Dynamic regulation of innate immune responses in Drosophila by Senju-mediated glycosylation.

The innate immune system is the first line of defense encountered by invading pathogens. Delayed and/or inadequate innate immune responses can result in failure to combat pathogens, whereas excessive and/or inappropriate responses cause runaway inflammation. Therefore, immune responses are tightly regulated from initiation to resolution and are repressed during the steady state. It is well known that glycans presented on pathogens play important roles in pathogen recognition and the interactions between host molecules and microbes; however, the function of glycans of host organisms in innate immune responses is less well known. Here, we show that innate immune quiescence and strength of the immune response are controlled by host glycosylation involving a novel UDP-galactose transporter called Senju. In senju mutants, reduced expression of galactose-containing glycans resulted in hyperactivation of the Toll signaling pathway in the absence of immune challenges. Genetic epistasis and biochemical analyses revealed that Senju regulates the Toll signaling pathway at a step that converts Toll ligand Spatzle to its active form. Interestingly, Toll activation in immune-challenged wild type (WT) flies reduced the expression of galactose-containing glycans. Suppression of the degalactosylation by senju overexpression resulted in reduced induction of Toll-dependent expression of an antimicrobial peptide, Drosomycin, and increased susceptibility to infection with Gram-positive bacteria. These data suggest that Senju-mediated galactosylation suppresses undesirable Toll signaling activation during the steady state; however, Toll activation in response to infection leads to degalactosylation, which raises the immune response to an adequate level and contributes to the prompt elimination of pathogens.

Tumor-suppressive function of protein-tyrosine phosphatase non-receptor type 23 in testicular germ cell tumors is lost upon overexpression of miR142-3p microRNA.

Protein-tyrosine phosphatase non-receptor type 23 (PTPN23) is a candidate tumor suppressor involved in the tumorigenesis of various organs. However, its physiological role(s) and detailed expression profile(s) have not yet been elucidated. We investigated the function and regulation of PTPN23 in the formation of testicular germ cell tumors (TGCTs). Expression of PTPN23 in human TGCT cell lines was significantly lower than that in spermatogonial stem cells in mice. Overexpression of PTPN23 in NEC8, a human TGCT cell line, suppressed soft agar colony formation in vitro and tumor formation in nude mice in vivo. These data indicate that PTPN23 functions as a tumor suppressor in TGCTs. Multiple computational algorithms predicted that the 3' UTR of human PTPN23 is a target for miR-142-3p. A luciferase reporter assay confirmed that miR-142-3p bound directly to the 3' UTR of PTPN23. Introduction of pre-miR-142 in the PTPN23 transfectant of NEC8 led to suppressed expression of PTPN23 and increased soft agar colony formation. Quantitative RT-PCR data revealed a significantly higher expression of miR-142-3p in human seminomas compared with normal testes. No difference in mRNA expression between seminoma and non-seminoma samples was detected by in situ hybridization. Both quantitative RT-PCR and immunohistochemical analyses revealed that PTPN23 expression was significantly lower in TGCTs than in normal testicular tissues. Finally, a lack of PTPN23 protein expression in human TGCTs correlated with a relatively higher miR-142-3p expression. These data suggest that PTPN23 is a tumor suppressor and that repression of PTPN23 expression by miR-142-3p plays an important role in the pathogenesis of TGCTs.

Successful treatment of acute respiratory distress syndrome after hysterectomy for life-threatening atonic bleeding by inhaled nitric oxide.

We report a case of a 33-year-old female who developed severe acute respiratory distress syndrome (ARDS) after emergency hysterectomy for life-threatening atonic bleeding. A marked decline in pulmonary oxygenation was observed during the surgery, which led to a diagnosis of ARDS. Following admission to the intensive care unit, hypoxia became critical, with a PaO(2)/F(I)O(2) value of 52 even after recruitment maneuvers. Inhaled nitric oxide (NO 10 ppm) was administered to the patient as a rescue treatment, resulting in a gradual but dramatic improvement in pulmonary oxygenation. Although several randomized trials have failed to confirm the beneficial effects of NO on morbidity in patients with ARDS, NO administration is worth consideration as treatment prior to invasive treatments, such as extracorporeal membrane oxygenation, for patients with acute lung injury/ARDS.

Disruption of CXC motif chemokine ligand-14 in mice ameliorates obesity-induced insulin resistance.

In obese individuals, white adipose tissue (WAT) is infiltrated by large numbers of macrophages, resulting in enhanced inflammatory responses that contribute to insulin resistance. Here we show that expression of the CXC motif chemokine ligand-14 (CXCL14), which targets tissue macrophages, is elevated in WAT of obese mice fed a high fat diet (HFD) compared with lean mice fed a regular diet. We found that HFD-fed CXCL14-deficient mice have impaired WAT macrophage mobilization and improved insulin responsiveness. Insulin-stimulated phosphorylation of Akt kinase in skeletal muscle was severely attenuated in HFD-fed CXCL14+/- mice but not in HFD-fed CXCL14-/- mice. The insulin-sensitive phenotype of CXCL14-/- mice after HFD feeding was prominent in female mice but not in male mice. HFD-fed CXCL14-/- mice were protected from hyperglycemia, hyperinsulinemia, and hypoadiponectinemia and did not exhibit increased levels of circulating retinol-binding protein-4 and increased expression of interleukin-6 in WAT. Transgenic overexpression of CXCL14 in skeletal muscle restored obesity-induced insulin resistance in CXCL14-/- mice. CXCL14 attenuated insulin-stimulated glucose uptake in cultured myocytes and to a lesser extent in cultured adipocytes. These results demonstrate that CXCL14 is a critical chemoattractant of WAT macrophages and a novel regulator of glucose metabolism that functions mainly in skeletal muscle.

Variety of nucleotide sugar transporters with respect to the interaction with nucleoside mono- and diphosphates.

Nucleotide sugar transporters have long been assumed to be antiporters that exclusively use nucleoside monophosphates as antiport substrates. Here we present evidence indicating that two other types of nucleotide sugar transporters exist that differ in their antiport substrate specificity. Biochemical studies using microsomes derived from Saccharomyces cerevisiae cells expressing either human (h) UGTrel7 or the Drosophila (d) FRC (Fringe connection) transporter revealed that (i) efflux of preloaded UDP-glucuronic acid from the yeast microsomes expressing hUGTrel7 was strongly enhanced by UDP-GlcNAc added in the external medium, but not by UMP or UDP, suggesting that hUGTrel7 may be described as a UDP-sugar/UDP-sugar antiporter, and (ii) addition of UDP-sugars, UDP, or UMP in the external medium stimulated the efflux of preloaded UDP-GlcNAc from the yeast microsomes expressing dFRC to a comparable extent, suggesting that UDP, as well as UMP, may serve as an antiport substrate of dFRC. Antiport of UDP-sugars with these specific substrates was reproduced and definitively confirmed using proteoliposomes reconstituted from solubilized and purified transporters. Possible physiological implications of these observations are discussed.

Efficacy of landiolol in attenuating hemodynamic responses to local epinephrine infiltration in patients undergoing vaginal total hysterectomy.

PURPOSE: Local epinephrine infiltration often causes beta1-adrenoceptor-mediated tachycardia, hypertension, and arrhythmia. Landiolol, a short acting beta1-adrenoceptor blocker, may represent the most ideal agent to attenuate these adverse effects. In this study, we examined the effects of landiolol on the hemodynamic changes resulting from local infiltration of epinephrine. METHODS: Thirty-six patients undergoing vaginal total hysterectomy under general anesthesia were randomly assigned to one of three groups: control group (n = 12), L5 group (n = 12), and L10 group (n = 12). In the control, L5, and L10 groups, the patients were given saline, landiolol 5 mg, and 10 mg, respectively, just before infiltration of epinephrine(1 : 300,000; total dose, about 100 microg) into the surgical field. Blood pressure and heart rate was assessed before and 5, 10, 15, 20, 25, 30 min after the initiation of epinephrine infiltration. If systolic blood pressure and heart rate exceeded 160 mmHg and 120 beats.min(-1), respectively, Ca blockers of either diltiazem 5 mg or nicardipine 1 mg and/or 2% sevoflurane were given. RESULTS: Epinephrine infiltration significantly increased systolic blood pressure from 122 +/- 15 to 170 +/- 29 mmHg and heart rate from 63 +/- 8 to 106 +/- 10 beats.min(-1). In both the L5 and L10 groups, the increase in heart rate (from 69 +/- 16 to 87 +/- 16 beats.min(-1), P < 0.01, and from 70 +/- 18 to 76 +/- 9 beats.min(-1), P < 0.01, respectively) was significantly smaller compared to the control group, but the increase in systolic blood pressure was significantly attenuated in the L10 group (from 116 +/- 18 to 140 +/- 27 mmHg, P < 0.01). The number of patients given either Ca blockers or sevoflurane in the control group was significantly higher than that in the landiolol groups (P < 0.01). CONCLUSION: The present study suggests that landiolol 10 mg may be a more suitable dose than landiolol 5 mg to antagonize hyperdynamic states induced by local administration of epinephrine.

[A clinical study of total intravenous anesthesia by using mainly propofol, fentanyl and ketamine--with special reference to its safety based on 26,079 cases].

During a period of five years from January 1996 through December 2000 total intravenous anesthesia with mainly propofol, fentanyl and ketamine was administered to 26,079 patients including cardiac and neurosurgical patients at the University of Hirosaki Hospital and five other affiliated hospitals. The patients studied ranged from 1 year 8 months to 93 years in age, 9.2 kg to 135.0 kg in body weight and from 18 min to 22 hours 50 min in anesthetic time. With adequate monitoring, fentanyl 1-2 micrograms.kg-1 was given at first, then total-dose of ketamine 1 mg.kg-1 and propofol 1-2 mg.kg-1 were administered for the induction of anesthesia in adult patients. A total dose of fentanyl 3-15 micrograms.kg-1 was given combined with propofol 5-10 mg.kg-1 and ketamine 0.3-1.0 mg.kg.h-1. In craniotomy patients, ketamine was excluded. For pediatric patients, sevoflurane anesthesia was employed to establish i.v. route, and intravenous agents were given almost same as in the same manner as in adult patients. None of them developed either cardiac arrest or severe cardiovascular insufficiencies due to anesthesia alone. Their postoperative hepatic and renal functions evaluated by various biochemical indices and urine output were adequately maintained during anesthesia and for a week postoperatively. They were followed up to 3 months postoperatively only to fail to detect any adverse events related directly to this method of anesthesia. These data suggest that total intravenous anesthesia with propofol, fentanyl and ketamine has a very wide margin of safety.

[Does a high inspired oxygen concentration consistently play a key role in developing combustion in the airway during fiberoptic bronchoscopy guided laser treatment?--A case of firing in the airway under total intravenous anesthesia].

We experienced combustion of a fiberoptic bronchoscope and an endotracheal tube, as well as tracheo-bronchial burn during a diode laser treatment in a hypoxemic patient requiring continuous oxygen administration. Total intravenous anesthesia and a high concentration of inspired oxygen (FIO2 0.60) were used for the procedure. The complication occurred abruptly at the beginning of the second treatment after the first uneventful 15 min treatment. Several reports suggest that laser treatment can be performed even under FIO2 1.0 without firing in the airway, and a high FIO2 itself would not consistently play a key role in developing combustion in the airway, even though combustion is more vigorous when a higher FIO2 is used. Based on our experience and reports of firing in the airway during laser treatment, the following recommendations are presented. The laser treatment should be done (1) at the FIO2 just enough to maintain adequate oxygenation in each individual patient, (2) at the greatest possible distance between a bronchoscope and an endotracheal tube, and (3) after removing small pieces of carbonized tissues produced by each laser treatment.

Effect of phenylephrine on histamine-induced bronchoconstriction in dogs.

PURPOSE: Although an α-adrenoceptor has been suggested to be involved in the mechanism of asthma, the effect of α1-agonist on the airway is still unclear. In this study we evaluated the effect of phenylephrine on the airway with a direct visualization method using a superfine fiberoptic bronchoscope (SFB). METHODS: Seven mongrel dogs were anesthetized with pentobarbital (30 mg·kg-1 IV) and paralyzed by pancuronium (0.2mg·kg-1·h-1). The trachea was intubated with an endotracheal tube (ID 7 mm) that has a second lumen for insertion of a SFB (OD 2.2 mm) to monitor the bronchial cross-sectional area (BCA) continuously. The tip of a SFB was placed at the level between the second and third bronchial bifurcation. To assess hemodynamics, the direct arterial blood pressure (ABP) and pulmonary arterial pressure (PAP) were monitored via a femoral arterial catheter and Swan-Granz catheter. Bronchoconstriction was elicited by histamine (10 µg·kg-1+ 500 µg·kg-1·h-1_. At 30 min after the histamine was started, saline or phenylephrine (1, 10, and 100µg·kg-1) was given intravenously. The BCA and hemodynamic variables were assessed before (basal) and 30 min after the histamine was started and 5 min after saline and each phenylephrine dose. RESULTS: Histamine reduced BCA by 40.3±6.3%. Phenylephrine at 10 and 100 µg·kg-1 significantly increased the ABP and PAP; and it significantly decreased the BCA, by 6.5±6.9% and 14.2±7.9%, respectively. Plasma epinephrine and norepinephrine were also significantly reduced following phenylephrine 100 µg·kg-1 IV. CONCLUSION: The dose of phenylephrine that produced vasopressive actions worsened the histamine-induced bronchoconstriction slightly but significantly. Therefore, phenylephrine should be used with caution in asthmatic patients.