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Biomedical subjects

T Shitara

Publications and source records attributed to T Shitara.

At least 37 records · Page 2Linked to original sources
PubMed1995

Synthesis of 5-deoxy-5-epifluoro derivatives of arbekacin, amikacin, and 1-N-[(S)-4-amino-2-hydroxybutanoyl]tobramycin (study on structure--toxicity relationships).

As part of a study on fluorination--toxicity relationships for aminoglycoside antibiotics, 5,3'-dideoxy-5-epifluorokanamycin B (10), 5,3',4'-trideoxy-5-epifluorokanamycin B (11), 1-N-[(S)-4-amino-2-hydroxybutanoyl]-5-deoxy-5-epifluorotobramyc in (19), 5-deoxy-5-epifluoroarbekacin (20), and 5-deoxy-5-epifluoroamikacin (21) have been prepared. The acute toxicities of these three 5-deoxy-5-epifluoro compounds showed values almost identical or similar to those for arbekacin (ABK) and amikacin (15), making a sharp contrast with the toxicities of the corresponding 5-deoxy-5-fluoro derivatives. This fact is explained on the basis of basicity changes (retention for the 5-epifluoro derivatives and reduction for the 5-fluoro derivatives) at the H2N-3 groups of the fluorinated compounds compared to the parent compounds; this hypothesis was substantiated by the pKa values at the H3N(+)-1, 3 groups (determined by the shift changes depending on pD values at C-2 and C-4, 6 in their 13C NMR spectra) of 2,5-dideoxy-5-epifluorostreptamine (23) and 2,5-dideoxy-5-fluorostreptamine (24), chosen as model compounds, and 2-deoxystreptamine (DST).

Amikacin↗
PubMed1995

Comparison of continuous brachial plexus infusion of butorphanol, mepivacaine and mepivacaine-butorphanol mixtures for postoperative analgesia.

We have reported recently that continuous administration of butorphanol into the brachial plexus sheath provided analgesia of a quality superior to that of continuous i.v. administration. In the present study, we have compared postoperative pain relief produced by continuous infusion of one of three types of solution into the axillary sheath: opioid alone, local anaesthetic alone or a mixture of local anaesthetic and opioid. In patients undergoing upper extremity surgery with continuous axillary brachial plexus block, we injected one of the three solutions into the axillary neurovascular sheath: butorphanol 2 mg (group B), 0.5% mepivacaine alone (group M) and 0.5% mepivacaine-butorphanol (group MB); the volume of each solution was 50 ml, administered at a rate of 50 ml per 24 h. At 3 h after operation, visual analogue scale (VAS) scores were significantly higher in group M than in group MB (P < 0.01), and higher in group B than in group MB (P < 0.05).

Adolescent↗
PubMed1995

[Changes in hearing features according to days from onset of sudden deafness].

We analyzed 746 patients with idiopathic sudden hearing loss who visited our clinic within 16 days after the onset. Patients were divided into 10 groups according to the number of days between the initial visit and the onset. Initial hearing levels, audiometric types and hearing recoveries were investigated in these groups to estimate the natural history of sudden deafness. The results were as follows: 1) There were no significant differences among the 10 groups regarding the averaged five-frequency hearing levels of initial audiograms. 2) Regarding the audiometric types of the initial audiograms, flat and upward slope types were frequently seen in the groups who visited us within 6 days. In contrast, the population of down slope types gradually increased in the groups presenting after 7 days. In the ultimate audiograms, flat and down slope types were frequently seen in all groups. 3) There were significant differences among the 10 groups regarding the averaged five-frequency improvement (one-way analysis of variance, p < 0.01). After 9 days, hearing recovery became less likely.

Hearing↗
PubMed1995

[A case of atopic dermatitis treated with stellate ganglion block--the change of serum IgE and blood eosinophil levels].

Stellate ganglion block (SGB) therapy was tried on a patient with severe adult type atopic dermatitis. SGB was performed 102 times in total and clinical symptoms improved gradually. Serum IgE and blood eosinophil levels, which correlate with disease severity, increased gradually following repeated SGB. After a series of SGB was stopped, clinical symptoms became worse and serum IgE and blood eosinophil levels increased again. We conclude that although SGB is presumably one of the effective therapies for severe adult type atopic dermatitis, it might be difficult to improve atopic constitution entirely because the patient was not cured completely following repeated SGB.

Adult↗
PubMed1995

[Changes in dementia rating scale scores of elderly patients with femoral neck fracture during perioperative period].

We evaluated changes in dementia rating scale scores in the revised version of Hasegawa's dementia scale (HDS-R), and rated dementia, 2 days before and 7 days after surgery in the elderly patients with femoral neck fracture. The 50 patients examined ranged in age from 70 years to 101 years. A perfect score in the HDS-R is 30 points, and a score below 20 points strongly suggests dementia. The results were as follows. In septuagenarian and octogenarian patients, the scale score was higher after surgery than the value before the surgery. Although the preoperative and postoperative scores of the patients who had been under epidural anesthesia were not significantly different, the score of patients who had been under general anesthesia was higher in the postoperative period than in the preoperative period. In octogenarian patients, there was a negative correlation between "postoperative score minus preoperative score" and "the number of the days from suffering fracture to surgery". These results showed that general anesthesia is more advantageous than epidural anesthesia from the viewpoint of the intellectual faculty in septuagenarian and octogenarian patients with femoral neck fracture, and it is within the bounds of possibility that the intellectual faculty may decline if an octogenarian patient is operated after a long delay from the occurrence of fracture. To prevent this decline, patients must be operated on as soon as possible.

Age Factors↗
PubMed1994

Suppression of H-ras-mediated transformation in NIH3T3 cells by a ras ribozyme.

Murine NIH3T3 cells were used to study the effect of ribozymes on H-ras-mediated transformation. Parental 3T3 cells were transfected with the activated H-ras gene. H-ras-transformed cells had altered morphology and increased colony formation in soft agar in contrast to untransfected 3T3 cells. A hammerhead ribozyme (site-specific ribonuclease) designed to cleave codon 12 (GUC) of the activated H-ras RNA was expressed in transformed cells. 3T3 clones expressing the ras ribozyme displayed decreased expression of activated H-ras RNA. The ras ribozyme reversed the transformed phenotype to resemble that of untransfected 3T3 cells. Furthermore, 3T3 cells containing the ras ribozyme were shown to suppress transformation when they were subsequently transfected with activated H-ras. Insertion of a mutant ribozyme largely devoid of cleaving capacity into H-ras-transformed cells resulted in smaller reductions in H-ras gene expression and colony formation in soft agar when compared with the ras ribozyme. Finally, the ras ribozyme alone did not perturb normal 3T3 cell growth. This study suggests the possible utility of anti-oncogene ribozymes as suppressors of tumor cell growth as well as inhibitors of cellular transformation.

3T3 Cells↗
PubMed1994

Cytokine profile during high-dose rhG-CSF therapy in severe congenital neutropenia.

The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on cytokine profile was evaluated in a case of severe congenital neutropenia. The plasma levels of cytokines were measured before and during rhG-CSF therapy. These included G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 alpha, interleukin-1 beta, interleukin-2 (IL-2), interleukin-3 (IL-3), interleukin-4, interleukin-6 (IL-6), and tumor necrosis factor-alpha. Soluble interleukin-2 receptor (sIL-2R) was measured serially during rhG-CSF therapy. Lymphocyte subpopulations including CD2, CD3, CD4, CD8, CD19, CD20, and CD25 were also measured, rhG-CSF was administered once daily as a 30-min infusion. The patient was treated with increasing dose levels of 100, 200, 400, 800, and 1,600 micrograms/m2/day. The level of endogenous G-CSF was elevated to 334 pg/ml before treatment and GM-CSF, IL-2, IL-3, and IL-6 were slightly elevated. Clinically, he showed a moderate response to a high dose of rhG-CSF (1,600 micrograms/m2/day). Plasma levels of G-CSF markedly increased during therapy but plasma levels of other cytokines did not show significant changes during therapy and lymphocyte subpopulations did not significantly change. A drastic increase in sIL-2R expression was observed after rhG-CSF infusion and an increase in sIL-2R expression occurred even before a major increase in granulocyte counts. These results showed that a high dose rhG-CSF therapy may influence the cytokine network as judged by the increased sIL-2R expression.

Child, Preschool↗
PubMed1994

Estimated annual number of patients treated for sensorineural hearing loss in Japan. Results of a nationwide epidemiological survey in 1987.

We mailed questionnaires to 98 university hospitals and 939 hospitals with 200 beds or more throughout Japan asking for information on patients treated for sensorineural hearing loss between January 1 and December 31, 1987. The number of patients treated for sensorineural hearing loss in 1987 in Japan was estimated 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss in 800-2,000, iii) perilymphatic fistula in 200-310, iv) mumps deafness in 200-400, and v) unilateral profound deafness in 2,000-3,000. Sex ratio (men over women) was 0.9 in sudden deafness and mumps deafness, 1.1 in idiopathic bilateral progressive sensorineural hearing loss and 1.5 in perilymphatic fistula. Patients were distributed with a definite peak from 50 to 59 years old in sudden deafness, from 30 to 39 years old in perilymphatic fistula, and two apparent peaks in teenagers and those aged 60-69 years in idiopathic bilateral progressive sensorineural hearing loss.

Adolescent↗
PubMed1994

Comparative study on sudden deafness by two nationwide epidemiological surveys in Japan.

Nationwide epidemiological surveys of sudden deafness were conducted in 1972 and 1987 by the Research Committee of the Japanese Ministry of Health and Welfare. Sex ratio (men over women) of definite cases of sudden deafness was 1.19 in 1972 and 0.96 in 1987. The number of patients with sudden deafness was more common between 30 and 49 years of age in 1972, whereas it was more common between 50 and 59 years of age in 1987. When the incidence of sudden deafness in the overall population was calculated, this disorder was found to be more frequent in people between 50 and 59 years of age both in 1972 and 1987. However, the incidence of sudden deafness per population was more increased in people from 50 to 75 years of age in 1987 than in 1972.

Adolescent↗
PubMed1994

Investigation of pure-tone hearing levels at a single frequency in sudden deafness.

Hearing levels in patients with sudden deafness are commonly discussed in terms of average thresholds at 3 or 5 frequencies, but an investigation of hearing levels at a single frequency is also important. In this paper, pure tone thresholds at 500 Hz and 4,000 Hz were investigated in patients with sudden deafness who came to our clinic within 4 days of onset. Particular attention was paid to the relationship between audiometric types according to the contour of the initial loss and degree of hearing recovery at each frequency. In the group of patients whose initial hearing level at 500 Hz was between 55 and 70 dB, the hearing recovery at 500 Hz in the upward slope type was significantly greater than that in the downward slope type, but in other groups no significant differences in hearing recovery were observed among the different types of initial audiograms. We considered that the hearing recovery at a single frequency was not related to the audiometric type except in the patients with the upward slope type with moderate hearing loss.

Adolescent↗
PubMed1994

Sudden deafness accompanied by asymptomatic mumps.

In this study we investigated asymptomatic mumps as a possible cause of sudden deafness. We studied 131 sudden deafness patients by measuring their serum mumps antibody values. Positive IgM antibody results, which strongly suggest recent mumps infection, were revealed in 9 of the 130 patients tested (6.9%). Asymptomatic mumps infections are apparently closely related to sudden deafness. Further studies will provide more definite diagnoses of mumps deafness and might be applicable to the treatment of such hearing loss.

Adolescent↗
PubMed1994

Study on the distribution of hearing levels in idiopathic bilateral sensorineural hearing loss.

The pattern of aggravation in hearing was investigated in 105 patients who were diagnosed as having idiopathic bilateral sensorineural hearing loss at the Hearing Loss Clinic, Department of Otolaryngology, Kitasato University Hospital. Audiograms were taken 1,069 times from the 105 cases over more than 3 years, and were used to obtain the distribution of hearing levels at each test frequency. The clinical course of idiopathic bilateral sensorineural hearing loss was divided into three stages: Stages I, II and III, based on the pattern of aggravation. The pattern of distribution of hearing levels at different stages was compared with each other with reference to peaks or clustering points. Similar peaks were noted at Stage II and Stage III as aggravation proceeded from Stage I. Another peak was noted in the zone of scale-out.

Adolescent↗
PubMed1994

Transient deafness with iopamidol following angiography.

A case of transient, severe sensorineural hearing loss with iopamidol following angiography is reported. The 26-year-old woman had previously been diagnosed with Arnold-Chiari malformation, and underwent vertebral angiography by a retrograde transfemoral catheterization. Immediately following the second injection of iopamidol she did not react on the nurse's call. An ABR revealed no response in either ear even when the click intensity was 105 dB. The patient was immediately treated with steroid and OHP. Fortunately, 24 h after the angiography she was able to communicate at a normal conversation level. Transient severe sensorineural hearing loss is thought to result from bilateral anoxia of the cochlea due to hypoplasia of the basilo-vertebral artery systems. Cochlea anoxia lasts 10-20 min after which the hearing loss is recovered.

Adult↗
PubMed1994

Increased cytokine levels and abnormal response of myeloid progenitor cells to granulocyte colony-stimulating factor in a case of severe congenital neutropenia. In vitro effects of stem cell factor.

PURPOSE: The cytokine levels and the in vitro granulopoiesis were studied to evaluate the mechanism of impaired granulopoiesis in severe congenital neutropenia (SCN). PATIENT AND METHODS: The patient was a 5-year-old boy with SCN. We assayed the colony-stimulating activity (CSA) produced by peripheral blood (PB) cells from the patient. The plasma levels of cytokines were measured using enzyme immunoassay. These included granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-3, IL-4, IL-6, and tumor necrosis factor-alpha. The effects of IL-3 and stem cell factor (SCF) on the proliferation of granulocyte-macrophage colony-forming cells (GM-CFCs) were studied. RESULTS: CSA produced by PB cells from the patient was almost the same as in the healthy control. The level of endogenous G-CSF was elevated to 334 pg/ml, and GM-CSF, IL-2, IL-3, and IL-6 were slightly elevated. The numbers of GM-CFCs were markedly depressed in the presence of G-CSF alone and showed no increment on additional stimulation by IL-3. SCF in combination with G-CSF significantly augmented the proliferation of GM-CFCs. CONCLUSIONS: These findings suggest that some cytokines including G-CSF may be elevated in SCN patients and that CSF may play an important role in the pathogenesis of SCN.

Colony-Stimulating Factors↗
PubMed1994

Myringoplasty in the outpatient clinic.

In 1990, the authors first started performing myringoplasty with temporal fascia homografts and fibrin glue in the outpatient clinic with consequent reduction in expenditure, time and patient physical stress. Of primary consideration in homogeneous transplantation is the possibility of infection by HIV or other pathogens from donors. The fascial grafts were submitted to treatment with 99% ethyl alcohol and pasteurization resulting in the inactivation of pathogenic viruses. This paper discusses methods, eardrum perforation closing rates, hearing improvement and future application of myringoplasty.

Adolescent↗