Effects of endogenous and exogenous N-acetyl-5-methoxy kynuramine on object recognition memory in male C3H mice.

Prevention of dementia is important, because it is a leading cause of disability in elderly people. We previously reported that acute intraperitoneal treatment with N-acetyl-5-methoxy kynuramine (AMK), a melatonin (MEL) metabolite, enhanced long-term object recognition memory in ICR mice, a MEL deficient strain. Despite the presumable availability of AMK for dementia, its effects on cognitive performance have not been elucidated. It is unclear whether endogenous AMK is responsible for modulating long-term memory performance. To address this question, we assessed the effects of endogenous AMK on learning and memory using an object recognition test. C3H mice, a MEL-proficient strain, showed peak MEL levels at zeitgeber times (ZT) 19 and 22. Object recognition memory at ZT20 was superior to that at ZT8. Norharmane (NHM, 100 mg/kg), an indoleamine-2,3-dioxygenase (IDO) inhibitor, prevented the transformation of MEL to AMK, thereby suppressing AMK synthesis at ZT20. NHM (100 mg/kg) and another IDO inhibitor, 1-methyl-L-tryptophan (1-MT, 100 mg/kg), disrupted elevated cognitive performance at ZT20. These data imply that endogenous AMK may play a physiological role in the modulation of cognitive function. We also investigated the effects of pharmacological doses of MEL and AMK on object recognition memory in young C3H mice. MEL administration of 0.1 mg/kg, but not 0.01 mg/kg, enhanced object recognition memory, whereas 0.01 and 1 mg/kg AMK enhanced object recognition memory. Administration of 0.1 and 1 mg/kg AMK also enhanced object recognition memory in old C3H mice. These findings in MEL-proficient mice should be confirmed in other learning and memory tests before encouraging the clinical use of AMK.

Risk factors for antibiotic resistance in hospital-acquired and ventilator-associated pneumonia.

INTRODUCTION: Understanding risk factors for antibiotic resistance (AR) in patients with hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) is important to select appropriate initial antibiotics and reduce broad-spectrum antibiotic overuse. However, available evidence is limited. We aimed to identify risk factors for AR in those patients. METHODS: This prospective observational study was conducted at a tertiary-care hospital. Pathogens with AR were defined as those resistant to ampicillin-sulbactam or ceftriaxone. Risk factors for AR in patients with HAP and VAP were assessed using penalized logistic regression analysis. RESULTS: In total, 557 patients with HAP and VAP were enrolled. Pathogens were isolated from 315 patients, with AR identified in 68.3% (215/315). Among antibiotic-resistant pathogens (ARPs), Pseudomonas aeruginosa was isolated most frequently, followed by methicillin-resistant Staphylococcus aureus (MRSA). Significant risk factors for AR were chronic renal diseases (adjusted odds ratio: 2.82, 95% confidence interval: 1.79-7.83), history of ARP infection/colonization within the past 1 year (2.80, 1.90-7.02), bedridden state (1.84, 1.28-3.91), tube feeding (1.58, 1.09-2.98), and peripheral or central venous catheterization (1.57, 1.06-2.96). Additionally, a risk factor for ARPs that should be treated with anti-MRSA antibiotics was prior MRSA infection/colonization history. Those for ARPs requiring dual antipseudomonal antibiotics included prior non-MRSA ARP or MRSA infection/colonization history and bedridden state. CONCLUSIONS: The five factors we highlighted can be important criteria for identifying patients at risk of AR. Physicians should consider these potential risk factors when selecting antibiotics for initial empirical therapy in patients with HAP and VAP.

A prediction rule for severe adverse events in all inpatients with community-acquired pneumonia: a multicenter observational study.

BACKGROUND: Prediction of inpatients with community-acquired pneumonia (CAP) at high risk for severe adverse events (SAEs) requiring higher-intensity treatment is critical. However, evidence regarding prediction rules applicable to all patients with CAP including those with healthcare-associated pneumonia (HCAP) is limited. The objective of this study is to develop and validate a new prediction system for SAEs in inpatients with CAP. METHODS: Logistic regression analysis was performed in 1334 inpatients of a prospective multicenter study to develop a multivariate model predicting SAEs (death, requirement of mechanical ventilation, and vasopressor support within 30 days after diagnosis). The developed ALL-COP-SCORE rule based on the multivariate model was validated in 643 inpatients in another prospective multicenter study. RESULTS: The ALL-COP SCORE rule included albumin (< 2 g/dL, 2 points; 2-3 g/dL, 1 point), white blood cell (< 4000 cells/µL, 3 points), chronic lung disease (1 point), confusion (2 points), PaO2/FIO2 ratio (< 200 mmHg, 3 points; 200-300 mmHg, 1 point), potassium (≥ 5.0 mEq/L, 2 points), arterial pH (< 7.35, 2 points), systolic blood pressure (< 90 mmHg, 2 points), PaCO2 (> 45 mmHg, 2 points), HCO3- (< 20 mmol/L, 1 point), respiratory rate (≥ 30 breaths/min, 1 point), pleural effusion (1 point), and extent of chest radiographical infiltration in unilateral lung (> 2/3, 2 points; 1/2-2/3, 1 point). Patients with 4-5, 6-7, and ≥ 8 points had 17%, 35%, and 52% increase in the probability of SAEs, respectively, whereas the probability of SAEs was 3% in patients with ≤ 3 points. The ALL-COP SCORE rule exhibited a higher area under the receiver operating characteristic curve (0.85) compared with the other predictive models, and an ALL-COP SCORE threshold of ≥ 4 points exhibited 92% sensitivity and 60% specificity. CONCLUSIONS: ALL-COP SCORE rule can be useful to predict SAEs and aid in decision-making on treatment intensity for all inpatients with CAP including those with HCAP. Higher-intensity treatment should be considered in patients with CAP and an ALL-COP SCORE threshold of ≥ 4 points. TRIAL REGISTRATION: This study was registered with the University Medical Information Network in Japan, registration numbers UMIN000003306 and UMIN000009837.

Clinicopathologic and Immunohistochemical Findings from Autopsy of Patient with COVID-19, Japan.

An autopsy of a patient in Japan with coronavirus disease indicated pneumonia lung pathology, manifested as diffuse alveolar damage. We detected severe acute respiratory syndrome coronavirus 2 antigen in alveolar epithelial cells and macrophages. Coronavirus disease is essentially a lower respiratory tract disease characterized by direct viral injury of alveolar epithelial cells.

Pneumatocele formation in a fatal adult pneumonia patient coinfected with Streptococcus pyogenes emm-type 3 and influenza A: a case report.

BACKGROUND: A pneumatocele is a transient thin-walled lesion and rare complication in adult pneumonia. A variety of infectious pathogens have been reported in children with pneumatoceles. We report the first case of adult pneumonia with pneumatocele formation that is likely caused by Streptococcus pyogenes and coinfection with influenza A virus. CASE PRESENTATION: A 64-year-old Japanese man presented with a one-week history of fever, sore throat, and arthralgia. He was referred to our university hospital for respiratory distress. He required mechanical ventilation in the intensive care unit (ICU). Bacterial culture detected S. pyogenes in the bronchoscopic aspirates, which was not detected in blood. Although a rapid influenza antigen test was negative, an influenza A polymerase chain reaction (PCR) test was positive. Therefore, he was diagnosed with coinfection of influenza A and group A streptococcus (GAS) pneumonia complicated by probable streptococcal toxic shock syndrome. A chest radiograph on admission showed diffuse patchy opacification and consolidation in the bilateral lung fields. Multiple thin-walled cysts appeared in both middle lung fields on computed tomography (CT). On the following day, the bilateral cysts had turned into a mass-like opacity. The patient died despite intensive care. An autopsy was performed. The pathology investigation revealed multiple hematomas formed by bleeding in pneumatoceles. CONCLUSIONS: There have been no previous reports of a pneumatocele complicated by S. pyogenes in an adult patient coinfected with influenza A. Further molecular investigation revealed that the S. pyogenes isolate had the sequence type of emm3.

A Hypothesis-Generating Study of the Combination of Aspirin plus Macrolides in Patients with Severe Community-Acquired Pneumonia.

While the inflammatory response to severe pneumonia is paramount in limiting and resolving the infection, excessive inflammation can lead to deleterious effects. We theorized that patients with severe community-acquired pneumonia (CAP) who were treated with macrolides and aspirin would receive benefit beyond that of conventional antibiotic therapy. An observational study was conducted with patients with severe CAP. All patients were admitted to 5 teaching hospitals (in Italy, the United States, Japan, and China), and data were gathered from their electronic medical records. Severe pneumonia was defined according to Infectious Diseases Society of America/American Thoracic Society criteria. Patients were divided into 4 groups, i.e., (i) the aspirin-only group (ASG), (ii) the macrolide-only group (MG), (iii) the aspirin plus macrolide group (ASMG), or (iv) the neither aspirin nor macrolide group (NASMG). Survival rates for the 4 groups were evaluated after adjustment for confounders and after weighting by propensity score. A total of 1,295 patients were included in the analysis. There were 237 patients (18.3%) in the ASG, 294 (22.7%) in the MG, 148 (11.4%) in the ASMG, and 616 (47.6%) in the NASMG. The mortality rate at 30 days was 15.5% in the ASMG, compared to 28.2% in the NASMG, 23.8% in the MG, and 21.1% in the ASG. After propensity score analysis, receipt of aspirin plus macrolide (hazard ratio, 0.71 [95% confidence interval, 0.58 to 0.88]; P = 0.002) was associated with a higher 30-day survival rate. This is a hypothesis-generating study in which data suggest that the combination of aspirin plus a macrolide improves 30-day survival rates for patients with severe CAP. Further randomized studies will need to be undertaken to confirm this phenomenon.

Mortality in patients with community-onset pneumonia at low risk of drug-resistant pathogens: Impact of ß-lactam plus macrolide combination therapy.

BACKGROUND AND OBJECTIVE: Drug-resistant pathogen (DRP) risk stratification is important for choosing a treatment strategy for community-onset pneumonia. Evidence for benefits of non-antipseudomonal ß-lactam plus macrolide combination therapy (BLM) on mortality is limited in patients at low DRP risk. Risk factors for mortality remain to be clarified. METHODS: Post hoc analysis using a prospective multicentre study cohort of community-onset pneumonia was performed to assess 30-day differences in mortality between non-antipseudomonal ß-lactam monotherapy (BL) and BLM groups. Logistic regression analysis was performed to assess the therapeutic effect and risk factors for mortality in patients at low DRP risk. RESULTS: In total, 594 patients with community-onset pneumonia at low DRP risk (369 BL and 225 BLM) were analysed. The 30-day mortality in BL and BLM was 13.8% and 1.8%, respectively (P < 0.001). Multivariate analysis showed that BLM reduced the 30-day mortality (adjusted odds ratio: 0.28, 95% CI: 0.09-0.87) compared with BL. Independent prognostic factors for 30-day mortality included arterial partial pressure of carbon dioxide (PaCO2 ) > 50 mm Hg, white blood cell count < 4000/mm3 , non-ambulatory status, albumin < 3.0 g/dL, haematocrit < 30%, age ≥ 80 years, respiratory rate > 25/min and body temperature < 36°C. CONCLUSION: In patients with community-onset pneumonia at low DRP risk, BLM treatment reduced 30-day mortality compared with BL. Independent risk factors for mortality are potential confounding factors when assessing antibiotic effects in randomized clinical trials.

Proposal for a screening questionnaire for detecting habitual mouth breathing, based on a mouth-breathing habit score.

BACKGROUND: When mouth breathing becomes habitual, it can cause sleep disorders and abnormal maxillofacial growth, thus early detection of habitual mouth breathing is important. We created a questionnaire for early detection of habitual mouth breathing using a score based on a spectrum of factors found to be characteristic of mouth breathers. METHODS: First, a draft 50-question questionnaire was given to 101 random dental clinic patients, classified by dental professionals into habitual mouth breathers (n = 28) and nose breathers (n = 73). The 10 questions that significantly differentiated mouth and nose breathers (p < 0.05) were identified from this questionnaire. These questions, regarding nasal obstruction, open mouth at rest, awareness of mouth breathing, gum swelling and dental staining of the front teeth, bad breath, maxillary protrusion, nasal obstruction in childhood, bottle-feeding, and history of asthma, formed the basis for a second questionnaire. This second survey was completed by another 242 participants, separately classified into mouth breathing (n = 26), suspected mouth breathing (n = 40), and nose breathing groups (n = 176). RESULTS: Receiver operating characteristic curve analysis of the resulting mouth breathing habit scores, representing the responses to the 10-question survey, showed moderate checklist diagnosability. Sensitivity of cut-off values was 61.5% (specificity 92.0%) for the mouth-breathing group, and 77.5% (specificity 56.3%) for the suspected mouth-breathing group. Information was also obtained from visual assessment of maxillofacial characteristics. We found that the mouth-breathing and suspected mouth-breathing groups showed significantly high odds ratios for 7 items: discomfort while breathing and increased chin muscle tonus with lip closure, maxillary protrusion, tongue thrust, open mouth at rest, open bite, and childhood asthma. For 94.6% of the nose breathing group, ≥1 of these items applied. CONCLUSIONS: These findings were then used together to create a sample screening form. We believe that screening of this kind can facilitate more accurate diagnosis of habitual mouth breathing and contribute to its early detection.

Expressions of lipoprotein receptors and cholesterol efflux regulatory proteins during luteolysis in bovine corpus luteum.

The corpus luteum (CL) synthesises and secretes progesterone (P4), which is essential for the establishment and maintenance of pregnancy in mammals. P4 is synthesised from cholesterol. Cholesterol is internalised by low-density lipoprotein receptor (LDLR) and/or scavenger receptor B1 (SR-BI), and is effluxed by ATP-binding cassette (ABC) transporter A1 (ABCA1) and G1 (ABCG1). To test the hypothesis that lipoprotein receptors and ABC transporters are involved in functional luteolysis, we examined the expression of LDLR, SR-BI, ABCA1 and ABCG1 in bovine CL during the luteal stages and after injection of prostaglandin (PG) F2α on Day 10 after ovulation. Expression of LDLR and SR-BI mRNA and protein was lower in the regressed luteal than late luteal stage. Injection of cows with a PGF2α did not affect LDLR mRNA and protein levels in the CL. Although expression of SR-BI mRNA did not change, SR-BI protein expression decreased 12 and 24h after PGF2α injection. The overall findings of the present study suggest that the decreased expression of SR-BI induced by PGF2α is one of the factors responsible for the continuous decrease in P4 production during functional luteolysis.

Salmon nasal cartilage proteoglycan enhances growth of normal human dermal fibroblast through Erk1/2 phosphorylation.

Proteoglycan (PG) is a heavily glycosylated protein, localized to cell surface and extracellular matrix, and has various functions. Recently, it has been gradually revealed that PG interacts with various growth factors and morphogens and regulates cellular functions. Although salmon nasal cartilage PG (Salmon-PG) increases proliferation of immortalized cells, its mechanism remains unclear. In this study, we confirmed the effect of Salmon-PG on normal human dermal fibroblast (NHDF) and investigated the mechanism of PG action on NHDF. Salmon-PG dose- and time-dependently increased NHDF proliferation. Receptor tyrosine kinase array revealed that Salmon-PG increased only Erk1/2 signaling. Erk1/2 phosphorylation was significantly increased by Salmon-PG in a time-(10 min) and dose-(400 or 800 µg/mL) dependent manner. MEK inhibitor suppressed the enhancement of NHDF proliferation by Salmon-PG. The overall findings indicate that Salmon-PG plays a role as a growth factor in NHDF via Erk1/2 activation, suggesting that Salmon-PG contributes to the maintenance of skin homeostasis.

Possible Contribution of Alpha2,6-Sialylation to Luteolysis in Cows by Inhibiting the Luteotropic Effects of Galectin-1.

The corpus luteum (CL) is essential for establishing pregnancy. If pregnancy does not occur during the estrous cycle, luteolysis is induced by prostaglandin (PG) F2alpha secreted from the uterus. Galectin-1, a beta-galactose-binding protein, is expressed in the functional CL of cows and increases the viability of bovine luteal steroidogenic cells (LSCs) by modifying the functions of membrane glycoproteins. The binding of galectin-1 to glycoproteins is blocked by alpha2,6-sialylation of the terminal galactose residues of glycoconjugates, which is catalyzed by a sialyltransferase (ST6Gal-I). However, the physiological role of alpha2,6-sialic acid in bovine CL is unclear. The level of alpha2,6-sialylation of the bovine CL was higher during the regressed-luteal stage than in other luteal stages. Lectin histochemistry revealed that alpha2,6-sialylated glycoconjugates were localized to luteal endothelial cells throughout the estrous cycle. In addition, alpha2,6-sialylated glycoconjugates concentrated to the membrane of LSCs during the regressed-luteal stage. PGF2alpha treatment for 72 h enhanced the expression of ST6Gal-I mRNA and the level of alpha2,6-sialylated glycoproteins in mid-LSCs. The level of alpha2,6-sialylated glycoproteins of late-stage LSCs (Days 15-17 after ovulation) was higher than that of mid-stage LSCs (Days 8-12 after ovulation), and galectin-1 increased the viability of mid-LSCs but not that of late-stage LSCs. Furthermore, galectin-1 increased the viability of late-LSCs when alpha2,6-sialic acid residues were removed by neuraminidase. The overall findings suggest that alpha2,6-sialylation stimulated by PGF2alpha contributes to luteolysis by inhibiting the luteotropic effects of galectin-1 in bovine CL.

Potential role of hCG in apoptosis of human luteinized granulosa cells.

The corpus luteum (CL) forms after ovulation and acts as a temporary endocrine gland that produces progesterone (P4), a hormone that is essential for implantation and maintenance of pregnancy in mammals. In pregnant women, human chorionic gonadotropin (hCG) secreted by the conceptus prevents luteolysis. hCG also increases the survival of cultured human luteinized granulosa cells (hLGCs). To clarify the maintenance mechanism of the human CL, we investigated the effects of hCG and P4 receptor antagonists, onapristone (OP) and RU486, on the viability of hLGCs. With the patients' consent, hLGCs were isolated from follicular aspirates for in vitro fertilization. The cells were cultured with hCG (0.1, 1, 10, 100 IU/ml), OP (10, 25, 50, 100 µM), RU486 (100 µM), P4 (1, 10, 25, 50 µM) or some combination of the four for 24 h. Cell viability was significantly increased by hCG (100 IU/ml) and significantly decreased by OP (100 µM) compared with the control. Cells treated with hCG and OP together were significantly less viable than the control and OP-treated cells. The combined treatment also significantly increased CASP3 activity and cleaved CASP3 protein expression. Furthermore, P4 addition reversed the reduction in cell viability caused by the combination of hCG and OP treatment. The overall findings suggest that hCG cooperates with P4 to increase survival of hLGCs and to induce apoptosis when P4 action supported by hCG is attenuated in the human CL.

The luteotrophic function of galectin-1 by binding to the glycans on vascular endothelial growth factor receptor-2 in bovine luteal cells.

The corpus luteum (CL) is a temporary endocrine gland producing a large amount of progesterone, which is essential for the establishment and maintenance of pregnancy. Galectin-1 is a ß-galactose-binding protein that can modify functions of membrane glycoproteins and is expressed in the CL of mice and women. However, the physiological role of galectin-1 in the CL is unclear. In the present study, we investigated the expression and localization of galectin-1 in the bovine CL and the effect of galectin-1 on cultured luteal steroidogenic cells (LSCs) with special reference to its binding to the glycans on vascular endothelial growth factor receptor-2 (VEGFR-2). Galectin-1 protein was highly expressed at the mid and late luteal stages in the membrane fraction of bovine CL tissue and was localized to the surface of LSCs in a carbohydrate-dependent manner. Galectin-1 increased the viability in cultured LSCs. However, the viability of LSCs was decreased by addition of ß-lactose, a competitive carbohydrate inhibitor of galectin-1 binding activity. VEGFR-2 protein, like galectin-1, is also highly expressed in the mid CL, and it was modified by multi-antennary glycans, which can be recognized by galectin-1. An overlay assay using biotinylated galectin-1 revealed that galectin-1 directly binds to asparagine-linked glycans (N-glycans) on VEGFR-2. Enhancement of LSC viability by galectin-1 was suppressed by a selective inhibitor of VEGFR-2. The overall findings suggest that galectin-1 plays a role as a survival factor in the bovine CL, possibly by binding to N-glycans on VEGFR-2.

Galectin-3 contributes to luteolysis by binding to Beta 1 integrin in the bovine corpus luteum.

Luteolysis is characterized by a reduction in progesterone (P4) production and tissue degeneration in the corpus luteum (CL). One of major events during luteolysis is luteal cell death. Galectin-3, a ubiquitously expressed protein involved in many cellular processes, serves as an antiapoptotic and/or proapoptotic factor in various cell types. Although galectin-3 is detected in the bovine CL, its role remains unclear. The expression of galectin-3 in the bovine CL was higher at the regressed stage than at the other luteal stages. Galectin-3 was localized on luteal steroidogenic cells (LSCs). When cultured LSCs were exposed to prostaglandin F2alpha (PGF) for 48 h, the expression and secretion of galectin-3 increased. When the cultured LSCs were treated with galectin-3 for 24 h, cleaved caspase-3 expression was increased, and the cell viability was decreased, whereas P4 production did not change. Beta 1 integrin, a target protein of galectin-3, was expressed in bovine CL and possessed glycans, which galectin-3 binds. Furthermore, galectin-3 bound to glycans of luteal beta 1 integrin. The decreased cell viability of cultured LSCs by galectin-3 was suppressed by beta 1 integrin antibody. The overall findings suggest that the secreted galectin-3 stimulated by PGF plays a role in structural luteolysis by binding to beta 1 integrin.

A case of community-acquired Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (MRSA) necrotizing pneumonia successfully treated with two anti-MRSA drugs.

A 22-year-old Vietnamese man was referred to our hospital owing to cough, dyspnea, and difficulty moving. The patient was diagnosed with community-acquired Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and necrotizing pneumonia. Treatment involved vancomycin (VCM) and meropenem, and the MRSA bacteremia improved. However, lung tissue destruction progressed. Therefore, linezolid was added to the VCM regimen, and this intervention led to the patient's recovery, and he was discharged from the hospital. Here, we report a case in which the patient was treated with a combination of two anti-MRSA drugs and was cured.

Diazepam induces retrograde facilitation of object recognition and object location memory in male mice.

Benzodiazepines are widely prescribed for patients suffering from anxiety and insomnia. Although amnesic effects of benzodiazepines are commonly known as side effects, it has also been reported that these drugs improve memory for information learned before drug intake, a phenomenon called retrograde facilitation. However, the retrograde effects of benzodiazepines on cognitive performances in rodents remain controversial. It should be considered that studies on diazepam-induced retrograde facilitation in humans have been conducted using a recall paradigm focused on short-term memory, whereas these studies in rodents have been conducted using memory tasks that mainly target long-term memory and/or require negative or positive reinforcers. In the current study, we investigated whether diazepam, a benzodiazepine, induces retrograde facilitation for object recognition memory and spatial memory in mice, using a novel object recognition test and an object location test, respectively. These tests are available for short-term memory and do not require any reinforcer. The mice treated with diazepam retained object recognition memory for at least 180 min and spatial memory for at least 150 min. In contrast, vehicle-treated control mice retained object recognition memory for 120 min but not 150 min or longer, and spatial memory for 90 min but not 120 min or longer. These data clearly demonstrated diazepam-induced retrograde facilitation for both object recognition and spatial memories in mice. The present study is expected to contribute to the elucidation of the neural basis of retrograde facilitation.

N-acetyl-5-methoxykynuramine enhance object location and working memory performances via modulating CaMKII, ERK and CREB phosphorylation.

OBJECTIVES: Melatonin (MEL) has been reported to enhance cognitive performance. Recently, we have demonstrated that a MEL metabolite N-acetyl-5-methoxykynuramine (AMK) promoted the formation of long-term object recognition memory more potently than MEL. Here, we examined the effects of 1 mg/kg MEL and AMK on both object location memory and spatial working memory. We also investigated the effects of the same dose of these drugs on relative phosphorylation/activation levels of memory-related proteins in the hippocampus (HP), the perirhinal cortex (PRC) and the medial prefrontal cortex (mPFC). METHODS: Object location memory and spatial working memory were assessed using the object location task and the Y-maze spontaneous alternation task, respectively. Relative phosphorylation/activation levels of memory-related proteins were assessed using western blot analysis. RESULTS: AMK, as well as MEL, enhanced object location memory and spatial working memory. AMK increased the phosphorylation of cAMP-response element-binding protein (CREB) in both the HP and the mPFC 2 h after the treatment. AMK also increased the phosphorylation of extracellular signal-regulated kinases (ERKs) but decreased that of Ca2+/calmodulin-dependent protein kinases II (CaMKIIs) in the PRC and the mPFC 30 min after the treatment. MEL increased CREB phosphorylation in the HP 2 h after the treatment, whereas no detectable changes in the other proteins examined were observed. CONCLUSION: These results suggested the possibility that AMK exerts stronger memory-enhancing effects than MEL by more remarkably altering the activation of memory-related proteins such as ERKs, CaMKIIs and CREB in broader brain regions, including the HP, mPFC and PRC, compared to MEL.

Effects of melatonin on phosphorylation of memory-related proteins in the hippocampus and the perirhinal cortex in male mice.

We recently demonstrated that a single post-training administration of either melatonin, an MT1/MT2 melatonin receptor agonist ramelteon, or a brain melatonin metabolite N1-acetyl-5-methoxyquinuramine (AMK) enhanced object recognition memory. The present study aims to investigate the effects of melatonin, ramelteon, and AMK on relative phosphorylation levels of memory-related proteins in order to explore candidate signaling pathways associated with the receptor-mediated and nonreceptor-mediated memory-enhancing effects of melatonin. We first confirmed that post-training administration of either melatonin, ramelteon, or AMK at 1 mg/kg promoted long-term memory formation, using the novel object recognition task. Next, the effects of the same doses of these drugs on relative phosphorylation levels of the extracellular signal-regulated kinase (ERK) and calcium/calmodulin-dependent kinases (CaMKs) in the hippocampus and the perirhinal cortex (PRC) were examined by western blot analysis. In the hippocampus, treatment with ramelteon or AMK significantly increased and decreased phosphorylation levels of ERK and cAMP-response element binding protein (CREB) and those of CaMKIIα and ß, respectively. In the PRC, phosphorylation levels of ERK and those of CaMKIIß were significantly increased by both ramelteon and AMK and by ramelteon, respectively. Neither ramelteon nor AMK altered the phosphorylation levels of CaMKIV in either hippocampus or PRC. These results suggest that melatonin may be involved in promoting the formation of long-term object recognition memory in a similar, if not identical, manner by modulating the phosphorylation levels of memory-related proteins such as ERK, CaMKIIs, and CREB in both receptor-mediated and nonreceptor-mediated signaling pathways.

Factors associated with adverse drug reactions or death in very elderly hospitalized patients with pulmonary tuberculosis.

The aging of patients with tuberculosis and better therapeutic management for them are recent concerns. This study aimed to identify risk factors for adverse drug reactions (ADRs) or death in very elderly patients with pulmonary tuberculosis and to assess the association between the dosage of antituberculosis drugs and outcomes. We conducted a multicenter retrospective study at two hospitals. Hospitalized patients (≥ 80 years old) with pulmonary tuberculosis who were treated with antituberculosis drugs were enrolled. Multivariate analysis was performed to assess factors associated with ADRs or death within 60 days after treatment initiation. In total, 632 patients were included. The primary endpoint occurred in 268 patients (190 ADRs and 78 deaths). A serum albumin level < 2.5 g/dL, respiratory failure, and dependent activities of daily living were independent risk factors for ADRs or death. However, a low dosage (< 8 mg/kg/day) of rifampicin was associated with a lower risk of the primary outcomes. Delayed time to negative sputum culture conversion was not observed in the lower dosage of rifampicin group. Very elderly hospitalized tuberculosis patients with the aforementioned risk factors should be carefully monitored to receive safer treatment. Rifampicin dosage reduction may be considered for very elderly tuberculosis patients to prevent ADRs/death.

N-glycans of SREC-I (scavenger receptor expressed by endothelial cells): essential role for ligand binding, trafficking and stability.

Scavenger receptor expressed by endothelial cells (SREC-I) mediates the endocytosis of chemically modified lipoproteins such as acetylated low-density lipoprotein (Ac-LDL) and oxidized LDL and is implicated in atherogenesis. We produced recombinant SREC-I in Chinese hamster ovary-K1 cells and identified three potential glycosylation sites, Asn(289), Asn(382) and Asn(393), which were all glycosylated. To determine the function of N-glycans in SREC-I, we characterized SREC-I mutant proteins by intracellular distribution and the cellular incorporation rate of Ac-LDL. N382Q/N393Q and N289Q/N382Q/N393Q were sequestered in the endoplasmic reticulum, resulting in a severe reduction in the cellular incorporation of Ac-LDL. N382Q showed a normal cell surface residency and an enhanced affinity for Ac-LDL, resulting in an elevated Ac-LDL cellular incorporation. These results indicate that the N-glycan of Asn(393) regulates the intracellular sorting of SREC-I and that the N-glycan of Asn(382) controls ligand-binding affinity. Furthermore, we detected an enhanced trypsin sensitivity of the N289Q. Glycan structure analyses revealed that the core-fucosylated bi-antennary is the common major structure at all glycosylation sites. In addition, tri- and tetra-antennary were detected as minor constituents at Asn(289). A bisecting GlcNAc was also detected at Asn(382) and Asn(393). Structural analyses and homology modeling of SREC-I suggest that the N-glycan bearing a ß1-6GlcNAc branch at Asn(289) protects from proteinase attack and thus confers a higher stability on SREC-I. These data indicate that Asn(289)-, Asn(382)- and Asn(393)-linked N-glycans of SREC-I have distinct functions in regulating proteolytic resistance, ligand-binding affinity and subcellular localization, all of which might be involved in the development of atherogenesis.