Biomedical subjects

S Soda

Publications and source records attributed to S Soda.

At least 19 recordsLinked to original sources

PubMed2006

Effects of light intensity and water temperature on oxygen release from roots into water lettuce rhizosphere.

The oxygen release rate into the rhizosphere by a floating aquatic plant-water lettuce-was determined under various light intensities (0.0-1.2x10(5)lx) and water temperatures (10-35 degrees C). The net specific oxygen release rate was expressed by a model equation comprising the gross oxygen release rate and the rhizosphere respiration terms. Experimental and simulated results show that the net specific oxygen release rate increased with light intensity up to the optimal value, but slight inhibition by higher light intensities was observed at 10-20 degrees C. With increased water temperature, the respiration rate became larger than the gross oxygen release rate. The maximum net specific oxygen release rate of 11.0-12.5mg-O(2)kg-wet(-1)h(-1) was obtained at the optimal condition of about 25 degrees C and 9.0x10(4)-1.1x10(5)lx. The net oxygen release rate was negligible at 35 degrees C at any light intensity because the respiration rate was much greater than the gross oxygen release rate into the rhizosphere.

Hydroponics↗

PubMed2004

The effect of valsartan on regression of left ventricular hypertrophy in type 2 diabetic patients.

AIM: The aim of the present study was to examine the effects of an angiotensin II receptor antagonist, valsartan, on echocardiographically proven left ventricular hypertrophy (LVH) in patients with type 2 diabetes. METHODS: Outpatients with type 2 diabetes mellitus were recruited at Niigata University Hospital. The left ventricular mass index (LVMI) was calculated by echocardiography. LVH was considered to be present if the LVMI was > 131 g/m(2) in males and > 100 g/m(2) in females. Patients with LVH received a low dose (40 mg/day) of valsartan for 12 months. This low dose had no clinical effect on blood pressure. RESULTS: Of the 38 patients who entered the study, 14 (36.8%) had LVH. After only 6 months of valsartan therapy, the mean LVMI decreased significantly, from 126.5 +/- 27.8 to 119.0 +/- 23.5 g/m(2) (p < 0.01 vs. baseline). Also, a significant decrease was observed after 12 months (116.5 +/- 30.9 g/m(2), p < 0.05 vs. baseline). Compared to baseline, there were no significant differences after treatment in body mass index, glycosylated haemoglobin (HbA(1c)), systolic blood pressure and diastolic blood pressure. CONCLUSIONS: In type 2 diabetic patients with LVH, treatment with a low dose of valsartan, an angiotensin II receptor antagonist, for 12 months, reduced LVMI, with no reduction in systemic blood pressure. This drug may be safely administered to type 2 diabetic patients with LVH. The long-term risk-reduction effects will have to be evaluated in further trials.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2003

Brain-derived neurotrophic factor modulates glucagon secretion from pancreatic alpha cells: its contribution to glucose metabolism.

AIM: Brain-derived neurotrophic factor (BDNF) reduces plasma glucose levels in obese db/db diabetic mice and is speculated to produce its effects via the hypothalamus, the regulatory centre of satiety and the autonomic nervous system. The potential effect of BDNF directly on peripheral endocrine organs, however, remains to be clarified. Here we report the effects of BDNF on hormonal secretion from pancreatic islets of Langerhans using their isolated culture. METHODS AND RESULTS: In an immunohistochemical study, mouse pancreatic alpha cells were stained specifically with the anti-TrkB (a specific receptor for BDNF) antibody. After 7 days culture of isolated islets of the normal mouse pancreas, 10 ng/ml BDNF decreased the secretion of glucagon per 6 h significantly less than that of the control (p = 0.016). In contrast, there were no significant changes in insulin secretion or glucagon and insulin contents in the islets cultured under the same conditions. In vivo administration of BDNF (10 mg/kg/day) to normal mice for 7 days significantly decreased their food consumption (p < 0.05). The fasting plasma glucose levels were decreased on day 7 compared with day 1 more significantly in BDNF-treated mice (p = 0.043) than in pair-fed control mice (p = 0.14). In newborn BDNF-knockout mice, fasting plasma glucose levels increased in the order of homozygote, heterozygote and wild type (p = 0.033). No apparent immunohistochemical abnormality was observed for pancreatic glucagon in the BDNF-knockout mice. CONCLUSION: These data suggest that BDNF affects glucose metabolism not only with its anorectic effect but also with modulated glucagon secretion from pancreatic alpha cells.

Animals↗

PubMed2003

Effects of reduction of the number of primordial follicles on follicular development to achieve puberty in female rats.

Effects of reduction of the number of primordial follicles on follicular development and concentrations of circulating hormones were examined in immature female rat offspring of dams given busulfan intraperitoneally on day 14 of gestation. The offspring of dams treated with 5 mg busulfan kg(-1) showed vaginal opening at an age comparable with the offspring of dams treated with 2.5 mg busulfan kg(-1) or with corn oil as a control, although they exhibited an irregular oestrous cycle until week 14 after birth. The serum concentrations of immunoreactive inhibin and FSH on day 26 after birth of the offspring treated with 5 mg busulfan kg(-1) were similar to those of age-matched controls. On day 15 after birth, however, the concentration of their immunoreactive inhibin was markedly lower than that of controls, whereas the concentration of their FSH was increased inversely. Comparison of the numbers of ovarian follicles in the controls and groups treated with 2.5 mg busulfan kg(-1) and 5 mg busulfan kg(-1) revealed that prenatal treatment with busulfan reduced the number of follicles in the primordial or primary phase and in the preantral phase on day 7 after birth. Although the increase of the ratio of the number of preantral follicles during days 7-13 after birth tended to vary with the prenatal dose of busulfan, the number of preantral follicles in the group treated with 5 mg busulfan kg(-1) was still smaller than in the controls. The concentration of serum immunoreactive inhibin of the offspring treated with busulfan was reduced on day 7 after birth without alteration of the concentration of gonadotrophin. On day 13 after birth, the concentration of serum immunoreactive inhibin was reduced only in the offspring treated with 5 mg busulfan kg(-1), and the concentration of serum FSH of the offspring was increased inversely as found on day 15 after birth. These results indicate that a reduction in the number of primordial follicles decreases the number of follicles that enter the growing phase, a major source of circulating inhibin in the neonatal and infantile ovary, and that consequently increased circulating FSH may accelerate follicular development to achieve puberty.

Alkylating Agents↗

PubMed2001

Gitelman's syndrome first diagnosed as Bartter's syndrome.

A 29-year-old man, who had been treated with potassium, spironolactone and indomethacin for over 9 years, was admitted because of nausea, vomiting, diarrhea and tetany manifestation. At the age of 20, he had been diagnosed as having Bartter's syndrome according to the criteria of the Japanese Ministry of Health and Welfare. Findings on admission were hypokalemia, hypomagnesemia and hypocalciuria. Renal distal fractional reabsorption rates of sodium, chloride and calcium were markedly decreased by administration of furosemide but there was no obvious change with administration of thiazide. These findings indicate that the patient had Gitelman's syndrome rather than Bartter's syndrome.

Adult↗

PubMed2000

Decolorization of heat-treatment liquor of waste sludge by a bioreactor using polyurethane foam-immobilized white rot fungus equipped with an ultramembrane filtration unit.

A bench-scale bioreactor using immobilized fungal cells equipped with an ultramembrane filtration unit was developed as a means of decolorizing brown color components (melanoidins) arising from the heat-treatment liquor (HTL) of waste sludge. Artificial HTL containing 4200 color units of synthetic melanoidin supplemented with 1000 mg/l ethanol was first subjected to decolorization by the fungus Coriolus hirsutus IFO4917 immobilized onto polyurethane foam cubes. Then, the resultant biologically treated HTL was subjected to ultrafiltration to obtain the permeate (filtrate) as the effluent. The retentate (concentrate) of the filtration unit, containing the remaining melanoidin of high molecular weight and extracellular decolorizing enzymes, was returned to the fungal bioreactor to allow further decolorization. This system was operated in a sequencing batch mode under nonsterile conditions. Contamination of the bioreactor with air/water-born microbes markedly lowered the decolorization efficiency. However, this problem was solved by heating the returned concentrate at 50 degrees C for 10 min. Under the almost stable condition of a hydraulic retention time of 2 d in a 1-d cycle sequencing batch mode, about 70% decolorization was routinely achieved using the entire system (bioreactor + ultrafiltration), while the contribution of the fungal bioreactor alone to the decolorization was about 45%.

Journal Article↗

PubMed1999

Adsorption of bacterial cells onto activated sludge flocs.

The adsorption of 9 species of bacteria onto laboratory-activated sludge flocs were investigated and a kinetic model describing the adsorption process was proposed in order to design an effective bioaugmentation strategy. The typical time course of bacterial adsorption, which is a triphasic process, consisted of lag, rapid adsorption, and stationary phases. The equilibrium of the cells in the stationary phase obeyed the Freundlich isotherm. The reversible and nonlinear model could describe the process to a certain degree and the Freundlich parameters and specific sorption rates were estimated for each bacterial strain. There was no apparent relationship between the estimated parameters and characteristics of the bacterial strains, such as specific growth rate, hydrophobicity of the cells, and flocculation activity against kaolin clays. However, the high floc formation ability of the bacterial strains was observed to be related to high cell concentrations although a longer lag time was required.

Journal Article↗

PubMed1999

Application of a floc-forming genetically engineered microorganism to a sequencing batch reactor for phenolic wastewater treatment.

For enhancing the survival of genetically engineered microorganisms (GEMs) in activated sludge processes, the use of a floc-forming bacterium as the host for a recombinant plasmid was proposed. The floc-forming and phenol-degrading GEM Sphingomonas paucimobilis 551 (pS10-45) was cultured to demonstrate this proposal. Although the maximum growth rate of the host strain S. paucimobilis 551 was low and the recombinant plasmid pS10-45 was unstable in the host, the resultant GEM S. paucimobilis 551 (pS10-45) was difficult to wash out together with the effluent, and it maintained population 3-4 times higher than the non-floc-forming GEM Escherichia coli HB101 (pS10-45) in a model activated sludge process operated in a sequencing batch mode. In the long run, the GEM-inoculated activated sludge process showed better phenol removal ability by the recombinant plasmid and better sludge settlement by the host strain.

Journal Article↗

PubMed1999

Modeling and simulation of competition between two microorganisms for a single inhibitory substrate in a biofilm reactor.

A simple biofilm model was developed to simulate the competition between two microorganisms for a common inhibitory substrate. The following assumptions were made for the simulations: (1) the biofilm has a uniform thickness and is composed of 5 segments, (2) growth of two microorganisms A and B which utilize the common substrate is expressed by the Haldane kinetics with a spatial limitation term and is independent of the other microorganism in the biofilm reactor, and (3) diffusion of the substrate, movement of the microorganisms, and continuous loss of the biomass by shearing are expressed by Fick's Law-type equations. The qualitative behavior of the biofilm reactor is characterized by five regions, I-V, depending on the operation conditions, the substrate concentration in feed, and the dilution rate. In region I, both microorganisms are washed out of the biofilm reactor. In region II, microorganism B is washed out, and in region III, microorganism A is washed out of the biofilm. In region IV, both microorganisms coexist with one another. In region V, both microorganisms coexist with a sustained oscillatory behavior. Convergence to regions I-V depends on the initial conditions. In regions II-V, washout of either or both microorganisms is also observed with initial conditions too far away.

Biofilms↗

PubMed1996

In vivo ESR studies on pharmacokinetics and metabolism of parenteral lipid emulsion in living mice.

PURPOSE: We applied non-invasive and real-time method with in vivo ESR spectroscopy to determining pharmacokinetics and metabolism of lipid emulsion as a drug carrier in living mice. METHODS: A spin-labeled triglyceride (SL-TG) was newly synthesized and lipid emulsion containing SL-TG was prepared. In vivo ESR spectra in mice were observed after intravenous administration of the lipid emulsion. RESULTS: In vivo ESR spectra consisted of three components, coinciding with the in vitro spectra of SL-TG particles, free and immobilized fatty acids. The amount of the components depended on both the observing domain and the period after administration. In the chest, all three components were observed, while SL-TG particle was lacking in the abdomen. The half-life of the lipid particles in the chest was 2 hr. CONCLUSIONS: Non-invasive and real-time analysis of drug carriers in living animal is successfully accomplished using an in vivo ESR method.

Animals↗

PubMed1991

[A case of gas gangrene following operation of cervical esophageal carcinoma].

A 74-year-old woman underwent surgery for cervical esophageal carcinoma. After operation, she had abdominal distension, high fever, and suddenly fell into shock and died. Autopsy revealed necrosis and multiple gas blebs in the entire digestive tract and liver. Direct smear specimens Gram-stained disclosed clostridium septicum and the cause of death was found to be gas gangrene. This is the first of clostridium infection localized in the digestive tract and liver after operation. Abdominal radiogram showed massive gas in the intestine, intramural bowel gas and gas in the portal vein, and these are very suggestive of gas gangrene of the intestinal tract.

Aged↗

PubMed1987

Specific interaction of arabinose residue in ginsenoside with egg phosphatidylcholine vesicles.

The interaction of the specific sugar residue in ginsenosides with egg phosphatidylcholine vesicles was investigated by ESR spectrometry using phosphatidic acid spin-labeled at the polar head groups. Ginsenoside-Rc, which has an alpha-L-arabinofuranose residue and agglutinability toward egg yolk phosphatidylcholine vesicles (Fukuda, K. et al. (1985) Biochim. Biophys. Acta 820, 199-206), caused the restriction of the segmental motion of spin-labeled phosphatidic acid in egg phosphatidylcholine vesicles, indicating that the saponin interacted with the polar head groups of vesicles. Other ginsenosides-Rb2, Rb1, Rd and p-nitrophenyl glycoside derivatives which have less or no agglutinability were also investigated in the same manner. Only ginsenoside-Rb2 and p-nitrophenyl alpha-L-arabinofuranoside which have the specific sugar residue (arabinose) showed a strong interaction with the polar head groups of vesicles. To gain an insight into the mechanism of agglutination by ginsenoside-Rc, the interaction with the fatty acyl groups was also studied by using phosphatidylcholine spin-labeled at the fatty acyl groups. Ginsenoside-Rc increased the order parameter of the spin-labeled phosphatidylcholine, indicating that the saponin was inserted into lipid bilayers. In other saponins investigated, only ginsenoside-Rb2 interacted with the fatty acyl part of vesicles. The process of expression of agglutination by ginsenoside-Rc was discussed on the basis of the ESR studies.

Arabinose↗

PubMed1976

Production and properties of theta-toxin of Clostridium perfringens with special reference to lethal activity.

theta-Toxin of Clostridium perfringens produced in a synthetic medium showed high toxicity. The mouse was killed with 5-10 hemolytic units of the toxin. Neutralization experiments showed that lethal and hemolytic activities were due to the same toxic entity. The amount of theta-toxin expressed in lethal activity reached more than 30% that of alpha-toxin in the synthetic medium SM67. Although the activities of alpha-and theta-toxins were not additive in terms of LD50, increase in the ratio of theta-toxin to alpha-toxin resulted in reduction of the survival time of the mouse injected with a lethal dosis of the mixture of the two toxins when compared with alpha-toxin alone. Unlike those produced in other media, the hemolytic and lethal activities of theta-toxin produced in the synthetic medium was not activated by reduction with thioglycollate, even after partial purification. In other respects, the toxin was not different significantly from those reported in the past. The toxic form was detected also in complex medium. It was suggested that theta-toxin may be produced as a nascent entity.

Animals↗

PubMed1974