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Biomedical subjects

Y Ohi

Publications and source records attributed to Y Ohi.

At least 19 recordsLinked to original sources
PubMed1999

Expression of vascular endothelial growth factor in patients with testicular germ cell tumors as an indicator of metastatic disease.

BACKGROUND: Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor (PD-ECGF) are involved in increased angiogenic activity and disease progression in solid tumors. However, there is no information regarding the association of these angiogenic factors with clinicopathologic findings in testicular germ cell tumors (GCTs). METHODS: The authors examined the expression of VEGF and TP as well as microvessel density in GCTs and their association with clinicopathologic findings. Expression of VEGF and TP and microvessel density were examined immunohistochemically in 80 GCTs, including 33 seminomas (25 tumors with organ-confined disease and 8 with metastasis) and 47 nonseminomatous testicular GCTs (NSGCTs) (20 tumors with organ-confined disease and 27 with metastasis). Expression of VEGF also was examined in four GCTs and one nonneoplastic testis by immunoblotting. RESULTS: VEGF protein was expressed more highly in GCTs compared with nonneoplastic testes. VEGF expression in GCTs was correlated significantly with microvessel count (P < 0.001). Both VEGF expression and microvessel count were correlated with metastasis in seminoma (P = 0.008 and P < 0.001, respectively), but only VEGF expression was identified as statistically significant by multiple regression analysis (P = 0.006). Conversely, four variables (VEGF expression, microvessel count, the presence of venous invasion, and the presence of embryonal carcinoma elements in the primary tumor) were correlated with metastasis in NSGCT (P < 0.001, P < 0.001, P = 0.004, and P = 0.029, respectively). However, multiple regression analysis revealed that only VEGF expression and microvessel count were significant factors for metastasis (P < 0.007 and P < 0.001, respectively). In contrast, high levels of TP were observed in infiltrating cells, but not in the majority of cancer cells. CONCLUSIONS: The findings of the current study suggest that VEGF expression is involved in tumor development, angiogenesis, and metastasis in GCT.

Adolescent↗
PubMed1999

In vitro bactericidal activities of beta-lactamases, amikacin, and fluoroquinolones against Pseudomonas aeruginosa biofilm in artificial urine.

OBJECTIVES: To compare bactericidal activities of antimicrobial agents against Pseudomonas aeruginosa biofilms by employing an in vitro model of catheter-associated infection because such infections are refractory to antimicrobial treatment. METHODS: Bactericidal activities of piperacillin (PIPC), ceftazidime (CAZ), panipenem (PAPM), amikacin (AMK), ciprofloxacin (CPFX), and levofloxacin (LVFX) were examined against a P. aeruginosa biofilm generated on a Teflon catheter in artificial urine. The colony-forming activities of biofilm bacteria were determined for 48 hours during the treatment with each drug at concentrations of 1 up to 128 times the minimal bactericidal concentration (MBC), and time-kill curves were constructed by plotting the viable cell counts against time. RESULTS: Although CAZ was more bactericidal to the biofilm bacteria than PIPC, the biofilm bacteria still remained on the catheter during CAZ treatment at a concentration 128 times the MBC for 48 hours. Biofilm bacteria were completely eradicated within 48 hours by treatment with PAPM and AMK at a concentration 64 and 128 times the MBC, respectively. Both CPFX and LVFX eradicated biofilm bacteria completely by 24 hours at a concentration 32 times the MBC. CONCLUSIONS: These results indicate that fluoroquinolones have the most potent bactericidal activity against the P. aeruginosa biofilm generated in urine.

Amikacin↗
PubMed1999

Diagnosis and treatment of priapism: experience with 5 cases.

OBJECTIVES: Priapism is a rare disease, but needs early intervention and appropriate management. We present 5 cases, 2 of nonischemic high-flow priapism and 3 of ischemic low-flow priapism. METHODS: Focusing on the differential diagnosis of priapism between the nonischemic high-flow type and the ischemic low-flow type, we reviewed the medical records of 5 patients. RESULTS: Of the examinations carried out, cavernosography, blood gas analysis of cavernosal blood, color Doppler ultrasound, and internal pudendal arteriography were useful in differentiating the type of priapism. Complete detumescence of the penis in 2 cases of high-flow priapism and 3 cases of low-flow priapism was achieved by selective embolization with gelform and by glandular-cavernosal shunting, respectively. No recurrence was observed in any patient, and postoperative erectile function was preserved in 4 patients and is unknown in 1. CONCLUSIONS: These results indicate that angiographic studies provide the most reliable information for the differentiation of the type of priapism. However, color flow Doppler ultrasound and cavernosal blood gas determination can obviate the need for angiographic studies and are noninvasive. Although conservative treatment or even expectant management may be feasible with high-flow priapism, aggressive treatment should be carried out for low-flow priapism immediately after initial treatment fails to achieve detumescence of the penis. Selective embolization of the internal pudendal artery may be the treatment of choice for patients with high-flow priapism.

Adult↗
PubMed1999

Bacterial biofilms and catheters in experimental urinary tract infection.

Employing in vitro and in vivo models of catheter-associated infection, biofilm formation of Pseudomonas aeruginosa in artificial urine and bactericidal activity of several classes alone or in combination with a macrolide antibiotic were investigated. In the course of continuous urine flow, bacteria adherent to a Teflon catheter formed microcolonies at 6 h and a biofilm at 24 h. Following 24 h of urine flow, the thickness and the density of the biofilm increased to about 20 microm and 10(8) cfu/mm3, respectively. Of the antibiotics examined, the fluoroquinolones showed the most potent bactericidal activity against the P. aeruginosa biofilms. However, those antibiotics were not always potentiated by the combination with a macrolide antibiotic.

Animals↗
PubMed1999

Obesity affects expression of progesterone receptors and node metastasis of mammary carcinomas in postmenopausal women without a family history.

Possible relationships between risk factors, such as obesity and a family history of breast cancer, and prognostic factors of mammary carcinomas were investigated by examining the body mass index of patients and the expression of estrogen (ER) and progesterone receptors (PgR), c-erbB-2 and p53, grade of histology, size of tumors and nodal status of mammary carcinomas. There was no significant difference in the body mass index of premenopausal patients either with or without a family history. For postmenopausal patients, the body mass index was significantly low in patients with a family history compared with patients without a family history. In premenopausal patients with or without a family history and in postmenopausal patients with a family history, there was no significant difference in the body mass index regardless of the mammary carcinoma prognostic factor, such as expression of ER, PgR, c-erbB-2 and p53, grade of histology, size of tumors and nodal status. However, in postmenopausal patients without a family history, body mass index was significantly high for patients with mammary carcinomas that had PgR expression and node metastasis. These results suggest that obesity may affect the PgR status and nodal status of mammary carcinomas in postmenopausal patients without a family history.

Body Mass Index↗
PubMed1999

Endorectal ultrasonography for the assessment of rectal wall invasion in intrapelvic tumor: a preliminary report.

BACKGROUND: The purpose of the present study was to determine the usefulness of endorectal ultrasonography (ERUS) in assessing rectal wall involvement in intrapelvic tumors. METHODS: Rectal wall invasion was assessed in 16 patients; 14 with deeply invasive bladder tumors, one with prostatic leiomyosarcoma, and one with prostatic leiomyoma. Computed tomography (CT), magnetic resonance (MR) imaging and ERUS with a flexible-type radial scanner (7.5 MHz) were used and the results were compared with the histopathologic findings in surgical specimens. RESULTS: The normal rectum was shown by ERUS to be a five- or seven-layer structure. Characteristic abnormal ERUS findings included disappearance of the perirectal fat tissue layer with or without disruption of the propria muscle layer. Endorectal ultrasonography accurately assessed rectal wall involvement in all four patients who had two bladder tumors, plus the one patient with prostatic leiomyoma and the one with prostatic leiomyosarcoma. However, ERUS overstaged one of 12 bladder tumors with no rectal wall involvement, which was strongly adhesive to the rectum because of an inflammatory change but had no tumor invasion. There were no cases of understaging by ERUS. In comparison, CT accurately assessed rectal wall involvement in two patients, but overstaged in three and understaged in two. Magnetic resonance imaging, which was performed in 14 patients, accurately assessed rectal wall involvement in two patients, but overstaged in three and understaged in one. CONCLUSION: This preliminary study suggests that ERUS more accurately assesses rectal wall involvement in intrapelvic tumor than CT or MRI.

Adult↗
PubMed1999

Multidisciplinary treatment, including laser hyperthermia, for extensive regional metastasis of a penile tumor.

BACKGROUND: There is no reliable treatment for penile tumor with lymph node metastasis. METHODS: We report on a patient with a penile tumor with extensive regional metastasis that was successfully managed with combined laser hyperthermia, radiation and chemotherapy. RESULTS: The patient has survived more than 7 years without evidence of disease. CONCLUSIONS: Multidisciplinary treatment, including laser hyperthermia, may be useful for the treatment of regional metastasis of penile tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Ca2+ spark as a regulator of ion channel activity.

Ca2+ spark is a local and transient Ca2+ release from sarcoplasmic reticulum (SR) through the ryanodine receptor Ca2+-releasing channel (RyR). In cardiac myocytes, Ca2+ spark is an elementary unit of Ca2+-induced Ca2+ release (CICR) by opening of RyR(s) in junctional SR (jSR), which is triggered by Ca2+-influx through L-type Ca2+ channels to the narrow space between a transverse tubule and jSR. Ca2+ spark has, therefore, been described as the evidence for "the local control of excitation-contraction coupling". In contrast, Ca2+ sparks in smooth muscle have been reported in relation to Ca2+-dependent K+ (K(Ca)) channel activation and muscle relaxation. A spontaneous Ca2+ spark in a superficial area activates 10-100 K(Ca) channels nearby and induces membrane hyperpolarization, which reduces Ca2+ channel activity. In several types of smooth muscle cells, which have relatively high membrane excitability, an action potential (AP) elicits 5-20 Ca2+ hot spots (evoked sparks with long life) in the early stage via CICR in discrete superficial SR elements and activates K(Ca)-channel current highly responsible for AP repolarization and afterhyperpolarization. CICR available for contraction may occur more slowly by the propagation of CICR from superficial SR to deeper ones. The regulatory mechanism of ion channel activity on plasma membrane by superficial SR via Ca2+ spark generation in smooth muscle cells may be analogously common in several types of cells including neurons.

Action Potentials↗
PubMed1999

Activation and the interaction of proapoptotic genes in modulating sensitivity to anticancer drugs in gastric cancer cells.

Taxotere (Docetaxel) is a novel microtubulin inhibitor which is currently in phase II/III clinical trial. We found that the sensitivity to taxotere was correlated with apoptotic cell death determined by the internucleosomal DNA ladders in gastric cancer cell lines. The treatment of taxotere activated proapoptotic genes such as bcl-Xs and bax genes. The relationship between the mRNA induction of bcl-Xs and bax genes and the internucleosomal DNA ladders by taxotere was significant, respectively (p<0.05). The introduction of bcl-Xs gene into MKN45 gastric cancer cells increased the sensitivity to VP-16 and taxotere 2-3-fold in the IC50 values, whereas the introduction of bax gene increased the sensitivity to CDDP, VP-16 and taxotere 2-5-fold in the IC50 values, as compared to that of the Neo-transfected MKN45 cells. The mRNA overexpression of bax gene was found in the bcl-Xs-transfected cells. Likewise, the mRNA overexpression of bcl-Xs gene was also found in the bax-transfected cells. These results indicate that the activation of bcl-2 family genes such as bcl-Xs and bax plays a crucial role in modulating apoptotic cell death in the sensitivity to anticancer drugs, and suggest that these proapoptotic genes might interact in the up-regulation for activating downstream signals leading to apoptosis in gastric cancer cells.

Antineoplastic Agents↗
PubMed1999

Comparative study of single-dose and three-day therapy for acute uncomplicated cystitis.

To assess the efficacy and safety of a single-dose therapy for acute uncomplicated cystitis (AUC), we compared 4 treatment regimens in 120 women. Patients eligible for the study were randomly assigned to one of four treatment groups: Ciprofloxacin (CPFX) 200 mg in a single oral dose (group A); 200 mg once daily for 3 days (group B); 200 mg twice daily for 3 day (group C); and cefpodoxime-proxcetil (CPDX-PR) 200 mg once daily for 3 days (group D). The efficacy was evaluated 3 days after the single-dose therapy or at the end of a three-day therapy according to the criteria proposed by the Japanese UTI Committee. The overall clinical efficacy in a total of 107 patients was evaluated to be excellent, moderate, and poor in 72 (67.3%), 35 (31.8%), and 1 (0.9%), respectively. The causative organisms were eradicated in 88.0, 85.2, 85.2, and 82.1% of the patients in groups A, B, C, and D, respectively. Recurrence was identified in 3 (2 in group A and one in group D) of 16 patients who were followed at 2 to 3 weeks after the treatment. No adverse reactions related to the antibiotics were recognized in the study. There were no significant differences in the clinical efficacy or recurrence rate among these four treatment regimens. These results indicate that the single-dose therapy of CPFX is the treatment of choice in women with AUC.

Acute Disease↗
PubMed1999

[Spontaneous rupture of renal cell carcinoma: a case report].

A 74-year-old man with severe right flank pain and hypochondralgia, was admitted to a hospital where he was found to have an abnormality of the right kidney on computed tomographic (CT) scan. He was referred to our department for further examination and treatment on the next day. Spontaneous rupture of the right renal cell carcinoma was mostly suspected from preoperative clinical findings obtained by ultrasonography. CT scan and angiography. Extravasation was not recognized on angiography. We chose emergent transcatheter arterial embolization prior to radical nephrectomy. The surgical specimen contained a solid and yellowish mass invading into the renal pelvis. Subcapsular rupture was identified. Histopathological diagnosis was renal cell carcinoma consisting of invasive growth of highly atypical epithelial cells with a sarcomatous pattern, and the tumor cells were present in the renal pelvis. He died of lung cancer 26 months after the operation.

Aged↗
PubMed1999

A phase II trial of low dose administration of 5-fluorouracil and cisplatin in patients with advanced and recurrent gastric cancer.

The clinical efficacy of chemotherapy for patients with advanced gastric cancer has not been established. We investigated in a phase II study the combination chemotherapy of low dose 5-fluorouracil (5-FU) and cisplatin (low dose FP) to evaluate its clinical efficacy in terms of response, quality of life and survival in 43 gastric cancer patients including 29 advanced and 14 recurrent cases. The administration of 5-FU was done by continuous intravenous infusion for 28 consecutive days with a dose of 250 mg/m2, while the administration of cisplatin was done by 1-h intravenous drip-infusion for 5 consecutive days and 2-day intervals per week with a dose of 3.5 mg/m2, that was repeated for 4 weeks in one cycle. The response rate in advanced cases was 48.3%, evaluated in 14 cases of partial response (PR), whereas its response rate in recurrent cases was 35.7%, evaluated in 5 cases of PR. The most effective lesions for low dose FP chemotherapy were primary lesion and lymph node metastasis. The quality of life assessed by performance status and oral intake was improved in 13.8% and 37.9% of advanced cases, and 21.4% and 28.6% of recurrent cases, respectively, as compared to those of pretreatment. The median survival time and 1-year survival rate were 6 months, 21.6% in advanced cases and 10 months, 28.8% in recurrent cases, respectively. The major adverse effect was observed in gastrointestinal toxicity and leukopenia, and the all toxicities were less than grade 2, that were controllable during the treatment. These results indicated that the combination chemotherapy of low dose administration of 5-FU and cisplatin might have therapeutic efficacy in tumor response and offer improvement in quality of life in patients with advanced and recurrent gastric cancer.

Adult↗
PubMed1998

Ca2+ images and K+ current during depolarization in smooth muscle cells of the guinea-pig vas deferens and urinary bladder.

1. Electrical events and intracellular calcium concentration ([Ca2+]) imaged using fluo-3 and laser scanning confocal microscopy were simultaneously monitored in single smooth muscle cells freshly isolated from guinea-pig vas deferens or urinary bladder. 2. Images obtained every 8 ms, during stepping from -60 to 0 or +10 mV for 50 ms under voltage clamp, showed that a rise in [Ca2+] could be detected within 20 ms of depolarization in five to twenty small (< 2 micrometer diameter) 'hot spots', over 95 % of which were located within 1.5 micrometer of the cell membrane. Depolarization at 30 s intervals activated hot spots at the same places. 3. Cd2+ or verapamil abolished both hot spots and Ca2+-activated K+ current (IK,Ca). Caffeine almost abolished hot spots and markedly reduced IK,Ca. Cyclopiazonic acid, which raised basal global [Ca2+], decreased the rise in hot spot [Ca2+] and IK,Ca amplitude during depolarization. These results suggest that Ca2+ entry caused Ca2+-induced Ca2+ release (CICR). 4. Under voltage clamp, hot spot [Ca2+] closely paralleled the rise in IK,Ca and reached a peak within 20 ms of the start of depolarization, but the rise in global [Ca2+] over the whole cell area was much slower. Step depolarization to potentials positive to -20 mV caused hot spots to grow in size and coalesce, leading to a rise in global [Ca2+] and contraction. Ca2+ hot spots also occurred during the up-stroke of an evoked action potential under current clamp. 5. It is concluded that the entry of Ca2+ in the early stages of an action potential evokes CICR from discrete subplasmalemma Ca2+ storage sites and generates hot spots that spread to initiate a contraction. The activation of Ca2+-dependent K+ channels in the plasmalemma over hot spots initiates IK,Ca and action potential repolarization.

Action Potentials↗
PubMed1998

A long-term surviving patient with cancer of papilla of Vater after local resection.

We report successful local resection for cancer of papilla of Vater in an 86-year-old woman. She was referred to our hospital because of right hypochondralgia. Abdominal ultrasonography and computed tomography showed marked dilatation of the common bile duct (CBD). Endoscopic retrograde cholangiography disclosed a small shadow defect in the terminal of the dilated CBD. Biopsy of the papilla revealed well-to-moderately differentiated adenocarcinoma. Considering her extreme old age and keeping in mind her quality of life after the operation, and the finding that the tumor was localized within the papilla and highly differentiated, we performed local resection. In addition, the intrapancreatic portion of the CBD and part of the main pancreatic duct (MPD) were further resected to secure a negative margin, confirmed by frozen section. The MPD was reapproximated to the duodenal mucosa and a choledocho-duodenostomy was performed for CBD reconstruction. Histopathological examination showed the tumor was papillary adenocarcinoma, 10 x 15 mm in size; there was no invasion beyond the sphincter of Oddi, it had partly infiltrated the CBD, but had not invaded to the pancreas or duodenum. The patient's postoperative course was not eventful and she has had good quality of life for the past 6 years since the operation, without any evidence of recurrence. Although radical pancreaticoduodenectomy is now the standard procedure in patients with malignant tumor of the papilla of Vater, local resection is a reasonable alternative for high-risk patients with highly differentiated, apparently localized carcinomas.

Adenocarcinoma↗
PubMed1998

A new treatment for penile conservation in penile carcinoma: a preliminary study of combined laser hyperthermia, radiation and chemotherapy.

OBJECTIVE: To investigate the role of laser hyperthermia in penis-conserving therapy for penile carcinoma. PATIENTS, MATERIALS AND METHODS: Penile carcinoma KPK-1 cells were transplanted into nude mice to induce tumour; the effects of laser hyperthermia, the chemotherapeutic agent peplomycin, or their combination on the inhibition of KPK-1 tumour growth were assessed. In a clinical study, two patients with well-differentiated, stage T2 penile tumours with corporeal involvement were treated to conserve the penis using concurrent radiation, laser hyperthermia and peplomycin. They had no pathologically identified regional lymph node metastasis. Radiation was given for 5 days a week for 3 weeks at a total dose of 30 Gy. Nd:YAG laser hyperthermia was administered at 42-43 degrees C for 15 min twice a week for 3 weeks immediately after radiation. Peplomycin (10 mg per day) was administered intravenously over 24 h together with the laser hyperthermia. RESULTS: The combined treatment with laser hyperthermia and peplomycin completely inhibited KPK-1 tumour growth, but the treatment with either laser hyperthermia or peplomycin alone had little effect. The results were also corroborated by the histopathological findings; the necrotic area in mice treated with combined therapy was much larger than that in those treated with laser hyperthermia alone. Both patients given combined laser hyperthermia, radiation and peplomycin were treated successfully, with the penis and sexual function conserved, and both survived for > 7 years with no evidence of any local or regional recurrence. There were no major complications related to the combined treatment. CONCLUSIONS: This preliminary study showed that combined treatment with laser hyperthermia, radiation and peplomycin might be a promising therapy for conserving the penis in some patients with stage T2 penile tumours.

Animals↗
PubMed1998

Endoscopic treatment of refractory filarial chyluria: a preliminary report.

PURPOSE: We report our experiences treating 5 patients who had filarial chyluria using an endoscopic approach. MATERIALS AND METHODS: Two men and 3 women 47 to 83 years old with chyluria were treated with endoscopic coagulation using guide tube methods. Intrarenal pelvic instillation of silver nitrate was not effective in 4 patients and catheterization was impossible in 1. RESULTS: The responsible lesion was successfully coagulated in all 5 patients. Because the lesion was in the ruptured portion of the caliceal fornix, we thought that chyluria had arisen in the fragile portion of the fornix (fistulization). After endoscopic treatment there was no recurrence in any patient. CONCLUSIONS: Endoscopy is effective and minimally invasive therapy for filarial chyluria.

Aged↗