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Biomedical subjects

K Kaga

Publications and source records attributed to K Kaga.

At least 109 records · Page 6Linked to original sources
PubMed1996

Auditory nerve disease of both ears revealed by auditory brainstem responses, electrocochleography and otoacoustic emissions.

We report on two patients who showed absence of auditory brainstem response (ABR) but broad compound action potentials on electrocochleograms and almost normal otoacoustic emissions, together with absence of caloric response and preservation of per rotatory nystagmus for both ears. Patient 1, a 53-year-old woman, had noted auditory and vestibular problems since the age of 15 years, and Patient 2, a 68-year-old woman, had noted problems of the same age of 30 years. They could hear words and understand sentences if spoken slowly, but they could not discriminate monosyllables very well. Their auditory examinations disclosed mild threshold elevation in pure-tone audiometry and markedly poor scores in speech audiometry and good scores in auditory comprehension test. They were diagnosed as having auditory nerve disease of unknown cause.

Acoustic Stimulation↗
PubMed1996

[Temporal bone pathology in neonates with severe visceral anomalies].

It is well known that hearing loss is often associated with anomalads, syndromes involving multiple anomalies. The incidence is especially high in severe cases of facial and visceral malformations. However, otologic features remain unclear in patients with a sequence of various anomalies which can not be classified into any known syndrome. We examined 11 temporal bones from 6 patients with severe visceral anomalies, which could not be classified into any known systemic bone diseases, chromosomal abnormalities, or congenital metabolic disorders. Temporal bone pathology was compared with external and visceral anomalies in each case. The temporal bones had been removed at autopsy, fixed in 10% formaldehyde, decalcified and embedded in celloidin. Serial horizontal sections were made at 20 microns and every tenth section was stained with hematoxylin eosin. Most abnormalities in the middle and inner ear were found to have an ectodermal or mesodermal origin. Inner ear abnormalities were noted in 6 temporal bones from 3 patients; the predominant feature was hypoplasia of the semicircular canals. Middle ear abnormalities excluding residual mesenchymal tissue were noted in 5 temporal bones from 4 patients; the predominant feature was an abnormal course of the facial nerve. It was also suspected that auricular and maxillomandibular abnormalities, which are often associated with severe visceral anomalies, indicate a high incidence of disorders affecting the auditory and vestibular systems.

Abnormalities, Multiple↗
PubMed1996

Thoracoscopic surgery for lung cancer using the two small skin incisional method. Two windows method.

Pulmonary lobectomy and mediastinal lymph node dissection was performed in 25 patients with Stage I lung cancer under thoracoscopic guidance using the two-windows method. A posterior skin incision (3 cm) and lateral skin incision (2 cm) were made in the 4th intercostal space centering on the inferior angle of the scapula. The site closest to the operating surgeon was used for direct vision, while the distant site was used for insertion of the thoracoscope. The mean operative time was 2 hours and 15 minutes, and the mean blood loss was 82.6 ml. The mean number of dissected mediastinal lymph nodes was 32. The length of hospitalization ranged from 5 to 17 days. Recovery was uneventful, and analgesics were not required by postoperative day 6. The two-windows method overcomes the three-dimentional inaccuracy due to the one-directional observation of the operative field employed during conventional thoracoscopy. In addition, since we developed this method for mediastinal lymph node dissection, the tracheal bifurcation can be confirmed under direct vision, increasing the accuracy of the procedure. The advantages of the two-window thoracoscopic method of pulmonary lobectomy are cosmesis, preservation of respiratory function, and reduced postoperative pain. In addition, there is reduced intraoperative bleeding and shortened operative time, while achieving mediastinal dissection similar to that of standard thoracotomy. The two-windows method of thoracoscopic pulmonary lobectomy is equal or superior to standard thoracotomy in every respect. This method should become the standard surgical technique for Stage I lung cancer.

Adenocarcinoma↗
PubMed1996

Aromatase in human common epithelial ovarian neoplasms.

The expression of aromatase was evaluated in 44 ovarian carcinomas, 7 carcinomas of low malignant potential (LMP), and 14 benign adenomas. Aromatase immunoreactivity was observed in stromal cells in 35 of 44 (79.5%) ovarian carcinomas and 3 of 7 carcinomas of LMP. However, no immunoreactivity was pronounced at sites of frank invasion in ovarian carcinoma. To characterize aromatase in ovarian carcinoma, aromatase activity, mRNA expression, and alternative uses of exon 1 were determined. Quantitation of aromatase activity with the tritiated water method demonstrated 41.62 +/- 9.15 pmol/hour/mg protein in 11 ovarian carcinomas. The mean concentration of aromatase mRNA for 14 ovarian carcinomas was 3 +/- 4 amol/ng RNA, which significantly correlated with aromatase immunoreactivity. The alternative use of multiple copies of exon 1 was examined by reverse transcriptase polymerase chain reaction in 11 carcinomas. The transcript, mainly using exons 1c and 1d, was detected in 4 and 5 cases of carcinoma, respectively. Patterns of utilization of exon 1, however, did not significantly correlate with aromatase overexpression. These results suggest that aromatase is expressed in stromal cells of ovarian carcinoma but not in benign ovarian neoplasms. Increased aromatase expression in stromal cells of human ovarian carcinoma is, therefore, considered to play an important role in the biological behavior of these tumors by producing estrogens in situ as in other female sex-steroid-dependent neoplasms.

Adenocarcinoma↗
PubMed1996

17 beta-hydroxysteroid dehydrogenase in common epithelial ovarian tumors.

Type 1 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) is an estrogen-metabolizing enzyme that catalyzes the conversion of estrone to the more biologically potent estradiol. We examined the immunolocalization of 17 beta-HSD in five specimens of normal human ovary and in 51 specimens of common epithelial tumors of the ovary to study the expression of 17 beta-HSD in these ovarian neoplasms. 17 beta-HSD immunoreactivity was detected in granulosa cells of dominant preantral follicles but not in the surface epithelium of the normal cycling human ovary. In 12 patients, the enzyme was not expressed in tumor cells of benign cystadenoma. 17 beta-HSD was immunolocalized in the cytoplasm of four specimens (50%) of eight of tumors of low malignant potential and in 20 specimens (67%) of 30 of invasive carcinoma. 17 beta-HSD immunoreactivity was also observed in nonluteinized stromal cells of mucinous tumors (two adenomas of six, three tumors of five with low malignant potential, and two of 10 invasive carcinomas) but not in other histologic types. Type 1 17 beta-HSD expression, therefore, correlated with malignant transformation of the surface epithelium of the human ovary, supporting a possible role in its progression by increasing in situ estradiol concentration.

17-Hydroxysteroid Dehydrogenases↗
PubMed1995

Auditory brainstem responses in children with Cornelia de Lange syndrome.

Auditory brainstem evoked responses (ABRs) were recorded in 10 Japanese infants and children with Cornelia de Lange syndrome to determine the level of the lesion causing their poor response to sound. Behavioral audiometry showed severe threshold elevation compared to an age-matched control group. ABR thresholds, peak latencies of wave I and IV and the peak interval latency of waves I-V were measured. ABR abnormalities of 4 types: no ABRs following 85 dB clicks in both ears (4 cases), no ABRs in one ear but normal ABR in the other (2 cases), mild wave V threshold elevation of ABR with a markedly prolonged wave V (2 cases) and normal ABR pattern in the one side and abnormal ABR pattern in the opposite side suggesting brainstem immaturity for age (2 cases). Our results demonstrate a high prevalence of peripheral sensorineural hearing loss in Cornelia de Lange syndrome, but brainstem immaturity was not ruled out in 2 cases.

Adolescent↗
PubMed1995

Auditory air and bone conduction brainstem responses and damped rotation test for young children with bilateral congenital atresia of the ears.

This paper describes our assessment of auditory and vestibular functions at a very early age using the auditory air and bone conduction brainstem responses and the damped rotation test for infants and children with bilateral congenital atresia of the ear. Twelve infants and children with congenital microtia and occlusion of bilateral auditory canals were evaluated by this assessment to determine their function of hearing and balance and their suitability for fitting and surgical improvement.

Audiometry, Evoked Response↗
PubMed1995

Neuro-otological and neuropathological findings in two cases with Machado-Joseph disease.

We report chronological changes of neuro-otological findings and associated neuropathological findings in 2 patients. Concerning gaze limitation, upward gaze was primarily disturbed, followed by downward gaze and abduction. Adduction tended to be preserved although convergence was disturbed at the early stage. And, upward gaze limitation was followed by loss of oculocephalic responses (OCRs). Bell's phenomenon was preserved until the late stage of the disease. Caloric nystagmus was absent at the early stage. One patient showed dissociation between nystagmus and vestibulo-collic reflex in the caloric test at the early stage of the disease. Neuropathological examination revealed gliosis in the interstitial nucleus of Cajal and the MLF as well as neuronal loss and gliosis in the oculomotor nuclei. The vestibular nuclei also showed gliosis and atrophy of nerve cells.

Brain Stem↗
PubMed1995

Magnetic resonance angiographic findings in vertiginous patients with slow vertebrobasilar blood flow.

To investigate arterial lesions underlying slow vertebrobasilar blood flow (SBF) which appears as a high intravascular signal on proton-density images, we examined 35 vertiginous patients, 15 with SBF and 20 without, using magnetic resonance angiography. Vertebrobasilar dolichoectasia, segmental stenosis with elongation and diffuse narrowing of the vertebrobasilar arteries (VBA) were found in 4, 4 and 2 patients with SBF, respectively. In one patient with SBF, the thrombi that induced SBF seemed to have embolized to distal arteries. These abnormalities were not detected in patients without SBF, although 2 patients demonstrated aneurysm in the VBA. Because SBF is frequently associated with atherosclerotic arterial lesions, patients with SBF should be treated to prevent more severe ischemic brain disease.

Aged↗
PubMed1995

Ocular movement during reading in patients with congenital nystagmus.

When a healthy person reads sentences arranged horizontally, the eye movement pattern is a series of regular saccades and rest periods. However, eye movements while patients with oculomotor disturbances are reading remain to be defined. In this study, 4 patients with congenital nystagmus (CN) were studied. Coordinated movements of eye and head are also studied by a new apparatus with terrestrial magnetism sensor. While subjects were reading, an eye movement pattern was superimposed by the CN waveform and showed few rest periods. Eye velocity of less than 4 degrees/s was noted in almost every cycle of the eye movements while the patients with CN were reading. When they were requested to read sentences and simultaneously rotate their head naturally, the head movements had the effect of cancelling the eye instability. This finding may be interpreted as a kind of "eye-head coordination".

Attention↗
PubMed1995

Apogeotrophic type of direction-changing positional nystagmus related to slow vertebrobasilar blood flow.

We examined the incidence of slow blood flow (SBF) in the vertebrobasilar system by magnetic resonance imaging (MRI) in 35 patients showing direction-changing positional nystagmus (DCPN). The subjects consisted of 20 patients with apogeotrophic type (group A) and 15 with geotrophic type (group B) of DCPN. Fifty-seven age-matched subjects without vestibular symptoms were examined as a control group (group C). SBF was detected in 11 (55%), 3 (20%) and 6 (11%) patients in groups A, B and C, respectively. Lacunae of the brainstem were found in 7 (35%) patients in group A and 1 (7%) in group B. The higher incidence of SBF in group A suggested a possible relationship between SBF and apogeotrophic type of DCPN. Apogeotrophic type of DCPN associated with SBF was considered to be caused by ischemia in the posterior circulation, though it was unclear whether the vestibular labyrinth or the hindbrain was mainly involved.

Adult↗
PubMed1995

Auditory brainstem response and temporal bone and brainstem pathology in brainstem death, with special reference to autolysis of red blood cells.

We studied the pathological changes in the temporal bone and brainstem, with particular attention to the autolysis of red blood cells in and around the blood vessels, in six cases of brainstem death determined by auditory brainstem responses (ABRs). Our findings showed that the cochlea, the visceral organs and the spinal cord below a certain level of the cervical segments continued to live after brainstem death. Red blood cells in the vessels of the brainstem and cerebellum exhibited severe autolysis, whereas most red blood cells in the cochlea were preserved. Our findings of autolytic changes in red blood cells in the brainstem, and the preservation of red blood cells in the cochlea, imply initial loss of brainstem function and delayed loss of cochlear function after prolonged absence of ABRs.

Adolescent↗
PubMed1995

[Distribution and origin of corpola amylacea in the vestibulocochlear nerve].

The distribution of the corpora amylacea in the vestibulocochlear nerve is very limited. We studied the relation between the number of corpora amylacea in the cochlear nerve and the aging of cochlea and developed some hypotheses on the origin of corpora amylacea. This study involved 11 subjects, 14 samples. The results were as follows. There was no relationship between the number of corpora amylacea in the cochlear nerve and aging of the cochlea. Corpora amylacea probably have no relation to cochlear disorders. However, it was reported that corpora amylacea were produced more than 10 years after the organ's obstruction. There is a possibility that corpora amylacea increased 10 years after disorders developed in the cochlear nerve. There is a neurilemma-Schwann sheath junction (NSS junction) in the vestibulocochlear nerve. Corpora amylacea characteristically exist only in the central portion of the vestibulocochlear nerve on one side of the NSS junction. There are 3 possibilities regarding the origin of corpora amylacea which include consideration of the hypothesis that the NSS junction is the point where the vestibulocochlear nerve pierces the encephal dura mater. 1) Supposing that the origin of the corpora amylacea is the vestibulocochlear nerve itself, we would expect that the oligodendrocytes which are components of the vestibulocochlear nerve to be the origin of the corpora amylacea because they exist only in the central portion of the nerve, but not in peripheral portions of the nerve. 2) Supposing that the origin of the corpora amylacea is not the vestibulocochlear nerve itself, we would expect that the perineurium from the encephal dura mater to be the origin of corpora amylacea.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Clinical use of EVAR and OVAR by the dumped rotation test--comparison of normal volunteers and patients with unilateral vestibular nerve section].

Horizontal eye movements in response to either earth vertical axis rotation (EVAR) or off vertical axis rotation (OVAR) by a 10 degree tilted axis were recorded in six normal subjects and three patients with unilateral vestibular nerve section. Both trials consisted of acceleration at approximately 400 deg/sec2 until an angular velocity of 180 deg/sec was reached followed by deceleration at -4 deg/sec2 until rotation ceased. This is the so-called dumped rotation procedure. Total numbers of nystagmic beats and the duration of perrotatory nystagmus in these two different trials were compared. The results were as follows: 1) Total numbers of nystagmic beats in OVAR were significantly larger than in EVAR. 2) The duration of perrotatory nystagmus in OVAR was significantly longer than in EVAR. Only the horizontal semicircular canals were stimulated by angular acceleration in EVAR, whereas both otolith organs and semicircular canals were stimulated on changing the position of the head around the direction of the gravity in OVAR.

Acceleration↗
PubMed1995

[Secondary tumor of the temporal bone with internal auditory meatus involvement--histopathological study].

Nineteen cases of secondary tumor of the temporal bone with involvement of the internal auditory meatus (IAM) were studied. The cases were classified into 4 invasion modes; direct extension from head and neck tumors (12 cases), hematological dissemination (3 cases), diffuse leptomeningeal carcinomatosis (3 cases), and direct extension of tumors from the intracranium (1 case). There were some differences in the manner in which the tumor had spread among these 4 modes. In most cases involving "direct extension from head and neck tumors", the tumor had invaded the pyramis, and then the Eustachian tube and the middle ear. When the inner ear or the IAM was involved, it was directly invaded by massive tumor. In all cases of "hematological dissemination", metastatic tumor was found bilaterally, but there were some differences in the manner of invasion between the two sides. In "leptomeningeal carcinomatosis" and "intracranial tumor", the tumor had invaded the temporal bone bilaterally via the IAM. In the IAM, cochlear and inferior vestibular nerves were more vulnerable to tumor invasion than facial and superior vestibular nerves. It was suggested that there are some differences in vulnerability to tumor invasion between the superior and inferior vestibular nerves. The bottom of the IAM presented a barrier-like effect against the spread of tumor from the IAM to the labyrinth. In some cases, however, there was massive tumor invasion of the internal ear directly from the IAM. Whether denervation of the ganglionic neurons (spiral or vestibular) causes secondary degeneration of peripheral sensory endorgans remains controversial. In some cases in our series, degeneration of the auditory or vestibular peripheral organs might be attributed to denervation of neurons in the spiral or vestibular ganglia. In other cases, however, auditory and vestibular peripheral organs remained intact despite severe degeneration of ganglionic neurons.

Adolescent↗
PubMed1995

[Pure word deafness after cerebral hemorrhage in the left temporal lobe: a case report].

We report a patient with pure word deafness after subcortical hemorrhage in the left temporal lobe. Repetition and auditory comprehension were severely impaired, while reading and visual comprehension of the same material were almost normal. He did not show hearing loss, but speech discrimination and melody recognition was poor. On the speech discrimination test, his score was low especially in the right ear. The threshold on the directional hearing test was mildly elevated. There was no temporal summation by click sounds. CT and MRI disclosed a subcortical hematoma in the left superior temporal gyrus. PET demonstrated hypoperfusion in the surrounding area, which was not activated by hearing a story. It was considered that pure word deafness in this case was due to the interruption of auditory inputs to Wernicke's area from both hemisphere by the hematoma. After 5 months, auditory comprehension recovered so that he did not have difficulty in conversation. Speech discrimination improved in both ears, probably due to the recovery of two auditory pathways; the ipsilateral pathway through the left auditory radiation and the contralateral pathway through the right auditory radiation and the corpus callosum. This case suggests that in pure word deafness due to a unilateral lesion, the improvement in speech discrimination during follow-up period may provide a clue as to the site of the responsible lesion and its recovery.

Aged↗
PubMed1995

[Video assisted lung resection and mediastinal lymph nodes dissection for lung cancer: small incisions for 4th intercostal space].

We established a thoracotomy method in which visual observation and a thoracoscope are used in combination. This method requires only small dermal incision--a three-cm-long posterior and two-cm-long anterior incision--in the fourth intercostal space around the angulus inferior scapulae. Using this method, we performed lobectomy and mediastinal lymph node dissection on 20 lung cancer cases (preoperatively diagnosed as stage I, T1N0M0 cases). Because the conventional thoracoscopic surgery relies strictly on two-dimensional images obtained from a thoracoscope, stereoscopic information on the location of the operation could not be obtained. Our new method, however, in corporates both a direct view obtained from two small incisions and a view on a video monitor, so the surgeon has constant access to a stereoscopic information on the location of the operation. We found that this thoracotomy using a thoracoscope was not only very useful in terms of respiratory function, the alleviation of pain, and aesthetic appearance, but that it also reduced hemorrhaging during surgery, decreased the length of time required for the thoracotomy and suturing, and enabled mediastinal dissection equal to that of standard thoracotomy.

Adult↗