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.

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)

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.

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.

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.

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.

[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.

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).

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.

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.

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.

The effect of extraanatomic bypass on aortic input impedance studied in open chest dogs. Should the vascular prosthesis be compliant to unload the left ventricle?

Left ventricular hypertrophy has been reported after ascending aorta-abdominal aorta bypass, despite seemingly insignificant changes in cardiac output and mean arterial pressure. Such a bypass procedure may be used for the treatment of complex coarctation of the aorta, hypoplastic aortic arch, or thoracoabdominal aortic aneurysm. To investigate the effect of the bypass procedure on left ventricular afterload, we measured aortic input impedance in six open chest dogs by placing a knitted Dacron graft from the ascending aorta to the abdominal aorta and occluding the aortic arch. Cardiac output and mean arterial pressure remained unaltered throughout the experiment, consistent with clinical reports. Systolic pressure increased by 25% of control, and the ratio of diastolic pressure-time index to tension-time index decreased by 27%. The measured input impedance was then approximated with the three-element windkessel model, which consists of resistance, compliance, and characteristic impedance (average of impedance modulus between 5 and 15 Hz). There was no change in resistance and compliance; characteristic impedance increased to 255% of control. Connecting an air chamber to the vascular prosthesis doubled the compliance and decreased the characteristic impedance nearly to the control value without altering resistance. It also reduced the systolic pressure by 14% of the bypass protocol and increased the ratio of diastolic pressure-time index to tension-time index (by 32% of control value and 82% of bypass value). Arterial systolic pressure and pulse pressure were both linearly correlated with the characteristic impedance. Thus we conclude that although ascending aorta-abdominal aorta bypass does not affect cardiac output, mean arterial pressure, resistance, or compliance, it does increase characteristic impedance. Left ventricular systolic load is directly correlated with characteristic impedance. Increased systolic wall stress might be the cause of left ventricular hypertrophy of the previously reported cases. Because decrease in the distensibility of the proximal aorta is one of the factors causing the increase in characteristic impedance, using a compliant graft might help to unload the heart.

Interactive statistical analysis system for clinical investigators

We have developed an interactive statistical analysis system (ISAS-Q) with which clinical investigators with little experience in computers and programming can easily perform statistical analyses. ISAS-Q can perform most of the frequently used statistical methods, including multivariate analysis, in an interactive mode. Furthermore, ISAS-Q has self-consistent and extensive help functions.

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.

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.

A unique, efficient, implantable, electromechanical, total artificial heart

A completely implantable, one piece electromechanical total artificial heart (TAH) intended for permanent human use was developed. It consisted of left and right conically shaped pusher-plate blood pumps sandwiching a thin centerpiece with a compact, efficient electromechanical actuator. The actuator consisted of a direct current brushless motor; a planetary roller screw fit the space between the two conically shaped pusher-plates. The rotational motion of the motor was converted to the rectilinear motion of the rollerscrew to displace the left and right pusher-plates in the left master alternate mode. The diameter of the assembled TAH was 97 mm, with a central thickness of 82 mm. The overall weight was 620 g, with a displaced volume of 510 ml. The pump provided flows of 3-8 L/min with a preload of 1-15 mmHg against an afterload of 100 mmHg. The net efficiency ranged from 15% to 18%. This model showed good fit in the pericardial space of heart transplant recipients (body weight, 77 kg).

Problems of protocol practice in Japan

With progress in medical knowledge and in the technology of medical care, the contents of medical practice have become increasingly complicated year by year. The protocol practice (clinical algorithms or scheduled care) has been experimentally employed as one of medical-practice systems aimed at providing better medical care and maintaining its high standards. In the protocol practice the criteria for decision-making, which are clinically employed, are precisely made up in advance so that practice will be performed systematically. The WHO has recommended this protocol practice as a medical-care system appropriate for realizing clinical experiments. In recent years a number of clinical studies have been born from the protocol practice and, thus, it has been considered to be a formula for conducting clinical experiments tolerant of scientific criticism. The protocol practice, however, since it is difficult to conduct smoothly, has not yet been settled. This study aims at considering what we should do to make the protocol practice system settled through the observation of pitfalls in the course of its application.

A 24-hour ordering system for clinical examinations

We have developed a 24-hour ordering system for clinical examinations, making use of the features of multi-function workstation (IBM5550) which performs two functions both in an on-line terminal and in a personal computer. It is used as an on-line terminal for the host computer (IBM4381) in day time. At night or on holiday, it is used as a stand-alone type personal computer to order clinical examinations. For this purpose, basic information of the inpatients (patient number, name, sex, date of birth, clinic, ward) are transferred from the host computer to the disket in the workstation in the evening when host computer finished on-line service. A physician can input the patient number followed by examination items using the touch panel according to the dialogue type guides written in Chinese character. Then, specimen label, list of ordered tests and an order form are printed out instantly. The date (patient number, examination items, identification number of the specimen, etc.) stored in the disket in the workstation at night are transferred from workstation to the host computer next morning. The host computer merges the information ordered in day time and at night and supplies working documents for examination (worksheets, master log, etc.) to technicians. Thus physicians can order examinations all day long using workstation, which make it possible to spare the time.

A personal computer network system for equitable allocation of cadaver organs

We developed a personal computer network system for the equitable allocation of cadaveric organs. This network consists of a host computer (IBM PS55 model 5570 T) and various kinds of personal computers manufactured by many different computer makers in Japan. The merits of our personal computer network include lower cost and an easy access to the host computer from all the centres participating in this network while using their own favourite personal computers. Among the programs made for allocating cadaveric organs, we present in this paper the program for livers. This program was developed with a modified version of the logic developed by Starzl et al. The grade modification for the United Network for Organ Sharing (UNOS) in the United States was used as the basis for classification of medical urgency. Our program weighed the factors of medical urgency, compatibility of blood group and waiting time. Distance factors were omitted because of the smaller area of the network compared to that of UNOS. This computer network would be linked to other computer networks in creating a national organ procurement and transplant network in Japan, in order to help them to catch up with other advanced transplant countries. Such an equal and objective computer system should allow organ transplantation to become more widely accepted.

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.

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.

Risk of gastric cancer in patients with non-surgically treated peptic ulcer

We followed up 2072 patients with unoperated gastric and duodenal ulcer, diagnosed from 1963 to 1975, and evaluated the risk of development of gastric cancer. During the follow-up period of 9-23 years 38 patients had a gastric cancer or died of gastric cancer. The number of gastric cancers in patients with duodenal ulcer (observed/expected = 3:12) was statistically low (p less than 0.01) compared with the number expected from the sex- and age-matched general population. On the other hand, the number of patients with gastric ulcer and the number of those with both gastric and duodenal ulcers was 29 and 6, neither of which differed significantly from the expected occurrence. These results suggest that in peptic ulcer patients the risk of developing gastric cancer is equal to or low compared with that of the general population.

Lack of relationship between perioperative blood transfusion and survival time after curative resection for gastric cancer

To better comprehend the relationship between perioperative blood transfusion and survival time after curative gastrectomy for advanced gastric cancer, the authors reviewed retrospectively data on 568 patients treated in their clinics from 1965 to 1983. Of these 568, 195 (34.3%) required no blood transfusion and 373 (65.7%) required transfusions within the perioperative period. Univariate analysis indicated that the survival time of the transfusion recipients was significantly less than that of the patients who had no transfusions (P less than 0.01). In subgroups of the authors' patients stratified to adjust for stage of disease, there was, however, no significant difference between the survival rates. Subsequently, multivariate analysis, using the Cox regression analysis, which adjusted for sex, age, and other covariates, indicated that perioperative blood transfusion was not a useful factor for predicting survival time. Multivariate analysis suggested that tumor size (P less than 0.01), degree of invasion into the gastric wall (P less than 0.01) and status of lymph node metastasis (P less than 0.01) were the most important covariates after curative gastrectomy for advanced gastric cancer. The authors' findings revealed the lack of any relationship between perioperative blood transfusion and survival time of patients who underwent curative resection for advanced gastric cancer.

Electronic control of laryngeal spasm. I. Blockage of orthodromically induced action potentials in intact canine recurrent laryngeal nerves

Spastic dysphonia is a central nervous system phenomenon of unknown etiology characterized by uncoordinated voice tremor with erratic patterns of laryngeal contraction. Standard treatments have not been entirely satisfactory. The authors propose to apply a concept of selective nerve activity blockage, which leaves normal contractions undisturbed, as the basis for suppression of laryngeal spasticity. Single pulses of constant duration and increasing amplitude were injected into specially designed blocking electrodes placed around six recurrent laryngeal nerves (three dogs). Vocal cord adduction was reduced or arrested within given "windows" of stimulation levels of the blocking electrodes, while it increased with higher amplitudes when the current was injected via standard bipolar electrodes (controls). Although this study demonstrates the feasibility of blocking action potentials passing along recurrent laryngeal nerves, it might eventually allow control of laryngeal spasm from information taken directly from the affected musculature.