Search PubMed⌕ Search

Biomedical subjects

M Murai

Publications and source records attributed to M Murai.

At least 127 records · Page 7Linked to original sources

[Clinical background and treatment of brain metastasis from renal cell carcinoma].

OBJECTIVE: The objective of this study is to evaluate the clinicopathological characteristics and the effect of therapy of brain metastasis from renal cell carcinoma. METHOD: Of 306 cases with renal cell carcinoma treated at Keio University Hospital from June, 1976 to May, 1996, 20 (6.5%) developed brain metastasis. Metastasis-free rate and survival rate were evaluated by Kaplan-Meier's method and tested statistically with Long-rank test. RESULT: As for the time of the brain metastasis, it was already at the time of initial diagnosis in 6 cases, and in the other 14, it was after the diagnosis of original disease. The average interval between the diagnosis of original disease and metastasis was 53.9 months. Only 2 cases have no metastasis without brain, and 17 of 20 cases (85.0%) were complicated by pulmonary metastasis and 10 (50.0%) by bone metastasis. It was considered that the brain metastasis was accompanied with other metastases. As for the treatment, cytokine therapy was performed on 18 cases without efficacy. It was supposed that in cases with pulmonary metastasis, IL-2 therapy may have the possibility of increasing the frequency of brain metastasis. 9 of 20 cases were subjected to surgical treatment with significantly better prognosis than the cases without the operation. Two cases were long-term survivors more than 5 years after the diagnosis of brain metastasis and both underwent surgical treatment to brain metastasis. CONCLUSION: Cytokine therapy was not effective to brain metastasis from renal cell carcinoma. On the other hand, however, it was suggested that surgical treatment could improve prognosis if the metastatic lesions could be resected.

Adult↗

[Anti-proliferative effects of heating on the human prostatic carcinoma cells in culture].

Prostatic cancers are well-known to be sensitive to heat stress. However, the mechanism by which the cancer cells are killed by high temperature remains poorly understood. The present study was undertaken to determine the anti-proliferative effects of heat stress on the prostatic cancer cells in culture. Heat shock at 43 degrees C inhibited the cell growth of three different prostatic cell lines. Flow cytometrical analysis using BrdU and PI showed a decrease in the proportion of cells in an S phase, accompanied by cell accumulation in G1 and G2, in both JCA-1 and PC-3 but not in LNcap. Both JCA-1 and PC-3 presented a strong expression of hsp70 at 37 degrees C. The heat shock caused apparent enhancement of the expression of hsp70 through the cell cycle. A treatment at 43 degrees C for 8 hours resulted in not only an apparent increment of positive hsp70 cells, but cells with subdiploid DNA content in LNcap. Flow cytometrical analysis by FITC-labeled Annexin V showed increment of apoptotic cells at 43 degrees C for 8 hours in LNcap cells. The results suggest that apoptosis is an important pathway of heat-induced killing of these cells. In conclusion, the cell growth of prostatic cancers may be affected by the temperature through relationship of the cell cycle and hsp70.

Apoptosis↗

Learning curve and conversion to open surgery in cases of laparoscopic adrenalectomy and nephrectomy.

PURPOSE: We examine how the level of experience acquired by the laparoscopist affects the outcome of laparoscopic adrenalectomy and nephrectomy, and what is necessary to avoid complications in these surgeries. MATERIALS AND METHODS: We retrospectively evaluated the experience levels of 8 urological laparoscopists between 1991 and 1995. In addition, other cases that were converted to open surgery were collected from the institutes with which the 8 laparoscopists were affiliated. RESULTS: The rates of conversion to open surgery were 6.4% in 204 cases of adrenalectomy and 14.3% in 63 of nephrectomy. Conversion rates were related to blood loss volume but not operative time. The major causes of conversion were bleeding in 45% of cases and adhesion in 34%. There were no mortalities. Mean operative time decreased significantly, reaching that of open surgery as the number of procedures increased up to 20 adrenalectomies and 10 nephrectomies. The volume of blood lost remained low from the early experience. Blood transfusion rates were 4.4% for adrenalectomy and 11.1% for nephrectomy. CONCLUSIONS: Operative time of these procedures decreased significantly with surgeon experience and reached that of open surgery. Cases in which adhesion is anticipated should be restricted to avoid conversion. These laparoscopic procedures are acceptable as a standard operative techniques for adrenal and renal diseases.

Adrenal Gland Diseases↗

[A case of Prader-Willi syndrome accompanied with a renal stone].

Little information is available regarding the correlation between Prader-Willi syndrome and urolithiasis. We report a patient with Prader-Willi syndrome with a renal uric acid (UA) stone. A 23-year-old male patient was admitted to our department with gross hematuria and left flank pain. The blood and urine examination demonstrated hyperuricemia with the presence of UA crystals in the urine. Excretory urography revealed a radiolucent stone (17 x 27 mm) in the left renal pelvis suggesting a UA stone. The stone was removed successfully using extracorporeal shockwave lithotripsy (ESWL) combined with medication for UA metabolism. The stone was thought to have formed as a result of overeating associated with Prader-Willi syndrome, and accompanying overproduction of purine.

Adult↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996). I. Susceptibility distribution].

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 680 bacterial strains isolated from patients with urinary tract infections (UTIs) in 10 hospitals during the period of June 1996 to May 1997. Of the above bacterial isolates, Gram-positive bacteria accounted for 30.4% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 69.6% and most of them were Escherichia coli. Susceptabilities of several isolated bacteria to antimicrobial agents were as followed; 1. Enterococcus faecalis Ampicillin (ABPC) showed the highest activity against E. faecalis isolated from patients with UTIs. Its MIC90 was 1 microgram/ml. Imipenem (IPM) and vancomycin (VCM) were also active with the MIC90S of 2 micrograms/ml. The others had low activities with the MIC90S of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA Arbekacin (ABK) and VCM showed the highest activities against both S. aureus and MRSA isolated from patients with UTIs. The MIC90S of them were 1 or 2 micrograms/ml. The others except minocycline (MINO) had low activities with the MIC90S of 32 micrograms/ml or above. 3. Staphylococcus epidermidis ABK and VCM showed the strongest activities against S. epidermis isolated from patients with UTIs. The MICs for all strains were equal to or lower than 2 micrograms/ml. Cefazolin (CEZ), cefotiam (CTM) and cefozopran (CZOP) were also active with the MIC90S of 4 micrograms/ml. Compared with antimicrobial activities of cephems is 1995, the MIC90S of them had changed into a better state. They ranged from 4 micrograms/ml 16 micrograms/ml in 1996. 4. Streptococcus agalactiae All drugs except MINO were active against S. agalactiae. ABPC, CZOP, IPM, and clarithromycin (CAM) showed the highest activities. The MICs for all strains were equal to or lower than 0.125 micromilligrams. Tosufloxacin (TFLX) and VCM were also active with the MIC90S of 0.5 micromilligrams. 5. Citrobacter freundii Gentamicin (GM) showed the highest activity against C. freundii isolated from patients with UTIs. Its MIC90 was 0.5 micrograms/ml. IPM and amikacin (AMK) were also active with the MIC90S of 1 microgram/ml and 2 micrograms/ml, respectively. Cefpirome (CPR) and CZOP were also active with the MIC90S of 8 micrograms/ml. The MIC90S of the others were 16 micrograms/ml or above. 6. Enterobacter cloacae IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 0.5 microgram/ml. The MIC90S of ciprofloxacin (CPFX) and TFLX were 1 microgram/ml, the MIC90 of AMK was 2 micrograms/ml, the MIC90S of CZOP, GM and ofloxacin (OFLX) were 4 micrograms/ml. The MIC50S of cephems except CEZ, cefmetazole (CMZ) and cefaclor (CCL) had changed into a better state in 1996, compared with those in 1995. 7. Escherichia coli All drugs except penicillins and MINO were active against E. coli. Particularly CPR, CZOP and IPM showed the highest activities against E. coli. The MIC90S of them were 0.125 microgram/ml or below. Among E. coli strains, those with low susceptibilities to cephems except CEZ, cefoperazone (CPZ), latamoxef (LMOX) and CCL have increased in 1996, compared with those in 1995. 8. Klebsiella pneumoniae K. pneumoniae was susceptible to all drugs except penicillins, with the MIC90S of 2 micrograms/ml or below. CPR had the strongest activity, the MICs for all strains were equal to or lower than 0.25 microgram/ml. Flomoxef (FMOX), cefixime (CFIX), CZOP and carumonam (CRMN) were also active with the MIC90S of 0.125 microgram/ml or below. 9. Pseudomonas aeruginosa All drugs except quinolones were not so active against P. aeruginosa with the MIC90S were 32 micrograms/ml or above. Quinolones were more active in 1996 than 1995. The MIC90S of them were between 4 micrograms/ml and 8 micrograms/ml, and the MIC50S of them were between 1 microgram/ml and 2 micrograms/ml. 10. Serratia marcescens GM showed the highest activity against S. marcescens. Its MIC90 was 1 micro

Anti-Bacterial Agents↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996). II. Background of patients].

Clinical background was investigated on patients with urinary tract infections (UTIs) from whom 752 bacterial strains were isolated in 10 hospitals during the period from June, 1996 through May, 1997. 1. Distribution of age and sex of patients and type of infections. Among males, those with ages 40 years or older were more frequent, the higher the ages of them. Among females, those with ages in the 60's were the most frequent (24.6%), and those with ages in the 20's, 40's and 50's were about 13%. With regard to type of infections, more than a half of infections among males with ages 30 years or older were of complicated types, but most of infections among females were of uncomplicated types, especially among females of ages less than 60 years. 2. Ages of patients and types of pathogens. The higher the ages of patients, the lesser became the isolation frequencies of Escherichia coli, but the higher were those of Pseudomonas aeruginosa and Klebsiella spp. 3. Effect of antibiotic use on isolation frequencies of pathogens. Use of antibiotics decreased pathogens isolated from patients with uncomplicated UTIs drastically (231 isolates before antibiotics compared to 60 after). Even isolated pathogens from patients with complicated UTIs decreased drastically with the use of antibiotics when indwelling catheters were not in use (193 isolates before antibiotics compared to 75 after), but when indwelling catheters were in use, antibiotics apparently failed to decrease the isolation frequency. 4. Surgical procedures and types of causative organisms for UTIs. From cases of uncomplicated UTIs, E. coli was the most frequently isolated, followed by Enterococcus Faecalis and Klebsiella spp. E. coli was the most frequently isolated organism from complicated UTIs without indwelling catheters. When a surgical procedures were not done, E. coli was isolated most frequently. From cases of complicated UTIs with indwelling catheters, P. aeruginosa, E. coli and E. faecalis were the organisms that were mainly isolated, with isolation frequencies of 23.2%, 15.2, 12.2, respectively. When no surgical procedures were used, isolation frequencies of P. aeruginosa, E. faecalis and Enterobacter spp. were 17.2%, 13.8%, 13.8%, respectively.

Adolescent↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996), III. Secular changes in susceptibility].

Susceptibilities to various antimicrobial agents were examined for Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp., and Pseudomonas aeruginosa that were isolated from patients with urinary tract infections (UTIs) in 10 hospitals during June 1996 to May 1997, and the results were compared with those obtained during the same period in earlier years. 1. E. faecalis Among E. faecalis strains, those with high susceptibilities to ampicillin and minocycline appeared to have decreased in the latest study period. 2. S. aureus To almost antimicrobial agents, S. aureus isolated from uncomplicated UTIs showed low susceptibilities. But the MIC50s of those agents for S. aureus from complicated UTIs have changed better state. Particularly, the MIC50s of imipenem and clindamycin were 0.125 microgram/ml or below in the latest period for the first time in our history. 3. E. coli The susceptibilities to piperacillin and quinolones of E. coli isolated from uncomplicated UTIs were better than those isolated from complicated UTIs. 4. Klebsiella spp. The susceptibilities to almost antimicrobial agents of Klebsiella spp. have been better during the latest period, compared to those during period of 1995-1996, but to ofloxacin and ciprofloxacin have appeared to have been lower. 5. P. aeruginosa The susceptibilities to quinolones of P. aeruginosa have been better during the latest period compared those during periods of 1995-1996. But, the susceptibilities to cefozopran, carbapenems and monobactams of P. aeruginosa isolated from complicated UTIs appeared to have been lower. These susceptibility changes should be utilized in determining clinical treatments.

Anti-Bacterial Agents↗

Association between tumor necrosis factor in serum and cachexia in patients with prostate cancer.

The present study was undertaken to evaluate the relationship between serum tumor necrosis factor (TNF) and cachexia in patients with prostate cancer. TNF levels were determined in 110 serum samples from prostate cancer patients by an enzyme immunoassay. Serum TNF activity was positive in 76% of the patients with relapsed disease, whereas only 11% of the untreated patients and 0% of the patients in remission as a result of endocrine therapy were positive. The serum total protein and albumin levels, hemoglobin levels, and body mass index of the patients with elevated serum TNF levels were significantly lower (P < 0.05) than the corresponding values in patients with undetectable serum TNF levels. The serum TNF levels of patients with serum albumin levels of <3.5 g/dl, serum total protein levels of <7.0 g/dl, hemoglobin levels of <11.0 g/dl, and a body mass index of <21 kg/m2 were significantly higher (P < 0.05) than the values in their respective counterparts. There was a significant correlation between the detectability of serum TNF and performance status (P < 0.05). Patients with elevated serum TNF levels had a significantly higher mortality rate (P < 0.05) than those with undetectable serum TNF levels. These findings suggest that TNF may be one of the factors contributing to the complex syndrome of cachexia in patients with prostate cancer.

Adenocarcinoma↗

G-CSF production in human bladder cancer and its ability to promote autocrine growth: a review.

A variety of non-hematopoietic malignant tumors have been demonstrated to secrete granulocyte colony-stimulating factor (G-CSF) in amounts large enough to cause a significant systemic hematopoietic effect. Meanwhile, bladder cancer cells have been shown to secrete a variety of biological factors with no direct relation to urothelial cell origin. G-CSF produced by non-hematopoietic malignant cells in particular has been reported to be capable of inducing a leukemoid reaction in the host through intense stimulation of leukocyte production. This is most frequently associated with aggressive tumor cell growth and a poor clinical outcome. On the other hand, receptors for G-CSF have also been found on the cell surfaces of several non-hematopoietic cell types. These observations lead naturally to the tempting speculation that simultaneous acquisition of the ligand promotion and its receptor expression by a malignant tumor may provide a strong autocrine growth advantage. However, the role of autocrine growth factors in malignancy is even less clear, although it is undoubtedly important. In this review, G-CSF and tumor cell growth, particularly of human transitional cell carcinomas of the bladder, are discussed, and autocrine growth of human solid tumors is also summarized.

Autocrine Communication↗

Effects of endocrine therapy on the primary lesion in patients with prostate carcinoma as evaluated by endorectal magnetic resonance imaging.

BACKGROUND: Little effort has been made at the quantitative and qualitative evaluation of patients with prostate carcinoma, including downsizing and downstaging of the primary lesion, after conservative therapy. The current study was undertaken to investigate the qualitative and quantitative effects of endocrine therapy on the primary prostate carcinoma using magnetic resonance imaging (MRI). METHODS: The primary prostate carcinoma was evaluated by endorectal MRI approximately 4 months after the initiation of endocrine therapy in 48 patients with histologically confirmed prostate carcinoma detected by endorectal MRI before therapy. RESULTS: The volumes of the prostate gland, the carcinoma, and the noncarcinomatous components were reduced to 60.2 +/- 2.7%, 25.5 +/- 2.9%, and 83.2 +/- 6.3% of their pretreatment volumes respectively after endocrine therapy, indicating that the tumors are more susceptible to endocrine therapy than the nontumorous components. The number of prostate carcinomas that demonstrated low signal intensity compared with the normal peripheral zone on T2-weighted images decreased after endocrine therapy and the number of carcinomas with enhancement of T1-weighted contrast-enhanced images increased after therapy. Seven of the 48 patients underwent downstaging after endocrine therapy, based on the endorectal MRI evaluation. CONCLUSIONS: The results of the current study suggest that downsizing and occasionally downstaging of the carcinoma may occur after endocrine therapy in patients with prostate carcinoma. In addition, the androgen sensitivity of the prostate carcinoma tissue is relatively high compared with the residual noncancerous prostate gland.

Antineoplastic Agents, Hormonal↗

A posterior lumbar approach for retroperitoneoscopic adrenalectomy: assessment of surgical efficacy.

OBJECTIVES: To compare the efficacy of retroperitoneoscopic adrenalectomy by a posterior lumbar approach (RPA) with that obtained by a transperitoneal anterior approach (TAA) or retroperitoneal lateral flank approach (RLA). METHODS: Fifty-one patients underwent endoscopic adrenalectomy by three approaches, including laparoscopic adrenalectomy by TAA in 33, retroperitoneoscopic adrenalectomy by RLA in 5, and retroperitoneoscopic adrenalectomy by RPA in 13. RESULTS: The average adrenal tumor size was 27 mm (range 8 to 65). The average number of trocars required for RPA was 3.2 which was significantly less than that for TAA and for RLA (4.2 and 4.1, respectively). The conversion rate to open surgery was 9.1% by TAA, 0% by RLA, and 7.7% by RPA. The average operating time for TAA was 252 minutes, which was significantly shortened to 194 minutes by RLA and 142 minutes by RPA (P < 0.02). The average blood loss was 101 mL for TAA and was negligible by RLA and RPA (22 and 32 mL. respectively). CONCLUSIONS: RPA allowed direct access to the main adrenal vascular supply before the gland was greatly manipulated. Endoscopic adrenalectomy by TAA or even by RLA required extra ports for retraction of liver, spleen, vena cava, or adrenal gland, with higher chance of vein avulsion. RPA was technically feasible and most effective for retroperitoneoscopic adrenalectomy in regard to the simplicity of vascular control. The operating time, perioperative morbidity, and cost were reduced with this approach.

Adrenal Gland Neoplasms↗

A cadaver study on volume and surface area of the fingertip.

The volume of the volar soft tissue, dorsal soft tissue, and bone and the area of the dorsal and volar surfaces were estimated in 35 adult cadaver fingertips. The fingertip was defined as the part of the finger distal to the plane of the palmar skin crease and the major dorsal crease at the distal interphalangeal articulation. An impression molding technique, involving silicone rubber, was used to determine the volume, while dyed imprints of the dorsal and palmar surfaces were used to determine the surface area. In all digits, the mean volume of the volar soft tissue of the fingertip was found to be about 56%, the dorsal soft tissue about 26%, and the volume of bone about 18%. The volar soft tissue includes the skin and fascia (51% of the total fingertip volume), the flexor tendon and its sheath, and the volar plate and volar joint capsule (5% of the total). Power relationships for the total fingertip volume, the volume of volar soft tissue, and the volume of bone in terms of the length of the fingertip were noted. There was also a linear relationship found between the volume of the volar soft tissue and the volar surface area. This study provides data on the ratio of soft tissue to bone in the fingertip. The maintenance of the soft tissue-to-bone ratio, so as to regain fingertip form and function, may be of particular importance when designing flaps and coverage in the reconstruction of the fingertip.

Adult↗

Sigma 1 receptor subtype is involved in the facilitation of cortical dopaminergic transmission in the rat brain.

Our previous studies have shown that three sigma (sigma) receptor ligands, (+)-N-allylnormetazocine ((+)-SKF-10,047), (+/-)-pentazocine and 1,3-di(2-tolyl)guanidine (DTG) differently regulated the dopamine (DA) transmission in the rat brain. In the present study, we attempted to clarify the role of sigma 1 receptor subtype in the regulation of DA transmission using a novel and selective sigma 1 receptor agonist, 1-(3,4-dimethoxyphenethyl)-4(3-phenylpropyl)piperazine dihydrochloride (SA4503) in the rat brain. Acute administration of SA4503 (1.0 mg/kg, p.o.) significantly increased DA and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the rat frontal cortex, but not in the other six regions, hippocampus, striatum, midbrain, cerebellum, medulla/pons and hypothalamus. The increase of cortical DA level elicited by SA4503 was fully reversed by N,N-dipropyl-2-(4-methoxy-3-(2-phenylethoxy)phenyl)ethylamine (NE-100) (0.25 mg/kg, p.o.), a putative sigma 1 receptor antagonist. In addition, SA4503 (1.0 mg/kg, p.o.) showed an increase of cortical L-3,4-dihydroxyphenylalanine (L-DOPA) accumulation under the inhibition of dopa decarboxylase activity with m-hydrobenzylhydrazine (NSD-1015), suggesting that SA4503 has activated the cortical DA synthesis rate. These results suggest that the sigma 1 receptor subtype plays an important role in the facilitation of cortical DA transmission. In addition, this phenomenon is partially involved in the augmentation of DA synthesis rate.

3,4-Dihydroxyphenylacetic Acid↗

Granulocyte colony-stimulating factor receptor expression on human transitional cell carcinoma of the bladder.

Receptors for granulocyte colony-stimulating factor (G-CSFRs) have been confirmed on the cell surfaces of several non-haematopoietic cell types, including bladder cancer cells. This observation has naturally led to the hypothesis that the expression of G-CSFR on these cells may enhance their growth by G-CSF. In this study, the expression of G-CSFR was determined in both established human bladder cancer cell lines and primary bladder cancers. We studied five different human bladder cancer cell lines (KU-1, KU-7, T-24, NBT-2 and KK) and 26 newly diagnosed bladder tumours. G-CSFR mRNA expressions on cultured cell lines were determined using the reverse transcriptase polymerase chain reaction (RT-PCR) method. Furthermore, the G-CSFR binding experiments on the cultured cell lines were conducted using the Na(125)I-labelled G-CSF ligand-binding assay method. Moreover, the G-CSFR mRNA expressions on primary bladder tumour specimens were assessed using the in situ RT-PCR method. Three out of the five cultured cell lines (KU-1, NBT-2 and KK) exhibited G-CSFR mRNA signals when the RT-PCR method was used. The G-CSFR binding experiments showed an equilibrium dissociation constant (K[d]) of 490 pM for KU-1, 340 pM for NBT-2 and 103 pM for KK cells. With in situ RT-PCR, the tumour cells of 6 out of 26 primary bladder tumour specimens (23.1%) presented positive G-CSFR mRNA signals. Thus, in this study, G-CSFR expression was frequently observed on bladder cancer cells. Therefore, the clinical use of G-CSF for patients with bladder cancer should be selected with great care.

Carcinoma, Transitional Cell↗

Constitutive production of multiple cytokines and a human chorionic gonadotrophin beta-subunit by a human bladder cancer cell line (KU-19-19): possible demonstration of totipotential differentiation.

Bladder cancer cells have been shown to secrete a variety of factors that are not related to cells of urothelial origin. The histogenesis of these tumour developments is uncertain, and a variety of theories have been previously reported. In the present manuscript, we identify the factors constitutively produced by a human bladder cancer cell line (KU-19-19) that was found to produce beta human chorionic gonadotrophin (beta-hCG), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1alpha (IL-1alpha), interleukin 6 (IL-6) and interleukin 8 (IL-8). The cells were obtained from a case of metastatic carcinoma that was originally diagnosed to be a grade 3 (WHO classification), invasive transitional cell carcinoma of the bladder. On microscopic observation, the cultured cells exhibited an epithelial appearance with vacuole formation in their cytoplasm. Ultrastructural observations revealed relatively marked microvilli and a tight junction. Significant amounts of beta-hCG, G-CSF, GM-CSF, IL-1alpha, IL-6 and IL-8 concentrations in the supernatant from cultured cells were demonstrated by enzyme-linked immunosorbent assays, while the expression of mRNA of these marker proteins in cancer cells was also significantly exhibited by reverse transcription polymerase chain reaction (RT-PCR). In addition, the expression of G-CSF receptor and IL-6 receptor mRNA was also shown by RT-PCR. Xenograft transplantability using nude mice was observed in association with the presence of severe neutrophilia in the peripheral blood. These results indicate that this cell line appears to be an effective model for the study of transitional cell carcinoma of the bladder with multipotent differentiation potentials.

Aged↗

Role of reactive oxygen species in cis-dichlorodiammineplatinum-induced cytotoxicity on bladder cancer cells.

This study was undertaken to investigate the intracellular induction of reactive oxygen species (ROS) by cis-dichlorodiammineplatinum (CDDP) and the augmentation of their cytotoxicity in bladder cancer cells (KU7) by enhancement of ROS generation by the glutathione (GSH) depletors buthionine sulphoximine (BSO) and diethylmaleate (DEM). CDDP-induced cytotoxicity in KU7 cells and its modulation by GSH depletors were determined using spectrophotometric measurement with crystal violet staining. The effects of GSH depletors on intracellular GSH levels were confirmed using the GSH reductase-DTNB recycling method. Intracellular ROS generation induced by CDDP with or without GSH depletors was estimated from the amount of intracellular dichlorofluorescein (DCF), an oxidized product of dichlorofluorescein (DCFH), which was measured with an anchored cell analysis and sorting system. The cytotoxic effects of CDDP (IC50 15.0 +/- 2.5 microM) were significantly enhanced by BSO (IC50 9.3 +/- 2.6 microM, P < 0.01) and DEM (IC50 10.3 +/- 0.3 microM, P <0.01). BSO and DEM produced a significant depletion in intracellular GSH levels (9.6 +/- 0.4 nmol 10(-6) cells, 17.9 +/- 1.0 nmol 10(-6) cells) compared with the controls (30.5 +/- 0.6 nmol 10(-6) cells). Intracellular DCF production in KU7 cells treated with CDDP (1.35 +/- 0.33 microM) was significantly enhanced by the addition of BSO (4.43 +/- 0.33 microM) or DEM (3.12 +/- 0.22 microM) at 150 min. These results suggest that ROS may play a substantial role in CDDP-induced cytotoxicity and that GSH depletors augment its cytotoxicity through an enhancement of ROS generation in bladder cancer cells.

Antimetabolites↗

Autocrine growth induced by transferrin-like substance in bladder carcinoma cells.

Ample evidence confirms that certain cancer cells have the capacity to produce multiple peptides as growth factors and that expression of their receptor may act in tumour cell paracrine and/or autocrine loop mechanisms, either by extracellular release of the growth factor or by the tumour itself. To study the possibility of an autocrine growth mechanism in bladder carcinoma, we investigated the ability of various bladder carcinoma cell lines to proliferate in serum-free medium. A rat bladder carcinoma cell line, BC47, demonstrated exponential and density-dependent growth in serum-free medium. Furthermore, conditioned medium from BC47 cells induced growth-stimulating activity for BC47 cells themselves. Purification and further characterization of this activity was performed by chromatographic methods, SDS-PAGE and N-terminal amino acid analysis. Finally, we have identified that a transferrin-like 70-kDa protein is found to be the main growth-promoting factor in this conditioned medium. In addition, specific antibodies against transferrin and the transferrin-receptor inhibit the in vitro growth of this cell line. Our data suggest that this transferrin-like factor possibly acts as an autocrine growth factor for cancer cells.

Amino Acid Sequence↗