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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 667 records · Page 37Linked to original sources

[Detection of tumor markers by genetic diagnostic methods and its clinical application].

Since the development of the polymerase chain reaction (PCR) method of DNA amplification in 1985, numerous improvements, modifications, and novel applications of PCR have been devised. These developments eventually made it possible to examine minute clinical samples. It has become clear that cancer arise and progress through the accumulation of various genetic alterations. Certain genetic changes are now considered to be molecular markers useful not only for early diagnosis but also for predicting the behavior of cancer and the clinical outcome of patients. Some molecular markers are also useful for diagnosis of inherited cancer and susceptibility to cancer. We describe the latest improvements of detecting these molecular markers and clinical application of them in digestive cancer.

Biomarkers, Tumor↗

[Tricuspid valve closure for pulmonary atresia with intact ventricular septum].

Tricuspid valve closure was performed on four children who had pulmonary atresia with intact ventricular septum. All of them had major right ventricle-coronary communications and severely hypoplastic right ventricle under 30% of normal right ventricle volume. Their coronary circulations were not right ventricle dependent. All of four patients survived tricuspid valve closure. Three children were performed Fontan procedure. One child, with severe change in her coronary arteries preoperatively, once improved her myocardial ischemia in early stage after tricuspid valve closure, however, the myocardial ischemia progrssed in one year later and died suddenly three years and five months after tricuspid valve closure. Three survivors remained good condition in their left ventricle function postoperatively. In this study, we investigated changes in LVEF, LVEDVI, LVEDP and mitral regurgitation as indicators of left ventricle functions through tricuspid valve closure. It revealed that tricuspid valve closure had advantages in preservation of left ventricle function and in preparation for Fontan procedure consequently.

Child↗

[Genetic diagnosis of colorectal cancer].

Accumulating evidences that carcinogenesis requires multiple gene alterations of oncogenes and tumor suppressor genes have recently emerged. In addition, genes related to invasion and metastasis are also important in understanding development of colorectal cancer. In this study, clinical significance and application of tumor suppressor genes and invasion related genes such as APC (adenomatous polyposis coli), DCC (deleted in colorectal carcinoma) tumor suppressor genes and invasion related gene, matrilysin were studied. In the mouse tumor induced by mutagen contained in cooked food, PhIP (2-amino-1-methyl-6- phenylimidazo [4,5-b] pyridine), nonsense mutations of APC gene that is similar to human colorectal cancer have been observed. These results suggested the quite interesting issue of mutagen contained in daily food having etiological role of colorectal cancer. DCC gene alteration, decreased expression of DCC mRNA was detected in 60% of advanced colorectal cancer. In all cases with liver metastasis, DCC expression was absent or markedly decreased, a finding that detection of DCC expression have an clinical importance that predicts metastatic potential of colorectal cancer. Matrilysin, the member of MMPs (matrix metalloproteinases) which degrade matrix components such as type IV collagen, laminin or fibronectin. In most of colorectal cancer, matrilysin was overexpressed in tumor cells. Matrilysin-transfected colorectal cancer cells showed more invasive ability in vitro and gained metastatic potential in SCID mice. Suppression of matrilysin expression by treated with all-trans retinoic acid (ATRA) or introduction of anti-sense matrilysin decreased the invasive ability in vitro. This result suggests that matrilysin plays an important role in invasion and metastasis and have a possibility of new anti-invasion therapy.

Animals↗

[Usefulness of NODSS (nasal/oral discriminate sampling system) in end-tidal carbon dioxide gas monitoring].

We investigated the usefulness of nasal/oral discriminate sampling system (NODSS) that had been developed recently in order to obtain the accurate end-tidal carbon dioxide (PET(CO2)) from a spontaneously breathing patient through a nomal airway. Fifty patients were monitored using a capnograph with NODSS following extubation in the postanesthesia unit. PET(CO2) data were collected by means of nasal, oral or nasal/oral sampling. The levels of arterial carbon dioxide (PaCO2) were determined simultaneously. In addition to examining the correlation between PET(CO2) and PaCO2, we investigated the influence of method of anesthesia, age and respiratory rate on the (PaCO2 - PET(CO2)) gradient. In most patients without nasal obstruction breathing through the nostril, PET(CO2) determined by selective nasal sampling was closer to PaCO2 than those by oral or nasal/oral sampling. Furthermore, the mean (PaCO2 - PET(CO2)) gradient was 4.98 mmHg in patients aged over 60, while it was 2.02 mmHg in patients aged under 60, suggesting that PET(CO2) could not be a good index in elderly people. There was no significant difference in the mean (PaCO2 - PET(CO2)) gradient among different methods of anesthesia. In conclusion, NODSS was useful in determining PET(CO2) more accurately and estimating PaCO2 precisely when used in relatively young people by selective nasal or oral sampling.

Adolescent↗

[Outcome of initial treatment with high-dose vitamin B6, valproate sodium or clonazepam in West syndrome].

We reviewed the outcome (seizures and development) of 25 cases with West syndrome in which antiepileptic drugs (valproate sodium, clonazepam) or high doses of vitamin B6, instead of ACTH therapy, were administered for the initial treatment. Five of 9 cryptogenic cases (56%) and 4 of 16 symptomatic cases (25%) showed complete cessation of spasms. In cryptogenic cases, response to vitamin B6, valproate sodium or clonazepam was not predicted by clinical features (age of onset, seizure type, initial EEG finding or treatment lag). On the other hand, response to these drugs was correlated with some clinical findings in symptomatic cases; all infants with neurocutaneous syndrome (tuberous sclerosis, neurofibromatosis type 1) had controlled infantile spasms, while none of patients with severe neonatal asphyxia or with prior other seizures responded. Twenty of 25 patients have been followed-up. The average age at follow-up was 5 years and 8 months. Prognosis of both cryptogenic and symptomatic "responders" was favorable; all had seizures controlled, and 50% had normal psychomotor development or only mild impairment (DQ > 70). Symptomatic "nonresponders" had the worst prognosis. Our results suggest that choice of drug in the initial treatment of West syndrome should be determined by clinical features (especially etiology).

Anticonvulsants↗

[SPECT, MRI and EEG in infants with lissencephaly].

Single photon emission tomography (SPECT), MRI and EEG were studied in two infants with lissencephaly. One infant had generalized tonic convulsions at 7 month of age and continuous high voltage fast activities on EEG. The other infant developed infantile spasms at the age of 2.5 months, and showed low voltage disorganized background with pseudorhythmic high voltage sharp waves on EEG. Cranial CT and MRI in both infants revealed abnormally thick cortex, dilatation of the lateral ventricles, and smooth or relatively smooth cerebral surface. In SPECT studies, a diffuse increase of tracer uptake was shown at the cerebral cortex compared with the basal ganglia or cerebellum in both infants. The SPECT finding might reflect the abnormal cortical architectures in this cerebral malformation.

Brain↗

Increase of protein tyrosine phosphorylation in rat retina after ischemia-reperfusion injury.

PURPOSE: This study was conducted to examine the effect of retinal ischemia-reperfusion injury on protein tyrosine phosphorylation, the production of angiogenic growth factors, and the activation of signal proteins in tyrosine kinase pathways. METHODS: Ischemia-reperfusion injury was induced in rats by compression of the optic nerve for 2 hours. The rats were killed, and the retinas were collected at 0, 1, 6, 24, 48, 96, or 168 hours of reperfusion. Tyrosine phosphorylation of proteins in the retina was examined by Western blot analysis and immunohistochemistry. Angiogenic growth factors and their receptors, such as basic fibroblast growth factor (bFGF) and Flg, vascular endothelial growth factor (VEGF) and Flk-1, platelet-derived growth factor (PDGF)-B chain and PDGF-beta receptor, and five intracellular signal proteins (phosphatidylinositol 3-kinase [PI3K], phospholipase C gamma [PLC gamma], C-Src, SHC, and mitogen-activated protein kinase [MAPK]) were examined by Western blot analysis. RESULTS: Protein tyrosine phosphorylation increased after ischemia-reperfusion injury, reaching a peak at 48 hours of reperfusion. Increased staining of tyrosine-phosphorylated proteins in the inner retina were evident on immunohistochemical examination. The amount of bFGF decreased after injury, but the amounts of VEGF and PDGF-B chain increased. Tyrosine phosphorylation of PLC gamma, SHC, and MAPK was increased at 48 hours of reperfusion, and tyrosine phosphorylation of PDGF-beta receptor and PI3K was increased at 168 hours of reperfusion. CONCLUSIONS: Ischemia-reperfusion injury in the rat retina leads to activation of the tyrosine kinase pathway, increasing the amounts of angiogenic growth factors. The resultant activation of signal proteins PLC gamma, SHC, MAPK, PI3K, and PDGF-beta receptor may play an important role in ischemia-induced retinal changes such as cell proliferation.

Animals↗

[An allogeneic bone marrow transplantation for chronic myelocytic leukemia with a large extramedullary tumor in the pelvic cavity].

A 16-year-old girl developed a pain and paresis in the right hip joint in April 1994. Abdominal CT scan revealed hepatosplenomegaly and large tumor mass (6 x 7 x 13 cm) invading the right psoas muscle in the pelvic cavity. Laboratory data disclosed marked granulocytosis, the presence of Ph1 translocation and bcr-abl rearrangement, thus a diagnosis of CML was made. The tumor was shown to be consisted of granulocytes at all stages of development by a fine needle aspiration cytology. According to the criteria of IBMTR, the disease was classified as accelerated phase solely because the sum of myeloblasts and promyelocytes exceeded over 20%. The patient was treated with hydroxycarbamide, 6MP and dexamethasone, and marked reduction of the tumor mass was observed. Then an allogeneic BMT was performed from her HLA- identical brother on August 1994. She did not develop clinically significant symptoms except for grade I skin GVHD. The tumor was completely disappeared after the BMT as assessed by the abdominal CT scan. No cytological and chromosomal relapse has been observed for 20 months after the BMT.

Adolescent↗

[Bilateral non-Hodgkin's lymphoma of the adrenal glands with adrenal insufficiency].

A 66-year-old female presented with anorexia, fatigue, skin pigmentation, weight loss and low grade fever. Imaging studies demonstrated bilateral bulky masses confined to the adrenal glands. Ultrasonography guided needle biopsy of the mass showed findings of diffuse large B-sell lymphoma. Low levels of serum cortisol, urinary 17-OHCS and 17-KS, a high level of ACTH and a non-reactive pattern on the rapid ACTH test led to a diagnosis of Addison's disease. Only a partial regression was achieved by the first chemotherapy. She died due to disease progression, while the next course of chemotherapy had been postponed because of interstitial pneumonitis due to methotrexate.

17-Hydroxycorticosteroids↗

Serial changes in proximal urethral function after transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in a canine model.

We performed transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in 6 mongrel dogs. To evaluate the changes in proximal urethral function after TUBAL-H, the urethral cross sectional area (CSA, cm2) and urethral pressure (Pu, cmH2O) were measured using a balloon probe that allows their simultaneous measurement, and the urethral compliance (Comp, cm3/cmH2O) was calculated from these parameters and serially evaluated. In addition, the changes in Pu, CSA and Comp after administration of an alpha-adrenoceptor antagonist were evaluated before and 16 weeks after TUBAL-H. Before TUBAL-H, the mean Comp was 0.013, and the mean maximum CSA (MCSA) was 0.66. Eight weeks after TUBAL-H, the mean Comp was 0.038, and the mean MCSA was 1.39, showing a significant increase (p < 0.01). Sixteen weeks, after TUBAL-H, the mean Comp was 0.026, and the mean MCSA was 1.21, being lower than those at 8 weeks after TUBAL-H, but significantly higher than those before TUBAL-H (p < 0.05). After administration of the alpha-adrenoceptor antagonist, phentolamine (1 mg/kg), before TUBAL-H, the mean Comp significantly increased to 0.046 (p < 0.05), and the mean MCSA to 1.40 (p < 0.01). The mean Comp was significantly increased to 0.033 (p < 0.05), by phentolamine administration 16 weeks after TUBAL-H, but no other changes were observed. After TUBAL-H, urethral elasticity increased, and this increase persisted for 4 months. The responses of Comp and MCSA to alpha-adrenoceptor antagonist administration before and 16 weeks after TUBAL-H suggested that part of the effects of TUBAL-H is due to damage to alpha-adrenoceptors.

Adrenergic alpha-Antagonists↗

[Recent progress of molecular oncology and its contribution to clinical gastroenterology].

Recent progress of molecular oncology has made it possible for us to begin to understand the molecular mechanism for tumor development. However, from a viewpoint of its diagnostic and therapeutic applications, it seems that we have just left a starting line. Even Ki-ras and p53 genes that have been most extensively analysed, their most important clinical significances are considered to be giving us pathogenetic informations at the present time. Of note, allelic loss of chromosome 18q was shown a significant prognostic factor for colorectal cancer patients in stage II. One of most important clinical applications of molecular oncology in near future in our country is diagnosis of hereditary cancer. Analyses of sporadic cases with mutations in hereditary cancer genes will be of special importance.

Chromosome Deletion↗

[Relationship between exercise induced ischemia and left ventricular dysfunction; simultaneous assessment of perfusion and function images with 99mTc-tetrofosmin myocardial scintigraphy].

The purpose of this study was to evaluate the relationship between exercise induced ischemia and left ventricular dysfunction, ergometer exercise 99mTc-tetrofosmin myocardial scintigraphy was performed using one day protocol (exercise/rest). Subjects consisted of 68 patients without previous myocardial infarction; without coronary artery disease (CAD) (n = 36) and with CAD (n = 32). Perfusion and function images were evaluated simultaneously. Perfusion image was taken by single photon emission tomography (SPECT). Quantitative analysis was performed with normal data-base. The area of abnormal perfusion, less than normal lower limits, was named as extent score (ES). Left ventricular ejection fraction (LVEF) was measured by first-pass study. According to ES on stress image, 32 patients with CAD were divided into 3 groups; ES < 10% (n = 15), ES = 10-20% (n = 7) and ES > 20% (n = 10). LVEF at rest among 4 groups were not different. LVEF at peak exercise was 61.7+/ -5.3% in CAD (-), 59.0 +/- 5.8% in ES < 10%, 57.4 +/- 6.6% in ES = 10-20% and 47.4 +/- 10.5% in ES > 20%. LVEF in ES > 20% at peak exercise was lowest significantly. Thus, simultaneous perfusion and function images were evaluated for the relationship between exercise induced ischemia and left ventricular dysfunction. If extent score on stress image was more than 20% of left ventricle, significant left ventricular dysfunction was observed.

Aged↗

[Development of deep vein thrombosis in an aplastic anemia patient with antiphospholipid antibodies].

A 38-year-old female was admitted to our hospital because of pancytopenia in April 1992. She was diagnosed as aplastic anemia by bone marrow biopsy and other examinations. Then she was treated with methyl-prednisolone pulse therapy followed by administration of cyclosporin in out-patient clinic. Though the modest improvement of peripheral blood count was observed, the worsening of pancytopenia was developed in association with tapering of cyclosporin. Anabolic steroid was given from June 1994 and gradual improvement of peripheral blood count was observed. On June 1995, she developed sudden onset of swelling and discoloration of a lower extremity, and thrombosis in the femoral vein was detected by Doppler ultrasonography. She was positive for lupus anticoagulant and anticardiolipin antibody, thus a diagnosis of antiphospholipid syndrome was made. Aplastic anemia associated with antiphospholipid syndrome has never been reported as far as we know. This case will be of importance for analyzing the cause of thrombosis in aplastic anemia.

Adult↗

[Effects of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs].

Gosha-Jinki-Gan is clinically used for the treatment of pollakiuria in patients with benign prostatic hyperplasia. The effect of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs was examined. Gosha-Jinki-Gan (100 mg/kg) inhibited the rhythmic bladder contractions (RBC). However, the frequency of RBC increased resembling the effect of atropine (0.1 mg/body), and the amplitude decreased. On the cystometrogram, Gosha-Jinki-Gan caused an increase in maximum vesical volume (not significant). These findings indicated that Gosha-Jinki-Gan is a useful drug for the treatment of pollakiuria.

Anesthesia↗