PubMed Health⌕ Search

Biomedical subjects

Y Kume

Publications and source records attributed to Y Kume.

At least 19 recordsLinked to original sources
PubMed2005

A clinical analysis of prognostic parameters of survival in children with congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) still has a high mortality because of accompanying lung hypoplasia and persistent pulmonary hypertension. Although prognostic parameters based on perinatal measurements have been proposed, our ability to accurately predict the surgical results remains insufficient. METHODS: We treated 55 infants with CDH from 1981 to 2004. Among them, 46 patients presented respiratory distress within the first 24 hours of life. Results of surgical treatment in the 46 infants were retrospectively correlated with gender, birth weight, gestational age at diagnosis, laterality, cardiac anomalies, diaphragmatic defect area, contents of herniated viscera, and the great vessel diameters measured by echocardiography. RESULTS: Out of 46 CDH neonates, 27 (58.7 %) survived and 19 (41.3 %) died aged 3 to 17 days. Non survivors had a significantly larger diaphragmatic defect and more frequent liver herniation. Out of possible predictive parameters studied, an index of the main pulmonary artery (cross-sectional area/diaphragmatic defect area ratio) most closely correlated with the surgical outcomes. CONCLUSIONS: The postoperative prognosis of CDH infants does not depend only on pulmonary hypoplasia, but also on other factors including the magnitude of abdominal visceral herniation. In this series of patients, the most reliable prognostic predictor was a clinical index reflecting the degree of both pulmonary hypoplasia and diaphragmatic maldevelopment.

Female↗
PubMed2002

[Is minimal skin incision and partial sternotomy approach for congenital heart defects less invasive?; evaluation of SIRS on ventricular septal defect].

OBJECTIVES: Minimally invasive cardiac surgery (MICS) has been developed to offer patients the benefits of open heart operations with limited skin incision. But it is unclear whether this procedure is less invasive. We evaluate postoperative duration of systemic inflammatory response syndrome (SIRS) on ventricular septal defect (VSD). METHODS: From August 1997 to March 2000, 47 patients VSD underwent total repair by the minimal skin incision and lower partial median sternotomy (MICS group). We compared duration of SIRS between MICS and conventional method group (n = 14) and between early MICS and recent MICS group. We also evaluated the relationship between MICS and postoperative clinical course. RESULTS: Duration of SIRS of MICS group were obviously shorter than that of conventional method group (p < 0.05). That of recent MICS group is also significantly shorter than that of early MICS group (p < 0.05). Operative time, bypass time, postoperative intubation time and length of skin incision were related duration of SIRS. CONCLUSIONS: The results of this study indicate that MICS for VSD may be less invasive method.

Cardiac Surgical Procedures↗
PubMed1999

Zebrafish leopard gene as a component of the putative reaction-diffusion system.

It has been suggested, on a theoretical basis, that a reaction-diffusion (RD) mechanism underlies pigment pattern formation in animals, but as yet, there is no molecular evidence for the putative mechanism. Mutations in the zebrafish gene, leopard, change the pattern from stripes to spots. Interestingly each allele gives a characteristic pattern, which varies in spot size, density and connectivity. That mutations in a single gene can generate such a variety of patterns can be understood using a RD model. All the pattern variations of leopard mutants can be generated in a simulation by changing a parameter value that corresponds to the reaction kinetics in a putative RD system. Substituting an intermediate value of the parameter makes the patterns similar to the heterozygous fish. These results suggest that the leopard gene product is a component of the putative RD mechanism.

Animals↗
PubMed1998

Power spectral analysis of heart rate variability in type A females during a psychomotor task.

This study investigated changes in autonomic nervous activities due to psychological stress in Type A females. Eight Type A and eight Type B females performed a psychomotor task for 30 minutes. Power spectral analysis of heart rate variability (HRV) was used to examine the autonomic nervous activities. Results showed the low frequency (LF) component and LF/HF ratio in Type A females increased after the onset of the task. There were no significant differences in task performance between Type A and Type B females. The subjective mental workload increased gradually in Type A females during the tasks, whereas in Type B females this parameter did not change in a consistent manner. The results suggest that the sympathetic nervous system in Type A females was more stimulated by the task and Type A females felt a greater subjective mental workload than did Type B females.

Adult↗
PubMed1996

[Iatrogenic injury of tracheobronchial membranous wall].

Tracheobronchial injuries remain uncommon, but they are of great significance, because they can result in death or substantinal functional compromise. Such injuries are mostly from blunt trauma and motor vehicle accidents, but there also is an incidence of penetrating thoracic trauma inclunding iatrogenic accidents. Three cases of iatrogenic injury of tracheobronchial membranous wall were reported. Two cases were tear at the membraneous portion of the left main bronchus and trachea by forceful endotracheal intubation. Another case was tracheal membranous wall injury during operation at blunt dissection for esophageal carcinoma. We reported the emergent managements for iatrogenic injury of tracheobroncheal membranous wall in differents 3 ways. We should select the best treatment according to the condition of the patients and situation of the injury.

Aged↗
PubMed1996

[Repair of total anomalous pulmonary venous return using an ultra-short acting beta blockade (esmolol)--case reports].

In 2 infants with asplenic syndrome associated with total anomalous pulmonary venous return (TAPVR), a repair of TAPVR was done under mild hypothermic cardiopulmonary bypass (CPB) using esmolol, an ultra short-acting beta-blocker to obtain good operative field without aortic-cross clamping. Both cases were weaned from CPB uneventfully. Pulmonary venous obstruction was not found after surgery. This strategy seems to be applicable in pediatric cardiac surgery which is mainly limited to the atrial level.

Adrenergic beta-Antagonists↗
PubMed1995

Spontaneous aortic thrombosis in a neonate with multiple thrombi in the main branches of the abdominal aorta.

Spontaneous aortic thrombosis in the neonate is a rare entity with a high mortality rate. The present patient, who was diagnosed after showing haematuria and cyanosis, underwent aortic thrombectomy with a Fogarty catheter through a left thoracotomy, but died of sepsis, disseminated intravascular coagulation and multiple organ failure. Autopsy revealed multiple residual thrombi in the main branches of the abdominal aorta and necrosis of the abdominal organs despite a patent thoracoabdominal aorta. In patients with no blood flow in the main branches of the abdominal aorta on preoperative examination, removal of thrombi, including those in the main branches of the abdominal aorta, might be performed in a single, early and aggressive procedure.

Aorta, Abdominal↗
PubMed1994

[Subaortic stenosis in coarctation or interruption of the aorta--changes of left ventricular outflow tract dimension after aortic arch repair and pulmonary artery banding].

Left ventricular outflow tract (LVOT) dimension was measured in seven patients with coarctation (CoA) or interruption (IAA) of the aorta before and after aortic arch repair and pulmonary artery banding. The age of patients ranged 3 to 69 (mean 16) days, the weight 3.0 to 3.9 (mean 3.4) kg. Associated cardiac anomalies were VSD in 6, MA and DORV in 1. In five patients compared by ultrasound, preoperative LVOT dimension ranged from 3.5 to 5.0 (mean 4.4) mm with the ratio to the normal aortic valve dimension (n-AVD; 16.6 x BSA0.6) from 54 to 82 (mean 69)%. Postoperative dimension increased 5.0 to 7.4 (mean 5.7) mm and the ratio to the n-AVD increased 65 to 89 (mean 80)%. In three patients compared by LV graphy, preoperative LVOT dimension ranged from 4.0 to 4.5 (4.2) mm and the ratio ranged from 61 to 72 (68)%. Postoperative dimension increased from 4.5 to 6.7 (5.3) mm, and 74 to 80 (78)% to n-AVD after operation. Postoperative pressure gradients between LV and ascending aorta in each patient were 1 to 9 (mean 6) mmHg. In any patients, LVOT obstruction did not advance after aortic arch repair and pulmonary artery banding.

Aorta↗
PubMed1993

Kinetic modeling of liposome degradation in blood circulation.

The aim of this study is to develop a kinetic model for the quantitative evaluation of, and to examine dose dependency in liposome degradation in blood circulation in vivo. Multilamellar liposomes labeled with 3H-inulin were administered intravenously into rats and the time courses of blood concentration and urinary excretion of 3H-inulin were measured. The dosages of liposomes were fixed at 1, 5, and 100 mumolPCkg-1. Remarkable saturation was found in the time courses of both blood concentration and urinary excretion. Then a kinetic model for the degradation of liposomes in blood was developed, assuming that the degradation follows the first order rate process for each dose. The model fitted the observed time courses of excreted 3H-inulin well, and dose dependency could be observed in the rate constants for liposome degradation, which are more sensitive than urinary excretion of 3H-inulin. The degradation rate constant correlated well with the uptake rate constant, which suggests the same underlying mechanism for both uptake and degradation. These results indicate the usefulness of kinetic modeling in the quantitative evaluation of liposome degradation in blood circulation in vivo.

Animals↗
PubMed1993

Kinetic analysis of AUC-dependent saturable clearance of liposomes: mathematical description of AUC dependency.

The objective of this study was to examine the AUC dependency of saturable hepatic clearance (CLh) of liposomes and to postulate a mathematical model to describe the characteristics. The AUC dependency of saturable CLh was examined under intravenous rapid administration at various doses. The CLh increased with increasing blood concentration but decreased with the increase of AUC at each dose. In addition, the relationship between AUC and CLh was consistent with that observed in previously reported infusion studies. These experimental data confirm the AUC dependency of saturable CLh of liposomes. A mathematical model was developed for this AUC dependency. The decrease of CLh was described by the uptake amount (X) as follows: CLh = CLm(1-X/Xm), where CLm and Xm represent the maximum uptake clearance and the maximum uptake amount, respectively. The rate equation for uptake was analytically solved as CLh = X/AUC = Xm/AUC(1-exp(CLm/XmAUC)). Uptake clearance can be described by CLm, Xm, and AUC, and so uptake clearance is constant if AUC is constant. These experimental analyses and theoretical considerations show the validity of the AUC-dependent saturable CLh of liposomes.

Animals↗
PubMed1992

Non-Michaelis-Menten type hepatic uptake of liposomes in the rat.

The objective of this study was to verify the methodology for measuring uptake clearance of liposomes and to characterize kinetically the saturable hepatic uptake of liposomes-through phagocytosis. The correction of vascular space was important in the evaluation of hepatic uptake. The efflux of liposomes from liver was shown to be negligible, by a repeated dose study, and thus, hepatic clearance can be obtained by the hepatic uptake divided by the area under the blood concentration-time curve (AUC). The determinant parameter which describes the saturability of uptake clearance of liposomes, independent of infusion rate, was investigated, using the data of an in-vivo constant infusion study, where infusion rate-dependent saturable hepatic clearance was observed. The mean blood concentration failed to obtain an infusion rate-independent function. On the other hand, the AUC could explain the saturability of hepatic clearance for every infusion rate by a unique relationship. The hepatic uptake amount could also explain this saturability, independent of infusion rate. These kinetic characteristics are inconsistent with Michaelis-Menten type kinetics, therefore a new model is required to describe the saturable hepatic clearance in the disposition of liposomes.

Animals↗
PubMed1991

Saturable, non-Michaelis-Menten uptake of liposomes by the reticuloendothelial system.

Multilamellar vesicles (300-350 nm) were infused into the rat femoral vein at the rate of 4, 40 and 400 nmol phosphatidycholine min-1 for 6 h using [3H]inulin as an aqueous marker. The time courses of blood concentration of vesicles, normalized for infusion rate, were not superimposable, showing the non-linearity of liposome disposition in the blood circulation. These time courses of blood concentration were well fitted by a single Michaelis-Menten equation. On the other hand, the time courses of tissue content could not be so accommodated. Additionally, the observed relationship between the uptake of liposomes by the liver and their clearance from it and other organs differed essentially from a simulation based on Michaelis-Menten type saturable kinetics. Therefore, it is suggested that there is a time-dependent non-Michaelis-Menten type process in the phagocytosis of macrophages in the reticuloendothelial system.

Animals↗
PubMed1990

An epidemiological study on cancer in certified arsenic poisoning patients in Toroku.

A mortality study has been made to assess the carcinogenic effect of arsenic exposure by analyzing a group of certified chronic arsenic poisoning patients at a small mining village in Japan. When compared with expected number of deaths, based on sex-, age-specific mortality of Japanese in 1975, '80 and '85, all cancer, cancer of respiratory system and cancer of bladder, kidney and other and unspecified urinary organs showed a significant excess over the expected number. Divided by employment history, death due to all cancers, to respiratory cancer and to urinary tract cancer showed a significant excess among former workers of the mine. Classified into four cohorts by both employment history and smoking habit, death from respiratory cancer showed a significant excess only in the cohort respiratory cancer showed a significant excess only in the cohort of former workers with smoking history, suggesting an interaction between exposure to arsenic and smoking. Eight cases among ten respiratory cancers and two urinary tract cancer cases were accompanied by cancer of other organs, including Bowen's disease.

Arsenic Poisoning↗
PubMed1988

Inhibitory effects of quinolone antibacterial agents on gamma-aminobutyric acid binding to receptor sites in rat brain membranes.

The specific binding of 3H-labeled gamma-aminobutyric acid ([3H]GABA) to synaptic plasma membranes from rat brains was inhibited by various quinolonecarboxylic acid derivatives (quinolones), and these inhibitions were concentration dependent. The binding of [3H]muscimol to GABAA sites was also inhibited. These inhibitory potencies differed widely among the quinolones examined. The Dixon plots showed that a newly developed difluorinated quinolone, NY-198 [1-ethyl-6,8-difluoro-1,4-dihydro-7-(3-methyl-1-piperazinyl)-4-oxo-3- quinolinecarboxylic acid hydrochloride], competitively inhibits the receptor bindings of [3H]GABA and [3H]muscimol. In conclusion, our findings suggest that the inhibition of GABA binding to receptors (including uptake sites) in the brain may be involved in the induction of epileptogenic neurotoxicities by quinolones.

Animals↗
PubMed1987

Basic imaging properties of a large image intensifier-TV digital chest radiographic system.

The basic imaging properties of a large (57 cm) image intensifier (I.I.)-TV digital imaging system were examined to determine the effects of various physical parameters on the quality of the digital chest images obtained, and also to explore the clinical usefulness of the system. The characteristic curve of the digital system, which relates the output pixel value to the input relative x-ray intensity, was measured with an aluminum stepwedge. MTFs were determined using slit images, and the veiling-glare fraction was measured with a lead-disk technique. Noise Wiener spectra were obtained from uniformly exposed images. The current limitations of the large II-TV digital chest system are its low spatial resolution, and the presence of large amounts of veiling glare and structure mottle. Advantages of this system over other digital chest imaging systems include the high speed of image data acquisition and the capability of "real-time" dynamic imaging of the chest at a radiation dose comparable to that in conventional radiography of the chest.

Humans↗