Clinical investigation of neuroblastoma with partial deletion in the short arm of chromosome 1.

Several loci on the short arm of chromosome 1 (1p) have been reported as the consensus deleted regions for the putative suppressor genes of neuroblastoma by deletion mapping. The significance of deletion in 1p on the clinical features of neuroblastoma remains controversial. To clarify the relationship between the clinical features of neuroblastoma cases and genetic status of 1p, we performed deletion mapping on 1p on samples obtained from 58 cases with neuroblastoma using 12 highly polymorphic microsatellite or minisatellite loci. Loss of heterozygosity of 1p was detected in 19 cases (33%) of primary tumors and in 21 cases (36%) when metastatic and recurrent sites were included. They were classified into two groups according to the 1p deletion pattern: interstitial deletion (group I, n = 11) and terminal deletion (group T, n = 10). The shortest region of overlap in group I ranged between FGR and D1S170 (1p36.1-2). Clinically, all group I cases survived disease free, and none of these cases showed MYCN amplification. However, in group T, eight (80%) cases showed a large terminal deletion from D1S162 (1p32-pter), including the shortest region of overlap of group I, and two (20%) showed a very terminal deletion from D1S160 (1p 36.3). Of the group T cases, only two survived disease free, and seven (70%) showed MYCN amplification. Thus, the candidates for the locations of neuroblastoma suppressor genes on 1p may involve at least two regions, which demonstrate different clinical features.

Characterization and expression of the genes for cytochrome c oxidase subunit VIb (COX6b) from rice and Arabidopsis thaliana.

Many of the subunits of cytochrome c oxidase (COX) in the mitochondria of higher plants are encoded by nuclear genes. These genes are less characterized compared to mitochondrial-encoded genes. We previously isolated a cDNA encoding COX6b (designated OsCOX6b1 in this study) from the rice nuclear genome and analyzed its expression. The deduced protein had an extended N-terminus compared with human and yeast COX6b proteins. In this study, we identified another COX6b gene (OsCOX6b2) in rice and revealed that it was actually expressed. The deduced protein of this gene did not have an extended N-terminus and had about the same size as the human and yeast proteins. Genomic Southern hybridization analysis revealed that there was at least one OsCOX6b-homologus sequences in the rice genome other than OsCOX6b1 and OsCOX6b2. Furthermore, we identified three COX6b genes in a dicotyledonous plant, Arabidopsis thaliana. One of these genes (AtCOX6b1) was relatively long, with a length similar to that of OsCOX6b1, and the other two (AtCOX6b2 and AtCOX6b3) were shorter, with lengths similar to the length of OsCOX6b2. Genomic Southern hybridization analysis indicated there were no additional COX6b genes in the Arabidopsis genome. The coding regions of OsCOX6b1 and AtCOX6b1 were separated by four introns and those of OsCOX6b2, AtCOX6b2 and AtCOX6b3 were separated by three introns. A Northern hybridization analysis showed that OsCOX6b1, AtCOX6b1 and AtCOX6b3 were expressed in all organs examined, although with some differences in the amount of expression among the organs. OsCOX6b2 and AtCOX6b2 were strongly expressed in roots but most of the transcripts of AtCOX6b2 were degraded. The evolution of COX6b genes from rice and Arabidopsis is discussed.

Telomerase activity in neuroblastoma: is it a prognostic indicator of clinical behaviour?

Neuroblastomas show remarkable biological heterogeneity, resulting in favourable prognosis or unfavourable prognosis due to aggressive growth despite multimodal therapy. Recently, we proposed that aggressive tumours express telomerase at a high level while the favourable tumours lack or have low telomerase expression. To evaluate the correlation between telomerase activity and other biological characteristics reported as prognostic markers (MYCN gene amplification, loss of heterogeneity (LOH) in the short arm of chromosome 1, trk-A expression, Ha-ras p21 expression, and DNA ploidy), we investigated these biological features in 105 untreated neuroblastomas. In these cases, 23 showed high telomerase activity, 78 showed low activity, and telomerase activity was undetectable in 4 cases. Most tumours with genetic alterations (MYCN amplification or 1p32 LOH) showed high telomerase activity. Most tumours with low or undetectable activity were aneuploid, and showed trk-A and Ha-ras expression. Three of the four tumours with undetectable telomerase activity regressed. In 2 of the tumours with low telomerase activity, the residual tumours maturated and showed repression of telomerase activity. Thus, the level of telomerase activity correlated with other genetic alterations and/or gene expression and may be a useful prognostic indicator in neuroblastoma.

Identification of cDNA encoding cytochrome c oxidase subunit 5c (COX5c) from rice: comparison of its expression with nuclear-encoded and mitochondrial-encoded COX genes.

Little is presently known about the nuclear-encoded genes for cytochrome c oxidase (COX) in higher plants. In rice, only the nuclear-encoded COX5b gene has been reported. To understand the relationship between the expression of nuclear-encoded and mitochondrial-encoded COX genes in rice, we first characterized a cDNA encoding one of the other nuclear COX genes, COX5c, which encodes 63 amino acids. The deduced amino acid sequence of COX5c from rice was highly homologous to that from sweet potato. Genomic Southern hybridization indicated that the rice COX5c subunit is encoded by a single copy of the COX5c gene. Furthermore, we compared the expression patterns of the nuclear-encoded COX5c and COX5b genes with the expression pattern of the mitochondrial-encoded COX1 gene among several organs by Northern blot analysis. The results suggested that regulatory systems of expression between the nuclear-encoded and the mitochondrial-encoded COX genes are different among different organs in rice.

A photoproduct with 13-cis retinal generated by irradiation with violet light in the octopus retina.

The photoconversion between rhodopsin (R) and metarhodopsin (MR) was investigated in the retina of Octopus ocellatus by measurements of the fast photovoltage (FPV) in conjunction with high pressure liquid chromatography (HPLC). Following conversion of most of R to MR by short-term exposure to an intense violet light, a large vitreous negative FPV due to photon absorption by MR was observed with an orange test flash. By continuing the exposure to the same violet light, however, the negative FPV became very small, though long-term irradiation with blue-green light produced a recovery. With the violet light exposure a substance other than R and MR is produced, which hardly contributes to FPV generation. Analysis of retinal isomers with HPLC show that such an exposure produces a substance with 13-cis retinal as its chromophore and that it was significantly reduced after exposure to blue-green light.

Structural and functional differences of two forms of GTP-binding protein, Gq, in the cephalopod retina.

The major GTP-binding protein (G-protein) in the rhabdomeric photoreceptor membranes of the squid (Watasenia scintillans) has been identified as a Gq-class G-protein. Anti-Gq alpha antibodies recognized a protein not only in the photoreceptor membranes but also in soluble fractions of the retina. The 42 kD protein in the soluble fractions (soluble Gq alpha) had the same molecular mass and the same reactivities to anti-Gq antibodies as those of membrane-bound Gq alpha. The G beta subunit was scarcely detected in the soluble fractions, being found mostly in the membrane fraction, indicating soluble Gq alpha exists in monomeric form. Soluble Gq alpha had no effect on the GTPase activity of the photoreceptor membranes, suggesting that it does not interact with photoactivated rhodopsin or G beta gamma. Soluble Gq alpha would be an inactive form of Gq alpha. In the retina of Octopus fangsiao, soluble Gq alpha was scarcely detected after dark adaptation, but increased during subsequent light exposure and decreased on returning to dark adaptation. These results with Octopus suggest that functional membrane-bound Gq alpha is converted to soluble Gq alpha on exposure to light. Transformation of membrane-bound Gq alpha into the soluble form by hydroxylamine suggests that the difference between membrane-bound and soluble Gq alpha is associated with the attachment of fatty acid(s).

Vertical ocular dysmetria--vertical rebound nystagmus and optokinetic vertical ocular dysmetria.

Ocular dysmetria in vertical eye movement was confirmed by electronystagmographic recording in 100 cases. Ocular dysmetria in spontaneous vertical ocular movement was reported in seven cases. It can be called vertical rebound nystagmus. This phenomenon was more prominent in vertical movement of the eyes returning from upward gazing to mid-position than in the movements of downward gazing. Optokinetic vertical ocular dysmetria induced by vertical optokinetic stimulation was observed in 93 cases. This phenomenon was far more prominent in upward optokinetic nystagmus than in downward optokinetic nystagmus. The pattern of optokinetic vertical ocular dysmetria was classified into the following four types: the dysrhythmic type, the overshoot type, the ataxic type and the saccadic (semi-inversive) type. The pathophysiological mechanism of horizontal ocular dysmetria should be different from the mechanism of vertical ocular dysmetria.

Positional nystagmus of benign paroxysmal type (BPPN) due to cerebellar vermis lesions. Pseudo-BPPN.

Positioning nystagmus accompanied by severe vertigo had been reported in patients with partial lesions of the inner ear, especially otolith lesions. Typically this type of nystagmus represents a latent period and subsequent fatiguability. We concur with this finding and have constantly emphasized the significance of this phenomenon in clinical diagnosis. Since we started to use CT-scanning, this type of nystagmus has been noted in 20 patients, all of whom had cerebellar vermis lesions. Attention should be focused on this association. A simple coincidence could not be excluded if such a combination were seen in only 1 or 2 patients, it could be attributed to simple coincidence. But its occurrence in as many as 20 patients a causal role of cerebellar vermis lesions. Its mechanism may be explained by incomplete inhibition of the vestibulo-oculomotor system including the cerebellar flocculonodular lobe or vestiburo-cerebellum.

[Classification of optokinetic after-nystagmus and its topographical-diagnostic significance in man]. / Die Klassifizierung des optokinetischen Nachnystagmus (optokinetic after nystagmus, OKAN) und seine topisch-diagnostische Bedeutung beim Menschen.

The existence of optokinetic after-nystagmus (OKAN) has long been known, as far back as the age of Bárány. The term OKAN means nystagmus appearing after first inducing optokinetic nystagmus, and then the optokinetic stimulation is removed. It appears easily with the eyes open in a dark place. There have been various theories about the mechanism of the onset of OKAN. Sakata et al. previously classified the types of OKAN into the following 7 types: 1) The normal type, (2) the directional preponderance type, (3) the disinhibitory type, (4) the inversive type, (5) the inhibitory type, (6) the dysmetric type, (7) the clonic type. In the present study, the authors performed a vestibular equilibrium function inspection, including an OKAN inspection, on about 10,000 patients who visited the Department of Neuro-Otology with complaints of vertigo and equilibrium disturbance. The results of the inspection were classified in accordance with Sakata's method, and the diagnostic contribution of the OKAN inspection was examined. The diagnostic significance of the OKAN inspection is considered as follows: (1) This inspection can detect a very small difference between the left and right of nystagmus in the vestibular-optokinetic system, which difference cannot be detected with OKP inspection giving a rather strong stimulation or with the caloric test giving a non-physiological strong stimulation. (2) This can be a focal localization diagnostic method by the classification by type.

Recent development of the study on clinical significance of abnormal eye movement.

As a general trend, the diagnosis in medical clinics often depends on laboratory test results. Neurotological diagnosis, however, requires detailed neurological examinations on a patient by a neurotologist. Therefore, there are differing diagnostic skills among physicians, and there is a kind of "man-made flavor" in neurotological diagnostic procedure. In the present study, current development in the knowledge on the clinical diagnostic significance of pathological eye movement during the last 2-3 years is summarized. Acquired pendular wondering eye-movement. Fixation jerks. Spontaneous and transitory eyeball burst or seizure. Vertical rebound nystagmus. Optokinetic vertical ocular dysmetria. Divergence nystagmus. Counterolling, pure rotatory positioning nystagmus. Inversion of optokinetic after-nystagmus (OKAN). Vertical congenital nystagmus and inversion of optokinetic nystagmus (OKN). Treatment of congenital nystagmus. Vertical spontaneous nystagmus to lower eyelid or so-called "downbeat nystagmus." Downbeat nystagmus seen in bilateral labyrinthine dysfunction. The significance of bilateral vestibular lesion, or symmetric lesion in other is emphasized in the present report for reader's reference and criticism. Our experience on the clinical significance of the abnormal eye movement was reported. It is our wish that accumulation of data on important cases along with the results of experimental studies directly connected with clinical medicine may contribute to the progress of our neurotology in the right direction as "neurology of the posterior fossa."

Early diagnosis of acoustic neuroma (1989) after experience of 37 cases.

Although the diagnosis of acoustic neuroma as classically described is generally thought to be easy, this is not always true for this so-called "ear tumor" which is localized within the internal auditory meatus. Recently, remarkable progress has been made in the diagnostic instrumentation and operative techniques used to treat acoustic neuroma, emphasizing the need for early diagnosis so that treatment can take place earlier than before. Through early diagnosis, some cases of total resection of acoustic neuroma have recently become possible, with preservation of not only facial nerve function, but preservation of auditory function as well. In the present report, we outline the early diagnosis of acoustic neuroma by summarizing 37 cases of acoustic neuroma experienced at our institution. We discuss historical presentations, and laboratory tests used in diagnosis including pure tone audiometry, speech audiometry, auditory brainstem evoked response (ABR), vestibular caloric stimulation, and computed tomography (CT) enhanced by introduction of air into the posterior fossa. Two representative cases are also presented. It should be emphasized that no clinical test is 100% sensitive or specific, and attention must be paid to chronological discrepancies in the patient's presentation and "cookbook"-type approaches to evaluation should be avoided.

Classification of non-nystagmic spontaneous pathological eye movements.

We attempted to classify the well-known spontaneous pathological eye movement (SPEM), to provide a unified nomenclature, to describe its pathophysiology, and to determine its significance in determining a differential diagnosis. Nomenclature was according to the first reporter. These phenomena are easy to confuse with artifact when recording ENGs. A careful analysis which considers history and general neurological findings can identify many of these as true clinical findings which may be as important as nystagmus in the establishing of a clinical diagnosis. Each SPEM, once confirmed, plays a decisive role in the localization of lesions within the central nervous system.

Caloric eye-tracking pattern test: visual suppression and the possibility of simplified differential diagnosis between peripheral and central vertigo.

During the examination of patients who complain of vertigo or who have equilibrium disorders, often identifying the etiology of the disorders is difficult (i.e., determining whether it is dependent on a peripheral or a central vestibular disorder). To attempt to determine the etiology in these cases, we devised a new method: the caloric eye-tracking pattern test. In normal subjects and in patients with peripheral disorders, as is well-known, caloric nystagmus has little influence on the eye-tracking pattern. In contrast, in patients with central vestibular disorders, caloric nystagmus evoked abnormalities in the eye-tracking pattern, either superimposed or as saccades, despite the fact that the eye-tracking pattern before caloric stimulation was normal. These findings result from the visual suppression mechanism to vestibular nystagmus. We can conclude that the visual suppression to vestibular nystagmus is evoked more strongly by pursuing a moving visual stimulus than by gazing at a stationary target. These results are interesting, not only from the physiological viewpoint but from the clinical viewpoint. The differential diagnosis should include both peripheral and central vertigo.

[Cell kinetic study on the healing process of indomethacin-induced gastric mucosal lesion of rats].

In healing process of indomethacin (IND)-induced gastric mucosal lesion of rats, cell kinetics in the cells from margin of mucosal lesion, background mucosa and pyloric gland mucosa were investigated with histochemistry using bromodeoxyuridine. Results obtained were as follows; 1) In marginal cells of mucosal lesion, cell number of s-phase expressing the cell renewal abruptly increased 6 hours after IND injection, showed maximal value at 24 hours and kept higher value even at 72 hours, when the lesions were in scar stage. 2) In background mucosal cells, the cell number of s-phase showed higher value at 12 hours after IND injection, although statistically not significant, and significantly lower value at 24 and 48 hours after IND injection. 3) Some s-phase cells were observed in the surface epithelial cells covering the mucosal defect. 4) In pyloric gland mucosal cells, there was no remarkable change in cell number of s-phase during the experimental period. It was concluded that in healing process of acute gastric mucosal lesion, there was a time lag between the macroscopic observation and cell kinetics in normalization of s-phase cell number.