Residential maze as a task for testing rats' maze learning ability: effects of hippocampal lesions and cholinergic receptor antagonists

We investigated whether rats can learn mazes by a procedure in which rats were left in the maze (residential maze) in groups for 1 h a day. Water and food locations, which served as the start and goal boxes respectively in the test trial, were at the opposite ends of the maze. On the test trial conducted everyday before the residence period, animals put in the start box showed a significant decrease of the error response into the blind alleys and running time to reach the goal box. Systemic administration of scopolamine (0.25, 0.5 mg/kg), a muscarinic receptor antagonist, dose-dependently increased the number of errors, but mecamylamine, a nicotinic receptor antagonist, had no effect. Bilateral hippocampal lesions retarded both the acquisition and retention of this maze learning. The results suggest that this residential maze procedure is useful for testing maze learning ability in rats.     

Renal tubular damage detected by dynamic micro-MRI with a dendrimer-based magnetic resonance contrast agent

BACKGROUND: A noninvasive technique to evaluate the structure and function of the kidney would be useful to investigate renal diseases, especially acute renal failure. We have developed a novel technique to visualize functional micro-magnetic resonance (MR) images of the mouse kidney with a dendrimer-based macromolecular renal MR contrast agent.METHOD: Mice were injected with cisplatin or vehicle, then examined three days later by contrast-enhanced, dynamic high-resolution micro-MRI with 160 microm spatial resolution using a 1.5 T clinical MRI unit, a surface coil, and the renal contrast agent G4D-(1B4M-Gd)64.RESULTS: The cortex and outer stripe of the outer medulla of the mouse kidney were clearly visualized in the normal mice. In animals treated with cisplatin, the gradation of tubular damage as assessed by contrast enhanced dynamic MRI correlated with renal function.CONCLUSION: Contrast-enhanced, dynamic high-resolution micro-MRI with a novel dendrimer-based macromolecular renal MR contrast agent can be a powerful tool for in vivo observation of renal structural and functional damage.     

Mid-term results of an endovascular stent-graft by means of median sternotomy for distal aortic arch aneurysm

Migration and perigraft leakage are major problems after endovascular stent graft (EVG) by means of median sternotomy for distal aortic arch aneurysm. Anchoring sutures have been applied to prevent these problems. We evaluate the mid-term results and the efficacy of anchoring sutures. The operation was performed on 19 men and 2 women with a mean age of 70 years (range, 59-81). The aneurysms were 19 true (12 fusiform, 7 saccular), 1 chronic dissection, and 1 penetrating aortic ulcer. EGVs were implanted by way of the aortic arch under retrograde cerebral perfusion in 13 patients and selective cerebral perfusion in 8. Total arch replacement was performed in 2 patients, and aortocoronary bypass grafting in 4. Anchoring sutures to fix the EVG were applied in 9 patients. The average follow-up period was 28 months (range, 2-56). There were no operative mortalities, but 1 paraplegia, 1 stroke, and 2 cases of temporary spinal cord dysfunction occurred. All aneurysms were thrombosed completely after surgery and reduced in diameter (66.9 +/- 17.4 mm to 57.3 +/- 15.7 mm, p < 0.0001). EVG-related complications arose in 4 patients. A chronic Type B dissection revealed impending rupture because of false lumen infection 1 year after operation, and redo surgery was performed. Migration occurred in 3 patients, all with fusiform aneurysms. One of these had a graft kink 1 year later. Another showed aneurysm enlargement with serous pleural effusion 3 years after operation. The third required redo surgery because of perigraft leakage at 3 years after surgery. There were 2 late deaths caused by stroke. There were no EVG-related complications in the 9 cases in which anchoring sutures were applied and in the 7 cases with saccular aneurysms. No spinal cord dysfunction occurred in 8 cases with low-flow antegrade perfusion by way of both axillary arteries while the aorta was opened. Logistic regression analysis showed significant relevance to complications of large aneurysms, greater than 80 mm in diameter. A large aneurysm tends to give rise to complications involving EVG migration. Anchoring sutures of EVG may prevent EVG-related complications.     

Late recurrence of subarachnoid hemorrhage due to regrowth of aneurysm after neck clipping surgery

Late recurrence of subarachnoid hemorrhage (SAH) due to regrowth of aneurysm after neck clipping surgery occurred in four patients. Two patients underwent surgical treatment, and two patients received endovascular treatment. Endovascular treatment was successful in one case, but emergent surgery was necessary for the other case because of possible pseudoaneurysm formation. Postoperative course of all patients was excellent. Late recurrence of SAH can occur even after complete clipping, and further treatment should be considered.     

T-cell malignant lymphoma of the ileum causing ileac fistulas: report of a case

We herein present a rare case of three fistulas caused by a recurrence of T-cell lymphoma of the ileum. A 67-year-old man presented at a local hospital with left lower abdominal pain in May 1997. Upper and lower gastrointestinal examinations did not reveal any abnormal findings, but an abdominal aortic aneurysm was diagnosed by computed tomography, and thus was determined to be the source of the pain. The patient was referred to our hospital to undergo a grafting operation; however, a laparotomy performed in July 1997 revealed an unexpected small intestinal tumor, and therefore a partial ileectomy between 15 and 70 cm in an oral direction from the terminal ileum was carried out instead. Histopathological and genetic examinations demonstrated diffuse small malignant lymphocytic T-cell lymphomas of the ileum invading all layers. Metastasis of the facial skin and local recurrence were recognized 5 months later, and chemotherapy with THP-COP and ESHAP only resulted in progressive disease. An ileac fistula was found to have formed between the intestine and abdominal wall in March 1998, and the patient died in May 1998. An autopsy revealed three fistulas caused by metastatic tumors, one of which communicated with the duodenum from the ileum, one with the skin from the ileum, and one to the transverse colon from the ileum. Received: February 16, 2001 / Accepted: July 17, 2001     

Staple-Line Ulcer in the Ileal Reservoir Following Restorative Proctocolectomy

Purpose. Following restorative proctocolectomy, seven cases with staple line ulcer around the pouch anal anastomosis and/or staple line in the ileal pouch were experienced. Their clinical, endoscopical characteristics were analyzed. Methods. The patients noted anal bleeding following restorative proctocolectomy were examined with colonofiberscopy and histological study was conducted. Results. Staple line ulcer was seens in seven cases (2.3%, 7/304). The onset was immediate or within 2 months postoperatively in 5 cases. Bleeding occurred in all the patients and lower abdominal pain, anal pain, increased bowel movements and anal fissure were seen frequently. Ulcers were linear along the staple line and there were no cases complicated by simultaneous pouchitis. Most of the patients responded to treatments with metronidazol, 5-ASA, and topical or oral steroids, although one patient required ligation of bleeding ulcer and two complicated perianal excoriation required ileostomy. Conclusion. Staple line ulcer should be recognized as different complication to pouchitis. Received: February 8, 2001 / Accepted: July 17, 2001     

Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2000--I. Gram-positive bacteria

The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2000 were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, and penicillins. Fifteen species, 1,062 strains, of Gram-positive bacteria were isolated from the clinical materials annually collected from January to December, and consisted of methicillin-susceptible Staphylococcus aureus (MSSA; n = 127), methicillin-resistant Staphylococcus aureus (MRSA; n = 123), Staphylococcus epidermidis (n = 104), Staphylococcus haemolyticus (n = 58), Streptococcus pyogenes (n = 100), Streptococcus agalactiae (n = 50), Streptococcus pneumoniae (n = 125), Enterococcus faecalis (n = 150), Enterococcus faecium (n = 50), Enterococcus avium (n = 50), and Peptostreptococcus spp. (P. anaerobius, P. asaccharolyticus, P. magnus, P. micros, P. prevotii; n = 125). CZOP possessed stable antibacterial activities against all strains tested throughout 5 years. The MIC90 of CZOP against MRSA and S. haemolyticus tended to decrease while against S. pneumoniae and Peptostreptococcus spp., tended to increase year by year. However, the MIC90 just changed a little and were consistent with the results from the studies performed until the new drug application approval. Increases in the MIC90 against S. pneumoniae were also observed with cefpirome (CPR), cefepime (CFPM), flomoxef (FMOX), sulbactam/cefoperazone (SBT/CPZ), and imipenem (IPM). Increases in the MIC90 against Peptostreptococcus spp. were also observed with ceftazidime (CAZ), CPR, CFPM, FMOX, SBT/CPZ, and IPM. The decreases in the sensitivities were not always considered to depend upon generation of resistant bacteria because the annual MIC range of each antibacterial agent was almost generally wide every year and the annual sensitivity of each strain to the agents extremely varied. In conclusion, the annual antibacterial activities of CZOP against the Gram-positive bacteria did not considerably change. It, therefore, was suggested that CZOP had maintained high antibacterial activity during 5 years of post-marketing.     

Highly sensitive liquid chromatography-tandem mass spectrometry method for quantification of a new bone anabolic agent,TAK-778, in human serum

A liquid chromatography-tandem mass spectrometric (LC-MS-MS) method for the highly sensitive determination of a new bone-anabolic agent, TAK-778 in human serum was developed. The internal standard (I.S.) used was deuterated TAK-778. TAK-778 and I.S. were extracted from serum samples with diethyl ether at neutral pH. A turbo ion spray interface was used as the ion source of LC-MS-MS, and the analysis was performed in the selected reaction monitoring mode. The lower limit of quantification was 0.02 ng/ml when 0.4 ml of serum was used, and the standard curve was linear in the range of 0.02-10 ng/ml. The method was precise; the intra- and inter-day precision of the method was not more than 17.9%. The accuracy of the method was good with the deviations between added and calculated concentration of TAK-778 being typically within 9.0%.