Development of two transmitter release components during the critical period for imprinting in the chick IMHV

Transmitter release at an excitatory synapse has two components, fast synchronous and slow asynchronous transmitter release. Using the whole cell recording technique, we investigated the developmental properties of neurotransmitter release, which is composed of the two components in the intermediate and medial part of the hyperstriatum ventral (IMHV) of chicks during the critical period for imprinting. Analysis of the paired-pulse responses revealed that the depression of the excitatory postsynaptic currents (EPSCs), driven mainly by fast synchronous release, was frequently observed in P0-1 chicks but not in those at P5-8. The spontaneous excitatory postsynaptic currents (sEPSCs) after the paired-pulse stimulation, which were thought to be driven by asynchronous transmitter releases, were observed more frequently in P0-1 chicks than P5-8 chicks. Furthermore, examination of Ca2+ dependency in the evoked EPSCs showed that the amplitudes in P5-8 chicks were more sensitive to reduction of the extracellular Ca2+ concentration than younger chicks. Considering that the Ca2+ dependency of EPSCs is defined by both Ca2+ sensitivity and the proportion of each type of release machineries at the release site, these results indicate that the ratio of fast synchronous to slow asynchronous transmitter release machinery changed during the critical period. These changes may play critical roles in the capacity of the avian brain to consolidate novel experience in the immediate period after hatching.     

Changes in repolarization properties with long-term cardiac memory modify dispersion of repolarization in patients with Wolff-Parkinson-White syndrome

INTRODUCTION: Transient T wave changes after cessation of preexcitation have been attributed to cardiac memory. However, there have been no reports on the effects of long-term cardiac memory on repolarization dispersion before and after catheter ablation in patients with Wolff-Parkinson-White (WPW) syndrome. METHODS AND RESULTS: We investigated 47 patients with an accessory pathway (AP; 24 manifest left-sided, 14 manifest right-sided, and 9 concealed left-sided). Repolarization dispersion was analyzed by two methods, recovery time (RT) dispersion and newly proposed T wave width (WT), from 87-lead body surface maps before, 1 day after, and 7 days after catheter ablation. RT dispersion and WT were significantly correlated before, 1 day after, and 7 days after catheter ablation (r = 0.78). In patients with preexcitation, RT dispersion and WT increased significantly (P < 0.05) 1 day after catheter ablation (178 +/- 32 msec and 172 +/- 30 msec) compared with those before (154 +/- 24 msec and 156 +/- 18 msec) and 7 days after catheter ablation (147 +/- 19 msec and 156 +/- 16 msec), respectively. However, there were no significant changes in RT dispersion and WT before and after catheter ablation in concealed WPW syndrome. CONCLUSION: The findings suggest that the abrupt changes in activation sequence increase repolarization dispersion in the presence of previous cardiac memory, and that the dispersion decreases days or weeks after alteration of activation sequence by catheter ablation, with development of new cardiac memory in patients with manifest WPW syndrome.     

Contribution of bone marrow cells to liver regeneration after partial hepatectomy in mice

BACKGROUND/AIMS: We examined whether bone marrow (BM) cells can commit to liver-consisting cells during liver regeneration after partial hepatectomy, using mice transplanted with green fluorescent protein (GFP) positive BM from GFP transgenic mice. METHODS: Partial hepatectomy or sham operation was performed. Lineage marker analysis of GFP positive liver cells was by immunostaining and flow cytometry. DiI-labeled acetylated low-density lipoprotein uptake or microsphere phagocytosis was examined in vitro. Lineage marker expression in BM and peripheral blood (PB) cells, and the vascular endothelial growth factor (VEGF) concentration in the liver were also examined. RESULTS: In hepatectomized mice, significantly more GFP positive cells participated in liver sinusoid than in sham-operated mice, expressing CD31 but not albumin. The percentage of cells that incorporated acetylated low-density lipoprotein but not microspheres was 69.5+/-3.4%, while 28.3+/-2.6% incorporated both, revealing sinusoidal endothelial and Kupffer cells, respectively. Increased expression of the CD31 and CD16/CD32 on GFP positive liver cells was also detected. The elevation of the VEGF concentration during liver regeneration and the increase in the CD34 and Flk-1 expression in the liver, BM, and PB cells suggested endothelial progenitor cell mobilization. CONCLUSIONS: GFP cell-marking provided direct evidence of the BM cells participation in liver regeneration after hepatectomy, where the majority was committed to sinusoidal endothelial cells probably through endothelial progenitor cell mobilization.     

Perindopril effect on uncoupling protein and energy metabolism in failing rat hearts

Uncoupling proteins, inner mitochondrial membrane proton transporters, are important for regulating myocardial energy efficiency. We investigated the effects of the ACE inhibitor perindopril on cardiac performance, myocardial energy efficiency, and uncoupling protein expression in an aortic regurgitation rat model. Twenty male Sprague-Dawley rats, in which aortic regurgitation was produced, were divided into untreated and perindopril-treated (5 mg x kg(-1) x d(-1)) rats. The treatments were initiated 3 days after operation. Ten control rats were sham-operated. Measurements of blood pressure and echocardiography were repeated before and 100 days after operation (endpoint). Left ventricular uncoupling protein-2 expression, creatine phosphate, and adenosine triphosphate were measured at endpoint. In perindopril-treated rats, systolic and diastolic blood pressure decreased after treatment (92+/-4/65+/-2 mm Hg). At endpoint, left ventricular end-diastolic dimension in untreated (10.7+/-0.2 mm) and treated rats (9.2+/-0.2 mm) was increased, and fractional shortening was reduced in untreated rats (28+/-1%) but did not change in treated rats (36+/-2%). Uncoupling protein-2 mRNA expression increased in untreated rats (3.7-fold) and was suppressed by perindopril (1.5-fold). The creatine phosphate was reduced in untreated rats (10.6+/-0.7 micro mol/g) but not in treated rats (15.9+/-2.0 micro mol/g). In the chronic stage of aortic regurgitation, perindopril improved cardiac performance and myocardial energy efficiency, in which the suppression of uncoupling protein-2 may play an important role.     

Sevoflurane metabolite production in a small cohort of coronary artery bypass graft surgery patients

OBJECTIVE: To determine hepatic and renal effects of hexafluoroisopropanol in patients undergoing coronary artery bypass graft surgery under sevoflurane anesthesia. DESIGN: Prospective, clinical comparison. SETTING: University hospital. PARTICIPANTS: Adult patients scheduled for coronary artery bypass graft surgery (n = 56) were divided into 3 groups according to renal function: group 1, patients with normal renal function (plasma creatinine <1.7 mg/dL), subdivided into 2 groups (group 1a and group 1b), and group 2, patients with impaired renal function (plasma creatinine > or = 1.7 mg/dL). INTERVENTIONS: Anesthesia was maintained with fentanyl, 20 microg/kg, and sevoflurane. In group 1a and group 2, sevoflurane dosage was 0.5 minimum alveolar concentration (MAC). In group 1b, it was 1.0 MAC of sevoflurane. During cardiopulmonary bypass, the same concentration of sevoflurane was given through a membrane oxygenator. MEASUREMENTS AND MAIN RESULTS: Serum hexafluoroisopropanol concentration was measured before induction of anesthesia, at the initiation of cardiopulmonary bypass, at the release of the aortic cross-clamp, at the end of cardiopulmonary bypass, at the end of surgery, and on the 1st postoperative day. Blood urea nitrogen, creatinine, 24-hour urinary output, aspartate aminotransferase, alanine aminotransferase, and total bilirubin were measured at preoperative evaluation, at the end of surgery, and on the 1st and 3rd postoperative days. The levels of hexafluoroisopropanol increased and peaked on the 1st postoperative day. Laboratory values showed no significant differences among all groups. CONCLUSION: The serum level of hexafluoroisopropanol after 0.5 MAC of sevoflurane anesthesia does not aggravate hepatic and renal functions.     

Expression of matrix metalloproteinase-7 on cancer cells and tissue endothelial cells in renal cell carcinoma: prognostic implications and clinical significance for invasion and metastasis.

PURPOSE: The expression of matrix metalloproteinase-7 (MMP-7) correlates with the malignant potential of various tumors and patient survival. We investigated the clinical and prognostic significance of MMP-7 expression in cancer cells and endothelial cells in human renal cell carcinoma (RCC). EXPERIMENTAL DESIGN: We reviewed tissue samples of 156 patients with RCC who had undergone radical operation. MMP-7 expression was examined by immunohistochemistry. Sections containing MMP-7-positive vessels were also stained for CD34. The density of MMP-7-positive vessels was determined by a computer-aided image analysis system. Multivariate analysis was done to assess relevant variables for invasion, metastasis, and cause-specific survival. RESULTS: The proportion of MMP-7-expressing tumor cells were significantly higher (P < 0.001) than that of normal cells. MMP-7-positive vessels were considered blood vessels based on staining for CD34, and their density was increased in tumor areas. The proportion of MMP-7-expressing cancer cells and density of MMP-7-positive vessels correlated with grade, pathologic tumor stage, and metastasis. Multivariate analysis showed that MMP-7 expression on cancer cells correlated with pathologic tumor stage only, whereas MMP-7-positive vessel density correlated with metastasis only. The elevated status of MMP-7 in cancer tissues was an independent predictor for cause-specific survival (odds ratio, 8.61; P = 0.040) by multivariate analysis. CONCLUSIONS: Our results showed that MMP-7 influences tumor progression by regulating invasion and angiogenesis. Multivariate analysis showed that MMP-7 status of cancer tissues was strong predictor of poor prognosis. Our results suggest that MMP-7 targeting treatment may be a potential target against RCC.     

Gastric carcinoma presenting with extensive extraluminal growth: Report of a case

(Received for publication on Apr. 23, 1999; accepted on Nov. 11, 1999)     

Laparoscopic ethanol injection therapy for hepatocellular carcinoma.

Ethanol injection into HCC tumors is an effective therapy and percutaneous ethanol injection therapy (PEIT) is performed on many HCC patients. However, there are cases in which PEIT becomes difficult because the HCC could not be detected by ultrasonography or the tumor is located in an area where it is impossible to perform PEIT. Nine patients with HCC underwent laparoscopic ethanol injection therapy (LEIT) in our institution. Their tumors were located on the liver surface and could be visualized by laparoscopic examination. Ethanol injection was performed under laparoscopic direct visualization. The total injected ethanol volume required ranged from 4 to 15 ml and in most cases both tumor size and alpha-fetoprotein (AFP) levels decreased after LEIT. Three cases showed a transient complication of abdominal pain or/and portal vein damage. Other severe complications were not observed. All cases required additional therapies, including transcatheter arterial chemoembolization (TAE) or PEIT to complete the tumor necrosis. In conclusion, LEIT is a safe and effective therapy for HCC located on the liver surface, but should be combined with other therapies to facilitate its effect against HCC.     

PULMONARY NODULES IN PATIENTS WITH A HISTORY OF RADICAL NEPHRECTOMY FOR RENAL CELL CARCINOMA

Background:
Nine patients with a history of radical nephrectomy for renal cell carcinoma underwent surgical removal of newly detected pulmonary nodules at the Hiroshima University Hospital. Six patients had metastatic lung tumors two patients had bronchogenic primary carcinomas and one had a granulomatous infection.
Methods:
To determine if any characteristics can distinguish a new primary carcinoma from metastatic renal cell carcinoma, we reviewed the nine patients described above. The patients with pulmonary metastases and those with new primary lung cancers did not differ in age, sex, history of smoking, clinical stage and pathological findings of the renal primary site, on the location and size of the pulmonary nodules.
Results:
Only the interval between the nephrectomy and the appearance of the new pulmonary lesion may be a predictive factor. This interval was 48 and 51 months for the patients with new primary lung cancers but varied from 0 to 39 months for the patients with metastatic renal cell carcinoma. A solitary nodule had an equal chance of being metastatic or primary. Conclusions: These results indicate that a solitary nodule that is detected at a longer inferval after radical nephrectomy may be a new primary lung cancer. Once new pulmonary nodules are identified in a patient with a history of radical nephrectomy for renal cell carcinoma, surgical excision is required for a final diagnosis before initiating therapy for metastases.