Anionic sites on Reissner's membrane, stria vascularis, and spiral prominence.

We demonstrated anionic sites on the lateral wall of cochlear duct and Reissner's membrane (RM) of ICR mice by Lowicryl K4M resin post-embedding and poly-L-lysine-colloidal gold conjugate (PL-CG) as a polycationic probe. The basement membrane and endolymphatic cell surface of RM were labeled with PL-CG pH 2.5 and pH 1.0. However, the perilymphatic cell surface was not labeled. PL-CG pH 2.5 and pH 1.0 strongly labeled the endolymphatic surface of the spiral prominence epithelium (SP), whereas the endolymphatic surface of the marginal cell (MC) in the stria vascularis was not labeled. Pre-digestion with several glycosidases eliminated PL-CG labeling. Our result suggests that an anionic charge located on the basement membrane of RM is largely due to the presence of heparan sulfate, chondroitin sulfate, and hyaluronic acid. An anionic charge on the endolymphatic cell surface of RM was mainly dependent on the presence of heparan sulfate. An anionic charge on the SP epithelium was caused to a substantial degree by chondroitin sulfate. We obtained histochemical evidence that the glycoconjugate content of the MC surface was quite different from that of the endolymphatic cell surface of RM and SP. We also identified RM-MC and SP-MC junctions at the ends of the stria vascularis between the marginal cells and the other endolymphatic epithelial cells of the cochlear duct.

Iodine-123-metaiodobenzylguanidine myocardial imaging in patients with right ventricular pressure overload.

UNLABELLED: Iodine-123-metaiodobenzylguanidine ([123I]MIBG) has been used to evaluate the cardiac sympathetic nervous system, particularly that of the left heart. To clarify whether the right ventricular (RV) sympathetic neuronal function could be evaluated by [123I]MIBG myocardial imaging, we applied the technique in patients with pulmonary hypertension that was associated with either chronic pulmonary diseases or pulmonary vascular diseases. METHODS: All patients underwent right heart catheterization, and right heart hemodynamics were determined during a clinically stable state. SPECT was performed in the resting state 15 min (early imaging) and 4 hr (delayed imaging) postadministration of [123I]MIBG. Seven regions of interest (ROI) were selected on the delayed short-axis images on the RV free wall, left ventricular (LV) free wall and interventricular septum (IVS). We calculated the IVS-to-LV uptake ratio from the scintillation counts of the ROI. Thallium-201 myocardial imaging was also performed within 1 wk after [123I]MIBG imaging. RESULTS: Images obtained with these techniques were analyzed for the RV-to-LV uptake ratio. The IVS-to-LV ratio on [123I]MIBG correlated negatively and significantly with the mean pulmonary arterial pressure (PAm). The RV-to-LV uptake ratio on 201Tl images correlated significantly with PAm. CONCLUSION: Our results suggest that the uptake ratio of [123I]MIBG in the IVS is a useful index for evaluating the severity of pulmonary hypertension, and that chronic RV pressure overload contributes to disturbances of the cardiac sympathetic nervous system.

Noninvasive assessment of right heart function by 81mKr equilibrium radionuclide ventriculography in chronic pulmonary diseases.

Noninvasive multigated equilibrium radionuclide ventriculography with krypton-81m (81mKr) was used to assess right heart relaxation in patients with chronic pulmonary diseases (CPD). The subjects consisted of 30 patients with CPD and 8 patients free of cardiopulmonary diseases admitted to our department. A region of interest (ROI) was selected on both the right atrium (RA) and right ventricle (RV). A time activity curve was obtained for each ROI. As a diastolic index of the right heart performance, the right atrial early emptying rate (RAER) was obtained from the right atrial time activity curve, while the right ventricular rapid filling rate (RVRFR) was obtained from the right ventricular time activity curve. The mean RAER was significantly lower in CPD patients compared with the control (CPD, 9.5 +/- 4.5; control, 16 +/- 3.4%/100 ms). Similarly, the mean RVRFR was significantly lower in CPD patients compared with the control (CPD, 27.3 +/- 9.9; control, 34 +/- 8.5%/100 ms). A strong negative correlation was noted between the mean pulmonary arterial pressure (mPAP) and RAER (r = -0.77; p < 0.001) and between the mPAP and the RVRFR (r = -0.63; p < 0.001). Our results suggest that RAER and RVRFR measured by 81mKr are clinically useful in the noninvasive assessment of right heart relaxation in patients with CPD.

Measurement of intracellular free Ca2+ concentration in guinea pig spiral ganglion cells.

Intracellular free Ca2+ concentration ([Ca2+]i) in spiral ganglion cells (SGC) of guinea pig was measured using the fura-2 fluorescence method. Application of high-K+ external solution increased [Ca2+]i. [Ca2+]i elevation was suppressed by either depletion of external Ca2+ or application of the dihydropyridine Ca2+ channel antagonist, nicardipine. One of the putative hair cell afferent nerve neurotransmitters, L-glutamate (Glu), induced [Ca2+]i elevation in SGC. Pharmacological studies suggested that the Glu receptor may be a non-NMDA subtype. Glu-induced response was suppressed by either depletion of external Ca2+ or application of nicardipine, indicating that Glu-induced [Ca2+]i elevation is mainly carried out by the voltage-dependent Ca2+ channel in SGC.

Development of endocochlear potential and its negative component in mouse cochlea.

The chronological developmental processes of endocochlear potential (EP) and negative endocochlear potential (-EP) were investigated as a function of age from birth in the basal and second cochlear turns in normal ICR-strain mice. The EP of the basal turn developed between 5 and 17 days after birth (DAB). The -EP of the basal turn attained to its mature level on 11 DAB and it increased its absolute value further between 12 and 16 DAB and then, recovered to its mature level again on 20 DAB. The developmental processes of EP and -EP of the second turn followed similar courses to those of the basal turn although they were several millivolts different on each day in detail. The results suggest that the developmental processes of the +EP and the -EP are different. The time of reaching minimum -EP during anoxia were measured and the rate of EP decline were calculated on each animal. The rate of EP decline increased rapidly on 10 DAB, almost coinciding the day which EP began to increase abruptly. Although the rate of EP decline is influenced by several processes, this result showed one of the possibility that the sensitivity of the stria vascularis to hypoxia may develop parallel to the development of the EP.

Anionic sites in blood capillaries of the mouse cochlear duct.

The blood-cochlear barrier, which consists of the molecular size and ionic charge barriers, is known to play an important role in production and absorption of inner ear fluids. In this study, we employed poly-L-lysine colloidal gold conjugates (PL-CG) in combination with Lowicryl K4M resin to demonstrate anionic sites in blood capillaries of the cochlear duct. Male ICR mice weighing 30-40 g with a positive Preyer's reflex were used. The basement membranes of blood capillaries of the stria vascularis and the spiral ligament were successfully labeled with PL-CG pH 2.5. The luminal surface of capillaries in the stria vascularis and the spiral ligament intensely reacted with PL-CG pH 2.5. However, PL-CG pH 1.0 stained only the basement membrane of the spiral ligament. Predigestion with several glycosidases nearly eliminated PL-CG labeling. Anionic charge located on the luminal surface of the endothelial cell was mainly caused by the presence of sialic acid. On the contrary, anionic charge of the basement membrane was caused in a substantial degree by chondroitin and heparan sulfate-rich glycosaminoglycans. We obtained histochemical evidence that blood capillaries of the stria vascularis differ from those of the spiral ligament.

Effect of intermittent sound stimulation on cochlear microphonics and the possible preventive effect of coenzyme Q10.

Observations have been made on the effect of intermittent intense sound stimuli, using the CM as an index. Experiments were conducted regarding the effectiveness of the drug CoQ10 in ameliorating the acoustic injury due to this traumatization. The CM was measured by the differential electrode method from the basal turn of the cochlea. The individual differences between animals were monitored using intensity functions. Pure tones at a frequency of 4 kHz were used both for the traumatizing signal and the CM generating signal. Acoustic traumatizing signals lasted 1 min with a 5 min silent interval, and were repeated 10 times. Both the chronic depression and the transient depression of CM were measured after each traumatization. In control animals, the chronic depression progressed in an exponential manner and the transient depression was constant after each stimulation. In CoQ10 treated animals, the chronic depression was milder than that in the control animals. The transient depression was equivalent in the two groups. The effectiveness of CoQ10 on the acoustic injury was discussed on the basis of the results obtained with the present experiment.

Fibrinolytic enzyme in tracheobronchial secretion of rats: existence of plasminogen activator.

It is known that a plasminogen activator exists in the secretion of various organs, i.e., the existence of plasminogen activator in milk, tears, saliva, seminal fluids, urine and bile has been already demonstrated. However, the existence of the fibrinolytic enzyme in tracheobronchial secretions has not been known until this time. We found a new method to collect the tracheobronchial secretion of rats, and succeeded in detecting the fibrinolytic activity in the tracheobronchial secretions. Furthermore, it was found that the substance exhibiting the fibrinolytic activity in this secretion was not protease but plasminogen activator. In addition, some chemical properties of this plasminogen activator are presented, and the physiological and pathophysiological significances of it are discussed in this paper.

Congenital cricoid stenosis.

A case of congenital cricoid stenosis in a 9-year-old girl was reported. The stenosis was confirmed by direct laryngoscopy and laryngotracheograms performed through the tracheostoma. The excess cartilaginous tissue was removed under a midline incision of the cricoid cartilage (cricoidplasty). Seventeen cases of cricoid stenosis reported since 1960 were studied and the clinical entity was discussed. On the basis of the embryology of the larynx, the mechanism of origin of this malformation was also discussed. Although cricoid stenosis was a fatal malformation before 1968, it is now a curable disease using an emergency tracheostomy and a cricoidplasty.

Plasminogen activators in tissue extract of aural cholesteatoma.

Using a biochemical technique, the authors characterized and identified the plasminogen activator (PA) derived from tissue extracts of six aural cholesteatomas. The results of fibrin zymography indicated that the tissue extracts of two cholesteatomas demonstrated two lytic zones on fibrin-agarose plates. One of the lytic zones was at about 72 kd, while the other zone was at about 64 kd. Using various goat immunoglobulin G (IgG)-containing antibodies (anti-human uterine tissue type PA (t-PA), anti-human low-molecular-weight (LMW) urokinase, and nonspecific goat IgG) and plasminogen-free fibrin-agarose plates, we confirmed that the cholesteatoma tissue extracts contained 72 kd t-PA and 64 kd urokinase type PA (u-PA). Furthermore, we measured the t-PA and u-PA activities in the tissue extracts selectively by parabolic rate assay. In order to estimate the PA activity, we developed optimal conditions for this assay. The specific t-PA activity ranged from 0.03 to 0.43 mIU/micrograms-protein and the specific u-PA activity ranged from 0 to 0.35 mIU/microgram-protein. The highest percentage of u-PA with respect to the total PA activity was 44.9%. However, in four of the six cases, we failed to detect u-PA activity. In the present study, we thus clarified the presence of PAs in tissue extracts of aural cholesteatomas. Furthermore, we confirmed that measureable u-PA occurred in some tissue extracts. We anticipate that the u-PA in inflammatory tissues plays an important role in the degradation of the extracellular matrix via the formation of plasmin and collagenases.

Recurrent meningitis due to spontaneous cerebrospinal fluid otorrhea. A case report.

Bilateral congenital deafness was observed in a 9-year-old girl with recurrent meningitis. A careful workup, including polytomograph, CT scanning and Radioisotope (RI)-cisternography revealed an inner ear dysplasia of the Mondini type, viz. dilation of the lateral semicircular canal, vestibule and cystic degeneration of cochlea on both ears. RI-cisternography demonstrated an abnormal accumulation of radioisotope in the left mastoid region, suggesting spontaneous cerebrospinal fluid (CSF) otorrhea. At exploratory tympanotomy of the left ear, the CSF leak was found from a round defect in the center of the stapedial foot plate. The CSF leak was treated successfully by packing the vestibule with temporal fascia. Spontaneous CSF otorrhea is seldom the cause of meningitis but has to be considered especially if associated with a dead ear and with recurrent meningitis. The diagnosis and management are discussed.

Effects of experimental round window membrane laceration on the free amino acid profile of perilymph.

To evaluate biochemical changes of inner ear fluid following perilymphatic fistula (PLF), free amino acid (FAA) profiles of perilymph in experimental PLF were determined using high performance liquid chromatography (HPLC). Thirty-five guinea pigs were anesthetized and prepared as PLF models by perforating the round window membrane (RWM) of the left ear. Right ears served as controls. Samples (2 microliters) were aspirated from scala tympani through a RWM perforation. Animals were divided into two groups according to time of sampling following PLF induction: 2-week group (n = 17) and 4-week group (n = 18). Compound action potential (CAP) evoked by 1, 2, 4 and 8 kHz tone bursts were measured using a round window electrode from the left ear before PLF induction and from both ears before final sampling. RWM perforations were completely closed at the time of the final sampling in 8 of 17 animals from the 2-week group, and 15 of 18 animals from the 4-week group. In comparison with that in control ears, concentrations of FAA throughout all profiles was dramatically elevated in the PLF ears with a healed RWM perforation. Most PLF ears with persistent RWM perforation showed minimal differences between 2-week and 4-week groups. No remarkable CAP threshold changes were found at any frequencies tested following PLF induction in both the 2-week and 4-week groups. The unchanged 8 kHz threshold suggests that FAA concentration increases only at the basal end of the cochlea. FAAs accumulate within the basal end of scala tympani in ears with a healed RWM.(ABSTRACT TRUNCATED AT 250 WORDS)

The ultrastructure of lymphatic vessels in the human middle ear with cholesteatoma.

Lymphatic vessels were few in the edematous portion of the cholesteatoma perimatrix of the human middle ear. But the lymphatic vessels contained mucus and consisted of degenerated endothelial cells. Edema of the perimatrix was considered to be caused by the degeneration of lymphatic vessels. Normal lymphatic vessels were found in the fibrous perimatrix, while macrophages infiltrated and phagocytosed cell debris. In addition, regenerating blood vessels were observed. Degeneration of connective tissue due to lymphatic edema and its repair were both present in the perimatrix. The degeneration of perimatrix was hypothesized to be caused by confined mucous epithelium behind the cholesteatoma matrix.

A new test of Eustachian tube function with otoadmittance meter: tubotympanometry.

A new method for testing Eustachian tube function using an otoadmittance meter (Tubotympanometry) is reported. The otoadmittance meter is set for the aural reflex test, namely in the position of Y-T- recording. The patient is asked to carry out deep breathing. Valsalva's maneuvre, normal breathing, and swallowing in succession. In normal 40 ears, three types of the tubotympanogram were classified. In type A, observed in 32 ears, the graph shows no changes during deep breathing, a sudden downward deflection with Valsalva's maneuvre, a return to a level after the maneuvre and on repeated swallowing the graph returns to the initial level in stepwise. In type B, observed in 5 ears, the graph returns to the initial level directly after Valsalva's maneuvre without swallowing. This indicates a slightly patent tube, even though in the normal range. Type C was observed in 3 ears of patients who failed to perform Valsalva's maneuvre correctly. In the case of a patent tube, the graph shows a remarkable fluctuation synchronizing with inspiration and expiration. In the case of an occluded tube, the graph shows slower recovery after Valsalva's maneuvre and no complete return to the initial level even after repeated swallowing. In another case of occluded tube, the graph was deflected upward by Valsalva's maneuvre and showed no change on deglutition. The greatest advantage of this test is the simplicity of the equipment and of the test procedure.

Iodine-123 metaiodobenzylguanidine myocardial imaging in patients with pulmonary hypertension.

Iodine-123-metaiodobenzylguanidine [123I-MIBG] has been used to evaluate the cardiac sympathetic nervous system. We evaluated the effect of pulmonary hypertension on the sympathetic neuronal function of the left ventricle in patients with pulmonary hypertension. We studied 20 patients with either chronic lung disease or pulmonary vascular disease. The patients were divided into a pulmonary hypertensive group and a control group. Single photon emission tomography was performed in the resting state 15 min and 4 h after administration of 123I-MIBG. Regions of interest (ROI) were set in the left ventricular (LV) free wall, the interventricular septum (IVS) and outside the LV free wall on short-axis images. The washout rate and the ROI/LV uptake ratio were calculated in each ROI. The IVS:LV uptake ratio was significantly lower in the pulmonary hypertensive group than in the control group. Our results suggest that left heart sympathetic neuronal dysfunction initially occurs in the IVS before it involves the LV free wall subsequently.

Histopathology of eighth cranial nerve of mass stranded dolphins at Goto Islands, Japan.

We examined four dolphins (Grampus griseus) of 582 mass-stranded. Almost no contents were found in the alimentary canal. Nasitrema gondo and Crassicauda grampicola were found in the tympanic cavity. Severe degeneration of the eighth cranial nerve was observed microscopically in all animals and an egg of Nasitrema was found in a tissue crevice of the nerve. We propose that the nerves were damaged directly by Nasitrema.

Mass stranding of Odontoceti caused by parasitogenic eighth cranial neuropathy.

Hearing organs of the Odontoceti from two mass strandings in 1983 and 1986 were examined histopathologically. In the 1983 stranding, two of three pilot whales (Globicephala macrorhynchus) were necropsied and numerous Nasitrema sp. were found close to the eighth cranial nerve (nervus vistibulo cochlearis) in both animals. Patchy degeneration of the eighth cranial nerve in and out of the modiolus of the cochlea was observed. In the 1986 stranding, five of 125 false killer whales (Pseudorca crassiclens) were examined and numerous trematodes (Nasitrema gondo) were found in the tympanic cavities. Severe degeneration of the eighth cranial nerve was discovered and there were many trematode eggs in the nervous and surrounding tissues. Parasitogenic eighth neuropathy is proposed again as the cause of mass stranding of the Odontoceti.

Tl-201 SPECT in Kimura's disease involving the parotid glands and cervical nodes.

Kimura's disease is a chronic inflammatory condition producing subcutaneous tumor-like nodules, mainly in the head and neck region. Most patients have involvement of regional lymph nodes and major salivary glands. The authors present two cases of Kimura's disease with parotid gland and postauricular lymph node involvement. With Tl-201 SPECT, elevated uptake was noted on early and delayed images. Kimura's disease should be included in the differential diagnosis when increased Tl-201 uptake in head and neck mass lesions is noted.

Utilization of nickel-titanium shape memory alloy for stapes prosthesis.

A new type of stapes prosthesis made of nickel-titanium shape memory alloy wire was developed and its biocompatibility was examined in 24 ears of 12 cats. The prosthesis was implanted at the long crus of the incus. The incus was examined 27-355 days after operation. In 23 ears, the prosthesis was found macroscopically well implanted at the aimed position. In one ear the prosthesis was found to be dislocated and in another the prosthesis was slightly loosened. The incudes were removed and five specimens were prepared for scanning electron microscopy and the other specimens were observed under light microscopy. Histological studies revealed severe bone resorption of the long crus in the dislocated case and moderate bone resorption in the slightly loosened case. These bone resorptions were found to be caused by the inadvertent removal of the mucosal membrane during the implant operations. In seven ears under a light microscope and in one ear under a scanning electron microscope, slight bone resorption as bone erosion was seen at the contact area of the prosthesis. This bone resorption was induced by the mechanical pressure of the prosthesis and was not progressive due to fading of the pressure of the prosthesis. With the exception of pressure induced bone erosions, there was no progressive bone resorption which was prosthesis induced. The biocompatibility of the nickel-titanium alloy stapes prosthesis with the long crus of the incus was proved. The prosthesis should be implanted loosely at the long crus of the incus without removal of the mucosal membrane.

Long-term effects of intense sound on hair cells of Corti's organ and endocochlear DC potential.

Cochleograms of guinea pig ears were made 30-40 days after exposure to intense pure tones of 300 Hz, 500 Hz, 2 kHz, or 4 kHz at 130-150 dB SPL for 4-24 h. At 4 kHz, hair cells in the basal turn disappeared totally, in the second turn moderately, and were relatively undamaged in the third and apical turns. At 500 Hz, hair cells in the second and third turns were almost completely injured and at 300 Hz moderately damaged in the third and apical turns although the basal turn remained undamaged. At 2 kHz for 9 h, hair cells were almost completely injured in all turns. Negative endocochlear DC potential (negative EP) induced by furosemide was observed in the basal turn but not in the third turn of animals exposed to 300 Hz. Contrarily, negative EP was observed in the third turn but not in the basal turn of animals exposed to 4 kHz. We conclude that the hair cells of Corti's organ play an essential role in the production of negative EP.