Biomedical subjects
Publications and source records attributed to H Koga.
A new method for determining the MICs for Aspergillus species with slant-shaking incubation is described. The method was rapid (24 h), produced sharp visual end points, and showed high reproducibility. Additionally, MICs measured by this method correlated well with, as well as were two- to sixfold lower than, those by a reference method.
The nested polymerase chain reaction technique was compared with the conventional smear and culture methods for detection of Mycobacterium tuberculosis. The nested polymerase chain reaction used in this study showed excellent specificity, sensitivity, and agreement with the conventional methods for 417 clinical samples, indicating a contribution to the rapid diagnosis of mycobacterial infectious diseases.
Twelve patients with aspergilloma were treated with intracavitary or endobronchial administration of antifungals. Patients with successful therapy had significantly shorter mean duration of the disease course (3.6 months) than the less effective group (44.4 months, p < 0.01). Minimal inhibitory concentrations of antifungal agents against isolated strains of aspergilli were considerably lower than estimated intracavitary concentrations of the antifungals. A pathologic examination suggested that the old mycetoma was for the most part comprised of dead mycelial cells, against which antifungal agents were not effective. However, clinical improvement was obtained, regardless of the roentgenographic improvement. Our study suggested that early diagnosis and therapy are recommended to achieve better therapeutic effect.
Susceptibility, clinical features, and response to treatment were compared between 29 cases of Mycobacterium avium infection and 43 cases of Mycobacterium intracellulare infection detected in the Nagasaki (Japan) area and identified by a DNA probe method. In vitro susceptibility of two species to antituberculous agents was determined by a microdilution method, and M avium was more resistant to enviomycin at 25 mg/L than M intracellulare, while M intracellulare was more resistant to isoniazid at 5 mg/L and to cycloserine at 20 mg/L. No significant difference was found between infections caused by two species as to background factors, laboratory data, clinical symptoms, and chest radiographic findings at the onset of the disease. Approximately 70 percent of the patients in each group had underlying diseases; among them, pulmonary tuberculosis was the most common. Negative conversion of bacilli during the 6-month treatment was seen in 17 of 29 patients (59 percent) with M avium infection and in 21 of 43 patients (49 percent) with M intracellulare infection. Bacilli-negative conversion was slightly faster in the former than in the latter. However, these differences were statistically not significant. In conclusion, most M avium-intracellulare complex organisms are clearly identified as M avium or M intracellulare by the DNA probe method, and there was no significant difference in clinical features and response to treatment between infections caused by the two species.
The effect of human recombinant interleukin-1 beta (hrIL-1 beta) on tumor growth was studied in eight glioma cell lines. hrIL-1 beta inhibited growth in all cell lines, but to varying extents. Two cell lines were suppressed by 0.5 ng/ml hrIL-1 beta, and three cell lines required 20 ng/ml. hrIL-1 beta also induced morphological changes and increased F-actin contents. hrIL-1 beta-treated cells demonstrated multipolar shapes and numerous processes with a greater number of cell-cell contacts 24 hours after treatment. Fluorescence microscopy revealed that these processes contained a large amount of polymerized F-actin. These results suggest that hrIL-1 beta-mediated growth inhibition may be related to the differentiation of glioma cells.
An interstitial radiofrequency (RF) hyperthermia system for brain tumor was evaluated in cranial phantoms and cat brains. An intracranial RF applicator and thermocouple microprobes were emplaced in the brain and a headband-type flexible extracranial electrode fixed over the scalp. An 8 MHz RF capacitive-type heating machine provided power. The temperature distribution was measured by thermography. In phantom and animal studies, the RF power had good penetration into the tissue and generated uniform and easily controllable high-temperature fields within the intracranial cavity. There was little change in temperature near or in the cranium itself. Six cases of human malignant glioma were treated with this interstitial RF hyperthermia system, achieving therapeutic temperature without adverse effects.
A 53-year-old male presented with hearing impairment and facial nerve paralysis following tinnitus of the right ear. Neuroimaging revealed a tumor extensively damaging the temporal bone, and extending into the middle cranial fossa and cerebellopontine angle. The tumor was removed in a two-stage operation. The histological diagnosis was facial schwannoma.
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The efficacy of the combination therapy of fluconazole plus flucytosine against pulmonary cryptococcosis was investigated. The minimal inhibitory concentrations of antifungal agents were measured by growth inhibition on Yeast-morphology agar plates, and the fractional inhibitory concentration index of each antifungal combination were calculated by checker-board titration. Eight of Cryptococcus neoformans clinical isolates showed sensitivity for AMPH, 5-FC, MCZ and ITZ. C. neoformans showed resistance against FLCZ. The combination of FLCZ plus 5-FC showed synergistic effect against C. neoformans. Three cases of pulmonary cryptococcosis were treated by combination therapy of fluconazole plus flucytosine. After treatment, C. neoformans isolates were eradicated and the chest X-ray improved remarkably. The combination therapy of fluconazole plus flucytosine was effective for the treatment of pulmonary cryptococcosis.
A 78-year-old man developed herpes zoster virus (HZV) encephalitis. Initially, treatment with aciclovir (750 mg per day) improved CSF cell count and protein level. During the treatment, however, encephalitis in the patient deteriorated in spite of the treatment with aciclovir, suggesting that HZV in the patient had become resistant to aciclovir. Subsequent treatment with vidarabine (600 mg per day, for 15 days) resulted in dramatic improvement in CSF pleocytosis. About two months after the discontinuation of vidarabine, the CSF cell count was normal. The patient became alert gradually, but his amnestic syndrome remained unchanged. Vidarabine may be recommended in the treatment of HZV encephalitis when aciclovir is not effective.
The purpose of this study was to analyse the fluoride content of Japanese infant foods and foods in Brazil and to estimate daily fluoride intake calculated for a 6-month-old infant which reflects supplemental fluoride increased from infant foods and decreasing breast-feeding and commercial milk-feeding. Fluoride concentrations of 26 samples were assessed by a modified microdiffusion method and fluoride ion selective electrode. The fluoride content varied from 0.53 to 1.33 microgram/g for milk-base formulas, from 0.46 to 2.94 micrograms/g for infant foods in Japan, and from 0.06 to 0.25 microgram/g for foods in Brazil. The daily fluoride intake was calculated according to feeding pattern. The minimum and maximum fluoride values were 0.080 mg/day and 0.248 mg/day, respectively. These fluoride intakes, expressed in milligrams per kg of fluoride intake, ranged from 0.010 to 0.033 mg F/kg body weight. No significant differences in fluoride intake values were found between Japanese infant foods and foods in Brazil. The results of this study indicate that daily fluoride intakes of Japanese infant foods and foods in Brazil could be considered within the optimal recommended level.
The long term efficacy of low residue diet (LRD) for the maintenance of remission in patients with Crohn's disease was studied. The patients consisted of 60 with quiescent Crohn's disease who were given LRD (Clinimeal or Ensure Liquid) for maintenance therapy for more than one year (average 2.4 years) after discharge from our institute. On the basis of the quantity of LRD given per day, the patients were classified into three groups: A; O to 799 kcal a day, B; 800 to 1599 kcal a day and C; more than 1600 kcal a day. The remission rate and the avoidance rate of admission were calculated and compared among three groups. The remission rate in group C was significantly higher than those in groups A and B. The avoidance rates of admission in groups B and C were significantly higher than that in group A. These results suggest that drinking of LRD at home is useful for the maintenance of remission in patients with Crohn's disease and that the effect of LRD depends on the quantity of LRD given per day.
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A 57-year-old man with pulmonary tuberculosis underwent left upper lobectomy in 1984. In 1987, chest X-ray showed a fungus ball, and Aspergillus species was isolated from sputum. He was treated by intracavitary injection of amphotericin B (AMPH) in June, 1992. However, no change was observed in the chest CT scan after a total dose of 1,000 mg of AMPH. Combination therapy of intravenous administration of 100,000 units of urinastatin and intracavitary injection of AMPH resulted in complete disappearance of the fungus ball on chest CT scan. This report describes case of pulmonary aspergilloma successfully treated with the combination of AMPH and urinastatin.
Intraosseous tumor was found in a 63 year old male patient with lung cancer during metastatic work-up study. Plain skull X-ray film showed a large osteolytic lesion in the left temporo-parietal bone. Bone and Ga scintigrams revealed an increased activity in this lesion. CT scan demonstrated an isodense lentiform configuration, which was homogeneously enhanced with contrast medium. It was iso-intense in T1, and high-intense in T2 and proton weighted MR images. The tumor was removed en bloc with surrounding normal bone. The attached dura was markedly thickened, but there was no tumor infiltration. Histological diagnosis was transitional meningioma with psammoma body. Postoperatively he was transferred back to Okinawa Hospital and right lower lobectomy was performed for the lung tumor. Histological diagnosis was well-differentiated adenocarcinoma. We examined immunohistochemically p53 protein expression, but p53 immunoactivity was observed in neither tumor. Multiple neoplasms associated with brain tumor are relatively rare, but the incidence will increase in the future as the diagnostic work-up develops. Pathological diagnosis will give us the decisive opportunity for proper treatment. It is to be stressed that, in multiple neoplasms, care should be taken to avoid misdiagnosis of metastasis.
Mutations that prevent the normal expression of the retinoblastoma susceptibility gene (RB) have been linked to the pathogenesis of several human malignancies. Mutational inactivation of this tumor-suppressor gene appears to initiate the development of retinoblastoma, and may also contribute to the pathogenesis of osteosarcomas, soft-tissue sarcomas, small-cell lung cancer and other malignancies. In cooperation with the Lung Cancer Study Group, we studied the structure and expression of the RB gene in a cohort of 219 primary non-small-cell lung cancers (NSCLCs). RB gene structure was studied at the DNA level by Southern blot and chromosome 13 restriction fragment length polymorphism analyses. Expression of the RB gene was evaluated by Northern analysis of the transcript and immunohistochemical analysis of the protein (p105RB). Immunohistochemistry of the RB protein proved to be the most sensitive method for the detection of Rb gene inactivation. Absent or abnormal RB protein staining was detected in 53/163 (32%) evaluable cases studied, while Northern analysis showed 22/219 cases to have an altered or absent RB transcript. Southern analysis revealed only two cases of structural alteration of the gene, but loss of heterozygosity from chromosome 13 was common in tumors that failed to express the protein. Analysis of the clinical outcomes of the patients whose tumors were studied did not show any correlation of RB inactivation with time to relapse or death. The data from this study indicate that the RB gene is inactivated in a significant number of NSCLCs. The role that these mutations may play in the development of NSCLC remains to be defined.
Human tails have been attributed to a disturbance in fetal tail regression which normally occurs at the gestation age of about 6 weeks. To date, more than 100 cases of human tails have been reported. However, reports of true human tails, which involve the coccygeal vertebrae, are rare. We recently encountered a patient with a true human tail which involved the coccygeal vertebrae and was accompanied by lumbar spinal lipoma and spina bifida. A four-year-old boy was brought to our clinic with complaints primarily of painful mass. The boy had no neurological abnormalities. Physically, a tail bone projected, slightly in the lumbar area, with a linear depression in the center. A hard tail bone was palpable subcutaneously. A soft mass was palpable in the lumbar region, which was accompanied by hemangioma on the superficial layer of the skin in this region. On X-ray films, the tail bone lacked the normal curvature and it projected linearly in the posterior direction. CT scans revealed spina bifida at the level below L2. MRI disclosed spina bifida (at the level below L2), spinal lipoma and a tethered cord. During surgery, the tail bone was first resected over a distance of one and a half vertebral bodies. The lumbar tumor, which continued into the spinal canal, was removed as completely as possible after incision of the dura mater. To free the tethered cord, the tensioned, hypertrophic filum terminale was dissected. Although the morphological diagnosis of this condition is easy, the high incidence of complication by other anomalies makes it essential to perform thorough preoperative examinations with CT and MRI.(ABSTRACT TRUNCATED AT 250 WORDS)