Biomedical subjects

F Yamazaki

Publications and source records attributed to F Yamazaki.

At least 55 records · Page 3Linked to original sources

PubMed1996

Adhesive protein cDNA sequence of the mussel Mytilus coruscus and its evolutionary implications.

cDNA encoding the adhesive protein of the mussel Mytilus coruscus (Mcfp1) was isolated. The coding region encoded 848 amino acids (a.a.) comprising the 20-a.a. signal peptide, the 21-a.a. nonrepetitive linker, and the 805-a.a. repetitive domain. Although the first 204 nucleotides and the 3'-untranslated region of Mcfp1 cDNA were homologous to corresponding parts of M. galloprovincialis adhesive protein (Mgfp1) cDNA, the other parts diverged. The representative repeat motif of the repetitive domain, YKPK(I/P)(S/T)YPP(T/S), was similar but slightly different from the repeat motif of Mgfp1. The codon usage patterns for the same amino acids were different in different positions of the decapeptide motif. Almost identical nucleotide sequences encoding the two to 13 repeats appeared several times in the repetitive region, which suggests that the adhesive protein genes of mussels have evolved through the duplication of these repeat units.

Amino Acid Sequence↗

PubMed1996

[Invasive amebiasis at an institution for the mentally retarded in Shizuoka Prefecture].

Amebiasis caused by Entamoeba histolytica at an institution for mentally retarded in Shizuoka Prefecture is reported. Five of the 50 patients showed E. histolytica cysts in their stools and 4 were positive serologically. The polymerase chain reaction and restriction fragment length polymorphism revealed that the isolates were pathogenic-type E. histolytica. Epidemiological analysis revealed that the amebic infection was caused by the abnormal behavior of mentally retarded patients. Administration of diloxanide furoate and metronidazole for cyst-carriers eliminated cysts from the stool and lowered the antibody titer.

Adult↗

PubMed1996

Responses of sweating and body temperature to sinusoidal exercise in physically trained men.

The effect of physical training on the dynamic responses of sweating to transient exercise is still controversial. We determined the phase response and amplitude response (delta) of sweating rate and body temperature to sinusoidal exercise in physically trained and untrained subjects. Eight trained and seven untrained male subjects exercised on a cycle ergometer with a constant load for 30 min; for the next 28 min, they exercised with a sinusoidal load. The sinusoidal load variation ranged from approximately 10 to 60% of peak O2 uptake with a 4-min period. The ambient temperature and the relative humidity during exercise were 25 degrees C and 35%, respectively. There was no difference between the groups in the phase lags of esophageal temperature (Tes) and mean skin temperature (Tsk), whereas the phase lags of sweating rates for the chest and forearm were significantly shorter in the trained group (P < 0.05). The delta of Tes and Tsk per 1 W of exercise load in the trained group was significantly smaller than that in the untrained group (both, P < 0.05), whereas there was no difference between the groups in the delta of sweating rate for the chest and forearm. We conclude that subjects who have undergone long-term physical training show prompter dynamic characteristics of sweating response compared with untrained subjects and have a higher capacity to maintain constant body temperature during exercise at transient load.

Adult↗

PubMed1996

Exercise-induced change in beta-adrenergic receptor number in lymphocytes from trained and untrained men.

This study was undertaken to clarify whether beta-adrenergic receptor (beta-AR) translocation from intracellular sites to the cell surface contributes to an increase in the number of beta-AR in lymphocytes from trained and untrained men after exercise. Nine trained and 9 untrained subjects performed exercise on a bicycle ergometer until exhaustion. The number of beta-AR in the cell surface (beta-AR(surface)) and intracellular sites (beta-AR(intra)) was determined at rest and after maximal exercise by measuring the binding of the radioligand 125I-iodocyanopindolol in the presence or absence of hydrophilic (CGP-12177A) or lipophilic (propranolol) unlabeled ligands. The number of beta-AR(surface) increased after exercise from 1,524.4 +/- 321.4 to 3,432.6 +/- 503.3 sites/cell (p < 0.01), whereas that of beta-AR(intra) decreased from 356.2 +/- 85.7 to 190.3 +/- 60.2 sites/cell (p < 0.05). The isoproterenol-stimulated cAMP production per 1 x 10(6) lymphocytes after exercise was significantly higher than that at rest. However, the cAMP production per single beta-AR(surface) tended to be lower after exercise. No differences between the trained and untrained subjects were found in beta-AR numbers or intracellular cAMP levels. These findings demonstrate that maximal exercise induces the translocation of beta-AR from intracellular sites to the cell surface in human lymphocytes. However, this translocation accounts for only 10% of the increase in total cellular beta-AR, suggesting that other mechanisms are predominant and contribute substantially to the increase in beta-AR(surface).

Adult↗

PubMed1995

Repression of cell cycle progression by antisense HMG2 RNA.

The expression level of the HMG2 gene during the cell cycle of rat fibroblast cell lines was analyzed. Northern analysis demonstrated that the level of HMG2 mRNA was markedly enhanced in the post-S phase and reached a maximum at G2 phase, suggesting that expression of the HMG2 gene is not coupled with DNA synthesis. Progression of the cell cycle of COS-1 cells was repressed during G1 to S phase by expression of the antisense RNA for HMG2, resulting in a decrease of cell growth. These results suggest that the fluctuation of the HMG2 message during the cell cycle is not a consequence of but a prerequisite for cell proliferation.

Animals↗

PubMed1995

Effects of sensory stimulation on respiratory cardiac cycle variability in humans.

The effects of the phase of respiration on the response of respiratory cardiac cycle variability to sensory stimulation were studied in five healthy young male subjects. Transcutaneous electrical stimulation of the ulnar nerve or hand-grip exercise was applied during inspiration or expiration. Although both electrical stimulation and hand-grip exercise depressed respiratory cardiac cycle variability, the nature of the depression differed according to where in the respiration cycle the stimuli were applied. The amplitude of respiratory cardiac cycle variation was significantly decreased when either stimulus was applied during expiration (P < 0.05), and was unchanged when applied during inspiration (P > 0.05). These findings would suggest that cardiac vagal efferent activity was effectively inhibited by sensory stimulation during expiration, but was not inhibited by such stimulation during inspiration. This mechanism may account, in part, for the known suppression of respiratory cardiac cycle variability during exercise.

Adult↗

PubMed1995

Effect of theophylline on the production of interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-8 by human peripheral blood mononuclear cells.

Theophylline is a mild bronchodilator and has significant extrapulmonary effects, but it may also have some anti-inflammatory properties. We investigated the immunological effects of theophylline on peripheral blood mononuclear cells (PBMC), by examining the production of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), and interleukin 8 (IL-8) when PBMC were stimulated with lipopolysaccharide (LPS) or recombinant human IL-1 beta (rhIL-1 beta). At concentrations > or = 50 micrograms/ml, theophylline suppressed the proliferative activity of PBMC stimulated with phytohemagglutinin (p < 0.05). IL-1 beta production showed 23% suppression by 10 micrograms/ml theophylline (p < 0.05), while the suppression was 26% at 25 micrograms/ml (p < 0.05), 30% at 50 micrograms/ml (p < 0.05), and 33% at 100 micrograms/ml (p < 0.05). TNF-alpha production was suppressed in a dose-dependent manner by theophylline, being decreased by 24% at 10 micrograms/ml (p < 0.05), by 29% at 25 micrograms/ml (p < 0.05), by 41% at 50 micrograms/ml (p < 0.01), and by 54% at 100 micrograms/ml (p < 0.01). IL-8 production, in contrast, was not affected by theophylline. rhIL-1 beta induced IL-8 production in a dose-dependent manner at concentrations of 1-100 units/ml, and theophylline (particularly at concentrations of 50 and 100 micrograms/ml), increased IL-8 production in the presence of rhIL-1 beta. Suppression of the production of IL-1 beta and TNF-alpha by therapeutic levels of theophylline suggested that this drug might have anti-inflammatory and immunosuppressive effects.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1995

Effects of roxithromycin on proliferation of peripheral blood mononuclear cells and production of lipopolysaccharide-induced cytokines.

Roxithromycin (RXM), a new macrolide antibiotic, has a 14-member macrocycline ring structure which is similar to that of erythromycin. We investigated the effects of RXM on the proliferation of peripheral blood mononuclear cells (PBMCs) and the production of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha) by PBMCs stimulated with lipopolysaccharide (LPS). At concentrations greater than 25.0 micrograms/ml, RXM suppressed the proliferation of PBMCs stimulated with phytohemagglutinin, probably due to cytotoxicity. When the PBMCs were incubated with RXM for 7 d, the number of adherent cells (monocyte/macrophages) increased. Incubation with RXM at a concentration of 25.0 micrograms/ml induced the greatest increase (p < 0.05). IL-1 beta and TNF-alpha were present 3 h after LPS-stimulation, and IL-1 beta production reached a peak at 12 h and TNF-alpha production at between 6 and 12 h, and then their production declined. RXM (25 micrograms/ml) suppressed the production of IL-1 beta and TNF-alpha slightly during the entire course of the incubation. This suppression was dose-dependent. Anti-human granulocyte-macrophage colony-stimulating factor and anti-human macrophage colony stimulating factor antibodies had no effect on the RXM-induced proliferation of adherent cells. Suppression of the production of IL-1 beta and TNF-alpha by RXM suggested that this drug might have anti-inflammatory and immunosuppressive effects.

Anti-Bacterial Agents↗

PubMed1995

[The long-term results of isolated aortic valve replacement with 19 mm prostheses].

Twenty-five patients underwent isolated aortic valve replacement with 19 mm valves (8 cases with St. Jude Medical prostheses, 7 cases with Carpentier Edwards Pericardial prostheses and 10 cases with Björk-Shiley prostheses). Postoperative echocardiography revealed data as follows. Peak pressure gradients (mmHg) were 40.4 +/- 14.4 (mean +/- S.D.) in the SJM group, 23.4 +/- 9.8 in the CEP group and 50.5 +/- 16.7 in the BS group. End-diastolic left ventricular dimension in the BS group and interventricular septum thickness in the CEP group was reduced significantly. All but one case were in NYHA functional class I or II, and clinical improvement was almost satisfactory in all groups. However, in the BS group, 4 cases showed peak pressure gradients more than 50 mmHg. We conclude that 19 mm aortic prostheses in this study can provide satisfactory results. However, as for mechanical valve, it may be undesirable to choose BS prosthesis.

Adult↗

PubMed1995

[A case of thromboexclusion for thoracic descending aortic pseudoaneurysm with Behçet's disease].

A 59-year-old woman with Behçet's disease was admitted because of hemoptysis. She had undergone resection and patch closure of a thoracic descending aortic aneurysm 6 years before this current admission. The aortography after the first operation had shown a pseudoaneurysm at the operative site. In the current operation, we performed thromboexclusion with a temporary occlusion balloon in the distal thoracic descending aorta above Adamkiewicz. The post operative course was uneventful. Postoperative angiography demonstrated exclusion of the pseudoaneurysm and the patient was discharged without recurrent hemoptysis.

Aneurysm, False↗

PubMed1995

[Pseudoaneurysm of saphenous vein graft after CABG].

A 69-year-old man was admitted because of angina pectoris and thoracic descending aorta aneurysm. Staged operations were planned. First, he underwent CABG (coronary artery bypass grafting) with SVGs (saphenous vein grafts) to #4 PD, #7 and #12. Aprotinin was administrated to reduce blood loss. The routine postoperative graft angiography and enhanced CT showed a pseudoaneurysm in the SVG to #4 PD. We planned an elective operation of pseudoaneurysm repair and graft replacement of thoracic descending aorta. Also in this second operation, continuous infusion of aprotinin was started after the induction of anesthesia. About 30 minutes later, he suddenly fell in shock and cardiac arrest. Partial cardiopulmonary bypass was established and median sternotomy was performed. In the mediastinum, no bleeding was found. We found out a bleeding point of the SVG to #4 PD and a hemostatic clip on the right ventricule, and closed the bleeding point with suture. The cause of the pseudoaneurysm seemed to be defluxion of the hemostatic clip for a side brunch of the SVG. The cause of the preoperative shock may be an anaphylaxis to readministrated aprotinin.

Aged↗

PubMed1994

Mechanisms of potentiation in sweating induced by long-term physical training.

To evaluate the mechanism of potentiation of sweating after long-term physical training, we compared sweating function in trained and untrained subjects using the frequency of sweat expulsion (fsw) as an indicator of central sudomotor activity. Nine trained male subjects (trained group) and eight untrained male subjects (untrained group) performed 30-min cycle exercise at 35% maximal oxygen uptake at 25 degrees C ambient temperature and 35% relative humidity. Oesophageal temperature (T(oes)), mean body temperature (Tb), chest sweating rate (msw,chest), forearm sweating rate (msw,forearm), and fsw were measured. The slopes of the msw,chest versus body temperature (T(oes) and Tb) and versus fsw relationships in the trained group were significantly greater than those in the untrained group (both, P < 0.05), while there was no difference between the groups in the slopes of the msw,forearm versus body temperature or versus fsw relationships. Neither the body temperature threshold for initiation of chest or forearm sweating nor the slope of the fsw-Tb relationship differed between groups. We concluded that, during light exercise at moderate ambient temperature, the msw,chest in the subjects who had undergone long-term physical training was greater than that in the untrained subjects while the msw,forearm was not changed. The greater msw,chest in the trained subjects was concluded to be due to an increase of sensitivity of peripheral mechanisms.

Adult↗

PubMed1994

Responses of sweating and body temperature to sinusoidal exercise.

This study determined the phase response and amplitude response (delta) of esophageal temperature (T(es)), mean skin temperature (Tsk), and forearm sweating rate (Msw) to sinusoidal work. Six healthy male subjects exercised on a cycle ergometer with a constant load (approximately 35% maximal O2 uptake) for a 30-min period; for the next 40 min they exercised with a sinusoidal load at 25 degrees C at 35% relative humidity. The sinusoidal load varied between approximately 10 and 60% maximal O2 uptake, and three different time periods (1.3, 4, and 8 min) were selected. Each subject performed three experiments that differed only in the timing of sinusoidal work. During the 4- and 8-min periods, T(es), Tsk, and Msw changed almost sinusoidally. The phase of Msw change significantly preceded those of T(es) and Tsk changes (P < 0.05). During the 1.3-min period, the level of T(es) and Tsk remained almost constant (delta T(es) 0.01 +/- 0.00 degrees C, delta Tsk 0.03 +/- 0.01 degrees C), whereas Msw showed a clear sinusoidal pattern. We conclude that the sweating response during sinusoidal work depends on both thermal and nonthermal factors, the latter being emotional, mental, or sensory stimulation. The contribution of the nonthermal factors to the general sweating response during exercise can be separated from that of the thermal factors by using sinusoidal work during a short period (e.g., 1.3 min).

Adult↗

PubMed1994

Lymphocyte stimulation test with tetrazolium-based colorimetric assay for diagnosis of drug-induced allergic hepatitis.

The lymphocyte stimulation test (LST) is useful for diagnosing drug-induced allergy and identifying the causative drug. In this study, we examined the usefulness of 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) as a marker for LST in diagnosing drug allergy. In a basic study using normal peripheral blood mononuclear cells, the normal range of stimulation index (SI) was 0.92-1.38, and the mean SI for all drugs tested was 1.134 +/- 0.111 (mean +/- S.D.). The cut-off value of SI for diagnosis of drug allergy was thus set at over mean + 2S.D. for possibly positive, and at over mean + 3S.D. as a definitely positive reaction. Forty-six cases of suspected drug-induced allergic hepatitis involving 85 drugs were diagnosed by this assay, and the possibly positive and definitely positive rates were 54.3% (SI > or = 1.4) and 41.3% (SI > or = 1.5), respectively. A clinical study was made of 113 patients with diagnosed drug-induced allergic hepatitis. Forty-nine (43%) of the patients were male and 64 (57%) were female. In 85% of cases the allergic reaction occurred within one month of taking medication, but there were a number of cases in whom onset occurred after long-term incubation. The main clinical symptoms were jaundice, itching, eruption, fever, and general malaise. In about 75% of cases glutamic oxaloacetic transaminase (GOT) or glutamic pyruvic transaminase (GPT) returned to normal range within one month after medication was halted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

[Effects of "low dose" aprotinin in open heart surgery and its plasma concentration].

To determine the effects of "low dose" aprotinin in open heart surgery, we administrated it in 109 cases of CABG or prosthetic valve replacement. Patients in Group A (Aprotinin) received continuous infusion of aprotinin at the rate of 6*10(5) KIU/hr from the induction of anesthesia to the start of ECC (extra corporeal circulation), and from the end of ECC to the end of blood stanching. They also received additional 5*10(5) KIU aprotinin in ECC prime volumes. 50 patients in Group C (Control) received neither aprotinin nor placebo. Bleeding after ECC (Group A: 315.7 +/- 203.1 ml, Group C: 484.3 +/- 598.5 ml p < 0.01), the first 6 hours drainage (Group A: 273.0 +/- 210.0 ml, Group C: 404.7 +/- 243.2 ml p < 0.01), the first 24 hours drainage (Group A: 510.2 +/- 248.0 ml, Group C: 721 +/- 317.7 ml p < 0.01) was significantly reduced in Group A. Amounts of homologous blood transfusion were significantly reduced in group A. (Group A: 4.7 +/- 5.3 units, Group C: 8.5 +/- 6.4 units p < 0.01). Among the patients with autologous blood transfusion, the rate of the patients without homologous transfusion was significantly higher in Group A (group A: 40/66 cases, Group C: 8/33 cases p < 0.01). The ECC time and the operation time was significantly shorter in Group A. There were 69 patients (Group A: 40, Group C: 29) whose ECC time was longer than 120 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

[Aortic valve replacement in patients older than 75 years of age].

From 1988 to 1992, 16 patients older than 75 years underwent AVR (14 cases) or AVR+MVR (two cases). All patients were followed up for an average of 2.4 years after the operation and follow-up totaled to 38 patient-years. There were no hospital death and one late death. The survival rate was 93.8% through 1 to 5 years and 15 patients are now in NYHA class I or II. The problems of AVR for elderly patients were calcification and small annulus. Decalcification using CUSA was effective technique and supraannular fixing of bioprosthetic valve avoided from aortic annular enlargement. The improved quality of life after AVR supports the aggressive surgery in elderly population.

Aged↗

PubMed1993

A comparison of sweating responses during exercise and recovery in terms of sweating rate and body temperature.

Based on the hypothesis that the relation between sweating rate and body temperature should be different during exercise and rest after exercise, we compared the sweating response during exercise and recovery at a similar body temperature. Healthy male subjects performed submaximal exercise (Experiment 1) and maximal exercise (Experiment 2) in a room at 27 degrees C and 35% relative humidity. During exercise and recovery of 20 min after exercise, esophageal temperature (Tes), mean skin temperature, mean body temperature (Tb), chest sweating rate (msw), and the frequency of sweat expulsion (Fsw) were measured. In both experiments, msw and Fsw were clearly higher during exercise than recovery at a similar body temperature (Tes, Tb). msw was similar during exercise and recovery, or a little less during the former, at a similar Fsw. It is concluded that the sweating rate during exercise is greater than that during recovery at the same body temperature, due to greater central sudomotor activity during exercise. The difference between the two values is thought to be related to non-thermal factors and the rate of change in mean skin temperature.

Adult↗

PubMed1993

Electrically fused-egg induction and its development in the goldfish, Carassius auratus.

In this study, we report the induction of cell fusion between two fertilized eggs and viable chimeric fish from the fused egg in goldfish. Chemical fusion by polyethylene glycol between denuded fertilized egg induced egg adhesion but rarely egg fusion. This treatment seemed not suitable for egg fusion, because of tight adhesion between vitelline membrane and surrounding matrix. Electrically fertilized egg fusion was successfully induced at the rate of almost 100% under conditions of 400V/cm, 1 MHz dielectrophoresis pulse for 3 seconds and a successive, 750V/cm, 10 microseconds fusion pulse. The treatment had to be applied to the egg in the calcium-free low electrolyte medium within 20 min of fertilization at 20 degrees C. Small numbers of fused eggs developed into young chimeric fish, and the different cells originating from two eggs survived together as an individual.

Animals↗