Effect of chronic intermittent hypoxia on ocular and intraoral mechanical allodynia mediated via the calcitonin gene-related peptide in a rat

STUDY OBJECTIVES

Obstructive sleep apnea, a significant hypoxic condition, may exacerbate several orofacial pain conditions. The study aims to define the involvement of calcitonin gene-related peptide (CGRP) in peripheral and central sensitization and in evoking orofacial mechanical allodynia under chronic intermittent hypoxia (CIH).

METHODS

Male rats were exposed to CIH. Orofacial mechanical allodynia was assessed using the eyeblink test and the two-bottle preference drinking test. The CGRP-immunoreactive neurons in the trigeminal ganglion (TG), CGRP-positive primary afferents projecting to laminae I-II of the trigeminal spinal subnucleus caudalis (Vc), and neural responses in the second-order neurons of the Vc were determined by immunohistochemistry. CGRP receptor antagonist was administrated in the TG.

RESULTS

CIH-induced ocular and intraoral mechanical allodynia. CGRP-immunoreactive neurons and activated satellite glial cells (SGCs) were significantly increased in the TG and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly higher in CIH rats compared to normoxic rats. Local administration of the CGRP receptor antagonist in the TG of CIH rats attenuated orofacial mechanical allodynia; the number of CGRP-immunoreactive neurons and activated SGCs in the TG, and the density of CGRP-positive primary afferent terminals and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly lower compared to vehicle-administrated CIH rats.

CONCLUSIONS

An increase in CGRP in the TG induced by CIH, as well as orofacial mechanical allodynia and central sensitization of second-order neurons in the Vc, supported the notion that CGRP plays a critical role in CIH-induced orofacial mechanical allodynia.

Long-lasting adverse effects of short-term stress during the suckling-mastication transition period on masticatory function and intraoral sensation in rats

Early-life stress affects brain development, eventually resulting in adverse behavioral and physical health consequences in adulthood. The present study assessed the hypothesis that short-term early-life stress during infancy before weaning, a period for the maturation of mastication and sleep, poses long-lasting adverse effects on masticatory function and intraoral sensations later in life.Rat pups were exposed to either maternal separation (MS) or intermittent hypoxia (IH-Infancy) for 6 h/day in the light/sleep phase from postnatal day (P)17 to P20 to generate "neglect" and "pediatric obstructive sleep apnea" models, respectively. The remaining rats were exposed to IH during P45-P48 (IH-Adult). Masticatory ability was evaluated based on the rats' ability to chew pellets and bite pasta throughout the growth period (P21-P70). Intraoral chemical and mechanical sensitivities were assessed using two-bottle preference drinking tests, and hind paw pain thresholds were measured in adulthood (after P60).No differences were found in body weight, grip force, and hind paw sensitivity in MS, IH-Infancy, and IH-Adult rats compared with naïve rats. Masticatory ability was lower in MS and IH-Infancy rats from P28 to P70 than in naïve rats. MS and IH-Infancy rats exhibited intraoral hypersensitivity to capsaicin and mechanical stimulations in adulthood. The IH-Adult rats did not display inferior masticatory ability or intraoral hypersensitivity.In conclusion, short-term early-life stress during the suckling-mastication transition period potentially causes a persistent decrease in masticatory ability and intraoral hypersensitivity in adulthood. The period is a "critical window" for the maturation of oral motor and sensory functions.

The role of Zfp352 in the regulation of transient expression of 2-cell specific genes in mouse embryonic stem cells

Mouse ES cell populations contain a minor sub-population that expresses genes specifically expressed in 2-cell stage embryos. This sub-population consists of 2-cell-gene labeled cells (2CLCs) generated by the transient activation of the 2-cell specific genes initiated by the master regulator, Dux. However, the mechanism regulating the transient expression remains largely unclear. Here we reported a novel function of Zfp352, one of the 2-cell specific genes, in regulating the 2CLC sub-population. Zfp352 encodes zinc-finger transcription factor belonging to the Klf family. Dux transiently activates Zfp352 after the activation of Zscan4c in a subset of the 2CLC subpopulation. Interestingly, in the reporter assay, the transcriptional activation of Zscan4c by Dux is strongly repressed by the co-expression of Zfp352. However, the knockout of Zfp352 resulted in the repression of a subset of the 2-cell-specific genes. These data suggest the dual roles of Zfp352 in regulating the transient activation of the 2-cell-specific genes.

Initial loading of dexmedetomidine and continuous propofol sedation for prevention of delayed recovery: A randomized controlled trial

BACKGROUND

Sedation with continuous dexmedetomidine and bolus midazolam administration provides a lower incidence of unacceptable patient movement during procedures but requires a longer recovery time. The authors aimed to compare recovery time and unacceptable patient movement during sedation with initial loading of dexmedetomidine followed by continuous propofol infusion with those during sedation with continuous dexmedetomidine and bolus midazolam administration.

METHODS

In this prospective randomized controlled trial, 54 patients undergoing dental surgery and requiring intravenous sedation were assigned to either the dexmedetomidine and propofol group (n = 27, dexmedetomidine administered at 6 μg/kg/h for 5 minutes, followed by continuous propofol infusion using a target-controlled infusion) or the dexmedetomidine and midazolam group (n = 27, dexmedetomidine administered at 0.2-0.7 μg/kg/h continuously after the same initial loading dose with bolus midazolam). A bispectral index of 70 through 80 was maintained during the procedure. Patient movement that interfered with the procedure and time from the end of sedation to achieving a negative Romberg sign were assessed.

RESULTS

Times from the end of sedation to achieving a negative Romberg sign in the dexmedetomidine and propofol group (median, 14 minutes [interquartile range, 12-15 minutes]) were significantly shorter (P < .001) than in the dexmedetomidine and midazolam group (median, 22 minutes [interquartile range, 17.5-30.5 minutes]). The incidence of unacceptable patient movement was comparable between groups (n = 3 in the dexmedetomidine and propofol group, n = 4 in the dexmedetomidine and midazolam group; P = .999).

CONCLUSIONS

Sedation with a single loading dose of dexmedetomidine followed by continuous propofol infusion can prevent delayed recovery without increasing unacceptable patient movement.

PRACTICAL IMPLICATIONS

The combination of dexmedetomidine and propofol may provide high-quality sedation for ambulatory dental practice. This clinical trial was registered in the University Hospital Medical Information Network Clinical Trials Registry. The registration number is UMIN000039668.

STRA8-RB interaction is required for timely entry of meiosis in mouse female germ cells

Meiosis is differently regulated in males and females. In females, germ cells initiate meiosis within a limited time period in the fetal ovary and undergo a prolonged meiotic arrest until puberty. However, how meiosis initiation is coordinated with the cell cycle to coincide with S phase remains elusive. Here, we demonstrate that STRA8 binds to RB via the LXCXE motif. Mutation of the RB-binding site of STRA8 in female mice delays meiotic entry, which consequently delays progression of meiotic prophase and leads to precocious depletion of the oocyte pool. Single-cell RNA-sequencing analysis reveals that the STRA8-RB interaction is required for S phase entry and meiotic gene activation, ensuring precise timing of meiosis initiation in oocytes. Strikingly, the results suggest STRA8 could sequester RB from E2F during pre-meiotic G1/S transition. This study highlights the gene regulatory mechanisms underlying the female-specific mode of meiotic initiation in mice.

Cerebellar Nuclei Receiving Orofacial Proprioceptive Signals through the Mossy Fiber Pathway from the Supratrigeminal Nucleus in Rats

Proprioception from muscle spindles is necessary for motor function executed by the cerebellum. In particular, cerebellar nuclear neurons that receive proprioceptive signals and send projections to the lower brainstem or spinal cord play key roles in motor control. However, little is known about which cerebellar nuclear regions receive orofacial proprioception. Here, we investigated projections to the cerebellar nuclei from the supratrigeminal nucleus (Su5), which conveys the orofacial proprioception arising from jaw-closing muscle spindles (JCMSs). Injections of an anterograde tracer into the Su5 resulted in a large number of labeled axon terminals bilaterally in the dorsolateral hump (IntDL) of the cerebellar interposed nucleus (Int) and the dorsolateral protuberance (MedDL) of the cerebellar medial nucleus. In addition, a moderate number of axon terminals were ipsilaterally labeled in the vestibular group Y nucleus (group Y). We electrophysiologically detected JCMS proprioceptive signals in the IntDL and MedDL. Retrograde tracing analysis confirmed bilateral projections from the Su5 to the IntDL and MedDL. Furthermore, anterograde tracer injections into the external cuneate nucleus (ECu), which receives other proprioceptive input from forelimb/neck muscles, resulted in only a limited number of ipsilaterally labeled terminals, mainly in the dorsomedial crest of the Int and the group Y. Taken together, the Su5 and ECu axons almost separately terminated in the cerebellar nuclei (except for partial overlap in the group Y). These data suggest that orofacial proprioception is differently processed in the cerebellar circuits in comparison to other body-part proprioception, thus contributing to the executive function of orofacial motor control.

Antagonist of transient receptor potential melastatin 2 suppresses mechanical hypersensitivity and activation of microglia induced by infraorbital nerve ligation in male rats

Activation of microglia is known to be involved in neuropathic pain. However, the pathway that regulates the microglial activation is not completely understood. Transient receptor potential (TRP) melastatin 2 (TRPM2), which is part of the TRP superfamily, is reportedly expressed on microglia and is suggested to be involved in neuropathic pain. To explore the effect of a TRPM2 antagonist on orofacial neuropathic pain and the relationship between TRPM2 and the activation of microglia, experiments were conducted using male rats that underwent infraorbital nerve (ION) ligation as orofacial neuropathic pain models. TRPM2 expression was detected on microglia in the trigeminal spinal subnucleus caudalis (Vc). The immunoreactivity of TRPM2 in the Vc increased after ION ligation. Mechanical threshold for head-withdrawal response was measured using von Frey filament, and it decreased after ION ligation. When the TRPM2 antagonist was administered to the ION-ligated rats, the low mechanical threshold for head-withdrawal response increased, and the number of phosphorylated extracellular signal-regulated kinase (pERK)-immunoreactive cells in the Vc decreased. The number of CD68-immunoreactive cells in the Vc also decreased after the administration of the TRPM2 antagonist in the ION-ligated rats. These findings suggest that TRPM2 antagonist administration suppresses hypersensitivity to mechanical stimulation induced by ION ligation and microglial activation, and TRPM2 is also involved in microglial activation in orofacial neuropathic pain.

Longitudinal electromyographic analysis of jaw-closing muscle activities during ingestive behaviors from pre-weaning to juvenile periods in rats

This longitudinal study investigated developmental changes in jaw-closing muscle activities during ingestive behaviors in rats. On postnatal day (P) 10, electromyography (EMG) electrodes were inserted into the masseter and temporalis muscles of rat pups. EMG activities were recorded for the following ingestive behaviors between P14 and P49: for suckling, including nipple attachment and rhythmic sucking on P14 and for pasta biting, pellet chewing, and milk licking between P21 and P49. Burst rhythms and muscle coordination (i.e., the correlation and time lag) between masseter and temporalis activities were assessed for each behavior. The burst rhythms of nipple attachment and rhythmic sucking on P14 were significantly slower than those of pasta biting, pellet chewing, and milk licking on P21. Muscle coordination differed between suckling on P14 and mastication and licking on P21. Between P21 and P49, increases were observed in burst rhythms for pasta biting and pellet chewing. The rate of increases in burst rhythms was higher for pasta biting than for pellet chewing. Muscle coordination between the two muscle activities for pasta biting did not significantly change between P21 and P49, whereas that for pellet chewing significantly changed between P21 and P24 and stabilized after P24. Burst rhythms for milk licking did not significantly change over time, while muscle coordination between the two muscle activities changed from agonist to antagonist muscle-like activity on approximately P35. The present results demonstrate that distinct patterns of rhythmic jaw-closing muscle activities emerge before weaning, they continue to change over time, and they exhibit unique developmental dynamics for each behavior after weaning.

Effect of midazolam in autism spectrum disorder: A retrospective observational analysis

BACKGROUND

While midazolam is commonly used as premedication for uncooperative patients, its effects are difficult to predict in patients with autism spectrum disorder for whom abnormalities in gamma-aminobutyric acid have been reported. This study aimed to investigate the influence of autism spectrum disorder on the effect of midazolam when used as premedication.

METHODS

This retrospective observational study was performed between April 2017 and August 2018. Before inducing general anesthesia with sevoflurane for dental treatment, 390 uncooperative patients received premedication with midazolam. Ordinal logistic regression analysis was performed with the Observer's Assessment of Alertness/Sedation score 30 min after premedication as the objective variable. Age, sex, American Society of Anesthesiologists physical status class, premedication route, dose per body weight, presence of specific disorders (autism spectrum disorder, intellectual disability, epilepsy, cerebral palsy, and other psychiatric disorders), and regular benzodiazepine or non-benzodiazepine psychotropic administration were included as explanatory variables. Kendall's rank correlation coefficient was used to assess the correlation between the Observer's Assessment of Alertness/Sedation score and cooperation level (1, obvious negative response; 2, negative response; 3, positive reaction; 4, obvious positive reaction) during admission and inhalation induction. All data were extracted from anesthesia and medical records.

RESULTS

Age (odds ratio 1.437 [95% confidence interval (CI) 1.213-1.708], P < .001), autism spectrum disorder (1.318 [1.079-1.612], P = .007), benzodiazepine medication (0.574 [0.396-0.827], P = .002), and intramuscular route (1.478 [1.137-1.924], P = .004) were significantly associated with the Observer's Assessment of Alertness/Sedation score, while the score was negatively associated with cooperation levels during admission (τ = -0.714, P < .001) and inhalation induction (τ = -0.606, P < .001).

CONCLUSIONS

Patients with autism spectrum disorder may be susceptible to premedication with midazolam; however, regular benzodiazepine administration may reduce the effect.

Evaluation of the effects of manual acupuncture and electroacupuncture at LI4 and LI11 on perception thresholds: a prospective crossover trial

OBJECTIVE

The objective of the study was to investigate and compare the effects of manual acupuncture (MA) and electroacupuncture (EA) on current perception thresholds (CPTs) using quantitative methods.

METHODS

Twenty-nine healthy volunteers participated in this prospective crossover trial, in which three acupuncture methods were compared: control, MA, and EA. Acupuncture needles were inserted to a depth of 15 mm at LI4 and LI11 on the left side and retained for 30 min with or without electrical stimulation at a frequency of 2 Hz (EA and MA, respectively). The needles were removed and participants rested for 30 min. CPT in the left mental region was measured at 2000, 250, and 5 Hz, corresponding to the activation of Aβ, Aδ, and C-fibers, respectively, at four time points: baseline, T₀; 15 min after needle application, T₁; immediately after needle removal, T₂; and 30 min after needle removal, T₃. In the control session, only a sensory test was performed (without acupuncture).

RESULTS

Significant effects of time course on CPT were observed (p < 0.001). CPT values increased significantly at T₁, T₂, and T₃, compared with those at T₀, at all stimulation frequencies during MA and EA. Changes in CPT values with EA were not significantly greater than those with MA.

CONCLUSIONS

Both MA and EA increased the sensory thresholds of Aβ, Aδ, and C-fibers in the mental region for ⩾30 min after needle removal. Additional of electrical stimulation may not confer additional benefits over needling alone.

TRIAL REGISTRATION NUMBER

UMIN000017983 (University Hospital Medical Information Network Clinical Trials Registry).

Stepwise pluripotency transitions in mouse stem cells

Pluripotent cells in mouse embryos, which first emerge in the inner cell mass of the blastocyst, undergo gradual transition marked by changes in gene expression, developmental potential, polarity, and morphology as they develop from the pre-implantation until post-implantation gastrula stage. Recent studies of cultured mouse pluripotent stem cells (PSCs) have clarified the presence of intermediate pluripotent stages between the naïve pluripotent state represented by embryonic stem cells (ESCs-equivalent to the pre-implantation epiblast) and the primed pluripotent state represented by epiblast stem cells (EpiSCs-equivalent to the late post-implantation gastrula epiblast). In this review, we discuss these recent findings in light of our knowledge on peri-implantation mouse development and consider the implications of these new PSCs to understand their temporal sequence and the feasibility of using them as model system for pluripotency.

The polyol pathway is an evolutionarily conserved system for sensing glucose uptake

Cells must adjust the expression levels of metabolic enzymes in response to fluctuating nutrient supply. For glucose, such metabolic remodeling is highly dependent on a master transcription factor ChREBP/MondoA. However, it remains elusive how glucose fluctuations are sensed by ChREBP/MondoA despite the stability of major glycolytic pathways. Here, we show that in both flies and mice, ChREBP/MondoA activation in response to glucose ingestion involves an evolutionarily conserved glucose-metabolizing pathway: the polyol pathway. The polyol pathway converts glucose to fructose via sorbitol. It has been believed that this pathway is almost silent, and its activation in hyperglycemic conditions has deleterious effects on human health. We show that the polyol pathway regulates the glucose-responsive nuclear translocation of Mondo, a Drosophila homologue of ChREBP/MondoA, which directs gene expression for organismal growth and metabolism. Likewise, inhibition of the polyol pathway in mice impairs ChREBP’s nuclear localization and reduces glucose tolerance. We propose that the polyol pathway is an evolutionarily conserved sensing system for glucose uptake that allows metabolic remodeling.

The polyol pathway, which converts glucose to fructose via sorbitol, was thought to be largely silent, and only the negative effects of its activation were known. This study reveals that the polyol pathway is involved in glucose-responsive activation of Mondo/ChREBP-mediated metabolic remodeling in both mice and flies.

A Case of Wide QRS Tachycardia After the Local Administration of Epinephrine to Reduce Bleeding During General Anesthesia

We report a case of wide QRS tachycardia or ventricular tachycardia with a pulse after the administration of epinephrine under general anesthesia. After induction and achieving a sufficiently deep plane of general anesthesia, gauze soaked in a 1:100,000 epinephrine solution was applied to the patient's nasal mucosa and 1% lidocaine with 1:100,000 epinephrine was administered via intraoral infiltration. Several minutes after the start of surgery, the patient's blood pressure and heart rate suddenly increased and a wide QRS tachycardia was observed on the electrocardiogram, which then reverted to a normal sinus rhythm. According to the past reports, similar arrhythmias have occurred after administration of epinephrine in the head and neck. These findings suggest that anesthesia providers must be aware of the risks associated with epinephrine and local anesthetic use, particularly in the head and neck region.

Isoflurane induces Art2-Rsp5-dependent endocytosis of Bap2 in yeast

Although general anesthesia is indispensable during modern surgical procedures, the mechanism by which inhalation anesthetics act on the synaptic membrane at the molecular and cellular level is largely unknown. In this study, we used yeast cells to examine the effect of isoflurane, an inhalation anesthetic, on membrane proteins. Bap2, an amino acid transporter localized on the plasma membrane, was endocytosed when yeast cells were treated with isoflurane. Depletion of RSP5, an E3 ligase, prevented this endocytosis and Bap2 was ubiquitinated in response to isoflurane, indicating an ubiquitin‐dependent process. Screening all the Rsp5 binding adaptors showed that Art2 plays a central role in this process. These results suggest that isoflurane affects Bap2 via an Art2‐Rsp5‐dependent ubiquitination system.

Anti-calcitonin gene-related peptide antibody attenuates orofacial mechanical and heat hypersensitivities induced by infraorbital nerve injury

Currently, limited information regarding the role of calcitonin gene-related peptide (CGRP) in neuropathic pain is available. Intracerebroventricular administrations of an anti-CGRP antibody were performed in rats with infraorbital nerve ligation. Anti-CGRP antibody administration attenuated mechanical and heat hypersensitivities induced by nerve ligation and decreased the phosphorylated extracellular signal-regulated kinase expression levels in the trigeminal spinal subnucleus caudalis (Vc) following mechanical or heat stimulation. An increased CGRP immunoreactivity in the Vc appeared after nerve ligation. A decreased CGRP immunoreactivity resulted from anti-CGRP antibody administration. Our findings suggest that anti-CGRP antibody administration attenuates the symptoms of trigeminal neuropathic pain by acting on CGRP in the Vc.

Meiosis-specific ZFP541 repressor complex promotes developmental progression of meiotic prophase towards completion during mouse spermatogenesis

During spermatogenesis, meiosis is accompanied by a robust alteration in gene expression and chromatin status. However, it remains elusive how the meiotic transcriptional program is established to ensure completion of meiotic prophase. Here, we identify a protein complex that consists of germ-cell-specific zinc-finger protein ZFP541 and its interactor KCTD19 as the key transcriptional regulators in mouse meiotic prophase progression. Our genetic study shows that ZFP541 and KCTD19 are co-expressed from pachytene onward and play an essential role in the completion of the meiotic prophase program in the testis. Furthermore, our ChIP-seq and transcriptome analyses identify that ZFP541 binds to and suppresses a broad range of genes whose function is associated with biological processes of transcriptional regulation and covalent chromatin modification. The present study demonstrates that a germ-cell specific complex that contains ZFP541 and KCTD19 promotes the progression of meiotic prophase towards completion in male mice, and triggers the reconstruction of the transcriptional network and chromatin organization leading to post-meiotic development.

Increased expression of Netrin-4 is associated with allodynia in a trigeminal neuropathic pain model rats by infraorbital nerve injury

Neuropathic pain refers to pain caused by lesions or diseases of the somatosensory nervous system that is characteristically different from nociceptive pain. Moreover, neuropathic pain occurs in the maxillofacial region due to various factors and is treated using tricyclic antidepressants and nerve block therapy; however, some cases do not fully recover. Netrin is a secreted protein crucially involved in neural circuit formation during development, including cell migration, cell death, neurite formation, and synapse formation. Recent studies show Netrin-4 expressed in the dorsal horn of the spinal cord is associated with chronic pain. Here we found involvement of Netrin-4 in neuropathic pain in the maxillofacial region. Netrin-4, along with one of its receptors, Unc5B, are expressed in the caudal subnucleus of the trigeminal spinal tract nucleus. Inhibition of its binding by anti-Netrin-4 antibodies not only shows a behavioral analgesic effect but also neuronal activity suppression. There was increased Netrin-4 expression at 14 days after infraorbital nerve injury. Our findings suggest that Netrin-4 induced by peripheral nerve injury causes neuropathic pain via Unc5B.

Clinical Use of Preformed Microcuff® Pediatric Endotracheal Tubes in Japan

Preformed cuffed oral endotracheal tubes are widely used to intubate children undergoing oral surgery. To evaluate the efficacy and safety of oral Ring-Adair-Elwyn (RAE) Microcuff® pediatric endotracheal tubes, we retrospectively investigated the endotracheal tube exchange rate and associated complications in Japanese children younger than 2 years of age undergoing cheiloplasty or palatoplasty. The exchange rate was 3.5%, and although unplanned extubations occurred in 2 patients, no severe complications were observed. Our results suggest that oral RAE Microcuff® tubes are effective and safe for intubating Japanese children younger than 2 years of age, with a low tube exchange rate and minor complications.

Frequency of the requirement of inappropriate uncuffed tracheal tube size for pediatric patients: a retrospective observational analysis

BACKGROUND

The insertion of inappropriately sized uncuffed endotracheal tubes (ETTs) with a tight seal or presence of air leakage may be necessary in children. This study aimed to analyze the frequency of the requirement of inappropriately sized uncuffed ETT insertion, air leakage after the ETT was replaced with one of a larger size, and factors associated with air leakage after ETT replacement.

METHODS

Patients under 2 years of age who underwent oral surgery under general anesthesia with uncuffed ETTs between December 2013 and May 2015 were enrolled. The ETT size was selected at the discretion of the attending anesthesiologists. A leak test was performed after intubation. The ETT was replaced when considered necessary. Data regarding the leak pressure (P_Leak) and inspiratory and expiratory tidal volumes were extracted from anesthesia records. We considered a P_Leak of 10 < P_Leak ≤ 30 cmH₂O to be appropriate. The frequencies of the requirement of inappropriately sized ETTs, absence of leakage after ETT replacement, ETT size difference, and leak rate were calculated. A logistic regression was performed, with P_Leak, leak rate, and size difference included as explanatory variables and presence of leakage after replacement as the outcome variable.

RESULTS

Out of the 156 patients enrolled, 109 underwent ETT replacement, with the requirement of inappropriately sized ETTs being observed in 25 patients (23%). ETT replacement was performed in patients with P_Leak ≤ 10 cmH₂O; leakage was absent after replacement (P_Leak < 30 cmH₂O) in 52% of patients (25/48). In the multivariate logistic model, the leak rate before ETT replacement was significantly associated with the presence of leakage after replacement (p = 0.021).

CONCLUSIONS

Inappropriately sized ETTs were inserted in approximately 23% of the patients. The leak rate may be useful to guide ETT replacement.

Generation of Mitochondrial Toxin Rodent Models of Parkinson's Disease Using 6-OHDA , MPTP , and Rotenone

Several animal models are employed to discover novel treatments for the symptoms of Parkinson's disease (PD). PD models can be divided into two models: neurotoxin models and genetic models. Among neurotoxins to produce PD models, 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and rotenone, which inhibit the mitochondrial complex I, are widely used. Animal models of PD using these neurotoxins are also known as mitochondrial toxin models. Here this chapter describes the preparation of these mitochondrial toxin models.

Distinct transcriptional programs of SOX2 in different types of small cell lung cancers

SOX2 is recognized as an oncogene in human small cell lung cancer (SCLC), which is an aggressive neuroendocrine (NE) tumor. However, the role of SOX2 in SCLC is not completely understood, and strategies to selectively target SOX2 in SCLC cells remain elusive. Here, we show, using next-generation sequencing, that SOX2 expressed in the ASCL1-high SCLC (SCLC-A) subtype cell line is dependent on ASCL1, which is a lineage-specific transcriptional factor, and is involved in NE differentiation and tumorigenesis. ASCL1 recruits SOX2, which promotes INSM1 and WNT11 expression. Immunohistochemical studies revealed that SCLC tissue samples expressed SOX2, ASCL1, and INSM1 in 18 out of the 30 cases (60%). Contrary to the ASCL1-SOX2 signaling axis controlling SCLC biology in the SCLC-A subtype, SOX2 targets distinct genes such as those related to the Hippo pathway in the ASCL1-negative, YAP1-high SCLC (SCLC-Y) subtype. Although SOX2 knockdown experiments suppressed NE differentiation and cell proliferation in the SCLC-A subtype, they did not sufficiently impair the growth of the SCLC-Y subtype cell lines in vitro and ex vivo. The present results support the importance of the ASCL1-SOX2 axis as a main subtype of SCLC, and suggest the therapeutic potential of targeting the ASCL1-SOX2 axis.

Establishment of bone marrow-derived M-CSF receptor-dependent self-renewing macrophages

Recent studies have revealed that tissue macrophages are derived from yolk sac precursors or fetal liver monocytes, in addition to bone marrow monocytes. The relative contribution of these cells to the tissue macrophage pool is not fully understood, but embryo-derived cells are supposed to be more important because of their capacity to self-renew. Here, we show the presence of adult bone marrow-derived macrophages that retain self-renewing capacity. The self-renewing macrophages were readily obtained by long-term culture of mouse bone marrow cells with macrophage colony-stimulating factor (M-CSF), a key cytokine for macrophage development. They were non-tumorigenic and proliferated in the presence of M-CSF in unlimited numbers. Despite several differences from non-proliferating macrophages, they retained many features of cells of the monocytic lineage, including the differentiation into dendritic cells or osteoclasts. Among the transcription factors involved in the self-renewal of embryonic stem cells, Krüppel-like factor 2 (KLF2) was strongly upregulated upon M-CSF stimulation in the self-renewing macrophages, which was accompanied by the downregulation of MafB, a transcription factor that suppresses KLF2 expression. Indeed, knockdown of KLF2 led to cell cycle arrest and diminished cell proliferation in the self-renewing macrophages. Our new cell model would be useful to unravel differences in phenotype, function, and molecular mechanism of proliferation among self-renewing macrophages with different origins.

An Avulsed Tooth Detected Prior to Insertion of a Laryngeal Mask Airway

This case report describes the importance of inspecting the hypopharynx via direct laryngoscopy prior to laryngeal mask airway (LMA) insertion during induction of general anesthesia for dental patients with special needs. A 51-year-old man with cerebral palsy underwent induction of general anesthesia for dental extractions and subsequently was noted to be missing a tooth. Prompt inspection of the airway via direct laryngoscopy revealed the tooth resting within the pharynx, which was subsequently retrieved, prior to insertion of the LMA. Visual inspection of the oropharynx and hypopharynx by laryngoscopy prior to LMA insertion can be useful in preventing accidental aspiration and ingestion of foreign bodies, particularly with certain high-risk patients. Use of laryngoscopy should also be considered if an object is lost or possibly impinging upon the airway.

Anesthetic Management of a Patient With a Vagal Nerve Stimulator

Vagal nerve stimulation (VNS) is an established adjunctive treatment for patients with refractory epilepsy. VNS is effective in many cases, but few patients achieve complete elimination of seizures. Furthermore, VNS can cause respiratory complications, such as obstructive sleep apnea. This report describes the successful anesthetic management of a 28-year-old woman with a VNS device who underwent dental treatment under general anesthesia. She was morbidly obese and had undergone placement of a VNS device secondary to drug-resistant epilepsy 2 years prior but continued to experience daily epileptic seizures. Because of concerns about the risk of perioperative epileptic seizures and apneic events, use of the dedicated VNS device magnet was planned if such complications occurred. Total intravenous anesthesia was induced with propofol and remifentanil and a bispectral index sensor was used to help monitor brain wave activity for evidence of seizures along with the depth of anesthesia. Postoperatively, the patient received positional therapy and supplemental oxygen while being closely monitored in recovery. The anesthetic course was completed uneventfully without need of the VNS magnet. A thorough understanding of the mechanics of a VNS device, including proper use of the VNS magnet, is critical for an anesthesiologist during the perioperative period.

Mesenchymal-epithelial transition regulates initiation of pluripotency exit before gastrulation

The pluripotent epiblast gives rise to all tissues and organs in the adult body. Its differentiation starts at gastrulation, when the epiblast generates mesoderm and endoderm germ layers through epithelial-mesenchymal transition (EMT). Although gastrulation EMT coincides with loss of epiblast pluripotency, pluripotent cells in development and in vitro can adopt either mesenchymal or epithelial morphology. The relationship between epiblast cellular morphology and its pluripotency is not well understood. Here, using chicken epiblast and mammalian pluripotency stem cell (PSC) models, we show that PSCs undergo a mesenchymal-epithelial transition (MET) prior to EMT-associated pluripotency loss. Epiblast MET and its subsequent EMT are two distinct processes. The former, a partial MET, is associated with reversible initiation of pluripotency exit, whereas the latter, a full EMT, is associated with complete and irreversible pluripotency loss. We provide evidence that integrin-mediated cell-matrix interaction is a key player in pluripotency exit regulation. We propose that epiblast partial MET is an evolutionarily conserved process among all amniotic vertebrates and that epiblast pluripotency is restricted to an intermediate cellular state residing between the fully mesenchymal and fully epithelial states.

Bilateral Parkinson's disease model rats exhibit hyperalgesia to subcutaneous formalin administration into the vibrissa pad

We bilaterally injected 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle of rats and developed bilateral Parkinson’s disease (PD) model rats in order to experimentally investigate the neural mechanisms underlying the alteration of nociception in the orofacial region of patients with PD. We explored the effects of dopamine depletion on nociception by investigating behavioral responses (face rubbing) triggered by subcutaneous administration of formalin into the vibrissa pad. We also assessed the number of c-Fos–immunoreactive (c-Fos-IR) cells in the superficial layers of the trigeminal spinal subnucleus caudalis (Vc). Subcutaneous formalin administration evoked a two-phase increase in face rubbing. We observed the first increase 0–5 min after formalin administration (first phase) and the second increase 10–60 min after administration (second phase). The number of face rubbing behaviors of 6OHDA–injected rats did not significantly change compared with saline–injected rats in both phases. Significant increase of c-Fos-IR cells in the Vc was found in 6-OHDA–injected rats after formalin administration compared with those in saline–injected rats after formalin administration. We also assessed expression of c-Fos-IR cells in the paraventricular nucleus (PVN), and significant decrease of c-Fos-IR cells in the PVN of 6-OHDA–injected rats was found. Taken together, these findings suggest that bilateral dopaminergic denervation evoked by 6-OHDA administration causes hyperalgesia in the trigeminal region and the PVN may be involved in the hyperalgesia.

A novel surgical strategy for the resection of duodenal gastrointestinal stromal tumours located close to the duodenal ampulla: a case report

Although the optimal surgical procedure for the resection of duodenal gastrointestinal stromal tumours has not yet been characterised due to the low prevalence of these tumours and the anatomical complexity of the duodenopancreatic region, difficult surgical procedures such as pancreaticoduodenectomy are often proposed for stromal tumours located in the second portion of the duodenum. Our case report highlights a novel surgical strategy that can be implemented as an alternative to pancreaticoduodenectomy for such tumours close to the duodenal ampulla. A 70-year-old man incidentally diagnosed with a stromal tumour close to the duodenal ampulla in the second portion of the duodenum underwent local resection guided by an endoscopic nasobiliary drainage tube with primary closure. This tube was converted to a percutaneous trans-small intestinal biliary drainage tube during the procedure to prevent biliary leakage biliary stasis due to swelling of the duodenal ampulla. He also underwent a simple distal gastrectomy with Roux-en-Y reconstruction. This resulted in successful R0 resection. There were no procedure-related complications or post-surgery weight changes. Our simple novel surgical strategy may therefore be useful for avoiding pancreaticoduodenectomy and maintaining quality of life in patients with stromal tumours close to the duodenal ampulla.

Age-based prediction of uncuffed tracheal tube size in children to prevent inappropriately large tube selection: a retrospective analysis

Background

This study aims to validate our previously reported prediction technique for uncuffed tracheal tube (TT) sizes in children younger than 2 years of age based on a calculated outer diameter (OD_Cal, mm) in each patient according to the regression equation OD_Cal = 0.00223 × age (day) + 4.88 and to investigate a better method to select initial TT sizes to decrease re-intubation frequency, especially since large tubes can damage the trachea.

Methods

We included patients younger than 2 years of age who underwent oral surgery under general anesthesia with tracheal intubation between July 2011 and December 2016 at the Osaka University Dental Hospital. The OD of the actual TT and the age in days were extracted from anesthesia records. Agreement rates, estimated numbers of required tubes, and size reduction frequencies were compared to obtain recommended OD (OD_Rec) values in 2 selection groups: “average selection” in the range “nearest to the OD_Cal value (OD_Cal - 0.35 < OD_Rec ≤ OD_Cal + 0.35)” and “safe selection” in the range “nearest to the value below OD_Cal (OD_Cal - 0.7 < OD_Rec ≤ OD_Cal)”.

Results

The agreement rates for an OD_Rec in the average selection and safe selection groups were 60.8 and 55.1%, respectively (P = 0.001). The estimated number of required tubes per patient were 1.40 ± 0.51 and 1.47 ± 0.55 (P < 0.001), respectively. The estimated frequencies of size reductions were 13.3 and 4.0% (P < 0.001), respectively.

Conclusions

Because the size reduction frequency is lower despite a slightly higher number of required TTs, selecting an OD_Rec based on “safe selection” parameters is desirable to avoid complications due to intubation with larger TTs.

Klf5 suppresses ERK signaling in mouse pluripotent stem cells

Mouse embryonic stem cells (ESCs) are pluripotent stem cells, which have the ability to differentiate into all three germ layers: mesoderm, endoderm, and ectoderm. Proper levels of phosphorylated extracellular signal-regulated kinase (pERK) are critical for maintaining pluripotency, as elevated pERK evoked by fibroblast growth factor (FGF) receptor activation results in differentiation of ESCs, while, conversely, reduction of pERK by a MEK inhibitor maintains a pluripotent ground state. However, mechanisms underlying proper control of pERK levels in mouse ESCs are not fully understood. Here, we find that Klf5, a Krüppel-like transcription factor family member, is a component of pERK regulation in mouse ESCs. We show that ERK signaling is overactivated in Klf5-KO ESCs and the overactivated ERK in Klf5-KO ESCs is suppressed by the introduction of Klf5, but not Klf2 or Klf4, indicating a unique role for Klf5 in ERK suppression. Moreover, Klf5 regulates Spred1, a negative regulator of the FGF-ERK pathway. Klf5 also facilitates reprogramming of EpiSCs into a naïve state in combination with a glycogen synthase kinase 3 inhibitor and LIF, and in place of a MEK inhibitor. Taken together, these results show for the first time that Klf5 has a unique role suppressing ERK activity in mouse ESCs.

In vitro and in vivo characterization of the bifunctional μ and δ opioid receptor ligand UFP-505

BACKGROUND AND PURPOSE

Targeting more than one opioid receptor type simultaneously may have analgesic advantages in reducing side-effects. We have evaluated the mixed μ opioid receptor agonist/ δ opioid receptor antagonist UFP-505 in vitro and in vivo.

EXPERIMENTAL APPROACH

We measured receptor density and function in single μ, δ and μ /δ receptor double expression systems. GTPγ35 S binding, cAMP formation and arrestin recruitment were measured. Antinociceptive activity was measured in vivo using tail withdrawal and paw pressure tests following acute and chronic treatment. In some experiments, we collected tissues to measure receptor densities.

KEY RESULTS

UFP-505 bound to μ receptors with full agonist activity and to δ receptors as a low efficacy partial agonist At μ, but not δ receptors, UFP-505 binding recruited arrestin. Unlike morphine, UFP-505 treatment internalized μ receptors and there was some evidence for internalization of δ receptors. Similar data were obtained in a μ /δ receptor double expression system. In rats, acute UFP-505 or morphine, injected intrathecally, was antinociceptive. In tissues harvested from these experiments, μ and δ receptor density was decreased after UFP-505 but not morphine treatment, in agreement with in vitro data. Both morphine and UFP-505 induced significant tolerance.

CONCLUSIONS AND IMPLICATIONS

In this study, UFP-505 behaved as a full agonist at μ receptors with variable activity at δ receptors. This bifunctional compound was antinociceptive in rats after intrathecal administration. In this model, dual targeting provided no advantages in terms of tolerance liability.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

Overlapping functions of Krüppel-like factor family members: targeting multiple transcription factors to maintain the naïve pluripotency of mouse embryonic stem cells

Krüppel-like factors (Klfs) have a pivotal role in maintaining self-renewal of mouse embryonic stem cells (mESCs). The functions of three Klf family members (Klf2, Klf4 and Klf5) have been identified, and are suggested to largely overlap. For further dissection of their functions, we applied an inducible knockout system for these Klf family members and assessed the effects of combinatorial loss of function. As a result, we confirmed that any one of Klf2, Klf4 and Klf5 was sufficient to support self-renewal, whereas the removal of all three compromised it. The activity of any single transcription factor, except for a Klf family member, was not sufficient to restore self-renewal of triple-knockout mESCs. However, some particular combinations of transcription factors were capable of the restoration. The triple-knockout mESCs were successfully captured at primed state. These data indicate that the pivotal function of a Klf family member is transduced into the activation of multiple transcription factors in a naïve-state-specific manner.

The principles that govern transcription factor network functions in stem cells

Tissue-specific transcription factors primarily act to define the phenotype of the cell. The power of a single transcription factor to alter cell fate is often minimal, as seen in gain-of-function analyses, but when multiple transcription factors cooperate synergistically it potentiates their ability to induce changes in cell fate. By contrast, transcription factor function is often dispensable in the maintenance of cell phenotype, as is evident in loss-of-function assays. Why does this phenomenon, commonly known as redundancy, occur? Here, I discuss the role that transcription factor networks play in collaboratively regulating stem cell fate and differentiation by providing multiple explanations for their functional redundancy.

Co-precipitation molecules hemopexin and transferrin may be key molecules for fibrillogenesis in TTR V30M amyloidogenesis

The disease model of familial amyloidotic polyneuropathy—7.2-hMet30 mice—manifests amyloid deposition that consists of a human amyloidogenic mutant transthyretin (TTR) (TTR V30M). Our previous study found amyloid deposits in 14 of 27 7.2-hMet30 mice at 21–24 months of age. In addition, non-fibrillar TTR deposits were found in amyloid-negative 7.2hMet30 mice. These results suggested that TTR amyloidogenesis required not only mutant TTR but also an additional factor (or factors) as an etiologic molecule. To determine the differences in serum proteome in amyloid-positive and amyloid-negative mice in the 7.2-hMet30 model, we used proteomic analyses and studied serum samples obtained from these mice. Hemopexin (HPX) and transferrin (Tf) were detected in the serum samples from amyloid-positive mice and were also found in amyloid deposits via immunohistochemistry, but serum samples from amyloid-negative mice did not contain HPX and Tf. These two proteins were also not detected in non-fibrillar TTR deposits. In addition, in silico analyses suggested that HPX and Tf facilitate destabilization of TTR secondary structures and misfolding of TTR. These results suggest that HPX and Tf may be associated with TTR amyloidogenesis after fibrillogenesis in vivo.

Probing the OH Stretch in Different Local Environments in Liquid Water

We use resonant inelastic X-ray scattering (RIXS) to resolve vibrational losses corresponding to the OH stretch where the X-ray absorption process allows us to selectively probe different structural subensembles in liquid water. The results point to a unified interpretation of X-ray and vibrational spectroscopic data in line with a picture of two classes of structural environments in the liquid at ambient conditions with predominantly close-packed high-density liquid (HDL) and occasional local fluctuations into strongly tetrahedral low-density liquid (LDL).

Anaphylaxis with delayed appearance of skin manifestations during general anesthesia: two case reports

Background

Anaphylaxis is difficult to diagnose in the absence of skin or mucosal signs and symptoms. We report two cases of anaphylaxis under general anesthesia, in which the initial presentation was in the form of respiratory signs, followed by skin manifestations 10–15 min later. Diagnosis of anaphylaxis was delayed because skin symptoms were absent early on in the presentation.

Case presentation

In the first case, a 23-year-old male patient with jaw deformity was scheduled to undergo maxillary alveolar osteotomy. After intubation, auscultation indicated a sudden decrease in breath sounds, together with severe hypotension. Approximately 10 min later, flushing of the skin and urticaria on the thigh appeared and spread widely throughout the body. In the second case, a 21-year-old female patient with jaw deformity was scheduled to undergo maxillomandibular osteotomy. Twenty minutes after the start of dextran infusion, her lungs suddenly became difficult to ventilate, and oxygen saturation decreased to 90%. Approximately 15 min later, flushing of the skin and urticaria were observed.

Conclusion

In both cases, there was a time lag between the appearance of respiratory and skin symptoms, which resulted in a delay in the diagnosis, and hence, treatment of anaphylaxis. Our experience highlights the fact that it is difficult to diagnose anaphylaxis under general anesthesia.

Effective Dosage of Midazolam to Erase the Memory of Vascular Pain During Propofol Administration

Intravenous sedation with propofol is often administered to anxious patients in dental practice. Pain on injection of propofol is a common adverse effect. This study aimed to determine the age-adjusted doses of midazolam required to erase memory of vascular pain of propofol administration and assess whether the Ramsay Sedation Scale (RSS) after the pretreatment of midazolam was useful to predict amnesia of the vascular pain of propofol administration. A total of 246 patients with dental phobia requiring dental treatment under intravenous sedation were included. Patients were classified according to their age: 30s, 40s, 50s, and 60s. Three minutes after administration of a predetermined dose of midazolam, propofol was infused continuously. After completion of the dental procedure, patients were interviewed about the memory of any pain or discomfort in the injection site or forearm. The dosage of midazolam was determined using the Dixon up-down method. The first patient was administered 0.03 mg/kg, and if memory of vascular pain remained, the dosage was increased by 0.01 mg/kg for the next patient, and then if the memory was erased, the dosage was decreased by 0.01 mg/kg. The effective dosage of midazolam in 95% of each age group for erasing the memory of propofol vascular pain (ED95) was determined using logistic analysis. The accuracy of RSS to predict the amnesia of injection pain was assessed by receiver operating characteristic (ROC) analysis. The ED95 of midazolam to erase the memory of propofol vascular pain was 0.061 mg/kg in patients in their 30s, 0.049 mg/kg in patients in their 40s, 0.033 mg/kg in patients in their 50s, and 0.033 mg/kg in patients in their 60s. The area under the ROC curve was 0.31. The ED95 of midazolam required to erase the memory of propofol vascular pain demonstrated a downward trend with age. On the other hand, it was impossible to predict the amnesia of propofol vascular pain using the RSS.

Airway management for glossopexy in infants with micrognathia and obstructive breathing

STUDY OBJECTIVES

To identify airway management and tracheal intubation techniques for glossopexy in infants with preexisting airway obstruction under general anesthesia.

DESIGN

Retrospective, observational study.

SETTINGS

Operating room of a university hospital between January 2003 and March 2015. All operations were performed by oral and maxillofacial surgeons.

PATIENTS

Thirteen patients who received general anesthesia for glossopexy and reversal after 7 months.

MEASUREMENTS

The medical records of these infants were retrospectively examined to evaluate the following: age, sex, height and weight at surgery, preoperative airway status, tracheal intubation route (oral or nasal), method for inducing general anesthesia, method for establishing the airway during mask ventilation, apparatus used for tracheal intubation, Cormack-Lehane classification when using a Macintosh laryngoscope and video laryngoscope, and the need for airway placement after extubation.

RESULTS

Prone positioning and/or an airway of some kind before surgery were required in 38.5% of infants needing glossopexy. Difficult mask ventilation was common, occurring in 50% of the patients, and the incidence of airway placement during mask ventilation was significantly higher in infants with preoperative complete or incomplete obstruction (100%) than in infants with snoring (25%). Of these high-risk infants, 25% could not be intubated with a direct laryngoscope or Glidescope Cobalt and required fiberoptic intubation.

CONCLUSION

There are severe cases of infants with difficult mask ventilation and difficult tracheal intubation in which a fiberscope is required because video laryngoscopy fails to improve the view of the larynx.

Trigeminal nervous system sensitization by infraorbital nerve injury enhances responses in a migraine model

Background

Although the peripheral and central sensitizations of trigeminal nervous system may be one of the important factors of migraine, the precise mechanism is not fully understood. In this study, we examined the influence of the sensitization of the second division of the trigeminal nerve (V2) by chronic constriction injury (CCI) of the infraorbital nerve (ION) on migraine headache, using the capsaicin-induced migraine model.

Methods

Male Sprague-Dawley rats were assigned to four groups: (a) sham surgery and topical-dural vehicle application (Sham + Vehicle) group, (b) CCI-ION and topical-dural vehicle application (CCI-ION + Vehicle) group, (c) sham surgery and topical-dural capsaicin application (Sham + Capsaicin) group, (d) CCI-ION and topical-dural capsaicin application (CCI-ION + Capsaicin) group. Behavioral testing and immunohistochemical staining were performed.

Results

In the behavioral test, the Sham + Capsaicin group showed significantly longer duration of immobilization and shorter duration of exploration compared with the Sham + Vehicle group, which is similar to clinical features of migraine patients. Moreover, CCI-ION enhanced these effects in the CCI-ION + Capsaicin group. Immunohistochemical staining for phospho-extracellular signal-related kinase (pERK) in the trigeminal ganglion (TG) containing first and second divisions of the trigeminal nerve and the trigeminocervical complex (TCC) revealed that pERK expression was significantly increased in the CCI-ION + Capsaicin group compared with the other groups. However, comparing between effects of the peripheral and central sensitizations (in the TG and TCC), from our results, peripheral sensitization would play a much less or not significant role.

Conclusions

These data demonstrate that the sensitization of V2 could influence the activation and the sensitization of the first division of the trigeminal nerve in the TCC, subsequently exacerbating pain sensation and pain-related behaviors. We have shown for the first time that the existence of the central sensitization of V2 can be an exacerbating factor for migraine related nociceptive thresholds/activation.

Estrogens Exacerbate Nociceptive Pain via Up-Regulation of TRPV1 and ANO1 in Trigeminal Primary Neurons of Female Rats

Several trigeminal pain disorders show sex differences, and high levels of estrogens may underlie these differences. The interaction between transient receptor potential vanilloid 1 (TRPV1) and anoctamin 1 (ANO1) plays an important role in peripheral nociception. However, whether TRPV1 and ANO1 are involved in estrogen-modulated trigeminal pain sensitivity is unclear. In this study, we examined estradiol (E2) modulation of nociception through behavioral and immunohistological experiments after application of capsaicin (Cap), a selective TRPV1 agonist, onto the ocular surface in ovariectomized rats treated with high-dose E2 (HE) or low-dose E2 (LE) for 2 days. In addition, we used real-time PCR to study the effects of E2 on the expression levels of TRPV1 and ANO1 mRNA in trigeminal ganglia. In the behavioral experiment, the HE group showed significant potentiation of Cap-evoked nocifensive behavior compared with the LE group. Immunohistochemistry showed that Cap evoked a significantly greater number of cells that were immunoreactive for c-Fos, a marker of nociceptive activation, in the trigeminal subnucleus caudalis/upper cervical cord in the HE group than in the LE group. The number of c-Fos-immunoreactive cells in the ventral trigeminal interpolaris/caudalis were similar in the 2 groups. Real-time PCR showed that the levels of TRPV1 and ANO1 mRNA in the HE group were significantly higher than levels in the LE group. Thus, high levels of estrogens may be a risk factor for Cap-evoked nociceptive pain, and estrogen-dependent increases in TRPV1 and ANO1 are likely involved in modulating the nociceptive response in the trigeminal area.

The evolutionally-conserved function of group B1 Sox family members confers the unique role of Sox2 in mouse ES cells

BACKGROUND

In mouse ES cells, the function of Sox2 is essential for the maintenance of pluripotency. Since the Sox-family of transcription factors are well conserved in the animal kingdom, addressing the evolutionary origin of Sox2 function in pluripotent stem cells is intriguing from the perspective of understanding the origin of pluripotency.

RESULTS

Here we approach this question using a functional complementation assay in inducible Sox2-null ES cells. Assaying mouse Sox proteins from different Groups, we found that only Group B1 and Group G proteins were able to support pluripotency. Interestingly, invertebrate homologs of mammalian Group B1 Sox proteins were able to replace the pluripotency-associated function of mouse Sox2. Moreover, the mouse ES cells rescued by the Drosophila SoxNeuro protein are able to contribute to chimeric embryos.

CONCLUSIONS

These data indicate that the function of mouse Sox2 supporting pluripotency is based on an evolutionally conserved activity of the Group B1 Sox family. Since pluripotent stem cell population in developmental process could be regarded as the evolutional novelty in vertebrates, it could be regarded as a co-optional use of their evolutionally conserved function.

Premedication with midazolam in intellectually disabled dental patients: intramuscular or oral administration? A retrospective study

Background

The use of midazolam for dental care in patients with intellectual disability is poorly documented. The purpose of this study was to determine which method of premedication is more effective for these patients, 0.15 mg/kg of intramuscular midazolam or 0.3 mg/kg of oral midazolam.

Material and Methods

This study was designed and implemented as a non-randomized retrospective study. The study population was composed of patients with intellectual disability who required dental treatment under ambulatory general anesthesia from August 2009 through April 2013. Patients were administered 0.15 mg/kg of midazolam intramuscularly (Group IM) or 0.3 mg/kg orally (Group PO). The predictor variable was the method of midazolam administration. The outcome variables measured were Observer’s Assessment of Alertness/ Sedation (OAA/S) Scale scores, the level of cooperation when entering the operation room and for venous cannulation, post-anesthetic agitation and recovery time.

Results

Midazolam was administered intramuscularly in 23 patients and orally in 21 patients. More patients were successfully sedated with no resistance behavior during venous cannulation in Group PO than in Group IM (p=0.034). There were no differences in demographic data and other variables between the groups.

Conclusions

The results of this study suggest that oral premedication with 0.3 mg/kg of midazolam is more effective than 0.15 mg/kg of midazolam administered intramuscularly, in terms of patient resistance to venous cannulation. If both oral and intramuscular routes of midazolam are acceptable in intellectually disabled patients, the oral route is recommended.

Key words:Premedication, midazolam, intellectual disability.

Meticillin-resistant Staphylococcus aureus colonisation and infection in Thoroughbred racehorses and veterinarians in Japan

Meticillin-resistant Staphylococcus aureus (MRSA) infections have been confirmed in hospitalised Thoroughbred racehorses at the hospitals of two training centres in Japan since 2009. To investigate the source of infection, the authors examined the rate of nasal MRSA colonisation in 600 healthy Thoroughbred racehorses, 53 veterinarians and 16 office staff at the racehorse hospitals of the two training centres. MRSA was not isolated from healthy Thoroughbred racehorses or hospital office staff. However, MRSA was isolated from 16 veterinarians (30.1 per cent), and the colonisation rate was significantly higher in veterinarians than in the office staff of the same hospitals. Also, 10 of the 16 MRSA strains (62.5 per cent) isolated from veterinarians were classified as type II by staphylococcal cassette chromosome mec (SCCmec) typing and ST5 by multilocus sequence typing. Pulsed-field gel electrophoresis analysis demonstrated that these 10 MRSA strains of SCCmec type II and ST5 were genetically identical or very similar to 9 MRSA strains isolated from infected horses hospitalised at these hospitals between 2009 and 2013. These results indicate that SCCmec type II and ST5 MRSA strains were probably transmitted between veterinarians and infected horses.

Zscan4 Is Activated after Telomere Shortening in Mouse Embryonic Stem Cells

ZSCAN4 is a DNA-binding protein that functions for telomere elongation and genomic stability. In vivo, it is specifically expressed at the two-cell stage during mouse development. In vitro, it is transiently expressed in mouse embryonic stem cells (ESCs), only in 5% of the population at one time. Here we attempted to elucidate when, under what circumstances, Zscan4 is activated in ESCs. Using live cell imaging, we monitored the activity of Zscan4 together with the pluripotency marker Rex1. The lengths of the cell cycles in ESCs were diverse. Longer cell cycles were accompanied by shorter telomeres and higher activation of Zscan4. Since activation of Zscan4 is involved in telomere elongation, we speculate that the extended cell cycles accompanied by Zscan4 activation reflect the time for telomere recovery. Rex1 and Zscan4 did not show any correlation. Taken together, we propose that Zscan4 is activated to recover shortened telomeres during extended cell cycles, irrespective of the pluripotent status.

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At longer cell cycles, telomeres are shorter

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Zscan4 is activated when the cell cycles become long

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After the activation of Zscan4, the next cell cycle becomes short

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We propose Zscan4 is activated for telomere maintenance irrespective of pluripotency