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Biomedical subjects

F Tanaka

Publications and source records attributed to F Tanaka.

At least 253 records · Page 14Linked to original sources
PubMed1985

Industrial exposure to organophosphorus compounds. Studies of a group of workers with a decrease in esterase-staining monocytes.

When an automated counting instrument using an esterase stain was employed, decreased monocyte counts were observed in a group of process workers exposed to organophosphate esters. Their monocyte counts were not found to be depressed with manual counting or with an automated counter using another staining method. The apparent depression was transient. In these workers and a comparison group, theoretical adverse consequences of decreased monocyte esterase and also possible changes in other esterases were explored. No anergy was seen with mumps or staphylococcal phage lysate hypersensitivity skin tests. Histology of the mumps reaction was similar in both groups. The depressed monocyte counts were significantly associated with a mild reduction in erythrocyte cell acetylcholinesterase, but no reduction was seen in plasma pseudocholinesterase or lymphocyte neurotoxic esterase.

Adult↗
PubMed1985

[Cefmenoxime concentrations in human blood, bile and gallbladder in administration before surgery].

The pharmacokinetics of cefmenoxime (CMX) were studied in 13 patients with cholecystolithiasis, 6 male and 7 female, ranging from 27 to 69 years of age. All patients received a single intravenous dose of CMX 2 g given in a drip infusion over 30 minutes. The level of CMX in gallbladder tissues fell from 350 +/- 101 micrograms/g (mean concentrations, 2.7 hours after administration) to 68 +/- 13 micrograms/g by 7.2 hours. In bile, the mean concentrations of CMX, 2,595 +/- 624 micrograms/ml were reached at 2.7 hours after administration, and at 7.2 hours the mean concentrations were 103 +/- 60 micrograms/ml. In the study reported here, a single 2 g dose of CMX was administered intravenously, and high concentrations of CMX in gallbladder tissue and bile were reached at 2.7 hours after administration. These results suggested that the administration of CMX at about 2.5 hours before surgery might be most effective for prophylaxis.

Adult↗
PubMed1985

Inflammatory mediators and modulators released in organ culture from rabbit skin lesions produced in vivo by sulfur mustard. I. Quantitative histopathology; PMN, basophil, and mononuclear cell survival; and unbound (serum) protein content.

When applied topically to the skin of rabbits in vivo, sulfur mustard (SM), the vesicant used in World War I, produced a slowly developing inflammatory response, which peaked in size at 1 and 2 days, ulcerated within 3 days, and reepithelialized by 10 days. Histologically, basophils and polymorphonuclear leukocytes (PMNs) were common in both early and late lesions, and the crust over the ulcers was composed of dead epidermal cells, fibrin, and large numbers of PMNs. Healing occurred under the crust by migration of epidermal cells from the margins of the lesions and from the hair follicles. In organ culture, the lesion explants survived well, and reepithelialization even took place. Their excellent survival enabled us to compare the life spans of the infiltrating leukocytes within an inflammatory site. PMNs within the explants began disappearing during the first day of culture, and almost all had disappeared by 3 days. In contrast, over half of the basophils and the mononuclear cells within the explants were still present after 3 days of culture. The 1-, 2-, 3-, 6-, and 10-day (1.0-sq cm) SM lesion biopsies showed a 30-45% increase in weight (when compared with normal skin), presumably due to the extravasation of serum proteins and the fluids retained by them. When the biopsies were organ-cultured for 3 days, the 1-, 2-, and 3-day lesions lost weight, and the 6- and 10-day lesions (and normal skin) gained weight. These weight differences were not due to the amount of unbound protein extractable into the culture fluids, because both the early lesions and the late lesions contained about the same amount of unbound protein. The most likely explanation for these weight differences is that the newly formed ground substances of late lesions absorbed culture fluid, because the ground substance had changed from the sol state of acute inflammation (in which it was extractable) back to its normal gel state (in which it was not extractable). The unbound protein extractable into the culture fluids was mostly of serum origin. This protein averaged 1.9 mg for 1.0 sq cm normal skin explants (with a mean weight of 215 mg), and 6.4 mg for 1-day SM lesions (with a mean weight of 313 mg). Because rabbit serum contains about 60 mg protein/ml, these figures indicate that normal skin contained about 15% (unbound) serum by weight.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Inflammatory mediators and modulators release in organ culture from rabbit skin lesions produced in vivo by sulfur mustard. II. Evans blue dye experiments that determined the rates of entry and turnover of serum protein in developing and healing lesions.

Extravasated serum seems to be the major modulator of the local inflammatory response, because it provides both proinflammatory and antiinflammatory components. This report describes the rates of entry and turnover of extravasated serum protein in dermal inflammatory lesions produced by the military vesicant sulfur mustard (SM). Rabbits, bearing SM skin lesions, were given an intravenous injection of Evans blue dye, so that at the time of sacrifice, 2 hours later, their skin lesions were 2 hours and 1,2,3,6, and 10 days of age. Evans blue labels serum albumin, a representative serum protein. By multiplying the amount of Evans blue contained in the lesions by a factor that converted micrograms of Evans blue into milligrams of serum protein, the authors could estimate the 2-hour rate of entry of serum protein into these lesions. Serum protein in the lesions was both bound and unbound. The unbound protein was extractable from the lesions into the culture fluids, and, electrophoretically, was similar in composition to serum protein. Grossly edematous peak lesions (1 day of age) contained 7.8 mg of unbound serum protein per square centimeter of skin. Healing lesions (6 and 10 days of age) contained about 4.5 mg/sq cm, and normal skin about 1.7 mg/sq cm. Lesions 1 day of age had the highest rate of serum albumin entry, and about 36% of this Evans-blue-labeled protein was unbound, ie, extractable into the culture fluids. Lesions 3 and 6 days of age had a rate of serum albumin entry that was roughly half that of 1-day lesions, and only about 13% of this entering protein was unbound. Normal skin had a very low rate of serum albumin entry, and only 8% of this entering protein was unbound. The turnover rate of the unbound (extractable) serum protein could be estimated from the 2-hour entry rate of the Evans-blue-labeled albumin and the total protein in the culture fluids. In 1-day lesions, about 25% of the serum protein in the culture fluids was protein which had entered during the last 2 hours, so that 100% of this unbound protein should have been replaced once in 8 hours. In contrast, in 3- and 6-day lesions, this unbound serum protein should have been replaced once in about 35 hours, and in normal skin once in 80 hours. Evans-blue-labeled serum albumin continuously entered both the bound and unbound compartments of the SM lesions, even during the healing stages.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Mepacrine-induced inhibition of human platelet cyclic-GMP phosphodiesterase.

The effect of mepacrine (DL-quinacrine-HCI), a specific inhibitor of phospholipase C, on cyclic-GMP levels in human platelets was investigated. The concentrations of mepacrine producing 50% inhibition of human platelet aggregation induced by 5 microM ADP and 3 micrograms/ml of collagen were 50 +/- 8 and 70 +/- 15 microM, respectively. Addition of mepacrine to human platelet suspension resulted in increases in cyclic GMP. In contrast to cyclic-GMP levels, cyclic-AMP content was not affected by mepacrine. Mepacrine did not stimulate guanylate cyclase, but did specifically inhibit human platelet cyclic-GMP phosphodiesterase, separated from cyclic-AMP phosphodiesterase or other forms of phosphodiesterase on DEAE-cellulose columns. Stimulation by cyclic GMP of human platelet cyclic-GMP-stimulated cyclic-AMP phosphodiesterase activity was not inhibited by mepacrine. The IC50 value of the drug for cyclic-GMP phosphodiesterase was 40 microM, and IC50 for cyclic-AMP phosphodiesterase was 1.2 mM. Mepacrine was 30-times more potent as an inhibitor of human platelet cyclic GMP than of cyclic-AMP phosphodiesterase. Mepacrine blocks arachidonate release from human platelets by inhibiting phosphatidylinositol-specific phospholipase C. The increase in cyclic-GMP levels produced by addition of mepacrine will explain part of the pharmacological action of this drug.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1984

Immunosuppressive factors in ascites fluids from ovarian cancer patients.

The nonspecific immunosuppressive effect of ascites fluids from ovarian cancer patients was examined and compared with that of noncancerous abdominal effusion and sera from ovarian cancer patients. The malignant ascites fluids produced a noncytotoxic, dose-dependent suppression of DNA synthesis of phytohemagglutinin-stimulated human peripheral blood lymphocytes. The suppression was higher than that observed in sera from cancer patients. No suppressive effect was seen in control abdominal effusion. The factors responsible for inhibition of in vitro lymphocyte function were partially purified from ascites fluid by lentil lectin affinity chromatography and gel filtration. Major active factors had a high molecular weight (440-1500 kilodaltons), an affinity to lentil lectin, and were stable against heat and acid treatment.

Ascitic Fluid↗
PubMed1984

[Clinical evaluation of dynamic renoscintigraphy using 99mTc-DTPA in practical urology. I. Diagnosis of ureteral calculi, cystic kidney and hydronephrosis].

Clinical usefulness of the renoscintigraphy using 99mTc-DTPA in practical urology was investigated for two years. 99mTc-DTPA injection and injectable preparation kit (supplied by Nihon Medi-Physics Co.) were used. The dynamic blood flow of the renal parenchyma could be detected from serial images and curves on the perfusion phase. Information of clear nephrogram and function of the upper urinary tract could be obtained from serial images and renogram. Separate and total renal function could be evaluated. This method of examination is evaluated as very safe, because no side effects were produced and radiation dose is low. This examination may be a useful tool and the first choice in practical urology.

Adolescent↗
PubMed1983

Picosecond laser fluorometry of FAD of D-amino acid oxidase-benzoate complex.

Formation of a complex of D-amino acid oxidase (D-amino acid:O2 oxidoreductase (deaminating), EC 1.4.3.3) and benzoate, an enzyme-substrate complex model, was studied by measuring the fluorescence life-time of the coenzyme FAD of the complex by using a mode-locked Nd:YAG laser and a streak camera. The value of lifetime was 60 +/- 10 ps in the monomer of the complex and it was extremely short (much less than 5 ps) in the dimer of the complex. Since the values of fluorescence lifetime of the coenzyme are 130 ps in the monomeric form of free enzyme and 40 ps in the dimeric form of free enzyme, the decrease in the lifetime upon complex formation with benzoate is slight in the monomer (reduced to one-half) whereas marked in the dimer (reduced to less than 1/10). By analyzing the fluorescence decay curve, a dissociation constant of the monomer-dimer equilibrium of the complex was evaluated to be 0.4 +/- 0.3 microM, which is much smaller than that in free enzyme. Fluorescence analysis under steady state excitation revealed that the apparent dissociation constant (K) of FAD from the enzyme was decreased by 1:1000 upon the complex formation. Relative quantum yield of the fluorescence of FAD in the complex to that of free FAD exhibited appreciable dependence on the complex concentration: greater in the monomer and less in the dimer. These results suggest that a molecular interaction between FAD and amino acid residue(s) is strengthened by the complex formation, which contributes to a remarkable conformational change in the protein moiety of the complex.

Benzoates↗
PubMed1983

Methylation of 1-, 3-, 7-, 9-, and N6-methyladenines bearing a methoxyl group at the N6-position: a synthesis of 7,9-dimethyladenine.

The effect of the N6-methoxy group on regioselectivity in methylation of all five possible isomers of N-methyladenine has been investigated. The methoxyl group attached to all these isomers orients methylation to a considerable extent to nitrogen(s) in the same pyrimidine or imidazole moiety that the original N-methyl group is attached to. On the basis of the results of the present methylation study, 7,9-dimethyladeninium perchlorate has been synthesized from 7- or 9-methyl-N6-methoxyadenine.

Adenine↗