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Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

At least 145 records · Page 8Linked to original sources

[MALT lymphoma].

MALT lymphoma was first described by Isaacson et al., in 1983, as an extranodal lymphoma arising in the marginal zone of the mucosa-associated lymphoid tissue, and has recently aroused much interest among investigators. This disease was incorporated in the REAL classification in 1994, and has since been accepted as an established independent disease entity involving the lymphoid tissues. The purpose of this paper is to comment on the disease concept, pathology, diagnosis and therapy of MALT lymphoma as well as the outlook for its study and management, and to survey the relevant literature.

Antigens, Bacterial↗

[Measurement of formaldehyde-specific IgE antibodies in adult asthmatics].

Formaldehyde (FA) is known to be a potent contact sensitizer eliciting dermatitis or bronchial asthma in occupational settings. However, several pieces of recent evidence indicate that FA is a participant of indoor air pollution even at home and that it may be one of the causative agents for the sick-house syndrome. In the present study, we examined whether production of FA-specific IgE antibody (FA-IgE) occurred in adult chronic asthmatics or not. We randomly selected 80 adult asthmatics, and obtained blood sampling under the condition where the symptoms were well controlled. We measured FA-IgE, eosinophil count and serum concentration of eosinophil cationic protein (sECP), and also measured lung functions (FEV1%, %VC, V25/HT). We found that FA-IgE was positive in two patients (33-year-old female and 56-year-old male), while negative (less than 0.35 UA/ml) in the others. State of asthma was severe in the female patient, while mild intermittent in the male patient. In the female patient, the total IgE titer and the FA-IgE titer were 181 IU/ml and 0.81 UA/ml, respectively, and there was no occupational environments concerning FA. In the male patient, both the total IgE and the FA-IgE titer were quite high (8400 IU/ml and 2.99 UA/ml, respectively). In this case, there was an occupational environment where the adhesive smell was strong. sECP was 44.2 micrograms/l in the female patient, while 4.7 micrograms/l in the male patient. In the present study, IgE-mediated allergy for FA was rare in adult chronic asthmatics, and the FA-IgE titer did not seem parallel to severity or pathophysiological condition in bronchial asthma. But, further development of precise methodology for clinically clarifying FA-mediated mechanisms in allergic disorders, might be still important.

Adult↗

[The complication with tuberculosis of the central nervous system in patients with miliary tuberculosis].

The complication with tuberculosis of the central nervous system (CNS) were studied in 16 patients with miliary tuberculosis who were admitted to our hospital during a period of two years from April, 1997 to March, 1999, and were examined by head MRI. Twelve cases (75%) were diagnosed as having tuberculosis of CNS. Six cases had tuberculosis of CNS which was found during the screening of miliary tuberculosis cases, and all had only cerebral tuberculoma. Meningeal irritative symptoms led to the discovery of tuberculosis of CNS in the remaining six cases, in which cerebral tuberculoma was complicated with tuberculous meningitis. Of these cases of meningitis, three cases showing disturbance of consciousness died, but no cases of death was found in cases by the screening. The length of time from the onset of symptoms to the diagnosis of tuberculosis was long in many of the cases complicated with tuberculosis of CNS compared with the cases without such a complication. In the cases of miliary tuberculosis, the rate of complication with tuberculosis of CNS is high, and the possibility of patients developing serious symptoms suddenly even when they were asymptomatic at the time of diagnosis and the paradoxical expansion that becomes intensified after initiation of treatment have been reported. Therefore, it is necessary to make a close checkup of CNS when the diagnosis of miliary tuberculosis has been made.

Adult↗

[Frequency of complication of diabetes mellitus in pulmonary tuberculosis].

The frequency of complication of diabetes mellitus in patients with pulmonary tuberculosis is high, and the presence of diabetes mellitus plays an important role in the development of pulmonary tuberculosis. We studied the frequency of complication of diabetes mellitus by year, sex and age among patients with pulmonary tuberculosis who were discharged from our hospital during a period of 12 years from 1987 to 1998. The number of diabetic cases in patients with pulmonary tuberculosis was 588, namely 14.1% out of 4169 patients during the 12 years from 1987 to 1998. The frequency of complication of diabetes in every four years period showed an increasing trend; 144 cases (11.8%) out of 1225 cases from 1987 to 1990, 208 cases (14.5%) out of 1434 cases from 1991 to 1994, and 236 cases (15.6%) out of 1510 cases from 1995 to 1998. By sex, the frequency of complication with diabetes mellitus in male was about twice that of female, with 501 cases (16.0%) out of 3127 cases in male and 87 cases (8.3%) out of 1042 cases in female. By age, the frequency of complication of diabetes mellitus showed a peak in the 40s and 50s in male, being 21.3% and 23.4% respectively. In female, it showed a peak in the 60s, being 18.5%. In conclusion, in the 12 years the frequency of complication of diabetes mellitus in tuberculosis cases has been increasing, and the presence of diabetes mellitus has been playing more important role in the development of pulmonary tuberculosis.

Adult↗

[A comparative study of the prognosis for Japanese patients with idiopathic interstitial pneumonia or BOOP based on histopathologic subsets].

We explored the prognosis for 123 patients with either idiopathic interstitial pneumonia (IIP) or bronchiolitis obliterans organizing pneumonia (BOOP). All patients underwent either open lung biopsy or thoracoscopic lung biopsy procedures. The histopathologic diagnosis of IIP included patients with usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), and desquamative interstitial pneumonia with respiratory bronchiolitis-associated interstitial lung disease. The prognosis was poorest for patients with a histologic diagnosis of UIP, and excellent for those who received a diagnosis of BOOP. Although the prognosis is generally considered to be good for patients with NSIP, some NSIP patients in our study died. Histopathologic diagnosis based on surgical lung biopsy is useful in evaluating the prognosis for patients with IIP.

Aged↗

[Management of pulmonary tuberculosis patients complicated with diabetes mellitus before diagnosis as pulmonary tuberculosis and feasibility of chemoprophylaxis].

We studied whether diabetics who are one of the high risk groups of developing pulmonary tuberculosis had undergone chest X-ray examination periodically. The feasibility of chemoprophylaxis in diabetics was also studied by investigating whether fibrotic lesions of tuberculosis can be found on previous chest X-ray films of these patients. Of the pulmonary tuberculosis patients admitted to our hospital for treatment, 78 patients complicated with diabetes mellitus were enrolled in this study. As to the mode of detection, the majority, 63 cases, are discovered, by undergoing medical examination because of respiratory symptoms, followed by 8 patients in whom pulmonary tuberculosis was found by health examination and only 1 patient was found by the periodic observation of diabetes mellitus. Of the 57 patients receiving the original treatment for pulmonary tuberculosis preceded by the discovery of diabetes mellitus, only 15 (26%) had undergone chest X-ray examination periodically. This fact shows that physicians treating diabetes mellitus have only a little concern on tuberculosis, thus the re-training of physicians dealing with diabetics on tuberculosis is considered to be necessary. According to chest X-ray films of 21 patients who had undergone chest X-ray examination and in whom the previous films were available, there were 6 patients without any lesion of pulmonary tuberculosis, 8 patients with fibrotic lesions and 7 patients with active lesions. The 8 patients showing fibrotic lesions have developed pulmonary tuberculosis on the average 15 years after they were diagnosed with diabetes mellitus, and the fact suggests that the prevention of the development of pulmonary tuberculosis among diabetics could be possible by chemoprophylaxis.

Chemoprevention↗

Involvement of cyclin-dependent kinases in doxorubicin-induced apoptosis in human tumor cells.

Apoptotic cell death caused by doxorubicin, a chemotherapeutic agent, is suppressed by expression of p21 (waf1/cip1/sdi1), a cyclin-dependent kinase (cdk) inhibitor. To examine cdk activity required for doxorubicin-induced apoptosis, we transfected p21-deficient human tumor DLD1(p21-/-) cells with plasmids carrying wild-type p21 and mutated p21 unable to bind to cdks or proliferating cell nuclear antigen. The apoptosis induced at the G(2)/M phase after doxorubicin treatment was suppressed by transient expression of the p21 with cdk-binding activity but not by the p21 lacking the activity. We also transfected cells with plasmids carrying wild-type, dominant negative and constitutively active mutants of cdk2 or cdk4. The apoptosis was suppressed by transient expression of dominant negative mutants of cdk2 or cdk4. These findings indicate that cdk is involved in the doxorubicin-induced apoptosis pathway.

Antibiotics, Antineoplastic↗

[Is myocardial impairment in idiopathic dilated hypertrophic cardiomyopathy reversible by carvedilol?: a case report].

A 64-year-old woman with dilated hypertrophic cardiomyopathy was treated by beta-blocker, because of recurrent episodes of congestive heart failure. Carvedilol administration was started with a dose of 2.5 mg/day, and gradually increased to the dose of 20 mg/day 3 months later. Her functional class recovered from New York Heart Association stage IV to stage II. Thallium-201 scintigraphy demonstrated advanced myocardial damage: defect/low perfusion in the anteroseptal, infero-posterior and apical regions. Iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid scintigraphy confirmed these findings. However, the scintigraphic abnormalities had reversed to near normal perfusion and metabolism similar to those of stunned myocardium after an ischemic episode. This case demonstrates the recovery of myocardial impairment during beta-blocker therapy in a patient with dilated hypertrophic cardiomyopathy.

Adrenergic beta-Antagonists↗

[A study of patient's and doctor's delay in patients with pulmonary tuberculosis discovered by visiting doctors with symptoms in particular on doctor's delay].

Epidemiological trend of tuberculosis in Japan has reversed recently. The incidence of pulmonary tuberculosis (PTB) patients has increased again in Japan, and many outbreaks of PTB including nosocomial outbreaks in health-care facilities have been reported. The purpose of this study is to investigate patient's delay (interval between onset of the disease and first visit to a doctor) and doctor's delay (interval between first visit to a doctor and diagnosis as TB) in patients with PTB discovered by visiting doctors with symptoms, and especially, to investigate causes of doctor's delay in details. Of 236 PTB patients who were admitted to our hospital for treatment in 1997, 118 patients (85 males, 33 females) who were detected by their symptomatic visits were enrolled in to this study. 97 were initial treatment cases and the others were re-treatment cases. Among 34 initial treatment cases who were first seen at a general hospital and diagnosed as PTB by a close medical checkup after admission to our hospital, the 50 percentile of patient's delay was 17.0 days, and the 80 percentile was 36.4 days. The 50 percentile doctor's delay was 19.6 days, and the 80 percentile was 64.2 days. The average hospital stay was 16.2 days, the 50 percentile hospital stay was 7.8 days, and 80 percentile hospital stay was 23.5 days. On the sputum test for acid fast bacilli (AFB) performed on admission to our hospital, 26(76%) out of 34 cases were positive for tubercle bacilli, with 18 cases were positive for smear and 8 cases positive for culture. Therefore, risk of nosocomial infection was suspected. Doctor's delay had been attributed mainly to insufficient medical checkup. Among 25 initial treatment cases in whom doctor's delay as more than 4 weeks, 11 cases (44%) showed delay in chest X-ray examination and 8 cases (32%) ordered no sputum examination in spite of recognition of abnormal shadows on chest X-ray. On the sputum test for AFB on admission to our hospital, 22 (88%) out of 25 cases were positive for tubercle bacilli. Therefore, it is assumed that the delay in the adequate medical checkup was accountable for the doctor's delay. Shortening of the doctor's delay could be possible if hospitals perform the sputum examination for AFB and chest X-ray examinations properly for patients with respiratory symptoms.

Adult↗

[A successful case of preoperative intermittent hepatic arterial infusion of high-dose 5-FU and pharmacokinetic modulating chemotherapy against unresectable liver metastasis of colon cancer].

A 46-year-old adult who underwent a sigmoidectomy for sigmoid colon cancer at the age of 44 was found to have a liver tumor 2 years after the first operation. His CEA was elevated to 158.8 ng/ml. An abdominal CT showed a huge mass of 10 x 7 x 7 cm in the anterior segment of right lobe of the liver invading into segment 4 and 7, which compressed the left hepatic vein and the umbilical portion of the portal vein. We diagnosed an unresectable liver metastasis of sigmoid colon cancer. Intermittent hepatic arterial infusion of high-dose 5-FU was started on a weekly schedule and oral UFT was added as pharmacokinetic modulating chemotherapy 4 weeks after the initial chemotherapy. Chemotherapy was continued for 13 weeks and the tumor shrunk up to 64%. An extended right hepatectomy was performed. Pathological examination showed residual cancer cells in the central part of the tumor, but fibrous degeneration and calcification were observed in the surrounding area and considered to be the effect of chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

[Percutaneous transluminal septal myocardial ablation combined with permanent dual-chamber pacing in hypertrophic obstructive cardiomyopathy: a case report].

A 74-year-old woman suffering from dyspnea on effort and chest pain (New York Heart Association functional class III) was admitted to our hospital. Echocardiography and left ventriculography showed severe hypertrophy of the left ventricular wall and a severe intraventricular pressure gradient of about 150 mmHg. The diagnosis was hypertrophic obstructive cardiomyopathy. The intraventricular pressure gradient was decreased from 157 to 68 mmHg by percutaneous transluminal septal myocardial ablation (PTSMA), but this reduction was not adequate. Thereafter, dual-chamber pacing was additionally performed. The intraventricular pressure gradient was decreased to 26 mmHg with no complication. PTSMA is a certain way to decrease pressure gradient, but has some complications. Permanent dual-chamber pacing also can show the same effect, but is inferior to PTSMA. Combination of these 2 methods succeeded in abolishing the intraventricular pressure gradient with no complication.

Aged↗

[A clinical study in the collagen disease patients developed pulmonary tuberculosis during corticosteroid administration].

The study subjects consisted of 14 pulmonary tuberculosis (PTB) patients with collagen disease. They are under corticosteroid treatment and the mean age is 56.4 years. The length of time from the development of collagen disease to the development of PTB averaged 4.1 years. The breakdown of collagen disease are SLE (6 patients), MCTD (3 patients), PN (2 patients), and PSS, PM, Sjogren syndrome (1 case, each). Thirteen cases were bacilli positive by the sputum examination on admission to our hospital. Chest X-ray findings on admission revealed cavitation in 3 cases and non-cavitation in 11 cases, of which 5 cases had miliary tuberculosis. Corticosteroid preparation had been administered to all of the 14 cases for more than one year. The mean dose of corticosteroid preparation administered when PTB developed was 13.9 mg (prednisolone) and it was more than 20 mg in 8 cases. The median duration from the start of the respiratory symptoms to diagnosis was 39.2 days. The delay in the discovery exceeding 1 month were seen in 9 cases. In the cases of collagen disease, when the disease course extends over a long period of time, and even when the dose of corticosteroid preparations are decreased, there is a need to be note on the risk of developing PTB. There are many non-cavitary cases with sputum smear positive. The fact suggested that an appropriate diagnosis is need so that the discovery of PTB should not be delayed.

Adrenal Cortex Hormones↗

Proteins of the CNR family are multiple receptors for Reelin.

Layering and positioning of neurons require Reelin- and Src family-associated mammalian Disabled (mDab1). Cadherin-related neuronal receptor (CNR) genes are expressed in neurons of the cortical layer, but not in Cajal-Retzius cells expressing Reelin. This leads us to hypothesize that CNRs bound to Fyn of the Src family are receptors for Reelin. Herein we confirm the association and colocalization of CNR proteins with Reelin. This binding is blocked by CR-50 antibody against Reelin, as well as by monoclonal antibodies produced against CNRs. Both disturb the signaling pathway from Reelin to mDab1 and the positioning of cortical neurons in vitro. These results strongly suggest that the CNR family proteins are multiple Reelin receptors. In addition, differential conservation of the Reelin-binding domain among terrestrial vertebrates may be pertinent to the diversity or complexity of brains.

Animals↗

Expression of a mammalian DNA photolyase confers light-dependent repair activity and reduces mutations of UV-irradiated shuttle vectors in xeroderma pigmentosum cells.

Photoreactivation is one of the DNA repair mechanisms to remove UV lesions from cellular DNA with a function of the DNA photolyase and visible light. Two types of photolyase specific for cyclobutane pyrimidine dimers (CPD) and for pyrimidine (6-4) pyrimidones (6-4PD) are found in nature, but neither is present in cells from placental mammals. To investigate the effect of the CPD-specific photolyase on killing and mutations induced by UV, we expressed a marsupial DNA photolyase in DNA repair-deficient group A xeroderma pigmentosum (XP-A) cells. Expression of the photolyase and visible light irradiation removed CPD from cellular DNA and elevated survival of the UV-irradiated XP-A cells, and also reduced mutation frequencies of UV-irradiated shuttle vector plasmids replicating in XP-A cells. The survival of UV-irradiated cells and mutation frequencies of UV-irradiated plasmids were not completely restored to the unirradiated levels by the removal of CPD. These results suggest that both CPD and other UV damage, probably 6-4PD, can lead to cell killing and mutations.

Base Sequence↗

Mre11 is essential for the maintenance of chromosomal DNA in vertebrate cells.

Yeast Mre11 functions with Rad50 and Xrs2 in a complex that has pivotal roles in homologous recombination (HR) and non-homologous end-joining (NHEJ) DNA double-strand break (DSB) repair pathways. Vertebrate Mre11 is essential. Conditionally, MRE11 null chicken DT40 cells accumulate chromosome breaks and die upon Mre11 repression, showing frequent centrosome amplification. Mre11 deficiency also causes increased radiosensitivity and strongly reduced targeted integration frequencies. Mre11 is, therefore, crucial for HR and essential in mitosis through its role in chromosome maintenance by recombinational repair. Surprisingly perhaps, given the role of Mre11 in yeast NHEJ, disruption of NHEJ by deletion of KU70 greatly exacerbates the effects of MRE11 deficiency, revealing a significant Mre11-independent component of metazoan NHEJ.

Animals↗

Characterization of the putative 2x[4Fe-4S]-binding NQO9 subunit of the proton-translocating NADH-quinone oxidoreductase (NDH-1) of Paracoccus denitrificans. Expression, reconstitution, and EPR characterization.

Molecular properties of the NQO9 subunit of Paracoccus denitrificans NDH-1, which is predicted to contain 2x[4Fe-4S] clusters, were investigated using recombinant expression techniques and EPR spectroscopy. The full-length form of NQO9 subunit co-expressed with thioredoxin in Escherichia coli at ambient temperature was found dominantly in the cytoplasmic membrane with low amplification. Genetic deletion of relatively hydrophobic and less conserved N-terminal stretches (30 or 40 amino acid residues long) of the NQO9 subunit resulted in the overexpression of the truncated soluble form of the subunit in a high yield in the cytoplasm. The purified soluble form of the NQO9 subunit contained only a small quantity of Fe and S(2-) (2.0-2.2 mol each per mol of subunit). However, the iron-sulfur content was considerably increased by in vitro reconstitution. The reconstituted NQO9 subunit contained 7.6-7.7 mol each of Fe and S(2-) per molecule and exhibited optical absorption spectra similar to those of 2x[4Fe-4S] ferredoxins. Two sets of relatively broad axial-type EPR signals with different temperature dependence and power saturation profile were detected in the dithionite-reduced preparations at a low temperature range (8-18 K). Due to a negative shift (<600 mV) of the apparent redox midpoint potential of the iron-sulfur clusters in the soluble form of the truncated NQO9 subunit, the following two possible cases could not be discriminated: (i) two sets of EPR signals arise from two distinct species of tetranuclear iron-sulfur clusters with two intrinsically different spectral parameters g(, perpendicular) = 2.05, approximately 1.93, and g(parallel, perpendicular) = 2.08, approximately 1.90, and respective slow (P((1)/(2)) = 8 milliwatts) and fast (P((1)/(2)) = 342 milliwatts) spin relaxation; (ii) two clusters exhibit similar intrinsic EPR spectra (g(parallel, perpendicular) = 2.05, approximately 1.93) with slow spin relaxation. When both clusters in the same subunit are concomitantly paramagnetic, their spin-spin interactions cause a shift of spectra to g(parallel, perpendicular) = 2.08, approximately 1.90, with enhanced spin relaxation. In either case, our EPR data provide the first experimental evidence for the presence of two [4Fe-4S] iron-sulfur clusters in the NQO9 subunit.

Amino Acid Sequence↗

H(+)-translocating NADH-quinone oxidoreductase (NDH-1) of Paracoccus denitrificans. Studies on topology and stoichiometry of the peripheral subunits.

The proton-translocating NADH-quinone oxidoreductase (NDH-1) of Paracoccus denitrificans is composed of at least 14 subunits (NQO1-14) and is located in the cytoplasmic membrane. In the present study, topological properties and stoichiometry of the 7 subunits (NQO1-6 and NQO9) of the P. denitrificans NDH-1 in the membranes were investigated using immunological techniques. Treatments with chaotropic reagents (urea, NaI, or NaBr) or with alkaline buffer (pH 10-12) resulted in partial or complete extraction of all the subunits from the membranes. Of interest is that when NaBr or urea were used, the NQO6 and NQO9 subunits remained in the membranes, whereas the other subunits were completely extracted, suggesting their direct association with the membrane part of the enzyme complex. Both deletion study and homologous expression study of the NQO9 subunit provided a clue that its hydrophobic N-terminal stretch plays an important role in such an association. In light of this observation and others, topological properties of the subunits in the NDH-1 enzyme complex are discussed. In addition, determination of stoichiometry of the peripheral subunits of the P. denitrificans NDH-1 was completed by radioimmunological methods. All the peripheral subunits are present as one molecule each in the enzyme complex. These results estimated the total number of cofactors in the P. denitrificans NDH-1; the enzyme complex contains one molecule of FMN and up to eight iron-sulfur clusters, 2x[2Fe-2S] and 6x[4Fe-4S], provided that the NQO6 subunit bears one [4Fe-4S] cluster.

Base Sequence↗