Biomedical subjects

S Sakata

Publications and source records attributed to S Sakata.

At least 55 records · Page 3Linked to original sources

PubMed1999

Primary pulmonary collision tumor including squamous cell carcinoma and T-cell lymphoma.

We report a very rare occurrence of a primary collision tumor in the lung consisting of squamous cell carcinoma and T-cell lymphoma. A squamous cell carcinoma was diagnosed histologically following a transbronchial lung biopsy in a 71-year-old woman, but the other component was diagnosed histologically and immunohistochemically only on examination of the resection specimen. The malignant lymphoma was stained by the monoclonal antibody UCHL-1 (anti-D45RO) against T-lymphocytes but was not stained by the L26 (anti-CD20) antibody against B-lymphocytes. Immunostaining for CD3 was positive, confirming a T-cell lineage. Despite systemic chemotherapy, the patient died 7 months after operation, from progression of the lymphoma. Our case, which illustrates interesting attributes of collision tumors, consisted of an ordinary squamous cell carcinoma and a rare T-cell lymphoma arising in the lung, with the latter part of the combination dictating subsequent treatment and outcome.

Aged↗

PubMed1999

Does an incomplete interlobar fissure influence survival or recurrence in resected non-small-cell lung cancer?

OBJECTIVE: There have been various reports on prognostic factors in non-small-cell lung cancer (NSCLC) under a complete resection, but an incomplete interlobar fissure has not been discussed yet. We attempted to clarify whether this influences survival or recurrence. PATIENTS AND METHODS: From 1981 to 1994, 239 patients (43%) who had a single lobectomy with mediastinal lymph node dissection were pathologically diagnosed as stage IA/IB or IIA/IIB (excluding T3N0M0). These patients were divided in two groups: patients with a complete interlobar fissure group (group L); and patients with an incomplete one (group NL). Postoperative survivals and cancer-free periods were retrospectively assessed. Patients' characteristics had no statistical difference between groups L and NL by N category. RESULTS: The 5-year survival was 77.0% in group L-N0, 79.3% in group NL-N0, 48.7% in group L-N1, and 66.2% in group NL-N1. No statistical difference was found between groups L-N0 and NL-N0, L-N1 and NL-N1, L-T1N0 and NL-T1N0, L-T1N1 and NL-T1N1, L-T2N0 and NL-T2N0, and L-T2N1 and NL-T2N1. The 5-year-relapse-free survival was 81.2% in group L-N0, 85.4% in group NL-N0, 69.4% in group L-N1, and 72.2% in group NL-N1. No statistical difference was found between groups L-N0 and NL-N0, L-N1 and NL-N1, L-T1N0 and NL-T1N0, L-T1N1 and NL-T1N1, L-T2N0 and NL-T2N0, and L-T2N1 and NL-T2N1. There was no statistical difference in recurrent sites between groups L-N0 and NL-N0, and L-N1 and NL-N1. CONCLUSION: We conclude that the incomplete interlobar fissure does not influence the prognosis of resected stage I or II NSCLC (excluding T3N0M0).

Adult↗

PubMed1999

Muscle venous PO2 and VO2 are linearly related in repetitive tetanic contractions of canine muscle during hypoxic hypoxia.

1. It has previously been shown that perfusion with high O2-affinity-erythrocytes decreases venous PO2 (PVO2) and decreases O2 uptake (VO2) in contracting muscle at the same O2 delivery (arterial O2 concentration x flow). A linear VO2-PVO2 relationship has been obtained with a VO2-axis intercept, suggesting that, during this type of hypoxia, VO2 is composed of a PVO2-dependent and -independent VO2. However, the VO2-PVO2 relation during hypoxic hypoxia has not been examined. 2. To clarify this relation, PVO2 and VO2 have been measured in contracting gastrocnemius (1 Hz trains of 0.2 s isometric tetani) under both normoxic and hypoxic conditions during 5 min of stimulation. 3. Venous O2 changes proportionally with O2 delivery. Each VO2-PVO2 relation was linear, with the mean described by the equation VO2 = 5.06 + 0.41 x PVO2 (n = 6, r = 0.81, P < 0.05). The VO2-axis intercept was significantly different from zero (P < 0.05). 4. These results were similar to those obtained during hypoxia induced by high O2-affinity-erythrocytes. We conclude that there is a linear relationship between PVO2 and VO2 above the VO2-axis intercept, regardless of the type of hypoxia.

Animals↗

PubMed1999

Lipoprotein(a) as a risk factor for coronary artery disease in hemodialysis patients.

BACKGROUND: We studied whether lipoprotein(a) [Lp(a)] is an independent risk factor for coronary artery disease (CAD) in hemodialysis (HD) patients. METHODS: A serum concentration of Lp(a) was measured in 212 patients with chronic glomerulonephritis and 56 patients with diabetic nephropathy (a total of 268 patients). The causes of death during five years of follow-up were studied and classified into either cardiovascular or noncardiovascular events. RESULTS: The mortality of these 268 HD patients during the observation period was 26.1%. Seventy-eight percent were due to cardiovascular events. Those who died of cardiovascular events had significantly higher serum Lp(a) levels than those died of noncardiovascular events. The relative risk of death from CAD was 0.71 in HD patients with a Lp(a) concentration above 30 mg/dl. CONCLUSIONS: This study indicates that the serum Lp(a) levels are independent indicators of the future risk of death from CAD in HD patients.

Adult↗

PubMed1999

Carbon dioxide insufflation aids video-assisted thoracic surgery in a young child.

A 3-year-old girl with pectus excavatum successfully underwent exploration using video-assisted thoracic surgery. A complete pericardial defect was identified. The lung was kept totally collapsed during the procedure using low-flow (1 L/min), low-pressure (7 mmHg) carbon dioxide insufflation. This technique is expected to be a safe adjunct to thoracoscopic procedures in infants and small children.

Carbon Dioxide↗

PubMed1999

Prognostic value of heart rate variability during long-term follow-up in chronic haemodialysis patients with end-stage renal disease.

BACKGROUND: Mortality is high in chronic haemodialysis patients with cardiovascular disease, and many of them die suddenly. Reduced heart rate variability (HRV) is an increased risk for death in various populations, but its prognostic value in haemodialysis patients remains uninvestigated. METHODS: We analysed the associations between 24-h HRV measures and long-term mortality through a prospective follow-up of 31 chronic haemodialysis patients who underwent diagnostic coronary angiography. RESULTS: Of the 31 patients, at baseline, seven had a previous myocardial infarction, five had a history of congestive heart failure and 14 had significant (> or =75%) coronary stenosis (four had multi-vessel stenosis). During follow-up for 60+/-5 months, 14 patients died, 11 of them suddenly. A left ventricular ejection fraction of <0.45, multi-vessel coronary stenosis, ventricular tachycardia on 24-h ECG and decreased/abnormal 24-h HRV (triangular index <22 and abnormal Poincaré plot) carried a univariate risk of all-cause death, while the risk of sudden death was only correlated with decreased HRV (standard deviation of normal-normal R-R interval <50 ms, triangular index <22 and ultra-low frequency power <8.7 ln(ms2)). Multivariate analysis revealed that a triangular index <22 was the best predictor of increased risk for both all-cause and sudden death (hazards ratio (95% CI); 8.1 (1.3-48.6) and 12.6 (1.3-126.4), respectively) and that the association was independent of cardiac function, macrovascular diseases, ventricular arrhythmias and cardiovascular risk factors. The 5-year mortality when the triangular index was > or =22 or <22 was 33 or 88% for patients with coronary artery disease and 0 or 50% for those without. CONCLUSIONS: These results indicate that HRV has an independent prognostic value in chronic haemodialysis patients and identifies an increased risk for all-cause and sudden death.

Adult↗

PubMed1999

Management of malignant pericardial effusion resulting from recurrent cancer with local instillation of aclarubicin hydrochloride.

To determine the efficacy of aclarubicin hydrochloride in local control of malignant pericardial effusion, the authors carried out a trial of pericardial drainage with local administration of this agent in five patients, whose effusions had produced cardiac tamponade. All patients were women, and their primary cancers, all initially treated surgically, had arisen in the breast (two patients), or lung (three patients). Mean patient age was 54.2 years (range, 43-62). In four patients, improvement permitted removal of the drainage catheter. Two patients (40%) had a complete remission of the malignant pericardial effusion. The other three patients were difficult to evaluate because nonpericardial metastases limited their survival. All patients, however, showed disappearance of malignant cells from the pericardial sac with no cytopathologically demonstrable recurrence. In our few patients, intrapericardial aclarubicin appeared to be highly effective against malignant pericardial effusion.

Aclarubicin↗

PubMed1999

[Study on the verotoxin-producing Escherichia coli--isolation of the bacteria from deer dung].

To identify the source and route of verotoxin-producing Escherichia coli (VTEC) infection in humans, we tried to isolate VTEC from fresh deer dung collected from free-range animals in two parks during the period from August 1997 to January 1998. The results are presented below. 1) VTEC were isolated from 21 of 200 deer dung samples (10.5%), consisting of 15 of 100 samples (15.0%) collected in park A and 6 of 100 samples (6.0%) collected in park B, suggesting that the incidence of VTEC isolation differs depending on location. 2) With respect to typing of verotoxin, the 21 isolated VTEC strains consisted of 10 strains (47.6%) as VT1 producer, 5 strains (23.8%) as VT2 producer, and 6 strains (28.6%) as double producer of both types. 3) With respect to serogroup of the isolated VTEC strains, 2 strains belonged to O128:H2.1 strain each belonged to the O8:H10, O128:H12, and O169:HUT groups. The remaining 16 strains failed to be identified as particular serotypes. Regarding local distribution of the serotype, in park A, 1 strain each belonged to the O128:H2, O8:H10, and O169:HUT groups. The remaining 12 strains did not clearly show particular serotypes. In park B, 2 strains belonged to O128:H2, and 4 strains failed to show particular serotypes. The remaining 1 strains showed autoagglutination. In conclusion, we isolated VTEC strains from deer that showed types of toxin and serogroups identical to those of human VTEC. Therefore, VTEC found in deer dung could well be a source of VTEC-infectious diseases in humans.

Animals↗

PubMed1999

[Prevalence and serotypes of verocytotoxin-producing Escherichia coli (VTEC) isolates from dairy cattle].

To clarify the source of infection and route of transmission of Verocytotoxin-producing Escherichia coli (VTEC) in humans, we collected fresh feces from healthy dairy cattle reared in Hokkaido, Fukushima, Kanagawa and Okinawa prefectures between June 1996 and March 1997, and attempted to isolate VTEC. The results are described below. 1) VTEC was isolated from 68 (27.1%) of 251 fecal samples tested. VTEC was isolated from 14 (28.0%) of 50 in Hokkaido, 13 (26.0%) of 50 in Fukushima, 20 (39.2%) of 51 in Kanagawa and 21 (21.0%) of 100 in Okinawa. There were no difference in the prevalence among the prefectures. 2) Toxin type and serotype of 85 isolates were determined. Thirty-three isolaties (38.8%) were classified into VT1 toxin and VT2 toxin, respectively, and 19 isolates (22.4%) were classified as the strain that produces both VT1 and VT2 toxins. The toxin types of these isolates were divided by serotypes. The VT1-producing isolates were the most frequent among O111:H-. The VT2-producing isolates included O2:H12, O2:H29, O2:H-, O82:H8, O82:HUT, O153:H19, O153:H42 and O153:H-. Among the isolates producing both VT1 and VT2 toxins, O153:H19 was relatively frequent. Based on findings that many bacterial strains coinciding with toxin types and serotypes of human-derived VTEC isolated from dairy cattle, it was suggested that dairy cattle are closely related to VTEC infection in human as a source of infection.

Animals↗

PubMed1999

Energy expenditure by Ba(2+) contracture in rat ventricular slices derives from cross-bridge cycling.

To clarify the energy-expenditure mechanism during Ba(2+) contracture of mechanically unloaded rat left ventricular (LV) slices, we measured myocardial O(2) consumption (VO(2)) of quiescent slices in Ca(2+)-free Tyrode solution and VO(2) during Ba(2+) contracture by substituting Ca(2+) with Ba(2+). We then investigated the effects of cyclopiazonic acid (CPA) and 2,3-butanedione monoxime (BDM) on the Ba(2+) contracture VO(2). The Ca(2+)-free VO(2) corresponds to that of basal metabolism (2.32 +/- 0.53 ml O(2). min(-1). 100 g LV(-1)). Ba(2+) increased the VO(2) in a dose-dependent manner (from 0.3 to 3.0 mmol/l) from 110 to 150% of basal metabolic VO(2). Blockade of the sarcoplasmic reticulum (SR) Ca(2+) pump by CPA (10 micromol/l) did not at all decrease the Ba(2+)-activated VO(2). BDM (5 mmol/l), which specifically inhibits cross-bridge cycling, reduced the Ba(2+)activated VO(2) almost to basal metabolic VO(2). These energetic results revealed that the Ba(2+)-activated VO(2) was used for the cross-bridge cycling but not for the Ca(2+) handling by the SR Ca(2+) pump.

Animals↗

PubMed1999

Aging and spectral characteristics of the nonharmonic component of 24-h heart rate variability.

To examine whether heart rate variability (HRV) during daily life shows power law behavior independently of age and interindividual difference in the total power, log-log scaled coarse-graining spectra of the nonharmonic component of 24-h HRV were studied in 62 healthy men (age 21-79 yr). The spectra declined with increasing frequency in all subjects, but they appeared as broken lines slightly bending downward, particularly in young subjects with a large total power. Regression of the spectrum by a broken line with a single break point revealed that the spectral exponent (beta) was greater in the region below than above the break point (1.63 +/- 0. 23 vs. 0.96 +/- 0.21, P < 0.001). The break point frequency increased with age (r = 0.51, P < 0.001) and beta correlated with age negatively below the break point (r = 0.39) and positively above the break point (r = 0.70). The contribution to interindividual difference in total power was greater from the differences in the power spectral density at frequencies closer to both ends of the frequency axis and minimal from that at -3.25 log(Hz), suggesting hingelike movement of the spectral shape at this frequency with the difference in total power. These characteristics of the 24-h HRV spectrum were simulated by an artificial signal generated by adding two noises with different beta values. Given that the power law assumption is fundamental to the analysis of dynamics through the log-log scaled spectrum, our observations are substantial for physiological and clinical studies of the heartbeat dynamic during daily life and suggest that the nonharmonic component of HRV in normal subjects during daily life may include at least two 1/fbeta fluctuations that differ in dynamics and age dependency.

Adult↗

PubMed1999

Effect of cysteine protease of Porphyromonas gingivalis on adhesion molecules in gingival epithelial cells.

We examined the effect of cysteine protease of Porphyromonas gingivalis (P. gingivalis) on cell adhesion molecules including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and very late antigen-4 (VLA-4) of human gingival epithelial cells. The cells were incubated for 48 hr with or without P. gingivalis protease. Their cell adhesion molecule expression levels were increased at 12 hr, but decreased at 18-48 hr. This result suggests that protease degrades cell adhesion molecules. After the stimulation with protease for 12 hr, P. gingivalis fimbrial binding to a monolayer of the cells was effectively inhibited by the addition of the cell adhesion molecules, suggesting the fimbrial binding to the cells occurred through cell surface adhesion molecules.

Bacterial Adhesion↗

PubMed1999

New index for oxygen cost of contractility from curved end-systolic pressure-volume relations in cross-circulated rat hearts.

We have already reported the linear oxygen consumption per beat (VO(2))-systolic pressure-volume area (PVA) relation from the curved left ventricular (LV) end-systolic pressure-volume relation (ESPVR) in the cross-circulated rat heart. The VO(2) intercept (PVA-independent VO(2)) is primarily composed of VO(2) for Ca(2+) handling in excitation-contraction (E-C) coupling and basal metabolism. The aim of the present study was to obtain the oxygen cost of LV contractility that indicates VO(2) for Ca(2+) handling in E-C coupling per unit LV contractility change in the rat heart. Oxygen cost of LV contractility is obtainable as a slope of a linear relation between PVA-independent VO(2) and LV contractility. We obtained a composite VO(2)-PVA relation line at a mid-range LV volume (mLVV) under gradually enhanced LV contractility by stepwise increased Ca(2+) infusion and thus the gradually increased PVA-independent VO(2) values. As a LV contractility index, we could not use E(max) (ESP-V ratio; ESP/ESV) for the linear ESPVR because of the curved ESPVR in the rat LV. A PVA at a mLVV (PVA(mLVV)) has been proposed as a good index for assessing rat LV mechanoenergetics. Since the experimentally obtained PVA(mLVV) was not triangular due to the curved ESPVR, we propose an equivalent ESP-V ratio at a mLVV, (eESP/ESV)(mLVV), as a LV contractility index. This index was calculated as an ESP-V ratio of the specific virtual triangular PVA(mLVV) that is energetically equivalent to the real PVA(mLVV). The present approach enabled us to obtain a linear relation between PVA-independent VO(2) and (eESP/ESV)(mLVV) and the oxygen cost of LV contractility as the slope of this relation.

Animals↗

PubMed1999

[Intrapulmonary lymph node detected as a small coin lesion: a case report and a review of the Japanese literature].

Intrapulmonary lymph node (IPLN) is commonly identified to the level of fourth-order bronchi and is seldom recognized on a plain chest roentgenogram. We experienced a case of intrapulmonary lymph node, and presented a review of the Japanese literature. A 52-year-old female without a smoking history was discovered to have a coin lesion in a mass screening chest roentgenogram. A Chest CT scan showed a small peripheral nodule in segment 9 of the left lung. Malignancy could not be ruled out and an exploratory thoracotomy was performed, and the definite diagnosis was IPLN. We have encountered more frequent detection of small peripheral pulmonary nodules because of increasing availability of chest CT scans. Although reports of IPLN are rare, it should be considered as one of differential diagnoses for benign or malignant pulmonary nodules.

Female↗

PubMed1999

[Effects of pentobarbital on coronary and cerebral circulation and metabolism in dogs subjected to hemorrhage].

Mongrel dogs were divided into a neuroleptanesthesia group (n = 10) and a pentobarbital group (neuroleptanesthesia plus pentobarbital; n = 10). The dogs were subjected to stepwise hemorrhage increasing from 30 to 40 and 50 ml.kg-1. In the neuroleptanesthesia group, mean arterial pressure, and cerebral and coronary blood flow decreased. Furthermore the oxygen and hydrogen ion balance in both the brain and the myocardium was aggravated, even at 30 ml.kg-1 of hemorrhage. Compared to the neuroleptanesthesia group, mean arterial pressure, and cerebral and coronary blood flow showed a greater decrease, cerebral oxygen consumption was lower, and the brain and myocardial metabolism worsened similarly at equivalent hemorrhage in the pentobarbital group. These results suggest that pentobarbital in combination with neuroleptanesthesia reduces cerebral oxygen consumption, but does not improve cerebral metabolism in the state of acute hemorrhage due to simultaneous induction of severe circulatory depression.

Acute Disease↗

PubMed1999

Predictors of survival in continuous ambulatory peritoneal dialysis patients: the importance of left ventricular hypertrophy and diabetic nephropathy.

We retrospectively evaluated the factors that are prognostic in long-term continuous ambulatory peritoneal dialysis (CAPD). From 1986 to 1997, 91 CAPD patients (59 male, 32 female, mean age 48 years) entered the study. Their primary renal diseases were chronic glomerulonephritis (CGN, n = 80), diabetic nephropathy (DN, n = 10), and polycystic kidney disease (PKD, n = 1). The roles of primary renal disease, hypertension, left ventricular hypertrophy (LVH), left ventricular ejection fraction (LVEF), cardiac sympathetic activity, anemia, hypoalbuminemia, and plasma concentration of parathyroid hormone (PTH) on patient prognosis were analyzed. Among the 91 CAPD patients, 26 died during the observation period. Of these deaths, 17 resulted from cardiovascular diseases including cerebrovascular events (n = 7), myocardial infarction (n = 2), sudden death (n = 7), and aortic aneurysmal rupture (n = 1). Nine patients died of non cardiovascular events. Sclerosing encapsulating peritonitis and others, mainly cachexia, accounted for 2 and 7 of these deaths, respectively. The 5-year survival rate was 74%; the 10-year rate was 49%. The cumulative 5- and 10-year success rates of CAPD were 69% and 39%, respectively. DN, hypertension, severe LVH (more than 200 g/m2), and hypoalbuminemia were contributors to poor prognosis. Among these, DN and severe LVH were the two main predictors by Cox proportional hazards model. We conclude that CAPD patients with DN or severe LVH, or both, have a greater chance of drop-out from cardiovascular events.

Aortic Aneurysm↗

PubMed1998

Different response to inflammation of the multiple mRNAs of rat N-acetylglucosaminyltransferase I with variable 5'-untranslated sequences.

We found that there are at least five subclasses of N-acetylglucosaminyltransferase I (GnT-I; EC 2.4.1.101) mRNA with different 5'-untranslated regions in rat brain. These five subclasses were also expressed in many tissues with distinct tissue-specific patterns. Moreover, they were regulated differently in response to acute-phase inflammation. The expression of the most abundant subclass of GnT-I mRNA in rat liver decreased 2.5-fold in response to inflammation, concomitantly with a significant decrease in the total amount of GnT-I mRNA. In contrast, one of the minor subclasses of GnT-I mRNA was induced 10-fold by inflammation.

Animals↗

PubMed1998

Complex demodulation of cardiorespiratory dynamics preceding vasovagal syncope.

BACKGROUND: The dynamic autonomic processes leading to vasovagal syncope are poorly understood. METHODS AND RESULTS: We used complex demodulation to continuously assess changes in respiration, R-R interval, and arterial pressure (blood pressure) variability during 60 degree head-up tilt in 25 healthy subjects with tilt-induced vasovagal syncope and 25 age-matched nonsyncopal control subjects. Coherence and transfer function analyses were used to examine the relation between respiration and R-R interval variability before syncope. Baseline blood pressure, R-R, and ventilation were similar between syncope subjects and control subjects. Syncope subjects experienced an increase in tidal volume and decrease in BP beginning 3 minutes before impending syncope (systolic blood pressure <80 mm Hg) necessitated termination of tilt. Approximately 90 seconds before syncope there was a sudden prolongation of R-R interval and increase in amplitude of high and low frequency R-R interval variability, indicating an abrupt enhancement of vagal tone. The increase in respiratory amplitude between 180 and 90 seconds before syncope was not accompanied by changes in R-R interval or R-R variability, suggesting a dissociation between respiration and the respiratory sinus arrhythmia. The coherence analysis showed fewer syncope subjects with coherence between respiratory and R-R interval variabilities and lower transfer magnitudes in syncope subjects compared with control subjects. Nonsyncopal subjects had no change in respiratory, R-R interval, or blood pressure dynamics during matched time periods before the time of syncope. CONCLUSIONS: Vasovagal syncope is preceded by a period of hyperpnea and cardiorespiratory decoupling followed by an abrupt increase in cardiovagal tone. Respiratory pumping without inspiratory cardiac slowing may partially counteract preload reduction until sudden bradycardia precipitates syncope.

Adult↗