Search PubMed⌕ Search

Biomedical subjects

A Fukuda

Publications and source records attributed to A Fukuda.

At least 55 records · Page 3Linked to original sources
PubMed2000

Responses to umami substances in taste bud cells innervated by the chorda tympani and glossopharyngeal nerves.

The chorda tympani (CT) and glossopharyngeal (GL) nerves of several mammalian species respond differently to umami substances (US) such as monosodium glutamate (MSG), disodium 5'-inosinate (IMP) and disodium 5'-guanylate (GMP). In mice and rhesus monkeys, responses to US are greater in the GL than the CT nerve, with the GL nerve containing larger numbers of MSG-sensitive fibers. Gurmarin, a sweet response inhibitor, suppresses the mouse CT responses to the mixture of MSG and IMP to approximately 65% of control levels but not to the metabotropic and ionotropic glutamate agonists 2-amino-4-phophonobutyrate and N-methyl-D-aspartate. Gurmarin does not inhibit any taste responses in the GL. In mice, CT responses to MSG may be masked by their greater sensitivity to sodium ions. Calcium imaging studies demonstrate that some mouse taste cells isolated from the fungiform papilla innervated by the CT respond selectively (as indicated by a rise in intracellular Ca(2+) concentrations) to MSG and/or IMP or GMP. These MSG responses are not suppressed notably by reducing the Ca(2+) concentration of the stimulus solution, suggesting that the observed Ca(2+) release is from intracellular stores. Measurements of second messengers in the mouse fungiform papilla have revealed consistently that MSG elicits increases in both inositol 1,4,5-trisphosphate and adenosine 3', 5'-cyclic monophosphate levels. Together, these results suggest that US may stimulate two different transduction mechanisms in the fungiform papilla. They also suggest that gurmarin-insensitive components of receptors for US, including metabotropic and ionotropic glutamate receptors, may be commonly involved in transduction for umami taste in taste cells on both anterior and posterior parts of the tongue.

Animals↗
PubMed2000

Molecular model for the anticlinic smectic-C(A) phase

Both phenomenological and molecular-statistical theories of the anticlinic smectic-C(A) phase (Sm-C(A)) are considered in detail. The anticlinic structure produces antiferroelectricity in the chiral smectic-C(A) phase (Sm-C(A)*). The molecular theory is based on a simple model potential which stabilizes Sm-C(A) with respect to the synclinic smectic-C phase (Sm-C). Conventional dispersion and steric interactions between mesogenic molecules generally do not promote Sm-C(A). It may be stabilized by interlayer orientational correlations between transverse molecular dipoles located in the flexible chains. Such correlations are not sensitive to molecular handedness (chirality), and thus the theory accounts for the formation of the anticlinic phase in racemic mixtures. The model is also confirmed by other experimental data. Finally a simple phase diagram of the perfectly ordered smectic liquid crystal is presented which contains Sm-A, Sm-C, and Sm-C(A).

Journal Article↗
PubMed2000

Metastatic cardiac papillary carcinoma originating from the thyroid in both ventricles with a mobile right ventricular pedunculated tumor.

A 62-year-old man with a history of surgical therapy for papillary thyroid carcinoma was admitted because of chest pain, dyspnea on effort, pretibial edema, and slight fever. An electrocardiogram showed ST segment elevation in the precordial leads and low voltage in the limb leads. A large solid mass was demonstrated in both ventricles, with pericardial effusion, by echocardiography, thoracic computed tomography scan, transesophageal echocardiography, and angiography. A punch biopsy of the tumor revealed metastatic papillary carcinoma. During radiation therapy, the patient suddenly died of ventricular fibrillation. At autopsy, the tumor occupied almost the entire right ventricular cavity, expanding toward the main trunk of the pulmonary artery with a mobile peduncle and it had infiltrated the left ventricular wall through the interventricular septum. Microscopic examination confirmed metastatic papillary thyroid carcinoma. Only 2 other cases of cardiac metastases of papillary thyroid carcinoma have been reported and this case is the first report of metastases in both ventricles with a mobile right ventricular pedunculated tumor.

Carcinoma, Papillary↗
PubMed2000

Light- and temperature-dependence of the melatonin secretion rhythm in the pineal organ of the lamprey, Lampetra japonica.

To identify the characteristics of the oscillator located in the pineal organ, we examined the effects of temperature and light on melatonin secretion rhythm using pineal organs in cultures. At 20 degrees C, the melatonin rhythm was obvious: low secretion during the daytime and high during the nighttime. When the temperature was lowered from 20 to 10 degrees C, the melatonin rhythm disappeared. When the temperature was returned from 10 to 20 degrees C, the rhythm quickly reappeared. The plasma melatonin level was measured in living lampreys kept at 7 degrees C to establish the melatonin profile at low temperature in vivo: secretion was not significantly different between daytime and nighttime. Under continuous light conditions, the melatonin elevation normally seen during the subjective night became obscure after 72 h. When the LD cycle was shifted by 6 h (phase-advanced or phase-delayed), the melatonin rhythm shifted to remain in the same phase relation to the LD cycle. This re-synchronization took several LD cycles. The results indicate that, in cultures, the melatonin secretion rhythm in the pineal organ of the lamprey is both light- and temperature-sensitive, and that in vivo, the melatonin rhythm is not the critical factor maintaining the locomotor activity rhythm of the lamprey. The role of the pineal organ and melatonin in the circadian organization of the lamprey is discussed.

Animals↗
PubMed2000

Remnant-like particle cholesterol, triglycerides, and insulin resistance in nonobese Japanese type 2 diabetic patients.

OBJECTIVE: The aim of the study was to investigate the relationships between remnant-like particle (RLP) cholesterol, triglycerides, and insulin resistance in nonobese Japanese type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A total of 86 nonobese Japanese type 2 diabetic patients (72 men and 14 women, aged 40-83 years, BMI 20.1-26.6 kg/m2) were studied. BMI, HbA1c levels, and fasting concentrations of plasma glucose, serum lipids (RLP cholesterol, total cholesterol, HDL cholesterol, and triglycerides), and serum insulin were measured. Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). The subjects were divided into two groups according to the value of HOMA-IR. Values >2.5 were indicative of the insulin-resistant state, and values <2.5 were indicative of the insulin-sensitive state. RESULTS: The insulin-resistant group had significantly higher RLP cholesterol and triglyceride levels and lower HDL cholesterol levels compared with the insulin-sensitive group. Univariate regression analysis showed that insulin resistance was positively correlated with BMI (r = 0.254, P = 0.019), HbA1c levels (r = 0.278, P = 0.011), RLP cholesterol levels (r = 0.315, P = 0.004), and triglyceride levels (r = 0.332, P = 0.002) and was negatively correlated with HDL cholesterol levels (r = -0.301, P = 0.006) in our diabetic patients. Multiple regression analysis showed that insulin resistance was independently associated with serum triglyceride levels, which explained 13.5% of the variability of insulin resistance in our nonobese Japanese type 2 diabetic patients. CONCLUSIONS: These results indicate that 1) nonobese Japanese type 2 diabetic patients with insulin resistance are characterized by high RLP cholesterol and triglyceride levels, and low HDL cholesterol levels; and 2) the level of serum triglycerides is an independent predictor of insulin resistance in these patients.

Apolipoproteins↗
PubMed2000

[Is it able to simplify the classifications of staging and curability for pancreatic cancer?].

This study was undertaken to simplify the classifications of the staging and curability of pancreatic cancer by the Japan Pancreas Society (JPS). A total of 461 patients who underwent surgical resection from 1968 to 1997 were analyzed in this study in accordance with our new classification of staging and curability. This staging mainly consists of three factors based on tumor extent:invasion to the retroperitoneum (rp); invasion to the extrapancreatic nerve plexus (pl); and lymph node metastasis (n). Each factor is simply judged as + (positive) or - (negative). Curability is also judged simply based on whether the presence of tumor is detected or not, and the degree of lymph node dissection is not included in curability. Our staging and curability assessment is strongly associated with survival rates after surgery. The 5-year survival rate of stage I patients is 50% and curability of A is > or = 50%. It is concluded that it is possible to simplify the classification of the staging and curability of pancreatic cancer by the JPS.

Humans↗
PubMed2000

[Neuromonitoring of acute internal carotid artery occlusion].

We experienced a patient with acute thrombosis of the unilateral internal carotid artery. We monitored the brain tissue temperature and intracranial pressure not only in both hemispheres simultaneously but also continuously throughout the process of brain death. The patient was a 73-year-old male who presented to our emergency room with right hemiparesis and aphasia. On admission to our department, no specific pathological findings were identified by brain CT. However a following investigation with left carotid arteriogram demonstrated a complete occlusion of the left internal carotid artery. Probes to monitor intraparenchymal temperature (Tip) and intracranial pressure(ICP) were inserted surgically into the bilateral hemispheres, and these two parameters were monitored continuously until the patient's death. Initially, Tip in the infarcted hemisphere was lower than that in the intact hemisphere, and the left hemisphere's ICP was significantly higher than that of the right one. When the ICP in the left hemisphere exceeded 40 mmHg, bilateral ICPs became equal. Brain herniation was confirmed when the ICP became progressively elevated thereafter. Subsequently the bilateral Tips became equal and lower than the bladder temperature following the brain herniation. In this case, we successfully monitored two parameters while the patient was in the process of brain death; i.e., brain ischemia, complete loss of brain circulation and subsequent decrease in the brain tissue temperature.

Acute Disease↗
PubMed2000

[Clinical data obtained through coagulation testing suggests that hypothermia exerts influence on a patient's blood coagulation reaction].

It often takes longer to achieve hemostasis when performing an operation on a patient in cerebral hypothermia therapy than in a normal patient, despite the lack of abnormal clinical blood coagulation findings, and this study was conducted to investigate the cause of delays in coagulation in patients with hypothermia. In this study, 93 samples of plasma were collected at our center from 10 patients(7 men and 3 women; mean age, 33.7) who were in cerebral hypothermia therapy with a urinary bladder temperature maintained at 32-34 degrees C. Each sample was divided into two, and PT(prothrombin time) and APTT(activated partial thromboplastin time) were measured at the normal analysis temperature of 37 degrees C in one sample, and at the hypothermia temperature of 32-34 degrees C in the other sample. The results showed that PT and APTT tended to shorter at 37 degrees C, than those measured at 32-34 degrees C. Thus, we suggest that it is necessary to regulate the temperature of patients with accidental hypothermia or in whom hypothermia therapy is performed.

Adult↗
PubMed1999

Inhibition of the generation of thrombin and factor Xa by a fucoidan from the brown seaweed Ecklonia kurome.

The effects of a fucoidan (C-II), which was purified from the brown seaweed Ecklonia kurome, on the generation of thrombin and factor Xa have been investigated by measuring the amidolytic activities by using the respective specific chromogenic substrates in both plasma and purified systems. C-II inhibited significantly the generation of thrombin in both the intrinsic and the extrinsic pathways, although the intrinsic inhibitory effect by C-II was more remarkable than the extrinsic one. On the other hand, C-II was a good inhibitor of the factor Xa generation in the intrinsic pathway, while it was a poor one in the extrinsic pathway. In the purified systems C-II also inhibited the formation of prothrombin-activating complex (i.e., prothrombinase), but not its activity. The concentration of C-II required for 50% inhibition of thrombin generation was about one-tenth to one-seventh of that of the activity of the generated thrombin in plasma. These results indicate that C-II has an inhibitory effect on the generation of thrombin by blocking the formation of prothrombinase and by preventing the generation of intrinsic factor Xa in addition to its antithrombin activity, and also that the generation-inhibitory effect is more remarkable than C-II's enhancement effect on the antithrombin activity by heparin cofactor II in plasma.

Animals↗
PubMed1999

Molecular cloning and expression of the Na+/H+ exchanger gene in Oryza sativa.

Na+/H+ exchanger catalyzes the countertransport of Na+ and H+ across membranes. We isolated a rice cDNA clone the deduced amino acid sequence of which had homology with a putative Na+/H+ exchanger in Saccharomyces cerevisiae, NHX1. The sequence contains 2330 bp with an open reading frame of 1608 bp. The deduced amino acid sequence is similar to that of NHX1 and NHE isoforms in mammals, and shares high similarity with the sequences within predicted transmembrane segments and an amiloride-binding domain. The expression of the gene was increased by salt stress. These results suggest that the product of the novel gene, OsNHX1, functions as a Na+/H+ exchanger, and plays important roles in salt tolerance of rice.

Amino Acid Sequence↗
PubMed1999

Membrane deinsertion of SecA underlying proton motive force-dependent stimulation of protein translocation.

The proton motive force (PMF) renders protein translocation across the Escherichia coli membrane highly efficient, although the underlying mechanism has not been clarified. The membrane insertion and deinsertion of SecA coupled to ATP binding and hydrolysis, respectively, are thought to drive the translocation. We report here that PMF significantly decreases the level of membrane-inserted SecA. The prlA4 mutation of SecY, which causes efficient protein translocation in the absence of PMF, was found to reduce the membrane-inserted SecA irrespective of the presence or absence of PMF. The PMF-dependent decrease in the membrane-inserted SecA caused an increase in the amount of SecA released into the extra-membrane milieu, indicating that PMF deinserts SecA from the membrane. The PMF-dependent deinsertion reduced the amount of SecA required for maximal translocation activity. Neither ATP hydrolysis nor exchange with external SecA was required for the PMF-dependent deinsertion of SecA. These results indicate that the SecA deinsertion is a limiting step of protein translocation and is accelerated by PMF, efficient protein translocation thereby being caused in the presence of PMF.

Adenosine Triphosphatases↗
PubMed1999

Concomitant analysis of the epidermal growth factor receptor family in esophageal cancer: overexpression of epidermal growth factor receptor mRNA but not of c-erbB-2 and c-erbB-3.

The epidermal growth factor receptor family consists of four closely related transmembrane receptors: epidermal growth factor receptor (EGF-R), c-erbB-2, c-erbB-3, and c-erbB-4. Overexpression of each receptor may lead to cell transformation and contributes to tumor progression in various malignancies. Although these factors have been analyzed in many cancers separately, little is known about their concomitant expression in esophageal cancer. Based on the finding that EGF-R and c-erbB-2 form highly active transmembranous heterodimers that enhance cell growth and proliferation, we used Northern blot analysis and immunohistochemistry to analyze the concomitant expression of EGF-R, c-erbB-2, and c-erbB-3 in tissue samples obtained from 39 patients undergoing esophagectomy for esophageal cancer. Northern blot analysis revealed a fourfold increase (p < 0.01) in EGF-R mRNA levels in the esophageal cancer samples in comparison with normal tissue samples. The c-erbB-2 receptor was only 1.25-fold elevated in the esophageal cancers, which failed to be statistically significant (p = 0.31). In contrast, c-erbB-3 mRNA levels were 3.5-fold lower (p < 0.01) in the esophageal cancers than in the normal tissues. Immunohistochemical analysis showed weak EGF-R, c-erbB-2, and c-erbB-3 immunostaining in the normal esophageal tissue. In esophageal cancer samples, immunoreactivity for EGF-R, c-erbB-2, and c-erbB-3 was mainly located in the cancer cells. Strong EGF-R, c-erbB-2, and c-erbB-3 immunoreactivity was present in 59%, 64%, and 64% of the esophageal cancer samples, respectively. In consecutive tissue sections, identical cancer cell clusters often exhibited these three closely related receptors simultaneously. However, correlation of the immunohistochemical findings with the clinicopathologic patient parameters revealed that the presence of EGF-R, c-erbB-2, or c-erbB-3 had no influence on patient survival (p > 0.05). In addition, the simultaneous presence of these receptors did not influence survival. Our findings indicate that in esophageal cancer the presence of EGF-R, c-erbB-2, and c-erbB-3 alone or in combination seems to have no major influence on patient prognosis and does not alter tumor growth behavior significantly.

Adenocarcinoma↗
PubMed1999

Growth factor receptors are differentially expressed in cancers of the papilla of vater and pancreas.

OBJECTIVE: To compare growth factor receptor expression in papilla of Vater cancer and pancreatic cancer. SUMMARY BACKGROUND DATA: Cancer of the papilla of Vater has a much better prognosis than pancreatic cancer. Earlier symptoms may result in earlier diagnosis, but different biologic growth behaviors and genetic alterations might also be explanations. PATIENTS AND METHODS: Surgical specimens from papilla of Vater cancers (24 patients) and pancreatic cancers (80 patients), normal papilla of Vater tissues (20 patients), and normal pancreatic tissues (24 patients) were frozen and fixed. The authors compared the expression of the epidermal growth factor receptor (EGFR) and c-erbB2 and c-erbB3 by Northern blot, in situ hybridization, and immunohistochemistry. RESULTS: In papilla of Vater cancer, Northern blots showed comparable EGFR and c-erbB2 mRNA expression but significantly lower c-erbB3 mRNA levels than in normal papilla. In pancreatic cancer, mRNA expression was enhanced compared with normal controls for EGFR (4-fold), c-erbB2 (2.5-fold), and c-erbB3 (5.2-fold). In situ hybridization confirmed this and showed mRNA expression only in cancer cells. EGFR immunohistochemical staining scores were comparable in papilla of Vater cancer (1.17 +/- 0.22) and normal papilla (1.42 +/- 0.25). Staining scores for c-erbB2 (2.72 +/- 0.40 vs. 3.89 +/- 0.37) and c-erbB3 (2.78 +/- 0.35 vs. 3.89 +/- 0.53) were slightly lower than controls in papilla of Vater cancer. In pancreatic cancer, immunostaining scores for EGFR, c-erbB2, and c-erbB3 were significantly higher than controls. CONCLUSION: Members of the EGFR family show similar or lower expression in papilla of Vater cancer than in normal controls. In pancreatic cancer, these receptors are upregulated. This supports the hypothesis that papilla of Vater cancer and pancreatic cancer have biologic differences that may contribute to the different growth of these tumors.

Adult↗
PubMed1999

[A case of hypertensive intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion].

We report a case of intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion. The patient was a 54-year-old man, who developed a small cerebral hemorrhage in the left internal capsule. He was admitted with mild right hemiparesis to out hospital. Left carotid angiography showed an occlusion at the origin of the internal carotid artery. Right cerebral angiography revealed the slow filling of cerebral arteries of left hemisphere by the cross flow. He was treated conservatively. Two days after admission, the neurological examination revealed no notable abnormalities. The etiology of hemorrhage of this case is presumed as the arterial necrosis due to hypertension. There has been no report on the intracerebral hemorrhage associated with ipsilateral internal carotid artery occlusion. Our case suggests that the volume and enlargement of cerebral hemorrhage may be influenced by cerebral perfusion pressure.

Carotid Stenosis↗
PubMed1999

[Induction of molecular chaperones HSP70 and HSP90 in rat liver cytosol by a highly toxic coplanar PCB].

We report here that a highly toxic coplanar polychlorinated biphenyl (PCB), 3,3',4,4',5-pentachlorobiphenyl (PenCB) induces molecular chaperones, HSP70 and HSP90 in liver cytosol of rats. Male Wistar rats received PenCB in corn oil once at a dose of 25 mg/kg i.p. Pair-fed control groups were treated with the vehicle and given the amount of chow matched with that taken by the PenCB-treated animals, and free-fed controls were given the vehicle. The liver cytosolic HSP70 level in rats treated with PenCB was 5-fold higher than those in free-fed controls, though that for pair-fed controls was approximately 2-fold higher than that in free-fed controls. The liver cytosolic HSP90 alpha and HSP90 beta levels were also higher in PenCB-treated rats than in both control groups, but the induction extent was lesser than that for HSP70. Inductive effect on the chaperones was examined with a single different dose of PenCB 0, 0.5, 1.0, 5.0, 10 and 25 mg/kg. Marked induction of the HSP70 level was observed with a minimum dose of PenCB 0.5 mg/kg. The HSP90 alpha level was induced with PenCB-dose dependent manner although the HSP90 beta induction was greatest with a dose of PenCB 5.0 mg/kg. HSP70 and HSP90 are essential for cells under normal conditions and act as molecular chaperones. HSP90 is well known to modulate the function of sex steroid hormone or aromatic hydrocarbon receptors while HSP70 is required for receptor-HSP90 heterocomplex assembly. The role of molecular chaperones may be involved in the endocrine disrupting properties of coplanar PCB and dioxins.

Animals↗
PubMed1999

[Usefulness of POCT in critical care medicine].

The need for speedy and accurate test results is becoming increasingly urgent in the areas of emergency medicine and ICU. The form of emergency testing is changing from conventional testing conducted by laboratory technicians to point-of-care testing (POCT) performed by the doctor or nurse. Therefore, the skill and time of the technician, which used to be expended for emergency testing, is now utilized for maintenance and precision control of POCT equipment so that the doctors and nurses can conduct POCT with confidence at all times. We also attempted point of prehospital care testing (POPCT), comprised of prehospital care and POCT. Here, the laboratory technician rides with the doctor to provide patient information to the clinicians from the perspective of a laboratory technician in the field to support emergency treatment. This has not yet been made fully practical, but the usefulness of POCT in critical care medicine seems to be essential to the forthcoming advanced emergency medicine, considering its usefulness outside the hospital environment.

Critical Care↗