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Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 325 records · Page 18Linked to original sources
PubMed2001

[Rational lymph node dissection for lung cancer according to the occurrence lobe and histological type].

Between January 1989 and December 1998, 134 cases of squamous cell carcinoma and 244 cases of adenocarcinoma underwent surgical resection of the lung with systematic lymph node dissection in our hospital. The cN diagnosis by CT scan and pN diagnosis were compared. In squamous cell carcinoma pN 2-3 cases were only one patient (2%) out of 60 patients with cN 0, 5 patients (18%) out of 28 patients with cN 1, and 21 patients (46%) out of 46 patients with cN 2-3. On the other hand in adenocarcinoma pN 2-3 cases were 27 patients (14%) out of 193 patients with cN 0, 3 patients (25%) out of 12 patients with cN 1, and 24 patients (62%) out of 39 patients with cN 2-3. The pathways of the lymphatic metastases to the mediastinal nodes were analized in 27 patients with squamous cell carcinoma and 54 patients with adenocarcinoma undergoing systematic lymph node dissection. All patients had histologically proven mediastinal metastasis. Histologically there was no difference in pathways of the lymphatic metastases to the mediastinal nodes. 1. The dominant lymphatic drainage from the right upper lobe flowed into the superior mediastinal nodes. The direct metastatic passages to the superior mediastinal nodes were observed (47%). Subcarinal and inferior mediastinal node involvement was rare (3%). 2. The dominant lymphatic drainage from the middle and the lower lobe flowed into the subcarinal nodes (85%). The involvement of the superior mediastinal nodes occurred in 53% of subcarinal node positive patients on the right side. 3. The dominant lymphatic drainage from the left upper lobe flowed into the subaortic or paraaortic nodes (69%). Subcarinal and inferior mediastinal node involvement was rare (6%). We conclude that subcarinal and inferior mediastinal lymph node dissection is not necessary for upper lobe lung cancers, and that superior mediastinal lymph node dissection can be omitted in middle and lower lobe lung cancers without hilar and subcarinal lymph node involvement, especially in the cases of cN 0.

Adenocarcinoma↗
PubMed2001

[Case of thoracoabdominal aortic aneurysm complicated with Buerger's disease].

We report a rare case of 65-year-old man who developed thoracoabdominal aortic aneurysm of Crawford type III complicated with Buerger's disease. He was admitted to our hospital with chief complaints of upper abdominal and back pain. CT showed that the aneurysm extended from the descending thoracic aorta to the aortic bifurcation and its had a maximum width of 95 mm. Angiogram (IA-DSA) revealed that both popliteal arteries were occluded slightly above the level of the knee joint, although collateral vessels were visualized. He underwent preliminary graft replacement of the abdominal aorta with the end-to-side supplemental branch for cannulation. Subsequently we performed graft replacement of the thoracoabdominal aorta with reconstruction of the celiac and superior mesenteric arteries and intercostal arteries on under partial cardiopulmonary bypass. This supplemental branch of abdominal aortic graft was useful in preventing ipsilateral leg ischemia. During the reconstruction of the major visceral branches, the branches were perfused selectively via partial extracorporeal circulation. Post operative courses were uneventful without paraplegia and leg ischemia. Angiographic examination revealed excellent hemodynamic results.

Aged↗
PubMed2001

Neurovirulence of Sabin 1-derived polioviruses isolated from an immunodeficient patient with prolonged viral excretion.

We have analysed the neurovirulence of Sabin 1-derived isolates which persisted more than nine years in an immunodeficient patient in the U.S.A. Samples were collected from stool specimens at days 11 (St1), 23 (St2), 48 (St3), 126 (St5), and 200 (St7) after the onset of paralysis. Critical nucleotides associated with the reversion of virulence were examined. All the isolates had the substitutions at nucleotide positions 480 (G to A) in the 5'-non-coding region (NCR), 2438 (A to U) in VP3, 2795 (A to G) in VP1, and 6203 (C to U) in 3D. Serially diluted samples were injected intracerebrally to transgenic mice harbouring the human poliovirus receptor gene. Samples St2, 3, 5 and 7 showed typical virulent characters in transgenic mice, whereas the sample ST1 showed intermediate neurovirulence. It seemed that there were two variant viruses providing for a major (M) and a minor (m) populations. After disappearance of the m-variant, samples obtained at the later stages showed neurovirulence almost equivalent to that of the Mahoney strain. Thus, the Sabin 1 strain evolved towards full neuropathogenicity after long-term replication in humans by accumulating mutations. Therefore, OPV-vaccination of immunodeficient persons should be avoided.

Animals↗
PubMed2001

Association of the DD genotype and development of Japanese type 2 diabetic nephropathy.

We determined the insertion/deletion (I/D) polymorphism of the angiotensin-coverting enzyme (ACE) gene in a multicenter trial of ethnically homogeneous Japanese type 2 diabetes mellitus (DM) patients. All patients (n = 748) were divided into 5 groups as follows: group I (normoalbuminuric patients), group II (microalbuminuric patients), group III (overt albuminuric patients with serum creatinine (s-Cr) levels of less than 1.2 mg/dl), group IV (overt albuminuric patients with s-Cr levels of more than 1.3 mg/dl but excluding hemodialysis patients), and group V (hemodialysis patients). We selected patients with a diabetic duration of more than 15 years in the mild stage (groups I and II), but placed no limits on those in the advanced and end-stages (groups III, IV and V). The frequency of the DD genotype was slightly higher in the advanced and end stages. The frequency of the DD genotype in the mild stage differed from that in the end stage (II/ID/DD 47.8%/41.0%/11.2% vs. 37.0 %/43.3%/19.7% p = 0.07, II + ID/DD 88.8%/11.2% vs. 80.3%/19.7%, p < 0.05). D allele frequency in the mild stage also differed from that in the end stage (I/D 68.3%/31.7% vs. 58.7%/41.3%, p < 0.02). The presence of the DD genotype increased the risk of end-stage renal disease (ESRD) more than that of the other genotypes (odds ratio ID/II = 1.37, 95% CI 0.82-2.27; DD/II = 2.27, 95% CI 1.12-4.61). It appears that the DD genotype is associated with progression of Japanese type 2 diabetic nephropathy.

Aged↗
PubMed2001

[Comparison of the newly developed MYCOACID system with mycobacteria growth indicator tube (MGIT) and newly developed 2% Ogawa medium (S) for recovery of mycobacteria in clinical specimens].

The detection rate of mycobacteria from patients' specimens and the time required to get positive culture were compared among newly developed MYCOACID SYSTEM, MGIT, Ogawa K medium and 2% Ogawa medium (S). A total of 249 sputum samples taken from patients were used as the study subjects and 124 kinds of mycobacteria were isolated. For 135 cases clinically diagnosed as pulmonary tuberculosis, the detection rate was 44.4% for MYCOACID, 47.4% for MGIT and 38.5% for Ogawa K medium, showing that there are no significant differences in the detection rate between MYCOACID and MGIT, and MYCOACID and Ogawa K medium but the differences was significant between MGIT and Ogawa K medium (p = 0.02). The mean days needed for detection of Mycobacterium tuberculosis complex was 12.3 days for MYCOACID, 13.4 days for MGIT, and 26.8 days for Ogawa K medium, indicating significant differences in the time to get positive culture between Ogawa K medium and either of both liquid media (p < 0.001). Furthermore, 2% Ogawa medium (S) was used only for the detection of mycobacteria among previously untreated tuberculosis and there were no significant differences in the detection rate between 2% Ogawa medium (S) and either of both liquid media. The time to get positive culture for 2% Ogawa medium (S) was 18.2 days, which was longer than that for either of liquid media, MYCOACID and MGIT, but it was significantly shorter (7.9 days) than that for Ogawa K medium (p = 0.003). These results demonstrate that the liquid culture systems both MYCOACID and MGIT were very useful for the detection of mycobacteria compared with Ogawa K medium.

Bacteriological Techniques↗
PubMed2001

[Pulmonary infection due to Mycobacterium szulgai, a group 2 nontuberculous mycobacterium].

A 37-year-old male was admitted to our hospital because of abnormal findings seen in a chest radiograph from a physical examination. There was nothing unusual about his past history, and he had been healthy. Chest radiography showed an infiltrative shadow with a cavity in the right upper lobe. A smear test of the sputum was negative but a culture was positive for a mycobacterium, which was identified as M. szulgai. A diagnosis of atypical pulmonary mycobacteriosis caused by M. szulgai. The patient was treated with isoniazid, rifampicin and ethambutol, which gradually improved the infiltration shadow, and his sputum cultures became negative for mycobacteria. In recent years, the frequency of atypical mycobacteriosis has increased up to 10% to 15% of all mycobacterial infections. In Japan, M. avium complex and M. kansasii account for more than 90% of such infections, so other isolates are rare. Most previous cases of atypical mycobacteriosis were secondary infections associated with underlying disease. In this patient, however, we describe a rare case of pulmonary infection due to M. szulgai appearing in a healthy male without underlying disease.

Adult↗
PubMed2000

Lipopolysaccharide induces the expression of cellular inhibitor of apoptosis protein-2 in human macrophages.

Apoptosis is an important process in normal animal development as well as in diseases, and inhibitor of apoptosis protein (IAP) is one of the important factors that regulate apoptotic cell death. We found that lipopolysaccharide (LPS) enhances the expression of mRNA and protein of cellular IAP-2 (cIAP2) in human monoblastic U937 cells differentiated by phorbol ester pretreatment. cIAP2 mRNA was not detected in undifferentiated U937 cells. mRNAs of cIAP1 and X-chromosome-linked IAP (XIAP) were expressed constitutively and not affected by LPS in both undifferentiated and differentiated cells. LPS stimulated the expression of cIAP2 mRNA and protein in time- and concentration-dependent manners. LPS enhanced the expression of cIAP2 mRNA and protein in human monocyte-derived macrophages, which was associated with the inhibition of the caspase-3 activation, i.e., decrease in active p17 fragment of caspase-3 with simultaneous accumulation of precursor p20 fragment. We conclude that LPS may inhibit apoptosis of macrophages, at least in part, through the induction of cIAP2.

Apoptosis↗
PubMed2000

Prolongation of the QT interval and ventricular tachycardia in patients treated with arsenic trioxide for acute promyelocytic leukemia.

BACKGROUND: Recently, arsenic trioxide has increasingly been used for relapsed acute promyelocytic leukemia. However, it is known to have several adverse effects, including acute cardiac toxicities. OBJECTIVE: To determine cardiac toxicities resulting from arsenic trioxide therapy in patients with relapsed or refractory acute promyelocytic leukemia. DESIGN: Phase II clinical prospective cohort study. SETTING: A university hospital in Hamamatsu, Japan. PATIENTS: 8 patients with relapsed acute promyelocytic leukemia. INTERVENTION: Arsenic trioxide, 0.15 mg/kg of body weight, administered daily by 2-hour infusion for a maximum of 60 days. MEASUREMENTS: Continuous monitoring with ambulatory electrocardiography. RESULTS: Five patients (63%) achieved complete remission. During induction therapy with arsenic trioxide, prolonged QT intervals were observed in all patients. Ventricular premature contractions were noticed during 8 of 12 courses of therapy. Four patients developed nonsustained ventricular tachycardia and required treatment with antiarrhythmic agents. CONCLUSIONS: Cardiac toxicity occurs during arsenic trioxide therapy in patients with acute promyelocytic leukemia. Such patients should be monitored for prolonged QT intervals and ventricular arrhythmia.

Adult↗
PubMed2000

Virulence factors of Helicobacter pylori responsible for gastric diseases in Mongolian gerbil.

Helicobacter pylori infection induces various gastroduodenal diseases. We examined the role of two genes, vacA and cagE, in the gastric pathogenesis induced by H. pylori using a long-term (62 wk) animal model. Reportedly, both genes are associated with the virulence of H. pylori: vacA encodes vacuolating cytotoxin, and cagE, with other genes in the cag pathogenicity islands, encodes a type IV secretion system. Mongolian gerbils were challenged in this study by a wild-type TN2 strain and its isogenic mutants of cagE or vacA. The wild-type and vacA mutants induced severe gastritis, whereas cagE mutants induced far milder changes. Gastric ulcer was induced at the highest rate (22/23) by the wild-type TN2, followed by the vacA mutant (19/28). No ulcer was found in the gerbils infected with the cagE mutant (0/27) or in controls (0/27). Intestinal metaplasia was also found in the gerbils infected with the wild-type (14/23) or vacA mutant (15/28). Gastric cancer developed in one gerbil with wild-type infection and in one with vacA mutant infection. In conclusion, the knocking out of the cagE gene deprived wild-type H. pylori of the pathogenicity for gastritis and gastric ulcer, suggesting that the secretion system encoded by cag pathogenicity island genes plays an essential role.

Adenocarcinoma↗
PubMed2000

Rapid detection of candidate metastatic foci in the orthotopic inoculation model of androgen-sensitive prostate cancer cells introduced with green fluorescent protein.

BACKGROUND: An in vivo spontaneous metastatic model using androgen-sensitive prostate cancer cells is needed to the better understanding of prostate cancer progression. Orthotopically inoculated LNCaP cells to SCID mice manifests metastases, but it takes no less than 12 weeks to detect them by conventional methods. METHODS: The green fluorescent protein (GFP) gene was introduced into LNCaP cells by conventional lipofection technique. Biological characteristics of a subline (LNCaP-GFP) that expressed GFP at high level were compared to those of the parental cells. LNCaP-GFP cells were orthotopically inoculated to the SCID mouse, and metastases to distant organs were chronologically examined under fluorescence microscopy. RESULTS: There was no difference in growth rates and androgen-responsiveness in vitro between LNCaP-GFP and LNCaP cells. LNCaP-GFP cells inoculated to SCID mice produced prostate specific antigen. Histopathological examination at 12 weeks after inoculation of LNCaP-GFP revealed that metastases were identified as the inoculation of LNCaP cells. Colonies consisting of a few LNCaP-GFP cells, however, were detected in the lung under fluorescence microscopy as early as 4 weeks after inoculation. CONCLUSIONS: Orthotopic inoculation of LNCaP-GFP to SCID mice may provide a useful tool to investigate the molecular mechanism of progression, in particular the early stage of metastasis, of androgen-sensitive prostate cancer cells.

Androgens↗
PubMed2000

Effects of sugar concentration on recombinant human alpha(1)-antitrypsin production by genetically engineered rice cell.

Productivity of recombinant human alpha(1)-antitrypsin (rAAT) with a genetically engineered rice cell using an inducible promoter has been studied by batch-wise and continuous production. A simple model explained the effect of proteases released from the disrupted cells on the rAAT degradation. Glucose concentration in the medium significantly affected the rAAT productivity in the continuous production, because the rAAT was induced by sugar depletion. When the fresh medium containing 5mM glucose was supplied to the continuous bioreactor, induction time was long and the productivity was low, indicating that the glucose concentration in the cells was high enough as to repress the promoter. When the glucose concentration in the fresh medium was reduced to 0.5mM, total amount of rAAT produced in 70h cultivation reached 6.7-7.6mg/g-dry cell, which was two times larger than the control medium without glucose.

Journal Article↗
PubMed2000

Large isoform of hepatitis delta antigen activates serum response factor-associated transcription.

Hepatitis delta virus infection sometimes causes severe and fulminant hepatitis as a coinfection or superinfection along with the hepatitis B virus. To elucidate the underlying mechanism of injury caused by hepatitis delta virus, we examined whether two isoforms of the hepatitis delta antigen (HDAg) had any effect on five well defined intracellular signal transduction pathways: serum response factor (SRF)-, serum response element (SRE)-, nuclear factor kappaB-, activator protein 1-, and cyclic AMP response element-dependent pathways. Reporter assays revealed that large HDAg (LHDAg) activated the SRF- and SRE-dependent pathways. In contrast, small HDAg (SHDAg) did not activate any of five pathways. LHDAg enhanced the transcriptional ability of SRF without changing its DNA binding affinity in an electrophoretic mobility shift assay. In addition, LHDAg activated a rat SM22alpha promoter containing SRF binding site and a human c-fos promoter containing SRE. In conclusion, LHDAg, but not SHDAg, enhances SRF-associated transcriptions. Despite structural similarities between the two HDAgs, there are significant differences in their effects on intracellular signal transduction pathways. These results may provide clues that will aid in the clarification of functional differences between LHDAg and SHDAg and the pathogenesis of delta hepatitis.

Animals↗
PubMed2000

Nuclear translocation of TSC-22 (TGF-beta-stimulated clone-22) concomitant with apoptosis: TSC-22 as a putative transcriptional regulator.

We examined the alteration of the subcellular localization of TSC-22 (TGF-beta-stimulated clone-22) after induction of apoptosis and the transcription-regulatory activity of TSC-22. In the living cells, TSC-22-green fluorescent protein (GFP) fusion protein was clearly localized to the cytoplasm, however, in the apoptotic cells, the TSC-22-GFP fusion protein was translocated from the cytoplasm to the nucleus. TSC-22 fused to GAL4-DNA binding domain (GAL4BD) did not show the transcriptional activity on the reporter genes in yeast and in HSG (salivary gland cancer cells) and Hela. However, in CHO cells, TSC-22-GAL4BD fusion protein strongly activated the reporter gene. The transcriptional activity of the leucine zipper structure of TSC-22 is greater than that of the full-length TSC-22. These findings suggest that after receiving the apoptotic stimuli, TSC-22 translocates from the cytoplasm to the nucleus and shows the transcription-regulatory activity.

Animals↗
PubMed2000

Co-expression of epidermal growth factor receptor and transforming growth factor-alpha predicts worse prognosis in breast-cancer patients.

Epidermal growth factor receptor (EGF-R) and its ligand, transforming growth factor-alpha (TGF-alpha), play an important role through the autocrine growth-regulation system in several human cancers, including breast cancer. However, the clinical significance of co-expression of EGF-R and TGF-alpha has not been elucidated. One hundred seventy-three female patients diagnosed as invasive ductal carcinoma who had undergone a mastectomy (159 patients) or breast-conserving surgery (14 patients) were followed up for 81 to 119 months (median 94 months) post-operatively. Immunoreactivity for EGF-R, TGF-alpha, p53 and c-erbB-2 with paraffin-embedded carcinoma tissue was investigated using labeled streptavidin-biotin methods. Positive rates of carcinoma cells were 27%, 33%, 32% and 26% for EGF-R, TGF-alpha, p53 and c-erbB-2, respectively. Expression of EGF-R only was observed in 16% (28/173), of TGF-alpha only in 22% (38/173), of both EGF-R and TGF-alpha in 11% (19/173) and of neither in 51% (88/173). By univariate analysis, significant differences in overall survival and disease-free survival were noted according to the co-expression of EGF-R and TGF-alpha (p< 0.0001, p<0.0001), co-expression of EGF-R and c-erbB-2 (p = 0.0029, p = 0.0028), nodal status (p = 0.0028, p = 0.0001), tumor size (p = 0.0001, p<0.0001) and c-erbB-2 expression (p = 0.0034, p = 0.018), respectively. The status of p53 expression (p = 0.01), estrogen receptor (p = 0.042) and progesterone receptor (p = 0.046) showed significant differences in overall survival. According to Cox's multivariate analysis, co-expression of EGF-R and TGF-alpha had the most significant effect on disease-free survival (p<0.0001) and overall survival (p<0.0001), followed by nodal status. Co-expression of EGF-R and TGF-alpha by immunohistochemical detection is an independent prognostic indicator, and it may be helpful for determining the group of breast-cancer patients with an aggressive phenotype.

Adult↗
PubMed2000

5-Amino-4-sulfanylphthalhydrazide as a chemiluminescence derivatization reagent for aromatic aldehydes in liquid chromatography.

5-Amino-4-sulfanylphthalhydrazide (ASPH) was synthesized as a chemiluminescence derivatization reagent for aromatic aldehydes in liquid chromatography (LC). Benzaldehyde, 4-tolualdehyde, 4-chlorobenzaldehyde, 4-formylbenzoic acid, 4-hydroxybenzaldehyde and vanillin were used as model compounds to optimize the derivatization conditions. This reagent, ASPH, reacts selectively with aromatic aldehydes in the presence of sodium sulfite and disodium hydrogenphoshite in acidic medium at 100 degrees C to give the corresponding highly chemiluminescent 2-arylbenzothiazole derivatives. The resulting derivatives generated intense chemiluminescence by reaction with hydrogen peroxide and potassium hexacyanoferrate(III) in alkaline solution. The ASPH derivatives of aromatic aldehydes were separated by reversed-phase liquid chromatography with isocratic elution, and detected chemiluminometrically after mixing with oxidizing agents. The detection limits (signal-to-noise ratio = 3) for aromatic aldehydes are in the range 0.2-4.0 fmol for a 20-microl injection volume. Currently, the method is not effective for aliphatic aldehydes because of interfering LC peaks.

Aldehydes↗
PubMed2000

Diastolic fractional flow reserve to assess the functional severity of moderate coronary artery stenoses: comparison with fractional flow reserve and coronary flow velocity reserve.

BACKGROUND: Coronary blood flow occurs mainly during the diastolic phase of each cardiac cycle and is mainly dependent on diastolic driving pressure, especially in the left anterior descending coronary artery (LAD). We hypothesized that calculation of the ratio of the diastolic driving pressure of a stenotic LAD to its normal value, namely diastolic FFR (d-FFR), might provide precise insight into the mechanism of FFR for assessment of the functional severity of the stenosis. We compared d-FFR with FFR, coronary flow reserve (CFR), and exercise myocardial thallium scintigraphy in an lesion of intermediate severity. METHODS AND RESULTS: The study population consisted of 46 consecutive patients with a moderate stenosis in the LAD in whom simultaneous measurements of aortic pressure, left ventricular pressure, and coronary pressure distal to the stenosis were obtained. Coronary flow velocity was successfully measured with a Doppler guidewire in 37 of the 46 patients. Values for FFR, d-FFR, and CFR in the noninvasive test-positive group were significantly lower than those in the negative group. With cutoff values of 0.75, 0.76, and 2.0 for FFR, d-FFR, and CFR, sensitivities were 83.3%, 95.8%, and 88.2% and specificities were 100%, 100%, and 95.0%, respectively. CONCLUSIONS: The close similarity of the sensitivity and specificity of FFR and d-FFR, around almost identical cutoff values (0.75 versus 0.76), confirms the physiological validity of FFR as a clinical standard. In clinical practice, FFR remains the index of choice for assessment of the functional severity of moderate coronary artery stenoses.

Blood Flow Velocity↗