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Biomedical subjects

K Kaga

Publications and source records attributed to K Kaga.

At least 73 records · Page 4Linked to original sources
PubMed1998

Experience with the two-windows method for mediastinal lymph node dissection in lung cancer.

BACKGROUND: Continuing to refine minimally invasive thoracoscopic surgical procedures, we have established the two-windows method. METHODS: Skin incisions required by this method consist of a 2- to 3-cm skin incision posteriorly, and a 2- to 3-cm skin incision anteriorly in the fourth intercostal space, with the inferior angle of the scapula as the midpoint. We used this method to perform pulmonary lobectomies in combination with thoracoscopy and mediastinal lymph node dissection in 100 consecutive patients with lung cancer (preoperative diagnosis, stage I, T1 N0 M0). RESULTS: The mean operative time was 2 hours 46 minutes, the mean blood loss was 68.2 mL, and the mean number of mediastinal lymph nodes dissected was 24.3. In developing this minimally invasive thoracoscopic procedure, which facilitates mediastinal lymph node dissection, we realized that it is best performed through the fourth intercostal space. Because the tracheal bifurcation can be seen directly below this level, surgical manipulation in this area can be easily performed. This enables the same extent of mediastinal lymph node dissection as that performed during a standard thoracotomy. Another advantage of this method is that a standard posterolateral thoracotomy incision can be made whenever necessary by simply connecting the two incisions. CONCLUSIONS: We believe that the two-windows method is capable of serving as the standard method for the surgical treatment of stage I lung cancer.

Adult↗
PubMed1998

A preliminary report: clinical effects of otic solution of ofloxacin in infantile myringitis and chronic otitis media.

Patients with infantile myringitis or chronic otitis media may refuse treatment when antibiotics are to be administered orally. The present study was undertaken to treat myringitis and chronic otitis media with an otic solution of non-ototoxic ofloxacin in 21 children aged 0-15 years. They consisted of eight normal children, four children operated on for microtia, and nine so-called handicapped children mainly with advanced hearing impairment and retardation in mental development, or eight children with myringitis and 13 children with chronic suppurative otitis media. Otic solution of ofloxacin was instilled into the ear twice daily, in the morning and evening, for 7 days or more, the treatment time being 10 min. With the causative pathogen completely eradicated in 14 patients and the bacterial count reduced in three patients and unchanged in two patients, the results of treatment with ofloxacin may be considered to be excellent.

Anti-Infective Agents↗
PubMed1998

Development of the blood-labyrinth barrier in the rat.

Systemically administered cationic polyethyleneimine (PEI) passes through the capillary endothelial cell and attaches to anionic sites on the capillary basal lamina (BL). Thus, the distribution of PEI on the BL reflects the changes in the endothelial cell transport system. A 0.1% PEI solution was administered by intravenous injection (7.5 ml/kg) to developing (4, 7, 11, 14, 21 days after birth) and adult rats to evaluate the development of endothelial cell transport in the cochlear capillary as related to age. One hour later, the bony labyrinth was removed and embedded in Epoxy resin. Ultrathin sections of the cochlear lateral wall were then viewed with a transmission electron microscope. The distribution of PEI in the capillary BL in the stria vascularis of the 4-, 7- and 11-day-old rats was significantly greater compared to the adult rats. The distribution of PEI in the capillary BL in the spiral ligament of the 4- and 7-day-old rats was also significantly greater compared to the adult rats. These findings suggest that the endothelial cell transport is more robust in the developing rat cochlea and that the blood-labyrinth barrier becomes mature by 14 days after birth in rats.

Animals↗
PubMed1998

Brainstem pathology of infantile Gaucher's disease with only wave I and II of auditory brainstem response.

We studied the auditory brainstem response (ABR) and neuropathology in a female infant who died at six months of age because of typical infantile Gaucher's disease. The patient was hospitalized for hepatosplenomegaly and failure to thrive. Her ABR showed only waves I and II. The neuropathological study disclosed that: (1) Gaucher's cells were found in the perivascular region of the cerebrum and anterior ventral nucleus of the thalamus. (2) Gliosis was found in the dorsal part of the brainstem rather than the ventral part. (3) Neuronal cells in the superior olivary nucleus were lost, and marked gliosis was found in the cochlear nucleus. The disappearance of wave III and later waves of ABR could be supported by these pathological findings.

Brain Stem↗
PubMed1998

Induction of KGF, basic FGF, and TGFalpha mRNA expression during healing of experimental TM perforations.

KGF (KGF), synthesized and secreted exclusively by stromal cells in epithelialized organs, specifically promotes proliferation of cells of epithelial origin, including keratinocytes. A related peptide, basic fibroblast growth factor (bFGF), has mitogenic properties for fibroblasts and endothelial cells. KGF expression is stimulated markedly in the skin during wound healing. To investigate the physiologic action of KGF in the healing of TM (TM) perforations, we examined KGF and KGF receptor (KGFR) mRNA transcript levels as well as those of bFGF and transforming growth factor-alpha (TGFalpha) in normal and wounded rat TM at varying intervals, using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). We found KGF and TGFalpha mRNA expression to be induced rapidly, peaking 3 days after wounding and then declining. Expression of bFGF was induced gradually and remained increased until 7 days. In contrast, we found KGFR to be expressed in normal TM, remaining unchanged during TM repair. These results indicate that KGF and TGFalpha may mediate migration and proliferation of epithelial cells of the outer layer in the early stage of TM repair while bFGF may mediate the connective tissue reaction in the middle layer in a subsequent stage.

Animals↗
PubMed1998

Average thresholds in the 8 to 20 kHz range in young adults.

The sound-pressure level thresholds in the extended high-frequency range (8 to 20 kHz) were measured in 25 non-hearing-impaired young adults from 20 to 29 years of age. The result was not unlike that obtained by previous investigators; the thresholds increased gradually as a function of frequency. However, two notable points were found: one that the threshold reached a plateau above 18 kHz, and the other that it decreased slightly at 12 kHz. As the subjects might respond to the low-frequency noise of the stimulus wave, the threshold became a plateau above 18 kHz. An acoustic resonance in the ear canal caused the threshold to decrease at 12 kHz. In clinical studies of extended high-frequency audiometry, the threshold data should be carefully evaluated above 18 kHz and at 12 kHz.

Adult↗
PubMed1998

Average thresholds in the 8 to 20 kHz range as a function of age.

The sound-pressure thresholds at the extended high frequencies of 8-20 kHz were measured for 65 normal subjects aged between 10 and 69 years. The results are not unlike those obtained by previous investigators. The thresholds increased gradually as a function of frequency, except around 12 kHz and above 19 kHz, and also as a function of age. To clarify the connections between threshold, frequency and age, we introduced the regression lines for the threshold by analysing two ranges of frequencies (8-10 kHz and 14-19 kHz) and determining their slopes and intercepts. The regression line analysis reveals that the thresholds at 8-10 kHz tend to increase more at higher frequencies as subject age increased above 30 to 39 years, and those at 14-19 kHz increase translationally with increase of age. Our results did not contradict earlier reports on the pathological changes of the inner ear.

Adolescent↗
PubMed1998

Effects of chronic administration of kanamycin on the basement membrane anionic sites in the crista ampullaris of guinea pigs.

The authors investigated the effects of chronic kanamycin (KM) administration on the basement membrane (BM) anionic sites in the ampulla by studying the binding of cationic polyethyleneimine (PEI). KM sulfate was administered intramuscularly to guinea pigs with normal Preyer's reflexes daily for 10 or 17 days. The PEI distribution was unchanged on the subepithelial BM in the dark cell region and on the capillary BM in the crista ampullaris. However, PEI binding decreased significantly on the subepithelial BM in the sensory cell and transitional cell regions of those guinea pigs administered KM for 17 days. In the sensory cell region, the PEI distribution did not recover until 6 weeks after KM treatment. Findings suggest that chronic administration of KM severely alters the number of subepithelial BM anionic sites in the sensory cell region.

Animals↗
PubMed1998

Keratinocyte growth factor and its receptor messenger RNA expression in nasal mucosa and nasal polyps.

To examine the potential biologic role of fibroblast growth factors (FGFs) in nasal polyps and nasal mucosa during chronic inflammatory conditions, we investigated messenger RNA (mRNA) expression of three members of the FGF family -- acidic FGF, basic FGF, and keratinocyte growth factor (KGF)-- in nasal polyp tissues, as well as in hyperplastic nasal mucosa. Using the sensitive method reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated that of the examined FGFs, KGF had the most abundant mRNA expression in nasal polyps and nasal mucosa. We also found that significantly higher levels of KGF mRNA were expressed in nasal polyps than in nasal mucosa, whereas mRNA expression of acidic FGF and basic FGF was relatively low in these tissues. In addition, we showed that KGF receptor mRNA was present in most of the nasal mucosa; however, none or little was expressed in nasal polyps. These results suggest that KGF might play an important role in nasal epithelial proliferation and that excessive synthesis of KGF in nasal polyp stroma may contribute to hypertrophy of the nasal mucosa in patients with chronic sinusitis associated with nasal polyposis.

Adult↗
PubMed1998

[Facial nerve anomalies of children with congenital anomalies].

It is well known that congenital anomalies are often associated with malformation of the inner, middle and external ear. In temporal bone studies, it has been found that abnormality of the facial nerve often occurs in patients with congenital aberrations. The temporal bone collections of the Teikyo University School of Medicine include 32 human temporal bones obtained from 19 infants ranging in age from one day to 7 months, who had chromosomal aberration and severe visceral anomalies. We histologically studied routinely processed sections of these temporal bones under a light microscope. Facial anomaly was observed in 20 of the 32 ears (63%). An abnormal course was observed in 18 ears (56%); 5 ears showed hypoplastic development, 4 showed displacement of geniculate ganglion cells into the internal auditory meatus, and 3 ears showed bifurcation. Abnormal course of the facial nerve was found in a significant number of ears with aural and mandibulal abnormalities (76%). However patients with multiple inner ear anomalies showed an abnormal course and hypoplasia of the facial nerve. There was no correlation between the incidence of facial abnormalities and inner ear anomalies.

Abnormalities, Multiple↗
PubMed1998

A new device for thoracic access: the Thoraco Holder.

BACKGROUND: We present a novel invention (Thoraco Holder; Fuji Systems Corporation, Tokyo, Japan) for thoracoscopic surgery. Made of silicone, automatically stops bleeding from the chest wall, increases range of motion for manipulation, and decreases postoperative pain. METHODS: Under general anesthesia using the Univent tube (Fuji Systems Corporation, Tokyo, Japan), two Thoraco Holders were used in each of 300 thoracoscopic procedures for lung cancer, mediastinal tumor, pneumothorax, chest trauma, and emphysema, most using the Two Windows Method). RESULTS: No patient experienced more than 10 mL of bleeding from the chest wall. In addition, analgesics were not needed by any patient for over 1 week. No patient experienced trouble caused by the Thoraco Holder. CONCLUSIONS: The Thoraco Holder is made of silicone. Silicone rubber causes less pain postoperatively. The silicone cuff (balloon) causes less bleeding from the chest wall. This Thoraco Holder is useful access for video assisted thoracoscopic surgery.

Endoscopes↗
PubMed1997

Temporal bone pathology of acoustic neuroma correlating with presence of electrocochleography and absence of auditory brainstem response.

The temporal bone pathology of a 74-year-old female affected by vestibular schwannoma was compared with findings of auditory brainstem response and electrocochleography. At age 71, she complained of hearing loss in the left ear in which pure tone audiometry revealed threshold elevation in the middle- and high-frequency range. Temporal bone CT scanning revealed a medium-sized cerebellopontine angle tumour in the left ear. ABR showed no response in the left ear, but the electrocochleography showed clear compound action potentials. Three years later, at age 74, she died of metastatic lung cancer and sepsis. The left temporal bone pathology consisted primarily of a large vestibular schwannoma occupying the internal auditory meatus. The organ of Corti was well preserved in each turn. In the modiolus, the numbers of spiral ganglion cells and cochlear nerve fibres in each turn were decreased. These histological findings suggest that clear compound action potentials were recorded from the distal portion of the cochlear nerve in spite of the presence of the vestibular schwannoma, but ABR could not be detected because of the blockade of the proximal portion of the cochlear nerve by the vestibular schwannoma.

Aged↗
PubMed1997

Sudden bilateral hearing loss due to gastric carcinoma and its histological evidence.

Six temporal bones and a brain tissue sample removed at autopsy from four patients with bilateral sudden hearing loss related to gastric adenocarcinoma were histologically studied. The pathological remains suggest that the sudden hearing loss of these patients may have occurred via one of two different mechanisms: (1) metastasis to the internal auditory meatus damaging the auditory nerve or (2) inner ear haemorrhage damaging Corti's organ. These two mechanisms may cause bilateral sudden deafness in patients with gastric adenocarcinoma.

Adenocarcinoma↗
PubMed1997

Effect of cisplatin on the basement membrane anionic sites in the ampulla, macula, and stria vascularis of guinea pigs.

Our objective was to compare changes in the basement membrane anionic sites (BMAs) in the ampulla, macula, and stria vascularis following the infusion of cisplatin (CDDP). After CDDP was administered to anesthetized Hartley guinea pigs, the bony labyrinth was immersed in a solution of polyethyleneimine (PEI). The size and distribution of PEI particles associated with BMAs in the stria vascularis and in the dark cell and sensory cell areas of the vestibular labyrinth were determined by electron microscopy. A significant reduction in the number and size of PEI particles was observed on CDDP-treated strial vessels. The number and size of PEI particles on the basement membranes of the vestibular labyrinth did not differ from those in the control. Our findings suggest that the BMAs of the vestibular labyrinth were not significantly affected by the administration of a single dose of CDDP.

Acoustic Maculae↗
PubMed1997

Auditory evoked responses under total spinal anesthesia in rats.

In order to investigate the function of the auditory pathway from the cochlea to the brain stem under total spinal anesthesia, the auditory brain stem response (ABR), compound action potential of the cochlear nerve (CAP), and cochlear microphonics (CM) were simultaneously recorded in rats. Total spinal anesthesia was induced by infusion of 2% lidocaine hydrochloride at a constant rate of 0.10 mL/min into the cerebrospinal fluid through the rats' skulls. The ABR completely disappeared within 1.5 to 4 minutes. After cessation of the injection, the ABR reappeared, starting from wave I and progressing through waves II and III to wave IV. The latency change of the CAP throughout the recording period was quite similar to that of wave I of the ABR. A reduction in amplitude of the CM was observed, but the CM did not disappear during the recording period. Disappearance of the ABR was due, not to loss of cochlear function, but to anesthetic effects on the acoustic nerve and the brain stem. Monitoring of the ABR provided information on the level of neural activity in the brain stem under total spinal anesthesia.

Action Potentials↗