Biomedical subjects

T Takasaka

Publications and source records attributed to T Takasaka.

At least 55 records · Page 3Linked to original sources

PubMed1999

Endoscopic sinus surgery improves pulmonary function in patients with asthma associated with chronic sinusitis.

We evaluated the clinical efficacy of endonasal endoscopic sinus surgery (ESS) in patients with asthma associated with chronic sinusitis. Twenty-one patients (13 men and 8 women) from 27 to 72 years old were enrolled in this study. All patients had had sinus-related symptoms for more than 3 months and had computed tomographic evidence of paranasal sinus opacification. Fifteen patients underwent bilateral endonasal ESS under local anesthesia, and 6 other patients without surgery were controls. The sinus-related symptoms of the preoperative and postoperative periods were assessed via a questionnaire. The period 6 months prior to surgery was compared with that 6 months postoperatively with regard to peak expiratory flow and total dosage of systemic glucocorticoids. Sinus-related symptoms in the ESS group were significantly improved 6 months postoperatively. The average peak expiratory flow 6 months following surgery was improved in the ESS patients, ranging from 40 to 190 L/min. Seven patients showed a reduction in the need for corticosteroids, whereas 2 patients were unchanged and 2 patients required larger dosages. The remaining 4 patients needed no corticosteroids before or after ESS. No significant changes in sinus-related symptoms or peak expiratory flow were obtained for the control group. Improvement of paranasal sinus disease by successful ESS can alleviate pulmonary dysfunction in asthma associated with chronic sinusitis. We believe that adequate and positive treatment for chronic sinusitis would reduce not only the nasal and sinus-related symptoms evoked by chronic sinusitis, but also some of the signs induced by asthma.

Adult↗

PubMed1999

Sensorineural hearing loss associated with Byler disease.

Progressive familial intrahepatic cholestasis, sometimes described as Byler disease, is a lethal liver disease and its inheritance is autosomal recessive. There is a previous report on the occasional association between this disease and sensorineural hearing loss without any audiological findings. We report here two siblings, an 18-year-old female and a 16-year-old male, suffering from Byler disease and hearing loss. Pure tone, Bekesy and speech audiometries and auditory brain stem response examination were performed. Audiometric data showed hearing characteristics of cochlear origin, high-frequency loss and progressiveness. This sensorineural hearing loss possibly results from a genetic mutation. The mechanism of cochlear disorder in patients with Byler disease is unknown, however, a novel gene responsible for deafness might be found to be related to Byler disease.

Adolescent↗

PubMed1999

[Multiple primary cancers of oral cavity and pharynx].

Multiple primary cancers were found in 23 of 68 patients (34%) with an index cancer in the oral cavity or pharyngeal area treated in our institute from June 1995 to July 1998. Four cases had triple primary cancers. All 68 cases underwent upper and lower gastrointestinal endoscopy as well as ultrasonography of the liver. Lung CT was performed in cases with abnormal findings on chest roentgenograms. Multiple cancers were found in 5 of 25 oral cavity cases (20%), 6 of 14 mesopharynx cases (43%) and 12 of 29 hypopharynx cases (41%). Nine of 23 cases (39%) were synchronous and 14 (61%) were metachronous. Eighteen of 27 (69%) secondary cancers occurred in the upper aerodigestive tract with an especially high incidence (22%) in the esophagus. Gastroendoscopy also revealed 7 neoplastic lesions, aside from cancers, with the total abnormal rate of 24% (24/68). Thus, gastroendoscopy is useful for the diagnosis of multiple primary cancers. The frequency of multiple primary cancers in males (33%) was not different from that in females (35%). The average age of multiple primary cancer patients (65.1 years) was a little higher than that of single cancer patient (62.7 years). Smoking or drinking was not related to the incidence of multiple cancers. The interval between the first and the second cancer in metachronous cancer cases was 25.5 months on average, and within 4 years in 71% (10/14) of the cases. This result suggests that close follow-up including endoscopy should be required for at least 4 years after treatment of oral or pharyngeal cancer. Radical treatment for each of the multiple cancer lesions was performed in 22 of 23 cases, and the mortality rate of multiple primary cancer cases was not significantly different from that of single cancer cases. Among 7 cases who died of disease, 5 cases died of distant metastasis, suggesting that control of distant metastasis is an important issue in the treatment of multiple primary cancers.

Adult↗

PubMed1999

[Simultaneous reconstruction of pharyngoesophagus and phonetic shunt following laryngopharyngoesophagectomy].

Because of its many advantages, free jejunal transfer has gained wide acceptance for pharyngoesophageal reconstruction after ablative surgery. Because the jejunum is well vascularized, it facilitates good wound healing, and has a low incidence of anastomotic insufficiency, fistula formation and stricture. However, voice rehabilitation in this group of patients can be difficult. Therefore, we performed primary tracheojejunal shunt operations for voice restoration with jejunum siphons using Nozaki's method (type 3). In this procedure, after dividing a section of the jejunum into two segments, the reconstructed neopharyngoesophagus is anastomosed in a side-to-end fashion to the fabricated shunt using the other segment of the jejunum, as an "elephant nose shunt" so called because of its appearance. Voice restoration can be achieved in patients who undergo laryngopharyngoesophagectomy through these reconstructive procedures. We performed this surgery for nine hypopharyngeal cancer patients after total pharyngo-laryngo-esophagectomy. Following placement of the shunt, no special care was required. Only one patient developed a severe aspiration. No leakage was seen and the swallowing function was preserved in all patients. Four of nine patients could speak well following these procedures. A vibratory source is created in the neoesophagus, above the elephant shunt. During speech production, narrowing of the inside and vibration of the jejunal mucosa can be observed using a laryngeal fiber scope. In order to study the acoustical characteristics of shunt speech, voice analysis was performed in patients with restored phonatory function using Computerized Speech Lab Model 4300 (KAY). Irregularities of pitch periods in the voice sample were measured using Jita (the pitch period) and Jitt (relative evaluation of the pitch) for the very short term (cycle-to-cycle), and PPQ (pitch period pertubation quotient) for the short term (cycle-to-cycle with a smoothing factor of 5 periods). Irregularities of the peak-to-peak amplitude were measured using ShdB (evaluation in dB of the peak-to-peak amplitude) and Shim (relative evaluation of the peak-to-peak amplitude) for the very short term (cycle-to-cycle), and APQ (amplitude perturbation quotient) for the short term (cycle-to-cycle with a smoothing factor of 11 periods). The pertubation parameters of shunt speech are larger than normal ones not only in terms of the period but also in terms of the amplitude. These results are similar to those of laryngeal polyps, recurrent nerve palsy and esophageal speech. Recovery of phonation using Nozaki's type 3 method with the elephant nose shunt appears promising for pharyngo-laryngo-esophagectomized patients.

Aged↗

PubMed1999

[Prediction about daily scattering count of Japanese cedar pollen].

We investigated the relationship between the daily count of pollen scattered, the count of days during the scattering period and the highest temperature during the sugi (Japanese cedar) pollen scattering season from 1983 to 1997, and whether prediction of the count of pollen scattered for the following day is possible. Our studies clearly demonstrated that the count of sugi pollen scattered is small in the early period of the scattering season with some daily variations in amount; this cycle is repeated for several days in the middle period of the season then decreases again in the late period. These findings showed that both the cumulative value of the count of pollen scattered daily and the total count of pollen scattered formed an S-shaped curve when compared with the count of days after the start of the scattering season and the cumulative highest temperature for the season. Predicting the daily count of pollen scattered after the start of the scattering season against the cumulative highest temperature is possible by drawing a regression curve from the S-shaped curve. Also, a regression curve was useful in predicting the total count of pollen scattered during the season from the cumulative count of pollen scattered 10 to 20 days after the start of the scattering season. Using these data, we were able to improve the accuracy for predicting the scattering of sugi pollen.

Air Pollutants↗

PubMed1999

[Loss of heterozygosity of 3p21 and 9p21 in head and neck squamous cell carcinomas and its prognostic implication].

To examine whether genetic factors influence the prognosis of cancer patients, several microsatellite markers were used to determine the allelic loss of certain areas of the genome. Three microsatellite markers, D3S1067, IFNA and D9S171 were used to study the loss of heterozygosity (LOH) of 3p21 and 9p21 in 93 head and neck squamous cell carcinomas. Of 57 informative cases, LOH was detected in 27 of 57 (47%) DNA samples obtained from cancer specimens when at least one marker was used. The frequency of LOH was not correlated with the clinical factors. However, the frequency of LOH was significantly higher in the recurrent cases than in the non-recurrent cases, and patients with 3p21 and/or 9p21 LOH tended to survive for a shorter period of time. These results suggested that the allelic loss at 3p21 and/or 9p21 could be correlated with the prognosis of the patients, and that it was a novel prognostic factor independent of other clinical factors concerning head and neck cancers. LOH at 3p21 and/or 9p21 may help to identify head and neck cancer patients with a poor prognosis, who need an intensive postoperative follow-up protocol, or who are suitable for novel investigational therapeutic approaches.

Carcinoma, Squamous Cell↗

PubMed1999

[Indication of tracheostomy for advanced oral or mesopharyngeal cancer resection].

In advanced oral or mesopharyngeal cancer requiring reconstruction, preventive tracheostomy have been performed to insure an airway postoperatively. However, tracheostomy often causes difficulty in swallowing and stress in the postoperative period for the patients. We have devised a strategy to avoid tracheostomy as much as possible in the cases requiring reconstruction except for the cases with over 2/3 resection of the base of the tongue or with prospective difficulty of re-intubation. Eleven cases were treated without tracheostomy out of 20 cases operated on with reconstruction in our hospital from 1995 through 1997. These patients were managed under nasal intubation for less than 2 days on average with careful observation postoperatively. In 11 non-tracheostomized cases, 1 case experienced venous thrombosis of a free flap and tracheostomy was performed at the salvage operation. Other 10 non-tracheostomized case were compared with 10 tracheostomized cases who were treated from 1991 though 1995. It was revealed that non-tracheostomized cases tended to have shorter periods until they could speak or eat, and also have a shorter postoperative admission term. In these cases, we have not experienced serious complications such as aspiration pneumonia or dyspnea, instead, special care in the postoperative period was needed. Thus, certain advanced cases who undergo curative resection followed by reconstruction can be managed without tracheostomy. The indication of tracheostomy in surgery for oral or mesopharyngeal cancer should be decided carefully.

Adult↗

PubMed1998

Density of motility-related charge in the outer hair cell of the guinea pig is inversely related to best frequency.

Whole cell voltage clamp and freeze fracture were used to study the electrophysiological and ultrastructural correlates of the outer hair cell (OHC) lateral membrane molecular motors. We find that specific voltage-dependent capacitance, which derives from motility-related charge movement, increases as cell length decreases. This increasing non-linear charge density predicts a corresponding increase in sensor-motor density. However, while OHC lateral membrane particle density increases, a quantitative correspondence is absent. Thus, the presumed equivalence of particle and motor is questionable. The data more importantly indicate that whereas the voltage driving OHC motility, i.e. the receptor potential, may decrease with frequency due to the OHC's low-pass membrane filter, the electrical energy (Q x V) supplied to the lateral membrane will tend to remain stable. This conservation of energy delivery is likely crucial for the function of the cochlear amplifier at high frequencies.

Animals↗

PubMed1998

Acoustic reflex threshold and loudness in patients with unilateral hearing losses.

The relationship between the acoustic reflex threshold (ART) and loudness was examined in patients with unilateral hearing losses and subjects with simulated hearing losses using a masking method. Significant differences in the ART between the two ears of patients with unilateral hearing losses were correlated with differences in loudness at the level of the ART with differences in loudness determined by the alternate binaural loudness balance test. A similar relationship of ART and the sensation of loudness was also observed in ears with simulated hearing losses. The results obtained in the present study suggest a positive relationship between the ART and loudness, and provide some support for the assumption that a common neuronal information pathway plays an important role both in producing the loudness and eliciting the acoustic reflex.

Adolescent↗

PubMed1998

Measurement of guinea pig basilar membrane using computer-aided three-dimensional reconstruction system.

Cochleas are known to have the ability to analyze a frequency widely, and this ability seems to be owed mostly to the basilar membrane (BM) configuration. However, the relationship between the cochlear frequency-position map and the BM configuration is not clear. Therefore, in this paper, the internal structures of a guinea pig cochlea, especially the BM configuration, were reconstructed and measured using a computer-aided three-dimensional (3-D) reconstruction system. Then, an attempt was made to examine the influence of the BM configuration on the cochlear frequency-position map. The measurement results indicate that the width of the BM increased and its thickness decreased with an increase in the distance from the basal turn towards the apical turn. Theoretical consideration reveals that the wide frequency-position of the cochlea is achieved by not only the BM configuration change along the length of the cochlea but also the change of the Young's modulus of the BM along the length of the cochlea.

Animals↗

PubMed1998

pH regulation of the globular substance in the otoconial membrane of the guinea-pig inner ear.

Physiological and pharmacological characteristics of the globular substance, a precursor of otoconia, are not well understood. In the present study, we investigated the variations and regulation of internal pH (pHi) of the globular substance of the guinea-pig inner ear. The otoconial membrane was dissected out from the utricular macula and loaded with the pH-sensitive fluorophore, carboxyseminaphthorhodafluor-1. Dynamic changes of fluorescence were directly observed under a confocal laser scanning microscope, and pHi was calculated from dual emission ratio. In the NaCl standard solution buffered with 5 mM HEPES/Tris at pH 7.4, the pHi of the globular substance varied from 6.26 to 8.55 with an average of 7.21 (n = 270). Exposure to 25 mM NH+4 induced a rapid increase of the pHi followed by a slow relaxation. The, wash-out of NH+4 caused a prompt and pronounced acidification followed by a gradual pHi recovery to the initial level. This gradual pHi recovery was significantly inhibited by the absence of external Na+, indicating the presence of an external Na(+)-dependent H+ extrusion mechanism. This pHi recovery was also inhibited by 1 mM amiloride and 10 microM 3-amino-N-(aminoiminomethyl)-6-[ethyl(2-propyl)amino]pyrazine-2-ca rboxamide. These results suggest the presence of an Na(+)-H+ exchanger in the globular substance of the guinea pig. However, HCO3(-)-transporting mechanisms were not determined. The working hypothesis for the otoconial formation is discussed.

Acetazolamide↗

PubMed1998

Endonuclease cleavage of DNA in the aged cochlea of Mongolian gerbil.

Apoptosis is the most common form of physiological cell death, plays an important role in a variety of physiological and pathological situations, and is characterized by an endonuclease activation. Aged gerbils (24-month-old) showed a significant elevation of the distortion product otoacoustic emission (DPOAE) threshold and a significant decrease of the DPOAE level as compared to young gerbils (3- to 6-month-old), suggesting a disturbance of the outer hair cell in the aged cochlea. Furthermore, the endocochlear potential in the aged (15-75 mV) was apparently lower than that in the young (80-90 mV), indicating strial damage with aging. A terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method demonstrated the presence of the DNA fragmentation predominantly in the outer hair cells and spiral ganglion cells. These changes were sporadically observed in the inner hair cells and supporting cells. TUNEL positive cells were markedly observed in some aged gerbils showing deterioration in cochlear function, which may suggest the individual variability of presbycusis. On the other hand, the strial cells showed a marked atrophy, but no DNA fragmentation. These findings suggest that the aged change in the outer hair cells and spiral ganglion cells involves an apoptotic death pathway. However, strial atrophy with aging seems to be unrelated to apoptosis.

Aging↗

PubMed1998

Midfacial degloving approach facilitated by endoscope to the sinonasal malignancy.

Midfacial degloving is known to provide excellent exposure of the central compartment of the anterior and middle cranial fossae without facial incisions. In this study, an endoscope was adapted for midfacial degloving technique in the medial maxillectomy with ethmoidectomy in five patients with sinonasal malignancy. Meticulous and safe manipulation in the medial and inferior aspect of the orbit, sphenoid sinus and olfactory fossa can be obtained by endoscopic management without serious complications. This procedure, employing an endoscope, offers accurate and safe resection of selected cases with the sinonasal malignancy.

Adult↗

PubMed1998

The usefulness of computed tomography in the diagnosis of impacted fish bones in the oesophagus.

The usefulness of computed tomography (CT) in the diagnosis of fish bone impaction in the oesophagus was evaluated. Thirty-two patients were examined by plain X-ray followed by direct oesophagoscopy for suspected fish bone impaction. Among 25 cases in which fish bones were actually removed, foreign bodies were not clearly demonstrated by plain X-ray in 14 cases (56 per cent). Eleven cases underwent CT prior to the oesophagoscopic examination. Fish bones were clearly demonstrated by CT in all patients. CT also clearly visualized secondarily-induced inflammatory changes in the neighbouring structures. In order to confirm this result, we made a simulation model of oesophageal fish bone impaction, using fish bones of three different species surrounded by a water bag. In comparison with plain X-ray, CT depicted a superior image of fine fish bones and provides extremely useful information for the management of impacted fish bones in the oesophagus.

Aged↗

PubMed1998

A2 adenosine receptors in Mongolian gerbil middle ear epithelium and their regulation of Cl- secretion.

The present study investigates the effects of adenosine and its analogues on Cl- secretion in primary cultures of gerbil middle ear epithelium. Short-circuit current (Isc), an index of transepithelial active transport, was measured on the same cells cultured on porous filters. Baseline Isc and transepithelial resistance were 27.0 +/- 0.7 microA cm-2 and 275 +/- 7 omega cm2, respectively (n = 178). Extracellular adenosine and its analogues elicited a sustained increase in Isc when added to apical or basolateral surfaces. Both the A2A selective agonist 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamido adenosine and the A2A/A2B nonselective agonist 5'-(N-ethyl-carboxamido)adenosine (NECA) increased Isc, but NECA was more effective than CGS21680. A1 selective antagonist 8-cyclopentyl-1,3-dipropylxanthine did not reduce NECA-induced Isc. These results suggest the presence of both A2A and A2B receptors. NECA did not stimulate a rise in the intracellular Ca2+ concentration ([Ca2+]i) in single middle ear epithelial cells cultured on glass coverslips. Dibutyryl cAMP (dbcAMP) induced an initial transient increase in Isc followed by the sustained plateau. Addition of dbcAMP also caused a transient increase in [Ca2+]i. The protein kinase A inhibitor, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide, greatly reduced the increase in the Isc responses to NECA. 1,2-Bis-(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid-acetoxymethyl ester influenced neither the NECA-induced increase in Isc nor the dbcAMP-induced sustained phase of Isc, but greatly inhibited the dbcAMP-induced transient increase in Isc. Glibenclamide, a cystic fibrosis transmembrane conductance regulator (CFTR) channel inhibitor, reduced the NECA-induced Isc. These results indicate that extracellular adenosine and its analogues activate the cAMP-protein kinase A system, but not intracellular Ca(2+)-dependent mechanisms, leading to Cl- secretion, possibly through the CFTR Cl- channels in the cultured gerbil middle ear epithelium.

Adenosine↗

PubMed1998

Clinical evaluation of a portable digital hearing aid with narrow-band loudness compensation.

A new portable digital hearing aid referred to as CLAIDHA (Compensate for Loudness by Analyzing Input-signal Digital Hearing Aid), which employs frequency-dependent amplitude compression based on narrow-band loudness compensation, was clinically evaluated in 159 subjects with hearing loss. The results of speech tests revealed better intelligibility compared with the subject's own hearing aids; the advantage of using CLAIDHA in daily life was also indicated by the results of a questionnaire completed by the subjects. In about 64% of the subjects with a flat, gradually sloping type of hearing loss, CLAIDHA was satisfactorily adopted for daily use. However, in the subjects with a steeply sloping type of hearing loss and subjects with losses mainly at high and low frequencies, with near-normal mid-frequency hearing. this loudness compensation scheme seems to be slightly less effective.

Aged↗

PubMed1998

Mitochondrial DNA deletion is a predisposing cause for sensorineural hearing loss.

Composed of a postmitotic stable tissue, the inner ear is a target organ for mitochondrial DNA (mtDNA) mutation. To determine whether mtDNA mutation is a predisposing factor in patients with sensorineural hearing loss (SNHL), the authors assessed the mtDNA4977 deletion from 60 patients with SNHL and 47 normal control subjects. All cases had no past history of ototoxic or noise exposure, middle ear disease, or other known etiological factors for SNHL. DNA specimens extracted from peripheral blood leukocytes were used for detection of mtDNA4977 deletion by polymerase chain reaction. Patients with SNHL had a significantly higher rate of the mtDNA4977 deletion than did controls (75% vs. 30%, P < 0.0001). The detection rate of mtDNA4977 deletion was significantly increased with the deterioration of the hearing threshold. Aging did not influence the detection rate of mtDNA4977 deletion in either the control or SNHL group. The authors have described high detection rates of the mtDNA4977 deletion in patients with idiopathic bilateral SNHL and propose that at least some of the advanced SNHL cases should be categorized as mitochondrial oxidative phosphorylation diseases. This inference would offer novel possibilities for treatment and prevention of SNHL including presbycusis.

Adult↗

PubMed1998

Expression of adhesion molecules in cultured human nasal mucosal microvascular endothelial cells activated by interleukin-1 beta or tumor necrosis factor-alpha: effects of dexamethasone.

Adhesion molecules of microvascular endothelial cells play a key role in the inflammatory processes involved in nonallergic sinusitis. We investigated the cytokine-regulated expression of intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1 (VCAM-1), and the effect of dexamethasone on these expressions in cultured human nasal microvascular endothelial cells (HNMEC). ICAM-1 was enhanced, and E-selectin and VCAM-1 were induced in a dose-dependent fashion following stimulation with IL-1beta or TNF-alpha. HNMEC differed from human umbilical vein endothelila cells in that (1) maximal upregulation of ICAM-1 expression induced by IL-1beta or TNF-alpha required more time (2) TNF-alpha was more potent than IL-1beta in VCAM-1 expression, and (3) dexamethasone inhibited the upregulation of E-selectin expression alone. These findings contribute to a better understanding of the characteristic features of leukocyte infiltration into inflamed tissue and the effect of glucocorticoid in nonallergic chronic sinusitis.

Cell Adhesion Molecules↗