Spermatogonial asynchrony in Tex14 mutant mice lacking intercellular bridges.

The existence of cytoplasmic passages between germ cells and their potential function in the control of the spermatogenic process has long been an intriguing question. Evidence of the important role of such structures, known as intercellular bridges (ICB), in spermatogenesis has been implicated by the failure of spermatogenesis in testis-expressed gene 14 (Tex14) mutant mice, which lack the ICBs, to progress past the pachytene spermatocyte stage. Using these Tex14 mutants, the present study evaluated, for the first time, the behavior and synchrony of the spermatogonial lineage in the absence of ICBs. Our data suggest that the absence of these cytoplasmic connections between cells affects the expansion of the undifferentiated type A (Aundiff) spermatogonia compartment and their transition to A1, resulting in a significant numerical reduction of differentiating A1 spermatogonia, but did not interfere with cell amplification during subsequent mitotic steps of differentiating spermatogonia from A1 through intermediate (In). However, beginning at the type B spermatogonia, the synchrony of differentiation was impaired as some cells showed delayed differentiation compared to their behavior in a normal seminiferous epithelium cycle. Thus although spermatogonial development is able to proceed, in the absence of ICBs in Tex14-/- mutants, the yield of cells, specific steps of differentiation, the synchrony of the cell kinetics, and the subsequent progression in meiosis are quantitatively lower than normal.

Redefining Mild Traumatic Brain Injury (mTBI) delineates cost effective triage.

OBJECTIVES: Mild traumatic brain injury (mTBI) is defined as Glasgow Coma Score (GCS) of 14 or 15. Despite good outcomes, patients are commonly transferred to trauma centers for observation and/or neurosurgical consultation. The aim of this study is to assess the value of redefining mTBI with novel radiographic criteria to determine the appropriateness of interhospital transfer for neurosurgical evaluation. METHODS: A retrospective study of patients with blunt head injury with GCS 13-15 and CT head from Jan 2014-Dec 2016 was performed. A novel criteria of head CT findings was created at our institution to classify mTBI. Outcomes included neurosurgical intervention and transfer cost. RESULTS: A total of 2120 patients were identified with 1442 (68.0%) meeting CT criteria for mTBI and 678 (32.0%) classified high risk. Two (0.14%) patients with mTBI required neurosurgical intervention compared with 143 (21.28%) high risk TBI (p < 0.0001). Mean age (55.8 years), and anticoagulation (2.6% vs 2.8%) or antiplatelet use (2.1% vs 3.0%) was similar between groups (p > 0.05). Of patients with mTBI, 689 were transferred without receiving neurosurgical intervention. Given an average EMS transfer cost of $700 for ground and $5800 for air, we estimate an unnecessary transfer cost of $733,600. CONCLUSION: Defining mTBI with the described novel criteria clearly identifies patients who can be safely managed without transfer for neurosurgical consultation. These unnecessary transfers represent a substantial financial and resource burden to the trauma system and inconvenience to patients.

Detection of the Metastable Ice Phase during Water Crystallization.

BACKGROUND: Under atmospheric pressure, the identifiable phases of ice crystals are hexagonal (stable) and cubic (metastable). OBJECTIVE: This study aimed to test the hypothesis that water crystallizes into the cubic phase at the beginning and then changes to the hexagonal phase. MATERIALS AND METHODS: Aqueous solutions of 40% (w/w) and 50% (w/w) glucose, and 40% (w/w) ammonium hydrogen sulfate, as well as emulsified water, were investigated. RESULTS: The cubic-to-hexagonal ice phase transition was detected in 40% (w/w) glucose solution within a 1 s integration interval, whereas the cubic ice formed in 50% (w/w) glucose solution did not transition to the hexagonal phase. The cubic phase was also confirmed in the 40% (w/w) ammonium hydrogen sulfate solution, but not in emulsified water. CONCLUSION: The cubic-to-hexagonal ice phase transition was detected in three aqueous solutions tested upon freezing. It was not possible to clearly capture the transition process in emulsified water under the study condition.

The relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles in healthy elderly.

We conducted a clinical cross-sectional study to examine the relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles and whole skeletal muscle mass. Subjects were healthy 39 males and 51 females without dysphagia and sarcopenia, aged 65 years and older. Jaw-opening force was measured three times using a jaw-opening sthenometer; the maximum of these three was taken as the measurement value. The cross-sectional area of the geniohyoid and anterior belly of the digastric muscles were evaluated using ultrasonography. The skeletal muscle mass index, gait speed and grip strength were evaluated according to the diagnostic criteria of the Asian Working Group for Sarcopenia. For each sex, a multiple regression analysis determined the factors that affect jaw-opening force. Jaw-opening force was associated with the cross-sectional area of the geniohyoid muscle in males (regression coefficient [ß] = 0.441, 95% confidence interval [CI] = 14.28-56.09) and females (ß = 0.28, 95% CI = 3.10-54.57). Furthermore, in females only, jaw-opening force was associated with the skeletal muscle mass index (ß = 0.40, 95% CI = 3.67-17.81). In contrast, jaw-opening force was not associated with the cross-sectional area of the anterior belly of the digastric muscle in either sex. In healthy elderly males and females, jaw-opening force was positively associated with the cross-sectional area of the geniohyoid muscle. However, the jaw-opening force was positively associated with the skeletal muscle mass index only in females.

HFD-induced energy states-dependent bidirectional control of anxiety levels in mice.

BACKGROUND: The association between the development of obesity and its metabolic comorbidities, and chronic consumption of high-fat diet (HFD) has been well-demonstrated. Interestingly, emerging evidence indicates that obesity is also associated with an increased risk for psychiatric disorders including anxiety and depression. Although HFD feeding is associated with anxiety-related behaviors, previous studies have reported inconsistent findings on the direction of this relationship. Therefore, in this study we sought to investigate the link between HFD feeding, body weight, energy states and anxiety levels in mice and specifically to determine if the duration of HFD exposure has distinct effects on anxiety-related behaviors. METHODS: To disentangle the temporal dynamic effects of HFD feeding on anxiety-related behaviors, mice were fed a HFD or regular chow (RC) diet and were assayed periodically for anxiety-related behaviors by using behavioral tests (open field test; OFT) and the elevated plus maze. To determine if obesity phenotypes correlate with anxiety-related behaviors, changes in anxiety-related behaviors in OFTs were correlated with changes in both body weight and glucose sensitivity following various levels of HFD and RC exposure. RESULTS: Our results demonstrate a time-dependent biphasic effect of HFD feeding on anxiety-related behaviors. At 5 weeks, mice fed HFD show a reduction in anxiety-related behaviors when compared to pair-fed RC mice. At 8 weeks of HFD or RC feeding, anxiety levels were the same in both groups. Following 15 weeks of HFD and RC feeding, however, mice displaying metabolic symptoms of obesity showed increased anxiety-related behaviors relative to mice resilient to obesity phenotypes, independent of feeding conditions. CONCLUSIONS: Taken together our findings suggest that HFD bi-directionally effects anxiety-related behaviors such that short-term exposure to a HFD reduces anxiety levels, while longer exposure to a HFD promotes anxiety levels selectively in mice that display metabolic symptoms of obesity. Regardless of diet (HFD or RC), heavier animals display increased anxiety-like behaviors. These findings indicate diverse overlapping roles for HFD and body weight in modulating anxiety-related behaviors, and may partly resolve previous inconsistencies in studies examining the relationship between HFD feeding and anxiety.

Chloride ion transport and overexpression of TMEM16A in a guinea-pig asthma model.

BACKGROUND: TMEM16A, a Ca-activated Cl channel, regulates various physiological functions such as mucin secretion. However, the role of TMEM16A in hyper-secretion in asthma is not fully understood. OBJECTIVE: The aim of this study is to evaluate Cl ion transport via TMEM16A and determine the localization of TMEM16A in a guinea-pig asthma model. METHODS: Guinea-pigs were sensitized with ovalbumin (OVA) i.p. on Days 1 and 8. On Day 22, we assessed OVA challenge-induced Cl ion transport in the sensitized tracheas ex vivo in an Ussing chamber, compared with the non-sensitized tracheas. We then examined the effect of T16Ainh-A01, a TMEM16A inhibitor, on the increase in Cl ion transport. The tracheal epithelium was immunostained with an anti-TMEM16A antibody. Epithelial cells from guinea-pig tracheas were cultured at the air-liquid interface in the presence of IL-13 for in vitro study. We studied the effect of TMEM16A inhibitors on Ca-dependent agonist, uridine triphosphate (UTP)-induced increases in Cl ion transport in the cultured cells. The cells were immunostained with an anti-TMEM16A antibody, an anti-MUC5AC antibody and an anti-α-tubulin antibody. RESULTS: OVA challenge induced an increase in short circuit current within 1 min in the OVA-sensitized tracheas but not in the non-sensitized tracheas, which was inhibited by pretreatment of T16Ainh-A01. Sensitized tracheas showed goblet cell metaplasia with more positive TMEM16A immunostaining, particularly in the apical portion compared with the non-sensitized tracheas. The in vitro UTP-induced increase in Cl ion transport was strongly inhibited by pretreatment with T16Ainh-A01, benzbromarone, and niflumic acid. TMEM16A was positively immunostained at the apical portion and in the MUC5AC-positive area in IL-13-induced goblet cell metaplasia. CONCLUSIONS: Antigen challenge and Ca-dependent agonist treatment increased Cl ion transport via the overexpression of TMEM16A in goblet cell metaplasia in a guinea-pig asthma model. TMEM16A inhibitors may be useful for the treatment of hyper-secretion in asthma.

Comparative evaluation of new and conventional classifications of magnifying endoscopy with narrow band imaging for invasion depth of superficial esophageal squamous cell carcinoma.

A new classification of magnifying endoscopy with narrow band imaging (ME-NBI) for diagnosing and staging superficial esophageal squamous cell carcinoma (SESCC) was proposed by the Japan Esophageal Society in 2011. This study aimed to compare the new classification with the conventional classifications (Inoue's classification and Arima's classification). This was a prospective analysis of data from a single cancer center involving 151 consecutive patients with 156 SESCCs that were endoscopically or surgically resected. Initially, only ME-NBI images were selected and reviewed independently by three experienced endoscopists. White light imaging (WLI) was then evaluated separately after an interval. The diagnostic performance of each classification and interobserver agreement were assessed, and the WLI findings that affect the diagnosis by the new classification were identified. The specificity for classifying invasive depth as epithelium (EP)/lamina propria mucosae (LPM) confined was higher with the new classification than with Inoue's classification (0.512 vs. 0.349; P = 0.02) and Arima's classification (0.512 vs. 0.279; P < 0.01). However, the sensitivity was lower (0.902 vs. 1.000; P < 0.01) compared with Arima's classification. The concordance rates of three evaluators (κ values) were 0.52 for the new classification, 0.50 for Inoue's classification, and 0.23 for Arima's classification. On multivariate analysis, thickness on WLI independently affected the accuracy of diagnosis with the new classification (OR 3.23; 95%CI, 1.30-8.03). The new classification is superior to conventional classifications with respect to specificity for diagnosing SESCC with depth EP/LPM. Thickness on WLI was a factor negatively affecting the diagnostic performance of the new classification.

Intestinal epithelial culture under an air-liquid interface: a tool for studying human and mouse esophagi.

This study investigated whether an intestinal epithelial culture method can be applied to mouse and human esophageal cultures. The esophagi harvested from 1-day-old mice and adult humans were maintained in collagen gels. A commercially available culture medium for human embryonic stem cells was used for the human esophageal culture. We discovered that the intestinal epithelial culture method can be successfully applied to both mouse and human esophageal cultures. The long-term cultured esophageal organoids were rod-like luminal structures lined with myofibroblasts. We discovered that regeneration of the esophageal mucosal surface can be almost completely achieved in vitro, and the advantage of this method is that organoid cultures may be generated using host-derived fibroblasts as a niche. This method is a promising tool for mouse and human research in intestinal biology, carcinogenesis, and regenerative medicine.

Vero/BC-F: an efficient packaging cell line stably expressing F protein to generate single round-infectious human parainfluenza virus type 2 vector.

A stable packaging cell line (Vero/BC-F) constitutively expressing fusion (F) protein of the human parainfluenza virus type 2 (hPIV2) was established for production of the F-defective and single round-infectious hPIV2 vector in a strategy for recombinant vaccine development. The F gene expression has not evoked cytostatic or cytotoxic effects on the Vero/BC-F cells and the F protein was physiologically active to induce syncytial formation with giant polykaryocytes when transfected with a plasmid expressing hPIV2 hemagglutinin-neuraminidase (HN). Transduction of the F-defective replicon RNA into the Vero/BC-F cells led to the release of the infectious particles that packaged the replicon RNA (named as hPIV2ΔF) without detectable mutations, limiting the infectivity to a single round. The maximal titer of the hPIV2ΔF was 6.0 × 10(8) median tissue culture infections dose per ml. The influenza A virus M2 gene was inserted into hPIV2ΔF, and the M2 protein was found to be highly expressed in a human lung cancer cell line after transduction. Furthermore, in vivo airway infection experiments revealed that the hPIV2ΔF was capable of delivering transgenes to hamster tracheal cells. Thus, non-transmissible or single round-infectious hPIV2 vector will be potentially applicable to human gene therapy or recombinant vaccine development.

IL-22 produced by cancer-associated fibroblasts promotes gastric cancer cell invasion via STAT3 and ERK signaling.

BACKGROUND: Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion. METHODS: Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay. RESULTS: Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs. CONCLUSIONS: Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling.

Performance of a rapid human metapneumovirus antigen test during an outbreak in a long-term care facility.

Using a newly developed rapid test, an outbreak of human metapneumovirus (HMPV) infection in a long-term care facility was detected within only 2 days after the onset of symptoms in a putative index case. The outbreak was almost under control within 8 days mainly by zoning patients, with the exception of two cases of HMPV that were diagnosed 16 and 17 days after the onset of the outbreak. According to an immunological diagnosis as well as the rapid test, it was eventually proven that 18 patients had HMPV infections. We suspected that even asymptomatic residents, who had not been completely separated from the facility population, were a source of infection. That suggested that all asymptomatic residents should be tested and that the separation of the infected patients should be absolute, if an outbreak of HMPV infection is suspected in such a facility.

Continuous wound infiltration with ropivacaine for analgesia after caesarean section: a randomised, placebo-controlled trial.

BACKGROUND: We evaluated the analgesic effect of ropivacaine infiltration into the surgical wound after caesarean section. METHODS: In a double-blind trial, 67 patients who were scheduled for caesarean section under spinal anaesthesia were randomly assigned to receive either 0.75% ropivacaine or placebo (NaCl 0.9%) through a multi-orifice catheter that was placed into the surgical wound, between the muscle fascia and the subcutaneous tissue. The study drug was administered as a bolus of 10 ml at the end of the operation, followed by an infusion at 2 ml/h for 48 h. All patients were also given paracetamol and ibuprofen. The primary outcome was the total amount of rescue oxycodone needed during the first 48 h post-operatively. Secondary outcomes included pain and patient satisfaction scores. Analyses were according to intention to treat. RESULTS: The mean (± standard deviation) amount of oxycodone administered during the first 48 h was 47.5 ± 20.9 mg in the ropivacaine group and 57.8 ± 29.4 mg in the placebo group (95% confidence interval for the difference between means, -22.8-2.2 mg; P = 0.10). There were no differences between the groups in pain scores or in patient satisfaction scores. CONCLUSION: Continuous wound infiltration with ropivacaine did not decrease the need for opioids and had no impact on pain scores or patient satisfaction after caesarean section.

Prospective evaluation of a transnasal endoscopy utilizing flexible spectral imaging color enhancement (FICE) with the Valsalva maneuver for detecting pharyngeal and esophageal cancer.

BACKGROUND/AIMS: This study evaluated the efficacy and safety of transnasal endoscopy (TNE) with flexible spectral imaging color enhancement (FICE) for detection of superficial cancer in the pharyngeal and esophageal regions for high-risk populations. METHODOLOGY: Patients who previously had head and neck or esophageal squamous cell carcinoma were enrolled. Screening was conducted using TNE with conventional white-light endoscopy (WLE) followed by FICE chromoendoscopy. For observation of the pharyngeal region, the Valsalva maneuver was employed. RESULTS: 99 patients were eligible. Six esophageal cancers were detected in four patients (4.0%). The sensitivity, specificity, and accuracy for the detection of cancer were 25.0% (95% CI, 3.4- 71.0), 97.8% (95% CI, 92.1-99.8), and 94.9 % (95% CI, 88.4-98.1), respectively for WLE; 100% (95% CI, 45.4%- 100%), 96.8% (95% CI, 90.7%-99.3%), and 96.9% (95% CI, 89.3%-99.1%), respectively for FICE chromoendoscopy. Pain in the nose and nasal hemorrhage were observed in 3 (3.0%) and 2 patients (2.0%), respectively. Following the Valsalva maneuver, endoscopic scores significantly increased from a mean of 1.1 (0.8-1.4) to 2.0 (1.3-2.6) (p<0.05). CONCLUSIONS: TNE with the Valsalva maneuver is a promising screening method for the pharyngeal and esophageal regions. TNE with FICE chromoendoscopy for detecting pharyngeal and esophageal cancer was more sensitive than WLE.

A call for early, effective, and scalable parent education programs for high-conflict separated/divorcing parents: A synthesized perspective from prevention science and family law.

Conflict between parents is stressful and disruptive to children living in the midst of parental separation or divorce. Although some level of post-separation/divorce conflict is understandable in an emotionally-charged separation/divorce, it undermines the extent to which parents protect their children from short- and long-term problems. In this article, we weave together a synthesized perspective informed by our respective training and experience in prevention science and family law on the role of parent education programs for high-conflict separating/divorcing parents. To do so, we first describe the research on the effects of high interparental conflict on children's outcomes and then discuss current approaches and challenges to reducing these negative effects by offering parent education programs for high-conflict separating/divorcing parents. Then, we propose and describe a new model for early, effective, and scalable parent education programs with the ultimate goal of protecting children after separation/divorce.

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near PAX4.

AIMS/HYPOTHESIS: Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians. METHODS: We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations. RESULTS: We identified CDKN2A/B and four novel type 2 diabetes association signals with p < 1 × 10(-5) from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (p meta = 2.6 × 10(-8); OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (p meta = 2.3 × 10(-10)) and a population of European descent (p = 8.6 × 10(-3)). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians. CONCLUSIONS/INTERPRETATION: Our study identifies rs10229583 near PAX4 as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.

Evidence for B- → τ- ν(τ) with a hadronic tagging method using the full data sample of Belle.

We measure the branching fraction of B- → τ- ν(τ) using the full Υ(4S) data sample containing 772×10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Events with BB pairs are tagged by reconstructing one of the B mesons decaying into hadronic final states, and B- → τ- ν(τ) candidates are detected in the recoil. We find evidence for B- → τ- ν(τ) with a significance of 3.0 standard deviations including systematic errors and measure a branching fraction B(B- → τ- ν(τ))=[0.72(-0.25)(+0.27)(stat)±0.11(syst)]×10(-4).

Prospective clinical study of endoscopic ultrasound-guided choledochoduodenostomy with direct metallic stent placement using a forward-viewing echoendoscope.

A prospective clinical study was conducted to evaluate the safety, feasibility, and efficacy of endoscopic ultrasound (EUS)-guided choledochoduodenostomy (CDS) with direct metallic stent placement using a prototype forward-viewing echoendoscope. The indication for EUS - CDS in this study was lower biliary obstruction only, and not failed endoscopic biliary drainage, because the aim was to evaluate EUS - CDS for first-line biliary drainage therapy. The technical and functional success rates were 94 % (17 /18) and 94 % (16 /17), respectively. Early complications (focal peritonitis) were encountered in two patients (11 %). No patients developed late complications. EUS - CDS with direct metallic stent placement using a forward-viewing echoendoscope was generally feasible and effective for malignant distal biliary tract obstruction. The forward-viewing echoendoscope was useful, especially for deploying the metallic stent.

Endoscopic ultrasound-guided celiac ganglia neurolysis vs. celiac plexus neurolysis: a randomized multicenter trial.

BACKGROUND AND STUDY AIMS: No prospective comparison of endoscopic ultrasonography-guided direct celiac ganglia neurolysis (EUS - CGN) vs. EUS-guided celiac plexus neurolysis (EUS - CPN) has been reported. The aim of the current study was to compare the effectiveness of EUS - CGN and EUS - CPN in providing pain relief from upper abdominal cancer pain in a multicenter randomized controlled trial. PATIENTS AND METHODS: Patients with upper abdominal cancer pain were randomly assigned to treatment using either EUS - CGN or EUS - CPN. Evaluation was performed at Day 7 postoperatively using a pain scale of 0 to 10. Patients for whom pain decreased to ≤ 3 were considered to have a positive response, and those experiencing a decrease in pain to ≤ 1 were considered to be completely responsive. Comparison between the two groups was performed using intention-to-treat analysis. The primary endpoint was the difference in treatment response rates between EUS - CGN and EUS - CPN at postoperative Day 7. Secondary endpoints included differences in complete response rates, pain scores, duration of pain relief, and incidence of adverse effects. RESULTS: A total of 34 patients were assigned to each group. Visualization of ganglia was possible in 30 cases (88 %) in the EUS - CGN group. The positive response rate was significantly higher in the EUS - CGN group (73.5 %) than in the EUS - CPN group (45.5 %; P = 0.026). The complete response rate was also significantly higher in the EUS - CGN group (50.0 %) than in the EUS - CPN group (18.2 %; P = 0.010). There was no difference in adverse events or duration of pain relief between the two groups. CONCLUSIONS: EUS - CGN is significantly superior to conventional EUS - CPN in cancer pain relief. CLINICAL TRIAL REGISTRATION: http://www.umin.ac.jp/ctr/index.htm (ID: UMIN-000002536).

The pharmacokinetic and safety profiles of zanamivir after single and repeat intravenous administration in healthy Japanese males.

WHAT IS KNOWN AND OBJECTIVE: Neuraminidase inhibitors are important options for the treatment of infection by the influenza virus. For the treatment of severe influenza, parenteral administration of a neuraminidase inhibitor may be desirable. This study was conducted to evaluate the pharmacokinetic and safety profiles of intravenous zanamivir, an influenza viral neuraminidase inhibitor, in Japanese subjects to further characterize these profiles particularly following relatively high-doses when compared with inhalation doses and to provide reassurance that there are no marked differences with profiles reported for other ethnically different populations. METHODS: Single doses of 100, 300, 600 mg zanamivir were administered to healthy Japanese men in a randomized, double-blind, ascending dose, placebo-controlled, incomplete three-period cross-over study. In period 3, subjects were given 600 mg of zanamivir on day 1, followed by a 60 h washout period and then a 5-day course of 600 mg zanamivir twice daily. Each subjects received two of three active dosages of zanamivir from 100, 300 and 600 mg, and placebo. RESULTS: Adverse events reported in the study were all mild in intensity and resolved without any treatment. The mean AUC0-∞ values after single intravenous administration of 100, 300 and 600 mg were 16768, 53462 and 100400 ng·h/mL, respectively, demonstrating dose proportionality. No accumulation or time variance was observed after 5 days of twice-daily administration of 600 mg zanamivir. Urinary concentrations of zanamivir after single doses ranging from 100 to 600 mg indicated that over 94% of the zanamivir administered was excreted in urine within 24 h. WHAT IS NEW AND CONCLUSION: Single and 5-day BID repeat dosing of 600 mg were safely administered in Japanese healthy subjects. The pharmacokinetic profile of zanamivir after intravenous administration was consistent with previously reported findings in non-Japanese subjects.