Factors associated with household transmission of SARS-CoV-2 omicron variant to health care workers: A retrospective cohort study.

AIM: The aim of this study was to determine the risk factors for household transmission of the omicron variant of SARS-CoV-2. BACKGROUND: The household infection rate has been reported to be higher for the omicron variant than for non-omicron variants of SARS-CoV-2. Determination of the risk factors for household transmission of the omicron variant is therefore important. DESIGN: A Retrospective Cohort Study was conducted. METHODS: When family members of health care workers (HCWs) were found to be infected with SARS-CoV-2, the HCWs had to receive two nucleic acid amplification tests for SARS-CoV-2: immediately after and 5 to 10 days after the onset of COVID-19 in the family members. Risk factors of household transmission were analysed by comparing cases (HCWs infected with SARS-CoV-2) and controls (HCWs not infected with SARS-CoV-2) using multivariable analysis. RESULTS: Unvaccinated status (OR: 3.97), age of index cases (≤6 years) (OR: 1.94) and staying at home with index cases (OR: 10.18) were risk factors for household transmission. CONCLUSION: If there is a strong desire to avoid household infection, family members infected with SARS-CoV-2 should live separately during the period of viral shedding.

Efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli.

BACKGROUND: The efficacy and safety of colistin for the treatment of infections caused by multidrug-resistant gram-negative bacilli have been poorly investigated in Japanese patients. This study was performed to investigate the efficacy and safety of colistin in Japanese patients by analyzing a considerable number of cases. Furthermore, we evaluated the relationship between the plasma concentration and efficacy and safety of colistin in some cases. METHODS: A retrospective cohort study was conducted at Hokkaido University Hospital, analyzing patients treated with colistin (colistimethate sodium) during the period from January 2007 to December 2019. RESULTS: Overall, 42 cases were enrolled. Favorable clinical response was observed in 25 cases (59.5%), with an all-cause 30-day mortality of 33.3% (14/42 cases). Microbiological eradication was achieved in 18 cases (42.9%). Nephrotoxicity was observed in 20 cases (47.6%) and was mild and reversible in all cases. Plasma trough concentrations of colistin determined in nine patients correlated with changes in serum creatinine concentration (⊿) and creatinine clearance (%). The cutoff value of colistin trough concentration for nephrotoxicity was 2.02 µg/mL. CONCLUSION: Our results showed approximately 60% clinical efficacy of colistin therapy against infections caused by multidrug-resistant gram-negative bacilli in the patients. Further studies with larger populations are needed to elucidate the efficacy and safety of colistin in Japanese patients.

Necessity for a Significant Maintenance Dosage Reduction of Voriconazole in Patients with Severe Liver Cirrhosis (Child-Pugh Class C).

Therapeutic drug monitoring for voriconazole, an antifungal agent, is essential for maximizing efficacy and preventing toxicity. The aim of this study was to elucidate the optimal maintenance dose of voriconazole in patients with severe liver cirrhosis (Child-Pugh class C) by reviewing the plasma trough concentrations obtained by therapeutic drug monitoring and daily doses of voriconazole. We retrospectively evaluated 6 patients with Child-Pugh class C cirrhosis who received oral voriconazole treatment and were liver transplant recipients or were awaiting liver transplantation. We compared their voriconazole trough concentrations and daily maintenance doses to those of patients who did not have liver cirrhosis (n=56). We found that plasma voriconazole trough concentrations in all patients with Child-Pugh class C were almost within therapeutic range, and the median plasma trough concentration at steady state was not significantly different from that of patients who did not have liver cirrhosis. In addition, the median daily maintenance dose of voriconazole was significantly lower (2.13 mg/kg/d) than that of the control patients (6.27 mg/kg/d), suggesting that trough voriconazole concentrations are elevated in Child-Pugh class C patients. Thus, we conclude that oral voriconazole maintenance doses in patients with Child-Pugh class C should be reduced to approximately one-third that of patients with normal liver function, with the follow-up dose adjusted by therapeutic drug monitoring.

Association of wastewater SARS-CoV-2 load with confirmed COVID-19 cases at a university hospital in Sapporo, Japan during the period from February 2021 to February 2023.

Wastewater surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been used to monitor trends in SARS-CoV-2 prevalence in a community without being influenced by clinical testing resources or healthcare-seeking behaviors. Since the rate of mortality from COVID-19 is higher in elderly patients with comorbidities, it is important to protect hospitalized patients from nosocomial infections caused by SARS-CoV-2. SARS-CoV-2 dissemination within a hospital ward was mostly mediated by healthcare workers (HCWs) and patients. HCWs need to understand the occurrence of COVID-19 and reflect this in their infection control measures. The aim of the present study was to determine the potential of SARS-CoV-2 RNA in wastewater as a leading indicator of confirmed COVID-19 cases at a university hospital. The trend of the geometric mean RNA concentrations in wastewater collected in Sapporo corresponded well with that of the number of newly confirmed COVID-19 cases at Hokkaido University Hospital between February 15, 2021 and February 26, 2023 (Pearson's r = 0.8823, p < 0.0001). Our results showed that monitoring SARS-CoV-2 RNA in municipal wastewater was useful for estimating the number of COVID-19 patients in healthcare facilities in the city.

Correlation between antibiotic use and resistance of gram-negative bacteria at a university hospital in Japan from 2013 to 2021: a study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system.

OBJECTIVES: The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures. We aimed to investigate the correlation between antibiotic use and AMR at a university hospital from 2013 to 2021 in a time series analysis using the J-SIPHE system. We also studied this correlation in each ward (inter-ward analysis). METHODS: Data on antibiotic use and resistance rates were collected from the J-SIPHE system, except for the resistance rate in each ward, which was calculated from the source data prepared for this system. RESULTS: Piperacillin/tazobactam use was positively correlated with piperacillin/tazobactam resistance in Escherichia coli and Klebsiella pneumoniae in the inter-ward analysis, and in Pseudomonas aeruginosa in both analyses. Carbapenem use was positively correlated with meropenem resistance in Enterobacter cloacae in the time series analysis and in P. aeruginosa in both analyses, and imipenem/cilastatin resistance in P. aeruginosa in inter-ward analysis. Quinolone use was positively correlated with levofloxacin resistance in E. coli in both analyses, and in K. pneumoniae in inter-ward analysis. CONCLUSIONS: This is the first study to investigate the correlation between antibiotic use and AMR at a single hospital in time series and inter-ward analyses using the J-SIPHE system and data prepared for this system, suggesting that this system may be useful for promoting AMR measures.

Breaking away from an endemic state of multidrug-resistant Pseudomonas aeruginosa by daily sink disinfection.

The detection rate of multidrug-resistant Pseudomonas aeruginosa in patients admitted to 2 wards and the intensive care unit decreased from 20.3% (129 of 636 isolates) to 4.2% (37 of 889 isolates) after the start of disinfection of hand washing sinks using alkyl diaminoethylglycine hydrochloride.

Correlation between antibiotic use and antibiotic resistance: A multicenter study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system in Hokkaido, Japan.

BACKGROUND: The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures in participating medical institutions nationwide and is intended to be used for promotion of AMR measures in participating facilities and their communities. This multicenter study aimed to determine the usefulness of the J-SIPHE system for evaluating the correlation between antibiotic use and antibiotic resistance in Hokkaido, Japan. METHODS: Data on antibiotic use and detection rate of major resistant Gram-negative bacteria at 19 hospitals in 2020 were collected from the J-SIPHE system, and data correlations were analyzed using JMP Pro. RESULTS: The detection rate of carbapenem-resistant Pseudomonas aeruginosa was significantly positively correlated with carbapenem use (Spearman's ρ = 0.551; P = .015). There were significant positive correlations between the detection rate of fluoroquinolone-resistant Escherichia coli and the use of piperacillin/tazobactam, carbapenems, and quinolones [ρ = 0.518 (P = .023), ρ = 0.76 (P < .001), and ρ = 0.502 (P = .029), respectively]. CONCLUSIONS: This is the first multicenter study to investigate the correlation between antibiotic use and antibiotic resistance using the J-SIPHE system. The results suggest that using this system may be beneficial for promoting AMR measures.

Effect of antithyroid drug on chick embryos during the last week of development: delayed hatching and decreased cerebellar acetylcholinesterase activity.

AIM: Hypothyroid state during embryogenesis disturbs normal growth and brain development, influencing later life. To evaluate the harmful consequences of the state during embryogenesis using an animal model, we inhibited thyroid hormone biosynthesis in chick embryos by using methimazole (MMI). MATERIAL AND METHODS: Typically, embryos were treated with MMI (20 µmol/egg) on day 14, and examined on specific days. RESULTS: Of the control embryos, 94% hatched on day 21, whereas 0% and 60% of MMI-treated embryos hatched on days 21 and 24, respectively. MMI retarded the rates of bodyweight gain as well as liver and heart development, and delayed hatching. However, the external differences in appearance and differences in the weights of the newly hatched control chicks on day 21 and the MMI-treated chicks on day 24 were less obvious. Embryos treated with MMI exhibited increased mass in their brain parts on day 24. Most notably, the treatment resulted in a 1.35-fold increase in cerebellum weight compared to that of the untreated animals. Acetylcholinesterase activity in the cerebellum on the day of hatching decreased significantly to 0.85-fold that of the untreated controls. Thyroid hormone receptor ß mRNA was detected from day 12 and dramatically expressed from day 19 to the day of hatching. CONCLUSION: The 'fertilized hen's egg-chick embryo-chick system' is an appropriate animal model for investigating the hypothyroid state during embryogenesis. Decreased cerebellar acetylcholinesterase activity after MMI treatment was assumed to relate to a mechanism of motor and cognitive deficits in congenital hypothyroidism.

Clinical outcomes of intervention for carbapenems and anti-methicillin-resistant Staphylococcus aureus antibiotics by an antimicrobial stewardship team.

BACKGROUND: There are no reports on the effects of interventions, such as discontinuation and change and/or de-escalation of carbapenems and anti-methicillin-resistant Staphylococcus aureus (MRSA) antibiotics by an antimicrobial stewardship team focusing on detailed patient outcomes. This study aimed to evaluate these effects. METHODS: This retrospective cohort study was conducted at a tertiary care hospital from December 2018 to November 2019. RESULTS: Favorable clinical responses were obtained in 165 of 184 cases (89.7%) in the intervention-accepted group, higher than those in the not accepted group (14/19 cases, 73.7%; P = .056). All-cause 30 day mortality was lower in the accepted group than in the not accepted group (1.1% and 10.5%, respectively; P = .045). The microbiological outcomes were similar between the two groups. Duration of carbapenem and anti-MRSA antibiotic use in the accepted group was significantly lower than that in the not accepted group (median [interquartile range]: 8 days [5-13] versus 14 days [8-15], respectively, P = .026 for carbapenem; 10 days [5.3-15] vs 15.5 days [13.8-45.3], respectively, P = .014 for anti-MRSA antibiotic). CONCLUSIONS: This is the first study to investigate the effects of interventions such as discontinuation and change and/ or de-escalation of antibiotics on detailed outcomes. Our intervention could reduce the duration of carbapenem and anti-MRSA antibiotic use without worsening clinical and microbiological outcomes.

Effects of naturally occurring polymethyoxyflavonoids on cell growth, p-glycoprotein function, cell cycle, and apoptosis of daunorubicin-resistant T lymphoblastoid leukemia cells.

Effects of polymethoxyflavonoids tangeretin and nobiletin and the related polyphenolic compounds baicalein, wogonin, quercetin, and epigallocatechin gallate on the cell growth, P-glycoprotein function, apoptosis, and cell cycle of human T lymphoblastoid leukemia MOLT-4 and its daunorubicin-resistant cells were investigated. The IC50 values of these compounds on the cell growth were 7.1-32.2 micromol/L, and the inhibitory effects were observed to be almost equal to the parent MOLT-4 and the daunorubicin-resistant cells. Tangeretin and nobiletin showed the strongest effects with the IC50 values of 7.1-14.0 micromol/L. These polymethoxyflavonoids inhibited the P-glycoprotein function and significantly influenced the cell cycle (p<.05), whereas they did not induce apoptosis.

Protective effects of coffee-derived compounds on lipopolysaccharide/D-galactosamine induced acute liver injury in rats.

OBJECTIVES: The protective effects of coffee-derived compounds on lipopolysaccharide/D-galactosamine (LPS/D-GalN) induced acute liver injury in rats were investigated. METHODS: Wistar rats were orally administered saline (control) or one of the test compounds (caffeine, chlorogenic acid, trigonelline, nicotinic acid or eight pyrazinoic acids) at a dose of 100 mg/kg, respectively. This was followed by intraperitoneal injection with LPS (100 mug/kg)/D-GalN (250 mg/kg) 1 h after administration of the test compounds. Blood samples were collected up to 12 h after LPS/D-GalN injection, followed by determination of plasma aspartate aminotransferase, alanine aminotransferase, tumour necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10) levels. KEY FINDINGS: Plasma aspartate aminotransferase and alanine aminotransferase levels were significantly increased after LPS/D-GalN-treatment, but were suppressed by pretreatment with caffeine (n = 5), nicotinic acid, non-substituted pyrazinoic acid or 5-methylpyrazinoic acid (n = 6, respectively) 12 h after LPS/D-GalN-treatment (P < 0.01, respectively). Moreover, the animals pretreated with these test compounds showed significantly higher survival rates (83-100%) compared with the control (23%). Only pretreatment with caffeine significantly suppressed the LPS/D-GalN induced elevation of plasma TNF-alpha levels 1 and 2 h after LPS/D-GalN-treatment (P < 0.01, respectively). Pretreatment with caffeine, nicotinic acid or non-substituted pyrazinoic acid activated the LPS/D-GalN induced elevation of plasma IL-10 levels at 1 and 2 h, although there were no statistically significant differences in IL-10 levels between control and nicotinic acid or non-substituted pyrazinoic acid treated rats. CONCLUSIONS: The results suggest that caffeine, nicotinic acid, non-substituted pyrazinoic acid and 5-methylpyrazinoic acid can protect against LPS/D-GalN induced acute liver injury, which may be mediated by the reduction of TNF-alpha production and/or increasing IL-10 production.

Suppression of blood lipid concentrations by volatile Maillard reaction products.

OBJECTIVE: Although the chemistry of Maillard reaction products (MRPs) in foods has been well studied, few reports on the nutritional characteristics of MRPs in experimental animals and humans have been found. In this study, our interest was focused on the volatile MRPs (vMRPs) found in heated foods. METHODS: To confirm the metabolic oxidations of six methylpyrazines and pyrrole-2-carboxaldehyde to carboxylic acid derivatives in vivo, we administrated these compounds orally to Wistar rats with a single dose of 50 mg/kg. Urine samples were collected over 24 h, followed by determination using high-performance liquid chromatographic procedures. Eight pyrazinoic acids, 2-furoic acid, and 5-hydroxymethyl-2-furoic acid were administered orally to rats with a single dose of 100 or 300 mg/kg, and blood non-esterified fatty acid and triacylglycerol concentrations were analyzed. RESULTS: Monomethylpyrazine, 2,3-, 2,5-, and 2,6-dimethylpyrazine, trimethylpyrazine, and tetramethylpyrazine were metabolized to a corresponding pyrazinoic acid such as non-substituted pyrazinioic acid, 3-, 5-, or 6-methylpyrazinoic acid, 3,5-, 3,6-, and 5,6-dimethylpyrazinoic acid, and trimethylpyrazinoic acid, in appropriate yields, respectively. Further, pyrrole-2-carboxaldehyde was metabolized to pyrrole-2-carboxylic acid. Non-substituted and 5-methylpyrazinoic acid and 2-furoic and 5-hydroxymethyl-2-furoic acid showed significant non-esterified fatty acid-lowering effects. 5-Methyl and 6-methylpyrazinoic acid and 2-furoic acid showed significant triacylglycerol-lowering effects. Pyrazinoic acids with methyl substitution at position 3 showed no lipid-lowering effect. CONCLUSION: These results suggest that the vMRPs such as methylpyrazines are metabolized to their corresponding pyrazinoic acids. These vMRPs and their metabolites exhibit blood lipid-lowering effects in rats.

Protective effect of caffeine on streptozotocin-induced beta-cell damage in rats.

Many epidemiological studies have shown that coffee consumption reduces the risk of type 2 diabetes mellitus (T2D), although the reasons as to why remain unclear. In this study we investigated the effect of caffeine on pancreatic beta-cell damage in rats using the diabetogenic agent, streptozotocin (STZ). Wistar rats were given intraperitoneal injections of saline or caffeine (10, 50 or 100 mg kg(-1)). After 15 min, the rats were injected with a citrate buffer or 65 mg kg(-1) STZ. Three days after injection, an oral glucose tolerance test (OGTT) was performed on the rats. Furthermore, three days after the OGTT, the pancreas was isolated and homogenized, followed by determination of insulin content. STZ treatment significantly increased the plasma glucose level compared with the control at all times during the OGTT, which was significantly diminished by caffeine pretreatment at all doses. STZ treatment significantly decreased the plasma insulin level, however, which was not recovered by caffeine pretreatment. Pancreatic insulin content was significantly reduced by STZ treatment compared with the control, which was significantly recovered by caffeine pretreatment at a dose of 100 mg kg(-1) (P<0.01). We showed that caffeine protects pancreatic beta-cells against STZ toxicity. Further investigation will be required to understand the protective effect of caffeine against beta-cell destruction in T2D.

[Evaluation of the Stability of Indomethacin Oral Spray in Two Different Formulation Conditions].

　Indomethacin (IM) oral spray is a hospital preparation that is used to reduce pain from oral mucositis induced by radiotherapy and chemotherapy. IM oral spray consists of IM (0.25%) dissolved in KH2PO4-NaOH buffer (Formulation A) or Formulation A containing xylitol (Xyl) and glycerin (Gly) (Formulation B). To clarify the stability of IM oral spray in two different formulation conditions, we evaluated the residual rates of IM in these formulations to determine the optimal storage temperature and shelf-life. IM oral spray was stored at freezer temperature (-20°C), refrigerator temperature (4°C) and room temperature (25°C) for up to 16 weeks after preparation. The residual rate of IM was determined by using HPLC. The residual rates of IM in Formulation A and Formulation B after storage for 16 weeks at freezer temperature were ≥95%. When stored at refrigerator temperature, the residual rate of IM in Formulation A was 96.1% after 12 weeks, and the residual rates of IM in Formulation B were 95.8% after 2 weeks, 90.1% after 4 weeks and 72.7% after 12 weeks. These results suggested that Formulation A is stable for at least 12 weeks when stored at 4°C. However, degradation of IM seemed to be accelerated in the formulation containing Xyl and Gly, suggesting that the expiration date should be shortened to 2 weeks at 4°C. In addition, both formulations were stable for at least 16 weeks in a freezer, indicating that long-term preservation is possible.

[Possibility of Poor Outcomes after Treatment Using Teicoplanin at the Minimum Inhibitory Concentration of >2 µg/mL in Methicillin-resistant Staphylococcus aureus Bacteremia].

　Only minimal information exists regarding the treatment outcomes of patients suffering from methicillin-resistant Staphylococcus aureus (MRSA) bacteremia treated with teicoplanin (TEIC) when the TEIC minimum inhibitory concentration (MIC) is close to the upper limit of the "susceptibility range" according to the Clinical Laboratory Standards Institute (CLSI). We investigated the outcome of TEIC-treated patients in MRSA bacteremia, focusing on TEIC MIC against MRSA. A retrospective cohort study was conducted on patients with MRSA bacteremia. TEIC treatment failure was defined as any of the following: (1) all-cause 60-day mortality, (2) persistent bacteremia until the end of TEIC treatment, or (3) 30-day recurrence of MRSA bacteremia. Nineteen patients were enrolled, of whom 15 exhibited TEIC MICs ≤2 µg/mL and the remaining 4 exhibited >2 µg/mL. The rate of treatment failure and all-cause 60-day mortality in patients with MIC >2 µg/mL were significantly higher than those in patients with MIC ≤2 µg/mL [4 patients (100%) versus 4 patients (26.7%) (p=0.018) and 4 patients (100%) versus 2 patients (13.3%) (p=0.004), respectively]. Three of four patients (75%) with MIC >2 µg/mL had persistent bacteremia, which was quantitatively higher than in patients with MIC ≤2 µg/mL (1 of 7 patients, 14.3%). Our finding suggests that TEIC MIC >2 µg/mL may be related to poor treatment outcome in MRSA bacteremia, and that TEIC should not be used in this case.

Improved Clinical Outcomes in Patients with Positive Blood Culture by Proactive Intervention of Antimicrobial Use-Impact of Antimicrobial Stewardship Program Implementation on Clinical Practice.

Bacteremia is one of the most serious infectious illness resulting from nosocomial infection. Therefore, appropriate antimicrobial chemotherapy should be provided as soon as possible to patients exhibiting symptoms of infectious disease and having positive blood culture results. Antimicrobial stewardship (AS) guidelines were recently released by the Infectious Diseases Society of America. The guidelines recommend "proactive intervention and feedback" as one of the core strategies for implementing optimal antimicrobial drug use to improve patient outcomes in clinical settings. We began using the AS program for optimizing antimicrobial chemotherapy in patients with positive blood culture results. The results of blood cultures and antimicrobial prescriptions for the corresponding patients were daily reviewed by a pharmacist and a physician, members of the infection control team (ICT). If the antimicrobial agents selected were inappropriate, ICT made a recommendation to the attending physicians who prescribed the antibiotics. To evaluate the outcomes of this program, we conducted a single-center, retrospective investigation for near a hundred of patients who underwent intervention by infection-control physician and pharmacist. Resolution of bacteremia (determined by blood culture results) was 96.3% in the group that accepted intervention, whereas only 16.7% of the cases resolved in the group that did not accept intervention. These results strongly suggest the importance of the infection disease-specialist team intervention. This program could become an important method for improving clinical outcomes in patients with bacteremia.

Validating the Effectiveness of Switching the Vancomycin TDM Analysis Software Based on the Predictive Accuracy.

Based on the predictive performance in our previous study, we switched the therapeutic drug monitoring (TDM) analysis software for dose setting of vancomycin (VCM) from "Vancomycin MEEK TDM analysis software Ver2.0" (MEEK) to "SHIONOGI-VCM-TDM ver.2009" (VCM-TDM) in January 2015. In the present study, our aim was to validate the effectiveness of the changing VCM TDM analysis software in initial dose setting of VCM. The enrolled patients were divided into two groups, each having 162 patients in total, who received VCM with the initial dose set using MEEK (MEEK group) or VCM-TDM (VCM-TDM group). We compared the rates of attaining the therapeutic range (trough value; 10-20 µg/mL) of serum VCM concentration between the groups. Multivariate logistic regression analysis was performed to confirm that changing the VCM TDM analysis software was an independent factor related to attaining the therapeutic range. Switching the VCM TDM analysis software from MEEK to VCM-TDM improved the rate of attaining the therapeutic range by 21.6% (MEEK group: 42.6% vs. VCM-TDM group: 64.2%, p<0.01). Patient age ≥65 years, concomitant medication (furosemide) and the TDM analysis software used VCM-TDM were considered to be independent factors for attaining the therapeutic range. These results demonstrated the effectiveness of switching the VCM TDM analysis software from MEEK to VCM-TDM for initial dose setting of VCM.

Upregulation of inorganic pyrophosphatase 1 as a JNK phosphatase in hypothyroid embryonic chick cerebellum.

AIM: Thyroid hormones play important roles in vertebrate neuronal development and differentiation. In our previous study, we showed that fetal thyroid dysfunction led to impaired social behaviors of hatchlings on post-hatch day 3, as well as to impaired learning and memory determined by the imprinting preference. However, little is known about the mechanisms underlying the direct adverse effects of fetal thyroid dysfunction on neuronal development. MATERIALS AND METHODS: We used a chick embryo as a fetal model to investigate the effects of prenatal exposure to antithyroid drugs on neuronal development in the chick cerebellum. Methimazole (MMI) at a dose of 20µmol/egg was administered to eggs on day 14, while the control was given only a vehicle. In order to address the underlying mechanisms of the impaired behavior, proteomic approaches were employed in the chick cerebellum two days after MMI treatment. KEY FINDINGS: In this experiment, we found that inorganic pyrophosphatase 1 (PPA1) was upregulated in the chick cerebellum treated with MMI, and we confirmed this upregulation of PPA1 by Western blot analysis as well as by RT-PCR analysis. Concomitant with the upregulation of PPA1, a marked reduction in JNK activity, as well as of phospho-JNK level, was detected in the MMI-treated chick cerebellum. SIGNIFICANCE: Since PPA1 can dephosphorylate JNK, these results suggest that the upregulation of PPA1 during neuronal development in the hypothyroid chick cerebellum may lead to impaired social behaviors as well as to impaired learning and memory via JNK dephosphorylation and inactivation in the chick cerebellum.

Impaired imprinting and social behaviors in chicks exposed to mifepristone, a glucocorticoid receptor antagonist, during the final week of embryogenesis.

UNLABELLED: The effects of glucocorticoid receptor dysfunction during embryogenesis on the imprinting abilities and social behaviors of hatchlings were examined using "fertile hen's egg-embryo-chick" system. METHODS AND RESULTS: Of embryos treated with mifepristone (0.4µmol/egg) on day 14, over 75% hatched a day later than the controls (day 22) without external anomalies. The mifepristone-treated hatchlings were assayed for imprinting ability on post-hatching day 2 and for social behaviors on day 3. The findings were as follows: imprinting ability (expressed as preference score) was significantly lower in mifepristone-treated hatchlings than in controls (0.65±0.06 vs. 0.92±0.02, P<0.005). Aggregation tests to evaluate the speed (seconds) required for four chicks, individually isolated with cardboard dividers in a box, to form a group after removal of the barriers showed that aggregation was significantly slower in mifepristone-treated hatchlings than in controls (8.7±1.1 vs. 2.6±0.3, P<0.001). In belongingness tests to evaluate the speed (seconds) for a chick isolated at a corner to join a group of three chicks placed at the opposite corner, mifepristone-treated hatchlings took significantly longer than controls (4.5±0.4/40 cm vs. 2.4±0.08/40 cm, P<0.001). In vocalization tests, using a decibel meter to measure average decibel level/30s (chick vocalization), mifepristone-treated hatchlings had significantly weaker vocalizations than controls (14.2±1.9/30s vs. 26.4±1.3/30s P<0.001). In conclusion, glucocorticoid receptor dysfunction during the last week embryogenesis altered the programming of brain development, resulting in impaired behavioral activities in late life.