Cricoid pressure impedes tracheal intubation with the Pentax-AWS Airwayscope®: a prospective randomized trial.

BACKGROUND: It is unclear how cricoid pressure affects tracheal intubation with the Pentax-AWS Airwayscope(®) (AWS). We conducted a prospective randomized clinical trial in anaesthetized patients. METHODS: Sixty patients were allocated to either the cricoid pressure (CP) group (n=30) or the sham group (n=30). We compared the two groups with regard to intubation time, number of attempts required for insertion of the Intlock blade (disposable blade of the AWS) and tracheal intubation, percentage of glottic opening (POGO) score, and subjective difficulty of both laryngoscopy and passage of a tube through the glottis. RESULTS: Intubation time was significantly longer in the CP group (median 45[IQR40-59] s) than in the sham group (32[28-45] s) (P=0.003, 95% CI for median difference 5-24 s). The number required for insertion of the Intlock blade did not differ between the groups (P=0.08), but the number for tracheal intubation was significantly higher in the CP group (1 attempt in 14 patients, 2 in 7, 3 in 9) than in the sham group (1 attempt in 24 patients, 2 in 6; P=0.002). POGO score did not differ significantly between the groups (P=0.60), nor did the subjective difficulty of laryngoscopy (P=0.06). The visual analogue scale score for passage of a tube through the glottis was significantly higher in the CP group than in the sham group (P<0.001). CONCLUSIONS: Cricoid pressure impedes tracheal intubation using the AWS, and is associated with longer intubation time, which can be attributed to increased difficulty in the passage of a tube through the glottis. CLINICAL TRIAL REGISTRY NUMBER: UMIN000018209.

Glass transition and stable glass formation of tetrachloromethane.

Physical vapor deposition (PVD) has been used to prepare organic glasses with very high kinetic stability and it has been suggested that molecular anisotropy is a prerequisite for stable glass formation. Here we use PVD to prepare glasses of tetrachloromethane, a simple organic molecule with a nearly isotropic molecular structure. In situ AC nanocalorimetry was used to characterize the vapor-deposited glasses. Glasses of high kinetic stability were produced by deposition near 0.8 Tg. The isothermal transformation of the vapor-deposited glasses into the supercooled liquid state gave further evidence that tetrachloromethane forms glasses with high kinetic stability, with the transformation time exceeding the structural relaxation time of the supercooled liquid by a factor of 10(3). The glass transition temperature of liquid-cooled tetrachloromethane is determined as Tg ≈ 78 K, which is different from previously reported values. The frequency dependence of the glass transition was also determined and the fragility was estimated as m ≈ 118. The successful formation of PVD glasses of tetrachloromethane which have high kinetic stability argues that molecular asymmetry is not a prerequisite for stable glass formation.

Expanding holes driven by convectionlike flow in vibrated dense suspensions.

Surface instabilities in vertically vibrated suspensions of various powders dispersed in silicone oil are investigated in quasi-two-dimensional (2D) and quasi-one-dimensional (1D) systems. As vibration acceleration exceeded a critical value, the flat surface became unstable against a finite-amplitude perturbation. We found an expanding hole or viscous fingerlike pattern in the quasi-2D system and segregation between dried and wet areas in the quasi-1D system. We show that these instabilities are accompanied by convectionlike flow at their rim and in the quasi-1D system, the height of the convectionlike flow can be scaled by acceleration, vibration frequency, diameter of the dispersed powder, mean density of the suspension, and viscosity of silicone oil. We propose a simple model that accounts for the scaling and concentric motion of the convectionlike flow.

Role of Ca2+ transporters and channels in the cardiac cell volume regulation.

Na+/K+ pump is one of key mechanisms to maintain cell volume. When it is inhibited, cells are at risk of swelling. However, in guinea pig ventricular myocytes, the cell area as an index of cell volume was almost constant during 90 min Na+/K+ pump blockade with 40 microM ouabain despite the marked membrane depolarization. In this study, involvements of Ca2+ transporters and channels in the cardiac cell volume regulation were proposed by conducting the computer simulation in parallel with the experimental validation.

Characterization of the 5' flanking region of the human NPT-1 Na+/phosphate cotransporter gene.

To elucidate the expression and regulation of the human type I Na+/phosphate transporter gene (NPT-1), the 5' flanking region of the NPT-1 gene was cloned, and its nucleotide sequence and function were determined. A genomic clone that contained approximately 14.0 kb of the 5'-flanking region of the NPT-1 gene was isolated. A single transcription start site was located 104 base pairs (bp) upstream of the 3' end of exon 1. In addition to the sequence of the 5'-flanking region contained a sequence weakly homologous to a TATA box at position -41 to -36 and many transcriptional regulatory elements. Transient expression revealed that a 45-bp region of proximal to exon 1, which contained TATA-like sequence, was sufficient for promoting luciferase expression in OK-cells derived from opossum kidney proximal tubule.

Involvement of Rho-kinase in inflammatory and neuropathic pain through phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS).

Myristoylated alanine-rich C-kinase substrate (MARCKS) is a major in vivo substrate for protein kinase C in the brain and has been implicated in cellular processes associated with cytoskeletal restructuring such as synaptic trafficking and neurotransmitter release. A phosphorylation-site specific antibody against Ser159-phospho-MARCKS (pS159-Mar-Ab) revealed that MARCKS is phosphorylated at Ser159 by Rho-kinase and that its phosphorylation is inhibited by the Rho-kinase specific inhibitor H-1152. Since the function of MARCKS is regulated by phosphorylation at multiple sites, here we examined the involvement of Rho-kinase in relation to phosphorylation of MARCKS at Ser159 in inflammatory and neuropathic pain by H-1152. When intrathecally administered 10 min before s.c. injection of formalin, H-1152 at 10 and 100 ng attenuated the second-phase, but not the first-phase, pain-like behaviors in the formalin test. Neuropathic pain induced by selective L5 spinal nerve transection was also relieved by intrathecal injection of H-1152. Nitric oxide synthase activity visualized by NADPH diaphorase histochemistry increased in the superficial layer of the spinal cord 30 min after formalin injection and 7 days after nerve transection, which were blocked by H-1152. Phosphorylation of MARCKS at Ser159 was detected in the spinal cord by pS159-Mar-Ab and the level of phosphorylation increased in the superficial layer after nerve transection. In contrast, immunoreactivities of neuronal nitric oxide synthase and MARCKS did not change significantly in the spinal cord before and after nerve transection. Taken together, the present study demonstrates that Rho-kinase is involved in inflammatory pain and the maintenance of neuropathic pain through phosphorylation of MARCKS at Ser159.

Structural organization of the human vitamin D receptor chromosomal gene and its promoter.

The vitamin D receptor (VDR) is known to mediate the pleiotropic biological actions of 1,25-dihydroxyvitamin D3 through its ability to modulate the expression of target genes. The regulation of this ligand-activated cellular transcription factor is reported to occur at both transcriptional and posttranslational levels. To begin to address the molecular basis by which the VDR gene is regulated transcriptionally, we report here an initial characterization of the human VDR gene and its promoter. We isolated several overlapping A-phage and cosmid clones that cover more than 100 kb of human DNA and contained the entire VDR gene. The gene is comprised of 11 exons that, together with intervening introns, span approximately 75 kb. The noncoding 5'-end of the gene includes exons 1A, 1B, and 1C. Eight additional exons (exons 2-9) encode the structural portion of the VDR gene product. While primer extension and S1 nuclease-mapping studies reveal several common transcriptional start sites, three unique mRNA species are produced as a result of the differential splicing of exons 1B and 1C. The DNA sequence lying upstream of exon 1A is GC rich and does not contain an apparent TATA box. Several potential binding sites for the transcription factor SP1 and other activators are evident. Fusion of DNA fragments containing putative promoter sequences upstream of the luciferase structural gene followed by transient transfection of these plasmids into several mammalian cell lines resulted in significant reporter activity. Due to the size and complexity of the 5'-end of the VDR gene, we examined the activity of a DNA fragment surrounding exon 1C. An intron fragment 3' of exon 1C conferred retinoic acid responsivity when fused to a reporter gene plasmid, suggesting a molecular mechanism for the previously observed ability of retinoic acid to induce the VDR. The recovery of the gene for the human VDR will enable further studies on the transcriptional regulation of this gene.

Molecular cloning and hormonal regulation of PiT-1, a sodium-dependent phosphate cotransporter from rat parathyroid glands.

The extracellular concentration of inorganic phosphate (Pi) is an important determinant of parathyroid cell function. The effects of Pi may be mediated through specific molecules in the parathyroid cell membrane, one candidate molecule for which would be a Na+-dependent Pi cotransporter. A complementary DNA encoding a Na+-Pi cotransporter, termed rat PiT-1, has now been isolated from rat parathyroid. The 2890-bp complementary DNA encodes a protein of 681 amino acids that shows sequence identities of 97% and 93% with the type III Na+-Pi cotransporters mouse PiT-1 and human PiT-1, respectively. Expression of rat PiT-1 in Xenopus oocytes revealed that it possesses Na+-dependent Pi cotransport activity. PiT-1 messenger RNA (mRNA) is widely distributed in rat tissues and is most abundant in brain, bone, and small intestine. The amount of PiT-1 mRNA in the parathyroid of vitamin D-deficient rats was reduced compared with that in normal animals and increased markedly after administration of 1,25-dihydroxyvitamin D3. Furthermore, the abundance of PiT-1 mRNA in the parathyroid was much greater in rats fed a low-Pi diet than in those fed a high-Pi diet. Thus, rat PiT-1 may contribute to the effects of Pi and vitamin D on parathyroid function.

Effects of silver ion on the calcium-induced calcium release channel in isolated sarcoplasmic reticulum.

Ag+-induced Ca2+ release in isolated sarcoplasmic reticulum (SR) was studied by the stopped flow method monitoring chlortetracycline fluorescence change. After improving the experimental procedure, the initial rate of Ca2+ release could be determined more precisely than before. Micromolar concentrations of Ag+ specifically enhanced Ca2+ efflux from heavy fraction of SR vesicles (HSR). This specific effect was referred to as Ag+-induced calcium release. The Ag+-induced Ca2+ efflux was activated by caffeine and ATP, but was inhibited by Mg2+ and procaine. Further, Ag+ enhanced the Ca2+-induced Ca2+ release over the whole range of Ca2+ concentrations, similarly to ATP. Parallel to Ca2+ efflux, Mg2+ efflux, measured by the same method, was also activated by Ag+. Choline permeability determined by the light scattering method was also activated by Ag+. The results suggest that Ag+ binds to the activation site of the Ca2+-induced Ca2+ release channel and opens the channel. The Ag+ binding site is different from the Ca2+ binding site but similar to the ATP binding site.

Acute regulation by dietary phosphate of the sodium-dependent phosphate transporter (NaP(i)-2) in rat kidney.

Alteration of the dietary intake of phosphate (P(i)) leads to rapid changes in renal P(i) transport activity. The present study, examined the underlying cellular mechanisms of the rapid regulation, with special reference to renal P(i) cotransporter. Rats were fed either a low-P(i) (0.02%) diet (CLP rats), the low-P(i) diet followed by a high-P(i) (1.2%) diet (AHP rats), or a normal (0.6%) diet (control rats). Na(+)-dependent P(i) transport activity in the brush border membrane was significantly increased in CLP rats compared with control rats, and this activity decreased rapidly within 2 h after the change of diet in AHP rats. Kinetic analysis of P(i) transport in the AHP rats indicated that the reduction was accompanied by a decrease in the apparent Vmax for Na(+)-dependent P(i) uptake. Northern blot analysis showed no difference in the abundance of NaP(i)-2 mRNA of the kidney between AHP and CLP rats. In contrast, Western blot analysis of renal brush border membrane proteins of AHP rats indicated a significant decrease in the abundance of NaP(i)-2 protein as compared with CLP rats. Immunoreactive signals for NaP(i)-2 were detected in lysosomal fractions of AHP and CLP rats. Immunohistochemical analysis showed that, NaP(i)-2 immunoreactivity in AHP rats was largely reduced in the apical membrane of the proximal tubular epithelial cells. Neither cycloheximide nor actinomycin D affected high-P(i)-induced reduction of NaP(i)-2 protein in the brush border membrane of AHP rats, indicating that de novo protein synthesis of an unidentified regulator protein was not involved in the mechanism of this reduction. In contrast, treatment with colchicine, which disrupts microtubulers, abolished the effect of high-P(i) diet on NaP(i)-2 expression. These results suggested that rapid endocytotic internalization of NaP(i)-2 may occur specifically in the brush border membrane following an acute increase in dietary P(i) intake.

Studies on papillary function and effect of prifinium bromide and other antispasmodics on motility of the papillary region (sphincter of Oddi) in humans.

We determined endoscopically the motility of the papillary region in humans, using a pressure sensor devised in our department. The subjects were 184 patients with various diseases. Prifinium bromide and four other antispasmodics were given to 60 of the 184 patients, and their effects were investigated. In 41 (85%) of the 48 patients with chronic gastritis, regular wave patterns were noted. In 35 (85%) of the 41 patients with diseases of the biliary tract and papillary region, in nine (82%) of the 11 patients with pancreatic diseases, and in six (67%) of the nine patients with liver diseases, irregular wave patterns were observed. It was postulated that a high incidence of papillary dysfunction accompanies biliary and pancreatic diseases. Additionally, it was concluded that prifinium bromide has as potent an effect on motility of the papillary region as does a massive dose (40 mg) of hyoscine N-butylbromide.

Immunohistochemical and RT-PCR detection of Na+-dependent inorganic phosphate cotransporter (NaPi-2) in rat brain.

Expression of a renal Na+-dependent inorganic phosphate (Pi) cotransporter (NaPi-2) was studied in rat forebrain with reverse transcription and polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-PCR analysis for total RNA from whole brain and sequencing of the PCR products showed expression of NaPi-2 mRNA in the brain. Immunohistochemical analysis revealed NaPi-2 staining in many nonpyramidal neurons of all six layers throughout neocortical areas and in neurons of proisocortical and periallocortical areas. NaPi-2-immunoreactive neurons were also detectable in the piriform cortex, hippocampal formation, caudate-putamen, amygdaloid nuclei and lateral geniculate nucleus. Furthermore, NaPi-2 staining was shown in ependymal cells and microvascular endothelial cells. The present results suggest that NaPi-2 is synthesized within the brain and involved in maintaining Pi homeostasis of certain neurons and/or the entire brain.

Developmental profiles of substance P and GABA contents in the substantia nigra of rat.

The developmental changes of concentrations of substance P and GABA in the substantia nigra at various postnatal ages of the rat were investigated. Both substance P and GABA were present in measurable amount at birth and continuously increased with age thereafter. When the two curves were compared, GABA seemed to develop slightly faster than substance P in the substantia nigra. Therefore, in contrast to previous reports, there was no discontinuously rapid increase in the concentrations of these transmitter candidates during normal postnatal development of the rat substantia nigra.

A novel Na+/Ca2+ channel blocker, NS-7, suppresses hypoxic injury in rat cerebrocortical slices.

The substance 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7) has been developed recently as a cerebroprotective compound with Na+ and Ca2+ channel blocking action. In the present study, the effect of NS-7 in an in vitro model of hypoxic injury was examined and the possible involvement of Na+ and Ca2+ channels in the hypoxic injury subsequently determined. When slices of rat cerebral cortex were exposed to hypoxia/glucose deprivation followed by reoxygenation and restoration of the glucose supply, marked leakage of lactate dehydrogenase (LDH) occurred 3-6 h after reoxygenation. This hypoxia/reoxygenation-induced injury was blocked almost completely by the removal of extracellular Ca2+ or by chelating intracellular Ca2+ with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl)ester (BAPTA/AM). In addition, combined treatment with the N-type Ca2+ channel blocker omega-conotoxin GVIA and the P/Q-type Ca2+ channel blocker omega-agatoxin IVA significantly reduced LDH leakage, although neither of these Ca2+ channel blockers alone, nor nimodipine, an L-type Ca2+ channel blocker, was effective. On the other hand, several Na+ channel blockers, including tetrodotoxin, local anaesthetics and antiepileptics, significantly reduced the hypoxic injury. NS-7 (3-30 microM) concentration-dependently inhibited LDH leakage caused by hypoxia/reoxygenation, but had no influence on the reduction of tissue ATP content and energy charge during hypoxia and glucose deprivation. It is suggested that blockade of Na+ and Ca2+ channels is implicated in the cerebroprotective action of NS-7.

A novel cognition enhancer NS-105 modulates adenylate cyclase activity through metabotropic glutamate receptors in primary neuronal culture.

The effect of (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105), a novel cognition enhancer, on adenylate cyclase activity was investigated in cultured neurons of the mouse cerebral cortex. NS-105 (10(-7) and 10(-6) M) inhibited forskolin-stimulated cyclic AMP formation, an action that was dependent on pertussis toxin-sensitive G proteins. Conversely, in pertussis toxin-pretreated neurons, NS-105 (10(-7)-10(-5) M) significantly enhanced the forskolin-stimulated cyclic AMP formation, and this action was completely reversed by cholera toxin. A metabotropic glutamate receptor agonist (1S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S, 3R-ACPD) produced similar bi-directional actions on the cyclic AMP formation. Both of these inhibitory and facilitatory actions of NS-105 and 1S, 3R-ACPD were blocked by L(+)-2-amino-3-phosphopropinoic acid (L-AP3). NS-105 (10(-6) M) and 1S, 3R-ACPD (10(-4) M) significantly enhanced isoproterenol- and adenosine-stimulated cyclic AMP formation. The enhancement of such Gs-coupled receptor agonists-stimulated cyclic AMP formation was also produced by quisqualate but not by L(+)-2-amino-4-phosphonobutanoate (L-AP4). The phosphoinositides hydrolysis was enhanced by 1S, 3R-ACPD (10(-4) M) but not by NS-105 (10(-6) M), however, 1S, 3R-ACPD-induced increase in phosphoinositides turnover was attenuated by NS-105. These findings suggest that NS-105 stimulates metabotropic glutamate receptor subclasses that are coupled both negatively and positively to adenylate cyclase, but it acts as an antagonist at the receptor subclasses that are linked to phosphoinositides hydrolysis.

Blockade of voltage-sensitive sodium channels by NS-7, a novel neuroprotective compound, in the rat brain.

The effects of 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7), a novel neuroprotective compound, on the voltage-sensitive sodium channels (VSSC) were examined in the rat brain and cardiac myocytes. NS-7 inhibited [3H]batrachotoxinin A 20 alpha-benzoate (BTX) binding (neurotoxin receptor site 2) in brain membranes with a Ki value of 1 microM, while the compound was less effective in the cardiac myocytes (Ki = 13 microM). Aconitine, on the other hand, inhibited [3H]BTX binding to brain membranes and cardiac myocytes with the same potency. In contrast. NS-7 had no affinity for [3H]saxitoxin binding in brain (neurotoxin receptor site 1). In superfused slices of the rat cerebral cortex, NS-7 inhibited the veratridine (5 microM)-evoked glutamate release in a concentration-dependent manner, the IC50 value of which was 7.7 microM, whereas the compound showed a weak and not significant suppression of KCl-evoked glutamate release. The tissue concentrations of NS-7 in the rat cerebral cortex and heart were 89 and 28 nmole/g tissue, respectively, 5 min after its intravenous injection (8 mg/kg). Furthermore, in the cerebral cortex, NS-7 distributed preferentially to the membrane-enriched synaptosomal fraction. Since neurotoxin receptor site 2 is located in the transmembrane region of the VSSC moiety, the channel function may be substantially inhibited by a peripheral administration of NS-7. These results suggest that the blockade of neurotoxin receptor site 2 of VSSC in the brain contributes to the neuroprotective action of NS-7.

Demonstration of a pancreatic fistula by endoscopic pancreatography in a patient with chronic pleural effusion.

A patient with massive pancreatic pleural effusion in whom the use of endoscopic retrograde cholangiopancreatography (ERCP) revealed the site of a pancreatic fistula to the pleural cavity is presented. It is suggested that with this form of pleural effusion, ERCP may aid in the selection of those patients whose lesions may be surgically correctable.

A case report of FSH-producing nasal ectopic pituitary adenoma extending to the frontal cranial fossa.

We report the first case of an ectopic pituitary adenoma in the nasal cavity that produced follicle-stimulating hormone (FSH). A 60-year-old man complaining of left nasal bleeding had a polypoid tumor in the left nasal cavity. Findings of computed tomographic scanning and magnetic resonance imaging showed that the tumor originated from the olfactory cleft, occupied the nasal cavity, and extended to the frontal cranial fossa. Results of histologic examination suggested ectopic pituitary adenoma. Magnetic resonance imaging results showed the pituitary gland to be normal. Electron microscopy findings demonstrated a large number of secretory granules in the tumor cells that were positive for FSH on immunohistochemical analyses. Serum gonadotropin levels were normal, and no clinical signs of hypersecretory syndrome were noted. The above findings led us to establish the diagnosis of FSH-producing ectopic pituitary adenoma. The patient underwent craniofacial resection of the tumor followed by an uneventful recovery. The pathologic findings and clinical course of the case were comparable to those of FSH-producing adenomas arising from the pituitary gland.

Evaluation of cholangeographic procedures in diagnosis of obstructive jaundice.

Endoscopic retrograde cholangiography, percutaneous transhepatic cholangiography with external bile drainage and a combined method utilizing both procedures were evaluated in 187 patients with obstructive jaundice. Ductal obstructive regions were located in 90 per cent of cases by endoscopic retrograde cholangiography, and 55 per cent of these were correctly diagnosed. Complications were observed in 7.9 per cent with a mortality rate of 2.9 per cent. The most serious complication was cholangitic sepsis. By percutaneous transhepatic cholangiography with external bile drainage, ductal obstructive regions were correctly located in 82 per cent, 37 per cent of these patients were correctly diagnosed. Complications occurred in 9.2 per cent with a mortality rate of 1.5 per cent. The most serious complication was massive bleeding. Successful external bile drainage could be obtained in most cases. The combined method overcomes the disadvantages of the single methods and the cause of obstructive jaundice can be diagnosed more precisely. The surgeon has a better knowledge of the type and the extent of the lesion prior to definitive surgery and can operate more safely on patients with obstructive jaundiced when the serum total bilirubin, has decreased to a level below 5 mg/dl.

An autopsy case of a charred body which committed suicide after arson.

A severely burned body was found lying on its right side at the scene of the fire in a 2-story wooden apartment house. The presence of a ligature (an electrical cord) running horizontally around the neck aroused suspicion of arson after homicidal strangulation (murder-arson). The entire body was severely burned and partly charred. The head and neck were severely charred, and the left temporal bone had been consumed exposing the brain. Around the neck was looped an electrical cord, which ran horizontally and canted downward toward the nape, leaving a furrow resulting from the knot being tightened up. No other injuries or pathologic lesions suggestive of the cause of death were noted. No drug, poison or alcohol was detectable in the blood or urine. The peculiar method of making a noose of the ligature around the neck is called clove hitch, which makes the noose tighten further with increased load. The fallen curtain rod had a bend with an acute angle, which was considered to have been the point of suspension in hanging. In addition, a lighter was found under the corpse, which was presumably used to ignite the gasoline that the deceased sprinkled. We speculate, therefore, that the deceased hanged himself by placing the electrical cord around his neck (by clove hitch), suspending it from the curtain rod, sprinkling gasoline in his room, igniting it with a lighter, executing suicidal hanging after the start of the fire. Probably the body was wrapped in flames while dangling, then fell to the floor together with the collapsing curtain rod.