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Biomedical subjects

M Sakagami

Publications and source records attributed to M Sakagami.

At least 37 records · Page 2Linked to original sources
PubMed2000

Postoperative results for cholesteatoma in children.

OBJECTIVES: to review the postoperative results for cholesteatoma in children. MATERIALS: 32 ears with acquired cholesteatoma in children operated on by a single surgeon between 1987 and 1995 and followed up more than 2 years. The mean follow-up period was 5.4 years. RESULTS: a one-stage operation was performed in seven ears (21.9%) and preplanned stage operation in 25 ears (78.1%). In the first operation, closed tympanoplasty was performed in 31 ears (96.9%) and open tymapanoplasty in one ear (3.1%). During the second stage operation, residual cholesteatoma was found in 16 ears (64.0%). Recurrent cholesteatoma was detected in 19.4% of ears treated with closed tympanoplasty. The mean postoperative air conduction hearing level was within 20 dB in 12.5%, 30 dB in 40.6% and 40 dB in 78.1%. The hearing results of type III tympanoplasty was better than those of type IV tympanoplasty. CONCLUSIONS: preplanned stage tympanoplasty is safer because of the high risk of recurrent and residual cholesteatoma. Surgical methods should be selected flexibly in individual cases depending upon cavity size, eustachian tube function and hearing level. Cholesteatoma in children should be operated on while stapes is present.

Adolescent↗
PubMed2000

Bilateral same day surgery for bilateral perforated chronic otitis media.

OBJECTIVE: Bilateral same day surgery has been performed rarely because of the risk of postoperative sensorineural hearing loss following conventional myringoplasty or tympanoplasty (CMT). Simple underlay myringoplasty (SUM) through the ear canal has been developed by Yuasa R, Saijo S, Tomioka Y, et al. Office closure of eardrum perforation with fibrin glue (in Japanese), Otolaryngol Head Neck Surg (Tokyo) 1989;61:1117-1122, which has little risk of sensorineural hearing loss. We tried bilateral same day surgery using this technique and evaluated its outcome. METHODS: Of 86 cases with bilateral perforated chronic otitis media that we treated between 1995-1997, 25 cases underwent bilateral same day surgery. Bilateral SUMs was performed on seven patients, SUM and CMT on 16 patients, and bilateral CMTs on two patients. RESULTS: Closure of perforation was successful in 18 patients (72%) on both sides and in seven patients (28%) on one side. Postoperative air-bone gap of less than 20 dB was achieved in 15 cases (60%) on both sides and in 23 cases (92%) on one side. CONCLUSION: Bilateral same day surgery for bilateral perforated chronic otitis media is possible if the operative indications are considered.

Adolescent↗
PubMed2000

Long-term observation on hearing change in patients with chronic otitis media.

OBJECTIVE: Very few reports are available in the literature to clarify the natural long course of hearing change in an individual patient with chronic otitis media (COM). We reviewed hearing change in patients suffering from perforated COM without an operation. METHODS: Eighty-seven ears of 70 patients had COM with tympanic perforation and were observed without an operation. The mean follow-up period was 10.7 years (5-22 years) and the mean age at the first examination was 51.3 years. To minimize the effect of aging, 23 patients with normal ear drums on the other side were further analyzed. RESULTS: All 87 ears tended to show deterioration of hearing gradually under long observation. In 23 patients, hearing deterioration was 0.13 dB/year in the control side and 0.61 dB/year in the COM side (P < 0.02). Although elevation of bone conduction hearing level tended to be larger at high frequencies than at low and middle frequencies, there was no significant difference between COM and normal ears. CONCLUSIONS: Air conduction hearing levels deteriorated with the passage of time and surgery is recommended at the early stage of COM to prevent progress of hearing loss.

Adult↗
PubMed2000

Interference from irrelevant features on visual discrimination by macaques (Macaca fuscata): a behavioral analogue of the human Stroop effect.

To study the operation of selective attention in a conflict situation with automatic processes, we trained 4 Japanese macaques (Macaca fuscata) extensively on a manual go/no-go task. The monkey had to discriminate either the color, shape, motion direction, or location of a visual stimulus. In each trial, the behavioral meaning of the relevant feature (go or no-go) could either be congruent or incongruent with irrelevant features of the same stimulus. Reaction times were slowed, and error rates increased when irrelevant stimulus features were incongruent with the required response. The effects were obtained when the monkey attended to the color, shape, or motion direction, but not when it attended to the location of the stimulus. The effects were cumulative so that the interference from 1 incongruent feature was smaller than that from 2 incongruent features. We propose that the present paradigm provides a behavioral analogue of the human Stroop effect.

Analysis of Variance↗
PubMed2000

Effect of the sialyl Lewis X (SLe(x)) moiety on splenic accumulation of SLe(x)-carboxymethylpullulan conjugate.

Sialyl Lewis X (SLe(x)), an E-selectin ligand, was conjugated with carboxymethylpullulan (CMPul) and the disposition characteristics of this conjugate after intravenous administration were investigated using mice with ear edema. The concentration of 3H-labeled SLe(x)-CMPul in the spleen was significantly high. When CMPul was modified with a saccharide unable to bind to E-selectin, this splenic accumulation was not observed. The uptake of radiolabeled SLe(x)-CMPul by the spleen was completely inhibited by a 100-fold molar of cold SLe(x)-CMPul but not by a sialyl N-acetyllactosamine-CMPul conjugate (SLN-CMPul). Microautoradiography analyses revealed that SLe(x)-CMPul accumulated in the marginal zone of the spleen.

Animals↗
PubMed2000

Synthesis of sialyl Lewis X-polysaccharide conjugates.

Sialyl Lewis X (SLeX) is well known as a ligand of the cell adhesion molecule E-selectin which is specifically expressed at inflammatory lesion sites. We have synthesized several SLeX-polysaccharide conjugates and examined their potential for drug delivery to inflammatory lesions. The AUC (area under the blood concentration-time curve) 0-24 h of SLeX-CMCht (1), SLeX-CMPul (2) and SLeX-DSH (3) at the inflammatory lesion was about 60-, 300-, and 30-fold higher than that of the monovalent SLeX (7), respectively. Moreover, 1 showed 2-fold higher accumulation in the inflammatory lesion than SLN-CMCht (4), and 2 showed 2.5-fold higher accumulation than SLN-CMPul (5).

Animals↗
PubMed2000

Synthesis of methoxy-2-quinolones via pummerer-type cyclization of N-aryl-N-methyl-3-(phenylsulfinyl)propionamides.

The thionium ions 10 generated by Pummerer reaction of N-aryl-N-methyl-3-(phenylsulfinyl)propionamides 4 caused not only an electrophilic cyclization reaction producing 2-quinolones 8, but also the formation of the vinyl sulfides 5 and 6 in favor of the latter reaction. On the other hand, the treatment of the vinyl sulfides 5 and 6 with p-toluenesulfonic acid induced cyclization to afford the 2-quinolones 8 in excellent to moderate yields, depending on the electronic properties of the aromatic ring, thus providing a convenient method for the synthesis of methoxy-2-quinolones.

Acetic Anhydrides↗
PubMed2000

[Forecast of total pollen counts of sugi (Cryptomeria japonica) from the amount of male flower development and the revised total pollen counts].

We have successfully forecast the total pollen counts of sugi (Cryptomeria japonica) since 1996 by the amount of male flower development. The amount of male flower development was observed at 11 forests in the Tanba Mountains and 10 forests in the Chugoku Mountains depending on both in Hyogo Prefecture. The amount of male flower development on each tree was assigned to one of five classes by the number of male flowers per spring. After a large harvest of male flowers, the production of male flowers declined in the following years, especially at high altitudes. It was also followed by a decrease in the number of airborne pollen grains in the later pollen season. According to an analysis of weather conditions, total pollen counts were correlated with the high temperature between July 6 and 20 and the total pollen counts of the previous season. However, the amount of male flower development was the most significant indicator for forecasting total pollen counts. Decrease in total pollen counts due to abnormal weather during the pollen season was correlated with discrepancies in forest flowering time according to observations made in the Rokko Mountains. Increase in total pollen counts was connected by a development of the sugi forest areas. Twenty percent of mature sugi forests from 1992 which showed an annual increase were associated with an increase in total pollen counts. The accuracy of the forecast was improved by revising the total pollen counts for weather conditions during the dispersion stage, a decrease in the production of male flowers at high altitude, and an increase in the production of male flowers connected by a developing forest areas.

Air Pollutants↗
PubMed1999

Benzoquinoid ansamycins (herbimycin A and geldanamycin) interfere with the maturation of growth factor receptor tyrosine kinases.

Benzoquinoid ansamycins, such as herbimycin A (HA) and geldanamycin (GA), are antibiotics that exhibit anti-tumor effects. These compounds have been shown to result in the intracellular depletion of important growth signaling molecules. Recently, GA has been shown to bind tightly to Hsp90, thereby implicating Hsp90 as a possible chaperone for those signaling molecules adversely affected by the benzoquinoid ansamycins. Here we have investigated the effects of HA and GA on the synthesis, maturation and stability of different protein tyrosine kinases. Exposing cells to either compound blocked normal maturation of the epidermal growth factor (EGF) receptor, platelet-derived growth factor (PDGF) receptor, and pp60(v-src). We show that only the nascent forms of the EGF and PDGF receptors are degraded under these conditions. Once the newly synthesized receptors had been translocated into the endoplasmic reticulum membrane, addition of the drugs no longer affected their stability. For the cytoplasmic tyrosine kinase, pp60(v-src), both the nascent as well as the mature forms of the protein were degraded in cells treated with the drugs. We discuss these observations as they pertain to the possible role of Hsp90 as a substrate-specific molecular chaperone, perhaps involved in the maturation and/or stability of proteins important for growth control.

Antibiotics, Antineoplastic↗
PubMed1999

The hierarchical organization of decision making in the primate prefrontal cortex.

The prefrontal cortex plays an important role in making the association between sensory information and specific behavior. For example, in a complex stimulus response situation, such as the Wisconsin card sorting test, prefrontal patients show difficulty in making appropriate decisions. To understand the neural mechanisms, we recorded prefrontal cell activity while monkeys performed a go/no-go selective attention task where the subjects made a go or no-go response depending on the color or the motion direction of compound visual stimuli (moving colored dots). Groups of cells showed differential activity for go and no-go stimuli (go/no-go activity): some showed the activity either in the color or motion attending condition, and others showed the activity both in the color and motion conditions. Cells of shorter latencies, found mainly in the prefrontal subareas receiving visual input, showed go/no-go activity only when task demands necessitated that the monkeys attended to that cell's preferred visual dimension. We also found cells with longer latencies in the motor-related periarcuate area that showed go/no-go activity regardless of the dimension attended. These results suggest that subareas in the prefrontal cortex play different roles in associating the sensory information with its behavioral meaning and are hierarchically organized to make appropriate decisions in complex tasks.

Animals↗
PubMed1999

Cholesteatoma otitis media with intact ossicular chain.

Thirty-one cases of cholesteatoma with intact ossicular chain were reviewed to examine the extension of cholesteatoma, operation procedures, pre- and postoperative hearing levels, and postoperative condition of the ear drum. They were operated on at Departments of Hyogo College of Medicine and Osaka University Medical School from 1989-1996, which were 20.4% of all of the primary cholesteatoma cases (n = 152). Twelve cases located at attic were operated by atticotomy or canal wall up and scutumplasty, 17 cases located at attic/antrum were operated by canal wall down and reconstruction, and two cases located around stapes were operated through the ear canal. Preoperative hearing level was mild (34.2 +/- 18.4 dB) and postoperative one was slightly improved (28.7 +/- 11.2 dB). In ossicular reconstruction, modified Wullstein type III method showed better hearing gain than Wullstein type I method. Postoperative attic retraction and/or pocket occurred in 15 cases (48.4%), but no recurrent cholesteatoma was found during the present follow-up period. These findings suggested that cholesteatoma with intact ossicular chain showed good postoperative hearing results, but postoperative retraction of the ear drum should be followed up for a long time.

Adolescent↗
PubMed1999

Enhanced accumulation of sialyl Lewis X-carboxymethylpullulan conjugate in acute inflammatory lesion.

PURPOSE: E-selectin is a cell adhesion molecule that is specifically expressed in the inflammatory vascular endothelium in response to cytokines such as IL-1 beta and TNF-alpha, and interacts with specific ligands containing sialyl Lewis X (Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc-, SLex). In order to investigate the ability of E-selectin ligands to target the inflammatory site, the tissue distribution of carboxymethylpullulan (CMPul) modified with SLex was studied. METHODS: CMPul conjugates with various saccharides containing SLex and monovalent SLex were intravenously administered to mice with ear edema induced by arachidonic acid, and their distributions to the inflamed ear and other tissues were studied. To determine the microdistributions of these compounds, the inflamed ear was subjected to microautoradiography. RESULTS: After intravenous administration AUC0-24h of SLex-CMPul, which binds to E-selectin, in the inflamed ear was about 300-fold and 2.5-fold higher than that of monovalent SLex and CMPul conjugated with other saccharides, which can not serve as ligands for E-selectin. Microautoradiography also revealed SLex-CMPul accumulated at the microvessels in the inflammatory lesions. CONCLUSIONS: SLex-CMPul was found to have the potential to target drugs to the inflammatory lesion.

Acute Disease↗
PubMed1999

Syntheses and evaluation of biantennary oligosaccharide ligands mimicking sialyl Lewis X.

Sialyl Lewis X (1) is known to be a ligand of the cell adhesion molecule E-selectin. We have synthesized several biantennary glycoside-terminated ligands mimicking sialyl Lewis X (1), and evaluated their binding activity to E-selectin using HL-60 cells expressing sialyl Lewis X epitope and human umbilical vein endothelial cells (HUVECs). These compounds were found to possess moderate binding activities to E-selectin. Among them, di-fucoside analog (8) which has no sialic acid carboxylate group was more active than 2, which had both the sialyl-galactose residue and the fucose residue (IC50, 8: 4.7 mM, 2: 11.7 mM). Furthermore, in the rat pleuritic model in vivo induced by carrageenin, 8 was found to reduce neutrophil infiltration at inflammatory lesions.

Animals↗
PubMed1999

[Local injection of dexamethasone acetate suspension into the nasal mucosa in cases of olfactory disturbance].

Local injections of suspended steroid solution into the nasal mucosa were performed for 102 patients with olfactory disturbances. Dexamethasone acetate suspension in a concentration of 4 mg/0.5 ml was injected into the mucosa of the nasal septum on each side every 2 weeks for a total of 8 times. Mecobalamin and ATP were also administrated in a daily dose of 750 micrograms and 300 mg, respectively. Of the 102 olfactory disturbance patients, 32 patients had chronic sinusitis, 24 patients had common cold, 14 patients had allergic rhinitis, 9 patients had head trauma and the remaining 23 patients the reason for the disturbance was unknown. Using a visual analogue scale, improvements were found in 63.7%. We assessed the effect of this therapy on the threshold of olfactory sensation and perception using a T & T olfactogram. The overall mean values of olfactory sensation and perception were significantly improved; from 4.75 +/- 1.44 (SD) to 3.01 +/- 2.13 (SD) and from 5.30 +/- 0.88 (SD) to 4.19 +/- 1.60 (SD), respectively. All but the cases of head trauma showed significant improvement. Overall, 44 (43.1%) of the 102 patients were defined as having had a positive olfactory response to this treatment (an improvement in the average perception olfactory score of > = 1.0). In cases of chronic sinusitis, 15 (46.9%) of the 32 patients were positive. 12 (50.0%) of the common cold 24 patients, 7 (50.0%) of the 14 allergic rhinitis patients, 2 (22.2%) of the 9 head trauma patients and 11 (47.8%) of the 23 unknown etiology patients were positive for this treatment. Patients with severe olfactory dysfunction and anosmia showed a lower response than the patients who were mildly to moderately affected. Patients showing no response in the Alinamin intravenous test showed also lower improvement rates than those showing a normal response. Interestingly, 8 (27.6%) of 29 patients with a normal appearance of the olfactory clefts and no response for the Alinamin test responded positively to this treatment. This meant that the olfactory disturbance might be due to the existence of edema surrounding the olfactory nerve, not of the olfactory cleft. The improvement rate of patients treated within one year from the onset of these olfactory disturbance was better than the rate of those over one year. The present new therapeutic modality is very useful as a treatment which showed only be performed by otolaryngologists.

Adenosine Triphosphate↗
PubMed1999

[Cervical lymphnode metastasis of early or late T2 tongue carcinoma].

Between 1986 and 1997, 72 patients (47 males, 25 females) with previously untreated tongue cancer were treated at our institution (surgery: 67, interstitial radiotherapy: 3, palliative therapy: 2). These patients, especially T2 tongue cancer, were classified into two groups (early T2: < or = 3 cm, late T2: > 3 cm) according to the maximum diameter of the primary lesion, and were analyzed for treatment outcome and cervical lymphnode metastasis. (1) The cumulative 5-year survival rates were 65.9% for all cases, 95.0% for T1 cases, 77.5% (94.1% for early T2, 59.7% for late T2) for T2 cases, 24.3% for T3 cases (4-year survival rate), and 0% for T4 cases. (2) The cumulative 5-year survival rates were 90.8% for pN- patients and 21.7% for pN+ patients and the difference was statistically significant (p < 0.05%). In prognosis, pN- patients were better than pN+ patients. Since the N factor was related to the cause of death in 87.5% (7/8) of T2 tongue cancer, control of regional lymph node involvement was the most important prognostic factor. (3) The overall incidence of cervical lymph node metastasis (pN+ or secondary nodal metastasis) was 35.3% for early T2 and 750% for late T2. The control rate of secondary nodal metastasis was 75.0% for early T2 and 33.3% for late T2. Partial glossectomy only (observation for occult lymphnode metastasis) is recommended for treatment of T2N0, whereas glossectomy with selective neck dissection by the pull-through method is recommended for treatment of late T2.

Adult↗
PubMed1999

[Esophageal reconstruction for esophageal stricture after corrosive injury].

Swallowing a corrosive agent (alkali or acid) often causes severe pharyngeal, laryngeal or esophageal stricture (caustic stenosis), which is usually very difficult to treat. This paper reports two cases of esophageal stricture treated by esophagoplasty. Both cases had attempted suicide by swallowing a sodium hydroxide solution or acid. Case 1 was a 66-year-old man found to have severe hypopharynx and thoracic esophagus stenosis with supraglottic stricture. The supraglottic stricture was reconstructed with an ileocolon graft and laryngectomy. The intestinal anastomosis was patent, but the peristaltic motion in the ileocolon was not good. The patient continues to have difficulty achieving sufficient oral feeding and to receive supplemental feeding via a jejunostomy. Case 2 was a 81-year-old woman with severe thoracic esophagus stenosis after gastrectomy. The lesion was reconstructed with a jejenum graft. The intestinal anastomosis was patent. She achieved oral alimentation of both liquids and solids without aspiration after surgery. Esophagectomy in these cases can be difficult and hazardous due to extensive fibrosis and many adhesions to adjacent structures. In both cases, the reconstructed intestine passed through the ante-sternal route, so there was severe scar formation in the mediastinum, and an esophago-skin fistula formed in the cervical skin. Cervical vessels and intestinal vessels were anastomosed for blood supply to the reconstructed intestinal tract. This method is useful because it is safe and results in good deglution.

Aged↗