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Biomedical subjects

S Fujisawa

Publications and source records attributed to S Fujisawa.

At least 181 records · Page 10Linked to original sources
PubMed1983

Anti-streptococcal cell membrane and anti-human glomerular basement membrane titers in sera of patients with poststreptococcal acute glomerulonephritis and anaphylactoid purpura.

To clarify the immunological mechanisms in poststreptococcal acute glomeulonephritis (PSAGN) and anaphylactoid purpura (AP), anti-streptococcal cell membrane (anti-SCM) and anti-human glomerular basement membrane (anti-GBM) titers in the sera of patients with PSAGN and AP were determined by passive hemagglutination with chromic chloride-treated sheep erythrocytes. Sodium lauryl sulfate (SLS) soluble SCM and collagenase soluble GBM were used as soluble antigens. Positive anti-SCM titers (greater than 1:8) were demonstrated in 10 of 14 patients (71.4%) with PSAGN and in 4 of 9 patients (44.4%) with AP with evidence of antecedent streptococcal infection. Two of 4 patients with AP without evidence of antecedent streptococcal infection had positive anti-SCM titers. No correlation was noted between anti-streptolysin O (ASO) titers and anti-SCM titers in patients with PSAGN or AP, but many patients with high ASO titers also had high anti-SCM titers. No positive anti-GBM reactions were detected in patients with PSAGN or AP. No cross-reactions were noted between SLS soluble SCM and collagenase soluble GBM.

Acute Disease↗
PubMed1983

Paraquat-induced enhancement of vascular permeability.

Paraquat, intradermally injected in the dorsal skin of rats, demonstrated three phasic actions; enhancement of vascular permeability within 30 min (Phase I) and at 6-24 hr after the injection (Phase II) by dye leakage method and bleeding in skin at 2-7 days after the injection (Phase III). Phase I was induced in the presence of paraquat in the skin. However, phases II and III occurred in the absence of paraquat. Morphological study indicated inflammatory observations such as infiltration of mononuclear cells and swelling of venular endothelial cells throughout these three phases. And the most severe morphological changes occurred in phase II. Aspirin, indomethacin, tripelennamine and dexamethasone decreased dye leakage but superoxide dismutase increased it in phase I. These drugs including superoxide dismutase decreased dye leakage in phase II. Bleeding in phase III was decreased by the administration of aspirin and indomethacin. Because of higher effective dose of indomethacin used in this experiment as compared with a clinical dose, aspirin seemed among drugs examined in our experimental models to be the most potent drug that depressed the progression of paraquat-induced enhancement of permeability.

Animals↗
PubMed1981

Determination of partition coefficients of acrylates, methacrylates, and vinyl monomers using high performance liquid chromatography (HPLC).

Retention times (Rt) for acrylates, methacrylates, and vinyl monomers were measured with two different columns (C18 Corasil and C8 LiChrosorb) using reverse-phase HPLC in order to obtain their partition coefficients between 1-octanol and water (log P). The log P values of test compounds were determined from the regression curves between RT and log P values of a number of standards using C8 LiChrosorb. The log P values obtained in this manner agreed closely with the log P values observed in previous studies. However, the peaks of these compounds were not sharp and some compounds were eluted for more than 10 min. Thus, the measurement of accurate Rt values is tedious. C18 Corasil was therefore used for this experiment in a mobile phase (methanol : water = 85 : 15). The Rt of some methacrylates with P values over 4 were delayed due to the hydrophobic interaction between these compounds and the C18 packing material. However, in the measurable region of the log P values (about -1 to +4), log P correlated linearly with log Rt following two different regression curves: one for aliphatic and aromatic compounds with the functional groups (r = 0.92), and the other for compounds without these groups (r = 0.99). It is concluded that log P values of methacrylates widely used in dentistry can be determined easily and accurately by HPLC.

1-Octanol↗
PubMed1981

Binding of eugenol and o-ethoxybenzoic acid to bovine serum albumin.

The binding constants (log K) of eugenol, o-ethoxy-benzoic acid, and their analogues, plus other organic compounds widely used in dentistry with bovine serum albumin, were examined with respect to the partition coefficients of these compounds in octanol-water (log P). Linear relationships between log K and log P values were obtained with high relative coefficients. Eugenol and o-ethoxybenzoic acid showed a relatively large log K value.

Alcohols↗
PubMed1981

Study on the absorption and protein binding of carbaryl, dieldrin and paraquat in rats fed on protein diet.

Carbaryl was well absorbed from the small intestine of rats. In the cytosol fraction of intestinal mucosa, it was bound to a smallmolecular component (M. W. 2,200 daltons). In serum, carbaryl was bound mainly to albumin and partly to globulins. Dieldrin was slowly absorbed from small intestine. The peak of dieldrin concentration in blood was observed 2.5 hr after the administration. Binding of dieldrin to mucosal protein in cytosol was not detectable. In serum, dieldrin was bound to lipoproteins, globulins and partly to albumin. Absorption of paraquat from the small intestine was more rapid than that of dieldrin in situ study. However, in vivo study, the absorption of paraquat was the lowest among these three chemicals. In the cytosol fraction of intestinal mucosa, paraquat was bound to a small-molecular component (M. W. 3,100 daltons). In serum, it was present in unbound fraction. In the comparative studies with protein diets, absorption of paraquat from small intestine in situ was higher in low protein diet rats than that in high protein diet rats. However, difference in absorption in vitro and in histopathological study was not noted between low protein diet rats and high protein diet rats.

Animals↗
PubMed1981

[Determination of hydrophobic parameters (log PHPLC) for methacrylates, initiators and miscellaneous compounds used in dentistry by high-performance liquid chromatography (HPLC) (author's transl)].

The use of partition coefficients Poct obtained from an n-octanol-water partitioning system has become a standard method for modelling biological membranes and thereby quantifying the hydrophobicity of a given compound as log Poct = log Coct--log Cwater. However, there is no convenient method available to determine the log Poct value accurately. The conventional flask-shaking method is a laborious and time consuming procedure, often complicated by instability in aqueous media, impurities and the tendency for the compound to dissociate. There have been recently attempts using HPLC to determine the hydrophobicity of organic compound. The retention behaviour of about fifty organic compounds in HPLC systems have been examined. Using methanol-water as the mobile phase, a linear relationship between the volume fraction of organic modifier and the logarithm of the capacity factor (log K') over limited range was obtained for standards. However, unfortunately, the correlation between log Kw obtained from the extrapolated K' values with pure water as eluent and log Poct values was not good (r = 0.83). Using this octadecylsilyl column with the mobile phase (methanol: water = 70:30), standards fall on the three straight lines with good correlations (r = 0.99) between the log Poct and log K' values.: one for benzenes and aliphatic compounds, the second for phenols, anilines and hydrogenacceptor benzene derivatives and the third for benzoic acids, respectively. The PHPLC values of methacrylates, initiators and miscellaneous compounds which are widely in dentistry were determined using these three regression lines.

Acrylates↗
PubMed1980

Effect of captopril, a converting enzyme inhibitor on renal vascular resistance in pentobarbital anesthetized dogs.

The effects of captopril administered intravenously in a dose of 1 mg/kg on systemic blood pressure (SBP), renal blood flow (RBF) and renal vascular resistance (RVR) were examined in pentobarbital anesthetized dogs. Untreated dogs were used in experiments in which the renal artery remained intact and others in which the renal artery was partially occluded (RAO). Captopril significantly decreased SBP, increased RBF and decreased RVR in untreated dogs. RAO induced an increase in arterial plasma renin activity and this increase was accompanied by an increase in RVR in the contralateral kidney and rise in SBP. During RAO, captopril induced qualitatively similar, but greater decreases in SBP and RVR of the contralateral kidney compared with those in the untreated dogs. These results suggest the vasodilator effect of captopril depends on the background level of angiotensin II and the enhanced effect would be expected under conditions such as RAO where circulating angiotensin II contributes to vascular tone.

Anesthesia↗
PubMed1980

Distribution and biliary excretion of carbaryl, dieldrin and paraquat in rats: effect of diets.

Carbaryl and dieldrin were accumulated mostly in the liver, and paraquat was accumulated in the kidney of normal diet (casein 24.5%) rats at 1 hr after the oral administration. At 5 hr after the administration, the concentration of carbaryl in liver or fat, and that of paraquat in kidney were markedly decreased. However, dieldrin in liver, kidney, lung, fat or others was signficantly increased at the same period. The absorption of paraquat from gastrointestinal tract was the least among the chemicals used. Biliary excretion of carbaryl was the highest and that of paraquat was the least by 5 hr after intravenous administration. The excretion ratio was about 100: 10: 1 for carbaryl, dieldrin and paraquat in normal diet rats. Biliary excretion of these chemicals was higher in high protein diet (casein 45%) rats and retention of the chemicals in tissue was higher in low protein diet (casein 5%) rats.

Animals↗
PubMed1979

[Analysis of eluate extracted from dental filling resin by high performance liquid chromatography (author's transl)].

Since the residual monomer of cured filling resin has been implicated in toxicological effects, a high performance liquid chromatography (HPLC) was used to analyze the eluate of bisphenol A diglycidylmethacrylate (Bis-GMA) and methyl methacrylate (MMA) type resins presently used. The main chemicals of the eluate from resin into three kinds of solution, water, 85% methanol water solution and 100% methanol were the residual monomers which formely were Bis-GMA, triethylenglycol dimethacrylate and latterly MMA. Residual initiators, benzoyl peroxide and hydroquinone were also determined. This investigation has shown that HPLC is rapid, reliable and an acurate method to analyze the residual monomers of cured dental filling resins.

Chromatography, High Pressure Liquid↗
PubMed1979

[The in vitro biological evaluation of dental cements using elution and binding by bovine serum albumin (author's transl)].

In order to evaluate in vitro biological properties of dental cements sixteen different cements including zinc oxide eugenol (ZOE), EBA, resin, polycarboxylate, glass ionomer cement and calcium hydroxide base material were tested regarding elution and binding by bovine serum albumin (BSA). The persistency of elution over long time after subsequent transfer to fresh water was calculated at 210 nm absorbance with ultra violet spectrometer. Also the eluates obtained were analyzed by high performance liquid chromatograpy. The continuous leaching of eugenol from ZOE cement was observed. Binding of eluates from cement to BSA was evaluated spectrophotometrically by utilizing the competition with 2-(4' hydroxyphenylazo) benzoic acid (HABA). EBA cement showed the highest binding ability by BSA because of the leaching o-ethoxybenzoic acid from this cement. The relevance of protein and pulp toxicity is discussed.

Animals↗