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Biomedical subjects

T Ichikawa

Publications and source records attributed to T Ichikawa.

At least 73 records · Page 4Linked to original sources
PubMed2001

Optically active antifungal azoles. XII. Synthesis and antifungal activity of the water-soluble prodrugs of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone.

1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (1: TAK-456) was selected as a candidate for clinical trials, but since its water-solubility was insufficient for an injectable formulation, the quaternary triazolium salts 2 were designed as water-soluble prodrugs. Among the prodrugs prepared, 4-acetoxymethyl-1-[(2R,3R)-2-(2,4-difluorophenyl)-2-hydroxy-3-[2-oxo-3-[4-(1H-1-terazolyl)phenyl]-1-imidazolidinyl]butyl]-1H-1,2,4-triazolium chloride (2a: TAK-457) was selected as an injectable candidate for clinical trials based on the results of evaluations on solubility, stability, hemolytic effect and in vivo antifungal activities.

Alkylation↗
PubMed2001

Optically active antifungal azoles. XIII. Synthesis of stereoisomers and metabolites of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (TAK-456).

1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone [(1R,2R)-1: TAK-456] is a new antifungal agent selected as a candidate for clinical trials. The three stereoisomers [(1S,2R)-, (1S,2S)- and (1R,2S)-1] of this compound were prepared as authentic samples to determine the enantiomeric and diastereomeric purity of TAK-456 as well as to compare their in vitro antifungal activity. Pharmacokinetic studies of TAK-456 using rats identified the existence of metabolites in the liver homogenate. The structures of the major metabolites were assigned as 4-hydroxy-2-imidazolidinone (3) and/or 5-hydroxy-2-imidazolidinone (4), based on HPLC and LC/MS/MS analyses. These hydroxylated compounds, 3 and 4, were prepared by reduction of the corresponding imidazolidinediones, 11 and 12, and confirmed to be identical to the metabolites by HPLC. In vitro antifungal activities of the three stereoisomers and the synthesized metabolites were considerably weaker than TAK-456.

Animals↗
PubMed2001

A synthesis of 3-phenyl-1,2,3,4-tetrahydroisoquinoline and 2-phenyl-1,2,4,5-tetrahydro-3H-3-benzazepine via Pummerer-type cyclization: enhancing effect of boron trifluoride diethyl etherate on the cyclization.

A synthesis of 6,7-dimethoxy-3-phenyl-1,2,3,4-tetrahydroisoquinoline (14a) and 7,8-dimethoxy-2-phenyl-1,2,4,5-tetrahydro-3H-3-benzazepine (14b) was achieved via the cyclization of N-(3,4-dimethoxyphenyl)methyl-1-phenyl-2-(phenylsulfinyl)ethylformamide (6a) and N-2-(3,4-dimethoxyphenyl)ethyl-1-phenyl-2-(phenylsulfinyl)-ethylformamide (6b) using the Pummerer reaction as a key step, respectively. The Pummerer reaction of 6a,b under usual conditions using trifluoroacetic anhydride yielded the vinyl sulfides (8a, b), non-cyclized products, as a major product. The cyclization proceeded when boron trifluoride diethyl etherate was used as an additive reagent, thus giving rise to the corresponding cyclized products (7a) and (7b) in moderate yields. We propose that the enhancing effect of the Lewis acid on the cyclization may be attributable to the involvement of a dicationic intermediate, sulfonium-carbenium dication (23).

Benzazepines↗
PubMed2001

Roles of mast cells and histamine in mosquito bite-induced allergic itch-associated responses in mice.

We investigated itch-associated responses (scratching) to mosquito bites and the role of histamine and mast cells in mosquito-induced itching in mice. Although the first bites of mosquito Aedes albopictus did not increase scratching, repeated bites increased scratching. The response was not diminished even after an interval of 2 months. Similarly, repeated intradermal (i.d.) injections of salivary gland extract (SGE) from Aedes albopictus increased scratching after SGE injection itself and mosquito bites. The scratching peaked within 10 min and almost subsided by 60 min. The opioid antagonist naloxone (1 mg/kg, s.c.) inhibited scratching following SGE injection. Although the non-sedative H1-histamine-receptor antagonist terfenadine (30 mg/kg, p.o.) significantly suppressed scratching induced by histamine (100 nmol/site, i.d.) in either naive or mosquito-sensitized mice, it did not affect mosquito-induced scratching in mosquito-sensitized mice. Repeated injections of SGE increased scratching in mast cell-deficient (WBB6F1-W/Wv) mice as well as in normal (WBB6F1-+/+) littermates. Repeated exposure to mosquito bites roughly doubled serum concentrations of total IgE and IgG1, but not IgG2a. Repeated injections of SGE markedly increased plasma extravasation induced by mosquito bites and such an increase was almost completely suppressed by terfenadine (30 mg/kg, p.o.). The results show the presence of histamine-mediated and histamine-independent mechanisms in cutaneous itching and suggest that histamine probably released from mast cells does not play an important role in itching in immediate allergic reaction. Our murine model of mosquito itching may be useful for studying the mechanisms of immediate allergic itching.

Aedes↗
PubMed2001

Inhibition of expression of ornithine decarboxylase by c-myc antisense oligonucleotide at the promotion stage of lung tumorigenesis in mice.

Regulation of ornithine decarboxylase (ODC) expression at a promotion stage of lung carcinogenesis is a key clue to suppress the cancer. In this study, we investigated that the ODC induction at the promotion stage of lung carcinogenesis in mice could be inhibited through the suppression of the expression of c-myc, a transcription factor for ODC. The treatment with c-myc antisense oligonucleotide decreased the carcinogen-elevated level of pulmonary ODC protein at the promotion stage, but the sense oligonucleotide had no influence on the level. Overall, it is possible that the induction of ODC in the carcinogenic process of lung is regulated at its transcriptional level.

Animals↗
PubMed2001

Pretreatment serum level of testosterone as a prognostic factor in Japanese men with hormonally treated stage D2 prostate cancer.

Pretreatment serum level of testosterone (T) is a potential prognostic factor for prostate cancer. However, T levels in Japanese prostate cancer patients are unknown to date. To evaluate the clinical significance of pretreatment serum T level in such patients, serum T level was analyzed in relation to several clinical factors in a total of 130 patients with various stages of prostate cancer, 74 of whom had metastatic disease (stage D2) and received endocrine therapy as first-line treatment. The mean pretreatment T level in patients with non-metastatic prostate cancer (stages B + C) was significantly lower than that in stage D2 patients (B + C: 4.05 +/- 2.01 ng/ml; D2: 4.85 +/- 2.18 ng/ml, p = 0.0344). On the other hand, the mean serum level of T was higher in stage D2 patients who showed good response to endocrine therapy (CR: 5.42 +/- 1.55 ng/ml; non-CR: 4.30 +/- 2.63 ng/ml, p = 0.0320). When the 74 stage D2 patients were divided into high and low T level groups according to the median value, those patients with a high T level had significantly better cause-specific and progression-free survival. Multivariate analysis demonstrated that extent of bone metastases (EOD) grade, pretreatment serum T level and tumor marker response to endocrine therapy were significant predictors for progression-free survival. In conclusion, a higher pretreatment T level appears to be predictive of the marker response to endocrine therapy, showing positive prognostic value and indicating good prognosis in patients at the metastatic stage. However, a higher T level was also associated with stage progression of this disease.

Aged↗
PubMed2001

Acute changes in bronchoconstriction influences exhaled nitric oxide level.

In previous studies the exhaled nitric oxide (NO) level of asthma patients was investigated only in association with bronchial inflammation, and whether the degree of bronchoconstriction itself influences the exhaled NO level has never been investigated. We therefore evaluated the effect of inhalation of a bronchoconstrictor (methacholine) or a bronchodilator (salbutamol) on the exhaled NO level of healthy volunteers and asthma patients. The exhaled NO level of the healthy volunteers decreased after methacholine inhalation. The exhaled NO level of patients with mild or moderate persistent asthma, who had no asthma attacks on the day of measurement, increased after salbutamol inhalation, and the exhaled NO level of asthma patients during asthma attacks increased after salbutamol inhalation followed by intravenous drip infusion of aminophylline. It is suspected that large amounts of NO are trapped in the lung distal to the constricted airway, contributing little to the exhaled NO level at the mouth. However, we expect that the trapped NO is exhaled at a larger fraction after the dilatation of the constricted small airway, thereby increasing the exhaled NO level at the mouth. In conclusion, the results of this study suggest that acute changes in bronchoconstriction themselves influence the exhaled NO level independently of the change in NO synthase activity associated with airway inflammation.

Adult↗
PubMed2001

Using CT and cholangiography to diagnose biliary tract carcinoma complicating primary sclerosing cholangitis.

OBJECTIVE: The objective of our study was to determine the value of CT and cholangiography for diagnosing biliary tract carcinoma complicating primary sclerosing cholangitis. MATERIALS AND METHODS: One hundred thirteen abdominal CT examinations and cholangiograms in 45 patients with primary sclerosing cholangitis, including 18 patients with established biliary tract carcinoma, were analyzed for tumor. Four radiologists who were unaware of the presence or absence of carcinoma rated each study as to the probability of malignancy. Receiver operating characteristic curve analysis was used to assess the diagnostic performance of CT and cholangiography, the value of imaging signs, and the degree of inter-observer variation in interpretation. Sensitivity and specificity values were calculated. RESULTS: CT outperformed cholangiography in the detection of carcinoma. The average area under the receiver operating characteristic curve was 0.82 for CT and 0.57 for cholangiography (p = 0.003). Sensitivity and specificity for detecting carcinoma using CT were good, with average values of 82% and 80%, respectively. Average sensitivity and specificity for cholangiography were 54% and 53%, respectively. The most reliable sign of tumor on CT was a discrete mass. Progressive biliary dilatation on sequential studies was the most useful sign on cholangiography. Interobserver agreement assessed using the Cronbach alpha was fair for cholangiography and good for CT. CONCLUSION: CT provides good sensitivity and specificity and significantly outperforms cholangiography in detecting biliary tract carcinoma complicating primary sclerosing cholangitis. Despite limitations, CT and cholangiography provide useful information not otherwise available in the treatment of patients with primary sclerosing cholangitis.

Adult↗
PubMed2001

[Sexual function in men with lower urinary tract symptoms].

PURPOSE: Recently there have been several alternatives not only to improve symptoms but to retain an acceptable quality of life as well as to reduce the complications. Therefore the objective of this study was to evaluate quantitatively and qualitatively the degree of erectile dysfunction in the population of men with lower urinary tract symptoms (LUTS). MATERIALS AND METHODS: Total 252 men with LUTS were investigated using the International Prostate Symptom Score (I-PSS) and sexual function inventory (SFI) consisting of sexual drive, erection and ejaculation. Spearman's rank order correlation was used to determine the degree of any correlation between age, the total I-PSS, the individual I-PSS questions and the various sexual function scores. RESULTS: 208 patient data were available for analysis. There were poor function patients in 67.8% for sexual drive, in 46.2% for erection and in 47.1% for ejaculation. On the other hand, 24% considered their sexual drive to be a big or medium problem, 20.7% for erection and 18.3% for ejaculation. Overall, 27.4% of the men were mostly or very dissatisfied with their sex life. There was a significant correlation between a patient's age and his score for each of the three sexual variables (p < 0.05). Furthermore, a significant correlation was noticed between the total I-PSS and the SFI score (p < 0.05). It might be suggested that the more symptomatic a patient for LUTS, the poorer his sexual function will be. CONCLUSIONS: About 20% men with LUTS are bothered by their sexual symptoms. Erectile dysfunction in dependent of age and the extent of LUTS. Consideration of the high population of erectile dysfunction in men with LUTS is necessary to the treatment of their urinary symptoms.

Adult↗
PubMed2001

[Septic shock due to pyonephrosis-calculosa: a case report].

A 69-year-old female was admitted to hospital with the complaint of high-grade fever and clouding of consciousness. Physical examination and laboratory data revealed septic shock, disseminated intravascular coagulation and multiple organ failure. Ultrasonography demonstrated left hydronephrosis and a cystic mass in peri-renal fatty tissue. KUB showed a left ureteral stone. A diagnosis of septic shock due to pyonephrosis-calculosa and peri-renal abscess was considered. A left nephrectomy, endotoxin removal therapy and continuous hemodiafiltration was performed. Thereafter all morbidities improved. A nephrectomy and intensive treatment are the good alternative method for such a case.

Aged↗
PubMed2001

[A case of adult neuroblastoma arising in the retroperitoneal space].

Neuroblastoma, common in children, rarely develops in adults. We recently treated a patient with adult neuroblastoma. A 34-year-old man complained of a swelling in right inguinal region. CT scan showed swelling of retroperitoneal and inguinal lymph nodes, and bone scintigram by 99mTc-HMDP showed an abnormal uptake in the swollen lymph nodes. Chemotherapy with CDDP (cisplatinum), VP-16 (etoposide), BLM (bleomycin), ADM (adriamycin) was not effective. Histopathological examination of a biopsy specimen revealed neuroblastoma. Another chemotherapy with CPM (cyclophosphamide), VCR (vincristine), ADM, DTIC (dacarbazine), CDDP, VP-16 was effective in decreasing the tumor size. Further high dose chemotherapy with CPM, ADM, CDDP, VP-16 combined with peripheral blood stem cell transplantation led to almost complete disappearance of the tumor and normalization of blood tumor markers (neuron specific enolase and immunosuppressive acidic protein). Retroperitoneal lymph node dissection demonstrated well-differentiated neuroblastoma in the excised tissue. Six months postoperatively, the tumor recurred in the pelvic cavity. Although chemotherapy and radiotherapy were given, he died of the disease 12 months postoperatively.

Adult↗
PubMed2001

[Two cases of alimentary tract perforation owing to ingested foreign bodies: diagnosis by CT].

We report the CT diagnosis of two cases of alimentary tract perforation caused by the ingestion of foreign bodies. The first case was a common fish bone perforation of the ileum with postoperative scar. The second case was a rare perforation caused by the impact of an uncooked rice cake on sigmoid colon diverticula. Helical CT scan clearly revealed the fish bone as a linear high-density area in the soft tissue between the right abdominal oblique muscles and ileum, and demonstrated the rice cake as high-density material in the bowel.

Colon, Sigmoid↗
PubMed2001

[Assessment of intra and extrahepatic perfusion during hepatic artery infusion chemotherapy using slow-injected gadolinium-enhanced MR imaging through implanted catheter-port-system].

Twenty-four studies of intra-arterially slow-injected gadolinium-enhanced MR imaging through an implanted catheter-port system (reservoir-MR) were carried out in 15 patients with liver tumor. The flow rate of gadolinium injection was 0.1 ml/sec and a total of 3 mL was injected. Six consecutive phases, each with an acquisition time of 14 seconds, were obtained every 30 seconds. In all studies, the signal intensity of the drug delivery portion became very high. Twenty-three of 24 studies showed intrahepatic perfusion in the first phase. The hepatic vein was enhanced at the first phase in 10 and the second phase in 14. The abdominal aorta was enhanced at the second phase in all 24 studies. The portal vein was enhanced at the first phase in 4, the second phase in 13, and the third phase in 7 studies. Both intra- and extrahepatic perfusion were more clearly demonstrated by reservoir-MRI than by digital subtraction angiography through an implanted catheter-port system (reservoir-DSA); however, morphological changes in the hepatic artery were better demonstrated by reservoir-DSA than by reservoir-MRI.

Adult↗
PubMed2001

[A case of IgA2-lambda type M-protein that IgA concentration differs from the values of M-protein by serum protein electrophoresis].

We report an IgA-lambda type M-protein in which the IgA concentration differed from the values of M-protein by serum protein electrophoresis found in a 53-year-old man with multiple myeloma. The M-protein value as determined by serum protein electrophoresis was 6,170 mg/dl. However, the serum IgA concentration was 3,052 mg/dl by turbidimetric immunoassay. Immuno-fixation electrophoresis using IgA subclass antisera revealed that this M-protein was the IgA2-lambda type. Western blotting analysis showed that the IgA2 molecules were composed of two approximately 68 kDa alpha 2 chains and two 28 kDa lambda chains. In addition the free lambda chain band was detected at the position of 28 kDa without 2-mercaptoethanol(2-ME) even though the patient IgA was purified. Since it is known that IgA2m(1) allotype easily release light chains from the IgA molecules in SDS-PAGE without 2-ME, we speculated that in this patient the IgA was the IgA2m(1) allotype. After peripheral blood stem cell transplantation(PBSCT), immunofixation electrophoresis of the patient serum revealed not only the bands of IgA2-lambda type M-protein, but also three bands of IgG1-kappa type M-protein in the gamma region.

Blood Protein Electrophoresis↗
PubMed2001

[Dynamic MRI].

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Carcinoma, Hepatocellular↗