness until the first psychiatric help was noted.

RESULTS

In total, 14 contacts were made among the 18 patients. Of these, the most common contacts were either through a family member, teacher or the Internet. Thirty-three percent of high risk for psychosis adolescents sought help themselves.

CONCLUSION

Our findings showed that the Internet and family members were the key contacts in as many as 57% of high risk adolescents. In Korea, patients and caregivers both serve important roles in help seeking efforts. It is important for adolescents who are at high risk of psychosis in Korea to have easy access to information in recognizing mental health problems. Therefore, mass in-depth educating and public campaigning are important in recognizing the symptoms of early psychosis and in doing so can reduce the DUP.

Clozapine-induced tardive dyskinesia in schizophrenic patients taking clozapine as a first-line antipsychotic drug

OBJECTIVE

Clozapine causes few extrapyramidal symptoms and is recommended as a treatment drug for severe tardive dyskinesia (TD). However, several case reports have suggested that clozapine could also cause TD. We investigated whether clozapine used as a first-line antipsychotic drug can cause TD.

METHOD

We identified 101 patients at Yanbian Socio-Mental Hospital and Yanbian Brain Hospital in China who had received clozapine as a primary antipsychotic drug since their first episode of illness and evaluated the prevalence rate, type, and severity of TD using the Extrapyramidal Symptoms Rating Scale (ESRS). The criterion for TD was a score of > or = 3 on one item or 2 on two or more items of the ESRS.

RESULTS

The mean age and duration of illness of the patients were 38.93+/-8.36 and 12.88+/-6.90 years, respectively. The mean duration of clozapine treatment was 12.10+/-6.26 years. The prevalence of TD was 3.96% (4/101). Compared to patients without TD, patients with TD had a long duration of illness and clozapine treatment; all had the orolingual type of TD. TD was relatively mild, with a mean score of 4.75, and tended to accentuate with an activation procedure of rapid pronation and supination of the hands.

CONCLUSIONS

These results suggest that clozapine may cause TD; however, the prevalence is low and the severity is relatively mild, with no or mild self-reported discomfort. Therefore, we recommend that regular examination for TD using the activation procedure should be performed in patients who use clozapine on a long-term basis.

Optical performance monitoring technique using asynchronous amplitude and phase histograms

We report a new optical performance monitoring technique based on the amplitude and phase histograms of the optical signal. The amplitude and phase histograms are obtained by using an intradyne receiver and the asynchronous delay-tap sampling method. From these histograms, we can evaluate the amplitude and phase Q-factors of the optical signal regardless of its modulation format. In addition, by using these Q-factors, we can estimate the bit-error rate (BER) of the monitoring signal.

Transmission of 108-Gb/s PDM 16ADPSK signal on 25-GHz grid using non-coherent receivers

We demonstrate the transmission of 108-Gb/s polarization-division-multiplexed (PDM) 16-ary amplitude- and differential phase-shift-keying (16ADPSK) signal by using a non-coherent receiver. We generate the 16ADPSK signal by using a differential 8-ary phase-shift-keying (D8PSK) modulator and a phase-distortion-free amplitude-shift-keying (ASK) modulator. On the other hand, the receiver is implemented by using a delay interferometer based on a 3x3 fiber coupler and the data-aided phase-noise estimation (DAPNE) algorithm. By using these transmitter and receiver, we achieve a nearly quantum-limited receiver sensitivity in the back-to-back condition. In addition, we examine the possibility of transmitting 108-Gb/s signals on a 25-GHz grid without using the coherent detection technology. The results show that we can secure a sufficient optical-signal-to-noise (OSNR) margin after the transmission of 80-km long dispersion managed link. The achieved spectral efficiency is 4.0 bit/s/Hz.

Effect of donepezil added to atypical antipsychotics on cognition in patients with schizophrenia: an open-label trial

BACKGROUND

Despite the beneficial effects of atypical antipsychotics on cognition, many schizophrenic patients continue to suffer from cognitive impairment. Postmortem findings suggest that altered cholinergic activity is involved in cognitive impairment in schizophrenia.

OBJECTIVE

This study investigated whether adjunctive donepezil added to atypical antipsychotics can improve cognition in schizophrenic patients.

METHOD

We conducted an open-label trial of donepezil, at doses of up to 10 mg/day for 12 weeks, added to ongoing atypical antipsychotics in 28 stable schizophrenic patients. At baseline and 12 weeks, the patients were evaluated using the Positive and Negative Syndrome Scale (PANSS), Schizophrenia Cognition Rating Scale (SCoRS), and Computerized Neurocognitive Function Test (CNT).

RESULTS

Donepezil treatment resulted in significant improvements in attention, memory, psychomotor speed, and mental set-shifting ability.

CONCLUSIONS

Adjunctive treatment with donepezil improves cognition in patients with schizophrenia who are stabilized on atypical antipsychotics. Further studies controlling for smoking, age, and severity of cognitive impairment of the participants are needed.

Daytime sleepiness and sleep quality among Malaysian medical students

Poor sleep quality and daytime somnolence is reported to be associated with cardiovascular events, road traffic accident, poor academic performance and psychological distress. Some studies documented that it is prevalent in most populations but its frequency among medical students has not been documented in Malaysia. This is a self-administered questionnaire survey of medical students from International Medical University, Malaysia. Daytime sleepiness of medical students was assessed using Epworth Sleepiness Scale (ESS). Student scoring ESS > 11 was regarded as having excessive daytime sleepiness. Psychological distress was measured using 12-item General Health Questionnaire (GHQ-12). A total of 799 medical students participated in this survey (response rate 69.5%). Daytime sleepiness occurred in 35.5%, psychological distress was present in 41.8% and 16.1% reported bad sleep quality. Daytime sleepiness was significantly more common among the clinical students, those with self-reported bad sleep quality and psychological distress; but unrelated to the number of hours sleep at night. We have documented high prevalence of daytime sleepiness, poor sleep quality and psychological distress. Higher frequency among clinical students and the significant relationship with psychological distress suggest possible link to the stressful clinical training.

Effect of PDL-induced coherent crosstalk on polarization-division-multiplexed direct-detection systems

We analyze the effect of polarization-dependent loss (PDL) on the performance of the polarization-division-multiplexed (PDM) signals in direct-detection systems. We present the theoretical analysis of the sensitivity penalty caused by PDL-induced coherent crosstalk and compare the results with experimental data obtained by using a simple variable PDL emulator based on a LiNbO3 Mach-Zehnder modulator. Also presented is the performance degradation caused by the polarization misalignment between the received signals and the polarization beam splitter at the receiver in the presence of PDL.

High-strength nitrogenous wastewater treatment in biofilm and granule anammox processes

Biofilm and granule reactors were employed to remove nitrogen via an anammox reaction applying synthetic nitrogen wastewater, whose concentration was in the range of 20 to 1,400 mg N/L as total nitrogen. A biofilm reactor was packed with non-woven fabric and a granule reactor was filled with anaerobic granular sludge taken from the brewery wastewater treatment plant. Both reactors were seeded with Planctomycetes KSU-1 and operated for 450 days. The biofilm reactor showed high NH(4) (+)-N and NO(2) (-)-N removal efficiencies of over 88% and 94%, respectively, until total nitrogen concentration was reached at 800 mg N/L. However, the biofilm reactor showed severe inhibition at over 1,000 mg N/L of total nitrogen due to nitrogen overloading. The granule reactor revealed better nitrogen removal performance than the biofilm reactor, showing high NH(4) (+)-N and NO(2) (-)-N removal efficiencies of over 90%, even at a total nitrogen concentration of 1,400 mg N/L. However, aggregation of anammox bacteria grown in the sludge bed after long-term operation resulted in the deterioration of nitrogen. The removal ratio of NH(4) (+)-N and NO(2) (-)-N was close to 1:1, suggesting other reactions related to ammonium oxidation could occur simultaneously. Free ammonia inhibition as well as NO(2) (-)-N could be significant when high-strength nitrogenous wastewater was applied.