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.     

The Acute and Chronic Toxicities of Nivalenol in Mice

The Acute and Chronic Toxicities of Nivalenol in Mice. Ryu,J.-C, Ohtsubo, K., Izumiy-ama, N., Nakamura, JL, Tanaka, T.,Yamamura, H., and Ueno, Y. (1988). Fundam. Appl Toxicol. 11,38–47. In an attempt to ascertain precisely the toxiceffects of nivalenol (N1V), we conducted the determination ofLD50 values, and interim kills during the carcinogenic studyin mice. LD50 values (mg/kg) of NIV in 6-week-old male ddY micewere determined as 38.9 (po), 7.4 (ip), 7.2 (sc), and 7.3 (iv).Seven-week-old female C57BL/6CrSlc SPF mice were fed diets containing0, 6, 12, and 30 ppm (mg/kg) NIV over 1 year, and were assessedfor effects on body weight gain, feed efficiency, terminai organweights, hematology, and histopathology. The rates of body weightgain and feed efficiency showed a good dose-dependent correlationin all experimental periods. Gross and histopathological evaluationof the liver, thymus, spleen, kidneys, stomach, adrenal glands,pituitary gland, ovaries, sternum, bone marrow, lymph node,brain, and small intestines with or without Peyer's patch portionfrom control and all NIV-exposed mice revealed that these tissueswere normal in appearance and in histopathological structure.Also, no changes were observed in the ultrastructural studieson the bone marrow. Dietary NIV did, however, cause dose-dependentdecreases of absolute organ weights (mg) and increases of relativeorgan weights (mg/g body weight) in the terminal organ weightsrecorded. A significant leukopenia was observed in the 30 ppmgroup at 6 months and in all NIV-treated groups at 1 year. Nomarked changes were observed in the other hematological parameters.These results indicated that 6 ppm or more of dietary NIV for1 year showed a characteristic toxic effect of trichothecenemycotoxins in mice.     

The Role of the Biopsy in Diagnosis of Early Gastric Cancer

In order to determine the reliability of endoscopic biopsy indiagnosis of early gastric cancer, and to clarify the problemswith biopsies, preoperative endoscopic biopsies from 771 earlygastric cancer cases were reviewed and analyzed clinicopathologicallyin comparison with surgically resected specimens. The 771 cancerswere surgically resected at the National Cancer Center Hospitalduring the period from 1972 to 1982. Definite histological diagnosiswas obtained in 87.4% of the carcinomas at the initial biopsies.Repeated biopsy raised the percentage of correct definite diagnosesto 96.1%. False-negative (including suspicion of cancer) diagnosiswas most frequent in the case of depressed lesions (50 lesions).Half of the false negatives were found to be due to samplingerrors by the endoscopists. The other half of these 50 lesionswere diagnosed as "suspicious of malignancy" because of thehistological difficulty in differentiating early gastric cancerfrom regenerative atypia with intestinal metaplasia, or becausethere was not enough information, or for the other reasons.Most of the 31 false-negative diagnoses at the initial biopsyfrom elevated lesions were reported as adenoma (group III) orsuspicious of carcinoma (group IV), indicating that differentialdiagnosis between well-differentiated adenocarcinoma and adenomais very difficult. The result of the present study suggeststhat repeated biopsy from correct sites and discussion of thelesions between clinicians and pathologists are very important. ^**Present affiliation: Toranomon Hospital, Toranomon 2-2-2,Minato-ku, Tokyo 105, Japan.     

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.     

Comparison of Injection Materials for the Elevation of Gastric Mucosa Prior to Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR), namely strip biopsy, to eradicate gastric mucosal lesions requires certain special techniques, including submucosal injection of appropriate agents. This experimental study using dogs was conducted to compare, with regard to the degree of duration of mucosal elevation and subsequent histologic changes of the gastric wall, three injection materials; physiological saline, hypertonic saline with epinephrine (HSE) and 10% soybean oil. The duration of mucosal elevation which should be sufficient for the EMR procedure did not differ between the three agents. The post-injection histologic changes included vessel dilatation in the peri-muscularis mucosae, dilatation of the lymphatic channels and vessel congestion. These changes appeared in all injection material groups, and the vessel congestion was found to be more conspicuous in the HSE group. All EMRs in this series were performed by single snare cutting, which was also evaluated. The margin of the stripped material was well limited to the submucosal layer in all cases, but the depth of the ulcers formed varied. The healing process of the ulcer for the first 4 weeks was delayed in the soybean oil group. Although there were few cases of perforation in this experiment and some subjects had adhesion between the gastric serosa and adjacent organs, the single snare method could be applicable for clinical use by skilled hands.     

QUALITATIVE DIFFERENCES BETWEEN PROTEIN IN BLOOD SERUM AND IN CEREBROSPINAL FLUID OF PSYCHOTICS —THE POLAROGRAPHIC AND ELECTROPHORETIC STUDIES—

SUMMARY By the use of the polarographic method and paper electrophoresis, the proteins in the serum and in the CSF of schizophrenic, epileptic, and general paretic groups were examined. The examinations for the serum were carried out on 157 cases and for the CSF on 139 cases with the use of PLG; for the serum on 157 cases and for CSF on 105 cases with the use of PEP and a normal group were used as the controls. A comparison of the results from the serum and the CSF according to each symptom type group, the qualitative difference of the proteins is discussed.

• 1) In the normal group the difference between the quantity of the proteins in the serum and in the CSF is great with marked qualitative difference. The PLG findings show that the SH group activity of the protein surface is higher in the CSF than in the serum, while those of all three types are higher in the serum. The PEP findings show that the v-fraction is contained only in the CSF and that there is a difference between the fraction patterns in terms of the percentage of the protein and glycoprotein.
• 2) As to the PLG findings, the schizophrenic group as a whole showed protein surface SH group activity in the CSF and mucoprotein SH group activity in the serum higher than the normal group. Consequently, there was a disparity between the CSF/serum ratio of each and that of the normal group. The PEP findings showed an increase of the u-fraction of the CSF above the normal and in most cases a decreases in Al and α₂-Gl in the glycoproteins of both the fluids. As to the CSF/serum ratio, that of the γ- and β-Gl is lower and of α₁-Gl higher than the normal. As to the glycoprotein, Al and α₂-Gl are smaller and α₁-, β-, and γ-Gl greater than the normal. The differences according to the case development and symptom types were discussed.
• 3) In the intermittent period between epileptic seizures, the protein surface SH group activity is higher in the CSF and lower in the serum than in the normal, while the mucoprotein SH group activity is lower in the CSF and higher in the serum than in the normal; with a resulting variation in the CSF/serum ratio. As regards the PEP findings, many cases showed an v-fraction and α₂-Gl increase in the CSF, and an α₁-Gl increase and Al, and α₂-Gl decreases of the glycoproteins. In comparison with the normal group CSF/serum ratio, Al, α₁ and α₂-Gl showed a higher ratio and γ-Gl, a lower ratio, whereas in glycoprotein α₁-, and γ-Gl were higher and α₂- and β₂-Gl lower.
• 4) The general paresis groups examined were chronic cases. In them, both the serum and the CSF showed an increase in the proteins. In spite of the PLG finding that the protein SH group activity in each is higher than the normal, the CSF/serum ratio is nearly the same as the normal. The PEP findings showed many cases of v-fraction, γ-, and α₂-Gl increases in the CSF, and α₁-Gl increase in the serum. As to the glycoprotein, many cases showed α₁-, α₂- and γ-Gl increases and Al, α₂-, and α₂-Gl decreases in the CSF, and a β-Gl increase in the serum. Al and γ-Gl were high in the CSF/serum ratio, and α₁, and β-Gl were low; α₁- and γ-Gl of the glycoprotein, were high, and Al, α₁- and β-Gl low.
• 5) In general, the CSF showed greater changes than the serum in spite of the fact that the former is smaller in quantity than the latter. A discussion was attempted concerning the qualitative difference between the serum and the CSF.

     

Cyclic peptides

In order to investigate the role of the L-2-hydroxy-3-methylbutanoic acid residue at position 2 of AM-toxin I (cyclic tetradepsipeptide) on necrotic activity for apple leaves, two analogs, [L-lactic acid²] AM-toxin I and [L-2-hydroxy-4-methylpentanoic acid²] AM-toxin I, were synthesized by the conventional method for peptide synthesis. The toxic activity of the former analog was much weaker than that of the natural AM-toxin I and the latter analog. CD spectra of AM-toxin I and these analogs were correlated to those toxic activities, indicating that bulkiness of the side chain at position 2 is important for the maintenance of active conformation and the induction of necrotic activity.     

Three-dimensional analysis of occlusal curvature in healthy Japanese young adults

Summary  Knowledge of the standard value of the occlusal curvature would be helpful when providing oral rehabilitation for patients with or without occlusal derangement. Dentists often use a 4-inch radii arc as the standard based on Monson spherical theory. However, the validity of application of this theory in Japanese has not yet been verified. The objective of this study was to determine the typical shape of the occlusal curvature in Japanese adults and investigate the relative contribution of each factor to the depth of the curvature, as the initial phase, to prove the validity of determination of occlusal curvature. Seventy-nine Japanese adults (42 males and 37 females, aged 18 to 37 years) with intact dental arches were recruited, and the occlusal curvature was estimated by calculating the radius and center position of the approximate sphere. Besides, the relative contribution of gender, age, dental arch length and width, overjet, overbite for the radii was calculated. The median radius of the sphere was 110·6 mm, larger than the 4-inch value advocated by Monson. This indicates the necessity to reconsider the application of the method of occlusal plane analysis in Japanese individuals. Median position of the centre was 64·6 mm anterior to and 68·5 mm above the mid-point between condyles. Relative contribution of overbite for the radii was 10·9%, the highest amongst the factors. Therefore, a typical shape of the occlusal curvature was observed in Japanese subjects. Overbite is considered as one of the principal factors correlated to the depth of the occlusal curvature.     

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.