Iron-Catalyzed Biomimetic Dimerization of Tryptophan-Containing Peptides.

Biomimetic oxidative dimerization of tryptophan derivatives in aqueous media with oxygen as a bulk oxidant catalyzed by an iron octacarboxy phthalocyanine complex was established. The discovery of the extremely active iron catalyst enables aerobic enzyme-mimetic oxidation to be performed in a flask. This method was applicable to the oxidative dimerization of a wide range of tryptophan derivatives, including various dipeptides and oligopeptides, with remarkable functional-group tolerance without the protection of the amino acid residues. Furthermore, oxidative dimerization of tryptophan derivatives bearing dioxopiperazine units enabled the convergent total synthesis of five natural pyrroloindole compounds and unnatural congeners. The established chemical method provides facile access to a broad range of dimerized peptides with a unique scaffold to link two turn structures, which will serve as a powerful tool to create new small- and medium-sized-molecules as drug candidates.

Synthesis of 2-Thio-Substituted 1,6-Diazabicyclo[3.2.1]octane Derivatives, Potent ß-Lactamase Inhibitors.

Approval of avibactam by the FDA has led to the recognition of 1,6-diazabicyclo[3.2.1]octane (DBO) derivatives as attractive compounds for ß-lactamase inhibition. We achieved a concise and collective synthesis of 2-thio-substituted DBO derivatives. The synthesis involves diastereoselective photo-induced Barton decarboxylative thiolation, which can be applied to large-scale synthesis. The DBO analogues exhibited strong inhibitory activities against serine ß-lactamases and acceptable solution stabilities for clinical development.

Geminin is an indispensable inhibitor of Cdt1 in mouse embryonic stem cells.

Geminin is implicated in regulation of the cell cycle and differentiation. Although loss of Geminin triggers unscheduled DNA rereplication as a result of interruption of its interaction with Cdt1 in some somatic cancer cells, whether such cell cycle regulation also operates in embryonic stem cells (ESCs) has remained unclear. To characterize the Geminin-Cdt1 axis in ESCs and compare it with that in somatic cells, we established conditional knockout (KO) of Geminin in mouse ESCs and mouse embryonic fibroblasts (MEFs). Geminin KO ESCs manifest a large flattened morphology, develop polyploidy accompanied by DNA damage and G2 -M checkpoint activation, and subsequently undergo apoptosis. Rereplication in Geminin KO ESCs was attenuated by inhibition of G2 -M checkpoint signaling or by expression of wild-type Geminin, but not by expression of a Geminin mutant that does not bind to Cdt1, indicating the importance of sequestration of Cdt1 by Geminin in G2 phase. In contrast, Geminin KO MEFs did not manifest disturbance of the cell cycle unless they were treated to force abnormal accumulation of Cdt1. Together, our results indicate that Geminin is a key inhibitor of Cdt1 in mouse ESCs, but that it plays a backup role in MEFs to compensate for accidental up-regulation of Cdt1.

Heterogeneity of patients receiving artificial nutrition in Japanese psychiatric hospitals: a cross-sectional study.

AIM: Artificial nutrition, including tube feeding, continues to be given to dementia patients in numerous geriatric facilities in Japan. However, the clinical characteristics of patients receiving artificial nutrition have not been fully investigated. Therefore, we tried to evaluate the clinical features of those patients in this study. METHODS: Various clinical characteristics of all inpatients at 18 of 20 psychiatric hospitals in Okayama Prefecture, Japan, with a percutaneous endoscopic gastrostomy tube, nasogastric tube, or total parenteral nutrition were evaluated. RESULTS: Two hundred twenty-one patients (5.4% of all inpatients) had been receiving artificial nutrition for more than 1 month, and 187 (130 women, 57 men; 84.6% of 221 patients) were fully investigated. The mean age was 78.3 years old, and the mean duration of artificial nutrition was 29.8 months. Eighty-four patients (44.7% of 187 patients) were receiving artificial nutrition for more than 2 years. Patients with Alzheimer's disease (n = 78) formed the biggest group, schizophrenia (n = 37) the second, and vascular dementia (n = 26) the third. CONCLUSION: About one-fifth of the subjects receiving artificial nutrition were in a vegetative state. More than a few patients with mental disorders, including schizophrenia, also received long-term artificial nutrition. We should pay more attention to chronic dysphasia syndrome in mental disorders.

Effects of Heat-Killed Lacticaseibacillus paracasei MCC1849 on Immune Parameters in Healthy Adults-A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study.

Previous clinical studies have shown that heat-killed Lacticaseibacillus paracasei MCC1849 suppresses subjective symptoms among healthy adults. However, the mechanism underlying this beneficial effect remains unclear. This clinical study aimed to investigate the effects of MCC1849 on immune functions in humans. In this randomized, double-blind, placebo-controlled, parallel-group study, 100 healthy adults were randomly divided into MCC1849 or placebo groups. Participants ingested test powder with 5 × 1010 MCC1849 cells or placebo powder for 4 weeks. Immune functions were evaluated using expression levels of CD86 and HLA-DR on dendritic cells (DCs), neutrophils, and natural killer cells. The expression levels of interferon (IFN)-α, -ß, and -γ in peripheral blood mononuclear cells incubated with Cpg2216 in vitro were quantified. Efficacy analysis was performed on participants in the per-protocol set (placebo group; n = 47, MCC1849 group; n = 49). The expression level of CD86 on pDCs and the gene expression levels of IFN-α, -ß, and -γ upon TLR9 agonist stimulation were significantly higher in the MCC1849 group at 4 weeks. No side effects were observed. This is the first report to show the positive effects of MCC1849 on human immune cells. These findings reveal one possible mechanism of how MCC1849 suppresses subjective symptoms.

Effects of Bifidobacterium longum BB536 and Bifidobacterium breve MCC1274 on Body Composition in Normal and Overweight Adults in Randomized Placebo-Controlled Study.

Visceral fat accumulation is considered to be associated with a higher risk of chronic diseases. We investigated the effects of Bifidobacterium longum subsp. longum (B. longum) BB536 and Bifidobacterium breve (B. breve) MCC1274 on body composition, including visceral fat, in a randomized, parallel-group, placebo-controlled study. Participants were between 29 and 64 years of age and had a body mass index (BMI) of greater than 23 and less than 30. One hundred participants were randomly assigned to the probiotics group or placebo group. Participants were administered probiotic capsules containing 1 × 1010 colony-forming units (CFUs) of B. longum BB536 and 5 × 109 CFU of B. breve MCC1274 or placebo capsules without bifidobacteria for 16 weeks. In the probiotics group, abdominal visceral fat area, total abdominal fat area, and serum triglyceride levels were significantly decreased compared to those in the placebo group. Additionally, the increase in BMI observed in the placebo group was significantly suppressed in the probiotics group. This study showed that B. longum BB536 and B. breve MCC1274 reduced abdominal visceral fat and total fat levels in healthy normal and overweight adults, suggesting their beneficial effects on body composition.

Effects of Heat-Killed Lacticaseibacillus paracasei MCC1849 on the Maintenance of Physical Condition in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study.

We previously reported that the intake of heat-killed Lacticaseibacillus paracasei MCC1849 suppressed the onset of cold-like symptoms in healthy young women who were susceptible to colds. This study aimed to investigate the effects of MCC1849 on subjective symptoms of physical condition in healthy adults of a wide age range. In this randomized, double-blind, placebo-controlled, parallel-group study, 200 healthy adults were randomly divided into the MCC1849 group or placebo group. The participants received test powder with 50 billion MCC1849 cells or placebo powder without MCC1849 for 24 weeks. Subjective symptoms were assessed by diary scores. Analysis was performed on 183 participants (MCC1849 group; n = 91, placebo group; n = 92) in the per-protocol set. The number of days of stuffy nose and cold-like symptoms was significantly reduced in the MCC1849 group compared with the placebo group. In addition, the duration of stuffy nose, sore throat and cold-like symptoms was significantly lower in the MCC1849 group. No side effects were observed. Therefore, oral intake of MCC1849 suppressed subjective symptoms in healthy adults of a wide age range. These data suggest that MCC1849 may help maintain physical condition.

Highly Potent and Oral Macrocyclic Peptides as a HIV-1 Protease Inhibitor: mRNA Display-Derived Hit-to-Lead Optimization.

Human immunodeficiency virus type-1 (HIV-1) protease is essential for viral propagation, and its inhibitors are key anti-HIV-1 drug candidates. In this study, we discovered a novel HIV-1 protease inhibitor (compound 16) with potent antiviral activity and oral bioavailability using a structure-based drug design approach via X-ray crystal structure analysis and improved metabolic stability, starting from hit macrocyclic peptides identified by mRNA display against HIV-1 protease. We found that the improvement of the proteolytic stability of macrocyclic peptides by introducing a methyl group to the α-position of amino acid is crucial to exhibit strong antiviral activity. In addition, macrocyclic peptides, which have moderate metabolic stability and solubility in solutions containing taurocholic acid, exhibited desirable plasma total clearance and oral bioavailability. These approaches may contribute to the successful discovery and development of orally bioavailable peptide drugs.

[Basis of prescribing antipsychotics].

After the introduction of novel antipsychotic agents to Japanese clinical settings, the goal of treating patients suffering from schizophrenia has changed from response to recovery. However, there is a situation we, clinicians occasionally face, in which the standardized medication with novel antipsychotic monotherapy does not work well. So we have to consider the medication with older antipsychotic agents because we cannot give up treating patients even though there are no convincing evidences which support augmentation therapy with a conventional antipsychotic. Now we are at the age of combining the evidence and the experience to construct the practical strategy of treating schizophrenia.

Discovery of 2-Sulfinyl-Diazabicyclooctane Derivatives, Potential Oral ß-Lactamase Inhibitors for Infections Caused by Serine ß-Lactamase-Producing Enterobacterales.

Coadministration of ß-lactam and ß-lactamase inhibitor (BLI) is one of the well-established therapeutic measures for bacterial infections caused by ß-lactam-resistant Gram-negative bacteria, whereas we have only two options for orally active BLI, clavulanic acid and sulbactam. Furthermore, these BLIs are losing their clinical usefulness because of the spread of new ß-lactamases, including extended-spectrum ß-lactamases (ESBLs) belonging to class A ß-lactamases, class C and D ß-lactamases, and carbapenemases, which are hardly or not inhibited by these classical BLIs. From the viewpoints of medical cost and burden of healthcare personnel, oral therapy offers many advantages. In our search for novel diazabicyclooctane (DBO) BLIs possessing a thio-functional group at the C2 position, we discovered a 2-sulfinyl-DBO derivative (2), which restores the antibacterial activities of an orally available third-generation cephalosporin, ceftibuten (CTB), against various serine ß-lactamase-producing strains including carbapenem-resistant Enterobacteriaceae (CRE). It can be orally absorbed via the ester prodrug modification and exhibits in vivo efficacy in a combination with CTB.

Introduction of a Thio Functional Group to Diazabicyclooctane: An Effective Modification to Potentiate the Activity of ß-Lactams against Gram-Negative Bacteria Producing Class A, C, and D Serine ß-Lactamases.

By the emergence and worldwide spread of multi-drug-resistant Gram-negative bacteria, there have been growing demands for efficacious drugs to cure these resistant infections. The key mechanism for resistance to ß-lactam antibiotics is the production of ß-lactamases, which hydrolyze and deactivate ß-lactams. Diazabicyclooctane (DBO) analogs play an important role as one of the new classes of ß-lactamase inhibitors (BLIs), and several compounds such as avibactam (AVI) have been approved by the FDA, along with many derivatives under clinical or preclinical development. Although these compounds have a similar amide substituent at the C2 position, we have recently reported the synthesis of novel DBO analogs which possess a thio functional group. This structural modification enhances the ability to restore the antimicrobial activities of cefixime (CMF) against pathogens producing classes A, C, and D serine ß-lactamases compared with AVI and expands the structural tolerance at the six position. Furthermore, some of these analogs showed intrinsic microbial activities based on multipenicillin binding protein (PBP) inhibition. This is the unique feature which has never been observed in DBOs. One of our DBOs had a pharmacokinetic profile comparable to that of other DBOs. These results indicate that the introduction of a thio functional group into DBO is a novel and effective modification to discover a clinically useful new BLI.

Pyk2 activation is integral to acid stimulation of sodium/hydrogen exchanger 3.

The present study examines the role of Pyk2 in acid regulation of sodium/hydrogen exchanger 3 (NHE3) activity in OKP cells, a kidney proximal tubule epithelial cell line. Incubation of OKP cells in acid media caused a transient increase in Pyk2 phosphorylation that peaked at 30 seconds and increased Pyk2/c-Src binding at 90 seconds. Pyk2 isolated by immunoprecipitation and studied in a cell-free system was activated and phosphorylated at acidic pH. Acid activation of Pyk2 (a) was specific for Pyk2 in that acid did not activate focal adhesion kinase, (b) required calcium, and (c) was associated with increased affinity for ATP. Transfection of OKP cells with dominant-negative pyk2(K457A) or small interfering pyk2 duplex RNA blocked acid activation of NHE3, while neither had an effect on glucocorticoid activation of NHE3. In addition, pyk2(K457A) blocked acid activation of c-Src kinase, which is also required for acid regulation of NHE3. The present results demonstrate that Pyk2 is directly activated by acidic pH and that Pyk2 activation is required for acid activation of c-Src kinase and NHE3. Given that partially purified Pyk2 can be activated by acid in a cell-free system, Pyk2 may serve as the pH sensor that initiates the acid-regulated signaling cascade involved in NHE3 regulation.

Correlation between emetic effect of phosphodiesterase 4 inhibitors and their occupation of the high-affinity rolipram binding site in Suncus murinus brain.

We employed an ex vivo [(3)H]rolipram binding experiment to elucidate the mechanism of emetic activity of phosphodiesterase 4 inhibitors. In Suncus murinus (an insectivore used for evaluation of emesis), emetic potential as well as ability to occupy the high-affinity rolipram binding site in brain membrane fraction in vivo were determined for phosphodiesterase 4 inhibitors. In vitro, [(3)H]rolipram bound to the membrane fraction of S. murinus brain with high affinity and its value was comparable to that for rat brain (K(d)=3.6 nM and 3.5 nM, respectively). The test compounds included denbufylline, rolipram, piclamilast, CDP840 and KF19514, each of which possessed similar affinities for the rolipram binding sites in both S. murinus and rat brain. In S. murinus, these compounds induced emesis via intraperitoneal administration. Their ED(50) values were as follows: denbufylline (1.4 mg/kg), rolipram (0.16 mg/kg), piclamilast (1.8 mg/kg), CDP840 (20 mg/kg), and KF19514 (0.030 mg/kg). In addition, these compounds occupied the high-affinity rolipram binding site in vivo as detected by dose-dependent reduction in capacity of ex vivo [(3)H]rolipram binding in brain membrane fractions. A clear correlation was observed between dose required to induce emesis and that to occupy the high-affinity rolipram binding site for individual phosphodiesterase 4 inhibitors. We conclude that the emetic effect of phosphodiesterase 4 inhibitors is caused at least in part via binding to the high-affinity rolipram binding site in brain in vivo.

AgNTf2-Mediated Allylation with Allylsilanes at C3a-Position of Hexahydropyrroloindoles: Application to Total Syntheses of Amauromine Alkaloids.

A protocol for the allylation at the C3a-position of hexahydropyrroloindole using allylsilanes is developed. AgNTf2 proved to be an efficient activator of halopyrroloindoline substrates. This method is applicable to the introduction of various allyl groups including the reverse prenyl group. The utility of this reaction is demonstrated by total synthesis of amauromine alkaloids. Stepwise bromocyclizations of the bis-indolylmethyl diketopiperazine derivative and subsequent double reverse prenylation furnished (+)-novoamauromine and (-)-epiamauromine.

Quality of life for patients with schizophrenia in a Japanese psychiatric hospital.

Providing a good quality of life (QOL) has recently been recognized as a central purpose of health care in psychiatry. In this study, we performed a detailed evaluation of the subjective QOL of schizophrenic inpatients and examined the relationship of QOL to various patient characteristics. This study was conducted on schizophrenic inpatients and nursing staff members in a Japanese private psychiatric hospital. As a result, only depression showed a weak, but significant, relationship with subjective QOL. Other characteristics showed no meaningful correlation to subjective QOL. Comparison between the schizophrenic group and the nursing staff group revealed that schizophrenic inpatients showed a lower QOL in the domains of physical health and social relationships. Schizophrenia itself and/or accompanying disabilities might induce lower subjective QOL. It is difficult to determine what the important factors are, except for depression, for subjective QOL of schizophrenic inpatients. However, depression should receive more attention for the QOL in the physical health and psychological health domains.

Challenges in treating patients with major depressive disorder: the impact of biological and social factors.

Major depressive disorder (MDD) is frequently unrecognized and underdiagnosed by clinicians and thus remains untreated or inappropriately treated in routine clinical practice. Although the symptoms of MDD are widely acknowledged and recognized by clinicians, numerous epidemiological studies have reported that this disorder is more prevalent than had previously been thought, and that it is challenging to diagnose and treat, particularly because somatic symptoms and comorbid conditions are common in real clinical situations. MDD is associated with increased morbidity and mortality as well as with higher healthcare costs and more severe functional impairment. Therefore, optimal treatment for MDD should include collaboration focussed on comorbid physical diseases, rehabilitation aimed at restoring social functioning, and pharmacotherapy designed to ensure complete remission including psychological and physical symptoms, as well as functional recovery.

Evidence for the benefits of nonantipsychotic pharmacological augmentation in the treatment of depression.

Failure to achieve an adequate response after initial antidepressant treatment in patients with depression is common and remains a clinical challenge. In recent years, some atypical antipsychotic agents have been approved by the US Food and Drug Administration for use in an augmentation strategy for major depressive disorder, and other agents are already in common use in clinical practice. We conducted a search of MEDLINE for relevant studies of augmentation strategies using randomized controlled trials and meta-analyses, and we summarize and discuss the various agents other than atypical antipsychotics. Lithium and thyroid hormone augmentation may improve the response of tricyclic antidepressants but not that of selective serotonin reuptake inhibitors. The efficacy of augmentation with modafinil, buspirone, methylphenidate, folic acid, pindolol and lamotrigine is limited or equivocal. Most of the studies have not focused on treatment-resistant depression (TRD). More trials are needed to help develop evidence-based options for augmentation in TRD.

Management of chronic depressive patients with residual symptoms.

Various clinical issues are involved in the appropriate diagnosis and proper treatment interventions for patients with major depressive disorder (MDD). Despite a number of diverse antidepressants for treating MDD now, response and remission rates following adequate trials of antidepressant intervention are still not satisfactory. Furthermore, a significant proportion of MDD patients have residual symptoms, which are associated with increased relapse and recurrence of MDD, leading to negative impacts on the clinical course and outcomes of MDD. Timely and appropriate decision-making regarding the proper management of such cases is required in our routine daily practice. These issues are illustrated and also framed by one MDD case with a complicated clinical course. This review paper may give physicians clinical insight into how we can effectively and properly evaluate and manage such patients in clinical practice.

Efficacy of second-generation antipsychotics in patients at ultra-high risk and those with first-episode or multi-episode schizophrenia.

AIM: The aim of this study was to examine the speed of response, doses, and safety of treatment with second-generation antipsychotics (SGAs) in patients at ultra-high risk (UHR) compared to those with schizophrenia. METHODS: A 12-week open-label, prospective study of SGAs was performed in UHR patients and those with first-episode schizophrenia (FES) and multi-episode schizophrenia (MES). The subjects were 14-30 years old and were recruited at Zikei Hospital, Okayama, Japan from December 1, 2006 to December 1, 2011. Treatment was carried out in a natural setting in an open-label format, but clinical evaluation was performed blind. The clinical rating scales include the Global Assessment of Functioning (GAF), the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression-Severity scale (CGI-S). RESULTS: UHR (n = 17), FES (n = 23), and MES (n = 21) patients all showed significant improvements on the GAF, PANSS, and CGI-S. However, the UHR patients showed significantly greater improvement on the GAF at weeks 4, 8, and 12 compared to the other groups, and a significantly lower modal dose of SGAs (chlorpromazine equivalent: 183 [201.1] mg/day, mean [SD]) was needed for improvement in the UHR group. Each group was also prescribed anticholinergic agents during the study period and the UHR group had significantly fewer extrapyramidal symptoms (only 6%) compared with the FES group. CONCLUSION: Our findings suggest that UHR patients have a better response to SGAs compared to patients with schizophrenia, and that these drugs can be given safely by minimizing the dosage of SGAs and using anticholinergic agents.