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Biomedical subjects

H Koga

Publications and source records attributed to H Koga.

At least 397 records · Page 22Linked to original sources
PubMed1986

camR, a negative regulator locus of the cytochrome P-450cam hydroxylase operon.

A 4.27-kilobase insert from a HindIII DNA library of Pseudomonas putida carrying the CAM plasmid allowed coordinate expression of genes camD and camC under control of camR, an upstream regulator. The camC gene specifies cytochrome P-450cam, and camD specifies the 5-exo-alcohol dehydrogenase. A 1.38-kilobase deletion from the insert results in the constitutive expression of genes camC and camD; transformation in trans restores the substrate control, indicating that camR is a negative regulator.

Alcohol Dehydrogenase↗
PubMed1986

[Radiosensitive meningioma--report of a case].

The patient was a 24-year-old male who was admitted to the Dept. of Neurosurgery of Miyazaki Medical College in April of 1982 with a history of generalized convulsive seizures. Neurological examination on admission revealed slight mental disturbance, bilateral marked papilloedema and homonymous right upper quadrantanopsia. Plain skull X-ray films showed a destructive change of the bone in the left sphenoid ridge and sella floor. CT scan showed a huge mass of slightly high density in the left anterior and middle fossae with a marked enhancement with contrast media. It was fed mainly by the left anterior and middle cerebral arteries and partly by the left middle meningeal artery on angiogram. The tumor was considered to be a type of malignant meningioma originating from the left sphenoid ridge. Total removal of the tumor without any morbidity was thought to be difficult because of its size, hypervascularity and location. From clinical and radiological features, this tumor was thought to be an angioblastic meningioma of hemangiopericytoma type and to be radiosensitive. Cobalt-60 irradiation to the tumor was attempted with a total dose of 49 Gy for over a period of 6 weeks. CT scan performed at the stage of 23 Gy-irradiation showed high radiosensitivity of the tumor and CT scan two weeks after the completion of irradiation showed a marked reduction of its volume to one third. The patient became free from headache and memory disturbance after radiotherapy. On the forty eighth day after completion of the irradiation, the tumor was totally removed with ease and minimal bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Treatment of recurrent chronic subdural hematoma--setting an Ommaya tube].

The rate of postoperative recurrences of chronic subdural hematomas is high. Several methods have been advocated, but each one remains controversial. We proposed a simple method of setting an Ommaya tube after burr-hole evacuation. The reservoir was placed in the subcutaneous space, the tip of the tube was placed in the subdural space. The reservoir was punctured with a needle, thereby allowing aspiration of fluid from the subdural space. Sixty one cases of chronic subdural hematomas were operated by simple burr-hole evacuation. The Ommaya tube was used in 46 selected patients.: 1) the volume of hematoma was more than 100 ml and, or 2) older than 70 years of age. Reaccumulation of subdural effusion was detected in 10 cases. The subdural effusions were drained by percutaneously needling the reservoir of the Ommaya tube. This procedure was curative in 9 of the patients. However 1 patient required a small craniotomy. The patient had two outer membranes therefore inner hematoma could not be removed. The authors propose this technique and discuss about it.

Aged↗
PubMed1985

P450cam gene cloning and expression in Pseudomonas putida and Escherichia coli.

The gene camC, which encodes the cytochrome P450 monoxygenase protein, was cloned into the shuttle vector pKT240 and recovered as the recombinant pKG201 with a 2.3 kb insert from the CAM plasmid in the PstI site. The gene product is expressed constitutively in P. putida and in E. coli whereas the inverted insert clone lacks expression, indicating absence of an insert promoter.

Animals↗
PubMed1985

Production of monoclonal antibodies against Legionella pneumophila serogroup 1.

Four monoclonal antibodies to Legionella pneumophila Philadelphia 1 were produced by the fusion of immunized BALB/c lymphocytes to a murine myeloma cell line. Two (Lp1-1 and Lp1-3) of the four monoclonal antibodies reacted with 14 L. pneumophila serogroup 1 strains, and the other (Lp1-2 and Lp1-4) reacted with only three out of 20 strains tested. These four monoclonal antibodies did not bind to any strains of L. pneumophila serogroup 2-7 and other Legionella species. In addition, it has been shown that these monoclonal antibodies may be useful not only for subserotyping of L. pneumophila but also for retrospective diagnosis using immunopathological methods.

Antibodies, Monoclonal↗
PubMed1985

Susceptibility of Legionella pneumophila to ofloxacin in vitro and in experimental Legionella pneumonia in guinea pigs.

The antimicrobial activity of ofloxacin was tested against 15 standard strains and 37 clinical and environmental strains of Legionella pneumophila by agar dilution susceptibility studies with a new growth medium. The ofloxacin MICs were inoculum dependent and ranged from 0.03 to 0.125 microgram/ml. The antibacterial activities of other agents tested relative to ofloxacin were rifampin greater than ofloxacin greater than josamycin greater than pipemidic acid. Ofloxacin, at concentrations equal to or greater than 0.05 microgram/ml, inhibited the growth of L. pneumophila grown in human monocytes. The therapeutic efficacy of ofloxacin in experimental guinea pig L. pneumophila pneumonia was greater than that observed with erythromycin or josamycin therapy; it was less effective than was rifampin. Ofloxacin was very active against intracellular L. pneumophila in these experiments and should be studied in the therapy of human Legionnaires disease.

Animals↗
PubMed1985

Study of the motility and contractility of cultured brain-tumor cells.

The motility of cultured cells and contractility of their cytoplasmic microfilament system were studied in benign compared with malignant brain-tumor cells. Motility of cultured cells was continuously monitored in a perfusion chamber by a computerized microscope system equipped with an autotracking device. The contractility of the microfilament system was defined by the increase in cell motility when the cell was perfused with an antimicrofilamentous agent, cytochalasin B. The motility and contractility of malignant cells were greater than those of benign cells. The increased contractility of malignant astrocytoma cells was associated with conspicuous morphological changes on electron microscopy. No significant change was observed in the motility, contractility, or morphology in various cells during perfusion with an antimicrotubular agent, colchicine. The significant differences in the motility and contractility of benign compared with malignant cells are believed to originate from qualitative differences of the microfilament system.

Astrocytoma↗
PubMed1985

[Encapsulated subdural empyema--a case report with special reference to CT findings and operative indications].

A case of encapsulated subdural empyema was reported. This 1.5-year-old boy was admitted with the increasing confusion and convulsion. Eight months prior to admission, he had craniotomy for traumatic acute epidural hematoma on the left side. Following a coagulation of the middle meningeal artery which was the bleeding source, the dura was opened but no cortical damage was noted at that time. The computed tomographic (CT) scan on admission revealed a large subdural collection with a thin enhancing rim on the left side. Emergency craniotomy revealed a collection of subdural pus, which was irrigated and a catheter was put for continuous drainage. Postoperatively, the patient did well, however, following removal of the catheter, three weeks after the first operation, the subdural empyema was reexpanded with a very thick enhancing rim on CT scan. Ultrasonography also clearly demonstrated the formation of the thick membranes. The large craniotomy was performed and empyema with the outer and inner membranes of 8 mm thick was totally excised. Postoperative CT scan did not show any enhancing rim, indicating that enhancement was caused by newly formed vessels within the membranes per se. This findings are totally different from those observed in the brain abscess in which ring enhancement on CT continues months to years following so-called extracapsular excision of abscess. In the brain abscess, surrounding glial tissue with plenty neovascularization is left intact, even after the operation.

Drainage↗
PubMed1985

Functional recovery of the bladder in patients with spinal cord injury--prognosticating programs of an aseptic intermittent catheterization.

Ninety patients with spinal cord injury were managed by aseptic intermittent catheterization program I (preventing the over-distension of the bladder) and program II (allowing overdistension) in which recovery of bladder function and the clinical effects were comparatively investigated. Using program I, cases with positive BCR restored the automaticity of the bladder on average 8 weeks after injury. When urinary incontinence first occurs during aseptic intermittent catheterization, urinary training may be commenced since the bladder has then recovered from spinal shock. Cases with no BCR do not restore automatic bladder contraction. Program II delayed or weakened the recovery of bladder function considerably. Patients with incomplete lesions and sacral sparing, particularly those with urinary sensation, should be managed by program I which does not impair recovery of the bladder. It is possible to prevent urinary incontinence and infection, if paraplegics with complete lesions are managed by program II. The percentage of urinary infection was 22.6 +/- 16.0% (N = 90) during aseptic intermittent catheterization (non-touch technic) among whom no statistically significant difference between those with trigger voiding (22.2 +/- 17.2%, N = 57) and those with self-catheterization (23.2 +/- 14.0%, N = 33) was found.

Adolescent↗