Long-term cortical plasticity evoked by electric stimulation and acetylcholine applied to the auditory cortex

Auditory fear conditioning with tone bursts followed by electric leg stimulation activates neurons not only in the auditory and somatosensory systems but also in many other regions of the brain and elicits shifts in the best frequencies (BFs) of collicular and cortical neurons, i.e., reorganization of the frequency (co-chleotopic) maps in the inferior colliculus and auditory cortex (AC). What are the neural elements minimally necessary for evoking long-term cortical BF shifts? We found that: (i) both electric stimulation and acetylcholine applied to the AC evoke the long-term cortical BF shift as does the conditioning; (ii) both electric stimulation of the AC and acetylcholine applied to the inferior colliculus increase the short-term collicular BF shift evoked by the cortical electric stimulation but do not change it into long-term; and (iii) as this short-term collicular BF shift is blocked by atropine, the development of the long-term cortical BF shift becomes slow and small. Therefore, the most essential neural elements for evoking the long-term cortical BF shift are the AC, corticofugal feedback and the cholinergic nucleus. Our current data support the Gao-Suga model, which hypothesizes that the small short-term cortical BF shifts are evoked by tonal stimuli without the association of conditioned and unconditioned stimuli in the multisensory thalamic nuclei and that these BF shifts are augmented and changed into the large long-term BF shifts by cholinergic neurons.     

A failed case to diagnose cardiac sarcoidosis presenting advanced atrioventricular block

A 53-year-old-male developed atrioventricular block in January 2001. A chest X-ray and laboratory tests, including serum angiotensin converting enzyme, were normal. The patient underwent permanent pacemaker implantation and attended for semiannual follow-up after discharge since the etiology of advanced atrioventricular block remains unknown. One year later, the patient was diagnosed with uveitis related to sarcoidosis. No clinical finding specific to cardiac sarcoidosis was notable at that time. Four years after onset, the patient developed congestive heart failure. An echocardiogram revealed diffuse LV hypokinesis, but no asymmetric interventricular septal thinning. Laboratory tests showed normal angiotensin converting enzyme. Noncaseating granuloma was not confirmed by transbronchial biopsy. Despite normal myocardial uptake of gallium-67, uptake of (18)F-Fluorodeoxyglucose increased in the myocardium. Nevertheless, clinical manifestations did not match the criteria for cardiac sarcoidosis. Prednisolone was administered daily. Two months after tapering dosage, the patient developed multiple organ failure and died. Post mortem histological findings were consistent with cardiac sarcoidosis. We experienced great difficulty in detecting cardiac involvement in the early stage of sarcoidosis. A specific method with greater sensitivity is required to diagnose cardiac involvement in the early stages of sarcoidosis.     

Phase II study of tailored S-1 monotherapy with a 1-week interval after a 2-week dosing period in elderly patients with advanced non-small cell lung cancer

Background

S-1 is an oral fluoropyrimidine that is active in the treatment of non-small cell lung cancer (NSCLC); however, an optimal treatment schedule and appropriate dose adjustments of S-1 in elderly patients have not yet been established.

Pillared honeycomb nanoarchitectures formed on solid surfaces by the self-assembly of lipid-packaged one-dimensional Pt complexes

A highly lipophilic polyion complex [Pt(en)(2)][PtCl(2)(en)(2)](1)(4) (en, 1,2-diaminoethane) is prepared from one-dimensional mixed valence Pt(II)/Pt(IV) complex and newly designed chiral amphiphile 1. The powdery sample showed purple color, which is a result of the mixed valence absorption of the linear chlorobridged complex (Pt(II)-Cl-Pt(IV)-Cl-)(n). When the lipid complex is dispersed in dichloromethane, purple-colored dispersion is obtained at 0 degrees C, whereas the color disappears after heating the solution to 21 degrees C. The observed thermochromism is reversible with respect to the temperature changes and is ascribed to the reversible dissociation and reassembly of the self-assembling inorganic wires. Casting of the 0 degrees C-purple dispersion on solid substrates affords honeycomb nanostructures in addition to the nanowires with the width of about 20 nm. The honeycomb patterns seem to be templated by the condensed water droplets that are formed and aligned on the rapidly evaporating dichloromethane solution. On the other hand, more regular honeycomb structures are exclusively obtained by casting the 21 degrees C-colorless solution. These observations indicate that the ordered honeycomb structures are obtainable on solid surfaces by the self-assembly of molecularly dispersed components [Pt(en)(2)](1)(2) and trans-[PtCl(2)(en)(2)](1)(2.) Very interestingly, formation of double-layered honeycomb nanostructure is observed by scanning electron microscopy. The unit hexagons and pillars of the honeycombs are made of nanowires that are hierarchically assembled from the lipid-packaged Pt(II)/Pt(IV) complexes. The surface self-organization of lipophilic inorganic complexes has a potential to fabricate novel nanoarchitectures with conjugated electronic structures.     

Multiple duodeno-jejunal diverticula causing massive intestinal bleeding

A case of massive intestinal blood loss from multiple duodeno-jejunal diverticula is described. A 39-year-old man was referred to our hospital because of recurrent bloody stool and worsening anemia. Upper and lower endoscopy, selective abdominal angiography, and radionuclide scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. Small-bowel barium follow-through examination showed numerous diverticula in the distal duodenum and proximal jejunum. Excision of the duodenal diverticulum and resection of the involved portion of the jejunum cured the patient. On histopathological examination, an ulcerative lesion with an exposed vessel suggestive of the source of bleeding was seen in the resected duodenal diverticulum. Although duodeno-jejunal diverticula are rare, the importance of a careful search for this malformation in a patient with intestinal blood loss is stressed. Received: September 28, 1998 / Accepted: June 25, 1999     

A rare case of gastric lipoma with early gastric cancer

An 84-year-old man was admitted to our hospital with a 1-month history of epigastralgia. Upper gastrointestinal endoscopy revealed gastric cancer and a gastric submucosal tumor (SMT) on the greater curvature of the gastric body. By endoscopic ultrasonography, SMT was demonstrated as a well-circumscribed, smooth-bordered and hypoechoic mass localized in the submucosal layer. Total gastrectomy was performed. The histology of the resected specimen revealed a gastric lipoma and an early gastric cancer widespread to the surface on the lipoma. Two lesions were present in the same lesion, but not linked. We report a rare case of gastric lipoma complicated with early gastric cancer.     

Plasma levels of brain natriuretic peptide in various forms of obstruction to the left ventricular outflow tract

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the relationship between plasma concentrations of brain natriuretic peptide (BNP) and the type or degree of stenosis in the left ventricular outflow tract (LVOT). METHODS: The relationship between BNP plasma level and pressure gradient (PG) in the LVOT and LV wall thickness (LVWth) was analyzed in 25 patients with a PG > or = 30 mmHg in the LVOT from the mid-left ventricle to the aortic valve. Among patients, 14 had aortic valve stenosis (AS), five had subaortic type hypertrophic obstructive cardiomyopathy (HOCM), three had mid-ventricular type HOCM, and three had angled ventricular septum. Three patients with AS showed LV systolic dysfunction (ejection fraction (EF) < 50%). All patients were in sinus rhythm. LV peak-systolic pressure (LVPSP) was derived by adding maximum PG to cuff systolic arterial pressure. RESULTS: In AS patients without LV systolic dysfunction and HOCM patients, there was a significant positive correlation between BNP and LVPSP (r = 0.78, p = 0.001; r = 0.76, p = 0.007, respectively). In AS patients without LV systolic dysfunction, BNP was positively correlated with LVWth (r = 0.79, p = 0.001), but no correlation was found between BNP and LVWth in patients with HOCM. In AS patients including systolic LV dysfunction, BNP was negatively correlated with LVEF (r = -0.87, p < 0.0001), but no correlation was found between BNP and LVEF in patients with HOCM. CONCLUSION: These results suggest that BNP level is closely associated with severity of stenosis in patients with HOCM, but mainly with severity of stenosis and also degree of LV systolic dysfunction in patients with AS. The BNP-LVWth relationship appeared to differ between AS (a fixed stenosis with uniform myocardial hypertrophy) and HOCM (a dynamic stenosis with uneven myocardial hypertrophy).     

Two cases of herpes simplex esophagitis during treatment for lung cancer]

Herpes simplex virus (HSV) is one of the three major causes of infectious esophagitis, along with Candida albicans and Cytomegalo virus (CMV). Most cases occur in immunocompromised hosts, in whom this can be life threatening. We report two cases of herpes simplex esophagitis occurring during treatment for lung cancer. Case 1: An 80-year-old man with radiation pneumonia caused by radiotherapy for lung cancer was admitted for treatment with antibiotics and corticosteroids. Shortly after initiation of treatment, he complained of dysphasia. Endoscopic examination revealed herpes simplex esophagitis. Case 2: A 71-year-old man was given corticosteroids for cryptogenic organizing pneumonia following chemotherapy for lung cancer. During treatment, the patient complained of odynophagia. Endoscopic examination revealed herpes simplex esophagitis. Both cases died due to progression of lung cancer and acute respiratory distress syndrome, despite administration of acyclovir. When immunocompromised patients complain of prolonged dysphagia and odynophagia, the presence of herpes simplex esophagitis should be clarified by endoscopic examination. It is occasionally difficult to distinguish between HSV and Candida esophagitis by endoscopic observation alone. Esophageal mucosal endoscopic cytology can help differentiate between these three infectious agents.     

A long-term surviving patient with cancer of papilla of Vater after local resection

We report successful local resection for cancer of papilla of Vater in an 86-year-old woman. She was referred to our hospital because of right hypochondralgia. Abdominal ultrasonography and computed tomography showed marked dilatation of the common bile duct (CBD). Endoscopic retrograde cholangiography disclosed a small shadow defect in the terminal of the dilated CBD. Biopsy of the papilla revealed well-to-moderately differentiated adenocarcinoma. Considering her extreme old age and keeping in mind her quality of life after the operation, and the finding that the tumor was localized within the papilla and highly differentiated, we performed local resection. In addition, the intrapancreatic portion of the CBD and part of the main pancreatic duct (MPD) were further resected to secure a negative margin, confirmed by frozen section. The MPD was reapproximated to the duodenal mucosa and a choledocho-duodenostomy was performed for CBD reconstruction. Histopathological examination showed the tumor was papillary adenocarcinoma, 10 × 15 mm in size; there was no invasion beyond the sphincter of Oddi, it had partly infiltrated the CBD, but had not invaded to the pancreas or duodenum. The patient's postoperative course was not eventful and she has had good quality of life for the past 6 years since the operation, without any evidence of recurrence. Although radical pancreaticoduodenectomy is now the standard procedure in patients with malignant tumor of the papilla of Vater, local resection is a reasonable alternative for high-risk patients with highly differentiated, apparently localized carcinomas.     

Effects of intraperitoneally administered <Emphasis Type="SmallCaps">l</Emphasis>-histidine on food intake,taste, and visceral sensation in rats

To evaluate relative factors for anorectic effects of l-histidine, we performed behavioral experiments for measuring food and fluid intake, conditioned taste aversion (CTA), taste disturbance, and c-Fos immunoreactive (Fos-ir) cells before and after i.p. injection with l-histidine in rats. Animals were injected with saline (9 ml/kg, i.p.) for a control group, and saline (9 ml/kg, i.p.) containing l-histidine (0.75, 1.5, 2.0 g/kg) for a l-histidine group. Injection of l-histidine decreased the average value of food intake, and statistically significant anorectic effects were found in animals injected with 1.5 or 2.0 g/kg l-histidine but not with 0.75 g/kg l-histidine. Taste abnormalities were not detected in any of the groups. Animals injected with 2.0 g/kg l-histidine were revealed to present with nausea by the measurement of CTA. In this group, a significant increase in the number of Fos-ir cells was detected both in the area postrema and the nucleus tractus solitarius (NTS). In the 0.75 g/kg l-histidine group, a significant increase in the number of Fos-ir cells was detected only in the NTS. When the ventral gastric branch vagotomy was performed, recovery from anorexia became faster than the sham-operated group, however, vagotomized rats injected with 2.0 g/kg l-histidine still acquired CTA. These data indicate that acute anorectic effects induced by highly concentrated l-histidine are partly caused by induction of nausea and/or visceral discomfort accompanied by neuronal activities in the NTS and the area postrema. We suggest that acute and potent effects of l-histidine on food intake require substantial amount of l-histidine in the diet.