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Biomedical subjects

I Nakamura

Publications and source records attributed to I Nakamura.

At least 37 records · Page 2Linked to original sources

Palladium-catalyzed addition of alcohol pronucleophiles to alkylidenecyclopropanes.

Palladium-catalyzed addition of alcohol pronucleophiles 1 to alkylidenecyclopropane derivatives 2 afforded the corresponding allylic ethers 3 in excellent to moderate yields. Catalyst optimization indicated the Pd(PPh3)4-P(o-tolyl)3 combination as the best system among all catalysts tested. Intramolecular reaction also proceeded smoothly. A plausible mechanism for this catalytic reaction was proposed.

Journal Article↗

Production of recombinant bovine lactoferrin N-lobe in insect cells and its antimicrobial activity.

Lactoferrin is a multifunctional, iron-binding glycoprotein found in physiological fluids of mammals. In the present study, a gene encoding the N-terminal half (N-lobe) of bovine lactoferrin was cloned and expressed in cultured insect cells using a baculovirus expression system. One mutation was found in the lactoferrin N-lobe gene, but it resulted in no amino acid substitution. The recombinant lactoferrin N-lobe was secreted into the culture medium and partially purified by means of an immobilized heparin column. The recombinant lactoferrin N-lobe secreted was not glycosylated, but it possessed antimicrobial activity toward Escherichia coli O111. The recombinant product synthesized and accumulated in the host cells exhibited greater electrophoretic mobility on SDS-PAGE than the secreted product and showed no potency to inhibit the growth of bacteria. It is thought that the product accumulated intracellularly lacks antimicrobial ability due to its degradation in the host cells or due to disruption of the active conformation.

Animals↗

The STR locus D11S554: allele frequencies and sequence data in a Japanese population.

A population study on the short tandem repeat (STR) locus D11S554 was carried out in a sample of 362 unrelated Japanese individuals living in the Gifu Prefecture. A total of 46 different alleles ranging from 180 bp to 340 bp and 135 genotypes were revealed. Sequence analysis of alleles was carried out for 185 samples. The sequence structures of the repeat regions of the alleles were found to be complex and the alleles were classified into nine sequence types, including four new sequence types. According to the system of Adams et al. (1993), we designated the new sequence types IA3, IA4, IA5 and IB3, respectively. Out of the 46 different alleles, 11 showed sequence heterogeneity. The results of this study demonstrated that the D11S554 locus is a powerful and useful genetic marker for forensic practice in the Japanese population.

Alleles↗

Increased Fas ligand expression in the tumor tissue and serum of patients with testicular germ cell tumors with seminomatous elements.

OBJECTIVES: To measure the expression levels of Fas and Fas ligand (FasL) in testicular germ cell tumor (TGCT) and to determine whether the serum level of soluble FasL (sFasL) could be used as a marker for patients with TGCT. METHODS: The expression of Fas and FasL in 51 specimens obtained from patients with TGCT was examined by reverse transcriptase-polymerase chain reaction, and the results were confirmed by Western blot analysis. The serum levels of sFasL in 24 patients with TGCT were measured using an enzyme-linked immunosorbent assay system. RESULTS: Of 33 TGCT specimens that included seminomatous elements, Fas and FasL was expressed in 24 (73%) and 24 (73%), respectively. On the other hand, 10 (56%) and 2 (11%) specimens expressed Fas and FasL, respectively, in 18 TGCT specimens without seminomatous elements. Moreover, the serum levels of sFasL were significantly higher in patients with TGCT with a seminomatous element than in those without it. CONCLUSIONS: These results indicate that FasL is strongly expressed in tumor tissue and is present at high levels in the serum of patients with TGCT with a seminomatous element compared with those without it and that the serum levels of sFasL could be used as a novel diagnostic marker for TGCT with seminomatous elements.

Biomarkers, Tumor↗

Origin of DNA in human serum and usefulness of serum as a material for DNA typing.

The aims of this study were to clarify the origin of DNA in human serum and to investigate whether serum is a material available for DNA typing in routine forensic practice. Blood was donated from 10 healthy adult volunteers and stored for up to 8 days, at 4 degrees C and at room temperature. The serum DNA concentration at zero time was in the range of 5.6 to 21.8 ng/ml with a mean of 12.2+/-1.6 ng/ml. The concentrations increased with storage time. On agarose gel electrophoresis, all serum samples showed ladder patterns and the size of each band was an integer multiple of approximately 180 bp considered to be characteristic of apoptosis. DNA typing from DNA released by apoptosis was possible. Exact DNA typing of D1S80, HLA DQA1, PM, CSF1PO, TPOX, TH01 and vWA was possible for each sample. These results indicate that serum contains fragmented DNA derived from apoptosis of leukocytes, especially neutrophils, and that fragmented DNA is an appropriate material for DNA typing.

Journal Article↗

Fatal Aspergillus pancarditis after incompatible blood transfusion intended to be an autologous blood transfusion.

Aspergillus pancarditis is a rare infection, and it has rarely been reported after blood transfusion. In this report, we describe a fatal case of Aspergillus pancarditis in a patient who received antibiotics and corticoids after an incompatible blood transfusion intended to be an autologous blood transfusion. A 64-year-old man suffering from herniation of intervertebral disk between C4 and C5 received an anterior cervical spinal fusion. After the operation, he received incompatible blood transfusion and fell into disseminated intravascular coagulation (DIC) and preshock state. Anticoagulants and corticoids were given and he recovered from DIC and the preshock state. However, he remained quadriplegic because of enlargement of cervical epidural hematoma that was initially brought out by the operation. He developed bacterial bronchopneumonia 2 weeks after the transfusion and received antibiotic therapy. The pneumonia was cured a week later. Five weeks after the transfusion, he developed Aspergillus pneumonia and received antimycotic therapy. However, his condition grew worse and died 2 months after the transfusion. Autopsy revealed Aspergillus pancarditis. In this case, the relationship between the erroneous transfusion and the patient's death was obvious and it was considered that the erroneous transfusion should be blamed for the patient's death.

Journal Article↗

Pathogenesis of experimental neonatal woodchuck hepatitis virus infection: chronicity as an outcome of infection is associated with a diminished acute hepatitis that is temporally deficient for the expression of interferon gamma and tumor necrosis factor-alpha messenger RNAs.

Surgical biopsies of the liver were obtained from woodchuck hepatitis virus (WHV)-infected neonatal woodchucks at 2 time points before the self-limited or chronic outcomes became obvious by serologic criteria. Following segregation of outcomes, livers were analyzed for intrahepatic type 1 cytokine messenger RNAs (mRNAs) (interleukin 2 [IL-2], interferon gamma [IFN-gamma], tumor necrosis factor-alpha [TNF-alpha]) and leukocyte inflammatory phenotype (IgG+ plasma cells, lysozyme+ macrophages, CD3+ T cells). Baselines were assessed using age-matched uninfected control livers. At week 8 (early acute phase), intrahepatic type 1 cytokine mRNAs were similarly low in both outcome settings and no different from age-matched uninfected controls. This was consistent with the minimal initial viral loads and lack of histologic inflammation at this time. At week 14 (mid-acute phase), changes in viral load between outcome groups related inversely to the intrahepatic inflammatory responses. Animals that eventually became resolved had increased intrahepatic expression of IFN-gamma and TNF-alpha mRNAs and robust inflammation by CD3+ T cells, plasma cells, and macrophages. At the same time point of infection, animals that eventually became chronic carriers had an acute hepatitis involving the same cell types, but at diminished levels, and markedly deficient intrahepatic expression of IFN-gamma and TNF-alpha mRNAs. IL-2 mRNA remained at baseline control levels in both outcome groups. These cotemporal comparisons map a critical deviation in host response to the acute stage of an evolving chronic infection. They strongly suggest that increasing viral load and chronicity as an outcome of neonatal WHV infection result from a temporal deficiency in the acute intrahepatic effector mechanisms mediated by IFN-gamma and TNF-alpha.

Actins↗

Posttraumatic thrombosis of the middle cerebral artery.

Posttraumatic cerebral infarction resulting from carotid or cerebral artery occlusion is rare. Traumatic dissection of the carotid artery is the most frequent cause of infarction, whereas posttraumatic thrombosis of the cerebral artery is very rare. The authors describe a case of posttraumatic thrombosis of the left middle cerebral artery. Early in the morning, a 16-year-old boy was found unconscious in the parking lot of a supermarket. He had received fist blows and kicks to the head, face, body, back, and hip during the night. Computed tomography 10 hours after the violence revealed a gross cerebral infarction in the area of the left middle cerebral artery. He died 9 days after the violence. The autopsy revealed a thrombosis in the left middle cerebral artery. Microscopically, granulation tissue in the intima and a rupture of the internal elastic lamina were observed near the beginning of the artery. It was concluded that the blows to the head and face caused a partial rupture in the arterial wall, leading to thrombosis and cerebral infarction.

Adolescent↗

[Two patients with Bartonella henselae infection from a dog].

Two patients were reported as having been infected with Bartonella henselae after having contact with a dog. Both of the patients owned a dog, but had no contact with cats. One patient was a 10-year-old boy who had experienced a fever of 38-39 degrees C for 11 days, as well as having bilateral cervical lymphadenopathy. The boy's serum IgM antibodies to B. henselae were negative on the 6th and 16th day of his illness, whereas his IgG value, using indirect fluorescence antibody (IFA) method, was found to be elevated from 1:256 to 1:1,024. B. henselae DNA was detected, by PCR method, in swabs from the gingiva and buccal membrane of the dog with which the boy had been in contact. The boy was first treated with cefdinir (300 mg daily) for 6 days without beneficial effect. He responded, however, to minocycline (100 mg daily) with symptom resolution in four days. The other patient was a 64-year-old man who had experienced a fever of 38-39 degrees C for 27 days, as well as having right inguinal lymphadenopathy. The man's serum IgM antibody to B. henselae was negative, although his IgG value, determined by IFA, was 1:1,024. In addition, B. henselae DNA was detected, by PCR method, in parafin-embedded tissue obtained from the biopsied inguinal lymph nodes. The man was treated with cefazolin (2 g daily). His fever resolved, but his lymph nodes remained swollen. After a regimen of erythromycin (1,200 mg daily), the swelling in his inguinal lymphnodes gradually disappeared. Careful review of suspected CSD victims' history of contact with animals is important in making a prompt diagnosis of B. henselae infection.

Animals↗

Analysis of Clostridium difficile isolates from nosocomial outbreaks at three hospitals in diverse areas of Japan.

Clostridium difficile isolates recovered from patients with C. difficile-associated diarrhea (CDAD) at three hospitals located in diverse areas of Japan were analyzed by three typing systems, PCR ribotyping, pulsed-field gel electrophoresis (PFGE), and Western immunoblotting. At the three hospitals examined, a single PCR ribotype strain (type smz) was predominant and accounted for 22 (65%) of 34, 18 (64%) of 28, and 11 (44%) of 25 isolates, respectively. All of the 51 isolates that represented PCR ribotype smz were nontypeable by PFGE because of DNA degradation. Since the type smz strain did not react with any of the antisera against 10 different serogroups (A, B, C, D, F, G, H, I, K, and X), we prepared a new antiserum against a type smz isolate. All 51 type smz isolates presented identical banding patterns, reacting with the newly prepared antiserum (designated subserogroup JP-0 of serogroup JP). These results were compared with those of a strain from a hospital outbreak that occurred in New York, which has been identified as type J9 by restriction enzyme analysis and type 01/A by arbitrarily primed PCR but was nontypeable by PFGE because of DNA degradation. This strain was reported to be epidemic at multiple hospitals in the United States. The J9 strain represented a PCR ribotype pattern different from that of a type smz strain and was typed as subserogroup G-1 of serogroup G by immunoblot analysis. A single outbreak type causing nosocomial CDAD in Japan was found to be different from the strain causing multiple outbreaks in the United States, even though the outbreak strains from the two countries were nontypeable by PFGE because of DNA degradation.

Bacterial Typing Techniques↗

Differences in parasympathetic vasodilator and salivary responses in the cat submandibular gland between lingual and chorda-lingual nerve stimulation.

Experimental activation of parasympathetic vasodilatation and salivation in the submandibular gland by a "pseudoreflex" method has definite advantages over other commonly used methods. However, it is unclear which stimulation sites allow for avoidance of direct activation of the parasympathetic efferents to this gland. We examined this question in heavily anesthetized (alpha-chloralose and urethane), artificially ventilated, cervically vago-sympathectomized cats, using the intersection of the chorda-lingual nerve and the submandibular gland duct ("the intersection") as our reference point. Both vasodilatation and salivation evoked by electrical stimulation of the lingual nerve were abolished by section of the chorda-lingual nerve (10 mm proximal to the intersection), provided the stimulation site was distal to the intersection by 4 mm or more. This salivation was abolished by the muscarinic receptor antagonist, scopolamine. Thus, by careful choice of stimulation site, submandibular gland responses mediated solely by reflex parasympathetic mechanisms can be evoked by lingual nerve stimulation in this preparation.

Adrenergic alpha-Antagonists↗

Abnormal localisation and hyperclustering of (alpha)(V)(beta)(3) integrins and associated proteins in Src-deficient or tyrphostin A9-treated osteoclasts.

The non-receptor tyrosine kinase Src was shown to be essential for osteoclast function in vivo. We have previously reported that engagement of (alpha)(v)(beta)(3) integrin in osteoclasts induces tyrosine phosphorylation and activation of the adhesion kinase PYK2 and the adaptor protein p130(Cas) in a Src-dependent manner. The objective of this study was to analyse the role of c-Src in the (alpha)(v)(beta)(3) integrin-dependent recruitment of signalling and cytoskeletal molecules in osteoclasts during bone resorption. Using prefusion osteoclasts (pOCs) obtained from cocultures of osteoblasts and spleen cells isolated from Src(-/-) mice or their normal littermates, we found: (1) similar expression levels and ligand binding affinities of (alpha)(v)(beta)(3) integrins in Src(-/-) and Src(+/?) pOCs, (2) reduced adhesion and spreading of Src(-/-) pOCs, (3) defective organisation of the microfilament proteins, F-actin, vinculin and paxillin, and of PYK2 and p130(Cas) in the sealing zone of Src(-/-)OCLs, and (4) hyperclustering of (alpha)(v)(beta)(3) integrins together with microfilament and signalling proteins in the basal membrane of Src-deficient OCLs. In normal OCLs, the tyrosine kinase inhibitor tyrphostin A9 inhibits actin ring formation, bone resorption and tyrosine phosphorylation of several proteins, including c-Src. Furthermore, tyrphostin A9 induced similar hyperclustering of (alpha)(v)(beta)(3) integrins in osteoclasts as observed in Src(-/-) OCLs. Taken together, these findings suggest that normal localisation of (alpha)(v)(beta)(3) and recruitment of its downstream effectors to the appropriate compartments of the osteoclast during resorption depend on Src kinase activity.

Animals↗

Critical pathway improves arrival-in-cath-lab interval for patients with acute myocardial infarction in the emergency department.

A newly developed critical pathway has been applied to emergency medical care of patients with acute myocardial infarction (AMI) in the emergency department. The arrival-in-cath-lab interval (ACI) was selected as a clinical indicator of quality assurance, according to American Heart Association and American College of Cardiology guidelines. This report describes the first experience of applying the critical pathway to patients with AMI in an emergency department in Japan. The ACI of 35 AMI patients who underwent primary percutaneous transluminal coronary angioplasty during a 24-month period following application of the pathway were compared with those of 50 AMI patients during the 48 months before application of the pathway. The median ACI value was significantly reduced from 65.5 min to 50.0 min. Also, the proportion of patients with acceptably short ACI (<60 min) significantly improved from 42.0% to 68.6%.

Adolescent↗

Structure and characterization of the gene encoding alpha subunit of soybean beta-conglycinin.

beta-conglycinin, a soybean seed storage protein, is comprised of three different subunits, a, alpha', and beta. Several candidates for the alpha subunit gene have been isolated, however, the structure of the alpha subunit gene has not been completely determined. Accordingly, it was also unknown which of the gene candidates are functionally active. Here, we have determined the nucleotide sequence and transcription start site of the alpha subunit gene, and compared the structural components with those of the other subunits or other seed protein genes. The a subunit gene, which is located on a 7.6-kb EcoRI fragment, was composed of six exons that had the same organization as those for the alpha' subunit gene. Within a 400 bp upstream region of the transcription start site, four regions (designated as boxes I, II, III, and IV) were found to be conserved among the alpha, alpha', and other seed protein genes. Genomic Southern blot analysis of soybean varieties lacking the alpha subunit gene candidate indicated that the gene characterized in this paper actually encodes the a subunit and is functionally active. In addition, these experiments revealed the presence of an additional gene which is also responsible for the expression of the a subunit.

Amino Acid Sequence↗

Investigation of usefulness of sperm analyses in dogs for male fertility study.

The usefulness of sperm analyses in dogs, including sperm motion analysis, was investigated. Sperm motion analysis was performed with the CellSoft-4000 computer-assisted sperm analysis (CASA) system. First, we examined the conditions for preservation of optimal semen quality. We found that sperm retained more of their motility at 4 degrees C than at 37 degrees C. Secondly, we observed sperm motion, concentration and morphology in dog semen continuously for 11 weeks. We collected semen samples during the test period, and the samples retained sperm motion, concentration and morphology. Finally, we administrated alpha-chlorohydrin, which decreases rodent sperm motion, at a single oral dose of 100 mg/kg or 150 mg/kg to dogs. Sperm motion was inhibited immediately after alpha-chlorohydrin treatment, and recovered after 2 weeks. None of the experimental animals were sacrificed in the above-mentioned examinations. We thus confirmed that sperm analyses including motion analysis in dogs are useful in male fertility studies.

Animals↗

Pheochromocytoma of the urinary bladder revealed with cerebral hemorrhage.

The case was a 51-year-old man, who has been undergoing treatment with oral medication for hypertension for three years. The patient was admitted to the author's clinic for hemorrhage in the left putamen. He was diagnosed as having primary pheochromocytoma of the bladder from such symptoms as paroxysmal blood pressure elevation after urination, mild increase in catecholamine levels before and after urination, and from the results of 131I-MIBG scintigraphy, and cystoscopy, and underwent excision of the bladder tumor. Upon endocrinological examination, only mild increases in catecholamine levels were found. Therefore, constant monitoring of blood pressure and 131I-MIBG scintigraphy were useful for a definitive diagnose.

Catecholamines↗

[Interferon-treated hepatitis C virus(HCV) patients with sustained biochemical response without eradication of HCV(asymptomatic HCV carrier)].

Patients with hepatitis C virus(HCV) responding differently to interferon(IFN) therapy were speculated to have different incidence of disease progression to cirrhosis and of the development of hepatocellular carcinoma(HCC). However, the background and prognosis of the patients with sustained biochemical response without eradication of HCV (BR) (asymptomatic HCV carrier) has not been revealed so far. Review of recent studies suggest that the characteristics of the patients with BR are lower HCV RNA load, higher rate of HCV subtype-2 and lower score of liver fibrosis when compared with those with NR. The IFN therapy in patients who have not cleared HCV and showed normal ALT retards progression of fibrosis and reduces the incidence of cirrhosis and HCC.

Carcinoma, Hepatocellular↗