Biomedical subjects

S Kitada

Publications and source records attributed to S Kitada.

At least 73 records · Page 4Linked to original sources

PubMed1993

Role of adrenoceptors in the proximal urethral function of female and male rabbits using an in vivo model of isovolumetric pressure generation.

The role of alpha-1 and alpha-2 adrenoceptors in the contractile response of the proximal urethra to agonists and antagonists was studies in female and male New Zealand White rabbits. The response pattern for alpha-1 agonists showed a sharp rise, while that for alpha-2 agonists showed a gradual increase to a maximum pressure. The duration of the response of alpha-2 agonists was significantly longer than that of alpha-1 agonists. A difference in the response between alpha-1 and alpha-2 would be produced mainly through different receptor functions. The magnitude of the response of alpha-1 adrenoceptors in the male rabbits was almost twice that of the female rabbits. In contrast, the response of alpha-2 in the male rabbits was less than that of the female rabbits. Our experimental findings indicate that alpha-2 stimulation mediates a slow and prolonged response that is essential for urinary continence in female rabbits.

Animals↗

PubMed1993

Investigations of antisense oligonucleotides targeted against bcl-2 RNAs.

Expression of the bcl-2 gene becomes deregulated in many non-Hodgkin lymphomas as the result of t(14;18) chromosomal translocations. Because bcl-2 regulates the survival of cells, and because its over-expression is associated with cellular resistance to killing by chemotherapeutic drugs and gamma-irradiation, this gene and its mRNA and protein products represent ideal targets for designing novel therapeutic strategies for the treatment of cancer. Here we describe the effects of an 18-mer phosphodiester oligonucleotide that is complementary to the first 6 codons of the bcl-2 mRNA's open reading frame. When tested for inhibition of in vitro protein synthesis using RNAse-H-supplemented reticulocyte lysates and RNA prepared by in vitro transcription of a human bcl-2 cDNA, the bcl-2 antisense (AS) oligomer completely abolished Bcl-2 protein production at 10 microM, but had no effect on the in vitro translation of a chicken bcl-2 RNA that contained three mismatches relative to the oligomer binding site on the human bcl-2 RNA. A control 18-mer having the same base composition as the AS oligomer but with scrambled order (SC) was not inhibitory. Addition of AS and SC oligomers to cultures of a NIH-3T3 fibroblast cell line that had been stably infected with a recombinant retrovirus containing the same human bcl-2 cDNA used for in vitro transcription/translation experiments revealed concentration-dependent reductions in the relative levels of the 26-kD human Bcl-2 protein (as determined by immunoblotting) by the AS but not by the SC oligomer. Similar results were obtained when AS and SC oligomers were applied to a t(14;18)-containing lymphoma cell line SU-DHL-4 that was cultured in low-serum media. When used at 200 microM, the bcl-2 AS oligomer produced 84-95% reductions in Bcl-2 protein levels in SU-DHL-4 cells but had relatively little effect on the levels of other mitochondrial control proteins, suggesting that the inhibitory effects were specific. Treatment of SU-DHL-4 cells with AS oligomer lead to essentially complete loss of bcl-2 mRNA from cells within 1 day of addition to cultures, but presumably because of the long half-life of the Bcl-2 protein (approximately 14 h), commensurate reductions in Bcl-2 protein levels did not occur until 3 days.(ABSTRACT TRUNCATED AT 400 WORDS)

3T3 Cells↗

PubMed1993

Pitfalls in evaluation of photosensitizing agents: an example with Q-switch II dye.

Photosensitizing agents potentiating laser therapy should have limited toxicity, no mutagenicity, stable spectral characteristics, and acceptable solubility when administered in vivo. Q-Switch II dye (QII) has been shown by others to be an effective chromophore for photodynamic therapy at 1051 nm in fibroblast cell culture. The objective of this study was to determine the spectral stability of QII in biological media and then to localize QII after administration in vivo. Spectral evaluation was performed between 250 and 1100 nm. QII dissolved in dimethyl sulfoxide (DMSO) rapidly lost its spectral characteristics, including its 1051-nm peak, when contacting water, minimal essential medium, human serum, organ surfaces, and intracellular fluid. One minute following intramuscular (IM) injection of 0.1 mg QII in 0.2 mL of DMSO, the dose precipitated as a discrete mass which was excised and reconstituted in DMSO. A new spectral pattern was seen, with no absorption between 850 and 1100 nm. Following intravenous (i.v.), (IM), or intraperitoneal (IP) injection, QII was not detected in any organ. Q-Switch II dye is not a suitable chromophore for in vivo photodynamic therapy at 1051 nm. Previous cell culture reports to the contrary did not account for the QII spectral change caused by biological media. Simple rapid assays are described to avoid this pitfall.

Absorption↗

PubMed1993

[Urokinase-type plasminogen activator antigen as a prognostic factor in bladder cancer].

The relationship between the urokinase-type plasminogen activator (u-PA) content in extracts of cancer tissues and the histological grade or the extent of the primary tumor as prognostic factors in bladder cancer were examined in 55 cases of bladder cancer. The patients were divided into 2 groups, high u-PA (8 ng/ml of protein and more) and low u-PA (less than 8 ng/mg of protein) groups. The incidence of vascular invasion was 37% in the high u-PA group, and 7.1% in the low u-PA group (p < 0.05). The incidence of high u-PA group increased with the grade of cancer and the extent of the primary tumor. The 3-year survival rates were 87.3% in low u-PA group and 42.6% in high group (p < 0.005). The survival rates of the patients in the high u-PA group were lower than in the low group, by grade or stage. In a multivariate analysis, the prognostic value of u-PA antigen content was the same as that of tumor grade and stage. Therefore, the content of u-PA may be a useful prognostic marker for bladder cancer in addition to tumor grade and stage although the prognosis of the patients with bladder cancer is considered to be determined by many factors.

Adult↗

PubMed1992

The content of urokinase-type plasminogen activator antigen as a prognostic factor in urinary bladder cancer.

Urokinase-type plasminogen activator (u-PA) is thought to be implicated in cancer invasion and metastasis. The aim of this study was to determine whether the u-PA content of cancer tissue is a prognostic factor in bladder cancer. Tissue samples from 46 patients with bladder cancer were assessed for u-PA antigen by a highly sensitive enzyme immunoassay. The relationships between the u-PA level in extracts of bladder cancer and the survival rates of the bladder-cancer patients were examined. Patients with a high u-PA level (8 ng/mg of protein and more) showed a statistically significantly higher rate of survival than those with a low u-PA level (p less than 0.005). The u-PA antigen level in cancer tissue was significantly lower in low-graded and non-invasive cancers than in others (p less than 0.01).

Aged↗

PubMed1992

The relationship between cardiovascular complications of estrogen therapy and fibrinolysis in patients with prostatic cancer.

To determine the relationship between cardiovascular complications of estrogen therapy and fibrinolysis, fibrinolysis parameters plasminogen, urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1), were assessed in 12 prostatic cancer patients before and 6 weeks after the onset of estrogen therapy. The levels of plasminogen, u-PA, and PAI-1 in the patients treated with the estrogen therapy were significantly higher than those in the patients before the therapy. The t-PA level in the patients during the therapy was significantly lower than that before the treatment. Cardiovascular complications were found in two patients (16.7%) during estrogen therapy. In the two patients, marked elevation of PAI-1 and decreased level of t-PA were observed during the therapy. These results indicate that cardiovascular complications of estrogen therapy in patients with prostatic cancer may be related to hypofibrinolysis resulting from changes of PAI-1 and t-PA.

Aged↗

PubMed1992

Molecular evolution of human paramyxoviruses. Nucleotide sequence analyses of the human parainfluenza type 1 virus NP and M protein genes and construction of phylogenetic trees for all the human paramyxoviruses.

The nucleotide sequences of the NP and M genes of human parainfluenza type 1 virus (HPIV-1) were determined. The NP gene was 1677 nucleotides long excluding polyadenylic acid. The NP gene contained a single large open reading frame (ORF), which encoded a polypeptide of 524 amino acids with a calculated molecular weight of 57,736. The M gene 1173 nucleotides long excluding the poly(A) tract and the sequence also contained a single large ORF which encoded a polypeptide of 348 amino acid with a molecular weight of 38,445, which was inconsistent with 28 kDa previously determined by SDS-PAGE. We aligned the deduced HPIV-1 NP and M protein sequences with 12 and 13 other paramyxoviruses, respectively, suggesting that a common tertiary structure was found in the NPs or Ms of HPIV-1, Sendai virus (SV), HPIV-3 and BPIV-3 and that other common structure was also maintained in these proteins of HPIV-2, SV 41 and 5, MuV, HPIV-4. Phylogenetic trees were constructed for the NP and M proteins of all the paramyxoviruses of which nucleotide sequences had been previously reported. Paramyxoviruses could be subdivided into two groups, i.e., PIV-1 group and PIV-2 group; the former group is composed of HPIV-1, SV, HPIV-3 and BPIV-3, and the latter group consists of HPIV-2, SV 41, SV 5, MuV, HPIV-4 A and HPIV-4 B.

Amino Acid Sequence↗

PubMed1992

The prognostic significance of vascular invasion in upper urinary tract transitional cell carcinoma.

The prognostic significance of vascular invasion was evaluated in a retrospective series of 30 patients with upper urinary tract cancer who underwent a potentially curative operation. Vascular invasion was found in 11 patients (36.7%). The incidence of vascular invasion was well correlated with tumor grade and stage. The incidence of metastases postoperatively was significantly higher in the patients with (72.7%) than without (21.1%) vascular invasion (p < 0.01). The survival rate of the patients with vascular invasion was significantly lower than in those without vascular invasion (p < 0.005). In multivariate Cox regression analysis the prognostic value of vascular invasion was independent of tumor stage and grade. These results indicate that vascular invasion should predict a more unfavorable outcome in patients with upper urinary tract cancer as an independent morphological indicator.

Adult↗

PubMed1992

Bladder function in elderly men with subclinical brain magnetic resonance imaging lesions.

Among 43 men more than 60 years old who complained of urinary irritative symptoms 40 had subclinical lesions in the brain on magnetic resonance imaging (MRI). Of these 40 patients 23 (57.5%) had detrusor hyperreflexia. The mean age of the patients with and without detrusor hyperreflexia was 75.8 and 68.2 years, respectively, which is a statistically significant difference. Patients with detrusor hyperreflexia were more likely to have lesions of the basal ganglia than patients without detrusor hyperreflexia. This study suggests that detrusor hyperreflexia, subclinical MRI lesions in the brain and aging are intimately interrelated.

Aged↗

PubMed1992

The effects of transferrin receptor antibody, transferrin receptor antibody bound to Pseudomonas exotoxin and transforming growth factor-alpha bound to Pseudomonas exotoxin on human tenon's capsule fibroblast proliferation.

Pharmacological agents which modulate the wound healing process by the inhibition of proliferation of fibroblasts may improve the success of glaucoma filtration surgery. Since cell proliferation is essential to the wound healing process, we targeted the surface receptors that are associated with proliferating cells. We present the effects of three such agents-purified mouse anti-human transferrin receptor monoclonal antibody 42/6 (anti-TfR-42/6), anti-transferrin monoclonal antibody bound to a Pseudomonas exotoxin (anti-TfR-PE40) and transforming growth factor-alpha Pseudomonas exotoxin (TGF-alpha-PE40)--on human fibroblasts from Tenon's capsule. The inhibition of human subconjunctival fibroblast proliferation by anti-TfR-42/6 (with a concentration up to 25 micrograms/ml) and by anti-TfR-PE40 and TGF-alpha-PE40 (both with a concentration range of 5000-0.00001 micrograms/ml) was determined by colorimetric (OD), and cell counting (CC) assays over a 9-day period. Neither anti-TfR-42/6 nor anti-TfR-PE40 had an antiproliferative effect on the fibroblasts. TGF-alpha-PE40 demonstrated an antiproliferative effect in a dose response manner. The mean 50% inhibitory dose (ID50) by OD was 32.91 micrograms/ml, while the ID50 by CC was 27.88 micrograms/ml. EGF was used as a negative control for TGF-alpha-PE40 toxin. The inhibitory effect of the toxin conjugate was completely blocked by the addition of 1000 micrograms/ml of EGF. These in vitro studies show that TGF-alpha-PE40 may be useful in modulating the proliferation of human ocular fibroblasts; they also give some indication of drug dosages for future in vivo testing.

ADP Ribose Transferases↗

PubMed1992

[Studies on vessel invasion by cancer of the renal pelvis and ureter].

The significance of vessel invasion by cancer of the renal pelvis and ureter was estimated with surgical specimens of 45 patients. The vessel invasion by cancer was observed in 25 out of 45 cases (55.6%). The incidence of vessel invasion increased with the grade of cancer and the extent of the primary tumor. The postoperative metastases by cancer was noted in 22 of the 25 patients with vessel invasion (88%) and in 4 of 20 (20%) patients without vessel invasion. The incidence of metastases in patients with vessel invasion was significantly higher than that without it (p < 0.01). The 5-year survival rate was 13.1% in the patients with vessel invasion and 80.6% in the patients without it (p < 0.005). Postoperative chemotherapy had no effect on the unfavorable outcome of the patients with vessel invasion. Therefore, vessel invasion by cancer may be one of the prognostic factors in renal pelvic and ureteral cancer. The patients with vessel invasion should be treated with more aggressive therapy to improve the poor prognosis.

Adult↗

PubMed1992

[Clinical significance of urinary flow pattern--based on combined uroflowmetry and external sphincter electromyography].

We performed combined uroflowmetry and external sphincter electromyography in 108 patients (87 males and 21 females); 16 serving as normal controls, 49 with benign prostatic hyperplasia, 16 with overactive type of neurogenic bladder, 27 with underactive type of neurogenic bladder. Urinary flow pattern was classified into 5 categories. All of urinary flow patterns of normal controls showed pattern A which had the form of a bell. EMG showed complete suppression during micturition followed by a few intermittent increases in amplitude. Urinary flow patterns of BPH patients were distributed widely from pattern A to E. Intermittent increases in EMG amplitude during a late phase of micturition were characteristic in patients with BPH. We must pay attention to sex differences to evaluate urinary flow pattern because it could be influenced by abdominal pressure such as stressing or Créde maneuver in female patients with an underactive type of neurogenic bladder.

Adult↗

PubMed1992

[The effects of autonomic agonists on the female rabbits urethra--in vitro isovolumetric and isometric study].

To investigate the characteristics of adrenoceptors of the proximal urethra in female rabbits, we performed the in vitro isovolumetric urethral pressure study and isometric study with three parts of muscle strips of the proximal urethra (whole layers, inner layers and outer layers). Both alpha-1 and alpha-2 agonist caused dose dependent response in in vitro isovolumetric pressure study as well as in vivo study. However, the response of alpha-2 agonist in in vitro was small in magnitude compared to in vivo study, suggesting the influence of permeability of drugs from serosa to mucosa in in vitro whole urethra study. The response of the strips of inner layers to alpha-1 agonist is almost the same as that of outer layers and whole layers, while the response of inner layers to alpha-2 agonist is almost twice as that of other layers. These findings are suggestive of predominance of alpha-2 adrenoceptors mediating contractions in the inner layers of the proximal urethra in female rabbits. Alpha-2 adrenoceptors which probably are distributed in mucosal and submucosal layers may have an important role in the mechanism of urinary continence in female rabbits.

Adrenergic alpha-Agonists↗

PubMed1992

Effects of timolol, betaxolol, and levobunolol on human tenon's fibroblasts in tissue culture.

Evidence has been found suggesting that long-term therapy with topical antiglaucoma medications may decrease the success of glaucoma filtering surgery. To investigate this question further, the antiproliferative effects of the preservative benzalkonium chloride and three pure and commercially available beta-adrenergic antagonist preparations (timolol, betaxolol, and levobunolol) were studied on tissue cultures of human Tenon's capsule fibroblasts. Each drug preparation was tested on three different cell lines. Fibroblast growth was measured with tritiated thymidine uptake and hexosaminidase assays. Trypan blue uptake was used to assess cell viability microscopically. The commercially available preparations containing benzalkonium chloride and those of betaxolol and levobunolol without the preservative had similar inhibitory doses for 50% of cells. The timolol preparation without preservative was significantly less toxic than its commercially available one. The three tested beta-adrenergic blockers did not stimulate fibroblast proliferation directly in this in vitro model. Even when the cultures were washed free of the drugs, growth continued to be suppressed, suggesting that the inhibition was not reversible. An increase in fibroblasts and inflammatory cells after long-term antiglaucoma medical therapy thus may be caused not by a direct stimulation of cell proliferation but by chronic inflammation from the irritating effects of antiglaucoma medications and/or their preservatives.

Benzalkonium Compounds↗

PubMed1991

Comparative immunohistochemistry of malignant fibrous histiocytoma and sarcomatoid carcinoma of the urinary tract.

An immunohistochemical analysis using antibodies to cytokeratin, epithelial membrane antigen, alpha-1-antitrypsin, alpha-1-antichymotrypsin and factor XIIIa was performed in four cases of malignant fibrous histiocytoma and five cases of sarcomatoid carcinoma in the urinary tract. All cases of malignant fibrous histiocytoma showed positive staining for factor XIIIa, alpha-1-antitrypsin and alpha-1-antichymotrypsin. No case was positive for factor XIIIa, but one case with sarcomatoid carcinoma stained positive for alpha-1-antitrypsin and alpha-1-antichymotrypsin. All cases showed positive staining for cytokeratin and 4 cases with sarcomatoid carcinoma were positive for epithelial membrane antigen, but no cases with malignant fibrous histiocytoma were positive. Immunohistochemical analysis would thus help to distinguish malignant fibrous histiocytoma from sarcomatoid carcinoma of the urinary tract.

Aged↗

PubMed1991

Inhibition of rabbit ocular fibroblast proliferation by 5-fluorouracil and cytosine arabinoside.

Inhibition of rabbit subconjunctival fibroblast attachment and proliferation by the antimetabolites 5-fluorouracil (5-FU) and cytosine arabinoside (ara-C) was determined by radionucleotide uptake, cell counting, and colorimetric assays for the concentration range of 1000 to 0.0001 micrograms/ml over an 11-day period. The mean 50% inhibitory doses (ID50s) against proliferation were calculated for each assay. Rabbit fibroblast attachment was not inhibited at any drug concentration by either 5-FU or ara-C. Ara-C was a 10 to 100 times more potent inhibitor of rabbit fibroblast proliferation than 5-FU. The mean ID50s for rabbit subconjunctival fibroblasts were compared with the mean ID50s from a similar series of experiments conducted in our laboratory on human subconjunctival fibroblasts. Unpaired t-test analysis showed a significant difference between the inhibitory effects of 5-FU on rabbit and human fibroblast proliferation. An ID50 against rabbit fibroblasts was detectable after 24 hours of incubation with 5-FU by the 3H-thymidine uptake assay, whereas the ID50 against human fibroblasts was detectable after 48 hours of incubation. Once inhibition of proliferation occurred, however, human fibroblasts were up to six times more sensitive to the antiproliferative effects of 5-FU than rabbit fibroblasts as measured by the 3H-thymidine uptake assay (p = 0.0005). Unpaired t-test analysis showed no statistical difference between the ID50s of ara-C on rabbit and human fibroblasts. Starting on day 3, however, doses greater than 1 micrograms/ml of ara-C were cytotoxic to rabbit fibroblasts but only cytostatic to human fibroblasts as determined by trypan blue uptake assay microscopically. Rabbit ocular fibroblasts may be useful in modelling the proliferation of human ocular fibroblasts in vitro to a limited degree. This tissue culture system may be useful for predicting optimal drug dosages for in vivo rabbit and human glaucoma filtering surgery.

Animals↗

PubMed1991

Molecular relationships between human parainfluenza virus type 2, and simian viruses 41 and 5: determination of nucleoprotein gene sequences of simian viruses 41 and 5.

The nucleotide sequences of cDNAs of the simian virus 5 (SV5) nucleoprotein (NP) gene, and the 3' end of the genome and NP gene of SV41 were determined. The open reading frames of the SV5 and SV41 NP genes encode polypeptides with Mrs of 56,582 and 60,575, respectively, values which are consistent with those estimated by SDS-PAGE. The NP of human parainfluenza virus type 2 (hPIV-2) was more closely related to that of SV41 (amino acid sequence identity 70.5%) than that of SV5 (57.0%); the amino acid sequence identity between the NPs of SV41 and SV5 was 63.3%. The sequence of the 3' end of the genome of SV41 showed a high level of similarity to that of hPIV-2, the terminal 18 nucleotides being identical. It is concluded from these findings that SV41 is related most closely to hPIV-2, even though SV5 had been thought to be an animal type of hPIV-2.

Amino Acid Sequence↗

PubMed1991

Experimental hyperreflexia: effect of intravesical administration of various agents.

In anesthetized rabbits, we can induce a significant degree of spontaneous activity in the urinary bladder by placing a ligature around the proximal portion of the external urethra. Previous studies characterized the activity as primarily reflex in nature, since intravesical hexamethonium selectively inhibited the hyperreflexia. In this current study we determined the effect of intravesical administration of a variety of compounds to inhibit the induced hyperreflexia. The following agents were tested at concentrations of 1, 10, 100 and 500 mumol/l (intravesically): verapamil, cromakalim, nifedipine, diltiazem, and atropine; lidocaine was tested in 0.05, 0.5 and 5% solutions. The results are summarized as follows: (1) Lidocaine was the most effective agent tested, virtually eliminating both the amplitude and frequency of the spontaneous activity at the lowest concentration (0.5%). (2) Verapamil and nifedipine were somewhat more potent than cromakalim and diltiazem. Atropine sulfate was the least potent, inhibiting both the amplitude and frequency of the hyperreflexia by less than 50% at 500 mumol/l. (3) In all cases, the amplitude of the spontaneous activity was inhibited to a significantly greater degree than the frequency of the spontaneous activity. (4) In general, there was no effect of any of the agents on mean arterial pressure at 1 or 10 mumol/l. At 100 and 500 mumol/l, all agents except for lidocaine and cromakalim decreased arterial pressure. These two agents produced no consistent fall in blood pressure at any concentration. In conclusion, the acute hyperreflexic (rabbit) preparation provides a highly reproducible and consistent model for the study of the effect of drugs on hyperreflexia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗