A Method to Collect Cerebrospinal Fluid from Mouse Cisterna Magna to Determine Extracellular Tau Levels.

Despite being a cytoplasmic protein abundant in neurons, tau is detectable in various extracellular fluids. In addition to being passively released from dying/degenerating neurons, tau is also actively released from living neurons in a neuronal activity-dependent mechanism. In vivo, tau released from neurons first appears in brain interstitial fluid (ISF) and subsequently drains into cerebrospinal fluid (CSF) by glymphatic system. Changes in CSF tau levels alter during the course of AD pathogenesis and are considered to predict the disease-progression of AD. A method to collect CSF from various mouse models of AD will serve as a valuable tool to investigate the dynamics of physiological/pathological tau released from neurons. In this chapter, we describe and characterize a method that reliably collects a relatively large volume of CSF from anesthetized mice.

Detection of Glymphatic Outflow of Tau from Brain to Cerebrospinal Fluid in Mice.

Glymphatic system denotes a brain-wide pathway that eliminates extracellular solutes from brain. It is driven by the flow of brain interstitial fluid (ISF) and cerebrospinal fluid (CSF) via perivascular spaces. Glymphatic convective flow is driven by cerebral arterial pulsation, which is facilitated by a water channel, aquaporin-4 (AQP4) expressed in astrocytic end-foot processes. Since its discovery, the glymphatic system receives a considerable scientific attention due to its pivotal role in clearing metabolic waste as well as neurotoxic substances such as amyloid b peptide. Tau is a microtubule binding protein, however it is also physiologically released into extracellular fluids. The presence of tau in the blood stream indicates that it is eventually cleared from the brain to the periphery, however, the detailed mechanisms that eliminate extracellular tau from the central nervous system remained to be elucidated. Recently, we and others have reported that extracellular tau is eliminated from the brain to CSF by an AQP4 dependent mechanism, suggesting the involvement of the glymphatic system. In this chapter, we describe the detailed protocol of how we can assess glymphatic outflow of tau protein from brain to CSF in mice.

In-Hospital Prescription Checking System for Hospitalized Patients with Decreased Glomerular Filtration Rate.

Background: Clinical decision support systems (CDSS) are reported to be useful in preventing dosage errors in renally excreted drugs by alerting hospital pharmacists to inadequate dosages for hospitalized patients with decreased GFR. However, it is unclear whether CDSS can reduce dosage errors in renally excreted drugs in hospitalized patients. To prevent dosage errors in renally excreted drugs, we introduced a prescription checking system (PCS) for in-hospital prescriptions. This retrospective study aimed to evaluate whether a prescription audit by hospital pharmacists using the PCS reduced the rate of dosage errors in renally excreted drugs. Methods: The target drugs were allopurinol, cibenzoline, famotidine, and pilsicainide. Interrupted time series analysis was used to evaluate trends in the 4-weekly dosage error rates over 52 weeks before PCS implementation and 52 weeks after PCS implementation. Results: Before and after PCS implementation, 474 and 331 prescriptions containing one of the targeted drugs, respectively, were generated. The estimated baseline level of the 4-weekly dosage error rates was 34%. The trend before the PCS implementation was stable with no observable trend. The estimated level change from the last point in the pre-PCS implementation to the first point in the PCS implementation was -20% (P<0.001). There was no change in the trend after PCS implementation. Conclusions: We demonstrated that a prescription audit by hospital pharmacists using the PCS reduced the rate of dosage errors in the target renally excreted drugs in hospitalized patients. Although further studies are needed to confirm whether our results can be generalized to other health facilities, our findings highlight the need for a PCS to prevent the overdose of renally excreted drugs.

Prediction Accuracy of Area under the Concentration-Time Curve of Vancomycin by Bayesian Approach Using Creatinine-Based Equations of Estimated Kidney Function in Bedridden Elderly Japanese Patients.

An administration plan for vancomycin (VCM) in bedridden elderly patients has not been established. This retrospective study aimed to evaluate the prediction accuracy of the area under the concentration-time curve (AUC) of VCM by the Bayesian approach using creatinine-based equations of estimated kidney function in such patients. Kidney function was estimated using the Japanese equation of estimated glomerular filtration rate (eGFR) and the Cockcroft-Gault equation of estimated creatinine clearance (eCCr). eCCr (serum creatinine (SCr) + 0.2) was calculated by substituting the SCr level +0.2 mg/dL into the Cockcroft-Gault equation. For eGFR/0.789, eGFR, eCCr, and eCCr (SCr + 0.2), the AUC values were calculated by the Bayesian approach using the therapeutic drug monitoring (TDM) software, BMs-Pod (ver 8.06) and denoted as AUCeGFR/0.789, AUCeGFR, AUCeCCr, and AUCeCCr (SCr + 0.2) respectively. The reference AUC (AUCREF) was calculated by applying VCM's peak and trough steady-state concentrations to first-order pharmacokinetic equations. The medians (range) of AUCeGFR/0.789/AUCREF, AUCeGFR/AUCREF, AUCeCCr/AUCREF, and AUCeCCr (SCr + 0.2)/AUCREF were 0.88 (0.74-0.93), 0.90 (0.79-1.04), 0.92 (0.81-1.07), and 1.00 (0.88-1.11), respectively. Moreover, the percentage of patients within 10% of the AUCREF, defined as |Bayesian-estimated AUC - AUCREF| < AUCREF × 0.1, was the highest (86%) in AUCeCCr (SCr + 0.2). These results suggest that the Bayesian approach using eCCr (SCr + 0.2) has the highest prediction accuracy for the AUCREF in bedridden elderly patients. Although further studies are required with more accurate determination methods of the CCr and AUC, our findings highlight the potential of eCCr (SCr + 0.2) for estimating VCM's AUC by the Bayesian approach in such patients.

Glymphatic system clears extracellular tau and protects from tau aggregation and neurodegeneration.

Accumulation of tau has been implicated in various neurodegenerative diseases termed tauopathies. Tau is a microtubule-associated protein but is also actively released into the extracellular fluids including brain interstitial fluid and cerebrospinal fluid (CSF). However, it remains elusive whether clearance of extracellular tau impacts tau-associated neurodegeneration. Here, we show that aquaporin-4 (AQP4), a major driver of the glymphatic clearance system, facilitates the elimination of extracellular tau from the brain to CSF and subsequently to deep cervical lymph nodes. Strikingly, deletion of AQP4 not only elevated tau in CSF but also markedly exacerbated phosphorylated tau deposition and the associated neurodegeneration in the brains of transgenic mice expressing P301S mutant tau. The current study identified the clearance pathway of extracellular tau in the central nervous system, suggesting that glymphatic clearance of extracellular tau is a novel regulatory mechanism whose impairment contributes to tau aggregation and neurodegeneration.

Role of the DEK oncogene in the development of squamous cell carcinoma.

DEK is a highly conserved nuclear factor that plays an important role in the regulation of multiple cellular processes. DEK was discovered to be an oncogene as a fusion with NUP214 gene, which results in producing DEK-NUP214 proteins, in a subset of patients with acute myeloid leukemia. Subsequently, DEK overexpression was reported in many cancers, thus DEK itself is considered to be an oncoprotein. DEK has been reported to play important roles in the progression of early and late stage squamous cell carcinoma (SCC) and is useful for early diagnosis of the disease. These findings have made DEK an attractive therapeutic target, especially for human papillomavirus (HPV)-associated SCC. However, the mechanism of DEK in SCC remains unclear. In this review, we discuss human DEK oncogene-related SCC.

Specific Deletion of p16INK4a with Retention of p19ARF Enhances the Development of Invasive Oral Squamous Cell Carcinoma.

The cyclin-dependent kinase inhibitor 2A (CDKN2A)/alternate reading frame (ARF) locus consists of two overlapping tumor suppressor genes, p16INK4a and p14ARF (p19ARF in mice), encoding two unrelated proteins in alternative reading frames. Previous reports suggest that p16INK4a and p14ARF alterations independently exhibit differential roles, and p16INK4a is more closely associated with a poor prognosis in oral cancer. However, the role of p16INK4a-specific loss in oral squamous cell carcinogenesis remains unclear. The authors assessed chemical carcinogen 4-nitroquinoline 1-oxide (4NQO)-induced multistep oral squamous cell carcinogenesis in mice carrying p16INK4a-specific loss with retention of the p19ARF gene (p16INK4a-/-). 4NQO-treated p16-/- mice exhibited a higher incidence and multiplicity of oral squamous cell carcinoma (OSCC) development relative to 4NQO-treated wild-type mice. 4NQO-treated p16INK4a-/- OSCC cells exhibited higher proliferation and up-regulation of Arf, transcription factor E2f1, tumor protein p63 (tp63), and oncogenic ΔNp63, an isoform p63, compared with observations in 4NQO-treated wild-type OSCC cells. Furthermore, the overexpression of oncogenic ΔNp63 was associated with human OSCC. In conclusion, these results in mice indicate the biological significance of p16INK4a-specific loss with retention of p19ARF in oral squamous cell carcinogenesis, and ΔNp63 may be a potential target for OSCC.

Treatment Strategies Based on Histological Targets against Invasive and Resistant Glioblastoma.

Glioblastoma (GBM) is the most common and the most malignant primary brain tumor and is characterized by rapid proliferation, invasion into surrounding normal brain tissues, and consequent aberrant vascularization. In these characteristics of GBM, invasive properties are responsible for its recurrence after various therapies. The histomorphological patterns of glioma cell invasion have often been referred to as the "secondary structures of Scherer." The "secondary structures of Scherer" can be classified mainly into four histological types as (i) perineuronal satellitosis, (ii) perivascular satellitosis, (iii) subpial spread, and (iv) invasion along the white matter tracts. In order to develop therapeutic interventions to mitigate glioma cell migration, it is important to understand the biological mechanism underlying the formation of these secondary structures. The main focus of this review is to examine new molecular pathways based on the histopathological evidence of GBM invasion as major prognostic factors for the high recurrence rate for GBMs. The histopathology-based pharmacological and biological targets for treatment strategies may improve the management of invasive and resistant GBMs.

Current mouse models of oral squamous cell carcinoma: Genetic and chemically induced models.

Oral squamous cell carcinoma (OSCC) patients have a low 5-year survival rate and poor prognosis. To improve survival and prognosis, the causes and processes involved in lesion development should be evaluated. For this purpose, the use of OSCC mouse models, such as chemically induced mouse models, genetically modified mouse models, and transplanted (xenograft) models, is crucial. These OSCC models exhibit both advantages and disadvantages when studying OSCC development and progression. Until a model resembling human OSCC is developed, both the advantages and disadvantages of each model should be carefully considered. In this review, we discuss OSCC mouse models and their use in cancer research worldwide.

Promotion of cell proliferation by the proto-oncogene DEK enhances oral squamous cell carcinogenesis through field cancerization.

Oral squamous cell carcinoma (OSCC) develops through a multistep carcinogenic process involving field cancerization. The DEK gene is a proto-oncogene with functions in genetic and epigenetic modifications, and has oncogenic functions, including cellular proliferation, differentiation, and senescence. DEK overexpression is associated with malignancies; however, the functional roles of DEK overexpression are unclear. We demonstrated that DEK-expressing cells were significantly increased in human dysplasia/carcinoma in situ and OSCC. Furthermore, we generated ubiquitous and squamous cell-specific doxycycline (DOX)-inducible Dek mice (iDek and iDek-e mice respectively). Both DOX+ iDek and iDek-e mice did not show differences in the oral mucosa compared with DOX- mice. In the environment exposed to carcinogen, DOX-treated (DOX+) iDek mice showed field cancerization and OSCC development. Microarray analysis revealed that DEK overexpression was mediated by the upregulation of DNA replication- and cell cycle-related genes, particularly those related to the G1 /S transition. Tongue tumors overexpressing DEK showed increased proliferating cell nuclear antigen and elongator complex protein 3 expression. Our data suggest that DEK overexpression enhanced carcinogenesis, including field cancerization, in OSCC by stimulating the G1 /S phase transition and promoting DNA replication, providing important insights into the potential applications of DEK as a target in the treatment and prevention of OSCC.

Distinctive crypt shape in a sessile serrated adenoma/polyp: Distribution of Ki67-, p16INK4a-, WNT5A-positive cells and intraepithelial lymphocytes.

Serrated lesions in the colorectum are currently predominantly classified as hyperplastic polyps (HPs), sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs) according to their morphology. However, the histological morphology and the molecular changes in the serrated lesions are still unclear. We performed immunohistochemistry for Ki67, p16INK4a, and WNT5A in human HPs (n=22), SSA/Ps (n=41), and TSAs (n=19). The distribution of Ki67 and p16INK4a positive cells in TSAs was different from that in HPs and SSA/Ps. Co-expression of Ki67 and P16INK4a was infrequent in HPs and SSA/Ps; p16INK4a-positive cells were found in the crypt cleft and stromal WNT5A-positive stromal cells were localized near the cleft in SSA/Ps, while intraepithelial lymphocytes (IELs) in SSA/Ps were more abundant than HPs. In conclusion, our study provides evidence that HPs branch because of the increase in and patchy distribution of senescent and proliferative cells, with increased and misdistributed stromal and inflammatory cells, which might contribute to creation of L- and/or T-shaped crypts, which are of distinctive shapes in SSA/Ps. Our findings may facilitate better understanding and therapy in the serrated lesions.

Predictive factors for effectiveness and safety of enoxaparin for total knee arthroplasty in aged Japanese patients: a retrospective review.

BACKGROUND: The aims of this study were to investigate predictive factors involved in effectiveness and safety of enoxaparin for prevention of postoperative venous thromboembolism in aged Japanese total knee arthroplasty (TKA) patients. METHODS: Japanese patients over 65 years old who were administered enoxaparin for TKA were enrolled in this study. Their medical records were retrospectively reviewed. Data were corrected at the Izumi Regional Medical Center, from September 2009 to March 2014. Patients were stratified into groups according to whether enoxaparin was effective (no deep vein thrombosis event up to postoperative day 7) or not, and whether they had an adverse drug event (ADE) or not. RESULTS: A total of 128 patients were included in this study. One hundred five (82.0%) patients were in the effective group and 20 (15.6%) in the adverse drug event (ADE) group. Anemia (13 patients), abnormalities in liver function tests (4 patients), clinically relevant non-major bleeding (4 patients) and urticaria (1 patient) were observed as ADEs. Multivariate logistic regression analysis showed that the serum total protein level at postoperative day 1 (POD1, before enoxaparin administration), was associated with effectiveness of enoxaparin, while the serum total protein and hemoglobin level at POD1 were involved in ADE caused by enoxaparin. CONCLUSIONS: Although further large scale studies will be warranted, our results suggest that serum total protein level just before enoxaparin treatment for TKA relates to the effectiveness and safety of enoxaparin in a Japanese aged population. In addition, the results indicate that the development of anemia should be carefully monitored during enoxaparin treatment for TKA, particularly in patients with lower levels of serum hemoglobin before treatment.

Factors affecting serum albumin in the perioperative period of colorectal surgery: a retrospective study.

BACKGROUND: Albumin is considered a negative acute-phase protein because its concentration decreases during injury and sepsis. Hypoalbuminemia is a risk factor for mortality, postoperative complications, and prolonged hospital stay. The magnitude of the systemic inflammatory response during the perioperative period, as indicated by the acute-phase proteins-C-reactive protein (CRP) in particular-, may help identify the risk of postoperative infectious complication. The correlation between serum albumin and CRP with gastrointestinal cancer has been reported. However, it is unclear whether antecedent CRP could be utilized to predict future hypoalbuminemia in the perioperative period in colorectal surgery. The primary endpoint of this study was to reveal that antecedent CRP could be utilized to predict future hypoalbuminemia in the perioperative period of colorectal surgery. METHODS: Thirty-seven patients who underwent elective open colorectal surgery were included in this study. Correlations between preoperative CRP and serum albumin on postoperative day (POD) 3, between preoperative CRP and serum albumin on POD 7 and between CRP on POD 3 and serum albumin on POD 7 were examined. Relationships between preoperative CRP and hypoalbuminemia on POD 3, between preoperative CRP and hypoalbuminemia on POD 7 and between CRP on POD 3 and hypoalbuminemia on POD 7 were examined by receiver operating characteristic analysis. RESULTS: Three-quarters of patients were older than 65 years of age. Significant correlations were observed between preoperative CRP and serum albumin on POD 3 (p = 0.023), between preoperative CRP and serum albumin on POD 7 (p = 0.023) and between CRP on POD 3 and serum albumin on POD 7 (p < 0.001). The area under the receiver operating characteristic curve of CRP on POD 3 to development of hypoalbuminemia on POD 7 was 0.833 (95 % CI 0.679-0.987) with an optimal threshold of 12.43 mg/dL, sensitivity 75 % and specificity 80 %. CONCLUSIONS: The present study revealed that antecedent CRP was associated with future serum albumin. Additionally, CRP on POD 3 could be useful in predicting the development of hypoalbuminemia on POD 7. This result suggests that CRP on POD 3 may be a valuable indicator for early nutritional intervention.