Association of SLC6A3 variants with treatment-resistant schizophrenia: a genetic association study of dopamine-related genes in schizophrenia

Background

Most genetic analyses that have attempted to identify a locus or loci that can distinguish patients with treatment-resistant schizophrenia (TRS) from those who respond to treatment (non-TRS) have failed. However, evidence from multiple studies suggests that patients with schizophrenia who respond well to antipsychotic medication have a higher dopamine (DA) state in brain synaptic clefts whereas patients with TRS do not show enhanced DA synthesis/release pathways.

Patients and methods

To examine the contribution (if any) of genetics to TRS, we conducted a genetic association analysis of DA-related genes in schizophrenia patients (TRS, n = 435; non-TRS, n = 539) and healthy controls (HC: n = 489).

Results

The distributions of the genotypes of rs3756450 and the 40-bp variable number tandem repeat on SLC6A3 differed between the TRS and non-TRS groups. Regarding rs3756450, the TRS group showed a significantly higher ratio of the A allele, whereas the non-TRS group predominantly had the G allele. The analysis of the combination of COMT and SLC6A3 yielded a significantly higher ratio of the putative low-DA type (i.e., high COMT activity + high SLC6A3 activity) in the TRS group compared to the two other groups. Patients with the low-DA type accounted for the minority of the non-TRS group and exhibited milder psychopathology.

Conclusion

The overall results suggest that (i) SLC6A3 could be involved in responsiveness to antipsychotic medication and (ii) genetic variants modulating brain DA levels may be related to the classification of TRS and non-TRS.

Can brexpiprazole be switched safely in patients with schizophrenia and dopamine supersensitivity psychosis? A retrospective analysis in a real-world clinical practice

BACKGROUND

Several studies have reported that a switch to the dopamine partial agonist (DPA) aripiprazole (ARP), especially when the switch is abrupt, is likely to fail and sometimes worsen psychosis in schizophrenia patients already under high-dose antipsychotic treatment. Such a switching failure is speculated to be related to be the dopamine supersensitivity state. The risks of switching to the DPA brexpiprazole (BREX) have not been reported.

AIMS AND METHODS

We retrospectively analyzed the cases of 106 patients with schizophrenia to identify any factors related to the success or failure of switching to BREX.

RESULTS

The comparison between the patients with dopamine supersensitivity psychosis (n = 44) and those without (n = 62) revealed no significant difference in the switching failure judged at the sixth week. A comparison of the patients with successful switching (n = 80) and those who failed (n = 26) revealed that patients with treatment-resistant schizophrenia (TRS) were significantly more likely to fail. A logistic regression analysis also revealed that patients with past failure of switching to ARP are likely to succeed in switching to BREX. The 2-year follow-up of the patients with successful switching to BREX suggested that the patients who were treated with BREX, even temporarily, experienced some improvement in their Global Assessment of Functioning and Clinical Global Impression-Severity scores.

CONCLUSIONS

Overall, the results indicate that patients with schizophrenia can be switched more safely to BREX compared to ARP. However, the failure of switching to BREX could be higher in patients with TRS, and thus, starting BREX treatment in refractory patients warrants careful monitoring.

Predictive factors for dissection-free sentinel node micrometastases in early oral squamous cell carcinoma

This sentinel node (SN) biopsy trial aimed to assess its effectiveness in identifying predictive factors of micrometastases and to determine whether elective neck dissection is necessary in oral squamous cell carcinoma. This retrospective study included 55 patients from three previous trials, with positive SNs. The relationship between the sizes of the metastatic focus and metastasis in non-sentinel node (NSN) was investigated. Four of the 55 largest metastatic focus were isolated tumor cells, and the remaining 51 were ranged from 0.2 to 15 mm, with a median of 2.6 mm. The difference of prevalence between 46 negative- and 9 positive-NSN was statistically significant with regard to age, long diameter of primary site and number of cases with regional recurrence. In comparing the size of largest metastatic focus dividing the number of positive SN, with metastaic focus range of < 3.0 mm in one-positive SN group, there were 18 (33%) negative-NSN and no positive-NSN. Regarding prognosis, 3-year overall survival rate of this group (n = 18) and other (n = 37) were 94% and 73% (p = 0.04), and 3-year recurrence free survival rate of this group and other were 94% and 51% (p = 0.03), respectively. Absolutely a further prospective clinical trial would be needed, micrometastases may be defined as solitary SN metastasis with < 3.0 mm of metastatic focus, and approximately 33% of neck dissections could be avoided using these criteria.

Dopamine supersensitivity psychosis and delay of clozapine treatment in patients with treatment-resistant schizophrenia

Both the underutilization of clozapine and treatment resistance of patients to clozapine are serious problems worldwide. Identifying clinical markers predicting response to clozapine would help clinicians more effectively utilize clozapine treatment. The present study retrospectively assessed dopamine supersensitivity psychosis (DSP) in addition to other measures such as age at disease onset and delay of clozapine introduction for a total of 47 treatment-resistant schizophrenia (TRS) patients. The response to clozapine was judged with CGI-C at 1 and 2 years from clozapine introduction. Results revealed that the DSP group tended to have a longer delay between designation of TRS and introduction of clozapine and continued to have slightly more severe psychopathology after treatment with clozapine, showing only slight improvement. The logistic regression analysis showed that the age at disease onset was the only significant indicator, predicting responsiveness to clozapine: patients with an onset age <20 years had a significantly better response to clozapine than patients with an onset age ≥20 years. The present study suggests that DSP might be related to a longer delay in clozapine introduction and the persistence of refractory symptoms despite clozapine treatment, whereas early age of disease onset might be related to a better response to clozapine.

[Stanford Type A Acute Aortic Dissection with Myonephropathic Mrtabolic Syndrome]

A 57-year-old man was transferred with sudden onset chest pain and evolving paralysis and numbness in the left leg. Contrast computed tomography (CT) revealed Stanford type A acute aortic dissection from the ascending aorta to bilateral internal and external iliac arteries with blood flow obstruction to the left kidney and left lower limb. Surgery was initiated 10 hours after onset of ischemic symptoms in the leg. Femoro-femoral bypass was carried out first, and we ensured sufficient phlebotomy from the ischemic limb during reperfusion and continuous hemodiafiltration to prevent myonephropathic metabolic syndrome. Total aortic arch replacement was then performed. Our treatment strategy was effective in this case of Stanford type A aortic dissection with prolonged lower limb ischemia. Although left hip disarticulation was subsequently required due to intractable infection, the patient became able to walk with an artificial limb after post-rehabilitation.

Super-strong magnetic field-dominated ion beam dynamics in focusing plasma devices

High energy density physics is the field of physics dedicated to the study of matter and plasmas in extreme conditions of temperature, densities and pressures. It encompasses multiple disciplines such as material science, planetary science, laboratory and astrophysical plasma science. For the latter, high energy density states can be accompanied by extreme radiation environments and super-strong magnetic fields. The creation of high energy density states in the laboratory consists in concentrating/depositing large amounts of energy in a reduced mass, typically solid material sample or dense plasma, over a time shorter than the typical timescales of heat conduction and hydrodynamic expansion. Laser-generated, high current–density ion beams constitute an important tool for the creation of high energy density states in the laboratory. Focusing plasma devices, such as cone-targets are necessary in order to focus and direct these intense beams towards the heating sample or dense plasma, while protecting the proton generation foil from the harsh environments typical of an integrated high-power laser experiment. A full understanding of the ion beam dynamics in focusing devices is therefore necessary in order to properly design and interpret the numerous experiments in the field. In this work, we report a detailed investigation of large-scale, kilojoule-class laser-generated ion beam dynamics in focusing devices and we demonstrate that high-brilliance ion beams compress magnetic fields to amplitudes exceeding tens of kilo-Tesla, which in turn play a dominant role in the focusing process, resulting either in a worsening or enhancement of focusing capabilities depending on the target geometry.

The cortical silent period in schizophrenia: A systematic review and meta-analysis focusing on disease stage and antipsychotic medication

BACKGROUND

Although numerous studies reported some changes of cortical silent period (CSP), an indicator of gamma-aminobutyric acid (GABA) function in central nervous system, in schizophrenia patients, it has been unknown how the disease stage and antipsychotic medication affect CSP values.

METHODS

The present study conducted a systematic review of previous literature comparing CSP between schizophrenia patients and healthy subjects, and then performed meta-analysis on the effects of (1) the disease stage and (2) antipsychotics on CSP.

RESULTS

(1) In the comparison of the disease stage comprising a total of 17 reports, there was no significant difference in CSP between patients under drug-naïve first-episode psychoses and healthy controls, or between patients with antipsychotic medication and healthy controls. (2) In the comparison of the antipsychotic class, patients treated with clozapine were longer in CSP compared to healthy controls. Patients treated with olanzapine/quetiapine or with other type of antipsychotics were not different from healthy controls. Regarding other type of antipsychotics, the iteration analysis after leaving out one literature showed that patients were shorter in CSP than healthy controls.

CONCLUSION

The results showed that clozapine seems to surely prolong CSP, indicating the enhancement of GABA transmission via GABA_B receptors, suggesting the possible relationship between the CSP prolongation by clozapine and its high efficacy in psychopathology. The finding of shorter CSP in patients with other type of antipsychotics was distinct from clozapine/olanzapine/quetiapine, but was difficult to interpret since this group included a variety of transcranial magnetic stimulation (TMS) methodologies and patients' background.

Interacting Roles of COMT and GAD1 Genes in Patients with Treatment-Resistant Schizophrenia: a Genetic Association Study of Schizophrenia Patients and Healthy Controls

The projection from dopaminergic neurons to gamma-aminobutyric acid (GABA) interneurons in the prefrontal cortex is involved in the etiology of schizophrenia. The impact of interacting effects between dopamine signals and the expression of GABA on the clinical phenotypes of schizophrenia has not been studied. Since these interactions could be closely involved in prefrontal cortex functions, patients with specific alleles of these relevant molecules (which lead to lower or vulnerable genetic functions) may develop treatment-refractory symptoms. We conducted a genetic association study focusing on COMT and GAD1 genes for a treatment-resistant schizophrenia (TRS) group (n=171), a non-TRS group (n=592), and healthy controls (HC: n=447), and we examined allelic combinations specific to TRS. The results revealed that the percentage of subjects with Met allele of rs4680 on the COMT gene and C/C homozygote of rs3470934 on the GAD1 gene was significantly higher in the TRS group than the other two groups. There was no significant difference between the non-TRS group and HC groups. Considering the direction of functions of these single-nucleotide polymorphisms revealed by previous studies, we speculate that subjects with the Met/CC allelic combination could have a higher dopamine level and a lower expression of GABA in the prefrontal cortex. Our results suggest that an interaction between the dopaminergic signal and GABA signal intensities could differ between TRS patients and patients with other types of schizophrenia and healthy subjects.

Oxytocin system dysfunction in patients with treatment-resistant schizophrenia: Alterations of blood oxytocin levels and effect of a genetic variant of OXTR

Treatment-resistant schizophrenia (TRS) has a quite complex pathophysiology that includes not only severe positive symptoms but also other symptom domains. Much attention has been devoted to the overlapping psychological and biological profiles of schizophrenia and autistic spectrum disorder (ASD). We compared TRS patients (n = 30) with schizophrenia patients in remission (RemSZ, n = 28) and ASD patients (n = 28), focusing on general cognitive and social cognitive impairment and oxytocin system dysfunction. Our analyses revealed that there was no difference in oxytocin concentration among the three groups. The TRS patients' oxytocin blood concentrations were positively correlated with their processing speed and theory-of-mind scores, whereas the RemSZ and ASD groups had no significant relation with any measures. Rs53576, a single nucleotide polymorphism on the oxytocin receptor gene, affected social cognition abilities in the schizophrenia group. Although the overall findings are preliminary, they indicate that oxytocin system dysfunction could be involved in the serious cognitive deficits in TRS patients. Further, these results suggest that patients with TRS might have early neurodevelopmental abnormalities based on their shared biological features with ASD patients.

Clozapine Prolongs Cortical Silent Period in Patients with Treatment-Resistant Schizophrenia

OBJECTIVES

Although clozapine exhibited high efficacy for treating the symptoms of patients with treatment-resistant schizophrenia (TRS), its precise action mechanisms have not been fully understood. Recently, accumulating evidence has suggested the presence of abnormalities in the gamma-aminobutyric acid (GABA) systems in patients with schizophrenia, and the potential effects of clozapine on GABA receptors have gained a great deal of attention.

EXPERIMENTAL DESIGNS

In the present study, the cortical silent period (CSP), an electrophysiological parameter of GABA function via GABA_B receptors, was measured using with the transcranial magnetic stimulation in patients with schizophrenia and healthy control subjects. Then the CSP of patients treated with clozapine (N = 12) was compared with that of patients treated with other antipsychotics (N = 25) and with that of healthy controls (N = 27).

PRINCIPAL OBSERVATIONS

The CSP of the patients treated with clozapine was significantly longer compared to those of the other two groups. The CSP of patients treated with other antipsychotics was similar to that of healthy subjects. There was a positive correlation between CSP and global assessment of function (GAF) in patients with TRS.

CONCLUSIONS

The present study indicated that CSP was prolonged in patients receiving clozapine, and suggested that clozapine enhances the transmission signal via GABAB receptors.

Autistic traits and cognitive profiles of treatment-resistant schizophrenia

The complex pathophysiology of treatment-resistant schizophrenia (TRS) includes severe positive symptoms but also other symptom domains. The overlapping psychological profiles of schizophrenia and autistic spectrum disorder (ASD) are not established. We compared TRS patients (n = 30) with schizophrenia patients in remission (RemSZ, n = 28) and ASD patients (n = 28), focusing on both neurodevelopmental aspects and general and social cognitive impairments. The TRS group performed the worst on general neurocognition (measured by the MATRICS Consensus Cognitive Battery) and social cognition (measured by the theory of mind and emotional expression). The RemSZ group performed the best among the three groups. Regarding autistic traits, all measurements by the Autism-Spectrum Quotient/Autism Screening Questionnaire/Pervasive Developmental Disorder Assessment Rating Scale showed that (1) the ASD patients had the highest autistic traits (2) the TRS patients' scores were less severe than the ASD group's, but (3) the overall trends placed the TRS group between the ASD and the RemSZ group. These findings indicate that TRS patients and remitted patients could have distinctive neurodevelopmental and cognitive profiles. Further, the degrees of social cognitive dysfunction and autistic traits in TRS patients could be close to those of ASD patients, suggesting similarities between TRS and ASD.

MRI Findings of Immune Checkpoint Inhibitor-Induced Hypophysitis: Possible Association with Fibrosis

BACKGROUND AND PURPOSE

Hypophysitis is one of the well-known adverse effects of immune checkpoint inhibitors. Immune checkpoint inhibitor-induced hypophysitis frequently causes irreversible hypopituitarism, which requires long-term hormone replacement. Despite the high frequency and clinical significance, characteristic MR imaging findings of immune checkpoint inhibitor-induced hypophysitis have not been established. In the present study, we aimed to review and extract the MR imaging features of immune checkpoint inhibitor-induced hypophysitis.

MATERIALS AND METHODS

This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor-induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Clinical symptoms and hormone levels were also recorded.

RESULTS

Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively, which persisted in 12/19 and 10/12 patients, respectively, throughout the study period.

CONCLUSIONS

Pituitary geographic hypoenhancing lesions in the anterior lobe of the pituitary gland are characteristic and frequent MR imaging findings of immune checkpoint inhibitor-induced hypophysitis. They reflect fibrosis and are useful in distinguishing immune checkpoint inhibitor-induced hypophysitis from other types of hypophysitis/tumors.

Plasma monoamines change under dopamine supersensitivity psychosis in patients with schizophrenia: A comparison with first-episode psychosis

BACKGROUND

Patients with first-episode psychosis respond well to initial antipsychotic treatment, but among patients experiencing a relapse of psychosis, the response rate falls to approximately 30%. The mechanism of this discrepancy has not been clarified, but the development of dopamine supersensitivity psychosis with the underlying up-regulation of post-synaptic dopamine D2 receptors could be involved in this lesser response. It is uncertain whether elevated dopamine synthesis and release occurs in patients with dopamine supersensitivity psychosis, in contrast to those with first-episode psychosis.

PATIENTS AND METHODS

We examined a first-episode psychosis group (n=6) and a chronic schizophrenia group, i.e. patients experiencing relapse (n=23) including those who relapsed due to dopamine supersensitivity psychosis (n=18). Following the initiation of treatment, we measured the patients' blood concentrations of homovanillic acid and 3-methoxy-4-hydroxyphenylglycol at two weeks and four weeks after the baseline measurements.

RESULTS

The first-episode psychosis group tended to show decreased homovanillic acid, accompanied by an improvement of symptoms. The chronic schizophrenia group showed no alteration of homovanillic acid or 3-methoxy-4-hydroxyphenylglycol over the treatment period. These results were the same in the dopamine supersensitivity psychosis patients alone.

CONCLUSIONS

Our findings suggest that unlike first-episode psychosis, the release of dopamine from presynaptic neurons did not increase in relapse episodes in the patients with dopamine supersensitivity psychosis. This indirectly indicates that the development of supersensitivity of post-synapse dopamine D2 receptor is involved in relapse in dopamine supersensitivity psychosis patients.

Expressions of ezrin, ERK, STAT3, and AKT in tongue cancer and association with tumor characteristics and patient survival

Background

Ezrin, ERK, STAT3, and AKT are proteins that are overexpressed in various types of cancer, although their expressions in tongue cancer has received less focus. This study aimed to address associations between the expression levels of these proteins and with characteristics of the tumor and patient survival.

Methods

We performed immunohistochemical staining of ezrin, ERK, STAT3, and AKT in tumors from patients with tongue carcinoma in situ (CIS, n = 17) and tongue squamous cell carcinoma (SCC, n = 46). Statistical differences between the SCC versus the CIS cohorts were estimated by calculations of bivariate odds ratios of low versus high expression of the proteins. Fisher's exact tests were used to appraise interassociations between the proteins, as well as expression levels versus patient and tumor characteristics. Survival based on Kaplan–Meier statistics in combination log‐rank tests were used to address potential effects of the patient and tumor characteristics versus 5‐year survival rate.

Results

The relative high: low expression of all four proteins in the two cohorts differed, and particularly ERK was markedly overexpressed in the SCC versus the CIS cohort (odds ratio = 45.3, p < .01). The relative high: low expression each protein versus patient and tumor characteristics; showed associations between AKT expression and T stage (p = .002) plus node metastases (p = .12), and between ERK expression and drinking (p = .01) and smoking history (p = .01). There was no significant difference observed between ERK and the three other molecules, nor any significant difference between the degree of expression of each protein and the 5‐year disease‐specific survival rate.

Conclusion

Ezrin, ERK, STAT3, and AKT appear to be involved in the progress from carcinoma in situ in the tongue into squamous cell carcinoma. ERK in particular is overexpressed, suggesting that ERK may be a novel therapeutic target for preventing tongue cancer.

Helicity-Changing Brillouin Light Scattering by Magnons in a Ferromagnetic Crystal

Brillouin light scattering in ferromagnetic materials usually involves one magnon and two photons and their total angular momentum is conserved. Here, we experimentally demonstrate the presence of a helicity-changing two-magnon Brillouin light scattering in a ferromagnetic crystal, which can be viewed as a four-wave mixing process involving two magnons and two photons. Moreover, we observe an unconventional helicity-changing one-magnon Brillouin light scattering, which apparently infringes the conservation law of the angular momentum. We show that the crystal angular momentum intervenes to compensate the missing angular momentum in the latter scattering process.

Vulnerable combinations of functional dopaminergic polymorphisms to late-onset treatment resistant schizophrenia

Background

A significant portion of patients with schizophrenia who respond to initial antipsychotic treatment acquire treatment resistance. One of the possible pathogeneses of treatment-resistant schizophrenia (TRS) is antipsychotic-induced dopamine supersensitivity psychosis (Ai-DSP). Patients with this disease progression might share some genetic vulnerabilities, and thus determining individuals with higher risks of developing Ai-DSP could contribute to preventing iatrogenic development of TRS. Therefore, we decided to examine whether combinations of functional single nucleotide polymorphisms (SNPs) known to affect dopaminergic functions are related to Ai-DSP development.

Methods

In this case-control study, 357 Japanese participants diagnosed with schizophrenia or schizoaffective disorder were recruited and divided into two groups, those with and without Ai-DSP. As functional SNPs, we examined rs10770141 of the tyrosine hydroxylase gene, rs4680 of the catechol-O-methyltransferase gene, and rs1799732 and rs1800497 of the DRD2 genes, which are known to possess strong directional ties to dopamine synthesis, dopamine degradation and post-synaptic DRD2 prevalence, respectively.

Results

Among the 357 Japanese patients with schizophrenia or schizoaffective disorder, 130 were classified as Ai-DSP(+) and the other 227 as Ai-DSP(-). Significantly higher proportions of Ai-DSP(+) patients were found to have the SNP combinations of rs10770141/rs4680 (57.9%, OR2.654, 95%CI1.036–6.787, P = 0.048) and rs10770141/rs4680/ rs1800497 (64.3%, OR4.230, 95%CI1.306–13.619, P = 0.029). However, no single SNP was associated with Ai-DSP.

Conclusions

We preliminarily found that carrying particular combinations of functional SNPs, which are related to relatively higher dopamine synthesis and dopamine degradation and lower naïve DRD2, might indicate vulnerability to development of Ai-DSP. However, further studies are needed to validate the present results.

Total lesion glycolysis on FDG-PET/CT before salvage surgery predicts survival in laryngeal or pharyngeal cancer

We investigated whether 18F-fluorodeoxyglucose uptake parameters using positron emission tomography combined with computed tomography predicts several survival outcomes, including lung metastasis-free survival, in patients with laryngeal or pharyngeal cancer who underwent salvage surgery. The maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis were calculated as 18F-fluorodeoxyglucose uptake parameters in 51 patients with laryngeal or pharyngeal cancer before salvage surgery. In univariate analysis, the maximum standardized uptake value ≥ 22.8, metabolic tumor volume ≥ 2.4, and total lesion glycolysis ≥ 5.4 were significantly correlated with shorter overall survival. In multivariate analysis with adjustment for clinical stage, patients with total lesion glycolysis ≥ 5.4 exhibited significantly shorter overall survival. Furthermore, total lesion glycolysis ≥ 5.4 was significantly correlated with shorter disease-specific survival, distant metastasis-free survival, and lung metastasis-free survival in univariate analysis. In conclusion, total lesion glycolysis predicts the survival outcomes including lung metastasis in patients with laryngeal or pharyngeal cancer who underwent salvage surgery.

Dopamine supersensitivity psychosis in schizophrenia: Concepts and implications in clinical practice

Dopamine supersensitivity psychosis (DSP) is observed in patients with schizophrenia under antipsychotic treatment, and it is characterized by rebound psychosis, an uncontrollable psychotic episode following a stable state and tardive dyskinesia. DSP, first described in patients taking typical antipsychotics in the late 1970s, sometimes appears even in patients who are treated with current atypical antipsychotics. It was recently demonstrated that DSP can have a negative impact on the long-term prognosis of schizophrenia patients and that DSP could be involved in the etiology of some cases of treatment-resistant schizophrenia. Accumulating evidence suggests that an up-regulation of dopamine D2 receptors (DRD2) in the brain caused by long-term exposure to antipsychotics is related to the DSP phenomenon. The present review describes the clinical characteristics and the etiology of DSP in the era of second-generation antipsychotics for patients with schizophrenia. Based on the mechanism of DSP, several potential treatments for patients presenting with a DSP episode or the dopamine supersensitivity state are also discussed.

Alterations in glutamatergic signaling in the brain of dopamine supersensitivity psychosis and non-supersensitivity psychosis model rats

BACKGROUND

The long-term administration of antipsychotics is known to induce dopamine supersensitivity psychosis (DSP). Although the mechanism of DSP involves mainly a compensatory upregulation of dopamine D2 receptors, the precise mechanisms underlying DSP are unknown. It is known that glutamatergic signaling plays a key role in psychosis. We thus conducted this study to investigate whether glutamatergic signaling plays a role in the development of DSP.

METHODS

Haloperidol (0.75 mg/kg/day for 14 days) or vehicle was administered to rats via osmotic mini-pump. Haloperidol-treated rats were divided into groups of DSP rats and non-DSP rats based on locomotion data. Tissue levels of glutamate, glutamine, glycine, L-serine, D-serine, and GABA and the protein expressions of N-methyl-D-aspartate receptors (NMDAR), glutamic acid decarboxylase (GAD), and serine hydroxymethyltransferase (SHMT) in the rat brain regions were examined.

RESULTS

In the DSP rats, the ratio of GABA to glutamate was significantly increased. In addition, the ratio of L-serine to glycine was increased. The striatal expressions of GAD and SHMT2 in the DSP rats were significantly increased. In contrast, the striatal expression of NMDAR2B in the non-DSP rats was significantly decreased.

CONCLUSIONS

The present study suggests that glutamatergic signaling is relatively decreased to GABA in DSP rats. Our results also showed that excessive doses of haloperidol can induce striatal NMDAR hypofunction in non-DSP rats, which could prevent the formation of tardive dyskinesia but cause treatment resistance. In view of the need for therapeutic strategies for treatment-resistant schizophrenia, further research exploring our present findings is necessary.

Comparison between chemoselection and definitive radiotherapy in patients with cervical esophageal squamous cell carcinoma

BACKGROUD

Laryngeal preservation is an important consideration when treating cervical esophageal cancers (CECs) such as laryngeal cancer. The standard treatment for CEC allowing laryngeal preservation is chemoradiotherapy. However, in cases of laryngeal cancer, chemoselection has also been applied as a treatment strategy that promotes larynx preservation. This strategy involves assigning the appropriate radical treatment according to the primary tumor's response to induction chemotherapy. Since there have been no studies of the application of chemoselection in CEC cases, the present study compared the results, including laryngeal preservation rates, obtained upon applying chemoselection and chemoradiotherapy to CEC.

STUDY DESIGN

This was a retrospective cohort study of cervical esophageal squamous cell carcinoma patients treated using chemoselection or chemoradiotherapy at Aichi Cancer Center Hospital between January 2000 and March 2013. A total of 42 patients were enrolled.

RESULTS

The 2-year overall survival and laryngeal preservation rates for the chemoselection group versus the primary radiotherapy group were 65.1 and 57.3 versus 40 and 83.3%, respectively (P = 0.017 and P = 0.122, respectively). The 2-year locoregional control rates for the chemoselection and primary radiotherapy groups were 68 and 25%, respectively (P = 0.045).

CONCLUSION

The chemoselection group achieved favorable results. Therefore, chemoselection can be applied as a treatment strategy for CEC.

The platelet-activating receptor C-type lectin receptor-2 plays an essential role in liver regeneration after partial hepatectomy in mice

Essentials Regeneration role of C-type lectin receptor-2 (CLEC-2) after 70% hepatectomy (HPx) was investigated. Wild-type or CLEC-2 deleted from platelets of chimeric mice (flKO) underwent HPx. The liver/body weight ratio was significantly lower in the flKO than in the wild-type. CLEC-2 plays an essential role in liver regeneration after HPx.

SUMMARY

Background and aim The aim of the present study was to investigate the role of C-type lectin receptor (CLEC)-2 in liver regeneration following partial liver resection in mice. Materials and methods Irradiated chimeric mice transplanted with fetal liver cells from wild-type (WT) mice, CLEC-2-deleted (KO) mice or mice with CLEC-2 deleted specifically from platelets (flKO) were generated. Mice underwent 70% partial hepatectomy (PH). Immunohistochemical staining was performed to investigate the expression of the endogenous ligand for CLEC-2, podoplanin. The accumulation of platelets in the liver was also quantified. The hepatic expression of the IL-6/gp130 and STAT3, Akt and ERK1/2 was also examined. Results The liver/body weight ratio and expression of all cell proliferation markers were significantly lower in the flKO group than in the WT group. The expression of phosphorylated (p) Akt and pERK1/2 was similar in the WT and flKO groups. On the other hand, the expression of pSTAT3 and IL-6 was significantly stronger in the WT group than in the flKO group. The expression of podoplanin was detected in the hepatic sinusoids of both groups. However, the extent to which platelets accumulated in hepatic sinusoids was significantly less in the flKO group than in the WT group. Conclusion CLEC-2 was involved in hepatic regeneration after liver resection and CLEC-2-related liver regeneration was attributed to the interaction between platelets and sinusoidal endothelial cells.

Efficacy of clozapine on dopamine supersensitivity psychosis in schizophrenia

Although the effectiveness of clozapine (CLZ) for patients with treatment-resistant schizophrenia (TRS) has been well established, its active mechanism has not been completely clarified. Several clinical studies showed that neuroleptic-induced dopamine supersensitivity psychosis (DSP) could be involved in the etiology of TRS. We preliminarily explored the possible beneficial effect of CLZ for dopamine supersensitivity schizophrenia. The present study is a case series. We followed 15 patients with DSP for about 2.5 years from the introduction of CLZ and compared the prevalence of episodes (particularly, rebound psychosis, tolerance to antipsychotic effects, or tardive dyskinesia) between the period before and during CLZ treatment. Our observation over 2.5 years following the introduction of CLZ showed that 13 of the 15 DSP patients presented no further DSP episodes. One patient showed continued tardive dyskinesia, which had already existed in the preperiod, and the other patient presented with rebound psychosis that appeared immediately after discontinuation of CLZ. The results of the present study indicated that DSP in schizophrenic patients treated with general antipsychotics disappeared over the subsequent 2.5 years under CLZ treatment, suggesting that the agent ameliorates the dopamine supersensitivity state induced by previous antipsychotic treatment.

Long-term Intraarterial Infusion Therapy with Prostaglandin E1 in Patients with Ischemic Ulcer of the Extremities

There is confusion about blood flow of the foot during intraarterial infusion of prostaglandin E 1. The authors studied blood flow in the dorsalis pedis arter ies of patients with ischemic ulcer during the infusion and report the results in this paper.

Prostaglandin E1 was continuously infused intraarterially for a mean of 30.9 ±14.5 days in 17 lower extremities of 11 patients with intractable ischemic ulcers. Thirteen of the 17 cases responded to the treatment—especially the cases in which peripheral arteries near the foot joint were patent. In the dorsalis pedis artery, the blood flow increased by 266.3% during the arterial infusion, but no differences were seen in the peak frequency or the percent window denoting the degree of spectral broadening in the infused lower limb. On the other hand, there was no statistically significant difference between the blood flow, peak frequency, or percent window of the contralateral lower limb before, and those parameters during, the infusion. The authors observed complications in 9 of 17 cases, which necessitated the discontinuation of the infusion.

Distinct X chromosomal rearrangements in four haemophilia B patients with entire F9 deletion

INTRODUCTION

Haemophilia B is an X-linked bleeding disorder caused by a coagulation factor IX gene (F9) abnormality. Numerous F9 defects have been identified to date; however, only a few with an entire F9 deletion have been reported in detail.

AIM

To elucidate the cause of severe haemophilia B, we investigated the precise X chromosome abnormalities in four Japanese patients who did not show all amplifications in F9-specific PCR.

METHODS

We analysed the patient's genomic DNA using Multiplex ligation-dependent probe amplification (MLPA). To assess the extent of any deletions, we further performed mapping PCRs, inverse PCRs or long-range PCRs and direct sequencing analyses of the X chromosome.

RESULTS

We detected entire F9 deletions in four haemophilia B patients and identified the precise deleted regions of the X chromosome including F9. Patient 1 had a 149-kb deletion with breakpoints 90-kb upstream and 30-kb downstream from F9. Patients 2 and 3 showed 273-kb and 1.19-Mb deletions respectively. Patient 4 had two deleted regions: a 1663-bp deletion 1.34-Mb upstream from F9 and a 7.2-Mb deletion including F9. These distinct breakpoints found in four different patients suggest that the mechanism of X chromosome deletion may be different between individuals. Non-allelic homologous recombination (NAHR), microhomology-mediated break-induced replication (MMBIR) or fork stalling and template switching (FoSTeS) may occur in respective X chromosomes of the four haemophilia B patients analysed.

CONCLUSIONS

We identified diverse X chromosomal rearrangements in four haemophilia B patients, which might be caused by distinct mechanisms of genomic rearrangement.

Weight change after 20 years of age and the incidence of dyslipidemia: a cohort study of Japanese male workers

BACKGROUND

While heavier weight is known to increase the incidence of dyslipidemia, limited data are available on the relationship between weight gain and its development.

METHODS

A total of 2647 males were categorized into the following four groups according to the difference between their self-reported weight at 20 years of age and their measured weight in 1994-95: a loss of ≥5% (decrease), loss of <5% or gain of <5% (no change), gain of ≥5 to <15% (increase) and gain of ≥15% (sizable increase). They were followed up until their 2002-03 health examination. Using the 'no change' group as reference, the multivariable-adjusted odds ratio (adjusted for age, body mass index at 20 years of age, physical activity, smoking and alcohol intake) and 95% confidence interval (95% CI) for the incidence of dyslipidemia were determined using logistic regression models.

RESULTS

A total of 1342 participants developed dyslipidemia during the follow-up period. The 'increase' and 'sizable increase' groups had odds ratios for the incidence of dyslipidemia of 1.97 (95% CI, 1.59-2.45) and 2.68 (2.15-3.34), respectively, demonstrating that there was a significant dose-response association between weight gain since 20 years of age and the incidence of dyslipidemia (P < 0.001 for trend).

CONCLUSION

These results suggest that dyslipidemia could be prevented by avoiding weight gain in adulthood.

Simple model of pH-induced protein denaturation

The pH-induced conformational changes of proteins are systematically studied in the framework of a hydrophobic-polar (HP) model, in which proteins are dramatically simplified as chains of hydrophobic (H) and polar (P) beads on a lattice. We express the electrostatic interaction, the principal driving force of pH-induced unfolding that is not included in the conventional HP model, as the repulsive energy term between P monomers. As a result of the exact enumeration of all of the 14- to 18-mers, it is found that lowest-energy states in many sequences change from single "native" conformations to multiple sets of "denatured" conformations with an increase in the electrostatic repulsion. The switching of the lowest-energy states occurs in quite a similar way to real proteins: it is almost always between two states, while in a small fraction of ≥16-mers it is between three states. We also calculate the structural fluctuations for all of the denatured states and find that the denatured states contain a broad range of incompletely unfolded conformations, similar to "molten globule" states referred to in acid or alkaline denatured real proteins. These results show that the proposed model provides a simple physical picture of pH-induced protein denaturation.

Hyperspectroscopic imager for baby fibers

Hyperspectral imaging system for diagnosing digestive diseases was newly developed in order to obtain information on pathology beyond morphology of lesions. In order to guide light reflected from a lesion, a baby fiber, which can be inserted in a forceps channel of the electronic endoscope, was also developed. The performance of the system was evaluated by animal experiment. Obtained hyperspectral data were found to have sufficient quality endurable to practical use. Harmful phenomena to a living body were not observed within the experiment. It was considered from the animal experiment that the present system could be practically used for humans.

Amitriptyline up-regulates connexin43-gap junction in rat cultured cortical astrocytes via activation of the p38 and c-Fos/AP-1 signalling pathway

BACKGROUND AND PURPOSE

Intercellular communication via gap junctions, comprised of connexin (Cx) proteins, allow for communication between astrocytes, which in turn is crucial for maintaining CNS homeostasis. The expression of Cx43 is decreased in post-mortem brains from patients with major depression. A potentially novel mechanism of tricyclic antidepressants is to increase the expression and functioning of gap junctions in astrocytes.

EXPERIMENTAL APPROACH

The effect of amitriptyline on the expression of Cx43 and gap junction intercellular communication (GJIC) in rat primary cultured cortical astrocytes was investigated. We also investigated the role of p38 MAPK intracellular signalling pathway in the amitriptyline-induced expression of Cx43 and GJIC.

KEY RESULTS

Treatment with amitriptyline for 48 h significantly up-regulated Cx43 mRNA, protein and GJIC. The up-regulation of Cx43 was not monoamine-related since noradrenaline, 5-HT and dopamine did not induce Cx43 expression and pretreatment with α- and β-adrenoceptor antagonists had no effect. Intracellular signalling involved p38 MAPK, as amitriptyline significantly increased p38 MAPK phosphorylation and Cx43 expression and GJIC were significantly blocked by the p38 inhibitor SB 202190. Furthermore, amitriptyline-induced Cx43 expression and GJIC were markedly reduced by transcription factor AP-1 inhibitors (curcumin and tanshinone IIA). The translocation of c-Fos from the cytosol and the nucleus of cortical astrocytes was increased by amitriptyline, and this response was dependent on p38 activity.

CONCLUSION AND IMPLICATION

These findings indicate a novel mechanism of action of amitriptyline through cortical astrocytes, and further suggest that targeting this mechanism could lead to the development of a new class of antidepressants.

Post-purchase reassessment and improvement of neuroendoscope holder: importance of physician-manufacturer communication

BACKGROUND

Modern medical management requires constant quality improvement of the various instruments used for surgical procedures. Higher quality, less complicated handling, and reduced maintenance are all desirable qualities. However, any improvements in instrumentation require that surgeons must clearly understand the application of the device by adherence to the manufacturer's instructions. The weakness of this one-way information flow depends on the low interest among medical personnel for post-purchase reassessment.

OBJECTIVE

Service industries have research departments to investigate the post-purchase behavior of customers, and service recovery is considered essential to retain customers after service failure. All service providers can suffer service failures, and even the best providers may make errors in delivering service. Such an approach has been increasingly adopted in the risk management at medical institutions.

METHODS

We report our clinical trials of the post-purchase reassessment and product improvement of surgical instrumentation. Medical personnel reassessed the use of a newly developed endoscope holder based on the manufacturer's manual and made recommendations for possible improvements, which were examined by the manufacturer.

RESULTS

Simple but important improvement was achieved for reducing the instability and uncertainty of instrument fixation.

CONCLUSION

This bi-directional post-purchase communication between medical personnel and manufacturers can improve risk management in medical institutions.

Primary cultures of rat cortical microglia treated with nicotine increases in the expression of excitatory amino acid transporter 1 (GLAST) via the activation of the α7 nicotinic acetylcholine receptor

Although the clearance of glutamate from the synapse under physiological conditions is performed by astrocytic glutamate transporters, their expression might be diminished under pathological conditions. Microglia glutamate transporters, however, might serve as a back-up system when astrocytic glutamate uptake is impaired, and could have a prominent neuroprotective function under pathological conditions. In the current study, the effect of nicotine, well known as a neuroprotective molecule, on the function of glutamate transporters in cultured rat cortical microglia was examined. Reverse transcription polymerase chain reaction and pharmacological approaches demonstrated that, glutamate/aspartate transporter (GLAST), not glutamate transporter 1 (GLT-1), is the major functional glutamate transporter in cultured cortical microglia. Furthermore, the α7 subunit was demonstrated to be the key subunit comprising nicotinic acetylcholine (nACh) receptors in these cells. Treatment of cortical microglia with nicotine led to a significant increase of GLAST mRNA expression and (14)C-glutamate uptake in a concentration- and time-dependent manner, which were markedly inhibited by pretreatment with methyllycaconitine, a selective α7 nACh receptor antagonist. The nicotine-induced expression of GLAST mRNA and protein is mediated through an inositol trisphosphate (IP3) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) depend intracellular pathway, since pretreatment with either xestospongin C, an IP3 receptor antagonist, or KN-93, a CaMKII inhibitor, blocked GLAST expression. Together, these findings indicate that activation of nACh receptors, specifically those expressing the α7 subunit, on cortical microglia could be a key mechanism of the neuroprotective effect of nACh receptor ligands such as nicotine.

Recent progress in gene therapy for Parkinson's disease

Parkinson's disease (PD) is an age-related and the second most common neurodegenerative disorder beyond Alzheimer's disease. A neuropathological hallmark of PD is a prominent loss of dopaminergic neurons in the substantia nigra projecting into the caudate and putamen. Oral administration of L-dopa and/or dopamine agonists ameliorates cardinal motor symptoms of PD. However, an intermittent and long-term treatment with L-dopa frequently induces adverse side effects such as motor fluctuations and dyskinesia. As alternative therapeutic strategies, the following four approaches are currently under evaluation for clinical gene therapy trials in PD; 1) recombinant adeno-associated virus 2 system encoding aromatic L-amino acid decarboxylase (AADC), 2) glutamic acid decarboxylase (GAD) and 3) Neurturin, and 4) equine infectious anemia virus-based lentiviral system encoding AADC, tyrosine hydroxylase (TH) and GTP cyclohydrolase I (GCH) in a single transcriptional unit. GAD and Neurturin have been assessed in double blind placebocontrolled phase II studies; GAD showed a significant improvement in motor function, and Neurturin, although it failed to show significant effects at 12 months post-treatment, exhibited promising outcomes in additional examinations at 18 months. The other two approaches also represented significant effects in phase I or I/II studies. Adverse side effects due to surgery have not been observed. Here, we review preclinical and clinical trials encouraging further investigations of curative treatment for the patients suffering from PD.

Postoperative transient reduced diffusion in the ipsilateral striatum and thalamus

BACKGROUND AND PURPOSE

Restriction of diffusion has been reported in the early phase of secondary neuronal degeneration, such as wallerian degeneration. The purpose of this study was to investigate postoperative transient reduced diffusion in the ipsilateral striatum and thalamus as a remote effect of surgery.

MATERIALS AND METHODS

Six hundred two postoperative MR imaging examinations in 125 patients after cerebral surgery were retrospectively reviewed, focusing on the presence of reduced diffusion in the striatum and/or thalamus. The distribution of reduced diffusion in the striatum was classified into 3 groups: anterior, central, and posterior. Reduced diffusion in the thalamus was also classified on the basis of the anatomic locations of the thalamic nuclei. Further follow-up MRI was available in all patients with postoperative reduced diffusion, and acute infarctions were excluded. The patient medical records were reviewed to evaluate neurologic status.

RESULTS

Restriction of diffusion was observed in the striatum and/or thalamus ipsilateral to the surgical site in 17 patients (13.6%). The distribution of signal abnormality correlated with the location of the operation, in concordance with the architecture of the striatocortical and thalamocortical connections. Reduced diffusion was observed from days 7 to 46 after the operation, especially during days 8-21. The signal abnormalities completely resolved on follow-up examinations. The median follow-up period was 202 days (interquartile range, 76-487 days).

CONCLUSIONS

Postoperative transient reduced diffusion in the ipsilateral striatum and/or thalamus likely represents an early phase of secondary neuronal degeneration based on its characteristic distribution and time course. Clinically, this reduced diffusion should not be mistaken for postoperative ischemic injury.

Glutamatergic changes in the cerebral white matter associated with schizophrenic exacerbation

OBJECTIVE

Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. This study was aimed to examine several brain chemical mediators, including Glx (glutamate + glutamine), using (1)H magnetic resonance spectroscopy (MRS) in medicated patients with schizophrenia, with and without psychotic exacerbation.

METHOD

(1)H MRS was acquired in 24 patients with schizophrenia, with psychotic exacerbation; 22 patients without exacerbation; and 27 age- and sex-matched healthy volunteers. The levels of metabolites were measured in the left frontal and inferior parietal white matter and compared across the three groups.

RESULTS

The Glx level was significantly elevated in the left inferior parietal white matter in the patients with psychotic exacerbation in comparison with that in the healthy volunteers and the patients without exacerbation (P < 0.05). We also detected that there was a significant correlation between Positive and Negative Syndrome Scale-positive scale and Glx level in the left parietal white matter (r = 0.51, P < 0.001).

CONCLUSION

Higher than normal Glx levels indicate glutamatergic overactivity in the left inferior parietal white matter with schizophrenic exacerbation, a finding that is in accordance with the glutamatergic hypothesis in schizophrenia. The Glx level measured by (1)H MRS could be a biomarker for exacerbation in schizophrenia.

Study of Bandgap Profiling Control on Photovoltaic Performance in the Three Stacked Amorphous Solar Cells

A series of systematic experiments has been made on a bandgap profiling control using a-SiGe and a-SiC cells to clarify the cause for the improvement of the photovoltaic performance by the bandgap profiling in the photovoltaic active layer. It has been shown from the analysis that the most important contribution to the cell performance is an optimization of the ambipolar carrier collection by the bandgap profiling. On the basis of the results, an efficiency of 10.1% was obtained at the promising a-SiC/a-Si/ a-SiGe multi-bandgap stacked cell by the bandgap profiling.

Parasellar T2 dark sign on MR imaging in patients with lymphocytic hypophysitis

BACKGROUND AND PURPOSE

MR imaging findings of LYH and pituitary adenomas are similar, but the therapeutic strategies are completely different. The purpose of this study was to evaluate sellar and parasellar MR imaging findings in patients with both diseases, as well as characteristic clinical findings.

MATERIALS AND METHODS

Clinical findings, including endocrinologic study and MR images of 20 patients with LYH and 22 patients with pituitary adenoma, were retrospectively reviewed. We evaluated the MR images in relation to the following: 1) the PPHI on T1-weighted images, 2) thickened stalk (>3.5 mm), 3) pituitary symmetry, 4) pituitary enhancement pattern, 5) a dural tail, and 6) parasellar signal intensity on T2- and T1-weighted images.

RESULTS

Between patients with LYH and those with pituitary adenoma, a significant difference was identified for the number of patients with loss of PPHI, thickened stalk, pituitary symmetry, homogeneous enhancement, and parasellar dark signal intensity on T2-weighted images by statistical analysis (Fisher exact probability test, P < .05). Among them, only parasellar dark signal intensity on T2-weighted images had no false-positive cases.

CONCLUSIONS

The parasellar T2 dark sign can be a specific finding used to distinguish pituitary adenoma from LYH.