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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 145 records · Page 8Linked to original sources
PubMed2000

Inspiratory effort sensation to added resistive loading in patients with obstructive sleep apnea.

STUDY OBJECTIVES: Repeated episodes of upper-airway occlusion are the main characteristics of patients with obstructive sleep apnea (OSA) during sleep. It has been reported that an impairment in the sensation of detection and a depression of ventilatory compensation to added load could be observed in such patients. In this study, we examined patients with OSA to evaluate the inspiratory effort sensation (IES), ventilation, and mouth occlusion pressures during added resistive loading while awake and to determine whether they can be reversed by nasal continuous positive airway pressure (CPAP) treatment. DESIGN: A hospital-based case-control study. SETTING: A sleep laboratory of a medical unit in Japan. SUBJECTS: Seventeen patients with moderate to severe OSA and 10 control subjects were included in this study. MEASUREMENTS: All patients with OSA had undergone standard nocturnal polysomnography. Patients with OSA and control subjects were evaluated for IES measured by a modified Borg score, ventilation, and mouth occlusion pressure during control and inspiratory resistive loaded breathing. These tests were repeated in all patients with OSA after 2 weeks of nasal CPAP treatment. RESULTS: IES to inspiratory resistive loading was lower in patients with OSA than in control subjects. There were no differences in ventilation and mouth occlusion pressure between patients and control subjects during loaded breathing. After 2 weeks of nasal CPAP, the decreased IES was increased in patients with OSA. CONCLUSION: In patients with OSA, the decreased IES to inspiratory resistive loaded breathing is reversible with nasal CPAP. This could be one additional benefit of nasal CPAP in the treatment of OSA.

Airway Obstruction↗
PubMed2000

Effects of nasal continuous positive airway pressure on awake ventilatory responses to hypoxia and hypercapnia in patients with obstructive sleep apnea.

This study was aimed to examine the short- and long-term effects of nasal continuous positive airway pressure (CPAP) on the chemosensitivity to hypoxia and hypercapnia in the patients with obstructive sleep apnea (OSA). Awake ventilatory responses to hypoxia and hypercapnia were examined in 28 patients (3 female) with moderate to severe OSA. All these tests were examined before and after 2 weeks of nasal CPAP. In 10 patients these tests were repeated after 3-6 months of nasal CPAP. All were also tested for spirometry and arterial blood gas analysis. Patients were middle-aged (48.9 +/- 9.9 years) and their mean apnea-hypopnea index was 58.3 +/- 20.4/hour. After 2 week of nasal CPAP, PaO2 significantly increased (77.7 +/- 11.8 vs. 84.6 +/- 9.8 mmHg) and PaCO2 significantly decreased (44.9 +/- 3.8 vs. 42.3 +/- 3.7 mmHg). The ventilatory response to hypoxia significantly decreased (0.80 +/- 0.51 vs. 0.61 +/- 0.51 liter/min/%) whereas the ventilatory response to hypercapnia significantly increased after 2 weeks (1.47 +/- 0.73 vs. 1.80 +/- 0.76 liter/min/mmHg). Similar findings were also observed after 3-6 months of nasal CPAP in 10 OSA patients. Nasal CPAP treatment can alter the ventilatory responses in patients with OSA.

Blood Gas Analysis↗
PubMed2000

Effects of inhalation of essential oils on EEG activity and sensory evaluation.

The purpose of this study was to investigate EEG changes in subjects directly after inhalation of essential oils, and subsequently, to observe any effect on subjective evaluations. EEG and sensory evaluation were assessed in 13 healthy female subjects in four odor conditions. Four odor conditions (including lavender, chamomile, sandalwood and eugenol) were applied respectively for each subject in the experiment. The results were as follows. 1) Four basic factors were extracted from 22 adjective pairs by factor analysis of the sensory evaluation. The first factor was "comfortable feeling", the second "cheerful feeling", the third "natural feeling" and the fourth "feminine feeling". In the score of the first factor (comfortable feeling), the odors in order of high contribution are lavender, eugenol, chamomile and sandalwood. 2) Alpha 1 (8-10 Hz) of EEG at parietal and posterior temporal regions significantly decreased soon after the onset of inhalation of lavender oil (p < 0.01). Significant changes of alpha 1 were also observed after inhalation of eugenol or chamomile. The change after inhalation of sandalwood was not significant. These results showed that alpha 1 activity significantly decreased under odor conditions in which subjects felt comfortable, and showed no significant change under odor conditions in which subjects felt uncomfortable. These results suggest a possible correlation between alpha 1 activity and subjective evaluation.

Administration, Inhalation↗
PubMed2000

Personality and dietary habits.

BACKGROUND: The personality of healthy individuals has not been well studied in relation to health consciousness, dietary habits and actual food intake, simultaneously. OBJECTIVE: Our objective was to study the association between personality and dietary habits. DESIGN: Information on dietary habits, including taste preferences and the frequency of food consumption, was collected through a questionnaire from 76 male and 394 female students. The personality of students was determined by a modified NEO-FFI test. Health status, height, body weight, body fat percentage and blood pressure were measured by physical examination. Main outcome measures were personality scores as indicators of a healthy dietary pattern. RESULTS: Food intake was influenced by neuroticism (N), extraversion (E), openness (O) and agreeableness (A) of personality. Taste preferences and receptivity to dietary advice were also influenced by personality: the odds ratios (ORs) between the high and low tertiary points of the NEO-FFI scores for salty and sweet taste preferences were significantly higher in the group that scored high for neuroticism (N) (salty taste preference: OR = 2.25, NS in males and OR = 2.39, 95%CI = 1.16-4.93 in females; sweet taste preference: OR = 21.00, 95%CI = 2.40-183.99 in males and OR = 3.33, 95%CI = 1.61-6.91 in females). On the other hand, the groups with high scorer for O and A did not like salty tastes. The groups with high scores for A and C were receptive to dietary advice. High scores of each N, E, O, A, and C factor were characterized by distinguishable, dietary habits and lifestyle. For nutritional or health education, group classes are sufficient for high A and O. High C scorer displayed discrepancies between health consciousness and dietary habits, so intervention or a close follow-up by medical professionals would be necessary to improve the health of individuals in this group. High E scorer possessed a confident attitude towards their health, but they were not interested in developing healthy habits. High N scorer was adverse to receiving health information and learning healthy dietary habits. CONCLUSION: Personality determined by NEO-FFI test was related to dietary habits and health attitude. Effective health education methods must take the personality of the targeted individuals into consideration.

Adult↗
PubMed2000

Health effects of chronic exposure to polychlorinated dibenzo-P-dioxins (PCDD), dibenzofurans (PCDF) and coplanar PCB (Co-PCB) of municipal waste incinerator workers.

A national survey of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) in emission gases from the municipal waste incinerators in 1997 revealed that the Nose Bika Center was heavily contaminated by PCDF. Ninety-four workers underwent a physical examination, and blood biochemistry, lymphocyte marker, and NK activity studies were carried out, along with blood dioxin measurements. Information on working history, life-style, and dietary habits was obtained by questionnaire and interview. The blood dioxin levels were as follows. The median TEQ of dioxins was 39.7 pg I-TEQ/g lipid, and the range was 13.3 to 805.8. The median 2,3,7,8-TCDD concentration was 3.9 pg TEQ/g lipid, and the range was <1 pg TEQ/g lipid (one case) to 13.4 pg TEQ/g lipid. The median TEQ of coplanar PCB was 10.8 pg I-TEQ/g lipid, and the range was 3.1 to 54.2 pg TEQ/g lipid. The congener-specific distribution was quite similar to that in soil around incinerator and waste in the factory. The relationship between dioxin concentrations and work history in the factory showed that the fluidized incinerator and fly ash treatment areas were high-risk work areas. Correlation analyses between body burden, PCDD/PCDF TEQ, Co-PCB TEQ and various laboratory data showed significant positive correlations between dioxin levels and GGT, total protein, uric acid and calcium, and a negative correlation with Fe. However, these correlations disappeared as a result of multivariate analysis adjusted for age, smoking status, and alcohol drinking. Increased NK activity and lower response to PHA stimulation remained significant even after adjusting for age. History of hyperlipidemia and allergy had significantly increased odds ratios. A study on the risk to other workers in the same type of incinerators is under way. Health effects of chronic exposure mainly to PCDF will be clarified by follow-up.

Adolescent↗
PubMed2000

Antiangiogenic and antitumor effects of tranilast on mouse lung carcinoma cells.

We examined the effects of tranilast on tumor angiogenesis, tumor growth and metastasis in the mouse Lewis lung carcinoma and C57BL mouse system. Tranilast significantly reduced the dense capillary network induced by Lewis lung cancer cells in a mouse dorsal air sac angiogenesis model. Intraperitoneal administration of tranilast at 200 mg/kg/day reduced the tumor size of mouse Lewis lung carcinoma to about 63% of that of the control and suppressed pulmonary metastasis in a spontaneous system. Immunohistochemistry revealed that tranilast reduced the tumor vascularity and increased apoptosis of the tumor cells in vivo. Tranilast potentiated the inhibition of the tumor growth induced by cyclophosphamide, cis-diamminedichloroplatinum(II), adriamycin and vindesine in vivo. These results suggest that tranilast has antiangiogenic and antitumor effects and might have possible therapeutic applications.

Angiogenesis Inhibitors↗
PubMed2000

[Aortic valve replacement with a stentless porcine aortic root bioprosthesis].

From April, 1999 to November, 1999, 8 patients underwent the aortic valve replacement using Medtronic Freestyle aortic root bioprosthesis. Mean age was 67.8 years old. Aortic valve etiology was as follows, AS: 1 case, AR: 2 cases, ASR: 3 cases, IE: 1 case, mechanical valve malfunction due to subvalvular pannus: 1 case. The implanted valve size was 25: 2 cases, 23: 3 cases, 21: 1 cases, 19: 2 cases. Surgical technique was subcoronary: 7 cases, full-root: 1 case. Post-op 2D-echo revealed tribial aortic valve incompetence in two cases because of size discrepancy between the aortic annulus and the ascending aorta. Pacemaker implantation was needed in 1 case because of the complete A-V block. In comparison with 5 cases of aortic valve replacement with Hancock II performed in same period, there were no significant differences about the implanted valve size and mean systolic pressure gradient, but the effective orifice area in Freestyle cases was significantly larger than Hancock II cases.

Aged↗
PubMed2000

[A case of chronic localized thoracoabdominal aortic dissecting aneurysm].

A rare case of chronic localized thoracoabdominal aortic dissecting aneurysm was surgically treated. The patient was a 76-year-old woman. She was reffered to our hospital because of the abnormality of the chest roentogenogram. Chest CT and aortography revealed localized thoracoabdominal dissecting aneurysm 70 mm in diameter. Patch closure of intimal tear was carried out under partial cardiopulmonary femoro-femoral bypass. The patient discharged on the 23rd post operative day without any complications.

Aortic Dissection↗
PubMed2000

Patients with renal hypouricemia with exercise-induced acute renal failure and chronic renal dysfunction.

We here report the case of a 38-year-old male with back pain and vomiting occurring after exercise. Serum creatinine level was elevated, and he was admitted to our hospital with diagnosis of acute renal failure (ARF). He had experienced similar attacks at least 4 times, including the present episode, from the age of 22 years. After admission, the patient was managed only by resting, and remission was nearly attained in about 1 month. The renal biopsy specimen performed on day 15 showed findings of acute tubular necrosis, thickening of the tubular basement membrane, and interstitial fibrosis. After remission, the serum uric acid level was 0.7-0.8 mg/dl, fractional excretion of uric acid was 0.63, and the possibility of other diseases facilitating the excretion of uric acid was denied. Therefore, ARF associated with idiopathic renal hypouricemia was diagnosed. Since only mild responses were observed in a pyradinamide loading test and a benzbromarone loading test, the case was considered to be a presecretary reabsorption disorder type. Renal function tests showed the almost complete recovery of the glomerular filtration rate (GFR: 114 ml/min/1.73 m2), but the urine concentrating ability was markedly decreased (specific gravity 1.019 and osmolarity 516 mOsm/kgxH2O in Fishberg test). Past data from this patient indicated that this renal dysfunction had been persisting for ten years. We examined 9 patients with renal hypouricemia and focused on the differences between the two groups (with or without complications). Four patients had a history of exercise-induced ARF or calculus. The urine concentrating ability was significantly lower in these patients (group A) than in the other patients without complications (group B). The glomerular filtration rate in group A was within the normal range, but was lower than in group B. These results suggested the possibility that patients with renal hypouricemia with complications may have chronic renal dysfunction in the future.

Acute Kidney Injury↗
PubMed2000

[Concomitant surgical treatment of valvular heart disease and coronary artery disease].

Concomitant valvular surgery and coronary artery bypass grafting were performed in 24 patients. Aortic valve replacement was carried out in 18 cases (A group), and mitral valve surgery (M group) was done in 6 cases (replacement in 3, and plasty in 3). There were two hospital deaths (11.1%) in the A group, and two (33.3%) in the M group of mitral valve replacement with Hancock II. One late death was observed in the M group. Aortic valve replacement with coronary revascularization resulted in satisfactory outcome. However, surgical management of concomitant mitral valve and coronary artery disease may need to be improved.

Aged↗
PubMed2000

Complementation of an hMSH2 defect in human colorectal carcinoma cells by human chromosome 2 transfer.

The human colorectal tumor cell line LoVo has a homozygous deletion in the hMSH2 gene from exon 3 to exon 8, is deficient in mismatch repair (MMR) activity, and exhibits microsatellite instability. To determine whether the introduction of a wild type hMSH2 into LoVo restores MMR activity and stabilizes microsatellite loci, we transferred a chromosome 2 fragment containing hMSH2 into a homologous recombination-proficient chicken DT40/human hybrid (DT40 2C) and a human chromosome 2 in a mouse A9 hybrid to LoVo. Transfers of these chromosomes into LoVo resulted in LoVo both with and without a wild-type hMSH2. Complete correlation was found between the presence of the wild-type hMSH2 and hMSH2 expression, an increased stability in microsatellite loci, and competency in MMR. The hMSH2-positive LoVo hybrids also showed an increased sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine. This enhanced toxicity is associated with G(2) cell-cycle arrest followed by premature mitosis and cell death. These results suggest that hMSH2 may be responsible for complementing mutator and drug-resistant phenotypes in chromosome 2-transferred LoVo cells. To test whether the hMSH2 in DT40 2C cells can be modified by homologous recombination, we transfected DT40 2C with a targeting vector containing an hMSH2 exon 4 disrupted by the zeocin-resistant gene. The results showed that the hMSH2 locus in DT40 2C was efficiently targeted by an exogeneously transfected homologous sequence, suggesting that transfer of a modified hMSH2 from DT40 2C to LoVo via chromosome transfer could be used to determine the function of hMSH2.

Animals↗
PubMed2000

[Minimally invasive direct coronary artery bypass grafting using subxiphoid approach].

We report twelve cases of minimally invasive coronary artery bypass grafting via small laparotomy using right gastroepiploic artery (RGEA) to the right coronary artery. Seven patients were operated on without partial sternotomy (N group), and lower partial sternotomy with Octopus 2 stabilization system was used in five of the cases (P group). Postoperative Doppler echographic imaging or angiographic study showed all RGEA grafts were functioning well in P group. However, graft occlusion was observed in two of the cases in N group. Inferior partial sternotomy combined with Octopus 2 stabilization system produce a clear surgical view, which avoids of both full-sternotomy and cardiopulmonary bypass. This method might be useful especially for reoperation.

Aged↗
PubMed2000

Treatment with paclitaxel alone rather than combination with paclitaxel and cisplatin may be selective for cisplatin-resistant ovarian carcinoma.

BACKGROUND: We have previously reported that paclitaxel (taxol) results in cisplatin sensitization to human ovarian cancer cells with cisplatin resistance in vitro. This study was designed to determine effects of taxol and its combination with cisplatin on growth of cisplatin-sensitive cell line (KF28) and the cisplatin-resistant counterpart (KFr13) in nude mice. METHODS: From 14 days after tumor inoculation treatment was initiated. Taxol (3 mg/kg) and cisplatin (2 mg/kg) were administered i.p. once a week for 5 weeks. RESULTS: In nude mice bearing cisplatin-sensitive cells (KF28), taxol followed by cisplatin and cisplatin plus taxol inhibited significantly (P < 0.05) the tumor growth rate compared with that in nude mice treated with cisplatin alone or taxol alone and cisplatin followed by taxol. On the other hand, in nude mice bearing cisplatin-resistant KFr13 cells, treatment with taxol alone inhibited completely the tumor growth rate, whereas no schedule-dependent interaction of taxol with cisplatin was observed. CONCLUSION: These results suggest that treatment with taxol alone may be superior to combination of taxol with cisplatin in patients with cisplatin-resistant ovarian carcinoma.

Animals↗
PubMed2000

[Comparative genomic hybridization for analysis of chromosomal changes in cisplatin-resistant ovarian cancer].

In our attempt to find characteristic genetic changes in resistant tumors, we screened the whole genome for gene aberrations in 28 primary ovarian cancers, using the comparative genomic hybridization (CGH) method. These cancers included 14 tumors from patients who did not respond to cisplatin-based combination chemotherapy in comparison with 14 tumors from patients who completely responded to the chemotherapy. We found gains in chromosomal region 1q21-q22 and 13q12-q14 to be related to the drug-resistant phenotype in ovarian cancer patients. Several genes encoding transcription factors, oncogenes, cell cycle regulators and regulators of the apoptotic pathway are found to be located on these regions of the chromosomes, and these genes are potential modulators for toxic insults in cancer cells. This is the first report that shows the relationship between certain genomic aberrations and clinical resistance for cisplatin-based chemotherapy in ovarian cancer patients based on the CGH analysis. Present findings suggest that these chromosomal gains may be potential indicators for prediction of resistance in ovarian cancer patients prior to cisplatin-based chemotherapy.

Antineoplastic Agents↗
PubMed1999

Anti-HIV effect of saquinavir combined with ritonavir is limited by previous long-term therapy with protease inhibitors.

Combination therapy of saquinavir (SQV) and ritonavir (RTV) seems to have a strong antiretroviral effect pharmacokinetically. The purpose of this study was to examine the effectiveness of combined therapy using SQV and RTV in patients previously treated with protease inhibitors (PIs) and to identify the factors compromising the response to such combination therapy. Nineteen HIV-infected Japanese patients participated in this trial between June 1997 and July 1998, and were monitored until November 1998. Patients were treated with SQV (400 mg twice daily) and RTV (300 or 400 mg twice daily). Among the 17 patients who continued such therapy for longer than 3 months, 6 were responders. Among nonresponders, the duration of PI therapy was longer and a higher frequency of preexisting PI resistance viral mutations was detected than in responders. No significant differences were found in previous use of reverse transcriptase inhibitor therapy, CD4+ and CD8+ T cell counts, viral load at baseline, and plasma concentrations of SQV and RTV between responders and nonresponders. Our results suggest that the response to SQV combined with RTV therapy is complicated by previous long-term treatment with PIs, probably owing to multiple PI resistance mutations. Even in patients with a PI-sensitive HIV genotype, however, resistance mutations can develop during therapy and abrogate the effect of high plasma SQV concentrations.

Adolescent↗
PubMed1999

Expression of chimeric P450 genes encoding flavonoid-3', 5'-hydroxylase in transgenic tobacco and petunia plants(1).

Flavonoid-3',5'-hydroxylase (F3'5'H), a member of the cytochrome P450 family, is the key enzyme in the synthesis of 3', 5'-hydroxylated anthocyanins, which are generally required for blue or purple flowers. A full-length cDNA, TG1, was isolated from prairie gentian by heterologous hybridization with a petunia cDNA, AK14, which encodes F3'5'H. To investigate the in vivo function of TG1 and AK14, they were subcloned into a plant expression vector and expressed under the control of the CaMV35S promoter in transgenic tobacco or petunia, both of which originally lack the enzyme. Transgenic petunia plants had a dramatic change in flower color from pink to magenta with a high content of 3',5'-hydroxylated anthocyanins. In contrast, transgenic tobacco plants had minimal color change with at most 35% 3',5'-hydroxylated anthocyanin content. These results indicate that the products of TG1 and AK14 have F3'5'H activity in planta and that interspecific gene transfer alters anthocyanin pigment synthesis. The difference in apparent F3'5'H activity between tobacco and petunia is discussed.

Amino Acid Sequence↗