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Biomedical subjects

T Fujino

Publications and source records attributed to T Fujino.

At least 181 records · Page 10Linked to original sources

Determination of the O/M ratios of polynary uranium oxides by Ce(IV)-Fe(II) back titration after dissolution in mixed sulphuric and phosphoric acids.

Uranium (IV) in polynary uranium oxides is determined after the solid has been dissolved in a warm mixed solution of sulphuric and phosphoric acids containing excess Ce(IV). The latter is titrated with a Fe(II) standard solution using ferroin as indicator. This method is especially effective for (mixed) uranium oxides which are difficult to dissolve in hot Ce(IV) sulphuric acid. The standard deviation of the determined x value in polynary oxides is estimated to be below +/- 0.004 for samples of 10-30 mg.

Journal Article↗

Production of interleukin 10 during malaria caused by lethal and nonlethal variants of Plasmodium yoelii yoelii.

We investigated the induction of T-helper cell subsets during the course of lethal or nonlethal bloodstage Plasmodium yoelii 17X infection in C57BL/6 mice, which are relatively susceptible to these intraerythrocytic parasites. C57BL/6 mice infected with the nonlethal variant (PyNL) showed a moderate level of parasitemia and resolution of primary acute infection by week 4. Mice infected with the lethal variant (PyL) developed fulminating parasitemia and ultimately died. T-helper subset function was assessed during infection by determining the kinetics of in vitro production of the Th1-derived cytokine interferon-gamma (IFN-gamma) and the Th2-derived cytokine interleukin 10 (IL-10) by means of bioassay and enzyme-linked immunosorbent assay (ELISA), respectively. Spleen cells obtained from mice infected with PyL within the 1st week of infection produced high levels of IL-10 and IFN-gamma in response to malaria antigen. IL-10 also appeared in sera from PyL-infected mice at the same time at which the in vitro IL-10 response peaked. In contrast, spleen cells from mice infected with PyNL failed to produce IL-10 during the course of infection. CD4+ T-lymphocytes from mice infected with the lethal variant were a major source of IL-10, although non T-cells were also involved in the production of IL-10 during this malaria infection. In addition, the initial burst of IL-10 in response to malaria antigens was seen concomitantly with the production of IFN-gamma within the 1st week of infection. These results indicate that both Th1 and Th2 subsets of T-helper lymphocytes are activated during infection with the lethal variant of P. yoelii and support the contention of other investigators that a strong Th2 response early in infection is associated with the lethal outcome of malaria.

Animals↗

Immunogenicity of Leucocytozoon caulleryi sporozoites and their reactivity with specific immune sera.

The immunogenicity of Leucocytozoon caulleryi sporozoites for chickens and their reactivity in vitro with specific immune sera were studied. Almost all of the chickens that had been immunized with the sporozoite antigens survived the sporozoite challenge. The degree of parasitemia observed in the immunized chickens was significantly lower than that found in the nonimmunized chickens. Specific antibodies against sporozoites were tested by the circumsporozoite precipitation (CSP) reaction. Antibodies were demonstrated in the sera of chickens that had been immunized with the sporozoite antigens or chickens that had recovered from a primary infection with L. caulleryi sporozoites. When viable mature sporozoites were incubated in vitro with serum from immune chickens, agglutination and a long, thread-like precipitate at one end of the sporozoite could be seen within a few minutes under a phase-contrast microscope. The effects of specific immune serum on the infectivity of sporozoites were examined by the sporozoite neutralization activity (SNA) test. Sporozoites that had been incubated in vitro with serum from immune chickens lost their infectivity to chickens. The CSP reaction and the SNA test in L. caulleryi infection were stage- and species-specific.

Animals↗

Rapid expulsion of the intestinal trematodes Echinostoma trivolvis and E. caproni from C3H/HeN mice after infection with Nippostrongylus brasiliensis.

The number of goblet cells in the small intestines of C3H/HeN mice increased rapidly following their infection with about 500 third-stage larvae (L3) of the intestinal nematode Nippostrongylus brasiliensis. The number of goblet cells reached its peak on day 9 postinfection (p.i.). Worm burdens in the hosts' small intestines were determined following a challenge infection with encysted metacercariae of the intestinal trematodes Echinostoma trivolvis or E. caproni on days 8 and 16 after primary infections with N. brasiliensis. All metacercariae of E. trivolvis or E. caproni used to challenge the hosts on day 8 p.i. were expelled. Considerable numbers of E. trivolvis (48.6%) and E. caproni (67.1%) remained in the intestines of hosts challenged with these echinostomes on day 16 p.i. All the controls used for E. trivolvis and E. caproni infections without primary infections with N. brasiliensis showed recovery rates greater than 70%. An enzyme-linked immunosorbent assay (ELISA) showed that the IgM titer rose remarkably and plateaued on day 11 p.i. No marked rise in the IgG or IgA titer occurred during the experiment. These results indicate that mucins increased by hyperplastic goblet cells associated with primary infections with N. brasiliensis are responsible for a rapid expulsion of the worms of the challenge infection with E. trivolvis or E. caproni from the mouse host.

Animals↗

Rapid expulsion of the intestinal trematodes Echinostoma trivolvis and E. caproni from C3H mice by trapping with increased goblet cell mucins.

Echinostoma trivolvis (Cort, 1914) adults were rejected from C3H mice by 15 days post-exposure, corresponding to the increase in the number of goblet cells. Homologous and heterologous infections with the allopatric species E. caproni (Richard, 1964) were used to confirm the effect of increased secretion of goblet cell mucins in rejecting metacercariae of challenge infections of E. trivolvis or E. caproni on days 10, 16 and 20 p.i. after primary infections of E. trivolvis metacercariae. Five-day-old juveniles of E. trivolvis and E. caproni, which were recovered from C3H mice or hamsters, were also used for challenge infections on day 10 p.i. The metacercariae and juveniles, which were challenged homologously and heterologously on day 10 p.i., were almost all expelled. The metacercariae of E. trivolvis, which were challenged homologously on day 16, were completely rejected, but only a few challenged metacercariae of E. caproni in heterologous infection were recovered. Considerable numbers of E. caproni were recovered when challenge infections with the metacercariae were done on day 20 p.i., while only a small number of E. trivolvis was recovered. All controls without primary infections showed a recovery rate of over 50% of the worms. These results indicate that increased secretion of mucins by hyperplastic goblet cells associated with primary infections of E. trivolvis may be responsible for the expulsion of worms challenged homologously with E. trivolvis and heterologously with E. caproni from the mouse host.

Animals↗

Two types of parenchymal cells in the lung fluke Paragonimus ohirai (Digenea: Troglotrematidae) characterized by the cytochemistry of their mitochondria.

Morphology and respiratory function were studied in situ and in the isolated mitochondria of Paragonimus ohirai. Two types of parenchymal cells (i.e., Pc1 and Pc2 cells), whose mitochondria differ in terms of morphology and staining for cytochrome c oxidase activity, were found in fluke tissues. Enzymatic and spectrophotometric analyses of the isolated mitochondria showed that fluke mitochondria possess both aerobic and anaerobic respiratory chains. These results suggest that there are two mitochondrial populations in fluke parenchymal cells, one possessing an aerobic respiratory chain and the other an anaerobic respiratory chain.

Animals↗

Attenuation of Eimeria caviae by selection for precocious development.

An attenuated line of Eimeria caviae was produced by selection for early maturation of oocysts during serial passage in guinea pigs. The prepatent period of the parasite was reduced from 11 to 6 days. Parasites of the precocious line and the parent strain were found in the crypts of the epithelial cells of caecum and colon and were morphologically indistinguishable. The period of development of type I, type II and type III merozoites of the E. caviae precocious line in guinea pigs was similar to that of the parent strain until the 3rd day. The time of the transition from gametocytes to oocysts was 2 days in both the precocious line and the parent strain. The maximum number of oocysts per gram of faeces and the pathogenicity of the precocious line were less than those of the parent strain.

Aging↗

The expulsion of Echinostoma trivolvis from C3H mice: differences in glycoconjugates in mouse versus hamster small intestinal mucosa during infection.

Mucosal glycoconjugates were examined in C3H mice and in hamster small intestines infected with Echinostoma trivolvis and in uninfected rodents, using periodic-acid Schiff (PAS) and high-iron diamine-alcian blue (HID-AB) staining and three different fluorescein-conjugated lectins: Triticum vulgaris agglutinin (WGA), Helix pomatia agglutinin (HPA) and Griffonia simplicifolia agglutinin (GSA-II). Lectin-labelling by electron microscopy was also undertaken with WGA and HPA lectin-gold probes. HID-AB stain demonstrated that the most mature goblet cells of the mouse villi contain sulfomucins, whereas those of hamsters contain sialomucins. The expression of lectin-binding sites and the intensity of the lectin binding in the small intestines were changed by echinostome infection. Specific differences in the reaction to mucin glycoproteins were clearly observed between the mouse and hamster intestines infected with E. trivolvis; lectin-binding to hyperplastic goblet cells and crypts in the infected mice increased, while no marked increase in the number of goblet cells and reaction to the glycoconjugates were observed in the infected hamsters. These findings indicate that the expression of terminal N-acetyl-D-galactosamine, sialic acid and N-acetyl-D-glucosamine increased in mucins secreted from hyperplastic goblet cells associated with E. trivolvis infection in mice. No marked increase in these glycoconjugates occurred in hamster infections. These findings reflect clear differences in infectivity of E. trivolvis in C3H mice versus hamsters.

Animals↗

The expulsion of Echinostoma trivolvis: suppressive effects of dexamethasone on goblet cell hyperplasia and worm rejection in C3H/HeN mice.

C3H/HeN mice were infected with Echinostoma trivolvis metacercariae on day 0, given intramuscular injections of dexamethasone daily for 5 or 7 days, and necropsied on days 5, 8, 12, 15, 20 and 30 p. i. Controls consisted of mice that were infected with echinostomes, but were not treated with dexamethasone. Dexamethasone treatment caused a delay in worm expulsion from the small intestine of the hosts, and the increase in goblet cell numbers that occurred in untreated mice was markedly delayed in the treated mice. Mast cell number in the small intestine increased rapidly from just after day 5 p. i. and reached a peak on day 15 p. i. in both dexamethasone-treated and control mice, although the increase in cell numbers was delayed slightly in the dexamethasone-treated mice. The eosinophil number in the small intestine of dexamethasone-treated mice was suppressed until 8 days p. i. and then increased reaching a peak on day 12 p. i., although the number was about one half that of the control. As determined on day 12 p. i., the mean body area of worms from dexamethasone-treated animals was significantly greater than that of the controls. Histological examination of the small intestine showed that the goblet and Paneth cell hyperplasia seen in mice infected with E. trivolvis was suppressed by dexamethasone treatment. Transmission electron microscopy revealed no marked ultrastructural differences in the small intestine of the dexamethasone-treated and control mice except that the former had an increased number of intracristal granules in mitochondria, an increase in vesicles in the apical epithelial cells and an increase in amorphous bodies and autophagic vacuoles in the Paneth cells. These results indicate that dexamethasone treatment delayed the expulsion of E. trivolvis from the small intestine of the host mouse in association with the suppression of goblet cell hyperplasia and increase in the number of mast cells and eosinophils.

Animals↗

Inhibition of microbial growth by ajoene, a sulfur-containing compound derived from garlic.

Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad-spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacterium smegmatis, and Streptomyces griseus, was inhibited at 5 micrograms of ajoene per ml. Staphylococcus aureus and Lactobacillus plantarum also were inhibited below 20 micrograms of ajoene per ml. For gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Xanthomonas maltophilia, MICs were between 100 and 160 micrograms/ml. Ajoene also inhibited yeast growth at concentrations below 20 micrograms/ml. The microbicidal effect of ajoene on growing cells was observed at slightly higher concentrations than the corresponding MICs. B. cereus and Saccharomyces cerevisiae were killed at 30 micrograms of ajoene per ml after 24 h of cultivation when cultivation was started at 10(5) cells per ml. However, the minimal microbicidal concentrations for resting cells were at 10 to 100 times higher concentrations than the corresponding MICs. The disulfide bond in ajoene appears to be necessary for the antimicrobial activity of ajoene, since reduction by cysteine, which reacts with disulfide bonds, abolished its antimicrobial activity.

Anti-Bacterial Agents↗

Caffeine induces ventricular tachyarrhythmias possibly due to triggered activity in rabbits in vivo.

Caffeine induces delayed afterdepolarizations (DADs) and triggered activity in isolated cardiac tissue. We investigated the ability of caffeine to induce triggered ventricular arrhythmias in rabbits in vivo. During continuous infusion of caffeine at doses of 0.3 or 1.0 mg/kg per min, ventricular pacing was performed with 50 stimuli with a cycle length of 220 msec (basic pacing train) every 5 min until ventricular tachycardia (VT) was induced. The effects of programmed stimulation and pharmacologic agents on the induction of ventricular ectopic beats (VEBs) were examined. Pacing protocols were carried out in the presence of vagal-induced slowing of sinus rhythm. VT was induced by a basic pacing train during the infusion of caffeine at 1.0 mg/kg per min, but not at 0.3 mg/kg per min. An increase in the pacing rate or the number of stimuli resulted in 1) a decrease in the first postpacing interval, and 2) an increase in the number of postpacing VEBs. Induction of VT was suppressed by intravenous bolus injections of verapamil, propranolol and adenosine. At the time of the initial induction of VT, the plasma concentration of caffeine was 87 +/- 2 micrograms/ml and the plasma level of norepinephrine increased from 666 +/- 166 pg/ml at baseline to 1121 +/- 245 pg/ml. These results suggest that catecholamine-associated triggered activity may be responsible for caffeine-induced VT.

Animals↗

Antimutagenic effects of ajoene, an organosulfur compound derived from garlic.

The antimutagenic effects of ajoene, which is an organosulfur compound derived from garlic, were investigated by the Ames test. Ajoene inhibited mutagenesis induced by both benzo[a]pyrene (B[a]P) and 4-nitro-1,2-phenylenediamine (NPD) in a dose-dependent manner. In particular, NPD-induced mutagenesis was more effectively suppressed by ajoene than the B[a]P-induced type. Furthermore, the inhibition of mutagenesis by ajoene was more effective for transition-type mutations than for the frame shift type. HPLC analysis of B[a]P metabolism in the presence of the rat liver microsomal fraction (S-9) showed that ajoene dose-dependently inhibited the metabolic activation of B[a]P. This suggests that ajoene affected the metabolic enzymes in the S-9 fraction.

Animals↗

[A case of mitochondrial encephalomyopathy (MELAS)].

Mitochondrial encephalomyopathy is a hereditary syndrome showing impairment of muscle and the central nervous system. In this disorder, the following three syndromes have been identified on the basis of characteristic symptoms: Kearns-Sayre syndrome (KSS), mitochondrial encephalomyopathy with lactic acidosis, and stroke-like episodes (MELAS), and myotonic epilepsy with ragged-red fibers (MERRF). In this report, we describe a case of mitochondrial encephalomyopathy with renal disease. A 25-year-old man was referred to our hospital in May, 1992 for evaluation of long-standing proteinuria. He had a small stature, exotropia and no pretibial edema. No mental retardation was observed. Urinary protein excretion was 2.0 g/day and urine sugar was negative. Laboratory examination revealed a serum urea nitrogen 19 mg/dl, and a creatinine value of 1.5 mg/dl. Creatinine clearance was 45.8 ml/min. His serum and spinal fluid lactate value were elevated. Biopsied muscle showed an absence of ragged-red fibers, and the presence of an A-to-G point mutation at nucleotide pari 3243 in the mitochondrial tRNA(Leu(UUR)) in peripheral blood leucocytes. He was thought to have MELAS. On the renal biopsy specimens, light microscopic examinations showed minor glomerular abnormalities with two glomerular collapses and tubulo-interstitial damage. Electron microscopic examinations showed partial thickening of the glomerular basement membrane. We report here this rare case of MELAS with renal disease, and also review seventeen cases of mitochondrial encephalopathy associated with renal disease. The existence of a relationship between mitochondrial disorder and renal damage remains obscure.

Adult↗

[An analysis of pelvic and para-aortic lymph node metastasis in ovarian carcinoma by systematic retroperitoneal lymph node dissection].

We performed a systematic retroperitoneal lymph node dissection (RPLND) on 137 patients with primary ovarian carcinoma, of whom 97 had undergone RPLND during the primary surgery before chemotherapy and 40 had undergone RPLND during the secondary cytoreductive surgery after preoperative chemotherapy. The tentative staging of the ovarian carcinoma used in this study was determined according to the FIGO criteria without considering the pathologic findings of retroperitoneal lymph nodes. Nodal metastasis was seen in 21.9% (30/137) of them. Thirteen had positive pelvic lymph nodes (PLN) but no positive para-aortic nodes (PAN). Eleven had both positive PLN and positive PAN. Six had positive PAN but no positive PLN. The PAN was the most frequent site of metastasis (17/137). Next were the common iliac, obturator, and lateral group of deep inguinal nodes. Solitary metastasis in the patients who had undergone RPLND during the primary surgery was seen in a PAN and a common iliac node. Among 24 patients with PLN metastasis, there was a significant (p < 0.05) difference in the number of positive PLN between the patients with PAN metastasis (5.27 +/- 3.00) and the patients without PAN metastasis (2.62 +/- 1.66). These results indicate that the PAN and common iliac nodes are the most important site of nodal metastasis in ovarian carcinoma. The metastasis to PLN such as obturator node and internal iliac node seems to occur independently of the PAN metastasis, and the PAN metastasis occurs not only through the direct route but also as a consequence of extension of PLN metastases. Systematic retroperitoneal lymph node exploration therefore seems to be necessary to clarify the lymph node status.

Aorta↗

[Detection of rifampicin-resistant strains of Mycobacterium tuberculosis by a non-radioactive PCR-SSCP method].

PCR-SSCP method to detect genetic mutations in rpoB gene as a marker of rifampicin-resistance was developed by Telenti et al., and we have modified it applying non-radioactive PhastSystem for more practical use in the detection of rifampicin-resistance of Mycobacterium tuberculosis. PCR products amplified with the primers specific to rpoB gene using extracted DNA from 89 strains of M. tuberculosis were sequenced and the amino acid sequences were morphism was determined by the PhastSystem. The bands were stained by silver staining. Among 89 strains of M. tuberculosis, 43 were confirmed as rifampicin-resistant (RFPr) and 46 were rifampicin-sensitive (RFPs) by the culture on the drug-containing media. All of the 43 RFPr strains had one or more mutations in the DNA sequence of rpoB gene, while none of the RFPs strains had such mutations. However, by PCR-SSCP, only 20 out of 43 RFPr strains showed clear differences in the band pattern of electrophoresis from that of RFPs strains. Other 23 RFPr strains had only slight differences in the band pattern of the PCR-SSCP from that of RFPs strains. But it was noticed that the main bands of RFPr strains were distinguishable from the main bands of RFPs strains even their patterns were similar. Thus, it is possible to apply a non-radioactive PCR-SSCP for the detection of rifampicin resistance of M. tuberculosis with further improvement of the condition of gel electrophoresis or staining techniques.

Amino Acid Sequence↗

[Detection of Mycobacterium tuberculosis in clinical specimens other than sputum by the Mycobacterium Tuberculosis Direct Test (MTD)--assessment of sample preparation methods and clinical evaluation].

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) has been widely used as a rapid test for the identification of Mycobacterium tuberculosis complex in clinical samples, and several research groups have verified its clinical usefulness. However, most of the specimens they tested were sputum, and there have been few reports on other specimens. In particular, there have been no reports on assessments of methods of preparing samples other than sputum for the MTD. We assessed methods of preparing samples other than sputum and the influence of a local anesthetic and an anticoagulant that may be present in samples, and also evaluated the MTD as a means of detecting M. tuberculosis in pleural fluid, bronchial lavage cerebrospinal fluid, urine and ascitic fluid. 1. Assessment of three sample preparation methods, i.e., the NALC-NaOH method GuSCN-Diatom nucleic acid extraction method, and the ultrasonication method, revealed that the combination of the NALC-NaOH method and the ultrasonication method, widely used to prepare sputum samples, is also a valid method of preparing other samples. 2. The local anesthetic and the anticoagulant used clinically and remained in specimens did not affect the results of the MTD. 3. Seven (36.8%) of 19 pleural fluid samples from patients diagnosed as tuberculous pleurisy were positive of M. tuberculosis by the MTD, while five (27.8%) of 18 pleural fluid samples cultured for bacteria were positive for M. tuberculosis complex. None of the 20 pleural fluid samples from patients diagnosed as non-tuberculous pleurisy were positive for M. tuberculosis complex either by MTD or culture. 4. Eight (32.0%) of 25 bronchial lavage samples from patients diagnosed as pulmonary tuberculosis were positive for M. tuberculosis complex by the MTD, while 3 (12.0%) were positive by culture. None of the 18 bronchial lavage samples from patients diagnosed as non-tuberculous disease were positive for M. tuberculosis complex either by the MTD or culture. Based on these results, it is concluded that the MTD is a very useful method of detecting M. tuberculosis in clinical samples other than sputum because it is more sensitive than culture on Ogawa's egg medium in detecting M. tuberculosis complex in pleural fluid samples, bronchial lavage samples, and so on, with the same preparation method as used for sputum.

Bacteriological Techniques↗

[Factors predictive of early mortality after acute myocardial infarction].

OBJECTIVES: (1) To define the clinical and laboratory findings predictive of early mortality after myocardial infarction (AMI), 100 consecutive patients were studied. (2) To elucidate the serum potassium (K) concentration and its clinical significance after AMI, 38 patients were studied. RESULTS: (1) The 30-day mortality was greater for women than for men, for patients with diabetes mellitus than for those without, and for patients with previous MI than for those without. Clinical and laboratory findings predictive of early mortality were cardiogenic shock, congestive heart failure, perforation or rupture of the ventricle, and presence of bundle branch block and extensive anterior AMI on electrocardiogram. The presence of bradyarrhythmia, ventricular tachyarrhythmias, and high blood levels of peak creatinine phosphokinase (CPK) or myosin or atrial natriuretic peptide (ANP) were not independent predictors of early mortality. Patients complicated with congestive heart failure showed higher levels of peak CPK and ANP and patients with cardiogenic shock showed higher levels of ANP. (2) Serum K concentration was lower on admission than the following days, and it showed a negative correlation with plasma epinephrine. The lower serum K was accompanied with more severe ventricular arrhythmias on 24-hour electrocardiogram. CONCLUSION: (1) Early mortality after AMI is related to left ventricular function rather than to arrhythmias. (2) Serum K is lower in the early phase of AMI and is related with plasma catecholamines and severe ventricular arrhythmias.

Aged↗

[Effects of exercise on mitral regurgitation in healthy subjects].

Transthoracic echocardiography including color Doppler echocardiography and graded exercise (supine bicycle ergometer) were performed to examine both the changes of mitral regurgitation (MR) flow during exercise and the effects of cathecholamine on the MR flow in 20 young males (mean age 19 years) and 9 male long-distance runners (mean age 20 years) with presumably normal hearts. MR flow was detected in 13 of the 20 young males at rest. The severity of MR was mild in 12 subjects, and moderate in 1. After exercise, MR flow vanished in 4 of the 13 subjects (group B). In the other nine subjects, MR flow lasted during and after exercise (group A). In the seven subjects without MR flow at rest, MR flow did not appear during and after exercise (group C). Group A had significantly lower left ventricular ejection fraction than group C at rest (A 64.9 +/- 4.25%, B 69.4 +/- 4.32%, C 73.9 +/- 3.46%; p < 0.05). However, no significant differences were observed in other echocardiographic parameters (including left ventricular end-diastolic dimension, mitral annulus diameter and left atrial diameter), heart rate and serum cathecholamine levels between the three groups before and after exercise. In the nine male long-distance runners, MR flow was detected in six of nine subjects at rest. The severity of MR was mild in all subjects. After exercise, MR flow vanished in two of these six subjects (group A). In the other four subjects, MR flow lasted during and after exercise (group B). In three subjects without MR flow at rest, MR flow did not appear during and after exercise (group C). There were no significant differences in echocardiographic parameters, heart rate and serum cathecholamine levels between the three groups before and after exercise. These data suggest that MR flow detected in healthy subjects correlates with tension and contractility of papillary muscle.

Adolescent↗