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Biomedical subjects

H Fujii

Publications and source records attributed to H Fujii.

At least 217 records · Page 12Linked to original sources

Disulfide bonds in rat cutaneous fatty acid-binding protein.

Unlike other fatty acid-binding proteins, cutaneous (epidermal) fatty acid-binding proteins contain a large number of cysteine residues. The status of the five cysteine residues in rat cutaneous fatty acid-binding protein was examined by chemical and mass-spectrometric analyses. Two disulfide bonds were identified, between Cys-67 and Cys-87, and between Cys-120 and Cys-127, though extent of formation of the first disulfide bond was rather low in another preparation. Cys-43 was free cysteine. Homology modeling study of the protein indicated the close proximity of the sulfur atoms of these cysteine pairs, supporting the presence of the disulfide bonds. These disulfide bonds appear not to be directly involved in fatty acid-binding activity, because a recombinant rat protein expressed in Escherichia coli in which all five cysteines are fully reduced showed fatty acid-binding activity as examined by displacement of a fluorescent fatty acid analog by long-chain fatty acids. However, the fact that the evolutionarily distant shark liver fatty acid-binding protein also has a disulfide bond corresponding to the one between Cys-120 and Cys-127, and that fatty acid-binding proteins play multiple roles suggests that some functions of cutaneous fatty acid-binding protein might be regulated by the cellular redox state through formation and reduction of disulfide bonds. Although we cannot completely exclude the possibility of oxidation during preparation and analysis, it is remarkable that a protein in cytosol under normally reducing conditions appears to contain disulfide bonds.

Amino Acid Sequence↗

Suppression of neurocognitive damage in LP-BM5-infected mice with a targeted deletion of the TNF-alpha gene.

Brain levels of TNF-alpha increase in many inflammatory conditions, including HIV-1 infection, and may contribute to neurodegenerative processes. The paucity of agents that can selectively and potently block TNF-alpha processing or its receptors has led us to investigate the role of TNF-alpha in chronic neurodegeneration associated with retroviral infection using mice with targeted deletions of the TNF-alpha gene. Infection of wild-type C57BL/6 mice with the LP-BM5 murine leukemia retrovirus mixture leads to the development of a severe immunodeficiency as well as cognitive deficits and neuronal damage. TNF-alpha-(-/-) mice infected with LP-BM5 developed a systemic immunopathology indistinguishable in severity from that observed in contemporaneously infected wild-type mice. In contrast, the performance of infected TNF-alpha-(-/-) mice in the Y-maze and Morris water maze was not different from that of uninfected TNF-alpha-(-/-) mice. The extent of glial activation in the striatum, as indicated by the increase in density of peripheral benzodiazepine receptors, was equivalent in both groups of LP-BM5-infected mice. However, the decrease in striatal MAP-2 expression, a marker of neurodegeneration observed in infected wild-type mice, was not found in infected TNF-alpha-(-/-) mice. While the loss of TNF-alpha appeared to have no effect on the course or severity of the central or peripheral immunopathology resulting from LP-BM5 infection, the behavioral and biochemical manifestations were substantially curtailed in the TNF-alpha-(-/-) mice. These findings directly support a role for TNF-alpha in the neurodegenerative processes associated with viral infections such as HIV-1.

Animals↗

Hybrid radioassay of multiple radionuclide mixtures in waste solutions by using liquid and NaI(Tl) scintillation monitors.

A new analytical technique for radioactive waste solutions has been developed by using a combination of a liquid and a NaI(Tl) scintillation monitor, which enables beta-emitter mixtures to be radioassayed using one calculation process with the method of least squares. This hybrid system can facilitate the analysis of beta-emitter mixtures with very similar liquid scintillation pulse height distributions, such as 3H, 51Cr, and 125I. All that is required for the technique are sets of quench standards of the nuclides to be analyzed and calibration standards for the gamma-emitters. Detection limits for seven nuclides were estimated to be about 0.005 Bq mL(-1), which are sufficiently low compared with the values of authorized safety guidelines.

Chromium Radioisotopes↗

An annular pancreas derived from paired ventral pancreata, supporting Baldwin's hypothesis.

An annular pancreas is a rare malformation. It is generally accepted that the ring formation originates from a single ventral pancreas, as suggested by Lecco. No reports of resected and/or autopsied annular pancreata derived from paired ventral pancreata, thus supporting Baldwin's hypothesis, have been published. We describe an annular pancreas originating from paired ventral pancreata, thus supporting Baldwin's hypothesis, and attempt to clarify the pathogenesis of an annular pancreas. The patient was a 1-day-old Japanese male newborn, born at 32 weeks of pregnancy. He died from respiratory failure owing to esophageal atresia the next day. Autopsy incidentally revealed an annular pancreas that was examined histologically. Multiple 4 microm thick serial sections were obtained from paraffin-embedded pancreatic tissue. Sections for histologic analysis were subjected to hematoxylin-eosin staining and pancreatic polypeptide immunostaining. An unusually large pancreatic duct encircled by pancreatic tissue ran around the duodenum, and the duct was confirmed to flow into the major papilla. The islets of the encircling pancreas were positive for pancreatic polypeptide. A normal main and accessory pancreatic duct were also identified. Histologic and immunohistochemical evaluation revealed that the ring formation originated from the left lobe of paired ventral pancreata. An annular pancreas that was investigated histopathologically and immunohistochemically and found to support Baldwin's hypothesis is described.

Esophageal Atresia↗

Mechanism of increases in L-kynurenine and quinolinic acid in renal insufficiency.

Marked increases in metabolites of the L-tryptophan-kynurenine pathway, L-kynurenine and quinolinic acid (Quin), were observed in serum and cerebrospinal fluid (CSF) of both the rat and human with renal insufficiency. The mechanisms responsible for their accumulation after renal insufficiency were investigated. In patients with chronic renal insufficiency, elevated levels of serum L-kynurenine and Quin were reduced by hemodialysis. In renal-insufficient rats, Quin and L-kynurenine levels in serum, brain, and CSF were also increased parallel to the severity of renal insufficiency. Urinary excretion of Quin (3.5-fold) and L-kynurenine (2.8-fold) was also increased. Liver L-tryptophan 2,3-dioxygenase activity (TDO), a rate-limiting enzyme of the kynurenine pathway, was increased in proportion to blood urea nitrogen and creatinine levels. Kynurenine 3-hydroxylase and quinolinic acid phosphoribosyltransferase were unchanged, but the activities of kynureninase, 3-hydroxyanthranilate dioxygenase, and aminocarboxymuconate-semialdehyde decarboxylase (ACMSDase) were significantly decreased. Systemic administrations of pyrazinamide (ACMSDase inhibitor) increased serum Quin concentrations in control rats, demonstrating that changes in body ACMSDase activities in response to renal insufficiency are important factors for the determination of serum Quin concentrations. We hypothesize the following ideas: that increased serum L-kynurenine concentrations are mainly due to the increased TDO and decreased kynureninase activities in the liver and increased serum Quin concentrations are due to the decreased ACMSDase activities in the body after renal insufficiency. The accumulation of CSF L-kynurenine is caused by the entry of increased serum L-kynurenine, and the accumulation of CSF Quin is secondary to Quin from plasma and/or Quin precursor into the brain.

Adult↗

Cardiac dysfunction and long-term prognosis in patients with nonobstructive hypertrophic cardiomyopathy and abnormal (123)I-15- (p-Iodophenyl)-3(R,S)-methylpentadecanoic acid myocardial scintigraphy.

To evaluate the relationship between myocardial scintigraphic abnormalities based on (123)I-radioiodinated 15-(p-iodophenyl)-3(R, S)-methylpentadecanoic acid (BMIPP) uptake and cardiac function and the relationship between these abnormalities and long-term prognosis in patients with hypertrophic cardiomyopathy (HCM), 27 patients with nonobstructive HCM underwent BMIPP myocardial scintigraphic study, echocardiography, and exercise radionuclide study. Based on the extent of BMIPP scintigraphic defects, the patients were divided into two groups: Group A (n = 19) patients had no or small defects, and group B (n = 8) patients had moderate to large defects. Cardiac events were recorded over an average period of 64 months. The left ventricular end-diastolic and end-systolic dimensions were significantly greater in group B than in group A. The fractional shortening in group B was less than in group A (p = 0.0002). The BMIPP score and fractional shortening at rest correlated significantly (p < 0.05). The BMIPP score and the change in ejection fraction between rest and peak exercise correlated significantly (p < 0.05). While only 1 cardiac event occurred in the 19 patients in group A during a mean follow-up period of 64 months, 6 cardiac events occurred in the 8 patients in group B. The 84-month event-free survival rate was 94.4% in group A and 14.6% in group B (p < 0.01). These results suggest that patients with HCM and moderate to large defects as assessed by BMIPP myocardial scintigraphy have decreased cardiac function and a poor prognosis.

Adult↗

Reciprocal functions of liver tumor cells and endothelial cells. Involvement of endothelial cell migration and tumor cell proliferation at a primary site in distant metastasis.

BACKGROUND: The mechanism by which tumor cells interact with endothelial cells at the primary site in metastasis remains obscure. MATERIALS AND METHODS: To disclose the precise mechanisms and processes of metastasis and angiogenesis, we investigated the interactions of endothelial cells (CPAE; calf pulmonary arterial endothelial cells) with two mouse liver tumor cell lines, G-5, a highly metastatic clone, and G-1, a poorly metastatic clone, based on the difference in their angiogenic activities in vivo at a primary site. RESULTS: G-5 cell cultured conditioned medium (CM) promoted migration of endothelial cells more than did G-1 cell CM, in migration assay using modified Boyden chambers. Anti-basic FGF antibody inhibited G-5-induced endothelial cell migration. Furthermore, endothelial cells stimulated proliferation of G-5 cells more than that of G-1 cells in coculture assay using Transwell chambers (pore size; 0.4 microm). Pretreated endothelial cells with bFGF enhanced tumor cell proliferation, suggesting the ability of activated endothelial cells to support tumor growth. In addition, incubation with endothelial cell CM also improved the proliferative activity of G-5 cells more than that of G-1 cells in a concentration-dependent fashion, indicating production and secretion of liver tumor cell growth substance by endothelial cells. CONCLUSION: These results provide evidence that liver tumor cells stimulate endothelial cell migration and migrated endothelial cells facilitate liver tumor cell proliferation. Tumor growth at a primary site may initially be dependent on migrated endothelial cells rather than vascularization or blood nutrient supply. This bi-directional paracrine relationship between liver tumor cells and endothelial cells may influence their metastatic ability.

Animals↗

Creation of aortic dissection model in swine.

The use of mongrel dogs for experimental purposes was recently restricted and this report presents the experience of creating an aortic dissection model in swine. All the swine in group 1 were anesthetized without pentobarbital and the descending aorta was side-clamped during the creation of the aortic dissection. The false lumen of the completed dissection was patent in the long term despite not having the anchoring suture that the previous canine model required to stabilize the opening of the entry tear. All the swine anesthetized with pentobarbital (ie, group 2) died of heart failure either during cross-clamping of the descending aorta or postoperative aortography. In conclusion, creation of a thoracic aortic dissection is possible in swine, but cross-clamping of the thoracic descending aorta and pentobarbital anesthesia should be avoided.

Aortic Dissection↗

Diagnostic usefulness of the post-exercise systolic blood pressure response for the detection of coronary artery disease in patients with diabetes mellitus.

Patients with diabetes mellitus (DM) often have a positive result on exercise testing despite a normal coronary arteriogram, which indicates that exercise-induced ST depression is not always an accurate indicator of the presence of coronary artery disease (CAD) in such patients. The present study evaluated the usefulness of the post-exercise systolic blood pressure (SBP) response for the detection of CAD in 47 consecutive patients with DM. Significant stenotic lesions were detected by angiography in 25 patients; 18 of these had true positive (TP) exercise testing results, and 7 had false negative (FN) results. No significant stenotic lesions were detected in the remaining 22 patients and of these 10 had true negative (TN) exercise testing results, and 12 had false positive (FP) results. The SBP ratio (SBP after 3 min of recovery divided by the SBP at peak exercise) was significantly higher in patients with coronary stenoses than in those without. Analysis of the relative cumulative frequency revealed that a SBP ratio greater than 0.87 was associated with significant stenoses. The sensitivity, specificity, and accuracy of ST change combined with a SBP ratio greater than 0.87 for detecting stenoses in patients with DM were 68%, 82%, and 74%, respectively. These results suggest that calculating the SBP ratio, in combination with monitoring for ST depression, improves the accuracy of treadmill exercise testing for the detection of CAD in patients with DM.

Adult↗

Expression of prophenoloxidase mRNA during silkworm hemocyte development.

Two clones encoding different prophenoloxidase isoforms were amplified by polymerase chain reaction of RNA from the hemocytes of an experimental strain of Bombyx mori. The nucleotide sequences of the clones and the deduced amino acid sequences were confirmed to be nearly identical to those of the orthologous clones previously obtained from a commercial race of B. mori. Northern blot hybridization using these clones as probes demonstrated that the prophenoloxidase mRNA in the hemocytes is expressed in a stage-specific manner during the final larval instar and pupal stage, showing a peak one day before pupation in males and on the day of pupation in females. A sexual difference was also observed when the content of prophenoloxidase protein in the hemolymph (including hemocytes) was measured by an enzyme-linked immunosorbent assay.

Amino Acid Sequence↗

Identical twins with long QT syndrome associated with a missense mutation in the S4 region of the HERG.

Familial long QT syndrome (LQTS) is caused by mutations in genes encoding ion channels important in determining ventricular repolarization. Mutations in at least five genes have been associated with the LQTS. Fire genes, KCNQ1, HERG, SCN5A, KCNE1, and KCNE2, have been identified. We have identified a missense mutation in the HERG gene in identical twins in a Japanese family with LQTS. The identical twins in our study had QT prolongation and the same missense mutation. However only the proband had a history of syncope. Although many mutations in LQT genes have been reported, there are few reports of twins with LQTS. This is the first report, to our knowledge, of identical twins with a HERG gene mutation.

Adult↗

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 21). Comparison of the effects of 2- and 4-weeks pyrimethamine treatment in rats.

Pyrimethamine (PYR), clinically used as an antimalarial or antiparasitic agent, is known to exert testicular toxicity in rats on oral administration for 8 weeks. This study was performed to examine whether 2-weeks daily repeated doses of PYR might induce detectable toxicity on the male reproductive organs in rats. PYR was orally administered to Slc:SD male rats at doses of 12.5, 25 or 50 mg/kg for 2 weeks, or 6.25, 12.5 or 25 mg/kg for 4 weeks. No effects were seen in any group on physical examination and body weight measurement. Gross findings in autopsy exhibited no abnormalities in any of the animals. There were no meaningful changes in the weights of reproductive organs, or in the number and activity of sperm in the epididymides. Loss and degenerative changes of pachytene spermatocytes in stages I to III seminiferous tubules were observed in the rats given 50 mg/kg PYR for 2 weeks. From the results obtained, it is concluded that 2-weeks repeated dosing with PYR is sufficient to detect toxicity on male reproductive organs in rats using histopathological examination.

Administration, Oral↗

Sjögren's syndrome complicated with autoimmune hepatitis and antiphospholipid antibody syndrome.

A 56-year-old Japanese female simultaneously developed thrombocytopenia, sicca symptoms, and an elevation of transaminase. Antiphospholipid antibodies were detected in her serum. The presence of anti-SS-A antibodies in the serum and sialectasis, disclosed by sialography, suggested the presence of primary Sjogren's syndrome (SjS). The laboratory data and the biopsy of the liver showed compatible findings with autoimmune hepatitis (AIH). Thrombocytopenia and liver dysfunction satisfactorily responded to corticosteroid. To our knowledge, this is the first reported case of SjS with AIH and antiphospholipid antibody syndrome (APAS). Analysis of serum cytokine levels showed a predominance of Th0-Th1 response, which is not compatible with AIH, in this complicated autoimmune state.

Antibodies, Antiphospholipid↗

Duration of systemic corticosteroids in the treatment of asthma exacerbation; a randomized study.

OBJECTIVE: To determine an appropriate duration for a short course of oral steroids in cases of asthma exacerbations. SETTING: A 1,000 bed city hospital in Kobe, Japan. PATIENTS: Patients with asthma exacerbations who needed hospital admission. METHODS: Following an initial treatment with a 3-day course of intravenous methylprednisolone, patients were allocated to either a 1-week (1 W) or a 2-week (2 W) course of oral prednisolone (PSL, 0.5 mg/kg). OUTCOME MEASURES: Peak expiratory flow rate (PEF) and rate of unscheduled hospital visits and readmission. RESULTS: Twenty patients were enrolled (10 in 1 W, 10 in 2 W). Mean PEF just before starting oral PSL in 1 W and 2 W were 51 and 58% of each patient's best value. PEF was significantly improved and to a similar degree over the course of time in both 1 W and 2 W. The frequency of unexpected hospital visits during a 3-month period after discharge was similar (2 in 1 W and 2 in 2 W). No readmission occurred during the same period. CONCLUSIONS: Because both the 1-week and the 2-week course of oral PSL were equally effective in the treatment of asthma exacerbations, 1 week may be appropriate as the maximum duration of a short rescue course of oral steroids.

Acute Disease↗

Genetic basis of the complex pathological manifestations of collagen disease: lessons from MRL/lpr and related mouse models.

The pathological findings in collagen disease including systemic lupus erythematosus show complex lesions such as glomerulonephritis, systemic vasculitis, polyarthritis, sialoadenitis, etc. Moreover, some cases of collagen disease are categorized into overlapping syndromes. It is still controversial whether such diversity and similarity of pathological manifestations among the collagen disease depends on ambiguity in diagnosis or is an intrinsic quality of the collagen diseases themselves. In this paper, we reviewed this subject focusing on a series of our genetic studies of murine models of collagen disease, MRL strains of mice with a deficit in Fas-mediated apoptosis, which spontaneously develop glomerulonephritis, systemic vasculitis, polyarthritis and sialoadenitis. We observed that each lesion was controlled by a different set of genes and they appeared to act in an additive manner on the development of each lesion. We conclude that various disease categories in collagen disease will be a result of the combination of polygenes.

Animals↗

Familial neurohypophyseal diabetes insipidus associated with a novel mutation in the vasopressin-neurophysin II gene.

Familial neurohypophyseal diabetes insipidus (FNDI) is an autosomal dominant disorder of renal water conservation due to deficiency of arginine vasopressin as the result of mutations in the arginine vasopressin-neurophysin II (AVP-NPII) gene that encodes the hormone or its carrier protein. Thirty-one different mutations have been reported. In this study, we evaluated the AVP-NPII gene in a family with FNDI and identified a new mutation (1911Gright curved arrow A) in the coding sequence for NPII in affected family members. This mutation substitutes Tyr for 74 Cys in the NPII moiety. NPII is an intracellular carrier protein for AVP during the axonal transport from the hypothalamus to the posterior pituitary and contains 14 conserved cysteine residues forming 7 disulfide bonds. Because the mutation cosegregates with the phenotype, it is possible that this mutation causes neurohypophyseal diabetes insipidus in this family.

Adolescent↗

Expression levels of thymidine phosphorylase and dihydropyrimidine dehydrogenase in various human tumor tissues.

Thymidine phosphorylase (dThdPase) is the rate-limiting enzyme that metabolizes 5'-deoxy-5-fluorouridine (5'-dFUrd, doxifluridine), an intermediate metabolite of capecitabine, to the active drug 5-fluorouracil (5-FUra), while dihydropyrimidine dehydrogenase (DPD) catabolizes 5-FUra to an inactive molecule. The susceptibility of tumors to fluoropyrimidines is reported to correlate with tumor levels of these enzymes. To obtain some insight into the tumor types susceptible to fluoropyrimidine therapy, we measured expression levels of these two enzymes in various types of human cancer tissues (241 tissue samples) by the ELISA methods. DPD exists in all the cancer types studied, such as bladder, breast, cervical, colorectal, esophageal, gastric, hepatic, pancreatic, prostate, and renal cancers. Among them, the cervical, hepatic, pancreatic, esophageal, and breast cancer tissues expressed high levels of DPD (median >70 U/mg protein), while high concentrations of the dThdPase were expressed in esophageal, cervical, breast, and pancreatic cancers and hepatoma (median >150 U/mg protein). The dThdPase/DPD ratio, which was reported to correlate with the susceptibility of human cancer xenografts to capecitabine, was high in esophageal, renal, breast, colorectal, and gastric cancers (median ratio of >1.5). In any of these three parameters, the inter-patient DPD variability for each cancer type was much larger than the DPD variability among cancer types; highest/lowest ratios for dThdPase, DPD, and dThdPase/DPD were 10-321, 7-513, and 2-293, respectively. These results indicate that measurements of the three parameters, DPD, dThdPase and dThdPase/DPD, would be useful criteria for selecting cancer patients suitable for fluoropyrimidine therapy rather than for selecting cancer types.

Animals↗