Development and external validation of a nomogram for overall survival after curative resection in serosa-negative, locally advanced gastric cancer.

BACKGROUND: Few nomograms can predict overall survival (OS) after curative resection of advanced gastric cancer (AGC), and these nomograms were developed using data from only a few large centers over a long time period. The aim of this study was to develop and externally validate an elaborative nomogram that predicts 5-year OS after curative resection for serosa-negative, locally AGC using a large amount of data from multiple centers in Japan over a short time period (2001-2003). PATIENTS AND METHODS: Of 39 859 patients who underwent surgery for gastric cancer between 2001 and 2003 at multiple centers in Japan, we retrospectively analyzed 5196 patients with serosa-negative AGC who underwent Resection A according to the 13th Japanese Classification of Gastric Carcinoma. The data of 3085 patients who underwent surgery from 2001 to 2002 were used as a training set for the construction of a nomogram and Web software. The data of 2111 patients who underwent surgery in 2003 were used as an external validation set. RESULTS: Age at operation, gender, tumor size and location, macroscopic type, histological type, depth of invasion, number of positive and examined lymph nodes, and lymphovascular invasion, but not the extent of lymphadenectomy, were associated with OS. Discrimination of the developed nomogram was superior to that of the TNM classification (concordance indices of 0.68 versus 0.61; P < 0.001). Moreover, calibration was accurate. CONCLUSIONS: We have developed and externally validated an elaborative nomogram that predicts the 5-year OS of postoperative serosa-negative AGC. This nomogram would be helpful in the assessment of individual risks and in the consideration of additional therapy in clinical practice, and we have created freely available Web software to more easily and quickly predict OS and to draw a survival curve for these purposes.

Analysis of DNA endoreplication in the brain neurons in the terrestrial slug, Limax valentianus.

DNA endoreplication is the DNA synthesis without cell division, resulting in the generation of a nucleus containing a larger amount of genomic DNA compared to a normal diploid genome. There are many such giant neurons in the molluscan brain that are generated as a result of repeated endoreplication. However, it has been controversial whether the endoreplication is the whole genome replication (polyploidy) or the local amplification of the genes that are necessary for the neuron's function (polyteny/polysomy). Here in this study, we investigated these two possibilities by (1) immunohistochemical analysis of the distribution of 5'-bromodeoxyuridine incorporated into the nuclei of the brain neurons, and by (2) quantitative genomic PCR directed to two different genes expressed in specific brain regions. Our data supported the view that the DNA endoreplication is the whole genome replication rather than the local amplification of a specific genomic region.

Recovery of learning ability after the ablation of the procerebrum in the terrestrial slug, Limax valentianus.

The procerebrum (PC) is indispensable for odor-aversion learning in Limax. On the other hand, the central nervous system (CNS) of some Pulmonata shows robustness against injury, recovering from nerve injury both at the histological and functional levels. To investigate whether the PC of Limax also shows robustness against nerve injury, we tested whether or not the slugs can acquire and retrieve odor-aversion memory after a long recovery period from PC ablation. When the recovery period is short (7 days), the PC-ablated slugs failed to avoid the conditioned odor. But when the recovery period is long (1 month), the PC-ablated slugs successfully avoided the conditioned odor. These results indicate that the CNS including the PC can recover from injury at least at the functional level.

Isotopic dependence of the giant monopole resonance in the even-A 112-124Sn isotopes and the asymmetry term in nuclear incompressibility.

The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV alpha particles in the angular range 0 degrees -8.5 degrees . We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208Pb and 90Zr very well. From the GMR data, a value of Ktau = -550 +/- 100 MeV is obtained for the asymmetry term in the nuclear incompressibility.

Salivary secretion, taste and hyposalivation.

Saliva has many essential functions. As the first digestive fluid in the alimentary canal, saliva is secreted in response to food, assisting intake and initiating the digestion of starch and lipids. During this process, saliva acts as a solvent of taste substances and affects taste sensitivity. Clinically, a more important role is in the maintenance of oral health, including the protection of teeth and mucosa from infections, maintenance of the milieu of taste receptors, and communication ability through speech. Variations in salivary flow can be affected, reversibly or irreversibly, by numerous physiological and pathological factors. Decreased salivary flow results in clinically significant oral discomfort that may manifest as increased caries, susceptibility to oral candidiasis, altered taste sensation or as a host of other problems. Hyposalivation is a condition that is frequently encountered in dental practice. The most common cause is the use of certain systemic medications, which put the elderly at greater risk because they are usually more medicated. Other causes include high doses of radiation and certain diseases such as Sjögren's syndrome. This article reviews the mechanism of salivary secretion, effect of saliva on taste, importance of saliva in oral health, and hyposalivation in relation to ageing, medicine and/or disease and management of hyposalivation.

Activation of presynaptic 5-HT3 receptors facilitates glutamatergic synaptic inputs to area postrema neurons in rat brain slices.

Whole-cell voltage-clamp recordings were performed to investigate the serotonergic modulation of neurotransmitter release onto rat area postrema neurons in vitro. The bath application of serotonin (5-HT; 50 microM) or phenylbiguanide (PBA; 50 microM), a potent 5-HT3 receptor agonist, increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) or miniature EPSCs (mEPSCs) in 35 of 83 neurons (42%). These increases occurred in all electrophysiological cell classes. No cells exhibited a decrease in EPSC frequency. The majority of responding cells showed no inward currents during the application of serotonergic agonists (n = 34/35). However, the amplitude of mEPSCs was increased in 11/11 cells with 5-HT or 3/11 cells with PBA. ICS-205,930, a potent 5-HT3 receptor antagonist, markedly suppressed the 5-HT-induced facilitation of sEPSCs (n = 5) or mEPSCs (n = 5). An increase in the frequency of mEPSCs after PBA exposure was found, even with media containing Cd2+ (50 microM) or zero Ca2+. mEPSCs and evoked EPSCs were completely blocked in media containing the non-NMDA ionotropic receptor antagonist, CNQX (10 microM), indicating that EPSCs were glutamate events. These results suggest that glutamate release is increased in the area postrema by presynaptic 5-HT3 receptor activation. Furthermore, we present evidence that 5-HT3 receptor activation may be able to directly release glutamate from terminals, bypassing a requirement for voltage-dependent calcium entry into terminals. Such a mechanism may contribute to the chemosensitive function of area postrema neurons.

Evidence for insulating behavior in the electric conduction of (NH(3))K(3)C(60) systems.

Microwave study using the cavity perturbation technique revealed that the conductivity of the antiferromagnet (NH(3))K(3-x)Rb(x)C(60) at 200 K is already 3-4 orders of magnitude smaller than those of superconductors, K(3)C(60) and (NH(3))(x)NaRb(2)C(60), and that the antiferromagnetic compounds are insulators below 250 K without metal-insulator transitions. The striking difference in the magnitude of the conductivity between these materials strongly suggests that the Mott-Hubbard transition in the ammoniated alkali fullerides is driven by a reduction of lattice symmetry from face-centered-cubic to face-centered-orthorhombic, rather than by the magnetic ordering.

LIRF, a gene induced during hippocampal long-term potentiation as an immediate-early gene, encodes a novel RING finger protein.

We describe here an LTP-induced gene, LIRF, which encodes a novel protein with RING finger and B30.2 domains in its N- and C-terminal portions, respectively. Each domain is encoded by one exon, suggesting that the organization of the gene was generated by exon shuffling. The amino acid sequences of the mouse, rat, and human LIRF proteins are highly conserved and contain a putative PEST sequence. LIRF is an immediate-early gene in hippocampal granule cells, and its expression is upregulated immediately after the induction of long-lasting long-term potentiation at perforant pathway-dentate gyrus synapses and returns to the basal level within 150 min. A heterologously expressed LIRF protein fused to EGFP localizes specifically to the cytoplasm in COS-7 cells. These findings suggest a possible involvement of LIRF in a limited, early phase of synaptic plasticity.

Propofol suppresses a hyperpolarization-activated inward current in rat hippocampal CA1 neurons.

We examined the effect of propofol and thiopental, intravenous anesthetics, on the hyperpolarization-activated inward current (I(H)), whose functional role on the neuronal activity has been evaluated. Whole-cell recordings of I(H) evoked by hyperpolarizing step pulses were taken from hippocampal CA1 neurons in rat brain slices. Propofol reduced I(H) current in a dose-dependent manner. However, thiopental had no significant effect on the activation of I(H). According to the functional role of I(H), the suppression of I(H) should result in a reduction of neuronal activity. We suggest that the effectiveness of propofol as an anticonvulsant or an antiemetic is associated with the blockade of the I(H) channel.

Regulated expression of an actin-associated protein, synaptopodin, during long-term potentiation.

We report NMDA receptor-dependent expression of synaptopodin mRNA in the dentate granule cells of the hippocampus following induction of long-term potentiation (LTP) in vivo. Synaptopodin did not belong to immediate-early genes, as de novo protein synthesis was required for the induction of synaptopodin gene transcription. An increased level of synaptopodin mRNA was observed at 75 min and 3.5 h after the onset of LTP. Importantly, there was correlation between the induction of mRNA expression and the persistence of LTP. Synaptopodin immunoreactivity was elevated specifically in synaptic layers, middle and outer molecular layers of dentate gyrus where LTP was induced. As synaptopodin is an actin-associated protein present in spine neck and implicated in the modulation of cell morphology, our results suggest that synaptopodin, by regulating the dynamics of the actin cytoskeleton, contributes to the morphological change in spine shape considered to be important for the maintenance of synaptic plasticity.

Role of parabrachial nucleus in submandibular salivary secretion induced by bitter taste stimulation in rats.

When rats lick a bitter taste solution such as quinine-hydrochloride, they secrete profuse amounts of saliva. The salivation has a higher flow rate than that induced by other qualities of taste stimulation: sweet, salty, and sour. The present study is aimed to clarify the neural mechanism of the quinine-evoked salivation by means of behavioral, neuroanatomical, and electrophysiological experiments. Behaviorally, submandibular salivary secretion and rejection behavior (gaping) were observed in normal rats, as well as in rats chronically decerebrated at the precollicular level. In chronically decerebrate rats, these quinine-evoked reactions were strongly suppressed by destruction of the medial part of the parabrachial nucleus, including the so-called taste area, and ventral part of the parabrachial nucleus, including the pontine reticular formation. Neuroanatomical study using a retrograde tracer, Fluoro-gold, revealed that the neurons sending their axons to the superior salivatory nucleus, parasympathetic secretory center, were located mainly in the pontine reticular formation ventral to the parabrachial nucleus, not in the parabrachial taste area. Extracellular neural activity was recorded from the parabrachial region in decerebrate rats, and responsiveness to taste stimulation, jaw movements, and electrical stimulation of the superior salivatory nucleus was examined. Neurons responsive to both taste stimulation and antidromic stimulation of the superior salivatory nucleus were found in the pontine reticular formation ventral to the parabrachial nucleus, which responded well to quinine and HCl taste stimuli. Neurons in the parabrachial taste area could respond to four qualities of taste stimulation, but not to antidromic stimulation of the salivary center. These results suggest that aversive taste information from the parabrachial taste area reaches the salivary secretory center via the reticular formation ventral to the parabrachial nucleus.

Intravenous anesthetics inhibit nonadrenergic noncholinergic lower esophageal sphincter relaxation via nitric oxide-cyclic guanosine monophosphate pathway modulation in rabbits.

BACKGROUND: Nonadrenergic noncholinergic (NANC) nerves have important roles in the regulation of the lower esophageal sphincter (LES) motility and function. The effects of thiopental, ketamine, and midazolam on NANC LES relaxation were investigated. METHODS: The isometric tension of circular muscle strips from Japanese White rabbits was examined. The NANC relaxation was induced by KCl (30 mM) in the presence of atropine (3 x 10(-6) M) and guanethidine (3 x 10(-6) M). The modifications of the NANC and sodium nitroprusside (SNP; 10(-5) M)-induced relaxation by the anesthetics were examined. The content of 3',5'-cyclic guanosine monophosphate (cGMP) was measured by radioimmunoassay. RESULTS: The KCl-induced relaxation was abolished by pretreating with tetrodotoxin (10(-6) M). The NANC relaxation was inhibited in the presence of N(G)-nitro-L-arginine (L-NNA; 3 x 10(-5) M), methylene blue (10(-6) M), apamin (10(-7) M), and glibenclamide (10(-5) M). The SNP-induced relaxation was inhibited by methylene blue but was not affected by tetrodotoxin, L-NNA, apamin, or glibenclamide. Ketamine (EC50 = 8.8 x 10(-5) M) and midazolam (EC50 = 4.8 x 10(-6) M) suppressed the NANC response in a concentration-dependent manner, leaving SNP-induced response unchanged. Thiopental altered neither of the relaxations. cGMP content was decreased in the presence of ketamine and midazolam. CONCLUSION: The NANC relaxation was mediated by nitric oxide and by low-conductance calcium- and adenosine triphosphate-sensitive potassium channels of smooth muscle. The modulation of the nitric oxide-cGMP pathway was related, at least in part, to the inhibitory actions of ketamine and midazolam on the NANC LES relaxation.

Neuronal activity in the putamen and the globus pallidus of rabbit during mastication.

The pattern of jaw movements is changed during a masticatory sequence from ingestion of food to its deglutition. The masticatory sequence is divided into three distinct stages in the rabbit. However, the neural mechanism involved in the alteration of the masticatory stages is still unknown. This study was designed to determine whether neuronal activity in the putamen and globus pallidus is related to the alteration of the masticatory stages. Fifty-three percent of the recorded neurons showed significant alterations of activity during mastication. Of these neurons, 16% changed their firing frequency throughout the masticatory sequence (sequence-related neurons) and 84% changed their firing frequency with the transition of the masticatory stages (stage-related neurons). The stage-related neurons were classified into two groups based on their neuronal activity patterns observed during mastication, i.e. simple type and complex type. The former are the neurons that were either facilitated or inhibited once during mastication, and the latter are those showing the facilitation or inhibition twice or more during mastication. Complex-type neurons were observed more frequently in the globus pallidus than in the putamen. These results suggest that the basal ganglia is involved in mastication and may related to the transition between the masticatory stages.

A new expression cloning strategy for isolation of substrate-specific kinases by using phosphorylation site-specific antibody.

Signal transduction from cell surface receptors to the nucleus is regulated in most part by protein phosphorylation. For the purpose of identification of kinases which play an important role at a particular phosphorylation step in a series of signal transduction pathways, we have developed a new expression-screening method using a phosphorylation site specific antibody and a vector encoding substrate polypeptide. We have applied this method for screening kinases which phosphorylate STAT3 at serine(727). In this screening, antibody (PS727 antibody) specifically recognizing STAT3 in which serine(727) is phosphorylated was first prepared. Escherichia coli, bacteria expressing a serine(727)-containing fragment of STAT3 which was fused to glutathione-S-transferase (GST) (GST-STAT3-WT) were infected by lambda phage cDNA expression libraries. Phosphorylation of GST-STAT3-WT was effectively performed in E. coli as expected, and clones positive for PS727 antibody immunoreactivity were selected. Isolated 53 clones encode four serine/threonine kinases; extracellular signal regulated kinase 1 (ERK1/p44-MAPK), dual specificity Yak1 related kinase (DYRK), dual specificity Yak1 related kinase 2 (DYRK2) and homeodomain interacting protein kinase 2 (HIPK2). These kinases have a potential to phosphorylate serine(727) in STAT3 protein also in mammalian cells. The present method is considered to be applicable in general to isolate kinases.

Spontaneous regression of hepatocellular carcinoma--a case report.

We report a 72-year-old man with hepatocellular carcinoma, which showed spontaneous regression. He was diagnosed as having chronic hepatitis type C five years before admission. In January 1998, a liver mass was found by ultrasonography. In February, computed tomography showed a low-density mass, 3.5 cm in diameter in the S5 region. Although liver biopsy was not performed, findings obtained by computed tomography and ultrasonography indicated that the tumor was hepatocellular carcinoma. The levels of alpha-fetoprotein and PIVKA (protein induced by vitamin K antagonist)-II were increased to 1000 ng/mL and 2000 mAU/mL, respectively. The patient was admitted to our hospital in March 1998. At the time, the size of liver mass was reduced to 2.5 cm in diameter on computed tomography, and the tumor markers, alpha-fetoprotein and PIVKA-II, spontaneously decreased to the normal range. We considered that hepatocellular carcinoma of this patient regressed spontaneously. Because it was hard to exclude the possibility that the mass contained residual malignant cells, we resected the mass on April 28, 1998. Microscopically, the resected mass did not contain any malignant cells. The parenchyma surrounding tumor necrosis, which is reflected by severe inflammatory infiltration with lymphocytes, indicates spontaneous regression. Although the precise mechanism regarding spontaneous regression of hepatocellular carcinoma is not fully understood, either ischemia due to rapid growth of the tumor or some inflammatory mechanism may be involved in regression of hepatocellular carcinoma.

Development of a new heating needle for interstitial hyperthermia compatible with interstitial radiotherapy.

PURPOSE: We have developed a new heating needle for interstitial hyperthermia compatible with brachytherapy. We studied the heating characteristics of interstitial needles and the usefulness of these needles for interstitial hyperthermia. MATERIALS AND METHODS: As heating needles, we used MicroSelectron HDR interstitial needles. These needles were only heated at the metal tip, and were insulated in the middle and grounded from the top. The hyperthermia system was based on the principles of RF capacitive heating, and we used a Thermotron RF-8. We examined whether the temperature and the heating area could be elevated to a level required for hyperthermia. RESULT: Good heating was obtained around the metal tip of the needle. The heating area of the longitudinal axis of the needle varied with the length of the metal part, while the transverse heating area of the needle was almost unchanged. If heating was performed while maintaining the elevation of temperature in each needle at the same level using variable coils (tuning box), heating was homogeneous over the regions in accordance with the arrangement of the needles. CONCLUSION: With this heating system, the temperature rises easily, and a uniform temperature distribution can be obtained.

Propagation of synchronous burst discharges from entorhinal cortex to morphologically and electrophysiologically identified neurons of rat lateral amygdala.

Intracellular and field potential recordings were taken from the lateral nucleus of the amygdala in a rat horizontal brain slice preparation that included hippocampal formation. Pyramidal cells comprised the majority of labeled cells (77%). Electrophysiological classification based on hyperpolarizing or depolarizing afterpotentials subdivided both the pyramidal and non-pyramidal cell classes, although pyramidal cells tended to have hyperpolarizing afterpotentials (70%) and non-pyramidal cells tended to have depolarizing afterpotentials (63%). Synchronous population bursts were triggered with single extracellular stimuli in the deep layers of entorhinal cortex. These events propagated from deep layers of entorhinal cortex into the lateral nucleus of the amygdala. Latencies were consistent with a direct entorhinal to amygdala projection. Individual lateral nucleus neurons exhibited responses ranging from a long burst response that included an initial period of 200 Hz firing and a tail of gamma frequency firing lasting over 100 ms (grade 1) to an epsp with no firing (grade 4). Half of pyramidal cells responding to events initiated in entorhinal cortex were found to receive epsps strong enough to trigger firing. Only one stellate neuron fired in response to entorhinal stimulation. Excitatory postsynaptic responses included NMDA and non-NMDA receptor mediated components. We demonstrate that synchronous population events can propagate from entorhinal cortex to the lateral nucleus of the amygdala and that pyramidal neurons of the lateral nucleus are more common targets than stellate neurons. We conclude that other synchronous events such as sharp waves and interictal spikes can spread from entorhinal cortex to amygdala in the same manner.

Water stimulation of the posterior oral cavity induces inhibition of gastric motility.

The response of gastric motility to the administration of water and saline in the larynx and epiglottis was investigated in urethan-chloralose anesthetized rats. Administration of water inhibited motility of the distal stomach, but 0.15 M NaCl did not induce the inhibitory response. Bilateral sectioning of the superior laryngeal nerve (SLN) abolished the inhibitory response induced by water. Bilateral cervical vagotomies abolished the inhibitory responses, although spinal transection did not affect the inhibitory response. These inhibitory responses have been observed in immobilized animals. The degree of inhibition by water and hypotonic saline was negatively correlated with the sodium concentration. In contrast, the degree of inhibition to hypertonic saline was positively correlated with the sodium concentration. The proximal stomach also showed a reduction in intragastric pressure in response to the administration of water. These findings suggest that water-responsive afferent neurons in the SLN suppress gastric motility via the vagal efferent nerve.

Isolated dissection of the celiac artery--a case report.

Isolated arterial dissection, which occurs with the absence of aortic dissection, has been reported in carotid and renal arteries but rarely in visceral arteries. A case of isolated celiac artery dissection is reported here. A healthy 58-year-old man experienced sudden upper abdominal pain, which continued for several days. A body computed tomogram (CT) showed a multiple low-density wedge-shaped area in the spleen, which was diagnosed as splenic infarction, and an aneurysm with thrombus in the celiac artery. A selective angiogram showed dilatation of the celiac artery with wall irregularity, and proximal occlusion of the hepatic artery. The distal hepatic artery was fed by collateral arteries from the superior mesenteric artery. Splenic infarction was probably due to the embolism from the thrombus in the dissected celiac artery. The absence of other vascular lesions and causes or risks for the arterial dissection would suggest the occurrence of spontaneous dissection. The dissection of visceral arteries should be considered in diagnosing acute abdominal pain.

Reflex secretion of proteins into submandibular saliva in conscious rats, before and after preganglionic sympathectomy.

1. An indwelling catheter was placed in the left submandibular duct of rats, under pentobarbitone anaesthesia, and connected to an outflow cannula that emerged above the skull. 2. Saliva was collected from the outflow cannula in conscious rats, the same day after recovery from anaesthesia, under four different reflex conditions: grooming, heat exposure, rejection of a bitter tasting substance and feeding on softened chow, repeated in different orders. 3. Saliva flow was greatest for grooming and least for rejection. Protein concentrations were least with heat but much greater and similar for the other stimulations. Acinar peroxidase activity was high for feeding, intermediate for grooming and rejection, and again lowest with heat. Tubular tissue kallikrein activities were moderately low, being greatest with feeding and least with grooming. Secretory immunoglobulin A (SIgA) concentration was least with heat and similar for the other stimulations. 4. The next day, under pentobarbitone anaesthesia, the left preganglionic sympathetic trunk was sectioned (sympathetic decentralization) and, after recovery, the preceding stimulations were repeated. Flow of saliva showed little change, but protein and peroxidase concentrations and outputs decreased dramatically with grooming, rejection and feeding to levels similar to those with heat, which showed little change. Tissue kallikrein was lowered less dramatically, but the reductions in output were significant except with heat. Patterns of proteins resolved by electrophoresis changed for grooming, rejection and feeding and became similar to saliva from heat, which showed little change. No significant effects on SIgA concentrations occurred. 5. Gland weights from the sympathetically decentralized side were greater than from the intact side at the end of the experiments and histologically showed retention of acinar mucin. 6. Thus reflex sympathetic drive varied with the different stimulations; it was least during heat, but it had pronounced effects on acinar secretion of proteins during the other stimulations. At the same time this sympathetic drive had less impact on tissue kallikrein secretion from tubules and had little influence on flow or the concentration of SIgA secreted.