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Biomedical subjects

S Kagawa

Publications and source records attributed to S Kagawa.

At least 145 records · Page 8Linked to original sources
PubMed1994

Analysis of nm23 gene expressions in human bladder and renal cancers.

We measured nm23-H1 and nm23-H2 mRNA levels in tissues from 22 human bladder cancers and 16 renal cell carcinomas, and in 7 bladder cancer and 6 renal cancer cell lines by Northern blot and slot blot hybridization analyses. Differences in mRNA levels were evaluated in primary tumor tissues and in paired normal tissues and cell lines. Moreover, nm23 gene expression in primary tumor tissues was compared with clinicopathological features. High nm23-H1 and nm23-H2 expression was observed in cancerous areas of human bladder tissue (nm23-H1: p = 0.001, nm23-H2: p = 0.001) and bladder cancer cell lines (nm23-H1: p = 0.001, nm23-H2: p < 0.001) compared with that in normal bladder mucosa. However, mRNA levels of both nm23 genes were not associated with histological grade, pathological stage, tumor metastasis or prognosis. On the other hand, in human renal cell carcinomas, levels of both nm23 mRNAs in tumor tissues were similar to those in paired normal kidneys, but elevated in cultured cell lines (nm23-H1: p = 0.002, nm23-H2: p = 0.014). Moreover, there was a tendency towards high nm23 gene expression in grade 2 tumors compared with grade 1 (grade 1 vs grade 2, nm23-H1: p = 0.107, nm23-H2: p = 0.008; no grade 3 tumors in this study) and in high stage renal cancers (< or = stage II vs stage III < or =, nm23-H1: p = 0.023, nm23-H2: p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Biochemical and histochemical studies of the effects of cerebral metabolism-improving drugs on NADPH diaphorase activity in mouse brain.

The effects of cerebral metabolism-improving drugs on NADPH diaphorase activity in the mouse brain were studied, and we found that diaphorase activity in the post-mitochondrial fraction of brain homogenate was enhanced by idebenone in a concentration-dependent manner. Histochemical studies also indicated that diaphorase staining was intensified by idebenone at the same concentration. These results suggest that idebenone may stimulate the production of nitric oxide, probably through its direct action on nitric oxide synthase, thus producing its protective action on neurological disorders due to cerebral hypoxia or ischemia as a consequence of dilating the cerebral blood vessels.

Amino Acid Oxidoreductases↗
PubMed1994

Effects of flavonoid compounds on the activity of NADPH diaphorase prepared from the mouse brain.

The effects of flavonoids on NADPH diaphorase activity were studied in vitro, and we found that the enzyme activity was markedly inhibited by quercetin. This inhibitory action was shown to be accompanied by an increase in the apparent Km value of the enzyme for the cofactor NADPH, with a decrease in the Vmax, and an increase in the apparent Km for the substrate nitro blue tetrazolium, without any significant change in the Vmax. These results indicate that quercetin may directly inhibit NADPH diaphorase, thus suggesting the possibility that this compound may be able to inhibit the production of nitric oxide in the brain.

Animals↗
PubMed1994

[Distribution of NADPH diaphorase-positive nerves in human penile tissue].

Recently, nitric oxide (NO) has been thought to be a neuronal messenger to evoke penile erection. NO synthase (NOS)-containing nerve fibers were identified and localized in human penile tissue, but detail distribution of NOS-containing nerve fibers in the human penis was unclear. In the present study we examined their distribution using histochemical staining of NADPH diaphorase (ND), which is a specific marker of neuronal NOS. In the crura penis some various sizes of ND-positive nerve bundles were observed in the cavernous spaces. In the penile shaft large bundles (> 50 microns) decreased in number and were observed only near deep artery. There were abundant ND-positive nerve terminals with fine varicosity innervating both corpus cavernous smooth muscles and deep, dorsal and helicine arteries. In the wall of deep dorsal vein there were also many groups of ND-positive fibers. Endothelium of deep artery and its large branches was clearly ND-positive, but parts of endothelium of deep dorsal vein or corpus cavernous sinus were only faintly stained. Some of the dorsal penile nerve fibers were ND-positive. In corpus spongiosum many ND-positive nerve fibers were observed and urethelium was clearly ND-positive. In conclusion, NO may have an important role in the function of both corpus cavernosum and corpus spongiosum because NOS-containing nerve fibers were widely distributed in both cavernous tissues.

Amino Acid Oxidoreductases↗
PubMed1994

[Serum levels and gene expressions of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in human renal cell carcinomas].

We examined serum levels of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in 32 patients with renal cell carcinoma. Serum IL-1 beta was elevated in only one patient (3.1%), IL-6 in 17 (53.1%) and TNF-alpha in 6 (18.8%). Positive rate of serum IL-6 increased with progression of the stage (stage I and II: stage III and IV = 14.3%: 88.9%, p < 0.0001) and was higher for rapid growth type (slow and intermediate growth type: rapid growth type = 36.4%: 90.0%, p < 0.005). However, increased serum levels of IL-1 beta and TNF-alpha were not correlated with stage, grade, or growth type. Gene expressions of IL-1 beta, IL-6, IL-6 receptor and TNF-alpha in the tissues resected from 15 patients with renal cell carcinoma and 3 cell lines established from renal cancers were evaluated by Northern blot analysis. Gene expression of IL-1 beta and TNF-alpha were not detected in any of the tissues or cell cultures, but highly enhanced expressions of IL-6 were revealed in two tumor specimens (13.3%, 1 rapid and 1 slow growth type) and 2 of 3 cell lines. Expressions of IL-6 receptor in tissues and cells were weak. These results suggest that IL-6 plays an important role in the progression of renal cell carcinoma, and that measurement of IL-6 in patients with renal cell carcinoma may be useful clinically.

Adult↗
PubMed1994

B cells are required as APC for antigen-specific T cell proliferation but not for the differentiation or priming of those T cells.

We studied the influences of B cells on functional differentiation of T cells using SCID mice grafted with fetal thymus of C.B-17 mice (TG mice). T cells were shown to be reconstituted in TG mice without B cell development. These mice showed normal DTH response to SRBC and OVA. LN cells of these mice produced cytokines including IL-2, IL-4, IL-6 and IFN-gamma according to Con A stimulation. Thus, majority of T cell functions seem to differentiate in the absence of B cells. However, T cells of TG mice failed to proliferate in response to immunizing antigens in vitro, although they responded well to stimulation with Con A. This unresponsiveness of T cells in TG mice to these antigens was restored when antigen-primed B cells were added to the proliferation assay. Such an inability of T cells in antigen-specific proliferation was not seen in SCID mice grafted with C.B-17 fetal liver cells, in which B cells as well as T cells were efficiently reconstituted (FLT mice). T cell proliferation to immunizing antigen was also abrogated in FLT mice when B cells were depleted from lymphoid population. These results indicate that T cells can functionally differentiate and be primed in the absence of B cells, but they require B cells to proliferate in response to foreign antigens.

Animals↗
PubMed1994

[Genetic diagnosis of phenylketonuria. III. Mutations of phenylalanine hydroxylase gene in Orientals].

Phenylketonuria (PKU) is an autosomal recessive disorder caused by lesions in the phenylalanine hydroxylase (PAH) gene. The recent studies on PAH mutations show the genetic drift of PKU alleles among some Oriental populations. Therefore, we searched for PKU mutations among Japanese, Chinese and Taiwanese. Direct sequencing was conducted on DNA fragments amplified by the polymerase chain reaction, using solid-phase technology involving the biotin-streptavidin system. Two new mutations (R241C and G247V) and two of the known mutant alleles (Y204C and R243Q) were found in two Taiwanese and two Chinese PKU patients, and three known mutations (R111X, Y204C and R413P) were recognized in three Japanese; two new mutations were identified in exon 7 of the PAH gene at codon 241 and codon 247, where the single base changes from C to T and from G to T substituted cysteine for arginine and valine for glycine, respectively. Further all the PAH mutations detected are common in Oriental populations as they have been thus far unreported among Caucasians. From these data as well as the clinical phenotype of the patients, we suggest that the R241C and G247V substitutions may interfere with proper enzyme function, although we have not yet performed functional studies. More detailed studies would be needed to clarify the regional distribution of mutant chromosomes in Oriental populations and other unidentified mutations.

Alleles↗
PubMed1994

[Genetic diagnosis of phenylketonuria. IV. Mutations of phenylalanine hydroxylase gene in Caucasian and Gypsy populations in Czech and Slovakia Republics].

Direct sequencing was conducted on the regions of the exon 7 and 12 in the phenylalanine hydroxylase (PAH) gene amplified by the polymerase chain reaction, using solid-phase technology involving the biotin streptavidin system. A novel mutation and seven previously known mutations were identified in the PAH genes among 15 Caucasians and 10 Gypsies in the Czech and Slovakia republics, affected with classical phenylketonuria (PKU). Two of these substitutions (R243X and G272X) resulted in the generation of a premature stop codon, and a single base transition of G to A at codon 261 resulted in the substitution of Arg for Gln (R261Q). These three mutations together accounted for 16.7% of PKU alleles among 15 Caucasians. The R252W mutation was detected in these two groups: two Caucasians were compound heterozygous for the P281L or R408W mutations (6.7% of all mutant alleles). However, all 10 Gypsy PKU patients were homozygous for the R252W transition. The R408W mutation accounted for 43% of PKU alleles in 15 Caucasian PKU patients. A novel heterozygous C-to-G transversion at the third base of codon 263 in the exon 7, resulting in the substitution of Phe for Leu (F263L), was detected in a Caucasian PKU patient (3.3% of all mutant alleles). In this study, we revealed a novel PKU mutation of the F263L in Caucasian populations and a high-risk PKU mutation of the R252W in Gypsy populations.

Base Sequence↗
PubMed1994

[Detection of methicillin-resistant Staphylococcus aureus using PCR and non-radioactive DNA probes: IV. Mutational sequences in the region upstream of the mec A gene in clinical staphylococcal strains].

Expression of mec A is regulated by two regulatory genes (mecR1 and mecI); the intact regulatory genes exist in the N315 strain of methicillin-sensitive S. aureus, whereas the repressor gene (mecI) is deleted in the MR108 strain of methicillin-resistant S. aureus (MRSA). However, our previous findings that clinical strains of N315 type were methicillin-resistant suggest possible mutations within the operator region, by which the inhibitory effect of MecI is released to induce the constitutive expression of mec A. Therefore, we analyzed nucleotide sequences in the region upstream of the mec A gene and in the regulatory genes, by using PCR-direct sequencing and ASO probes. Analysis of selected clinical strains by ASO probes revealed that 74% of MRSA and 36% of MRSE (methicillin-resistant S. epidermidis) lacked the mecI gene whereas 26% of MRSA and 64% of MRSE possessed the intact regulatory genes. Furthermore, PCR-direct sequencing identified four different mutations in the operator nucleotide sequence and one mutation in Shine-Dalgarno sequence. Additionally, these mutations were shown to occur in the strains of N315 type with higher probability rather than in those of MR108 type. The data suggest that one or more of these mutational sequences at least may have some influence on the expression of methicillin-resistance in clinical staphylococcal strains.

Base Sequence↗
PubMed1994

[Detection of Campylobacter species by using polymerase chain reaction and nonradioactive DNA probes. III. DNA probe for identification of C. laridis].

The development of a rapid and specific DNA probe assay for identification of Campylobacter species, including C. jejuni, C. coli, C. laridis, C. fetus, and C. hyointestinalis is important in determining the precise diagnosis of Campylobacter infections. Sequence data of our previous studies for a 240-base DNA fragment was used to select primers and probes conjugated to alkaline phosphatase, complementary to a portion of DNA between primers. However, a 21-base probe (CL (1)) tested here for detection of C. laridis was cross-reactive with PCR-amplified fragments of C. jejuni, C. coli and C. hyointestinalis, although it was not reactive with C. fetus and C. fetus subsp. fetus. To solve this problem, further modifications of the probe were therefore made to improve the specificity for those particular species. A second 21-base probe with a single base-substitution (CL (2)) and a third 20-base probe (CL(3)) were ineffective for identification of C. laridis, too. A fourth 20-base probe with a single base substitution (CL(4)) was a significant improvement over the results obtained by other three probes specifically to detect C. laridis, Thus, the alkaline phosphatase-labeled probe method developed so far is an interesting alternative without access to radioisotopes for clinical laboratories for identification of Campylobacter species, including C. jejuni/coli/hyointestinalis, C. laridis, and C. fetus/fetus subsp. fetus.

Base Sequence↗
PubMed1994

[Partial resection of superior vena cava using two stage venous return catheter for a new application].

A case of invasive lung cancer was reported, in which operation partial resection and reconstruction of the invaded superior vena cava (SVC) was performed. During procedure in SVC, a two stage venous return catheter, which is ordinary used in cardiac operations, was used as a temporary SVC-right atrial internal bypass. This new application of the catheter was convenient and effective for resection and reconstruction of SVC.

Aged↗
PubMed1994

[A case of chronic traumatic dissecting aneurysm of the thoracic aorta].

A case of chronic traumatic dissecting aneurysm was reported. A 61-year-old man was admitted to our hospital for multiple trauma caused in traffic accident. MRI, performed for evaluation of the spinal injury, revealed dissection of the thoracic descending aorta by chance, seven months after injury. Retrospectively CT, just after admission, showed bleeding around the thoracic descending aorta. Replacement of thoracic aorta was performed after 33 months from the traffic accident, for enlargement of dissecting lumen accompanied with hoarseness. The postoperative course was uneventful and the patient returned to his daily life successfully.

Aortic Dissection↗
PubMed1994

[Detection of methicillin-resistant Staphylococcus aureus using PCR and non-radioactive DNA probes: III. Mutations of the fem A gene in clinical strains of Staphylococcus aureus].

Methicillin resistance in S. aureus is primarily due to the presence of the mec A gene. However, in addition to mec, the phenotypic expression of methicillin resistance requires the presence of an additional gene(s), fem A which is chromosomally encoded. Previous studies suggest an increase in the biochemical function of fem A gene products due to base substitutions in the region upstream of the fem A gene and in its coding frame. The partial nucleotide sequences of fem A regions in reference and clinical strains of S.aureus were therefore analyzed by PCR-direct solid-phase sequencing and suitable DNA probes. Amplified target DNAs of 251, 330 and 271 bp were resolved on ethidium bromide-stained gels and hybridized with DNA probes conjugated to alkaline phosphatase. In ATCC 12600 strain, a palindromic sequence was conserved in the region upstream of fem A. However, it was destroyed by the occurrence of mutations in other reference, and clinical strains tested regardless of whether they are methicillin-susceptible or resistant. Furthermore, in the coding frame of fem A, two missense mutations were present in MSSA and MRSA without any regularity. These findings suggest that mutations in the fem A region may not be a single factor essential for regulation of methicillin resistance, although fem A probably functions cooperatively with mec A.

Base Sequence↗
PubMed1993

Scanning electron microscopic study of the effect of citrate and pyrophosphate on calcium oxalate crystal morphology.

The effects of citrate and pyrophosphate on the morphology of calcium oxalate monohydrate crystals formed in a supersaturated calcium oxalate solution were examined by scanning electron microscopy. Within the normal range of urinary concentrations, citrate and pyrophosphate affected the morphology of the crystals. The length/width ratio of the crystals decreased at higher concentrations of citrate and pyrophosphate. Citrate seems to have a dual mechanism of inhibition of crystal growth (binding to the crystal surfaces) and of complexation (with calcium in the solution). Pyrophosphate is believed to bind preferentially to calcium in the solid phase rather than in the solution phase, as it affected crystal morphology at very low concentrations and was detected on the crystals by X-ray microanalysis. Pyrophosphate seems to bind to the monohydrate but not to the dihydrate.

Calcium Oxalate↗
PubMed1993

[Detection and identification of HBV DNA and DNA subtypes of HBs-antigen by the use of the polymerase chain reaction and non-radioactive probes].

A technique of nested polymerase chain reaction (PCR) and hybridization with non-radioactive probes was developed for the detection and identification of HBV DNA and HBs-subtypes in very small volumes of human sera. Four oligonucleotide primers (20 mer) complementary to DNA sequences in the S region of HBV and probes (18 or 20 mer) conjugated to alkaline phosphatase were used for the present PCR assay. The results of the PCR assay coincide with those of enzyme immunoassay (EIA) in 14 HBe-positive and 59 HBe-negative samples with 98.6% of specificity. The HBV subtypes adr and adw were identified using an 18-mer DNA probe in 30 samples with an accuracy of 100%. Further, the DNA subtypes were clearly demonstrated in 3 samples where HBs-antigen was undetectable. These results indicate that amplification of HBV DNAs by PCR and their detection with non-radioactive probes is a reliable tool for diagnosis of HBV infection in clinical laboratories.

Base Sequence↗
PubMed1993

[Transition of diagnosis and treatment for impotence].

Statistic study was made on 685 outpatients with erectile dysfunction during 13 years periods from 1979 to 1991 in the Department of Urology, Takamatsu Red Cross Hospital. The age distribution showed the highest frequency in the thirties decade (27.9%). 1. Diagnosis Nocturnal penile tumescence monitoring was the only method to distinguish organic impotence from functional impotence during the first 5 years. From 1984 we have been able to diagnose corporal veno-occlusive insufficiency (CVI) by papaverine test and dynamic infusion cavernosometry and cavernosography. Measurement of penile brachial index and pelvic angiography were performed to diagnose arterial insufficiency (AI). In neurological examination we have measured bulbo-cavernosus reflex latency and nerve conduction velocity of the dorsal penile nerve and performed microvibration measurement and sweat spots test. All diagnostic methods were established in 1987 and we have been able to classify about 80% patients. We classified 305 patients during the last 5 years from 1987 as follows: psychogenic; 31.1%, CVI; 20.0%, AI; 7.9%, neurogenic; 7.9%, others; 14.1%, drop-out and unknown; 19.0%. 2. Treatment In the beginning only counseling and drug therapy were performed. However we lately performed various suitable methods for individuals based on their diagnoses. We performed counseling, drug therapy and intracavernous injection of vasoactive drug therapy for recovery of spontaneous erection (vascular training) for psychogenic IMP. The efficacy rate of counseling was low (30.4%) but that of drug therapy was 41.6%, and that of vascular training, 64.2%. For CVI without other factors we performed venous surgeries. Only about 25% of them perform sexual intercourse with or without self injection of vasoactive drug (self injection).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[The relaxation of human corpus cavernosum caused by nitric oxide].

Non-adrenergic non-cholinergic nerves (NANC) are thought to be important in the relaxation of corpus cavernosum for erectile function. On the other hand, it has been shown that nitric oxide (NO) is synthesized from L-arginine and released by the endothelium of blood vessels and accounts for the activity of endothelium-derived relaxing factor (EDRF). We studied whether electrical field stimulation (EFS) of isolated strips of human corpus cavernosum released NO and whether it could act as a NANC neurotransmitter. Human penile tissue specimens were mounted in an organ bath and the isometric tension recorded. EFS was applied to precontracted strips between two parallel platinum electrodes. Relaxation induced by EFS was not influenced by guanethidine or atropine, but was markedly inhibited by NG-nitro-L-arginine which is an analog of L-arginine that inhibits the conversion of L-arginine to NO, and hemoglobin which is an agent that inhibits the biological actions of NO. Methylene blue which is an inhibitor of cytosolic guanylate cyclase also reduced the relaxation of EFS, but not completely. The inhibitory effect of NG-nitro-L-arginine was reversed by addition of excess L-arginine. Exogenous NO relaxed human corpus cavernosum. The relaxation was only a transient response and concentration-dependent. The profile of responses is similar to that evoked by EFS. Our data clearly demonstrate the release of NO during EFS and the function of NO as a NANC neurotransmitter. Human penile erection may be mediated by NO generated in response to NANC neurotransmission.

Adult↗