Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 271 records · Page 15Linked to original sources

PubMed1997

Protective effect of recombinant human leukemia inhibitory factor against thrombocytopenia in carboplatin-treated mice.

The protective effect of recombinant human leukemia inhibitory factor (rhLIF) against development of thrombocytopenia in carboplatin (CBDCA; cis-diammine-1,1-cyclobutane dicarboxylate platinum II)-treated mice was examined. The optimal dose of rhLIF was determined by administering doses of rhLIF ranging from 0.2 to 20 micrograms/day intraperitoneally to normal BALB/c mice, and by analyzing platelet counts. Platelet counts significantly increased at doses over 0.2 microgram/day. When 20 micrograms/day rhLIF was injected for 7 days, platelet counts increased to 240% of control. A remarkable weight loss occurred in the 20 micrograms/day group, but no weight loss was detected at doses of less than 10 micrograms/day. The rhLIF dose of 4 micrograms/day was therefore used to examine the protective effect against carboplatin-induced thrombocytopenia in mice. The intravenous injection of 100 mg/kg carboplatin caused a significant thrombocytopenia with a nadir on day 8. The administration of 4 micrograms/day rhLIF intraperitoneally for 7 days promoted the recovery of platelet counts from day 5 after the injection of carboplatin. These results suggest that rhLIF at a suboptimal dose might be a useful therapeutic agent for chemotherapy-induced thrombocytopenia.

Animals↗

PubMed1997

Calcifying fibrous pseudotumor.

A case of calcifying fibrous pseudotumor arising in the ingune of a 20-year-old Japanese female is described. The patient had a well-circumscribed subcutaneous mass measuring 2.0 cm in greatest diameter, which had been present for 3 months. Microscopically, the tumor was not encapsulated but well defined. The tumor was composed largely of dense interwoven bundles of collagen. Uniform, elongated spindle cells were scattered among the collagenous bundles and showed a wavy pattern. Lymphoid follicles with germinal centers and an infiltration of lymphocytes and plasma cells were intermingled. The tumor was characterized by the presence of microcalcifications, chiefly dystrophic calcifications, throughout the lesion. The spindle cells were diffusely positive for vimentin and alpha-smooth muscle actin. They were uniformly negative for desmin, muscle specific actin HHF35, factor-VIII related antigen, S-100 protein, neurofilament, cytokeratin CAM5.2, CD34, and CD31. By flow cytometry the tumor had a diploid DNA content with S-phase fractions of 2.5%. The patient was well with no evidence of disease 2 months after excision.

Adult↗

PubMed1997

Mutational analysis of the feedback sites of phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase of Escherichia coli.

In Escherichia coli, aroF, aroG, and aroH encode 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase isozymes that are feedback inhibited by tyrosine, phenylalanine, and tryptophan, respectively. In vitro chemical mutagenesis of the cloned aroG gene was used to identify residues and regions of the polypeptide essential for phenylalanine feedback inhibition.

3-Deoxy-7-Phosphoheptulonate Synthase↗

PubMed1997

Characterization of a second lysine decarboxylase isolated from Escherichia coli.

We report here on the existence of a new gene for lysine decarboxylase in Escherichia coli K-12. The hybridization experiments with a cadA probe at low stringency showed that the homologous region of cadA was located in lambda Kohara phage clone 6F5 at 4.7 min on the E. coli chromosome. We cloned the 5.0-kb HindIII fragment of this phage clone and sequenced the homologous region of cadA. This region contained a 2,139-nucleotide open reading frame encoding a 713-amino-acid protein with a calculated molecular weight of 80,589. Overexpression of the protein and determination of its N-terminal amino acid sequence defined the translational start site of this gene. The deduced amino acid sequence showed 69.4% identity to that of lysine decarboxylase encoded by cadA at 93.7 min on the E. coli chromosome. In addition, the level of lysine decarboxylase activity increased in strains carrying multiple copies of the gene. Therefore, the gene encoding this lysine decarboxylase was designated Idc. Analysis of the lysine decarboxylase activity of strains containing cadA, ldc, or cadA ldc mutations indicated that ldc was weakly expressed under various conditions but is a functional gene in E. coli.

Amino Acid Sequence↗

PubMed1997

Lack of ventilatory threshold in patients with chronic obstructive pulmonary disease.

We investigated whether the ventilatory threshold (VET) could be detected in 25 patients with severe chronic obstructive pulmonary disease (COPD). Exercise on a treadmill was performed until symptom-limited maximum oxygen uptake (VO2SL) was obtained. VET was absent in 14 patients (56%, VET(-) group) and present in the others (44%, VET(+) group). Basal pulmonary functions and dyspnea index (VE,SL/MVV) were not different between the two groups. Endurance time and exercise tolerance (VO2SL/bw) were significantly less in VET(-) than in VET(+). In the former group, PaO2 and pH at maximal exercise decreased and PaCO2 increased significantly, but HCO3- did not change compared with the corresponding values before exercise. In the latter group, PaCO2 at maximal exercise increased significantly, and pH and HCO3- decreased significantly compared with the values before exercise, but PaO2 did not. The changes in PaO2 and PaCO2 were not different between the two groups, but changes in pH and HCO3- in VET(+) were greater than those in VET(-). These results suggest that the absence of VET in some COPD patients indicates a lower exercise capacity without producing metabolic acidosis. This may be caused by rapidly developing dyspnea.

Aged↗

PubMed1997

The activation of the JAK2/STAT5 pathway is commonly involved in signaling through the human IL-5 receptor.

The JAK (Janus kinase) family of protein tyrosine kinases and the STATs (signal transducers and activators of transcription) have been shown to be activated in response to a number of cytokines and growth factors. In this study, we evaluated the activation of JAK/STAT pathway upon human interleukin-5 (hIL-5) stimulation of two different hIL-5-responsive cell lines, hIL-5 receptor alpha-subunit (hIL-5R alpha) cDNA-transfected TF-1 (TF-h5R alpha) and butyric-acid-treated YY-1 (YY-Bu), and peripheral eosinophils. Immunoprecipitation and electrophoretic mobility shift analysis revealed that tyrosine phosphorylation of JAK2 and activation of STAT5 were induced upon stimulation with hIL-5 in all three cell types, while STAT1 activation was only observed in eosinophils. These results indicate that JAK2/STAT5 activation is a common JAK/STAT pathway for hIL-5-mediated signal in these cells.

Cell Line↗

PubMed1997

Demonstration of the distal end of the oesophagus by transabdominal ultrasound.

This study aimed to demonstrate the distal end of the oesophagus using a transabdominal ultrasound technique (TUS) and to measure the normal oesophageal wall thickness in adults. 65 patients without oesophageal disease and 38 normal volunteers were examined by TUS. A left subcostal approach was used to demonstrate the oesophagus. The wall thickness and length were measured in both the supine and 45 degrees right side up oblique (RUO) positions. The abdominal oesophagus was visualized in 80% of patients in the supine position and 92% in the RUO position. Satisfactory demonstration was obtained in 67% of patients in the supine and 85% in the RUO position. The oesophageal wall thickness averaged 2.8 mm (range 2.0-4.0 mm, SD 0.7 mm). The visualized length in these subjects averaged 2.3 cm in the supine position and 3.0 cm in the RUO position, which included approximately 1.5 cm of the lowest portion of the thoracic oesophagus in addition to the abdominal oesophagus. TUS can demonstrate the abdominal oesophagus in the majority of patients and has the potential to provide information on disorders of structure and motility.

Abdomen↗

PubMed1997

Improvement of exercise performance with short-term nasal continuous positive airway pressure in patients with obstructive sleep apnea.

We examined the effects of nasal continuous positive airway pressure (CPAP) on exercise performance in patients with obstructive sleep apnea (OSA). Six patients were treated with nasal CPAP on seven successive days and underwent overnight sleep studies and multiple sleep latency test (MSLT) at the beginning and after the last day of the treatment. The subjects also performed incremental exercise testing using a bicycle ergometer followed by 0-w, 25-w, 50-w,--(3 minutes each) until maximum level. Arterial oxygen pressure, arterial carbon dioxide pressure at rest while awake, apnea/ hypopnea index, longest apnea duration, the lowest percutaneous oxygen saturation measured by a pulse oximeter and the value of MSLT were significantly improved after nasal CPAP. Moreover, maximal oxygen consumption was significantly increased from 1841 ml/min +/- 350 to 2125 ml/min +/- 351 (p < 0.05); however, other cardiorespiratory parameters did not change significantly. The improvement of exercise performance by short-term nasal CPAP treatment in OSA patients may correlate with the improvement of sleepiness.

Adult↗

PubMed1997

Conventional molecular diagnosis of steroid 21-hydroxylase deficiency using mismatched primers and polymerase chain reaction.

We tested a conventional method based on polymerase chain reaction (PCR) and specific primers with one mismatched base at the 3' end to introduce restriction enzyme sites in order to detect mutations of the CYP21 gene without radioisotope. Using this method, the intron 2 mutation causing aberrant splicing of mRNA (In2G) and the exon 4 mutation (Ile->Asn, Ex4) in the CYP21 gene were analyzed. The nonsense mutation in exon 8 (Ex8NON) of the CYP21 gene was also investigated by PCR and subsequent restriction enzyme digestion. The mismatched primers successfully amplified the CYP21 gene containing the In2G and the Ex4 mutation sites, and the presence of these two mutations could be determined by restriction enzyme digestion after PCR. We used this new method to study 33 patients. Twenty-five of these patients were found to have at least one mutation (In2G and/or Ex4 mutation). By enzyme digestion after PCR, the Ex8NON mutation was also identified (7 out of 33 patients). In conclusion, we have developed a new method to detect point mutations in the CYP21 gene. This method was proved to be sensitive and rapid for the detection of the mutations studied. Therefore, this method is suitable for clinical genetic diagnosis.

Adrenal Hyperplasia, Congenital↗

PubMed1997

Cerebral abscess as an unusual complication of coil embolization in a dural arteriovenous fistula. Case report.

This 63-year-old man presented with a right temporoparietal cortical infarction. A dural arteriovenous fistula involving the right transverse sinus was diagnosed on cerebral angiography. Transvenous embolization using detachable coils was performed; however, postembolization angiograms demonstrated retrograde filling of a cortical draining vein that was not seen on initial angiography. The patient subsequently developed a cerebral abscess in the region of the previous cortical infarction 2 months after the embolization. The abscess was successfully treated with drainage and antibiotic therapy. The authors report this case to illustrate an unusual complication associated with this procedure and the possible contribution of the cortical draining vein in the pathogenesis of the cerebral abscess.

Angiography, Digital Subtraction↗

PubMed1997

Innovation in nursing education: development of computer-assisted thinking.

In order to enhance students' active thinking, faculty members at International University of Health and Welfare developed the CAT (Computer Assisted Thinking) program. The CAT program is different from CAI (Computer Assisted Instruction), which mainly asks users to choose correct answers. Instead, the CAT program asks users to type in short sentences. There are two functions in the CAT program: one is to keep the students' action log each time they use the program and the other is to serve as medical dictionary. An analysis of the action log revealed that the students demonstrated little skill in inferential thinking. Their observations were very concrete. In order to help the students to develop their abstract thinking skills, we need to review our curriculum.

Computer-Assisted Instruction↗

PubMed1997

Basic study on the rectangular numeric keys for touch screen.

The present study was conducted to examine the optimum inter-key spacing of numeric rectangular keys for touch screens. Six male students (22-25 years old) and three female students (21-24 years old) participated in the experiment. Each subject performed the data entry task using rectangular keys of touch devices. These keys were arranged in both horizontal and vertical layouts. The sizes of the rectangular keys in both layouts were 12 x 21 mm and 15 x 39 mm, and each of the inter-key spacing of each key was 0, 3, 6, 12 and 21 mm. The response time with inter-key spacing of 3 mm was significantly faster than with the inter-key spacing of 0, 12 and 21 mm (p < 0.05). Keys of vertical position produced faster response time than that of horizontal position. The subjective ratings showed that the inter-key spacing of 6 mm was significantly better than the inter-key spacing of 0, 3, 12 and 21 mm (p < 0.05).

Adult↗

PubMed1997

[A case of tricuspid valve endocarditis in a non-addicted adult person without underlying cardiac disease].

A very rare case of tricuspid valve endocarditis which developed in a healthy adult was observed. An 18-year-old man with no history of heart disease nor use of stimulant drugs was diagnosed as having cardiac tumor, introduced to this hospital and admitted. Before the operation, symptoms characteristic to infective endocarditis such as high fever and embolism were not observed, but the tumor was detected in the right ventricle by echocardiography. The patient underwent cardiotomy. The thrombus was removed and annuloplasty was performed by Kay's method, and good results were obtained. Pathologically the disease was diagnosed as infective endocarditis accompanied by thrombus. The postoperative course has been good. When the injury of the valve is slight, the surgical method preserving patient's own valve such as excision of localized vegetation and annuloplasty appears to be useful.

Adolescent↗

PubMed1997

[A case of localized pleural mesothelioma].

Localized pleural mesothelioma is reported. A 62-year-old male had been observed as a patient with old tuberculosis of the left lung for a few decades. For detailed examination of fever of unknown cause and abnormal shadow on the chest X-ray, the patient was introduced to our hospital. By percutaneous cytodiagnosis, the illness was diagnosed as pleural mesothelioma, and the patient underwent surgery. Since adhesion of the tumor to the lower lobe of the lung was extremely tight, the tumor and the left lower lobe were resected as a mass. The tumor was about 15 cm in diameter, weighed 1,300 g and a slight pleural effusion was observed. The tumor was diagnosed as malignant localized pleural mesothelioma pathologically. Localized pleural mesothelioma should be subjected to surgery in the early stage, in principle. Even in cases difficult to diagnose, operation should not be delayed by repeating easy-going needle-biopsy or a long-term treatment with antitubercular drugs. The postoperative course of this case has been good, and no recurrence nor metastasis has been detected.

Humans↗

PubMed1997

[Evaluation of 99mTc-ECD SPECT for the detection of brain tumor: comparison with 201TI SPECT].

For the evaluation of brain tumor (n = 15), we performed both dynamic and static 99mTc-ECD (ECD) SPECT studies 201Tl SPECT was also used for comparison with the results of ECD SPECT. Dynamic ECD SPECT was obtained following the injection of 600 MBq of ECD. Five min after the injection of ECD, static ECD SPECT was performed. 201Tl SPECT was obtained 10 min after the injection of 74MBq. Abnormal uptake was recognized in 7 of 15 tumors with dynamic ECD: 5 of 7 meningiomas, 1 of 1 glioblastoma and 1 of 1 astrocytoma. However, no abnormal uptake was seen in 3 of 3 benign tumors (1 low grade astrocytoma, 1 hemangioma, 1 cranio-pharyngioma) and in 2 of 2 brain metastases. In contrast abnormal uptake was seen in 11 of 15 tumors with 201Tl:7 of 7 meningiomas; 2 of 2 brain metastases, 1 of 1 glioblastoma and 1 of 1 craniopharyngioma. No abnormal uptake was seen in 3 of 3 benign tumors (1 hemangioma and 2 low grade astrocytomas). Equivocal uptake was seen in 1 low grade astrocytoma with dynamic ECD and 201Tl. The mechanism of the accumulation of dynamic ECD to brain tumor is unclear. However, it may reflect not only blood flow, but also metabolism.

Adult↗

PubMed1997

[Quantitative evaluation of magnetization transfer ratio in irradiated breast with breast conservation therapy].

To assess the late effects of radiotherapy, magnetization transfer was evaluated in 2 patients with breast conservation treatment and in 4 patients without treatment. The magnetization transfer ratios (MTRs) were measured from a pair of images obtained by the conventional SPGR pulse sequence and the MT-prepared SPGR sequence on a 1.5-TMR system. The MTR values of irradiated breast were higher than those of non-irradiated breast. The difference in MTR between them was considered to represent tissue change due to irradiation. We showed that MTR is a useful parameter in estimating the late effects of radiotherapy.

Adipose Tissue↗

PubMed1997

[Abdominal aortic surgery in Stanford type B chronic dissecting aortic aneurysm].

Three cases of a chronic type B dissecting aneurysm which required abdominal aortic reconstruction are presented. Constriction of the iliac artery due to dissection was found in case 1, in case 2 the left subclavian artery originated from a giant false lumen, and arteriosclerosis obliterans was observed in case 3. The left renal artery originated from a false lumen in all cases. Each patient underwent preliminary graft replacement of the abdominal aorta because using the femoral artery for extracorporeal circulation had a higher risk factor. The distal arch and descending aorta were then replaced with woven dacron graft. In a chronic type B dissecting aneurysm, the surgical procedure is sometimes complex because of the narrowing of the true lumen and the enlargement of the false lumen or arteries originating from the false lumen to major organs. It is necessary to consider preliminary abdominal reconstruction in cases of 1) dilatation of abdominal aneurysm, 2) obstruction, stenosis or thrombus below the abdominal aorta, or 3) presence of a giant false lumen.

Aged↗

PubMed1997

[A case of successful surgical treatment of recurrent Stanford type A thrombosed aortic dissection].

A 70-year-old female was hospitalized with a complaint of anterior chest pain. Enhanced CT scan demonstrated acute type A aortic dissection with the clotted false lumen. Aortography showed ulcer-like projection in the ascending aorta. The patient received the conservative medical treatment and had been followed up medically at outpatient clinic. One year later, she was admitted with the general malaise, chest discomfort and the enlargement of the mediastinum on the chest X-ray. Aortography revealed recrudescent enlarged false lumen. Graft replacement of the ascending aorta was successfully performed. Careful medical follow up should be necessary for the thrombosed Stanford type A aortic dissections.

Aged↗