Biomedical subjects

T Komatsu

Publications and source records attributed to T Komatsu.

At least 37 records · Page 2Linked to original sources

PubMed2003

Central and peripheral concentrations of tumor necrosis factor-alpha in Chinese Meishan pigs stimulated with lipopolysaccharide.

The objective of this study was to investigate the presence of tumor necrosis factor-alpha (TNF-alpha) in the central nervous system and the effects of lipopolysaccharide on central and peripheral concentrations of TNF-alpha, behavioral conditions (standing or lying), elimination scores (defecation or urination), rectal temperature, and food intake (as-fed basis) in Chinese Meishan pigs. Intravenous injections of lipopolysaccharide resulted in increased (P < 0.05) plasma concentrations of TNF-alpha and cortisol. Although urination was not affected by the administration of lipopolysaccharide, defecation was stimulated (P < 0.05). Lipopolysaccharide increased (P < 0.05) rectal temperature and standing rate, and inhibited (P < 0.05) food intake in pigs. To determine whether TNF-alpha is present in the porcine central nervous system as well as in peripheral blood, TNF-alpha and its specific transcripts in brain tissues (hypothalamus, amygdala, or hippocampus) and the pituitary were determined. The abundance of TNF-alpha messenger RNA and immunoreactive TNF-alpha were observed in all tissues, and the concentrations of TNF-alpha were increased (P < 0.05) by the intramuscular injection of lipopolysaccharide. These results suggest that TNF-alpha is present in the central nervous system, and plays some roles in its biological regulation in Chinese Meishan pigs.

Animals↗

PubMed2002

Anaerobic digestion of organic waste in Japan: the first demonstration plant at Kyoto City.

Recycling of Municipal Solid Waste is vigorously promoted in Japan and the necessity of energy recovery from organic waste is increasing. An anaerobic digestion demonstration plant for organic waste in Kyoto City, Japan has been operated for about two years. Three kinds of wastes (garbage and leftovers from hotels, yard waste and used paper) mixed at various ratios are used. The plant has maintained stable operations with each mixture, generating biogas by the decomposition of VS at the rate of about 820 m3N/ton-VS.

Bacteria, Anaerobic↗

PubMed2001

CREB-H: a novel mammalian transcription factor belonging to the CREB/ATF family and functioning via the box-B element with a liver-specific expression.

The expression of liver-specific genes is regulated by unequivocally allocated transcription factors via proper responsible elements within their promoters. We identified a novel transcription factor, CREB-H, and found that its expression was restricted in the liver among 16 human tissues tested. A region of CREB-H exhibited significant homology to the basic leucine zipper (b-Zip) domain of members of the CREB/ATF family: mammalian LZIP and Drosophila BBF-2 that binds to box-B, a Drosophila enhancer modulating the fat-body-specific gene expression. CREB-H contained a hydrophobic region representing a putative transmembrane domain, like LZIP. Constructing a variety of CREB-H fusion proteins with the GAL4 DNA-binding domain disclosed that CREB-H functioned as a transcriptional activator and its N-terminal 149 amino acids accounted for the activation ability. Gel mobility sift assays revealed that CREB-H did not bind to the C/EBP, AP-1 and NF-kappaB elements but specifically bound to CRE and the box-B element. Luciferase reporter assays demonstrated that like BBF-2, CREB-H activated transcription via the box-B element and that a deletion of the putative transmembrane domain increased the activation of reporter expression significantly. Furthermore, a fusion protein of GFP and full-length CREB-H was localized in reticular structures surrounding the nucleus, whereas a fusion protein of GFP and a deletion mutant lacking the putative transmembrane domain was mainly in the nucleus. These findings suggest that CREB-H plays an important role in transcriptional regulation of genes specifically expressed in the liver, and that the putative transmembrane domain may be associated with modulation of its function as the transcriptional activator.

Activating Transcription Factors↗

PubMed2001

Evaluation of the effects of exercise and a mild hypocaloric diet on cardiovascular risk factors in obese subjects.

A weight reduction program to improve cardiovascular risk factors was implemented in obese subjects. The program consisted of exercise training corresponding to the anaerobic threshold (AT) and a mild hypocaloric diet for 12 weeks. In this program, we evaluated the effects of a combination of exercise training and a diet on cardiovascular risk factors such as obesity, dyslipidemia, and poor exercise performance in obese subjects. In addition, we also evaluated the independent effects of exercise training and dietary modification. For this purpose, we adopted a relative training time and a diet score. A relative training time was calculated as the number of times that the subject performed exercises divided by all of the training sessions scheduled, and the diet score was calculated from information which each subject provided on a self-assessment questionnaire. Twenty three obese subjects (Age: 24-54 years old, 19 men and 4 women, body mass index (BMI) > 26 kg/m2) participated in this study. After the 12-week intervention, the mean reductions in body weight, body mass index and body fat were 4.7 kg, 1.7 kg/m2 and 2.9%, respectively (P < 0.0001). The % change in body weight was significantly associated with the diet score and with the relative training time. The mean reductions in total cholesterol, triglyceride and low density lipoprotein cholesterol were 21 mg/dl (P < 0.002), 34 mg/dl (P < 0.01) and 15.9 mg/dl (P < 0.01), respectively, and the % change in triglyceride was significantly associated with the diet score (P = 0.0056) and tended to correlate with the relative training time (P = 0.0596). Oxygen uptake at AT and at peak exercise were increased from 14.1 +/- 1.6 to 16.0 +/- 3.1 ml/min/kg (P < 0.005) and from 26.3 +/- 4.8 to 28.4 +/- 4.9 ml/min/kg (P < 0.002), respectively. A combination of aerobic exercise and a mild hypocaloric diet significantly contributed not only to weight loss but also to the improvement of dyslipidemia and exercise performance, but either hypocaloric diet or mild exercise independently did less. The diet score and the relative training time were useful for evaluating separately dietary modification and the quantity of exercise.

Adult↗

PubMed2001

Characterization of semen collected from beagles and captive Japanese black bears (Ursus thibetanus japonicus).

This study characterized semen collected from the Japanese black bear, Ursus thibetanus aponicus, to provide information on semen cryopreservation for artificial breeding. Preliminary studies using a beagle dog as the model species showed that sperm concentration and total sperm count were lower in semen collected by electroejaculation than in semen collected by digital manipulation, but that sperm motility, viability and morphology were similar. Characterization of semen obtained from Japanese black bears by electroejaculation under general anesthesia revealed that semen volume and total number of spermatozoa collected were lower; but that sperm concentration, motility, viability and morphology were equivalent to those reported in other ursids. When semen was collected via a catheter inserted into the urethra during the stimulation for ejaculation, the sperm concentration, total sperm count and motility were relatively higher than when semen was collected directly in a test tube. Specific normal semen characteristics (mean +/- SEM) were pH, 7.6 +/- 0.0; volume, 0.212 +/- 0.038 mL; sperm concentration, 361 +/- 100 x 10(6)/mL; total sperm count, 84.0 +/- 32.2 x 106; +++ motility, 30 +/- 5%; motility, 77 +/- 3%; viability 77 +/- 2%; and abnormal morphology, 11+/- 2%. These results suggest that semen can be collected from Japanese black bears by electroejaculation.

Animals↗

PubMed2001

IGF-I-induced apoptosis in LM2d6 cultured at a low concentration of fetal bovine serum.

We examined the effects of IGF-I (1-1000 ng/ml) on cell proliferation in LM2d6 mouse fibroblast cells at 0.1, 1.0 and 5.0% fetal bovine serum (FBS). In medium containing 0.1% FBS, treatment of LM2d6 cells with IGF-I significantly reduced the cell number in a dose- and time-dependent manner, whereas no effects were seen at 1 or 5% FBS. Treatment of the cells with 0.1% FBS for 72 h caused DNA laddering and nuclear condensation. However, Scatchard analysis for IGF-I binding sites on the cells revealed that both the number and the affinity of IGF-I receptors were not greater than that of Balb/3T3 cells. Furthermore, the apoptotic action of Long (R(3))-IGF-I, an analogue of IGF-I that has a reduced affinity for IGF binding proteins, was not greater than that of IGF-I. Taken together, we conclude that IGF-I reduces cell proliferation at low levels of FBS due to the induction of apoptosis. This effect is probably not caused by an excess production of IGF binding proteins in LM2d6 cells.

Animals↗

PubMed2001

[Perioperative management of a patient with purpura fulminans syndrome due to protein C deficiency].

PURPOSE: Protein C is a vitamin K-dependent anticoagulant and homozygous protein C deficiency is a rare fatal thrombotic disease. This report describes the perioperative management of homozygous protein C deficiency in a patient who underwent a total of three surgical procedures under general anesthesia and the successful use of activated protein C concentrate. CLINICAL FEATURES: A female baby, who developed disseminated intravascular coagulation and purpura fulminans shortly after birth, was diagnosed as purpura fulminans syndrome due to homozygous protein C deficiency. At one month of age, she suffered bilateral retinal detachment and glaucoma due to retinal hemorrhage. After marked improvement of her condition after administration of activated protein C concentrate, she underwent a left iridectomy and implantation of a Broviak catheter under general anesthesia. Her intraoperative course was uncomplicated but, on postoperative day four, she presented another episode of massive cutaneous necrosis and gangrene. Activated protein C concentrate was administered again, with good results. She underwent replacement of a Broviak catheter at four months of age, and right iridectomy for glaucoma at eight months. Both were uneventful. CONCLUSION: The perioperative management of homozygous protein C deficiency and purpura fulminans requires appropriate measures for thromboembolic prophylaxis. Sufficient iv fluid administration is necessary. Attention should be paid to decrease the risk of tissue compression such as that associated with positioning, blood pressure cuff, and endotracheal intubation, which may cause necrosis over pressure points. Replacement therapy with activated protein C concentrate appears safe and effective. The anesthetic management is reviewed and discussed.

Anesthesia, General↗

PubMed2001

Archaeology of Archaea: geomicrobiological record of Pleistocene thermal events concealed in a deep-sea subseafloor environment.

A record of the history of the Earth is hidden in the Earth's crust, like the annual rings of an old tree. From very limited records retrieved from deep underground, one can infer the geographical, geological, and biological events that occurred throughout Earth's history. Here we report the discovery of vertically shifted community structures of Archaea in a typical oceanic subseafloor core sample (1410 cm long) recovered from the West Philippine Basin at a depth of 5719 m. Beneath a surface community of ubiquitous deep-sea archaea (marine crenarchaeotic group I; MGI), an unusual archaeal community consisting of extremophilic archaea, such as extreme halophiles and hyperthermophiles, was present. These organisms could not be cultivated, and may be microbial relicts more than 2 million years old. Our discovery of archaeal rDNA in this core sample, probably associated with the past terrestrial volcanic and submarine hydrothermal activities surrounding the West Philippine Basin, serves as potential geomicrobiological evidence reflecting novel records of geologic thermal events in the Pleistocene period concealed in the deep-sea subseafloor.

Archaea↗

PubMed2001

Lack of positive interaction between CO2 and hypoxic stimulation for P(CO2)-VAS response slope in humans.

To compare the effect of hypoxia on ventilatory responses and respiratory sensation to carbon dioxide, 29 young adults were examined using a modified Read's rebreathing method with four experimental conditions. We used varying gas mixtures and kept PET(O2) constant at >300, 100, 80 and 60 mmHg for each four rebreathing tests. Respiratory sensation was measured by visual analog scale (VAS). The slope of the CO2-ventilation response curve increased significantly with hypoxia, confirming a positive ventilatory interaction between hypoxia and hypercapnia. However, the slope of the CO2-VAS response curve remained unchanged. The V(E)-VAS relation slope tended to become depressed with advancing hypoxia, i.e. the magnitude of VAS elicited by a given ventilation decreased with hypoxia, signifying that dyspneic sensation was effectively mitigated during hypoxic hyperventilation. We suggest that this relief of dyspneic sensation might be due to the inhibitory respiratory effect from augmented pulmonary stretch receptor (PSR) activity.

Adult↗

PubMed2001

Developmental toxicity of orally administered thiabendazole in ICR mice.

Thiabendazole (TBZ) is a potent anthelmintic and fungicide used in the treatment of parasitic infections in humans and domestic animals and post-harvest protection of agricultural commodities. TBZ is not teratogenic or selectively foetotoxic in rats or rabbits, in contrast to several other benzimidazole derivatives. However, when administered orally to pregnant (Jcl:ICR) mice at lethal dosages, malformations were observed in treated fetuses. To assess whether the effects found in this previous study were attributable to maternal toxicity or TBZ the present study was conducted. TBZ doses of 25, 100 or 200 mg/kg/day were selected based on a preliminary range-finding study in which maternotoxicity was evident at doses of 200 mg/kg/day or above. The compound was administered during gestation days 6-15 as a solution in olive oil. Caesarean sections were completed on gestation day 18 and complete fetal examinations conducted. Decreases in maternal weight gain relative to controls were found at doses of 100 mg/kg/day or above, which paralleled decreases in foetal weights in these same dose groups. However, there were no treatment-related external, visceral or skeletal anomalies in any treatment group. Therefore, TBZ was not teratogenic or selectively foetotoxic in mice, with no-observed-effect levels (NOEL) of 25 and greater than 200 mg/kg/day for maternal and fetal weight effects and teratogenicity, respectively. These results indicate that foetal effects noted in previous studies in mice were probably secondary to severe maternal toxicity.

Abnormalities, Drug-Induced↗

PubMed2001

Sendai virus C protein physically associates with Stat1.

BACKGROUND: The P/C gene of the Sendai virus (SeV), a member of the family Paramyxoviridae, encodes C protein, which plays a crucial role in counteracting the antiviral effect of interferon (IFN). The C protein blocks IFN signalling to prevent the activation of IFN stimulated genes. However, its underlying molecular mechanism remains to be defined. RESULTS: Signal transducer and activator of transcription 1 (Stat1) is a critical component of IFN-alpha/beta and IFN-gamma signalling. We found that both unphosphorylated Stat1 and tyrosine-phosphorylated (pY) Stat1 were present in a form of aberrant high molecular weight complexes (HMWCs) of over 2 MDa in infected cell extracts under low-salt conditions. Of recombinant vaccinia viruses carrying each SeV gene, only those expressing the C gene induced Stat1-HMWC. SeV infected cell extracts further displayed an in vitro ability to convert the pY-Stat1 homodimer to pY-Stat1-HMWC. This cell extract activity was not seen after removal of the C protein from the extracts. C protein was therefore involved in the formation of HMWCs. The HMWCs decomposed into smaller complexes in a high-salt buffer, and under this stringent (high-salt) condition, as well as a physiological (isotonic) condition, both unphosphorylated Stat1 and pY-Stat1 were co-precipitated with anti-C antibody. CONCLUSION: The C protein physically associates with Stat1. This suggests that SeV C protein directly targets Stat1 for inhibitory control on the transcriptional activation of IFN stimulated genes.

DNA-Binding Proteins↗

PubMed2001

Phylogenetic investigation for the risk of hepatitis C virus transmission to surgical and dental patients.

Blood loss during treatment carries a potential risk for the transmission of blood-borne pathogens in hospital patients. To determine whether nosocomial transmission of hepatitis C virus (HCV) occurs in surgical wards and dental hospitals, we tested anti-HCV antibodies and HCV RNA in sera from these patients and analysed the hypervariable region 1 (HVR1) sequence of HCV phylogenetically in the HCV RNA-positive patients. Five of 83 patients from a surgical ward were positive for HCV RNA, and six patients from one dental hospital and nine patients from a second were found to be positive for HCV RNA during the examination period. The HVR1 sequences were amplified from these patients' serum, and after subcloning, multiple clones of the HVR1 sequence from each patient were determined. The phylogenetic analysis of these sequences showed that HVR1 species from each patient could be classified into one to three genetic clusters of HVR1 quasi-species and that these clusters were independent of each other among patients. Thus, there was no evidence of HCV transmission in our study, and unrecognized transmission of HCV may be a rare event in surgical and dental patients at university hospitals.

Adult↗

PubMed2001

Spectral analysis of epicardial 60-lead electrograms in dogs with 4-week-old myocardial infarction.

There were few studies on the spectral analysis of multiple-lead epicardial electrograms in chronic myocardial infarction. Spectral analysis of multi-lead epicardial electrograms was performed in 6 sham-operated dogs (N group) and 8 dogs with 4-week-old myocardial infarction (MI group). Four weeks after the ligation of left anterior descending coronary artery, fast Fourier transform was performed on 60-lead epicardial electrograms, and then inverse transform was performed on 5 frequency ranges from 0 to 250 Hz. From the QRS onset to QRS offset, the time integration of unsigned value of reconstructed waveform was calculated and displayed as AQRS maps. On 0-25 Hz AQRS map, there was no significant difference between the 2 groups. In the frequency ranges of 25-250 Hz, MI group had significantly smaller AQRS values than N group solely in the infarct zone. It was shown that high frequency potentials (25-250 Hz) within QRS complex were reduced in the infarct zone.

Animals↗

PubMed2001

Nutritional status of middle-aged Vietnamese in Ho Chi Minh City.

OBJECTIVE: To investigate the nutritional status of middle-aged Vietnamese in Ho Chi Minh City. METHODS: A cross-sectional survey in 300 Vietnamese aged 40 to 59 years (113 men, 187 women) was conducted in an urban, suburban and rural area of Ho Chi Minh City based on interviews that included a 24-hour dietary recall, food frequency questionnaire, and a short socioeconomic questionnaire. Anthropometry and blood pressure were measured, and blood was collected for serum protein and lipid analysis. RESULTS: A high prevalence of underweight (BMI < 18.5) was observed in the rural and suburban populations (35% and 23%, respectively), and overweight (BMI > or = 25) was observed in the urban population (18%). A high percentage of serum total cholesterol (TC) below 150 mg/dL was observed in the rural and suburban areas (43% and 37%, respectively). By contrast, the prevalence of TC above 220 mg/dL was twofold higher in the urban and suburban residents (13% and 12%, respectively) than in rural residents (6%). More than 80% of urban residents were of medium or high-income status, whereas 61% of suburban residents were of medium-income status and 66% of rural residents were of low-income status. CONCLUSIONS: The nutritional status of middle-aged Vietnamese in Ho Chi Minh City was characterized by undernutrition in 35% of the low-income population and by overnutrition in 18% the high-income population. Undenutrition was still a public health problem in the rural area whereas overnutrition started to become a noteworthy problem in the urban area. The suburban area suffered from both under- and overnutrition problems. Low lipid intake was the most important problem related to undernutrition in middle-aged residents of Ho Chi Minh City.

Adult↗

PubMed2001

The Kaposi' s sarcoma-associated herpesvirus latency-associated nuclear antigen.

Kaposi's sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (6,7,10). While the vast majority of tumor cells from these malignancies are latently infected, only a small subset of viral genes are actually expressed (5,40,47). Of these genes, the latency-associated nuclear antigen (LANA-1, LNA, or LNA1) is the only protein consistently shown to be highly expressed by in situ hybridization and immunohistochemistry (11,20,21,32). Moreover, within the past few years LANA-1 has proven to be a quite versatile protein, playing not only a pivotal role in KSHV episome persistence, but also in interacting with and influencing several cellular genes.

Animals↗

PubMed2001

Oolong tea increases metabolic rate and fat oxidation in men.

According to traditional Chinese belief, oolong tea is effective in the control of body weight. Few controlled studies, however, have been conducted to measure the impact of tea on energy expenditure (EE) of humans. A randomized cross-over design was used to compare 24-h EE of 12 men consuming each of four treatments: 1) water, 2) full-strength tea (daily allotment brewed from 15 g of tea), 3) half-strength tea (brewed from 7.5 g tea) and 4) water containing 270 mg caffeine, equivalent to the concentration in the full-strength tea treatment. Subjects refrained from consuming caffeine or flavonoids for 4 d prior to the study. Tea was brewed each morning; beverages were consumed at room temperature as five 300 mL servings. Subjects received each treatment for 3 d; on the third day, EE was measured by indirect calorimetry in a room calorimeter. For the 3 d, subjects consumed a typical American diet. Energy content of the diet was tailored to each subject's needs as determined from a preliminary measure of 24-h EE by calorimetry. Relative to the water treatment, EE was significantly increased 2.9 and 3.4% for the full-strength tea and caffeinated water treatments, respectively. This increase over water alone represented an additional expenditure of 281 and 331 kJ/d for subjects treated with full-strength tea and caffeinated water, respectively. In addition, fat oxidation was significantly higher (12%) when subjects consumed the full-strength tea rather than water.

Absorptiometry, Photon↗

PubMed2001

Hypocoagulable state of human preovulatory ovarian follicular fluid: role of sulfated proteoglycan and tissue factor pathway inhibitor in the fluid.

Ovulation accompanied by tissue damage can cause an increase in the level of tissue factor (TF) in the follicular fluid, triggering the extrinsic coagulation pathway. However, follicular fluid must block fibrin formation and maintain fluidity until the release of the oocyte at ovulation. The combination of sulfated proteoglycan, antithrombin, and TF pathway inhibitor (TFPI) appears to play a critical role in the hypocoagulability of human follicular fluid. When compared with plasma, folicular fluid differs markedly in the levels of a number of important coagulation proteins. Principal among these are 15-fold, 13-fold, and 3.7-fold increases in free TFPI, thrombin-antithrombin complex, and TF, respectively. The excessively prolonged activated partial thromboplastin time (APTT) and prothrombin time (PT) of human ovarian follicular fluid appear to be primarily due to high concentrations of sulfated proteoglycans, which accelerate the inactivation of thrombin and the anti-Xa activity of TFPI. Thus, heparitinase treatment shortened the clotting times of follicular fluid and reduced the inhibition of thrombin by the proteoglycan fraction combined with a fraction containing antithrombin. The remaining prolongation of APTT and PT may be caused by high levels of free TFPI in follicular fluid, which were confirmed by Northern blotting analysis, demonstrating TFPI mRNA expression by granulosa cells.

Antithrombin III↗

PubMed2001

Changes in sex steroids, gonadotropins, prolactin, and inhibin in pregnant and nonpregnant Japanese black bears (Ursus thibetanus japonicus).

We examined changes in the concentrations of serum progesterone (P4), estradiol-17beta (E2), FSH, LH, prolactin (PRL), and inhibin to determine their interaction and their effect on the reproductive endocrine controls of pregnant and nonpregnant female Japanese black bears. Fourteen female bears were used in this study over a 2-yr period. In the first year, six of the bears were divided into two groups; a pseudopregnant group and a nonpregnant group. In the second year, the remaining eight bears were also divided into two groups; a pregnant group and a nonpregnant group. Pregnant and pseudopregnant bears had similar P4 trends with both groups exhibiting a significant increase in December, which is the suspected time of implantation in pregnant bears. These trends correlated with an increase in PRL levels, whereas low levels of LH were maintained throughout the year. Nonpregnant bears maintained low concentrations of P4, and compared with pregnant and pseudopregnant bears, they also exhibited a delayed elevation in PRL. Luteinizing hormone activity varied among individual animals, but regardless of reproductive status, fluctuation patterns of E2, FSH, and inhibin did not differ among bears. Our results suggest that PRL may play a luteotropic role in both pregnant and pseudopregnant bears, and is possibly responsible for inducing reactivation of the dormant corpus luteum that precedes implantation in the Japanese black bear.

Animals↗