Parietal projection of thalamocortical fibers from the ventroanterior-ventrolateral complex of the cat thalamus

Anterograde labelling following focal injections of Phaseolus vulgaris leucoagglutinin was used to identify the parietal distribution of thalamocortical (TC) fibers from the ventroanterior-ventrolateral (VA-VL) complex of the cat thalamus. In injections in the ventrolateral or the caudal part of the VA-VL complex, labelled TC fibers were distributed in layers I, III and IV of the parietal areas 5a and/or 5b, whereas in injections located more rostrally or dorsomedially, labelled TC fibers were almost confined to layer I.     

Cerebral oxygenation changes in response to post-hemodialysis standing

Journal of Artificial Organs - Few reports have examined the association between changes in cerebral oxygenation and clinical factors, including blood pressure (BP), upon standing after...     

Ghrelin regulates insulin release and glycemia: physiological role and therapeutic potential

Insulin release from pancreatic islet beta-cells is stimulated by glucose. Glucose-induced insulin release is potentiated or suppressed by hormones and neural substances. Ghrelin, a novel acylated 28-amino acid peptide isolated from stomach, is the endogenous ligand for the growth hormone (GH) secretagogue-receptor (GHS-R). Circulating ghrelin is produced predominantly in stomach. Ghrelin is a potent stimulator of GH release and feeding as well as exhibiting positive cardiovascular effects. In relation to the glucose metabolism, initial studies indicated that low plasma ghrelin levels are associated with elevated fasting insulin levels, insulin resistance, and obesity. It has recently been demonstrated that ghrelin suppresses glucose-induced insulin release via G alpha(i2) subtype of GTP-binding proteins and delayed outward K(+) (Kv) channels, representing a novel signaling mechanism, and that the ghrelin originating from islets regulates insulin release and thereby glycemia. Furthermore, elimination of ghrelin enhances insulin release to prevent or ameliorate glucose intolerance in high-fat diet fed mice and ob/ob mice. This review focuses on the physiological roles of ghrelin in regulating insulin release and glycemia, the insulinostatic mechanisms of ghrelin in islet beta-cells, and the potential of ghrelin-GHS-R system as the therapeutic target to treat type 2 diabetes.     

Impairment of the discrimination of the direction of single-whisker stimulation induced by the lemniscal pathway lesion

In the rodent somatosensory system, stimulus information received by the whiskers is relayed to the barrel cortex via two parallel pathways, the lemniscal pathway and the paralemniscal pathway. The lemniscal pathway includes the principal trigeminal nucleus (Pr5) and the ventral posteromedial thalamic nucleus (VPm). The paralemniscal pathway includes the spinal trigeminal subnucleus interpolaris (Sp5i) and the medial division of posterior thalamic nucleus (POm). The purpose of this study was to investigate the roles of those pathways in perceptions of the direction of the single-whisker stimulation in the rat. Rats were trained to perform a go/no-go task that required the discrimination of forward or backward stimulation applied to their single whisker. When a selective lesion was made in VPm or Pr5, error rate for the task performance increased significantly. In contrast, when a selective lesion was made in POm or Sp5i, we found no significant change in performance. These results suggest that the lemniscal pathway plays more important roles in a discrimination of stimulus direction applied to the single whisker.     

Successful remission using metyrapone in an elderly patient with Cushing disease accompanied by generalized edema

An 82-year-old woman was referred to our hospital because of hypoalbuminemia and generalized edema. Hypercortisolemia was subsequently found as the levels of serum cortisol and plasma adrenocorticotropic hormone (ACTH) sampled in a fasting morning were 140 pg/mL and 41.9 μg/dL, respectively. These hormones were not suppressed after taking low-dose dexamethasone the previous night and increased to a mild extent in response to administration of corticotrophin-releasing hormone, suggesting presence of pituitary adenoma producing ACTH (Cushing's disease). However, intrasella localization of pituitary adenoma could not be determined by magnetic resonance imaging. Soon after administration of metyrapone was started in an attempt to reduce her cortisol levels, the patient suffered from severe pneumonia. The pulmonary infection and peripheral edema were improved with decreases in cortisol levels by continuing metyrapone administration with antibiotics and finally she was discharged from the hospital on foot. Metyrapone is a useful therapeutic choice to achieve a remission of cortisol levels in the elderly patients with Cushing's disease in association with serious hypercortisolemia impending severe infection.     

Glucagon-like peptide-1 evokes action potentials and increases cytosolic Ca2+ in rat nodose ganglion neurons

We previously reported that the intraportal appearance of glucagon-like peptide-1 (GLP-1) facilitates the afferent activity (the spike discharge firing rate) of the rat hepatic vagus in a dose-dependent fashion. To examine whether GLP-1 directly activates single neurons isolated from the rat nodose ganglion, GLP-1-induced changes of the membrane potential and cytosolic-free Ca2+ concentration ([Ca2+]i) in the cells were measured using whole-cell patch-clamp and microfluorometric techniques, respectively. GLP-1 application (3 x 10(-12) - 3 x 10(-9) M) induced a gradual depolarization from a mean resting membrane potential of - 55.0 +/- 3.1 mV and evoked a burst of action potentials with a time lag of 7.5 +/- 4.5 min after its starting (n = 4). The burst of action potentials continued during the application and even up to 13 min or more after its cessation. GLP-1 at a concentration of 10(-12) - 10(-8) M induced an increase of [Ca2+]i. The GLP-1-induced [Ca2+]i responses were often oscillatory and lasted even up to 10 min or more after the washout of GLP-1. An adenylate cyclase activator, forskolin, mimicked the GLP-1-induced increase in [Ca2+]i. The present results indicate that GLP-1 activates nodose ganglion neurons as manifested by membrane depolarization, a burst of action potentials and [Ca2+]i increase, possibly via the cAMP pathway. Together with our previous observations, the results strongly suggest cellular mechanisms by which the postprandial humoral information, intraportal appearance of GLP-1, is uniquely converted to the neural information in the hepatoportal area.     

Clinical Application of Serum Pepsinogen I and II Levels for Mass Screening to Detect Gastric Cancer

A considerable number of gastric cancers derive from stomach mucosa where chronic atrophic gastritis is severe and extensive. Based on the fact that the serum pepsinogen levels provide a precise measure of the extent of chronic atrophic gastritis, we have devised a mass screening method involving serum pepsinogen measurement to identify subjects at high risk of gastric cancer. In 1991, we screened 4,647 workers (male: 4,113, female: 534, mean age: 49.0 years) at a Japanese company using this method. Out of 875 subjects (18.8%) with a serum pepsinogen I level of less than 50 μg/liter and a pepsinogen I/II ratio of less than 3.0, 676 subjects (14.5%) were selected for further investigation by endoscopy. This led to the detection of four subjects (0.086%) with gastric cancer (three in an early stage) and four subjects with adenoma. The cancer detection rate of this new screening method was comparable, and in some respects superior, to that of the traditional barium X-ray screening. Since the incidence of test-positive subjects was as low as 10% amongst subjects aged less than 40, this screening method appears to be especially useful for screening of younger generations. The new method is less expensive than the traditional barium X-ray and subjects experience little discomfort. Further, many serum samples can be quickly measured simultaneously. The results of this study have indicated that serum pepsinogen screening provides a valuable method for detecting gastric cancers.     

The Significance of Low Serum Pepsinogen Levels to Detect Stomach Cancer Associated with Extensive Chronic Gastritis in Japanese Subjects

Serum pepsinogen levels were measured in 137 stomach cancer patients and compared with those of 288 normal cancer-free subjects. The serum pepsinogen levels of stomach cancer patients, especially pepsinogen I and the pepsinogen I/pepsinogen II ratio were significantly lower than those of normal controls and correlated well with the extent of chronic gastritis associated with the cancerous stomach. These results were in good accordance with the results of previous studies indicating that the cancer derived from the stomach where chronic gastritis/intestinal metaplasia is extensive. The high sensitivity and specificity of this non-invasive serum test to detect chronic gastritis suggested the possibility of its application to the mass screening of stomach cancer.     

Reduction of radiation dose at HRCT of the temporal bone in children

PURPOSE: The purpose of this study was to reduce the radiation exposure of the eye lens in high resolution computed tomography (HRCT) of the temporal bone using an experimental phantom. MATERIALS AND METHODS: The HRCT image that was used for analysis was obtained by changing parameters including effective-mAs (E-mAs), distance coverage, and height of object in the Y-axis. Radiation exposure was measured to calculate equivalent doses by glass rod dosimeters that were fixed above the right orbit parallel to the body axis. Deterioration in image quality was evaluated by three radiologists and the following three-point rating method was employed: grade 1 (good image quality without diagnostic limitations), grade 2 (image was deteriorated, but there were no diagnostic limitations), and grade 3 (image was deteriorated with diagnostic limitations). RESULTS: Assuming that the equivalent dose was y (mSv), and E-mAs was x, a simple regression line, y=0.506x-0.494 (decision coefficient, R2=0.999), was obtained. A standard deviation (S.D.) less than 120 (E-mAs, 220-120) was judged as grade 1, an S.D. between 120 and 150 was judged as grade 2, and an S.D. higher than 150 was judged as grade 3, indicating that deterioration of the quality of images with reduced E-mAs affected the diagnosis by imaging at S.D. higher than 150. CONCLUSION: Radiation dose at the eye lens in HRCT could be reduced up to an equivalent dose corresponding to 70 mAs without compromising diagnostic quality in the phantom experiment.