Biomedical subjects

A Kondo

Publications and source records attributed to A Kondo.

At least 163 records · Page 9Linked to original sources

PubMed1997

Effects of ethanol on responses of isolated rabbit urinary bladder and urethra.

BACKGROUND: Acute ethanol ingestion increases the risk of urinary retention in patients with benign prostatic hyperplasia (BPH). To elucidate the mechanism of this effect, we investigated the in vitro effects of ethanol on lower urinary tract function in rabbits. METHODS: The responses to various stimuli of muscle strips isolated from male rabbit bladder and urethra were determined in the presence of 0%, 0.5%, 1.0%, and 3.0% ethanol. RESULTS: Basal tension of tissue strips taken from the bladder and the urethra was reduced by ethanol in a dose-dependent manner, as were bladder contractions induced by field stimulation, bethanechol, and ATP. Ethanol also reduced phenylephrine-induced contractions of the prostatic urethra. A high (3%) concentration of ethanol significantly reduced KCl-induced contraction of both the bladder and urethra, as well as urethral relaxation induced by field stimulation following contraction with 200 mumol/L phenylephrine. CONCLUSION: Responsiveness of the rabbit lower urinary tract was significantly reduced by exposure to ethanol. A similar decrease in tonus and contractility of the detrusor and inhibition of relaxation in the prostatic urethra may lead to urinary retention in men following acute ingestion of ethanol.

Adenosine Triphosphate↗

PubMed1997

Effect of mucosal resection on detrusor function in the disused rabbit bladder.

A new rabbit model of disused bladder was developed. Disused bladders were created by sagittal splitting of the bladders along the midline and closure of one side (reservoir side), leaving the remaining side unclosed (disused). The mucosa was dissected from some of the disused sides. Tissue elasticity and the weight of the detrusor muscle were decreased by bladder disuse. The responsiveness to field stimulation, bethanechol, ATP, KCl, or isoproterenol, was decreased by disuse. Tissue elasticity and responsiveness to stimuli were decreased to a lesser extent in disused tissue with intact mucosa. Results suggest that the bladder mucosa helps to preserve the function of the disused bladder.

Animals↗

PubMed1997

Response of isolated human neurogenic bladders to tachykinins.

Tachykinins act as stimulants of the isolated urinary bladder. However, the efferent role of tachykinins on detrusor function is controversial. We investigated the contractility of isolated human neurogenic bladders taken from patients with myelomeningocele or sacral agenesis, and tested the response to neurokinin A (NKA), neuromedin K (NKB), and substance P (SP). The contractile strengths were compared with normal controls. All tachykinins investigated induced significant contractions in both neurogenic and control bladders. The rank order of contractile potency was the same in both groups, namely, NKA > NKB > SP. The contraction induced by SP was not affected by atropine, but was completely blocked by [Sar9,Met(O2)11]-SP (a SP antagonist). Responses to electrical field stimulation were not changed by the SP antagonist. The contractile magnitude to field stimulation was also not altered by administration of 10(-6) M tachykinins. Responses of the neurogenic bladder to NKA and SP were significantly greater than the control. There were no differences in the response to KCl administration between the 2 groups. We conclude that hypersensitivity to NKA and SP in neurogenic bladders may contribute to bladder dysfunction in patients with sacral cord lesions.

Adolescent↗

PubMed1997

Effects of partial outflow obstruction on bladder contractility and blood flow to the detrusor: comparison between mild and severe obstruction.

Detrusor dysfunction secondary to partial outflow obstruction is caused in part by decreased blood flow to the detrusor. We investigated changes in blood flow to the bladder and in bladder function after inducing partial outflow obstruction. The urethras of male Sprague-Dawley rats were constricted by sutures to degrees representing either mild and severe obstruction. Blood flow to the bladder was measured by a Doppler flowmeter prior to and 7 days after obstruction. In vivo and in vitro experiments were performed 7 days after surgery. After cystometry was used to determine bladder capacity, the pressure at which micturition was induced, and maximum voiding pressure, the bladder was removed and placed in an organ bath where increases in intravesical pressure in response to field stimulation were evaluated. Finally, volume-pressure studies were performed in order to determine passive detrusor compliance and response to field stimulation at each specific capacity in vitro. Although blood flow to the bladder was significantly decreased by severe obstruction, no differences in blood flow between control and mildly obstructed bladders was observed. While maximum voiding pressure decreased in severely obstructed bladders, both the pressure at which micturition was induced and bladder capacity were increased. The response to field stimulation was increased by mild obstruction but decreased by severe obstruction, although bladder compliance was increased by both. The peak response to filled stimulation was observed at a larger capacity in severely obstructed bladders than the others. In conclusion, when outflow obstruction was mild, blood flow to the bladder remained unchanged and detrusor contractility increased. On the other hand, severe obstruction decreased bladder blood flow and induced deterioration of detrusor function.

Animals↗

PubMed1997

Comparison of cellular characteristics between human hepatoma cell lines with wild-type p53 and those with mutant-type p53 gene.

Characteristics of human hepatoma cell lines with the wild-type p53 were compared with those of human hepatoma cell lines with the mutant-type p53. The p21 protein located downstream of p53 was expressed in cell lines with the wild-type p53 but was not expressed in cell lines with the mutant-type p53. As to other tumor suppressor genes such as p16 and p27, there was no difference in their expression between both types of cell lines. In addition, no marked difference was observed in the activities of CDK2 and CDK4 between cell lines with the wild-type and the mutant-type p53. Phosphorylated Rb protein was detected in all cell lines except the HLE line, indicating that this cell line may have a deletion of and/or a mutation of the Rb gene. These results indicate that abnormalities of tumor suppressor genes other than p53, p16, p27, and Rb may be involved in hepatocarcinogenesis. The population doubling time of the wild-type p53 cells was significantly longer than that of the mutant p53 cells. Neither type of cell line showed a specific chromosome distribution which would indicate karyotype instability. The cell lines expressing the wild-type p53 produced tumors at lower frequency than those with the mutant p53 gene. Although there was no significant difference in effects of TGF-beta 1, EGF, cholera toxin, and db-cAMP on cell growth between the two types of cells, all three cell lines with the wild-type p53 were resistant to cytotoxicity of TNF-alpha, while two of the three with the mutant p53 were very sensitive to its cytotoxic effects.

Animals↗

PubMed1997

[Determination of malondialdehyde-modified LDL(MDA-LDL) and its potential usefulness].

Numerous studies have indicated that oxidative modification of low-density lipoprotein(LDL) plays a critical role in the pathogenesis of atherosclerosis. Malondialdehyde-modified LDL(MDA-LDL) is one of the candidates which is the oxidative product of LDL. However, the existence of MDA-LDL in the circulation has been in dispute. Therefore, for the assessment of oxidized-LDL in human serum, we developed a sensitive enzyme-linked-immunosorbent assay(ELISA) for the detection of MDA-LDL. In our method, monoclonal antibody against MDA-LDL, ML25 was used. ML25 recognized MDA-LDL as well as MDA-modified proteins by a solid-phase competitive enzyme immunoassay. Therefore, to establish an ELISA method which is specific for detection of MDA-LDL, ML25 was combined with apoB-specific antibody (AB16) as the second antibody. Using this method, MDA-LDL was detectable in the sera of 314 healthy individuals. The concentration of MDA-LDL preferably ranged from 20 to 80 units/l when the absorbance with artificially prepared MDA-LDL at the concentration of 1 mg/l was defined as 1 unit/l. Furthermore, assays for lipoprotein subfractions separated by density-gradient ultracentrifugation revealed that MDA-LDL was mainly distributed in the LDL fraction as expected, and MDA-LDL/apoB ratio showed a peak at small, dense LDL fractions. This finding seems to be quite interesting since an elevated level of small, dense LDL has been reported to be associated with an increased risk of atherosclerosis. We concluded that our method is useful for specific detection of MDA-LDL in human serum and might be an elevation method for atherogenicity.

Arteriosclerosis↗

PubMed1997

Morphological and biochemical analyses on fibroblasts and self-produced collagens in a novel three-dimensional culture.

The addition of L-ascorbic acid 2-phosphate (Asc 2-P), which is active and stable under a conventional culture condition, could render dermal fibroblasts to the organization of a dermis-like structure on a plastic dish without any prior treatment. The cell layer was composed of multilayered fibroblasts surrounded by dense extracellular matrices. Confocal microscopic examination disclosed that the fibroblasts in the upper layer were spindle-shaped and those in the lower layer were polygonal. Electron microscopic examination revealed the accumulation of mature collagen fibrils in the intercellular space. These morphological observations suggest that the cell layer may resemble the dermis-like structure. Biochemical analyses revealed that the hydroxyproline content of the cell layer increased in a time-dependent manner, while the monolayer culture system without. Asc 2-P yielded no measurable amount of hydroxyproline. On sodium dodecylsulphate-polyacrylamide gel electrophoresis, neutral insoluble collagens extracted from the cell layer showed the identical electrophoretic pattern to those from the human dermis. In addition, these bands were completely digested by bacterial collagenase. This novel culture system could provide a simple tool with which to investigate the collagen metabolism by fibroblasts under more physiological conditions.

Adolescent↗

PubMed1997

[Incidence and clinical features of lung cancer in patients with idiopathic interstitial pneumonia].

We studied the incidence of lung cancer in the 599 patients with idiopathic interstitial pneumonia (IIP) who had visited to 37 institutions during 1991. In addition to 89 patients with lung cancer registered initially 29 were found during more than 4 years of follow-up, which indicates that annual incidence of lung cancer in these patients with IIP was a few percent. A total of 118 lung cancers accounted for 19.7% of all the IIP patients registered and also for 27.2% of the 435 IIP patients in whom a definite outcome was certified by this study. Most of the patients with lung cancer were older men who were heavy smokers. The distribution of histological types was not noteworthy. On the chest rentgenogrms, the tumors were found predominantly in the peripheral lung fields even in the patients with squamous cell cancer, but no apparent association with IIP lesion was observed. Surgical resection was done in only 52% of the patients with the disease at stage I or II; chemotherapy and/or radiotherapy were given to 52.4% of the patients with advanced disease, which may have been due to considerations of the adverse effects of anticancer treatment on the prognoses. The mortality in IIP patients with lung cancer was higher than in those without lung cancer, mainly due to progression of the lung cancer, not the IIP. This indicates the importance of lung cancer as a prognostic factor in patients with IIP.

Age Factors↗

PubMed1997

[Pneumonitis induced by the herbal medicine Sho-saiko-to in Japan].

We studied the clinical characteristics of pneumonitis induced by Sho-saiko-to (SST). Of 94 cases reported to a drug maker, 72 were judged to be SST-induced pneumonitis (52 men and 20 women, mean age 63.7 years). Most patients took SST for chronic liver diseases due to infection with the hepatitis C virus. The mean duration of SST therapy before the onset of pneumonitis was 50.2 +/- 42.1 days. Most patients presented with coughing, dyspnea, and fever of acute onset. Chest X-ray films showed diffuse ground-glass shadows and infiltration. Abnormally high levels of C-reactive protein and lactate dehydrogenase were common, as was hypoxia. Analysis of bronchoalveolar lavage fluid revealed abnormally high percentages of lymphocytes and neutrophils and a low CD4/CD8 ratio. Although 64 of 72 patients survived after cessation of SST only or steroid therapy, 8 died of respiratory failure despite high-dose steroid therapy. Compared with patients who survived those who died were more likely to have an underlying lung disease, had been taking SST longer after the onset of pneumonitis, and had more severe hypoxemia.

Adverse Drug Reaction Reporting Systems↗

PubMed1996

Accumulation of advanced glycation end products of the Maillard reaction with age in human hippocampal neurons.

The recent immunological demonstration of advanced glycation end products (AGE) of the Maillard reaction in several human tissues suggests a possible involvement of AGE in the aging process. We previously prepared a monoclonal anti-AGE antibody (6D12) which recognized N epsilon-(carboxymethyl)lysine. We examined, immunohistochemically, the effect of aging on AGE-immunoreactivity in hippocampal pyramidal neurons in ten brain tissue samples obtained at autopsy from subjects aged 20-85 years old. Using 6D12 antibody, our results demonstrated a positive correlation between AGE-immunoreactivity in hippocampal pyramidal neurons and age. A more intense immunoreaction was observed in the CA3-4 pyramidal neurons compared with that of the CA1 neurons, known to be vulnerable to the formation of neurofibrillary tangles. Our results suggest that AGE are probably involved in the aging process affecting the human central nervous system, and that AGE do not mainly contribute to the formation of neurofibrillary tangles, at least in the CA1 neurons.

Adult↗

PubMed1996

Comparison of Adsorption and Conformation of Hemoglobin and Myoglobin on Various Inorganic Ultrafine Particles.

Human hemoglobin and horse myoglobin were adsorbed on the two types of ultrafine silica (silica 1 and 2), titania, and zirconia particles under various conditions. The order of the affinity of the ultrafine particles to these proteins was silica 1 < silica 2 < zirconia = titania under the same adsorption condition. The conformational changes in these proteins upon adsorption and desorption were monitored by both circular dichroism and absorbance spectra. In both spectrum measurements, a similar tendency was observed, indicating that the adsorption of proteins causes the changes not only in the secondary structure but also in the tertiary structure. In all the particles, the extent of conformational changes upon adsorption increased with decreasing pH and adsorption amount. On the other hand, the extent of conformational changes was significantly affected by the particle type (its order was silica 1 < silica 2 < zirconia = titania) under the same adsorption condition. The percentage of desorption and the extent of refolding of desorbed proteins were lower when the extent of conformational changes in the adsorbed states was higher. These results clearly demonstrate that higher affinity between particle surfaces and proteins causes larger conformational changes and consequently leads to higher irreversibility in adsorption and conformational states.

Journal Article↗

PubMed1996

Effects of long-term partial outflow obstruction on bladder function in the rat.

The effects of chronic partial outflow obstruction in rats were investigated. The urethra of male rats was partially obstructed for 3 or 6 months and bladder function was compared with that of age-matched controls. Bladder function was studied in vivo by infusion cystometry and in vitro by measuring the response of bladder muscle strips to stimulation. Cystometrograms of outflow-obstructed bladders were categorized into three types: type 1 was equivalent to a normal bladder; type 2 was characterized by large capacity, enhanced voiding pressure, and some residual urine; type 3 had the largest capacity, an impaired voiding pressure, and considerable residual volume (overflow-type of incontinence). The type 3 bladder was the most frequently observed type in rats obstructed for 6 months. Bladder weight increased significantly in rats with outflow obstruction. When five in vivo cystometric parameters (pressure at which micturition was induced, capacity, maximum voiding pressure, voided urine volume, and residual urine volume) were analyzed according to duration of obstruction, only two parameters (capacity and residual urine volume) in rats obstructed for 6 months differed significantly from those in age-matched controls. Evaluation of these values according to cystometric type showed a significant deterioration in four of five parameters in type 3 bladders. Contractile responses of the bladder in vitro to field stimulation, bethanechol, ATP, and KCI were significantly impaired in those obstructed for 3 or 6 months. When in vitro responses were analyzed according to the classification of cystometric type, deterioration of contractility was confirmed in both types 2 and 3 bladders. The present animal model of outflow obstruction can serve as a model of benign prostatic hyperplasia in humans.

Animals↗

PubMed1996

Effect of magnesium on the function of the rabbit corpus cavernosum.

Contraction and relaxation of the smooth muscle, including the corpus cavernosum, are mediated by changes in the intracellular concentration of calcium. Since magnesium modulates the movement of calcium, it can modify the function of the erectile tissue. We designed this study to investigate the effects of magnesium in doses ranging from 5 to 30 mM on the function of the rabbit corpus cavernosum in vitro. The resting tension of tissue strips was significantly reduced by exposure to a solution high in magnesium (5-30 mM). The contractile response to field stimulation under resting conditions, and the contraction to phenylephrine, were significantly decreased by magnesium (5-30 mM). There were no differences in the contractile strength of the corpus cavernosum to KCl. Although the relaxation induced by field stimulation under preincubation with 200 microM phenylephrine was abolished in the presence of 30 mM magnesium, there were no differences at a concentration of 5 mM or of 10 mM magnesium. The relaxation induced by sodium nitroprusside under precontraction with 200 microM phenylephrine was further increased by magnesium dose dependently. A high concentration of magnesium (30 mM) enhanced both bethanechol-induced and ATP-induced relaxations under precontraction with phenylephrine. Our study demonstrated that magnesium reduced the receptor-mediated contraction of the rabbit corpus cavernosum and enhanced the relaxation of this tissue induced by sodium nitroprusside, bethanechol, and ATP.

Animals↗

PubMed1996

Functional restoration of rat bladder after subtotal cystectomy: in vivo cystometry and in vitro study of whole bladder.

Functional restoration of the rat urinary bladder following subtotal cystectomy was studied via in vivo infusion cystometry and an in vitro whole bladder model. After the bladder had been separated from the prostate, subtotal cystectomy was achieved by ligating the bladder completely at a level just above the insertion of the ureters into the bladder. Bladder function was investigated immediately and 7, 14, and 28 days after surgery. Bladder weight was reduced to 17% that in sham-operated controls immediately after surgery, but recovered to 76% of that in controls 28 days after the operation. In vivo capacity also increased after surgery from 13% that of controls to 59% 28 days later. However, voiding pressure remained low (34% of control) 28 days later. An in vitro whole bladder study showed that the response to field stimulation decreased significantly on day 7, but had recovered considerably by day 28. The maximal response to bethanechol decreased significantly 7 days after surgery, but recovered thereafter. The response to phenylephrine increased significantly immediately after surgery, but gradually returned to the control level. An in vitro volume-pressure study showed that passive compliance of the cystectomized bladder decreased after surgery, but improved with time. The peak of the active pressure increase to field stimulation occurred at a low infusion volume immediately after surgery, but bladder capacity increased gradually until 28 days later, when the maximal active pressure was obtained. Our results suggest that restoration of the bladder following subtotal cystectomy may not derive simply from an expansion of the bladder wall. Functional alteration involving the bladder base was also observed.

Animals↗

PubMed1996

Transfer of Man9GlcNAc to L-fucose by endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae.

We have reported that transglycosylation activity of endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (endo-A) can be enhanced to near completion using GlcNAc as an acceptor in a medium containing 30% acetone (Fan J-Q, Takegawa K, Iwahara S, Kondo A, Kato I, Abeygunawardana C, Lee YC (1995) J Biol Chem 270: 17723-29). In this paper, we found that the endo-A can also transfer an oligosaccharide, Man9GlcNAc, to L-Fuc using Man9GlcNAc2Asn as donor substrate in a medium containing 35% acetone. The transglycosylation yield was greater than 25% when 0.2 M L-Fuc was used as acceptor. The transglycosylation produce was purified by high performance liquid chromatography on a graphitized carbon column and the presence of L-Fuc was confirmed by sugar composition analysis and electrospray mass spectrometry. Sequential exo-glycosidase digestion of pyridyl-2-aminated transglycosylation product, Man9GlcNAc-L-Fuc-PA, revealed that a beta-anomeric configuration linkage was formed between GlcNAc and L-Fuc. The GlcNAc was found to be 1,2-linked to L-Fuc by two methods: i) collision-induced decomposition on electrospray mass spectrometry after periodate oxidation, reduction and permethylation of Man9GlcNAc-L-Fuc; and ii) preparation of Man9GlcNAc-L-Fuc-PA, its periodate oxidation and reduction, followed by hydrolysis and HPLC analysis. Thus, the structure of the oligosaccharide synthesized by endo-A transglycosylation was determined to be Man9GlcNAc beta (1,2)-L-Fuc. Methyl-beta-L-fucopyranoside, L-Gal are also acceptors for the enzymic transglycosylation. However, transglycosylation failed when methyl alpha-L-fucopyranoside, D-Fuc and D-Gal were used. These results indicate that the endo-A requires not only 3-OH and 4-OH to be equatorial but also a 4C1-conformation or equivalent conformation of the acceptor to perform transglycosylation.

Acetylglucosaminidase↗

PubMed1996

Hypotonic intraperitoneal cisplatin chemotherapy for peritoneal carcinomatosis in mice.

The intraperitoneal (i.p.) administration of cisplatin (CDDP) is one of the most effective therapies for cancers that are confined to the abdominal cavity. However, the effect of fluid osmolarity on the therapeutic efficacy of i.p. administration of CDDP has not been well established. In the current study, hypotonic (154 mosmol 1-1), isotonic (308 mosmol 1-1) and hypertonic (616 mosmol 1-1) solutions of CDDP were prepared for an evaluation of their therapeutic efficacy in an experimental system. After i.p. administration, uptake of CDDP in vivo by tumor cells in hypotonic solution was significantly greater than in isotonic or hypertonic solution. The 50% lethal dose (LD50) value of CDDP in hypotonic solution (12.1 mg kg(-1)) was lower than that in isotonic solution (16.9 mg kg(-1)) and than that in hypertonic solution (28.6 mg kg(-1)). However, when a dose equal to one-half of the LD50 was administered in each solution to mice with i.p. tumours, survival of mice given the CDDP in hypotonic solution was significantly prolonged as compared with the survival of the other mice. These results demonstrate that the therapeutic efficacy of i.p. CDDP in mice is augmented when the drug is administered in hypotonic solution.

Animals↗

PubMed1996

The ICS-'BPH' Study: the psychometric validity and reliability of the ICSmale questionnaire.

OBJECTIVE: To assess the validity and reliability of the ICSmale questionnaire developed for the International Continence Society-'Benign Prostatic Hyperplasia' (ICS-'BPH') study. PATIENTS AND METHODS: Urology departments in 12 countries recruited 1271 consecutive men > 45 years old, with lower urinary tract symptoms and possible benign prostatic obstruction, to the ICS-'BPH' study (the clinical group); 423 ambulent men were recruited from a general practice in the UK to provide a community group. Each individual was asked to complete the wide-ranging ICSmale questionnaire, comprising questions concerned with urinary symptoms, the bother they cause, and issues of quality of life and sexual function. Content, construct and criterion validity of the symptom and problem questions were assessed by interviews with patients and urologists, testing hypotheses within sub-studies, and in relation to frequency-volume diaries and uroflowmetry. Reliability was assessed by measures of internal consistency and a test-retest analysis. RESULTS: The ICSmale questionnaire was easy to complete. It was clearly able to differentiate between men in clinical and community populations, and detected the expected positive age gradient for most symptoms in the community group. There was reasonable agreement between relevant parts of the questionnaire and frequency-volume charts when a relatively flexible approach was taken, but there was a very poor relationship between questions assessing strength of stream and the results of uroflowmetry. Internal consistency was high, and overall the questionnaire demonstrated good test-retest reliability. CONCLUSION: The self-completed ICSmale questionnaire had high levels of psychometric validity and reliability.

Aged↗

PubMed1996

Effects of alterations in potassium and calcium concentrations on the pressure generated in rat whole bladder in vitro.

BACKGROUND: Various physiologic systems maintain the ionic equilibrium essential for normal neuron and smooth muscle function. These systems are impaired by nonphysiologic concentrations of extracellular cations. This study investigated the effects of altered extracellular concentrations of potassium and calcium on the in vitro pressure generation in the whole bladder of rats. METHODS: Pressure increases in response to field stimulation, as well as low and high doses of bethanechol, were determined in a Krebs solution containing a normal amount of potassium, and in excess of 10 mmol/L and 20 mmol/L of potassium. Each of these solutions had calcium concentrations, that were low (0.8 mmol/L), normal (2.5 mmol/L), or high (7.5 mmol/L). RESULTS: The response to field stimulation was significantly decreased at the 20-mmol/L concentration of potassium in the presence of the different concentrations of calcium. The response to field stimulation increased as the extracellular concentration of calcium increased. The pressure increase caused by a low dose of bethanechol was significantly enhanced by elevations in the concentrations of both potassium and calcium. There was no difference in the response to a high dose of bethanechol in the presence of the various concentrations of potassium and calcium. CONCLUSION: These findings indicated that changes in the cationic equilibrium that result in blocking of the neuronal sodium channels, as well as increasing the level of intracellular bound calcium in smooth muscle, alter bladder function in vitro.

Animals↗