Design and evaluation of a reflectance oxygen sensor in critically ill patients.
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Animals↗
Biomedical subjects
Y Nose
Publications and source records attributed to Y Nose.
A visual field quantification system for the Goldmann Perimeter.
We have developed a visual field quantification system that can accurately quantify the measurement results by the Goldmann Perimeter (GP). This system calculates the plural indexes introduced in published papers. In recent years, several isopter quantification methods have been proposed. In these methods, the isopters are digitized and the data are input into a computer, after which a computer program evaluates the changes in the isopters quantitatively. However, each program is only able to evaluate private indexes. We have developed a system that quantifies data using multiple methods. This system used five methods that have been introduced in published papers. With this system, a physician can analyze GP data with multiple methods and can diagnose diseases accurately. We have already input about 2500 GP recording papers into the computer by this system. We then calculated the plural indexes, and visualized the temporal changes in the perimetry.
Humans↗
The effect of a multiple literature database search--a numerical evaluation in the domain of Japanese life science.
In literature database searching, we show that it is necessary to use plural databases for a more improved search. We also compare the results of a single database search with that of multiple database search in the domain of Japanese life sciences. We searched the MEDLINE and EMBASE using the same search terms. There were some differences in the results, owing to differences in the journals and recording methods. We herein show some of the differences in the journals contained in both databases. Furthermore, we show the differences in the number of papers derived from the same journal. Next, as an example of a practical search, we selected some universities in Japan, searched both databases regarding papers published from these universities and then merged the results by hand. According to our results, only 63% of all papers were common to both databases.
Biological Science Disciplines↗
Experimental and clinical evaluation of a noninvasive reflectance pulse oximeter sensor.
The objective of this study was to evaluate a new reflectance pulse oximeter sensor. The prototype sensor consists of 8 light-emitting diode (LED) chips (4 at 665 nm and 4 at 820 nm) and a photodiode chip mounted on a single substrate. The 4 LED chips for each wavelength are spaced at 90-degree intervals around the substrate and at an equal radial distance from the photodiode chip. An optical barrier between the photodiode and LED chips prevents a direct coupling effect between them. Near-infrared LEDs (940 nm) in the sensor warm the tissue. The microthermocouple mounted on the sensor surface measures the temperature of the skin-sensor interface and maintains it at a present level by servoregulating the current in the 940-nm LEDs. An animal study and a clinical study were performed. In the animal study, 5 mongrel dogs (weight, 10-20 kg) were anesthetized, mechanically ventilated, and cannulated. In each animal, arterial oxygen saturation (SaO2) was measured continuously by a standard transmission oximeter probe placed on the dog's earlobe and a reflectance oximeter sensor placed on the dog's tongue. In the first phase of the experiment, signals from the reflectance sensor were recorded while the dog was immersed in ice water until its body temperature decreased to 30 degrees C. In the second phase, the animal's body temperature was normal, and the oxygen content of the ventilator was varied to alter the SaO2. In the clinical study, 18 critically ill patients were monitored perioperatively with the prototype reflectance sensor. The first phase of the study investigated the relationship between local skin temperature and the accuracy of oximeter readings with the reflectance sensor. Each measurement was taken at a high saturation level as a function of local skin temperature. The second phase of the study compared measurements of oxygen saturation by a reflectance oximeter (SpO2[r]) with those made by a co-oximeter (SaO2[IL]) and a standard transmission oximeter (SpO2[t]). Linear regression analysis was used to determine the degree of correlation between (1) the pulse amplitude and skin temperature; (2) SpO2(r) and SaO2(IL); and (3) SpO2(t) and SaO2(IL). Student's t test was used to determine the significance of each correlation. The mean and standard deviation of the differences were also computed. In the animal study, pulse amplitude levels increased concomitantly with skin temperature (at 665 nm, r = 0.9424; at 820 nm, r = 0.9834; p < 0.001) and SpO2(r) correlated well with SaO2(IL) (r = 0.982; SEE = 2.54%; p < 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Sequence variation in Japanese HLA-DRw8 specificity.
There are four DRw8 haplotypes with different DQ alleles in Japanese: DRw8-DQw6 (w1), DRw8-DQw4, DRw8-DQw8(w3), and DRw8-DQw7 (w3). We previously reported the nucleotide sequence of DRB1 gene of DRw8-DQw6(w1) and it was named DRB1*08032. The nucleotide sequences of the other DRw8 DRB1 alleles and their correspondence to internationally recognized DRw8 subspecificities were still unclear. We have cloned these DRB1 genes and determined the nucleotide sequences. The comparison of the sequences with the published sequences revealed that the differences were occurred at two amino acid positions, and these four haplotypes are classified in two groups: (a) DRw8-DQw6(w1) and DRw8-DQw7(w3), and (b) DRw8-DQw4 and DRw8-DQw8(w3). The DRB1 molecules of DRw8-DQw6(w1) and DRw8-DQw7(w3) have Ser57 and Ile67, and those of DRw8-DQw4 and DRw8-DQw8(w3) have Asp57 and Phe67. The former has the same sequence as that of DRB1*08032, and the latter is same as that of DRB1*0802. The classification corresponds to the serologic subtyping, which divides DRw8 into DR8.1 and DR8.2, reported in the 10th Japan HLA Workshop.
Alleles↗
Risk factors which predict pattern of recurrence after curative surgery for patients with advanced gastric cancer.
The objective of the study was to define risk factors for peritoneal dissemination and haematogenous metastasis after curative resection of patients with an advanced gastric cancer. In retrospective analyses of 405 patients, 168 died of a tumour recurrence. Patients who died of gastric cancer were more likely to have large, invasive tumours which had spread throughout the stomach, metastasized to lymph nodes, and vessel invasion by gastric cancerous cells (P < 0.01 or P < 0.05). Of the 168 deaths, 60 (35.7%) were secondary to haematogenous recurrence, 53 (31.5%) were related to peritoneal dissemination, and 19 (11.3%) were related to a local recurrence. To determine the independent risk factors related to peritoneal dissemination and haematogenous metastasis, multivariate analyses using a stepwise logistic model suggested that serosal invasion (P < 0.01, relative risk = 2.57) and Borrmann type 4 (P < 0.01, relative risk = 1.95) were the greatest risk factors for peritoneal dissemination. The presence of lymph node metastasis (P < 0.01, relative risk = 2.62) and presence of vessel invasion by cancerous cells (P < 0.05, relative risk = 1.59) were the greatest risk factors for a haematogenous metastasis.
Cause of Death↗
Strong and unique associations of HLA-DPB1 alleles with other HLA antigens in a Japanese population.
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Alleles↗
How to encode arterial pressure into carotid sinus nerve to invoke natural baroreflex.
The purpose of this study was to develop an artificial baroreceptor that was capable of invoking the "natural" baroreflex by electrically stimulating the afferent nerve. In six anesthetized, vagotomized dogs, we first identified, using the white-noise method, the transfer function from carotid sinus pressure to aortic pressure (HCSP.AoP) and that from the electrical carotid sinus nerve stimulation to aortic pressure (HCSN.AoP). We then backcalculated the transfer function required for the artificial baroreceptor (HCSP.CSN) as the ratio of HCSP.AoP to HCSN.AoP. To activate the artificial baroreceptor, we electrically stimulated the carotid sinus nerve with the frequency-modulated pulse train obtained in real time by convolving the impulse response of HCSP.CSN with instantaneous aortic pressure. We tested performance of the artificial baroreceptor by imposing random changes in blood volume. The pressure-stabilizing effects of the artificial baroreceptor were indistinguishable from those of the native one. We conclude that the artificial baroreceptor can invoke the natural baroreflex. The proposed framework generally would be applicable to interface artificial devices with the central nervous system.
Animals↗
Dynamic effects of carotid sinus baroreflex on ventriculoarterial coupling studied in anesthetized dogs.
We evaluated dynamic effects of the carotid sinus baroreflex on ventriculoarterial coupling. In seven anesthetized, vagotomized dogs, we bilaterally isolated carotid sinuses and randomly changed carotid sinus pressure while measuring aortic pressure, aortic flow, and left ventricular pressure. Estimating left ventricular end-systolic elastance (Ees) and effective arterial elastance (Ea) on a beat-to-beat basis, we determined transfer functions from the carotid sinus pressure to Ees (HEes) and from the carotid sinus pressure to Ea (HEa) over the frequency range spanning 0.002-0.25 Hz. Both HEes and HEa exhibited characteristics of a second-order low-pass filter. The gains of HEes and HEa were 0.085 +/- 0.065 (mean +/- SD) and 0.081 +/- 0.049 mm Hg/ml/mm Hg, respectively. There were no significant differences in natural frequencies (0.039 +/- 0.013 versus 0.039 +/- 0.007 Hz) or damping ratios (0.65 +/- 0.11 versus 0.64 +/- 0.24). The results indicated that the carotid sinus baroreflex dynamically altered Ees and Ea to the same extent in the process of stabilizing arterial pressure. Because the arterial system extracts maximal external work from a given heart when Ea equals Ees, the carotid sinus baroreflex appeared to be designed to regulate the ventricular and arterial properties to optimize the energy transmission from the left ventricle to the arterial system in anesthetized, vagotomized dogs.
Anesthesia↗
Potential clinical applications of the oxygen carrying solutions.
Two major areas of research of the oxygen carrying solutions are 1) utilization of hemoglobin and 2) perfluorochemicals. Even though they are not perfect red blood cell substitutes, the "oxygen carrying solutions" have many potential clinical applications because they will reach tissues more easily than normal human red cells and can deliver oxygen directly to tissues. In this paper, important examples of such usages are suggested. Additional clinical and non-clinical applications of the oxygen carrying solutions may be added in the near future.
Artificial Organs↗
[A case of pulmonary metastasis of ovarian leiomyosarcoma responsive to CTP therapy].
One case of pulmonary metastasis of leiomyosarcoma responsive to CTP therapy was reported. The patient was a 44-year-old woman who had undergone total simple hysterectomy for uterine myoma 6 years before. Five years after the operation she underwent ovariectomy for ovarian tumor. Based on the histopathological findings, she was diagnosed to have leiomyosarcoma. One year later the patient was referred to use because of pulmonary metastasis. After admission to our hospital CTP therapy was started. Disappearance of the metastatic lesion was demonstrated by the chest X-ray findings at the end of five courses of treatment.
Adult↗
Prediction of survival time after curative surgery for advanced gastric cancer.
This study was carried out to define independent prognostic factors influencing survival time and to examine the survival time of patients with advanced gastric cancer treated by curative resection. Six hundred and forty-eight patients were identified of whom 275 patients died of tumor recurrence during follow-up. Univariate analysis using Mantel-Cox analysis, indicated that tumor size, tumor location, gross appearance, degree of gastric wall invasion, lymph node metastasis and operative procedures were significant factors related to survival time (P less than 0.01 to P less than 0.05). Multivariate analysis using the Cox proportional hazard model adjusted for sex, age and other factors, suggested that tumor size (P less than 0.01, relative risk = 1.79), degree of gastric wall invasion (P less than 0.01, rr = 1.24) and lymph node metastasis (P less than 0.01, rr = 2.39) were the most independent prognostic factors statistically, although these three prognostic factors were inter-related. When the tumor is less than 5 cm and there is no serosal invasion or lymph node metastasis, then a longer survival time can be expected (88.7% at 5-years). If the tumor size exceeds 10 cm and there is invasion into neighboring structures and lymph node metastases, then survival time will be short (11.9% at 4-years).
Analysis of Variance↗
Fluorimetric and high-performance liquid chromatographic determination of D-lactate in biological samples.
D-Lactate in biological samples was converted into a strongly fluorescent substance in a one-vial reaction. It was first converted into the pyruvate hydrazone in the presence of D-lactate dehydrogenase, an NADH-reoxidation system using diaphorase, D,L-6,8-thioctamide and hydrazine. This hydrazone was then converted into 2-hydroxy-6,7-dimethoxy-3-methylquinoxaline by 1,2-diamino-4,5-dimethoxybenzene in 1 M hydrochloric acid, and the quinoxaline was extracted and measured fluorimetrically at 432 nm (excitation at 365 nm). The calibration curve for D-lactate was linear up to at least 100 nmol/ml of the assay mixture, with a determination limit of 2 nmol/ml. The quinoxaline was also analysed by high-performance liquid chromatography with fluorimetric detection. The calibration curve for D-lactate was linear from 500 fmol to 75 nmol in the reaction mixture. This method was 4000 times more sensitive than the fluorimetric method, and could determine D-lactate in blood plasma volumes of less than 1 microliter.
Animals↗
Clinical features of the differentiated and undifferentiated types of advanced gastric carcinoma: univariate and multivariate analyses.
This study was done to define clinical features for the different pathological types of advanced gastric carcinoma. One thousand one hundred three patients were identified and classified into two groups: 479 patients (43.4%) had a differentiated adenocarcinoma and 624 patients (56.6%) had an undifferentiated adenocarcinoma. Patients with the undifferentiated type were more likely to have large invasive tumors and a higher incidence of peritoneal dissemination. Conversely, the patients with the differentiated type were more likely to have a liver metastasis. Multivariate analysis, using Cox' proportional hazard model adjusted for sex, age, and other factors, suggested that tumor size was one of the seven most independent prognostic factors in patients with the undifferentiated type (relative risk = 1.01), but this parameter lost prognostic value in patients with the differentiated type. With regard to correlation between survival time and tumor size, the larger the tumor (over 10 cm), the shorter the survival time of patients with the undifferentiated type, as compared to findings in patients with the differentiated type (P less than 0.01). Thus, differences in clinical characteristics, including characteristics in the individual patients, extent of tumor, distant metastasis, prognostic factors, and prognosis correlate with the histopathological type of gastric carcinoma.
Adenocarcinoma↗
Micro-mainframe-like personal clinical research system.
We constructed a micro-mainframe-link clinical research system for personal use (Personal Clinical Research System). This system was developed with both a mainframe computer and a personal computer (PC). The prepared programs included a database manager (on the mainframe computer), a user interface program (on the PC), and a communication control program that connected the mainframe computer with the PC. The database on the mainframe computer was constructed by two methods. The first method was to transmit data from the PC to the mainframe computer. The second method was to extract data from the patient information database. Using this system, a physician is able to construct a personal research database that contains interesting data for the physician. In addition, the physician is able to accumulate data on a special field using this system. A discharge summary system is now in operation as an example of this system.
Computers, Mainframe↗
A random allocation system with the minimization method for multi-institutional clinical trials.
This paper describes the random allocation system used to perform precise and rapid treatment assignments in multi-institutional clinical trials. This system is based on sophisticated randomization procedures, according to Pocock and Simon's minimization method and Zelen's method for institution balancing. The major advantage of randomized treatment assignments with this system is to balance treatment numbers for each level of various prognostic factors over the entire trial and at the same time balance the allocation of treatments within an institution. Therefore, the randomized treatment assignments by this system can prevent degrading of the statistical power of a particular treatment factor. This system is designed to run on a small-sized notebook computer and therefore can be set up beside a telephone for registration, without occupying a large space. At present, this system is conveniently being used in two clinical trials.
Algorithms↗
Simulation program for estimating statistical power of Cox's proportional hazards model assuming no specific distribution for the survival time.
Small sample properties of the maximum partial likelihood estimates for Cox's proportional hazards model depend on the sample size, the true values of regression coefficients, covariate structure, censoring pattern and possibly baseline hazard functions. Therefore, it would be difficult to construct a formula or table to calculate the exact power of a statistical test for the treatment effect in any specific clinical trial. The simulation program, written in SAS/IML, described in this paper uses Monte-Carlo methods to provide estimates of the exact power for Cox's proportional hazards model. For illustrative purposes, the program was applied to real data obtained from a clinical trial performed in Japan. Since the program does not assume any specific function for the baseline hazard, it is, in principle, applicable to any censored survival data as long as they follow Cox's proportional hazards model.
Clinical Trials as Topic↗
Death due to recurrence following curative resection of early gastric cancer depends on age of the patient.
This study was done to define the relationship between age at the time of surgery and the prognosis after curative resection for patients with an early gastric cancer. Three hundred and eighty-two patients were identified and 25 patients died of tumour recurrence. Overall, the cumulative survival rate was 94.9% at 5 years and 92.4% at 10 years. Patients with a recurrence of the gastric cancer tended to be older, were more likely to have large differentiated type of tumour and lymph node metastases were often present. Stratified into age-classified groups, the survival rate decreased with increase of age (for patients under age 34 years, 35 to 44, 45 to 54, 55 to 64, 65 to 74, over age 75 years, the 5-year survival rates were 100.0, 97.7, 97.6, 94.2, 94.1 and 84.4 (%]. Of the 25 patients with a tumour recurrence and who died, the survival time of 18 patients over age 55 years was significantly shorter than that of seven patients under age 54 years (median, 1.7 vs 5.6 years, P less than 0.05). The multivariate analysis showed that, over and above the differentiated type of tumour (P less than 0.01) and the presence of lymph node metastases (P less than 0.01), age was one of the prognostic factors (P less than 0.05). We conclude that age at the time of primary surgery is a significant factor in patients with an early gastric cancer.
Adult↗