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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 307 records · Page 17Linked to original sources
PubMed1999

Simple and reproducible model of rat spinal cord injury induced by a controlled cortical impact device.

Consistently reproducible experimental trauma was inflicted on the rat spinal cord (L3-L4) employing a controlled cortical impact device. The spinal cord was injured with one of three sizes of chips; thick (3 mm diameter), medium (2 mm diameter), thin (1 mm diameter). Each chip was applied at 1, 2 and 3 mm deformation depths. The correlations of the magnitude of the primary trauma were examined histopathologically. It was found that the extent and intensity of the trauma could be changed by altering the depth of deformation and the chip diameter at a fixed velocity of 4.6 m per sec. The injury caused by the 2 mm diameter chip at 0.5 mm-deformation damaged one to two segments of the perifocal spinal cord. In the surviving animals, the histological changes could be classified as primary, secondary, and late phase changes, and finally the lesion became a cavity. This study reports the application of a controlled cortical impact device to morphological research on a spinal cord injury. We found that the injury by the 2 mm chip at 0.5 mm deformation was the most advantageous and reproducible model for further investigations.

Animals↗
PubMed1999

Trends in HIV and AIDS based on HIV/AIDS surveillance data in Japan.

BACKGROUND: In recent years a decline in the number of new AIDS cases has been observed in several industrialized countries. It is important to know whether these recent trends observed in North America and Europe are also occurring in Japan. METHODS: The number of people reported with HIV and AIDS by nationality, route of infection, and sex was calculated based on the HIV/AIDS surveillance data available in Japan through December 1997. The effect of reporting delay, which was defined as those HIV and AIDS cases reported in the calendar year following diagnosis, on the trends was examined. The coverage rate in reporting HIV cases was estimated as the ratio of the reported AIDS cases with prior report as an HIV-positive to the total number of reported AIDS cases. RESULTS: The cumulative number of reported cases of HIV among Japanese and non-Japanese residents of Japan up to the end of 1997 were 1,300 and 1,190, respectively. The cumulative number of reported cases of AIDS among Japanese and non-Japanese up to the end of 1997 were 758 and 298, respectively. The number of reported cases of HIV among Japanese was found to be still increasing, with the major contribution from male cases. The increasing trend in the number of reported AIDS cases among Japanese began to slow in 1996 and 1997. The number of reported cases of HIV among non-Japanese residents of Japan peaked in 1992, and has decreased since then, and remained constant after 1994. In contrast, the number of reported AIDS cases among these non-Japanese tended to increase gradually. There was a slight reporting delay for people with HIV and AIDS. The estimated coverage rate in reporting HIV cases tended to decrease in 1996 and 1997 (1/7.2, 1/10.2, respectively). We point out several reasons for this recent decline and suggest the possibility of an ostensible decline in the estimates. CONCLUSIONS: We suggest that the number of people with HIV among Japanese has continued to increase, and that the increase in the number of AIDS cases among Japanese is now slowing.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Prf, a novel Ets family protein that binds to the PU.1 binding motif, is specifically expressed in restricted stages of B cell development.

During the development of lymphocytes, expression of the Ig genes is strictly regulated in a tissue-specific manner and in a time-ordered fashion. We have previously shown that the PU.1 binding motif in the Igkappa 3' enhancer (kappaE3') and a novel Ets family protein other than PU.1 may be possibly involved in the control of V(kappa)-J(kappa) joining. In the attempt to isolate the novel Ets family protein, we have screened cDNA libraries with the yeast one-hybrid method and identified a new PU.1-related factor, Prf. This novel Ets family protein is shown to interact with the PU.1 binding sequences in various promoters and enhancers, including kappaE3'. It was found that expression of the prf gene is predominant in the B-lineage cells, with the exception of immature B cells. Since Prf does not exhibit functions of transcriptional activity, this novel protein may act as an antagonist against other Ets family proteins, e.g. PU.1 and Spi-B. Possible roles of Prf with respect to the B cell differentiation are discussed.

Amino Acid Sequence↗
PubMed1999

beta-hydroxyisovalerylshikonin inhibits the cell growth of various cancer cell lines and induces apoptosis in leukemia HL-60 cells through a mechanism different from those of Fas and etoposide.

beta-Hydroxyisovalerylshikonin (beta-HIVS), which was isolated from the plant, Lithospermium radix, inhibited the growth of various lines of cancer cells derived from human solid tumors at low concentrations between 10(-8) and 10(-6) M. When HL-60 cells were treated with 10(-6) M beta-HIVS for 3 h, characteristic features of apoptosis, such as DNA fragmentation, nuclear fragmentation, and activation of caspase-3-like activity, were observed. The most characteristic features of the effect of beta-HIVS were the remarkable morphological changes induced upon treatment of HL-60 cells with beta-HIVS, as visualized on the staining of actin filaments with phalloidin labeled with tetramethylrhodamine B isothiocyanate. Moreover, activation of MAP kinases, such as ERK2, JNK and p38, was detected after treatment with 10(-6) M beta-HIVS preceding the appearance of the characteristics of apoptosis, and the features of the activation of these MAP kinases were quite different from those of Fas and anticancer drug-induced apoptosis. The activation of JNK by beta-HIVS was not inhibited by inhibitors of caspases, suggesting that JNK is located either upstream or independent of the caspase signaling pathway. beta-HIVS did not inhibit the activity of topoisomerase II. These results indicate that beta-HIVS induces apoptosis in HL-60 cells through a mechanism unlike those reported for anti-Fas antibodies and etoposide.

Antineoplastic Agents↗
PubMed1999

Unique synthetic peptides stimulating streptolysin S production in streptococci.

A peptide has been isolated from pronase digest of bovine serum albumin as the stimulatory factor of streptolysin S (SLS) production by Streptococcus pyogenes, and its primary structure has been deduced [Akao et al. (1992) Infect. Immun. 60, 4777-4780]. To determine the essential structure for the stimulation, a peptide (P-1) having the deduced structure, in which three peptide fragments are linked by two disulfide bonds, and shorter analogs (P-2 to P-4) of peptide P-1 were chemically synthesized. Another peptide (P-5), in which Ala is inserted between the two Cys residues in the middle peptide chain of P-1, was also synthesized. These synthetic peptides were identified by mass spectrometry and analysis of amino acid compositions. The synthetic P-1 stimulated SLS production in a dose-dependent manner. Other peptide analogs also showed remarkable stimulation of SLS production. Treatment of P-1 with performic acid resulted in loss of its stimulatory activity, indicating that disulfide bridges of the peptides are necessary for their activity on SLS production. These results suggest that the unique primary structure of three peptide chains linked by two disulfide bridges is requisite for the stimulatory effect on SLS production.

Amino Acid Sequence↗
PubMed1999

Effect of temporary hepatic venous occlusion on hepatic arterial embolization. An experimental study.

RATIONALE AND OBJECTIVES: The authors evaluated the effect of hepatic venous occlusion on hepatic arterial embolization in rats. METHODS: A Lipiodol-Iopamidol mixture was injected into the proper hepatic artery in rats during clamping the right side of the hepatic venous confluence. The distribution of Lipiodol-Iopamidol mixture in the sinusoids was analyzed by histological examination with en bloc silver impregnation. The extent of the distribution of Lipiodol-Iopamidol mixture was compared in sinusoids with hepatic venous occlusion and in sinusoids without hepatic venous occlusion. RESULTS: Lipiodol-Iopamidol mixture was more widely distributed in the lobules with hepatic venous occlusion than in the lobules without occlusion. CONCLUSIONS: Hepatic venous occlusion may enhance the effect of hepatic arterial embolization using Lipiodol emulsions and could be useful in the treatment of hepatocellular carcinoma.

Animals↗
PubMed1999

An evaluation of three-dimensional ultrasonography for the measurement of gallbladder volume.

OBJECTIVE: Various three-dimensional ultrasonography systems have been developed. We estimated the accuracy of a three-dimensional ultrasonography system for measuring gallbladder volume and compared the results to the sum-of-cylinders method. METHODS: In an in vitro study, 10 balloons of various shapes, sized 5-68 mL were scanned by real-time ultrasonography. In an in vivo study, we evaluated the gallbladder emptying of 14 healthy male volunteers after ingestion of two raw egg yolks. In both studies, volume measurement was performed by the three-dimensional ultrasonography method and the sum-of-cylinders method. RESULTS: With the three-dimensional ultrasonography method, the mean difference between the measured volume and the true volume and the limits of agreement were smaller than those of the sum-of-cylinders method. Gallbladder volumes did not differ significantly with both ultrasound methods. CONCLUSION: The three-dimensional ultrasonography method accurately determined gallbladder volumes.

Adult↗
PubMed1999

Evaluation of a new laboratory test measuring plasma (1-->3)-beta-D-glucan in the diagnosis of Candida deep mycosis: comparison with a serologic test.

We evaluated the effectiveness of the newly developed WAKO beta-glucan test which measures plasma (1-->3)-beta-D-glucan concentrations in the diagnosis of Candida deep mycosis. This test was compared to the Cand-Tec test. The WAKO beta-glucan test and Cand-Tec test were performed on 212 plasma specimens which were taken at 212 instances from 62 immunocompromised patients with serious diseases; i.e. hematopoietic malignancy, solid malignant tumor, etc. The sensitivities and specificities for the WAKO beta-glucan test were 84.8 and 85.9%, respectively, and 60.9 and 80.0% for the Cand-Tec test.

Candidiasis↗
PubMed1999

[Bacteriological studies of traveller's diarrhoea (6). Analysis of enteropathogenic bacteria at Kansai Airport Quarantine Station from September 4th, 1994 through December 1996].

During the period of investigation from Sept. 4, 1994 to Dec, 1996, a total of 11,446,534 overseas travellers were quarantined at Kansai Airport Quarantine Station, and 22,187 voluntarily reported of episodes suffering from diarrhoea. Bacteriological examination of the stools a total of 9,299 individuals' was performed, and the following results were obtained. 1) Various enteropathogenic bacteria were isolated from 33.3% of the stools examined. Bacterial species isolated were as follows: Plesiomonas shigelloides, 2,066 cases (66.7%); Vibrio parahaemolyticus, 358 cases (11.6%); Aeromonas sobria, 360 cases (11.6%); Shigella spp., 291 cases (9.4%); Salmonella spp., 183 cases (5.9%); A. hydrophila, 126 cases (4.1%); and V. cholerae non-O1, 121 cases (3.9%). However, ETEC was not done with an object of test. 2) In 502 cases (16.2%), plural enteropathogenic bacteria were isolated from single patient, suggesting high frequency of a mixed infections. 3) From Feb. to Mar. 1995, thirteen cases cholera were found from patients who had travelled to Bali, Indonesia. Cases with enteropathogenic bacteria other than V. cholerae O1 were found without any seasonal variation. 4) The major regions where the travellers were infected with the pathogens are as follows: Vibrio spp., were from only Asia; Shigella, widely distributed but especially in India and Indonesia; P. shigelloides and Salmonella, widely distributed. 5) Among the Shigella strains, S. sonnei were isolated the most, followed by S. flexneri, S. boydii and S. dysenteriae. A strain of S. boydii provisional serovar E 16553 was isolated from a patient infected in India. 6) Among the Salmonella serovars, Salmonella Enteritidis was isolated the most frequently (49 cases, 25.7%). 7) 265 (89.2%) of 297 Shigella strains, 52 (27.2%) of 19] Salmonella strains, and 19 (95.0%) of 20 V. cholerae O1 were resistant to one or more drugs tested (SM. CP. TC. KM. ABPC. NA. OFLX). 8) All of the 20 V. cholerae O1 strains were Ogawa, E1 Tor. All of them were toxigenic strains. 9) The most frequently isolated serovar of V. parahaemolyticus was O3: K6. 89.8% of all V. parahaemolyticus strains were positive for thermostable direct hemolysin (TDH) gene, and 14.6% of them were positive for TDH-related hemolysin (TRH) gene by DNA-probe or PCR method.

Asia, Southeastern↗
PubMed1999

[A clinical evaluation of the new laboratory method that diagnoses bacterial infection, using silkworm larvae plasma].

Based upon the phenomenon that the peptidoglycan, a common component of Gram positive and negative bacteria, reacts specifically with silkworm larvae plasma (SLP), a new laboratory method named "SLP test" was developed to measure the reaction products in plasma quantitatively as SLP. This SLP test seems to be able to diagnose both Gram positive and negative bacterial infection. So we evaluated its usefulness in diagnosing clinical infectious diseases. This study included 14 patients with result to positive bacterial blood culture, 22 patients with bacterial local infection, 7 patients without any evidence of bacterial infection, and 19 healthy volunteers. It seemed that the cut-off value of this SLP test should be set at 0.6 ng/ml. The sensitivity and specificity of this SLP test were 57.1%, 100%, respectively. A significant difference was not detected statistically between SLP values of patients with Gram positive and Gram negative bacterial infectious diseases. So the SLP test did not appeared specific to either Gram positive or Gram negative bacteria. This test may become a new method diagnosing bacterial infectious disease.

Adult↗
PubMed1999

Which type of underlying disease facilitates cytomegalovirus infection? Comparison of benign disease, hematopoietic malignancy, and post-bone-marrow or renal transplantation status by using the first standardized objective PCR test for cytomegalovirus detection.

All immunocompromised hosts, such as infants, the elderly, patients with advanced cancer, and patients being treated with immunosuppressants, etc., are said to be more susceptible to cytomegalovirus (CMV) infection or CMV disease. However, we questioned the validity of this conclusion and attempted to detect CMV viremia in the plasma of subjects by using the AMPLICOR CMV test (Roche Diagnostics Systems, Branchburg, NJ), the first standardized PCR kit for CMV infection. One hundred healthy volunteers whose CMV IgG titer was < 4 and 100 healthy volunteers whose IgG titer for CMV was > or = 4 were studied. None of the subjects in either healthy group was positive for CMV viremia. Patients who were suspected of CMV infection were divided into four groups and tested: [1] 104 patients with benign disease, only one of whom was positive for CMV [2] 99 patients with hematopoietic malignancy who had not undergone bone marrow transplantation and all of whom were negative for CMV infection [3] 120 post-bone-marrow transplantation, 28 of whom were CMV positive, [4] 37 post-renal transplantation patients, 19 of whom were CMV positive. A statistically significant difference in CMV positivity was found by the non-parametric Kruskal-Wallis test (p < 0.0001) among the four disease group. CMV infection has been said to occur in all types of immunocompromised patients, however, based on our findings, we conclude that CMV infection tends to occur in post-transplantation status and does not tend to occur in patients with hematopoietic malignancy if they have not undergone transplantation.

Adult↗
PubMed1999

Effects of antibiotic therapy on Pseudomonas aeruginosa-induced lung injury in a rat model.

The effect of antibiotics on the acute lung injury induced by virulent Pseudomonas aeruginosa PA103 was quantitatively analyzed in a rat model. Lung injury was induced by the instillation of PA103 directly into the right lower lobes of the lungs of anesthetized rats. The alveolar epithelial injury, extravascular lung water, and total plasma equivalents were measured as separate, independent parameters of acute lung injury. Four hours after the instillation of PA103, all the parameters were increased linearly depending on the dose of P. aeruginosa. Next, we examined the effects of intravenously administered antibiotics on the parameters of acute lung injury in D-galactosamine-sensitized rats. One hour after the rats received 10(7) CFU of PA103, an intravenous bolus injection of aztreonam (60 mg/kg) or imipenem-cilastatin (30 mg/kg) was administered. Despite an MIC indicating resistance, imipenem-cilastatin improved all the measurements of lung injury; in contrast, aztreonam, which had an MIC indicating sensitivity, did not improve any of the lung injury parameters. The antibiotics did not generate different quantities of plasma endotoxin; therefore, endotoxin did not appear to explain the differences in lung injury. This in vivo model is useful to quantitatively compare the efficacies of parenteral antibiotic administration on Pseudomonas airspace infections.

Animals↗
PubMed1999

Depletion of alveolar macrophages by treatment with 2-chloroadenosine aerosol.

Alveolar macrophages (AMs) are localized in the alveoli and alveolar ducts of the lung and are the only macrophages living in an aerobic environment. Recent studies have demonstrated that AMs play a central role in lung diseases, such as pneumonia and acute respiratory distress syndrome. It has become important to find a simple, effective way to eliminate AMs in order to investigate the function of AMs in vivo. 2-Chloroadenosine (2-CA), a purine analog, is reported to be selectively cytotoxic to cultured macrophages, and we hypothesized that it would deplete the number of AMs in the bronchoalveolar lavage fluid (BALF) of mice without any effect on neutrophil or lymphocyte counts. After mice had inhaled 1 mM aerosolized 2-CA for 2 h, AMs were found to be significantly depleted at 0 h [(4.42 +/- 0.16) x 10(4)/ml], 24 h [(4.17 +/- 0.89) x 10(4)/ml], 48 h [(3.17 +/- 0.21) x 10(4)/ml], and 72 h [(5.00 +/- 0.64) x 10(4)/ml] compared with concentrations in untreated controls [(12.1 +/- 0.21) x 10(4)/ml]. Neutrophil and lymphocyte counts in BALF did not change and histological changes in the lung were not observed after 2-CA treatment. The lung wet-to-dry weight ratio did not change at 0, 24, and 48 h after 2-CA aerosol application. The 2-CA aerosol had no effect on lung vascular permeability, as assessed by the intravenous administration of Evans blue, or on other phagocytes, as assessed by Kupffer cell counts. Our study demonstrates the efficacy of 2-CA in reducing AM numbers in vivo.

2-Chloroadenosine↗
PubMed1999

Identification of Vibrio parahaemolyticus strains at the species level by PCR targeted to the toxR gene.

The DNA colony hybridization test with the polynucleotide probe for Vibrio parahaemolyticus toxR gene was performed. All 373 strains of V. parahaemolyticus gave positive results, and the strains belonging to four other Vibrio species including Vibrio alginolyticus gave weakly positive results, suggesting that toxR sequence variation may reflect the phylogenetic relationships of Vibrio species. We then established a toxR-targeted PCR protocol for the specific detection of V. parahaemolyticus.

Bacterial Proteins↗
PubMed1999

Purification and identification of p68 RNA helicase acting as a transcriptional coactivator specific for the activation function 1 of human estrogen receptor alpha.

The estrogen receptor (ER) regulates the expression of target genes in a ligand-dependent manner. The ligand-dependent activation function AF-2 of the ER is located in the ligand binding domain (LBD), while the N-terminal A/B domain (AF-1) functions in a ligand-independent manner when isolated from the LBD. AF-1 and AF-2 exhibit cell type and promoter context specificity. Furthermore, the AF-1 activity of the human ERalpha (hERalpha) is enhanced through phosphorylation of the Ser(118) residue by mitogen-activated protein kinase (MAPK). From MCF-7 cells, we purified and cloned a 68-kDa protein (p68) which interacted with the A/B domain but not with the LBD of hERalpha. Phosphorylation of hERalpha Ser(118) potentiated the interaction with p68. We demonstrate that p68 enhanced the activity of AF-1 but not AF-2 and the estrogen-induced as well as the anti-estrogen-induced transcriptional activity of the full-length ERalpha in a cell-type-specific manner. However, it did not potentiate AF-1 or AF-2 of ERbeta, androgen receptor, retinoic acid receptor alpha, or mineralocorticoid receptor. We also show that the RNA helicase activity previously ascribed to p68 is dispensable for the ERalpha AF-1 coactivator activity and that p68 binds to CBP in vitro. Furthermore, the interaction region for p68 in the ERalpha A/B domain was essential for the full activity of hERalpha AF-1. Taken together, these findings show that p68 acts as a coactivator specific for the ERalpha AF-1 and strongly suggest that the interaction between p68 and the hERalpha A/B domain is regulated by MAPK-induced phosphorylation of Ser(118).

Adenocarcinoma↗
PubMed1999

Seasonal changes of human circadian rhythms in Antarctica.

The human circadian rhythms in sleep, activity, plasma melatonin, and rectal temperature were explored under two conflicting time cues in Antarctica: an extreme photoperiod and a strict work schedule. The nine healthy male subjects stayed at the Antarctic zone (latitude 66.5-90 degrees south) for 15 mo including a 13-mo wintering at the Dome station (latitude 77 degrees south). Neither the phases nor the amounts of sleep and daily activity underwent a seasonal change. On the other hand, the peak phase of melatonin rhythm was phase delayed by 4.1 h in winter compared with summer. When the analysis is limited to the Dome data, the seasonal difference was reduced to 1.3 h. Similarly the trough phase of rectal temperature rhythm in two of three subjects was phase delayed by approximately 2 h in winter. From these findings, the sleep or activity rhythm is concluded to be reset predominantly by the work schedule, whereas the circadian rhythm in plasma melatonin and rectal temperature is substantially influenced by the photoperiod.

Activity Cycles↗
PubMed1999

Comparison of bone metabolic markers between maternal and cord blood.

We studied 41 normal pregnant women and their neonates in order to compare bone metabolism between them. We examined more specific bone formation markers (intact osteocalcin, bone-specific alkaline phosphatase) and a recently developed and more sensitive bone resorption marker (C-telopeptide of type I collagen; CTX) than previously available in maternal and umbilical cord venous blood taken at delivery. The concentrations of all markers of bone turnover, including CTX, in cord serum were significantly higher than those in maternal serum. There was no significant correlation between maternal and cord serum levels for any marker. These results indicate that fetal bone turnover is markedly enhanced compared with maternal bone turnover and is independent of maternal bone metabolism in late pregnancy.

Adolescent↗