PCR stands for polymerase chain reaction. It was invented to amplify specific regions of a DNA strand in tissues, resulting in the tremendous development in biochemical and molecular biological fields. Nowadays, the PCR method is also quite available in inner ear researches as modified versions, because it needs just small amounts of samples in inner ear tissues. The modified versions are as follows: reverse transcription (RT)-PCR, real-time quantitative PCR, in situ PCR, DNA subtraction, DNA microarray, single nucleotide polymorphism (SNP) analysis for using mRNA and reporter gene assay, gel mobility assay for using genomic DNA. Here in this paper, we would like to introduce the PCR method from original to modified in our inner ear biological field.
Introduction: Using the near-infrared spectroscopy (NIRS), we evaluated the central circulation of patients with either dizziness and orthostatic dysfunction or dizziness alone. Methods: We used the NIRO-200 NIRS instrument to monitor bilateral oxygenation changes in cerebellar hemoglobin levels in 57 subjects during an orthostatic exam. Of the 46 patients with dizziness, 8 had orthostatic dysfunction. To determine whether NIRS is useful for evaluating patients with dizziness, we compared blood pressure changes with orthostatic dysfunction test scores. Diagnostic criteria for orthostatic dysfunction were as follows: (1) a greater than 21 mmHg reduction in systemic blood pressure, (2) a greater than 16 mmHg reduction in pulse pressure, and (3) a greater than 21 beats per minute increase in pulse rate. Results: We observed four different types of changes in oxy-hemoglobin during the orthostatic test. In type I, a rapid temporal decline of oxy-hemoglobin was followed by rapid recovery. In type II, the decline of oxy-hemoglobin was followed by recovery of oxy-hemoglobin levels above the initial levels. In type III, the decline of oxy-hemoglobin was followed by recovery of oxy-hemoglobin levels below the initial levels. In type IV, the decline of oxy-hemoglobin persisted without recovery. Most of the control patients displayed type I changes. Patients with orthostatic hypertension more frequently displayed type II and IV changes. Nine of the dizzy patients had a positive orthostatic test. Of these patients, 3 displayed type II changes and 6 displayed type IV changes. Conclusions: In normal subjects, cerebellar circulation remains stable, at least if orthostatically induced changes in blood pressure remain within normal ranges due to autoregulation. We suspect that dysfunctional autoregulation was responsible for the reduced cerebellar circulation in patients with orthostatic dysfunction. We propose that NIRS is an excellent, non-invasive tool for evaluating patients with dizziness that present with orthostatic dysfunction.
Although transitory alternating saccade (TAS) is classically-observed as one of the cerebellar ocular-motor signs, its occurrence has been noted only in isolated cases in the literature. In the present study, we quantitatively examined a total of 29 TAS waveforms with spectral analysis by discrete Fourier transformation. TAS was characterized by periodic eye movements over a time course of several seconds coupled with fast eye movement that reverses its direction. That is, the low frequency component of TAS was a periodic eye drift with a frequency of 0.36±0.09 Hz and an amplitude of 11.4±4.4°, whereas the high frequency component was a nystagmus-like eye movement with an amplitude of 1.41±0.4°. Routine computerized electronystagmography (ENG) testing revealed that in only 3 cases TAS was observed during the testing of spontaneous nystagmus. In another 26 cases, TAS was evoked during head position-change, neck stimulation such as neck-torsion and carotid-compression, or after optokinetic and rotational stimulation. In 48% of the 29 cases, disorders in visual fixation, smooth pursuit, and optokinetic nystagmus were also seen. TAS may be a result of the pathological oculomotor findings associated with lesions in the vicinity of the midline of the cerebellum.
Hyperosmotic solution of isosorbide has been used for treatment of Meniere's disease since Kitahara et al., Larsen et al. and Nozawa et al.. In recent studies reported that ADH is acting to open water channels, AQP-2 at the endlymphatic membrane and may act worse for labyrinthine hydrops. It is important the serum concentration of isosorbide after administration because ADH should be released if the serum osmotic pressure is elevated by isosorbide above more than 2% of normal serum osmotic pressure. In this study the equation predicting isosrbide serum concentration after oral administration was proposed on the basis of the data by Wakiya's report. It was confirmed the serum osmotic pressure remains below the threshold level for increasing ADH secretion by the routine method of 30 ml/once, 3 times every day. However, the method of 30 ml/once, single or two times every day should be recommended when the serum osmotic pressure before the medication is above 289 mOsm/kg.
We investigated the difference of eye movement between both eyes during caloric testing by monocular recording of electronystagmography (ENG). We recruited those patients, who had normal or very close to normal peripheral and central vestibular function. We measured slow phase velocities, amplitudes and number of beats during 10 s of culmination phase of each caloric response. The eye of the cold-irrigated side moved significantly stronger than the eye of the non-irrigated side, while a warm irrigation did not induce a significant difference between the eyes of irrigated and non-irrigated sides. We concluded that the inhibitory effect of a cold caloric stimulation is probably transmitted more intensively to the eye of the irrigated side.