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Biomedical subjects

M Ohkawa

Publications and source records attributed to M Ohkawa.

At least 145 records · Page 8Linked to original sources
PubMed1994

Analysis of lung surfactant in the metamorphosing bullfrog (Rana catesbeiana).

In bullfrog (Rana catesbeiana) tadpoles, the lung begins to function at an advanced stage of metamorphosis. As a preliminary step for investigation of the mechanisms involved in lung maturation, pulmonary surfactant was prepared from tadpoles at advanced stages of metamorphosis and its biochemical properties were analyzed. Surfactant phospholipid analysis revealed that the major constituent was phosphatidylcholine (PC), as examined in the animals at late climax (stage 24). Other detectable phospholipids were phosphatidylethanolamine, phosphatidylserine, sphingomyelin, and phosphatidylglycerol, a marker lipid in mammalian surfactant. As in mammals, PC in the surfactant was rich in saturated fatty acids, about 50% of fatty acid moieties being palmitic acid. The content of surfactant PC in the lung increased moderately around mid-climax and markedly at the end of climax. The effect of antiserum against bullfrog prolactin (PRL) on the pulmonary surfactant was studied in climactic tadpoles. The content of surfactant PC in the lung of the antiserum-treated larvae was lower than that in the lung of the normal rabbit serum-injected larvae, whereas the content of PC in the whole lung did not differ between the antiserum-treated and control groups. The results suggest that synthesis of surfactant in the amphibian lung is enhanced as metamorphosis progresses and that PRL is involved in lung maturation.

Animals↗
PubMed1994

[Experimental investigation of 201TlCl-scintigraphy in evaluating therapeutic effect of hyperthermia].

We investigated the usefulness of 201Tl-scintigraphy in the evaluation of therapeutic effect of hyperthermia. Satoh's experimental lung cancer tumors implanted in the right thighs of donryu rats were treated with hyperthermia using water bath. Tumors were heated at 44 degrees C or 46 degrees C for 15 min. 201Tl-scintigraphy was obtained before, immediately after and 24 hrs after treatment. Counts ratio of the tumor to the normal muscle (T/N ratio) was measured by gamma camera. We examined blood flow of the tumor, and relative tumor growth rate, and performed autoradiogram and histopathological examination of the tumor after 201Tl-scintigraphy. Immediately after hyperthermia, T/N ratio and blood flow of the tumor significantly decreased (p < 0.05). Autoradiogram showed that the accumulation of 201TlCl in the tumor decreased diffusely. Histopathological finding showed congestion, thrombosis, and swelling of endothelial cells. These results suggest that the decrease in T/N ratio may be caused by the vascular damage due to hyperthermia. The T/N ratio recovered 24 hrs after hyperthermia but was still lower than that for the control. Autoradiogram showed that 201TlCl greatly accumulated in the viable tumor tissue but was hardly seen in the necrotic tumor tissue. These results suggest that the decrease in T/N ratio may be caused by increase of necrotic areas. The T/N ratio 24 hrs after hyperthermia correlated (r = 0.83) with relative tumor growth rate on 7th day after hyperthermia and, therefore, can be used as an indicator of relative tumor growth rate. 201Tl-scintigraphy can be useful for prediction of therapeutic effect of hyperthermia.

Animals↗
PubMed1994

[The effect of PTA on cerebral vessels in experimental vasospasm: a histopathological study].

Although the percutaneous transluminal angioplasty (PTA) is an useful procedure for the treatment of symptomatic vasospasm after subarachnoid hemorrhage, the morphological changes in spastic intracranial vessels after PTA are not yet clear. The purpose of this study was to evaluate the effects of PTA angiographically and histologically. Chronic cerebral vasospasm was induced by producing a blood clot in the subarachnoid space around the top of internal carotid siphon in Japanese monkey. After angiographic recognition of vasospasm, PTA was carried out with silicone microballoon at 1 atmosphere, 3 times for 10 seconds. Angiography after PTA disclosed significant dilatation at the site of PTA, without any significant dilatation of distal spastic vessels. Papaverine hydrochloride was then infused intra-arterially, which resulted in significant dilatation of distal spastic vessels. Upon histological examination, deformation and some denudation of endothelial cells were noted in the intimal layer. At the site of denudation, attachment of platelets was observed despite generalized heparinization. Internal elastic lamina and the media were also stretched and myocytes were deformed and arranged irregularly. These changes were not uniform all over the vascular walls. We conclude that the prolonged effect of PTA may be caused by mechanical damage of endothelial cells and myocytes, and the nonuniformity of histological changes in vascular wall may be a leading cause of its rupture during PTA.

Angioplasty, Balloon↗
PubMed1994

Intra-arterial chemotherapy for brain stem glioma: report of four cases.

Four patients with pontine gliomas were treated with radiation and intra-arterial chemotherapy using ACNU, cisplatin, and/or carboplatin. All underwent biopsy and were histologically proven to have gliomas. Even though three were benign histologically, all appeared malignant on neuroimaging. Two patients had complete remissions; the others had partial responses; three patients died, 36, 14, and 15 months after the primary diagnosis. One patient, now in complete remission, has been alive for 24 months. There was no neurotoxicity except for transient nausea and vomiting. Intra-arterial chemotherapy is effective against brain stem gliomas, producing remission with minimum side effects.

Adolescent↗
PubMed1994

Studies of effects of anticancer agents in combination with/without hyperthermia on metastasized human bladder cancer cells in chick embryos using the polymerase chain reaction technique.

Cultivated T24 cells derived from a human bladder cancer were inoculated into the chorioallantoic membrane vein of chick embryos. Hyperthermic treatment was performed following injection of anticancer agents 3 days after the inoculation of the T24 cells. DNA samples were obtained from the livers of the chick embryos, and the polymerase chain reaction technique was used to amplify a DNA fragment specific to the human beta-globin gene. The Southern hybridization method was used to evaluate the inhibitory effects of anticancer agents in combination with/without hyperthermia on T24 cells metastasized to the liver. The hyperthermia exerted an inhibitory effect on the growth of the T24 cells in the livers of the chick embryos, and this was dependent on the thermal dose. The antitumor effects of hyperthermia performed at 42.5 degrees C for 20 min and at 43.0 degrees C for 10 min were evidenced by 69.2% an 82.0% inhibition of the growth of the metastasized T24 cells, respectively, as compared with the growth of untreated T24 cell. Hyperthermia performed at 42.5 degrees C for 10 min alone produced 26.7% tumor growth inhibition, and these conditions for hyperthermia were subsequently used as a criterion for evaluating the effects of its combination with various anticancer agents. Adriamycin (20 micrograms/egg) alone, mitomycin C (10 micrograms/egg) alone, carboplatin (10 micrograms/egg) alone, and cisplatin (10 micrograms/egg) alone produced 13.5%, 58.9%, 27.3%, and 29.1% tumor growth inhibition, respectively. Adriamycin and mitomycin C applied in combination with hyperthermia showed additive inhibitory effects on the growth of the metastasized T24 cells in this chick embryo model.

Animals↗
PubMed1994

The influence of prostatic urethral anesthesia in overactive detrusor in patients with benign prostatic hyperplasia.

We examined the effects of prostatic urethral anesthesia on cystometrography in benign prostatic hyperplasia (BPH) patients with or without neurological disorders. Although cystometrography after anesthesia showed no disappearance of involuntary detrusor contraction, it did demonstrate significant increases in first sensation volume and maximum cystometric capacity in BPH patients without neurological diseases, as well as BPH patients with a history but no physical evidence of neurological disease. Furthermore, the bladder might be augmented more efficaciously in patients with involuntary detrusor contractions. No significant differences were found in first sensation volume or maximum cystometric capacity before and after anesthesia in patients without infravesical obstruction who had documented neurological disease with physical evidence. Our results demonstrated that prostatic urethral anesthesia can be used preoperatively in patients with infravesical obstruction to discriminate whether involuntary detrusor contractions are due to infravesical obstruction or to neurological disease.

Aged↗
PubMed1994

Crystal adherence to urinary catheter materials in rats.

Crystal adherence to the surfaces of indwelling urinary catheter materials was investigated by scanning electron microscopy and immunofluorescence method. Small sterile disks were inserted into the rat bladder transvesically. Crystals were frequently associated with fibrillar material, some of which was believed to be fibrin. Increases in fibrillar materials were paralleled by increases in crystal adherence. On the other hand, a decrease in the amount of fibrin adhering to the surfaces of heparinized material, resulting in a decrease in the quantity of encrusting deposits on these materials, was found as compared with other catheter materials, including latex, silicone and nonheparinized material. These findings suggest that early adherence of fibrin to the surfaces of indwelling urinary catheter materials plays an important role in the development of crystal adherence and encrustation on catheter materials. It is also suggested that heparin inhibits the adherence of fibrin, resulting in decreased encrustation on the surfaces of the heparinized material.

Adhesiveness↗
PubMed1994

Transrectal ultrasonography of the prostate and seminal vesicles with hemospermia.

Transrectal ultrasonography was performed in 46 patients with hemospermia. Abnormal findings in the prostate and seminal vesicles, including prostatic stones, benign prostatic hyperplasia, prostatitis, and dilatation and calculi of the seminal vesicles, were observed in 34 patients (73.9%). However, no malignant lesions were found in the prostate or seminal vesicles. Transrectal ultrasonography was a useful and noninvasive procedure to investigate the causes of hemospermia. Furthermore, transrectal ultrasonography could demonstrate latent diseases and exclude malignancy of the prostate and seminal vesicle in patients with hemospermia.

Blood↗
PubMed1994

Nuclear deoxyribonucleic acid content in inverted papilloma of the urothelium.

We analyzed formalin-fixed and paraffin-embedded materials from urothelial inverted papillomas using flow-cytometric DNA analysis to investigate the intrinsic nature in terms of the malignant potentials. DNA indices of the inverted papillomas ranged between 1.00 and 1.26 with a mean value of 1.12. The percentage of S phase of a tumor DNA histogram showed greater values in every case compared with a normal DNA histogram. This tumor form could be thus regarded as a diploid neoplastic disease with a relatively higher proliferative activity, although 1 case showed an aneuploid pattern (DNA index = 1.26), in which bladder carcinoma developed subsequently.

Adult↗
PubMed1994

[The mode of lymph node metastasis and post-operative recurrence in transitional cell carcinoma of the upper urinary tract].

We surveyed 34 patients of transitional cell carcinoma of the upper urinary tract treated with nephroureterectomy with excision of a cuff of bladder or combined with regional lymphadenectomy to investigate the mode of lymph node metastasis and post-operative recurrence. In 8 of 14 patients undergoing nephroureterectomy with excision of a cuff of bladder combined with regional lymphadenectomy, lymph node metastasis was histologically confirmed in the neighbouring lymph node, of which 2 patients showed the skipped lymph node metastasis simultaneously. Subsequent bladder cancer developed in 12 out of 34 patients (35.3%) and the primary tumor showed papillary growth in all patients except for one patient which showed non-papillary growth, but with pR1. During the observation period with the mean of 9.4 months, remote metastases in other organs were detected in 6 patients with invasive primary tumor more than pT2.

Aged↗
PubMed1994

[Coincident renal cell carcinoma and renal angiomyolipoma in tuberous sclerosis: a case report].

The coincidence of renal cell carcinoma and renal angiomyolipoma in tuberous sclerosis is extremely rare, although the coexistence of tuberous sclerosis and renal angiomyolipoma is well recognized. A case of bilateral renal angiomyolipomas and left renal cell carcinoma in a patient with tuberous sclerosis is reported. A 40-year-old male was referred to our hospital for further evaluation and treatment of left flank masses. Tuberous sclerosis was diagnosed on the basis of adenoma sebaceum, seizures, mental retardation and periventricular calcification. Contrast enhanced CT scan demonstrated irregularly enhanced masses in the upper pole and the middle portion of the left kidney, and multiple small low density nodules in the bilateral kidneys. Selective left renal angiography showed hypervascular areas in the upper pole and the middle portion of the left kidney. From the findings obtained, a clinical diagnosis of left renal cell carcinoma associated with bilateral renal angiomyolipomas was made. Left radical nephrectomy was performed. The histopathological examination revealed renal cell carcinoma and multiple renal angiomyolipoma nodules. The diagnostic considerations, particularly differential diagnosis between renal angiomyolipoma and renal cell carcinoma by imaging features, are discussed.

Adolescent↗
PubMed1994

[Clam ileocystoplasty for neurogenic bladder due to spina bifida].

A 24-year-old female with neurogenic bladder due to spina bifida consulted our department for further evaluation and treatment of a left renal stone. She innately voided urine by Crede's method. At the age of 15 years, intermittent self-catheterization was started because left severe hydronephrosis was found. At the age of 19 years, cystostomy was performed because of low compliance bladder and an aggravation of hydronephrosis in spite of intermittent catheterization. Thereafter, she was referred to our department for further evaluation and treatment of a left renal stone since the stone was increasing in size. First, left percutaneous nephrolithotomy was performed successfully. Secondly, clam ileocystoplasty using the ileum was carried out, followed by 1) increase of the bladder capacity, 2) improvement of the bladder compliance, 3) adequate intermittent self-catheterization, and 4) disappearance of urinous odor resulting from removal of the cystostomy catheter. Thus, the clinical effects were thought to be significant.

Adult↗
PubMed1993

[An improved method of preparation of autopsied human inflated-fixed whole lungs for radiologic-pathologic correlation].

Inflated-fixed lung specimens, prepared using polyethyleneglycol 400, the standard Heitzman method have the disadvantage of bad staining. The authors attempted to improve this short-coming using human autopsied lungs and evaluated both microscopical findings and the degree of specimen inflation. Fifty-five human autopsied whole lungs were examined. Forty-six lungs with cannulation through the main bronchus were distended with 20% formalin, after clamping the cannula for 15 minutes to six days, formalin in lungs was expelled by air at 10 cm H2O pressure, then fixed with fixative-fluid containing polyethyleneglycol 400, 95% ethyl-alcohol, 40% formalin and water mixed in a ratio of 10:5:2:3. In 9 lungs without cannulation, formalin was expelled manually. The degree of distension of 46 of the 55 cannulated specimens was satisfactory (score A: 42 specimens, score B: 4 specimens). In 9 specimens without cannulation, inflation was poor (Score C). Good or excellent staining was obtained in 29 specimens (Score A: 10 specimens, Score B: 19 specimens), but 3 specimens were not be improved (Score C). Both inflation and staining were good in 21 specimens. This new method, requiring cannulation in the main bronchus, inflated-fixation with 20% formalin and expulsion of formalin by air prior to the standard Heitzman method enables both high quality staining and radiographs of the inflated-fixed lung specimen.

Biopsy↗
PubMed1993

[Clinical trial of IVC filter to temporary placement].

We developed a new inferior vena caval filter to prevent pulmonary embolism for a patient with IVC thrombus. This filter made by covering top half of Dotter Intravascular Retriever catheter with Dacron mesh sheet, was placed in IVC through a 10 F sheath from right jugular vein. In one case, after anticoagulant therapy and thrombectomy using balloon catheter, many free-floating thrombus were trapped in this filter and were taken out from the IVC. This filter was useful for preventing pulmonary embolism when removing thrombus in IVC, iliac and lower extremity veins. We propose to call this device "Hino's filter".

Adolescent↗
PubMed1993

[Experimental studies on Nicaraven as radioprotector--free radical scavenging effect and the inhibition of the cellular injury].

In the present study, firstly the antioxidant effect of Nicaraven was observed by examining the direct free radical scavenging effect with ESR. Dose dependent effects were shown in scavenging both of superoxide and hydroxyl radicals. In the study to check whether Nicaraven inhibits hydroxyl radical formation or degrades the spin adduct of DMPO with hydroxyl radical, the effect of Nicaraven was suggested that it inhibited hydroxyl radical formation itself. Secondly, it was recognized fluorophotometrically that the inhibiting effect of the agent on the superoxide and hydroxyl radicals promoted damage to benzoate, deoxyribose and some amino acids. The inhibiting effect was nearly the same as that of mannitol. Furthermore, the inhibition of the cellular injury induced by ferrous sulphate was investigated in NIH3T3 cells. The addition of Nicaraven to the cells after 6 hours of reaction with FeSO4, the inhibition of the cellular injury was significant (p < or = 0.01). The effect of Nicaraven was recognized as a radioprotector in vitro. The agent suggested to be able to produce recovery from the damage induced by irradiation at the cellular level.

3T3 Cells↗
PubMed1993

An experimental model of ascending pyelonephritis due to Candida albicans in rats.

We developed a new experimental model of ascending Candida pyelonephritis in female rats with leukopenia and vesicoureteral reflux. Rats were treated transperitoneally with cyclophosphamide (200 mg/kg) to induce leukopenia 3 days before and transurethrally with diluted acetic acid solution to induce vesicoureteral reflux 1 day before inoculation of Candida albicans strain, ATCC 10259 (containing 10(7) cells). Microscopy revealed acute pyelonephritis in which Candida cells invaded from the fornix and/or papilla into the medulla within 3 days after inoculation. Between 7 and 28 days after inoculation, chronic pyelonephritis reached the cortex. The incidence of pyelonephritis increased gradually and was approximately 80% after 7 days. Candida colony counts of bladder urine specimens obtained by direct puncture were significantly greater in rats with pyelonephritis extending into the parenchyma than in those with pyelonephritis located along the pelvis (p < 0.01). These results suggest that this rat model shows the characteristic feature of ascending pyelonephritis due to C. albicans and that the severity of Candida pyelonephritis can be estimated from Candida counts of bladder urine.

Animals↗
PubMed1993

Diagnostic value of determination of serum mannan concentrations in patients with candiduria.

The diagnostic value of determination of serum mannan levels was studied in 41 patients with candiduria and 20 control patients without candiduria. The patients with candiduria comprised 18 asymptomatic afebrile patients (group 1) and 23 febrile patients with suspected Candida pyelonephritis (group 2). Mannan antigenemia (> or equal to 0.5 ng/ml) was detected in 14 patients in group 2, this rate being significantly higher than the rate of four patients in group 1 (p < 0.05) and none in the control group (p < 0.01). Serum mannan levels decreased gradually and became undetectable in six patients in whom therapy with an anticandidal agent was effective. Determination of serum mannan levels may be a useful parameter in diagnosing Candida pyelonephritis and deciding on effective treatment.

Antigens, Fungal↗