Event-related potential correlates of functional hearing loss: Reduced P3 amplitude with preserved Nl and N2 components in a unilateral case

Abstract A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event-related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was 'repressed'. Event-related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature.     

Aniracetam,a Pyrrolidinone-type Cognition Enhancer,Attenuates the Hydroxyl Free Radical Formation in the Brain of Mice with Brain Ischaemia

We demonstrate here that aniracetam has the ability to block the formation of cytotoxic hydroxyl radicals (· OH) during ischaemia-reperfusion of mouse brain. The fact that brain ischaemia for 40 min followed by reperfusion increased ·OH was evidenced by detection of a peaked increase at 20 min after an ischaemic insult in the formation of 2,3-dihydroxy-benzoate (DHBA) from salicylate in cerebroventricular perfusate, a means of monitoring ·OH formation. A clearcut increase in dopamine was also observed during and after brain ischaemia. The ischaemia-reperfusion mice given aniracetam at an intraperitoneal dose of 30 or 100 mg kg^?1 showed a smaller increase in the formation of DHBA than those given the vehicle only. Aniracetam at 100 mg kg^?1 significantly suppressed the formation of DHBA by approximately 80%, becoming evident at 20 min after reperfusion and thereafter. Protection against death in mice insulted with a 40-min brain ischaemia (3/13 vs 13/25) was observed following 100 mg kg^?1 aniracetam. The increase in the dopamine levels was substantially reduced following aniracetam treatment and the reduction became significant at 20 min after reperfusion and thereafter in parallel with attenuation by aniracetam of DHBA formation. This finding suggests that the inhibitory activity of aniracetam in attenuating the hydroxyl free-radical formation in ischaemic mice is probably due, at least in part, to its palliative action on the dopaminergic neurons.     

Vitamin D-dependent rickets type I and type II

Two distinct hereditary defects, vitamin D-dependent rickets type I (VDDR I) and type II (VDDR II), have been recognized in vitamin D metabolism. VDDR I is suggested to be a deficiency of the renal 25-hydroxyvitamin D (25(OH)D)-1α-hydroxylase. Muscle weakness and rickets are the prominent clinical findings. A normal physiologic dose of 1α-hydroxyvitamin D₃ and 1,25-dihydroxyvitamin D₃ is sufficient to maintain remission of rickets in this disorder. VDDR II consists of a spectrum of intracellular vitamin D receptor (VDR) defects and is characterized by the early onset of severe rickets and associated alopecia. This can be attributed to mutations in the VDR gene. Massive doses of vitamin D analogs and calcium supplementation is usually required for the treatment; however, the response to therapy is sometimes variable.     

Small renal oncocytoma with central cystic degeneration

A case of a small renal oncocytoma with central cystic degeneration, 15 mm in diameter, is reported. Contrast-enhanced computed tomography showed the tumor contained a central hypoattenuating region and had an irregular, heterogeneously enhanced wall. Magnetic resonance images showed a well-circumscribed lesion and the T(1)-weighted image indicated medium signal intensity, whereas the T(2)-weighted image indicated slight hypointensity. Both T(1)- and T(2)-weighted images showed central hyperintensity. Our preoperative diagnosis was renal cell carcinoma originating in a renal cyst wall or cystic renal cell carcinoma. Nephrectomy was performed because frozen-section examination did not completely rule out malignancy. The final pathological diagnosis of the entire surgical specimen was renal oncocytoma with cystic degeneration. To our knowledge, this is the 14th case of renal oncocytoma with central cystic degeneration reported in the published works. We discuss herein the variant forms of oncocytoma and difficulties with their preoperative diagnosis, especially when the tumor is small.     

Is a limited lymphadenectomy targeting obturator nodes alone an adequate procedure for Japanese men undergoing radical prostatectomy?

BACKGROUND: The objective of the present study was to investigate the significance of pelvic lymphadenectomy during radical prostatectomy in Japanese men with prostate cancer. METHODS: A total of 178 consecutive patients who underwent radical prostatectomy and standard pelvic lymphadenectomy targeting the external iliac nodes and obturator fossa for clinically localized prostate cancer were studied. The median observation period of this series was 18 months (range: 3-36 months). RESULTS: Lymph node metastases were detected in 13 patients; that is, positive nodes were located in the external iliac nodes alone in seven patients, the obturator fossa alone in four patients, and both external iliac nodes and obturator fossa in two patients. Of these 13 patients, all of the seven with more than one positive node demonstrated biochemical recurrence, whereas five of the six with single node involvement remained without signs of biochemical recurrence. Furthermore, a single positive node was located in the external iliac region in five of the six patients. When a group at high-risk for lymph node metastasis was defined as those meeting more than two of the following three criteria: (i) pretreatment serum prostate specific antigen value > or = 20 ng/mL; (ii) biopsy Gleason sum > or = 8; or (iii) percentage of positive biopsy core > or = 50%, the incidence of lymph node metastasis was 24.5% in the high-risk group and 0.8% in the low-risk group. CONCLUSIONS: These findings suggest that limited dissection of the obturator node alone may not be sufficient for Japanese men undergoing radical prostatectomy; therefore, we recommend performing standard pelvic lymphadenectomy targeting both the external iliac nodes and the obturator fossa for patients at high-risk of lymph node involvement.     

A sighted man with non-24-hour sleep-wake syndrome shows damped plasma melatonin rhythm

Abstract Twenty-four-hour profiles of plasma melatonin, cortisol and rectal temperature were measured longitudinally in a sighted man who has been suffering from sleep disorders for more than 10 years. The sleep-wake rhythm of this subject free-ran, despite his routine life, and occasionally showed a sign of internal desyn-chronization, where sleep was lengthened up to 30 h. These states were classified into the non-24-hour sleep-wake syndrome. Plasma melatonin concentrations in the subjective night remained at a low level and showed a damped circadian rhythm. At the same time, robust circadian rhythms were detected in plasma cortisol and rectal temperature, indicating that the circadian pacemaker was intact. The causal relationship between the damping of nocturnal melatonin rise and a failure of entrainment of the sleep-wake cycle is discussed.     

Effects of Isoquinolinesulphonamide Compounds on Multidrug-resistant P388 Cells

Abstract— The effects of eight isoquinolinesulphonamide compounds on resistance to vinblastine in adriamycin-resistant mouse leukaemia cells (P388/ADR) which overexpress the relative molecular weight (M_r) 140 kDa P-glycoprotein in the plasma membrane were investigated. N-[2-(Methylamino)ethyl]-5-isoquinolinesulphonamide (H-8) and N-(2-aminoethyl)-5-isoquinolinesulphonamide (H-9) did not reverse vinblastine resistance. N-[2-[N-[3-(4-Chlorophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulphonamide (H-86) and N-[2-[N-[3-(4-chlorophenyl)-1-methyl-2-propenyl]amino]ethyl]-5-isoquinolinesulphonamide (H-87) caused accumulation of intracellular vinblastine and inhibition of vinblastine efflux from the cells and reversed the resistance. Addition of an aminoethyl group to the nitrogen atom of the sulphonamide group (W-66) or a formyl group at the terminal amino group (H-85) of H-86 reduced those activities. Conversion of the chlorophenyl group of H-87 to pyridinyl (H-31) or furanyl (H-34) markedly decreased activities against the drug resistance. The activity against vinblastine accumulation closely correlated with the apparent partition coefficient of compounds. These compounds dose-dependently inhibited photoaffinity labelling of a photosensitive analogue of vinblastine, N-(p-azido-(3-[¹²⁵I])salicyl)-N′-β-aminoethylvindesine ([¹²⁵I]NASV), and there was a good correlation between inhibition of [¹²⁵I]NASV-photolabelling and hydrophobicity. Although these isoquinolinesulphonamides inhibited protein kinase A with different magnitudes, this activity did not correlate with the effect on the drug resistance. These results indicate that isoquinolinesulphonamide compounds with a hydrophobic group interact with antitumour drugs on P-glycoprotein and reverse multidrug resistance without involvement of their activity on protein kinase A.     

A Xanthanolide with Potent Antibacterial Activity against Methicillin-resistant Staphylococcus aureus

This study was conducted to find constituents of an annual herb, Xanthium sibiricum Patr er Widd, with effective antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). By monitoring antibacterial activity against MRSA strains, it was shown that a sesquiterpene lactone, identified as [3aR-(3aα,7β,8aβ)]-3,3a,4,7,8,8a-hexahydro-7-methyl-3-methylene-6-(3-oxo-1-butenyl)-2H-cyclohepta[b]furan-2-one, or xanthatin, isolated from leaves of the herb, had outstandingly potent activity against S. aureus species, including MRSA; its activity against MRSA and MSSA strains was similar. Other bacteria, e.g. Staphylococcus epidermidis, Klebsiella pneumoniae, Bacillus cereus, Pseudomonas aeruginosa and Salmonella typhi, were also susceptible at the concentrations tested but the compound had no inhibitory effect on some other bacteria, including Escherichia coli. The results show that xanthatin has outstandingly potent activity against strains of S. aureus but that the activity of the compound is highly species-specific.     

Enhancement of J–ST-Segment Elevation by the Glucose and Insulin Test in Brugada Syndrome

NOGAMI, A., et al. : Enhancement of J–ST-Segment Elevation by the Glucose and Insulin Test in Brugada Syndrome. The effects of glucose and insulin on J–ST-segment elevation were evaluated in seven men   (mean age 45 ± 10 years)   with Brugada syndrome. Six patients had been reanimated from VF and one patient had experienced syncope. The effects of intravenous (1) pilsicainide 50 mg, (2) glucose 50 g, and (3) glucose 50 g plus regular insulin 10 IU on the precordial ECG leads were examined. Pilsicainide significantly enhanced J-ST elevation in all patients and induced VF in 1 patient. A significant accentuation of the abnormal J-ST configuration was observed in all patients at a mean of   51 ± 40   minutes after glucose and insulin infusion. Changes in blood glucose and serum potassium concentration were   111 ± 158 mg/dL   and   −0.30 ± 0.48 mEq/L   , respectively. These changes were not directly related to the ECG changes. Glucose infusion without insulin caused a subtle increase in J-ST elevation. In conclusion, the administration of glucose and insulin safely unmasked or accentuation the J–ST-segment elevation in Brugada syndrome. Blood glucose and insulin concentrations may be factors modulating the circadian or day-to-day ECG variations in this syndrome. (PACE 2003; 26[Pt. II]:332–337)     

Prognostic significance of vascular invasion in patients with bladder cancer who underwent radical cystectomy

BACKGROUND: The objective of this study was to determine whether vascular invasion (i.e. lymphatic and blood vessel invasion) could be a useful prognostic predictor in patients with locally invasive transitional cell carcinoma (TCC) of the bladder who underwent radical cystectomy. METHODS: This series included 114 consecutive patients undergoing radical cystectomy for primary TCC of the bladder between November 1989 and July 2003. Several clinicopathological characteristics of these patients were analyzed, focusing on the association between vascular invasion and disease recurrence after radical cystectomy. RESULTS: Lymphatic and blood vessel invasions were detected in 55 (48.2%) and 33 (29.8%) specimens, respectively. Lymphatic invasion was significantly associated with pathological stage, tumor grade, lymph node metastasis, blood vessel invasion and disease recurrence, whereas blood vessel invasion was significantly related to pathological stage, lymph node metastasis, lymphatic invasion and disease recurrence. Recurrence-free survival in patients with lymphatic invasion was significantly lower than that in those without lymphatic invasion, and a similar significant difference in recurrence-free survival was observed between patients with and without blood vessel invasion. However, multivariate analysis using the Cox proportional hazards model showed that only pathological stage and lymph node metastasis could be used as independent predictors for disease recurrence after radical cystectomy. CONCLUSIONS: Despite a significant association between several prognostic parameters, vascular invasion was not an independent predictor of disease recurrence; therefore, if there are other conventional parameters available, there might not be any additional advantage to considering the presence of vascular invasion when predicting the prognosis of patients undergoing radical cystectomy for TCC of the bladder.