Cortical processing of musical consonance: an evoked potential study

Cortical processes underlying perception of musical consonance were investigated by long-latency auditory evoked potentials (EPs). Subjects listened to a random sequence of dyadic pure tones paired at various pitch intervals (1, 4, 6, 7, or 9 semitones). Amplitudes of P2 and N2 components of auditory EPs were significantly modulated by pitch interval of the dyads, being most negative for 1 semitone (minor second) and least negative or most positive for 7 semitones (perfect fifth). The results indicate that neural processing of consonance depend not only on peripheral mechanisms in the inner ear but also on higher associative processing of pitch relationships in the cerebral cortex.     

Dorsolateral prefrontal lobe activation declines significantly with age Functional NIRS study

Dorsolateral prefrontal cortex (DLPF) activation in response to cognitive paradigms engaging working memory was quantitatively evaluated using functional near infrared spectroscopy (fNIRS) in cognitively normal individuals across the age spectrum (20–90 years; 8 females, 52 males). DLPF activation score (DAS) demonstrated a significant decline (r² = −0561, p < 0.05) as a function of age. The study indicates that blood flow response associated with DLPF activation declines as a function of age in cognitively normal individuals and that fNIRS can be used as a convenient, portable tool for assessing such activation. Received: 11 December 2001, Received in revised form: 29 October 2002, Accepted: 15 November 2002 Correspondence to Ingrid L. Kwee, M. D.     

The role of ultrasonography in the detection of adrenal masses: Comparison with computed tomography and magnetic resonance imaging

To compare detection rates of adrenal tumors by ultrasonography,computed tomography and magnetic resonance image, we studied 61patients with adrenal tumor, who underwent adrenalectomy. In 45(73.8%) of the 61 patients, adrenal tumor was detected by ultrasonography. However, computed tomography and magnetic resonance imaging could detect all adrenal tumors. All adrenal tumors measuring more than 3.0 cm in diameter were detected by ultrasonography, computed tomography and magnetic resonance image. When adrenal tumors were smaller than 3.0 cm, however,ultrasonography, computed tomography and magnetic resonance imaging correctly found adrenal tumors in 30 (65.2%) and 46(100.0%) of 46 patients and 30 (100.0%) of 30 patients,respectively. These facts suggest that ultrasonography seems to be an effective diagnostic procedure for the prevention of overlooking adrenal tumors larger than 3.0 cm. This revised version was published online in September 2006 with corrections to the Cover Date.     

7E3 F(ab')2, an effective antagonist of rat alphaIIbbeta3 and alphavbeta3, blocks in vivo thrombus formation and in vitro angiogenesis

Abciximab (c7E3 Fab, ReoPro) blocks GPIIb/IIIa and alphavbeta3 and inhibits thrombotic and proliferative events only in humans and non-human primates. The bivalent F(ab')2 fragment is an effective anti-thrombotic agent in canine models. In the present study, 7E3 F(ab')2 was also found to bind to rat GPIIb/IIIa (KD = 27 +/- 4 microg/mL) and alphavbeta3 (KD = 9 +/- 8 microg/mL), to block in vitro rat platelet aggregation (IC50 = 16 +/- 6 microg/mL), and to inhibit alphavbeta3-mediated microvessel sprout formation in a rat aortic ring assay. Following administration of 7E3 F(ab')2 (4 mg/kg) to rats, platelet aggregation was completely blocked for up to 6 h and thrombus formation in response to a rat abdominal aorta double crush injury was prevented. Effective chronic dosing was achieved with 6 mg/kg daily I.P. injections. In vitro mixing experiments indicated that 7E3 F(ab')2 redistributed to unlabeled platelets in 2 h. Ex vivo, 7E3 F(ab')2 was detected on platelets for up to 4 days after a single 4-mg/kg injection. These data suggest that 7E3 F(ab')2 may be a useful agent to study the effects of GPIIb/IIIa and alphavbeta3 blockade in rat models of thrombosis and vascular disease.     

Developmental expression of a unique carbohydrate antigen, Tn antigen, in mouse central nervous tissues

Using an anti-Tn monoclonal antibody, the Tn antigen was detected immunohistochemically in prenatal and early postnatal central nervous tissues. On embryonic day 9 (E9), the antigen was distributed throughout the single neuroepithelial layer in the neocortex and then became more prominent in the preplate than in the ventricular zone along with formation of the preplate. Following division of the preplate and concomitant formation of the cortical plate, distinct labeling of the neocortex occurred in the marginal, subplate and intermediate zones, whereas in the cortical plate and ventricular zone were virtually not immunostained. It is notable that thalamocortical afferent fibers were also immunostained specifically on E14. After birth, the localization of the antigen became less noticeable and by 3 weeks after birth, the antigen had substantially disappeared. In the developing cerebellum, prominent labeling was also observed in the molecular layer and outskirts of the cerebellar nuclei on early postnatal days. To characterize the glycoprotein bearing the Tn antigen biochemically, immunoblot analysis was performed. The glycoprotein, most of which was extracted with a salt solution, migrated as a broad smeared band corresponding to a molecular weight of about 250 kDa on SDS-PAGE. Among the various tissues examined, this glycoprotein was only detected in the brain and its amount increased until an early postnatal stage with a peak on postnatal day 3 (P3), and then decreased gradually with age. This spatially and developmentally regulated expression of the Tn antigen suggests that this antigen plays a significant role in brain development.     

Tumour angiogenesis and Ki-67 expression in phaeochromocytoma

OBJECTIVE: To determine the expression of CD34 (to evaluate vascularity) and Ki-67 (as a proliferative index) in a variety of phaeochromocytomas and thus assess the utility of these markers as possible predictors of malignancy. PATIENTS AND METHODS: Deparaffinized tissue sections from 21 patients with benign and four with malignant phaeochromocytoma were assessed immunohistochemically to evaluate microvascular counts (using CD34 antigen) and the proliferative index (Ki-67 antigen, monoclonal antibody MIB-1). RESULTS: There was no statistical association between high microvascular counts and malignancy, but there was between the MIB-1 score and malignancy (P < 0.001). CONCLUSIONS: A high MIB-1 score in phaeochromocytoma suggests malignant behaviour in the component cells. The MIB-1 score may be a useful indicator for diagnosing malignant phaeochromocytoma.     

Hand-assisted laparoscopic renal surgery

The introduction of hand-assisted laparoscopic surgery (HALS) adds another dimension to standard laparoscopy, and particularly benefits the urologic laparoscopist who performs laparoscopic renal procedures. Hand assistance shortens the initial learning curve for laparoscopic nephrectomy and creates alternatives for more experienced laparoscopists. HALS can be performed on any kidney suitable for intact removal, and is well suited to laparoscopic donor nephrectomy, radical nephroureterectomy, and radical nephrectomy with intact removal. The authors' technique, early experience, and indications for hand assistance are described in detail.     

Clinical trial of prophylactic hepatic arterial chemotherapy for liver metastases in patients with Dukes' C colorectal cancer

Preliminary results of a prospective non-randomized trial of prophylactic hepatic arterial chemotherapy for liver metastases from colorectal cancer are presented. Twenty-two colorectal cancer patients (infusion group) in Dukes' C stage were given hepatic arterial infusion of 5-FU (500 mg/body for 1 hr per week, repeated 50 times) and peroral UFT-E (2.0 g/body, daily). Informed consent was obtained from all patients. Adverse effects and postoperative recurrence in the infusion group were compared with those of patients with UFT-E alone (control group). Complications related to hepatic arterial infusion in the infusion group were also demonstrated. There was no adverse effect in the control group, while diarrhea (grade 1) developed in one patient (5%) and pigmentation in five (24%) in the infusion group. Complications related to infusion were found in five patients (5%). Three patients in the infusion group presented with metachronous hepatic lesions, two of which were resected successfully. In the control group, one patient died of marked hepatic metastases, and one developed ovarian metastasis with lymph node involvement. Our regimen appears hematologically safe, however, the high frequency of pigmentation should be kept in mind. The oncological benefit of this chemotherapy would be clarified by a larger series of cases and longer follow-up.     

Effects of long-term treatment with nonselective endothelin receptor antagonist, TAK-044, on remodeling of cardiovascular system with sustained volume overload

To assess the role of endothelin-1 (ET-1) on cardiovascular remodeling, nonselective endothelin-receptor antagonist TAK-044 was administered for the long term to rabbits with or without arteriovenous (A-V) shunt formation. Six weeks after sham operation (n = 12) or carotid-jugular shunt formation (n = 21), TAK-044 (30 mg/day) or saline was infused subcutaneously using osmotic mini pumps for another 6 weeks. Twelve weeks after operation, left ventricular (LV) diameter was enlarged with the presence of an A-V shunt; however, the levels of LV diameter and arterial pressure or the postmortem weight of LVs of shunt rabbits were similar between saline and TAK-044 groups. A linear relation of the luminal diameter and the medial cross-sectional area of the left and right carotid arteries was similar between shunt + saline and shunt + TAK-044 groups. In saline groups, myocardial ET-1 levels were higher in shunt than in sham rabbits (217+/-22 vs. 136+/-19 pg/g tissue; p < 0.01 between rabbit groups) without changes in plasma ET-1 concentrations during saline infusion for 6 weeks. Differences in plasma ET-1 levels before and 6 weeks after the administration of TAK-044 were 0.32+/-0.78 and 0.16+/-0.28 pg/ml (NS between periods) in shunt and sham groups, respectively. In TAK-044 groups, myocardial ET-I levels 12 weeks after operation were similarly lower in both sham (105+/-7.4 pg/g tissue) and shunt rabbits (126+/-9.2 pg/g tissue) than in those with saline administration; however, the plasma ET-1 concentrations were increased significantly 6 weeks after TAK-044 administration by 5.0+/-0.6-fold and 3.5 +/-0.3-fold (p < 0.01) of the levels 6 weeks after operation in shunt and sham groups (NS between groups), respectively. Accordingly, myocardial but not plasma ET-1 levels were increased by a long-term burden of volume overload and were attenuated by a long-term administration of TAK-044 without altering drastically the hemodynamics or vascular remodeling. These results suggest that endogenous ET-1 does not play a major role in the compensatory stage of cardiovascular remodeling in the present volume-overload model.