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Biomedical subjects

H Kumon

Publications and source records attributed to H Kumon.

At least 37 records · Page 2Linked to original sources

Optimal starting time for flutamide to prevent disease flare in prostate cancer patients treated with a gonadotropin-releasing hormone agonist.

OBJECTIVE: Flare-up phenomena, such as an increase in prostate-specific antigen (PSA) and/or deterioration of symptoms, are observed in some patients undergoing gonadotropin-releasing hormone (GnRH) agonist therapy. This study was carried out to determine the optimal time for starting the administration of flutamide to prevent flare-up phenomena. PATIENTS AND METHODS: Twenty-six patients with prostate cancer and elevated serum levels of PSA were randomly assigned to 5 groups. Group A patients (n = 6) were treated with a subcutaneous injection of 3.75 mg leuprorelin acetate depot alone. Group B, C, D and E patients (5 patients in each group) were treated with 375 mg/day of orally administered flutamide combined with leuprorelin. Flutamide was initiated on the day of leuprorelin injection in group B, and at 1, 2 and 4 weeks before leuprorelin injection in groups C, D and E, respectively. Serum PSA and testosterone levels were measured in each patient. RESULTS: Pretreatment with flutamide increased the serum testosterone level, but the testosterone surge after leuprorelin administration was almost the same in all 5 treatment groups. In patients who had been treated with flutamide in combination with leuprorelin, the mean PSA level did not exceed the pretreatment levels after leuprorelin administration. The rate of decrease in PSA in the group receiving simultaneous administration of flutamide with leuprorelin showed a decline comparable to that during the period before leuprorelin administration in the flutamide pretreatment groups. CONCLUSION: Simultaneous administration of flutamide with a GnRH agonist is sufficient to prevent flare-up phenomena.

Adenocarcinoma↗

[Combination therapy against vancomycin-resistant enterococci].

The therapeutic options for patients infected with vancomycin-resistant enterococci are limited. Optimal therapy for serious enterococcal infections requires the use of synergistic combinations of a cell wall-active agent plus an aminoglycoside. Enterococci have acquired aminoglycoside resistance genes that mediate production of aminoglycoside-modifying enzymes, which eliminate this synergistic bactericidal effect. Traditional therapy has been compromised due to the increasing prevalence of enterococci with beta-lactam, glycopeptide, and high-level gentamicin resistance. Arbekacin, a semi-synthetic aminoglycoside, shows excellent activity against a wide variety of bacteria that produce aminoglycoside modifying enzymes, including AAC(6')-APH(2"). In recent studies, the combination of ampicillin and arbekacin demonstrated inhibitory activity against vancomycin-resistant enterococci, and may prove useful in the treatment of enterococcal infections where treatment options are limited.

Aminoglycosides↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). I. Susceptibility distribution].

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 499 strains. The breakdown of these strains was Gram-positive bacteria as 31.3% and Gram-negative bacteria as 68.7%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. The increase of low-susceptible strains which was noticed in the former year showed a slight recovery in this year. VCM showed a strong activity against MRSA preventing growth of all strains with 1 microgram/ml. In addition, the activity of arbekacin (ABK) was also strong with the MIC90 of 2 micrograms/ml against MRSA. However, MSSA and MRSA showing low susceptibilities were detected in one strain each (MIC: 16 micrograms/ml and 32 micrograms/ml, respectively). Carbapenems showed high activities against Citrobacter freundii and Escherichia coli. Meropenem (MEPM) prevented growth of all strains within 0.125 microgram/ml. Quinolone resistant E. coli decreased in this year compared with those in the last year, that percentage was less than 5%. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis. MEPM and carumonam (CRMN) prevented growth of all strains within 0.125 microgram/ml. On the other hand, one strain of K. pneumoniae showing resistance to cefaclor (CCL) and one strain of P. mirabilis showing low susceptibility to most of cephems were detected. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90s of carbapenems were 8 micrograms/ml and those of all other drugs were more than 16 micrograms/ml.

Anti-Bacterial Agents↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). II. Background of patients].

Five-hundred forty four bacterial strains isolated from 412 patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the clinical background of patients were investigated such as sex, age and type of infections, infections and kind of bacteria, frequency of isolation of bacteria by age and infections, bacteria and infections by timing of administration of antibiotics, and bacteria and infections by surgical procedures. About the relationship between age and sex of patients and type of infections, the number of male patients aged less than 50 years was few, and complicated UTIs without indwelling catheter was the most frequent. In females, the number of patients aged less than 20 years was few. Complicated UTIs without indwelling catheter was the most frequent among female patients aged between 40 to 59 years, in other age groups, uncomplicated UTIs was most frequent. As for type of infections and kind of bacteria, Escherichia coli decreased when the infections became complicated, and Pseudomonas aeruginosa and Enterococcus faecalis increased when the infection became complicated. Considering this result by age of patients, isolation frequency of E. coli was gradually decreased with aging in patients aged more than 20 years with uncomplicated UTIs or complicated UTIs without indwelling catheter. The isolation frequencies of E. faecalis and Staphylococcus aureus were gradually increased with aging in complicated UTIs without indwelling catheter. In patients with complicated UTIs with indwelling catheter, there was no difference between age group, and P. aeruginosa and E. faecalis were frequently isolated. As for type of causative organisms in UTIs before and after the administration of antibiotics, the isolation of bacteria was remarkably decreased after administration in patients with uncomplicated UTIs and complicated UTIs without indwelling catheter. E. coli decreased after administration of antibiotics, and P. aeruginosa and E. faecalis increased after administration in patients with all infections. As for type of causative organisms in UTIs and surgical procedures, E. coli were more frequently isolated in patients with uncomplicated UTIs when surgical procedures were experienced. Also, Klebsiella spp. and E. faecalis were more frequently isolated in patients with surgical procedures. However, in complicated UTIs, type of causative organisms had no relationship with surgical procedures.

Adolescent↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). III. Secular changes in susceptibility].

The bacteria (Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the susceptibilities of these bacteria to various antimicrobial agents were examined and the results were compared with those obtained between 1991 and 1998. Comparison was made by classifying strains isolated from patients into those with uncomplicated UTIs and those with complicated UTIs (including with or without indwelling catheter). About E. faecalis, increase of low sensitive strains noted in the former year showed a decreasing tendency, however, one strain each with MIC of 4 micrograms/ml to vancomycin (VCM) was detected in patients with both uncomplicated and complicated UTIs. As for S. aureus, many sensitive strains to cephems, imipenem (IPM) and VCM were noted, and each MIC50 was better than that in the former years. S. aureus strains showing low susceptibility to arbekacin (ABK) were detected in patients with complicated UTIs in this year as well as in the former year, and one strain each with MIC of 16 micrograms/ml and 32 micrograms/ml was detected. Susceptibilities of E. coli were effective to all drugs except for penicillins and minocycline (MINO). Decrease of low sensitive strains was also noted in all drugs except for quinolones. Each MIC90 of ciprofloxacin (CPFX) and sparfloxacin (SPFX) in patients with complicated UTIs against E. coli was 3 degrees classes lower than that in patients with uncomplicated UTIs. As for Klebsiella pneumoniae, decrease of low sensitive strains to cephems was noted in patients with uncomplicated UTIs in 1998. In 1999, low sensitive strains decreased also in patients with complicated UTIs, and few were detected. Susceptibilities of K. pneumoniae to quinolones were effective as compared with those in the former years with the MIC80s of 0.125 microgram/ml or below without detection of low sensitive strains. One low sensitive strain of K. pneumoniae with MIC of 8 micrograms/ml was detected for gentamicin (GM). Susceptibilities of P. aeruginosa to carbapenems were notable. The MIC90 of meropenem (MEPM) and IPM was 4 micrograms/ml each which was 2 degrees better than that in 1998. Resistant P. aeruginosa strains to other drugs except for monobactams decreased in 1999.

Anti-Bacterial Agents↗

Reliability of color Doppler ultrasound urodynamics in the evaluation of bladder outlet obstruction.

OBJECTIVES: To analyze the intrarater and interrater reliability of a newly developed noninvasive urodynamic technique based on color Doppler ultrasound for the evaluation of bladder outlet obstruction. We previously demonstrated the feasibility of this new technique. METHODS: Color Doppler ultrasound urodynamic evaluations were performed on 31 men with and without bladder outlet obstruction. An ultrasound image-directed Doppler system with a 3.75-MHz probe operated by a remote control robotic manipulator was used to obtain color scale data using the transperineal approach in men during voiding. We measured the flow velocities in the distal prostatic (V1) and membranous urethra (V2) and used them to obtain the velocity ratio (VR = V1/V2). Combining this information with simultaneous uroflowmetry, the functional cross-sectional area of the distal prostatic urethra (A1) was calculated. These parameters were independently reinterpreted by an inexperienced investigator using the color image data stored in a personal computer. The intrarater and interrater reliability for VR were assessed using a classification based on cutoff values previously shown to indicate the presence or absence of obstruction. RESULTS: The retest correlation using Spearman's rho for VR in terms of intrarater and interrater reliability was 0.95 and 0.57, respectively; that for A1 was 0.97 and 0.64, respectively. Using a VR of less than 1.1 (to indicate the absence of obstruction) and a VR greater than 1.6 (to indicate the presence of obstruction) for classification, intrarater and interrater agreement occurred in 93.6% to 96.8% and 77.4% to 83. 9% of cases, respectively. CONCLUSIONS: The color Doppler ultrasound urodynamic technique for noninvasive evaluation of bladder outlet obstruction can be performed with reasonable reliability.

Adult↗

Noninvasive urodynamic evaluation of bladder outlet obstruction using Doppler ultrasonography.

OBJECTIVES: Previously we had developed a new method of noninvasive urodynamics using color Doppler ultrasound. Using this technique, we attempted to identify parameters that would diagnose bladder outlet obstruction (BOO). METHODS: Twenty-two men who underwent pressure-flow urodynamic studies were included. Color scale transperineal ultrasound and uroflowmetry data were analyzed by custom-made software. The maximum flow velocities in the entire prostatic urethra (V(0)), in the distal prostatic urethra just proximal to the external urethral sphincter (V(1)), and in the membranous urethra (V(2)) were obtained. Corresponding functional cross-sectional areas of the urethra at these three sites (A(0), A(1), and A(2)) were calculated as Qmax/V. The velocity ratio (VR), which was equal to V(1)/V(2), was also calculated as a parameter. All these parameters obtained by the velocity-flow urodynamics were compared with the Abrams-Griffiths number (AG). RESULTS: From the x-y plots obtained, VR correlated best with AG, with Spearman's rho of 0. 728. A(0) and A(1) had rho values of -0.461 and -0.708 against AG, respectively. All men with VR exceeding 1.6 had obstruction, whereas those with VR less than 1.1 did not. CONCLUSIONS: The VR was found to be the best parameter for diagnosing BOO. When prostatic urethral obstruction was present, the velocity in the prostatic urethra would be high but the velocity slows down to 62.5% or greater immediately below the sphincter. We believe that noninvasive pressure-flow-like urodynamic evaluation based on Doppler ultrasound has clear potential for diagnosing BOO.

Humans↗

Epidermal growth factor in urine from patients with bladder cancer.

Epidermal growth factor (EGF), a mitogenic polypeptide with a molecular weight of 6000, is excreted in human urine in nanomolar quantities. Recently, some reports showed that urothelial neoplasm was related to the concentration of EGF in urine. In this study, EGF concentration in urine was measured by enzyme-linked immunosorbent assay (ELISA) in 207 samples from 112 male patients (30-90 years old, median 66.2) who had previously been treated for bladder cancer. Then, we tried to clarify the significance of urinary EGF as a marker for recurrence of bladder cancer in comparison with urine cytology. The samples were collected on occasional follow up cystoscopy. Urine from nine age-adjusted males without urological disease was also measured to obtain normal control values. In 123 samples from patients without tumors, EGF concentrations in urine decreased with age. In 84 samples obtained from patients with recurrent tumor, EGF concentrations were significantly lower than those in 123 samples from patients without tumors (P < 0.001) Furthermore, EGF concentrations in longitudinal samples collected the same patients during tumor recurrence and at the times when no tumor was detected were measured in 56 patients. EGF concentrations in the samples collected during tumor recurrence was significantly lower than that in specimens collected when there was no tumor (P < 0.01). There were no significant differences between the same samples collected during tumor recurrence with regard to tumor grade, stage shape and number of tumors. However, EGF concentration in urine from patients with carcinoma in situ (CIS) was lower than that in specimens from patients without CIS. These results indicate the usefulness of determining the EGF concentration as a marker for detecting bladder cancer recurrence. Urine cytology was also examined in the same series and findings were compared with those of urinary EGF. On cytology, class IV and V were considered positive, and on urinary EGF, less than 10 ng/mgCr were considered positive. Sensitivity was 25% for cytology and 57% for urinary EGF, while specificity was 98% and 66%, respectively. The predictive positive value was 0.88 and 0.53, respectively. With the combined use of urinary EGF and cytology, the sensitivity, specificity and predictive positive value were 68%, 64% and 0.92, respectively. In conclusion, urinary EGF seems to be a useful marker for detecting bladder cancer recurrence if performed in addition to cytology. cancer recurrence if performed in addition to cytology.

Adult↗

Chromosomal numerical aberrations of exfoliated cells in the urine detected by fluorescence in situ hybridization: clinical implication for the detection of bladder cancer.

Numerical aberrations of chromosomes 7 and 9 of exfoliated cells from the urinary tract were examined using fluorescence in situ hybridization (FISH). To minimize contamination with inflammatory, squamous and normal transitional cells all samples were stained using Giemsa's solution and clusters of transitional cells were selected for FISH analysis. Samples collected from 21 patients who had cystoscopic monitoring for bladder cancer were used in this study. Cystoscopy was positive in seven patients and five biopsy-proven transitional cell carcinomas were identified. Among the patients with cancer recurrence, numerical chromosomal aberrations were detected in four cases (sensitivity: 80%) and positive cytology in two cases. This preliminary pilot study shows FISH can be a useful tool for the detection of recurrence during a follow up of bladder cancer.

Adult↗

Management of biofilm infections in the urinary tract.

Bacterial biofilms develop on a number of living and inert surfaces within the urinary tract, producing chronic intractable infections. The role of exopolysaccharides in producing a variety of extracellular polymeric substances according to the infection site and bacterial species and the clinical features of the resulting biofilm infections were reviewed. Although fluoroquinolone shows a considerable killing effect against bacterial biofilm, no commercially available drugs are sufficiently active against the cells in a mature biofilm. Combination therapy of fluoroquinolone and macrolide or fluoroquinolone and fosfomycin may be the most effective regimen available at present. Nevertheless, management of the local urinary condition and removal of the local underlying disease are the most effective approaches to treating urinary biofilm infection.

Biofilms↗

In-vitro synergistic activity of the combination of ampicillin and arbekacin against vancomycin-and high-level gentamicin-resistant Enterococcus faecium with the aph(2")-Id gene.

The combination of ampicillin plus arbekacin produced synergistic killing against 8 of 13 vancomycin-, ampicillin-, gentamicin-, and streptomycin-resistant Enterococcus faecium isolates that possess the high-level gentamicin resistance gene, aph(2")-Id. This combination may prove useful in treating infections caused by multiresistant enterococci.

Aminoglycosides↗

In-vitro activity of arbekacin alone and in combination with vancomycin against gentamicin- and methicillin-resistant Staphylococcus aureus.

In-vitro susceptibility studies were performed on 99 clinical Staphylococcus aureus isolates. A total of 68 of 73 methicillin-resistant S. aureus and 2 of 26 methicillin-susceptible S. aureus were gentamicin-resistant (gentamicin MIC range 16 to 1,024 microg/mL). All 70 gentamicin-resistant isolates contained the aac(6')-Ie-aph(2'')-Ia aminoglycoside resistance gene, and none possessed the aph(2'')-Ic or aph(2'')-Id aminoglycoside resistance genes. The arbekacin MIC for the 70 gentamicin-resistant isolates ranged from 0.25 to 4 microg/mL. The combination of arbekacin plus vancomycin produced synergistic killing against 12 of 13 gentamicin-resistant MRSA isolates. The combination of gentamicin plus vancomycin produced synergistic killing against 7 of the same 13 isolates. Arbekacin may prove useful when used in combination with vancomycin in treating infections caused by gentamicin-resistant MRSA.

Aminoglycosides↗

Antimutagenic activity of cacao: inhibitory effect of cacao liquor polyphenols on the mutagenic action of heterocyclic amines.

We investigated the effect of polyphenols derived from cacao liquor on the mutagenic action of heterocyclic amines (HCAs) in vitro and ex vivo. In the Ames test, the cacao liquor polyphenols showed antimutagenic effects in bacteria treated with HCA in the presence of an S-9 mixture; however, they showed less efficacy than quercetin. On the other hand, the cacao liquor polyphenols showed potent antimutagenic activity in bacteria treated with activated forms of HCA, compared with quercetin. We also evaluated the effect of these compounds on enzymatic activation of HCA. They weakly suppressed the production of activated HCA. In the host-mediated assay in mice, a method used to estimate the potential carcinogenicity of chemicals ex vivo, oral administration of the cacao liquor polyphenols, reduced the number of colonies of revertant bacteria recovered from the liver. These data suggest that the cacao liquor polyphenols have an antimutagenic effect not only in vitro, but also ex vivo.

Animals↗

Pre-penile arteries are dominant in the regulation of penile vascular resistance in the rat.

The amount of blood flow into the penis that will produce an erection is dependent on the sum of inflow resistance from the feeder arteries, arterioles and the intra-penile vasculature. In the present study, our objective was to determine quantitatively the contribution to inflow resistance of these different components of the rat penile vasculature. Using methods developed previously, we determined the resistance properties of the isolated perfused whole penis in situ, both in an intact system and after serial transactions of the vessels. These cuts eliminated progressively larger distal segments of the vascular bed. Perfusion pressures were recorded at different flow rates (0.5-3 ml/min/kg body weight) under conditions of maximal dilatation and maximal vasoconstriction induced by methoxamine (MXA, 40 microg/ml). Regardless of the level of vascular tone, the pudendal artery contributes approximately 70% of the total resistance of the penile vasculature. In contrast, the vasculature within the penis (tip, shaft, crus) contributes only about one quarter of the resistance. Penile arterial inflow resistance properties both at maximal vasodilation and maximal alpha1-adrenergic constriction are dominated by the extra-penile vasculature in the rat. The implications of these findings are that alterations in the pudendal-artery (eg vasodilation, vasoconstriction, stenosis) would have primary control of arterial inflow and suggest an important role for pharmacological agents which can promote a more generalized vasodilation (eg phosphodiesterase inhibitors) in contrast to selective corpus cavernosal agents.

Adrenergic alpha-Agonists↗

The absorption of pirarubicin instilled intravesically immediately after transurethral resection of superficial bladder cancer.

OBJECTIVES: To assess the validity of the prophylactic use of pirarubicin ([2'R]-4-O-tetrahydropyranyl-doxorubicin) immediately after transurethral resection of bladder tumour (TURBT), using pharmacodynamic studies. PATIENTS AND METHODS: The study included 20 consecutive patients with superficial bladder cancer. Pirarubicin (30 mg/50 mL or 30 mg/100 mL, 10 patients each) was instilled immediately after TURBT and retained in the bladder for 1 h. Blood samples were obtained before and at 15, 30, 60 and 120 min after the instillation. After retaining the drug for 1 h all the intravesical fluid was collected and assayed for pirarubicin. RESULTS: The plasma pirarubicin concentration in those receiving either dose was below detectable levels at any time after instillation. The mean recovery rate of pirarubicin in the drained fluid was 73%. CONCLUSION: The intravesical instillation of pirarubicin immediately after TURBT caused no detectable plasma concentration and few systemic side-effects.

Absorption↗

Suicide gene therapy for urogenital cancer: current outcome and prospects.

Viral-mediated transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene has been demonstrated by several investigators to confer sensitivity to nucleoside analogs such as ganciclovir (GCV) in a variety of tumor cells including brain, prostate, bladder, kidney, ovary, head and neck, lung, pancreas, and liver cancers. Fourteen suicide gene clinical protocols using adenovirus vectors have been conducted, including four in prostate cancer. Two additional protocols for prostate cancer are in preparation in Japan and the Netherlands. A study conducted at Baylor College of Medicine was the first to demonstrate the safety of HSV-tk plus GCV therapy for human prostate cancer and the anticancer activity of gene therapy in this disease. However, it is still in the early stage of its development, with a number of problems to be overcome. Systemic delivery, specific introduction, and specific expression of the target gene are the major issues to be managed in order to establish a clinically relevant treatment strategy.

Clinical Protocols↗