Biomedical subjects

H Tsuji

Publications and source records attributed to H Tsuji.

At least 19 recordsLinked to original sources

PubMed2001

The fate of autogenous free-fat grafts after posterior lumbar surgery: part 2. Magnetic resonance imaging and histologic studies in repeated surgery cases.

STUDY DESIGN: Histologic changes of free-grafted fat were investigated from surgical specimens taken at repeated lumbar surgery in 18 patients with degenerative spinal disease who previously had undergone posterior lumbar decompression and free fat graft. OBJECTIVE: To clarify the clinical usefulness of free-grafted fat by histologic analysis. SUMMARY OF BACKGROUND DATA: The clinical postoperative serial magnetic resonance imaging studies in Part 1 showed that the size of grafted fat was reduced, and that the shape changed along with the shape of the dura mater. The shape of the grafted fat was remodeled in relation to the postoperative transient shrinkage and reexpansion of the dura mater. METHODS: From repeated surgery cases, the status of the previously grafted fat tissue in the virgin operation was analyzed. Sections from the specimens resected surgically during repeated surgery were stained with hematoxylin and eosin or osmium. The size and quality of the grafted fat globules were analyzed by computer. RESULTS: In all cases, grafted fat tissue was identified as a survival. Hematoxylin and eosin staining showed increased collagen fiber and hyperplasia of blood vessels entering the fat tissue that survived. From osmium staining, the size of fat globules was reduced. The shape and quality of the fat globules were analyzed by original staging. They showed various sizes, polymorphism, and vacuolar degeneration. CONCLUSIONS: Finding showed that the grafted fat used in posterior lumbar surgery reduced the size and quality of the fat globules, as compared with normal fat tissue. However, the grafted fat tissues were confirmed to be alive over the long term. This study clarified the fate of the grafted fat as observed by magnetic resonance imaging and histology from repeated surgery cases.

Adipose Tissue↗

PubMed2001

Blends of aliphatic polyesters. VI. Lipase-catalyzed hydrolysis and visualized phase structure of biodegradable blends from poly(epsilon-caprolactone) and poly(L-lactide).

Phase-separated biodegradable polymer blends were prepared from poly(epsilon-caprolactone) (PCL) and poly(L-lactide) (PLLA), and Rhizopus arrhizus lipase-catalyzed hydrolysis and phase structure of the blend films were investigated. Gravimetry revealed that the lipase-catalyzed hydrolysis of PCL in PCL- and PLLA-rich phases is disturbed by the presence of PLLA. Polarimetry confirmed the occurrence of a predominant hydrolysis of PCL and subsequent removal of the hydrolyzed water-soluble PCL oligomers in the blend films. Gravimetry and gel permeation chromatography of the non-blended PLLA film indicated that R. arrhizus lipase has no catalytic effect on the hydrolysis of PLLA. The phase structure of the blend films could be visualized by selective enzymatic removal of one component and subsequent scanning electron microscopic observation.

Biocompatible Materials↗

PubMed2001

Phosphorylation of neurofibromin by cAMP-dependent protein kinase is regulated via a cellular association of N(G),N(G)-dimethylarginine dimethylaminohydrolase.

The neurofibromatosis type 1 (NF1) tumor suppressor (neurofibromin) is thought to play crucial roles in cellular Ras- and cAMP-dependent kinase (PKA)-associated signals. In this study, we identified a cellular neurofibromin-associating protein, N(G),N(G)-dimethylarginine dimethylaminohydrolase (DDAH) that is known as a cellular NO/NOS regulator. The interaction of DDAH was mainly directed to the C-terminal domain (CTD) and to the cysteine/serine-rich domain (CSRD) of neurofibromin, coinciding with the regions containing specific PKA phosphorylation sites. DDAH increased PKA phosphorylation of native neurofibromin in a dose-dependent manner, especially affecting the phosphorylation of CSRD. These findings suggest that the PKA accessibility of neurofibromin was regulated via DDAH interaction, and this regulation may modulate the cellular function of neurofibromin that is implicated in NF1-related pathogenesis.

Amidohydrolases↗

PubMed2001

Cloning of cDNA encoding a soybean allergen, Gly m Bd 28K.

A cDNA clone encoding a soybean allergen, Gly m Bd 28K, has been isolated. The clone has a 1567-bp cDNA insert with a 1419-bp open reading frame and a 148-bp 3'-untranslated region, followed by a polyadenylation tail. The open reading frame was shown to encode a polypeptide composed of 473 amino acids. The chemically determined amino acid sequences of the peptides obtained from the allergen, including its N-terminal peptide, were shown to be contained in the N-terminal region of the amino acid sequence deduced from the cDNA, showing that the first half of the cDNA encodes the allergen with a preceding segment of 21 amino acids. The peptide fragment including the allergen was expressed as a fusion protein with glutathione S-transferase in Escherichia coli and immunoblotted with the sera of soybean-sensitive patients and the monoclonal antibody against the allergen. Furthermore, homology analyses demonstrate that the polypeptide for the cDNA exhibits high homology with the MP27/MP32 proteins in pumpkin seeds and the carrot globulin-like protein. This finding suggests that the polypeptide may consist of a 21-amino acid segment as a part of the signal peptide and the proprotein, which may be converted to two mature proteins, Gly m Bd 28K and a 23-kDa protein, during the development of soybean cotyledons.

Allergens↗

PubMed2001

Serotonin induces the expression of tissue factor and plasminogen activator inhibitor-1 in cultured rat aortic endothelial cells.

Serotonin (5-hydroxytryptamine, or 5-HT), released from activated platelets, not only accelerates aggregation of platelets but also is known to promote mitosis, migration, and contraction of vascular smooth muscle cells (VSMCs). These effects are considered to contribute to thrombus formation and atherosclerosis. The aim of this study was to investigate the effects of 5-HT on the expressions of coagulative and fibrinolytic factors in rat aortic endothelial cells. Endothelial cells were stimulated with various concentrations of 5-HT (0.1 approximately 10 microM), and the expressions of tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), and tissue-type plasminogen activator (TPA) messenger RNAs (mRNAs) were evaluated by Northern blot analysis. The activities of TF and PAI-1 were also measured. TF and PAI-1 mRNA were increased significantly in a concentration- and time-dependent manner. However, TFPI and TPA mRNA expression did not change. The inductions of TF and PAI-1 mRNAs were inhibited by a 5-HT1/5-HT2 receptor antagonist (methiothepin) and a selective 5-HT2A receptor antagonist (MCI-9042). These results indicate that 5-HT increases procoagulant activity and reduces fibrinolytic activities of endothelial cells through the 5-HT2A receptor. It was concluded that the modulation of procoagulant and hypofibrinolytic activities of endothelial cells by 5-HT synergistically promotes thrombus formation at the site of vessel injury with the platelet aggregation, VSMC contraction, and VSMC proliferation.

Animals↗

PubMed2001

Asymmetric hydrosilylation of styrenes catalyzed by palladium-MOP complexes: ligand modification and mechanistic studies.

In the palladium-catalyzed asymmetric hydrosilylation of styrene (3a) with trichlorosilane, several chiral monophosphine ligands, (R)-2-diarylphosphino-1,1'-binaphthyls (2a-g), were examined for their enantioselectivity. The highest enantioselectivity was observed in the reaction with (R)-2-bis[3,5-bis(trifluoromethyl)phenyl]phosphino-1,1'-binaphthyl (2g), which gave (S)-1-phenylethanol (5a) of 98% ee after oxidation of the hydrosilylation product, 1-phenyl-1-(trichlorosilyl)ethane (4a). The palladium complex of 2g also efficiently catalyzed the asymmetric hydrosilylation of substituted styrenes on the phenyl ring or at the beta position to give the corresponding chiral benzylic alcohols of over 96% ee. Deuterium-labeling studies on the hydrosilylation of regiospecifically deuterated styrene revealed that beta-hydrogen elimination from 1-phenylethyl(silyl)palladium intermediate is very fast compared with reductive elimination giving hydrosilylation product when ligand 2g is used. The reaction of o-allylstyrene (9) with trichlorosilane catalyzed by (R)-2g/Pd gave (1S,2R)-1-methyl-2-(trichlorosilylmethyl)indan (10) (91% ee) and (S)-1-(2-(propenyl)phenyl)-1-trichlorosilylethanes (11a and 11b) (95% ee). On the basis of their opposite configurations at the benzylic position, a rationale for the high enantioselectivity of ligand 2g is proposed.

Journal Article↗

PubMed2001

Nitric oxide mediates the change of proteoglycan synthesis in the human lumbar intervertebral disc in response to hydrostatic pressure.

STUDY DESIGN: This in vitro study clarifies the role of nitric oxide (NO) in human lumbar intervertebral disc metabolism. OBJECTIVE: To investigate the effects of NO on proteoglycan synthesis in human lumbar discs and to test the hypothesis that NO is a mediator of the changes in proteoglycan synthesis in response to hydrostatic pressure. SUMMARY OF BACKGROUND DATA: The authors have clarified that hydrostatic pressure has an apparent effect on proteoglycan synthesis as well as matrix metalloproteinase production in the intervertebral disc. The cellular mechanisms underlying the response of disc cells to hydrostatic pressure remain to be clarified. Herniated lumbar discs produce NO in response to interleukin (IL)-1 beta. In articular cartilage, NO mediates the change of proteoglycan synthesis by IL-1 or shear stress. METHODS: Fifty-eight lumbar intervertebral disc specimens were obtained from patients who had undergone posterior discectomy. The specimens were chopped into 1-2-mm cubes and were incubated in a plastic syringe with 1 mL Dulbecco's modified Eagle's medium (DMEM). The syringes were placed in a water-filled pressure vessel kept at 37 C. Hydrostatic pressures of 1 (control), 3, and 30 atmospheres (atm) were applied. Proteoglycan synthesis was determined from (35)S-sulfate incorporation rates. Nitrite (the stable oxidation product of NO) concentration in DMEM was determined by a spectrophotometric method based on the Griess reaction. As a competitive inhibitor of NO synthases, N(G)-methyl-l-arginine (l-NMA, 10-1000 micromol) and as an organic donor of NO, S-nitroso-N-acetylpenicillamine (SNAP, 1-200 micromol) were used. RESULTS: Addition of l-NMA suppressed NO production and increased proteoglycan synthesis rates in the intervertebral disc specimens in a dose-dependent fashion. Addition of SNAP increased exogenous NO content in the medium significantly and suppressed proteoglycan synthesis rates in a dose-dependent fashion. Three-atmosphere hydrostatic pressure stimulated the proteoglycan synthesis rates. Rates were approximately 1.3-fold greater than at 1 atm, whereas 30-atm pressure inhibited proteoglycan synthesis rates. However, the hydrostaticpressure had inverse effect on NO production. At 3 atm, NO production decreased slightly relative to 1 atm, whereas at a pressure of 30 atm, NO production was increased and was approximately 1.32-fold greater than at 1 atm. L-NMA enhanced the 3-atm pressure-induced increase in proteoglycan synthesis and also relieved the suppression of proteoglycan synthesis at a pressure of 30 atm. CONCLUSION: The current study confirmed the previous finding that human herniated lumbar disc cultures spontaneously produce NO. Endogenously generated and exogenously supplied NO inhibited proteoglycan synthesis in the intervertebral disc. Hydrostatic pressure influenced NO production by disc cells, and NO is one of the mediators that changes proteoglycan synthesis in response to hydrostatic pressure. These results may show that autocrine and paracrine mechanisms of NO play an important role in the regulation of disc cell metabolism under mechanical stress and in the pathophysiology of intervertebral disc degeneration.

Adolescent↗

PubMed2001

Preliminary examinations for applying a carbazole-degrader, Pseudomonas sp. strain CA10, to dioxin-contaminated soil remediation.

A method for bioremediation of chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) by a carbazole-utilizing bacterium, Pseudomonas sp. strain CA10, was developed. CA10 cells transferred to carbon- and nitrogen-free mineral medium supplemented with 1 mg carbazole (CAR)/ml grew rapidly during the first 2 days; and the cells at the end of this rapid growth period showed the highest 2,3-dichlorodibenzo-p-dioxin (2,3-Cl2DD)-degrading activity. The CA10 cells pregrown for 2 days efficiently degraded 2,3-Cl2DD in aqueous solution at either 1 ppm or 10 ppm. The effect of inoculum density on the efficiency of 2,3-Cl2DD degradation was investigated in a soil slurry microcosm [ratio of soil:water = 1:5 (w/v)]. The results showed that a single inoculation with CA10 cells at densities of 10(7) CFU/g soil and 10(9) CFU/g soil degraded 46% and 80% of 2,3-Cl2DD, respectively, during the 7-day incubation. The rate of degradation of each CDD congener, 2-ClDD, 2,3-Cl2DD, and 1,2,3-Cl3DD (1 ppm each) by strain CA10 in the soil slurry system was not significantly influenced by the coexistence of the other congeners. Using this soil slurry system, we tried an experimental bioremediation of the actual dioxin-contaminated soil, which contained mainly tetra- to octochlorinated dioxins. Although the degradation rate of total CDD and CDF congeners by a single inoculation with CA10 cells was 8.3% after a 7-day incubation, it was shown that strain CA10 had a potential to degrade tetra- to hepta-chlorinated congeners including the most toxic compound, 2,3,7,8-tetrachlorinated dibenzo-p-dioxin.

Benzofurans↗

PubMed2001

Recurrent hepatocellular carcinoma versus radiation-induced hepatic injury: differential diagnosis with MR imaging.

The objective of this study was to assess the value of MR imaging in the differentiation between a recurrent hepatocellular carcinoma (HCC) and a radiation-induced hepatic injury. Nine male patients with suspected recurrence after radiotherapy for HCC underwent T(2)-, T(1)-weighted imaging and Gd-DTPA enhanced dynamic studies. T(2) relaxation times, signal intensity ratios in T(1)-weighted images (WI) and the relative enhancement of the dynamic study were calculated. Recurrent tumors and the irradiated area showed similar image characteristics: hypointense in T(1)-WI and hyperintense in T(2)-WI. T(2) values and signal intensity ratios in the T(1)-WI were not significantly different. In the gadolinium-enhanced dynamic study, a recurrent HCC showed early enhancement, followed by a rapid washout. However, the irradiated liver parenchyma showed hyperintensity from an early phase, and contrast enhancement tended to be more prominent and prolonged at the end of the dynamic studies. The characteristic findings of the dynamic MR study enable us to distinguish between a recurrent HCC and a radiation-induced hepatic injury.

Aged↗

PubMed2001

Prevalence and mortality of the Brugada-type electrocardiogram in one city in Japan.

OBJECTIVES: We sought to study the prevalence and mortality of subjects exhibiting the Brugada-type electrocardiogram (ECG) in a community-based population in Japan. BACKGROUND: The Brugada syndrome has been associated with sudden death in subjects without structural heart disease. Hospital-based studies showed 11% to 38% annual fatal arrhythmic events in patients with the Brugada syndrome. METHODS: Prevalence and mortality of the Brugada-type ECG were studied in subjects who had ECGs during a health examination in Moriguchi, Osaka, Japan. Information about death and relocation from Moriguchi city was obtained prospectively. RESULTS: The Brugada-type ECG was found in 98 of 13,929 study subjects (0.70%, 95% confidence interval [CI]: 0.57% to 0.86%). The typical coved-type with an rsR' pattern in V(1) lead ("typical" Brugada-type) was found in 0.12% of subjects (95% CI: 0.07% to 0.20%). The prevalence for male subjects with the Brugada-type ECG (81%) was significantly higher than it was for those without (26%, p < 0.0001). In male subjects, the Brugada-type ECG was found in 2.14% (95% CI: 1.70% to 2.66%), and the "typical" Brugada-type was found in 0.38% (95% CI: 0.21% to 0.64%). After 2.6 +/- 0.3 years of follow-up, there was 1 death (1.0%, 95% CI: 0.03% to 5.6%) of a subject with the Brugada-type ECG, whereas there were 139 deaths (1.0%, 95% CI: 0.85% to 1.2%) of those without the Brugada-type ECG (p = 0.9943, log-rank test). CONCLUSIONS: A substantial number of the Brugada-type ECG were observed in subjects in a community-based population in Japan, especially in men. The total mortality of subjects with the Brugada-type ECG did not differ from the mortality of those without the Brugada-type ECG in a community-based population.

Aged↗

PubMed2001

High prevalence of TT virus in human bile juice samples: importance of secretion through bile into feces.

TT virus (TTV) is much more prevalent than we once imagined. With the use of primers designed from the noncoding regions, a more than 90% rate of TTV infection in the general population by polymerase chain reaction (PCR) has been reported, showing that nonparenteral transmission must play an important role to its epidemiology. We considered that TTV may be secreted through bile juice into feces to establish nonparenteral infection. Paired bile juice and serum samples were obtained from 26 patients who were receiving bile drainage. Feces were also recovered after the drainage tube was removed. TTV DNA was detected from 22 patients in serum (84.6%), and they were all TTV DNA positive in bile juice. Most feces samples recovered from TTV-positive patients were also TTV DNA positive. Secretion of TTV into bile juice appears to be common, and this could play an important role to its transmission and its epidemiology.

Bile↗

PubMed2001

Immunohistochemical study of the phosphorylated and activated form of c-Jun NH2-terminal kinase in human aorta.

c-Jun NH2-terminal kinase is a key enzyme mediating the cellular response to a variety of extracellular stimuli. In the present study, we performed immunohistochemical studies of the expression of the phosphorylated form of the kinase in 51 human aortas of various ages. The phosphorylated kinase immunoreactivity was strongly detected in vascular smooth muscle cells of the medial vessel layer of atherosclerotic lesions from adults. Immunoreactivity was also strongly detected in similar cells of the intima. On the other hand, immunoreactive phosphorylated kinase was only weakly defected in the medial vascular smooth muscle cells of non-atherosclerotic lesions from adults. We also investigated the expression of the phosphorylated kinase in infant aortas. In contrast to its weak immunoreactivity in adult non-atherosclerotic lesions, the kinase immunoreactivity was detected in high amounts in vascular smooth muscle cells of non-atherosclerotic lesions from infants. Thus, the abundant expression of the phosphorylated kinase in these cells in atherosclerotic lesions of adults and non-atherosclerotic lesions of infants suggests that the activation of c-Jun NH2-terminal kinase may be an important element initiating the proliferation of vascular smooth muscle cells during atherogenesis and aortic development.

Adult↗

PubMed2001

Immunolocalisation of the janus kinases (JAK)--signal transducers and activators of transcription (STAT) pathway in human epidermis.

The janus kinases (JAK) and signal transducers and activators of the transcription (STAT) pathway have been shown to be activated by a number of cytokines or growth factors and to play significant roles in the differentiation of various cell types. In the present study, we investigated the distribution of the JAK-STAT pathway using immunohistochemistry in the human epidermis. Each element of the pathway showed abundant and differential expression in the epidermis. The differential distribution of the elements was most strikingly observed in the horny keratinised cell and granular layers of the epidermis. JAK2, JAK3, STAT1 and STAT5 were expressed in high amounts, and JAK1, TYK2, STAT2, STAT3, STAT4 and STAT6 to a much lesser extent in the horny cell layer. JAK3, TYK2, STAT2, STAT3, STAT4 and STAT6 were more abundantly expressed in the granular layer than the lower layers of the epidermis. JAK1, STAT1 and STAT5 were expressed at almost the same levels in the various layers of the epidermis. These results show that elements of the JAK-STAT pathway are abundantly and differentially expressed in the epidermis. It is suggested that each element of the pathway may play a role at a distinct stage of keratinocyte differentiation.

Adult↗

PubMed2001

Possible involvement of Fyn kinase in ethanol-stimulated Cas tyrosine phosphorylation in rat cerebellum and cerebral cortex.

In the present study, we have investigated the effect of intraperitoneal injection of ethanol (3.5 g/kg) on tyrosine phosphorylation in rat brain. Immunoblot analysis using an antiphosphotyrosine antibody revealed that a 130-kDa protein band was detected in the brain extract in response to ethanol administration. This ethanol-stimulated tyrosine phosphorylation of the 130-kDa protein was found in the brain but not in the heart, liver or thymus. The 130-kDa phosphotyrosine-containing protein was identified by immunoprecipitation to be Cas, a crk-associated src substrate. This ethanol-stimulated tyrosine phosphorylation of Cas was observed most prominently in the cerebellum and the cerebral cortex. We further examined the possible involvement of Fyn kinase in ethanol-stimulated Cas tyrosine phosphorylation. Immunecomplex kinase assay showed that Fyn was activated in the cerebellum and cerebral cortex of ethanol-administered rats. Immunoprecipitation experiments also showed that Fyn was co-immunoprecipitated with an anti-Cas antibody in these regions from ethanol-administered rats. Furthermore, exogenous Fyn was shown to phosphorylate Cas from cerebellum and cerebral cortex in vitro. These findings indicate that ethanol stimulates tyrosine phosphorylation of Cas in rat cerebellum and cerebral cortex, and that Fyn may be involved in the process.

Animals↗

PubMed2001

Immunolocalization of the mitogen-activated protein kinase signaling pathway in Hassall's corpuscles of the human thymus.

In the present study, we investigated the immunohistochemical localization of mitogen-activated protein kinase (MAPK) signaling pathway in the human thymus. Three members of MAPK, the extracellular signal-regulated kinase (ERK), the c-Jun N-terminal kinase (JNK) and the p38 kinase, showed differential expression patterns in the thymus medulla. The phosphorylated form of ERK (p-ERK) was abundantly present in the outer layer of Hassall's corpuscles, and the phosphorylated form of p38 kinase (p-p38 kinase) was present in the entire Hassall's corpuscles. The phosphorylated form of JNK (p-JNK) was expressed in medullary thymocytes. We also examined localization of MAPK kinases (MAPKK or MEK) which specifically activate MAPK. MEK1, an activator of ERK, was found in the outer layer of Hassall's corpuscles where p-ERK was expressed. MEK3, an activator of p38 kinase, was also expressed in the outer layer. MEK4 and MEK7, which are activators of JNK, were present in the entire Hassall's corpuscles. Thus, differential expression of MAPK in the thymus supports the concept that the MAPK signaling pathway controls the specificity of functional thymic responses to extracellular stimuli. Furthermore, the abundant expression of various elements of the pathway in Hassall's corpuscles suggests that the pathway is involved in thymic medullary epithelial maturation.

Child, Preschool↗

PubMed2001

Minimum 10-year follow-up study of anterior lumbar interbody fusion for isthmic spondylolisthesis.

The aims of the current study were to evaluate the long-term clinical and radiologic results of anterior lumbar interbody fusion (ALIF) for isthmic spondylolisthesis. Between 1981 and 1988, a total of 35 patients underwent ALIF for isthmic spondylolisthesis. Of these, 23 patients were followed clinically and radiographically for more than 10 years (average, 13.3 years). The Japanese Orthopaedic Association low-back pain score was used to evaluate the outcome of subjective symptoms and clinical signs. The preoperative and postoperative percentage of slip, preoperative and postoperative intervertebral disk height, interbody graft union, and pars defect union were evaluated by serial radiographs. The adjacent disk degeneration was also evaluated by radiographs and magnetic resonance imaging. Although the low-back pain score worsened after 5 years, ALIF provides satisfactory overall long-term clinical results. The preoperative percentage of slip and the disk height were corrected after surgery, but at the time of interbody graft union, slip and disk height recurred as a result of grafted bone collapse. The rate of union in the grafted area was 83%. In the nonunion cases, the scores gradually deteriorated with time, but the overall results were not different from those of union cases. Radiographs showed adjacent disk degeneration in 52% of cases in the upper adjacent level and in 70% of cases in the lower adjacent level, but these changes were not correlated with clinical outcomes.

Adolescent↗

PubMed2001

Effect of cicletanine on the nitric oxide pathway in human umbilical vein endothelial cells.

The purpose of this study was to evaluate the effects of cicletanine, a slightly diuretic antihypertensive drug, on human vascular endothelial cells with regard to nitric oxide, intracellular calcium concentration ([Ca2+]i), cyclic nucleotide, inositol 1,4,5-trisphosphate (IP3), and prostacyclin generation. Primary cultured human umbilical vein endothelial cells were used in this study. [Ca2+]i was measured by fura-2/AM. Cyclic adenosine monophosphate (AMP), cyclic guanosine monophosphate (GMP), IP3, and prostacyclin were measured by radioimmunoassay. Nitric oxide was measured by the Griess method. Cicletanine had no effect on [Ca2+]i. Cicletanine (10(-6)-10(-4) M) increased cyclic GMP but decreased prostacyclin generation. Cicletanine had no stimulating effect on cyclic AMP or IP3 generation. IP3 increased 45Ca release from storage sites. Cicletanine decreased prostacyclin generation via increase in cyclic GMP. Cicletanine had no stimulating effect on nitrogen oxides for 2 h after incubation but increased it after 3-24 h. Pretreatment with L-N(G)-monomethyl-arginine (L-NMMA) prevented this increase. The inhibitory effect of L-NMMA was prevented by pretreatment with L-arginine. These results indicate that nitric oxide and cyclic GMP may contribute to the antihypertensive action of cicletanine.

Antihypertensive Agents↗

PubMed2001

[Isolation and incidence of Cryptosporidium and Giardia from river water].

A study was conducted during the period from July to October in 1999, surface water samples were collected from 13 rivers in Hyogo Prefecture serving as tap water sources and examined for Cryptosporidium oocysts and Giardia cysts using the immunomagnetic separation method. In 9 (69%) of the 13 rivers, Cryptosporidium oocyst was detected. Giardia cyst was detected in 5 (38%) of the 13 rivers. The Cryptosporidium oocyst positive rate was comparable to that of fecal bacteriological indicators, which was also examined and detected in 10 (77%) of 13 rivers. Water samples were collected at 69 points in the 13 rivers. Cryptosporidium parvum oocyst was detected at 38 (55%) of the 69 points, demonstrating widely spread contamination. Comparing 3 areas which were divided on the basis of agricultural circumstance as well as geographical locating, the Cryptosporidium positive rate varied widely according to the area, ranging from 37% to 100%. To elucidate the reason for these differences, the relationship between positive rate and the species and number of livestock animals raised in each respective region was investigated. The results showed a strong correlation (r = 0.91) between the number of raised cattle and contamination with the rate of Cryptosporidium in each area. Furthermore, genetic analysis by PCR-restriction fragment length polymophism method revealed that C. parvum oocyst detected in the rivers studied was the bovine type, probably indicating that the oocyst was excreted from the cattle in the river basins. The degree of contamination with Cryptosporidium in river water was comparable to that of fecal bacteriological indicators, suggesting the possibility that fecal bacteriological indicators examination might be used as a criterion of Cryptosporidium contamination.

Animals↗