Biomedical subjects

M Tsuji

Publications and source records attributed to M Tsuji.

At least 73 records · Page 4Linked to original sources

PubMed2000

4-Nonylphenols and 4-tert-octylphenol in water and fish from rivers flowing into Lake Biwa.

Surveys of 4-nonylphenols (NOs) and 4-tert-octylphenol (OC) were performed for water and fish samples obtained from eight rivers flowing into Lake Biwa once every two months from April 1998 to March 1999. For water samples, NOs were detected all the year round (0.11-3.08 ng ml(-1)) at high frequency (48/48) in the eight rivers. OC was detected at lower concentrations (ND approximately 0.09 ng ml(-1)) and at lower frequency (23/48). The concentrations of NOs in the river water always showed minimum values at 5-8 degrees C in winter. It was presumed that the formation of NOs by the biotransformation of nonylphenol polyethoxylates decreased much in the sludge treatment of nonionic surfactants at the low temperature (5-8 degrees C) in winter. Average BCF values of NOs and OC in the six kinds of fish were calculated from the field data. The field BCF values of NOs 15-31 in the six kinds of fish were lower than the laboratory BCF values of 167 in Killifish and 282 in Salmon. For OC, the field BCF values 129-297 for the three kinds of fish were nearly equal to the laboratory BCF value, 261, in Killifish.

Animals↗

PubMed2000

Partial seizures in leukoencephalopathy with swelling and a discrepantly mild clinical course.

We report a patient with 'Leukoencephalopathy with swelling and a discrepantly mild clinical course', an entity of leukoencephalopathy recently clarified. Our patient presented with complex partial seizures in addition to characteristic radiological findings and clinical course. A review of the literature revealed that this new neurodegenerative disease complicates epilepsy in more than half of the patients, and that partial components in the seizure symptomatology are not infrequent.

Adolescent↗

PubMed2000

Co-segregation of benign infantile convulsions and paroxysmal kinesigenic choreoathetosis.

We report seven families and two sporadic cases in which benign infantile convulsions and paroxysmal kinesigenic choreoathetosis were co-segregated. Clinical investigations included physical and neurological examinations, blood electrolyte values, interictal and ictal electroencephalograms, and computed tomography or magnetic resonance imaging of the brain. The family pedigree was confirmed and the clinical history of the relatives was obtained. Seventeen individuals developed infantile convulsions followed by paroxysmal dyskinesias during childhood or adolescence. Six had only infantile convulsions, and two had only paroxysmal dyskinesias. The seizures never persisted into childhood or recurred in adulthood. The seizure type was a complex partial seizure, with or without secondary generalization, in nine of 14 patients. Paroxysmal dyskinesias, a subgroup of paroxysmal kinesigenic choreoathetosis, occurred for less than 5 min. The attacks of dyskinesias began at age 5-12 years in most patients, and tended to remit in adulthood. The mode of inheritance was apparently autosomal dominant in four of the families (17 affected individuals), who were diagnosed with ICCA syndrome (infantile convulsions and paroxysmal choreoathetosis). However, the condition occurred only among siblings in three families (six patients), and sporadically in two patients, suggesting genetic heterogeneity in this distinct co-segregation.

Adolescent↗

PubMed2000

Long-term postoperative functional evaluation of pylorus preservation in Imanaga pancreatoduodenectomy.

Our purpose was to determine whether pylorus-preservation in the Imanaga (PpPDI) method minimizes postoperative impairment of gastrointestinal function. Nine patients who had undergone PpPDI (postoperative years: 5.7 +/- 2.6) and nine patients who had undergone conventional Imanaga pancreatoduodenectomy (PDI) (postoperative years: 6.8 +/- 2.0) were evaluated for symptoms, nutritional parameters, and physiologic function of the biliary tract and residual stomach using gastric emptying and hepatobiliary scintigraphy. The body weight recovered to 99.3% +/- 3.8% of pre-illness body weight in PpPDI, showing a significantly better recovery than in patients after the PDI procedure (91.0% +/- 6.4%, P < 0.05). The mean gastric emptying half-time (GET1/2) in the upright position after PDI was significantly shorter (42.3 min) than after PpPDI (80.8 min, P < 0.05). Mixture of food with bile was conserved better in the PpPDI group than in the PDI group. In the long term, the pylorus-preserving Imanaga-type procedure minimizes disruption of gastric function and asynchrony between ingested food and bile.

Adult↗

PubMed2000

Interferon-gamma-independent CD8+ T cell-mediated protective anti-malaria immunity elicited by recombinant adenovirus.

Recombinant adenovirus, expressing the CS protein of Plasmodium yoelii, AdPyCS, was shown to induce a comparable degree of T cell-mediated protection against malaria as a single dose of irradiated P. yoelii sporozoites, causing inhibition of liver stage development. We now report that differently from sporozoite-induced immunity, interferon (IFN)-gamma does not mediate the protective immunity induced by AdPyCS, since a similar degree of protection was observed in AdPyCS immunized mice lacking IFN-gamma-/- and the IFN-gamma receptor (IFN-gammaR-/-) compared to that in wild-type mice. Depletion of CD8+ T cells from these immunized mice almost completely abolished the AdPyCS-induced immunity, indicating that the immunization with AdPyCS induces CD8+ T cell-mediated protective anti-malaria immunity, which is independent of IFN-gamma.

Adenoviridae↗

PubMed2000

Primary hepatic leiomyosarcoma in a patient with hepatitis C virus-related liver cirrhosis.

We describe an autopsy case of primary hepatic leiomyosarcoma in a 68-year-old man with hepatitis C virus-related liver cirrhosis. The patient, who had a history of acute hepatitis 20 years previously, died of a ruptured hepatic tumor. At autopsy, a well-circumscribed 14 x 16 x 15 cm tumor replaced the medial site of the right hepatic lobe with multiple intrahepatic and distant metastases. Histologically the tumor, which had extensive central necrosis, consisted predominantly of well or moderately differentiated spindle-shaped cells, which were positive for smooth muscle actin and vimentin on immunohistochemical staining. In addition, clusters of markedly atypical cells and myxoid change of the matrix were discretely found in the focal and small areas of the tumor. These findings indicated that many sections were necessary for the histologically accurate estimation of primary hepatic smooth muscle tumor. The histological examination of a non-tumorous lesion showed liver cirrhosis. Hepatitis C virus was detected in the cytoplasm of cirrhotic hepatocytes by immunohistochemistry and reverse transcriptase-polymerase chain reaction, but not in the tumor cells. This suggested that the virus was not directly involved in the development of primary hepatic leiomyosarcoma.

Actins↗

PubMed2000

Analysis of CD44 isoform v10 expression and its prognostic value in renal cell carcinoma.

OBJECTIVE: To examine the expression of CD44 isoform v10 (CD44v10) in patients with renal cell carcinoma (RCC), analyse its role in RCC and its relationship with conventional clinical-histopathological experience. Materials and methods Sixty-four RCC specimens and five metastatic specimens were analysed immunohistochemically using a CD44v10 specific antibody. The expression of CD44v10 was compared with the histological grade and clinical or pathological stage of the tumours. RESULTS: Of the 64 primary tumour specimens, 22 (34%) expressed CD44v10 protein; all of these positive specimens were clear-cell and mixed-cell RCC. Staining was also positive in four of five metastatic specimens and negative in all four cases of granular cell carcinoma. CD44v10 expression was significantly correlated with the histological grade (P<0.0001), clinical stage (P = 0.0050) and pathological stage (P = 0.0143) of the tumours. The prognosis for patients with clear-cell RCC who were CD44v10-positive was worse than for patients who were CD44v10-negative (P<0.0001). In subgroups with different tumour stage (< or =pT2 or > or =pT3), the prognosis for patients with positive CD44v10 expression was also worse than for those with no expression (P<0.05). CONCLUSION: The expression of CD44v10 correlated significantly with histological grade, clinical and pathological stage, and with survival in patients with clear-cell RCC. CD44v10 protein may play a role in the progression of clear-cell and mixed-cell RCC, and thus the analysis of CD44v10 expression may provide useful prognostic information.

Adult↗

PubMed2000

Multifactorial protective mechanisms to limit viral replication in the lung of mice during primary murine cytomegalovirus infection.

In this article, we investigated the protective host immune mechanisms against acute murine cytomegalovirus (MCMV) infection. For this purpose, we used various knockout mice lacking molecules, which include interferon-gamma (IFN-gamma), interferon-gamma receptor (IFN-gamma-R), interferon regulatory factor-1 (IRF-1), inducible nitric oxide synthase (iNOS), and perforin. We also used mutant mice lacking Fas molecule. When we infected these mice with MCMV and determined the viral titers in their lungs at different time points, we found that IFN-gamma, IFN-gamma-R, IRF-1, iNOS, and perforin-deficient mice developed significantly higher titers of infectious MCMV in the lung, compared to those observed in their respective wild-type controls. In the lungs of Fas-mutant mice, viral titers were similar to those obtained in wild-type mice.

Animals↗

PubMed2000

Acetabular development after reduction in developmental dislocation of the hip.

A radiologic study was conducted on 56 patients with developmental dislocation of the hip (63 hips). Fifty hips in which neither acetabular nor femoral osteotomy was performed were classified as satisfactory (Severin Groups I and II) or unsatisfactory (Severin Groups III and IV) based on radiographs when growth was completed. The sequential changes in the center edge angle and the acetabular index were compared when the patients were ages of 5, 10, and 15 years. There was a significant relationship between the center edge angle and the acetabular index when the patients were 5 years of age and at final outcome. Most (85.7%) patients with a center edge angle less than 8 degrees and an acetabular index greater than 26 degrees at 5 years of age eventually were classified as Severin Groups III and IV at skeletal maturity. These findings suggest that radiologic results at the time when growth is completed can be predicted based on the center edge angle and the acetabular index in radiologic measurements at 5 years of age. The authors recommend that if at 5 years of age the center edge angle is less than 8 degrees and the acetabular index is greater than 26 degrees, consideration be given to an osteotomy to bring these values to a more normal range to improve final outcome.

Acetabulum↗

PubMed2000

gammadelta T cells are a component of early immunity against preerythrocytic malaria parasites.

We tested the hypothesis that gammadelta T cells are a component of an early immune response directed against preerythrocytic malaria parasites that are required for the induction of an effector alphabeta T-cell immune response generated by irradiated-sporozoite (irr-spz) immunization. gammadelta T-cell-deficient (TCRdelta(-/-)) mice on a C57BL/6 background were challenged with Plasmodium yoelii (17XNL strain) sporozoites, and then liver parasite burden was measured at 42 h postchallenge. Liver parasite burden was measured by quantification of parasite-specific 18S rRNA in total liver RNA by quantitative-competitive reverse transcription-PCR and by an automated 5' exonuclease PCR. Sporozoite-challenged TCRdelta(-/-) mice showed a significant (P < 0.01) increase in liver parasite burden compared to similarly challenged immunocompetent mice. In support of this result, TCRdelta(-/-) mice were also found to be more susceptible than immunocompetent mice to a sporozoite challenge when blood-stage parasitemia was used as a readout. A greater percentage of TCRdelta(-/-) mice than of immunocompetent mice progressed to a blood-stage infection when challenged with five or fewer sporozoites (odds ratio = 2.35, P = 0.06). TCRdelta(-/-) mice receiving a single irr-spz immunization showed percent inhibition of liver parasites comparable to that of immunized immunocompetent mice following a sporozoite challenge. These data support the hypothesis that gammadelta T cells are a component of early immunity directed against malaria preerythrocytic parasites and suggest that gammadelta T cells are not required for the induction of an effector alphabeta T-cell immune response generated by irr-spz immunization.

Animals↗

PubMed2000

Transfusion-acquired, autochthonous human babesiosis in Japan: isolation of Babesia microti-like parasites with hu-RBC-SCID mice.

We have isolated piroplasms from a patient who developed the first case of human babesiosis in Japan by using NOD/shi-scid mice whose circulating erythrocytes (RBCs) had been replaced with human RBCs (hu-RBC-SCID mice). Following inoculation of the patient's blood specimen into hu-RBC-SCID mice, parasites proliferated within the human RBCs in the mice, resulting in a high level of parasitemia. Parasite DNA was prepared from blood samples of the patient and the mice, and the nuclear small-subunit rRNA gene (rDNA) was amplified and sequenced. Both DNA samples gave rise to identical sequences which showed the highest degree of homology (99.2%) with the Babesia microti rDNA. Because the patient had received a blood transfusion before the onset of babesiosis, we investigated the eight donors who were involved. Their archived blood samples were analyzed for specific antibody and parasite DNA; only a single donor was found to be positive by both tests, and the parasite rDNA sequence from the donor coincided with that derived from the patient. The donor's serum exhibited a high antibody titer against the isolate from the patient, whereas it exhibited only a weak cross-reaction against B. microti strains isolated in the United States. We conclude that the first Japanese babesiosis case occurred due to a blood transfusion and that the etiological agent is an indigenous Japanese parasite which may be a geographical variant of B. microti. Our results also demonstrated the usefulness of hu-RBC-SCID mice for isolation of parasites from humans and for maintenance of the parasite infectivity for human RBCs.

Animals↗

PubMed2000

Effects of fructose and glucose on plasma leptin, insulin, and insulin resistance in lean and VMH-lesioned obese rats.

To determine the influence of dietary fructose and glucose on circulating leptin levels in lean and obese rats, plasma leptin concentrations were measured in ventromedial hypothalamic (VMH)-lesioned obese and sham-operated lean rats fed either normal chow or fructose- or glucose-enriched diets (60% by calories) for 2 wk. Insulin resistance was evaluated by the steady-state plasma glucose method and intravenous glucose tolerance test. In lean rats, glucose-enriched diet significantly increased plasma leptin with enlarged parametrial fat pad, whereas neither leptin nor fat-pad weight was altered by fructose. Two weeks after the lesions, the rats fed normal chow had marked greater body weight gain, enlarged fat pads, and higher insulin and leptin compared with sham-operated rats. Despite a marked adiposity and hyperinsulinemia, insulin resistance was not increased in VMH-lesioned rats. Fructose brought about substantial insulin resistance and hyperinsulinemia in both lean and obese rats, whereas glucose led to rather enhanced insulin sensitivity. Leptin, body weight, and fat pad were not significantly altered by either fructose or glucose in the obese rats. These results suggest that dietary glucose stimulates leptin production by increasing adipose tissue or stimulating glucose metabolism in lean rats. Hyperleptinemia in VMH-lesioned rats is associated with both increased adiposity and hyperinsulinemia but not with insulin resistance. Dietary fructose does not alter leptin levels, although this sugar brings about hyperinsulinemia and insulin resistance, suggesting that hyperinsulinemia compensated for insulin resistance does not stimulate leptin production.

Animals↗

PubMed2000

Protective effect of aminoguanidine on hypoxic-ischemic brain damage and temporal profile of brain nitric oxide in neonatal rat.

Nitric oxide (NO) produced by inducible NO synthase contributes to ischemic brain damage. However, the role of inducible NO synthase-derived NO on neonatal hypoxic-ischemic encephalopathy has not been clarified. We demonstrate here that aminoguanidine, a relatively selective inhibitor of inducible NO synthase, ameliorated neonatal hypoxic-ischemic brain damage and that temporal profiles of NO correlated with the neuroprotective effect of aminoguanidine. Seven-day-old Wister rat pups were subjected to left carotid artery occlusion followed by 2.5 h of hypoxic exposure (8% oxygen). Infarct volumes (cortical and striatal) were assessed 72 h after the onset of hypoxia-ischemia by planimetric analysis of coronal brain slices stained with hematoxylin-eosin. Aminoguanidine (300 mg/kg i.p.), administered once before the onset of hypoxia-ischemia and then three times daily, significantly ameliorated infarct volume (89% reduction in the cerebral cortex and 90% in the striatum; p<0.001). NO metabolites were measured by means of chemiluminescence using an NO analyzer. In controls, there was a significant biphasic increase in NO metabolites in the ligated side at 1 h (during hypoxia) and at 72 h after the onset of hypoxia (p<0.05). Aminoguanidine did not suppress the first peak but significantly reduced the second one (p<0.05), and markedly reduced infarct size in a neonatal ischemic rat model. Suppression of NO production after reperfusion is a likely mechanism of this neuroprotection.

Animals↗

PubMed2000

Modulators of tumor necrosis factor alpha production bearing dicarba-closo-dodecaborane as a hydrophobic pharmacophore.

Previous studies on the structural development of tumor necrosis factor alpha (TNF-alpha) production regulators derived from thalidomide (N-alpha-phthalimidoglutarimide) revealed that a hydrophobic substituent at the nitrogen atom of the phthalimide ring is critical for potent activity. We have designed and prepared phthalimide derivatives bearing a boron cluster, dicarba-closo-dodecaborane (carborane), which has a hydrophobic character and spherical geometry, as a novel candidate of biological response modifiers. These compounds were shown to regulate TNF-alpha production by HL-60 cells, as expected. The result provides a further example of the application of carborane as a hydrophobic pharmacophore of biologically active molecules.

Enzyme-Linked Immunosorbent Assay↗

PubMed2000

[Multiplicity of anxiety and serotonin nervous system].

It has been recently suggested that the central serotonin (5-HT) nervous system may be involved in the modulation of anxiety. Especially, the possible importance of 5-HT1A receptors in anxiety was raised by evidence that the anxiolytic properties of 5-HT1A-receptor agonists have now been confirmed in clinical studies. On the other hand, in preclinical studies using various animal models of anxiety, these novel agents tend to have weak and/or variable effects in some paradigms used to detect the anxiolytic activities of benzodiazepines. These differential patterns of drug effects within various models promote the concept of "multiplicity of anxiety". Recently, a new experimental model called the T-maze was developed in attempts to analyze a different type of anxiety; i.e., conditioned fear and unconditioned fear response. The results of a series of behavioral studies using the T-maze test suggest that distinct 5-HT pathways may modulate the different classes of anxiety. In our recent studies using the hole-board test, apparent differential behavioral effects between benzodiazepine anxiolytics and 5-HT1A agonists on emotionality of stressed mice were also observed. These results suggest that benzodiazepine or 5-HT1A receptors may play a different role in modulating emotionality. These studies may provide new information to investigate the pathophysiological characteristics of various types of anxiety disorders and to develop novel therapeutic agents.

Animals↗

PubMed2000

Infectivity to experimental rodents of Cryptosporidium parvum oocysts from Siberian chipmunks (Tamias sibiricus) originated in the People's Republic of China.

We isolated Cryptosporidium parvum-type oocysts from naturally infected siberian chipmunks which originated in the People's Republic of China and examined the infectivity to rodents as experimental animals. The naturally infected chipmunks did not show any clinical symptoms. The oocysts were 4.8 x 4.2 microm on average in size. They were ovoid and morphologically similar to the C. parvum oocysts isolated from human and cattle. Experimental rodents were inoculated with 1.6 x 10(6) original oocysts each. SCID mice began to shed oocysts on day 7 and the OPG value was 10(5) from 50 days. The oocysts were found from ICR mice on days 13 and 16 by only sugar flotation method, however, any oocysts were not detected from the rats, guinea pigs and rabbits until 30 days. Two infected SCID mice were necropsied on days 100 and 102 and examined for coccidian organisms. Merozoites and oocysts were found in the low part of jejunum and ileum, however, no parasites were detected in the stomach. Consequently, it was considered that the present species was C. parvum and was probably genotype 2 from result of infectivity to rodents.

Animals↗

PubMed2000

Effects of in vivo administration of anti-IL-10 or anti-IFN-gamma monoclonal antibody on the host defense mechanism against Plasmodium yoelii yoelii infection.

Our previous reports indicated that C57BL/6 mice infected with a lethal variant of Plasmodium yoelii 17X (P. yoelii 17XL) produced high levels of interleukin 10 (IL-10) and interferon-gamma (IFN-gamma) while mice infected with the nonlethal variant of the parasite did not produce detectable levels of IL-10. In the present study, the involvement of IL-10 and IFN-gamma in exacerbation or regulation of blood-stage malaria was investigated by using the lethal variant of P. yoelii 17XL and monoclonal antibodies (mAb) against the cytokines. C57BL/6 mice were injected intraperitoneally with a neutralizing anti-IL-10 mAb or anti-IFN-gamma mAb after inoculation with P. yoelii 17XL. Treatment of mice with anti-IL-10 mAb resulted in substantial prolongation of survival and 60% of treated mice survived while 100% of control mice died by day 11. On the contrary, treatment of mice with anti-IFN-gamma mAb exacerbated infection and all mice died after an earlier period than those treated with normal rat Ig. No differences in parasitemias were found between treated and untreated mice. To elucidate the involvement of nitric oxide in the host protection or exacerbation, mice were treated with aminoguanidine, an inhibitor of nitric oxide synthetase, after inoculation of P. yoelii 17XL. Neither mortality nor parasitemia was influenced by the treatment. These results indicate that an IFN-gamma response is associated with protective immunity in mice infected with P. yoelii 17XL, while an IL-10 response is associated with disease exacerbation during the infection.

Animals↗

PubMed2000

Cerebral intravascular oxygenation correlates with mean arterial pressure in critically ill premature infants.

OBJECTIVES: Premature infants experience brain injury, ie, germinal matrix-intraventricular hemorrhage (GMH-IVH) and periventricular leukomalacia (PVL), in considerable part because of disturbances in cerebral blood flow (CBF). Because such infants are susceptible to major fluctuations in mean arterial blood pressure (MAP), impaired cerebrovascular autoregulation would increase the likelihood for the changes in CBF that could result in GMH-IVH and PVL. The objectives of this study were to determine whether a state of impaired cerebrovascular autoregulation could be identified reliably and conveniently at the bedside, the frequency of any such impairment, and the relation of the impairment to the subsequent occurrence of severe GMH-IVH and PVL. PATIENTS AND METHODS: To monitor the cerebral circulation continuously and noninvasively, we used near-infrared spectroscopy (NIRS) to determine quantitative changes in cerebral concentrations of oxygenated hemoglobin (HbO(2)) and deoxygenated hemoglobin (Hb) from the first hours of life. Our previous experimental study showed a strong correlation between a measure of cerebral intravascular oxygenation (HbD), ie, HbD = HbO(2) - Hb, determined by NIRS, and volemic CBF, determined by radioactive microspheres. We studied 32 very low birth weight premature infants (gestational age: 23-31 weeks; birth weight: 605-1870 g) requiring mechanical ventilation, supplemental oxygen, and invasive blood pressure monitoring by NIRS from 1 to 3 days of age. MAP measured by arterial catheter pressure transducer and arterial oxygen saturation measured by pulse oximetry were recorded simultaneously. The relationship of MAP to HbD was quantitated by coherence analysis. RESULTS: Concordant changes (coherence scores >. 5) in HbD and MAP, consistent with impaired cerebrovascular autoregulation, were observed in 17 of the 32 infants (53%). Eight of the 17 infants (47%) developed severe GMH-IVH or PVL or both. Of the 15 infants with apparently intact autoregulation, ie, coherence scores <.5, only 2 (13%) developed severe ultrasonographic lesions. Thus, for the entire study population of 32 infants, 8 of the 10 with severe lesions exhibited coherence scores >.5. CONCLUSIONS: We conclude that NIRS can be used in a noninvasive manner at the bedside to identify premature infants with impaired cerebrovascular autoregulation, that this impairment is relatively common in such infants, and that the presence of this impairment is associated with a high likelihood of occurrence of severe GMH-IVH/PVL.

Blood Pressure↗